Sample records for pelo tipo dose

  1. Estudo espectral em raios-X duros de fontes do tipo Z com o HEXTE/RXTE

    NASA Astrophysics Data System (ADS)

    D'Amico, F.; Heindl, W. A.; Rothschild, R. E.

    2003-08-01

    Apresentam-se os resultados de um estudo espectral em raios-X de fontes do tipo Z. As fontes do tipo Z são binárias de raios-X de baixa massa (BXBM) com campo magnético intermediário (B~109G). Esta classe de fontes é composta por apenas 6 fontes Galácticas (a saber: ScoX-1, 9, 7, CygX-2, 5 e 0). A nossa análise se concentra na faixa de raios-X duros (E ~ 20keV), até cerca de 200keV, faixa ótima de operação do telescópio "High Energy X-ray Timing Experiment" (HEXTE), um dos três telescópios de raios-X à bordo do Rossi X-ray Timing Explorer (RXTE). Nossa motivação para tal estudo, uma busca de caudas em raios-X duros em fontes do tipo Z, foi o pouco conhecimento sobre a emissão nesta faixa de energia das referidas fontes quando comparadas, por exemplo, as fontes do tipo atoll (também BXBM). Apresentam-se a análise/redução de dados e explicita-se a maneira como o HEXTE mede o ru1do de fundo. Especial atenção é direcionada a este item devido a localização das fontes do tipo Z e também ao problema de contaminação por fontes próximas. Com exceção de ScoX-1, nenhuma cauda em raios-X duros foi encontrada para as outras fontes, a despeito de resultados de detecção dessas caudas em algumas fontes pelo satélite BeppoSAX. As interpretações deste resultado serão apresentadas. Do ponto de vista deste estudo, nós deduzimos que a produção de caudas de raios-X duros em fontes do tipo Z é um processo disparado quando, pelo menos, uma condição é satisfeita: o brilho da componente térmica do espectro precisa estar acima de um certo valor limiar de ~4´1036ergs-1.

  2. On Ensino de Astronomia nas Cidades de Ribeirão Pires e Rio Grande da Serra

    NASA Astrophysics Data System (ADS)

    Faria, R. Z.; Voelzke, M. R.

    2007-08-01

    Apesar da astronomia ser um dos temas indicados pelos Parâmetros Curriculares Nacionais, observa-se que poucas mudanças ocorreram desde a implementação do mesmo em sala de aula. A presente pesquisa diz respeito sobre como os tópicos de astronomia estão sendo abordados pelos professores no ensino médio. Optou-se por aplicar um questionário com os professores que ministram a disciplina de física. Os mesmos trabalham em escolas estaduais situadas nas cidades de Ribeirão Pires e Rio Grande da Serra, ambas subordinadas a Diretoria de Ensino de Mauá, no Estado de São Paulo. O questionário foi aplicado durante o 2° semestre de 2006. Até o momento os resultados são preliminares. Dos 82,0% dos professores que responderam ao questionário no município de Rio Grande da Serra, 66,7% não aplicaram nenhum tópico de astronomia, 77,8% não utilizaram qualquer tipo de programa computacional, 66,7% não utilizaram laboratório, que 77,8% nunca levaram os alunos a museus e ou planetários e que 66,7% não indicaram qualquer tipo de revista ou livro sobre astronomia aos seus alunos. No município de Ribeirão Pires, 53,3% dos professores responderam ao questionário, destes 75,0% não aplicaram nenhum tópico de astronomia, 93,8% não utilizaram qualquer tipo de programa computacional, 75,0% não utilizaram laboratório, 81,3% nunca levaram os alunos a museus e ou planetário e 56,3% não indicaram qualquer tipo de revista ou livro sobre astronomia ao seus alunos. Apesar da maioria dos professores reconhecerem que o conteúdo de astronomia influi na formação do jovem, os mesmos não incluem o tema em seus planejamentos escolares.

  3. On Ensino de Astronomia: Desafios para Implantação

    NASA Astrophysics Data System (ADS)

    Faria, R. Z.; Voelzke, M. R.

    2008-09-01

    Em 2002 o ensino de Astronomia foi proposto como um dos temas estruturadores pelos Parâmetros Curriculares Nacionais e sugerido como facilitador para que o aluno compreendesse a Física como construção humana e parte do seu mundo vivencial, mas raramente seus conceitos foram ensinados. A presente pesquisa discute dois aspectos relacionados à abordagem de Astronomia. O primeiro aspecto é se ela está sendo abordada pelos professores do Ensino Médio e o segundo, aborda a maneira como ela está sendo ensinada. Optou-se pela aplicação de um questionário a partir do 2° semestre de 2006 e durante o ano de 2007 com professores que ministram a disciplina de Física, os quais trabalham em escolas estaduais em Rio Grande da Serra, Ribeirão Pires e Mauá no estado São Paulo. Dos 66,2% dos professores que responderam ao questionário nos municípios de Rio Grande da Serra, Ribeirão Pires e Mauá, 57,4% não aplicaram nenhum tópico de astronomia, 70,2% não utilizaram laboratório, 89,4% não utilizaram qualquer tipo de programa computacional, 83,0% nunca fizeram visitas com alunos a museus e planetários e 38,3% não indicaram qualquer tipo de livro ou revista referente à astronomia aos seus alunos. Mesmo considerando a Astronomia um conteúdo potencialmente significativo, esta não fez parte dos planejamentos escolares. Portanto são necessárias propostas que visem estratégias para a educação continuada dos professores como, por exemplo, cursos específicos sobre o ensino em Astronomia.

  4. Estudo de cavidade reentrante supercondutora a ser utilizada nos transdutores paramétricos do detector brasileiro de ondas gravitacionais Mario Schenberg

    NASA Astrophysics Data System (ADS)

    Ribeiro, K. L.; Furtado, S. R.; Aguiar, O. D.; Frajuca, C.

    2003-08-01

    Cavidades reentrantes de nióbio vêm sendo utilizadas pelo grupo Australiano nos transdutores eletromecânicos paramétricos do detector de ondas gravitacionais Niobè. Esses transdutores paramétricos são ativados por um sinal AC na faixa de microondas (banda X), que é modulado pelo sinal mecânico da vibração da antena esférica, com a variação de um parâmetro, que, no caso, é a capacitância da cavidade. Nós estudamos esse tipo de cavidade, com o objetivo de transformá-la de reentrante aberta para reentrante fechada, de forma a utilizá-la nos transdutores paramétricos do detector brasileiro Mario Schenberg. O desempenho do transdutor depende de alguns parâmetros da cavidade, como a sua Figura de Mérito (Q elétrico) e o seu acoplamento elétrico com o circuito externo. Neste trabalho mostramos a medida do Q elétrico como função do acoplamento, do acabamento superficial interno e do vazamento de microondas da cavidade, e mostramos o desempenho esperado para o detector Mario Schenberg usando uma cavidade supercondutora reentrante fechada de nióbio.

  5. Implementação de um algoritmo para a limpeza de mapas da RCFM

    NASA Astrophysics Data System (ADS)

    Souza, C. L.; Wuensche, C. A.

    2003-08-01

    A Radiação Cósmica de Fundo em Microondas (RCFM), descoberta por Penzias e Wilson em 1965, é uma das ferramentas mais poderosas para o estudo da cosmologia. Com a descoberta de flutuações de temperatura na RCFM, da ordem de uma parte em 105, pelo COBE (1992), uma nova era teve início. Nos últimos onze anos, diversos instrumentos fizeram novas medidas de alta precisão, refinando os resultados apresentados pelo COBE, culminando com os resultados recentes do satélite WMAP. A análise de dados da RCFM, especialmente no caso de experimentos com pequena cobertura do céu, apresenta uma série de dificuldades devido a emissões de contaminantes externos, tais como a emissão da Galáxia e de fontes pontuais, e de ruídos intrínsecos tanto ao sistema de detecção quanto à estratégia de observação do céu. Uma das soluções típicas para a filtragem de dados brutos de um experimento para medir flutuações de temperatura é aplicar um gabarito (template) e um filtro passa alta ao produzir mapas simplificados (sem considerar matrizes de correlação ou covariância). No caso de experimentos que utilizam detectores HEMT, essa combinação de filtros remove, satisfatoriamente, ruídos do tipo 1/f gerados pela instabilidade no ganho do detector acoplado ao movimento do instrumento, definido pela estratégia de observação. Entretanto, o sinal resultante medido, tanto em simulações quanto em séries temporais reais, sugere que parte do sinal cosmológico pode estar sendo removido junto com o ruído dos detectores. Este trabalho descreve as etapas para a produção de um mapa típico (simulado) e os testes preliminares de um algoritmo para remover ruídos do tipo 1/f introduzidos pela estratégia de observação sem prejudicar a qualidade do sinal cosmológico presente no mapa.

  6. Vínculos observacionais para o processo-S em estrelas gigantes de Bário

    NASA Astrophysics Data System (ADS)

    Smiljanic, R. H. S.; Porto de Mello, G. F.; da Silva, L.

    2003-08-01

    Estrelas de bário são gigantes vermelhas de tipo GK que apresentam excessos atmosféricos dos elementos do processo-s. Tais excessos são esperados em estrelas na fase de pulsos térmicos do AGB (TP-AGB). As estrelas de bário são, no entanto, menos massivas e menos luminosas que as estrelas do AGB, assim, não poderiam ter se auto-enriquecido. Seu enriquecimento teria origem em uma estrela companheira, inicialmente mais massiva, que evolui pelo TP-AGB, se auto-enriquece com os elementos do processo-s e transfere material contaminado para a atmosfera da atual estrela de bário. A companheira evolui então para anã branca deixando de ser observada diretamente. As estrelas de bário são, portanto, úteis como testes observacionais para teorias de nucleossíntese pelo processo-s, convecção e perda de massa. Análises detalhadas de abundância com dados de alta qualidade para estes objetos são ainda escassas na literatura. Neste trabalho construímos modelos de atmosferas e, procedendo a uma análise diferencial, determinamos parâmetros atmosféricos e evolutivos de uma amostra de dez gigantes de bário e quatro normais. Determinamos seus padrões de abundância para Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd, Sm, Eu e Gd, concluindo que algumas estrelas classificadas na literatura como gigantes de bário são na verdade gigantes normais. Comparamos dois padrões médios de abundância, para estrelas com grandes excessos e estrelas com excessos moderados, com modelos teóricos de enriquecimento pelo processo-s. Os dois grupos de estrelas são ajustados pelos mesmos parâmetros de exposição de nêutrons. Tal resultado sugere que a ocorrência do fenômeno de bário com diferentes intensidades não se deve a diferentes exposições de nêutrons. Discutimos ainda efeitos nucleossintéticos, ligados ao processo-s, sugeridos na literatura para os elementos Cu, Mn, V e Sc.

  7. BSSDATA - um programa otimizado para filtragem de dados em radioastronomia solar

    NASA Astrophysics Data System (ADS)

    Martinon, A. R. F.; Sawant, H. S.; Fernandes, F. C. R.; Stephany, S.; Preto, A. J.; Dobrowolski, K. M.

    2003-08-01

    A partir de 1998, entrou em operação regular no INPE, em São José dos Campos, o Brazilian Solar Spectroscope (BSS). O BSS é dedicado às observações de explosões solares decimétricas com alta resolução temporal e espectral, com a principal finalidade de investigar fenômenos associados com a liberação de energia dos "flares" solares. Entre os anos de 1999 e 2002, foram catalogadas, aproximadamente 340 explosões solares classificadas em 8 tipos distintos, de acordo com suas características morfológicas. Na análise detalhada de cada tipo, ou grupo, de explosões solares deve-se considerar a variação do fluxo do sol calmo ("background"), em função da freqüência e a variação temporal, além da complexidade das explosões e estruturas finas registradas superpostas ao fundo variável. Com o intuito de realizar tal análise foi desenvolvido o programa BSSData. Este programa, desenvolvido em linguagem C++, é constituído de várias ferramentas que auxiliam no tratamento e análise dos dados registrados pelo BSS. Neste trabalho iremos abordar as ferramentas referentes à filtragem do ruído de fundo. As rotinas do BSSData para filtragem de ruído foram testadas nos diversos grupos de explosões solares ("dots", "fibra", "lace", "patch", "spikes", "tipo III" e "zebra") alcançando um bom resultado na diminuição do ruído de fundo e obtendo, em conseqüência, dados onde o sinal torna-se mais homogêneo ressaltando as áreas onde existem explosões solares e tornando mais precisas as determinações dos parâmetros observacionais de cada explosão. Estes resultados serão apresentados e discutidos.

  8. Sabemos prescrever profilaxia de tromboembolismo venoso nos pacientes internados?

    PubMed Central

    Lopes, Bruno Abdala Candido; Teixeira, Isabela Pizzatto; de Souza, Taynara Dantas; Tafarel, Jean Rodrigo

    2017-01-01

    Resumo Contexto Embora preconizada, a profilaxia de tromboembolismo venoso (TEV) deixa de ser realizada sistematicamente em pacientes internados. Objetivo Verificar se os pacientes hospitalizados recebem a prescrição correta da profilaxia de TEV do médico responsável por sua internação, conforme sua categoria de risco. Métodos Estudo transversal com análise de prontuários de pacientes internados no Hospital Santa Casa de Misericórdia de Curitiba, PR, entre 20 de março e 25 de maio de 2015. Excluíram-se os pacientes em uso de anticoagulantes ou com sangramento ativo. Analisou-se gênero, idade, tipo de cobertura de saúde, especialidade responsável pelo paciente e fatores de risco dos pacientes para classificá-los em alto, moderado ou baixo risco para TEV. Comparou-se o uso ou não da profilaxia entre as prescrições das especialidades clínicas e cirúrgicas, pacientes internados pelo Sistema Único de Saúde (SUS) e por convênios e de acordo com seu risco para TEV. Resultados Dos 78 pacientes avaliados, oito preencheram os critérios de exclusão. Dos 70 pacientes elegíveis (média etária 56,9 anos; 41 homens; 62 cobertos pelo SUS), 31 eram tratados por clínicos e 39 por cirurgiões. Apenas 46 (65,71%) pacientes receberam profilaxia para TEV. Dentre os pacientes clínicos, 29 (93,5%) receberam profilaxia, contra 17 (43,6%) do grupo cirúrgico (p < 0,001). Pacientes clínicos de moderado e alto risco receberam mais profilaxia que os cirúrgicos (p < 0,001 e p = 0,002). Não houve diferenças quanto à cobertura de saúde (SUS versus convênios médicos). Conclusões No Hospital Santa Casa de Misericórdia de Curitiba, pacientes cirúrgicos estão menos protegidos de eventos tromboembólicos em relação aos clínicos. PMID:29930647

  9. Um supressor de fundo térmico para a câmara infravermelha CamIV

    NASA Astrophysics Data System (ADS)

    Jablonski, F.; Laporte, R.

    2003-08-01

    O ângulo sólido subtendido pelos pixels na câmara infravermelha do NexGal (CamIV) que operamos no OPD/LNA contém contribuições provenientes do sistema de coleta de fluxo propriamente dito - sendo esta a parte que interessa para as medidas astronômicas - e contribuições da obstrução central, sistema de suporte do espelho secundário e região exterior à pupila de entrada do telescópio. Estas últimas contribuições são devi-das à emissão de corpo negro à temperatura ambiente e aumentam exponencialmente para comprimentos de onda maiores que 2 micra (banda K, no infravermelho próximo). Embora a resultante pode ser quantificada e subtraída dos sinais relevantes, sua variância se adiciona à variância do sinal, e pode ser facilmente a contribuição domi-nante para a incerteza final das medidas, tornando ineficiente o processo de extração de informação e degradando a sensibilidade da câmara. A maneira clássica de resolver esse problema em sistemas ópticos que operam no infravermelho, onde os efeitos da emissão térmica do ambiente são importantes, é restringir o ângulo sólido subtendido pelos pixels individuais exclusivamente aos raios provenientes do sistema óptico. Para tanto, projeta-se uma imagem real, bastante reduzida, da pupila de entrada do sistema óptico num anteparo que transmita para o sistema de imageamento só o que interessa, bloqueando as contribuições das bordas externas à pupila de entrada, obstrução central do telescópio e sistema de suporte. Como a projeção é realizada em ambiente criogênico, a contribuição térmica espúria é efetivamente eliminada. Nós optamos por um sistema do tipo Offner para implementar na prática esta função. Trata-se de um sistema baseado em espelhos esféricos, bastante compacto e ajustado por construção. A opção por espelhos do mesmo material que o sistema de suporte (Alumínio) minimiza a dilatação diferencial, crítica nesse tipo de aplicação. Apresentamos as soluções detalhadas do projeto óptico-mecânico, bem como uma análise de flexões e desempenho em termos de qualidade de imagem.

  10. Quality of life in the workplace for nursing staff at public healthcare institutions.

    PubMed

    Zavala, María Olga Quintana; Klinj, Tatiana Paravic; Carrillo, Katia Lorena Saenz

    2016-08-08

    to determine the quality of life in the workplace for nursing staff at public institutions in Hermosillo, Sonora, Mexico. quantitative, correlational, cross-sectional, and comparative. We used a probabilistic sample of 345 nurses with data collected in 2013 using an instrument created by the authors to gather bio-socio-demographic data and the CVT-GOHISALO instrument with a Cronbach's alpha of 0.95. SPSS 15 was used to analyze the data. A Kolmogorov-Smirnov test was used to calculate the normality of the data; the medians were compared using the Mann-Whitney U test and Kruskal-Wallis test with the significance level set at 0.05. the average overall quality of life in the workplace for nursing staff was 207.31 (DE 41.74), indicating a moderate level. The quality of life in the workplace was higher for people with permanent contracts (p=0.007) who did not engage in other remunerative activities (p=0.046). Differences in the quality of life in the workplace were observed depending on the institution where the subjects worked (p=0.001). the nursing staff perceives itself as having a moderate-level quality of life in the workplace. This level was determined in the statistical analysis based on the type of contract, whether the person performed other remunerated activities, and the institution where the person worked. determinar el nivel de calidad de vida en el trabajo del personal de enfermería de instituciones públicas en Hermosillo, Sonora, México. cuantitativo, correlacional, transversal y comparativo. Muestreo probabilístico, de 345 enfermeras, datos recolectados en 2013, a través de instrumentos que recogen datos biososiodemográficos; creado por las autoras y CVT -GOHISALO con Alpha de Cronbach de 0.95. Para el análisis de datos se usó SPSS 15, para conocer la normalidad de los datos se utilizó Kolmogorov- Smirnov, se compararon medianas con U de Mann Whitney y Kruskal-Wallis, nivel de significancia admitido 0.05. promedio de calidad de vida en el trabajo global del personal de enfermería de 207.31 (DE 41.74), que indica un nivel medio. Según forma de contratación la calidad de vida en el trabajo fue mayor en las personas con contrato indefinido (p=0.007), que no realizan otra actividad remunerada (p=0.046), con diferencias en la calidad de vida en el trabajo, según la institución en donde labora (p=0.001). el personal de enfermería se percibe con mediana calidad de vida en el trabajo, la cual está determinada de forma estadísticamente significativa por el tipo de contrato, realizar o no otra actividad remunerada y por la institución donde labora. determinar a qualidade de vida no trabalho do pessoal de enfermagem de instituições públicas em Hermosillo, Sonora, México. quantitativo, correlacional, transversal e comparativo. Amostra probabilística de 345 enfermeiras, dados coletados em 2013 utilizando instrumentos que coletam dados biossociodemográficos; elaborado pelas autoras e o instrumento CVT-GOHISALO com um alfa de Cronbach de 0.95. Para a análise de dados, foi utilizado o SPSS 15. Para determinar a normalidade dos dados, foi utilizado o teste de Kolmogorov-Smirnov; as medianas foram comparadas pelos testes U de Mann-Whitney e Kruskal-Wallis, com os níveis de significância estabelecidos em 0,05. a média da qualidade de vida do pessoal de enfermagem no trabalho é de 207,31 (DP 41,74), o que indica um nível moderado. Em relação ao tipo de contrato, a qualidade de vida no trabalho foi mais alta para pessoas com contratos permanentes (p=0,007), que não exercem outras atividades remuneradas (p=0,046), com diferenças na qualidade de vida no trabalho dependendo da instituição onde trabalham (p=0,001). o pessoal de enfermagem percebe uma média qualidade de vida no trabalho, o que é determinado de maneira significativa pelo tipo de contrato, pelo fato de exercer ou não outras atividades remuneradas e pela instituição em que a pessoa trabalha.

  11. Myosin-binding Protein C Compound Heterozygous Variant Effect on the Phenotypic Expression of Hypertrophic Cardiomyopathy.

    PubMed

    Rafael, Julianny Freitas; Cruz, Fernando Eugênio Dos Santos; Carvalho, Antônio Carlos Campos de; Gottlieb, Ilan; Cazelli, José Guilherme; Siciliano, Ana Paula; Dias, Glauber Monteiro

    2017-04-01

    Hypertrophic cardiomyopathy (HCM) is an autosomal dominant genetic disease caused by mutations in genes encoding sarcomere proteins. It is the major cause of sudden cardiac death in young high-level athletes. Studies have demonstrated a poorer prognosis when associated with specific mutations. The association between HCM genotype and phenotype has been the subject of several studies since the discovery of the genetic nature of the disease. This study shows the effect of a MYBPC3 compound variant on the phenotypic HCM expression. A family in which a young man had a clinical diagnosis of HCM underwent clinical and genetic investigations. The coding regions of the MYH7, MYBPC3 and TNNT2 genes were sequenced and analyzed. The proband present a malignant manifestation of the disease, and is the only one to express HCM in his family. The genetic analysis through direct sequencing of the three main genes related to this disease identified a compound heterozygous variant (p.E542Q and p.D610H) in MYBPC3. A family analysis indicated that the p.E542Q and p.D610H alleles have paternal and maternal origin, respectively. No family member carrier of one of the variant alleles manifested clinical signs of HCM. We suggest that the MYBPC3-biallelic heterozygous expression of p.E542Q and p.D610H may cause the severe disease phenotype seen in the proband. Resumo A cardiomiopatia hipertrófica (CMH) é uma doença autossômica dominante causada por mutações em genes que codificam as proteínas dos sarcômeros. É a principal causa de morte súbita cardíaca em atletas jovens de alto nível. Estudos têm demonstrado um pior prognóstico associado a mutações específicas. A associação entre genótipo e fenótipo em CMH tem sido objeto de diversos estudos desde a descoberta da origem genética dessa doença. Este trabalho apresenta o efeito de uma mutação composta em MYBPC3 na expressão fenotípica da CMH. Uma família na qual um jovem tem o diagnóstico clínico de CMH foi submetida à investigação clínica e genética. As regiões codificadoras dos genes MYH7, MYBPC3 e TNNT2 foram sequenciadas e analisadas. O probando apresenta uma manifestação maligna da doença e é o único em sua família a desenvolver CMH. A análise genética pelo sequenciamento direto dos três principais genes relacionados à essa doença identificou uma variante em heterozigose composta (p.E542Q e p.D610H) em MYBPC3. A análise da família mostrou que os alelos p.E542Q e p.D610H tem origem paterna e materna, respectivamente. Nenhum familiar portador de um dos alelos variantes manifestou sinais clínicos de CMH. Sugerimos que a expressão heterozigótica bialélica de p.E542Q e p.D610H pode ser responsável pelo fenótipo severo da doença encontrada no probando.

  12. Heart rate variability based on risk stratification for type 2 diabetes mellitus.

    PubMed

    Silva-E-Oliveira, Julia; Amélio, Pâmela Marina; Abranches, Isabela Lopes Laguardia; Damasceno, Dênis Derly; Furtado, Fabianne

    2017-01-01

    To evaluate heart rate variability among adults with different risk levels for type 2 diabetes mellitus. The risk for type 2 diabetes mellitus was assessed in 130 participants (89 females) based on the questionnaire Finnish Diabetes Risk Score and was classified as low risk (n=26), slightly elevated risk (n=41), moderate risk (n=27) and high risk (n=32). To measure heart rate variability, a heart-rate monitor Polar S810i® was employed to obtain RR series for each individual, at rest, for 5 minutes, followed by analysis of linear and nonlinear indexes. The groups at higher risk of type 2 diabetes mellitus had significantly lower linear and nonlinear heart rate variability indexes. The individuals at high risk for type 2 diabetes mellitus have lower heart rate variability. Avaliar a variabilidade da frequência cardíaca em adultos com diferentes níveis de risco para diabetes mellitus tipo 2. O grau de risco para diabetes mellitus tipo 2 de 130 participantes (41 homens) foi avaliado pelo questionário Finnish Diabetes Risk Score. Os participantes foram classificados em baixo risco (n=26), risco levemente elevado (n=41), risco moderado (n=27) e alto risco (n=32). Para medir a variabilidade da frequência cardíaca, utilizou-se o frequencímetro Polar S810i® para obter séries de intervalo RR para cada indivíduo, em repouso, durante 5 minutos; posteriormente, realizou-se análise por meio de índices lineares e não-lineares. O grupo com maior risco para diabetes mellitus tipo 2 teve uma diminuição significante nos índices lineares e não-lineares da variabilidade da frequência cardíaca. Os resultados apontam que indivíduos com risco alto para diabetes mellitus tipo 2 tem menor variabilidade da frequência cardíaca. To evaluate heart rate variability among adults with different risk levels for type 2 diabetes mellitus. The risk for type 2 diabetes mellitus was assessed in 130 participants (89 females) based on the questionnaire Finnish Diabetes Risk Score and was classified as low risk (n=26), slightly elevated risk (n=41), moderate risk (n=27) and high risk (n=32). To measure heart rate variability, a heart-rate monitor Polar S810i® was employed to obtain RR series for each individual, at rest, for 5 minutes, followed by analysis of linear and nonlinear indexes. The groups at higher risk of type 2 diabetes mellitus had significantly lower linear and nonlinear heart rate variability indexes. The individuals at high risk for type 2 diabetes mellitus have lower heart rate variability.

  13. Older adults abuse in three Brazilian cities.

    PubMed

    Rodrigues, Rosalina Aparecida Partezani; Monteiro, Edilene Araújo; Santos, Ana Maria Ribeiro Dos; Pontes, Maria de Lourdes de Farias; Fhon, Jack Roberto Silva; Bolina, Alisson Fernandes; Seredynskyj, Fernanda Laporti; Almeida, Vanessa Costa; Giacomini, Suelen Borelli Lima; Defina, Giovanna Partezani Cardoso; Silva, Luipa Michele

    2017-01-01

    To analyze the police reports filed by older adults who suffered abuse in order to identify the socio-demographic characteristics of victims and aggressors, type of violence, location, as well as to compare rates in three Brazilian cities in the period from 2009 to 2013. Ecological study, in which 2,612 police reports registered in Police Stations were analyzed. An instrument was used to obtain data from the victim, the aggressor and the type of violence. Psychological abuse predominated and most cases occurred in the older adults own home. In the cities of Ribeirão Preto and João Pessoa, the older adults presented similar rates for both gender. Regarding the standardized rates, in João Pessoa, there was a rise of this type of abuse in the two first years, and later there was a certain stability. In the city of Teresina, there was an increase, also observed in the city of Ribeirão Preto in the three first years, followed by a decrease. Older adults abuse is a cultural phenomenon difficult to be reported by them, since it occurs in the family context. Analisar os boletins de ocorrência registrados por idosos que sofreram violência, a fim de identificar características sociodemográficas das vítimas e dos agressores, tipo de violência, local, bem como comparar as taxas em três municípios brasileiros no período de 2009 a 2013. Estudo ecológico, em que foram analisados 2.612 boletins de ocorrência registrados em Delegacias do Idoso. Utilizou-se um instrumento para obter dados da vítima, do agressor e tipo de violência. Predominou a violência psicológica, na maioria dos casos na própria residência do idoso. Em Ribeirão Preto e João Pessoa, os idosos mais jovens apresentaram taxas semelhantes entre ambos os sexos. Na comparação das taxas padronizadas, em João Pessoa, houve ascensão deste tipo de violência nos dois primeiros anos, e, posteriormente, certa estabilidade. Em Teresina, houve ascensão, também observada em Ribeirão Preto nos três primeiros anos, seguida de decréscimo. A violência é um fenômeno cultural de difícil notificação pelo idoso, por ocorrer no contexto familiar.

  14. Piezoresponse force microscopy of ferroelectric relaxors =

    NASA Astrophysics Data System (ADS)

    Kiselev, Dmitry

    Nesta tese, ferroelectricos relaxor (I dont know uf the order is correct) de base Pb das familias (Pb,La)(Zr,Ti)O3 (PLZT), Pb(Mg1/3,Nb2/3)O3-PbTiO3 (PMN-PT), Pb(Zn1/3,Nb2/3)O3-PbTiO3 (PZN-PT) foram investigados e analisados. As propriedades ferroelectricas e dielectricas das amostras foram estudadas por metodos convencionais de macro e localmente por microscopia de forca piezoelectrica (PFM). Nos cerâmicos PLZT 9.75/65/35 o contraste da PFM a escala nanometrica foi investigado em funcao do tamanho e orientacao dos graos. Apurou-se que a intensidade do sinal piezoelectrico das nanoestruturas diminui com o aumento da temperatura e desaparece a 490 K (La mol. 8%) e 420 K (9,5%). Os ciclos de histerese locais foram obtidos em funcao da temperatura. A evolucao dos parâmetros macroscopicos e locais com a temperatura de superficie sugere um forte efeito de superficie nas transicoes de fase ferroelectricas do material investigado. A rugosidade da parede de dominio e determinada por PFM para a estrutura de dominio natural existente neste ferroelectrico policristalino. Alem disso, os dominios ferroelectricos artificiais foram criados pela aplicacao de pulsos electricos a ponta do condutor PFM e o tamanho de dominio in-plane foi medido em funcao da duracao do pulso. Todas estas experiencias levaram a conclusao de que a parede de dominio em relaxors do tipo PZT e quase uma interface unidimensional. O mecanismo de contraste na superficie de relaxors do tipo PLZT e medido por PFMAs estruturas de dominio versus evolucao da profundidade foram estudadas em cristais PZN-4,5%PT, com diferentes orientacoes atraves da PFM. Padroes de dominio irregulares com tamanhos tipicos de 20-100 nm foram observados nas superficies com orientacao das amostras unpoled?. Pelo contrario, os cortes de cristal exibem dominios regulares de tamanho micron normal, com os limites do dominio orientados ao longo dos planos cristalograficos permitidos. A existencia de nanodominios em cristais com orientacao esta provisoriamente (wrong Word) atribuida a natureza relaxor de PZN-PT, onde pequenos grupos polares podem formar-se em coindicoes de zero-field-cooling (ZFC). Estes nanodominios sao considerados como os nucleos do estado de polarizacao oposta e podem ser responsaveis pelo menor campo coercitivo para este corte de cristal em particular. No entanto, a histerese local piezoeletrica realizada pelo PFM a escala nanometrica indica uma mudanca de comportamento de PZN-PT semelhante para ambas as orientacoes cristalograficas investigadas. A evolucao das estruturas de dominio com polimento abaixo da superficie do cristal foi investigada. O dominio de ramificacoes e os efeitos de polarizacao de triagem apos o polimento e as medicoes de temperatura tem sido estudados pela PFM e pela analise SEM. Alem disso, verificou-se que a intensidade do sinal piezoelectrico a partir das estruturas de nanodominio diminui com o aumento da temperatura, acabando por desaparecer aos 430 K (orientacao ) e 470 K (orientacao ). Esta diferenca de temperatura nas transicoes de fase local em cristais de diferentes orientacoes e explicada pelo forte efeito de superficie na transicao da fase ferroeletrica em relaxors. A comutacao da polarizacao em relaxor ergodico e nas fases ferroelectricas do sistema PMN-PT foram realizadas pela combinacao de tres metodos, Microscopia de Forca Piezoelectrica, medicao de um unico ponto de relaxamento eletromecânico e por ultimo mapeamento de espectroscopia de tensao. A dependencia do comportamento do relaxamento na amplitude e tempo da tensao de pulso foi encontrada para seguir um comportamento logaritmico universal com uma inclinacao quase constante. Este comportamento e indicativo da progressiva populacao dos estados de relaxamento lento, ao contrario de uma relaxacao linear na presenca de uma ampla distribuicao do tempo de relaxamento. O papel do comportamento de relaxamento, da nao-linearidade ferroelectrica e da heterogeneidade espacial do campo na ponta da sonda de AFM sobre o comportamento do ciclo de histerese e analisada em detalhe. Os ciclos de histerese para ergodica PMN- 10%PT sao mostrados como cineticamente limitados, enquanto que no PMN, com maior teor de PT, sao observados verdadeiros ciclos de histerese ferroelectrica com vies de baixa nucleacao.

  15. pelo Is Required for High Efficiency Viral Replication

    PubMed Central

    Wu, Xiurong; He, Wan-Ting; Tian, Shuye; Meng, Dan; Li, Yuanyue; Chen, Wanze; Li, Lisheng; Tian, Lili; Zhong, Chuan-Qi; Han, Felicia; Chen, Jianming; Han, Jiahuai

    2014-01-01

    Viruses hijack host factors for their high speed protein synthesis, but information about these factors is largely unknown. In searching for genes that are involved in viral replication, we carried out a forward genetic screen for Drosophila mutants that are more resistant or sensitive to Drosophila C virus (DCV) infection-caused death, and found a virus-resistant line in which the expression of pelo gene was deficient. Our mechanistic studies excluded the viral resistance of pelo deficient flies resulting from the known Drosophila anti-viral pathways, and revealed that pelo deficiency limits the high level synthesis of the DCV capsid proteins but has no or very little effect on the expression of some other viral proteins, bulk cellular proteins, and transfected exogenous genes. The restriction of replication of other types of viruses in pelo deficient flies was also observed, suggesting pelo is required for high level production of capsids of all kinds of viruses. We show that both pelo deficiency and high level DCV protein synthesis increase aberrant 80S ribosomes, and propose that the preferential requirement of pelo for high level synthesis of viral capsids is at least partly due to the role of pelo in dissociation of stalled 80S ribosomes and clearance of aberrant viral RNA and proteins. Our data demonstrated that pelo is a host factor that is required for high efficiency translation of viral capsids and targeting pelo could be a strategy for general inhibition of viral infection. PMID:24722736

  16. Restored Roots: "Muntu" as a Healing Agent in "Pelo bueno, Pelo malo" by Carmen Montañez

    ERIC Educational Resources Information Center

    Edison, Thomas Wayne

    2017-01-01

    Carmen Montañez's novel "Pelo bueno, pelo malo" acknowledges the struggle that some Caribbean individuals face in accepting their blackness. The novel integrates the union of ancestors with the living, thus reflecting the Bantu concept known as "Muntu". This Puerto Rican novel presents a deep social problem of internalized…

  17. A correlação índice espectral vs. luminosidade em QSOs e suas implicações

    NASA Astrophysics Data System (ADS)

    Garcia-Rissmann, A.

    2003-08-01

    Estudos de variabilidade de núcleos ativos já demonstraram ser comum o fato de seu contínuo óptico/UV tornar-se mais "duro" à medida que a luminosidade aumenta. Essa tendência ocorre tanto de forma individual quanto global, e pode ter implicações importantes (1) para estudos fotométricos de variabilidade conduzidos numa banda fixa no referencial do observador, comparando objetos a diferentes redshifts, e (2) no cálculo da correção K, com consequente impacto na determinação de massas de buracos negros e bojos de galáxias hospedeiras (através da relação de Magorrian). Confirmo aqui as correlações positivas entre o índice espectral e a luminosidade óptica, utilizando dados espectroscópicos de 11 QSOs monitorados no Brasil e no Chile, durante ~2 anos. O estudo é complementado com parâmetros extraídos de espectros e de dados fotométricos públicos de quasares. Destaco ainda as diferenças observadas em tais correlações para objetos do tipo radio-loud e radio-quiet. Este projeto é financiado pelo I. Milênio/CNPq.

  18. Life-cycle optimization model for distributed generation in buildings

    NASA Astrophysics Data System (ADS)

    Safaei, Amir

    O setor da construcao e responsavel por uma grande parte do consumo de energia e emissoes na Uniao Europeia. A Geracao Distribuida (GD) de energia, nomeadamente atraves de sistemas de cogeracao e tecnologias solares, representa um papel importante no futuro energetico deste setor. A otimizacao do funcionamento dos sistemas de cogeracao e uma tarefa complexa, devido as diversas variaveis em jogo, designadamente: os diferentes tipos de necessidades energeticas (eletricidade, aquecimento e arrefecimento), os precos dinamicos dos combustiveis (gas natural) e da eletricidade, e os custos fixos e variaveis dos diferentes sistemas de GD. Tal torna-se mais complexo considerando a natureza flutuante das tecnologias solares termicas e fotovoltaicas. Ao mesmo tempo, a liberalizacao do mercado da eletricidade permite exportar para a rede, a electricidade gerada localmente. Adicionalmente, a operacao estrategica de um sistema de GD deve atender aos quadros politicos nacionais, se tiver como objetivo beneficiar de tais regimes. Alem disso, considerando os elevados impactes ambientais do setor da construcao, qualquer avaliacao energetica de edificios rigorosa deve tambem integrar aspetos ambientais, utilizando uma abordagem de Ciclo de Vida (CV). Uma avaliacao de Ciclo de Vida (ACV) completa de um sistema de GD deve incluir as fases relativas a operacao e construcao do sistema, bem como os impactes associados a producao dos combustiveis. Foram analisadas as emissoes da producao de GN, as quais variam de acordo com a origem, tipo (convencional ou nao-convencional), e estado (na forma de GN Liquefeito (GNL) ou gas). Do mesmo modo, o impacte dos sistemas solares e afetado pela meteorologia e radiacao solar, de acordo com a sua localizacao geografica. Sendo assim, uma avaliacao adequada dos sistemas de GD exige um modelo de ACV adequado a localizacao geografica (Portugal), integrando tambem a producao de combustivel (GN), tendo em conta as suas diferentes fontes de abastecimento. O principal objetivo desta tese de doutoramento foi desenvolver um modelo para otimizar o desenho e operacao de sistemas de GD para o setor da construcao de edificios comerciais em Portugal, considerando os respetivos Impactes de Ciclo de Vida (IAVC) e Custos de Ciclo de Vida (CCV), de modo a satisfazer as necessidades energeticas do edificio. Tres tipos de tecnologias de cogeracao (Micro-Turbinas, Motores de combustao interna, e Celulas combustiveis de Oxido solido), e dois tipos de tecnologias de energia solar, solar termica e fotovoltaica, constituem os sistemas de GD que sao acoplados aos sistemas convencionais. Foi desenvolvido um modelo de CV, tendo em conta todos os impactes relacionados com a construcao e operacao dos sistemas de energia, bem como os processos a montante relacionados com a producao do GN. Em particular, o mix de GN consumido em Portugal em 2011 foi identificado (60% da Nigeria, 40% da Argelia) e os impactes relativos a cada uma das vias de abastecimento foram avaliados separadamente para quatro categorias de impacte ambiental: Consumo de Energia Primaria (CEP), Gases com Efeito de Estufa (GEE), acidificacao, e eutrofizacao. Devido a importancia das emissoes de GEE na formulacao de politicas, foi tambem realizada uma analise de incerteza as emissoes de GEE do GN fornecido a Portugal. Foi desenvolvido um modelo matematico, em linguagem de Programacao General Algebraic Modeling System (GAMS), que utiliza os resultados da ACV dos sistemas de energia e as suas implicacoes economicas para minimizar o CCV e IACV ao longo de um horizonte de planeamento definido pelo decisor. Foram derivadas fronteiras otimas de Pareto, representando as relacoes entre o tipo de IACV (CEP, GEE, acidificacao, eutrofizacao) e CCV decorrentes da satisfacao das necessidades energeticas do edificio. Para aumentar a robustez do modelo, dada a incerteza dos precos dos combustiveis (GN e eletricidade), foi desenvolvido um modelo de custos robusto para os sistemas de GD, que e menos afetado por perturbacoes relativas aos custos de combustivel. A aplicacao do modelo proposto foi testada num caso de estudo real, um edificio comercial localizado na cidade de Coimbra, em Portugal.

  19. Suppression of the pelo protein by Wolbachia and its effect on dengue virus in Aedes aegypti

    PubMed Central

    Asad, Sultan; Hussain, Mazhar; Hugo, Leon; Zhang, Guangmei; Watterson, Daniel

    2018-01-01

    The endosymbiont Wolbachia is known to block replication of several important arboviruses, including dengue virus (DENV), in the mosquito vector Aedes aegypti. So far, the exact mechanism of this viral inhibition is not fully understood. A recent study in Drosophila melanogaster has demonstrated an interaction between the pelo gene and Drosophila C virus. In this study, we explored the possible involvement of the pelo protein, that is involved in protein translation, in Wolbachia-mediated antiviral response and mosquito-DENV interaction. We found that pelo is upregulated during DENV replication and its silencing leads to reduced DENV virion production suggesting that it facilities DENV replication. However, in the presence of Wolbachia, specifically in female mosquitoes, the pelo protein is downregulated and its subcellular localization is altered, which could contribute to reduction in DENV replication in Ae. aegypti. In addition, we show that the microRNA aae-miR-2940-5p, whose abundance is highly enriched in Wolbachia-infected mosquitoes, might mediate regulation of pelo. Our data reveals identification of pelo as a host factor that is positively involved in DENV replication, and its suppression in the presence of Wolbachia may contribute to virus blocking exhibited by the endosymbiont. PMID:29641562

  20. New tools for subsurface imaging of 3D seismic Node data in hydrocarbon exploration =

    NASA Astrophysics Data System (ADS)

    Benazzouz, Omar

    A aquisicao de dados sismicos de reflexao multicanal 3D/4D usando Ocean Bottom NODES de 4 componentes constitui atualmente um sector de importancia crescente no mercado da aquisicao de dados reflexao sismica marinha na industria petrolifera. Este tipo de dados permite obter imagens de sub-superficie de alta qualidade, com baixos niveis de ruido, banda larga, boa iluminacao azimutal, offsets longos, elevada resolucao e aquisicao de tanto ondas P como S. A aquisicao de dados e altamente repetitiva e portanto ideal para campanhas 4D. No entanto, existem diferencas significativas na geometria de aquisicao e amostragem do campo de ondas relativamente aos metodos convencionais com streamers rebocados a superficie, pelo que e necessario desenvolver de novas ferramentas para o processamento deste tipo de dados. Esta tese investiga tres aspectos do processamento de dados de OBSs/NODES ainda nao totalmente resolvidos de forma satisfatoria: a deriva aleatoria dos relogios internos, o posicionamento de precisao dos OBSs e a implementacao de algoritmos de migracao prestack 3D em profundidade eficientes para obtencao de imagens precisas de subsuperficie. Foram desenvolvidos novos procedimentos para resolver estas situacoes, que foram aplicados a dados sinteticos e a dados reais. Foi desenvolvido um novo metodo para deteccao e correccao de deriva aleatoria dos relogios internos, usando derivadas de ordem elevada. Foi ainda desenvolvido um novo metodo de posicionamento de precisao de OBSs usando multilateracao e foram criadas ferramentas de interpolacao/extrapolacao dos modelos de velocidades 3D de forma a cobrirem a extensao total area de aquisicao. Foram implementados algoritmos robustos de filtragem para preparar o campo de velocidades para o tracado de raios e minimizar os artefactos na migracao Krichhoff pre-stack 3D em profundidade. Os resultados obtidos mostram um melhoramento significativo em todas as situacoes analisadas. Foi desenvolvido o software necessario para o efeito e criadas solucoes computacionais eficientes. As solucoes computacionais desenvolvidas foram integradas num software standard de processamento de sismica (SPW) utilizado na industria, de forma a criar, conjuntamente com as ferramentas ja existentes, um workflow de processamento integrado para dados de OBS/NODES, desde a aquisicao e controle de qualidade a producao dos volumes sismicos migrados pre-stack em profundidade.

  1. Considerations about gastric cancer proteomics.

    PubMed

    Carvalho, Carlos Eduardo; McCormick, Thaís Messias; Carvalho, Paulo Costa; Fischer, Juliana DE Saldanha DA Gama; Aquino, Priscila Ferreira DE; Bravo, Guilherme Pinto; Carvalho, Maria DA Glória DA Costa

    2016-01-01

    The frequency of molecular studies aimed to analyze promoter methylation of tumor suppressor genes and global proteomics in gastric carcinogenesis is increasing. Nonetheless, only a few considered the different types of stomach cells, the tumor location and the influence of Helicobacter pylori and Epstein Barr virus infection (EBV). Molecular differences relating to anatomical and histological tumor areas were also recently described. The authors propose a molecular classification of gastric cancer, dividing it into four subtypes: tumors positive for EBV; microsatellite unstable tumors; genomically stable tumors and tumors with chromosomal instability. RESUMO A frequência de estudos moleculares visando a analisar os promotores de metilação de genes supressores de tumor e proteômica globais na carcinogênese gástrica está aumentando. No entanto, apenas alguns consideraram os diferentes tipos de células do estômago, a localização do tumor e a influência da infecção por Helicobacter pylori e pelo vírus Epstein-Barr (EBV). Diferenças moleculares relacionadas com áreas tumorais anatômicas e histológicas também foram recentemente descritas. Os autores propõem uma classificação molecular de câncer gástrico, dividindo-o em quatro subtipos: tumores positivos para o EBV; tumores microssatélite instáveis; tumores genomicamente estáveis ​​e tumores com instabilidade cromossômica.

  2. RELATIONSHIP BETWEEN ESOPHAGITIS GRADES AND HELICOBACTER PYLORI.

    PubMed

    Ribeiro, Patrícia Fernanda Saboya; Kubrusly, Luiz Fernandao; Nassif, Paulo Afonso Nunes; Ribeiro, Irma Cláudia Saboya; Bertoldi, Andressa de Souza; Batistão, Venessa Caroline

    2016-01-01

    The Helicobacter pylori infection (HP) is related to the development of gastric lesions and lymphoma; however, it is not known if there is a relation with gastroesophageal reflux disease and reflux esophagitis. To evaluate HP's relationship with esophagitis in patients undergoing upper endoscopy. Observational, retrospective and cross-sectional study, being evaluated 9576 patients undergoing outpatient endoscopic examination during the period between January and December 2015. Were included patients with any esophageal alteration at the examination; greater than 18; of both genders; independent of the complaint or the reason for the examination, illness or drug use. Were excluded those with active bleeding during the examination and in use of anticoagulants. The variables gender, age, esophagitis and result of the urease test, were studied. For statistical analysis was used the Epi Info software 7.1.5.2. Most of the samples consisted of women and the overall average age was 46.54±16.32 years. The presence of infection was balanced for gender: 1204 (12.56%) women and 952 (13.92%) men. Relating degree of esophagitis HP- and HP+ was observed that the type A was the most common (58.79%, n=1460); 604 (24.32%) had grade B; 334 (13.45%) grade C, and 85 (3.42%) grade D. In the relation between the grade of esophagitis with gender, esophagitis A was predominant in women and present in 929 (63.33%), followed by type B, 282 (46.68%), 136 C (40.71%) and D 30 (35.29%). In men 531 (36.36%) showed type A, 322 (53.31%) B, 198 (59.28%) C, and 55 (64.70%) D. Among the groups 40-50 and over 60 years there was a significant difference in whether have or not have HP+. There is no significant difference between HP infection and the different grades of esophagitis. A infecção pelo Helicobacter pylori (HP) é relacionada com o desenvolvimento de lesões e linfoma gástricos; porém, ainda não se sabe ao certo se há relação dele com a doença do refluxo gastroesofágico e esofagite de refluxo. Avaliar a relação do HP com as esofagites em pacientes submetidos à endoscopia digestiva alta. Estudo observacional, retrospectivo e transversal, sendo avaliados 9576 pacientes submetidos ao exame endoscópico ambulatorial durante o período compreendido entre janeiro e dezembro de 2015. Foram incluídos pacientes que apresentaram alguma alteração esofágica ao exame; maiores que 18 anos; de ambos os gêneros; independente da queixa ou da razão para a realização do exame, doença ou uso de medicamentos. Excluíram-se os com sangramento ativo durante o exame e em uso de anticoagulantes. Foram avaliadas as variáveis gênero, idade, esofagite e resultado do teste da urease. Para a análise estatística utilizou-se o software Epi Info 7.1.5.2. A maioria das amostras foi composta por mulheres e a idade média geral foi de 46,54±16,32 anos. A presença da infecção foi equilibrada para a variável gênero: 1204 (12,56%) mulheres e 952 (13,92%) homens. Relacionando os graus da esofagite com HP+ e HP- observou-se que o tipo A foi o mais comum (58,79% da amostra, n=1460), que 604 (24,32%) possuíam o grau B; 334 (13,45%) o grau C e 85 (3,42%) o grau D. Já na relação entre os graus de esofagite com o gênero, a esofagite A foi predominante nas mulheres e presente em 929 (63,33%), seguido pelo tipo B, com 282 (46,68%), C com 136 (40,71%) e D com 30 (35,29%) mulheres. Nos homens 531 (36,36%) apresentam o tipo A, 322 (53,31%) o B, 198 (59,28%) o C e 55 (64,70%) o D. Entre os grupos de 40 a 50 anos e acima de 60 anos houve diferença significativa em ter ou não HP+. Não há diferença significativa entre infecção por HP nos diferentes graus de esofagite.

  3. Sugammadex ED90 dose to reverse the rocuronium neuromuscular blockade in obese patients.

    PubMed

    Silva, Mauro Prado DA; Matsui, Christiano; Kim, Daniel Dongiou; Vieira, Joaquim Edson; Malheiros, Carlos Alberto; Mathias, Ligia Andrade Silva Telles

    2017-01-01

    to determine the ED90 (minimum effective dose in 90% of patients) of sugammadex for the reversal of rocuronium-induced moderate neuromuscular blockade (NMB) in patients with grade III obesity undergoing bariatric surgery. we conducted a prospective study with the biased coin up-and-down sequential design. We chosen the following doses: 2.0mg/Kg, 2.2mg/Kg, 2.4mg/Kg, 2.6mg/Kg, 2.8mg/Kg. The complete reversal of rocuronium-induced NMB considered a T4/T1 ratio ≥0.9 as measured by TOF. After induction of general anesthesia and calibration of the peripheral nerve stimulator and accelerometer, we injected rocuronium 0.6mg/kg. We administered propofol and remifentanil by continuous infusion, and intermittent boluses of rocuronium throughout the procedure. we evaluated 31 patients, of whom 26 had displayed successful reversal of the NMB with sugammadex, and failure in five. The mean time to complete moderate NMB reversal was 213 seconds (172-300, median 25-75%). The ED90 of sugammadex calculated by regression was 2.39mg/kg, with a 95% confidence interval of 2.27-2.46 mg/kg. the ED90 of sugammadex in patients with grade III obesity or higher was 2.39mg/kg. determinar a ED90 (dose mínima eficaz em 90% dos pacientes) de sugamadex para a reversão de bloqueio neuromuscular (BNM) moderado induzido pelo rocurônio em pacientes com obesidade grau III submetidos à cirurgia bariátrica. estudo prospectivo com o método de projeção sequencial para cima e para baixo da moeda enviesada. As seguintes doses foram escolhidas: 2,0mg/kg-1, 2,2mg/kg-1, 2,4mg/kg-1, 2,6mg/kg-1, 2,8mg/kg-1. A reversão completa de BNM induzido por rocurônio considerou uma relação T4/T1 ≥0,9 na medida do TOF. Após a indução da anestesia geral e calibração do estimulador de nervo periférico e acelerômetro, rocurônio 0,6mg/kg-1 foi injetado. Infusão contínua de propofol e remifentanil, e bolus intermitente de rocurônio foram injetados durante todo o procedimento. trinta e um pacientes foram avaliados, 26 dos quais bem-sucedidos e cinco sem reversão completa do BNM moderado promovido pelo sugamadex. O tempo médio para completar reversão de BNM foi 213 segundos (172 a 300 segundos; mediana, 25-75%). O ED90 de sugamadex calculado pela regressão foi de 2,39mg/kg-1 com um intervalo de confiança de 95% (2,27 a 2,46mg/kg-1). o ED90 de sugamadex em pacientes com obesidade grau III ou superior foi 2,39mg/kg-1.

  4. Trombose induzida pelo calor endovenoso: relato de dois casos tratados com rivaroxabana e revisão da literatura

    PubMed Central

    de Araujo, Walter Junior Boim; Timi, Jorge Rufino Ribas; Erzinger, Fabiano Luiz; Caron, Filipe Carlos

    2016-01-01

    Resumo Define-se trombose induzida pelo calor endovenoso como a propagação do trombo a partir de uma veia superficial em direção a uma veia mais profunda. Em geral, é considerada clinicamente insignificante quando não há propagação do trombo para o sistema venoso profundo. Essa condição pode ser tratada com terapia anticoagulante, embora a observação pareça ser suficiente, principalmente para graus menores. Neste estudo, relatamos dois casos de trombose induzida pelo calor endovenoso que teriam indicação de heparina de baixo peso molecular até a resolução do quadro. Porém, optou-se pelo uso da rivaroxabana (15 mg de 12 em 12h), com resolução completa do trombo em 4 semanas (caso 1) e em 7 dias (caso 2). A rivaroxabana pode ser uma alternativa promissora no tratamento da trombose induzida pelo calor endovenoso avançada, pela simplicidade da posologia, sem comprometimento da eficácia ou da segurança. São necessários estudos prospectivos, randomizados e controlados que possibilitem melhor entendimento da condição e o desenvolvimento de recomendações mais definitivas sobre opções de prevenção e tratamento.

  5. Queda dos homicídios em São Paulo, Brasil: uma análise descritiva

    PubMed Central

    Peres, Maria Fernanda Tourinho; Vicentin, Diego; Nery, Marcelo Batista; de Lima, Renato Sérgio; de Souza, Edinilsa Ramos; Cerda, Magdalena; Cardia, Nancy; Adorno, e Sérgio

    2012-01-01

    Objetivo Descrever a evolução da mortalidade por homicídios no Município de São Paulo segundo tipo de arma, sexo, raça ou cor, idade e áreas de exclusão/inclusão social entre 1996 e 2008. Métodos Estudo ecológico de série temporal. Os dados sobre óbitos ocorridos no Município foram coletados da base de dados do Programa de Aprimoramento das Informações sobre Mortalidade, seguindo a Classificação Internacional de Doenças, Décima Revisão (CID-10). Foram calculadas as taxas de mortalidade por homicídio (TMH) para a população total, por sexo, raça ou cor, faixa etária, tipo de arma e área de exclusão/inclusão social. As TMH foram padronizadas por idade pelo método direto. Foram calculados os percentuais de variação no período estudado. Para as áreas de exclusão/inclusão social foram calculados os riscos relativos de morte por homicídio. Resultados As TMH apresentaram queda de 73,7% entre 2001 e 2008. Foi observada redução da TMH em todos os grupos analisados, mais pronunciada em homens (−74,5%), jovens de 15 a 24 anos (−78,0%) e moradores de áreas de exclusão social extrema (−79,3%). A redução ocorreu, sobretudo, nos homicídios cometidos com armas de fogo (−74,1%). O risco relativo de morte por homicídio nas áreas de exclusão extrema (tendo como referência áreas com algum grau de exclusão social) foi de 2,77 em 1996, 3,9 em 2001 e 2,13 em 2008. Nas áreas de alta exclusão social, o risco relativo foi de 2,07 em 1996 e 1,96 em 2008. Conclusões Para compreender a redução dos homicídios no Município, é importante considerar macrodeterminantes que atingem todo o Município e todos os subgrupos populacionais e microdeterminantes que atuam localmente, influenciando de forma diferenciada os homicídios com armas de fogo e os homicídios na população jovem, no sexo masculino e em residentes em áreas de alta exclusão social. PMID:21390415

  6. Evolução temporal da explosão solar de 06 de junho de 2000 apresentando estruturas finas em rádio freqüências

    NASA Astrophysics Data System (ADS)

    Fernandes, F. C. R.; Sawant, H. S.; Cecatto, J. R.; Caracini, A. G.; Vats, H. O.; Karlický, M.; Meszarosova, H.

    2003-08-01

    Em 06 de junho de 2000 (~15: 00-17: 00 UT), o Brazilian Solar Spectroscope (BSS) registrou uma explosão solar intensa no intervalo de freqüência de (1000-2000) MHz, com alta resolução temporal (100 ms) e espectral (5 MHz). A atividade solar relacionada a esta explosão associada à região ativa (AR) 9026 e classificada como X2.3 foi grande. O Ondrejov Observatory registrou rádio emissões até 4,5 GHz. O satélite SOHO registrou uma série de erupções solares, incluindo uma Ejeção de Massa Coronal (CME) tipo "full-halo" (~15: 54 UT). Explosões tipo II/IV também foram registradas. Na faixa de ondas decimétricas, este evento apresentou dois picos distintos (~15: 21 UT e ~16: 42 UT). O primeiro pico coincide com a explosão registrada em raios-X moles (GOES) e em raios-X duros (Yohkoh). Os espectros dinâmicos com alta resolução do BSS revelaram várias estruturas finas, principalmente emissões tipo "zebra" e "fibra", rádio pulsações, emissões tipo III e do único caso de emissões "zebra" harmônicas observado na faixa decimétrica. Neste trabalho, analisamos a evolução temporal e o comportamento global do evento de 06 de junho de 2000, com ênfase na identificação e associação da ocorrência de cada tipo de estrutura fina registrada em rádio com cada etapa da explosão. Resultados preliminares mostraram que, na fase pré-flare, as estruturas finas apresentaram taxa de deriva negativa (~ 70-190 MHz/s). As emissões tipo "zebra" concentram-se na fase de descida do primeiro pico impulsivo e na de subida do segundo pico. Enquanto que as emissões tipo "fibra" ocorrem em ambas fases, mas preferivelmente durante a fase de descida. Os resultados serão apresentados e discutidos.

  7. Potential intravenous drug incompatibilities in a pediatric unit.

    PubMed

    Leal, Karla Dalliane Batista; Leopoldino, Ramon Weyler Duarte; Martins, Rand Randall; Veríssimo, Lourena Mafra

    2016-01-01

    To investigate potential intravenous drug incompatibilities and related risk factors in a pediatric unit. A cross-sectional analytical study conducted in the pediatric unit of a university hospital in Brazil. Data on prescriptions given to children aged 0-15 years from June to October 2014 were collected. Prescriptions that did not include intravenous drugs and prescriptions with incomplete dosage regimen or written in poor handwriting were excluded. Associations between variables and the risk of potential incompatibility were investigated using the Student's t test and ANOVA; the level of significance was set at 5% (p<0.05). Relative risks were calculated for each drug involved in potential incompatibility with 95% confidence interval. A total of 222 children participated in the study; 132 (59.5%) children were male and 118 (53.2%) were aged between 0 and 2 years. The mean length of stay was 7.7±2.3 days. Dipyrone, penicillin G and ceftriaxona were the most commonly prescribed drugs. At least one potential incompatibility was detected in about 85% of children (1.2 incompatibility/patient ratio). Most incompatibilities detected fell into the non-tested (93.4%), precipitation (5.5%), turbidity (0.7%) or chemical decomposition (0.4%) categories. The number of drugs and prescription of diazepam, phenytoin, phenobarbital or metronidazole were risk factors for potential incompatibility. Most pediatric prescriptions involved potential incompatibilities, with higher prevalence of non-tested incompatibilities. The number of drugs and prescription of diazepam, phenobarbital, phenytoin or metronidazole were risk factors for potential incompatibilities. Avaliar o potencial de incompatibilidade dos medicamentos intravenosos, identificando possíveis fatores de risco em uma unidade pediátrica. Trata-se de um estudo observacional analítico do tipo transversal realizado na unidade de pediatria de um hospital de ensino no Brasil. Os dados foram coletados de junho a outubro de 2014 a partir da análise das prescrições de crianças (0 a 15 anos) hospitalizadas. Foram excluídas prescrições sem medicamento intravenoso e com posologia incompletas ou grafia inadequada. A associação entre as variáveis e o risco de potenciais incompatibilidades foi determinada pelo teste t de Student e ANOVA, considerando significativo para p<0,05. Calculou-se o risco relativo com intervalo de confiança de 95% de cada medicamento envolvido. Duzentos e vinte e duas crianças participaram do estudo, 132 (59,5%) eram do gênero masculino, 118 (53,2%) tinham idade entre 0 a 2 anos e estiveram internados em média 7,7±2,3 dias. Os medicamentos mais prescritos foram dipirona, penicilina G e ceftriaxona. Quase 85% das crianças apresentaram ao menos uma potencial incompatibilidade, razão de 1,2 incompatibilidades/paciente. Os tipos de incompatibilidades mais comuns foram: não testada (93,4%), precipitação (5,5%), turbidez (0,7%) e decomposição química (0,4%). Os fatores associados a potenciais incompatibilidades foram: número de medicamentos e a prescrição dos medicamentos diazepam, fenitoína, fenobarbital e metronidazol. A maioria das prescrições pediátricas apresentou potenciais incompatibilidades e a incompatibilidade não testada foi o tipo mais comum. O número de medicamentos e a prescrição dos medicamentos diazepam, fenobarbital, fenitoína e metronidazol foram fatores de risco para potenciais incompatibilidades.

  8. Fifty-year flood-inundation maps for El Progreso, Honduras

    USGS Publications Warehouse

    Kresch, David L.; Mastin, Mark C.; Olsen, T.D.

    2002-01-01

    After the devastating floods caused by Hurricane Mitch in 1998, maps of the areas and depths of the 50-year-flood inundation at 15 municipalities in Honduras were prepared as a tool for agencies involved in reconstruction and planning. This report, which is one in a series of 15, presents maps of areas in the municipality of El Progreso that would be inundated by a 50-year flood of Rio Pelo. Geographic Information System (GIS) coverages of the flood inundation are available on a computer in the municipality of El Progreso as part of the Municipal GIS project and on the Internet at the Flood Hazard Mapping Web page (http://mitchnts1.cr.usgs.gov/projects/floodhazard.html). These coverages allow users to view the flood inundation in much more detail than is possible using the maps in this report. Water-surface elevations for a 50-year-flood on Rio Pelo at El Progreso were estimated using HEC-RAS, a one-dimensional, steady-flow, step-backwater computer program. The channel and floodplain cross sections used in HEC-RAS were developed from an airborne light-detection-and-ranging (LIDAR) topographic survey of the area. There are no nearby long-term stream-gaging stations on Rio Pelo; therefore, the 50-year-flood discharge for Rio Pelo, 235 cubic meters per second, was estimated using a regression equation that relates the 50-year-flood discharge to drainage area and mean annual precipitation. The drainage area and mean annual precipitation estimated for Rio Pelo at El Progreso are 47.4 square kilometers and 1,920 millimeters, respectively.

  9. Straight or Curly? Hair and Race in Carmen Montañez's "Pelo bueno, pelo malo"

    ERIC Educational Resources Information Center

    Ortiz-Loyola, Brenda

    2017-01-01

    Historically, black women's hair has been a site where power and social relations are defined. In Puerto Rico, cultural production has been critical in perpetuating as well as in contesting the prevailing white European ideal of beauty and its impact on women's hairstyling practices. Nevertheless, the link between aesthetic preferences and the…

  10. Use of technologies in intravenous therapy: contributions to a safer practice.

    PubMed

    Moreira, Ana Paula Amorim; Escudeiro, Cristina Lavoyer; Christovam, Bárbara Pompeu; Silvino, Zenith Rosa; Carvalho, Márglory Fraga de; Silva, Roberto Carlos Lyra da

    2017-01-01

    To identify what are the difficulties of the nursing staff in the management of technologies during intravenous therapy (IVT) and discuss the difficulties identified under the perspective of patient's safety. Descriptive study of qualitative approach with data collected by semi-structured interview and analyzed by the Alceste software. The greatest difficulty of cognitive and technical emphasis was the lack of training; and regarding administrative emphasis, the greatest difficulty was the lack of material and human resources. Infusion pumps and their proper use were highlighted as the technological resource that most contributed to patient safety. The lack of training is presented as the greatest difficulty of nursing professionals and permeates safety issues of both patient and professional when using the hard technologies in IVT. Training is essential to the development of techniques, considered nursing tools. Identificar quais são as dificuldades da equipe de Enfermagem no manejo das tecnologias durante a terapia intravenosa (TIV) e discutir as dificuldades identificadas sob a perspectiva da segurança do paciente. abordagem qualitativa, do tipo descritivo com dados coletados por entrevista semiestruturada e analisados pelo programa Alceste. A maior dificuldade de ênfase cognitiva e técnica foi a falta de treinamento; e de ênfase administrativa, foi a falta de recursos materiais e humanos. As bombas de infusão e sua utilização adequada foram destacadas como o recurso tecnológico que mais contribuiu para a segurança do paciente. A falta de treinamento é apresentada como a maior dificuldade dos profissionais de Enfermagem e permeia as questões de segurança do paciente e do profissional ao utilizar as tecnologias duras na TIV. O treinamento é imprescindível para o desenvolvimento das técnicas, consideradas como ferramentas do fazer da Enfermagem.

  11. X-Rays and Infrared Selected AGN

    NASA Astrophysics Data System (ADS)

    Kirhakos, S. D.; Steiner, J. E.

    1990-11-01

    RESUMEN. En la busqueda de nucleos activos galacticos (NAG) oscurecidos, seleccionamos una tnuestra de galaxias ernisoras de rayos S infrarrojos, Ia mayoria de las cuales son vistas de perf ii. La 6ptica de la regi6n nuclear de las galaxias seleccionadas revelan que el 76% de ellas muestran lineas de emisi5n La clasificaci6n de los es- pectros de acuerdo a los anchos y a la intensidad de cocientes de lineas muestran que existen 34 NAG, 34 objetos de tipo de transici6n y 34 galaxias de la regi6n con nucleos de tipo regi6n H II. Entre los NAG, 3 son del tipo Seyfert I y las otras son del tipo 2. Sugerimos que los objetos identificados como NAG de llneas angostas son objetos tipo Seyfert I oscurecidos ABSTRACT. Looking for obscured active galactic nuclei (AGN), we selected a sample of infrarediX-rays emitting galaxies, mos"t of which are seen as edge-on. Optical spectroscopy of the nuclear region of the selected galaxies revealed that 76 % of them show emission l 'nes. Classification of the spectra according to the widths and line intensity ratios shows that there are 34 AGN, 34 transition type objects and 43 nuclear HIl-like region galaxies. Among the AGN, three are Seyfert type 1 and the others are type 2 objects. We suggest that the objects identified as narrow line AGN are obscured Seyfert 1. o'L : GALAXIES-ACTIVE - X-RAY S-GENERAL

  12. Experiences and coping with the altered body image in digestive stoma patients.

    PubMed

    Hueso-Montoro, César; Bonill-de-Las-Nieves, Candela; Celdrán-Mañas, Miriam; Hernández-Zambrano, Sandra Milena; Amezcua-Martínez, Manuel; Morales-Asencio, José Miguel

    2016-12-08

    to describe the coping of stoma patients with the news about the ostomy, as well as to analyze the meaning and the experience of their new bodily reality. qualitative phenomenological study undertaken through semistructured interviews with 21 stoma patients. The analysis was based on the constant comparison of the data, the progressive incorporation of subjects and triangulation among researchers and stomal therapy nurses. The software Atlas.ti was used. two main categories emerge: "Coping with the news about receiving a stoma" and "Meaning and experience of the new bodily reality". The informants' answer varies, showing situations that range from the natural acceptance of the process to resignation and rejection. The previous experiences of other family members, the possible reconstruction of the stoma or the type of illness act as conditioning factors. the coping with the news about the stoma is conditioned by the type of illness, although the normalization of the process is the trend observed in most informants. Nursing plays a fundamental role in the implementation of cognitive-behavioral interventions and other resources to promote the patients' autonomy in everything related to care for the stoma. descrever o enfrentamento de pessoas ostomizadas diante da notícia da realização do estoma, assim como analisar o significado e a vivência diante de sua nova realizada corporal. estudo qualitativo fenomenológico mediante entrevistas semiestruturadas com 21 personas ostomizadas. Foi desenvolvido através da comparação constante de dados, incorporação progressiva de sujeitos e triangulação entre investigadores e enfermeiras especialistas em estomaterapia. Foi utilizado o software Atlas.ti. emergiram duas categorias centrais: "Enfrentamento diante da notícia de que serão ostomizados" e "Significado e vivência da nova realidade corporal". A resposta dos informantes é variável, revelando situações que vão desde a aceitação natural do seu processo até a resignação e a rejeição. As experiências prévias de outros familiares, a possibilidade de reconstrução do estoma ou o tipo de doença são fatores condicionantes. o enfrentamento diante da notícia do estoma está condicionado pelo tipo de doença. Apesar disso, observa-se que a maioria dos informantes tende a normalizar o processo. A enfermagem tem papel fundamental na implementação de intervenções cognitivas-comportamentais e outros recursos destinados à promoção da autonomia dos pacientes em tudo relacionado ao cuidado do estoma. describir el afrontamiento de personas ostomizadas ante la noticia de la realización de la ostomía, así como analizar el significado y la vivencia ante su nueva realidad corporal. estudio cualitativo fenomenológico mediante entrevistas semiestructuradas a 21 personas ostomizadas. Se realizó análisis mediante comparación constante de datos, incorporación progresiva de sujetos y triangulación entre investigadores y enfermeras expertas en estomaterapia. Se empleó el programa Atlas.ti. emergen dos categorías centrales: "Afrontamiento ante la noticia de que van a ser ostomizados" y "Significado y vivencia de la nueva realidad corporal". La respuesta de los informantes es variable, percibiéndose situaciones que van desde la aceptación natural de su proceso hasta la resignación y el rechazo. Las experiencias previas de otros familiares, la posibilidad de reconstrucción del estoma o el tipo de enfermedad, son factores condicionantes. el afrontamiento ante la noticia del estoma está condicionado por el tipo de enfermedad, aunque la normalización del proceso es la tendencia observada en la mayoría de los informantes. Enfermería tiene un papel fundamental en la puesta en marcha de intervenciones cognitivos-conductuales y otros recursos destinados a la promoción de la autonomía de los pacientes en todo lo relacionado con el cuidado del estoma.

  13. Protótipo do primeiro interferômetro brasileiro - BDA

    NASA Astrophysics Data System (ADS)

    Cecatto, J. R.; Fernandes, F. C. R.; Neri, J. A. C. F.; Bethi, N.; Felipini, N. S.; Madsen, F. R. H.; Andrade, M. C.; Soares, A. C.; Alonso, E. M. B., Sawant, H. S.

    2004-04-01

    A interferometria é uma poderosa ferramenta usada para investigar estruturas espaciais de fontes astrofísicas fornecendo uma riqueza de detalhes inatingível pelas técnicas convencionais de imageamento. Em particular, a interferometria com ondas de rádio abre o horizonte de conhecimento do Universo nesta ampla banda do espectro eletromagnético, que vai de cerca de 20 kHz até centenas de GHz já próximo ao infravermelho, e que está acessível a partir de instrumentos instalados em solo. Neste trabalho, apresentamos o interferômetro designado por Arranjo Decimétrico Brasileiro (BDA). Trata-se do primeiro interferômetro a ser desenvolvido no Brasil e América Latina que já está em operação na fase de protótipo. Apresentamos o desenvolvimento realizado até o momento, o sítio de instalação do instrumento, o protótipo e os principais resultados dos testes de sua operação, as perspectivas futuras e a ciência a ser desenvolvida com o instrumento nas fases II e III. Neste trabalho é dada ênfase ao desenvolvimento, testes de operação e principais resultados do protótipo. É discutida brevemente a ciência que pode ser feita com o instrumento. Tanto os detalhes técnicos quanto os principais parâmetros estimados para o instrumento nas próximas fases de desenvolvimento e o desempenho do protótipo serão publicados em breve.

  14. Perceptions of Regime Legitimacy in Mozambique: Legitimacy in Transition?

    DTIC Science & Technology

    2006-09-01

    West Africa Since Independence (Lagos: Lagos University Press, 1988) 170 . 52 James S. Wunsch and Dan Ottemoeller in Dele Olowu and James S. Wunsch...Ultramarina (RAU), aprovada pelo Decreto –Lei n. ˚23229, de 15 de Novembro de 1933. “Em cada uma das regedorias, a autoridade sobre as populações...2001. Artigo 94 da Reforma Adminsitrativa Ultramarina (RAU), aprovada pelo Decreto –Lei n. ˚23229, de 15 de Novembro de 1933. Ayittey, George B

  15. Tuberculosis control in people living with HIV/AIDS.

    PubMed

    Magnabosco, Gabriela Tavares; Lopes, Lívia Maria; Andrade, Rubia Laine de Paula; Brunello, Maria Eugênia Firmino; Monroe, Aline Aparecida; Villa, Tereza Cristina Scatena

    2016-09-09

    to analyze the offering of health actions and services for the control of tuberculosis for people living with HIV/AIDS being followed up in the Specialized Care Services for HIV/AIDS in Ribeirão Preto, SP, Brazil. quantitative, exploratory survey study. Participated 253 people living with HIV/AIDS followed up by this service, considering as inclusion criteria: individuals older than 18 years living in the city and not inmates. Data collection was conducted from January 2012 to May 2013 through interviews with the support of a specific instrument. Data were analyzed using indicators and a composite index. the offering of services for the control of tuberculosis in people living with HIV/AIDS by municipal services was considered as intermediate, reinforcing the need for better planning for comprehensive assistance, coordination of professionals in teams and among the services network, in addition to professional training and continuing education. it is necessary to implement strategies that promote shared actions between TB and HIV / AIDS programs and between different services in order to strengthen the local care network, aimed at producing an individualized care, comprehensive and responsive. analisar a oferta das ações e serviços de saúde para o controle da tuberculose nas pessoas vivendo com HIV/aids em seguimento pelos Serviços de Atenção Especializada ao HIV/aids de Ribeirão Preto, SP, Brasil. estudo quantitativo, exploratório, do tipo inquérito. Participaram 253 pessoas vivendo com HIV/aids em seguimento nos serviços, considerando os critérios de inclusão: indivíduos maiores de 18 anos, residentes no município e não pertencentes ao sistema prisional. A coleta de dados foi realizada no período de janeiro/2012 a maio/2013, por meio de entrevistas com apoio de um instrumento específico. Os dados foram analisados mediante indicadores e índice composto. a oferta de ações e serviços para o controle da tuberculose nas pessoas vivendo com HIV/aids pelos serviços do município foi considerada regular, reforçando a necessidade de melhor planejamento da assistência de forma integral, articulação dos profissionais nas equipes e entre os serviços da rede, além da formação profissional e educação permanente. faz-se necessário a implementação de estratégias que favoreçam ações compartilhadas entre os programas de tuberculose e HIV/aids e entre os diferentes serviços, com o intuito de fortalecer a rede local de atenção objetivando a produção de um cuidado singular, integral e resolutivo. analizar la oferta de acciones y servicios de salud para el control de la tuberculosis en las personas viviendo con VIH-SIDA acompañadas por los Servicios de Atención Especializada al VIH-SIDA de Ribeirao Preto, SP, Brasil. estudio cuantitativo, exploratorio, de tipo encuesta. Participaron 253 personas viviendo con VIH-SIDA seguidas por estos servicios, considerando como criterios de inclusión: individuos mayores de 18 años, residentes en el municipio y no ser del sistema de prisiones. La recolección de datos fue realizada en el periodo de enero de 2012 a mayo de 2013, por medio de entrevistas guiadas por un instrumento especifico. Los datos fueron analizados mediante indicadores y un índice compuesto. la oferta de acciones y servicios para el control de la tuberculosis en personas viviendo con VIH-SIDA fue considerada intermedia, reforzando la necesidad de mejorar la planificación de la asistencia en forma integral, la articulación de los profesionales en los equipos y entre los servicios de la red, además de la formación profesional y la educación permanente. se hace necesaria la implementación de estrategias que favorezcan las acciones compartidas entre los programas de tuberculosis y VIH-SIDA y entre los diferentes servicios, con el fin de fortalecer la red local de atención para producir un cuidado personalizado, integral y resolutivo.

  16. Effective Universal Coverage of Diabetes Mellitus Type 2 in Chile.

    PubMed

    Guerrero-Núñez, Sara; Valenzuela-Suazo, Sandra; Cid-Henríquez, Patricia

    2017-04-06

    determine the prevalence of Effective Universal Coverage of Diabetes Mellitus Type 2 in Chile and its relation with the variables: Health Care Coverage of Diabetes Mellitus Type 2; Average of diabetics with metabolic control in 2011-2013; Mortality Rate for Diabetes Mellitus; and Percentage of nurses participating in the Cardiovascular Health Program. cross-sectional descriptive study with ecological components that uses documentary sources of the Ministry of Health. It was established that there is correlation between the Universal Effective Coverage of Diabetes Mellitus Type 2 and the independent variables; it was applied the Pearson Coefficient, being significant at the 0.05 level. in Chile Universal Health Care Coverage of Diabetes Mellitus Type 2 (HbA1c<7% estimated population) is less than 20%; this is related with Mortality Rate for Diabetes Mellitus and Percentage of nurses participating in the Cardiovascular Health Program, being significant at the 0.01 level. effective prevalence of Universal Health Coverage of Diabetes Mellitus Type 2 is low, even though some regions stand out in this research and in the metabolic control of patients who participate in health control program; its relation with percentage of nurses participating in the Cardiovascular Health Program represents a challenge and an opportunity for the health system. determinar a prevalência de Cobertura Universal Efetiva da Diabetes Mellitus tipo 2 em Chile e sua relação com as variáveis; Cobertura da Diabetes Mellitus tipo 2, Média de diabéticos com controle metabólico em 2011-2013, Taxa de Mortalidade por Diabetes Mellitus e Percentagem de participação de enfermeiras no Programa de Saúde Cardiovascular. estudo descritivo transversal com componentes ecológicos, utilizando fontes documentais do Ministério da Saúde. Foi estabelecida correlação entre Cobertura Universal Efetiva da Diabetes Mellitus tipo 2 e as variáveis independentes, aplicando o Coeficiente de Pearson, sendo significante ao 0,05. no Chile a Cobertura Universal Efetiva da Diabetes Mellitus tipo 2 (HbA1c<7% em população estimada) é menor que 20%. Esta se relaciona com uma Taxa de Mortalidade por Diabetes Mellitus e Percentagem de participação de enfermeiras no Programa de Saúde Cardiovascular, que ademais é significativa ao 0,01. a prevalência de Cobertura Universal Efetiva da Diabetes Mellitus tipo 2 é baixa, mesmo quando algumas regiões se destacam nas pesquisas e no controle metabólico de pacientes assistentes ao controle. Sua relação com a Percentagem de participação de enfermeiras no Programa de Saúde Cardiovascular se constitui em um desafio e oportunidade em saúde. determinar la prevalencia de la Cobertura Universal Efectiva de la diabetes mellitus tipo 2 en Chile y su relación con las variables: Cobertura de Diabetes Mellitus tipo 2, Promedio de diabéticos con control metabólico en 2011-2013, Tasa de Mortalidad por Diabetes Mellitus y Porcentaje de participación de enfermeros en el Programa de Salud Cardiovascular. estudio descriptivo transversal con componentes ecológicos, utilizando fuentes documentales del Ministerio de Salud. Se estableció que existe correlación entre la Cobertura Universal Efectiva de la Diabetes Mellitus tipo 2 y las variables independientes, aplicando el Coeficiente de Pearson, siendo significativa al nivel 0,05. en Chile la Cobertura Universal Efectiva de Diabetes Mellitus tipo 2 (HbA1c<7% en población estimada) es menor que 20%; esta se relaciona con la Tasa de Mortalidad por Diabetes Mellitus y con el Porcentaje de participación de enfermeras en el Programa de Salud Cardiovascular, que es significativa al nivel 0,01. la prevalencia de Cobertura Universal Efectiva de la Diabetes Mellitus tipo 2 es baja; sin embargo algunas regiones se destacan en la cobertura y en el control metabólico de pacientes que participan del control de salud. La relación de la cobertura con el porcentaje de participación de enfermeras en el Programa de Salud Cardiovascular es un desafío y una oportunidad en salud.

  17. Overweight effect on spirometric parameters in adolescents undergoing exercise.

    PubMed

    Costa, Rayana de Oliveira; Silva, Juliana Pereira; Lacerda, Eliana Mattos; Dias, Rodrigo; Pezolato, Vitor Alexandre; Silva, Carlos Alberto da; Krinski, Kleverton; Correia, Marco Aurélio de Valois; Cieslak, Fabrício

    2016-01-01

    To evaluate effects of overweight on spirometric parameters in adolescents who underwent bronchial provocation test for exercise. We included 71 male adolescents. The diagnosis of asthma was done based on participants' clinical history and on the International Study Questionnaire Asthma and Allergies in Childhood, and the diagnosis of obesity was based on body mass index above 95th percentile. The bronchospasm induced by exercise was assessed using the run-walk test on a treadmill for eight minutes. The decrease in forced expiratory volume in one second > or equal to 10% before exercise was considered positive, and to calculate the intensity in exercise-induced bronchospasm we measured the maximum percentage of forced expiratory volume in one second and above the curve area. Data analysis was carried out using the Mann-Whitney U test and Friedman test (ANOVA), followed by Wilcoxon test (p<0.05). In addition, we used Fisher's exact test to analyze the exercise-induced bronchospasm frequency. Significant differences were observed among obese adolescents in exercise-induced bronchospasm frequency (p=0,013) and in relation to time required for recovery after exercise (p=0,007). Overweight can influence the increase in the exercise-induced bronchospasm frequency in non-asthmatic adolescents compared with eutrophic adolescents. Avaliar o efeito do excesso de peso sobre parâmetros espirométricos em adolescentes submetidos ao teste de broncoprovocação por exercício. Participaram do estudo 71 adolescentes do sexo masculino. O diagnóstico de asma foi obtido por meio de histórico clínico e do questionário International Study of Asthma and Allergies in Childhood, e o de obesidade, pelo índice de massa corporal acima do percentil 95. Para avaliar o broncoespasmo induzido pelo exercício, utilizou-se o teste correr/caminhar em esteira ergométrica, com duração de 8 minutos, considerando positivo se diminuição do volume expiratório forçado no primeiro segundo >10% do valor pré-exercício e, para a intensidade do broncoespasmo induzido pelo exercício, foram utilizados o cálculo da queda percentual máxima do volume expiratório forçado no primeiro segundo e a área acima da curva. A análise dos dados foi realizada pelo teste U Mann-Whitney e pela ANOVA de Friedman, seguido do teste de Wilcoxon (p<0,05). O teste de Fisher foi empregado para analisar a frequência de broncoespasmo induzido pelo exercício. Foram encontradas diferenças significativas quanto à frequência de broncoespasmo induzido pelo exercício (p=0,013) e ao tempo de recuperação pós-exercício (p=0,007) nos adolescentes obesos. O excesso de peso pode influenciar no aumento da frequência de broncoespasmo induzido pelo exercício em adolescentes não asmáticos, quando comparados a eutróficos.

  18. Sesión clínica de los NIH de tumores del estroma gastrointestinal (TEGI) infantiles y de tipo natural | Center for Cancer Research

    Cancer.gov

    Fecha de la sesión: Del 20 al 22 de junio de 2018 Esta solicitud es el primero de un proceso de varios pasos para considerar su participación en nuestra próxima sesión clínica de TEGI infantiles y de tipo natural. Por favor, lea las tres páginas y responda completamente todas las preguntas:

  19. A Novel Route Controlling Begomovirus Resistance by the Messenger RNA Surveillance Factor Pelota

    PubMed Central

    Lapidot, Moshe; Karniel, Uri; Gelbart, Dana; Fogel, Doron; Evenor, Dalia; Kutsher, Yaarit; Makhbash, Zion; Nahon, Sahadia; Shlomo, Haviva; Chen, Lea; Reuveni, Moshe; Levin, Ilan

    2015-01-01

    Tomato yellow leaf curl virus (TYLCV) is a devastating disease of tomato (Solanum lycopersicum) that can be effectively controlled by the deployment of resistant cultivars. The TYLCV-resistant line TY172 carries a major recessive locus for TYLCV resistance, designated ty-5, on chromosome 4. In this study, the association between 27 polymorphic DNA markers, spanning the ty-5 locus, and the resistance characteristics of individual plants inoculated with TYLCV in 51 segregating recombinant populations were analyzed. These analyses localized ty-5 into a 425 bp region containing two transversions: one in the first exon of a gene encoding the tomato homolog of the messenger RNA surveillance factor Pelota (Pelo), and a second in its proximal promoter. Analyses of susceptible and resistant lines revealed that the relative transcript level of the gene remained unchanged, regardless of whether the plants were infected with TYLCV or not. This suggests that the polymorphism discovered in the coding region of the gene controls the resistance. Silencing of Pelo in a susceptible line rendered the transgenic plants highly resistant, while in the resistant line TY172 had no effect on symptom development. In addition, over-expression of the susceptible allele of the gene in the resistant TY172 line rendered it susceptible, while over-expression of the resistant allele in susceptible plants had no effect. These results confirm that Pelo is the gene controlling resistance at the ty-5 locus. Pelo, implicated in the ribosome recycling-phase of protein synthesis, offers an alternative route to promote resistance to TYLCV and other viruses. PMID:26448569

  20. Phenotypes of asthma in low-income children and adolescents: cluster analysis.

    PubMed

    Cabral, Anna Lucia Barros; Sousa, Andrey Wirgues; Mendes, Felipe Augusto Rodrigues; Carvalho, Celso Ricardo Fernandes de

    2017-01-01

    Studies characterizing asthma phenotypes have predominantly included adults or have involved children and adolescents in developed countries. Therefore, their applicability in other populations, such as those of developing countries, remains indeterminate. Our objective was to determine how low-income children and adolescents with asthma in Brazil are distributed across a cluster analysis. We included 306 children and adolescents (6-18 years of age) with a clinical diagnosis of asthma and under medical treatment for at least one year of follow-up. At enrollment, all the patients were clinically stable. For the cluster analysis, we selected 20 variables commonly measured in clinical practice and considered important in defining asthma phenotypes. Variables with high multicollinearity were excluded. A cluster analysis was applied using a twostep agglomerative test and log-likelihood distance measure. Three clusters were defined for our population. Cluster 1 (n = 94) included subjects with normal pulmonary function, mild eosinophil inflammation, few exacerbations, later age at asthma onset, and mild atopy. Cluster 2 (n = 87) included those with normal pulmonary function, a moderate number of exacerbations, early age at asthma onset, more severe eosinophil inflammation, and moderate atopy. Cluster 3 (n = 108) included those with poor pulmonary function, frequent exacerbations, severe eosinophil inflammation, and severe atopy. Asthma was characterized by the presence of atopy, number of exacerbations, and lung function in low-income children and adolescents in Brazil. The many similarities with previous cluster analyses of phenotypes indicate that this approach shows good generalizability. Estudos que caracterizam fenótipos de asma predominantemente incluem adultos ou foram realizados em crianças e adolescentes de países desenvolvidos; portanto, sua aplicabilidade em outras populações, tais como as de países em desenvolvimento, permanece indeterminada. Nosso objetivo foi determinar como crianças e adolescentes asmáticas de baixa renda no Brasil são distribuídos através de uma análise de clusters. Foram incluídos 306 crianças e adolescentes (6-18 anos de idade) com diagnóstico clínico de asma e sob tratamento médico por pelo menos um ano de acompanhamento. No momento da inclusão, todos os pacientes estavam clinicamente estáveis. Vinte variáveis comumente determinadas na prática clínica e consideradas importantes na definição dos fenótipos de asma foram selecionadas para a análise de clusters. As variáveis com alta multicolinearidade foram excluídas. Uma análise de clusters foi realizada utilizando-se um teste aglomerativo em duas etapas e log-likelihood distance measure. Três clusters foram definidos para nossa população. O cluster 1 (n = 94) incluiu indivíduos com função pulmonar normal, inflamação eosinofílica leve, poucas exacerbações, início mais tardio da asma e atopia leve. O cluster 2 (n = 87) incluiu pacientes com função pulmonar normal, número moderado de exacerbações, início precoce da asma, inflamação eosinofílica mais grave e atopia moderada. O cluster 3 (n = 108) incluiu pacientes com função pulmonar ruim, exacerbações frequentes, inflamação eosinofílica e atopia graves. A asma foi caracterizada por presença de atopia, número de exacerbações e função pulmonar em crianças e adolescentes de baixa renda no Brasil. As muitas semelhanças entre esta e outras análises de clusters de fenótipos indicam que essa abordagem apresenta boa generalização.

  1. Factors associated with the healing of complex surgical wounds in the breast and abdomen: retrospective cohort study.

    PubMed

    Borges, Eline Lima; Pires, José Ferreira; Abreu, Mery Natali Silva; Lima, Vera Lúcia de Araújo; Silva, Patrícia Aparecida Barbosa; Soares, Sônia Maria

    2016-10-10

    to estimate the healing rate of complex surgical wounds and its associated factors. retrospective cohort study from 2003 to 2014 with 160 outpatients of a Brazilian university hospital. Data were obtained through consultation of the medical records. Survival function was estimated using the Kaplan-Meier method and Cox regression model to estimate the likelihood of the occurrence of healing. the complex surgical wound healing rate was 67.8% (95% CI: 60.8-74.9). Factors associated with a higher likelihood of wound healing were segmentectomy/quadrantectomy surgery, consumption of more than 20 grams/day of alcohol, wound extent of less that 17.3 cm2 and the length of existence of the wound prior to outpatient treatment of less than 15 days, while the use of hydrocolloid covering and Marlex mesh were associated with a lower likelihood of healing. the wound healing rate was considered high and was associated with the type of surgical intervention, alcohol consumption, type of covering, extent and length of wound existence. Preventive measures can be implemented during the monitoring of the evolution of the complex surgical wound closure, with possibilities of intervention in the modifiable risk factors. estimar a taxa de cicatrização de ferida cirúrgica complexa e seus fatores associados. coorte retrospectiva de 2003 a 2014 com 160 pacientes ambulatoriais de um hospital universitário brasileiro. Os dados foram obtidos por meio de consulta aos prontuários médicos. Função de sobrevida foi estimada pelo método de Kaplan-Meier e modelo de regressão de Cox para estimação do risco de ocorrência da cicatrização. a taxa de cicatrização da ferida cirúrgica complexa foi 67,8% (IC 95%: 60,8-74,9). Os fatores associados a um maior risco de cicatrização da ferida foram cirurgia de setorectomia / quadrantectomia, consumo de mais de 20 gramas/dia de etanol, extensão da ferida menor que 17,3 cm2 e tempo de existência da ferida pré-tratamento ambulatorial inferior a 15 dias, enquanto uso de cobertura hidrocoloide e tela de Marlex estiveram associados a um menor risco de cicatrização. a taxa de cura da ferida foi considerada elevada, e esteve associada ao tipo de intervenção cirúrgica, consumo de etanol, tipo de cobertura, extensão e tempo de existência da ferida. Condutas preventivas podem ser implementadas durante o acompanhamento da evolução do fechamento da ferida cirúrgica complexa, com possibilidades de intervenção nos fatores de risco modificáveis. estimar la tasa de cicatrización de herida quirúrgica compleja y sus factores asociados. cohorte retrospectivo de 2003 a 2014 con 160 pacientes de ambulatorio de un hospital universitario brasileño. Los datos fueron obtenidos por medio de consulta a las fichas médicas. La función de supervivencia fue estimada por el método de Kaplan-Meier y el modelo de regresión de Cox para estimar el riesgo de ocurrencia de cicatrización. la tasa de cicatrización de la herida quirúrgica compleja fue 67,8% (IC 95%: 60,8-74,9). Los factores asociados a un mayor riesgo de cicatrización de la herida fueron cirugía de sectorectomía / cuadrantectomía, consumo de más de 20 gramos/día de etanol, extensión de la herida menor que 17,3 cm2 y tiempo de existencia de la herida antes del tratamiento en ambulatorio inferior a 15 días; en lo que se refiere al uso de cubrimiento hidrocoloide y tela de Marlex estuvieron asociados a un menor riesgo de cicatrización. la tasa de cura de la herida fue considerada elevada, y estuvo asociada al tipo de intervención quirúrgica, consumo de etanol, tipo de cubrimiento, extensión y tiempo de existencia de la herida. Conductas preventivas pueden ser implementadas durante el acompañamiento de la evolución del cierre de la herida quirúrgica compleja, con posibilidades de intervenir sobre los factores de riesgo modificables.

  2. Cardiac Amyloidosis and its New Clinical Phenotype: Heart Failure with Preserved Ejection Fraction.

    PubMed

    Mesquita, Evandro Tinoco; Jorge, Antonio José Lagoeiro; Souza, Celso Vale; Andrade, Thais Ribeiro de

    2017-07-01

    Heart failure with preserved ejection fraction (HFpEF) is now an emerging cardiovascular epidemic, being identified as the main phenotype observed in clinical practice. It is more associated with female gender, advanced age and comorbidities such as hypertension, diabetes, obesity and chronic kidney disease. Amyloidosis is a clinical disorder characterized by the deposition of aggregates of insoluble fibrils originating from proteins that exhibit anomalous folding. Recently, pictures of senile amyloidosis have been described in patients with HFpEF, demonstrating the need for clinical cardiologists to investigate this etiology in suspect cases. The clinical suspicion of amyloidosis should be increased in cases of HFPS where the cardio imaging methods are compatible with infiltrative cardiomyopathy. Advances in cardio imaging methods combined with the possibility of performing genetic tests and identification of the type of amyloid material allow the diagnosis to be made. The management of the diagnosed patients can be done in partnership with centers specialized in the study of amyloidosis, which, together with the new technologies, investigate the possibility of organ or bone marrow transplantation and also the involvement of patients in clinical studies that evaluate the action of the new emerging drugs. Resumo A insuficiência cardíaca com fração de ejeção preservada (ICFEP) é hoje uma epidemia cardiovascular emergente, sendo identificada como o principal fenótipo observado na prática clínica. Está mais associado ao sexo feminino, idade avançada e a comorbidades como hipertensão arterial, diabetes, obesidade e doença renal crônica. A amiloidose é uma desordem clínica caracterizada pelo depósito de agregados de fibrilas insolúveis originadas de proteínas que apresentam dobramento anômalo. Recentemente, têm sido descritos quadros de amiloidose senil em pacientes com ICFEP, demonstrando a necessidade de os cardiologistas clínicos investigarem esta etiologia em casos suspeitos. Deve-se aumentar a suspeição clínica de amiloidose diante dos casos de ICFEP onde os métodos de cardioimagem sejam compatíveis com o quadro de cardiomiopatia infiltrativa. Os avanços nos métodos de cardioimagem aliados à possibilidade de realização de testes genéticos e identificação do tipo do material amiloide permitem a realização do diagnóstico. O manejo dos pacientes diagnosticados pode ser feito em parceria com centros especializados no estudo de amiloidose, que, aliados às novas tecnologias, investigam a possibilidade de transplante de órgãos ou medula óssea e também o envolvimento dos pacientes em estudos clínicos que avaliam a ação das novas drogas emergentes.

  3. Abundâncias químicas de estrelas T Tauri fracas

    NASA Astrophysics Data System (ADS)

    Rojas, G. A.; Gregorio-Hetem, J.

    2003-08-01

    Apresentamos resultados do estudo de 44 estrelas pré-seqüência principal, para as quais buscamos realizar uma classificação espectroscópica e determinar parâmetros estelares e abundâncias químicas. A amostra foi escolhida da seguinte maneira : 21 objetos selecionados a partir de catálogos de objetos jovens, como o Pico dos Dias Survey e o Herbig Bell Catalogue, e 23 objetos selecionados a partir de contrapartidas ópticas de fontes de raios X detectadas pelo satélite ROSAT. Dentre 24 objetos previamente classificados como estrelas T Tauri Fracas, apenas 7 revelaram ser realmente pertencentes à essa classe, sendo os demais objetos T Tauri Clássicas ou estrelas evoluídas da pré-seqüência principal. Esse resultado demonstra que o critério mais utilizado para distinguir as T Tauri Clássicas das T Tauri Fracas, baseado na largura equivelente da emissão Ha, não é suficiente para determinar o estágio evolutivo desses objetos. Para o cálculo de parâmetros estelares e abundâncias, foram escolhidas as estrelas que apresentam características ideais para esse tipo de estudo, como ausência de velamento, baixa velocidade de rotação e espectros com razão sinal-ruído adequada. Os parâmetros estelares como temperatura efetiva e gravidade foram determinados através do equilíbrio de excitação e ionização das linhas de Ferro, e as abundâncias químicas foram calculadas utilizando o método de síntese espectral. Serão apresentados os parâmetros estelares e as abundâncias de Lítio para toda a amostra, e abundâncias de vários elementos quimicos para 7 estrelas estudadas em maior detalhe

  4. A bone tissue engineering strategy based on starch scaffolds and bone marrow cells cultured in a flow perfusion bioreactor

    NASA Astrophysics Data System (ADS)

    Gomes, Maria Manuela Estima

    A Engenharia de Tecidos e uma area cientifica em continua expansao. Os desenvolvimentos conseguidos por esta area tem contribuido significativamente para diversos avancos no campo da Medicina Regenerativa. Esta ciencia interdisciplinar combina os conhecimentos de diversas outras areas, tao distintas como a Engenharia de Materiais e a Biologia, com o objectivo de desenvolver substitutos sinteticos para tecidos humanos. Para se atingir este objectivo utilizam-se, de uma forma generica, combinacoes especificas de celulas e de um material de suporte tridimensional com propriedades adequadas, gerando um material hibrido cujas caracteristicas podem ainda ser moduladas atraves do sistema de cultura usado. A presente tese e centrada no desenvolvimento de estrategias de engenharia de tecido osseo baseadas na cultura in vitro de celulas previamente "semeadas" num suporte tridimensional ("scaffold"). Esta estrategia permite que as celulas adiram ao suporte, proliferem e segreguem matriz extracelular especifica do tecido osseo, ate se obter um substituto artificial funcional com caracteristicas do tecido original, que pode finalmente ser transplantado para tratar o defeito em causa. Para que uma estrategia deste tipo seja bem sucedida, pelo menos tres componentes fundamentais devem ser cuidadosamente estudados: o material de suporte (scaffold), as celulas a usar e o sistema de cultura in vitro. Dai que os principais objectivos desta tese estejam relacionados com estes tres aspectos, nomeadamente: • Desenvolvimento de scaffolds biodegradaveis a partir de polimeros a base de amido de milho que induzam a adesao e proliferacao celular e que apresentem propriedades adequadas, tais como a porosidade e interconectividade entre poros, de forma a proporcionar um ambiente que favoreca o desenvolvimento in vitro de um material hibrido com caracteristicas similares ao osso humano. • Estudo da utilizacao de celulas da medula ossea como uma potencial fonte de celulas para engenharia do tecido osseo, uma vez que estas celulas podem ser facilmente recolhidas do proprio paciente a tratar por metodos nao-invasivos (bioppsia) e em quantidades suficientes. Alem disso, tratando-se de uma fonte de celulas autologas (obtidas do proprio paciente) permitem evitar os riscos de transmissao de doencas contagiosas e/ou de rejeicao pelo sistema imunologico. • Estudo da influencia das condicoes de cultura in vitro geradas por um bioreactor de perfusao (em comparacao com os metodos tradicionais de cultura em condicoes estaticas) no desenvolvimento dos materiais hibridos, compostos pelas celulas e scaffolds, assim como as interaccoes do ambiente proporcionado por este sistema de cultura com as diferentes estruturas/arquitecturas e porosidades dos scaffolds utilizados. Estes objectivos convergem para o objectivo geral desta tese que consistiu no desenvolvimento de uma terapia de engenharia do tecido osseo alternativa as existentes e com potencial para vir a ser posteriormente utilizada na pratica clinica. Este objectivo foi avaliado atraves do estudo da funcionalidade dos materiais hibridos obtidos em diferentes condicoes de cultura in vitro (e utilizando diferentes scaffolds), partindo do principio que o sistema de perfusao poderia eventualmente superar as limitacoes de difusao tipicas dos sistema de cultura estatica e simultaneamente proporcionar estimulos mecânicos as celulas, semelhantes aos encontrados em condicoes fisiologicas. (Abstract shortened by ProQuest.).

  5. Datação do disco galáctico pela nucleocosmocronologia do [Th/Eu

    NASA Astrophysics Data System (ADS)

    del Peloso, E. F.; da Silva, L.; Arany-Prado, L. I.

    2003-08-01

    A nucleocosmocronologia emprega abundâncias de nuclídeos radioativos na datação de escalas de tempo astrofísicas. O 232Th é um nuclídeo radioativo com meia-vida de 14 Gano, enquanto que os dois isótopos mais abundantes do Eu são estáveis. O decaimento radioativo do Th modifica as razões de abundâncias [Th/Eu], fornecendo assim um meio de sondar a escala de formação das populações estelares. O objetivo deste trabalho é averiguar a possibilidade de estimar uma idade para o disco Galáctico através da nucleocosmocronologia do [Th/Eu] e investigar o nível de incerteza associado a esta estimativa. Para tanto, foi selecionada uma amostra de 20 estrelas anãs ou subgigantes de tipos espectrais F5 a G9, com -1,00 £ [Fe/H] £ +0,30 e idade(Gano) £ 13. As abundâncias de Th e Eu foram obtidas por síntese espectral das linhas localizadas em 4019,1 Å e 4129,7 Å, respectivamente. Uma comparação destas abundâncias com outros resultados da literatura demonstra que nossos valores apresentam dispersão 2 a 3 vezes menor que qualquer trabalho anterior. Os parâmetros atmosféricos e abundâncias dos elementos que contaminam as regiões espectrais destas linhas foram determinados por nós, de maneira totalmente autoconsistente, através de análise espectral detalhada diferencial em relação ao Sol. As idades estelares individuais foram determinadas através de curvas isócronas teóricas no diagrama HR. Foi realizada, então, uma análise cronológica dos gráficos [Th/Eu] vs. [Fe/H] e [Th/Eu] vs. idade. Os dados estelares foram comparados a curvas calculadas para 3 idades do disco Galáctico - 9, 12, 15 Gano - e foi estudada a sensibilidade à idade assumida no cálculo do ajuste destas curvas aos dados. Estas curvas foram calculadas com base num modelo analítico de evolução química da Galáxia que leva em consideração a formação de refugos, que são compostos pelos remanescentes da evolução estelar, pelos resíduos da formação de estrelas de baixa massa (planetas, cometas, etc.) e por quaisquer outros objetos de massa não-estelar. A formação de resíduos tem o efeito indireto de diluir o meio interestelar, levando a um enriquecimento mais lento deste e a um bom ajuste de diversos vínculos da evolução química da Galáxia, como a distribuição de anãs-G e a relação idade-metalicidade. Os efeitos da destruição do Th por reações fotonucleares em interiores estelares também foram considerados.

  6. Identificação de radiofontes puntiformes presentes na região observada pelo telescópio BEAST

    NASA Astrophysics Data System (ADS)

    Oliveira, M. S.; Wuensche, C. A.; Leonardi, R.; Tello, C.

    2003-08-01

    Radiofontes extragalácticas são um dos principais contaminantes nas medidas da Radiação Cósmica de Fundo (RCF) em freqüências abaixo de 200 GHz. O estudo de seu comportamento espectral permite determinar a contribuição destas fontes às anisotropias intrísincas da RCF. Um dos experimentos recentes concebidos para estudar a RCF é o BEAST (Background Emission Anisotropy Scanning Telescope), cujos primeiros resultados foram publicados em fevereiro de 2003. Nos últimos meses, geramos mapas do céu nas freqüências de 30 GHz e 41 GHz, para um total de 648 horas de observação entre julho e outubro de 2002. Identificamos 4 fontes puntiformes extragalácticas na região do céu situada entre 0h < RA < 24 h e +32° < DEC < +42°, com relação S/R > 4,3 e situadas a pelo menos 25° acima do Plano Galáctico. Suas contrapartidas em 5 GHz, segundo o catálogo GB6, são: J1613+3412, J1635+3808, J0927+3902 e J1642+3948. Estas fontes também foram identificadas pelo satélite WMAP sendo que três coincidem com as observadas pelo BEAST dentro da incerteza do feixe do telescópio e a quarta encontra-se bastante próxima (J1613+3412), embora não seja coincidente. As estimativas preliminares de fluxos obtidas para esses objetos são, respectivamente, 0,51; 0,97; 1,08 e 1,6 Jy em 41 GHz. Usando estes resultados e medidas de fluxos em outras frequências existentes na literatura, apresentamos uma estimativa dos índices espectrais destes objetos no intervalo de frequências entre 4,85 GHz e 41 GHz.

  7. Jabuticaba-Induced Endothelium-Independent Vasodilating Effect on Isolated Arteries.

    PubMed

    Andrade, Daniela Medeiros Lobo de; Borges, Leonardo Luis; Torres, Ieda Maria Sapateiro; Conceição, Edemilson Cardoso da; Rocha, Matheus Lavorenti

    2016-09-01

    Despite the important biological effects of jabuticaba, its actions on the cardiovascular system have not been clarified. To determine the effects of jabuticaba hydroalcoholic extract (JHE) on vascular smooth muscle (VSM) of isolated arteries. Endothelium-denuded aortic rings of rats were mounted in isolated organ bath to record isometric tension. The relaxant effect of JHE and the influence of K+ channels and Ca2+ intra- and extracellular sources on JHE-stimulated response were assessed. Arteries pre-contracted with phenylephrine showed concentration-dependent relaxation (0.380 to 1.92 mg/mL). Treatment with K+ channel blockers (tetraethyl-ammonium, glibenclamide, 4-aminopyridine) hindered relaxation due to JHE. In addition, phenylephrine-stimulated contraction was hindered by previous treatment with JHE. Inhibition of sarcoplasmic reticulum Ca2+ ATPase did not change relaxation due to JHE. In addition, JHE inhibited the contraction caused by Ca2+ influx stimulated by phenylephrine and KCl (75 mM). JHE induces endothelium-independent vasodilation. Activation of K+ channels and inhibition of Ca2+ influx through the membrane are involved in the JHE relaxant effect. Embora a jabuticaba apresente importantes efeitos biológicos, suas ações sobre o sistema cardiovascular ainda não foram esclarecidas. Determinar os efeitos do extrato de jabuticaba (EHJ) sobre o músculo liso vascular (MLV) em artérias isoladas. Aortas (sem endotélio) de ratos foram montadas em banho de órgãos isolados para registro de tensão isométrica. Foram verificados o efeito relaxante, a influência dos canais de K+ e das fontes de Ca2+ intra- e extracelular sob a resposta estimulada pelo EHJ. Artérias pré-contraídas com fenilefrina apresentaram relaxamento concentração-dependente (0,380 a 1,92 mg/mL). O tratamento com bloqueadores de canais de K+ (tetraetilamônio, glibenclamida, 4-aminopiridina) prejudicaram o relaxamento pelo EHJ. A contração estimulada com fenilefrina também foi prejudicada pelo tratamento prévio com EHJ. A inibição da Ca2+ATPase do reticulo sarcoplasmático não alterou o relaxamento pelo EHJ. Além disso, o EHJ inibiu a contração causada pelo influxo de Ca2+ estimulado por fenilefrina e KCl (75 mM). O EHJ induz vasodilatação independente do endotélio. Ativação dos canais de K+ e inibição do influxo de Ca2+ através da membrana estão envolvidas no efeito relaxante do EHJ.

  8. Intimate partner violence and maternal educational practice.

    PubMed

    Silva, Josianne Maria Mattos da; Lima, Marília de Carvalho; Ludermir, Ana Bernarda

    2017-04-10

    The objective of this study is to analyze the association between intimate partner violence against women and maternal educational practice directed to children at the beginning of formal education. This is a cross-sectional study, carried out between 2013 and 2014, with 631 mother/child pairs, registered in the Family Health Strategy of the Health District II of the city of Recife, State of Pernambuco, Brazil. It integrates a prospective cohort study designed to investigate the consequences of exposure to intimate partner violence in relation to the child who was born between 2005 and 2006. The maternal educational practice has been assessed by the Parent-Child Conflict Tactics Scale and the intimate partner violence by a questionnaire adapted from the Multi-Country Study on Women's Health and Domestic Violence of the World Health Organization. Intimate partner violence referred to the last 12 months and was defined by specific acts of psychological, physical, and sexual violence inflicted to women by the partner. The crude and adjusted prevalence ratios were estimated for the association studied, using log-binomial regression. The prevalence of intimate partner violence was 24.4%, and violent maternal educational practice was 93.8%. The use of non-violent discipline was mentioned by 97.6% of the women, coexisting with violent strategies of discipline. Children whose mothers reported intimate partner violence presented a higher chance of suffering psychological aggression (PR = 2.2; 95%CI 1.0-4.7). The violence suffered by the mother interferes in the parental education. The findings show high prevalence of violent maternal educational practice, pointing to the need for interventions that minimize the damage of violence in women and children. Analisar a associação entre a violência pelo parceiro íntimo contra a mulher e a prática educativa materna direcionada às crianças no início da escolaridade formal. Estudo transversal, realizado entre 2013 e 2014, com 631 pares mãe/criança, cadastradas na Estratégia de Saúde da Família do Distrito Sanitário II da cidade do Recife, Pernambuco. Integra o estudo de coorte prospectivo delineado para investigar as consequências da exposição à violência pelo parceiro íntimo para a criança que nasceu da gestação que ocorreu entre 2005 e 2006. A prática educativa materna foi avaliada pela escala de conflitos Parent-Child Conflict Tactics Scale e a violência pelo parceiro íntimo por um questionário adaptado do Estudo Multipaíses sobre a Saúde da Mulher e Violência Doméstica da Organização Mundial da Saúde. A violência pelo parceiro íntimo referiu-se aos últimos 12 meses e foi definida por atos concretos de violência psicológica, física e sexual infligidos à mulher pelo parceiro. Foram estimadas as razões de prevalência brutas e ajustadas para a associação estudada, utilizando-se a regressão log-binominal. A prevalência da violência pelo parceiro íntimo foi de 24,4%, e da prática educativa materna violenta de 93,8%. O uso de disciplina não violenta foi referido por 97,6% das mulheres, coexistindo com estratégias violentas de disciplinamento. As crianças cujas mães relataram violência pelo parceiro íntimo apresentaram maior chance de sofrer agressão psicológica (RP = 2,2; IC95% 1,0-4,7). A violência sofrida pela mãe interfere na educação parental. Os achados demonstram alta prevalência de prática educativa materna que perpassa pela violência, o que aponta para a necessidade de intervenções que minimizem os prejuízos da violência na mulher e na criança.

  9. Summary of Meteorological Observations, Surface (SMOS), El Toro, California

    DTIC Science & Technology

    1983-10-01

    SURFACE WINDS DETACHMENT ASHEVILLE. NC PERCENTAGE FREQUENCY OF WIND DIRECTION AND SPEED (FROM HOURLY OBSERVATIONS) EL TIPO , CALIrQO𔃾IA 73-’.? A ir, U~~tiAL...OF WiND DIRECTION AND SPEED (FROM HOURLY OBSERVATIONS) ... 112L. E L TIPO , ALIODkI1A 71-q2 r ALL wEANCP _______ MEAN 11-11 6.S 7.A 1.U 11.W6 17.21 n...nTa IO STyVIO. *..M YUOnb0U T-mp. WIT BULl TEMPERATUIE DEPRESSION fF) TOTAL TOTAL 0 1- 2 3 -4 - j 8 9 10 11-12113 14,11516117. 18119 270:i21 . 2 23

  10. Estudo de soluções locais e cosmológicas em teorias do tipo tensor-escalar

    NASA Astrophysics Data System (ADS)

    Silva E Costa, S.

    2003-08-01

    Teorias do tipo tensor-escalar são a mais simples extensão possí vel da Relatividade Geral. Nessas teorias, cujo modelo padrão é a teoria de Brans-Dicke, a curvatura do espaço-tempo, descrita por componentes tensoriais, aparece acoplada a um campo escalar que, de certo modo, representa uma variação na constante de acoplamento da gravitação. Tais teorias apresentam soluções locais e cosmológicas que, em determinados limites, recaem nas apresentadas pela Relatividade Geral, mas que em outros limites trazem novidades, tais como conseqüências observacionais da evolução de flutuações primordiais distintas daquelas previstas pela Relatividade Geral (ver, por ex., Nagata et al., PRD 66, p. 103510 (2002)). Graças a esta possibilidade de trazer à luz novidades em relação à gravitação, teorias do tipo tensor-escalar podem ser vistas como um interessante campo alternativo de pesquisas para soluções dos problemas de massa faltante (ou escura) e/ou energia escura. Seguindo tal linha, este trabalho, ainda em sua fase inicial, apresenta soluções gerais de teorias do tipo tensor-escalar para diversas situações, verificando-se em que consiste a divergência dessas soluções dos casos tradicionais possí veis na Relatividade Geral. Como exemplos das soluções aqui apresentadas pode-se destacar uma expressão geral para diferentes soluções cosmológicas englobando diferentes tipos de matéria (representados por diferentes equações de estado), e a expressão para uma solução local representando um buraco negro com rotação, similar à solução de Kerr da Relatividade Geral. Por fim, é importante ressaltar que, embora aqui apresentem-se poucos resultados novos, na literatura sobre o assunto a maior parte das soluções apresentadas limita-se a uns poucos casos especí ficos, tal como soluções cosmológicas apenas com curvatura nula, e que mesmo as soluções disponí veis são, em geral, pouco divulgadas e, portanto, pouco conhecidas, e é tal situação que este trabalho busca, em parte, reverter.

  11. A Study of Black and White Men With a Family History of Prostate Cancer

    DTIC Science & Technology

    2002-03-01

    l4lbTyp)___ (QO l4lbAge)___ TIPO DE CANCER: 1 COLON 3 SENO 4 CERVIZ 5 PULMONES 6 OVARIOS 7 ENDOMIETPJO V OTRO W DK X RF Q014_lc Su hermana es... 1 su...diagnosticada? (QOl4 -2aAge) - (QOl4-2bAge)____ TIPO DE CANCER: 1 COLON 3 SENO 4 CERVJZ 5 PULMONES 6 OVARIOS 7 ENDOMIETRIO V OTRO W DK X RF QO142c Su...6_aTyp)___ (QO l6laAge)____ (QOl6_lbTyp)___ (QO l6lbAge)___ TWPO DE CANCER: 1 COLON 3 SENO 4 CERVIZ 5 PULMONES 6 OVARIOS 7 ENDOM[ETPJO V OTRO W DK X RF

  12. Factors associated with glycemic control in people with diabetes at the Family Health Strategy in Pernambuco.

    PubMed

    Lima, Rodrigo Fonseca; Fontbonne, Annick; Carvalho, Eduardo Maia Freese de; Montarroyos, Ulisses Ramos; Barreto, Maria Nelly Sobreira de Carvalho; Cesse, Eduarda Ângela Pessoa

    2016-01-01

    Identifying factors associated with glycemic control in people with type 2 Diabetes Mellitus (DM) registered in the Family Health Strategy (FHS) in Pernambuco, Brazil. Associations between glycemic control (glycosylated hemoglobin A lower or equal to 7%) presented by people with DM and variables related to sociodemographic conditions, lifestyle, characteristics of diabetes, treatment and follow-up of patients by health services were investigated by multiple regression. More than 65% of the participants presented inadequate glycemic control, especially those with lower age, longer illness duration, more annual contacts with FHS and complex therapeutic regimen. People with DM without referrals to specialists presented greater glycemic control. Associations with education level and obesity did not remain significant in the multivariate model. The evolution of diabetes hinders adequate control, however, attention to younger people with DM and referrals to specialists are factors that can improve glycemic control. Identificar fatores associados ao controle glicêmico em pessoas com Diabetes Mellitus (DM) tipo 2 cadastradas na Estratégia Saúde da Família (ESF) em Pernambuco, Brasil. Foram investigadas, por regressão múltipla, as associações entre o controle glicêmico (hemoglobina A glicosilada menor ou maior ou igual a 7%) apresentado pelas pessoas com DM e variáveis relacionadas com condições sociodemográficas, hábitos de vida, características do diabetes, de seu tratamento e acompanhamento dos pacientes pelos serviços de saúde. Mais de 65% dos participantes apresentaram controle glicêmico inadequado, principalmente aqueles com idade menor, duração da doença mais longa, mais contatos anuais com a ESF e regime terapêutico complexo. Pessoas com DM sem encaminhamentos para especialistas apresentaram um maior descontrole glicêmico. Associações com escolaridade e obesidade não permaneceram significativas no modelo multivariado. A evolução do diabetes dificulta o controle adequado, todavia, a atenção às pessoas com DM mais jovens e os encaminhamentos para especialistas são fatores suscetíveis de melhora do controle glicêmico.

  13. Estimativa de imagens solares soho através de redes neurais artificiais

    NASA Astrophysics Data System (ADS)

    Andrade, M. C.; Fernandes, F. C. R.; Cecatto, J. R.; Rios Neto, A.; Rosa, R. R.; Sawant, H. S.

    2003-08-01

    A Rede Neural Artificial (RNA), no âmbito da teoria computacional, constitui uma teoria emergente que, por possuir habilidade em aprender a partir de dados de entrada, encontra diferentes aplicações em diferentes áreas. Um exemplo é a utilização de RNA na caracterização de padrões associados à dinâmica de processos espaço-temporais relacionados a fenômenos físicos não-lineares. Para obter informações sobre o comportamento destes fenômenos físicos utiliza-se, em diversos casos, seqüências de imagens digitalizadas, onde a caracterização de alguns fenômenos espaço-temporais é o procedimento mais viável para descrever a dinâmica das regiões ativas do Sol. Com base em imagens observadas por telescópios a bordo de satélites, estudos de previsão de eventos solares podem ser programados, permitindo prever possíveis efeitos posteriores nas regiões mais próximas da Terra (tempestades geomagnéticas e irregularidades ionosféricas). Neste trabalho avaliamos o desempenho da RNA para estimar padrões espaço-temporais, ou seja, imagens solares em ultravioleta, obtidas através do telescópio a bordo do satélite SOHO. Os resultados mostraram que as RNA conseguem generalizar os padrões de maneira satisfatória sem perder de forma significativa os principais aspectos da configuração global da atmosfera solar, comprovando a eficácia da RNA como ferramenta para esse tipo de aplicação. Portanto, este trabalho comprova a viabilidade de uso desta ferramenta em projetos voltados ao estudo do comportamento solar, em trabalhos do grupo de Física do Meio Interplanetário (FMI) na DAS e em programas desenvolvidos pelo Núcleo de Simulação e Análise de Sistemas Complexos (NUSASC) do Laboratório Associado de Computação e Matemática Aplicada (LAC) do INPE.

  14. Identificabilidade e estabilidade dos parâmetros no método Grade of Membership (GoM): considerações metodológicas e práticas

    PubMed Central

    Guedes, Gilvan Ramalho; Caetano, André Junqueira; Machado, Carla Jorge; Brondízio, Eduardo Sonewend

    2011-01-01

    O método Grade of Membership (GoM) tem sido cada vez mais utilizado por demógrafos brasileiros e tem a vantagem de possuir um parâmetro que mensura a heterogeneidade individual, com base nas correlações não-observáveis entre as categorias de resposta das variáveis de interesse, gerando um medida do grau de pertencimento de cada indivíduo a perfis extremos. Alguns autores, contudo, chamam atenção para questões importantes na calibragem dos modelos finais que utilizam o programa GoM versão 3.4, como o problema de identificabilidade – soluções múltiplas para parâmetros estimados. Neste artigo, é sugerido um procedimento capaz de identificar um modelo final com solução única que descreva os tipos puros mais fidedignos à base de dados, em uma tentativa de otimização. Para ilustrar esse processo, utilizou-se uma base de dados correspondente a um levantamento econômico e sociodemográfico de uma população de pequenos agricultores residentes ao longo da Rodovia Transamazônica, no Estado do Pará. Também identificou-se a existência de instabilidade nos parâmetros estimados pelo programa GoM 3.4, sendo proposto um método de estabilização de seus valores. Com esses procedimentos combinados, os usuários do programa GoM 3.4 poderão descrever sua base de dados de forma mais adequada e responder às críticas sobre questões de identificabilidade e estabilidade dos modelos resultantes. Essas soluções empíricas são relevantes por afetarem cálculos de prevalência e de incidência de eventos de interesse, além de trazerem consequências importantes sobre o ponto e o momento corretos para intervenções de políticas públicas ou de planejamento prospectivo em análises de projeção. PMID:21709732

  15. Cost of nursing most frequent procedures performed on severely burned patients.

    PubMed

    Melo, Talita de Oliveira; Lima, Antônio Fernandes Costa

    2017-01-01

    to identify the mean direct cost (MDC) of the most frequent procedures performed by nursing professionals on severely burned patients in an Intensive Care Unit. exploratory-descriptive quantitative single-case study. The MDC was calculated by multiplying time (timed) spent by nursing professionals in the performance of the procedures by the unit cost of direct labor, and adding the costs of material and medicine/solutions. a MDC of US$ 0.65 (SD=0.36) was obtained for "vital signs monitoring"; US$ 10.00 (SD=24.23) for "intravenous drug administration"; US$ 5.90 (SD=2.75) for "measurement of diuresis"; US$ 0.93 (SD=0.42) for "capillary blood glucose monitoring"; and US$ 99.75 (SD=129.55) for "bandaging". the knowledge developed can support managerial decision-making, contribute to the efficiency distribution of the resources involved and, when possible, provide cost-containment or cost-minimization strategies without impairing the quality of nursing care. identificar o custo direto médio (CDM) dos procedimentos realizados, com maior frequência, por profissionais de enfermagem, em uma Unidade de Terapia Intensiva, aos pacientes grandes queimados. pesquisa quantitativa, exploratório-descritiva, do tipo estudo de caso único. O CDM foi calculado multiplicando-se o tempo (cronometrado) despendido por profissionais de enfermagem na execução dos procedimentos, objeto de estudo, pelo custo unitário da mão de obra direta, somando-se ao custo dos materiais e soluções/medicamentos. obteve-se o CDM de US$ 0.65 (SD=0.36) para "controle dos sinais vitais"; US$ 10.00 (SD=24.23) para "administração de medicamentos via intravenosa"; US$ 5.90 (SD=2.75) para "mensuração de diurese"; US$ 0.93 (SD=0.42) para "verificação de glicemia capilar"; e US$ 99.75 (SD=129.55) para "curativo". o conhecimento desenvolvido pode fundamentar as tomadas de decisão gerenciais subsidiando a eficiência alocativa dos recursos envolvidos e, quando possível, indicar estratégias de contenção/minimização de custos sem prejuízos à qualidade da assistência de enfermagem.

  16. Evolución de estrellas de Helio

    NASA Astrophysics Data System (ADS)

    Panei, J. A.; Benvenuto, O. G.; Althaus, L. G.

    Podríamos identificar a las estrellas de helio con estrellas Wolf-Rayet (WR) que han perdido su envoltura rica en hidrógeno ya sea porque las mismas pertenecen a sistemas binarios o a través de fuertes vientos estelares. Las WR representan una etapa evolucionaria normal de las estrellas masivas, cuya pérdida de masa es >= 3 × 10-5Msolar/yr y la cual es sufrida por la estrella en un tiempo de escala mucho menor que el tiempo en que se produce la quema del He. Esto garantiza la ``homogeneidad'' de las estrellas de helio para nuestros modelos. Este tipo de estrellas serían posibles progenitores de SN tipo Ib y Ic. Aquí presentamos un estudio sobre la evolución de estrellas de helio a partir de la secuencia principal de helio, pasando por el flash de carbono, hasta agotarlo en la región central; como así también la dependencia con la variable masa y con la pérdida de la misma para distintos tipos de masas. Para tal fin hemos utilizado un código de evolución estelar completo que realiza todas las reacciones de Fowler en forma simultánea. También se han tenido en cuenta los procesos de mezcla convectiva, los principales mecanismos de emisión de neutrinos y los efectos de la pérdida de masa. Las opacidades utilizadas fueron las de Rogers & Iglesias (1992). Debido a la pérdida de masa en este tipo de estrellas, hemos encontrado que los perfiles convectivos, la composición química, las condiciones centrales de temperatura y presión, luminosidad y temperatura efectiva dependen en forma esencial de la velocidad de pérdida de masa adoptada, lo que tendría profundas implicaciones en la evolución posterior de estos objetos.

  17. Sociodemographic factors and health conditions associated with the resilience of people with chronic diseases: a cross sectional study.

    PubMed

    Böell, Julia Estela Willrich; Silva, Denise Maria Guerreiro Vieira da; Hegadoren, Kathleen Mary

    2016-09-01

    to investigate the association between resilience and sociodemographic variables and the health of people with chronic kidney disease and / or type 2 diabetes mellitus. a cross-sectional observational study performed with 603 people with chronic kidney disease and / or type 2 diabetes mellitus. A tool to collect socio-demographic and health data and the Resilience Scale developed by Connor and Davidson were applied. A descriptive and multivariate analysis was performed. the study participants had on average 61 years old (SD= 13.2), with a stable union (52.24%), religion (96.7%), retired (49.09%), with primary education (65%) and income up to three minimum wages. Participants with kidney disease showed less resilience than people with diabetes. the type of chronic illness, disease duration, body mass index and religious beliefs influenced the resilience of the study participants. verificar a associação entre resiliência e variáveis sociodemográficas e de saúde de pessoas com diagnóstico de doença renal crônica e/ou diabetes mellitus tipo 2. estudo observacional transversal realizado com 603 pessoas com diagnóstico de doença renal crônica e/ou diabetes mellitus tipo 2. Aplicação de instrumento para coletar dados sociodemográficos e de saúde e Escala de Resiliência desenvolvida por Connor e Davidson. Foi realizada análise descritiva e multivariada dos dados. os participantes do estudo possuíam, em média, 61 anos de idade (DP=13,2), com união estável (52,24%), crença religiosa (96,7%), aposentados (49,09%), com ensino fundamental (65%) e renda de até três salários mínimos. Os participantes com doença renal apresentaram menor resiliência do que pessoas com diabetes. o tipo de doença crônica, o tempo de doença, o índice de massa corporal e a crença religiosa influenciaram a resiliência dos participantes do estudo. verificar la asociación entre resiliencia y variables sociodemográficas y de salud de personas con diagnóstico de enfermedad renal crónica y/o diabetes mellitus tipo 2. estudio observacional transversal, realizado con 603 personas con diagnóstico de enfermedad renal crónica y/o diabetes mellitus tipo 2. Aplicación de instrumento para recolectar datos sociodemográficos y de salud y Escala de Resiliencia desarrollada por Connor y Davidson. Fue realizado análisis descriptivo y multivariado de los datos. los participantes del estudio poseían, en promedio, 61 años de edad (DE=13,2), con unión estable (52,24%), creencia religiosa (96,7%), jubilados (49,09%), con enseñanza fundamental (65%) y renta de hasta tres salarios mínimos. Los participantes con enfermedad renal presentaron menor resiliencia que personas con diabetes. el tipo de enfermedad crónica, el tiempo de enfermedad, el índice de masa corporal y la creencia religiosa influenciaron la resiliencia de los participantes del estudio.

  18. Hypertriglyceridemic Waist Phenotype and Changes in the Fasting Glycemia and Blood Pressure in Children and Adolescents Over One-Year Follow-Up Period.

    PubMed

    Costa, Priscila Ribas de Farias; Assis, Ana Marlúcia Oliveira; Cunha, Carla de Magalhães; Pereira, Emile Miranda; Jesus, Gabriela Dos Santos de; Silva, Lais Eloy Machado da; Alves, Wilanne Pinheiro de Oliveira

    2017-07-01

    The hypertriglyceridemic waist (HTW) phenotype is defined as the simultaneous presence of increased waist circumference (WC) and serum triglycerides (TG) levels and it has been associated with cardiometabolic risk in children and adolescents. The objective was to evaluate the influence of HTW phenotype in the fasting glycemia and blood pressure in children and adolescents over one-year follow-up period. It is a cohort study involving 492 children and adolescents from 7 to 15 years old, both genders, who were submitted to anthropometric, biochemical and clinical evaluation at the baseline, and also after 6 and 12 months of follow-up. Generalized Estimating Equation (GEE) models were calculated to evaluate the longitudinal influence of the HTW phenotype in the glycemia and blood pressure over one-year. It was observed a prevalence of 10.6% (n = 52) of HTW phenotype in the students. The GEE models identified that students with HTW phenotype had an increase of 3.87 mg/dl in the fasting glycemia mean (CI: 1.68-6.05) and of 3.67mmHg in the systolic blood pressure (SBP) mean (CI: 1.55-6.08) over one-year follow-up, after adjusting for confounding variables. The results of this study suggest that HTW phenotype is a risk factor for longitudinal changes in glycemia and SBP in children and adolescents over one-year follow-up period. O fenótipo de cintura hipertrigliceridêmica (CHT) é definido como a presença simultânea de circunferência de cintura (CC) e níveis séricos de triglicérides (TG) aumentados e tem sido associado com risco cardiometabólico em crianças e adolescentes. Avaliar a influência do fenótipo CHT na glicemia de jejum e na pressão arterial em crianças e adolescentes em um período de acompanhamento de um ano. Trata-se de um estudo de coorte envolvendo 492 crianças e adolescentes de 7 a 15 anos de ambos os sexos, que foram submetidos à avaliação antropométrica, bioquímica e clínica no início e também após 6 e 12 meses de seguimento. Os modelos de Equação de Estimulação Generalizada (GEE) foram calculados para avaliar a influência longitudinal do fenótipo CHT na glicemia e na pressão arterial ao longo de um ano. Foi observada uma prevalência de 10,6% (n = 52) do fenótipo CHT nos estudantes. Os modelos GEE identificaram que os estudantes com fenótipo CHT apresentaram aumento de 3,87 mg/dl na média de glicemia em jejum (IC: 1,68-6,05) e de 3,67 mmHg na pressão arterial sistólica media (PAS) (IC: 1,55-6,08) depois de um ano de acompanhamento, após ajuste para variáveis de confusão. Os resultados deste estudo sugerem que o fenótipo CHT é um fator de risco para alterações longitudinais da glicemia e da PAS em crianças e adolescentes em um período de um ano de seguimento.

  19. Investigação dos perfís temporais de alta resolução de explosões solares tipo-III decimétricas

    NASA Astrophysics Data System (ADS)

    Cecatto, J. R.; Fernandes, F. C. R.; Sawant, H. S.; Madsen, F. R. H.

    2003-08-01

    Explosões solares tipo-III indicam a presença de feixes de elétrons acelerados durante "flares" solares. Sua investigação fornece informações tanto sobre os processos de aceleração de partículas quanto das características do agente causador e do local de aceleração. Explosões tipo-III decimétricas são geradas por feixes de elétrons viajando através de arcos magnéticos densos da baixa coroa solar. Os perfís temporais destes fenômenos, quando tomados com alta resolução, informam sobre os mecanismos de aceleração de partículas do feixe e o meio de transporte da energia liberada a partir da região de aceleração. Usando o Brazilian Solar Spectroscope (BSS), em operação no INPE, foram registradas dezenas de explosões tipo-III decimétricas, dentro da faixa de 2050-2250 MHz com alta resolução temporal (20 ms), em 13 de setembro de 2001, entre 13:00 e 16:10 UT. Foram selecionadas 10 explosões isoladas para uma investigação estatística detalhada de seus perfís temporais, em todos os cerca de 50 canais de freqüência. Os resultados indicam que cerca de 70% dos perfís temporais são complexos tanto durante a subida quanto descida. Os 30% restantes indicam que os perfís da subida podem ser bem representados, na maioria dos casos, por um processo não-linear e uma parcela significativa por processos lineares. Os perfís temporais da descida são dominados por um decaimento não-linear. Neste trabalho, será efetuada uma análise dos perfís temporais, tanto durante a subida quanto descida do fluxo, para as explosões selecionadas, em termos dos prováveis mecanismos de aceleração e relaxamento. 2

  20. [Not Available].

    PubMed

    MIján de la Torre, Alberto

    2016-06-03

    El síndrome de caquexia cancerosa es responsable de la muerte de un número significativo de pacientes con cáncer. Se caracteriza por la presencia de una ingesta reducida, con inflamación sistémica y un metabolismo alterado. Los enfermos presentan característicamente una progresiva pérdida de peso y de masa muscular, junto a deterioro funcional. La pérdida muscular se debe a la combinación de reducción de la síntesis proteica con aumento de su degradación. Ello conduce tanto a un acortamiento como a una reducción en el área de la fibra muscular. Asimismo, existen datos que apoyan que selectivamente algunos de los tipos de fibra muscular se ven más afectados. Es necesario definir bien los valores de corte de sarcopenia para diagnosticar la pérdida muscular y existen diferentes métodos. El sistema de la ubiquitina-proteasoma parece desempeñar un papel predominante en la degradación de la proteína miofibrilar. La tendencia a perder masa muscular en los pacientes con caquexia cancerosa parece estar asociada a la activación de señales catabólicas por citoquinas proinflamatorias, así como por productos tumorales del tipo factor inductor de proteólisis. En referencia a los factores pronósticos, el riesgo de muerte está bien documentado en pacientes con sarcopenia y, especialmente, en aquellos con obesidad asociada a la sarcopenia. Asimismo, se ha establecido una relación directa entre la pérdida intensa de masa muscular y la supervivencia en pacientes con diferentes tipos de tumores del tipo de cáncer de páncreas, pulmón, tracto biliar o cáncer colorrectal. Respecto de la terapia en el síndrome de caquexia cancerosa, es factible que requiera tratamiento con varios grupos combinados que incluyan, junto al soporte nutricional, fármacos orexígenos, con efecto anabólico y antinflamatorio, asociados a intervenciones que estimulen el ejercicio físico.

  1. Prediabetes

    MedlinePlus

    ... riesgo más alto de tener diabetes tipo 2, enfermedades del corazón, accidentes cerebrovasculares y otros problemas de ... del Instituto Nacional de la Diabetes y las Enfermedades Digestivas y Renales (NIDDK, por sus siglas en ...

  2. Quality of Primary Health Care for children and adolescents living with HIV.

    PubMed

    Nascimento, Leticia do; Paula, Cristiane Cardoso de; Magnago, Tania Solange Bosi de Souza; Padoin, Stela Maris de Mello; Harzheim, Erno; Silva, Clarissa Bohrer da

    2016-08-29

    to evaluate the quality of health care for children and adolescents living with HIV, among the different types of Primary Health Care services of Santa Maria, Rio Grande do Sul. cross-sectional study, developed with 118 Primary Health Care professionals. The Primary Care Evaluation Instrument, Professional version, was used. For verification of the variables associated with the high score, Poisson Regression was used. the professionals of the Family Health Strategy, when compared to those of the Primary Health Units, obtained a greater degree of orientation to primary care, both for the overall score and for the derived attributes score, as well as for the integrality and community orientation attributes. A specialization in Primary Health Care, other employment and a statutory work contract were associated with quality of care. the Family Health Strategy was shown to provide higher quality health care for children and adolescents living with HIV, however, the coverage is still low. The need was highlighted to expand this coverage and invest in vocational training directed toward Primary Care and making the professionals effective, through public selection procedure, as well as an improvement program that recognizes the care requirements, in these settings, of children and adolescents infected with HIV. avaliar a qualidade de atenção à saúde da criança e adolescente vivendo com HIV, entre os diferentes tipos de serviço de Atenção Primária à Saúde, de Santa Maria, Rio Grande do Sul. estudo transversal, desenvolvido com 118 profissionais da Atenção Primária à Saúde. Utilizou-se o Instrumento de Avaliação da Atenção Primária, versão Profissionais. Para verificação das variáveis associadas ao alto escore, foi utilizada a Regressão de Poisson. os profissionais da Estratégia Saúde da Família, quando comparados aos de Unidades Básicas de Saúde, obtiveram maior grau de orientação à atenção primária, tanto pelo escore geral quanto derivado, assim como nos atributos integralidade e orientação comunitária. Especialização em Atenção Primária à Saúde, outro emprego, vínculo estatutário mostraram-se associados à qualidade da atenção. destaca-se a Estratégia Saúde da Família com maior qualidade de atenção à saúde da criança e adolescente vivendo com HIV, entretanto, a cobertura ainda é baixa. Evidencia-se a necessidade de ampliação dessa cobertura, bem como investimento na qualificação profissional direcionada para Atenção Primária e na efetivação dos profissionais, por meio de concurso público, além de programa de aperfeiçoamento que reconheça a demanda do cuidado, nesses cenários, às crianças e adolescentes infectadas pelo HIV. evaluar la calidad de la atención de la Salud del niño y adolescente que viven con el virus HIV entre los diferentes tipos de servicio de Atención Primaria de la Salud, de Santa María, Rio Grande do Sul. estudio transversal, desarrollado con 118 profesionales de la Atención Primaria de la Salud. Se utilizó el Instrumento de Evaluación de la Atención Primaria, versión Profesionales. Para verificar las variables asociadas a un alto puntaje, fue utilizada la Regresión de Poisson. los profesionales de la Estrategia Salud de la Familia cuando comparados a los de Unidades Básicas de Salud, obtuvieron mayor grado de orientación para la atención primaria, tanto por el puntaje general como por el derivado, así como en los atributos integralidad y orientación comunitaria. La especialización en Atención Primaria de la Salud, tener otro empleo y el vínculo institucional se mostraron asociados a la calidad de la atención. se destaca la Estrategia Salud de la Familia con mayor calidad de atención de la Salud del niño y adolescente que viven con el virus HIV, entre tanto, la cobertura todavía es baja. Fue puesta en evidencia la necesidad de ampliar dicha cobertura, así como hacer inversiones en la calificación profesional orientada para la Atención Primaria y en la contratación de los profesionales por medio de concurso público, además de contar co¿n un programa de perfeccionamiento que reconozca la demanda del cuidado, en esos escenarios, a los niños y adolescentes infectados por el HIV.

  3. Comparação de modelos para o cálculo de perturbações orbitais devidas à maré terrestre

    NASA Astrophysics Data System (ADS)

    Vieira Pinto, J.; Vilhena de Moraes, R.

    2003-08-01

    Aplicações recentes de satélites artificiais com finalidades geodinâmicas requerem órbitas determinadas com bastante precisão. Em particular marés terrestres influenciam o potencial terrestre causando perturbações adicionais no movimento de satélites artificiais, as quais tem sido medidas por diversos processos. A atração exercida pela lua e pelo sol sobre a terra produz deslocamentos elásticos em seu interior e uma protuberância em sua superfície. O resultado é uma pequena variação na distribuição da massa na terra, consequentemente no geopotencial. As perturbações nos elementos orbitais de satélites artificiais terrestres devidas a maré terrestre podem ser estudadas a partir das equações de Lagrange, considerando-se um conveniente potencial. Por outro lado, como tem sido feito pelo IERS, as mudanças induzidas pela maré terrestre no geopotencial podem ser convenientemente modeladas como variações nos coeficientes Cnm e Snm do geopotencial. As duas teorias ainda não foram comparados para um mesmo satélite. Neste trabalho são apresentadas e comparadas as variações de longo período e seculares nas perturbações orbitais devidas à maré terrestre, calculadas por um modelo simples, o de Kozai, e pelo modelo do IERS. Resultados preliminares mostram, para os satélites SCD2 e CBERS1, e para a Lua em movimento elíptico e precessionando, as perturbações seculares no argumento do perigeu e na longitude do nodo ascendente.

  4. Trombose venosa profunda e vírus chicungunha

    PubMed Central

    Marques, Marcos Arêas; Adami de Sá, Fernanda Penza; Lupi, Otília; Brasil, Patricia; von Ristow, Arno

    2017-01-01

    Resumo Algumas infecções virais sistêmicas podem estar relacionadas ao desenvolvimento de trombose venosa profunda e/ou embolia pulmonar. Essa associação já está bem descrita em pacientes com infeções pelo vírus da imunodeficiência humana (HIV), hepatite C ou influenza. Recentemente introduzido no continente americano, o vírus chicungunha, agente etiológico da febre de chicungunha, ainda não tem essa relação bem sedimentada, mas com o aumento progressivo de sua incidência e pelo fato dessa infecção causar, muitas vezes, uma restrição severa da locomoção por poliartralgia e uma possível lesão endotelial direta, casos de tromboembolismo venoso podem começar a ser descritos. Neste relato de caso, descrevemos um paciente que desenvolveu trombose de veia poplítea direita durante internação para tratamento de febre por infecção por vírus chicungunha e poliartralgia severa. PMID:29930626

  5. Development and validation of educational technology for venous ulcer care.

    PubMed

    Benevides, Jéssica Lima; Coutinho, Janaina Fonseca Victor; Pascoal, Liliane Chagas; Joventino, Emanuella Silva; Martins, Mariana Cavalcante; Gubert, Fabiane do Amaral; Alves, Allana Mirella

    2016-04-01

    To develop and validate an educational technology venous ulcers care. Methodological study conducted in five steps: Situational diagnosis; literature review; development of texts, illustrations and layout; apparent and content validity by the Content Validity Index, assessment of Flesch Readability Index; and pilot testing. The developed technology was a type of booklet entitled Booklet for Venous Ulcers Care, consisting of seven topics: Diet and food intake, walking and light exercise, resting with elevated leg, bandage care, compression therapy, family support, and keeping healthy habits. The apparent validity revealed minimal agreement of 85.7% in the clarity and comprehensibility. The total content validity index was 0.97, the Flesch Readability Index was 75%, corresponding to the reading "fairly easy". The pilot test showed that 100% of people with venous ulcers evaluated the text and the illustrations as understandable, as appropriate. The educational technology proved to be valid for the appearance and content with potential for use in clinical practice. Construir e validar uma tecnologia educativa para cuidados com úlcera venosa. Estudo metodológico realizado em cinco fases: diagnóstico situacional; revisão da literatura; desenvolvimento de textos, ilustrações e diagramação; validade de aparência e de conteúdo pelo Índice de Validade de Conteúdo, avaliação do Índice de Legibilidade de Flesch; e teste piloto. A tecnologia desenvolvida foi do tipo cartilha intitulada Cartilha para cuidados com úlcera venosa, constituída de sete tópicos: Alimentação, Caminhadas e exercícios leves, Repouso com a perna elevada, Cuidados com o curativo, Terapia compressiva, Apoio familiar, e manter hábitos saudáveis. A validade aparente revelou concordância mínima de 85,7% na clareza e compreensibilidade. O Índice de Validade de Conteúdo total foi de 0,97, o Índice de legibilidade de Flesch foi de 75%, o que correspondeu à leitura "razoavelmente fácil". O teste piloto revelou que 100% das pessoas com úlcera venosa avaliaram o texto como compreensivo e as ilustrações, como adequadas. A tecnologia educativa mostrou-se válida quanto à aparência e ao conteúdo, com potencial de utilização na prática clínica.

  6. Intensive care unit team perception of palliative care: the discourse of the collective subject.

    PubMed

    Gulini, Juliana El Hage Meyer de Barros; Nascimento, Eliane Regina Pereira do; Moritz, Rachel Duarte; Rosa, Luciana Martins da; Silveira, Natyele Rippel; Vargas, Mara Ambrosina de Oliveira

    2017-05-25

    To learn the perception of health professionals in an intensive care unit towards palliative care. This was a descriptive and qualitative study based on the converging care approach conducted at an intensive care unit in the South of Brazil. Semi-structured interviews were used to investigate the understanding of the professionals about palliative care in this unit. The data were organized and analyzed using the discourse of the collective subject method with the help of Qualiquantisoft® software. Participants included 37 professionals (12 nurses, 11nursing technicians, 5 physical therapists and 9 doctors). The key ideas extracted from the interviews were: care in the end stage of life that avoids futile measures; comfort care; lack of standardized care and lack of team training. The professionals perceived palliative care as appropriate in the last stages of life, with no need for futile treatment or as comfort measures. However, they are aware of the lack of standardization and lack of capacity building in this area, which leads them to conceive palliative care as terminal care, and measures are recommended to break with this stigma. Conhecer a percepção dos profissionais de saúde de uma Unidade de Terapia Intensiva acerca do cuidado paliativo. Pesquisa descritiva, qualitativa do tipo Convergente Assistencial realizada em uma Unidade de Terapia Intensiva da região sul do Brasil. Utilizou-se de entrevista semiestruturada que investigou o entendimento e a compreensão sobre cuidado paliativo nesta unidade. Os dados foram organizados e analisados pela técnica do discurso do sujeito coletivo com auxílio do software Qualiquantisoft®. Participaram do estudo 37 profissionais (12 enfermeiros, 11 técnicos de enfermagem, cinco fisioterapeutas e nove médicos). As ideias centrais extraídas dos relatos: cuidado na fase terminal da vida sem medidas fúteis; cuidados de conforto; falta uniformizar a assistência e falta capacitação para a equipe. Os profissionais percebem o cuidado paliativo apropriado na fase terminal da vida, sem necessidade de medidas fúteis de tratamento e promotoras de conforto. No entanto, estão conscientes da falta de uniformização e da sua capacitação nesta matéria, o que os leva a conceber o paliativismo como cuidado de terminalidade, pelo que se recomendam medidas para romper com este estigma.

  7. Test-retest reliability of Brazilian version of Memorial Symptom Assessment Scale for assessing symptoms in cancer patients.

    PubMed

    Menezes, Josiane Roberta de; Luvisaro, Bianca Maria Oliveira; Rodrigues, Claudia Fernandes; Muzi, Camila Drumond; Guimarães, Raphael Mendonça

    2017-01-01

    To assess the test-retest reliability of the Memorial Symptom Assessment Scale translated and culturally adapted into Brazilian Portuguese. The scale was applied in an interview format for 190 patients with various cancers type hospitalized in clinical and surgical sectors of the Instituto Nacional de Câncer José de Alencar Gomes da Silva and reapplied in 58 patients. Data from the test-retest were double typed into a Microsoft Excel spreadsheet and analyzed by the weighted Kappa. The reliability of the scale was satisfactory in test-retest. The weighted Kappa values obtained for each scale item had to be adequate, the largest item was 0.96 and the lowest was 0.69. The Kappa subscale was also evaluated and values were 0.84 for high frequency physic symptoms, 0.81 for low frequency physical symptoms, 0.81 for psychological symptoms, and 0.78 for Global Distress Index. High level of reliability estimated suggests that the process of measurement of Memorial Symptom Assessment Scale aspects was adequate. Avaliar a confiabilidade teste-reteste da versão traduzida e adaptada culturalmente para o português do Brasil do Memorial Symptom Assessment Scale. A escala foi aplicada em forma de entrevista em 190 pacientes com diversos tipos de câncer internados nos setores clínicos e cirúrgicos do Instituto Nacional de Câncer José de Alencar Gomes da Silva e reaplicada em 58 pacientes. Os dados dos testes-retestes foram inseridos num banco de dados por dupla digitação independente em Excel e analisados pelo Kappa ponderado. A confiabilidade da escala mostrou-se satisfatória nos testes-retestes. Os valores do Kappa ponderado obtidos para cada item da escala apresentaram-se adequados, sendo o maior item de 0,96 e o menor de 0,69. Também se avaliou o Kappa das subescalas, sendo de 0,84 para sintomas físicos de alta frequência, de 0,81 para sintomas físicos de baixa frequência, de 0,81 também para sintomas psicológicos, e de 0,78 para Índice Geral de Sofrimento. Altos níveis de confiabilidade estimados permitem concluir que o processo de aferição dos itens do Memorial Symptom Assessment Scale foi adequado.

  8. Astronomia para/com crianças carentes em Limeira

    NASA Astrophysics Data System (ADS)

    Bretones, P. S.; Oliveira, V. C.

    2003-08-01

    Em 2001, o Instituto Superior de Ciências Aplicadas (ISCA Faculdades de Limeira) iniciou um projeto pelo qual o Observatório do Morro Azul empreendeu uma parceria com o Centro de Promoção Social Municipal (CEPROSOM), instituição mantida pela Prefeitura Municipal de Limeira para atender crianças e adolescentes carentes. O CEPROSOM contava com dois projetos: Projeto Centro de Convivência Infantil (CCI) e Programa Criança e Adolescente (PCA), que atendiam crianças e adolescentes em Centros Comunitários de diversas áreas da cidade. Esses projetos têm como prioridades estabelecer atividades prazerosas para as crianças no sentido de retirá-las das ruas. Assim sendo, as crianças passaram a ter mais um tipo de atividade - as visitas ao observatório. Este painel descreve as várias fases do projeto, que envolveu: reuniões de planejamento, curso de Astronomia para as orientadoras dos CCIs e PCAs, atividades relacionadas a visitas das crianças ao Observatório, proposta de construção de gnômons e relógios de Sol nos diversos Centros Comunitários de Limeira e divulgação do projeto na imprensa. O painel inclui discussões sobre a aprendizagem de crianças carentes, relatos que mostram a postura das orientadoras sobre a pertinência do ensino de Astronomia, relatos do monitor que fez o atendimento no Observatório e o que o número de crianças atendidas representou para as atividades da instituição desde o início de suas atividades e, em particular, em 2001. Os resultados são baseados na análise de relatos das orientadoras e do monitor do Observatório, registros de visitas e matérias da imprensa local. Conclui com uma avaliação do que tal projeto representou para as Instituições participantes. Para o Observatório, em particular, foi feita uma análise com relação às outras modalidades de atendimentos que envolvem alunos de escolas e público em geral. Também é abordada a questão do compromisso social do Observatório na educação do público em questão.

  9. Computerized nursing process in the Intensive Care Unit: ergonomics and usability.

    PubMed

    Almeida, Sônia Regina Wagner de; Sasso, Grace Teresinha Marcon Dal; Barra, Daniela Couto Carvalho

    2016-01-01

    Analyzing the ergonomics and usability criteria of the Computerized Nursing Process based on the International Classification for Nursing Practice in the Intensive Care Unit according to International Organization for Standardization(ISO). A quantitative, quasi-experimental, before-and-after study with a sample of 16 participants performed in an Intensive Care Unit. Data collection was performed through the application of five simulated clinical cases and an evaluation instrument. Data analysis was performed by descriptive and inferential statistics. The organization, content and technical criteria were considered "excellent", and the interface criteria were considered "very good", obtaining means of 4.54, 4.60, 4.64 and 4.39, respectively. The analyzed standards obtained means above 4.0, being considered "very good" by the participants. The Computerized Nursing Processmet ergonomic and usability standards according to the standards set by ISO. This technology supports nurses' clinical decision-making by providing complete and up-to-date content for Nursing practice in the Intensive Care Unit. Analisar os critérios de ergonomia e usabilidade do Processo de Enfermagem Informatizado a partir da Classificação Internacional para as Práticas de Enfermagem, em Unidade de Terapia Intensiva, de acordo com os padrões da InternationalOrganization for Standardization (ISO). Pesquisa quantitativa, quase-experimental do tipo antes e depois, com uma amostra de 16 participantes, realizada em uma Unidade de Terapia Intensiva. Coleta de dados realizada por meio da aplicação de cinco casos clínicos simulados e instrumento de avaliação. A análise dos dados foi realizada pela estatística descritiva e inferencial. Os critérios organização, conteúdo e técnico foram considerados "excelentes", e o critério interface "muito bom", obtendo médias 4,54, 4,60, 4,64 e 4,39, respectivamente. Os padrões analisados obtiveram médias acima de 4,0, sendo considerados "muito bons" pelos participantes. O Processo de Enfermagem Informatizado possui padrões ergonômicos e de usabilidade de acordo com os padrões estabelecidos pela ISO. Esta tecnologia apoia a decisão clínica do enfermeiro fornecendo conteúdo completo e atualizado para a prática de Enfermagem em Unidade de Terapia Intensiva.

  10. Espectroscopia infravermelha de núcleos ativos de galáxias: resultados adicionais

    NASA Astrophysics Data System (ADS)

    Rodríguez Ardila, A.; Viegas, S.; Pastoria, M. G.

    2003-08-01

    Apresentamos resultados parciais de um levantamento espectroscópico na região do infravermelho próximo (NIR) realizado em 30 núcleos ativos de galáxias (AGN), incluindo vários objetos selecionados do catálogo PG com z de até 0.55. O objetivo é estudar a natureza do contínuo observado e as condições físicas do gas emissor. Todas as fontes de tipo 1 apresentam uma mudança na inclinação do contínuo na região de 1.2mm, associada ao término da contribuição do contínuo emitido pelo AGN e ao início da contribuição do contínuo emitido pela poeira quente atribuída ao tórus que rodeia a fonte central. O índice espectral associado à segunda contribuição varia apreciavelmente de objeto para objeto. Este resultado é comparado com distribuições espectrais de energia preditas por modelos de toroides para testar a validez do modelo unificado. A partir das linhas de FeII observado nos espectros deriva-se, pela primeira vez nessa região espectral, um template empírico de FeII para estudar a intensidade e a origem dessa emissão. A intensidade do FeII é estudada em conjunto com aquela da região visível e comparada às predições de modelos teóricos que incluem fluorescência de Lya, excitação colisional e auto-fluorescência como mecanismos dominantes de exitação. Encontra-se que os dois primeiros processos dominam na formação do espectro de FeII observado. Indicadores de avermelhamento, entre eles Brg/Pab, Pab/Pag, Pab/Pad e [FeII] 1.257/1.644 mm são utilizados para mapear a distribuição de poeira nas regiões emissoras de linhas. Encontra-se valores de extinção Av~3 associados ao último indicador e valores significativamente menores (Av~1.5) para os restantes, o que sugere que o [FeII] se forma em uma região separada da maior parte do gás emissor de linhas estreitas.

  11. Correlação de longo alcance em sistemas binários de raios-x usando remoção de flutuações

    NASA Astrophysics Data System (ADS)

    Pereira, M. G.; Moret, M. A.; Zebende, G. F.; Nogueira, E., Jr.

    2003-08-01

    Neste trabalho é proposta uma metodologia de analise de series temporais de fontes astrofísicas, baseada no método proposto por Peng et al. (1994) e Liu et al. (1999), o qual consiste na idéia de que uma série temporal correlacionada pode ser mapeada por um processo de busca de auto-similaridades em diversas escalas de tempo n. Removendo as eventuais tendências e integrando o sinal observado, é obtida uma medida do desvio médio quadrático das flutuações do sinal integrado F(n)~na, onde a representa o fator de escala associado com a auto-similaridade da correlação de longo alcance do sinal. Baseado nos valores obtidos de a, é possível distinguir entre os casos de sinais não-correlacionados, tipo ruído branco (a = 0,5), sinal anti-persistentes (a < 0,5) e sinal persistente (a > 0,5). Usando esta metodologia, foram analisadas 129 curvas de luz de sistemas binários de raios-X, provenientes do banco de dados públicos de observações feitas pelo instrumento All Sky Monitor, a bordo do satélite Rossi X-Ray Timing Explorer (ASM-RXTE). Foram identificadas a presença de a'0,5 em mais de 90% dos sistemas estudados, implicando em dizer que as flutuações de intensidade observadas apresentam correlação de auto-similaridade, sem entretanto, indícios de apresentarem uma escala de tempo característica das flutuações de intensidade. Sistemas onde são observadas erupções (flares), apresentam sistematicamente a > 0,5, característica esta, possivelmente associada com persistência das flutuações de densidade de disco ou taxa de acréscimo de massa. Os sistemas com curvas de luz onde nao são observadas as erupções apresentam uma distribuição normal centrada em a~0,62+/-0,10. Referências ¾ Peng, C.-K., Buldyrev, S.V., Havlin, S., Simons, M., Stanley, H.E., e Goldberg, A.L., Phys. Rev. E, (49), 1685 (1994). ¾ Liu, Y., Gopikrishnan, P., Cizeau, P., Meyer, M., Peng,C.-K., e Stanley, H.E., Phys. Rev. E, (60), 1390 (1999).

  12. Trayectoria de los tornillos pediculares lumbares y sacros: Comparación entre el abordaje por linea media versus el abordaje posterolateral tipo wiltse

    PubMed Central

    Gagliardi, Martín; Guiroy, Alfredo; Molina, Federico Fernández; Fasano, Francisco; Ciancio, Alejandro Morales; Mezzadri, Juan José; Jalón, Pablo

    2017-01-01

    Resumen Objetivos: El objetivo de este estudio fue comparar, en fusiones lumbosacras cortas, el ángulo de convergencia de los tornillos pediculares entre el abordaje posterolateral tipo Wiltse y el abordaje mediano convencional. Método: Se revisaron en forma retrospectiva los controles en tomografía axial computada (TAC) de 76 tornillos pediculares lumbares y sacros colocados por vía posterior, mediante un abordaje mediano convencional (n: 38) o por vía posterolateral transmuscular tipo Wiltse (n: 38). Se incluyeron fusiones lumbosacras cortas desde L3 a S1, en pacientes adultos, con patología degenerativa. Se excluyeron los tornillos con una brecha ósea >4 mm en cualquier dirección, los casos con instrumentaciones pediculares previas y aquellos con curvas en el plano coronal mayores de 20°. Resultados: Considerando la totalidad de los implantes, el ángulo de convergencia fue de 23,3° (+/- 15,82). La angulación promedio, en el grupo AW, fue de 29,3° (+/- 9,72). En el grupo AC, el grado de convergencia de los implantes fue de 17,2° (+/- 10,58). Esta diferencia fue estadísticamente significativa (P < 0,0001). Para el grupo AW, el grado de convergencia según nivel fue el siguiente: L3: 31,2° (+/- 1,9); L4: 31,4° (+/- 2,76); L5: 31,1° (+/- 5,62); S1: 24,2° (+/- 12,16). El promedio del ángulo del tornillo según nivel para el grupo AC fue: L3: 16° (+/- 7,16); L4: 20,3° (+/- 6,9) L5: 15,9° (+/- 13,38); S1: 15,2° (+/- 14,32). Los implantes del grupo AW tuvieron ángulos significativamente más convergentes que el grupo AC en todos los segmentos explorados. Conclusión: En las fusiones lumbosacras cortas, la utilización del abordaje tipo Wiltse permitió la colocación de tornillos pediculares con más convergencia que en el abordaje mediano convencional. La relevancia clínica de este hecho es desconocida y se requerirían trabajos prospectivos randomizados para determinar la misma. PMID:29142777

  13. Abundâncias de oxigênio e enxofre nas estrelas de tipo solar da vizinhança solar

    NASA Astrophysics Data System (ADS)

    Requeijo, F.; Porto de Mello, G. F.

    2003-08-01

    Alguns resultados sugerem que o Sol seja 58% mais abundante em oxigênio que o meio interestelar local. Esta anomalia parece estender-se para o carbono e o criptônio. Entre as possíveis explicações deste fenômeno estão: uma supernova de tipo II que tenha enriquecido a nebulosa protosolar, tornando-a superabundante em oxigênio; um episódio de infall de material pobre em metais sobre o disco Galático, diluindo o meio interestelar local ou uma migração dinâmica do Sol de uma órbita mais interna da Galáxia para sua posição atual. A escolha entre estes cenários exige o conhecimento preciso da abundância solar em relação às anãs G da vizinhança. Neste contexto, o oxigênio e enxofre, são elementos-chave por serem ambos produzidos pelas supernovas de tipo II, devendo portanto possuir o mesmo padrão de abundância. Este projeto visa esclarecer qual a posição do Sol na distribuição local de abundâncias de enxofre e oxigênio para uma amostra de estrelas de tipo solar com idades e metalicidades bem conhecidas. Para tal, analisamos espectros de alta resolução e alta relação sinal-ruído nas regiões espectrais de ll 6300, 7774 (O) e l8695 (S). Para o enxofre encontramos que o Sol parece ser uma estrela típica dentre as da vizinhança, e que este elemento não mostra a sobreabundância para baixas metalicidades, já bem estabelecida para o oxigênio. Discutimos as abundâncias do enxofre no contexto da Evolução Química da Galáxia. Apresentamos resultados preliminares muito precisos para a linha proibida do oxigênio l6300 e comparamos estes com os obtidos para o tripleto em l7774. Quantificamos os efeitos não-ETL presentes no tripleto em função dos parâmetros atmosféricos estelares.

  14. Development of highly porous crystalline titania photocatalysts

    NASA Astrophysics Data System (ADS)

    Marszewski, Michal

    The objectives of this dissertation are the design, synthesis, and characterization of titania materials with surface area, porosity, crystallinity and doping tailored toward photocatalytic applications. Ultimately, the research should result in a strategy allowing the synthesis of titania with all these important features. The synthetic methods investigated in this research will include: i) soft-templating, ii) hard-templating, and iii) modified precursor strategy. Soft-templating strategy uses organic templates--either block copolymers or surfactants--that under specific conditions assemble into micelles, and later, these micelles are used to template the desired material around them. The resulting organic-inorganic composite is then calcined in air to remove the organic template and recover the final material with high surface area and large pore volume. This work explores 1) synthesis of titania materials in the presence of polymer templates, and the effects of different synthetic conditions on the structure of the resulting materials. Hard-templating, in contrast to soft-templating, uses inorganic templates. The hard template is introduced during the synthesis to cast its shape onto the fabricated material and removed afterwards, when the material has formed. The final material is an inverse replica of the hard template used, typically with a well-developed mesostructure. This work explores 1) hard templating synthesis of titania materials using silica and alumina, and 2) the effects of the template amount and type. The modified precursor strategy is a novel synthetic method, developed in this research, and designed specifically to achieve titania material with high surface area, large pore volume, high crystallinity, and possibly doping. The modified precursors are prepared by reacting generic titania precursors, such as titanium isopropoxide (TIPO), with organic acids, which results in substitution of some or all alkoxide groups in TIPO structure. The goal is to introduce new, easily carbonizable groups in TIPO structure so that the modified precursor can serve as titania and carbon precursor simultaneously. Subsequently, during carbonization in inert atmosphere, a carbon framework is formed that works as a scaffold, protecting titania during its crystallization. Afterwards, the carbon scaffold is removed by calcination in air. This work explores the modified precursor strategy by 1) preparing titania materials from TIPO modified with different carboxylic acids and 2) investigating the effect of the modifying acid on the properties of the carbon-titania composites and the final titania materials.

  15. The impact of the use of different types of gloves and bare hands for preparation of clean surgical instruments.

    PubMed

    Bruna, Camila Quartim de Moraes; Souza, Rafael Queiroz de; Massaia, Irineu Francisco Silva; Cruz, Áurea Silveira; Graziano, Kazuko Uchikawa

    2016-10-10

    to determine if there are differences on the safety of the preparation of clean surgical instruments using different types of gloves and bare hands and evaluate the microbiological load of these preparations without gloves. laboratory procedure with a pragmatic approach, in which the samples were handled with different types of gloves and bare hands. In addition, cytotoxicity assays were carried out by means of the agar diffusion method. Further samples were subjected to microbiological analysis after being handled without gloves. none of the samples showed cytotoxic effect. All microbiological cultures showed growth of microorganisms, but no microorganism has been recovered after autoclaving. there were no differences in the cytotoxic responses regarding the use of different types of gloves and bare hands in the handling of clean surgical instruments, which could entail iatrogenic risk. It is noteworthy that the use of gloves involves increase in the costs of process and waste generation, and the potential allergenic risk to latex. determinar se existe diferenças na segurança do preparo de instrumentais cirúrgicos relacionada ao uso de distintos tipos de luvas e das mãos nuas no preparo, e avaliar a carga microbiológica destes preparados sem luvas. experimento laboratorial com abordagem pragmática, onde amostras foram manipuladas com diferentes tipos de luvas e com as mãos nuas, elaborado teste de citotoxicidade por meio da difusão em ágar. Outras Amostras sofreram análise microbiológica após serem manipuladas sem luvas. nenhuma das amostras apresentou efeito citotóxico. Todas as culturas microbiológicas apresentaram crescimento de microrganismos, embora nenhum microrganismo tenha sido recuperado após a autoclavação. não houve diferenças nas respostas citotóxicas relacionadas ao uso de diferentes tipos de luvas e das mãos nuas na manipulação do instrumental cirúrgico limpo que sinalizasse risco de iatrogenia. Ressalta-se que o uso de luvas implica em aumento dos custos do processo e da geração de resíduos, além do potencial risco alergênico ao látex. determinar si existen diferencias en la seguridad de la preparación del instrumental quirúrgico relacionadas con el uso de diferentes tipos de guantes y de las manos desnudas y evaluar la carga microbiológica de estos preparados sin guantes. experimento de laboratorio con enfoque pragmático, en el que las muestras fueron manejadas con diferentes tipos de guantes y las manos desnudas. Además, un ensayo de citotoxicidad se llevó a cabo mediante el método de difusión en agar. Otras muestras fueron sometidas a análisis microbiológico después de haber sido manipuladas sin guantes. ninguna de las muestras presentó efecto citotóxico. Todos los cultivos microbiológicos mostraron crecimiento de microorganismos, pero ningún microorganismo ha sido recuperado después de la esterilización en autoclave. no hubo diferencias en las respuestas citotóxicas con respecto al uso de diferentes tipos de guantes y de las manos desnudas en el manejo del instrumental quirúrgico limpio, lo que podría conllevar riesgo de yatrogenia. Es de destacar que el uso de guantes implica un aumento de los costos del proceso y la generación de residuos, además del potencial riesgo alergénico al látex.

  16. Autofrecuencias de las ecuaciones de Helmholtz y Liouville para un modelo de tierra tipo Jeffreys simplificado.

    NASA Astrophysics Data System (ADS)

    Sevilla, M. J.; González-Camacho, A.

    The authors obtain expressions for the free frequencies of polar motion for an ellipsoidal, rotating and perturbed earth model constituted by an elastic mantle with an homogeneous liquid core of additional simple motion.

  17. Perfiles de luminosidad en galaxias con núcleo tipo Seyfert 1

    NASA Astrophysics Data System (ADS)

    Boris, N.; Rodriguez-Ardilla, A. A.; Pastoriza, M. G.

    Presentamos imágenes CCD en los filtros BVI y Hα de una muestra de 10 galaxias Seyfert 1 y Narrow Line Seyfert 1. Recientes observaciones muestran que hay una diferencia significante en el índice espectral óptico entre NLS1s y Sy1 normales, siendo para las primeras del orden de 2. Otra característica importante es que la mayor parte de las NLS1s muestran tasas de FeII/Hβ mayores que las observadas en otras Sy1s. Desde el punto de vista fotométrico, estas galaxias no tienenningún tipo de estudio previo. Presentamos magnitudes totales, perfiles de luminosidad y mapas de color junto con un detallado análisis de la formación estelar en estos objetos. Encontramos que la descomposición en bulbo + disco representa adecuadamente los perfiles de luminosidad de las galaxias de la muestra. Sin embargo, en todos los casos es necesario que el disco tenga un agujero en su centro. El radio de este agujero va desde los 3 a los 9 kpc. Si bien no tenemos aún una explicación para este hecho, los agujeros parecen estar asociados a anillos circumnucleares de alto oscurecimiento E(B-V) ~1. Los perfiles presentan también un fuerte gradiente de color, siendo notablemente más azules hacia la región nuclear. Los objetos de la muestra cubren todo el rango de tipos morfológicos, no obstante, no encontramos regiones de formación estelar en las regiones exteriores de las galaxias. La formación estelar está confinada a la región nuclear y se data en alrededor de 5 x 107 años.

  18. Estudo comparativo entre estrelas centrais de nebulosas planetárias deficientes em hidrogênio

    NASA Astrophysics Data System (ADS)

    Marcolino, W. L. F.; de Araújo, F. X.

    2003-08-01

    Apresentamos neste trabalho o resultado de um estudo das principais características espectrais das estrelas centrais de nebulosas planetárias (ECNP) deficientes em hidrogênio. A origem e a evolução dessas estrelas ainda constitui um problema em aberto na evolução estelar. Geralmente esses objetos são divididos em [WCE], [WCL] e [WELS]. Os tipos [WCE] e [WCL] apresentam um espectro típico de uma estrela Wolf-Rayet carbonada de população I e as [WELS] apresentam linhas fracas de carbono e oxigênio em emissão. Existem evidências que apontam a seguinte sequência evolutiva : [WCL] = > [WCE] = > [WELS] = > PG 1159 (pré anã-branca). No entanto, tal cenário apresenta falhas como por exemplo a falta de ECNP entre os tipos [WCL] e [WCE]. Baseados em uma amostra de 24 objetos obtida no telescópio de 1.52m em La Silla, Chile (acordo ESO/ON), ao longo do ano 2000, apresentamos os resultados da comparação das larguras equivalentes de diversas linhas relevantes entre os tipos [WCL], [WCE] e [WELS]. Verificamos que nossos dados estão de acordo com a sequência evolutiva. Baseado nas linhas de C IV, conseguimos dividir pela primeira vez as [WELS] em dois grupos principais. Além disso, os dados reforçam a afirmação de que as [WCE] são as estrelas que possuem a maior temperatura entre as ECNP deficientes em hidrogênio. Discutimos ainda, a escassez de dados disponíveis na literatura e a necessidade da obtenção de parametros físicos para estes objetos.

  19. Selected chemical compounds in firm and mellow persimmon fruit before and after the drying process.

    PubMed

    Senica, Mateja; Veberic, Robert; Grabnar, Jana Jurhar; Stampar, Franci; Jakopic, Jerneja

    2016-07-01

    Persimmon is a seasonal fruit and only available in fresh form for a short period of each year. In addition to freezing, drying is the simplest substitute for the fresh fruit and accessible throughout the year. The effect of mellowing and drying was evaluated in 'Tipo' persimmon, an astringent cultivar. 'Tipo' firm fruit contained high levels of tannins (1.1 mg g(-1) DW), which were naturally decreased to 0.2 mg g(-1) DW after mellowing. The drying process greatly impacted the contents of carotenoids, total phenols, individual phenolics, tannins, organic acids, sugars and colour parameters in firm and mellow fruit. The reduction of tannins, phenolic compounds and organic acids were accompanied by the increase of sugars and carotenoids, improving the colour of the analysed samples. These results showed that the drying process improved the quality of persimmon products and extended their shelf life. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  20. The Development and Airborne Testing of the PALE Seat.

    DTIC Science & Technology

    1981-06-20

    Development Center 02 Comptroller 10 Directorate Command Projects 20 Systems Directorate 30 Sensors & Avionics Technology Directorate 40 Communication...31. Horten, W.M.: Para volar a bajo precio: el planeador motorizando tipo ala volante. Rev. Nacional de Aeronautics 2:6:70-72, Buenos Aires, 1949. 91

  1. Nostalgia e Aspiracao pelo Livro: Santana Mestra na Colonia (Nostalgia and Longing for the Book: Santana Mestra na Colonia).

    ERIC Educational Resources Information Center

    Lopes, Eliane Marta Teixeira

    1997-01-01

    Proposes a historiographical reading about devotion and the figure of a saint, represented by a woman with a book teaching her daughter. Analyzes some episodes of the history of education in Brazil through the religious imagery in the geographic region of Brazil known as Minas Gerais. (PA)

  2. Cultural adaptation and validation of the Portuguese version of the Nursing Clinical Facilitators Questionnaire.

    PubMed

    Frederico-Ferreira, Maria Manuela; Camarneiro, Ana Paula Forte; Loureiro, Cândida Rosalinda Exposto da Costa; Ventura, Maria Clara Amado Apóstolo

    2016-08-15

    to perform the cultural adaptation to Portuguese of the Nursing Clinical Facilitators Questionnaire (NCFQ), which was designed by the Centre for Learning and Teaching at the University of Technology of Sydney, and to validate this instrument. this methodological study involved the cultural adaptation of the questionnaire by using translation, back-translation, semantic comparison, idiomatic and conceptual equivalence, and validation through validity and reliability analyses and used a sample of 767 students in their second year of the Nursing Program. construct validity had a two-factor solution according to the varimax rotation method. In addition, there was a high overall internal consistency for the questionnaire (Cronbach's alpha of 0.977) and for the factors found (0.966 and 0.952, respectively). the Portuguese version has good psychometric characteristics; therefore, it is adequate to obtain reliable information on the perception of nursing students concerning the type of supervision that is provided in clinical practice, and this version is adequate to improve teaching practices. realizar a adaptação cultural para a língua portuguesa do Nursing Clinical Facilitators Questionnaire (NCFQ) concebido pelo Centre for Learning and Teaching, University of Technology de Sydney e proceder à validação do instrumento. estudo metodológico de adaptação cultural do questionário através de tradução, retroversão, comparação semântica, idiomática e equivalência conceitual, seguido de validação em uma amostra de 767 estudantes do 2º ano do Curso de Licenciatura em Enfermagem, por meio de análise da validade e confiabilidade. a validade de constructo apresenta uma solução bifatorial após rotação varimax. A consistência interna global do questionário é elevada (alfa de Cronbach 0,977), assim como dos fatores encontrados (respectivamente, 0,966 e 0,952). a versão portuguesa apresenta boas características psicométricas, sendo um instrumento válido para obter informação fidedigna acerca da percepção dos estudantes de enfermagem relativamente ao tipo de orientação tida em contexto clínico, revelando-se importante para melhoria das práticas pedagógicas. llevar a cabo la adaptación cultural al portugués del Nursing Clinical Facilitators Questionnaire (NCFQ), diseñado por el Centre for Learning and Teaching, University of Technology Sydney, y validar este instrumento. este estudio metodológico implicó la adaptación cultural del cuestionario usando la traducción, la retrotraducción, la comparación semántica, la equivalencia idiomática y conceptual, y la validación usando una muestra de 767 estudiantes del segundo curso del Programa de Enfermería mediante análisis de validez y de fiabilidad. la validez del constructo presentó una solución bifactorial según el método de rotación Varimax. Además, hubo una consistencia interna total alta para el cuestionario (alfa de Cronbach de 0,977) y para los factores encontrados (de 0,966 y 0,952, respectivamente). la versión en portugués cuenta con buenas características psicométricas y, por lo tanto, es adecuada para obtener información fiable sobre la percepción de los estudiantes de enfermería sobre el tipo de supervisión proporcionada en la práctica clínica, y esta versión es adecuada para la mejora de las prácticas pedagógicas.

  3. Newborns' temperature submitted to radiant heat and to the Top Maternal device at birth.

    PubMed

    Albuquerque, Rosemeire Sartori de; Mariani, Corintio; Bersusa, Ana Aparecida Sanches; Dias, Vanessa Macedo; Silva, Maria Izabel Mota da

    2016-08-08

    to compare the axillar temperatures of newborns that are put immediately after birth in skin-to-skin contact under the Top Maternal device, as compared to those in a radiant heat crib. comparatives observational study of the case-control type about temperature of 60 babies born at the Obstetric Center and Normal Delivery Center of a public hospital of the municipality of Sao Paulo, being them: 29 receiving assistance in heated crib and 31 in skin-to skin contact, shielded by a cotton tissue placed on mother's thorax, called Top Maternal. the temperature of the babies of the skin-to-skin contact group presented higher values in a larger share of the time measures verified, as compared to those that were placed in radiant heat crib, independently from the place of birth. Differences between the two groups were not statistically significant. the study contributes to generate new knowledge, supporting the idea of keeping babies with their mothers immediately after birth protected with the Maternal Top, without harming their wellbeing, as it keeps the axillar temperature in recommendable levels. comparar a temperatura axilar dos recém-nascidos acomodados - imediatamente após o nascimento - em contato pele a pele, sob o Top Maternal, em berço de calor radiante. estudo comparativo observacional do tipo Caso-Controle sobre a temperatura de 60 bebês nascidos no Centro Obstétrico e Centro de Parto Normal de um hospital público do município de São Paulo, sendo: 29 assistidos em berço aquecido e 31 em contato pele a pele, protegidos por uma malha de algodão colocada sobre o tórax da mãe, denominada Top Maternal. a temperatura dos bebês do grupo de contato pele a pele teve maior valor na maioria dos tempos verificados comparada à dos que foram colocados em berço de calor radiante, independentemente do local de nascimento. A diferença entre os grupos não foi estatisticamente significante. o estudo contribui com a geração de um novo conhecimento que sustenta a manutenção dos bebês com suas mães imediatamente após o nascimento por meio do contato pele a pele protegidos pelo Top Maternal, sem prejuízos ao seu bem-estar, uma vez que a temperatura axilar se manteve em níveis recomendáveis. comparar la temperatura axilar de los recién nacidos (Rn) acomodados, inmediatamente después del nacimiento, en contacto piel con piel, bajo el Top Maternal, en cuna de calor radiante. estudio comparativo observacional del tipo Caso Control sobre la temperatura de 60 bebés nacidos en el Centro Obstétrico y Centro de Parto Normal de un hospital público del municipio de Sao Paulo, siendo: 29 asistidos en cuna calentada y 31 en contacto piel con piel, protegidos por un tejido de algodón colocado sobre el tórax de la madre, denominado Top Maternal. la temperatura de los bebés del grupo de contacto piel con piel fue más alta en la mayoría de los tiempos verificados, ello comparado con los que fueron colocados en cuna de calor radiante, independientemente del local de nacimiento. La diferencia entre los grupos no fue estadísticamente significativa. el estudio contribuye con la generación de un nuevo conocimiento que sustenta que se debe mantener a los bebés con sus madres inmediatamente después del nacimiento por medio del contacto piel con piel protegidos por el Top Maternal, sin perjuicios a su bienestar, una vez que la temperatura axilar se mantuvo en niveles recomendables.

  4. Current and Projected Government and Commercial Space Activities

    DTIC Science & Technology

    1975-04-01

    satellites. Reimbursable. Figure 1 Space Launches by NASA in 197 5—Continued m mm* m~ammm^m i^» ■^ Mission Improved TIPOS Operational Satellite...costs and development effort. Tiros-N, which will have much more capable sensors than existing low-altitude satellites, also will incorporate a

  5. Diabetes mellitus and drug abuse during pregnancy and the risk for orofacial clefts and related abnormalities.

    PubMed

    Trindade-Suedam, Ivy Kiemle; Kostrisch, Lília Maria von; Pimenta, Luiz André Freire; Negrato, Carlos Antônio; Franzolin, Solange Braga; Trindade, Alceu Sergio

    2016-08-08

    to assessed the prevalence of diabetes mellitus (DM) and drug abuse in mothers of children with orofacial clefts (OFC). 325 women who had children (0-3y) with clefts were interviewed. Data regarding type of diabetes, use of legal/illegal drugs during pregnancy, waist girth and fasting blood sugar at the first prenatal consult were collected. twenty seven percent of the women had DM, out of these, 89% had gestational DM, 5,5% type 1 DM and 5,5% type 2 DM. The prevalence of DM in mothers of children with OFC was 27%, it is significantly higher than the average Brazilian population which is 7.6% (p<0.01) (OR=4.5, 95%CI=3.5-5.8). Regarding drug abuse during pregnancy, 32% of the mothers used drugs and a significant positive correlation was observed between drug abuse and the occurrence of clefts and other craniofacial anomalies (p=0.028) (OR=2.87; 95%CI=1.1-7.4). DM and drug abuse during pregnancy increases the risk for OFC and related anomalies and early diagnosis of DM and prevention of drug abuse, especially in pregnant women, should be emphasized. esta investigación estableció la prevalencia de diabetes mellitus (DM) y el abuso de drogas en madres de niños con malformaciones creaneofaciales (MCF). 325 mujeres que tuvieron hijos (0-3 años) con malformaciones fueron entrevistadas. Se obtuvieron datos referentes a: tipo de diabetes; uso de drogas lícitas o ilícitas durante el embarazo; circunferencia de la cintura; y, glucemia en ayunas en la primera consulta prenatal. el veintisiete por ciento de las mujeres tenían DM. Entre estas, el 89% tuvieron DM gestacional, el 5,5% DM tipo 1 y el 5,5% DM tipo 2. La prevalencia de DM en madres de hijos con MCF fue de 27%. Esto es significativamente más alto que el promedio de la población brasileña afectada por esa enfermedad, que es de 7,6% (p<0.01) (OR=4,5, 95%IC=3,5-5,8). Observando el abuso de drogas durante el embarazo, el 32% de las madres había utilizado drogas y una correlación positiva significativa fue observada entre el abuso de drogas y la ocurrencia de hendiduras y otras malformaciones craneofaciales (p=0,028) (OR=2,87; 95%IC=1,1-7,4). la DM y el abuso de drogas durante el embarazo aumentan el riesgo de MCF y de anomalías relacionadas; se enfatiza la importancia del diagnóstico precoz de DM y la prevención del abuso de drogas, especialmente entre las mujeres embarazadas. avaliar a prevalência de diabetes mellitus (DM) e o uso de drogas em mães de crianças com fissuras orofaciais (FOF). 325 mulheres que tiveram filhos (0-3 anos) com fissuras foram entrevistadas. Os dados referentes tipo de diabetes, uso de drogas lícitas / ilícitas durante a gravidez, circunferência abdominal e glicemia em jejum na primeira consulta pré-natal foram coletados. vinte e sete por cento das mulheres tinham DM. Destes, 89% tinham DM gestacional, 5,5% DM tipo 1 e 5,5% DM tipo 2. A prevalência de DM em mães de crianças com FOF foi de 27%, significativamente mais elevado que a média da população brasileira que é de 7,6% (p <0,01) (OR = 4,5, IC de 95% = 3,5-5,8). Com relação ao uso de drogas, 32% das mães eram usuárias drogas durante a gravidez e uma correlação positiva foi observada entre o uso de drogas e a ocorrência de FOF e anomalias relacionadas (p = 0,028) (OR = 2,87; IC95% = 1,1-7,4). DM e uso de drogas durante a gravidez aumentam o risco de FOF e anomalias relacionadas e o diagnóstico precoce de DM e a prevenção do uso de drogas, especialmente em mulheres grávidas, devem ser enfatizados.

  6. Doença de depósito lisossomal induzida pelo consumo de Ipomoea verbascoidea (Convolvulaceae) em caprinos no semiárido de Pernambuco

    USDA-ARS?s Scientific Manuscript database

    The aim of this paper was to reproduce the poisoning of Ipomoea verbascoidea in goats and describe the epidemiological, clinical and pathological aspects of spontaneous poisoning by this plant in Pernambuco. For this, we studied the epidemiology of the disease in seven mu¬nicipalities in the semiari...

  7. Dissecção aórtica de tipo B de Stanford: relato de caso e revisão de literatura

    PubMed Central

    Michaelis, Wilson; Santos, Antônio Lacerda; Yokohama, Rogério Akira; Andretta, Marianne Ariely; Delazari, Mariana Vieira; Vieira, Luciano; Seguro, Erick Fernando; Sarquis, Lucas Mansano

    2017-01-01

    Resumo O complexo tratamento de dissecção da aorta ainda apresenta controvérsias devido à gravidade do caso e à necessidade de individualização da terapêutica. A gravidade relaciona-se ao difícil diagnóstico pelas queixas inespecíficas e pelas graves complicações inerentes à evolução da doença (ruptura aórtica, síndrome de má perfusão, dissecção retrógrada, dor ou hipertensão refratária). Este relato apresenta um homem de 61 anos, tabagista e hipertenso mal controlado, que evoluiu para dissecção aórtica de tipo B de Stanford. Foi abordado através de técnica endovascular com uso de endoprótese com stent para tratamento do caso após falha do tratamento medicamentoso. O tratamento endovascular mostrou-se uma ferramenta eficaz para o tratamento definitivo, com boa taxa de sobrevida ao final do primeiro ano após o procedimento.

  8. Basic Concepts of Astronomy: a Methodological Proposal. (Spanish Title: Conceptos Básicos de Astronomía: Una Propuesta Metodológica.) Conceitos Básicos de Astronomia: Uma Proposta Metodológica

    NASA Astrophysics Data System (ADS)

    Darroz, Luiz Marcelo; Heineck, Renato; Samudio Pérez, Carlos Ariel

    2011-12-01

    In this report, the development of a methodological proposal which approaches basic concepts of astronomy-grounded pedagogically on Meaningful Learning is described. The proposal, which consists of four meetings, was developed by teachers and academics of the course of Professor in Physics of the University of Passo Fundo (UPF), through an extension course to a group of highschool students of a public school of the town of Passo Fundo, RS. The work was focused into basic concepts of astronomy. The signs of Meaningful Learning have been obtained by means of research and evaluation tools that were applied at the end of each meeting. The evaluation of the proposal has been conducted by means of a final questionnaire which was answered by the participants at the end ofthe development of activities. By means of the results obtained from the different instruments, and the comments made by the participants during the activities and by means of the high rates of approval obtained in the final questionnaire, we think that the proposal reached the established goals and it may be repeated with the certainty of success. En este relato se describe una propuesta de desarrollo metodológico que aborda conceptos básicos de astronomía fundamentada pedagógicamente en el Aprendizaje Significativo. La propuesta que comprende cuatro encuentros, fue desarrollada por profesores y académicos del curso de Licenciatura en Física de la Universidad de Passo Fundo (UPF), a través de un curso de extensión para un grupo de Liceo del 6º año de una Escuela Pública de la ciudad de Passo Fundo/RS. El trabajo tuvo como eje principal los "conceptos básicos de astronomía". Los indicios de Aprendizaje Significativo fueron obtenidos por instrumentos de pesquisa y evaluación, siempre aplicados después de cada encuentro. La evaluación de la propuesta fue hecha a través de un cuestionario final y contestado por los participantes al finalizar el desarrollo de actividades. Por los resultados obtenidos en diferentes momentos, por los comentarios efectuados por los participantes durante las actividades y por los altos índices de aprobación al final de la etapa, consideramos que la propuesta atingió los objetivos establecidos y puede ser repetida con certeza de éxito. Neste relato, descreve-se o desenvolvimento de uma proposta metodológica que aborda conceitos básicos de astronomia fundamentada pedagogicamente na Aprendizagem Significativa. A proposta, que compreende quatro encontros, foi desenvolvida por professores e acadêmicos do curso de Licenciatura em Física da Universidade de Passo Fundo (UPF), através de um curso de extensão, a um grupo de dez estudantes do ensino médio de uma escola pública da cidade de Passo Fundo, RS. O trabalho centrou-se em conceitos básicos de astronomia. Os indícios da aprendizagem significativa foram obtidos por instrumentos de pesquisa e avaliação aplicados ao término de cada encontro. A avaliação da proposta foi efetuada através de um questionário final respondido pelos participantes ao término do desenvolvimento das atividades. Pelos resultados obtidos nos diferentes instrumentos, pelos comentários efetuados pelos participantes durante as atividades e pelos altos índices de aprovação alcançados no questionário final, consideramos que a proposta atingiu os objetivos estabelecidos e pode ser repetida com convicção de sucesso.

  9. The development of communication skills and the teacher's performance in the nursing student's perspective.

    PubMed

    Oliveira, Karime Rodrigues Emilio de; Braga, Eliana Mara

    2016-06-01

    To understand experiences in the development of communication skills and the teacher's role in this teaching-learning process under the perspective of undergraduate nursing students by considering two types of curriculum organization. Descriptive study with a qualitative approach conducted in two public schools located in São Paulo state, Brazil. Data were collected by means of self-completed forms from 81 students in the second and fourth years of the undergraduate program. Results were analyzed in light of Content Analysis. Results showed that the development of such skills is related to: students' individual characteristics, patients' characteristics, those of the health-disease process, the health-care team's profile and the theoretical knowledge acquired on communication in health-care provision and nursing. The teacher's role was perceived as one that supports and encourages interactions with patients and health-care teams by teaching and providing orientation about interpersonal communication. Students identify and value the importance of their teachers' performance in the development and acquisition of communication skills. Additionally, students who experience active teaching-learning methodologies acknowledge the teacher as essential to provide opportunities for students to express their knowledge and thoughts. Compreender, sob a ótica de graduandos de enfermagem, as experiências no desenvolvimento de habilidades comunicativas e a atuação do professor neste processo de ensino-aprendizagem, considerando dois tipos de organização curricular. Pesquisa descritiva com abordagem qualitativa, realizada em duas instituições de ensino públicas, situadas no interior do estado de São Paulo, Brasil. A coleta dos dados foi realizada pelo autopreenchimento de formulário por 81 alunos de segundo e quartos anos da graduação. Os resultados foram analisados à luz da Análise de Conteúdo. Revelaram que o desenvolvimento desta habilidade está relacionado à: características individuais dos alunos, dos pacientes, do processo saúde-doença, perfil da equipe e dos conhecimentos teóricos sobre comunicação em saúde e em enfermagem. O papel do professor foi percebido apoiando e incentivando as interações com pacientes e equipes de saúde e ensinando e orientando sobre comunicação interpessoal. Os alunos identificam e valorizam a importância da atuação de seus professores no desenvolvimento e aquisição de habilidades comunicativas. Além disso, os estudantes que vivenciaram as metodologias ativas de ensino-aprendizagem reconhecem o docente essencial para oportunizar a expressão de conhecimentos e pensamentos dos alunos.

  10. Biofunctionality and immunocompatibility of starch-based biomaterials

    NASA Astrophysics Data System (ADS)

    Marques, Alexandra Margarida Pinto

    A procura de novos biomateriais que desempenhem funcoes especificas sem, no entanto, desencadearem respostas negativas nos hospedeiros constitui um desafio permanente e actual nesta area. Biomateriais degradaveis foram uma das solucoes propostas e actualmente em aplicacao mas, embora possuam vantagens inegaveis, tambem apresentam alguns problemas nomeadamente no que diz respeito aos seus produtos de degradacao e respectivos efeitos negativos consequentes. Outros biomateriais, entre os quais polimeros de origem natural, foram propostos considerando que os seus produtos de degradacao poderao ser incorporados nas vias metabolicas normais evitando efeitos secundarios no hospedeiro. Ate ao momento, e apesar de todos os esforcos e do grande numero de dispositivos biomedicos desenvolvidos, o biomaterial ideal para uma aplicacao especifica ainda nao foi encontrado. Estudos com polimeros biodegradaveis a base de amido demonstraram que estes materiais possuem propriedades promissoras abrindo novas perspectivas para a sua possivel aplicacao numa variedade de aplicacoes biomedicas. Assim, de modo a demonstrar que estes materiais tem de facto potencial para serem utilizados em, por exemplo, substituicao ossea, sistemas de libertacao controlada, cimentos osseos e engenharia de tecidos, seria imperativo avaliar com maior profundidade a resposta biologica desencadeada pelos mesmos. Para tal foi delineado um plano de trabalhos com tres objectivos principais: i) avaliar a citocompatibilidade dos polimeros e compositos a base de amido com monitorizacao da citotoxicidade e analise da adesao e proliferacao celulares nas suas superficies. Foi dada particular atencao a osteoblastos considerando uma possivel aplicacao ortopedica para estes materiais; ii) estabelecer modelos in vitro para analisar e prever, tanto quanto possivel, uma situacao real de resposta inflamatoria; iii) validar os resultados in vitro com um modelo in vivo ja estabelecido em outros trabalhos de analise da resposta inflamatoria a biomateriais. Em resumo, os estudos de citocompatibilidade e imunocompatibilidade demonstraram que os polimeros e compositos a base de milho sao biomateriais promissores. Em comparacao com os biomateriais degradaveis actualmente em uso, possuem propriedades capazes de induzir um comportamento semelhante, ou mesmo melhor, em termos de citotoxicidade. Estes dados foram reconfirmados com a adesao e proliferacao de celulas do tipo osteoblastos na superficie de alguns dos materiais a base de amido, que demonstraram ser comparaveis as observadas no PLLA, evidenciando a possibilidade de usar esses materiais em aplicacoes ortopedicas. As conclusoes retiradas dos estudos in vitro e in vivo de imunocompatibilidade reforcam as observacoes das experiencias de citocompatibilidade e em conjunto, evidenciam a possibilidade de utilizacao dos biomateriais a base de amido, com fraca capacidade de desencadear uma reaccao inflamatoria, em aplicacoes biomedicas. (Abstract shortened by ProQuest.).

  11. Observação do abrilhantamento de limbo solar e de estruturas filamentares em 48 ghz utilizando a técnica de regularização adaptativa

    NASA Astrophysics Data System (ADS)

    Machado, W. R. S.; Mascarenhas, N.; Costa, J. E. R.; Silva, A. V. R.

    2003-08-01

    O radiotelescópio do Itapetinga tem sido utilizado em campanhas de observações de explosões solares gerando um grande número de mapas diários em 48 GHz como sub-produto destas observações. A resolução espacial do telescópio de 14m do Itapetinga nesta freqüência é de aproximadamente dois minutos de arco. Estruturas de interesse para análise da atmosfera solar quiescente tais como os filamentos e o anel de abrilhantamento do limbo são de dimensão angular moderada da ordem ou ligeiramente menores que a resolução do telescópio. É conhecido que a convolução da função de espalhamento do telescópio, PSF (padrão de ganho do feixe) borra as estruturas de dimensão angular abaixo do HPBW (largura a meia potência do feixe) e portanto é comum a busca por técnicas de restauração que eliminem pelo menos em parte este borramento. Estudamos a restauração destas radioimagens usando a técnica de regularização adaptativa e os resultados ressaltam estas estruturas espaciais de pequeno contraste. O algoritmo da regularização adaptativa faz uso de k imagens, chamadas protótipos, obtidas através da variação de parâmetros de um filtro de regularização. Para controle da qualidade da restauração utilizamos uma imagem de alta resolução espacial obtida na linha H-a e a PSF do Itapetinga para borrá-la. Pequenos desvios, entre a PSF utilizada para o borramento e a PSF utilizada na restauração, produziram alguns desvios notáveis na imagem restaurada porém a adição de ruído nas simulações de restauração foram mais influentes no cálculo da rugosidade da imagem e portanto mais limitante para a restauração. Apresentamos como nosso primeiro resultado uma imagem em 48 GHz com a presença clara do abrilhantamento de limbo que não estava evidente na imagem original e traços de estruturas filamentares, porém ainda sem grande evidência.

  12. Analysis of Service-learning activities adopted in health courses of Federal University of Bahia.

    PubMed

    Baldoino, Aline Silva; Veras, Renata Meira

    2016-06-01

    is study aimed to raise and discuss the data about the integration of health courses teaching and service activities o ered at the Federal University of Bahia (UFBA), pre- senting scenarios practices and major di culties existing in the relationship between the university and the services of health. is was a qualitative study of descriptive explo- ratory character, using a questionnaire as a research tool applied to the coordinators of selected health courses. e selection was by reading the political pedagogical project, the following courses were selected: nursing, physical therapy, speech therapy, medicine, nu- trition, dentistry and public health. e results indicated eight types of teaching-service integration activities, 57 scenarios of practice and the main di culties. It was concluded that these courses are sticking to changes in academic training in health, in view of the large number of basic health units in the teaching service process. us, it emphasizes that the UFBA includes activities in health care that enable the integration-education in the higher education process, although there are some di culties in this relationship indicated by the coordinators. Esse estudo teve como objetivo levantar e discutir os dados acerca das atividades de integração ensino-serviço de cursos de saúde oferecidos na Universidade Federal da Bahia (UFBA), apresentando os cenários de práticas e as principais di culdades existentes na relação entre a uni- versidadeeosserviçosdesaúde.Tratou-sedeumapesquisaqualitativa,decaráterdescritivoexploratório,utilizando-seumquestionáriocomo instrumento de investigação aplicado aos coordenadores dos cursos de saúde selecionados. A seleção foi mediante a leitura do projeto político pedagógico, sendo selecionados os seguintes cursos: enfermagem, sioterapia, fonoaudiologia, medicina, nutrição, odontologia e saúde coletiva. Os resultados indicaram 8 tipos de atividades de integração ensino-serviço, 57 cenários de prática e as principais di culdades. Concluiu-se que esses cursos estão aderindo às mudanças na formação acadêmica em saúde, tendo em vista o grande número de unidades básicas de saúde que integram o processo de ensino serviço. Dessa forma, ressalta-se que a UFBA contempla atividades na área de saúde que viabilizam a integração-ensino no processo de formação superior, embora existam algumas di culdades nesta relação apontadas pelos coordenadores.

  13. [In Process Citation].

    PubMed

    Cuerda, Cristina; Álvarez, Julia; Ramos, Primitivo; Abánades, Juan Carlos; García-de-Lorenzo, Abelardo; Gil, Pedro; De-la-Cruz, Juan José

    2016-03-25

    Introducción: la desnutrición relacionada con la enfermedad (DRE) es un problema sociosanitario frecuente que afecta preferentemente a los mayores de 65 años, que aumenta la morbimortalidad y disminuye la calidad de vida.  Objetivo: estudiar la prevalencia de DRE en mayores de 65 años en diferentes centros sociosanitarios del Servicio Regional de Bienestar Social de la Comunidad de Madrid. Métodos: estudio transversal en 33 centros sociosanitarios de Madrid (6 centros de atención primaria [AP], 9 centros de mayores [CM], 9 hospitales [H] y 9 residencias [R]) seleccionados mediante muestreo polietápico. Las variables estudiadas fueron edad, sexo, nivel de dependencia según la escala de incapacidad de la Cruz Roja, motivo de ingreso y enfermedad de base, hábitat (urbano-periurbano-rural) y distribución geográfica (norte centro-sur). Como herramienta de cribado nutricional se utilizó el Mini Nutritional Assessment (MNA-cribaje) en todos los centros. En los pacientes con cribado positivo (en riesgo-desnutrición) se realizó el MNA-evaluación. El estudio estadístico se realizó con el paquete SSS 21.0 e incluyó estadística descriptiva, test de Chi-cuadrado y prueba exacta de Fisher, ANOVA de un factor, Kruskal-Wallis y análisis de regresión logística (RL) binaria univariante y multivariante. Se consideró significación estadística p < 0,05. Resultados: se reclutaron 1.103 sujetos (275 AP, 278 CM, 281 H, 269 R), edad media de 79,5 ± 8,4 años (41,2% varones, 58,8% mujeres). Los sujetos procedentes de H y R tuvieron un mayor grado de incapacidad (p < 0,001). La prevalencia global de DRE fue del 10%, encontrándose un 23,3% en riesgo de desnutrición, con diferencias entre los cuatro tipos de centros sociosanitarios (p < 0,001). El análisis univariante de RL mostró diferencia significativas en la prevalencia de desnutrición según la edad, sexo, grado de dependencia, tipo de centro sociosanitario, hábitat y zona geográfica. Sin embargo, en el análisis multivariante solo el grado de dependencia, el tipo de centro y el hábitat tuvieron significación estadística. Conclusiones: la prevalencia de DRE en mayores de 65 años en la Comunidad de Madrid es del 10%, encontrándose además un 23,3% en riesgo de desnutrición. Las únicas variables que se relacionaron de forma independiente con la desnutrición en el análisis multivariante fueron el nivel de dependencia de los pacientes y el tipo y hábitat de centro sociosanitario.

  14. PubMed

    Benítez Brito, Néstor; Oliva García, José Gregorio; Delgado Brito, Irina; Pereyra-García Castro, Francisca; Suárez Llanos, José Pablo; Leyva González, Francisco Gustavo; Palacio Abizanda, José Enrique

    2016-11-29

    Introducción: la alimentación constituye el pilar fundamental del soporte nutricional de los pacientes hospitalizados. Evaluar el grado de aceptación de la dieta es imprescindible en aras de combatir la desnutrición hospitalaria.Objetivos: a) determinar el grado de satisfacción de los pacientes en relación con las dietas; y b) analizar posibles variables asociadas a un grado de satisfacción mayor (apetito y tipo de dieta).Material y métodos: estudio descriptivo de corte transversal. Se emplea una encuesta de 17 preguntas con datos sociodemográficos, datos cualitativos, así como la valoración general del paciente. Se comparó el grado de satisfacción global en función del apetito y el tipo de dieta (terapéutica vs.basal; con sal vs.sosa) (Test no paramétric o Krustal-Wallis y T-Student para muestras independientes, respectivamente).Resultados: mil cuatrocientos trece pacientes. Edad: 53,9 ± 19 años; 51,3% mujeres. Dieta terapéutica (34,9%). Solo el 39,4% tomó dieta con sal. El 66,8% refirió ingresos previos. La alimentación del hospital para un 43% de pacientes fue ''como esperaba'', mientras que para un 44,1% fue ''mejor de lo que esperaba''. El horario de comidas era adecuado (89,1%) y el tiempo para comer, suficiente (96,4%). En cuanto a las características de la comida servida, consideraron como buenas o muy buenas la misma el porcentaje reflejado: sabor/gusto (56.3%), olor (65,5%), cocinado (69,2%), presentación (80,4%), tamaño de ración (75,9%), calidad (73%), cantidad (77,9%), variedad (67,6%), temperatura (70,4%). La valoración global de la alimentación en una escala de 1 a 10 fue de 6,8 ± 2,3. El apetito se asoció a un aumento significativo de la satisfacción global alimentaria del paciente (p < 0,01). El tipo de dieta o la presencia de sal en la misma no se asociaron a un aumento significativo de la satisfacción con la dieta de los pacientes (p = 0,99 y 0,35, respectivamente).Conclusiones: aunque el grado de satisfacción de la dieta de nuestro hospital es aceptable, es preciso introducir mejoras que aumenten su aceptación. El apetito se asocia a un aumento significativo de la satisfacción global alimentaria. La presencia de sal y el tipo de dieta (basal versusterapéutica) no se relacionan con una mejoría significativa de la valoración global de la dieta.

  15. Resultados do desenvolvimento de um propulsor à plasma no Brasil

    NASA Astrophysics Data System (ADS)

    Ferreira, I. S.; Ferreira, J. L.

    2003-08-01

    Uma das partes mais importantes de um satélite é o controle de atitude do mesmo. E se tratando de um satélite científico, a atenção para este sistema deve ser redobrada. Uma possibilidade atraente para executar esta tarefa é a propulsão elétrica. Aqui, mostraremos resultados obtidos pelo propulsor à plasma PHALL-01, desenvolvido na Universidade de Brasília entre 2000 e 2003. Este é derivado do propulsor russo SPT-100 (Stationary Plasma Thruster), mas com o emprego inovador de um arranjo de imãs permanentes como fonte do campo magnético, este último o agente da aceleração do plasma. Esta alteração foi motivada pelo objetivo de que o mesmo operasse com o mínimo de potência elétrica. A partir da formulação teórica do mecanismo de aceleração, tendo como base as equações da magnetohidrodinâmica, pode-se obter vínculos sob os quais o propulsor pudesse ser construído. O mais forte destes é o que dita a topologia do campo magnético. Sendo assim, foram realizadas simulações computacionais, que definiram a geometria do propulsor. Após construído, este foi diagnosticado usando-se sondas de Langmuir e analisadores de energia. Como resultados, obtivemos a distribuição espacial da temperatura, densidade e potencial do plasma, bem como a distribuição angular do feixe produzido pelo mesmo em vários regimes de operação. O espectro de energia do feixe de plasma também foi medido, indicando íons de até 560eV. Combinando estes resultados, calculou-se o empuxo do propulsor: 84mN; e o impulso específico: 1083s. Estes demonstram que o mesmo estará qualificado, num futuro próximo, para o emprego no controle de atitude de satélites científicos, ou até mesmo como parte do conjunto propulsor primário, responsáveis pela transferência de órbitas.

  16. 75 FR 28551 - Certain Oil Country Tubular Goods From the People's Republic of China: Amended Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ... Zhongyou Tipo 32.07 Tubing Co., Ltd. Pipe & Tubing Co., Ltd. Baotou Steel International Seamless Tube Mill... Group New Century Machinery Co. Ltd.; Tianjin Seamless Steel Pipe Plant; Baoshan Iron & Steel Co. Ltd... Group Co., Ltd. Gallant Group Limited. Tianjin Seamless Steel Pipe Tianjin Seamless Steel 32.07 Plant...

  17. VizieR Online Data Catalog: M30 V1-V3 variable light curves (Rosino, 1949)

    NASA Astrophysics Data System (ADS)

    Rosino, L.

    2013-05-01

    Time-series photographic photometry for the variable stars V1-V3 in M30. We add the light curve of V1 from Rosini, 1961, Contr. Asiago-Padova, 117, "Osservazioni di due variabili peculiari e d'una variabile tipo RR Lyrae in ammassi stellari" (4 data files).

  18. Low Altitude Navigation Augmentation System.

    DTIC Science & Technology

    1981-12-01

    mtiem) 11maMM crew soer can use a SLA as the priwzy navigation sensor mdoaeteN imMIgM with the M.C generate d view (loodcing to the i il. the Pilot...t# ths s~hwtW include tim. locations &An an indication of -the tipo of messurmott 401oyed (*.I. sta’-trecker, lanmrk, bearing mssrment etc.).- TMe

  19. Continuous Dependence on Modeling in the Cauchy Problem for Nonlinear Elliptic Equations.

    DTIC Science & Technology

    1987-04-01

    problema di Cauchy per le equazione di tipo ellitico, Ann. Mat. Pura Appl., 46 (1958), pp. 131-153 [18] P. W. Schaefer, On the Cauchy problem for an...Continued) PP 438 PP 448 Fletcher, Jean W. Supply Problems in the Naval Reserve, Cymrot, Donald J., Military Retiremnt and Social Security: A 14 pp

  20. Transfer of the Subgenus Davismyia from Wyeomyia to Sabethes and Description of the Type Species, Miamyia Petrocchiae (Diptera: Culicidae)

    DTIC Science & Technology

    1990-12-01

    Ponte 1928) gave the following information about these specimens but did not indicate where they were deposited: “Localidad del tipo : Tucuman (Race...Balderama and R. Vargas. 1984. Associations of arbovirus vectors with gallery forests and domestic environments in south- eastern Bolivia. PAHO Bull . 18

  1. Zenith-100 Microcomputer Network for Air Command and Staff College.

    DTIC Science & Technology

    1987-04-01

    34 AD-A182 495 ZENI T-ipo ml CROCOMFUT E NET WOR( FOR AIR COMAND AND h SAFF CoLLG (U) AIl COMMAND ANDCSTAFF COLL MAX(WELL AFS "CAL W L GALWAY El AL...processing of documents by eliminating the time required to physically move the documents from one office to the next. Reproduction Savings. Information

  2. Aeroelastic Considerations for Torsionally Soft Rotors,

    DTIC Science & Technology

    1986-08-01

    Data potentiometers mounted on the rotor hub and Acquisition geared to the blade cuff. Rotor shaft speed is determined by a magnetic sensor . One...Anhedral Tipo I I* 9.2 ACR2 0 ACM1F LHNGIIUDINNL NOSE-OOWN ELASTICCYCLIC TWIS 0fC. ~J~M PITCH SLa ELASTIC .4 ICIIIDAt AT At# qV. AT , C I 0. 4 a, PIC

  3. Polarización lineal en estrellas simbióticas

    NASA Astrophysics Data System (ADS)

    Brandi, E.; García, L. G.; Ferrer, O. E.

    Se presenta un estudio de polarización lineal en las bandas UBVRI de un grupo de estrellas simbióticas, a fin de analizar el comportamiento del grado de polarización y del ángulo de posición en función de la longitud de onda. En aquellos sistemas observados repetidas veces, se analizan además variaciones temporales en los parámetros de polarización. En base a este comportamiento se determina si la polarización observada es puramente interestelar o si existe una contribución de polarización, intrínseca al objeto. La muestra de objetos estudiados presenta ciertas características comunes, es decir, son sistemas simbióticos tipo D, cuyas respectivas componentes gigantes son variables tipo Mira y además presentan nebulosas ionizadas extendidas con morfología y dimensiones conocidas. Esto es de importancia ya que el conocimiento de la estructura del gas extendido permite interpretar la geometría de scattering que produce la polarización observada. Las observaciones fueron realizadas con el Fotopolarímetro de Torino adosado al telescopio de 2.15 m del CASLEO.

  4. Cinética Química: el laboratorio

    NASA Astrophysics Data System (ADS)

    Cabañas Galán, B.

    La interpretación de las transformaciones químicas que se producen en la atmósfera requiere un profundo conocimiento de la cinética, productos y mecanismos de reacción de las posibles interacciones que pueden ocurrir entre las distintas especies presentes en ella. Información cuantitativa de este tipo es un prerrequisito para la construcción de modelos numéricos adecuados que expliquen el comportamiento químico-físico de la atmósfera. Esta información se obtiene a partir de experimentos realizados en laboratorios y por tanto independiente de medidas atmosféricas, por lo que los modelos atmosféricos derivados de ellos, pueden usarse para diagnosticar y predecir adecuadamente el comportamiento atmosférico. En esta exposición se recogen las técnicas experimentales más extendidas para la obtención de datos cinéticos así como los métodos de análisis de datos más utilizados en el estudio de las distintas reacciones de interés atmosférico. Se analizan sus características generales así como su adecuación a los distintos tipos de reacciones.

  5. Risk factors for unstable blood glucose level: integrative review of the risk factors related to the nursing diagnosis.

    PubMed

    Teixeira, Andressa Magalhães; Tsukamoto, Rosangela; Lopes, Camila Takáo; Silva, Rita de Cassia Gengo E

    2017-06-05

    to identify evidence in the literature on the possible risk factors for the risk of unstable blood glucose diagnosis in individuals with type 2 diabetes mellitus, and to compare them with the risk factors described by NANDA International. an integrative literature review guided by the question: what are the risk factors for unstable blood glucose level in people with type 2 diabetes mellitus? Primary studies were included whose outcomes were variations in glycemic levels, published in English, Portuguese or Spanish, in PubMed or CINAHL between 2010 and 2015. altered levels of glycated hemoglobin, body mass index>31 kg/m2, previous history of hypoglycemia, cognitive deficit/dementia, autonomic cardiovascular neuropathy, comorbidities and weight loss corresponded to risk factors described in NANDA International. Other risk factors identified were: advanced age, black skin color, longer length of diabetes diagnosis, daytime sleepiness, macroalbuminuria, genetic polymorphisms, insulin therapy, use of oral antidiabetics, and use of metoclopramide, inadequate physical activity and low fasting glycemia. risk factors for the diagnosis, risk for unstable blood glucose level, for persons with type 2 diabetes mellitus were identified, and 42% of them corresponded to those of NANDA International. These findings may contribute to the practice of clinical nurses in preventing the deleterious effects of glycemic variation. identificar evidências na literatura acerca de possíveis fatores de risco do diagnóstico risco de glicemia instável para pessoas com diabetes mellitus tipo 2 e compará-los com os fatores de risco descritos pela NANDA International . revisão integrativa norteada pela pergunta: quais são os fatores de risco de glicemia instável em pessoas com diabetes mellitus tipo 2? Incluíram-se estudos primários cujos desfechos eram variações nos níveis glicêmicos, publicados em inglês, português ou espanhol no PubMed ou CINAHL entre 2010 e 2015. observou-se que alteração nos níveis de hemoglobina glicada, índice de massa corpórea>31 Kg/m2, história prévia de hipoglicemia, déficit cognitivo/demência, neuropatia autonômica cardiovascular, comorbidades e perda de peso correspondiam a fatores de risco descritos pela NANDA International . Outros fatores de risco identificados foram: idade avançada, raça negra, maior tempo de diagnóstico de diabetes, sonolência diurna, macroalbuminúria, polimorfismos genéticos, insulinoterapia, uso de antidiabéticos orais, uso de metoclopramida, atividade física inadequada e glicemia de jejum baixa. identificaram-se fatores de risco do diagnóstico risco de glicemia instável para pessoas com diabetes mellitus tipo 2, dos quais 42% correspondiam àqueles da NANDA International . Esses achados podem contribuir para a prática de enfermeiros clínicos na prevenção dos efeitos deletérios da variação glicêmica. identificar evidencias en la literatura acerca de posibles factores de riesgo del diagnóstico "riesgo de nivel de glucemia inestable" para personas con diabetes mellitus tipo 2 y compararlos con los factores de riesgo descritos por la NANDA International . revisión integradora orientada por la pregunta: ¿Cuáles son los factores de riesgo de nivel de glucemia inestable en personas con diabetes mellitus tipo 2? Se incluyeron estudios primarios cuyos resultados eran variaciones en los niveles glucémicos, publicados en inglés, portugués o español en el PubMed o CINAHL entre 2010 y 2015. se observó que una alteración en los niveles de: hemoglobina glucosilada, índice de masa corporal >31 Kg/m2, historia previa de hipoglucemia, déficit cognitivo/demencia, neuropatía autonómica cardiovascular, comorbilidades y pérdida de peso, correspondían a factores de riesgo descritos por la NANDA International . Otros factores de riesgo identificados fueron: edad avanzada, raza negra, mayor tiempo de diagnóstico de diabetes, somnolencia diurna, macroalbuminuria, polimorfismos genéticos, insulinoterapia, uso de antidiabéticos orales, uso de metoclopramida, actividad física inadecuada y glucemia de ayuno baja. se identificaron factores de riesgo del diagnóstico riesgo de nivel de glucemia inestable para personas con diabetes mellitus tipo 2, de los cuales 42% correspondían a los de la NANDA International . Esos hallazgos pueden contribuir para la práctica de enfermeros clínicos en la prevención de los efectos deletéreos de la variación glucémica.

  6. JOURNAL ANALYSIS ON OPHTHALMOLOGY AND OTHERS.

    PubMed

    Freitas, Denise de

    2015-01-01

    To update knowledge and methods to access and view the journals included in Qualis of CAPES Medicine III, and how to measure the impact factor. Document review on the attempt to verify the way Qualis uses for ranking journals cited by the post-graduate programs of Medicine III in their evaluation periods, and the impact factors obtained by journals indexing base. The classification is annual and are ranking in strata ranging from A1, the highest, and A2; B1; B2; B3; B4; B5; C. The latter has zero evaluation weight. These strata take as reference the impact factor of the journals listed by the programs. The same journal can be classified into different Qualis in other areas, and this is no inconsistency, but expressed the assigned value, in each area, at that particular journal. The Impact Factor is measured using the Journal of Citation Report in Web of Knowledge website. Using the criteria established by WebQualis for stratification of journals there is a quality guidance of what is produced by the program and, based on it, can be made scientific comparison of program performance. Consulting the JCR is recommended because it defines exactly what is the journal's impact factor; Qualis stratifies numerical intervals and not individual journal specificity. Atualização do conhecimento dos meios e métodos de acessar e visualizar os periódicos do Qualis da Medicina III da CAPES e a mensuração do Fator de Impacto. Buscou-se verificar a forma utilizada pelo Qualis para classificar os periódicos referidos pelos programas de pós-graduação da Medicina III em seus períodos de avaliação e os fatores de impacto obtidos pelas revistas em base indexadora. A classificação é anual e são enquadrados em estratos que variam de A1, o mais elevado, a A2; B1; B2; B3; B4; B5; C. Este último tem peso zero. Esses estratos levam como referência o Fator de Impacto dos periódicos referidos pelos programas. Um mesmo periódico pode ter classificação em Qualis diferentes em outras áreas, e isto não constitui inconsistência, mas expressa o valor atribuído, em cada área, àquela determinada revista científica. O Fator de Impacto é mensurado navegando-se no site do Journal of Citation Report da Web of Knowledge. A utilização dos critérios estabelecidos pelo WebQualis para estratificação dos periódicos é norteadora da qualidade do que se produz nos programas e, com base nela, pode-se fazer comparações de desempenho científico. Já a consulta ao JCR é complementarmente adequada de ser feita porque define com exatidão qual é o fator de impacto da revista, em função de que o Qualis estratifica faixas numéricas e não especificidade individual do periódico.

  7. Costs of Public Pharmaceutical Services in Rio de Janeiro Compared to Farmácia Popular Program.

    PubMed

    Silva, Rondineli Mendes da; Caetano, Rosângela

    2016-12-22

    To analyze the costs of public pharmaceutical services compared to Farmácia Popular Program (Popular Pharmacy Program). Comparison between prices paid by Aqui Tem Farmácia Popular Program (Farmácia Popular is available here) with the full costs of medicine provision by the Municipal Health Department of Rio de Janeiro. The comparison comprised 25 medicines supplied by both the municipal pharmaceutical service and Aqui Tem Farmácia Popular Program. Calculating the cost per pharmaceutical unit of each medicine included expenditure by Municipal Health Department of Rio de Janeiro with procurement (price), logistics, and local dispensation. The reference price of medicines paid by Aqui Tem Farmácia Popular was taken from the Brazilian Ministry of Health standard in force in 2012. Comparisons included full reference price; reference price minus 10.0% copayment by users; and maximum reference paid by the Ministry of Health (minus copayment and taxes). Simulations were carried out of the differences between the costs of Municipal Health Department of Rio de Janeiro with the common medicines and those potentially incurred based on the reference price of Aqui Tem Farmácia Popular. The Municipal Health Department of Rio de Janeiro spent R$28,526,526.57 with 25 medicines of the common list in 2012; 58.7% accounted for direct procurement costs. The estimated costs of the Health Department were generally lower than the reference prices of the Aqui Tem Farmácia Popular Program for 20 medicines, regardless of reference prices. The potential costs incurred by Health Department if expenditure of its consumption pattern were based on the reference prices of Aqui Tem Farmácia Popular would be R$124,170,777.76, considering the best scenario of payment by the Brazilian Ministry of Health (90.0% of the reference price, minus taxes). The difference in costs between public provision by Municipal Health Department of Rio de Janeiro and Farmácia Popular Program indicates that some reference prices could be reviewed aiming at their reduction. Analisar custos da assistência farmacêutica pública frente ao Programa Farmácia Popular. Comparação entre os valores pagos pelo Programa Aqui Tem Farmácia Popular com os custos integrais relativos à provisão de medicamentos pela Secretaria Municipal de Saúde do Rio de Janeiro. A comparação compreendeu 25 medicamentos, comuns tanto à provisão pela assistência farmacêutica pública municipal quanto pelo Programa Aqui Tem Farmácia Popular. O cálculo do custo unitário por unidade farmacotécnica de cada medicamento envolveu os gastos da Secretaria Municipal de Saúde com custos de aquisição (preço), logísticos e com a dispensação em nível local. O valor de referência dos medicamentos pago pelo Aqui Tem Farmácia Popular foi extraído da norma ministerial em vigor em 2012. As comparações envolveram o valor de referência pleno; valor de referência com desconto dos 10,0% pagos de contrapartida pelos usuários; e valor de referência máximo pago pelo Ministério da Saúde (descontados contrapartida e sem impostos).Foram realizadas simulações das diferenças entre os gastos da Secretaria Municipal de Saúde do Rio de Janeiro com os medicamentos do elenco comum e os que seriam incorridos se esses tivessem sido executados com base no valor de referência do Aqui Tem Farmácia Popular. A Secretaria Municipal de Saúde do Rio de Janeiro gastou R$28.526.526,57 com 25 medicamentos do rol comum em 2012; 58,7% corresponderam a custos diretos com a aquisição dos produtos. Os custos estimados da Secretaria Municipal de Saúde do Rio de Janeiro foram, em geral, menores que os valores de referência do Programa Aqui Tem Farmácia Popular em 20 medicamentos, independentemente dos valores de referência. Os custos que seriam incorridos pela Secretaria Municipal de Saúde do Rio de Janeiro, caso seu padrão de consumo tivesse como valor de pagamento os valores de referência do Aqui Tem Farmácia Popular seriam de R$124.170.777,76 considerando a melhor situação de pagamento pelo Ministério da Saúde (90,0% do valor de referência, com impostos descontados). A diferença de custos entre a provisão pública pela Secretaria Municipal de Saúde do Rio de Janeiro e o Programa Aqui Tem Farmácia Popular sinaliza que alguns valores de referência poderiam ser objetos de exame para sua redução.

  8. AGARD Highlights.

    DTIC Science & Technology

    1980-09-01

    Air Vehicles as Sensor Platforms" (see inset) and would seek to determine the operational capability of advanced high altitude air vehicles as...Unmanned Air Vehicles as Sensor Platforms Determine the operational capability of advanced high-altitude air vehicles as platforms for surveillance...m) IT ala (1) a freccia ES sensacion (r) artificial ES indicador (m) tipo A NE pillvleugel FR I sensation MI artificielle FR indicateur (m) type A

  9. Experimental and Theoretical Studies of Hydrogenated Amorphous Semiconductor Alloys and Superlattices

    DTIC Science & Technology

    1994-02-04

    case may be expected ’G. Mao, H. Fritzsche. K. Chen, and D. Feng, Bull . Am. Phys. Soc. 35, in very thin films of a-Si:H where the high defect density" 7...coupling and do is the touching distance 2b. The a - 5 nm for difftrent gnglv of orientation of the sphehids with respect to the v+ tipo (s. The

  10. Assessment of the usability of a digital learning technology prototype for monitoring intracranial pressure.

    PubMed

    Carvalho, Lilian Regina de; Évora, Yolanda Dora Martinez; Zem-Mascarenhas, Silvia Helena

    2016-08-29

    to assess the usability of a digital learning technology prototype as a new method for minimally invasive monitoring of intracranial pressure. descriptive study using a quantitative approach on assessing the usability of a prototype based on Nielsen's ten heuristics. Four experts in the area of Human-Computer interaction participated in the study. the evaluation delivered eight violated heuristics and 31 usability problems in the 32 screens of the prototype. the suggestions of the evaluators were critical for developing an intuitive, user-friendly interface and will be included in the final version of the digital learning technology. avaliar a usabilidade de um protótipo educacional digital sobre um novo método para monitoração da pressão intracraniana de forma minimamente invasivo para enfermeiros e médicos. estudo descritivo com abordagem quantitativa sobre a avaliação de usabilidade de um protótipo com base nas dez Heurísticas de Nielsen. Participaram quatro especialistas da área de Interação Humano Computador. a avaliação resultou em oito heurísticas violadas e 31 problemas de usabilidade nas 32 telas do protótipo. as sugestões dos avaliadores foram cruciais para o desenvolvimento de uma interface amigável e intuitiva e serão consideradas na versão final da tecnologia educacional digital. evaluar la usabilidad de un prototipo educacional digital sobre un nuevo método para monitorización de la presión intracraneal, de manera mínimamente invasiva. estudio descriptivo con abordaje cuantitativo sobre la evaluación de usabilidad de un prototipo con base en las diez reglas Heurísticas de Nielsen. Participaron cuatro especialistas del área de Interacción Humana Computador. la evaluación resultó en ocho reglas heurísticas violadas y 31 problemas de usabilidad en las 32 pantallas del prototipo. las sugestiones de los evaluadores fueron cruciales para el desarrollo de una interfaz amigable e intuitiva y éstas serán consideradas en la versión final de la tecnología educacional digital.

  11. Uso de modelos mecânicos em curso informal de astronomia para deficientes visuais. Resgate de uma experiência

    NASA Astrophysics Data System (ADS)

    Tavares, E. T., Jr.; Klafke, J. C.

    2003-08-01

    O presente trabalho propõe-se a resgatar uma experiência que teve lugar no Planetário de São Paulo nos anos 60. Em 1962, o Sr. Acácio, então com 37 anos, deficiente visual desde os 27, passou a assistir às aulas ministradas pelo Prof. Aristóteles Orsini aos integrantes do corpo de servidores do Planetário. O Sr. Acácio era o único deficiente da turma e, embora possuísse conhecimentos básicos e relativamente avançados de matemática, enfrentava dificuldades na compreensão e acompanhamento da exposição, como também em estudos posteriores. Com o intuito de auxiliá-lo na superação desses problemas, o Prof. Orsini solicitou a construção de modelos mecânicos que, através do sentido do tato, permitissem o acompanhamento das aulas e a transposição do modelo para o "constructo" mental. Essa prática mostrou-se tão eficaz que facilitou sobejamente o aprendizado da matéria pelo sujeito. O Sr. Acácio passou a integrar o corpo de professores do Planetário/Escola Municipal de Astrofísica, tendo ficado responsável pelo curso de "Introdução à Astronomia" por vários anos. Além disso, a experiência foi tão bem sucedida que alguns dos modelos tiveram seus elementos constitutivos pintados diferencialmente para serem utilizados em cursos regulares do Planetário, tornando-se parte integrante do conjunto de recursos didáticos da instituição. É pensando nessa eficácia, tanto em seu objetivo original permitir o aprendizado de um deficiente visual quanto no subsidiário recurso didático sistemático da instituição que decidimos resgatar essa experiência. Estribados nela, acreditamos ser extremamente produtivo, em termos educacionais, o aperfeiçoamento dos modelos originais, agora resgatados e restaurados, e a criação de outros que pudessem ser utilizados no ensino dessa ciência a deficientes visuais.

  12. Validation of educational booklet for HIV/Aids prevention in older adults.

    PubMed

    Cordeiro, Luana Ibiapina; Lopes, Thais de Oliveira; Lira, Luciane Elise de Abreu; Feitoza, Sarah Maria de Sousa; Bessa, Maria Eliana Peixoto; Pereira, Maria Lúcia Duarte; Feitoza, Aline Rodrigues; Souza, Adriano Rodrigues de

    2017-01-01

    To describe the process of manufacturing and validation of an educational booklet for HIV/Aids prevention in older adults. Methodological study developed in two phases - manufacturing of the booklet and validation of the educational material by judges. The manufacturing process involved a situational diagnosis with older adults, and its result indicated gaps in the knowledge with respect to HIV/Aids. The validation process was performed by nine judges, selected by convenience. It was considered an agreement index of at least 0.80, analyzed through the content validity index. We opted for a dialogue between two older adults divided into three categories: myths and taboos; ignorance; and prevention and importance of diagnosis. The average of the items was 0.90. The suggestions made by the judges were observed and modified for the final version. The material had relevant content for the judges, in addition to being able to be used by health professionals in the education and clarification of issues on the subject. Descrever o processo de construção e validação de cartilha educativa para prevenção de HIV/Aids em idosos. Estudo metodológico desenvolvido em duas etapas - construção da cartilha e validação do material educativo por juízes. O processo de construção envolveu um diagnóstico situacional com idosos, cujo resultado apontou lacunas no conhecimento com relação ao HIV/Aids. Já o processo de validação foi realizado por nove juízes, selecionados por conveniência. Considerou-se uma concordância de no mínimo 0,80, analisado pelo índice de validade de conteúdo. Optou-se por um diálogo entre dois idosos dividido em três categorias: mitos e tabus; desconhecimento; e prevenção e importância do diagnóstico. A média dos itens foi de 0,90. As sugestões realizadas pelos juízes foram acatadas e modificadas para a versão final. O material apresentou conteúdo relevante para os juízes, além de poder ser utilizado pelos profissionais de saúde no ensino e esclarecimento de questões sobre a temática.

  13. Geriatric care: ways and means of providing comfort.

    PubMed

    Ribeiro, Patricia Cruz Pontifice Sousa Valente; Marques, Rita Margarida Dourado; Ribeiro, Marta Pontifice

    2017-01-01

    To know the ways and means of comfort perceived by the older adults hospitalized in a medical service. Ethnographic study with a qualitative approach. We conducted semi-structured interviews with 22 older adults and participant observation of care situations. The ways and means of providing comfort are centered on strategies for promoting care mobilized by nurses and recognized by patients(clarifying/informing, positive interaction/communication, music therapy, touch, smile, unconditional presence, empathy/proximity relationship, integrating the older adult or the family as partner in the care, relief of discomfort through massage/mobilization/therapy) and on particular moments of comfort (the first contact, the moment of personal hygiene, and the visit of the family), which constitute the foundation of care/comfort. Geriatric care is built on the relationship that is established and complete with meaning, and is based on the meeting/interaction between the actors under the influence of the context in which they are inserted. The different ways and means of providing comfort aim to facilitate/increase care, relieve discomfort and/or invest in potential comfort. Conhecer os modos e formas de confortar percecionadas pelos idosos hospitalizados num serviço de medicina. Estudo etnográfico com abordagem qualitativa. Realizamos entrevistas semiestruturadas com 22 doentes idosos e observação participante nas situações de cuidados. Os modos e formas de confortar centram-se em estratégias promotoras de conforto mobilizadas pelo enfermeiro e reconhecidas pelos doentes (informação/esclarecimento, interação/comunicação positiva, toque, sorriso, presença incondicional, integração do idoso/família nos cuidados e o alívio de desconfortos através da massagem/mobilização/terapêutica) e em momentos particulares de conforto (contato inaugural, visita da família., cuidados de higiene e arranjo pessoal), que se constituem como alicerces do cuidar/cuidado confortador. O cuidado geriátrico edifica-se na relação que se desenvolve, atribuída de sentido, e assenta-se num encontro/interação entre os atores sob influência do contexto em que está inserido. Os diferentes modos e formas de confortar objetivam facilitar/aumentar o conforto, aliviar o desconforto e/ou investir no conforto potencial.

  14. Evaluation in health: participatory methodology and involvement of municipal managers.

    PubMed

    Almeida, Cristiane Andrea Locatelli de; Tanaka, Oswaldo Yoshimi

    2016-08-04

    To analyze scopes and limits of the use of participatory methodology of evaluation with municipal health managers and administrators. Qualitative research with health policymakers and managers of the Comissão Intergestores Regional (CIR - Regional Interagency Commission) of a health region of the state of Sao Paulo in Brazil. Representatives from seven member cities participated in seven workshops facilitated by the researchers, with the aim of assessing a specific problem of the care line, which would be used as a tracer of the system integrality. The analysis of the collected empirical material was based on the hermeneutic-dialectic methodology and aimed at the evaluation of the applied participatory methodology, according to its capacity of promoting a process of assessment capable to be used as a support for municipal management. With the participatory approach of evaluation, we were able to promote in-depth discussions with the group, especially related to the construction of integral care and to the inclusion of the user's perspective in decision-making, linked to the search for solution to concrete problems of managers. By joint exploration, the possibility of using data from electronic information systems was opened, as well as information coming directly from the users of the services, to enhance discussions and negotiations between partners. The participants were disbelievers of the replication potential of this type of evaluation without the direct monitoring of the academy, given the difficulty of organizing the process in everyday life, already taken by emergency and political issues. Evaluations of programs and services carried out within the Regional Interagency Commission, starting from the local interest and facilitating the involvement of its members by the use of participatory methodologies, can contribute to the construction of integral care. To the extent that the act of evaluating stay invested with greater significance to the local actors, its involvement with the evaluations at the federal level can also be stimulated. Analisar alcances e limites do uso de metodologia participativa de avaliação junto a gestores e gerentes municipais de saúde. Pesquisa qualitativa com gestores e gerentes de saúde da Comissão Intergestores Regional de uma região de saúde do estado de São Paulo. Representantes de sete municípios membros participaram de sete oficinas facilitadas pelos pesquisadores, com o objetivo de avaliar um problema específico da linha de cuidados sob a perspectiva da integralidade. A análise do material empírico coletado baseou-se na metodologia hermenêutica-dialética e visou a avaliação da metodologia participativa aplicada, segundo sua capacidade de promover um processo de avaliação passível de ser utilizado como suporte à gestão municipal. Com a abordagem participativa de avaliação, foi possível promover debates em profundidade com o grupo, principalmente relacionados à construção da integralidade da atenção e à inclusão da perspectiva do usuário na tomada de decisão, de forma vinculada à busca de solução para problemas concretos dos gestores. Mediante a exploração conjunta, foi aberta a possibilidade de utilização de dados advindos dos sistemas eletrônicos de informação, bem como de informações advindas diretamente dos usuários dos serviços, para enriquecer debates e negociações entre parceiros. Os participantes se mostraram descrentes do potencial de replicação deste tipo de avaliação sem o acompanhamento direto da academia, dada a dificuldade de organização do processo no cotidiano, já tomado por questões emergenciais e políticas. Avaliações de programas e serviços realizadas no âmbito da Comissão Intergestores Regional, partindo do interesse local e facilitando o envolvimento de seus membros pelo uso de metodologias participativas, podem contribuir para a construção da integralidade do cuidado. Na medida em que o ato de avaliar fique investido de maior significado para os atores locais, seu envolvimento com as avaliações em nível federal poderá ser também estimulado.

  15. Air Distribution in Protective Shelters

    DTIC Science & Technology

    1993-11-01

    TIPO sensor which is used for hand-held gas monitoring. (TIP* is a Trademark of Photovac, Inc., of Thornhill, Ontario, Canada.) The TIP-SJ2 was...to develop it in-house. Fast-response concentration sensors have significant applications for chamber and outdoor field testing as well as for...the HRF400 High-Speed Hydrocarbon Analyzer (Cambustion, Ltd., Cambridge, England). Figure 2 shows a tripod-mounted HRF400 sensor . The advantages of the

  16. Intimate partner violence reported by female and male users of healthcare units.

    PubMed

    Barros, Claudia Renata Dos Santos; Schraiber, Lilia Blima

    2017-02-16

    To analyze nonfatal violence suffered and committed by adult men and women, in an intimate relationship. The participants in the research were women aged between 15 and 49 years and men between 18 and 60 years, interviewed by face-to-face questionnaire application. The sample selection was of consecutive type, according to the order of arrival of the users. We conducted temporarily independent investigations and covered different health services to avoid couples and relationships in which the retaliation could be overvalued. To improve the comparison, we also examined reports of men and women from the same service, i.e., a service that was common to both investigations. We compared the situations suffered by women according to their reports and cross-linked the information to what men, according to their own reports, do against intimate partners or ex-partners. We also examined the cross-linked situation in reverse: the violence committed by women against their partners, according to their reports, in comparison with the violence suffered by men, also according to their reports, even if, in this case, the exam refers only to physical violence. The variables were described using mean, standard deviation, frequencies and proportions, and the hypothesis testing used was: Fisher's exact and Pearson's Chi-square tests, adopting a significance level of 5%. Victimization was greater among women, regardless of the type of violence, when perpetrated by intimate partner. The perception of violence was low in both genders; however, women reported more episodes of multiple recurrences of any violence and sexual abuse suffered than men acknowledged to have perpetrated. The study in its entirety shows significant gender differences, whether about the prevalence of violence, whether about the perception of these situations. Analisar as violências não fatais sofridas e praticadas por homens e mulheres adultos, em situação de parceria íntima. Os sujeitos da pesquisa foram mulheres entre 15 a 49 anos e homens entre 18 a 60 anos, entrevistados por aplicação de questionário face a face. A seleção amostral foi do tipo consecutivo, captando-se os participantes por ordem de chegada ao serviço. Foram conduzidos como investigações temporalmente independentes e abrangendo diferentes serviços, para evitar o estudo em casais, nos quais o revide poderia estar supervalorizado. Para adensar um pouco mais a comparação, também examinamos relatos de homens e mulheres pertencentes a um mesmo serviço, ou seja, um serviço que foi participante comum às duas investigações. Comparamos as situações sofridas pelas mulheres segundo seus relatos e, de modo entrecruzado, as situações que os homens, segundo seus relatos, praticam contra as mulheres, suas parceiras íntimas ou ex-parceiras. Também examinamos a situação entrecruzada reversa: a violência praticada pelas mulheres contra seus parceiros, segundo seus próprios relatos, comparativamente à violência sofrida pelos homens, segundo seus relatos, ainda que, neste caso, o exame se refere apenas à violência física. As variáveis foram descritas por meio de média, desvio padrão, frequências e proporções e os testes de hipóteses utilizados foram: Exato de Fisher e Qui-quadrado de Pearson, adotando-se nível de significância de 5%. A vitimização foi maior entre as mulheres, independentemente do tipo de violência, quando perpetrada por parceiro íntimo. A percepção da violência foi baixa em ambos os sexos; entretanto, mulheres relataram mais episódios de múltiplas recorrências de quaisquer violências e de violência sexual sofrida do que os homens reconheceram que perpetraram. O estudo em seu todo mostra importantes diferenças de gênero, quer quanto às prevalências das violências, quer quanto à percepção dessas situações.

  17. Nursing interventions for rehabilitation in Parkinson's disease: cross mapping of terms.

    PubMed

    Tosin, Michelle Hyczy de Siqueira; Campos, Débora Moraes; Andrade, Leonardo Tadeu de; Oliveira, Beatriz Guitton Renaud Baptista de; Santana, Rosimere Ferreira

    2016-08-08

    to perform a cross-term mapping of nursing language in the patient record with the Nursing Interventions Classification system, in rehabilitation patients with Parkinson's disease. a documentary research study to perform cross mapping. A probabilistic, simple random sample composed of 67 records of patients with Parkinson's disease who participated in a rehabilitation program, between March of 2009 and April of 2013. The research was conducted in three stages, in which the nursing terms were mapped to natural language and crossed with the Nursing Interventions Classification. a total of 1,077 standard interventions that, after crossing with the taxonomy and refinement performed by the experts, resulted in 32 interventions equivalent to the Nursing Interventions Classification (NIC) system. The NICs, "Education: The process of the disease.", "Contract with the patient", and "Facilitation of Learning" were present in 100% of the records. For these interventions, 40 activities were described, representing 13 activities by intervention. the cross mapping allowed for the identification of corresponding terms with the nursing interventions used every day in rehabilitation nursing, and compared them to the Nursing Interventions Classification. realizar o mapeamento cruzado de termos da linguagem de Enfermagem, com o sistema de Classificação das Intervenções de Enfermagem, em prontuários de pacientes com doença de Parkinson em reabilitação. estudo de pesquisa documental, para realização de mapeamento cruzado. Amostra probabilística, do tipo aleatória simples, composta por 67 prontuários de pacientes com doença de Parkinson que participaram de programa de reabilitação, entre março de 2009 e abril de 2013. Pesquisa realizada em três etapas onde foram mapeados os termos de Enfermagem em linguagem livre e cruzados com o sistema de Classificação das Intervenções de Enfermagem. foram identificadas 1.077 intervenções normalizadas que, após o cruzamento com a taxonomia e o refinamento feito pelos especialistas, resultaram em 32 intervenções equivalentes ao sistema de Classificação das Intervenções de Enfermagem. "Ensino: Processo da doença", "Contrato com o Paciente" e "Facilitação da Aprendizagem" estiveram presentes em 100% dos prontuários. Para essas, foram descritas 40 atividades, representando 13 atividades por intervenção prescrita. o mapeamento cruzado permitiu levantar os termos correspondentes às Intervenções de Enfermagem utilizados no cotidiano dos enfermeiros de reabilitação e compará-los ao sistema de Classificação das Intervenções de Enfermagem. realizar el mapeo cruzado de términos del lenguaje de Enfermería con el Sistema de Clasificación de las Intervenciones de Enfermería en historias clínicas de pacientes con enfermedad de Parkinson en rehabilitación. estudio de investigación documental para realización de mapeo cruzado. Muestra probabilística de tipo aleatoria simple, compuesta por 67 historias clínicas de pacientes con enfermedad de Parkinson que participaron del programa de rehabilitación entre marzo de 2009 y abril de 2013. Investigación realizada en tres etapas donde fueron mapeados los términos de Enfermería en lenguaje libre y cruzados con el sistemas de Clasificación de Intervenciones de Enfermería. se identificaron 1077 intervenciones normalizadas que, después del cruzamiento con la taxonomía y el refinamiento hecho por los especialistas, resultaron en 32 intervenciones equivalentes al sistema de Clasificación de Intervenciones de Enfermería. "Enseñanza: Proceso de la enfermedad", "Contrato con el paciente" y "Facilitación del aprendizaje" estuvieron presentes en 100% de las historias clínicas. Para éstas, se describieron 40 actividades, representando 13 actividades por cada intervención prescripta. el mapeo cruzado permitió encontrar los términos correspondientes a las Intervenciones en Enfermería utilizados en el día a día de los enfermeros de rehabilitación y compararlos con el sistema de Clasificación de Intervenciones de Enfermería.

  18. Estimating KC-137 Aircraft Ownership Costs in the Brazilian Air Force

    DTIC Science & Technology

    1997-06-01

    Cycle Costing A-1 M manpower m meter Maint. Maintenance Mainten. Maintenance O&S Operation and Support OPAC Online Public Access Catalog PAMAGL Parque ...1.2 e 1.3. ))as informag6es quanto a pagarnento dar~o urn pouco de trabaiho, mas creio que podern ser conseguidas na tesouraria do Parque . N~o basta...pela Base na manutengo das aeronaves (e que n~o sejam fornecidos pelo Parque ), tais como gaxetas, componentes eletr6nicos, brocas, produtos qufmicos, etc

  19. A Negotiation Approach To Enrich Police And Security Intelligence: A Contemporary COIN Methodology for Afghanistan

    DTIC Science & Technology

    2012-04-01

    even indirectness. Whereas individualistic cultures de -emphasize the communication context and personal relationships; of which the “U.S. is a...appear to others; “there is no more powerful sanction than disapproval.” 39 Furthermore, loss of face (reputation and honor) is avoided at all costs ...married with TIPO model considerations (Appendix A) leads us to the cooperative negotiation strategy (CNS) as an appropriate launching point in

  20. Documentation of Software for the Neil Brown Instrument Systems/NORDA Velocity/CTD Profiler.

    DTIC Science & Technology

    1982-07-01

    maximum pressure of sensor M - cast start time (dec. days) * (12- 13 - cast end time (141 - magnetic variation shp’s speed (kt) 19 -ship’s heading...100 C I 265 10? C CHECK THAT THE TIPOE FIELDS APE EACH IN RA4 6E 1084 C 0T .. -- 105 49. VAR (153 .CE,24*.00 Ilo -___-TO_999- 106 IF 4VARfib6).G(E.6r

  1. The Impact of Different Types of Journaling Techniques on EFL Learners' Self-Efficacy (El impacto de diferentes tipos de diario en la autosuficiencia de estudiantes de inglés como lengua extranjera)

    ERIC Educational Resources Information Center

    Baleghizadeh, Sasan; Mortazavi, Mahboobeh

    2014-01-01

    This article reports on an investigation of the impact of different methods of journaling on self-efficacy of learners of English as a foreign language. Sixty upper-intermediate Iranian English language learners were randomly assigned to three experimental conditions, namely no-feedback, teacher-feedback, and peer-feedback, and one control…

  2. LINEA ALBA COLLAGEN ASSESSMENT IN MORBIDLY OBESE PATIENTS.

    PubMed

    Grossi, João Vicente Machado; Nicola, Felipe Fernandes; Zepeda, Ivan Alberto; Becker, Martina; Trindade, Eduardo Neubarth; Diemen, Vinicius Von; Cavazzola, Leandro Totti; Trindade, Manoel Roberto Maciel

    The evaluation of collagen in the abdominal wall has been increasingly studied because of the relevance on collagen in the healing process after laparotomy. To evaluate the amount of collagen in the linea alba of patients undergoing laparotomic bariatric surgery and comparing with non-obese cadavers. Were evaluated 88 samples of aponeurosis from abdominal linea alba of 44 obese patients (obesity group) and 44 non-obese cadavers (control group). The samples were collected in 2013 and 2104, and were sorted according to age (18-30, 31-45 and 46-60), gender, BMI, waist and cervical circumference, and subcutaneous tissue thickness. Material for biopsy was collected from the supraumbilical region of the linea alba for immunohistochemical analysis differentiating collagen type 1 and type 3 and the 1/3 ratio. Image-Pro Plus pixel counting software was used to measure the amount of collagen. The obesity group evidenced mean age 44.11±9.90 years; 18-30 age group had three (6.8%) obese individuals; 31-45 had 22 (50%) and 46-60 had 19 (43.1%). Females were present in 81.8% (n=36); BMI (kg/m²) was 48.81±6.5; waist circumference (cm) was 136.761±13.55; subcutaneous tissue thickness (cm) 4.873±0.916. Considering age groups, gender and BMI, there were statistical differences in all tests when compared with the cadavers. The amount of collagen in the linea alba above the umbilical region in the morbidly obese patients was smaller than in the non-obese cadavers in the same age group. A avaliação do colágeno na parede abdominal é cada vez mais estudada, em virtude da relevância dele no processo cicatricial após laparotomia. Avaliar a quantidade de colágeno na linha alba de pacientes submetidos à cirurgia bariátrica e compará-la com a de cadáveres não-obesos. Foram avaliados dois grupos com total de 88 amostras da aponeurose da linha alba abdominal, divididas em 44 de pacientes obesos (grupo obesidade) com indicação de cirurgia bariátrica e 44 de cadáveres não-obesos (grupo controle). As amostras foram retiradas da linha alba abdominal no período de 2013 a 2014 e inicialmente foram separadas conforme faixas etárias (18-30, 31-45 e 46-60), gênero, medidas de IMC, circunferência abdominal e cervical e espessura do subcutâneo do indivíduo. Foi coletado material para biópsia da linha alba supraumbilical para análise imunoistoquímica, diferenciando o colágeno tipo I e III e sua relação de tipo I/III. Utilizou-se o programa de contagem de pixels Image-Pro Plus(r), que mensurou a quantidade do colágeno. O grupo obesidade teve idade 44,11±9,90 anos, Na faixa etária de 18-30 anos foram incluídos três (6,8%) obesos; na de 31-45 anos 22 (50%) e na de 46-60 anos 19 (43,1%). O gênero feminino apresentou predomínio, com 36 (81,8%) pacientes. O IMC (kg/m²) foi de 48,81±6,5; a circunferência abdominal (cm) foi de 136,761±13,55; a espessura do subcutâneo (cm) foi de 4,873±0,916. A quantidade de colágeno tipo I foi de 134.683,3±206.657,4; a de colágeno tipo III foi de 413.137,2±283.656,1; a razão do colágeno tipo I/III foi 0,419±0,636. Considerando-se faixas de idade, gênero e IMC, foram constatadas diferenças estatísticas em todas as análises quando comparadas com às dos cadáveres. Os obesos mórbidos apresentaram quantidade de colágeno na linha alba supraumbilical menor que a do grupo controle de cadáveres não-obesos na mesma faixa etária.

  3. ANATOMIC VARIATIONS OF HEPATIC ARTERY: A STUDY IN 479 LIVER TRANSPLANTATIONS.

    PubMed

    Fonseca-Neto, Olival Cirilo Lucena da; Lima, Heloise Caroline de Souza; Rabelo, Priscylla; Melo, Paulo Sérgio Vieira de; Amorim, Américo Gusmão; Lacerda, Cláudio Moura

    2017-01-01

    The incidence of anatomic variations of hepatic artery ranges from 20-50% in different series. Variations are especially important in the context of liver orthotopic transplantation, since, besides being an ideal opportunity for surgical anatomical study, their precise identification is crucial to the success of the procedure. To identify the anatomical variations in the hepatic arterial system in hepatic transplantation. 479 medical records of transplanted adult patients in the 13-year period were retrospectively analyzed, and collected data on hepatic arterial anatomy of the deceased donor. It was identified normal hepatic arterial anatomy in 416 donors (86.84%). The other 63 patients (13.15%) showed some variation. According to the Michels classification, the most frequently observed abnormalities were: right hepatic artery branch of superior mesenteric artery (Type III, n=27, 5.63%); left hepatic artery branch of the left gastric artery (Type II, n=13, 2.71%); right hepatic artery arising from the superior mesenteric artery associated with the left hepatic artery arising from the left gastric artery (Type IV, n=4, 0.83%). Similarly, in relation to Hiatt classification, the most prevalent changes were: right hepatic accessory artery or substitute of the superior mesenteric artery (Type III, n=28, 6.05%)), followed by liver ancillary left artery or replacement of gastric artery left (Type II, n=16, 3.34. Fourteen donors (2.92%) showed no anatomical abnormalities defined in classifications, the highest frequency being hepatomesenteric trunk identified in five (01.04%). Detailed knowledge of the variations of hepatic arterial anatomy is of utmost importance to surgeons who perform approaches in this area, particularly in liver transplantation, since their identification and proper management are critical to the success of the procedure. A incidência das variações anatômicas da artéria hepática varia de 20-50% em diferentes casuísticas. Elas são especialmente importantes no contexto do transplante ortotópico hepático, visto que, além de representar oportunidade ideal para seu estudo anatômico cirúrgico, a sua precisa identificação é determinante para o sucesso do procedimento. Identificar as variações anatômicas no sistema arterial hepático em transplantes hepáticos. Foram analisados retrospectivamente, no período de 13 anos, 479 prontuários de pacientes adultos transplantados, sendo coletados dados referentes à anatomia arterial hepática do doador falecido. Identificou-se anatomia arterial hepática normal em 416 doadores (86,84%). Os outros 63 indivíduos (13,15%) apresentaram alguma variação. De acordo com a classificação de Michels, as anomalias mais frequentes foram: artéria hepática direita ramo da artéria mesentérica superior (Tipo III, n=27, 5,63%); artéria hepática esquerda ramo da artéria gástrica esquerda (Tipo II, n=13, 2,71%); artéria hepática direita ramo da artéria mesentérica superior associada à artéria hepática esquerda ramo da artéria gástrica esquerda (Tipo IV, n=4, 0,83%). Do mesmo modo, em relação à Classificação de Hiatt, as variações mais prevalentes foram: artéria hepática direita acessória ou substituta da artéria mesentérica superior (Tipo III, n=28, 6,05%), seguida da artéria hepática esquerda acessória ou substituta da artéria gástrica esquerda (Tipo II, n=16, 3,34%). Quatorze pessoas (2,92%) apresentaram alterações anatômicas sem classificação definida, sendo a de maior frequência o tronco hepatomesentérico, identificado em cinco (1,04%). O conhecimento detalhado das variações da anatomia arterial hepática é de grande importância aos cirurgiões que realizam abordagens nessa região, em especial no transplante hepático, visto que sua identificação e correto manejo são fundamentais para o êxito do procedimento.

  4. The Diterpene Sclareol Vascular Effect in Normotensive and Hypertensive Rats.

    PubMed

    Campos, Debora Ribeiro; Celotto, Andrea Carla; Albuquerque, Agnes Afrodite S; Ferreira, Luciana Garros; Monteiro, Ariadne Santana E Neves; Coelho, Eduardo Barbosa; Evora, Paulo Roberto Barbosa

    2017-06-29

    The diterpene Sclareol has antimicrobial action, cytotoxic and cytostatic effects and anti-tumor activities. However, researches on the cardiovascular system are scarce. This study was designed to investigate the mechanisms involved in the Sclareol cardiovascular effect in normotensive and hypertensive rats. The arterial hypertension was promoted using 2-kidneys 1-clip model in rats. The effect of sclareol on blood pressure was performed by using three dose (10, 20 and 40 mg/kg). Cumulative dose-response curves for Sclareol were determined for endothelium-intact and endothelium-denuded aortic rings in presence or absence of L-NAME and ODQ. The NOx levels were measure in the plasma sample. The Sclareol administration in vivo caused a significant reduction in blood pressure in both groups. In vitro the sclareol promoted relaxation in aorta, with endothelium, pre-contracted to Phe. The inhibitors of the nitric oxide synthase and soluble guanylate cyclase were as efficient as the removal of endothelium, in inhibiting the Sclareol-induced relaxation. Otherwise, it was no change of NOx. Also, for unknown reasons, the Sclareol is not selective for hypertensive animals. The diterpene Sclareol showed in vivo hypotensive and in-vitro vasodilator effects; The chemiluminescence plasmatic NO analysis showed no significant difference between groups and The Sclareol exhibit better effect on normotensive than hypertensive animals to reduce blood pressure. It is concluded that the diterpenes metabolites would be a promising source prototype for the development of new agents in the cardiovascular therapy. O diterpeno Esclareol tem ação antimicrobiana, efeitos citotóxicos e citostáticos e atividades antitumorais. No entanto, pesquisas sobre o sistema cardiovascular são escassas. Este estudo foi desenvolvido para investigar os mecanismos envolvidos no efeito cardiovascular de Esclareol em ratos normotensos e hipertensos. A hipertensão arterial foi promovida utilizando modelo de 2 clones de 1-clipe em ratos. O efeito do esclareol sobre a pressão arterial foi realizado utilizando três doses (10, 20 e 40 mg/kg). As curvas dose-resposta cumulativas para Esclareol foram determinadas para anéis aórticos endotélio-intactos e desprovidos de endotélio na presença ou ausência de L-NAME e ODQ. Os níveis de NOx foram medidos na amostra de plasma. A administração de Esclareol in vivo causou uma redução significativa na pressão sanguínea em ambos os grupos. In vitro o esclareol promoveu relaxamento na aorta, com endotélio, pré-contraído a Phe. Os inibidores da óxido nítrico sintase e da guanilato ciclase solúvel foram tão eficientes quanto a remoção do endotélio, na inibição do relaxamento induzido por Esclareol. Por outra parte, não houve mudança de NOx. Além disso, por razões desconhecidas, o Sclareol não é seletivo para animais hipertensos. O diterpeno Esclareol apresentou efeitos hipotensores in vivo e vasodilatadores in vitro; A análise de NO plasmático por quimioluminescência não mostrou diferença significativa entre os grupos e O Esclareol exibe melhor efeito sobre os animais normotensos do que hipertensos para reduzir a pressão arterial. Conclui-se que os metabólitos de diterpenos seriam um protótipo de fonte promissora para o desenvolvimento de novos agentes na terapia cardiovascular.

  5. Flying Off a Frictionless Curved Ramp

    DTIC Science & Technology

    2015-06-01

    mechanical energy . The object is assumed to start from rest at a point on the curve of zero slope. The launch speed and angle are calculated for the...Conservation of mechanical energy . Resumen Una ecuación general se deriva para un punto a lo largo de una trayectoria curvada descendente, de una partícula...porque no puede alcanzar la velocidad de un objeto en caída libre que coincide superficialmente con una trayectoria de este tipo. Palabras clave

  6. Biological and Theoretical Studies of Adaptive Networks: The Conditioned Response.

    DTIC Science & Technology

    1992-06-30

    suggest experimental tests and provide direction for physiological studies. 14 SU~la TIPO ~IS- NIJUMS Of PAGIS 17. @1d-ftA ITY CLASSIPtCATICON...mancte suditioned inhibition of the rabbit’s nictitating membrane response, CI tasks require the active suppression of CRs in the Bull . Psychon. Soc., 20... Bull ., 84 (1977) encephalon and mesencephalon26. 690-711. Several lines of evidence suggest that the septal and 8 Evans,J.A.C. and Thornton, E.W

  7. The Preschool Classroom as a Context for Cognitive Development: Type of Teacher Feedback and Children's Metacognitive Control (El aula Preescolar como espacio de desarrollo cognitivo: tipo de feedback docente y control metacognitivo en los niños)

    ERIC Educational Resources Information Center

    Muñoz, Liz; Cruz, Josefina Santa

    2016-01-01

    Introduction: The aim of this work was to determine whether the type of feedback given by the preschool teacher during class impacts the children's metacognitive control. For this purpose, the children's behavior was analyzed while teachers provided feedback during collaborative learning sessions. Method: A quasi-experimental, cross-sectional…

  8. PubMed

    Roldan, Mariela; Bella, Monica; Dionisio, Leandro

    2018-04-11

    Ciencias Médicas Universidad Nacional de Córdoba.ResumenLa violencia doméstica es actualmente un problema de salud pública debido a su magnitud y repercusiones sociosanitarias. Objetivo: explorar las características epidemiológicas sociodemográficas y psicopatológicas  de personas denunciadas como agresores en la ciudad de Córdoba. Material y Métodos: estudio exploratorio, retrospectivo y transversal de los registros de personas denunciadas como presuntos agresores de violencia intrafamiliar en la fiscalía de violencia familiar de los tribunales Judiciales Provinciales de Córdoba Capital en el período junio 2011 a mayo 2012. Resultados: el (86%) fueron varones y el (14%) mujeres con una  edad de ±35 años. La violencia de pareja fue la más prevalente en el (69%). El grupo etario más comprometido fue el de 20 a 39 años El tipo de lesión más frecuente fue la amenaza (45,6%), seguida de lesiones graves (35,3%). La mayor parte de  los casos no presentó diagnóstico de trastorno mental (64,3%). El trastorno mental más frecuente fue el consumo de sustancia (28,3%). Conclusión: el tipo de violencia denunciada con mayor frecuencia fue la violencia intrafamiliar de pareja y afectó a la gente de edad joven y productiva mostrando un comportamiento de género y factores de riesgo social.

  9. Resposta do detector de ondas gravitacionais Mario Schenberg ao "ringdown" de buraco negros

    NASA Astrophysics Data System (ADS)

    Costa, C. A.; Aguiar, O. D.; Magalhães, N. S.

    2003-08-01

    Acredita-se que quando duas estrelas de nêutrons coalescem, elas, eventualmente, formam um buraco negro com massa igual a soma das massas dos objetos originais. Durante a formação do buraco negro, o espaço-tempo em torno do sistema sofre perturbações que se propagam na forma de radiação gravitacional. A forma de onda associada a radiação gravitacional, durante este estágio, aproxima-se a uma senóide exponencialmente amortecida. Este tipo de sinal é conhecido como "ringdown", e seu comportamento e parametrização são muito bem conhecidos. Neste trabalho, simulamos computacionalmente sinais provenientes do "ringdown" de buracos negros, com a finalidade de testar o desempenho do detector de ondas gravitacionais Mario Schenberg em observá-los, quando entrar em funcionamento. Este primeiro teste teórico ajudou-nos a criar estratégias de detecção de sinais imersos no ruído instrumental. Calculamos a relação sinal-ruído como uma função da frequência, bem como sua integral dentro da faixa de sensibilidade do detector. Os resultados obtidos mostraram que o detector Schenberg terá sensibilidade suficiente para detectar este tipo de sinal, proveniente de fontes astrofísicas localizadas dentro de um raio de ~100kpc.

  10. Use of generic medicines by the Brazilian population: an evaluation of PNAUM 2014.

    PubMed

    Bertoldi, Andréa Dâmaso; Arrais, Paulo Sergio Dourado; Tavares, Noemia Urruth Leão; Ramos, Luiz Roberto; Luiza, Vera Lucia; Mengue, Sotero Serrate; Dal-Pizzol, Tatiane da Silva; Farias, Mareni Rocha; Oliveira, Maria Auxiliadora

    2016-12-01

    To analyze the existence of differences in the use of generic medicines in Brazil according to demographic and socioeconomic variables and acquisition sources of the medicines. Population-based cross-sectional study, conducted with data from the Pesquisa Nacional de Acesso, Utilização e Promoção do Uso Racional de Medicamentos (PNAUM - National Survey on Access, Use and Promotion of Rational Use of Medicines). Data collection took place between September, 2013 and February, 2014 in homes of Brazilian cities (urban area). The use of medicines has been investigated in relation to the treatment of chronic diseases and, in the case of acute events, regarding use over the previous 15 days. Generics were identified by visualization of packaging presented by the users of the medicines. The independent variables used were sex, age, education level, economic class, and region of the Country. The statistical significance of differences between the groups was evaluated by Pearson's Chi-squared test, considering a 5% significance level. The prevalence of generic medicines use was 45.5% (95%CI 43.7-47.3). There was no difference considering education level. The prevalence was higher in females (47.0%; 95%CI 44.9-49.0) than in males (43.1%; 95%CI 40.5-45.8), and were higher with increasing age. Generic medicines were more used in the economic class C (47.0%; 95%CI 44.9-49.1) and in the South (50.6%; 95%CI 46.6-54.6) and Southeast (49.9%; 95%CI 46.8-53.0) regions. Generics accounted for 37.3% of the medicines provided by the Brazilian Unified Health System. Currently, there is a choice of purchase or free provision by the Brazilian Unified Health System, characterized by quality assurance and reduced price regarding branded medicines considered as reference. In the private market, a considerable part of the population is choosing generic medicines thanks to the availability of this option for virtually all medicines most used by the population. Analisar se há diferença no uso de medicamentos genéricos no Brasil segundo variáveis demográficas, socioeconômicas e fontes de obtenção dos medicamentos. Estudo transversal de base populacional, conduzido com dados da Pesquisa Nacional de Acesso, Utilização e Promoção do Uso Racional de Medicamentos (PNAUM), com coleta de dados entre setembro de 2013 e fevereiro de 2014 em residências de municípios brasileiros urbanos. O uso dos medicamentos foi investigado em relação ao tratamento de doenças crônicas e, no caso de eventos agudos, quanto ao uso nos últimos 15 dias. Os genéricos foram identificados por visualização das embalagens apresentadas pelos usuários dos medicamentos. As variáveis independentes utilizadas foram sexo, idade, escolaridade, classe econômica e região do País. A avaliação da significância estatística das diferenças entre os grupos foi analisada pelo teste Qui-quadrado de Pearson, considerando nível de significância de 5%. A prevalência de uso de genéricos foi de 45,5% (IC95% 43,7-47,3). Não houve diferença por escolaridade, as prevalências foram maiores no sexo feminino (47,0%; IC95% 44,9-49,0) em relação ao masculino (43,1%; IC95% 40,5-45,8) e foram crescentes com o aumento da idade. Maiores usos de genéricos foram encontrados na classe econômica C (47,0%; IC95% 44,9-49,1) e nas regiões Sul (50,6%; IC95% 46,6-54,6) e Sudeste (49,9%; IC95% 46,8-53,0). Observou-se ainda que os genéricos representaram 37,3% dos medicamentos disponibilizados pelo Sistema Único de Saúde . Pode-se concluir que hoje existe uma alternativa de compra ou fornecimento gratuito pelo Sistema Único de Saúde, caracterizada por garantia de qualidade e preço reduzido em relação aos medicamentos de marca comercial considerados como referência. No mercado privado, boa parte da população está optando pelo uso de medicamentos genéricos, graças à disponibilidade dessa opção para praticamente todos os medicamentos mais utilizados pela população.

  11. População nuclear e extranuclear em rádio-galáxias

    NASA Astrophysics Data System (ADS)

    Raimann, D. I.; Storchi-Bergmann, T.; Quintana, H.; Alloin, D.; Hunstead, R.; Wisotzki, L.

    2003-08-01

    A natureza do contínuo UV/ótico em rádio-galáxias é muito importante para o seu entendimento. Em baixos redshifts existem evidências de que muitas delas são dominadas no ótico por luz de estrelas velhas, características de galáxias early-type e em altos redshifts a característica dominante é um excesso de luz no UV, freqüentemente associado com estruturas que estão alinhadas aos eixos das estruturas rádio em grande escala. Inicialmente esse excesso foi interpretado como devido a episódios intensos de formação estelar nas galáxias hospedeiras. Entretanto, as descobertas dos alinhamentos entre as estruturas UV e rádio modificaram essa idéia. Foi proposto que a formação estelar é iniciada pela passagem do jato rádio através do meio interestelar das galáxias hospedeiras. A natureza do excesso UV começou a ser compreendida em um estudo detalhado do continuo ótico da 3C321, onde se concluiu que o contínuo desta galáxia tem origem multicomponente, com contribuições de populações velhas e intermediárias, de luz espalhada oriunda de um quasar obscurecido e do contínuo nebular. No presente trabalho estudamos a população nuclear e extranuclear de uma amostra de 24 rádio-galáxias, utilizando espectros óticos de fenda longa, com alta razão sinal/ruído. Através do método de síntese espectral de populações estelares, foram estimadas as contribuições de populações estelares de diferentes idades (e de um contínuo tipo lei de potência devido a um AGN, FC) para a luz integrada das galáxias, em 4020Å. As principais conclusões deste trabalho são: apenas quatro dos objetos estudados têm contribuições significativas (maiores do que 10%) das populações de 100 milhões de anos ou mais jovens (ou de FC) ao longo da região espacial estudada (6 kpc centrais); nenhuma das rádio-galáxias de tipo FRI estudadas tem contribuição significativa destas populações ao longo desta região; duas (de oito) de tipo FRII tem contribuições significativas da luz que vem do AGN, na região nuclear; uma tem contribuição significativa das populações de 100 milhões de anos e mais jovens ao longo dos 4 kpc centrais, indicando claramente a presença de formação estelar recente. Comparando estes resultados com aqueles obtidos para uma amostra de galáxias não ativas de mesmo tipo de Hubble das rádio, encontramos que a principal diferença entre as duas amostras está na contribuição da população de 1 bilhão de anos, geralmente maior nas rádio-galáxias.

  12. Right hepatic artery aneurysm.

    PubMed

    Bernal, Astrid Del Pilar Ardila; Loures, Paulo; Calle, Juan Cristóbal Ospina; Cunha, Beatriz; Córdoba, Juan Camilo

    2016-01-01

    We report a case of an aneurysm of the right hepatic artery and its multidisciplinary management by general surgery, endoscopy and radiology services. Being a case of extremely low incidence, it is important to show its diagnostic and therapeutic approach. RESUMO Relatamos um caso de aneurisma da artéria hepática direita conduzido de forma multidisciplinar pelos Serviços de Cirurgia Geral, Endoscopia e Radiologia. Em se tratando de caso de incidência baixíssima, é importante mostrar o enfoque diagnóstico e terapêutico usado em seu manejo.

  13. Formación y evolución de planetas gigantes

    NASA Astrophysics Data System (ADS)

    Benvenuto, O. G.; Brunini, A.

    Presentamos el estado actual del trabajo que estamos realizando en el estudio de la formación de planetas gigantes. Detallamos los algoritmos numéricos necesarios para realizar este tipo de cálculo. Presentamos algunos resultados de la formación de objetos con masas de hasta una docena de veces la del planeta Júpiter, resaltando las principales caracteríticas. Finalmente detallamos los problemas que pensamos abordar en un futuro cercano en este tema de investigación.

  14. The Identification of Linker Characteristics among Venezuelan Students in the United States.

    DTIC Science & Technology

    1980-06-01

    MOVER RECURSOS TECNICOS, MATERIALES , M9TODOS E INFORMACI6N, DESDE EL LUGAR DE DESCUBRIMIENTO 0 INVENCIdN HASTA LOS NUEVOS USUARIOSŕ [Gilmore, 1969]. El...fabricar tin nuevo tipo de vidrio aislante con infinidad de aplicaciones. 6. Materiales resistentes al calor, usados para cubrir la ojiva y el cuerpo de...mientos (el inventor o doscubridor genera nuevas ideas, conceptos, materiales , etc.), (2) la difusio’n o diseminacio’n de esas ideas o conocimientos

  15. Stay at a Healthy Weight. Tips for Kids with Type 2 Diabetes = Mantente en un Peso Saludable. Consejos Para Muchachos con Diabetes Tipo 2

    ERIC Educational Resources Information Center

    US Department of Health and Human Services, 2005

    2005-01-01

    A healthy weight means you are not too fat or too thin. Your doctor may have said that you should not gain more weight or that you need to lose a few pounds. If you have diabetes and are overweight, you are not alone. The steps you take to manage your weight will help you feel better and may improve your blood sugar or glucose (GLOO-kos) levels.…

  16. Manual de métodos de campo para el monitoreo de aves terrestres

    Treesearch

    C. John Ralph; Geoffrey R. Geupel; Peter Pyle; Thomas E. Martin; David F DeSante; Borja Milá

    1996-01-01

    El presente manual es una recopilación de métodos de campo para la determinación de índices de abundancia y datos demográficos de poblaciones de aves terrestres en una amplia variedad de hábitats. Está dirigido a biólogos, técnicos de campo, e investigadores de cualquier parte del Continente Americano. Los métodos descritos incluyen cuatro tipos de censos...

  17. Hex-Chrome Free Hardware - BAE Experience

    DTIC Science & Technology

    2010-06-01

    plating, freedom from hydrogen embrittlement Cost is comparable to Type II chromate zinc • But much better corrosion performance Wide use by automotive...Fiat 9.57513/ Tipo IV • Ford S439 (WSS-M21P37-A1) • General Motors GM7114M, GMW3359 • Int’l Truck TMS-4518, Type I • ISO 10683 • JLG 4150701 • John...salt spray) to meet customer requirements (uses Geomet) • Fastener supplier provides similar dip-spin coatings • Cost virtually same as zinc plate • No

  18. High Energy Density Capacitors for Pulsed Power Applications

    DTIC Science & Technology

    2009-07-01

    As a result of this effort, the US Military has access to capacitors that are about a third the size and half the cost of the capacitors that were...resistor in terms of shock and vibration, mounting requirements, total volume, system reliability, and cost . All of these parameters were improved...it t tipo ymer m qua y an capac or cons ruc on. Energy Density of 10,000 Shot High Efficiency Pulse Power Capacitors The primary driver was 1 5

  19. The Hygiene Hypothesis and Breast Cancer a Novel Application of an Etiologic Theory for Allergies, Asthma, and Other Immune Disorders

    DTIC Science & Technology

    2007-05-01

    REFERENCE YEAR-2] and [REFERENCE YEAR], on average, how many days per month did you eat the following kinds of foods: Q68. Yogurt (not the frozen...kind)? days/month Q69. Kim chee or sauerkraut ( fermented cabbage) days/month Q70. Lactobacillus or probiotic supplements...entre [AÑO DE REFERENCIA-2] y [AÑO DE REFERENCIA]: Q68. Yogurt (no del tipo congelado)? días / mes Q69. Kim chee o chukrut (repollo

  20. Contenedores: Aspectos tecnicos, biologicos y economicos

    Treesearch

    Tara Luna; Thomas D. Landis; R. Kasten Dumroese

    2012-01-01

    La elección del contenedor es una de las consideraciones más importantes al establecer un nuevo vivero o empezar a producir una especie nueva. El tipo y tamaño de contenedor no sólo determina la cantidad de agua y nutrientes minerales que están disponibles para el crecimiento de una planta, sino que también afecta otros aspectos operativos del vivero, como el tamaño de...

  1. Minilaparoscopy-assisted transumbilical laparoscopic cholecystectomy.

    PubMed

    Lima, Geraldo José DE Souza; Leite, Rodrigo Fabiano Guedes; Abras, Gustavo Munayer; Pires, Livio José Suretti; Castro, Eduardo Godoy

    2016-01-01

    The role of laparoscopy in the modern surgery era is well established. With the prospect of being able to improve the already privileged current situation, new alternatives have been proposed, such as natural orifice endoscopic surgery (NOTES), the method for single transumbilical access (LESS - Laparo-endoscopic single-site surgery) and minilaparoscopy (MINI). The technique proposed by the authors uses a laparoscope with an operative channel like the flexible endoscope used in NOTES. All operative times are carried out through the umbilical trocar as in LESS, and assisted by a minilaparoscopy grasper. This new technic combines, and results from, the rationalization of technical particularities and synergy of these three approaches, seeking to join their advantages and minimize their disadvantages. RESUMO O papel da videolaparoscopia na era moderna da cirurgia encontra-se bem estabelecido. Com a perspectiva de ser possível melhorar a já privilegiada situação atual, novas alternativas têm sido propostas, como a cirurgia por orifícios naturais (NOTES), o método por acesso único transumbilical (LESS - Laparo-endoscopic single-site surgery) e a minilaparoscopia (MINI). A técnica proposta pelos autores utiliza-se de óptica com canal de trabalho como o endoscópio flexível do NOTES, executa-se todos os tempos operatórios pelo trocarte umbilical, como no LESS, e é assistido por pinça de minilaparoscopia. Esta nova técnica combina e resulta da racionalização de particularidades técnicas e do sinergismo destas três abordagens, buscando agregar suas vantagens e minimizar as suas desvantagens.

  2. GPU-Accelerated Optical Coherence Tomography Signal Processing and Visualization

    NASA Astrophysics Data System (ADS)

    Darbrazi, Seyed Hamid Hosseiny

    As piroxenas sao um vasto grupo de silicatos minerais encontrados em muitas rochas igneas e metamorficas. Na sua forma mais simples, estes silicatos sao constituidas por cadeias de SiO3 ligando grupos tetrahedricos de SiO4. A formula quimica geral das piroxenas e M2M1T2O6, onde M2 se refere a catioes geralmente em uma coordenacao octaedrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catioes numa coordenacao octaedrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catioes em coordenacao tetrahedrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclinica sao designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composicoes quimicas amplo, em conjugacao com a possibilidade de ajustar as suas propriedades fisicas e quimicas e a durabilidade quimica, tem gerado um interesse mundial devido a suas aplicacoes em ciencia e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicacoes funcionais. O estudo teve objectivos cientificos e tecnologicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formacao de fases cristalinas e solucoes solidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicacao dos novos materiais em diferentes areas tecnologicas, com especial enfase sobre a selagem em celulas de combustivel de oxido solido (SOFC). Com este intuito, prepararam-se varios vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsidio (CaMgSi2O6) e diopsidio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados atraves de um vasto leque de tecnicas. Todos os vidros foram preparados por fusao-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterizacao e cristalizacao de fritas, quer por nucleacao e cristalizacao de vidros monoliticos. Estudaram-se ainda os efeitos de varias substituicoes ionicas em composicoes de diopsidio contendo Al na estrutura, sinterizacao e no comportamento durante a cristalizacao de vidros e nas propriedades dos materiais vitro-cerâmicos, com relevância para a sua aplicacao como selantes em SOFC. Verificou-se que Foi observado que os vidros/vitro-cerâmicos a base de enstatite nao apresentavam as caracteristicas necessarias para serem usados como materiais selantes em SOFC, enquanto as melhores propriedades apresentadas pelos vitro-cerâmicos a base de diopsidio qualificaram-nos para futuros estudos neste tipo de aplicacoes. Para alem de investigar a adequacao dos vitro-cerâmicos a base de clinopyroxene como selantes, esta tese tem tambem como objetivo estudar a influencia dos agentes de nucleacao na nucleacao em volume dos vitro-cerâmicos resultantes a base de diopsidio, de modo a qualifica-los como potenciais materiais hopedeiros de residuos nucleares radioactivos.

  3. A Influência da Escola e da Mídia na Obtenção dos Conhecimentos Astronômicos

    NASA Astrophysics Data System (ADS)

    da Cunha, W. S.; Voelzke, M. R.; Amaral, L. H.

    2006-08-01

    O universo em que vivemos possui segredos jamais imaginados pelo homem, fruto da pequena proporção que ocupamos diante de um cosmos infinito. A astronomia funciona como um instrumento que sacia a sede humana em desvendar esses segredos, estudando as galáxias, quasares, pulsares além da existência de todos os elementos que preenchem o espaço cósmico, o vácuo, não mais vazio como se pensou em outros tempos. A mídia explora esse campo de forma mística e também científica. A difusão adequada e dentro dos padrões educacionais vigentes, de conceitos astronômicos, se faz necessária, devido sua presença nos conteúdos escolares, centros de ciência e na mídia, de modo geral. A reforma do Currículo Básico da Escola Pública da maioria dos Estados brasileiros introduziu conceitos astronômicos desde a pré-escola até o Ensino Médio. Num estudo realizado com 1.032 alunos do Ensino Médio de seis escolas estaduais, revelou-se através da aplicação de um questionário que abordava conheciment os básicos em astronomia, como estes foram adquiridos e qual era a infra-estrutura oferecida pela escola: para 66,2% dos entrevistados o professor já fez alguma apresentação a respeito de astronomia. O presente estudo revelou também que 44,5% dos alunos entrevistados adquiriram seus conhecimentos astronômicos na escola, 28,1% através da televisão e 27,4% afirmaram que seus conhecimentos foram obtidos através de outros tipos de mídia (internet, filmes e revistas). Embora o estudo revele claramente que há certo equilíbrio na forma em que os alunos obtiveram seus conhecimentos astronômicos, a mídia ainda explora e muitas vezes desperta o interesse pela astronomia com assuntos que não fazem parte de nosso cotidiano como, por exemplo, o homem na Lua, os projetos espaciais e a primeira viagem de um astronauta brasileiro no espaço. Porém, em certos casos, a mídia pode promover conhecimentos incompletos ou mesmo equivocados sobre os conceitos que envolvam a astronomia, como por exemplo a propagação do som no vácuo observado na maioria dos filmes de f icção científica ou da existência das estações do ano em função da distância da Terra ao Sol, em conformidade com o questionário aplicado.

  4. Albumin and fibronectin adsorption and osteoblast adhesion on titanium oxides

    NASA Astrophysics Data System (ADS)

    Freitas, Susana Maria Ribeiro e. Sousa Mendes de

    As piroxenas sao um vasto grupo de silicatos minerais encontrados em muitas rochas igneas e metamorficas. Na sua forma mais simples, estes silicatos sao constituidas por cadeias de SiO3 ligando grupos tetrahedricos de SiO4. A formula quimica geral das piroxenas e M2M1T2O6, onde M2 se refere a catioes geralmente em uma coordenacao octaedrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catioes numa coordenacao octaedrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catioes em coordenacao tetrahedrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclinica sao designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composicoes quimicas amplo, em conjugacao com a possibilidade de ajustar as suas propriedades fisicas e quimicas e a durabilidade quimica, tem gerado um interesse mundial devido a suas aplicacoes em ciencia e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicacoes funcionais. O estudo teve objectivos cientificos e tecnologicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formacao de fases cristalinas e solucoes solidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicacao dos novos materiais em diferentes areas tecnologicas, com especial enfase sobre a selagem em celulas de combustivel de oxido solido (SOFC). Com este intuito, prepararam-se varios vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsidio (CaMgSi2O6) e diopsidio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados atraves de um vasto leque de tecnicas. Todos os vidros foram preparados por fusao-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterizacao e cristalizacao de fritas, quer por nucleacao e cristalizacao de vidros monoliticos. Estudaram-se ainda os efeitos de varias substituicoes ionicas em composicoes de diopsidio contendo Al na estrutura, sinterizacao e no comportamento durante a cristalizacao de vidros e nas propriedades dos materiais vitro-cerâmicos, com relevância para a sua aplicacao como selantes em SOFC. Verificou-se que Foi observado que os vidros/vitro-cerâmicos a base de enstatite nao apresentavam as caracteristicas necessarias para serem usados como materiais selantes em SOFC, enquanto as melhores propriedades apresentadas pelos vitro-cerâmicos a base de diopsidio qualificaram-nos para futuros estudos neste tipo de aplicacoes. Para alem de investigar a adequacao dos vitro-cerâmicos a base de clinopyroxene como selantes, esta tese tem tambem como objetivo estudar a influencia dos agentes de nucleacao na nucleacao em volume dos vitro-cerâmicos resultantes a base de diopsidio, de modo a qualifica-los como potenciais materiais hopedeiros de residuos nucleares radioactivos.

  5. Birefringence and Bragg grating control in femtosecond laser written optical circuits

    NASA Astrophysics Data System (ADS)

    Fernandes, Luis A.

    As piroxenas sao um vasto grupo de silicatos minerais encontrados em muitas rochas igneas e metamorficas. Na sua forma mais simples, estes silicatos sao constituidas por cadeias de SiO3 ligando grupos tetrahedricos de SiO4. A formula quimica geral das piroxenas e M2M1T2O6, onde M2 se refere a catioes geralmente em uma coordenacao octaedrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catioes numa coordenacao octaedrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catioes em coordenacao tetrahedrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclinica sao designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composicoes quimicas amplo, em conjugacao com a possibilidade de ajustar as suas propriedades fisicas e quimicas e a durabilidade quimica, tem gerado um interesse mundial devido a suas aplicacoes em ciencia e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicacoes funcionais. O estudo teve objectivos cientificos e tecnologicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formacao de fases cristalinas e solucoes solidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicacao dos novos materiais em diferentes areas tecnologicas, com especial enfase sobre a selagem em celulas de combustivel de oxido solido (SOFC). Com este intuito, prepararam-se varios vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsidio (CaMgSi2O6) e diopsidio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados atraves de um vasto leque de tecnicas. Todos os vidros foram preparados por fusao-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterizacao e cristalizacao de fritas, quer por nucleacao e cristalizacao de vidros monoliticos. Estudaram-se ainda os efeitos de varias substituicoes ionicas em composicoes de diopsidio contendo Al na estrutura, sinterizacao e no comportamento durante a cristalizacao de vidros e nas propriedades dos materiais vitro-cerâmicos, com relevância para a sua aplicacao como selantes em SOFC. Verificou-se que Foi observado que os vidros/vitro-cerâmicos a base de enstatite nao apresentavam as caracteristicas necessarias para serem usados como materiais selantes em SOFC, enquanto as melhores propriedades apresentadas pelos vitro-cerâmicos a base de diopsidio qualificaram-nos para futuros estudos neste tipo de aplicacoes. Para alem de investigar a adequacao dos vitro-cerâmicos a base de clinopyroxene como selantes, esta tese tem tambem como objetivo estudar a influencia dos agentes de nucleacao na nucleacao em volume dos vitro-cerâmicos resultantes a base de diopsidio, de modo a qualifica-los como potenciais materiais hopedeiros de residuos nucleares radioactivos.

  6. Single Point Incremental Forming and Multi-Stage Incremental Forming on Aluminium Alloy 1050

    NASA Astrophysics Data System (ADS)

    Suriyaprakan, Premika

    As piroxenas sao um vasto grupo de silicatos minerais encontrados em muitas rochas igneas e metamorficas. Na sua forma mais simples, estes silicatos sao constituidas por cadeias de SiO3 ligando grupos tetrahedricos de SiO4. A formula quimica geral das piroxenas e M2M1T2O6, onde M2 se refere a catioes geralmente em uma coordenacao octaedrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catioes numa coordenacao octaedrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catioes em coordenacao tetrahedrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclinica sao designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composicoes quimicas amplo, em conjugacao com a possibilidade de ajustar as suas propriedades fisicas e quimicas e a durabilidade quimica, tem gerado um interesse mundial devido a suas aplicacoes em ciencia e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicacoes funcionais. O estudo teve objectivos cientificos e tecnologicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formacao de fases cristalinas e solucoes solidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicacao dos novos materiais em diferentes areas tecnologicas, com especial enfase sobre a selagem em celulas de combustivel de oxido solido (SOFC). Com este intuito, prepararam-se varios vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsidio (CaMgSi2O6) e diopsidio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados atraves de um vasto leque de tecnicas. Todos os vidros foram preparados por fusao-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterizacao e cristalizacao de fritas, quer por nucleacao e cristalizacao de vidros monoliticos. Estudaram-se ainda os efeitos de varias substituicoes ionicas em composicoes de diopsidio contendo Al na estrutura, sinterizacao e no comportamento durante a cristalizacao de vidros e nas propriedades dos materiais vitro-cerâmicos, com relevância para a sua aplicacao como selantes em SOFC. Verificou-se que Foi observado que os vidros/vitro-cerâmicos a base de enstatite nao apresentavam as caracteristicas necessarias para serem usados como materiais selantes em SOFC, enquanto as melhores propriedades apresentadas pelos vitro-cerâmicos a base de diopsidio qualificaram-nos para futuros estudos neste tipo de aplicacoes. Para alem de investigar a adequacao dos vitro-cerâmicos a base de clinopyroxene como selantes, esta tese tem tambem como objetivo estudar a influencia dos agentes de nucleacao na nucleacao em volume dos vitro-cerâmicos resultantes a base de diopsidio, de modo a qualifica-los como potenciais materiais hopedeiros de residuos nucleares radioactivos.

  7. Magnetism at the nanoscale: Nanoparticles, nanowires, nanotubes and their ordered arrays

    NASA Astrophysics Data System (ADS)

    Proenca, Mariana Jesus Paiva

    As piroxenas sao um vasto grupo de silicatos minerais encontrados em muitas rochas igneas e metamorficas. Na sua forma mais simples, estes silicatos sao constituidas por cadeias de SiO3 ligando grupos tetrahedricos de SiO4. A formula quimica geral das piroxenas e M2M1T2O6, onde M2 se refere a catioes geralmente em uma coordenacao octaedrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catioes numa coordenacao octaedrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catioes em coordenacao tetrahedrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclinica sao designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composicoes quimicas amplo, em conjugacao com a possibilidade de ajustar as suas propriedades fisicas e quimicas e a durabilidade quimica, tem gerado um interesse mundial devido a suas aplicacoes em ciencia e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicacoes funcionais. O estudo teve objectivos cientificos e tecnologicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formacao de fases cristalinas e solucoes solidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicacao dos novos materiais em diferentes areas tecnologicas, com especial enfase sobre a selagem em celulas de combustivel de oxido solido (SOFC). Com este intuito, prepararam-se varios vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsidio (CaMgSi2O6) e diopsidio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados atraves de um vasto leque de tecnicas. Todos os vidros foram preparados por fusao-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterizacao e cristalizacao de fritas, quer por nucleacao e cristalizacao de vidros monoliticos. Estudaram-se ainda os efeitos de varias substituicoes ionicas em composicoes de diopsidio contendo Al na estrutura, sinterizacao e no comportamento durante a cristalizacao de vidros e nas propriedades dos materiais vitro-cerâmicos, com relevância para a sua aplicacao como selantes em SOFC. Verificou-se que Foi observado que os vidros/vitro-cerâmicos a base de enstatite nao apresentavam as caracteristicas necessarias para serem usados como materiais selantes em SOFC, enquanto as melhores propriedades apresentadas pelos vitro-cerâmicos a base de diopsidio qualificaram-nos para futuros estudos neste tipo de aplicacoes. Para alem de investigar a adequacao dos vitro-cerâmicos a base de clinopyroxene como selantes, esta tese tem tambem como objetivo estudar a influencia dos agentes de nucleacao na nucleacao em volume dos vitro-cerâmicos resultantes a base de diopsidio, de modo a qualifica-los como potenciais materiais hopedeiros de residuos nucleares radioactivos.

  8. Improving the characteristics of foundry alloys AlSiCuMg during manufacturing

    NASA Astrophysics Data System (ADS)

    Fragoso, Bruno Filipe Marques

    As piroxenas sao um vasto grupo de silicatos minerais encontrados em muitas rochas igneas e metamorficas. Na sua forma mais simples, estes silicatos sao constituidas por cadeias de SiO3 ligando grupos tetrahedricos de SiO4. A formula quimica geral das piroxenas e M2M1T2O6, onde M2 se refere a catioes geralmente em uma coordenacao octaedrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catioes numa coordenacao octaedrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catioes em coordenacao tetrahedrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclinica sao designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composicoes quimicas amplo, em conjugacao com a possibilidade de ajustar as suas propriedades fisicas e quimicas e a durabilidade quimica, tem gerado um interesse mundial devido a suas aplicacoes em ciencia e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicacoes funcionais. O estudo teve objectivos cientificos e tecnologicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formacao de fases cristalinas e solucoes solidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicacao dos novos materiais em diferentes areas tecnologicas, com especial enfase sobre a selagem em celulas de combustivel de oxido solido (SOFC). Com este intuito, prepararam-se varios vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsidio (CaMgSi2O6) e diopsidio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados atraves de um vasto leque de tecnicas. Todos os vidros foram preparados por fusao-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterizacao e cristalizacao de fritas, quer por nucleacao e cristalizacao de vidros monoliticos. Estudaram-se ainda os efeitos de varias substituicoes ionicas em composicoes de diopsidio contendo Al na estrutura, sinterizacao e no comportamento durante a cristalizacao de vidros e nas propriedades dos materiais vitro-cerâmicos, com relevância para a sua aplicacao como selantes em SOFC. Verificou-se que Foi observado que os vidros/vitro-cerâmicos a base de enstatite nao apresentavam as caracteristicas necessarias para serem usados como materiais selantes em SOFC, enquanto as melhores propriedades apresentadas pelos vitro-cerâmicos a base de diopsidio qualificaram-nos para futuros estudos neste tipo de aplicacoes. Para alem de investigar a adequacao dos vitro-cerâmicos a base de clinopyroxene como selantes, esta tese tem tambem como objetivo estudar a influencia dos agentes de nucleacao na nucleacao em volume dos vitro-cerâmicos resultantes a base de diopsidio, de modo a qualifica-los como potenciais materiais hopedeiros de residuos nucleares radioactivos.

  9. Seismic assessment of reinforced concrete frame structures with a new flexibility based element

    NASA Astrophysics Data System (ADS)

    Arede, Antonio Jose Coelho Dias

    As piroxenas sao um vasto grupo de silicatos minerais encontrados em muitas rochas igneas e metamorficas. Na sua forma mais simples, estes silicatos sao constituidas por cadeias de SiO3 ligando grupos tetrahedricos de SiO4. A formula quimica geral das piroxenas e M2M1T2O6, onde M2 se refere a catioes geralmente em uma coordenacao octaedrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catioes numa coordenacao octaedrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catioes em coordenacao tetrahedrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclinica sao designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composicoes quimicas amplo, em conjugacao com a possibilidade de ajustar as suas propriedades fisicas e quimicas e a durabilidade quimica, tem gerado um interesse mundial devido a suas aplicacoes em ciencia e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicacoes funcionais. O estudo teve objectivos cientificos e tecnologicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formacao de fases cristalinas e solucoes solidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicacao dos novos materiais em diferentes areas tecnologicas, com especial enfase sobre a selagem em celulas de combustivel de oxido solido (SOFC). Com este intuito, prepararam-se varios vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsidio (CaMgSi2O6) e diopsidio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados atraves de um vasto leque de tecnicas. Todos os vidros foram preparados por fusao-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterizacao e cristalizacao de fritas, quer por nucleacao e cristalizacao de vidros monoliticos. Estudaram-se ainda os efeitos de varias substituicoes ionicas em composicoes de diopsidio contendo Al na estrutura, sinterizacao e no comportamento durante a cristalizacao de vidros e nas propriedades dos materiais vitro-cerâmicos, com relevância para a sua aplicacao como selantes em SOFC. Verificou-se que Foi observado que os vidros/vitro-cerâmicos a base de enstatite nao apresentavam as caracteristicas necessarias para serem usados como materiais selantes em SOFC, enquanto as melhores propriedades apresentadas pelos vitro-cerâmicos a base de diopsidio qualificaram-nos para futuros estudos neste tipo de aplicacoes. Para alem de investigar a adequacao dos vitro-cerâmicos a base de clinopyroxene como selantes, esta tese tem tambem como objetivo estudar a influencia dos agentes de nucleacao na nucleacao em volume dos vitro-cerâmicos resultantes a base de diopsidio, de modo a qualifica-los como potenciais materiais hopedeiros de residuos nucleares radioactivos.

  10. Viscoelastic nanocapsules under flow in microdevices

    NASA Astrophysics Data System (ADS)

    Cordeiro, Ana Lucinda Teixeira

    As piroxenas sao um vasto grupo de silicatos minerais encontrados em muitas rochas igneas e metamorficas. Na sua forma mais simples, estes silicatos sao constituidas por cadeias de SiO3 ligando grupos tetrahedricos de SiO4. A formula quimica geral das piroxenas e M2M1T2O6, onde M2 se refere a catioes geralmente em uma coordenacao octaedrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catioes numa coordenacao octaedrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catioes em coordenacao tetrahedrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclinica sao designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composicoes quimicas amplo, em conjugacao com a possibilidade de ajustar as suas propriedades fisicas e quimicas e a durabilidade quimica, tem gerado um interesse mundial devido a suas aplicacoes em ciencia e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicacoes funcionais. O estudo teve objectivos cientificos e tecnologicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formacao de fases cristalinas e solucoes solidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicacao dos novos materiais em diferentes areas tecnologicas, com especial enfase sobre a selagem em celulas de combustivel de oxido solido (SOFC). Com este intuito, prepararam-se varios vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsidio (CaMgSi2O6) e diopsidio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados atraves de um vasto leque de tecnicas. Todos os vidros foram preparados por fusao-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterizacao e cristalizacao de fritas, quer por nucleacao e cristalizacao de vidros monoliticos. Estudaram-se ainda os efeitos de varias substituicoes ionicas em composicoes de diopsidio contendo Al na estrutura, sinterizacao e no comportamento durante a cristalizacao de vidros e nas propriedades dos materiais vitro-cerâmicos, com relevância para a sua aplicacao como selantes em SOFC. Verificou-se que Foi observado que os vidros/vitro-cerâmicos a base de enstatite nao apresentavam as caracteristicas necessarias para serem usados como materiais selantes em SOFC, enquanto as melhores propriedades apresentadas pelos vitro-cerâmicos a base de diopsidio qualificaram-nos para futuros estudos neste tipo de aplicacoes. Para alem de investigar a adequacao dos vitro-cerâmicos a base de clinopyroxene como selantes, esta tese tem tambem como objetivo estudar a influencia dos agentes de nucleacao na nucleacao em volume dos vitro-cerâmicos resultantes a base de diopsidio, de modo a qualifica-los como potenciais materiais hopedeiros de residuos nucleares radioactivos.

  11. Stellar activity in high-precision photometric and spectroscopic transit observations

    NASA Astrophysics Data System (ADS)

    Oshagh, Mahmoudreza

    As piroxenas sao um vasto grupo de silicatos minerais encontrados em muitas rochas igneas e metamorficas. Na sua forma mais simples, estes silicatos sao constituidas por cadeias de SiO3 ligando grupos tetrahedricos de SiO4. A formula quimica geral das piroxenas e M2M1T2O6, onde M2 se refere a catioes geralmente em uma coordenacao octaedrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catioes numa coordenacao octaedrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catioes em coordenacao tetrahedrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclinica sao designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composicoes quimicas amplo, em conjugacao com a possibilidade de ajustar as suas propriedades fisicas e quimicas e a durabilidade quimica, tem gerado um interesse mundial devido a suas aplicacoes em ciencia e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicacoes funcionais. O estudo teve objectivos cientificos e tecnologicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formacao de fases cristalinas e solucoes solidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicacao dos novos materiais em diferentes areas tecnologicas, com especial enfase sobre a selagem em celulas de combustivel de oxido solido (SOFC). Com este intuito, prepararam-se varios vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsidio (CaMgSi2O6) e diopsidio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados atraves de um vasto leque de tecnicas. Todos os vidros foram preparados por fusao-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterizacao e cristalizacao de fritas, quer por nucleacao e cristalizacao de vidros monoliticos. Estudaram-se ainda os efeitos de varias substituicoes ionicas em composicoes de diopsidio contendo Al na estrutura, sinterizacao e no comportamento durante a cristalizacao de vidros e nas propriedades dos materiais vitro-cerâmicos, com relevância para a sua aplicacao como selantes em SOFC. Verificou-se que Foi observado que os vidros/vitro-cerâmicos a base de enstatite nao apresentavam as caracteristicas necessarias para serem usados como materiais selantes em SOFC, enquanto as melhores propriedades apresentadas pelos vitro-cerâmicos a base de diopsidio qualificaram-nos para futuros estudos neste tipo de aplicacoes. Para alem de investigar a adequacao dos vitro-cerâmicos a base de clinopyroxene como selantes, esta tese tem tambem como objetivo estudar a influencia dos agentes de nucleacao na nucleacao em volume dos vitro-cerâmicos resultantes a base de diopsidio, de modo a qualifica-los como potenciais materiais hopedeiros de residuos nucleares radioactivos.

  12. Starch and polyethylene based bone-analogue composite biomaterials

    NASA Astrophysics Data System (ADS)

    Reis, Rui Luis Goncalves dos

    As piroxenas sao um vasto grupo de silicatos minerais encontrados em muitas rochas igneas e metamorficas. Na sua forma mais simples, estes silicatos sao constituidas por cadeias de SiO3 ligando grupos tetrahedricos de SiO4. A formula quimica geral das piroxenas e M2M1T2O6, onde M2 se refere a catioes geralmente em uma coordenacao octaedrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catioes numa coordenacao octaedrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catioes em coordenacao tetrahedrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclinica sao designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composicoes quimicas amplo, em conjugacao com a possibilidade de ajustar as suas propriedades fisicas e quimicas e a durabilidade quimica, tem gerado um interesse mundial devido a suas aplicacoes em ciencia e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicacoes funcionais. O estudo teve objectivos cientificos e tecnologicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formacao de fases cristalinas e solucoes solidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicacao dos novos materiais em diferentes areas tecnologicas, com especial enfase sobre a selagem em celulas de combustivel de oxido solido (SOFC). Com este intuito, prepararam-se varios vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsidio (CaMgSi2O6) e diopsidio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados atraves de um vasto leque de tecnicas. Todos os vidros foram preparados por fusao-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterizacao e cristalizacao de fritas, quer por nucleacao e cristalizacao de vidros monoliticos. Estudaram-se ainda os efeitos de varias substituicoes ionicas em composicoes de diopsidio contendo Al na estrutura, sinterizacao e no comportamento durante a cristalizacao de vidros e nas propriedades dos materiais vitro-cerâmicos, com relevância para a sua aplicacao como selantes em SOFC. Verificou-se que Foi observado que os vidros/vitro-cerâmicos a base de enstatite nao apresentavam as caracteristicas necessarias para serem usados como materiais selantes em SOFC, enquanto as melhores propriedades apresentadas pelos vitro-cerâmicos a base de diopsidio qualificaram-nos para futuros estudos neste tipo de aplicacoes. Para alem de investigar a adequacao dos vitro-cerâmicos a base de clinopyroxene como selantes, esta tese tem tambem como objetivo estudar a influencia dos agentes de nucleacao na nucleacao em volume dos vitro-cerâmicos resultantes a base de diopsidio, de modo a qualifica-los como potenciais materiais hopedeiros de residuos nucleares radioactivos.

  13. Clinopyroxene based glasses and glass-ceramics for functional applications

    NASA Astrophysics Data System (ADS)

    Goel, Ashutosh

    As piroxenas sao um vasto grupo de silicatos minerais encontrados em muitas rochas igneas e metamorficas. Na sua forma mais simples, estes silicatos sao constituidas por cadeias de SiO3 ligando grupos tetrahedricos de SiO4. A formula quimica geral das piroxenas e M2M1T2O6, onde M2 se refere a catioes geralmente em uma coordenacao octaedrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catioes numa coordenacao octaedrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catioes em coordenacao tetrahedrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclinica sao designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composicoes quimicas amplo, em conjugacao com a possibilidade de ajustar as suas propriedades fisicas e quimicas e a durabilidade quimica, tem gerado um interesse mundial devido a suas aplicacoes em ciencia e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicacoes funcionais. O estudo teve objectivos cientificos e tecnologicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formacao de fases cristalinas e solucoes solidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicacao dos novos materiais em diferentes areas tecnologicas, com especial enfase sobre a selagem em celulas de combustivel de oxido solido (SOFC). Com este intuito, prepararam-se varios vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsidio (CaMgSi2O6) e diopsidio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados atraves de um vasto leque de tecnicas. Todos os vidros foram preparados por fusao-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterizacao e cristalizacao de fritas, quer por nucleacao e cristalizacao de vidros monoliticos. Estudaram-se ainda os efeitos de varias substituicoes ionicas em composicoes de diopsidio contendo Al na estrutura, sinterizacao e no comportamento durante a cristalizacao de vidros e nas propriedades dos materiais vitro-cerâmicos, com relevância para a sua aplicacao como selantes em SOFC. Verificou-se que Foi observado que os vidros/vitro-cerâmicos a base de enstatite nao apresentavam as caracteristicas necessarias para serem usados como materiais selantes em SOFC, enquanto as melhores propriedades apresentadas pelos vitro-cerâmicos a base de diopsidio qualificaram-nos para futuros estudos neste tipo de aplicacoes. Para alem de investigar a adequacao dos vitro-cerâmicos a base de clinopyroxene como selantes, esta tese tem tambem como objetivo estudar a influencia dos agentes de nucleacao na nucleacao em volume dos vitro-cerâmicos resultantes a base de diopsidio, de modo a qualifica-los como potenciais materiais hopedeiros de residuos nucleares radioactivos.

  14. Bacterial genus is a risk factor for major amputation in patients with diabetic foot.

    PubMed

    Cardoso, Natália Anício; Cisneiros, Lígia DE Loiola; Machado, Carla Jorge; Cenedezi, Juliana Merlin; Procópio, Ricardo Jayme; Navarro, Túlio Pinho

    2017-01-01

    to evaluate whether bacterial genus is a risk factor for major amputation in patients with diabetic foot and infected ulcer. we conducted a case-control, observational study of 189 patients with infected ulcers in diabetic feet admitted to the Vascular Surgery Service of the Risoleta Tolentino Neves Hospital, from January 2007 to December 2012. The bacteriological evaluation was performed in deep tissue cultures from the lesions and amputation was considered major when performed above the foot'smiddle tarsus. the patients'mean age was 61.9±12.7 years; 122 (64.6%) were men. The cultures were positive in 86.8%, being monomicrobial in 72% of the cases. In patients with major amputation, Acinetobacter spp. (24.4%), Morganella spp. (24.4%), Proteus spp. (23.1%) and Enterococcus spp. (19.2%) were the most frequent types of bacteria. The most commonly isolated species were Acinetobacter baumannii, Morganella morganii, Pseudomonas aeruginosa and Proteus mirabilis. As predictors of major amputation, we identified the isolation of the generaAcinetobacter spp. and Klebsiella spp., serum creatinine ≥1.3mg/dl and hemoglobin <11g/dl. the bacterial genera Acinetobacter spp. and Klebsiella spp. identified in infected ulcers of patients with diabetic foot were associated with a higher incidence of major amputation. avaliar se gênero bacteriano é fator de risco para amputação maior em pacientes com pé diabético e úlcera infectada. estudo observacional do tipo caso-controle de 189 pacientes com úlcera infectada em pé diabético admitidos pelo Serviço de Cirurgia Vascular do Hospital Risoleta Tolentino Neves, no período de janeiro de 2007 a dezembro de 2012. A avaliação bacteriológica foi realizada em cultura de tecido profundo das lesões e a amputação foi considerada como maior quando realizada acima do médio tarso do pé. a média de idade dos pacientes foi 61,9±12,7 anos e 122 (64,6%) eram homens. As culturas foram positivas em 86,8%, sendo monomicrobianas em 72% dos casos. Nos pacientes com amputação maior, os gêneros de bactérias mais frequentes foram Acinetobacter spp. (24,4%), Morganella spp. (24,4%), Proteus spp. (23,1%) e Enterococcus spp. (19,2%) e as espécies mais isoladas foram Acinetobacter baumannii, Morganella morganii, Pseudomonas aeruginosa e Proteus mirabilis. Identificou-se como fatores preditivos para amputação maior o isolamento dos gêneros Acinetobacter spp. e Klebsiella spp.,e níveis séricos de creatinina ≥1,3mg/dl e de hemoglobina <11g/dl. os gêneros bacterianos Acinetobacter spp. e Klebsiella spp. identificados nas úlceras infectadas dos pacientes com pé diabético associaram-se a maior incidência de amputação maior.

  15. Phlebitis associated with peripheral intravenous catheters in adults admitted to hospital in the Western Brazilian Amazon.

    PubMed

    Enes, Sandra Maria Sampaio; Opitz, Simone Perufo; Faro, André Ricardo Maia da Costa de; Pedreira, Mavilde de Luz Gonçalves

    2016-04-01

    To identify the presence of phlebitis and the factors that influence the development of this complication in adult patients admitted to hospital in the western Brazilian Amazon. Exploratory study with a sample of 122 peripheral intravenous catheters inserted in 122 patients in a medical unit. Variables related to the patient and intravenous therapy were analyzed. For the analysis, we used chi-square tests of Pearson and Fisher exact test, with 5% significance level. Complication was the main reason for catheter removal (67.2%), phlebitis was the most frequent complication (31.1%). The mean duration of intravenous therapy use was 8.81 days in continuous and intermittent infusion (61.5%), in 20G catheter (39.3%), inserted in the dorsal hand vein arc (36.9 %), with mean time of usage of 68.4 hours. The type of infusion (p=0.044) and the presence of chronic disease (p=0.005) and infection (p=0.007) affected the development of phlebitis. There was a high frequency of phlebitis in the sample, being influenced by concomitant use of continuous and intermittent infusion of drugs and solutions, and more frequent in patients with chronic diseases and infection. Identificar a presença de flebite e os fatores que influenciam o desenvolvimento desta complicação em pacientes adultos internados em hospital da Amazônia Ocidental Brasileira. Estudo exploratório, com amostra de 122 cateteres intravenosos periféricos instalados em 122 pacientes de uma unidade de clínica médica. Foram analisadas variáveis relacionadas ao paciente e à terapia intravenosa. Para a análise utilizaram-se os testes de Qui-quadrado de Pearson e Exato de Fisher, com nível de significância de 5%. A complicação foi o principal motivo da retirada do cateter (67,2%), e a flebite a complicação mais frequente (31,1%). O tempo médio de uso de terapia intravenosa foi de 8,81 dias, em infusão contínua e intermitente (61,5%), em cateter calibre 20G (39,3%), inseridos nas veias do arco dorsal da mão (36,9%), com média de tempo de permanência de 68,4 horas. O tipo de infusão (p=0,044) e a presença de doença crônica (p=0,005) e de infecção (p=0,007) influenciaram o desenvolvimento de flebite. Houve alta frequência de flebite na amostra estudada, sendo influenciada pelo emprego concomitante de infusão contínua e intermitente de fármacos e soluções, e mais frequente em pacientes com doenças crônicas e infecção.

  16. Mouthpiece ventilation in Duchenne muscular dystrophy: a rescue strategy for noncompliant patients.

    PubMed

    Fiorentino, Giuseppe; Annunziata, Anna; Cauteruccio, Rosa; Frega, Gianfranco Scotto di; Esquinas, Antonio

    2016-01-01

    To evaluate mouthpiece ventilation (MPV) in patients with Duchenne muscular dystrophy (DMD) who are noncompliant with noninvasive ventilation (NIV). We evaluated four young patients with DMD who had previously refused to undergo NIV. Each patient was reassessed and encouraged to try MPV. The four patients tolerated MPV well and were compliant with NIV at home. MPV proved to be preferable and more comfortable than NIV with any other type of interface. Two of the patients required overnight NIV and eventually agreed to use a nasal mask during the night. The advantages of MPV over other types of NIV include fewer speech problems, better appearance, and less impact on the patient, eliminating the risk of skin breakdown, gastric distension, conjunctivitis, and claustrophobia. The use of a mouthpiece interface should be always considered in patients with DMD who need to start NIV, in order to promote a positive approach and a rapid acceptance of NIV. Using MPV during the daytime makes patients feel safe and more likely to use NIV at night. In addition, MPV increases treatment compliance for those who refuse to use other types of interfaces. Avaliar a ventilação bucal (VB) em pacientes com distrofia muscular de Duchenne (DMD) não aderentes à ventilação não invasiva (VNI). Foram avaliados quatro pacientes jovens com DMD que anteriormente recusaram-se a se submeter à VNI. Cada paciente foi reavaliado e encorajado a tentar VB. Os quatro pacientes toleraram bem a VB e aderiram ao uso de VNI em casa. O uso de VB provou ser uma alternativa preferível e mais confortável que o uso de VNI com qualquer outro tipo de interface. Dois dos pacientes necessitaram de VNI noturna e eventualmente aceitaram utilizar uma máscara nasal durante a noite. As vantagens da VB sobre outros tipos de VNI incluem menores problemas na fala, melhor aparência e menor impacto no paciente, eliminando o risco de lesões na pele, distensão gástrica, conjuntivite e claustrofobia. O uso da interface bucal sempre deve ser considerado em pacientes com DMD que necessitam iniciar VNI a fim de promover uma abordagem positiva e uma rápida aceitação da VNI. O uso diurno de VB faz com que os pacientes sintam-se seguros e mais propensos a utilizar VNI à noite. Além disso, a VB aumenta a adesão ao tratamento naqueles pacientes que se recusam a utilizar outros tipos de interfaces.

  17. Leadership Practices in Hospital Nursing: A Self of Manager Nurses.

    PubMed

    Silva, Vânea Lúcia Dos Santos; Camelo, Silvia Helena Henriques; Soares, Mirelle Inácio; Resck, Zélia Marilda Rodrigues; Chaves, Lucieli Dias Pedreschi; Santos, Fabiana Cristina Dos; Leal, Laura Andrian

    2017-04-03

    To assess the frequency of the leadership practices performed by the manager nurses of hospital institutions and their association with the variables of the socioprofessional profile. Cross-sectional, descriptive, correlational study conducted in four hospitals in a city of the state of São Paulo. A sociodemographic questionnaire and the instrument Leadership Practices Inventory were used. Data collection and analysis were based on an exemplary Leadership Practices Model. Eighty-four manager nurses participated in the study. The mean values of the leadership practices used by the nurses were: enable others to act (50.6); encourage the heart (48.2); model the way (46.7); challenge the process (43.3); and inspire a shared vision (43.1). Data analysis also evidenced a correlation between the practice encourage the heart and the variables time of care and employment relationship. The study evidenced the presence of manager nurses exercising moderate leadership, and promoting teamwork, an environment of trust, and a horizontal vision. However, moderate values also reveal managerial aspects to be improved by the leaders by means of organizational strategies and/or tools aimed at best leadership practices. Avaliar a frequência das práticas de liderança executadas pelos enfermeiros gerentes de instituições hospitalares e sua associação às variáveis do perfil socioprofissional. Estudo transversal, descritivo e correlacional, realizado em quatro hospitaisde um município do interior paulista. Utilizou-se de questionário sociodemográfico e do instrumento Leadership Practices Inventory. A coleta e a análise de dados foram fundamentadas em um Modelo de Práticas para Liderança exemplar. Participaram 84 enfermeiros gerentes. As médias das práticas de liderança utilizadas pelos enfermeiros foram: capacitar os outros a agir (50,6), encorajar o coração (48,2), traçar o caminho (46,7), desafiar o processo (43,3) e inspirar uma visão compartilhada (43,1). Na análise dos dados também se constatou correlação entre a prática encoraje o coração e as variáveis tempo de assistência e vínculo empregatício. O estudo constatou a presença de enfermeiros gerentes exercendo liderança moderada, promovendo o trabalho em equipe, propiciando um clima de confiança e visão horizontalizada. No entanto, os valores moderados também revelam aspectos gerenciais a serem aprimorados pelos líderes, por meio de ferramentas e/ou estratégias organizacionais em busca de melhores práticas de liderança.

  18. Trombo flutuante em veia femoral

    PubMed Central

    Bertanha, Matheus; Pimenta, Rafael Elias Farres; Brandão, Gustavo Muçouçah Sampaio; Sobreira, Marcone Lima; Moura, Regina; Jaldin, Rodrigo Gibin; de Camargo, Paula Angeleli Bueno; Yoshida, Winston Bonetti

    2017-01-01

    Resumo O trombo venoso flutuante em veia femoral é um tipo de trombo com alto potencial de embolização pulmonar. Entretanto, ainda é controversa a conduta mais apropriada nesses casos. Tratamentos clínicos com anticoagulantes ou fibrinolíticos e trombectomias abertas ou por meio de dispositivos endovasculares vêm sendo empregados ainda sem um critério de indicação bem definido. Apresentamos três casos clínicos de trombos flutuantes em veia femoral, de etiologias distintas, cujos tratamentos e respectivas evoluções serão discutidos. PMID:29930666

  19. Archivo de placas astrométricas del Observatorio de La Plata

    NASA Astrophysics Data System (ADS)

    di Sisto, R.; Orellana, R. B.

    Se ha realizado una base de datos con las placas fotográficas obtenidas con el Astrográfico del Observatorio de La Plata. Se han clasificado un total de 3000 placas obtenidas para asteroides y cometas. El acceso a la base de datos se hará por FTP y la misma contendrá la siguiente información: fecha y tiempo de exposición, coordenadas del centro de placa, tipo de emulsión fotográfica, estado de la placa, objeto fotografiado.

  20. Disks Surrounding Massive Stars: When Computational Models are Confronted by Observations

    DTIC Science & Technology

    2010-01-01

    E. Jones,1 C. Tycner,2 J. A. Benson,3 D. J. Hutter,3 H. R. Schmitt,4,5 T. A. A. Sigut,1 and R. T. Zavala3 RESUMEN Las estrellas masivas se...ser detectados directamente, este material puede ser detectado en el espectro de la radiación que observamos de la estrella . A menudo, el material...circunestelar posee una distribución tipo disco, pero el proceso f́ısico que forma y mantiene estos discos no es bien entendido. Las estrellas Be son un

  1. NOAA Weather Radio

    Science.gov Websites

    Emergencia (EAS) de la Comisión Federal de Comunicaciones, Radio NOAA es una red para todo tipo de peligros . De este modo, es la fuente más comprensiva de información del tiempo y emergencias que està químicos o derramamientos de petróleo). Conocida como "La Voz del Servicio Nacional de Meteorología

  2. Comparing Teaching Styles and Personality Types of EFL Instructors in the Public and Private Sectors (Una comparación de los estilos de enseñanza y los tipos de personalidad de profesores de inglés de los sistemas educativos estatal y privado)

    ERIC Educational Resources Information Center

    Diaz Larenas, Claudio H.; Rodriguez Moran, Andrea Victoria; Poblete Rivera, Karen Jocelyn

    2011-01-01

    This is an exploratory non-experimental research study whose main objective is to compare the teaching styles of a group of thirty teachers of English working in either public or private secondary education in Chile. In order to collect the required data, two instruments were administered to the participants: a teaching style inventory and a…

  3. Representative Command Post Configurations, C3 Structures, and Reference Data. Volume I.

    DTIC Science & Technology

    1978-07-31

    when it becomes cost effective. (4) The configurations and employment concepts can be used for electronic warfare (EW) studies. The detailed layouts...TJI/0! 0, LIKAS INFCCOPERATOR mmTmOE1110"m - -.- an SKI WeI TIpO .o..< - UN THAN do Ma uSIm TIo a D CIM 1 0 ~To NtEN INTRABATTERY WIRE COMMUNICATIONS...34 DE ATTACH/ GIVARO I TTRY -IVARTY ATTACH/ A I A COMG REINF COMO SOC TOC NEW ITRY I (WO NTE 21O (NOTE 21 UNITS FCC FOC FCIR NOTES: I. COUNTERMORTAR

  4. Five-year Experience With Arterial Switch Operation in the First Hours of Life.

    PubMed

    Chasovskyi, Kyrylo; Mykychak, Yaroslav; Rudenko, Nadiia; Vorobyova, Hanna; Yemets, Illya

    2017-01-01

    We assessed morbidity after 2 management strategies for arterial switch operation (ASO) in a single institution: first hours of life surgery and conventional approach. From September 2009 to September 2014, 346 consecutive patients who underwent ASO were enrolled. The study group included 92 patients who underwent ASO in the first 24 hours after birth (group I). The control group consisted of 254 patients who underwent ASO after 24 hours of life in the conventional way (group II). Three outcomes were analyzed: postoperative ventilation time (VT), post-extubation hospital length of stay (peLOS), and a composite morbidity index, defined as postoperative VT + peLOS + occurrence of selected major complications. Overall 30-day survival was 98% (2 [2%] group I vs 5 [2%] group II, P = 1.000). Fifty (13.3%) major complications were observed: 14 (15%) in group I and 36 (15%) in group II (P = 0.635). Although peLOS and morbidity index did not differ significantly between groups, postoperative VT (42 hours [24, 67] vs 27 hours [22, 47], P = 0.008) and total hospital stay were significantly longer in group II (18 days [10, 19] vs 14 days [12, 18]). A median volume of 80 mL (60-100 mL) of autologous umbilical cord blood was collected (80 mL, group 1 vs 60 mL, group II; P = 0.090). Homologous blood cell transfusion was avoided in 70 patients (78%) in group I and in 13 patients (6%) in group II (P < 0.001). Arterial switch operation during the initial 24 hours of life has similar outcomes in view of morbidity and mortality to the conventional approach. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Incorporando a variabilidade no processo de identificação do modelo de máximo global no Grade of Membership (GoM): considerações metodológicas

    PubMed Central

    Guedes, Gilvan Ramalho; Siviero, Pamila Cristina Lima; Caetano, André Junqueira; Machado, Carla Jorge; Brondízio, Eduardo

    2012-01-01

    A disponibilidade de bases de dados cada vez mais complexas e multidimensionais é um dos principais motivadores para o aumento do número de estudos que utilizam análises multivariadas baseadas em lógica de conjuntos nebulosos. Apesar da disseminação do método Grade of Membership nos trabalhos empíricos brasileiros da área de ciências sociais e saúde, questões relativas à identificabilidade e estabilidade dos parâmetros finais estimados pelo programa GoM 3.4 não foram suficientemente aprofundadas. Dada a relevância de se obterem parâmetros únicos e estáveis, Guedes et al. (2010) propuseram um procedimento empírico para localizar um modelo de máximo global (MG) com parâmetros estáveis. Entretanto, seu localizador de MG não incorpora qualquer medida de variabilidade. Neste artigo, tal limitação é contornada por meio da utilização de uma estatística de ponderação – Máximo Global Ponderado (MGP) – semelhante ao coeficiente de variação. Esse indicador busca não penalizar de forma desproporcional situações nas quais os desvios médios, apesar de diferentes de zero, são muito pequenos. Apresentam-se evidências de que o localizador MGP reduz a distância do modelo identificado à real estrutura latente dos dados em análise, quando comparados ao modelo identificado pelo localizador não ponderado, MG. PMID:23293402

  6. Family violence against children and adolescents in context: How the territories of care are imbricated in the picture.

    PubMed

    Carlos, Diene Monique; Ferriani, Maria das Graças Carvalho

    2016-08-08

    to understand the context of care addressed to the families involved in family violence against children and adolescents (IVCA), as produced in the context of the Primary Health Care (PHC), from the vantage point of the practitioners of a municipality in the State of Sao Paulo. qualitative research of the social-strategic type, based on the Complexity Paradigm. The participants were 41 health practitioners in five health units of the municipality under study, pertaining to the five districts of the municipality. Data collection was done through 5 focus groups and 10 semi-structured interviews from April 24th 2013 to December 12th 2013. Data analysis was oriented by the comprehension and contextualization mindset and based on the dialogic, recursive and hologramatic principles. two main issues regarding the care provided by the Health of the Family team were identified: the context of this violence (the domestic space) and the power relations that prevail in the territory where this violence surfaces. The community health workers are the targets of specific attention because they experience the live/work dialogic in this same area. paying attention to the territory, and considering the complexity of contexts and dimensions is inherently linked to the design of care to families involved in IVCA in the PHC environment. compreender o contexto de cuidado direcionado às famílias envolvidas na violência intrafamiliar contra crianças e adolescentes (VICCA), produzido a partir da Atenção Primária à Saúde (APS), sob a ótica de profissionais de um município do interior do estado de São Paulo. pesquisa qualitativa, do tipo social estratégica, fundamentada pelo Paradigma da Complexidade. Participaram do estudo 41 profissionais de saúde de cinco unidades do município estudado, cada qual pertencente a um de seus cinco Distritos Sanitários. A coleta de dados foi realizada por meio de 5 grupos focais e 10 entrevistas semiestruturadas, no período de 24/04/13 a 17/12/13. As noções de compreensão e contextualização, e os princípios dialógicos, recursivo e hologramático direcionaram a análise dos dados. identificou-se duas questões cruciais para o cuidado desenvolvido pela equipe de saúde às famílias: o contexto onde essa violência ocorre (O espaço doméstico), e as relações de poder existentes na emergência desse cuidado no território. Os agentes comunitários merecem especial atenção por viverem a dialógica do morar-trabalhar em uma mesma área. o olhar para o território, considerando a complexidade de contextos e dimensões, se apresenta como inerente para o delineamento do cuidado às famílias envolvidas na VICCA no âmbito da APS. comprender el contexto de cuidado dirigido hacia las familias involucradas en violencia familiar contra niños y adolescentes (VICNA) que resulta de la Atención Primaria de la Salud (PHC) desde la óptica de los profesionales de un municipio del interior de Sao Paulo. investigación cualitativa del tipo social-estratégica, fundamentada en el Paradigma de la Complejidad. Participaron en el estudio 41 profesionales de salud de cinco unidades del municipio en estudio, cada una perteneciente a uno de los cinco Distritos Sanitarios. La recolección de datos se realizó por medio de cinco grupos focales y 10 entrevistas semi-estructuradas en el período entre 24/04/2013 y 17/12/2013. Las nociones de comprensión y contextualización y los principios dialógicos, recursivo y hologramático guiaron el análisis de los datos. se identificaron dos cuestiones cruciales para el cuidado desarrollado por el equipo de salud de las familias: el contexto en ocurre esta violencia (El espacio doméstico) y las relaciones de poder que existen en la emergencia de ese cuidado en el territorio. Los trabajadores comunitarios merecen una atención especial ya que viven la dialógica de trabajar/habitar en la misma área. la mirada sobre el territorio, considerando la complejidad de contextos y dimensiones, se presenta como inherente al diseño del cuidado de las familias involucradas en la VICNA en el ámbito de la APS.

  7. El espectro de KX TrA entre 1990 y 1996

    NASA Astrophysics Data System (ADS)

    Brandi, E.; García, L.; Ferrer, O.; Barbá, R.

    La estrella simbiótica KX TrA = He2-177 fue observada espectroscópicamente con el telescopio de 2.15 m del CASLEO entre los años 1990 y 1996, utilizándose resoluciones intermedia y alta. El rango espectral estudiado se extiende desde 4400 Åa 7200 Å. La historia fotométrica de KX TrA presenta explosiones del mismo tipo que las mostradas por la nova lenta RR Tel y su espectro de alta excitación, muy rico en líneas de emisión, es también similar al de RR Tel. Por lo tanto, es importante analizar la evolución espectral de KX TrA en el tiempo, prestando especial atención a los posibles cambios en los niveles de excitación. Las emisiones presentes corresponden a transiciones permitidas y prohibidas con un amplio rango de ionización, incluyéndose las anchas e intensas líneas originadas por scattering Raman de O VI en λλ 6825 y 7082 Å. En el período cubierto por nuestras observaciones se estudia la variación de la intensidad relativa de las emisiones, el comportamiento de las velocidades radiales y los cambios de perfiles de las líneas, especialmente en Hα y Hβ. El contínuo de la región roja observada indica un tipo espectral no más tardío que M3 para la componente gigante fría del sistema.

  8. Ventos em supergigantes B[e] das nuvens de Magalhães e da Galáxia

    NASA Astrophysics Data System (ADS)

    de Araújo, F. X.; Pilling, D. A.; Pereira, C. B.; Fernandes, M. B.

    2003-08-01

    As Supergigantes B[e] apresentam as seguintes características: (i) alta luminosidade; (ii) espectro típico de estrelas de tipo B; (iii) linhas permitidas e proibidas em emissão de metais de baixa ionização, especialmente FeII; (iv) linhas de Balmer, e por vêzes também dos ions HeI e FeII, com perfis tipo P Cygni indicativos de altas taxas de perda de massa. Atualmente estamos desenvolvendo um projeto que visa comparar as propriedades fisicas (principalmente e v¥) dos ventos destes objetos nas Nuvens de Magalhães e na Galaxia. O objetivo é estudar a influência da metalicidade. No presente painel apresentamos uma determinação das velocidades terminais de 11 estrelas, sendo 4 na GNM (Hen S111, 66, R126 e Hen S93), 4 na PNM (Hen S18, S23, S65 e R4) e 3 na Galaxia (CPD-529243, MWC 300 e GG Car). Nossos dados são espectros de alta resolução obtidos no telescópio 1.52m do ESO com o espectrógrafo FEROS. Para determinar as velocidades terminais usamos as linhas Hd e HeI 3888 Å cujas componentes em absorção costumam estar livres de "blends" e estruturas. Nossos resultados sugerem que as velocidades de expansão na GNM são maiores (ainda que apenas ligeiramente) do que aquelas da PNM, como esperado. No entanto, os objetos da Galaxia não parecem seguir a mesma tendência.

  9. Diagnosis of compliance of health care product processing in Primary Health Care.

    PubMed

    Roseira, Camila Eugenia; Silva, Darlyani Mariano da; Passos, Isis Pienta Batista Dias; Orlandi, Fabiana Souza; Padoveze, Maria Clara; Figueiredo, Rosely Moralez de

    2016-11-21

    identify the compliance of health care product processing in Primary Health Care and assess possible differences in the compliance among the services characterized as Primary Health Care Service and Family Health Service. quantitative, observational, descriptive and inferential study with the application of structure, process and outcome indicators of the health care product processing at ten services in an interior city of the State of São Paulo - Brazil. for all indicators, the compliance indices were inferior to the ideal levels. No statistically significant difference was found in the indicators between the two types of services investigated. The health care product cleaning indicators obtained the lowest compliance index, while the indicator technical-operational resources for the preparation, conditioning, disinfection/sterilization, storage and distribution of health care products obtained the best index. the diagnosis of compliance of health care product processing at the services assessed indicates that the quality of the process is jeopardized, as no results close to ideal levels were obtained at any service. In addition, no statistically significant difference in these indicators was found between the two types of services studied. identificar a conformidade do processamento de produtos para saúde na Atenção Primária à Saúde e avaliar possível diferença na conformidade entre as unidades caracterizadas como Unidade Básica de Saúde e Unidade Saúde da Família. estudo quantitativo, observacional, descritivo e inferencial, com a aplicação de indicadores de estrutura, processo e resultado referentes ao processamento de produtos para a saúde em dez unidades, de um município do interior de São Paulo - Brasil. todos os indicadores obtiveram índice de conformidade inferior ao ideal. Não houve diferença estatisticamente significante nos indicadores entre os dois tipos de unidades investigadas, sendo o indicador de limpeza de produtos para saúde o de menor índice de conformidade, enquanto indicador de recursos técnico-operacionais para preparo, acondicionamento, desinfecção/esterilização, guarda e distribuição de produtos para saúde, o de melhor índice. o diagnóstico de conformidade do processamento de produtos para saúde nas unidades avaliadas indica comprometimento da qualidade do processo, uma vez que não foram obtidos resultados próximos ao valor ideal em nenhuma unidade. Além disso, não houve diferença estatisticamente significante desses indicadores entre os dois tipos de unidades estudadas. identificar la conformidad del procesamiento de productos para la salud en la Atención Primaria a la Salud y evaluar una posible diferencia en la conformidad entre las unidades caracterizadas: Unidad Básica de Salud y Unidad Salud de la Familia. estudio cuantitativo, observacional, descriptivo e inferencial; se aplicaron indicadores de estructura, proceso y resultado, referentes al procesamiento de productos para la salud en diez unidades de un municipio del interior de Sao Paulo, Brasil. todos los indicadores obtuvieron índice de conformidad inferior a lo ideal. No hubo diferencia estadísticamente significativa de los indicadores entre los dos tipos de unidades investigadas, siendo el indicador de limpieza de productos para la salud el de menor índice de conformidad; por otro lado, como indicador de recursos técnico-operacionales para preparación, acondicionamiento, desinfección/esterilización, almacenamiento y distribución de productos para la salud, fue el de mejor índice. el diagnóstico de conformidad del procesamiento de productos para la salud en las unidades evaluadas indica que está comprometida la calidad del proceso, ya que no fueron obtenidos resultados próximos al valor ideal en ninguna unidad. Además de eso, no hubo diferencia estadísticamente significativa de esos indicadores entre los dos tipos de unidades estudiadas.

  10. Clinical and epidemiological aspects of cornea transplant patients of a reference hospital.

    PubMed

    Cruz, Giovanna Karinny Pereira; Azevedo, Isabelle Campos de; Carvalho, Diana Paula de Souza Rego Pinto; Vitor, Allyne Fortes; Santos, Viviane Euzébia Pereira; Ferreira, Marcos Antonio

    2017-06-08

    clinically characterizing cornea transplant patients and their distribution according to indicated and post-operative conditions of cornea transplantation, as well as estimating the average waiting time. a cross-sectional, descriptive and analytical study performed for all cornea transplants performed at a reference service (n=258). Data were analyzed using Statistical Package for the Social Sciences, version 20.0. the main indicator for cornea transplant was keratoconus. The mean waiting time for the transplant was approximately 5 months and 3 weeks for elective transplants and 9 days for urgent cases. An association between the type of corneal disorder with gender, age, previous surgery, eye classification, glaucoma and anterior graft failure were found. keratoconus was the main indicator for cornea transplant. Factors such as age, previous corneal graft failure (retransplantation), glaucoma, cases of surgeries prior to cornea transplant (especially cataract surgery) may be related to the onset corneal endothelium disorders. caracterizar clínicamente los pacientes trasplantados y su distribución, con descripción de las condiciones indicadoras y posoperatorias de los trasplantes de córneas, así como estimar el tiempo promedio en la fila de espera. estudio epidemiológico, transversal, descriptivo y analítico, realizado con todos los trasplantes de córnea realizados en un servicio de referencia (n=258). Los datos fueron analizados con el software Statistical Package for the Social Sciences, versión 20.0. la principal condición indicadora para el trasplante de córnea fue el queratocono. El tiempo promedio en fila de espera para realización del trasplante fue de aproximadamente 5 meses y tres semanas, para trasplantes electivos y de 9 días para los casos de urgencia. Existió asociación entre el tipo de disturbio de la córnea con: sexo, intervalo etario, cirugía previa, clasificación del ojo, glaucoma y rechazo del injerto anterior. el queratocono fue la principal condición indicadora para el trasplante de córnea. Factores como: edad; rechazo de injerto de córnea anterior (retrasplante); glaucoma; y casos de cirugías previas al trasplante de córnea, destacando la cirugía de catarata, pueden estar relacionados con el aparecimiento de disturbios de la córnea de tipo endotelial. caracterizar clinicamente os pacientes transplantados e sua distribuição com descrição das condições indicadoras e pós-operatórias dos transplantes de córneas, bem como estimar o tempo médio em fila de espera. estudo epidemiológico, transversal, descritivo e analítico, realizado com todos os transplantes de córnea realizados em um serviço de referência (n= 258). Os dados foram analisados com uso do software Statistical Package for the Social Sciences, versão 20.0. a principal condição indicadora para o transplante de córnea foi o ceratocone. O tempo médio em fila de espera para realização do transplante foi de aproximadamente 5 meses e três semanas para o transplantes eletivos e 9 dias para os casos de urgência. Existiu associação entre o tipo de distúrbio da córnea com sexo, faixa etária, cirurgia prévia, classificação do olho, glaucoma e falência do enxerto anterior. o ceratocone foi a principal condição indicadora para o transplante de córnea. Fatores como idade, falência de enxerto corneano anterior (retransplante), glaucoma, casos de cirurgias prévias ao transplante de córnea, com destaque para a cirurgia de catarata, podem estar relacionados com o aparecimento de distúrbios da córnea do tipo endotelial.

  11. Vandenberg AFB, California. Limited Surface Observations Climatic Summary (LISOCS). Parts A-F.

    DTIC Science & Technology

    1985-06-01

    TSURFACE WINDS BE .T S I i/, AZ PERCENTAGE FREQUENCY OF WIND DIRECTION AND SPEED (FROM HOURLY OBSERVATIONS) TATION STATION AM lAll COSTS CLASSl MOUSl (LI t...6 VARIL_. Ii CALM - _ _ _ _ _ _ _ _ _ _ _ TOTAL NUMBER OF OBSERVATIONS USAFETAC TO099 DES (OL A) PREVIOUS EDITIONS 0F THIS F0ORM AWE OSOLETE...I .. . . El....,,l IX) ll , x I i.IObl. MIe. Mo. of HIo...l .’II. TIpO ..?,.O IJ ~ .Hm 3l# :I R,.I. .n’. -, -. * +O sJ32P o6iF .73p *IlOp .93F T...I

  12. The Application of Lagrange and Pidduck-Kent Gradient Models to Guns Using Low Molecular Weight Gases

    DTIC Science & Technology

    1993-02-01

    E-1) the gas internal specific energy is RTo Eo ,(E-2) 91 / and the gas sound speed is 2 YPo -yRTo co = = (E-3) Po(1 - lpo) (1 - Tipo ) 2"" We note...Manager U.S. Army Aviation School 155mm Howitzer, M109A6, Paladin ATTN: Aviation Agency ATTN: SFAE-AR-HIP-IP, Mr. R, De Kleine Fort Rucker, AL 36360...etc.) 5. Has the information in this report led to any quantitative savings as far as man-hours or dollars saved, operating costs avoided, or

  13. Higher Order Logic for Platform Identification in a Production System. A Method of Extending the Capabilities of a Production System Applied to Tactical Situation Assessment.

    DTIC Science & Technology

    1979-10-17

    a y s, depending tipo t i f l i t ’ ortle’r of t I le’ rule at’ce’ssmng ami d the ’ order in ss hm~’h data are’ i’ece’ t te ’d - Ofle’ possible’ e h...BEARING The I’SM ss ste mn provide’s the typ e—num ber oh ’ an intercepte d signal S I , tilt ’ Iat ibutle ant i longitutit ’ of ’ t he sensor pos it ion

  14. Remedial Investigation Report, Presidio Main Installation, Presidio of San Francisco. Volume 5: Figures 7-15

    DTIC Science & Technology

    1997-01-01

    YFO U A .. SOIL BORING1 3 . 4 SURFACE SOIL SAM SSURFACES COVERE S::::::::::::::::i-•. PAVEMENT OR BUll ...EXPLANW SOIL BORING .A SURFACE SOIL SAIN LII. PVMNOR BUll .5____iSTAIN ED AREAS LITHOOGY E/DUNOTES: 1. ALL...WCALXI ~q~qJO~i II~ %~1, z U 0 a LL 0 L c 0S-0 F- tr C14 Uj- Ui -Z w- z zow w0 m Z z z 0 0on coLi/ in z On.. 0 LL -J Ua. z C 0 w D TIPo 44f -lot a26

  15. Use of cuff tear arthroplasty head prosthesis for rotator cuff arthropathy treatment in elderly patients with comorbidities.

    PubMed

    Carvalho, Cassiano Diniz; Andreoli, Carlos Vicente; Pochini, Alberto de Castro; Ejnisman, Benno

    2016-01-01

    To evaluate the clinical and functional behavior of patients undergoing cuff tear arthroplasty at different stages of the disease. Cuff tear arthroplasty hemiarthroplasties were performed in 34 patients with rotator cuff arthropathy and associated comorbidities, classified according to Seebauer. The mean age was 76.3 years, and the sample comprised 23 females (67.6%) and 11 males (32.4%). The mean follow-up period was 21.7 months, and evaluations were performed using the Visual Analog Scale for pain and the Constant scale. There were no statistically significant differences in the mean reduction in the Visual Analog Scale or in the Constant scale increase between the female and male groups. The variation between the pre- and postoperative Visual Analog Scale and Constant scale evaluations was significant. There was also no statistically significant difference between the Seebauer classification groups regarding the mean Visual Analog Scale reduction, or the mean Constant scale increase. Cuff tear arthroplasty shoulder hemiarthroplasty is a good option for rotator cuff arthropathy in patients with comorbidities. Avaliar o comportamento clínico e funcional dos pacientes submetidos à artroplastia do tipo cuff tear arthroplasty para o tratamento da artropatia do manguito rotador em diferentes estágios da afecção. Foram realizadas 34 hemiartroplastias do tipo cuff tear arthroplasty em 34 pacientes com artropatia do manguito rotador e comorbidades associadas, classificadas de acordo com Seebauer. A média de idade foi de 76,3 anos, sendo 23 pacientes do sexo feminino (67,6%) e 11 do sexo masculino (32,4%). O seguimento médio foi de 21,7 meses e a avaliação foi realizada por meio da Escala Visual Analógica da dor e pela escala de Constant. Não houve diferença estatisticamente significante entre os grupos feminino e masculino, tanto nas médias de redução na Escala Visual Analógica quanto nas de aumento na escala de Constant. A variação entre as avaliações da Escala Visual Analógica e da escala de Constant pré e pós-operatórias foi significante. Não houve diferença estatisticamente significante entre os grupos de classificação de Seebauer quanto às médias de redução na Escala Visual Analógica e nem quanto às médias de aumento na escala de Constant, e não houve casos de infecção. A hemiartroplastia do ombro tipo cuff tear arthroplasty é boa uma opção nos pacientes com artropatia do manguito rotador, especialmente em pacientes com comorbidades.

  16. Observações das explosões cósmicas de raios gama GRB021004 e GRB021211 com o satélite HETE

    NASA Astrophysics Data System (ADS)

    Braga, J.; Ricker, G.; Hurley, K.; Lamb, D.; Grew, G.; et al.

    2003-08-01

    O High Energy Transient Explorer (HETE) é o primeiro satélite inteiramente dedicado ao estudo das explosões cósmicas de raios gama (ECRGs). Lançado em 9 de outubro de 2000, o HETE possui instrumentação capaz de observar as ECRGs desde o UV até raios gama e localizá-las com precisão de ~ 1-10 minutos de arco. As localizações das ECRGs detectadas são disseminadas rapidamente (em alguns segundos) pela Internet através de uma rede de estações de recepção ao longo do equador. A participação brasileira nesse projeto se dá através da montagem e operação de uma estação de recepção em Natal, RN, e da participação na equipe científica da missão. Neste trabalho são apresentados resultados da observação pelo HETE de duas ECRGs: GRB 021004 e GRB 021211. A GRB021004 foi detectada em raios gama pelo HETE em 4 de outubro de 2002 e localizada em raios-X em apenas 48 s, quando a emissão de raios gama ainda estava se processando. A explosão, relativamente brilhante e longa, durou aproximadamente 100 s. Um transiente óptico de magnitude 15 foi detectado no local da explosão nove minutos após o evento, e observações realizadas após 7 horas determinaram um desvio para o vermelho de absorção de 1,6. O GRB021004 foi o burst mais bem observado até o momento e suas observações em vários comprimentos de onda têm sido fundamentais para o aprimoramento dos modelos de ECRGs. O GRB21211, um burst brilhante e rico em raios-X, foi detectado em 11 de dezembro de 2002 e localizado em raios-X em 22 s após o início do evento. A duração do burst foi de 2,3 s em altas energias (85 a 400 keV) e de 8,5 s em baixas energias (2 a 10 keV). Caso essa explosão não tivesse sido rapidamente localizada pelo HETE, ela teria sido classificada como "opticamente escura", já que o transiente óptico decaiu rapidamente de R < 14 a R»19 dentro dos primeiros 20 minutos e já estava mais fraco do que R»23 depois de 24 horas da ocorrência do burst. Serão discutidas as implicações desse resultado nos modelos de afterglows de ECRGs.

  17. A fonte ionizante do disco de acreção no núcleo de NGC1097

    NASA Astrophysics Data System (ADS)

    Silva, R. N.; Storchi-Bergmann, T.

    2003-08-01

    Observações em raios-X revelam o "coração" dos núcleos ativos de galáxias, pois esse tipo de radiação provém das suas regiões mais internas, próximas ao buraco negro central. Neste trabalho apresentamos observações em raios-X da região central da galáxia NGC1097, que hospeda um buraco negro supermassivo e um disco de acreção cuja emissão vem sendo observada há dez anos através da linha de emissão Ha larga (10000 km/s) e de duplo pico. As observações em raios-X - que foram obtidas com o Telescópio Chandra - foram combinadas com observações no ultravioleta obtidas com o Telescópio Espacial Hubble e são usadas para estudar as características da fonte central que ioniza o disco de acreção. A distribuição espectral de energia é comparada com a predita por modelos, em particular o de uma estrutura "ADAF" ("advection dominated accretion flow") na parte interna do disco. Tal estrutura produz um espectro de emissão de linhas estreitas tipo LINER, como observado em NGC1097 e em rádio-galáxias que apresentam linhas de Balmer largas de duplo pico. Apresentamos também uma comparação entre outros LINERs com linhas de emissão largas de duplo pico, disponíveis na literatura ou nos arquivos do Chandra e do Telescópio Espacial Hubble e discutimos as correspondentes implicações para modelos da fonte central.

  18. Sobre o uso das séries de Puiseux em mecanica celeste

    NASA Astrophysics Data System (ADS)

    Miloni, O. I.

    2003-08-01

    Neste trabalho é apresentada uma demonstração do uso dos diferentes desenvolvimentos em séries para as equações de perturbação em Mecânica Celeste no marco Hamiltoniano. Em trabalhos clássicos como os de Poincaré (Poincaré, 1893) por exemplo, já esta planteado o uso de potências não inteiras no pequeno parâmetro, o que evidencia a não analiticidade das funções quando uma ressonância ocorre. Nestes trabalhos os desenvolvimentos são na raíz quadrada da massa de Júpiter (o pequeno parâmetro). Mais recentemente (Ferraz-Mello, 1985) outros tipos de desenvolvimentos foram aplicados modificando substancialmente as ordens de grandeza e a velocidade de convergência das séries. Com esta abordagem, os desenvolvimentos foram expressados em termos da raíz cúbica do pequeno parâmetro. Neste trabalho apresentamos um enfoque geral, onde os diferentes tipos de desenvolvimentos em séries de Puiseux (Valiron, 1950) são obtidos a partir da aplicação de Teorema de Preparação de Weierstrass (Goursat, 1916) considerando a equação de Hamilton-Jacobi como uma equação algébrica. Os resultados são aplicados ao problema restrito dos três corpos em ressonância de primeira ordem e, dependendo da grandeza da excentricidade do asteróide em relação à de Júpiter, obtemos os diferentes desenvolvimentos, em raíz quadrada ou raíz cúbica da massa de Júpiter.

  19. Developing and Testing of a Software Prototype to Support Diagnostic Reasoning of Nursing Students.

    PubMed

    de Sousa, Vanessa Emille Carvalho; de Oliveira Lopes, Marcos Venícios; Keenan, Gail M; Lopez, Karen Dunn

    2018-04-01

    To design and test educational software to improve nursing students' diagnostic reasoning through NANDA-I-based clinical scenarios. A mixed method approach was used and included content validation by a panel of 13 experts and prototype testing by a sample of 56 students. Experts' suggestions included writing adjustments, new response options, and replacement of clinical information on the scenarios. Percentages of students' correct answers were 65.7%, 62.2%, and 60.5% for related factors, defining characteristics, and nursing diagnoses, respectively. Full development of this software shows strong potential for enhancing students' diagnostic reasoning. New graduates may be able to apply diagnostic reasoning more rapidly by exercising their diagnostic skills within this software. Desenvolver e testar um protótipo de software educativo para melhorar o raciocínio diagnóstico de estudantes de enfermagem. MÉTODOS: Uma abordagem mista foi utilizada e incluiu validação de conteúdo por 13 experts e testagem do protótipo por 56 estudantes. Sugestões dos experts incluíram ajustes na escrita, inclusão de novas opções de resposta e substituição de dados clínicos nos cenários. Os percentuais de respostas corretas dos estudantes foram 65,7%, 62,2% e 60,5% para fatores relacionados, características definidoras e diagnósticos de enfermagem respectivamente. CONCLUSÃO: O desenvolvimento deste software tem um forte potencial para melhorar o raciocínio diagnóstico de estudantes. IMPLICAÇÕES PARA A PRÁTICA EM ENFERMAGEM: Através deste software, enfermeiros poderão ser capazes de exercitar o raciocínio diagnóstico e aplicá-lo mais rapidamente. © 2016 NANDA International, Inc.

  20. Acute Ethanol Intake Induces NAD(P)H Oxidase Activation and Rhoa Translocation in Resistance Arteries.

    PubMed

    Simplicio, Janaina A; Hipólito, Ulisses Vilela; Vale, Gabriel Tavares do; Callera, Glaucia Elena; Pereira, Camila André; Touyz, Rhian M; Tostes, Rita de Cássia; Tirapelli, Carlos R

    2016-11-01

    The mechanism underlying the vascular dysfunction induced by ethanol is not totally understood. Identification of biochemical/molecular mechanisms that could explain such effects is warranted. To investigate whether acute ethanol intake activates the vascular RhoA/Rho kinase pathway in resistance arteries and the role of NAD(P)H oxidase-derived reactive oxygen species (ROS) on such response. We also evaluated the requirement of p47phox translocation for ethanol-induced NAD(P)H oxidase activation. Male Wistar rats were orally treated with ethanol (1g/kg, p.o. gavage) or water (control). Some rats were treated with vitamin C (250 mg/kg, p.o. gavage, 5 days) before administration of water or ethanol. The mesenteric arterial bed (MAB) was collected 30 min after ethanol administration. Vitamin C prevented ethanol-induced increase in superoxide anion (O2-) generation and lipoperoxidation in the MAB. Catalase and superoxide dismutase activities and the reduced glutathione, nitrate and hydrogen peroxide (H2O2) levels were not affected by ethanol. Vitamin C and 4-methylpyrazole prevented the increase on O2- generation induced by ethanol in cultured MAB vascular smooth muscle cells. Ethanol had no effect on phosphorylation levels of protein kinase B (Akt) and eNOS (Ser1177 or Thr495 residues) or MAB vascular reactivity. Vitamin C prevented ethanol-induced increase in the membrane: cytosol fraction ratio of p47phox and RhoA expression in the rat MAB. Acute ethanol intake induces activation of the RhoA/Rho kinase pathway by a mechanism that involves ROS generation. In resistance arteries, ethanol activates NAD(P)H oxidase by inducing p47phox translocation by a redox-sensitive mechanism. O mecanismo da disfunção vascular induzido pelo consumo de etanol não é totalmente compreendido. Justifica-se, assim a identificação de mecanismos bioquímicos e moleculares que poderiam explicar tais efeitos. Investigar se a ingestão aguda de etanol ativa a via vascular RhoA/Rho quinase em artérias de resistência e o papel das espécies reativas de oxigênio (ERO) derivadas da NAD(P)H oxidase nessa resposta. Nós também avaliamos se ocorreu translocação da p47phox e ativação da NAD(P)H oxidase após o consumo agudo de etanol. Ratos Wistar machos foram tratados com etanol via oral (1g/kg, p.o. gavagem) ou água (controle). Alguns ratos foram tratados com vitamina C (250 mg/kg, p.o. gavagem, 5 dias) antes de água ou etanol. O leito arterial mesentérico (LAM) foi coleado 30 min após a administração de etanol. A vitamina C preveniu o aumento da geração de ânion superóxido (O2 -) e lipoperoxidação no LAM induzidos pelo etanol. A atividade da catalase (CAT), da superóxido dismutase (SOD) e os níveis de glutationa reduzida(GSH), nitrato e peróxido de hidrogênio (H2O2) não foram afetados após a ingestão aguda de etanol. A vitamina C e o 4-metilpirazol preveniram o aumento na geração de O2 - induzido pelo etanol em cultura de células do músculo liso vascular (CMLV). O etanol não afetou a fosforilação da proteína quinase B (Akt) e nem da óxido nítrico sintase endotelial (eNOS) (nos resíduos de Ser1177 ou Thr495) ou a reatividade vascular do LAM. A vitamina C preveniu o aumento da razão membrana:citosol da p47phox e a expressão da RhoA no LAM de rato induzido pelo etanol. A ingestão aguda de etanol induz a ativação da via RhoA/Rho quinase por um mecanismo que envolve a geração de ERO. Nas artérias de resistência, o etanol ativa NAD(P)H oxidase induzindo a translocação da p47phox por um mecanismo redox-sensível.

  1. Transcultural adaptation to Brazilian Portuguese and reliability of the effort-reward imbalance in household and family work.

    PubMed

    Vasconcellos, Ilmeire Ramos Rosembach de; Griep, Rosane Härter; Portela, Luciana; Alves, Márcia Guimarães de Mello; Rotenberg, Lúcia

    2016-06-27

    To describe the steps in the transcultural adaptation of the scale in the Effort-reward imbalance model to household and family work to the Brazilian context. We performed the translation, back-translation, and initial psychometric evaluation of the questionnaire that comprised three dimensions: (i) effort (eight items, emphasizing quantitative workload), (ii) reward (11 items that seek to capture the intrinsic value of family and household work, societal esteem, recognition from the spouse/partner, and affection from the children), and (iii) overcommitment (four items related to intrinsic effort). The scale was included in a sectional study conducted with 1,045 nursing workers. A subsample of 222 subjects answered the questionnaire for a second time, seven to 15 days thereafter. The data were collected between October 2012 and May 2013. The internal consistency of the scale was evaluated using Cronbach's alpha and test-retest reliability analysis, square weighted kappa, prevalence and bias adjusted Kappa, and intraclass correlation coefficient. Prevalence and bias-adjusted Kappa (ka) of the scale dimensions ranged from 0.80-0.83 for overcommitment, 0.78-0.90 for effort, and 0.76-0.93 for reward. In most dimensions, the values of minimum and maximum scores, average, standard deviation, and Cronbach's alpha were similar in test and retest scores. Only on societal esteem subdimension (reward) was there little variation in standard deviation (test score of 2.24 and retest score of 3.36) and in Cronbach's alpha coefficient (test score of 0.38 and retest score of 0.59). The Brazilian version of the scale was found to have proper reliability indices regarding time stability, which suggests adapting it to be used in population with characteristics that are similar to the one in this study. Descrever as etapas da adaptação transcultural da escala do Effort-reward imbalance model to household and family work para o contexto brasileiro. Efetuou-se a tradução, retrotradução e avaliação psicométrica inicial do instrumento composto por três dimensões: (i) esforço (oito itens, enfatizando a carga quantitativa de trabalho), (ii) recompensa (11 itens que buscam captar o valor intrínseco da família e do trabalho doméstico, a estima social, o reconhecimento do cônjuge ou companheiro e a afeição dos filhos) e (iii) o excesso de comprometimento (quatro itens relacionados ao esforço intrínseco). A escala foi incluída em um estudo seccional aplicado em 1.045 trabalhadoras de enfermagem. Uma subamostra de 222 participantes respondeu ao questionário pela segunda vez, com intervalo de sete a 15 dias. Os dados foram coletados entre outubro de 2012 e maio de 2013. A consistência interna da escala foi avaliada pelo coeficiente de alpha de Cronbach e a confiabilidade teste-reteste, pelo índice kappa ponderado quadrático, pelo kappa ajustado pela prevalência e pelo coeficiente de correlação intraclasse. A confiabilidade ajustada pela prevalência (ka) das dimensões da escala variou de 0,80-0,83 para o excesso de comprometimento, 0,78-0,90 para o esforço e 0,76-0,93 para a recompensa. Na maioria das dimensões, os valores do escore mínimo e máximo, média, desvio-padrão e alpha de Cronbach no teste e no reteste foram semelhantes. Somente na subdimensão estima social (recompensa) houve pequena variação no desvio padrão (2,24 no teste e 3,36 no reteste) e no coeficiente de alpha de Cronbach (0,38 no teste e 0,59 no reteste). A versão brasileira da escala apresentou índices adequados de fidedignidade quanto à estabilidade temporal, o que sugere a adequação da escala para uso em populações com características semelhantes à do estudo.

  2. Cardiovascular Risk Stratification and Statin Eligibility Based on the Brazilian vs. North American Guidelines on Blood Cholesterol Management.

    PubMed

    Cesena, Fernando Henpin Yue; Laurinavicius, Antonio Gabriele; Valente, Viviane A; Conceição, Raquel D; Santos, Raul D; Bittencourt, Marcio S

    2017-06-01

    The best way to select individuals for lipid-lowering treatment in the population is controversial. In healthy individuals in primary prevention: to assess the relationship between cardiovascular risk categorized according to the V Brazilian Guideline on Dyslipidemia and the risk calculated by the pooled cohort equations (PCE); to compare the proportion of individuals eligible for statins, according to different criteria. In individuals aged 40-75 years consecutively submitted to routine health assessment at one single center, four criteria of eligibility for statin were defined: BR-1, BR-2 (LDL-c above or at least 30 mg/dL above the goal recommended by the Brazilian Guideline, respectively), USA-1 and USA-2 (10-year risk estimated by the PCE ≥ 5.0% or ≥ 7.5%, respectively). The final sample consisted of 13,947 individuals (48 ± 6 years, 71% men). Most individuals at intermediate or high risk based on the V Brazilian Guideline had a low risk calculated by the PCE, and more than 70% of those who were considered at high risk had this categorization because of the presence of aggravating factors. Among women, 24%, 17%, 4% and 2% were eligible for statin use according to the BR-1, BR-2, USA-1 and USA-2 criteria, respectively (p < 0.01). The respective figures for men were 75%, 58%, 31% and 17% (p < 0.01). Eighty-five percent of women and 60% of men who were eligible for statin based on the BR-1 criterion would not be candidates for statin based on the USA-1 criterion. As compared to the North American Guideline, the V Brazilian Guideline considers a substantially higher proportion of the population as eligible for statin use in primary prevention. This results from discrepancies between the risk stratified by the Brazilian Guideline and that calculated by the PCE, particularly because of the risk reclassification based on aggravating factors. Existe controvérsia sobre a melhor forma de selecionar indivíduos para tratamento hipolipemiante na população. Em indivíduos saudáveis em prevenção primária: avaliar a relação entre o risco cardiovascular segundo a V Diretriz Brasileira de Dislipidemias e o risco calculado pelas pooled cohort equations (PCE); comparar a proporção de indivíduos elegíveis para estatinas, de acordo com diferentes critérios. Em indivíduos de 40 a 75 anos submetidos consecutivamente a avaliação rotineira de saúde em um único centro, quatro critérios de elegibilidade para estatina foram definidos: BR-1, BR-2 (LDL-c acima ou pelo menos 30 mg/dL acima da meta preconizada pela diretriz brasileira, respectivamente), EUA-1 e EUA-2 (risco estimado pelas PCE em 10 anos ≥ 5,0% ou ≥ 7,5%, respectivamente). Foram estudados 13.947 indivíduos (48 ± 6 anos, 71% homens). A maioria dos indivíduos de risco intermediário ou alto pela V Diretriz apresentou risco calculado pelas PCE baixo e mais de 70% daqueles considerados de alto risco o foram devido à presença de fator agravante. Foram elegíveis para estatina 24%, 17%, 4% e 2% das mulheres pelos critérios BR-1, BR-2, EUA-1 e EUA-2, respectivamente (p < 0,01). Os respectivos valores para os homens foram 75%, 58%, 31% e 17% (p < 0,01). Oitenta e cinco por cento das mulheres e 60% dos homens elegíveis para estatina pelo critério BR-1 não seriam candidatos pelo critério EUA-1. Comparada à diretriz norte-americana, a V Diretriz Brasileira considera uma proporção substancialmente maior da população como elegível para estatina em prevenção primária. Isso se relaciona com discrepâncias entre o risco estratificado pela diretriz brasileira e o calculado pelas PCE, particularmente devido à reclassificação de risco baseada em fatores agravantes.

  3. Particulate matter and polycyclic aromatic hydrocarbons from forest fires: impacts on air quality and occupational risks assessment

    NASA Astrophysics Data System (ADS)

    Oliveira, Marta Madalena Marques de

    As piroxenas sao um vasto grupo de silicatos minerais encontrados em muitas rochas igneas e metamorficas. Na sua forma mais simples, estes silicatos sao constituidas por cadeias de SiO3 ligando grupos tetrahedricos de SiO4. A formula quimica geral das piroxenas e M2M1T2O6, onde M2 se refere a catioes geralmente em uma coordenacao octaedrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catioes numa coordenacao octaedrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catioes em coordenacao tetrahedrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclinica sao designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composicoes quimicas amplo, em conjugacao com a possibilidade de ajustar as suas propriedades fisicas e quimicas e a durabilidade quimica, tem gerado um interesse mundial devido a suas aplicacoes em ciencia e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicacoes funcionais. O estudo teve objectivos cientificos e tecnologicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formacao de fases cristalinas e solucoes solidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicacao dos novos materiais em diferentes areas tecnologicas, com especial enfase sobre a selagem em celulas de combustivel de oxido solido (SOFC). Com este intuito, prepararam-se varios vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsidio (CaMgSi2O6) e diopsidio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados atraves de um vasto leque de tecnicas. Todos os vidros foram preparados por fusao-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterizacao e cristalizacao de fritas, quer por nucleacao e cristalizacao de vidros monoliticos. Estudaram-se ainda os efeitos de varias substituicoes ionicas em composicoes de diopsidio contendo Al na estrutura, sinterizacao e no comportamento durante a cristalizacao de vidros e nas propriedades dos materiais vitro-cerâmicos, com relevância para a sua aplicacao como selantes em SOFC. Verificou-se que Foi observado que os vidros/vitro-cerâmicos a base de enstatite nao apresentavam as caracteristicas necessarias para serem usados como materiais selantes em SOFC, enquanto as melhores propriedades apresentadas pelos vitro-cerâmicos a base de diopsidio qualificaram-nos para futuros estudos neste tipo de aplicacoes. Para alem de investigar a adequacao dos vitro-cerâmicos a base de clinopyroxene como selantes, esta tese tem tambem como objetivo estudar a influencia dos agentes de nucleacao na nucleacao em volume dos vitro-cerâmicos resultantes a base de diopsidio, de modo a qualifica-los como potenciais materiais hopedeiros de residuos nucleares radioactivos.

  4. Reciprocal interaction between human microvascular endothelial cells and mesenchymal stem cells on macroporous granules of nanostructured-hydroxyapatite agglomerates

    NASA Astrophysics Data System (ADS)

    Laranjeira, Marta de Sousa

    As piroxenas sao um vasto grupo de silicatos minerais encontrados em muitas rochas igneas e metamorficas. Na sua forma mais simples, estes silicatos sao constituidas por cadeias de SiO3 ligando grupos tetrahedricos de SiO4. A formula quimica geral das piroxenas e M2M1T2O6, onde M2 se refere a catioes geralmente em uma coordenacao octaedrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catioes numa coordenacao octaedrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catioes em coordenacao tetrahedrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclinica sao designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composicoes quimicas amplo, em conjugacao com a possibilidade de ajustar as suas propriedades fisicas e quimicas e a durabilidade quimica, tem gerado um interesse mundial devido a suas aplicacoes em ciencia e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicacoes funcionais. O estudo teve objectivos cientificos e tecnologicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formacao de fases cristalinas e solucoes solidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicacao dos novos materiais em diferentes areas tecnologicas, com especial enfase sobre a selagem em celulas de combustivel de oxido solido (SOFC). Com este intuito, prepararam-se varios vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsidio (CaMgSi2O6) e diopsidio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados atraves de um vasto leque de tecnicas. Todos os vidros foram preparados por fusao-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterizacao e cristalizacao de fritas, quer por nucleacao e cristalizacao de vidros monoliticos. Estudaram-se ainda os efeitos de varias substituicoes ionicas em composicoes de diopsidio contendo Al na estrutura, sinterizacao e no comportamento durante a cristalizacao de vidros e nas propriedades dos materiais vitro-cerâmicos, com relevância para a sua aplicacao como selantes em SOFC. Verificou-se que Foi observado que os vidros/vitro-cerâmicos a base de enstatite nao apresentavam as caracteristicas necessarias para serem usados como materiais selantes em SOFC, enquanto as melhores propriedades apresentadas pelos vitro-cerâmicos a base de diopsidio qualificaram-nos para futuros estudos neste tipo de aplicacoes. Para alem de investigar a adequacao dos vitro-cerâmicos a base de clinopyroxene como selantes, esta tese tem tambem como objetivo estudar a influencia dos agentes de nucleacao na nucleacao em volume dos vitro-cerâmicos resultantes a base de diopsidio, de modo a qualifica-los como potenciais materiais hopedeiros de residuos nucleares radioactivos.

  5. Analysis of vegetation dynamics using time-series vegetation index data from Earth observation satellites

    NASA Astrophysics Data System (ADS)

    Rodrigues, Arlete da Silva

    As piroxenas sao um vasto grupo de silicatos minerais encontrados em muitas rochas igneas e metamorficas. Na sua forma mais simples, estes silicatos sao constituidas por cadeias de SiO3 ligando grupos tetrahedricos de SiO4. A formula quimica geral das piroxenas e M2M1T2O6, onde M2 se refere a catioes geralmente em uma coordenacao octaedrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catioes numa coordenacao octaedrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catioes em coordenacao tetrahedrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclinica sao designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composicoes quimicas amplo, em conjugacao com a possibilidade de ajustar as suas propriedades fisicas e quimicas e a durabilidade quimica, tem gerado um interesse mundial devido a suas aplicacoes em ciencia e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicacoes funcionais. O estudo teve objectivos cientificos e tecnologicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formacao de fases cristalinas e solucoes solidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicacao dos novos materiais em diferentes areas tecnologicas, com especial enfase sobre a selagem em celulas de combustivel de oxido solido (SOFC). Com este intuito, prepararam-se varios vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsidio (CaMgSi2O6) e diopsidio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados atraves de um vasto leque de tecnicas. Todos os vidros foram preparados por fusao-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterizacao e cristalizacao de fritas, quer por nucleacao e cristalizacao de vidros monoliticos. Estudaram-se ainda os efeitos de varias substituicoes ionicas em composicoes de diopsidio contendo Al na estrutura, sinterizacao e no comportamento durante a cristalizacao de vidros e nas propriedades dos materiais vitro-cerâmicos, com relevância para a sua aplicacao como selantes em SOFC. Verificou-se que Foi observado que os vidros/vitro-cerâmicos a base de enstatite nao apresentavam as caracteristicas necessarias para serem usados como materiais selantes em SOFC, enquanto as melhores propriedades apresentadas pelos vitro-cerâmicos a base de diopsidio qualificaram-nos para futuros estudos neste tipo de aplicacoes. Para alem de investigar a adequacao dos vitro-cerâmicos a base de clinopyroxene como selantes, esta tese tem tambem como objetivo estudar a influencia dos agentes de nucleacao na nucleacao em volume dos vitro-cerâmicos resultantes a base de diopsidio, de modo a qualifica-los como potenciais materiais hopedeiros de residuos nucleares radioactivos.

  6. Biological effects of polyacrylic acid-coated and non-coated superparamagnetic iron oxide nanoparticles in in vitro and in vivo experimental models

    NASA Astrophysics Data System (ADS)

    Couto, Diana Manuel Mocho de Bastos

    As piroxenas sao um vasto grupo de silicatos minerais encontrados em muitas rochas igneas e metamorficas. Na sua forma mais simples, estes silicatos sao constituidas por cadeias de SiO3 ligando grupos tetrahedricos de SiO4. A formula quimica geral das piroxenas e M2M1T2O6, onde M2 se refere a catioes geralmente em uma coordenacao octaedrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catioes numa coordenacao octaedrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catioes em coordenacao tetrahedrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclinica sao designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composicoes quimicas amplo, em conjugacao com a possibilidade de ajustar as suas propriedades fisicas e quimicas e a durabilidade quimica, tem gerado um interesse mundial devido a suas aplicacoes em ciencia e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicacoes funcionais. O estudo teve objectivos cientificos e tecnologicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formacao de fases cristalinas e solucoes solidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicacao dos novos materiais em diferentes areas tecnologicas, com especial enfase sobre a selagem em celulas de combustivel de oxido solido (SOFC). Com este intuito, prepararam-se varios vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsidio (CaMgSi2O6) e diopsidio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados atraves de um vasto leque de tecnicas. Todos os vidros foram preparados por fusao-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterizacao e cristalizacao de fritas, quer por nucleacao e cristalizacao de vidros monoliticos. Estudaram-se ainda os efeitos de varias substituicoes ionicas em composicoes de diopsidio contendo Al na estrutura, sinterizacao e no comportamento durante a cristalizacao de vidros e nas propriedades dos materiais vitro-cerâmicos, com relevância para a sua aplicacao como selantes em SOFC. Verificou-se que Foi observado que os vidros/vitro-cerâmicos a base de enstatite nao apresentavam as caracteristicas necessarias para serem usados como materiais selantes em SOFC, enquanto as melhores propriedades apresentadas pelos vitro-cerâmicos a base de diopsidio qualificaram-nos para futuros estudos neste tipo de aplicacoes. Para alem de investigar a adequacao dos vitro-cerâmicos a base de clinopyroxene como selantes, esta tese tem tambem como objetivo estudar a influencia dos agentes de nucleacao na nucleacao em volume dos vitro-cerâmicos resultantes a base de diopsidio, de modo a qualifica-los como potenciais materiais hopedeiros de residuos nucleares radioactivos.

  7. Impact evaluation of the large scale integration of electric vehicles in the security of supply

    NASA Astrophysics Data System (ADS)

    Bremermann, Leonardo Elizeire

    As piroxenas sao um vasto grupo de silicatos minerais encontrados em muitas rochas igneas e metamorficas. Na sua forma mais simples, estes silicatos sao constituidas por cadeias de SiO3 ligando grupos tetrahedricos de SiO4. A formula quimica geral das piroxenas e M2M1T2O6, onde M2 se refere a catioes geralmente em uma coordenacao octaedrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catioes numa coordenacao octaedrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catioes em coordenacao tetrahedrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclinica sao designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composicoes quimicas amplo, em conjugacao com a possibilidade de ajustar as suas propriedades fisicas e quimicas e a durabilidade quimica, tem gerado um interesse mundial devido a suas aplicacoes em ciencia e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicacoes funcionais. O estudo teve objectivos cientificos e tecnologicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formacao de fases cristalinas e solucoes solidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicacao dos novos materiais em diferentes areas tecnologicas, com especial enfase sobre a selagem em celulas de combustivel de oxido solido (SOFC). Com este intuito, prepararam-se varios vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsidio (CaMgSi2O6) e diopsidio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados atraves de um vasto leque de tecnicas. Todos os vidros foram preparados por fusao-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterizacao e cristalizacao de fritas, quer por nucleacao e cristalizacao de vidros monoliticos. Estudaram-se ainda os efeitos de varias substituicoes ionicas em composicoes de diopsidio contendo Al na estrutura, sinterizacao e no comportamento durante a cristalizacao de vidros e nas propriedades dos materiais vitro-cerâmicos, com relevância para a sua aplicacao como selantes em SOFC. Verificou-se que Foi observado que os vidros/vitro-cerâmicos a base de enstatite nao apresentavam as caracteristicas necessarias para serem usados como materiais selantes em SOFC, enquanto as melhores propriedades apresentadas pelos vitro-cerâmicos a base de diopsidio qualificaram-nos para futuros estudos neste tipo de aplicacoes. Para alem de investigar a adequacao dos vitro-cerâmicos a base de clinopyroxene como selantes, esta tese tem tambem como objetivo estudar a influencia dos agentes de nucleacao na nucleacao em volume dos vitro-cerâmicos resultantes a base de diopsidio, de modo a qualifica-los como potenciais materiais hopedeiros de residuos nucleares radioactivos.

  8. Visualization of the Flow at the Tip of a High Speed Axial Flow Turbine Rotor Blade - An Assessment of Flow Visualisation Techniques and the Requirement of the Experimental Turbine.

    DTIC Science & Technology

    1987-11-01

    71 AD-AI89 929 UI4A ~l HOFTEFOJA N TIPO IO PE /L S LO TUIN~. TCHN ?IRAEL’ITF 4XHH F IDNE AL. T U 87 AFOs -8-U N uNCLASSIFIED NIF-: Hrp li1.0 a18...Pulse tracer injection 16. 9) Detector sensor 17- 10) Focussed photomultiplier 17 Conceptual philosophy for the experimental turbine 18 Preliminary...tracing 35 2) Pulsed fluorescence 35 3) Single spot laser sensor 36 4) Two spot laser 36 5) Localised smoke pockets 37 6) Laser pulse smoke generation

  9. Dischi (E Jet) Nelle Stelle Massicce Giovani

    NASA Astrophysics Data System (ADS)

    Cesaroni, Riccardo

    2017-11-01

    In questo contributo verrà discussa l'importanza dei dischi e jet ad essi asso- ciati per la formazione delle stelle di tipo spettrale OB e verranno presentati i risultati recentemente ottenuti con ALMA in questo ambito. In particolare mostr- eremo che la struttura del disco sembra risentire della complessità dell'ambiente circostante e che la probabilità di rivelare un disco attorno alle stelle di più alta massa è massima in una fase evolutiva intermedia. Infine discuteremo la possibilità che il fenomeno di accrescimento dal disco sulla stella possa avvenire in maniera discontinua mediante "burst", probabilmente dovuti ad instabilità nel disco.

  10. Studies of Solar Flares and Coronal Loops.

    DTIC Science & Technology

    1984-07-10

    i( Tipo + T pl) and equations (5) and (8), we get P (D - w t P = + 0 (9j where 0 = o ’-, +T (k" -B,)- (o fTQ 10R B0 . G!) = ( - 1 ) R p + T ( k...andStegun. 1 . eds. 1970. HandhoolMathemarical Davis. J. M., and Webb. D F 1981. Bull • 4.4S. 13. -21 F!,n,; .ns INew York Do’er). p. 17 Einaudi. G...Sakanaka. P H 19-4. Ph s fIhids. 17, SIX 1951. Proc Ros Sit London. 1. 244. 17. Harsey. K. L. 1981. Bull . 44S. 13. ,90 tiider. C. Einaudi. G. and

  11. Análise cinemática bi-dimensional dos núcleos de NGC 4051 e NGC 4941

    NASA Astrophysics Data System (ADS)

    Barbosa, F. K. B.; Storchi-Bermagnn, T.; Schmitt, H. R.; Cid Fernandes, R.; Winge, C.

    2003-08-01

    Estudos recentes da cinemática da região dentro de 1 kpc do núcleo de galaxias Seyfert próximas usando espectroscopia de fenda longa com alta resolução espacial (~ 100 pc ou melhores) encontraram uma queda na dispersão de velocidades nas regiões centrais dentro de um raio de ~ 300 pc do núcleo. Essa queda vem sendo tentativamente explicada por um cenário evolutivo em que um evento de formação estelar recente cria as estrelas da região central em um disco de dimensões 300 pc. Desde sua criação, tais estrelas não tiveram tempo de "virializar", ou seja, seguir a distribuição radial de dispersões de velocidades determinada pelo campo gavitacional da galáxia e, portanto, a dispersão de velocidades medida nessa região do bojo acaba sendo menor do que a dispersão medida nas vizinhanças. No presente trabalho investigamos a cinemática estelar no núcleo das galáxias Seyfert NGC 4051 e NGC 4941 usando o tripleto do Ca ii (8500 Å) em absorção. Os dados foram obtidos com o IFU GMOS no telescópio Gemini. O elemento de resolução espacial nas galáxias é da ordem de 30 pc. No intervalo espectral coberto pelo espectrografo a linha [S iii] (9068 Å) também é visível, o que permite estudar a cinemática do gás na mesma região. Serão apresentados mapas bi-dimensionais da velocidade e dispersão de velocidades das estrelas e do gás, além de imagens na linha [S iii] que mapeia o gás de alta excitação.

  12. Memória fonológica em crianças bilíngues bimodais e crianças com implante coclear

    PubMed Central

    de Quadros, Ronice Müller; Cruz, Carina Rebello; Pizzio, Aline Lemos

    2014-01-01

    RESUMO Este estudo comparou o desempenho de crianças bilíngues bimodais ouvintes (filhas de pais surdos) e crianças surdas usuárias de implante coclear (filhas de pais surdos e de pais ouvintes), com diferentes contextos de acesso à Língua Brasileira de Sinais (Libras), em tarefas que envolvem memória fonologica. Os testes utilizados foram: Teste de Pseudopalavras (Santos e Bueno, 2003) e Teste de Pseudosinais (desenvolvido pelos pesquisadores responsáveis pelo Projeto ‘Desenvolvimento Bilíngue Bimoda’). Além disso, foram incluídos dois grupos de controle, formados por crianças surdas (usuarias de Libras), e adultos bilíngues bimodais ouvintes. Na análise dos resultados, em relação ao desempenho entre os dois grupos testados foi constatado que o grupo de crianças bilíngues bimodais ouvintes apresentou desempenho superior, nos dois testes. No entanto, ao ser analisado o desempenho da criança surda usuaria de implante coclear, filha de pais surdos, que possui acesso irrestrito à Libras e comparado com o das crianças surdas usuárias de implante coclear, que possuem acesso restrito à Libras, foi constatado que o seu desempenho foi semelhante ao do grupo de crianças bilíngues bimodais ouvintes. As crianças surdas usuárias de implante coclear com acesso restrito à Libras e, portanto, com acesso maior ao Português apresentaram escores mais baixos nas tarefas, principalmente do teste em Português. Os resultados sugerem que as crianças surdas usuárias de implante coclear em processo de aquisição da línguagem podem se beneficiar com o acesso irrestrito à Libras, atingindo inclusive desempenho semelhante a de crianças bilíngues bimodais ouvintes. PMID:25110473

  13. Ensino de Astronomia no Ensino Médio

    NASA Astrophysics Data System (ADS)

    Albrecht, E.; Voelzke, M. R.

    2008-09-01

    O presente trabalho de intervenção foi realizado junto a Escola Estadual Colônia dos Pescadores na cidade de Caraguatatuba, com três turmas do terceiro ano do Ensino Médio, envolvendo 119 alunos, 40 na turma A, 40 na turma B e 39 na turma C. A fase inicial foi composta de um questionário de vinte questões dissertativas e objetivas para diagnosticar nos educandos os conceitos prévios sobre Astronomia e, partindo destes realizar uma interferência nas classes envolvidas utilizando metodologias diferentes sendo elas: a tradicional, onde o professor é um repassador de informações, fazendo uso exclusivo de lousa e giz; a segunda também de forma tradicional, porém com auxílio de multimídia para desenvolvimento das aulas e a terceira sob forma de seminários, elaborados e apresentados pelos educandos, no qual o educador faz apenas as intervenções necessárias. Ao final do trabalho as mesmas turmas da fase inicial orientadas pelo mesmo professor responderam novamente ao questionário proposto para diagnosticar dentre as três metodologias utilizadas qual apresentou melhores resultados, sendo os iniciais comparados com os finais. Quando questionados a respeito do significado de Astronomia observou-se inicialmente que os acertos na turma A foram de 100%,turma B: 64%, turma C: 84%, após a intervenção os acertos foram: 100%, 97% e 85% respectivamente, demonstrando claramente uma absorção de conhecimentos. Quando interrogados sobre quantos planetas você acha que existem em nosso Sistema Solar? os acertos foram: turma A: 39%, turma B: 48% e turma C: 46%, após o desenvolvimento do trabalho os acertos foram 94%, 97% e 90% respectivamente.Dentro das respostas obtidas observa-se que a metodologia tradicional com o auxílio de multimeios, aplicada na turma B, demonstrou melhores resultados, foi a mais significativa.

  14. Telescópio de pequeno porte como suporte ao ensino em cidades com intensa poluição luminosa II

    NASA Astrophysics Data System (ADS)

    Pereira, P. C. R.; Santos-Júnior, J. M.; Cruz, W. S.

    2003-08-01

    Para a maioria dos estudantes, sua passagem pelo ensino formal fundamental envolve a transmissão de fatos que devem ser guardados para um exame, a habilidade para lembrar fórmulas e, eventualmente, a repetição de experimentos que devem produzir resultados exigidos pelo professor. O resultado deste modelo de ensino, ao longo dos anos, é conhecido por todos: desconhecimento e descontentamento, por parte dos estudantes, de temas relativos ao papel e aos processos da ciência. Acreditamos que a Astronomia, pelo seu caráter observacional, é uma das áreas do conhecimento que pode contribuir neste cenário. A Fundação Planetário da Cidade do Rio de Janeiro possui um telescópio Meade LX-200 (25cm) que, juntamente com as câmeras CCD ST-7E e ST8E, tem sido utilizado em projetos voltados aos estudantes do ensino médio desde o ano 2000. Tais projetos envolvem a condução de um projeto de pesquisa observacional num nível apropriado, e possibilitam o contato com técnicas e novas tecnologias: computador, software para manipulação de dados e gráficos, programas de tratamento e redução de dados, uso de equipamentos óptico-eletrônicos (telescópio e CCD), bem como o processo de aquisição de conhecimento. Dentro da proposta dos anos anteriores, priorizamos projetos de uma noite, ou seja, procuramos trabalhar com fenômenos que apresentem variabilidade com intervalo de recorrência relativamente curto. Em todos os casos, optamos pela fotometria diferencial, que tem se mostrado bastante eficiente para o céu luminoso como o da cidade do Rio de Janeiro. Neste painel, apresentamos alguns dos projetos desenvolvidos no último ano, com 25 estudantes. Apresentamos os resultados da observação da variável pulsante AI Vel (V = 6,6) e da variável cataclísmica FO Aqr (V = 13,5), e do monitoramento do trânsito da lua de Júpiter, Europa, ocorrido em 30 de abril de 2003. As curvas de luz produzidas para as primeiras estão concordantes com as da literatura, assim como os respectivos períodos encontrados (1h20min e 4h48min). No caso do FO Aqr, ficou evidente, também, a modulação decorrente da rotação da anã branca receptora (21min). O erro estimado é de 0,01 magnitude. Propomos uma maior utilização de telescópios de pequeno porte, como suporte ao ensino (médio e superior) em cidades com poluição luminosa. Escolas e Planetários seriam ambientes propícios para a localização do telescópio. Os critérios adotados na escolha dos objetos e o método observacional empregado são também apresentados.

  15. Evaluation of Reference Centers for Special Immunobiologicals implementation.

    PubMed

    Nóbrega, Laura Andrade Lagôa; Novaes, Hillegonda Maria Dutilh; Sartori, Ana Marli Christovam

    2016-09-01

    To describe the Reference Centers for Special Immunobiologicals and evaluate their implementation considering formal regulations. We conducted a program evaluation, of evaluative research type. From August 2011 to January 2012, a questionnaire was applied to the 42 Reference Centers for Special Immunobiologicals existing in the Country, approaching the structure, human resources, and developed activities dimensions. We conducted a descriptive analysis of data and used a clustering for binary data with the squared Euclidean distance, by the farthest neighbor method, to aggregate services with similar features. We observed great diversity among the services in the three dimensions. The clustering resulted in five service profiles, named according to their characteristics. 1) Best structure: 12 Reference Centers for Special Immunobiologicals with the highest proportion of services with the minimum of rooms recommended, purpose-built vaccine refrigerators, preventive maintenance of the cold chain, and oxygen source. 2) Immunobiologicals distributor: six Reference Centers for Special Immunobiologicals that distributed more than applied immunogens; no doctor present for more than half of the working hours and no purpose-built vaccine refrigerators . 3) Incipient implementation: five Reference Centers for Special Immunobiologicals with inadequate structure, such as absence of purpose-built vaccine refrigerators, preventive maintenance of the cold chain and oxygen source; none had computer. 4) Vaccination rooms: 13 Reference Centers for Special Immunobiologicals, everyone did routine immunization, most participated in vaccination campaigns. 5) Teaching and research: six services, all inserted into teaching hospitals, developed researches and received trainees; most had doctors in more than half of the working hours. The evaluation of the Reference Centers for Special Immunobiologicals implementation was based on the profiles found and considered the official regulations: services categorized as "better structure" and "teaching and research" were considered implemented; "immunobiologicals distributor" and "vaccination room" services, partially implemented, and the ones with the "incipient implementation" profile, not implemented. The results of this evaluation can contribute to the reformulation of the services, considering the current context. Descrever os Centros de Referência para Imunobiológicos Especiais e avaliar sua implantação considerando as regulamentações formais. Foi realizada uma avaliação de programa, tipo pesquisa avaliativa. De agosto de 2011 a janeiro de 2012, foi aplicado questionário aos responsáveis pelos 42 Centros de Referência para Imunobiológicos Especiais existentes no País, abordando as dimensões estrutura, recursos humanos e atividades desenvolvidas. Foi feita análise descritiva dos dados e utilizado agrupamento para dados binários com uso da distância euclidiana quadrática, pelo método do vizinho mais distante, para agregar serviços com características semelhantes. Observou-se grande diversidade entre os serviços nas três dimensões. O agrupamento resultou em cinco perfis de serviços, denominados de acordo com suas características. 1) Melhor estrutura: 12 Centros de Referência para Imunobiológicos Especiais com a maior proporção de serviços com o mínimo de salas preconizado, câmaras de vacinas, manutenção preventiva da rede de frio e fonte de oxigênio. 2) Dispensador de imunobiológicos: seis Centros de Referência para Imunobiológicos Especiais que mais dispensavam do que aplicavam imunógenos; sem médico presente por mais da metade do expediente do serviço e sem câmara de vacinas. 3) Implantação incipiente: cinco Centros de Referência para Imunobiológicos Especiais com estrutura inadequada, como ausência de câmaras de vacinas, de manutenção preventiva da rede de frio e de fonte de oxigênio; nenhum possuía computador. 4) Sala de vacinas: 13 Centros de Referência para Imunobiológicos Especiais, todos faziam imunização de rotina, a maioria participava de campanhas de vacinação. 5) Ensino e pesquisa: seis serviços, todos inseridos em hospitais de ensino, desenvolviam pesquisas e recebiam estagiários; a maioria possuía médicos em mais da metade do expediente. A avaliação de implantação dos Centros de Referência para Imunobiológicos Especiais baseou-se nos perfis encontrados e considerou as regulamentações oficiais: os serviços categorizados como "melhor estrutura" e "ensino e pesquisa" foram considerados implantados; os serviços "dispensador de imunobiológicos" e "sala de vacinas", parcialmente implantados e os do perfil "implantação incipiente", não implantados. Os resultados dessa avaliação podem contribuir para a reformulação dos serviços, considerando o contexto atual.

  16. Distribution of a Community of Mammals in Relation to Roads and Other Human Disturbances in Gabon, Central Africa

    PubMed Central

    Vanthomme, Hadrien; Kolowski, Joseph; Korte, Lisa; Alonso, Alfonso

    2013-01-01

    Abstract We present the first community-level study of the associations of both roads and other human disturbances with the distribution of mammals in Gabon (central Africa). Our study site was in an oil concession within a littoral mosaic landscape. We conducted surveys along 199 line transects and installed camera traps on 99 of these transects to document mammal presence and abundance. We used generalized linear mixed-effect models to document associations between variables related to the ecosystem (land cover, topography, and hydrology), roads (coating, width of rights of way, condition, type of vehicle used on the road, traffic level, affiliation of users, and general type of road), and other human disturbances (urbanization, agriculture, hunting, logging, gathering, and industrial activities) and the abundance or presence of 17 species or groups of mammals including elephant (Loxodonta cyclotis), buffalo (Syncerus caffer), sitatunga (Tragelaphus spekei), red river hog (Potamochoerus porcus), smaller ungulates, gorilla (Gorilla gorilla), chimpanzee (Pan troglodytes), side-striped jackal (Canis adustus), carnivores, monkeys, and large rodents. Some types of roads and other human disturbances were negatively associated with the abundance or presence of elephants, buffalos, gorillas, sitatungas, some monkeys, and duikers. The pattern of associations of mammals with roads and other human disturbances was diverse and included positive associations with road presence (red river hog, some monkeys, and duikers), agriculture (sitatunga, small carnivores, and large rodents) and industrial activities (sitatunga, red river hog, red duikers, and side-striped jackal). Our results suggest that the community of mammals we studied was mostly affected by hunting, agriculture, and urbanization, which are facilitated by road presence. We recommend increased regulation of agriculture, hunting, and road building in the area. Distribución de una Comunidad de Mamíferos en Relación a Carreteras y Otras Perturbaciones Humanas en Gabón, Africa Central Resumen Presentamos el primer estudio a nivel de comunidad de la relación entre carreteras y otras perturbaciones humanas con la distribución de mamíferos en Gabón (África central). Nuestro sitio de estudio está dentro de una concesión petrolera en un paisaje litoral heterogéneo. Realizamos muestreos a lo largo de 199 transectos lineales e instalamos cámaras trampa en 99 de ellos para documentar la presencia y abundancia de mamíferos. Utilizamos modelos lineales generalizados con efectos mixtos para documentar las asociaciones entre variables relacionadas con el ecosistema (cobertura de suelo, topografía e hidrología), carreteras (tipo de revestimiento, ancho de derecho de vía, condición, tipo de vehículos que utilizan la carretera, nivel de tráfico, afiliación de los usuarios y el tipo general de carretera) y otras perturbaciones humanas (urbanización, agricultura, caza, tala, recolecta y actividades industriales) y la abundancia o presencia de 17 especies o grupos de mamíferos incluyendo elefantes (Loxodonta cyclotis), búfalo (Syncerus caffer), sitatunga (Tragelaphus spekei), cerdo rojo de río (Potomochoerus porcus), ungulados pequeños, gorila (Gorilla gorilla), chimpancé (Pan troglodytes), chacal con rayas a los lados (Canis adustus), carnívoros, monos y roedores de talla grande. Ciertos tipos de carreteras y otras perturbaciones humanas estuvieron asociadas negativamente con la abundancia o presencia de elefantes, búfalos, gorilas, sitatungas, algunos monos y antílopes. Los patrones de asociación de mamíferos con carreteras y otras perturbaciones humanas fueron diversos e incluyen asociaciones positivas con la presencia de carreteras (cerdo rojo de río, algunos monos y antílopes), agricultura (sitatunga, carnívoros pequeños y roedores de talla grande) y actividades industriales (sitatunga, cerdo rojo de río, antílope rojo y chacal con rayas a los lados). Nuestros resultados sugieren que la comunidad de mamíferos que estudiamos fue afectada principalmente por la caza, agricultura y urbanización, que son facilitadas por la presencia de carreteras. Recomendamos una mayor regulación de la agricultura, caza y construcción de carreteras en el área. PMID:23410077

  17. Prevalence and Phenotypic Expression of Mutations in the MYH7, MYBPC3 and TNNT2 Genes in Families with Hypertrophic Cardiomyopathy in the South of Brazil: A Cross-Sectional Study.

    PubMed

    Mattos, Beatriz Piva E; Scolari, Fernando Luís; Torres, Marco Antonio Rodrigues; Simon, Laura; Freitas, Valéria Centeno de; Giugliani, Roberto; Matte, Úrsula

    2016-09-01

    Mutations in sarcomeric genes are found in 60-70% of individuals with familial forms of hypertrophic cardiomyopathy (HCM). However, this estimate refers to northern hemisphere populations. The molecular-genetic profile of HCM has been subject of few investigations in Brazil, particularly in the south of the country. To investigate mutations in the sarcomeric genes MYH7, MYBPC3 and TNNT2 in a cohort of HCM patients living in the extreme south of Brazil, and to evaluate genotype-phenotype associations. Direct DNA sequencing of all encoding regions of three sarcomeric genes was conducted in 43 consecutive individuals of ten unrelated families. Mutations for CMH have been found in 25 (58%) patients of seven (70%) of the ten study families. Fourteen (56%) individuals were phenotype-positive. All mutations were missense, four (66%) in MYH7 and two (33%) in MYBPC3. We have not found mutations in the TNNT2 gene. Mutations in MYH7 were identified in 20 (47%) patients of six (60%) families. Two of them had not been previously described. Mutations in MYBPC3 were found in seven (16%) members of two (20%) families. Two (5%) patients showed double heterozygosis for both genes. The mutations affected different domains of encoded proteins and led to variable phenotypic expression. A family history of HCM was identified in all genotype-positive individuals. In this first genetic-molecular analysis carried out in the south of Brazil, we found mutations in the sarcomeric genes MYH7 and MYBPC3 in 58% of individuals. MYH7-related disease was identified in the majority of cases with mutation. Mutações em genes do sarcômero são encontradas em 60-70% dos indivíduos com formas familiares de cardiomiopatia hipertrófica. (CMH). Entretanto, essa estimativa refere-se a populações de países do hemisfério norte. O perfil genético-molecular da CMH foi tema de poucos estudos no Brasil, particularmente na região sul do país. Realizar a pesquisa de mutações dos genes sarcoméricos MYH7, MYBPC3 e TNNT2 numa coorte de CMH estabelecida no extremo sul do Brasil, assim como avaliar as associações genótipo-fenótipo. Sequenciamento direto do DNA de todas as regiões codificantes dos três genes sarcoméricos foi realizada em 43 indivíduos consecutivos de dez famílias não-relacionadas. Mutações para CMH foram encontradas em 25 (58%) indivíduos de sete (70%) das dez famílias estudadas, sendo 14 (56%) deles fenótipo-positivos. Todas as mutações eram missense, quatro (66%) no gene MYH7 e duas (33%) no gene MYBPC3. Não foram encontradas mutações no gene TNNT2. Mutações em MYH7 foram identificadas em 20 (47%) indivíduos de seis (60%) famílias. Duas delas não haviam sido previamente relatadas. Mutações de MYBPC3 foram detectadas em sete (16%) membros de duas (20%) famílias. Dois (5%) indivíduos apresentaram dupla heterozigose com mutações em ambos os genes. As mutações acometeram distintos domínios das proteínas codificadas e produziram expressão fenotípica variável. História familiar de CMH foi identificada em todos os indivíduos genótipo-positivos. Nessa primeira análise genético-molecular da CMH realizada no sul do Brasil, foram encontradas mutações nos genes sarcoméricos MYH7 e MYBPC3 em 58% dos indivíduos. Doença relacionada ao gene MYH7 foi identificada na maioria dos casos com mutação.

  18. Lessons Learned from Analyses of the Improved TOW Vehicle with Implications for Future Systems

    DTIC Science & Technology

    1990-01-01

    on ECA on the ITV. This research was de - signed to identify the source of the discrepancy between the ECA and other source data, and to determine ways...not to prevent the transfer of bad ideas (and MANPRINT costs ) from system to system, but to facilitate the transfer of good ideas (and MANPRINT savings...AVERAGE PP 1 2 1.50 4 5 4.00 2.33 TIpo 1 1 1.00 2 5 2.00 1.33 FR 3 4 3.50 4 5 4.00 3.67 TLD 1 1 1.00 2 5 2.00 1.33 TT 1 1 1.00 2 5 2.00 1.33 DR 1 5

  19. Reservoir Control Center: Activities and Accomplishments of the Southwestern Division of the Army Corps of Engineers Related to Reservoir Regulation and Water Management. Part 3. Instream Flow Study. Appendix A.

    DTIC Science & Technology

    1981-01-01

    Inoduction I.. WHITE RIVER BASIN Bover Whilte LRD AR 66 1120,0 1130,0 1652 300 5 Table Rock White LRD AR/MO 58 915.0 931.0 2702 760 526 Bull Shoals...Benbrook Trinity 391 Big Hill Arkansas 120 Birch Arkansas 151 Blue Mountain Arkansas 266 Broken Bow Red 331 Bull Shoals White 15 Canton Arkansas 234 Canyon...RELAT IONS fPqnC FRCcn :324-M24) AT DAM SITE OCTOBER~ FLOWS (PER~ TIpO C REVZR CC?45-1T7NS U.. MY ENGINEER DISTRICT. FORT WORTH TO RCCCMDR4Y tNSTR~qr

  20. Estudio de los Efectos Gravitomagnéticos en Cuerpos Masivos Rotantes

    NASA Astrophysics Data System (ADS)

    Velandia Heredia, N.; Tejeiro, J. M.

    2008-03-01

    A partir del estudio de los Efectos Gravitomagnéticos en cuerpos masivos rotantes, planteamos la expresión para medir el desfase en el tiempo, para diferentes observadores, que se dan cuando viajan dos rayos de luz por una guía de onda o de manera libre (geodésicas), en el plano azimutal y en el plano polar. Con lo anterior queremos abordar el experimento tipo Michelson y Morley, de forma que podamos involucrar el valor de la densidad del momento angular (a) en el retraso temporal para los dos haces de luz que viajan por los brazos del interferómetro, cuando este último es ubicado en el plano ecuatorial.

  1. IMPACT OF VITAMIN D AND CALCIUM DEFICIENCY IN THE BONES OF PATIENTS UNDERGOING BARIATRIC SURGERY: A SYSTEMATIC REVIEW.

    PubMed

    Cabral, Jefry Alberto Vargas; Souza, Gabriela Pereira de; Nascimento, Juliana de Almeida; Simoneti, Luis Fernando; Marchese, Carolina; Sales-Peres, Silvia Helena de Carvalho

    Bariatric surgery is considered the most effective tool in the control and treatment of severe obesity, but patients undergoing this procedure are at increased risk of developing nutritional deficiencies by limiting the intake and absorption of many nutrients. To assess the impact of vitamin D deficiency and calcium in bone in patients after gastric bypass in Roux-en-Y, pointing directly at the type of administration, doses and effects after surgery. Was conducted a systematic review with articles related to the topic of the last 10 years searched in PubMed (US National Library of Medicine National Institutes of Health, Medline, Lilacs, Scielo and Cochrane using the headings "bariatric surgery", "bone", "obesity", "vitamin D '', "calcium" AND "absorption". Exclusion criteria to research on animals, smokers, pregnant women and patient treated with bisphosphonates. Five articles were included in this review. All refer that bariatric surgery can lead to nutritional deficiencies and poor absorption of fats and fat-soluble vitamins and other micronutrients such as calcium. Patients submitted to RYGB should make use of multivitamins and minerals especially vitamin D and calcium to prevent bone fractures. Monitoring, treatment and control of risk factors are essential to prevent complications after this operation. A cirurgia bariátrica é considerada o tratamento mais eficaz no controle e tratamento da obesidade severa; porém, indivíduos submetidos a este procedimento apresentam maior risco de desenvolver deficiências nutricionais pela limitação na ingestão e absorção de muitos nutrientes. Avaliar o impacto da deficiência de vitamina D e do cálcio ósseo de pacientes após gastroplastia em Y-de-Roux, relacionando tipo de administração, dose e efeito pós-cirúrgico. Realizou-se revisão sistemática com artigos relacionados ao tema dos últimos 10 anos e pesquisados na PubMed (US National Library of Medicine National Institutes of Health, Medline, Lilacs, Scielo e Cochrane usando os descritores "bariatric surgery", "bone", "obesity", " vitamin D'', "calcium'' AND "absortion". Foram excluídos os estudos em animais, fumantes, grávidas ou gestantes e indivíduos que ingeriram bisfosfonatos. Foram incluídos ao final cinco artigos. Todos referem que a cirurgia bariátrica pode levar à deficiências nutricionais como má absorção de gorduras, vitaminas lipossolúveis, micronutrientes e cálcio. Os pacientes submetidos ao RYGB devem fazer uso de polivitamínicos e minerais principalmente a vitamina D e o cálcio para evitar fraturas ósseas. Monitoramento, tratamento e controle dos fatores de risco são essenciais para prevenir estas complicações após a operação.

  2. Avaliação do conhecimento de pacientes diabéticos sobre medidas preventivas do pé diabético em Maringá (PR)

    PubMed Central

    Carlesso, Guilherme Pereira; Gonçalves, Mariana Helena Barboza; Moreschi, Dorival

    2017-01-01

    Resumo Contexto O atual envelhecimento da população tem gerado maior predominância de doenças crônicas, como o diabetes, a qual está associada a um risco elevado de complicações crônicas e agudas. Entre essas, o pé diabético (PD) destaca-se por possuir alta incidência e grande poder mutilador. Objetivo Avaliar o conhecimento da população diabética das Unidades Básicas de Saúde (UBS) de Maringá (PR) sobre a prevenção do PD. Métodos Estudo descritivo, quantitativo, tipo inquérito por entrevista. A população estudada foi composta por 80 portadores de diabetes, cadastrados em UBS de Maringá (PR). A coleta de dados buscou levantar dados sociodemográficos e epidemiológicos, bem como as atitudes de controle do diabetes e do autocuidado para prevenção do PD. Resultados Do total de entrevistados, nove não realizavam qualquer tipo de exame para controle do diabetes e a renda mensal predominante foi de até um salário mínimo. O grau de escolaridade e a renda mensal não se mostraram relevantes em relação ao conhecimento de cuidados preventivos do PD e nem uma maior adesão a hábitos de vida saudáveis. O cuidado com o PD tende a melhorar à medida que exista uma compreensão mais clara dos fatores que conduzem à perda do membro e um crescente consenso sobre a gestão de vários aspectos clínicos do cuidado com o pé. Conclusão Existe uma falta de aprendizado das medidas preventivas, mesmo nos pacientes com algum nível de instrução, o que induz a uma prática deficiente de cuidados.

  3. Teamwork: relevance and interdependence of interprofessional education.

    PubMed

    Tamayo, M; Besoaín-Saldaña, A; Aguirre, M; Leiva, J

    2017-04-27

    Determine the perception of university students regarding interprofessional and interdependent work between team members in their inclusion in primary care. Analytical cross-sectional study. The sampling had a probabilistic, stratified random type with 95% confidence and 5% margin of error. Seven-hundred and four students of Public Universities in Santiago (Chile) answered self-administered questionnaire. Ninety-seven point eight of students say that interprofessional work is important; 27.1% of them declare that their university did not seem to show that their study plans were important. The professionals listed as most important in teams are physicians and nurses. Spaces for development and institutional support are key elements to promote interprofessional work. If this competence can involve each academic unit in their different formative spaces there will be a significant contribution to said promotion. Teamwork is a pending task. Determinar la percepción de estudiantes universitarios respecto al trabajo interprofesional e interdependencia entre los miembros del equipo en su inserción en la atención primaria. Estudio de tipo analítico y transversal. El muestreo fue de tipo aleatorio, probabilístico estratificado con un 95% de confianza y un 5% de margen de error. Se utilizó un cuestionario auto-administrado en 704 estudiantes de Universidades del Estado en Santiago de Chile. Un 97,8% de los estudiantes opinan que el trabajo interprofesional es importante; un 27,1% de ellos declara que su universidad no le ha entregado importancia en sus planes de estudios. Los profesionales mencionados como más importantes en el equipo son los médicos y enfermeras. Espacios de desarrollo y respaldo institucional son elementos claves para promover el trabajo interprofesional. Que esta competencia logre involucrar a cada unidad académica en sus diferentes espacios formativos será un aporte significativo en aquello. Trabajo en equipo es una tarea pendiente.

  4. DIABETES MELLITUS COMO FACTOR DE RIESGO DE DEMENCIA EN LA POBLACIÓN ADULTA MAYOR MEXICANA

    PubMed Central

    Silvia, Mejía-Arango; Clemente, y Zúñiga-Gil

    2012-01-01

    Introduccion La diabetes mellitus y las demencias constituyen dos problemas crecientes de salud entre la población adulta mayor del mundo y en particular de los paises en desarrollo. Hacen falta estudios longitudinales sobre el papel de la diabetes como factor de riesgo para demencia. Objetivo Determinar el riesgo de demencia en sujetos Mexicanos con diabetes mellitus tipo 2. Materiales y Metodos Los sujetos diabéticos libres de demencia pertenecientes al Estudio Nacional de Salud y Envejecimiento en México fueron evaluados a los dos años de la línea de base. Se estudió el papel de los factores sociodemográficos, de otras comorbilidades y del tipo de tratamiento en la conversión a demencia. Resultados Durante la línea de base 749 sujetos (13.8%) tuvieron diabetes. El riesgo de desarrollar demencia en estos individuos fue el doble (RR, 2.08 IC 95%, 1.59–2.73). Se encontró un riesgo mayor en individuos de 80 años y más (RR 2.44 IC 95%, 1.46–4.08), en los hombres (RR, 2.25 IC 95%, 1.46–3.49) y en sujetos con nivel educativo menor de 7 años. El estar bajo tratamiento con insulina incrementó el riesgo de demencia (RR, 2.83, IC 95%, 1.58–5.06). Las otras comorbilidades que aumentaron el riesgo de demencia en los pacientes diabéticos fueron la hipertensión (RR, 2.75, IC 95%, 1.86–4.06) y la depresión (RR, 3.78, 95% IC 2.37–6.04). Conclusión Los sujetos con diabetes mellitus tienen un riesgo mayor de desarrollar demencia, La baja escolaridad y otras comorbilidades altamente prevalentes en la población Mexicana contribuyen a la asociación diabetes-demencia. PMID:21948010

  5. Espectroscopia de candidatos a remanescentes de aglomerados abertos

    NASA Astrophysics Data System (ADS)

    Pavani, D. B.; Bica, E.; Ahumada, A. V.; Clariá, J. J.

    2003-08-01

    A pesquisa sobre remanescentes de aglomerados abertos tem despertado grande interesse. Seguindo esta tendência encontramos estudos teóricos e observacionais. Os primeiros baseiam-se em simulações numéricas buscando determinar fração de binárias e distâncias galatocêntricas, tempo de vida e conteúdo estelar. Estes estão relacionados à função inicial de massa e densidade de estrelas, ou seja, se ricos ou pobremente povoados, compactos ou esparsos. No caso observacional procuram-se identificar os remanescentes considerando-se que trazem estas assinaturas de seus percursores. No presente estudo empregamos espectroscopia para analisar oito concentrações pobremente povoadas, previamente classificadas como aglomerados abertos, sendo sete compactas e uma esparsa. As observações foram obtidas através do telescópio de 2,15 m do CASLEO em San Juan, Argentina, em turnos entre 2001 e 2003. Utilizamos uma câmara CCD contendo um chip Tektronics de 1024X1024 pixeis aliado a um espectrógrafo REOSC. O domínio espectral vai de 3700 a 7000 Å. As reduções foram realizadas no Observatório Astronômico de Córdoba (Argentina) usando pacotes IRAF padrões. Determinamos idades, avermelhamentos e tipos espectrais através de comparações com biblioteca de estrelas e de aglomerados. Em alguns casos nossos espectros estavam dominados por estrelas individuais às quais determinamos seus tipos espectrais. Aos oito objetos adicionamos mais cinco da literatura recente analisados via espectro ou diagrama cor-magnitude. O histograma resultante contém idades típicas entre 0.5 e 3 Ganos. Considerando que predominantemente estes objetos encontram-se na vizinhança solar e, portanto, não cruzaram muitas vezes o plano Galático esperamos que a diferença no tempo necessário para dissolução destes prováveis remanescentes seja em função de diferentes massas iniciais.

  6. PubMed

    Ferrer Gómez, Mercedes; García Zafra, María Victoria; Cuenca Sánchez, Juan Ramón; Sánchez Romera, Juan Francisco; Aranda García, Ana; Rausell Rausell, Víctor José; Hernández Martínez, Antonio Miguel

    2016-09-20

    Introducción: en Murcia, y hasta 2010, la administración de la nutrición enteral domiciliaria (NED) dictaba cumplir la regulación marcada en cuanto a los facultativos con competencias para su prescripción.Objetivos: examinar aspectos esenciales de este recurso en el periodo 2007-2010, características de la muestra y evolución del coste, así como perspectivas de futuro.Métodos: estudio del perfil de la población NED en un área de salud específica. Selección de recetas facturadas de productos NED en el conjunto de la Región, clasificación por tipos y análisis de la evolución en importe y en envases para el periodo 2007-2010.Resultados: respecto al perfil de la muestra del Área I de Salud de la Región, la patología, vía de administración y tipo de nutrición más frecuentes resultaron, respectivamente, la enfermedad neurológica, la vía oral y la nutrición no específica. Por otro lado, el gasto sanitario en productos dietoterápicos, en el Servicio Murciano de Salud, aumentó alrededor del 50% entre los años 2007 y 2010. Tanto en envases como en importe, Murcia se sitúa por encima de la media nacional.Conclusiones: el perfil de la muestra no coincide con trabajos publicados en otras regiones. Este dato, junto a la posición de Murcia en gasto dietoterápico, y su evidente tendencia al alza en los años analizados, hace evidente la necesidad de medidas que mejoren la calidad de la NED en la Región de Murcia y, en caso de ser posible, conseguir alcanzar valores nacionales en relación con el consumo medio y el gasto.

  7. Astronomía Gamma desde El Leoncito

    NASA Astrophysics Data System (ADS)

    Rovero, A. C.; Colombo, E.; Sahade, J.; Weekes, T. C.

    La astronomía gamma, en el extremo de energías detectadas hasta el presente, se encuentra en desarrollo en muchas partes del mundo y proporciona resultados sorprendentes a medida que la tecnología avanza en el desarrollo de nuevos detectores. La técnica Cherenkov Atmosférica es la utilizada para la detección, mediante telescopios en tierra, del efecto secundario causado por la radiación gamma de muy altas energías (E ≈ TeV). Por medio de telescopios o arreglos de detectores y utilizando la técnica mencionada, se han podido detectar algunas fuentes puntuales de mucha importancia astrofísica como la Nebulosa del Cangrejo y la galaxia de núcleo activo Markarian 421. El sistema instalado en San Juan, en cooperación con el grupo de Radiación Gamma del Observatorio Whipple, está constituído por tres colectores de 1.5m que registran pulsos de luz generados por las cascadas de partículas producidas por rayos cósmicos de todo tipo al entrar en la atmósfera terrestre. El sistema opera por barrido en ascención recta de la fuente observada que, para esta etapa del experimento, es el Centro Galáctico. Esta fuente extensa es conocida como emisor gamma de energías inferiores al TeV y ha sido observada anteriormente en este rango de energía desde el hemisferio norte pero con elevaciones bajas, situación no óptima para este tipo de técnica. Se presentan los primeros resultados del análisis de los datos obtenidos observando la región del Centro Galáctico, luego de dos años de observaciones, así como una descripción de la técnica Cherenkov Atmosférica y del equipo utilizado en la experiencia.

  8. Products purchased from family farming for school meals in the cities of Rio Grande do Sul.

    PubMed

    Ferigollo, Daniele; Kirsten, Vanessa Ramos; Heckler, Dienifer; Figueredo, Oscar Agustín Torres; Perez-Cassarino, Julian; Triches, Rozane Márcia

    2017-02-16

    This study aims to verify the adequacy profile of the cities of the State of Rio Grande do Sul, Brazil, in relation to the purchase of products of family farming by the Programa Nacional de Alimentação Escolar (PNAE - National Program of School Meals). This is a quantitative descriptive study, with secondary data analysis (public calls-to-bid). The sample consisted of approximately 10% (n = 52) of the cities in the State, establishing a representation by mesoregion and size of the population. We have assessed the percentage of food purchased from family farming, as well as the type of product, requirements of frequency, delivery points, and presence of prices in 114 notices of public calls-to-bid, in 2013. Of the cities analyzed, 71.2% (n = 37) reached 30% of food purchased from family farming. Most public calls-to-bid demanded both products of plant (90.4%; n = 103) and animal origin (79.8%; n = 91). Regarding the degree of processing, fresh products appeared in 92.1% (n = 105) of the public calls-to-bid. In relation to the delivery of products, centralized (49.1%; n = 56) and weekly deliveries (47.4%; n = 54) were the most described. Only 60% (n = 68) of the public calls-to-bid contained the price of products. Most of the cities analyzed have fulfilled what is determined by the legislation of the PNAE. We have found in the public calls-to-bid a wide variety of food, both of plant and animal origin, and most of it is fresh. In relation to the delivery of the products, the centralized and weekly options prevailed. Verificar o perfil de adequação dos municípios do Rio Grande do Sul no que tange à aquisição de produtos da agricultura familiar pelo Programa Nacional de Alimentação Escolar. Trata-se de estudo quantitativo descritivo, com análise de dados secundários (chamadas públicas). A amostra foi composta por aproximadamente 10% (n = 52) dos municípios do estado, tomando-se o cuidado de estabelecer uma representatividade por mesorregião e tamanho da população. Foi avaliado o percentual destinado às compras de gêneros alimentícios da agricultura familiar, bem como o tipo de produto, exigências de periodicidade, pontos de entrega e presença de preços em 114 editais de chamadas públicas, no ano de 2013. Dos municípios analisados, 71,2% (n = 37) atingiram 30% de gêneros alimentícios oriundos de agricultura familiar. A maioria das chamadas públicas demandou tanto produtos de origem vegetal (90,4%; n = 103) como de origem animal (79,8%; n = 91). Quanto ao grau de processamento dos alimentos, os produtos in natura apareceram em 92,1% (n = 105) das chamadas públicas. Em relação à entrega dos produtos, a centralizada (49,1%; n = 56) e as entregas semanais (47,4%; n = 54) foram as mais descritas. Apenas 60% (n = 68) das chamadas públicas continham preço dos produtos. A maioria dos municípios analisados cumpriu o determinado pela legislação do Programa Nacional de Alimentação Escolar. Encontrou-se nas chamadas públicas uma grande diversidade de alimentos, tanto de origem vegetal quanto de origem animal, sendo a maior parte deles in natura. Em relação à entrega dos produtos, prevaleceu a centralizada e a semanal.

  9. Cross-Cultural adaptation of the General Functioning Scale of the Family.

    PubMed

    Pires, Thiago; Assis, Simone Gonçalves de; Avanci, Joviana Quintes; Pesce, Renata Pires

    2016-06-27

    To describe the process of cross-cultural adaptation of the General Functioning Scale of the Family, a subscale of the McMaster Family Assessment Device, for the Brazilian population. The General Functioning Scale of the Family was translated into Portuguese and administered to 500 guardians of children in the second grade of elementary school in public schools of Sao Gonçalo, Rio de Janeiro, Southeastern Brazil. The types of equivalences investigated were: conceptual and of items, semantic, operational, and measurement. The study involved discussions with experts, translations and back-translations of the instrument, and psychometric assessment. Reliability and validity studies were carried out by internal consistency testing (Cronbach's alpha), Guttman split-half correlation model, Pearson correlation coefficient, and confirmatory factor analysis. Associations between General Functioning of the Family and variables theoretically associated with the theme (father's or mother's drunkenness and violence between parents) were estimated by odds ratio. Semantic equivalence was between 90.0% and 100%. Cronbach's alpha ranged from 0.79 to 0.81, indicating good internal consistency of the instrument. Pearson correlation coefficient ranged between 0.303 and 0.549. Statistical association was found between the general functioning of the family score and the theoretically related variables, as well as good fit quality of the confirmatory analysis model. The results indicate the feasibility of administering the instrument to the Brazilian population, as it is easy to understand and a good measurement of the construct of interest. Descrever o processo de adaptação transcultural da escala de Funcionamento Geral da Família, subescala da McMaster Family Assessment Device, para a população brasileira. A escala de Funcionamento Geral da Família, original no idioma inglês, foi traduzida para o português e aplicada a 500 responsáveis de crianças do segundo ano do ensino fundamental de escolas públicas do município de São Gonçalo, Rio de Janeiro. Os tipos de equivalências investigados foram: conceitual e de itens, semântica, operacional, e mensuração. O estudo envolveu discussão com especialistas, traduções e retraduções do instrumento e avaliação psicométrica. Foi realizado estudo de confiabilidade e validade, por testagem da consistência interna (alpha de Cronbach), da correlação pelo método de split-half de Guttman e do coeficiente de correlação de Pearson, e por análise fatorial confirmatória. Associações entre Funcionamento Geral da Família e variáveis teoricamente associadas ao tema (embriaguez do pai ou da mãe e violência entre os pais) foram analisadas por estimação de razão de chance. A equivalência semântica encontrada foi entre 90,0% e 100%. O alfa de Cronbach variou de 0,79 a 0,81, indicando boa consistência interna do instrumento. O coeficiente de correlação de Pearson oscilou entre 0,303 e 0,549. Encontrou-se associação estatística entre o escore de funcionamento geral da família e as variáveis teoricamente relacionadas e constatou-se boa qualidade dos ajustes do modelo de análise confirmatória. Os resultados obtidos indicam a aplicabilidade do instrumento na população brasileira, que se mostra de fácil compreensão e boa aferição do constructo de interesse.

  10. Profile of skin cancer in Pomeranian communities of the State of Espírito Santo.

    PubMed

    Frasson, Patrícia Henriques Lyra; Duque, Danilo Schwab; Pinto, Estanrley Barcelos; Dalvi, Giulia Cerutti; Madalon, Sammy Zogheib; Nunes, Tarcizo Afonso; DE-Vargas, Paulo Roberto Merçon

    2017-01-01

    to evaluate the profile of skin cancer in Pomeranian communities of the State of Espírito Santo, composed of descendants of European immigrants, regarding gender and age at diagnosis, lesion size and histological type. we studied histopathological reports of 3,781 patients operated between 2000 and 2010, with resection of 4,881 lesions. We assessed histological type, lesion size, age and gender of the patients at diagnosis and their correlations in the 11-year period. the histopathological examination revealed basal cell carcinoma in 3,159 patients (83.5%), squamous cell carcinoma in 415 (11%), melanoma in 64 (1.7%), and 143 patients (3.8%) had combined lesions of basal cell carcinoma and squamous cell carcinoma. As to size, 47.1% measured between 5.1 and 10mm. The age group of 61 to 70 years was the one that sustained the largest number of surgical interventions (24.3%). There was a predominance of the female gender (2,027, 53.6%) in relation to the male (1,754, 46.4%). basal cell carcinoma was the most frequent histological type. The prevalences of squamous cell carcinoma and melanoma were below the national estimate of the National Cancer Institute. The diagnosis of tumors occurred at more advanced ages (above 60 years) and there was an increase in the incidence and size of skin tumors in the male population. avaliar o panorama do câncer de pele em comunidades pomeranas do Estado do Espírito Santo, compostas por descendentes de imigrantes europeus, quanto ao sexo e idade ao diagnóstico, tamanho da lesão e tipo histológico. foram avaliados laudos histopatológicos de 3781 pacientes operados entre os anos de 2000 e 2010, com ressecção de 4881 lesões. Foram avaliados tipo histológico, tamanho das lesões, idade e sexo dos pacientes ao diagnóstico e suas correlações no período de 11 anos. o exame histopatológico evidenciou carcinoma basocelular em 3159 pacientes (83,5%), carcinoma espinocelular em 415 (11%), melanoma em 64 (1,7%) e 143 pacientes (3,8%) apresentaram lesões combinadas de carcinoma basocelular e carcinoma espinocelular. Quanto ao tamanho, 47,1% media entre 5,1 e 10 mm. O grupo etário de 61 aos 70 anos foi o que sofreu o maior número de intervenções cirúrgicas (24,3%). Houve predomínio do sexo feminino (53,6%, n=2027) em relação ao masculino (46,4%, n=1754). carcinoma basocelular foi o tipo histológico mais frequente. As prevalências do carcinoma espinocelular e do melanoma se situaram abaixo da estimativa nacional do Instituto Nacional de Câncer. O diagnóstico dos tumores ocorreu em idades mais avançadas (acima de 60 anos) e houve aumento da incidência e dimensões dos tumores de pele na população masculina.

  11. Oral health evaluation in special needs individuals.

    PubMed

    Pini, Danielle de Moraes; Fröhlich, Paula Cristina Gil Ritter; Rigo, Lilian

    2016-01-01

    To identify the prevalence of the main oral problems present in special needs children and to relate the underlying conditions with the clinical and demographic variables. The study was based on the physical examination of 47 students from the Associação de Pais e Amigos dos Excepcionais diagnosed as Down syndrome, cerebral palsy and intellectual deficit. For data collection, we used a self-administered questionnaire that included indices of dental caries and oral hygiene, Angle classification, malposition of dental groups and oral hygiene habits. The predominant age group was 12-25 years (46.8%) and most patients were male (55.3%). Regarding daily brushing, 63.8% reported brushing their teeth three times a day, and 85.1% did it by themselves. A total of 48.9% were rated as Angle class I, and 25.5% had no type of malocclusion. A high dental carries index (decayed, missing, filled >10) was observed in 44.7%, and 53.2% had inadequate oral hygiene (zero to 1.16). There was a statistically significant difference between cerebral palsy and the act of the participants brushing their teeth by themselves. There was a high decayed-missing-filled teeth index and malocclusion class I, as well as inadequate oral hygiene. The type of underlying condition of the participants influenced the act of brushing teeth by themselves. Conhecer a prevalência dos principais problemas bucais em crianças com necessidades especiais, e relacionar as doenças de base com variáveis clínicas e demográficas. O estudo foi realizado a partir de exame clínico em 47 alunos da Associação de Pais e Amigos dos Excepcionais com diagnóstico médico de síndrome de Down, paralisia cerebral e deficit intelectual. Para a coleta de dados, foi utilizado um questionário autoaplicativo com índices de cárie dentária e higiene oral, classificação de Angle, malposição de grupos dentários e hábitos de higiene oral. A faixa etária predominante foi de 12 a 25 anos (46,8%) e a maioria era do sexo masculino (55,3%). Em relação à escovação dentária, 63,8% relataram escovar os dentes três vezes ao dia, sendo que 85,1% realizavam-na sozinhos. Constatou-se que 48,9% dos examinados apresentavam uma classificação de Angle tipo I e 25,5% não apresentavam qualquer tipo de maloclusão. Os avaliados (44,7%) apresentaram alto índice de cárie dentária (cariados, perdidos e obturados >10) e 53,2% apresentaram higiene oral inadequada (zero a 1,16). Houve diferença estatisticamente significativa entre a paralisia cerebral e o ato de escovar os dentes sozinho. Constataram-se altos índices de cárie e de maloclusão classe I, além de inadequada higiene oral. Houve influência do tipo de patologia de base na realização do ato de escovar os dentes sozinhos.

  12. Brazilian guidelines for the diagnosis and treatment of cystic fibrosis.

    PubMed

    Athanazio, Rodrigo Abensur; Silva Filho, Luiz Vicente Ribeiro Ferreira da; Vergara, Alberto Andrade; Ribeiro, Antônio Fernando; Riedi, Carlos Antônio; Procianoy, Elenara da Fonseca Andrade; Adde, Fabíola Villac; Reis, Francisco José Caldeira; Ribeiro, José Dirceu; Torres, Lídia Alice; Fuccio, Marcelo Bicalho de; Epifanio, Matias; Firmida, Mônica de Cássia; Damaceno, Neiva; Ludwig-Neto, Norberto; Maróstica, Paulo José Cauduro; Rached, Samia Zahi; Melo, Suzana Fonseca de Oliveira

    2017-01-01

    Cystic fibrosis (CF) is an autosomal recessive genetic disorder characterized by dysfunction of the CFTR gene. It is a multisystem disease that most often affects White individuals. In recent decades, various advances in the diagnosis and treatment of CF have drastically changed the scenario, resulting in a significant increase in survival and quality of life. In Brazil, the current neonatal screening program for CF has broad coverage, and most of the Brazilian states have referral centers for the follow-up of individuals with the disease. Previously, CF was limited to the pediatric age group. However, an increase in the number of adult CF patients has been observed, because of the greater number of individuals being diagnosed with atypical forms (with milder phenotypic expression) and because of the increase in life expectancy provided by the new treatments. However, there is still great heterogeneity among the different regions of Brazil in terms of the access of CF patients to diagnostic and therapeutic methods. The objective of these guidelines was to aggregate the main scientific evidence to guide the management of these patients. A group of 18 CF specialists devised 82 relevant clinical questions, divided into five categories: characteristics of a referral center; diagnosis; treatment of respiratory disease; gastrointestinal and nutritional treatment; and other aspects. Various professionals working in the area of CF in Brazil were invited to answer the questions devised by the coordinators. We used the PubMed database to search the available literature based on keywords, in order to find the best answers to these questions. RESUMO A fibrose cística (FC) é uma doença genética autossômica recessiva caracterizada pela disfunção do gene CFTR. Trata-se de uma doença multissistêmica que ocorre mais frequentemente em populações descendentes de caucasianos. Nas últimas décadas, diversos avanços no diagnóstico e tratamento da FC mudaram drasticamente o cenário dessa doença, com aumento expressivo da sobrevida e qualidade de vida. Atualmente, o Brasil dispõe de um programa de ampla cobertura para a triagem neonatal de FC e centros de referência distribuídos na maior parte desses estados para seguimento dos indivíduos. Antigamente confinada à faixa etária pediátrica, tem-se observado um aumento de pacientes adultos com FC tanto pelo maior número de diagnósticos de formas atípicas, de expressão fenotípica mais leve, assim como pelo aumento da expectativa de vida com os novos tratamentos. Entretanto, ainda se observa uma grande heterogeneidade no acesso aos métodos diagnósticos e terapêuticos para FC entre as diferentes regiões brasileiras. O objetivo dessas diretrizes foi reunir as principais evidências científicas que norteiam o manejo desses pacientes. Um grupo de 18 especialistas em FC elaborou 82 perguntas clínicas relevantes que foram divididas em cinco categorias: características de um centro de referência; diagnóstico; tratamento da doença respiratória; tratamento gastrointestinal e nutricional; e outros aspectos. Diversos profissionais brasileiros atuantes na área da FC foram convidados a responder as perguntas formuladas pelos coordenadores. A literatura disponível foi pesquisada na base de dados PubMed com palavras-chave, buscando-se as melhores respostas às perguntas dos autores.

  13. The effects of work on the health of nurses who work in clinical surgery departments at university hospitals.

    PubMed

    Silva, Rosângela Marion da; Zeitoune, Regina Célia Gollner; Beck, Carmem Lúcia Colomé; Martino, Milva Maria Figueiredo de; Prestes, Francine Cassol

    2016-08-08

    to analyze the effects of work on the health of nurses who work in clinical surgery departments at university hospitals in relation to physical, social and psychological suffering and pain. a quantitative transversal study was carried out between 2012 and 2013 in four institutions in a state located in the south of Brazil. We studied 65 nurses who responded to questions on their habits. We also obtained sociodemographical information on them as well as conducting an evaluation on work relational damage using an evaluation scale. Associations were checked through the use of the Chi-Sqaure and Fisher's exact test. Correlations were checked using the Spearmann test. we found that physical ailments persisted and that there were connections between social and psychological pain/suffering and variable physical activities as well as connections with accidents in the work place and the option to work shifts. We noted correlations between social and psychological pain/suffering. nurses had their health compromised due to their work in clinical surgery departments. analisar os efeitos do trabalho na saúde de enfermeiros que atuam em clínicas cirúrgicas de hospitais universitários, relacionando-os aos danos físicos, sociais e psicológicos. estudo quantitativo, transversal, realizado entre 2012 e 2013 em quatro instituições de um Estado da região sul do Brasil. A amostra foi composta por 65 enfermeiros que responderam questões sobre os hábitos de vida e dados sociodemográficos e a Escala de Avaliação de Danos Relacionados ao Trabalho. Associações foram verificadas pelo teste Qui-Quadrado e Exato de Fisher e as correlações pelo teste de Spearmann. prevaleceu o adoecimento físico, encontrando associação entre os fatores Danos Sociais e Psicológicos e as variáveis prática de atividade física, acidente de trabalho e opção pelo turno de trabalho. Evidenciou-se correlação entre Danos Sociais e Psicológicos. o trabalho realizado por enfermeiros que atuam em clínica cirúrgica nas instituições hospitalares pesquisadas produz efeitos danosos à saúde. analizar los efectos del trabajo en la salud de enfermeros que actúan en clínicas quirúrgicas de hospitales universitarios, relacionándolos a daños físicos, sociales y psicológicos. estudio cuantitativo, transversal, realizado entre 2012 y 2013, en cuatro instituciones de un estado de la región sur de Brasil. La muestra estuvo compuesta por 65 enfermeros que respondieron preguntas sobre los hábitos de vida y datos sociodemográficos; se uso la Escala de Evaluación de Daños Relacionados al Trabajo. Las asociaciones fueron verificadas con el test Chi-Cuadrado y Exacto de Fisher y las correlaciones con el test de Spearmann. prevaleció la enfermedad física, encontrando asociación entre los factores Daños Sociales y Psicológicos y las variables: práctica de actividades físicas, accidente de trabajo y opción por el turno de trabajo. Se evidenció correlación entre Daños Sociales y Psicológicos. el trabajo realizado por enfermeros, que actúan en clínica quirúrgica en las instituciones hospitalarias investigadas, produce efectos que perjudican a la salud.

  14. Dose tracking and dose auditing in a comprehensive computed tomography dose-reduction program.

    PubMed

    Duong, Phuong-Anh; Little, Brent P

    2014-08-01

    Implementation of a comprehensive computed tomography (CT) radiation dose-reduction program is a complex undertaking, requiring an assessment of baseline doses, an understanding of dose-saving techniques, and an ongoing appraisal of results. We describe the role of dose tracking in planning and executing a dose-reduction program and discuss the use of the American College of Radiology CT Dose Index Registry at our institution. We review the basics of dose-related CT scan parameters, the components of the dose report, and the dose-reduction techniques, showing how an understanding of each technique is important in effective auditing of "outlier" doses identified by dose tracking. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. SU-E-T-280: Reconstructed Rectal Wall Dose Map-Based Verification of Rectal Dose Sparing Effect According to Rectum Definition Methods and Dose Perturbation by Air Cavity in Endo-Rectal Balloon

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Park, J; Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul; Park, H

    Purpose: Dosimetric effect and discrepancy according to the rectum definition methods and dose perturbation by air cavity in an endo-rectal balloon (ERB) were verified using rectal-wall (Rwall) dose maps considering systematic errors in dose optimization and calculation accuracy in intensity-modulated radiation treatment (IMRT) for prostate cancer patients. Methods: When the inflated ERB having average diameter of 4.5 cm and air volume of 100 cc is used for patient, Rwall doses were predicted by pencil-beam convolution (PBC), anisotropic analytic algorithm (AAA), and AcurosXB (AXB) with material assignment function. The errors of dose optimization and calculation by separating air cavity from themore » whole rectum (Rwhole) were verified with measured rectal doses. The Rwall doses affected by the dose perturbation of air cavity were evaluated using a featured rectal phantom allowing insert of rolled-up gafchromic films and glass rod detectors placed along the rectum perimeter. Inner and outer Rwall doses were verified with reconstructed predicted rectal wall dose maps. Dose errors and extent at dose levels were evaluated with estimated rectal toxicity. Results: While AXB showed insignificant difference of target dose coverage, Rwall doses underestimated by up to 20% in dose optimization for the Rwhole than Rwall at all dose range except for the maximum dose. As dose optimization for Rwall was applied, the Rwall doses presented dose error less than 3% between dose calculation algorithm except for overestimation of maximum rectal dose up to 5% in PBC. Dose optimization for Rwhole caused dose difference of Rwall especially at intermediate doses. Conclusion: Dose optimization for Rwall could be suggested for more accurate prediction of rectal wall dose prediction and dose perturbation effect by air cavity in IMRT for prostate cancer. This research was supported by the Leading Foreign Research Institute Recruitment Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (MSIP) (Grant No. 200900420)« less

  16. Dose specification for radiation therapy: dose to water or dose to medium?

    NASA Astrophysics Data System (ADS)

    Ma, C.-M.; Li, Jinsheng

    2011-05-01

    The Monte Carlo method enables accurate dose calculation for radiation therapy treatment planning and has been implemented in some commercial treatment planning systems. Unlike conventional dose calculation algorithms that provide patient dose information in terms of dose to water with variable electron density, the Monte Carlo method calculates the energy deposition in different media and expresses dose to a medium. This paper discusses the differences in dose calculated using water with different electron densities and that calculated for different biological media and the clinical issues on dose specification including dose prescription and plan evaluation using dose to water and dose to medium. We will demonstrate that conventional photon dose calculation algorithms compute doses similar to those simulated by Monte Carlo using water with different electron densities, which are close (<4% differences) to doses to media but significantly different (up to 11%) from doses to water converted from doses to media following American Association of Physicists in Medicine (AAPM) Task Group 105 recommendations. Our results suggest that for consistency with previous radiation therapy experience Monte Carlo photon algorithms report dose to medium for radiotherapy dose prescription, treatment plan evaluation and treatment outcome analysis.

  17. Switching From Age-Based Stimulus Dosing to Dose Titration Protocols in Electroconvulsive Therapy: Empirical Evidence for Better Patient Outcomes With Lower Peak and Cumulative Energy Doses.

    PubMed

    O'Neill-Kerr, Alex; Yassin, Anhar; Rogers, Stephen; Cornish, Janie

    2017-09-01

    The aim of this study was to test the proposition that adoption of a dose titration protocol may be associated with better patient outcomes, at lower treatment dose, and with comparable cumulative dose to that in patients treated using an age-based stimulus dosing protocol. This was an analysis of data assembled from archived records and based on cohorts of patients treated respectively on an age-based stimulus dosing protocol and on a dose titration protocol in the National Health Service in England. We demonstrated a significantly better response in the patient cohort treated with dose titration than with age-based stimulus dosing. Peak doses were less and the total cumulative dose was less in the dose titration group than in the age-based stimulus dosing group. Our findings are consistent with superior outcomes in patients treated using a dose titration protocol when compared with age-based stimulus dosing in a similar cohort of patients.

  18. Probability Distribution of Dose and Dose-Rate Effectiveness Factor for use in Estimating Risks of Solid Cancers From Exposure to Low-Let Radiation.

    PubMed

    Kocher, David C; Apostoaei, A Iulian; Hoffman, F Owen; Trabalka, John R

    2018-06-01

    This paper presents an analysis to develop a subjective state-of-knowledge probability distribution of a dose and dose-rate effectiveness factor for use in estimating risks of solid cancers from exposure to low linear energy transfer radiation (photons or electrons) whenever linear dose responses from acute and chronic exposure are assumed. A dose and dose-rate effectiveness factor represents an assumption that the risk of a solid cancer per Gy at low acute doses or low dose rates of low linear energy transfer radiation, RL, differs from the risk per Gy at higher acute doses, RH; RL is estimated as RH divided by a dose and dose-rate effectiveness factor, where RH is estimated from analyses of dose responses in Japanese atomic-bomb survivors. A probability distribution to represent uncertainty in a dose and dose-rate effectiveness factor for solid cancers was developed from analyses of epidemiologic data on risks of incidence or mortality from all solid cancers as a group or all cancers excluding leukemias, including (1) analyses of possible nonlinearities in dose responses in atomic-bomb survivors, which give estimates of a low-dose effectiveness factor, and (2) comparisons of risks in radiation workers or members of the public from chronic exposure to low linear energy transfer radiation at low dose rates with risks in atomic-bomb survivors, which give estimates of a dose-rate effectiveness factor. Probability distributions of uncertain low-dose effectiveness factors and dose-rate effectiveness factors for solid cancer incidence and mortality were combined using assumptions about the relative weight that should be assigned to each estimate to represent its relevance to estimation of a dose and dose-rate effectiveness factor. The probability distribution of a dose and dose-rate effectiveness factor for solid cancers developed in this study has a median (50th percentile) and 90% subjective confidence interval of 1.3 (0.47, 3.6). The harmonic mean is 1.1, which implies that the arithmetic mean of an uncertain estimate of the risk of a solid cancer per Gy at low acute doses or low dose rates of low linear energy transfer radiation is only about 10% less than the mean risk per Gy at higher acute doses. Data were also evaluated to define a low acute dose or low dose rate of low linear energy transfer radiation, i.e., a dose or dose rate below which a dose and dose-rate effectiveness factor should be applied in estimating risks of solid cancers.

  19. SU-E-T-374: Evaluation and Verification of Dose Calculation Accuracy with Different Dose Grid Sizes for Intracranial Stereotactic Radiosurgery

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Han, C; Schultheiss, T

    Purpose: In this study, we aim to evaluate the effect of dose grid size on the accuracy of calculated dose for small lesions in intracranial stereotactic radiosurgery (SRS), and to verify dose calculation accuracy with radiochromic film dosimetry. Methods: 15 intracranial lesions from previous SRS patients were retrospectively selected for this study. The planning target volume (PTV) ranged from 0.17 to 2.3 cm{sup 3}. A commercial treatment planning system was used to generate SRS plans using the volumetric modulated arc therapy (VMAT) technique using two arc fields. Two convolution-superposition-based dose calculation algorithms (Anisotropic Analytical Algorithm and Acuros XB algorithm) weremore » used to calculate volume dose distribution with dose grid size ranging from 1 mm to 3 mm with 0.5 mm step size. First, while the plan monitor units (MU) were kept constant, PTV dose variations were analyzed. Second, with 95% of the PTV covered by the prescription dose, variations of the plan MUs as a function of dose grid size were analyzed. Radiochomic films were used to compare the delivered dose and profile with the calculated dose distribution with different dose grid sizes. Results: The dose to the PTV, in terms of the mean dose, maximum, and minimum dose, showed steady decrease with increasing dose grid size using both algorithms. With 95% of the PTV covered by the prescription dose, the total MU increased with increasing dose grid size in most of the plans. Radiochromic film measurements showed better agreement with dose distributions calculated with 1-mm dose grid size. Conclusion: Dose grid size has significant impact on calculated dose distribution in intracranial SRS treatment planning with small target volumes. Using the default dose grid size could lead to under-estimation of delivered dose. A small dose grid size should be used to ensure calculation accuracy and agreement with QA measurements.« less

  20. Probabilidad de colisión de cometas periódicos con partículas interplanetarias

    NASA Astrophysics Data System (ADS)

    Gil Hutton, R.

    Se presentan resultados sobre la probabilidad de colisión de cometas de corto período con la población de partículas interplanetarias presentes en la región del cinturón de asteroides. Se encuentra que este proceso colisional afecta la evolución física de los cometas de manera no despreciable y puede ser el responsable de variaciones de brillo de tipo ``outburst". Se presentan resultados para algunos cometas en particular y se obtiene un límite inferior para el tamaño de los núcleos en función de la distribución de radios del cinturón de asteroides.

  1. NASA Astrophysics Data System (ADS)

    Brunini, A.

    Se presenta una revisión de los conocimientos actuales sobre el proceso de acreción del sistema solar exterior. En base a nuevas y más realistas simulaciones numéricas, se analiza el impacto que tuvo dicho proceso en otras regiones del sistema solar tales como la nube de Oort, el cinturón de Kuiper y el sistema solar interior. Se presentan entonces, las principales limitaciones de los modelos numéricos actuales, los principales puntos aún oscuros en el problema, y algunos de los posibles caminos a seguir para mejorar nuestro conocimiento en el tema. Se discute a continuación la posible utilidad de este tipo de estudios para el diseño de estrategias de búsqueda de otros sistemas planetarios.

  2. Cúmulos globulares como trazadores de bimodalidad estelar en galaxias cD

    NASA Astrophysics Data System (ADS)

    Forte, J. C.

    Se muestra que tanto la forma de los perfiles de brillo como de color observados en dos galaxias arquetípicas de tipo cD (NGC 1399 y NGC 4486) son compatibles con la presencia de poblaciones estelares bi-modales que comparten la misma distribución espacial y composición química de las familias dominantes de cúmulos globulares asociadas con ellas. El modelo resultante también predice una variación de la frecuencia específica de los cúmulos como función del radio galactocéntrico. Se discute este resultado en el contexto de una variedad de escenarios astrofísicos que intentan describir la formación de galaxias cD.

  3. Combustión turbulenta de materia nuclear en materia extraña

    NASA Astrophysics Data System (ADS)

    Vucetich, H.

    La simulación numérica de supernovas tipo II muestra que los mecanismos físicos convencionales no son suficientes como para producir la explosión. La detonación de materia nuclear en materia extraña es un mecanismo físico capaz de proveer la energía faltante en las simulaciones. En esta comunicación se muestra que la turbulencia en el corazón compacto de una supernova, después del primer choque, es capaz de transformar una combustión lenta en una detonación. Se concluye que, si la materia extraña existe, todas las ``estrellas de neutrones'' son, en realidad, ``estrellas extrañas''.

  4. Extension of the IAU Metric to BE Considered for Inner Solar System Laser Experiments

    NASA Astrophysics Data System (ADS)

    Minazzoli, Olivier; Chauvineau, Bertrand

    An increasing number of forthcoming spatial experiments will require a description of the solar system gravitational field including all the second order terms in the PN (Post-Newtonian) metric. This will be the case for missions planned or in project, like TIPO, ASTROD, LATOR. However, the solar system metric recommended by the IAU resolution B1.3, during its 24th general assembly in 2000, allows light propagation calculations until order 1.5 only. Hence, it is necessary to generalize this framework to include relevant contributing terms, which indeed are required for a great number of near-future interplanetary space missions. The present paper proposes such an extension for both General Relativity and Scalar-Tensor theories.

  5. Typical doses and dose rates in studies pertinent to radiation risk inference at low doses and low dose rates

    PubMed Central

    Rühm, Werner; Azizova, Tamara; Bouffler, Simon; Cullings, Harry M; Grosche, Bernd; Little, Mark P; Shore, Roy S; Walsh, Linda; Woloschak, Gayle E

    2018-01-01

    Abstract In order to quantify radiation risks at exposure scenarios relevant for radiation protection, often extrapolation of data obtained at high doses and high dose rates down to low doses and low dose rates is needed. Task Group TG91 on ‘Radiation Risk Inference at Low-dose and Low-dose Rate Exposure for Radiological Protection Purposes’ of the International Commission on Radiological Protection is currently reviewing the relevant cellular, animal and human studies that could be used for that purpose. This paper provides an overview of dose rates and doses typically used or present in those studies, and compares them with doses and dose rates typical of those received by the A-bomb survivors in Japan. PMID:29432579

  6. [Evaluation of Organ Dose Estimation from Indices of CT Dose Using Dose Index Registry].

    PubMed

    Iriuchijima, Akiko; Fukushima, Yasuhiro; Ogura, Akio

    Direct measurement of each patient organ dose from computed tomography (CT) is not possible. Most methods to estimate patient organ dose is using Monte Carlo simulation with dedicated software. However, dedicated software is too expensive for small scale hospitals. Not every hospital can estimate organ dose with dedicated software. The purpose of this study was to evaluate the simple method of organ dose estimation using some common indices of CT dose. The Monte Carlo simulation software Radimetrics (Bayer) was used for calculating organ dose and analysis relationship between indices of CT dose and organ dose. Multidetector CT scanners were compared with those from two manufactures (LightSpeed VCT, GE Healthcare; SOMATOM Definition Flash, Siemens Healthcare). Using stored patient data from Radimetrics, the relationships between indices of CT dose and organ dose were indicated as each formula for estimating organ dose. The accuracy of estimation method of organ dose was compared with the results of Monte Carlo simulation using the Bland-Altman plots. In the results, SSDE was the feasible index for estimation organ dose in almost organs because it reflected each patient size. The differences of organ dose between estimation and simulation were within 23%. In conclusion, our estimation method of organ dose using indices of CT dose is convenient for clinical with accuracy.

  7. Optimizing drug-dose alerts using commercial software throughout an integrated health care system.

    PubMed

    Saiyed, Salim M; Greco, Peter J; Fernandes, Glenn; Kaelber, David C

    2017-11-01

    All default electronic health record and drug reference database vendor drug-dose alerting recommendations (single dose, daily dose, dose frequency, and dose duration) were silently turned on in inpatient, outpatient, and emergency department areas for pediatric-only and nonpediatric-only populations. Drug-dose alerts were evaluated during a 3-month period. Drug-dose alerts fired on 12% of orders (104 098/834 911). System-level and drug-specific strategies to decrease drug-dose alerts were analyzed. System-level strategies included: (1) turning off all minimum drug-dosing alerts, (2) turning off all incomplete information drug-dosing alerts, (3) increasing the maximum single-dose drug-dose alert threshold to 125%, (4) increasing the daily dose maximum drug-dose alert threshold to 125%, and (5) increasing the dose frequency drug-dose alert threshold to more than 2 doses per day above initial threshold. Drug-specific strategies included changing drug-specific maximum single and maximum daily drug-dose alerting parameters for the top 22 drug categories by alert frequency. System-level approaches decreased alerting to 5% (46 988/834 911) and drug-specific approaches decreased alerts to 3% (25 455/834 911). Drug-dose alerts varied between care settings and patient populations. © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Implementing apportionment strategy to identify costs in a multidisciplinary clinic.

    PubMed

    Ferraz, Renato Ribeiro Nogueira; Neri, Anna Sofia Costa; Barbosa, Estela Capelas; Silva, Marcus Vinícius Cesso da

    2017-01-01

    To present the implementation of an apportionment strategy proportional to the productive areas of a multidisciplinary clinic, defining the minimum values to be passed monthly to health professionals who work there. A study of the clinic structure was carried out, in which the area of occupation of each service was defined. Later the cost was prorated, allocating a value to each room, proportional to the space occupied. The apportionment implementation allowed the clinic managers to visualize the cost of each room, providing a value base for formation of a minimum amount necessary to be passed monthly to each professional, as a form of payment for rent of using their facilities. The risk of financial loss of the clinic was minimized due to variation of its productivity, as well as the conditions of transference at the time of hiring by professionals were clear, promoting greater confidence and safety in contract relations. Apresentar a implantação de uma estratégia de rateio proporcional às áreas produtivas de uma clínica multidisciplinar, definindo valores mínimos a serem repassados mensalmente aos profissionais de saúde que as ocupam. Estudo da estrutura da clínica, no qual foi definida, em metros quadrados, a área de ocupação de cada serviço. Em seguida, o custo foi rateado, alocando um valor a cada sala, proporcional ao espaço ocupado. A implantação do rateio possibilitou aos gestores da clínica estudada visualizar o custo de cada sala, fornecendo uma base de valor para formação de um valor mínimo necessário a ser repassado mensalmente para cada profissional, como forma de pagamento pelo aluguel de utilização de suas instalações. Minimizou-se o risco de prejuízo da clínica pela variação de sua produtividade, bem como ficaram claras as condições de repasse no momento de contratação do aluguel pelos profissionais, promovendo maior confiança e segurança na relação contratual.

  9. Camões e a cosmogonia

    NASA Astrophysics Data System (ADS)

    Costa, J. M.

    2003-08-01

    Os Lusíadas, escrito por Luis de Camões em 1572, é um poema épico renascentista e a visão Cosmogônica do autor é apresentada, principalmente, no último canto do poema, quando Tétis mostra ao Gama a Máquina do Mundo. A Cosmogonia de Camões neste poema reflete uma visão de uma época de transição, que ainda não incorporou os elementos da revolução Copernicana. É uma visão Grego- Ptolomaica e também medieval. O poeta guia-se pela tradução e notas feita por Pedro Nunes, inventor do Nonio, do Tratado da Esfera "De Sphaera" do Astrônomo Inglês John Holywood, mais conhecido pelo nome latinizado de Johannes Sacrobosco. Outra provável fonte de Camões, de acordo com Luciano Antonio Pereira da Silva em Astronomia de os Lusíadas, é o "Theoricae novae Planetarum" (1460) do astrólogo Alemão Jorge Purbáquio (1423 - 1461). A Astronomia de Os Lusíadas representa a ciência do tempo de Camões. Camões nunca emprega a palavra constelação e seu catálogo é bastante completo. A Máquina do Mundo tem a Terra no centro. Em redor, em círculos concêntricos, a lua (Diana), Mercúrio, Vênus, o Sol (Febo), Marte, Júpiter e Saturno. Envolvendo estes astros tem o firmamento seguido pelo "Céu Áqueo" ou cristalino, depois o 1o Móbil, esfera que arrasta todas as outras consigo. Este trabalho, multidisciplinar, serve tanto para ensinar aos alunos da Física como das Ciências Humanas, a concepção de mundo do renascimento de uma forma belamente poética em versos decassílabos Este trabalho também ajuda na apreciação do maior clássico da língua portuguesa e mostra como as Ciências e as artes, em geral, estão correlacionadas e refletem a visão de mundo da época em que foi produzida.

  10. Care necessities: the view of the patient and nursing team.

    PubMed

    Martins, Priscila Fernandes; Perroca, Marcia Galan

    2017-01-01

    To compare care necessities as perceived by the patient and nursing team and to investigate the sociodemographic factors associated with these perceptions. A comparative study was conducted in units and hospitalized patients of a hospital institution in the state of São Paulo. The participants comprised 100 health professionals (50 nurses and 50 nursing technicians and auxiliaries) and 50 patients. A questionnaire was constructed and validated regarding care needs and was completed by the participants. Considering cut-off value kappa ≥ 0.61, or that is, good and very good intervals, the greatest agreement between the perception of the patients and the nursing team was in the areas of: Care and Communication, both with 92.6% agreement; followed by Basic Care with 74.1%. The lowest value was found in the field of Care Planning and Organization, 64.3%. In a general manner, there was an agreement between the care needs from the view of the patients themselves and the nursing team. Comparar como as necessidades de cuidados são percebidas pelo paciente e equipe de enfermagem e investigar os fatores sociodemográficos associados a estas percepções. Estudo comparativo realizado em unidades e internação de uma instituição hospitalar do interior do Estado de São Paulo. Os participantes foram 100 profissionais (50 enfermeiros e 50 técnicos e auxiliares de enfermagem) e 50 pacientes. Construiu-se e validou-se um questionário sobre necessidades de cuidados preenchido pelos participantes. Considerando-se valor de corte kappa ≥ 0,61, ou seja, intervalos bom e muito bom, houve maior alinhamento entre a percepção dos pacientes e equipe de enfermagem nos domínios O Ambiente do Cuidado e Comunicação, ambos com 92,6% de concordância; seguido de Cuidados Básicos, com 74,1%. O menor valor foi encontrado no domínio Planejamento e Organização do Cuidado, 64,3%. De maneira geral, observou-se alinhamento no atendimento das necessidades de cuidados no olhar do próprio paciente e da equipe de enfermagem.

  11. AIDS and jail: social representations of women in freedom deprivation situations.

    PubMed

    Trigueiro, Débora Raquel Soares Guedes; Almeida, Sandra Aparecida de; Monroe, Aline Aparecida; Costa, Gilka Paiva Oliveira; Bezerra, Valéria Peixoto; Nogueira, Jordana de Almeida

    2016-01-01

    To graspthe AIDS social representations built by freedom-deprived women. Descriptive study with a quali-quantitative approach that involved 174 convicted women in a women's prison in a capital city of the Brazilian northeastern region. Aword-association test was applied in October and November 2014, using AIDS as a stimulus. The corpuswas processed usingIramuteq software. Descending Hierarchical Classification and Correspondence Factor Analysis were applied. The content that comprises the social representation of AIDS was influenced by the prison context, which was pervaded by a lack of assistance, lack of knowledge, discrimination, and suffering that disclosed vulnerability to HIV/AIDS factors such as unprotected sex and object sharing. This underlines the stigma and fear of the illness, in addition to favoring and supporting negative feelings and a sense of rejection. To consider the use of this representational amalgam to ensure a comprehensive, contextualized care can help redirect practices, motivate self-care practices, and reduce prejudiced attitudes. Apreenderas representações sociais sobre a aids construídas por mulheres privadas de liberdade. Estudo descritivo, com abordagem quali-quantitativa que envolveu 174 apenadas de Presídio Feminino situado em capital do nordeste brasileiro. Aplicou-se o Teste de Associação Livre de Palavras, em outubro e novembro de 2014, utilizando-se do estímulo aids. O corpus foi processado pelo software Iramuteq, sendo efetuadas a Classificação Hierárquica Descendente e Análise Fatorial de Correspondência. Os conteúdos que compõem a representação social sobre aids são influenciados pelo contexto prisional, permeado dedesassistência, desconhecimento, discriminação e condições de sofrimento, revelando fatores de vulnerabilidade ao HIV/Aids como atividade sexual desprotegida e compartilhamento de objetos; reiterando o estigma e o temor à doença; e favorecendo e sustentando sentimentos negativos e de rejeição. Considerar este amálgama representacional na garantia de um cuidado integral e contextualizado pode contribuir para redirecionar práticas, motivar condutas de autocuidado e reduzir atitudes preconceituosas.

  12. Communicating bad news: an integrative review of the nursing literature.

    PubMed

    Fontes, Cassiana Mendes Bertoncello; Menezes, Daniele Vieira de; Borgato, Maria Helena; Luiz, Marcos Roberto

    2017-01-01

    describe how the process of breaking bad news is established and identify how nurses approach the task of giving bad news. integrative review of the literature for articles in Portuguese and English published between 1993-2014, in the databases: Bireme, PubMed, Scopus, Web of Science, CINAHL and Embase. Nine articles were included using the selection flow chart. A digital form was completed for each article according to the Consolidated Criteria for Reporting Qualitative Research checklist and the level of scientific evidence was determined. Of the 99 articles in identified, nine were included after applying the selection flowchart. breaking bad news is frequent in the area of oncology and palliative care, with a strong cultural influence on the autonomy of nurses in this process. the approach and skills of the nurse during this task influences the patient's reaction to the message. The theme is scarce in the literature and merits further investigation. Descrever como se estabelece o processo de comunicação de más notícias e identificar como o enfermeiro pratica a comunicação de más notícias. Revisão integrativa da literatura com artigos em português e inglês referente ao período 1993-2014 nas bases de dados Bireme, PubMed, Scopus, Web of Science, CINAHL e Embase. Elegeram-se nove artigos pelo fluxograma de seleção. Para cada artigo foi preenchida uma ficha eletrônica, elaborado um checklist do Consolidated Criteria for Reporting Qualitative Research e verificado o nível de evidência científica. Foram identificados 99 artigos e incluídos nove pelo fluxograma de seleção. Transmitir más notícias é frequente nas áreas de oncologia e cuidados paliativos, com forte influência cultural na autonomia do enfermeiro nesse processo. O modo e a habilidade do enfermeiro durante a ação influenciarão a reação do paciente acerca da mensagem. O tema é escasso na literatura, necessitando ser explorado.

  13. Abundâncias em estrelas de Bário

    NASA Astrophysics Data System (ADS)

    Allen, D. M.

    2003-08-01

    Estrelas de Bário apresentam linhas intensas de elementos produzidos pelo processos (ex: Ba, Y, Sr, Zr) e bandas intensas de CN, C2 e CH. A hipótese mais aceita sobre a origem deste grupo peculiar é a de que essas estrelas façam parte de sistemas binários, tendo recebido material enriquecido em elementos pesados da companheira mais evoluída. Apresentamos neste trabalho uma análise detalhada de uma amostra de estrelas desta classe, incluindo determinação de parâmetros atmosféricos e cálculo de abundâncias. As temperaturas efetivas foram determinadas a partir de dados fotométricos obtidos com o Fotrap instalado no telescópio Zeiss do LNA (Laboratório Nacional de Astrofísica) (B-V, V-I, R-I, V-R), e coletados na literatura nos catálogos Hipparcos (B-V), 2MASS (Two Micron All Sky Survey) (V-K) e The General Catalogue Photometric Data (sistema Geneva). Obtivemos uma faixa de temperaturas de 4400 £ Tef £ 6500. As metalicidades foram determinadas a partir de linhas de Fe I e Fe II, estando os resultados no intervalo -1 £ [Fe/H] £ +0.1. O log g foi determinado pelo equilíbrio de ionização e pela relação com a magnitude bolométrica, a temperatura e a massa, sendo os resultados na faixa 1.5 £ log g £ 4.5. As distâncias utilizadas foram determinadas com o auxílio das paralaxes Hipparcos, e as massas determinadas por modelos de isócronas. Os espectros utilizados foram obtidos com o espectrógrafo FEROS no Telescópio de 1,5m do ESO (European Southern Observatory). As abundâncias foram calculadas por meio de síntese espectral de linhas individuais incluindo elementos alfa, pico do Fe, s e r. Encontramos um excesso de elementos pesados em relação ao Fe, como esperado para estrelas de Bário.

  14. Association between filial responsibility when caring for parents and the caregivers overload.

    PubMed

    Aires, Marinês; Mocellin, Duane; Fengler, Fernanda Laís; Rosset, Idiane; Santos, Naiana Oliveira Dos; Machado, Diani de Oliveira; Day, Carolina Baltar; Paskulin, Lisiane Manganelli Girardi

    2017-01-01

    To analyze the association between filial responsibility and the overload of the children when caring for their older parents. Cross-sectional study with 100 caregiver children of older adults. Filial liability was assessed by the attitudes of the responsible child (scale of expectation and filial duty) and by care behaviors (assistance in activities of daily living, emotional and financial support, and keeping company). The overload was assessed by the Caregiver Burden Inventory. To assess the associations, the correlation coefficients of Pearson and Spearman, Kruskal-Wallis Test, and Mann-Whitney were employed. Variables that presented p-value<0.20 in the bivariate analysis were inserted in a multivariate linear regression model. The factors associated with overload were: formal employment (p=0.002), feelings regarding family life (p<0.001), financial support (p=0.027), and assistance with Activities of Daily Living (ADLs) (p<0.001). Children who were more involved with the ADLs and provided financial support showed higher levels of overload. Analisar a associação entre a responsabilidade filial e a sobrecarga dos filhos cuidadores de pessoas idosas. Estudo transversal com 100 filhos cuidadores de pessoas idosas. A responsabilidade filial foi avaliada pelas atitudes de responsabilidade filial (escala de expectativa e dever filial) e pelos comportamentos de cuidar (auxílio nas atividades de vida diária, apoio emocional, financeiro e companhia). A sobrecarga foi avaliada pelo Inventário de Sobrecarga do Cuidador. Para avaliar as associações utilizaram-se os coeficientes de correlação de Pearson e Spearman, Teste de Kruskal-Wallis e Mann-whitney. Variáveis que apresentaram valor de p<0,20 na análise bivariada foram inseridas em um modelo multivariado de regressão linear. Os fatores associados com a sobrecarga foram: emprego formal (p=0,002), sentimentos na vida familiar (p<0,001), apoio financeiro (p=0,027) e ajuda nas Atividades da Vida Diária (AVDs) (p<0,001). Os filhos que mais auxiliavam nas AVDs e prestavam apoio financeiro apresentaram maiores níveis de sobrecarga.

  15. SU-E-T-802: Verification of Implanted Cardiac Pacemaker Doses in Intensity-Modulated Radiation Therapy: Dose Prediction Accuracy and Reduction Effect of a Lead Sheet

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, J; Chung, J

    2015-06-15

    Purpose: To verify delivered doses on the implanted cardiac pacemaker, predicted doses with and without dose reduction method were verified using the MOSFET detectors in terms of beam delivery and dose calculation techniques in intensity-modulated radiation therapy (IMRT). Methods: The pacemaker doses for a patient with a tongue cancer were predicted according to the beam delivery methods [step-and-shoot (SS) and sliding window (SW)], intensity levels for dose optimization, and dose calculation algorithms. Dosimetric effects on the pacemaker were calculated three dose engines: pencil-beam convolution (PBC), analytical anisotropic algorithm (AAA), and Acuros-XB. A lead shield of 2 mm thickness was designedmore » for minimizing irradiated doses to the pacemaker. Dose variations affected by the heterogeneous material properties of the pacemaker and effectiveness of the lead shield were predicted by the Acuros-XB. Dose prediction accuracy and the feasibility of the dose reduction strategy were verified based on the measured skin doses right above the pacemaker using mosfet detectors during the radiation treatment. Results: The Acuros-XB showed underestimated skin doses and overestimated doses by the lead-shield effect, even though the lower dose disagreement was observed. It led to improved dose prediction with higher intensity level of dose optimization in IMRT. The dedicated tertiary lead sheet effectively achieved reduction of pacemaker dose up to 60%. Conclusion: The current SS technique could deliver lower scattered doses than recommendation criteria, however, use of the lead sheet contributed to reduce scattered doses.Thin lead plate can be a useful tertiary shielder and it could not acuse malfunction or electrical damage of the implanted pacemaker in IMRT. It is required to estimate more accurate scattered doses of the patient with medical device to design proper dose reduction strategy.« less

  16. Dynamically accumulated dose and 4D accumulated dose for moving tumors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li Heng; Li Yupeng; Zhang Xiaodong

    2012-12-15

    Purpose: The purpose of this work was to investigate the relationship between dynamically accumulated dose (dynamic dose) and 4D accumulated dose (4D dose) for irradiation of moving tumors, and to quantify the dose uncertainty induced by tumor motion. Methods: The authors established that regardless of treatment modality and delivery properties, the dynamic dose will converge to the 4D dose, instead of the 3D static dose, after multiple deliveries. The bounds of dynamic dose, or the maximum estimation error using 4D or static dose, were established for the 4D and static doses, respectively. Numerical simulations were performed (1) to prove themore » principle that for each phase, after multiple deliveries, the average number of deliveries for any given time converges to the total number of fractions (K) over the number of phases (N); (2) to investigate the dose difference between the 4D and dynamic doses as a function of the number of deliveries for deliveries of a 'pulsed beam'; and (3) to investigate the dose difference between 4D dose and dynamic doses as a function of delivery time for deliveries of a 'continuous beam.' A Poisson model was developed to estimate the mean dose error as a function of number of deliveries or delivered time for both pulsed beam and continuous beam. Results: The numerical simulations confirmed that the number of deliveries for each phase converges to K/N, assuming a random starting phase. Simulations for the pulsed beam and continuous beam also suggested that the dose error is a strong function of the number of deliveries and/or total deliver time and could be a function of the breathing cycle, depending on the mode of delivery. The Poisson model agrees well with the simulation. Conclusions: Dynamically accumulated dose will converge to the 4D accumulated dose after multiple deliveries, regardless of treatment modality. Bounds of the dynamic dose could be determined using quantities derived from 4D doses, and the mean dose difference between the dynamic dose and 4D dose as a function of number of deliveries and/or total deliver time was also established.« less

  17. Comparison of 2D and 3D Imaging and Treatment Planning for Postoperative Vaginal Apex High-Dose Rate Brachytherapy for Endometrial Cancer

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Russo, James K.; Armeson, Kent E.; Richardson, Susan, E-mail: srichardson@radonc.wustl.edu

    2012-05-01

    Purpose: To evaluate bladder and rectal doses using two-dimensional (2D) and 3D treatment planning for vaginal cuff high-dose rate (HDR) in endometrial cancer. Methods and Materials: Ninety-one consecutive patients treated between 2000 and 2007 were evaluated. Seventy-one and 20 patients underwent 2D and 3D planning, respectively. Each patient received six fractions prescribed at 0.5 cm to the superior 3 cm of the vagina. International Commission on Radiation Units and Measurements (ICRU) doses were calculated for 2D patients. Maximum and 2-cc doses were calculated for 3D patients. Organ doses were normalized to prescription dose. Results: Bladder maximum doses were 178% ofmore » ICRU doses (p < 0.0001). Two-cubic centimeter doses were no different than ICRU doses (p = 0.22). Two-cubic centimeter doses were 59% of maximum doses (p < 0.0001). Rectal maximum doses were 137% of ICRU doses (p < 0.0001). Two-cubic centimeter doses were 87% of ICRU doses (p < 0.0001). Two-cubic centimeter doses were 64% of maximum doses (p < 0.0001). Using the first 1, 2, 3, 4 or 5 fractions, we predicted the final bladder dose to within 10% for 44%, 59%, 83%, 82%, and 89% of patients by using the ICRU dose, and for 45%, 55%, 80%, 85%, and 85% of patients by using the maximum dose, and for 37%, 68%, 79%, 79%, and 84% of patients by using the 2-cc dose. Using the first 1, 2, 3, 4 or 5 fractions, we predicted the final rectal dose to within 10% for 100%, 100%, 100%, 100%, and 100% of patients by using the ICRU dose, and for 60%, 65%, 70%, 75%, and 75% of patients by using the maximum dose, and for 68%, 95%, 84%, 84%, and 84% of patients by using the 2-cc dose. Conclusions: Doses to organs at risk vary depending on the calculation method. In some cases, final dose accuracy appears to plateau after the third fraction, indicating that simulation and planning may not be necessary in all fractions. A clinically relevant level of accuracy should be determined and further research conducted to address this issue.« less

  18. The impact of the oxygen scavenger on the dose-rate dependence and dose sensitivity of MAGIC type polymer gels

    NASA Astrophysics Data System (ADS)

    Khan, Muzafar; Heilemann, Gerd; Kuess, Peter; Georg, Dietmar; Berg, Andreas

    2018-03-01

    Recent developments in radiation therapy aimed at more precise dose delivery along with higher dose gradients (dose painting) and more efficient dose delivery with higher dose rates e.g. flattening filter free (FFF) irradiation. Magnetic-resonance-imaging based polymer gel dosimetry offers 3D information for precise dose delivery techniques. Many of the proposed polymer gels have been reported to exhibit a dose response, measured as relaxation rate ΔR2(D), which is dose rate dependent. A lack of or a reduced dose-rate sensitivity is very important for dosimetric accuracy, especially with regard to the increasing clinical use of FFF irradiation protocols with LINACs at high dose rates. Some commonly used polymer gels are based on Methacrylic-Acid-Gel-Initiated-by-Copper (MAGIC). Here, we report on the dose sensitivity (ΔR2/ΔD) of MAGIC-type gels with different oxygen scavenger concentration for their specific dependence on the applied dose rate in order to improve the dosimetric performance, especially for high dose rates. A preclinical x-ray machine (‘Yxlon’, E  =  200 kV) was used for irradiation to cover a range of dose rates from low \\dot{D} min  =  0.6 Gy min-1 to high \\dot{D} max  =  18 Gy min-1. The dose response was evaluated using R2-imaging of the gel on a human high-field (7T) MR-scanner. The results indicate that all of the investigated dose rates had an impact on the dose response in polymer gel dosimeters, being strongest in the high dose region and less effective for low dose levels. The absolute dose rate dependence \\frac{(Δ R2/Δ D)}{Δ \\dot{D}} of the dose response in MAGIC-type gel is significantly reduced using higher concentrations of oxygen scavenger at the expense of reduced dose sensitivity. For quantitative dose evaluations the relative dose rate dependence of a polymer gel, normalized to its sensitivity is important. Based on this normalized sensitivity the dose rate sensitivity was reduced distinctly using an increased oxygen scavenger concentration with reference to standard MAGIC-type gel formulation at high dose rate levels. The proposed gel composition with high oxygen scavenger concentration exhibits a larger linear active dose response and might be used especially in FFF-radiation applications and preclinical dosimetry at high dose rates. We propose in general to use high dose rates for calibration and evaluation as the change in relative dose sensitivity is reduced at higher dose rates in all of the investigated gel types.

  19. Rapid Acute Dose Assessment Using MCNP6

    NASA Astrophysics Data System (ADS)

    Owens, Andrew Steven

    Acute radiation doses due to physical contact with a high-activity radioactive source have proven to be an occupational hazard. Multiple radiation injuries have been reported due to manipulating a radioactive source with bare hands or by placing a radioactive source inside a shirt or pants pocket. An effort to reconstruct the radiation dose must be performed to properly assess and medically manage the potential biological effects from such doses. Using the reference computational phantoms defined by the International Commission on Radiological Protection (ICRP) and the Monte Carlo N-Particle transport code (MCNP6), dose rate coefficients are calculated to assess doses for common acute doses due to beta and photon radiation sources. The research investigates doses due to having a radioactive source in either a breast pocket or pants back pocket. The dose rate coefficients are calculated for discrete energies and can be used to interpolate for any given energy of photon or beta emission. The dose rate coefficients allow for quick calculation of whole-body dose, organ dose, and/or skin dose if the source, activity, and time of exposure are known. Doses are calculated with the dose rate coefficients and compared to results from the International Atomic Energy Agency (IAEA) reports from accidents that occurred in Gilan, Iran and Yanango, Peru. Skin and organ doses calculated with the dose rate coefficients appear to agree, but there is a large discrepancy when comparing whole-body doses assessed using biodosimetry and whole-body doses assessed using the dose rate coefficients.

  20. Dose density in adjuvant chemotherapy for breast cancer.

    PubMed

    Citron, Marc L

    2004-01-01

    Dose-dense chemotherapy increases the dose intensity of the regimen by delivering standard-dose chemotherapy with shorter intervals between the cycles. This article discusses the rationale for dose-dense therapy and reviews the results with dose-dense adjuvant regimens in recent clinical trials in breast cancer. The papers for this review covered evidence of a dose-response relation in cancer chemotherapy; the rationale for dose-intense (and specifically dose-dense) therapy; and clinical experience with dose-dense regimens in adjuvant chemotherapy for breast cancer, with particular attention to outcomes and toxicity. Evidence supports maintaining the dose intensity of adjuvant chemotherapy within the conventional dose range. Disease-free and overall survival with combination cyclophosphamide, methotrexate, and fluorouracil are significantly improved when patients receive within 85% of the planned dose. Moderate and high dose cyclophosphamide, doxorubicin, and fluorouracil within the standard range results in greater disease-free and overall survival than the low dose regimen. The sequential addition of paclitaxel after concurrent doxorubicin and cyclophosphamide also significantly improves survival. Disease-free and overall survival with dose-dense sequential or concurrent doxorubicin, cyclophosphamide, and paclitaxel with filgrastim (rhG-CSF; NEUPOGEN) support are significantly greater than with conventional schedules (q21d). The delivered dose intensity of adjuvant chemotherapy within the standard dose range is an important predictor of the clinical outcome. Prospective trials of high-dose chemotherapy have shown no improvement over standard regimens, and toxicity was greater. Dose-dense adjuvant chemotherapy improves the clinical outcomes with doxorubicin-containing regimens. Filgrastim support enables the delivery of dose-dense chemotherapy and reduces the risk of neutropenia and its complications.

  1. Derivation of mean dose tolerances for new fractionation schemes and treatment modalities

    NASA Astrophysics Data System (ADS)

    Perkó, Zoltán; Bortfeld, Thomas; Hong, Theodore; Wolfgang, John; Unkelbach, Jan

    2018-02-01

    Avoiding toxicities in radiotherapy requires the knowledge of tolerable organ doses. For new, experimental fractionation schemes (e.g. hypofractionation) these are typically derived from traditional schedules using the biologically effective dose (BED) model. In this report we investigate the difficulties of establishing mean dose tolerances that arise since the mean BED depends on the entire spatial dose distribution, rather than on the dose level alone. A formula has been derived to establish mean physical dose constraints such that they are mean BED equivalent to a reference treatment scheme. This formula constitutes a modified BED equation where the influence of the spatial dose distribution is summarized in a single parameter, the dose shape factor. To quantify effects we analyzed 24 liver cancer patients for whom both proton and photon IMRT treatment plans were available. The results show that the standard BED equation—neglecting the spatial dose distribution—can overestimate mean dose tolerances for hypofractionated treatments by up to 20%. The shape difference between photon and proton dose distributions can cause 30-40% differences in mean physical dose for plans having identical mean BEDs. Converting hypofractionated, 5/15-fraction proton doses to mean BED equivalent photon doses in traditional 35-fraction regimens resulted in up to 10 Gy higher doses than applying the standard BED formula. The dose shape effect should be accounted for to avoid overestimation of mean dose tolerances, particularly when estimating constraints for hypofractionated regimens. Additionally, tolerances established for one treatment modality cannot necessarily be applied to other modalities with drastically different dose distributions, such as proton therapy. Last, protons may only allow marginal (5-10%) dose escalation if a fraction-size adjusted organ mean dose is constraining instead of a physical dose.

  2. Validation of GPU based TomoTherapy dose calculation engine.

    PubMed

    Chen, Quan; Lu, Weiguo; Chen, Yu; Chen, Mingli; Henderson, Douglas; Sterpin, Edmond

    2012-04-01

    The graphic processing unit (GPU) based TomoTherapy convolution/superposition(C/S) dose engine (GPU dose engine) achieves a dramatic performance improvement over the traditional CPU-cluster based TomoTherapy dose engine (CPU dose engine). Besides the architecture difference between the GPU and CPU, there are several algorithm changes from the CPU dose engine to the GPU dose engine. These changes made the GPU dose slightly different from the CPU-cluster dose. In order for the commercial release of the GPU dose engine, its accuracy has to be validated. Thirty eight TomoTherapy phantom plans and 19 patient plans were calculated with both dose engines to evaluate the equivalency between the two dose engines. Gamma indices (Γ) were used for the equivalency evaluation. The GPU dose was further verified with the absolute point dose measurement with ion chamber and film measurements for phantom plans. Monte Carlo calculation was used as a reference for both dose engines in the accuracy evaluation in heterogeneous phantom and actual patients. The GPU dose engine showed excellent agreement with the current CPU dose engine. The majority of cases had over 99.99% of voxels with Γ(1%, 1 mm) < 1. The worst case observed in the phantom had 0.22% voxels violating the criterion. In patient cases, the worst percentage of voxels violating the criterion was 0.57%. For absolute point dose verification, all cases agreed with measurement to within ±3% with average error magnitude within 1%. All cases passed the acceptance criterion that more than 95% of the pixels have Γ(3%, 3 mm) < 1 in film measurement, and the average passing pixel percentage is 98.5%-99%. The GPU dose engine also showed similar degree of accuracy in heterogeneous media as the current TomoTherapy dose engine. It is verified and validated that the ultrafast TomoTherapy GPU dose engine can safely replace the existing TomoTherapy cluster based dose engine without degradation in dose accuracy.

  3. DICOM organ dose does not accurately represent calculated dose in mammography

    NASA Astrophysics Data System (ADS)

    Suleiman, Moayyad E.; Brennan, Patrick C.; McEntee, Mark F.

    2016-03-01

    This study aims to analyze the agreement between the mean glandular dose estimated by the mammography unit (organ dose) and mean glandular dose calculated using Dance et al published method (calculated dose). Anonymised digital mammograms from 50 BreastScreen NSW centers were downloaded and exposure information required for the calculation of dose was extracted from the DICOM header along with the organ dose estimated by the system. Data from quality assurance annual tests for the included centers were collected and used to calculate the mean glandular dose for each mammogram. Bland-Altman analysis and a two-tailed paired t-test were used to study the agreement between calculated and organ dose and the significance of any differences. A total of 27,869 dose points from 40 centers were included in the study, mean calculated dose and mean organ dose (+/- standard deviation) were 1.47 (+/-0.66) and 1.38 (+/-0.56) mGy respectively. A statistically significant 0.09 mGy bias (t = 69.25; p<0.0001) with 95% limits of agreement between calculated and organ doses ranging from -0.34 and 0.52 were shown by Bland-Altman analysis, which indicates a small yet highly significant difference between the two means. The use of organ dose for dose audits is done at the risk of over or underestimating the calculated dose, hence, further work is needed to identify the causal agents for differences between organ and calculated doses and to generate a correction factor for organ dose.

  4. An Adaptive Staggered Dose Design for a Normal Endpoint.

    PubMed

    Wu, Joseph; Menon, Sandeep; Chang, Mark

    2015-01-01

    In a clinical trial where several doses are compared to a control, a multi-stage design that combines both the selection of the best dose and the confirmation of this selected dose is desirable. An example is the two-stage drop-the-losers or pick-the-winner design, where inferior doses are dropped after interim analysis. Selection of target dose(s) can be based on ranking of observed effects, hypothesis testing with adjustment for multiplicity, or other criteria at interim stages. A number of methods have been proposed and have made significant gains in trial efficiency. However, many of these designs started off with all doses with equal allocation and did not consider prioritizing the doses using existing dose-response information. We propose an adaptive staggered dose procedure that allows explicit prioritization of doses and applies error spending scheme that favors doses with assumed better responses. This design starts off with only a subset of the doses and adaptively adds new doses depending on interim results. Using simulation, we have shown that this design performs better in terms of increased statistical power than the drop-the-losers design given strong prior information of dose response.

  5. Comparison of TID Effects in Space-Like Variable Dose Rates and Constant Dose Rates

    NASA Technical Reports Server (NTRS)

    Harris, Richard D.; McClure, Steven S.; Rax, Bernard G.; Evans, Robin W.; Jun, Insoo

    2008-01-01

    The degradation of the LM193 dual voltage comparator has been studied at different TID dose rate profiles, including several different constant dose rates and a variable dose rate that simulates the behavior of a solar flare. A comparison of results following constant dose rate vs. variable dose rates is made to explore how well the constant dose rates used for typical part testing predict the performance during a simulated space-like mission. Testing at a constant dose rate equal to the lowest dose rate seen during the simulated flare provides an extremely conservative estimate of the overall amount of degradation. A constant dose rate equal to the average dose rate is also more conservative than the variable rate. It appears that, for this part, weighting the dose rates by the amount of total dose received at each rate (rather than the amount of time at each dose rate) results in an average rate that produces an amount of degradation that is a reasonable approximation to that received by the variable rate.

  6. Accuracy of the dose-shift approximation in estimating the delivered dose in SBRT of lung tumors considering setup errors and breathing motions.

    PubMed

    Karlsson, Kristin; Lax, Ingmar; Lindbäck, Elias; Poludniowski, Gavin

    2017-09-01

    Geometrical uncertainties can result in a delivered dose to the tumor different from that estimated in the static treatment plan. The purpose of this project was to investigate the accuracy of the dose calculated to the clinical target volume (CTV) with the dose-shift approximation, in stereotactic body radiation therapy (SBRT) of lung tumors considering setup errors and breathing motion. The dose-shift method was compared with a beam-shift method with dose recalculation. Included were 10 patients (10 tumors) selected to represent a variety of SBRT-treated lung tumors in terms of tumor location, CTV volume, and tumor density. An in-house developed toolkit within a treatment planning system allowed the shift of either the dose matrix or a shift of the beam isocenter with dose recalculation, to simulate setup errors and breathing motion. Setup shifts of different magnitudes (up to 10 mm) and directions as well as breathing with different peak-to-peak amplitudes (up to 10:5:5 mm) were modeled. The resulting dose-volume histograms (DVHs) were recorded and dose statistics were extracted. Generally, both the dose-shift and beam-shift methods resulted in calculated doses lower than the static planned dose, although the minimum (D 98% ) dose exceeded the prescribed dose in all cases, for setup shifts up to 5 mm. The dose-shift method also generally underestimated the dose compared with the beam-shift method. For clinically realistic systematic displacements of less than 5 mm, the results demonstrated that in the minimum dose region within the CTV, the dose-shift method was accurate to 2% (root-mean-square error). Breathing motion only marginally degraded the dose distributions. Averaged over the patients and shift directions, the dose-shift approximation was determined to be accurate to approximately 2% (RMS) within the CTV, for clinically relevant geometrical uncertainties for SBRT of lung tumors.

  7. Fully automated treatment planning for head and neck radiotherapy using a voxel-based dose prediction and dose mimicking method

    NASA Astrophysics Data System (ADS)

    McIntosh, Chris; Welch, Mattea; McNiven, Andrea; Jaffray, David A.; Purdie, Thomas G.

    2017-08-01

    Recent works in automated radiotherapy treatment planning have used machine learning based on historical treatment plans to infer the spatial dose distribution for a novel patient directly from the planning image. We present a probabilistic, atlas-based approach which predicts the dose for novel patients using a set of automatically selected most similar patients (atlases). The output is a spatial dose objective, which specifies the desired dose-per-voxel, and therefore replaces the need to specify and tune dose-volume objectives. Voxel-based dose mimicking optimization then converts the predicted dose distribution to a complete treatment plan with dose calculation using a collapsed cone convolution dose engine. In this study, we investigated automated planning for right-sided oropharaynx head and neck patients treated with IMRT and VMAT. We compare four versions of our dose prediction pipeline using a database of 54 training and 12 independent testing patients by evaluating 14 clinical dose evaluation criteria. Our preliminary results are promising and demonstrate that automated methods can generate comparable dose distributions to clinical. Overall, automated plans achieved an average of 0.6% higher dose for target coverage evaluation criteria, and 2.4% lower dose at the organs at risk criteria levels evaluated compared with clinical. There was no statistically significant difference detected in high-dose conformity between automated and clinical plans as measured by the conformation number. Automated plans achieved nine more unique criteria than clinical across the 12 patients tested and automated plans scored a significantly higher dose at the evaluation limit for two high-risk target coverage criteria and a significantly lower dose in one critical organ maximum dose. The novel dose prediction method with dose mimicking can generate complete treatment plans in 12-13 min without user interaction. It is a promising approach for fully automated treatment planning and can be readily applied to different treatment sites and modalities.

  8. Fully automated treatment planning for head and neck radiotherapy using a voxel-based dose prediction and dose mimicking method.

    PubMed

    McIntosh, Chris; Welch, Mattea; McNiven, Andrea; Jaffray, David A; Purdie, Thomas G

    2017-07-06

    Recent works in automated radiotherapy treatment planning have used machine learning based on historical treatment plans to infer the spatial dose distribution for a novel patient directly from the planning image. We present a probabilistic, atlas-based approach which predicts the dose for novel patients using a set of automatically selected most similar patients (atlases). The output is a spatial dose objective, which specifies the desired dose-per-voxel, and therefore replaces the need to specify and tune dose-volume objectives. Voxel-based dose mimicking optimization then converts the predicted dose distribution to a complete treatment plan with dose calculation using a collapsed cone convolution dose engine. In this study, we investigated automated planning for right-sided oropharaynx head and neck patients treated with IMRT and VMAT. We compare four versions of our dose prediction pipeline using a database of 54 training and 12 independent testing patients by evaluating 14 clinical dose evaluation criteria. Our preliminary results are promising and demonstrate that automated methods can generate comparable dose distributions to clinical. Overall, automated plans achieved an average of 0.6% higher dose for target coverage evaluation criteria, and 2.4% lower dose at the organs at risk criteria levels evaluated compared with clinical. There was no statistically significant difference detected in high-dose conformity between automated and clinical plans as measured by the conformation number. Automated plans achieved nine more unique criteria than clinical across the 12 patients tested and automated plans scored a significantly higher dose at the evaluation limit for two high-risk target coverage criteria and a significantly lower dose in one critical organ maximum dose. The novel dose prediction method with dose mimicking can generate complete treatment plans in 12-13 min without user interaction. It is a promising approach for fully automated treatment planning and can be readily applied to different treatment sites and modalities.

  9. Radon Exposure and the Definition of Low Doses-The Problem of Spatial Dose Distribution.

    PubMed

    Madas, Balázs G

    2016-07-01

    Investigating the health effects of low doses of ionizing radiation is considered to be one of the most important fields in radiological protection research. Although the definition of low dose given by a dose range seems to be clear, it leaves some open questions. For example, the time frame and the target volume in which absorbed dose is measured have to be defined. While dose rate is considered in the current system of radiological protection, the same cancer risk is associated with all exposures, resulting in a given amount of energy absorbed by a single target cell or distributed among all the target cells of a given organ. However, the biological effects and so the health consequences of these extreme exposure scenarios are unlikely to be the same. Due to the heterogeneous deposition of radon progeny within the lungs, heterogeneous radiation exposure becomes a practical issue in radiological protection. While the macroscopic dose is still within the low dose range, local tissue doses on the order of Grays can be reached in the most exposed parts of the bronchial airways. It can be concluded that progress in low dose research needs not only low dose but also high dose experiments where small parts of a biological sample receive doses on the order of Grays, while the average dose over the whole sample remains low. A narrow interpretation of low dose research might exclude investigations with high relevance to radiological protection. Therefore, studies important to radiological protection should be performed in the frame of low dose research even if the applied doses do not fit in the dose range used for the definition of low doses.

  10. The diagnostic performance of reduced-dose CT for suspected appendicitis in paediatric and adult patients: A systematic review and diagnostic meta-analysis.

    PubMed

    Yoon, Hee Mang; Suh, Chong Hyun; Cho, Young Ah; Kim, Jeong Rye; Lee, Jin Seong; Jung, Ah Young; Kim, Jung Heon; Lee, Jeong-Yong; Kim, So Yeon

    2018-06-01

    To evaluate the diagnostic performance of reduced-dose CT for suspected appendicitis. A systematic search of the MEDLINE and EMBASE databases was carried out through to 10 January 2017. Studies evaluating the diagnostic performance of reduced-dose CT for suspected appendicitis in paediatric and adult patients were selected. Pooled summary estimates of sensitivity and specificity were calculated using hierarchical logistic regression modelling. Meta-regression was performed. Fourteen original articles with a total of 3,262 patients were included. For all studies using reduced-dose CT, the summary sensitivity was 96 % (95 % CI 93-98) with a summary specificity of 94 % (95 % CI 92-95). For the 11 studies providing a head-to-head comparison between reduced-dose CT and standard-dose CT, reduced-dose CT demonstrated a comparable summary sensitivity of 96 % (95 % CI 91-98) and specificity of 94 % (95 % CI 93-96) without any significant differences (p=.41). In meta-regression, there were no significant factors affecting the heterogeneity. The median effective radiation dose of the reduced-dose CT was 1.8 mSv (1.46-4.16 mSv), which was a 78 % reduction in effective radiation dose compared to the standard-dose CT. Reduced-dose CT shows excellent diagnostic performance for suspected appendicitis. • Reduced-dose CT shows excellent diagnostic performance for evaluating suspected appendicitis. • Reduced-dose CT has a comparable diagnostic performance to standard-dose CT. • Median effective radiation dose of reduced-dose CT was 1.8 mSv (1.46-4.16). • Reduced-dose CT achieved a 78 % dose reduction compared to standard-dose CT.

  11. Feasibility of online IMPT adaptation using fast, automatic and robust dose restoration

    NASA Astrophysics Data System (ADS)

    Bernatowicz, Kinga; Geets, Xavier; Barragan, Ana; Janssens, Guillaume; Souris, Kevin; Sterpin, Edmond

    2018-04-01

    Intensity-modulated proton therapy (IMPT) offers excellent dose conformity and healthy tissue sparing, but it can be substantially compromised in the presence of anatomical changes. A major dosimetric effect is caused by density changes, which alter the planned proton range in the patient. Three different methods, which automatically restore an IMPT plan dose on a daily CT image were implemented and compared: (1) simple dose restoration (DR) using optimization objectives of the initial plan, (2) voxel-wise dose restoration (vDR), and (3) isodose volume dose restoration (iDR). Dose restorations were calculated for three different clinical cases, selected to test different capabilities of the restoration methods: large range adaptation, complex dose distributions and robust re-optimization. All dose restorations were obtained in less than 5 min, without manual adjustments of the optimization settings. The evaluation of initial plans on repeated CTs showed large dose distortions, which were substantially reduced after restoration. In general, all dose restoration methods improved DVH-based scores in propagated target volumes and OARs. Analysis of local dose differences showed that, although all dose restorations performed similarly in high dose regions, iDR restored the initial dose with higher precision and accuracy in the whole patient anatomy. Median dose errors decreased from 13.55 Gy in distorted plan to 9.75 Gy (vDR), 6.2 Gy (DR) and 4.3 Gy (iDR). High quality dose restoration is essential to minimize or eventually by-pass the physician approval of the restored plan, as long as dose stability can be assumed. Motion (as well as setup and range uncertainties) can be taken into account by including robust optimization in the dose restoration. Restoring clinically-approved dose distribution on repeated CTs does not require new ROI segmentation and is compatible with an online adaptive workflow.

  12. Low Dose MDCT with Tube Current Modulation: Role in Detection of Urolithiasis and Patient Effective Dose Reduction

    PubMed Central

    Kakkar, Chandan; Sripathi, Smiti; Parakh, Anushri; Shrivastav, Rajendra

    2016-01-01

    Introduction Urolithiasis is one of the major, recurring problem in young individuals and CT being the commonest diagnostic modality used. In order to reduce the radiation dose to the patient who are young and as stone formation is a recurring process; one of the simplest way would be, low dose CT along with tube current modulation. Aim Aim of this study was to compare the sensitivity and specificity of low dose (70mAs) with standard dose (250mAs) protocol in detecting urolithiasis and to define the tube current and mean effective patient dose by these protocols. Materials and Methods A prospective study was conducted in 200 patients over a period of 2 years with acute flank pain presentation. CT was performed in 100 cases with standard dose and another 100 with low dose protocol using tube current modulation. Sensitivity and specificity for calculus detection, percentage reduction of dose and tube current with low dose protocol was calculated. Results Urolithiasis was detected in 138 patients, 67 were examined by high dose and 71 were by low dose protocol. Sensitivity and Specificity of low dose protocol was 97.1% and 96.4% with similar results found in high BMI patients. Tube current modulation resulted in reduction of effective tube current by 12.17%. The mean effective patient dose for standard dose was 10.33 mSv whereas 2.92 mSv for low dose with 51.13–53.8% reduction in low dose protocol. Conclusion The study has reinforced that low-dose CT with tube current modulation is appropriate for diagnosis of urolithiasis with significant reduction in tube current and patient effective dose. PMID:27437322

  13. Low Dose MDCT with Tube Current Modulation: Role in Detection of Urolithiasis and Patient Effective Dose Reduction.

    PubMed

    Koteshwar, Prakashini; Kakkar, Chandan; Sripathi, Smiti; Parakh, Anushri; Shrivastav, Rajendra

    2016-05-01

    Urolithiasis is one of the major, recurring problem in young individuals and CT being the commonest diagnostic modality used. In order to reduce the radiation dose to the patient who are young and as stone formation is a recurring process; one of the simplest way would be, low dose CT along with tube current modulation. Aim of this study was to compare the sensitivity and specificity of low dose (70mAs) with standard dose (250mAs) protocol in detecting urolithiasis and to define the tube current and mean effective patient dose by these protocols. A prospective study was conducted in 200 patients over a period of 2 years with acute flank pain presentation. CT was performed in 100 cases with standard dose and another 100 with low dose protocol using tube current modulation. Sensitivity and specificity for calculus detection, percentage reduction of dose and tube current with low dose protocol was calculated. Urolithiasis was detected in 138 patients, 67 were examined by high dose and 71 were by low dose protocol. Sensitivity and Specificity of low dose protocol was 97.1% and 96.4% with similar results found in high BMI patients. Tube current modulation resulted in reduction of effective tube current by 12.17%. The mean effective patient dose for standard dose was 10.33 mSv whereas 2.92 mSv for low dose with 51.13-53.8% reduction in low dose protocol. The study has reinforced that low-dose CT with tube current modulation is appropriate for diagnosis of urolithiasis with significant reduction in tube current and patient effective dose.

  14. Sensitivity and specificity of dosing alerts for dosing errors among hospitalized pediatric patients

    PubMed Central

    Stultz, Jeremy S; Porter, Kyle; Nahata, Milap C

    2014-01-01

    Objectives To determine the sensitivity and specificity of a dosing alert system for dosing errors and to compare the sensitivity of a proprietary system with and without institutional customization at a pediatric hospital. Methods A retrospective analysis of medication orders, orders causing dosing alerts, reported adverse drug events, and dosing errors during July, 2011 was conducted. Dosing errors with and without alerts were identified and the sensitivity of the system with and without customization was compared. Results There were 47 181 inpatient pediatric orders during the studied period; 257 dosing errors were identified (0.54%). The sensitivity of the system for identifying dosing errors was 54.1% (95% CI 47.8% to 60.3%) if customization had not occurred and increased to 60.3% (CI 54.0% to 66.3%) with customization (p=0.02). The sensitivity of the system for underdoses was 49.6% without customization and 60.3% with customization (p=0.01). Specificity of the customized system for dosing errors was 96.2% (CI 96.0% to 96.3%) with a positive predictive value of 8.0% (CI 6.8% to 9.3). All dosing errors had an alert over-ridden by the prescriber and 40.6% of dosing errors with alerts were administered to the patient. The lack of indication-specific dose ranges was the most common reason why an alert did not occur for a dosing error. Discussion Advances in dosing alert systems should aim to improve the sensitivity and positive predictive value of the system for dosing errors. Conclusions The dosing alert system had a low sensitivity and positive predictive value for dosing errors, but might have prevented dosing errors from reaching patients. Customization increased the sensitivity of the system for dosing errors. PMID:24496386

  15. High-dose Versus Low-dose Tranexamic Acid to Reduce Transfusion Requirements in Pediatric Scoliosis Surgery.

    PubMed

    Johnson, Daniel J; Johnson, Christine C; Goobie, Susan M; Nami, Nina; Wetzler, Joshua A; Sponseller, Paul D; Frank, Steven M

    2017-12-01

    Our objective was to quantify blood loss and transfusion requirements for high-dose and low-dose tranexamic acid (TXA) dosing regimens in pediatric patients undergoing spinal fusion for correction of idiopathic scoliosis. Previous investigators have established the efficacy of TXA in pediatric scoliosis surgery; however, the dosing regimens vary widely and the optimal dose has not been established. We retrospectively analyzed electronic medical records for 116 patients who underwent spinal fusion surgery for idiopathic scoliosis by a single surgeon and were treated with TXA. In total, 72 patients received a 10 mg/kg loading dose with a 1 mg/kg/h maintenance dose (low-dose) and 44 patients received 50 mg/kg loading dose with a 5 mg/kg/h maintenance dose (high-dose). Estimated blood loss and transfusion requirements were compared between dosing groups. Patient characteristics were nearly identical between the 2 groups. Compared with the low-dose TXA group, the high-dose TXA group had decreased estimated blood loss (695 vs. 968 mL, P=0.01), and a decrease in both intraoperative (0.3 vs. 0.9 units, P=0.01) and whole hospitalization (0.4 vs. 1.0 units, P=0.04) red blood cell transfusion requirements. The higher-dose TXA was associated with decreased intraoperative (P=0.01), and whole hospital transfusion (P=0.01) requirements, even after risk-adjustment for potential confounding variables. High-dose TXA is more effective than low-dose TXA in reducing blood loss and transfusion requirements in pediatric idiopathic scoliosis patients undergoing surgery. Level-III, retrospective cohort study.

  16. Dose rate mapping of VMAT treatments

    NASA Astrophysics Data System (ADS)

    Podesta, Mark; Antoniu Popescu, I.; Verhaegen, Frank

    2016-06-01

    Human tissues exhibit a varying response to radiation dose depending on the dose rate and fractionation scheme used. Dose rate effects have been reported for different radiations, and tissue types. The literature indicates that there is not a significant difference in response for low-LET radiation when using dose rates between 1 Gy min-1 and 12 Gy min-1 but lower dose rates have an observable sparing effect on tissues and a differential effect between tissues. In intensity-modulated radiotherapy such as volumetric modulated arc therapy (VMAT) the dose can be delivered with a wide range of dose rates. In this work we developed a method based on time-resolved Monte Carlo simulations to quantify the dose rate frequency distribution for clinical VMAT treatments for three cancer sites, head and neck, lung, and pelvis within both planning target volumes (PTV) and normal tissues. The results show a wide range of dose rates are used to deliver dose in VMAT and up to 75% of the PTV can have its dose delivered with dose rates  <1 Gy min-1. Pelvic plans on average have a lower mean dose rate within the PTV than lung or head and neck plans but a comparable mean dose rate within the organs at risk. Two VMAT plans that fulfil the same dose objectives and constraints may be delivered with different dose rate distributions, particularly when comparing single arcs to multiple arc plans. It is concluded that for dynamic plans, the dose rate range used varies to a larger degree than previously assumed. The effect of the dose rate range in VMAT on clinical outcome is unknown.

  17. Estimating thyroid dose in pediatric CT exams from surface dose measurement

    NASA Astrophysics Data System (ADS)

    Al-Senan, Rani; Mueller, Deborah L.; Hatab, Mustapha R.

    2012-07-01

    The purpose of this study was to investigate the possibility of estimating pediatric thyroid doses from CT using surface neck doses. Optically stimulated luminescence dosimeters were used to measure the neck surface dose of 25 children ranging in ages between one and three years old. The neck circumference for each child was measured. The relationship between obtained surface doses and thyroid dose was studied using acrylic phantoms of various sizes and with holes of different depths. The ratios of hole-to-surface doses were used to convert patients' surface dose to thyroid dose. ImPACT software was utilized to calculate thyroid dose after applying the appropriate age correction factors. A paired t-test was performed to compare thyroid doses from our approach and ImPACT. The ratio of thyroid to surface dose was found to be 1.1. Thyroid doses ranged from 20 to 80 mGy. Comparison showed no statistical significance (p = 0.18). In addition, the average of surface dose variation along the z-axis in helical scans was studied and found to range between 5% (in 10 cm diameter phantom/24 mm collimation/pitch 1.0) and 8% (in 16 cm diameter phantom/12 mm collimation/pitch 0.7). We conclude that surface dose is an acceptable predictor for pediatric thyroid dose from CT. The uncertainty due to surface dose variability may be reduced if narrower collimation is used with a pitch factor close to 1.0. Also, the results did not show any effect of thyroid depth on the measured dose.

  18. Real-time eye lens dose monitoring during cerebral angiography procedures.

    PubMed

    Safari, M J; Wong, J H D; Kadir, K A A; Thorpe, N K; Cutajar, D L; Petasecca, M; Lerch, M L F; Rosenfeld, A B; Ng, K H

    2016-01-01

    To develop a real-time dose-monitoring system to measure the patient's eye lens dose during neuro-interventional procedures. Radiation dose received at left outer canthus (LOC) and left eyelid (LE) were measured using Metal-Oxide-Semiconductor Field-Effect Transistor dosimeters on 35 patients who underwent diagnostic or cerebral embolization procedures. The radiation dose received at the LOC region was significantly higher than the dose received by the LE. The maximum eye lens dose of 1492 mGy was measured at LOC region for an AVM case, followed by 907 mGy for an aneurysm case and 665 mGy for a diagnostic angiography procedure. Strong correlations (shown as R(2)) were observed between kerma-area-product and measured eye doses (LOC: 0.78, LE: 0.68). Lateral and frontal air-kerma showed strong correlations with measured dose at LOC (AKL: 0.93, AKF: 0.78) and a weak correlation with measured dose at LE. A moderate correlation was observed between fluoroscopic time and dose measured at LE and LOC regions. The MOSkin dose-monitoring system represents a new tool enabling real-time monitoring of eye lens dose during neuro-interventional procedures. This system can provide interventionalists with information needed to adjust the clinical procedure to control the patient's dose. Real-time patient dose monitoring helps interventionalists to monitor doses. Strong correlation was observed between kerma-area-product and measured eye doses. Radiation dose at left outer canthus was higher than at left eyelid.

  19. Dose-volume metrics and their relation to memory performance in pediatric brain tumor patients: A preliminary study.

    PubMed

    Raghubar, Kimberly P; Lamba, Michael; Cecil, Kim M; Yeates, Keith Owen; Mahone, E Mark; Limke, Christina; Grosshans, David; Beckwith, Travis J; Ris, M Douglas

    2018-06-01

    Advances in radiation treatment (RT), specifically volumetric planning with detailed dose and volumetric data for specific brain structures, have provided new opportunities to study neurobehavioral outcomes of RT in children treated for brain tumor. The present study examined the relationship between biophysical and physical dose metrics and neurocognitive ability, namely learning and memory, 2 years post-RT in pediatric brain tumor patients. The sample consisted of 26 pediatric patients with brain tumor, 14 of whom completed neuropsychological evaluations on average 24 months post-RT. Prescribed dose and dose-volume metrics for specific brain regions were calculated including physical metrics (i.e., mean dose and maximum dose) and biophysical metrics (i.e., integral biological effective dose and generalized equivalent uniform dose). We examined the associations between dose-volume metrics (whole brain, right and left hippocampus), and performance on measures of learning and memory (Children's Memory Scale). Biophysical dose metrics were highly correlated with the physical metric of mean dose but not with prescribed dose. Biophysical metrics and mean dose, but not prescribed dose, correlated with measures of learning and memory. These preliminary findings call into question the value of prescribed dose for characterizing treatment intensity; they also suggest that biophysical dose has only a limited advantage compared to physical dose when calculated for specific regions of the brain. We discuss the implications of the findings for evaluating and understanding the relation between RT and neurocognitive functioning. © 2018 Wiley Periodicals, Inc.

  20. Investments and costs of oral health care for Family Health Care.

    PubMed

    Macêdo, Márcia Stefânia Ribeiro; Chaves, Sônia Cristina Lima; Fernandes, Antônio Luis de Carvalho

    2016-07-21

    To estimate the investments to implement and operational costs of a type I Oral Health Care Team in the Family Health Care Strategy. This is an economic assessment study, for analyzing the investments and operational costs of an oral health care team in the city of Salvador, BA, Northeastern Brazil. The amount worth of investments for its implementation was obtained by summing up the investments in civil projects and shared facilities, in equipments, furniture, and instruments. Regarding the operational costs, the 2009-2012 time series was analyzed and the month of December 2012 was adopted for assessing the monetary values in effect. The costs were classified as direct variable costs (consumables) and direct fixed costs (salaries, maintenance, equipment depreciation, instruments, furniture, and facilities), besides the indirect fixed costs (cleaning, security, energy, and water). The Ministry of Health's share in funding was also calculated, and the factors that influence cost behavior were described. The investment to implement a type I Oral Health Care Team was R$29,864.00 (US$15,236.76). The operational costs of a type I Oral Health Care Team were around R$95,434.00 (US$48,690.82) a year. The Ministry of Health's financial incentives for investments accounted for 41.8% of the implementation investments, whereas the municipality contributed with a 59.2% share of the total. Regarding operational costs, the Ministry of Health contributed with 33.1% of the total, whereas the municipality, with 66.9%. Concerning the operational costs, the element of heaviest weight was salaries, which accounted for 84.7%. Problems with the regularity in the supply of inputs and maintenance of equipment greatly influence the composition of costs, besides reducing the supply of services to the target population, which results in the service probably being inefficient. States are suggested to partake in funding, especially to cover the team's operational cost. Estimar os investimentos para implantação e os custos operacionais de uma Equipe de Saúde Bucal modalidade tipo I na Estratégia Saúde da Família. Estudo de avaliação econômica, tipo análise de investimentos e custos operacionais de uma equipe de saúde bucal no município de Salvador, Bahia, Brasil. O cálculo dos investimentos para implantação foi obtido pela soma dos investimentos em obras civis e instalações em rateio, equipamentos, móveis e instrumentais. Para os custos operacionais, foi analisada a série histórica de 2009 a 2012 e adotou-se o mês de dezembro de 2012 para levantamento dos valores monetários vigentes. Os custos foram classificados em custos diretos variáveis (materiais de consumo) e custos fixos diretos (salários, manutenção, depreciação do capital fixo dos equipamentos, instrumentais, móveis e edificações), além dos custos fixos indiretos (higienização, segurança, energia e água). Foi também calculada a participação do Ministério da Saúde no financiamento e descritos os fatores que influenciam o comportamento dos custos. O investimento para implantação de uma Equipe de Saúde Bucal modalidade tipo I foi de R$29.864,00. Os custos operacionais de uma Equipe de Saúde Bucal modalidade tipo I situaram-se em torno de R$95.434,00 por ano. Os incentivos financeiros do Ministério da Saúde para investimentos cobriram 41,8% dos investimentos com implantação, enquanto o município participou com 59,2% do total. Para os custos operacionais, a participação do Ministério da Saúde foi de 33,1%, enquanto o município participou com 66,9%. Dentro dos custos operacionais, o elemento de maior peso foram os salários, representando 84,7%. Problemas com a regularidade no abastecimento dos insumos e manutenção de equipamentos influenciam sobremaneira na composição dos custos, além de reduzir a oferta de serviços à população-alvo, resultando em provável ineficiência do serviço. Sugere-se o cofinanciamento estadual, especialmente para cobrir o custo operacional da equipe.

  1. BoLA class I polymorphism and in vitro immune response to M. bovis antigens.

    PubMed

    Longeri, M; Polli, M; Ponti, W; Zanotti, M

    1993-01-12

    From a sample of 119 Friesian calves, serologically typed for BoLA class I, 47 subjects were chosen expressing 9 different MHC types (A6, A6.9, A10, A11, A14, A15, A30, W16, M103) with the same age and reared in the same farm conditions. The animals were s.c. injected with a water in oil suspension of killed M. bovis and the treatment was repeated two days later. Before the treatment and 21 days later, calves were bled and on PBM (peripheral blood mononuclear leucocytes) were performed the following tests: 1. Lymphocyte Stimulation with bovine and avian PPDs (Purified protein derivative of Mycobacterium bovis and Mycobacterium avium, respectively). 2. Phagocytic activity towards M. bovis. 3. Class II molecules expression on cell surface. 4. Percentage of leucocyte populations and subpopulations. In the in vitro Lymphocyte Stimulation test, all the animals and classes were responders. Animals bearing A10 BoLA class I presented c.p.m. (counts per minute) and index values higher than the other cattle; these values were significantly positively related both to bovine and avian PPDs (P < .01). By variance analysis A14 BoLA type showed a slight positive significant correlation with more efficient phagocytic activity. BoLA class I type did not seem to significantly affect percentage of class II positive cells and leucocyte percentages on PBM. ZUSAMMENFASSUNG: Der BoLA Klasse I Polymorphismus und in vitro immunologische Antwort gegen die Antigene von M. bovis Aus einer Stichprobe von 119 für BoLA Klasse I serologisch typisierten Friesian Kälber, wurden 47 Subjekte ausgewählt, die 9 verschiedene MHC Typen ausdrückten (A6, A6.9, A10, A11, A14, A15, A30, W16, M103). Alle waren gleich alt und in gleichen Haltungsbedingungen. Die Tiere wurden mit einer Wasser-in-Ol Suspension abgetöteter M. bovis subkutan injiziert und die Behandlung nach zwei Tagen wiederholt. Vor und 21 Tage nach Behandlung wurden die folgenden Tests ausgeführt: 1. Lymphozyten-Stimulationstest mit bovinen und Geflügel PPDs. 2. Phagozyten Aktivität gegen M. bovis. 3. Zeil-Oberflächen, Expression der Klasse II Moleküle. 4. Anteile der Lymphozyten Populationen und Subpopulationen. Im in vitro Lymphozyten-Stimulationstest waren alle Tiere und Klassen responder. Tiere mit A10 BoLA I zeigten höhere c.p.m. und Indexwerte als die anderen; diese Werte waren in signifikant positiver Beziehung mit der PPD von M. bovis und auch mit M. avium (P < .01). BoLA Typ A14 zeigte leicht signifikant positive Korrelation mit wirksamerer Phagozyten Aktivität. BoLA Klasse I Typ scheint nicht den Prozentsatz der positiven Zellen der Klasse II und der Leukozyten der PBM signifikant zu beeinflussen. RESUMEN: Polimorfismo de BoLA clase I y immunidad a los antigenos del M. bovis Se escojeron 47 novillos dentro de un grupo de 119 animales que segun analisis previamente hecha tenian BoLA de clase I. Estos 47 novillos fueron escojidos de manera que tuvieran 9 distintos tipos de MHC (A6, A6.9, A10, A11, A14, A15, A30, W16, M103), la misma edad, las mismas condiciones de cria. Estos animales fueron inoculados subcutaneo con M. bovis matados en una suspension oleosa y la misma inoculacion fue repetida una secunda vez despues de dos dias. Por cada animal se tomaron muestras de sangre antes y 21 dias despues de la inoculacion de arriba. Las muestras de sangre fueron pruebaoas con: 1. Stimulacion Lymhocitaria con PPD bovina y avicola. 2. Actividad phagocitaria a M. bovis. 3. Expresion sobre la superficie celular de moleculas de clase II. 4. Porcentaje de poblaciones y de subpob-laciones de leucocitos. Todos los animales y todos los tipos de MHC dieron respuestas positivas en las pruebas de Stimulacion Lymphocitaria. Los animales que tenian la BoLA A10 presentaron valores de c.p.m. y indices mas altos de los demas animales. Estos valores se encontraron significativamente y positivamente relacionados sea a la PPD bovina que a la PPD avicola. Por medio de la analisis de varianzas se encontro que el tipo BoLA A14 muestraba una correlacion significativa y algo positiva con una mejor actividad fagocitaria. Los tipos de clase BoLA I no parecieron que influenzaran de manera appreciable el porcentaje de positividad por la clase II y el porcentaje de leucocitos en la sangre PBM. 1993 Blackwell Verlag GmbH.

  2. Spatial frequency performance limitations of radiation dose optimization and beam positioning

    NASA Astrophysics Data System (ADS)

    Stewart, James M. P.; Stapleton, Shawn; Chaudary, Naz; Lindsay, Patricia E.; Jaffray, David A.

    2018-06-01

    The flexibility and sophistication of modern radiotherapy treatment planning and delivery methods have advanced techniques to improve the therapeutic ratio. Contemporary dose optimization and calculation algorithms facilitate radiotherapy plans which closely conform the three-dimensional dose distribution to the target, with beam shaping devices and image guided field targeting ensuring the fidelity and accuracy of treatment delivery. Ultimately, dose distribution conformity is limited by the maximum deliverable dose gradient; shallow dose gradients challenge techniques to deliver a tumoricidal radiation dose while minimizing dose to surrounding tissue. In this work, this ‘dose delivery resolution’ observation is rigorously formalized for a general dose delivery model based on the superposition of dose kernel primitives. It is proven that the spatial resolution of a delivered dose is bounded by the spatial frequency content of the underlying dose kernel, which in turn defines a lower bound in the minimization of a dose optimization objective function. In addition, it is shown that this optimization is penalized by a dose deposition strategy which enforces a constant relative phase (or constant spacing) between individual radiation beams. These results are further refined to provide a direct, analytic method to estimate the dose distribution arising from the minimization of such an optimization function. The efficacy of the overall framework is demonstrated on an image guided small animal microirradiator for a set of two-dimensional hypoxia guided dose prescriptions.

  3. Assessing doses to interventional radiologists using a personal dosimeter worn over a protective apron.

    PubMed

    Stranden, E; Widmark, A; Sekse, T

    2008-05-01

    Interventional radiologists receive significant radiation doses, and it is important to have simple methods for routine monitoring of their exposure. To evaluate the usefulness of a dosimeter worn outside the protective apron for assessments of dose to interventional radiologists. Assessments of effective dose versus dose to dosimeters worn outside the protective apron were achieved by phantom measurements. Doses outside and under the apron were assessed by phantom measurements and measurements on eight radiologists wearing two routine dosimeters for a 2-month period during ordinary working conditions. Finger doses for the same radiologists were recorded using thermoluminescent dosimeters (TLD; DXT-RAD Extremity dosimeters). Typical values for the ratio between effective dose and dosimeter dose were found to be about 0.02 when the radiologist used a thyroid shield and about 0.03 without. The ratio between the dose to the dosimeter under and outside a protective apron was found to be less than 0.04. There was very good correlation between finger dose and dosimeter dose. A personal dosimeter worn outside a protective apron is a good screening device for dose to the eyes and fingers as well as for effective dose, even though the effective dose is grossly overestimated. Relatively high dose to the fingers and eyes remains undetected by a dosimeter worn under the apron.

  4. Dose-rate effects on the radiation-induced oxidation of electric cable used in nuclear power plants

    NASA Astrophysics Data System (ADS)

    Reynolds, A. B.; Bell, R. M.; Bryson, N. M. N.; Doyle, T. E.; Hall, M. B.; Mason, L. R.; Quintric, L.; Terwilliger, P. L.

    1995-01-01

    Dose-rate effects were measured for typical ethylene propylene rubber (EPR) and crosslinked polyethylene (XLPE) electric cable used in nuclear power plants. The radiation source was the 60Co Irradiation Facility at the University of Virginia. Dose rates were varied from 5 Gy/h to 2500 Gy/h. It was found that there is little or no dose-rate effect at low doses for four of the five EPR cable products tested from 2500 Gy/h down to dose rates of 5 Gy/h but perhaps a small dose-rate effect at high doses for dose rates above 340 Gy/h. A small dose-rate exists for the fifth EPR above 340 Gy/h at all doses. A dose-rate effect exists above 40 Gy/h for two of the three XLPE cable products tested, but there is no dose-rate for these XLPE's between 40 Gy/h and 5 Gy/h. These results indicate that the dose-rate effects observed are due to oxygen diffusion effects during heterogeneous aging and suggest that there is no dose-rate effect for either EPR or XLPE during homogeneous aging.

  5. SU-E-T-381: Evaluation of Calculated Dose Accuracy for Organs-At-Risk Located at Out-Of-Field in a Commercial Treatment Planning System for High Energy Photon Beams Produced From TrueBeam Accelerators

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, L; Ding, G

    Purpose: Dose calculation accuracy for the out-of-field dose is important for predicting the dose to the organs-at-risk when they are located outside primary beams. The investigations on evaluating the calculation accuracy of treatment planning systems (TPS) on out-of-field dose in existing publications have focused on low energy (6MV) photon. This study evaluates out-of-field dose calculation accuracy of AAA algorithm for 15MV high energy photon beams. Methods: We used the EGSnrc Monte Carlo (MC) codes to evaluate the AAA algorithm in Varian Eclipse TPS (v.11). The incident beams start with validated Varian phase-space sources for a TrueBeam linac equipped with Millenniummore » 120 MLC. Dose comparisons between using AAA and MC for CT based realistic patient treatment plans using VMAT techniques for prostate and lung were performed and uncertainties of organ dose predicted by AAA at out-of-field location were evaluated. Results: The results show that AAA calculations under-estimate doses at the dose level of 1% (or less) of prescribed dose for CT based patient treatment plans using VMAT techniques. In regions where dose is only 1% of prescribed dose, although AAA under-estimates the out-of-field dose by 30% relative to the local dose, it is only about 0.3% of prescribed dose. For example, the uncertainties of calculated organ dose to liver or kidney that is located out-of-field is <0.3% of prescribed dose. Conclusion: For 15MV high energy photon beams, very good agreements (<1%) in calculating dose distributions were obtained between AAA and MC. The uncertainty of out-of-field dose calculations predicted by the AAA algorithm for realistic patient VMAT plans is <0.3% of prescribed dose in regions where the dose relative to the prescribed dose is <1%, although the uncertainties can be much larger relative to local doses. For organs-at-risk located at out-of-field, the error of dose predicted by Eclipse using AAA is negligible. This work was conducted in part using the resources of Varian research grant VUMC40590-R.« less

  6. Dosimetric verification of lung cancer treatment using the CBCTs estimated from limited-angle on-board projections.

    PubMed

    Zhang, You; Yin, Fang-Fang; Ren, Lei

    2015-08-01

    Lung cancer treatment is susceptible to treatment errors caused by interfractional anatomical and respirational variations of the patient. On-board treatment dose verification is especially critical for the lung stereotactic body radiation therapy due to its high fractional dose. This study investigates the feasibility of using cone-beam (CB)CT images estimated by a motion modeling and free-form deformation (MM-FD) technique for on-board dose verification. Both digital and physical phantom studies were performed. Various interfractional variations featuring patient motion pattern change, tumor size change, and tumor average position change were simulated from planning CT to on-board images. The doses calculated on the planning CT (planned doses), the on-board CBCT estimated by MM-FD (MM-FD doses), and the on-board CBCT reconstructed by the conventional Feldkamp-Davis-Kress (FDK) algorithm (FDK doses) were compared to the on-board dose calculated on the "gold-standard" on-board images (gold-standard doses). The absolute deviations of minimum dose (ΔDmin), maximum dose (ΔDmax), and mean dose (ΔDmean), and the absolute deviations of prescription dose coverage (ΔV100%) were evaluated for the planning target volume (PTV). In addition, 4D on-board treatment dose accumulations were performed using 4D-CBCT images estimated by MM-FD in the physical phantom study. The accumulated doses were compared to those measured using optically stimulated luminescence (OSL) detectors and radiochromic films. Compared with the planned doses and the FDK doses, the MM-FD doses matched much better with the gold-standard doses. For the digital phantom study, the average (± standard deviation) ΔDmin, ΔDmax, ΔDmean, and ΔV100% (values normalized by the prescription dose or the total PTV) between the planned and the gold-standard PTV doses were 32.9% (±28.6%), 3.0% (±2.9%), 3.8% (±4.0%), and 15.4% (±12.4%), respectively. The corresponding values of FDK PTV doses were 1.6% (±1.9%), 1.2% (±0.6%), 2.2% (±0.8%), and 17.4% (±15.3%), respectively. In contrast, the corresponding values of MM-FD PTV doses were 0.3% (±0.2%), 0.9% (±0.6%), 0.6% (±0.4%), and 1.0% (±0.8%), respectively. Similarly, for the physical phantom study, the average ΔDmin, ΔDmax, ΔDmean, and ΔV100% of planned PTV doses were 38.1% (±30.8%), 3.5% (±5.1%), 3.0% (±2.6%), and 8.8% (±8.0%), respectively. The corresponding values of FDK PTV doses were 5.8% (±4.5%), 1.6% (±1.6%), 2.0% (±0.9%), and 9.3% (±10.5%), respectively. In contrast, the corresponding values of MM-FD PTV doses were 0.4% (±0.8%), 0.8% (±1.0%), 0.5% (±0.4%), and 0.8% (±0.8%), respectively. For the 4D dose accumulation study, the average (± standard deviation) absolute dose deviation (normalized by local doses) between the accumulated doses and the OSL measured doses was 3.3% (±2.7%). The average gamma index (3%/3 mm) between the accumulated doses and the radiochromic film measured doses was 94.5% (±2.5%). MM-FD estimated 4D-CBCT enables accurate on-board dose calculation and accumulation for lung radiation therapy. It can potentially be valuable for treatment quality assessment and adaptive radiation therapy.

  7. Reducing dose to the lungs through loosing target dose homogeneity requirement for radiotherapy of non small cell lung cancer.

    PubMed

    Miao, Junjie; Yan, Hui; Tian, Yuan; Ma, Pan; Liu, Zhiqiang; Li, Minghui; Ren, Wenting; Chen, Jiayun; Zhang, Ye; Dai, Jianrong

    2017-11-01

    It is important to minimize lung dose during intensity-modulated radiation therapy (IMRT) of nonsmall cell lung cancer (NSCLC). In this study, an approach was proposed to reduce lung dose by relaxing the constraint of target dose homogeneity during treatment planning of IMRT. Ten NSCLC patients with lung tumor on the right side were selected. The total dose for planning target volume (PTV) was 60 Gy (2 Gy/fraction). For each patient, two IMRT plans with six beams were created in Pinnacle treatment planning system. The dose homogeneity of target was controlled by constraints on the maximum and uniform doses of target volume. One IMRT plan was made with homogeneous target dose (the resulting target dose was within 95%-107% of the prescribed dose), while another IMRT plan was made with inhomogeneous target dose (the resulting target dose was more than 95% of the prescribed dose). During plan optimization, the dose of cord and heart in two types of IMRT plans were kept nearly the same. The doses of lungs, PTV and organs at risk (OARs) between two types of IMRT plans were compared and analyzed quantitatively. For all patients, the lung dose was decreased in the IMRT plans with inhomogeneous target dose. On average, the mean dose, V5, V20, and V30 of lung were reduced by 1.4 Gy, 4.8%, 3.7%, and 1.7%, respectively, and the dose to normal tissue was also reduced. These reductions in DVH values were all statistically significant (P < 0.05). There were no significant differences between the two IMRT plans on V25, V30, V40, V50 and mean dose for heart. The maximum doses of cords in two type IMRT plans were nearly the same. IMRT plans with inhomogeneous target dose could protect lungs better and may be considered as a choice for treating NSCLC. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  8. Out-of-field doses and neutron dose equivalents for electron beams from modern Varian and Elekta linear accelerators.

    PubMed

    Cardenas, Carlos E; Nitsch, Paige L; Kudchadker, Rajat J; Howell, Rebecca M; Kry, Stephen F

    2016-07-08

    Out-of-field doses from radiotherapy can cause harmful side effects or eventually lead to secondary cancers. Scattered doses outside the applicator field, neutron source strength values, and neutron dose equivalents have not been broadly investigated for high-energy electron beams. To better understand the extent of these exposures, we measured out-of-field dose characteristics of electron applicators for high-energy electron beams on two Varian 21iXs, a Varian TrueBeam, and an Elekta Versa HD operating at various energy levels. Out-of-field dose profiles and percent depth-dose curves were measured in a Wellhofer water phantom using a Farmer ion chamber. Neutron dose was assessed using a combination of moderator buckets and gold activation foils placed on the treatment couch at various locations in the patient plane on both the Varian 21iX and Elekta Versa HD linear accelerators. Our findings showed that out-of-field electron doses were highest for the highest electron energies. These doses typically decreased with increasing distance from the field edge but showed substantial increases over some distance ranges. The Elekta linear accelerator had higher electron out-of-field doses than the Varian units examined, and the Elekta dose profiles exhibited a second dose peak about 20 to 30 cm from central-axis, which was found to be higher than typical out-of-field doses from photon beams. Electron doses decreased sharply with depth before becoming nearly constant; the dose was found to decrease to a depth of approximately E(MeV)/4 in cm. With respect to neutron dosimetry, Q values and neutron dose equivalents increased with electron beam energy. Neutron contamination from electron beams was found to be much lower than that from photon beams. Even though the neutron dose equivalent for electron beams represented a small portion of neutron doses observed under photon beams, neutron doses from electron beams may need to be considered for special cases.

  9. Case Example of Dose Optimization Using Data From Bortezomib Dose-Finding Clinical Trials

    PubMed Central

    Backenroth, Daniel; Cheung, Ying Kuen Ken; Hershman, Dawn L.; Vulih, Diana; Anderson, Barry; Ivy, Percy; Minasian, Lori

    2016-01-01

    Purpose The current dose-finding methodology for estimating the maximum tolerated dose of investigational anticancer agents is based on the cytotoxic chemotherapy paradigm. Molecularly targeted agents (MTAs) have different toxicity profiles, which may lead to more long-lasting mild or moderate toxicities as well as to late-onset and cumulative toxicities. Several approved MTAs have been poorly tolerated during long-term administration, leading to postmarketing dose optimization studies to re-evaluate the optimal treatment dose. Using data from completed bortezomib dose-finding trials, we explore its toxicity profile, optimize its dose, and examine the appropriateness of current designs for identifying an optimal dose. Patients and Methods We classified the toxicities captured from 481 patients in 14 bortezomib dose-finding studies conducted through the National Cancer Institute Cancer Therapy Evaluation Program, computed the incidence of late-onset toxicities, and compared the incidence of dose-limiting toxicities (DLTs) among groups of patients receiving different doses of bortezomib. Results A total of 13,008 toxicities were captured: 46% of patients’ first DLTs and 88% of dose reductions or discontinuations of treatment because of toxicity were observed after the first cycle. Moreover, for the approved dose of 1.3 mg/m2, the estimated cumulative incidence of DLT was > 50%, and the estimated cumulative incidence of dose reduction or treatment discontinuation because of toxicity was nearly 40%. Conclusions When considering the entire course of treatment, the approved bortezomib dose exceeds the conventional ceiling DLT rate of 20% to 33%. Retrospective analysis of trial data provides an opportunity for dose optimization of MTAs. Future dose-finding studies of MTAs should take into account late-onset toxicities to ensure that a tolerable dose is identified for future efficacy and comparative trials. PMID:26926682

  10. Weekly, low-dose docetaxel combined with estramustine for Japanese castration-resistant prostate cancer: its efficacy and safety profile compared with tri-weekly standard-dose treatment.

    PubMed

    Nakai, Yasutomo; Nishimura, Kazuo; Nakayama, Masashi; Uemura, Motohide; Takayama, Hitoshi; Nonomura, Norio; Tsujimura, Akira

    2014-02-01

    We retrospectively investigated the efficacy and safety profile of weekly low-dose docetaxel (DTX) with estramustine in comparison with triweekly standard-dose DTX treatment for Japanese patients with castration-resistant prostate cancer (CRPC). Between April 2002 and January 2011, 75 CRPC patients were treated with triweekly DTX (60-75 mg/m(2) every 3 weeks) (standard-dose group), and 76 CRPC patients were treated with weekly low-dose DTX (20-30 mg/m(2) on days 2 and 9 with estramustine 560 mg on days 1-3 and 8-10) every 3 weeks (low-dose group). Prostate-specific antigen (PSA) response and progression-free and overall survival were analyzed in each group. Median serum PSA level of the standard-dose group and low-dose group was 25.0 and 35.5 ng/ml, respectively. In the standard-dose and low-dose groups, 57.8 and 65.2 % of patients, respectively, achieved a PSA decline ≥ 50 %. There was no significant difference in either median time to progression between the standard-dose group (10.0 months) and low-dose group (7.1 months) or in median duration of survival between the standard-dose group (24.2 months) and low-dose group (30.6 months). Multivariate analysis with a Cox proportional hazards regression model showed that DTX treatment protocol did not influence the risk of death. Incidences of grade 3-4 neutropenia, febrile neutropenia, and thrombocytopenia were significantly higher in the standard-dose versus low-dose group (58.7 vs. 7.9 %, 16.0 vs. 3.9 %, and 8.0 vs. 0 %, respectively). For Japanese CRPC patients, weekly low-dose DTX combined with estramustine has similar efficacy to standard-dose DTX but with fewer adverse events.

  11. β-blocker dosage and outcomes after acute coronary syndrome.

    PubMed

    Allen, Jason E; Knight, Stacey; McCubrey, Raymond O; Bair, Tami; Muhlestein, Joseph Brent; Goldberger, Jeffrey J; Anderson, Jeffrey L

    2017-02-01

    Although β-blockers increase survival in acute coronary syndrome (ACS) patients, the doses used in trials were higher than doses used in practice, and recent data do not support an advantage of higher doses. We hypothesized that rates of major adverse cardiac events (MACE), all-cause death, myocardial infarction, and stroke are equivalent for patients on low-dose and high-dose β-blocker. Patients admitted to Intermountain Healthcare with ACS and diagnosed with ≥70% coronary stenosis between 1994 and 2013 were studied (N = 7,834). We classified low dose as ≤25% and high dose as ≥50% of an equivalent daily dose of 200 mg of metoprolol. Multivariate analyses were used to test association between low-dose versus high-dose β-blocker dosage and MACE at 0-6 months and 6-24 months. A total of 5,287 ACS subjects were discharged on β-blockers (87% low dose, 12% high dose, and 1% intermediate dose). The 6-month MACE outcomes rates for the β-blocker dosage (low versus high) were not equivalent (P = .18) (hazard ratio [HR] = 0.76; 95% CI, 0.52-1.10). However, subjects on low-dose β-blocker therapy did have a significantly decreased risk of myocardial infarction for 0-6 months (HR = 0.53; 95% CI, 0.33-0.86). The rates of MACE events during the 6-24 months after presentation with ACS were equivalent for the 2 doses (P = .009; HR = 1.03 [95% CI, 0.70-1.50]). In ACS patients, rates of MACE for high-dose and low-dose β-blocker doses are similar. These findings question the importance of achieving a high dose of β-blocker in ACS patients and highlight the need for further investigation of this clinical question. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Case Example of Dose Optimization Using Data From Bortezomib Dose-Finding Clinical Trials.

    PubMed

    Lee, Shing M; Backenroth, Daniel; Cheung, Ying Kuen Ken; Hershman, Dawn L; Vulih, Diana; Anderson, Barry; Ivy, Percy; Minasian, Lori

    2016-04-20

    The current dose-finding methodology for estimating the maximum tolerated dose of investigational anticancer agents is based on the cytotoxic chemotherapy paradigm. Molecularly targeted agents (MTAs) have different toxicity profiles, which may lead to more long-lasting mild or moderate toxicities as well as to late-onset and cumulative toxicities. Several approved MTAs have been poorly tolerated during long-term administration, leading to postmarketing dose optimization studies to re-evaluate the optimal treatment dose. Using data from completed bortezomib dose-finding trials, we explore its toxicity profile, optimize its dose, and examine the appropriateness of current designs for identifying an optimal dose. We classified the toxicities captured from 481 patients in 14 bortezomib dose-finding studies conducted through the National Cancer Institute Cancer Therapy Evaluation Program, computed the incidence of late-onset toxicities, and compared the incidence of dose-limiting toxicities (DLTs) among groups of patients receiving different doses of bortezomib. A total of 13,008 toxicities were captured: 46% of patients' first DLTs and 88% of dose reductions or discontinuations of treatment because of toxicity were observed after the first cycle. Moreover, for the approved dose of 1.3 mg/m(2), the estimated cumulative incidence of DLT was > 50%, and the estimated cumulative incidence of dose reduction or treatment discontinuation because of toxicity was nearly 40%. When considering the entire course of treatment, the approved bortezomib dose exceeds the conventional ceiling DLT rate of 20% to 33%. Retrospective analysis of trial data provides an opportunity for dose optimization of MTAs. Future dose-finding studies of MTAs should take into account late-onset toxicities to ensure that a tolerable dose is identified for future efficacy and comparative trials. © 2016 by American Society of Clinical Oncology.

  13. Dose Equivalents for Second-Generation Antipsychotic Drugs: The Classical Mean Dose Method

    PubMed Central

    Leucht, Stefan; Samara, Myrto; Heres, Stephan; Patel, Maxine X.; Furukawa, Toshi; Cipriani, Andrea; Geddes, John; Davis, John M.

    2015-01-01

    Background: The concept of dose equivalence is important for many purposes. The classical approach published by Davis in 1974 subsequently dominated textbooks for several decades. It was based on the assumption that the mean doses found in flexible-dose trials reflect the average optimum dose which can be used for the calculation of dose equivalence. We are the first to apply the method to second-generation antipsychotics. Methods: We searched for randomized, double-blind, flexible-dose trials in acutely ill patients with schizophrenia that examined 13 oral second-generation antipsychotics, haloperidol, and chlorpromazine (last search June 2014). We calculated the mean doses of each drug weighted by sample size and divided them by the weighted mean olanzapine dose to obtain olanzapine equivalents. Results: We included 75 studies with 16 555 participants. The doses equivalent to 1 mg/d olanzapine were: amisulpride 38.3 mg/d, aripiprazole 1.4 mg/d, asenapine 0.9 mg/d, chlorpromazine 38.9 mg/d, clozapine 30.6 mg/d, haloperidol 0.7 mg/d, quetiapine 32.3mg/d, risperidone 0.4mg/d, sertindole 1.1 mg/d, ziprasidone 7.9 mg/d, zotepine 13.2 mg/d. For iloperidone, lurasidone, and paliperidone no data were available. Conclusions: The classical mean dose method is not reliant on the limited availability of fixed-dose data at the lower end of the effective dose range, which is the major limitation of “minimum effective dose methods” and “dose-response curve methods.” In contrast, the mean doses found by the current approach may have in part depended on the dose ranges chosen for the original trials. Ultimate conclusions on dose equivalence of antipsychotics will need to be based on a review of various methods. PMID:25841041

  14. Comparison of two dose regimens of ibuprofen for the closure of patent ductus arteriosus in preterm newborns.

    PubMed

    Dornelles, Laura Vargas; Corso, Andréa Lúcia; Silveira, Rita de Cássia; Procianoy, Renato Soibelmann

    2016-01-01

    To compare the efficacy of intravenous ibuprofen at high (20-10-10mg/kg/dose) and low doses (10-5-5mg/kg/dose) the closure of patent ductus arteriosus in preterm newborns. A cohort study with historical control of newborns that received high- and low-dose intravenous ibuprofen, from 2010 to 2013 in a neonatal intensive care unit, for closure of the patent ductus arteriosus, documented by echocardiography. Secondary outcomes included the number of ibuprofen cycles, incidence of bronchopulmonary dysplasia, necrotizing enterocolitis, changes in renal function, and death. Seventy-seven patients received three doses of ibuprofen for the treatment of patent ductus arteriosus, with 33 receiving high-dose and 44 low-dose therapy. The ductus closed after the first cycle in 25 (56.8%) low-dose patients and in 17 (51.5%) high-dose patients (p>0.99). Sixteen patients received a second cycle of ibuprofen, and the ductus closed in 50% after low-dose and in 60% after high-dose therapy (p>0.99). Seven patients required surgery for ductus closure, 13.6% in the low-dose group and 3% in the high-dose group (p=0.22). Thirty-nine patients developed bronchopulmonary dysplasia, 50% in the low-dose group and 51.5% in the high-dose group (p>0.99). Twenty-two (50%) low-dose patients died vs. 15 (45.5%) high-dose patients (p=0.86). There was no difference in closure of the ductus arteriosus or occurrence of adverse effects between the two dose regimens. Copyright © 2016 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  15. The impact of inter-fraction dose variations on biological equivalent dose (BED): the concept of equivalent constant dose.

    PubMed

    Zavgorodni, S

    2004-12-07

    Inter-fraction dose fluctuations, which appear as a result of setup errors, organ motion and treatment machine output variations, may influence the radiobiological effect of the treatment even when the total delivered physical dose remains constant. The effect of these inter-fraction dose fluctuations on the biological effective dose (BED) has been investigated. Analytical expressions for the BED accounting for the dose fluctuations have been derived. The concept of biological effective constant dose (BECD) has been introduced. The equivalent constant dose (ECD), representing the constant physical dose that provides the same cell survival fraction as the fluctuating dose, has also been introduced. The dose fluctuations with Gaussian as well as exponential probability density functions were investigated. The values of BECD and ECD calculated analytically were compared with those derived from Monte Carlo modelling. The agreement between Monte Carlo modelled and analytical values was excellent (within 1%) for a range of dose standard deviations (0-100% of the dose) and the number of fractions (2 to 37) used in the comparison. The ECDs have also been calculated for conventional radiotherapy fields. The analytical expression for the BECD shows that BECD increases linearly with the variance of the dose. The effect is relatively small, and in the flat regions of the field it results in less than 1% increase of ECD. In the penumbra region of the 6 MV single radiotherapy beam the ECD exceeded the physical dose by up to 35%, when the standard deviation of combined patient setup/organ motion uncertainty was 5 mm. Equivalently, the ECD field was approximately 2 mm wider than the physical dose field. The difference between ECD and the physical dose is greater for normal tissues than for tumours.

  16. The effect of dose heterogeneity on radiation risk in medical imaging.

    PubMed

    Samei, Ehsan; Li, Xiang; Chen, Baiyu; Reiman, Robert

    2013-06-01

    The current estimations of risk associated with medical imaging procedures rely on assessing the organ dose via direct measurements or simulation. The dose to each organ is assumed to be homogeneous. To take into account the differences in radiation sensitivities, the mean organ doses are weighted by a corresponding tissue-weighting coefficients provided by ICRP to calculate the effective dose, which has been used as a surrogate of radiation risk. However, those coefficients were derived under the assumption of a homogeneous dose distribution within each organ. That assumption is significantly violated in most medical-imaging procedures. In helical chest CT, for example, superficial organs (e.g. breasts) demonstrate a heterogeneous dose distribution, whereas organs on the peripheries of the irradiation field (e.g. liver) might possess a discontinuous dose profile. Projection radiography and mammography involve an even higher level of organ dose heterogeneity spanning up to two orders of magnitude. As such, mean dose or point measured dose values do not reflect the maximum energy deposited per unit volume of the organ. In this paper, the magnitude of the dose heterogeneity in both CT and projection X-ray imaging was reported, using Monte Carlo methods. The lung dose demonstrated factors of 1.7 and 2.2 difference between the mean and maximum dose for chest CT and radiography, respectively. The corresponding values for the liver were 1.9 and 3.5. For mammography and breast tomosynthesis, the difference between mean glandular dose and maximum glandular dose was 3.1. Risk models based on the mean dose were found to provide a reasonable reflection of cancer risk. However, for leukaemia, they were found to significantly under-represent the risk when the organ dose distribution is heterogeneous. A systematic study is needed to develop a risk model for heterogeneous dose distributions.

  17. Optimisation techniques in vaginal cuff brachytherapy.

    PubMed

    Tuncel, N; Garipagaoglu, M; Kizildag, A U; Andic, F; Toy, A

    2009-11-01

    The aim of this study was to explore whether an in-house dosimetry protocol and optimisation method are able to produce a homogeneous dose distribution in the target volume, and how often optimisation is required in vaginal cuff brachytherapy. Treatment planning was carried out for 109 fractions in 33 patients who underwent high dose rate iridium-192 (Ir(192)) brachytherapy using Fletcher ovoids. Dose prescription and normalisation were performed to catheter-oriented lateral dose points (dps) within a range of 90-110% of the prescribed dose. The in-house vaginal apex point (Vk), alternative vaginal apex point (Vk'), International Commission on Radiation Units and Measurements (ICRU) rectal point (Rg) and bladder point (Bl) doses were calculated. Time-position optimisations were made considering dps, Vk and Rg doses. Keeping the Vk dose higher than 95% and the Rg dose less than 85% of the prescribed dose was intended. Target dose homogeneity, optimisation frequency and the relationship between prescribed dose, Vk, Vk', Rg and ovoid diameter were investigated. The mean target dose was 99+/-7.4% of the prescription dose. Optimisation was required in 92 out of 109 (83%) fractions. Ovoid diameter had a significant effect on Rg (p = 0.002), Vk (p = 0.018), Vk' (p = 0.034), minimum dps (p = 0.021) and maximum dps (p<0.001). Rg, Vk and Vk' doses with 2.5 cm diameter ovoids were significantly higher than with 2 cm and 1.5 cm ovoids. Catheter-oriented dose point normalisation provided a homogeneous dose distribution with a 99+/-7.4% mean dose within the target volume, requiring time-position optimisation.

  18. Six steps to a successful dose-reduction strategy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bennett, M.

    1995-03-01

    The increased importance of demonstrating achievement of the ALARA principle has helped produce a proliferation of dose-reduction ideas. Across a company there may be many dose-reduction items being pursued in a variety of areas. However, companies have a limited amount of resource and, therefore, to ensure funding is directed to those items which will produce the most benefit and that all areas apply a common policy, requires the presence of a dose-reduction strategy. Six steps were identified in formulating the dose-reduction strategy for Rolls-Royce and Associates (RRA): (1) collating the ideas; (2) quantitatively evaluating them on a common basis; (3)more » prioritizing the ideas in terms of cost benefit, (4) implementation of the highest priority items; (5) monitoring their success; (6) periodically reviewing the strategy. Inherent in producing the dose-reduction strategy has been a comprehensive dose database and the RRA-developed dose management computer code DOMAIN, which allows prediction of dose rates and dose. The database enabled high task dose items to be identified, assisted in evaluating dose benefits, and monitored dose trends once items had been implemented. The DOMAIN code was used both in quantifying some of the project dose benefits and its results, such as dose contours, used in some of the dose-reduction items themselves. In all, over fifty dose-reduction items were evaluated in the strategy process and the items which will give greatest benefit are being implemented. The strategy has been successful in giving renewed impetus and direction to dose-reduction management.« less

  19. Dose gradient curve: A new tool for evaluating dose gradient.

    PubMed

    Sung, KiHoon; Choi, Young Eun

    2018-01-01

    Stereotactic radiotherapy, which delivers an ablative high radiation dose to a target volume for maximum local tumor control, requires a rapid dose fall-off outside the target volume to prevent extensive damage to nearby normal tissue. Currently, there is no tool to comprehensively evaluate the dose gradient near the target volume. We propose the dose gradient curve (DGC) as a new tool to evaluate the quality of a treatment plan with respect to the dose fall-off characteristics. The average distance between two isodose surfaces was represented by the dose gradient index (DGI) estimated by a simple equation using the volume and surface area of isodose levels. The surface area was calculated by mesh generation and surface triangulation. The DGC was defined as a plot of the DGI of each dose interval as a function of the dose. Two types of DGCs, differential and cumulative, were generated. The performance of the DGC was evaluated using stereotactic radiosurgery plans for virtual targets. Over the range of dose distributions, the dose gradient of each dose interval was well-characterized by the DGC in an easily understandable graph format. Significant changes in the DGC were observed reflecting the differences in planning situations and various prescription doses. The DGC is a rational method for visualizing the dose gradient as the average distance between two isodose surfaces; the shorter the distance, the steeper the dose gradient. By combining the DGC with the dose-volume histogram (DVH) in a single plot, the DGC can be utilized to evaluate not only the dose gradient but also the target coverage in routine clinical practice.

  20. Effectiveness of a Third Dose of MMR Vaccine for Mumps Outbreak Control.

    PubMed

    Cardemil, Cristina V; Dahl, Rebecca M; James, Lisa; Wannemuehler, Kathleen; Gary, Howard E; Shah, Minesh; Marin, Mona; Riley, Jacob; Feikin, Daniel R; Patel, Manisha; Quinlisk, Patricia

    2017-09-07

    The effect of a third dose of the measles-mumps-rubella (MMR) vaccine in stemming a mumps outbreak is unknown. During an outbreak among vaccinated students at the University of Iowa, health officials implemented a widespread MMR vaccine campaign. We evaluated the effectiveness of a third dose for outbreak control and assessed for waning immunity. Of 20,496 university students who were enrolled during the 2015-2016 academic year, mumps was diagnosed in 259 students. We used Fisher's exact test to compare unadjusted attack rates according to dose status and years since receipt of the second MMR vaccine dose. We used multivariable time-dependent Cox regression models to evaluate vaccine effectiveness, according to dose status (three vs. two doses and two vs. no doses) after adjustment for the number of years since the second dose. Before the outbreak, 98.1% of the students had received at least two doses of MMR vaccine. During the outbreak, 4783 received a third dose. The attack rate was lower among the students who had received three doses than among those who had received two doses (6.7 vs. 14.5 cases per 1000 population, P<0.001). Students had more than nine times the risk of mumps if they had received the second MMR dose 13 years or more before the outbreak. At 28 days after vaccination, receipt of the third vaccine dose was associated with a 78.1% lower risk of mumps than receipt of a second dose (adjusted hazard ratio, 0.22; 95% confidence interval, 0.12 to 0.39). The vaccine effectiveness of two doses versus no doses was lower among students with more distant receipt of the second vaccine dose. Students who had received a third dose of MMR vaccine had a lower risk of mumps than did those who had received two doses, after adjustment for the number of years since the second dose. Students who had received a second dose of MMR vaccine 13 years or more before the outbreak had an increased risk of mumps. These findings suggest that the campaign to administer a third dose of MMR vaccine improved mumps outbreak control and that waning immunity probably contributed to propagation of the outbreak. (Funded by the Centers for Disease Control and Prevention.).

  1. Alanine/EPR dosimetry applied to the verification of a total body irradiation protocol and treatment planning dose calculation using a humanoid phantom

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schaeken, B.; Lelie, S.; Meijnders, P.

    2010-12-15

    Purpose: To avoid complications in total body irradiation (TBI), it is important to achieve a homogeneous dose distribution throughout the body and to deliver a correct dose to the lung which is an organ at risk. The purpose of this work was to validate the TBI dose protocol and to check the accuracy of the 3D dose calculations of the treatment planning system. Methods: Dosimetry based on alanine/electron paramagnetic resonance (EPR) was used to measure dose at numerous locations within an anthropomorphic phantom (Alderson) that was irradiated in a clinical TBI beam setup. The alanine EPR dosimetry system was calibratedmore » against water calorimetry in a Co-60 beam and the absorbed dose was determined by the use of ''dose-normalized amplitudes'' A{sub D}. The dose rate of the TBI beam was checked against a Farmer ionization chamber. The phantom measurements were compared to 3D dose calculations from a treatment planning system (Pinnacle) modeled for standard dose calculations. Results: Alanine dosimetry allowed accurate measurements which were in accordance with ionization chamber measurements. The combined relative standard measurement uncertainty in the Alderson phantom was U{sub r}(A{sub D})=0.6%. The humanoid phantom was irradiated to a reference dose of 10 Gy, limiting the lung dose to 7.5 Gy. The ratio of the average measured dose midplane in the craniocaudal direction to the reference dose was 1.001 with a spread of {+-}4.7% (1 sd). Dose to the lung was measured in 26 locations and found, in average, 1.8% lower than expected. Lung dose was homogeneous in the ventral-dorsal direction but a dose gradient of 0.10 Gy cm{sup -1} was observed in the craniocaudal direction midline within the lung lobe. 3D dose calculations (Pinnacle) were found, in average, 2% lower compared to dose measurements on the body axis and 3% lower for the lungs. Conclusions: The alanine/EPR dosimetry system allowed accurate dose measurements which enabled the authors to validate their TBI dose protocol. Dose calculations based on a collapsed cone convolution dose algorithm modeled for regular treatments are accurate within 3% and can further be improved when the algorithm is modeled for TBI.« less

  2. Micronucleus induction in Vicia faba roots. Part 1. Absence of dose-rate, fractionation, and oxygen effect at low doses of low LET radiations.

    PubMed

    Marshall, I; Bianchi, M

    1983-08-01

    Micronucleus indication in Vicia faba roots has been evaluated after irradiation with 60Co gamma-rays. The dependence of the damage on dose, dose rate, fractionation, and oxygen has been studied. The best fit to the experimental data in the dose region between 7 and 190 cGy is represented, for single-dose exposures, by a linear + quadratic relationship. In the low-dose region, between 7 and 20 cGy, where the linear dose dependence is dominant, no dose-rate, fractionation, or oxygen effect could be observed. These effects were, however, present in the high-dose region, where the quadratic dependence is dominant.

  3. [In Process Citation].

    PubMed

    López Siguero, Juan Pedro

    2016-03-25

    La prevalencia de obesidad y de diabetes tipo 2 ha aumentado enormemente en las últimas décadas hasta convertirse en una epidemia amenazante. El listado de factores de riesgo es amplio, pero lo encabeza el cambio del estilo de vida (alimentación y actividad física) que constituye, además, la herramienta preventiva más importante. El trabajo de Caravalí-Meza y cols. en este número de la revista hace hincapié en el consumo de bebidas azucaradas y su relación con la obesidad. Sus autores concluyen que el consumo de azúcares refinados de las bebidas en adolescentes mexicanos, conlleva un riesgo de incremento del perímetro de la cintura y, en el caso de mantenerse, también del índice de masa corporal.

  4. Image-Based Approach to Mapping, Charting, and Geodesy.

    DTIC Science & Technology

    1982-02-01

    he..( reit- , st the .S Armyv I-npi ner Topographic Laboratories-, hll. Pi."ht inltete;(d inl de term ining the taipabil1i t ic e s nd 8 raotlhacho_...a.ve-ttor- bas-ed tipo I pi calIlIv t i l t ill-( I C I S) I (,r PiPC t; al p I( I i lt i ll (S fai-p i(%’ c t alI . , 1978’) , tr I F :TI, rt it I.,r...rt is to pr i de f 𔃻i : i t i t t he r in I ts of () Po r sei relit inidiui tic-d a t ,IllP. i n dir - ut t \\ Ii lisP Ordr l-P!U, Anit-odment Noe. 125

  5. Velocidad radial de Blue Stragglers en cúmulos abiertos

    NASA Astrophysics Data System (ADS)

    González, J. F.; Lapasset, E.

    Se presentan observaciones espectroscópicas de 32 blue stragglers en 6 cúmulos abiertos. Un mínimo de 4 espectros por objeto fueron obtenidos en base a los cuales se determina tipo espectral, velocidad radial y velocidad de rotación proyectada. La comparación con la velocidad media de los cúmulos aseguraría una alta probabilidad de pertenencia para la mayoría de los objetos estudiados. Un análisis de variabilidad conduce a la detección de un nuevo blue straggler binario en el cúmulo NGC 6530 además de otras probables binarias. En base a la frecuencia de binaridad y a la distribución de velocidades rotacionales se discuten los probables mecanismos de formación de los blue stragglers.

  6. M S MOLECULARES Rumo aos limites da miniaturiza o - (Molecular Magnets - towards the limits of miniaturization)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Reis, Mario S; Moreira Dos Santos, Antonio F

    Por s culos, acreditou-se que o magnetismo s se manifestava em metais, como aqueles contendo ferro; hoje, a imagem mais comum de um m talvez seja a daquelas plaquinhas flex veis coladas geladeira com propagandas dos mais diversos tipos. O leitor conseguiria imaginar um material puramente org nico daqueles que formam os seres vivos como magn tico? E m s do tamanho de mol culas? fato: ambos existem. Esses novos materiais, conhecidos como magnetos moleculares, descobertos e desenvolvidos em v rios laborat rios do mundo, j re nem longa lista de aplica es, do tratamento do c ncer a refrigeradoresmore » ecol gicos, passando pela transmiss o de eletricidade sem perda de calor e a fabrica o de computadores extremamente velozes.« less

  7. La distribución de objetos en el Cinturón de Kuiper y la posible existencia de un nuevo planeta en el Sistema Solar

    NASA Astrophysics Data System (ADS)

    Brunini, A.

    A pesar de que la capacidad observacional no lo limita, no se han descubierto objetos en el Cinturón de Kuiper más allá de las 50 AU. Recientemente, hemos propuesto que un embrión planetario originalmente formado en la región de Urano-Neptuno, y posteriormente migrado hacia distancias mayores a 50-60 AU, puede explicar este hecho. Presentamos simulaciones numéricas de acreción del Sistema Solar exterior que muestran cómo, naturalmente, podriamos esperar que un planeta de este tipo se encuentre actualmente en regiones distantes del sistema solar. Analizamos además la posibilidad de detectarlo con instrumentos actuales.

  8. Nanoparticulas basadas en complejos de Fe(II) con transicion de espin: sintesis, caracterizacion y aplicaciones en electronica molecular

    NASA Astrophysics Data System (ADS)

    Monrabal Capilla, Maria

    Esta tesis doctoral esta organizada en 5 capitulos y esta destinada al estudio de sistemas de Fe (II) que presentan el fenomeno de la transicion de espin a escala nanometrica. El capitulo 1 contiene una introduccion general sobre materiales moleculares multifuncionales, destacando aquellos ejemplos mas importantes. Por otro lado, se explicara el fenomeno de la transicion de espin, tratando aspectos conceptuales, los antecedentes mas importantes y la situacion actual. En el capitulo 2 se describen los diferentes procesos existentes para la obtencion de diferentes tipos de nanoparticulas. Ademas, se presenta la sintesis y caracterizacion de nanoparticulas del polimero de coordinacion unidimensional [Fe(Htrz)2(trz)]BF4, obtenidas mediante el metodo de micelas inversas. Estas nanoparticulas, con una estrecha distribucion de tamanos centrada alrededor de los 11 nm, presentan una transicion de espin muy abrupta, con un ancho ciclo de histeresis termica de unos 40K. En el capitulo 3 se describe el proceso de modificacion del tamano de las nanoparticulas descritas en el capitulo anterior, llevado a cabo variando la proporcion de surfactante/H2O en el medio. Ademas, con el objetivo de modificar las propiedades magneticas de las nanoparticulas obtenidas en el capitulo 2, se lleva a cabo la sintesis de nanoparticulas de polimeros de la misma familia del [Fe(Htrz)2(trz)]BF4. En concreto se sintetizaron 3 nuevos tipos de nanoparticulas basadas en el polimero [Fe(Htrz)1-x(NH2trz)x](ClO4)2, siendo x = 0.05, 0.15 y 0.3, en cada caso. Estas nanoparticulas siguen presentando una estrecha distribucion de tamanos y una transicion de espin muy abrupta y con un ancho ciclo de histeresis. Ademas, se observa que este ciclo se desplaza a temperaturas mas proximas a la temperatura ambiente a medida que se aumenta el porcentaje de 4-amino-1, 2, 4- triazol en la muestra. Pero al mismo tiempo se produce una disminucion de la anchura de este ciclo. Por ultimo, en este capitulo se presenta la sintesis de otro nuevo tipo de nanoparticulas, obtenidas a partir de otro polimero de la misma familia, el [FeO8ZnO2(Htrz)3](BF4). Estas nanoparticulas se sintetizaron con el objetivo de estudiar el efecto de la dilucion del metal en la muestra. Como resultado se obtuvieron nanoparticulas que tambien presentan una estrecha distribucion de tamanos pero en este caso la transicion de espin no es tan abrupta como en los casos anteriores. Aunque sigue presentando un ciclo de histeresis termica bastante ancho y a temperaturas proximas a la temperatura ambiente. En el capitulo 4 se describiran las estrategias que se han seguido para mejorar la estabilidad y afinidad sobre diferentes sustratos de las nanoparticulas sintetizadas en el capitulo 2. Tambien se hablara de los intentos realizados parar depositarlas en superficies y embeberlas en diferentes matrices organicas e inorganicas. En el capitulo 5 presentaremos la obtencion de un interruptor molecular realizado poniendo en contacto nanoparticulas individuales sintetizadas en el capitulo 2, con unos electrodos separados varios nanometros. Este dispositivo exhibe "switching" y efecto memoria a temperaturas proximas a la temperatura ambiente como consecuencia de la biestabilidad intrinseca de las nanoparticulas. Ademas demostraremos que el estado magnetico de estas nanoparticulas puede ser controlado electricamente, ya que la transicion de espin en este nanodispositivo molecular puede ser inducida simplemente aplicando un voltaje, lo que puede ser de gran interes para la electronica molecular.

  9. Effectiveness of Ivermectin and Albendazole against Haemonchus contortus in Sheep in West Java, Indonesia.

    PubMed

    Puspitasari, Silvia; Farajallah, Achmad; Sulistiawati, Erni; Muladno

    2016-02-01

    Administering a half dose of an anthelmintic is a simple method for detecting resistance in parasites infesting small ruminants. When a single anthelmintic fails in native sheep from Indonesia, a combination of anthelmintics from different chemical classes with different modes of action are administered as an alternative parasite-control strategy. This study compared the anthelmintic efficacy of ivermectin (IVM) and albendazole (ABZ) given either separately as a single dose or half dose or co-administered to sheep naturally infected with Haemonchus contortus. Twelve sheep from Bogor, West Java, Indonesia were divided into the following six treatment groups: half-dose IVM, full-dose IVM, half-dose ABZ, full-dose ABZ, combined IVM + ABZ, and control. The treatment efficacy was determined using the faecal egg count reduction test (FECRT) at day 0 (pre-treatment) and post-treatment at days 7, 14, 21, 28, 35, and 42. The efficacies of half-dose IVM, full-dose IVM, half-dose ABZ, full-dose ABZ, and the combination treatment ranged from -1900% to 100%, 99% to 100%, -167% to 100%, -467% to 89%, and -200% to 100%, respectively. The FECRT for the half-dose IVM, half-dose ABZ, full-dose ABZ showed that H. contortus is resistant to half-dose IVM and ABZ. Full-dose IVM was effective against H. contortus. The combined treatment was more effective against H. contortus than ABZ alone.

  10. Effectiveness of Ivermectin and Albendazole against Haemonchus contortus in Sheep in West Java, Indonesia

    PubMed Central

    Puspitasari, Silvia; Farajallah, Achmad; Sulistiawati, Erni; Muladno

    2016-01-01

    Administering a half dose of an anthelmintic is a simple method for detecting resistance in parasites infesting small ruminants. When a single anthelmintic fails in native sheep from Indonesia, a combination of anthelmintics from different chemical classes with different modes of action are administered as an alternative parasite-control strategy. This study compared the anthelmintic efficacy of ivermectin (IVM) and albendazole (ABZ) given either separately as a single dose or half dose or co-administered to sheep naturally infected with Haemonchus contortus. Twelve sheep from Bogor, West Java, Indonesia were divided into the following six treatment groups: half-dose IVM, full-dose IVM, half-dose ABZ, full-dose ABZ, combined IVM + ABZ, and control. The treatment efficacy was determined using the faecal egg count reduction test (FECRT) at day 0 (pre-treatment) and post-treatment at days 7, 14, 21, 28, 35, and 42. The efficacies of half-dose IVM, full-dose IVM, half-dose ABZ, full-dose ABZ, and the combination treatment ranged from −1900% to 100%, 99% to 100%, −167% to 100%, −467% to 89%, and −200% to 100%, respectively. The FECRT for the half-dose IVM, half-dose ABZ, full-dose ABZ showed that H. contortus is resistant to half-dose IVM and ABZ. Full-dose IVM was effective against H. contortus. The combined treatment was more effective against H. contortus than ABZ alone. PMID:27019686

  11. The efficacy of low dose azathioprine/6-mercaptopurine in patients with inflammatory bowel disease.

    PubMed

    Kim, Dong Uk; Kim, Young-Ho; Kim, Beom Jin; Chang, Dong Kyung; Son, Hee Jung; Rhee, Poong-Lyul; Kim, Jae J; Rhee, Jong Chul

    2009-01-01

    Azathioprine (AZA) and 6-mercaptopurine (6-MP) have been widely used in patients with ulcerative colitis (UC) and Crohn's disease (CD). However, some patients cannot tolerate standard doses (2-2.5 mg/kg for AZA or 1-1.5 mg/kg for 6-MP) due to side effects such as leukopenialneutropenia. The aim of this study was to evaluate the efficacy of low dose AZA/6-MP compared to the standard dose. From 1995 to 2005, 122 patients with UC or CD treated with AZA/6-MP at Samsung Medical Center in Korea were enrolled. We divided these patients into 2 groups (standard dose group versus low dose group) according to the maintenance dose. Among the 122 patients, 17 received the standard dose and 105 received a low dose. The mean maintenance doses were 2.25 mg/kg for the standard dose group and 1.35mg/kg for the low dose group. The clinical outcomes of remission induction, maintenance of remission and relapse rate showed no significant difference in comparisons between these two groups. Low dose AZA/6-MP was as effective as the standard dose for remission induction and maintenance of remission in patients with UC and CD. For patients that develop leukopenia/neutropenia during dose escalation, maintenance therapy with low dose AZA/6-MP should be considered.

  12. Escalation to High Dose Defibrotide in Patients with Hepatic Veno-Occlusive Disease

    PubMed Central

    Triplett, Brandon M.; Kuttab, Hani I.; Kang, Guolian; Leung, Wing

    2015-01-01

    Hepatic veno-occlusive disease (VOD) is a serious complication of high-dose chemotherapy regimens, such as those utilized in hematopoietic cell transplantation recipients. Defibrotide is considered a safe and effective treatment when dosed at 25 mg/kg/day. However, patients who develop VOD still have increased mortality despite the use of defibrotide. Data are limited on the use of doses above 60 mg/kg/day for persistent VOD. In this prospective clinical trial, 34 patients received escalating doses of defibrotide. For patients with persistent VOD despite doses of 60 mg/kg/day, doses were increased to a maximum of 110 mg/kg/day. There was no observed increase in toxicity until doses rose beyond 100 mg/kg/day. Patients receiving doses between 10–100 mg/kg/day experienced an average of 3 bleeding episodes per 100 days of treatment, while those receiving doses >100 mg/kg/day experienced 13.2 bleeding episodes per 100 days (p=0.008). Moreover, dose reductions due to toxicity were needed at doses of 110 mg/kg/day more often than at lower doses. Defibrotide may be safely escalated to doses well above the current standard without an increase in bleeding risk. However, the efficacy of this dose escalation strategy remains unclear, as outcomes were similar to published cohorts of patients receiving standard doses of defibrotide for VOD. PMID:26278046

  13. RADIANCE: An automated, enterprise-wide solution for archiving and reporting CT radiation dose estimates.

    PubMed

    Cook, Tessa S; Zimmerman, Stefan L; Steingall, Scott R; Maidment, Andrew D A; Kim, Woojin; Boonn, William W

    2011-01-01

    There is growing interest in the ability to monitor, track, and report exposure to radiation from medical imaging. Historically, however, dose information has been stored on an image-based dose sheet, an arrangement that precludes widespread indexing. Although scanner manufacturers are beginning to include dose-related parameters in the Digital Imaging and Communications in Medicine (DICOM) headers of imaging studies, there remains a vast repository of retrospective computed tomographic (CT) data with image-based dose sheets. Consequently, it is difficult for imaging centers to monitor their dose estimates or participate in the American College of Radiology (ACR) Dose Index Registry. An automated extraction software pipeline known as Radiation Dose Intelligent Analytics for CT Examinations (RADIANCE) has been designed that quickly and accurately parses CT dose sheets to extract and archive dose-related parameters. Optical character recognition of information in the dose sheet leads to creation of a text file, which along with the DICOM study header is parsed to extract dose-related data. The data are then stored in a relational database that can be queried for dose monitoring and report creation. RADIANCE allows efficient dose analysis of CT examinations and more effective education of technologists, radiologists, and referring physicians regarding patient exposure to radiation at CT. RADIANCE also allows compliance with the ACR's dose reporting guidelines and greater awareness of patient radiation dose, ultimately resulting in improved patient care and treatment.

  14. An FDA oncology analysis of immune activating products and first-in-human dose selection.

    PubMed

    Saber, Haleh; Gudi, Ramadevi; Manning, Michael; Wearne, Emily; Leighton, John K

    2016-11-01

    As sub-therapeutic doses are not medically justifiable in patients with cancer, we retrospectively analyzed data on immune activating products, to assess approaches used in first-in-human (FIH) dose selection, the utility of animal toxicology studies in dose selection, and the length of time to complete FIH trials. The information collected included pharmacology and toxicology data, FIH dose and rationale, and dose-finding trial design. We used the principles of the Hill equation to estimate the FIH doses for antibodies and compared them to the doses administered to patients with acceptable toxicities. For approximately half the antibodies (44%) examined, the FIH doses were at least a hundred-fold lower than the doses safely administered to patients, indicating optimization of FIH dose selection and/or optimization of dose-finding trial design is needed to minimize patient exposure to sub-therapeutic doses. However, selection of the FIH dose for antibodies based on animal toxicology studies using 1/6th the HNSTD or 1/10th the NOAEL resulted in human doses that were unsafe for several antibodies examined. We also concluded that antibodies with Fc-modifications for increased effector function may be less tolerated, resulting in toxicities at lower doses than those without such modifications. There was insufficient information to evaluate CD3 bispecific products. Published by Elsevier Inc.

  15. ELDRS Characterization for a Very High Dose Mission

    NASA Technical Reports Server (NTRS)

    Harris, Richard D.; McClure, Steven S.; Rax, Bernard G.; Kenna, Aaron J.; Thorbourn, Dennis O.; Clark, Karla B.; Yan, Tsun-Yee

    2010-01-01

    Evaluation of bipolar linear parts which may have Enhanced Low Dose Rate Sensitivity (ELDRS) is problematic for missions that have very high dose radiation requirements. The accepted standards for evaluating parts that display ELDRS require testing at a very low dose rate which could be prohibitively long for very high dose missions. In this work, a methodology for ELDRS characterization of bipolar parts for mission doses up to 1 Mrad(Si) is evaluated. The procedure employs an initial dose rate of 0.01 rad(Si)/s to a total dose of 50 krad(Si) and then changes to 0.04 rad(Si)/s to a total dose of 1 Mrad(Si). This procedure appears to work well. No change in rate of degradation with dose has been observed when the dose rate is changed from 0.01 to 0.04 rad(Si)/s. This is taken as an indication that the degradation due to the higher dose rate is equivalent to that at the lower dose rate at the higher dose levels, at least for the parts studied to date. In several cases, significant parameter degradation or functional failure not observed at HDR was observed at fairly high total doses (50 to 250 krad(Si)) at LDR. This behavior calls into question the use of dose rate trend data and enhancement factors to predict LDR performance.

  16. An FDA oncology analysis of CD3 bispecific constructs and first-in-human dose selection.

    PubMed

    Saber, Haleh; Del Valle, Pedro; Ricks, Tiffany K; Leighton, John K

    2017-11-01

    We retrospectively examined the nonclinical studies conducted with 17 CD3 bispecific constructs in support of first-in-human (FIH) trials in oncology. We also collected information on the design of dose-finding clinical trials. Sponsors have used different MABEL approaches for FIH dose selection. To better assess acceptable approaches, FIH doses were computed from nonclinical studies and compared to the maximum tolerated doses (MTDs) in patients, to the highest human doses (HHDs) when an MTD was not identified, or to the recommended human dose (RHD) for blinatumomab. We concluded that approaches based on receptor occupancy, highest non-severely toxic dose, or no-observed adverse effect level are not acceptable for selecting the FIH dose as they resulted in doses close to or above the MTDs, HHDs, or the RHD. A FIH dose corresponding to 10%-30% pharmacologic activity (PA) was an acceptable approach. A FIH dose corresponding to 50% PA was acceptable for all except one construct, potentially due to its biological or structural properties. The most common toxicities in animals and patients were those related to cytokine release. Doses were better tolerated when intra-animal or intra-patient dose escalation was used. Exposing naïve patients to an MTD achieved with intra-patient dose escalation design may be unsafe. Published by Elsevier Inc.

  17. Quantitative assessment of the accuracy of dose calculation using pencil beam and Monte Carlo algorithms and requirements for clinical quality assurance

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ali, Imad, E-mail: iali@ouhsc.edu; Ahmad, Salahuddin

    2013-10-01

    To compare the doses calculated using the BrainLAB pencil beam (PB) and Monte Carlo (MC) algorithms for tumors located in various sites including the lung and evaluate quality assurance procedures required for the verification of the accuracy of dose calculation. The dose-calculation accuracy of PB and MC was also assessed quantitatively with measurement using ionization chamber and Gafchromic films placed in solid water and heterogeneous phantoms. The dose was calculated using PB convolution and MC algorithms in the iPlan treatment planning system from BrainLAB. The dose calculation was performed on the patient's computed tomography images with lesions in various treatmentmore » sites including 5 lungs, 5 prostates, 4 brains, 2 head and necks, and 2 paraspinal tissues. A combination of conventional, conformal, and intensity-modulated radiation therapy plans was used in dose calculation. The leaf sequence from intensity-modulated radiation therapy plans or beam shapes from conformal plans and monitor units and other planning parameters calculated by the PB were identical for calculating dose with MC. Heterogeneity correction was considered in both PB and MC dose calculations. Dose-volume parameters such as V95 (volume covered by 95% of prescription dose), dose distributions, and gamma analysis were used to evaluate the calculated dose by PB and MC. The measured doses by ionization chamber and EBT GAFCHROMIC film in solid water and heterogeneous phantoms were used to quantitatively asses the accuracy of dose calculated by PB and MC. The dose-volume histograms and dose distributions calculated by PB and MC in the brain, prostate, paraspinal, and head and neck were in good agreement with one another (within 5%) and provided acceptable planning target volume coverage. However, dose distributions of the patients with lung cancer had large discrepancies. For a plan optimized with PB, the dose coverage was shown as clinically acceptable, whereas in reality, the MC showed a systematic lack of dose coverage. The dose calculated by PB for lung tumors was overestimated by up to 40%. An interesting feature that was observed is that despite large discrepancies in dose-volume histogram coverage of the planning target volume between PB and MC, the point doses at the isocenter (center of the lesions) calculated by both algorithms were within 7% even for lung cases. The dose distributions measured with EBT GAFCHROMIC films in heterogeneous phantoms showed large discrepancies of nearly 15% lower than PB at interfaces between heterogeneous media, where these lower doses measured by the film were in agreement with those by MC. The doses (V95) calculated by MC and PB agreed within 5% for treatment sites with small tissue heterogeneities such as the prostate, brain, head and neck, and paraspinal tumors. Considerable discrepancies, up to 40%, were observed in the dose-volume coverage between MC and PB in lung tumors, which may affect clinical outcomes. The discrepancies between MC and PB increased for 15 MV compared with 6 MV indicating the importance of implementation of accurate clinical treatment planning such as MC. The comparison of point doses is not representative of the discrepancies in dose coverage and might be misleading in evaluating the accuracy of dose calculation between PB and MC. Thus, the clinical quality assurance procedures required to verify the accuracy of dose calculation using PB and MC need to consider measurements of 2- and 3-dimensional dose distributions rather than a single point measurement using heterogeneous phantoms instead of homogenous water-equivalent phantoms.« less

  18. SU-F-T-659: Nanoparticle-Aided Eye Plaque Radiotherapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chin, J; Ngwa, W

    Purpose: Eye plaque brachytherapy is one of the approaches for radiotherapy treatment for ocular cancers: retinoblastoma and choroidal melanoma. This study, investigates the potential benefits of using gold nanoparticles to enhance therapeutic efficacy during eye plaque brachytherapy. Methods: The EYE PHYSICS Inc. Plaque Simulator program distributed by IsoAid, LLC, Port Richey, Florida was used. It is based on the superposition of dose contributions from individual seeds following the TG–43 formalism. Dose enhancement factor (DEF) values for feasible nanoparticle concentrations from previous studies was used to investigate the benefit of using nanoparticles to enhance dose to tumour or reduce dose tomore » healthy tissue. The dose enhancement factor (DEF) represents the ratio of the dose deposited in tumour with nanoparticles divided by dose deposited in the tumour without nanoparticles. The investigation was done for I–125 and Pd–103 typical sources employed for eye plaque brachytherapy. The prescription dose used is 85 Gy. Results: Lower dose enhancement values were obtained for Pd–103. With DEF of 2 due to gold nanoparticles, critical structure doses reduce by a factor of 2. Optic disc dose is 6.69 Gy and 4.571 Gy, opposite retina dose is 4.064 and 2.484 Gy, lens dose is 12.66 Gy and 9.870 Gy, and fovea dose is 9.85 Gy and 7.275 Gy. With DEF of 3 due to gold nanoparticles, critical structure doses reduce by a factor of 3. Optic disc dose is 4.352 Gy and 2.975 Gy, opposite retina dose is 2.644 Gy and 1.618 Gy, lens dose is 8.322 Gy and 6.427 Gy, and fovea dose is 4.815 Gy and 4.737 Gy. Conclusion: The results of this research predict that using gold nanoparticles will lead to major sparing of dose to critical structures. The finding provides more impetus for the development of nanoparticle–aided brachytherapy.« less

  19. Ultra-low-dose computed tomographic angiography with model-based iterative reconstruction compared with standard-dose imaging after endovascular aneurysm repair: a prospective pilot study.

    PubMed

    Naidu, Sailen G; Kriegshauser, J Scott; Paden, Robert G; He, Miao; Wu, Qing; Hara, Amy K

    2014-12-01

    An ultra-low-dose radiation protocol reconstructed with model-based iterative reconstruction was compared with our standard-dose protocol. This prospective study evaluated 20 men undergoing surveillance-enhanced computed tomography after endovascular aneurysm repair. All patients underwent standard-dose and ultra-low-dose venous phase imaging; images were compared after reconstruction with filtered back projection, adaptive statistical iterative reconstruction, and model-based iterative reconstruction. Objective measures of aortic contrast attenuation and image noise were averaged. Images were subjectively assessed (1 = worst, 5 = best) for diagnostic confidence, image noise, and vessel sharpness. Aneurysm sac diameter and endoleak detection were compared. Quantitative image noise was 26% less with ultra-low-dose model-based iterative reconstruction than with standard-dose adaptive statistical iterative reconstruction and 58% less than with ultra-low-dose adaptive statistical iterative reconstruction. Average subjective noise scores were not different between ultra-low-dose model-based iterative reconstruction and standard-dose adaptive statistical iterative reconstruction (3.8 vs. 4.0, P = .25). Subjective scores for diagnostic confidence were better with standard-dose adaptive statistical iterative reconstruction than with ultra-low-dose model-based iterative reconstruction (4.4 vs. 4.0, P = .002). Vessel sharpness was decreased with ultra-low-dose model-based iterative reconstruction compared with standard-dose adaptive statistical iterative reconstruction (3.3 vs. 4.1, P < .0001). Ultra-low-dose model-based iterative reconstruction and standard-dose adaptive statistical iterative reconstruction aneurysm sac diameters were not significantly different (4.9 vs. 4.9 cm); concordance for the presence of endoleak was 100% (P < .001). Compared with a standard-dose technique, an ultra-low-dose model-based iterative reconstruction protocol provides comparable image quality and diagnostic assessment at a 73% lower radiation dose.

  20. SU-F-P-56: On a New Approach to Reconstruct the Patient Dose From Phantom Measurements

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bangtsson, E; Vries, W de

    Purpose: The development of complex radiation treatment schemes emphasizes the need for advanced QA analysis methods to ensure patient safety. One such tool is the Delta4 DVH Anatomy software, where the patient dose is reconstructed from phantom measurements. Deviations in the measured dose are transferred to the patient anatomy and their clinical impact is evaluated in situ. Results from the original algorithm revealed weaknesses that may introduce artefacts in the reconstructed dose. These can lead to false negatives or obscure the effects of minor dose deviations from delivery failures. Here, we will present results from a new patient dose reconstructionmore » algorithm. Methods: The main steps of the new algorithm are: (1) the dose delivered to a phantom is measured in a number of detector positions. (2) The measured dose is compared to an internally calculated dose distribution evaluated in said positions. The so-obtained dose difference is (3) used to calculate an energy fluence difference. This entity is (4) used as input to a patient dose correction calculation routine. Finally, the patient dose is reconstructed by adding said patient dose correction to the planned patient dose. The internal dose calculation in step (2) and (4) is based on the Pencil Beam algorithm. Results: The new patient dose reconstruction algorithm have been tested on a number of patients and the standard metrics dose deviation (DDev), distance-to-agreement (DTA) and Gamma index are improved when compared to the original algorithm. In a certain case the Gamma index (3%/3mm) increases from 72.9% to 96.6%. Conclusion: The patient dose reconstruction algorithm is improved. This leads to a reduction in non-physical artefacts in the reconstructed patient dose. As a consequence, the possibility to detect deviations in the dose that is delivered to the patient is improved. An increase in Gamma index for the PTV can be seen. The corresponding author is an employee of ScandiDos.« less

  1. Comparative performance analysis for computer aided lung nodule detection and segmentation on ultra-low-dose vs. standard-dose CT

    NASA Astrophysics Data System (ADS)

    Wiemker, Rafael; Rogalla, Patrik; Opfer, Roland; Ekin, Ahmet; Romano, Valentina; Bülow, Thomas

    2006-03-01

    The performance of computer aided lung nodule detection (CAD) and computer aided nodule volumetry is compared between standard-dose (70-100 mAs) and ultra-low-dose CT images (5-10 mAs). A direct quantitative performance comparison was possible, since for each patient both an ultra-low-dose and a standard-dose CT scan were acquired within the same examination session. The data sets were recorded with a multi-slice CT scanner at the Charite university hospital Berlin with 1 mm slice thickness. Our computer aided nodule detection and segmentation algorithms were deployed on both ultra-low-dose and standard-dose CT data without any dose-specific fine-tuning or preprocessing. As a reference standard 292 nodules from 20 patients were visually identified, each nodule both in ultra-low-dose and standard-dose data sets. The CAD performance was analyzed by virtue of multiple FROC curves for different lower thresholds of the nodule diameter. For nodules with a volume-equivalent diameter equal or larger than 4 mm (149 nodules pairs), we observed a detection rate of 88% at a median false positive rate of 2 per patient in standard-dose images, and 86% detection rate in ultra-low-dose images, also at 2 FPs per patient. Including even smaller nodules equal or larger than 2 mm (272 nodules pairs), we observed a detection rate of 86% in standard-dose images, and 84% detection rate in ultra-low-dose images, both at a rate of 5 FPs per patient. Moreover, we observed a correlation of 94% between the volume-equivalent nodule diameter as automatically measured on ultra-low-dose versus on standard-dose images, indicating that ultra-low-dose CT is also feasible for growth-rate assessment in follow-up examinations. The comparable performance of lung nodule CAD in ultra-low-dose and standard-dose images is of particular interest with respect to lung cancer screening of asymptomatic patients.

  2. Neutrons in active proton therapy: Parameterization of dose and dose equivalent.

    PubMed

    Schneider, Uwe; Hälg, Roger A; Lomax, Tony

    2017-06-01

    One of the essential elements of an epidemiological study to decide if proton therapy may be associated with increased or decreased subsequent malignancies compared to photon therapy is an ability to estimate all doses to non-target tissues, including neutron dose. This work therefore aims to predict for patients using proton pencil beam scanning the spatially localized neutron doses and dose equivalents. The proton pencil beam of Gantry 1 at the Paul Scherrer Institute (PSI) was Monte Carlo simulated using GEANT. Based on the simulated neutron dose and neutron spectra an analytical mechanistic dose model was developed. The pencil beam algorithm used for treatment planning at PSI has been extended using the developed model in order to calculate the neutron component of the delivered dose distribution for each treated patient. The neutron dose was estimated for two patient example cases. The analytical neutron dose model represents the three-dimensional Monte Carlo simulated dose distribution up to 85cm from the proton pencil beam with a satisfying precision. The root mean square error between Monte Carlo simulation and model is largest for 138MeV protons and is 19% and 20% for dose and dose equivalent, respectively. The model was successfully integrated into the PSI treatment planning system. In average the neutron dose is increased by 10% or 65% when using 160MeV or 177MeV instead of 138MeV. For the neutron dose equivalent the increase is 8% and 57%. The presented neutron dose calculations allow for estimates of dose that can be used in subsequent epidemiological studies or, should the need arise, to estimate the neutron dose at any point where a subsequent secondary tumour may occur. It was found that the neutron dose to the patient is heavily increased with proton energy. Copyright © 2016. Published by Elsevier GmbH.

  3. SU-E-J-181: Effect of Prostate Motion On Combined Brachytherapy and External Beam Dose Based On Daily Motion of the Prostate

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Narayana, V; McLaughlin, P; University of Michigan, Ann Arbor, MI

    2015-06-15

    Purpose: In this study, the adequacy of target expansions on the combined external beam and implant dose was examined based on the measured daily motion of the prostate. Methods: Thirty patients received an I–125 prostate implant prescribed to dose of 90Gy. This was followed by external beam to deliver a dose of 90Gyeq (external beam equivalent) to the prostate over 25 to 30 fractions. An ideal IMRT plan was developed by optimizing the external beam dose based on the delivered implant dose. The implant dose was converted to an equivalent external beam dose using the linear quadratic model. Patients weremore » set up on the treatment table by daily orthogonal imaging and aligning the marker seeds in the prostate. Orthogonal images were obtained at the end of treatment to assess prostate intrafraction motion. Based on the observed motion of the markers between the initial and final images, 5 individual plans showing the actual dose delivered to the patient were calculated. A final true dose distribution was established based on summing the implant dose and the 5 external beam plans. Dose to the prostate, seminal vesicles, lymphnodes and normal tissues, rectal wall, urethra and lower sphincter were calculated and compared to ideal. On 18 patients who were sexually active, dose to the corpus cavernosum and internal pudendal artery was also calculated. Results: The average prostate motion in 3 orthogonal directions was less than 1 mm with a standard deviation of less than +2 mm. Dose and volume parameters showed that there was no decrease in dose to the targets and a marginal decrease in dose to in normal tissues. Conclusion: Dose delivered by seed implant moves with the prostate, decreasing the impact of intrafractions dose movement on actual dose delivered. Combined brachytherapy and external beam dose delivered to the prostate was not sensitive to prostate motion.« less

  4. A Bayesian Dose-finding Design for Oncology Clinical Trials of Combinational Biological Agents

    PubMed Central

    Cai, Chunyan; Yuan, Ying; Ji, Yuan

    2013-01-01

    Treating patients with novel biological agents is becoming a leading trend in oncology. Unlike cytotoxic agents, for which efficacy and toxicity monotonically increase with dose, biological agents may exhibit non-monotonic patterns in their dose-response relationships. Using a trial with two biological agents as an example, we propose a dose-finding design to identify the biologically optimal dose combination (BODC), which is defined as the dose combination of the two agents with the highest efficacy and tolerable toxicity. A change-point model is used to reflect the fact that the dose-toxicity surface of the combinational agents may plateau at higher dose levels, and a flexible logistic model is proposed to accommodate the possible non-monotonic pattern for the dose-efficacy relationship. During the trial, we continuously update the posterior estimates of toxicity and efficacy and assign patients to the most appropriate dose combination. We propose a novel dose-finding algorithm to encourage sufficient exploration of untried dose combinations in the two-dimensional space. Extensive simulation studies show that the proposed design has desirable operating characteristics in identifying the BODC under various patterns of dose-toxicity and dose-efficacy relationships. PMID:24511160

  5. 32 CFR 218.1 - Policies.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... radiation environment to which the veteran was exposed and shall include inhaled, ingested and neutron doses. In determining the veteran's dose, initial neutron, initial gamma, residual gamma, and internal... dose, neutron dose, and internal dose. The minimum standards for reporting dose estimates are set forth...

  6. 32 CFR 218.1 - Policies.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... radiation environment to which the veteran was exposed and shall include inhaled, ingested and neutron doses. In determining the veteran's dose, initial neutron, initial gamma, residual gamma, and internal... dose, neutron dose, and internal dose. The minimum standards for reporting dose estimates are set forth...

  7. 32 CFR 218.1 - Policies.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... radiation environment to which the veteran was exposed and shall include inhaled, ingested and neutron doses. In determining the veteran's dose, initial neutron, initial gamma, residual gamma, and internal... dose, neutron dose, and internal dose. The minimum standards for reporting dose estimates are set forth...

  8. 32 CFR 218.1 - Policies.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... radiation environment to which the veteran was exposed and shall include inhaled, ingested and neutron doses. In determining the veteran's dose, initial neutron, initial gamma, residual gamma, and internal... dose, neutron dose, and internal dose. The minimum standards for reporting dose estimates are set forth...

  9. 32 CFR 218.1 - Policies.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... radiation environment to which the veteran was exposed and shall include inhaled, ingested and neutron doses. In determining the veteran's dose, initial neutron, initial gamma, residual gamma, and internal... dose, neutron dose, and internal dose. The minimum standards for reporting dose estimates are set forth...

  10. Warfarin Dosing Algorithms Underpredict Dose Requirements in Patients Requiring ≥7 mg Daily: A Systematic Review and Meta-analysis.

    PubMed

    Saffian, S M; Duffull, S B; Wright, Dfb

    2017-08-01

    There is preliminary evidence to suggest that some published warfarin dosing algorithms produce biased maintenance dose predictions in patients who require higher than average doses. We conducted a meta-analysis of warfarin dosing algorithms to determine if there exists a systematic under- or overprediction of dose requirements for patients requiring ≥7 mg/day across published algorithms. Medline and Embase databases were searched up to September 2015. We quantified the proportion of over- and underpredicted doses in patients whose observed maintenance dose was ≥7 mg/day. The meta-analysis included 47 evaluations of 22 different warfarin dosing algorithms from 16 studies. The meta-analysis included data from 1,492 patients who required warfarin doses of ≥7 mg/day. All 22 algorithms were found to underpredict warfarin dosing requirements in patients who required ≥7 mg/day by an average of 2.3 mg/day with a pooled estimate of underpredicted doses of 92.3% (95% confidence interval 90.3-94.1, I 2 = 24%). © 2017 American Society for Clinical Pharmacology and Therapeutics.

  11. Radiation dose reduction in digital breast tomosynthesis (DBT) by means of deep-learning-based supervised image processing

    NASA Astrophysics Data System (ADS)

    Liu, Junchi; Zarshenas, Amin; Qadir, Ammar; Wei, Zheng; Yang, Limin; Fajardo, Laurie; Suzuki, Kenji

    2018-03-01

    To reduce cumulative radiation exposure and lifetime risks for radiation-induced cancer from breast cancer screening, we developed a deep-learning-based supervised image-processing technique called neural network convolution (NNC) for radiation dose reduction in DBT. NNC employed patched-based neural network regression in a convolutional manner to convert lower-dose (LD) to higher-dose (HD) tomosynthesis images. We trained our NNC with quarter-dose (25% of the standard dose: 12 mAs at 32 kVp) raw projection images and corresponding "teaching" higher-dose (HD) images (200% of the standard dose: 99 mAs at 32 kVp) of a breast cadaver phantom acquired with a DBT system (Selenia Dimensions, Hologic, CA). Once trained, NNC no longer requires HD images. It converts new LD images to images that look like HD images; thus the term "virtual" HD (VHD) images. We reconstructed tomosynthesis slices on a research DBT system. To determine a dose reduction rate, we acquired 4 studies of another test phantom at 4 different radiation doses (1.35, 2.7, 4.04, and 5.39 mGy entrance dose). Structural SIMilarity (SSIM) index was used to evaluate the image quality. For testing, we collected half-dose (50% of the standard dose: 32+/-14 mAs at 33+/-5 kVp) and full-dose (standard dose: 68+/-23 mAs at 33+/-5 kvp) images of 10 clinical cases with the DBT system at University of Iowa Hospitals and Clinics. NNC converted half-dose DBT images of 10 clinical cases to VHD DBT images that were equivalent to full dose DBT images. Our cadaver phantom experiment demonstrated 79% dose reduction.

  12. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gorissen, BL; Giantsoudi, D; Unkelbach, J

    Purpose: Cell survival experiments suggest that the relative biological effectiveness (RBE) of proton beams depends on linear energy transfer (LET), leading to higher RBE near the end of range. With intensity-modulated proton therapy (IMPT), multiple treatment plans that differ in the dose contribution per field may yield a similar physical dose distribution, but the RBE-weighted dose distribution may be disparate. RBE models currently do not have the required predictive power to be included in an optimization model due to the variations in experimental data. We propose an LET-based planning method that guides IMPT optimization models towards plans with reduced RBE-weightedmore » dose in surrounding organs at risk (OARs) compared to inverse planning based on physical dose alone. Methods: Optimization models for physical dose are extended with a term for dose times LET (doseLET). Monte Carlo code is used to generate the physical dose and doseLET distribution of each individual pencil beam. The method is demonstrated for an atypical meningioma patient where the target volume abuts the brainstem and partially overlaps with the optic nerve. Results: A reference plan optimized based on physical dose alone yields high doseLET values in parts of the brainstem and optic nerve. Minimizing doseLET in these critical structures as an additional planning goal reduces the risk of high RBE-weighted dose. The resulting treatment plan avoids the distal fall-off of the Bragg peaks for shaping the dose distribution in front of critical stuctures. The maximum dose in the OARs evaluated with RBE models from literature is reduced by 8–14\\% with our method compared to conventional planning. Conclusion: LET-based inverse planning for IMPT offers the ability to reduce the RBE-weighted dose in OARs without sacrificing target dose. This project was in part supported by NCI - U19 CA 21239.« less

  13. Low-dose or standard-dose proton pump inhibitors for maintenance therapy of gastro-oesophageal reflux disease: a cost-effectiveness analysis.

    PubMed

    You, J H S; Lee, A C M; Wong, S C Y; Chan, F K L

    2003-03-15

    Studies on the use of low-dose proton pump inhibitor for the maintenance therapy of gastro-oesophageal reflux disease have shown that it might be comparable with standard-dose proton pump inhibitor treatment and superior to standard-dose histamine-2 receptor antagonist therapy. To compare the impact of standard-dose histamine-2 receptor antagonist, low-dose proton pump inhibitor and standard-dose proton pump inhibitor treatment for the maintenance therapy of gastro-oesophageal reflux disease on symptom control and health care resource utilization from the perspective of a public health organization in Hong Kong. A Markov model was designed to simulate, over 12 months, the economic and clinical outcomes of gastro-oesophageal reflux disease patients treated with standard-dose histamine-2 receptor antagonist, low-dose proton pump inhibitor and standard-dose proton pump inhibitor. The transition probabilities were derived from the literature. Resource utilization was retrieved from a group of gastro-oesophageal reflux disease patients in Hong Kong. Sensitivity analysis was conducted to examine the robustness of the model. The standard-dose proton pump inhibitor strategy was associated with the highest numbers of symptom-free patient-years (0.954 years) and quality-adjusted life-years gained (0.999 years), followed by low-dose proton pump inhibitor and standard-dose histamine-2 receptor antagonist. The direct medical cost per patient in the standard-dose proton pump inhibitor group (904 US dollars) was lower than those of the low-dose proton pump inhibitor and standard-dose histamine-2 receptor antagonist groups. The standard-dose proton pump inhibitor strategy appears to be the most effective and least costly for the maintenance management of patients with gastro-oesophageal reflux disease in Hong Kong.

  14. Dose gradient curve: A new tool for evaluating dose gradient

    PubMed Central

    Choi, Young Eun

    2018-01-01

    Purpose Stereotactic radiotherapy, which delivers an ablative high radiation dose to a target volume for maximum local tumor control, requires a rapid dose fall-off outside the target volume to prevent extensive damage to nearby normal tissue. Currently, there is no tool to comprehensively evaluate the dose gradient near the target volume. We propose the dose gradient curve (DGC) as a new tool to evaluate the quality of a treatment plan with respect to the dose fall-off characteristics. Methods The average distance between two isodose surfaces was represented by the dose gradient index (DGI) estimated by a simple equation using the volume and surface area of isodose levels. The surface area was calculated by mesh generation and surface triangulation. The DGC was defined as a plot of the DGI of each dose interval as a function of the dose. Two types of DGCs, differential and cumulative, were generated. The performance of the DGC was evaluated using stereotactic radiosurgery plans for virtual targets. Results Over the range of dose distributions, the dose gradient of each dose interval was well-characterized by the DGC in an easily understandable graph format. Significant changes in the DGC were observed reflecting the differences in planning situations and various prescription doses. Conclusions The DGC is a rational method for visualizing the dose gradient as the average distance between two isodose surfaces; the shorter the distance, the steeper the dose gradient. By combining the DGC with the dose-volume histogram (DVH) in a single plot, the DGC can be utilized to evaluate not only the dose gradient but also the target coverage in routine clinical practice. PMID:29698471

  15. Comprehensive evaluations of cone-beam CT dose in image-guided radiation therapy via GPU-based Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Montanari, Davide; Scolari, Enrica; Silvestri, Chiara; Jiang Graves, Yan; Yan, Hao; Cervino, Laura; Rice, Roger; Jiang, Steve B.; Jia, Xun

    2014-03-01

    Cone beam CT (CBCT) has been widely used for patient setup in image-guided radiation therapy (IGRT). Radiation dose from CBCT scans has become a clinical concern. The purposes of this study are (1) to commission a graphics processing unit (GPU)-based Monte Carlo (MC) dose calculation package gCTD for Varian On-Board Imaging (OBI) system and test the calculation accuracy, and (2) to quantitatively evaluate CBCT dose from the OBI system in typical IGRT scan protocols. We first conducted dose measurements in a water phantom. X-ray source model parameters used in gCTD are obtained through a commissioning process. gCTD accuracy is demonstrated by comparing calculations with measurements in water and in CTDI phantoms. Twenty-five brain cancer patients are used to study dose in a standard-dose head protocol, and 25 prostate cancer patients are used to study dose in pelvis protocol and pelvis spotlight protocol. Mean dose to each organ is calculated. Mean dose to 2% voxels that have the highest dose is also computed to quantify the maximum dose. It is found that the mean dose value to an organ varies largely among patients. Moreover, dose distribution is highly non-homogeneous inside an organ. The maximum dose is found to be 1-3 times higher than the mean dose depending on the organ, and is up to eight times higher for the entire body due to the very high dose region in bony structures. High computational efficiency has also been observed in our studies, such that MC dose calculation time is less than 5 min for a typical case.

  16. Occupational radiation dose to eyes from interventional radiology procedures in light of the new eye lens dose limit from the International Commission on Radiological Protection

    PubMed Central

    Walsh, C; Gallagher, A; Dowling, A; Guiney, M; Ryan, J M; McEniff, N; O'Reilly, G

    2015-01-01

    Objective: In 2011, the International Commission on Radiological Protection (ICRP) recommended a substantial reduction in the equivalent dose limit for the lens of the eye, in line with a reduced threshold of absorbed dose for radiation-induced cataracts. This is of particular relevance in interventional radiology (IR) where it is well established that staff doses can be significant, however, there is a lack of data on IR eye doses in terms of Hp(3). Hp(3) is the personal dose equivalent at a depth of 3 mm in soft tissue and is used for measuring lens dose. We aimed to obtain a reliable estimate of eye dose to IR operators. Methods: Lens doses were measured for four interventional radiologists over a 3-month period using dosemeters specifically designed to measure Hp(3). Results: Based on their typical workloads, two of the four interventional radiologists would exceed the new ICRP dose limit with annual estimated doses of 31 and 45 mSv to their left eye. These results are for an “unprotected” eye, and for IR staff who routinely wear lead glasses, the dose beneath the glasses is likely to be significantly lower. Staff eye dose normalized to patient kerma–area product and eye dose per procedure have been included in the analysis. Conclusion: Eye doses to IR operators have been established using a dedicated Hp(3) dosemeter. Estimated annual doses have the potential to exceed the new ICRP limit. Advances in knowledge: We have estimated lens dose to interventional radiologists in terms of Hp(3) for the first time in an Irish hospital setting. PMID:25761211

  17. A prospective randomized study of the efficacy and cost-effectiveness of high and low dose regimens of I-131 treatment in hyperthyroidism.

    PubMed

    Pusuwan, Pawana; Tuntawiroon, Malulee; Sritongkul, Nopamol; Chaudakshetrin, Pachee; Nopmaneejumruslers, Cherdchai; Komoltri, Chulalak; Thepamongkhol, Kullathorn; Khiewvan, Benjapa; Tuchinda, Pongpija; Sriussadaporn, Sutin

    2011-03-01

    To compare the efficacy and cost-effectiveness of high and low dose regimens of I-131 treatment in patients with hyperthyroidism. One hundred fifty patients with proven hyperthyroidism were randomly allocated into the high (74 patients) and low (76 patients) dose regimen of I-131 treatment. Four patients of the high dose group and one patient of the low dose group were excluded because of lost follow-up. A gland-specific dosage was calculated on the estimated weight of thyroid gland and 24-hour I-131 uptake. The high and low I-131 dose regimens were 150 microCi/gm and 100 microCi/gm, respectively. The first mean radioiodine activity administered to the high and low dose group was 10.2 and 8 mCi, respectively. Repeated treatment was given to 25 patients of the high dose group and 40 patients of the low dose group. Clinical outcome and calculated costs for outpatient attendances, and laboratory tests together with initial and subsequent treatments were evaluated for one year after I-131 treatment. Elimination of hyperthyroidism that resulted in either euthyroidism or hypothyroidism was classified as therapeutic success. The cost effectiveness was also compared. At 6 months after treatment, 45 (64.3%) patients receiving high dose and 59 (78.7%) patients receiving low dose were hyperthyroidism. Clinical outcome at one year showed persistence of hyperthyroidism in 21 (30%) patients of the high dose regimen and 36 (48%) patients of the low dose regimen. At one year post treatment, it was demonstrated that the high dose regimen could eliminate hyperthyroidism in a significantly shorter time than the low dose regimen, i.e., 259.6 days and 305.5 days, respectively, p = 0.008). For the persistent hyperthyroid patients, the average total cost of treatment in the low dose group was significantly higher than that of the high dose group, i.e., 13,422.78 baht and 10,942.79 baht, respectively; p = 0.050). A high dose regimen of radioactive iodine treatment is more effective than the low dose regimen. The successful outcome of a high dose regimen occurred significantly earlier than that of the low dose regimen. For the persistent hyperthyroid patients, the average total cost in the low dose group was significantly higher than that of the high dose group.

  18. Weight-based dosing in medication use: what should we know?

    PubMed Central

    Pan, Sheng-dong; Zhu, Ling-ling; Chen, Meng; Xia, Ping; Zhou, Quan

    2016-01-01

    Background Weight-based dosing strategy is still challenging due to poor awareness and adherence. It is necessary to let clinicians know of the latest developments in this respect and the correct circumstances in which weight-based dosing is of clinical relevance. Methods A literature search was conducted using PubMed. Results Clinical indications, physiological factors, and types of medication may determine the applicability of weight-based dosing. In some cases, the weight effect may be minimal or the proper dosage can only be determined when weight is combined with other factors. Medications within similar therapeutic or structural class (eg, anticoagulants, antitumor necrosis factor medications, P2Y12-receptor antagonists, and anti-epidermal growth factor receptor antibodies) may exhibit differences in requirements on weight-based dosing. In some cases, weight-based dosing is superior to currently recommended fixed-dose regimen in adult patients (eg, hydrocortisone, vancomycin, linezolid, and aprotinin). On the contrary, fixed dosing is noninferior to or even better than currently recommended weight-based regimen in adult patients in some cases (eg, cyclosporine microemulsion, recombinant activated Factor VII, and epoetin α). Ideal body-weight-based dosing may be superior to the currently recommended total body-weight-based regimen (eg, atracurium and rocuronium). For dosing in pediatrics, whether weight-based dosing is better than body surface-area-based dosing is dependent on the particular medication (eg, methotrexate, prednisone, prednisolone, zidovudine, didanosine, growth hormone, and 13-cis-retinoic acid). Age-based dosing strategy is better than weight-based dosing in some cases (eg, intravenous busulfan and dalteparin). Dosing guided by pharmacogenetic testing did not show pharmacoeconomic advantage over weight-adjusted dosing of 6-mercaptopurine. The common viewpoint (ie, pediatric patients should be dosed on the basis of body weight) is not always correct. Effective weight-based dosing interventions include standardization of weight estimation, documentation and dosing determination, dosing chart, dosing protocol, order set, pharmacist participation, technological information, and educational measures. Conclusion Although dosing methods are specified in prescribing information for each drug and there are no principal pros and cons to be elaborated, this review of weight-based dosing strategy will enrich the knowledge of medication administration from the perspectives of safety, efficacy, and pharmacoeconomics, and will also provide research opportunities in clinical practice. Clinicians should be familiar with dosage and administration of the medication to be prescribed as well as the latest developments. PMID:27110105

  19. Image perception by expert readers as a function of patient skin entrance dose levels in digital radiography

    NASA Astrophysics Data System (ADS)

    Lehnert, T.; Korkusuz, H.; Khan, F.; Vogl, T. J.; Mack, M. G.

    2008-03-01

    In this study, image quality was based on required clinical criteria, in order to investigate to what degree entrance dose could be lowered and what kind of added filtration can be used without impinging on radiologist confidence levels in diagnosing. Images were taken of extremities from a cadaver using stepwise decreasing dose levels and variation of added filtration (no filtration, aluminum, aluminum/copper) under digital projection radiography (Kodak DirectView DR7500). The starting point dose level for all body parts imaged was the current x-ray technique. Two experienced and two resident radiologists were presented the images in a blinded fashion and rated each with an image quality score from 1 to 9 indicated very satisfied and 1 as very unsatisfied indicating loss of diagnostic value. The readers were not aware of which dose level and added filtration corresponded to which image. Dose levels considered were 100%, 75%, 50% and 25% of the normal and customary x-ray techniques used for the particular body part and projection. Images were reviewed on a clinical diagnostic workstation with no time limits imposed. Readers were also able to change the image presentation by adjusting the window width and level. Without added filtration image quality mean score was rated with 6.3 (dose level 100%), 6.2 (dose level 75%), 5.3 (dose level 50%) and with 4.4 (dose level 25%). An added aluminum filtration induced an image quality mean score of 6.3 (dose level 100%), 6.0 (dose level 75%), 5.1 (dose level 50%) and of 4.2 (dose level 25%). Using aluminum/copper filtration image quality mean score was rated with 6.0 (dose level 100%), 6.1 (dose level 75%), 5.0 (dose level 50%) and with 3.8 (dose level 25%). Regardless of the added filtration a differentiation between dose levels 100% and 75% was possible in 38.9%, between dose levels 75% and 50% in 66.7%, and between dose levels 50% and 25% in 70.0% of the cases. It is possible, in the case of extremities, to lower entrance doses up to 75 % of the normal value, a reduction of 25% in dose, under simultaneous use of added aluminum or aluminum/copper filtration, without comprising the diagnostic value required.

  20. Peak skin and eye lens radiation dose from brain perfusion CT based on Monte Carlo simulation.

    PubMed

    Zhang, Di; Cagnon, Chris H; Villablanca, J Pablo; McCollough, Cynthia H; Cody, Dianna D; Stevens, Donna M; Zankl, Maria; Demarco, John J; Turner, Adam C; Khatonabadi, Maryam; McNitt-Gray, Michael F

    2012-02-01

    The purpose of our study was to accurately estimate the radiation dose to skin and the eye lens from clinical CT brain perfusion studies, investigate how well scanner output (expressed as volume CT dose index [CTDI(vol)]) matches these estimated doses, and investigate the efficacy of eye lens dose reduction techniques. Peak skin dose and eye lens dose were estimated using Monte Carlo simulation methods on a voxelized patient model and 64-MDCT scanners from four major manufacturers. A range of clinical protocols was evaluated. CTDI(vol) for each scanner was obtained from the scanner console. Dose reduction to the eye lens was evaluated for various gantry tilt angles as well as scan locations. Peak skin dose and eye lens dose ranged from 81 mGy to 348 mGy, depending on the scanner and protocol used. Peak skin dose and eye lens dose were observed to be 66-79% and 59-63%, respectively, of the CTDI(vol) values reported by the scanners. The eye lens dose was significantly reduced when the eye lenses were not directly irradiated. CTDI(vol) should not be interpreted as patient dose; this study has shown it to overestimate dose to the skin or eye lens. These results may be used to provide more accurate estimates of actual dose to ensure that protocols are operated safely below thresholds. Tilting the gantry or moving the scanning region further away from the eyes are effective for reducing lens dose in clinical practice. These actions should be considered when they are consistent with the clinical task and patient anatomy.

  1. Hormones and Endocrine-Disrupting Chemicals: Low-Dose Effects and Nonmonotonic Dose Responses

    PubMed Central

    Colborn, Theo; Hayes, Tyrone B.; Heindel, Jerrold J.; Jacobs, David R.; Lee, Duk-Hee; Shioda, Toshi; Soto, Ana M.; vom Saal, Frederick S.; Welshons, Wade V.; Zoeller, R. Thomas

    2012-01-01

    For decades, studies of endocrine-disrupting chemicals (EDCs) have challenged traditional concepts in toxicology, in particular the dogma of “the dose makes the poison,” because EDCs can have effects at low doses that are not predicted by effects at higher doses. Here, we review two major concepts in EDC studies: low dose and nonmonotonicity. Low-dose effects were defined by the National Toxicology Program as those that occur in the range of human exposures or effects observed at doses below those used for traditional toxicological studies. We review the mechanistic data for low-dose effects and use a weight-of-evidence approach to analyze five examples from the EDC literature. Additionally, we explore nonmonotonic dose-response curves, defined as a nonlinear relationship between dose and effect where the slope of the curve changes sign somewhere within the range of doses examined. We provide a detailed discussion of the mechanisms responsible for generating these phenomena, plus hundreds of examples from the cell culture, animal, and epidemiology literature. We illustrate that nonmonotonic responses and low-dose effects are remarkably common in studies of natural hormones and EDCs. Whether low doses of EDCs influence certain human disorders is no longer conjecture, because epidemiological studies show that environmental exposures to EDCs are associated with human diseases and disabilities. We conclude that when nonmonotonic dose-response curves occur, the effects of low doses cannot be predicted by the effects observed at high doses. Thus, fundamental changes in chemical testing and safety determination are needed to protect human health. PMID:22419778

  2. Calculation of Organ Doses for a Large Number of Patients Undergoing CT Examinations.

    PubMed

    Bahadori, Amir; Miglioretti, Diana; Kruger, Randell; Flynn, Michael; Weinmann, Sheila; Smith-Bindman, Rebecca; Lee, Choonsik

    2015-10-01

    The objective of our study was to develop an automated calculation method to provide organ dose assessment for a large cohort of pediatric and adult patients undergoing CT examinations. We adopted two dose libraries that were previously published: the volume CT dose index-normalized organ dose library and the tube current-exposure time product (100 mAs)-normalized weighted CT dose index library. We developed an algorithm to calculate organ doses using the two dose libraries and the CT parameters available from DICOM data. We calculated organ doses for pediatric (n = 2499) and adult (n = 2043) CT examinations randomly selected from four health care systems in the United States and compared the adult organ doses with the values calculated from the ImPACT calculator. The median brain dose was 20 mGy (pediatric) and 24 mGy (adult), and the brain dose was greater than 40 mGy for 11% (pediatric) and 18% (adult) of the head CT studies. Both the National Cancer Institute (NCI) and ImPACT methods provided similar organ doses (median discrepancy < 20%) for all organs except the organs located close to the scanning boundaries. The visual comparisons of scanning coverage and phantom anatomies revealed that the NCI method, which is based on realistic computational phantoms, provides more accurate organ doses than the ImPACT method. The automated organ dose calculation method developed in this study reduces the time needed to calculate doses for a large number of patients. We have successfully used this method for a variety of CT-related studies including retrospective epidemiologic studies and CT dose trend analysis studies.

  3. Monte Carlo calculations for reporting patient organ doses from interventional radiology

    NASA Astrophysics Data System (ADS)

    Huo, Wanli; Feng, Mang; Pi, Yifei; Chen, Zhi; Gao, Yiming; Xu, X. George

    2017-09-01

    This paper describes a project to generate organ dose data for the purposes of extending VirtualDose software from CT imaging to interventional radiology (IR) applications. A library of 23 mesh-based anthropometric patient phantoms were involved in Monte Carlo simulations for database calculations. Organ doses and effective doses of IR procedures with specific beam projection, filed of view (FOV) and beam quality for all parts of body were obtained. Comparing organ doses for different beam qualities, beam projections, patients' ages and patient's body mass indexes (BMIs) which generated by VirtualDose-IR, significant discrepancies were observed. For relatively long time exposure, IR doses depend on beam quality, beam direction and patient size. Therefore, VirtualDose-IR, which is based on the latest anatomically realistic patient phantoms, can generate accurate doses for IR treatment. It is suitable to apply this software in clinical IR dose management as an effective tool to estimate patient doses and optimize IR treatment plans.

  4. Effective radiation dose of ProMax 3D cone-beam computerized tomography scanner with different dental protocols.

    PubMed

    Qu, Xing-min; Li, Gang; Ludlow, John B; Zhang, Zu-yan; Ma, Xu-chen

    2010-12-01

    The aim of this study was to compare effective doses resulting from different scan protocols for cone-beam computerized tomography (CBCT) using International Commission on Radiological Protection (ICRP) 1990 and 2007 calculations of dose. Average tissue-absorbed dose, equivalent dose, and effective dose for a ProMax 3D CBCT with different dental protocols were calculated using thermoluminescent dosimeter chips in a human equivalent phantom. Effective doses were derived using ICRP 1990 and the superseding 2007 recommendations. Effective doses (ICRP 2007) for default patient sizes from small to large ranged from 102 to 298 μSv. The coefficient of determination (R(2)) between tube current and effective dose (ICRP 2007) was 0.90. When scanning with lower resolution settings, the effective doses were reduced significantly (P < .05). ProMax 3D can provide a wide range of radiation dose levels. Reduction in radiation dose can be achieved when using lower settings of exposure parameters. Copyright © 2010 Mosby, Inc. All rights reserved.

  5. Review of reconstruction of radiation incident air kerma by measurement of absorbed dose in tooth enamel with EPR.

    PubMed

    Wieser, A

    2012-03-01

    Electron paramagnetic resonance dosimetry with tooth enamel has been proved to be a reliable method to determine retrospectively exposures from photon fields with minimal detectable doses of 100 mGy or lower, which is lower than achievable with cytogenetic dose reconstruction methods. For risk assessment or validating dosimetry systems for specific radiation incidents, the relevant dose from the incident has to be calculated from the total absorbed dose in enamel by subtracting additional dose contributions from the radionuclide content in teeth, natural external background radiation and medical exposures. For calculating organ doses or evaluating dosimetry systems the absorbed dose in enamel from a radiation incident has to be converted to air kerma using dose conversion factors depending on the photon energy spectrum and geometry of the exposure scenario. This paper outlines the approach to assess individual dose contributions to absorbed dose in enamel and calculate individual air kerma of a radiation incident from the absorbed dose in tooth enamel.

  6. Evaluation of various approaches for assessing dose indicators and patient organ doses resulting from radiotherapy cone-beam CT

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rampado, Osvaldo, E-mail: orampado@cittadellasalute.to.it; Giglioli, Francesca Romana; Rossetti, Veronica

    Purpose: The aim of this study was to evaluate various approaches for assessing patient organ doses resulting from radiotherapy cone-beam CT (CBCT), by the use of thermoluminescent dosimeter (TLD) measurements in anthropomorphic phantoms, a Monte Carlo based dose calculation software, and different dose indicators as presently defined. Methods: Dose evaluations were performed on a CBCT Elekta XVI (Elekta, Crawley, UK) for different protocols and anatomical regions. The first part of the study focuses on using PCXMC software (PCXMC 2.0, STUK, Helsinki, Finland) for calculating organ doses, adapting the input parameters to simulate the exposure geometry, and beam dose distribution inmore » an appropriate way. The calculated doses were compared to readouts of TLDs placed in an anthropomorphic Rando phantom. After this validation, the software was used for analyzing organ dose variability associated with patients’ differences in size and gender. At the same time, various dose indicators were evaluated: kerma area product (KAP), cumulative air-kerma at the isocenter (K{sub air}), cone-beam dose index, and central cumulative dose. The latter was evaluated in a single phantom and in a stack of three adjacent computed tomography dose index phantoms. Based on the different dose indicators, a set of coefficients was calculated to estimate organ doses for a range of patient morphologies, using their equivalent diameters. Results: Maximum organ doses were about 1 mGy for head and neck and 25 mGy for chest and pelvis protocols. The differences between PCXMC and TLDs doses were generally below 10% for organs within the field of view and approximately 15% for organs at the boundaries of the radiation beam. When considering patient size and gender variability, differences in organ doses up to 40% were observed especially in the pelvic region; for the organs in the thorax, the maximum differences ranged between 20% and 30%. Phantom dose indexes provided better correlation with organ doses than K{sub air} and KAP, with average ratios ranging between 0.9 and 1.1 and variations for different organs and protocols below 20%. The triple phantom setup allowed us to take into account scatter dose contributions, but nonetheless, the correlation with the evaluated organ doses was not improved with this method. Conclusions: The simulation of rotational geometry and of asymmetric beam distribution by means of PCXMC 2.0 enabled us to determine patient organ doses depending on weight, height and gender. Alternatively, the measurement of an in phantom dose indicator combined with proper correction coefficients can be a useful tool for a first dose estimation of in-field organs. The data and coefficients provided in this study can be applied to any patient undergoing a scan by an Elekta XVI equipment.« less

  7. Epinephrine Dosing Period and Survival after In-Hospital Cardiac Arrest

    PubMed Central

    Warren, Sam A.; Huszti, Ella; Bradley, Steven M.; Chan, Paul S.; Bryson, Chris L.; Fitzpatrick, Annette L.; Nichol, Graham

    2015-01-01

    Background Expert guidelines for treatment of cardiac arrest recommend administration of epinephrine every three to five minutes. However, different dosing periods of epinephrine have not been systematically assessed. Objective We evaluated the association between epinephrine dosing frequency and survival to hospital discharge in adults with an in-hospital cardiac arrest (IHCA). Methods Using data from 2000–2009 in the Get With the Guidelines(GWTG)-Resuscitation IHCA registry (formerly the National Registry of Cardiopulmonary Resuscitation [NRCPR]), we examined the association between epinephrine dosing period and survival to hospital discharge. Epinephrine dosing period was defined as the time between the first epinephrine dose and the resuscitation endpoint, divided by the total number of epinephrine doses received subsequent to the first epinephrine dose. Generalized estimating equations were used to construct multivariable logistic regression models, adjusted for patient and arrest characteristics. Results Included were 20,909 eligible IHCA events from 505 GWTG-Resuscitation participating hospitals. Compared to an epinephrine dosing period of 4 to <5 minutes per dose, survival to hospital discharge was significantly higher in patients with an epinephrine dosing period of 6 to <10 minutes per dose: for 6 to <7 min/dose, adjusted odds ratio [OR], 1.41 (95% CI: 1.12, 1.78); for 7 to <8 min/dose, adjusted OR, 1.30 (95%CI: 1.02, 1.65); for 8 to <9 min/dose, adjusted OR, 1.79 (95%CI: 1.38, 2.32); for 9 to <10 min/dose, adjusted OR, 2.17 (95%CI: 1.62, 2.92). This pattern was consistent for both shockable and non-shockable cardiac arrest rhythms. Moreover, for the majority (87%) of cardiac arrests due to non-shockable rhythms, an epinephrine dosing period of 1 to <3 minutes/dose was associated with lower rates of survival. Conclusion In this large, observational, national registry of in-hospital cardiac arrest, we found that epinephrine dosing at a less frequent dosing period than recommended by consensus guidelines was associated with improved survival of in-hospital cardiac arrest. Our findings suggest that clinical trials may be needed to determine the role and dose frequency of epinephrine in the treatment of in-hospital cardiac arrest. PMID:24252225

  8. Measurement of Individual Doses of Radiation by Personal Dosimeter Is Important for the Return of Residents from Evacuation Order Areas after Nuclear Disaster

    PubMed Central

    Orita, Makiko; Hayashida, Naomi; Taira, Yasuyuki; Fukushima, Yoshiko; Ide, Juichi; Endo, Yuuko; Kudo, Takashi; Yamashita, Shunichi; Takamura, Noboru

    2015-01-01

    To confirm the availability of individual dose evaluation for the return of residents after the accident at the Fukushima Dai-ichi Nuclear Power Plant (FNPP), we evaluated individual doses of radiation as measured by personal dosimeters in residents who temporarily stayed in Evacuation Order Areas in Kawauchi village, which is partially located within a 20 km radius of the FNPP. We also compared individual doses with the external radiation doses estimated from the ambient dose rates and with doses estimated from the concentrations of radionuclides in the soil around each individual’s house. Individual doses were significantly correlated with the ambient doses in front of the entrances to the houses (r = 0.90, p<0.01), in the backyards (r = 0.41, p<0.01) and in the nearby fields (r = 0.80, p<0.01). The maximum cumulative ambient doses in the backyards and fields around the houses were 6.38 and 9.27 mSv/y, respectively. The maximum cumulative individual dose was 3.28 mSv/y, and the median and minimum doses were 1.35 and 0.71 mSv/y. The estimated external effective doses from concentrations of artificial radionuclides in soil samples ranged from 0.03 to 23.42 mSv/y. The individual doses were moderately correlated with external effective doses in the backyards (r = 0.38, p<0.01) and in the fields (r = 0.36, p<0.01); however, the individual doses were not significantly correlated with the external effective doses in front of the entrances (r = 0.01, p = 0.92). Our study confirmed that individual doses are low levels even in the evacuation order area in Kawauchi village, and external effective dose levels are certainly decreasing due to the decay of artificial radionuclides and the decontamination of contaminated soil. Long-term follow-up of individual doses as well as internal-exposure doses, environmental monitoring and reconstruction of infrastructure are needed so that residents may return to their hometowns after a nuclear disaster. PMID:25806523

  9. SU-F-J-133: Adaptive Radiation Therapy with a Four-Dimensional Dose Calculation Algorithm That Optimizes Dose Distribution Considering Breathing Motion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ali, I; Algan, O; Ahmad, S

    Purpose: To model patient motion and produce four-dimensional (4D) optimized dose distributions that consider motion-artifacts in the dose calculation during the treatment planning process. Methods: An algorithm for dose calculation is developed where patient motion is considered in dose calculation at the stage of the treatment planning. First, optimal dose distributions are calculated for the stationary target volume where the dose distributions are optimized considering intensity-modulated radiation therapy (IMRT). Second, a convolution-kernel is produced from the best-fitting curve which matches the motion trajectory of the patient. Third, the motion kernel is deconvolved with the initial dose distribution optimized for themore » stationary target to produce a dose distribution that is optimized in four-dimensions. This algorithm is tested with measured doses using a mobile phantom that moves with controlled motion patterns. Results: A motion-optimized dose distribution is obtained from the initial dose distribution of the stationary target by deconvolution with the motion-kernel of the mobile target. This motion-optimized dose distribution is equivalent to that optimized for the stationary target using IMRT. The motion-optimized and measured dose distributions are tested with the gamma index with a passing rate of >95% considering 3% dose-difference and 3mm distance-to-agreement. If the dose delivery per beam takes place over several respiratory cycles, then the spread-out of the dose distributions is only dependent on the motion amplitude and not affected by motion frequency and phase. This algorithm is limited to motion amplitudes that are smaller than the length of the target along the direction of motion. Conclusion: An algorithm is developed to optimize dose in 4D. Besides IMRT that provides optimal dose coverage for a stationary target, it extends dose optimization to 4D considering target motion. This algorithm provides alternative to motion management techniques such as beam-gating or breath-holding and has potential applications in adaptive radiation therapy.« less

  10. Abdominal CT with model-based iterative reconstruction (MBIR): initial results of a prospective trial comparing ultralow-dose with standard-dose imaging.

    PubMed

    Pickhardt, Perry J; Lubner, Meghan G; Kim, David H; Tang, Jie; Ruma, Julie A; del Rio, Alejandro Muñoz; Chen, Guang-Hong

    2012-12-01

    The purpose of this study was to report preliminary results of an ongoing prospective trial of ultralow-dose abdominal MDCT. Imaging with standard-dose contrast-enhanced (n = 21) and unenhanced (n = 24) clinical abdominal MDCT protocols was immediately followed by ultralow-dose imaging of a matched series of 45 consecutively registered adults (mean age, 57.9 years; mean body mass index, 28.5). The ultralow-dose images were reconstructed with filtered back projection (FBP), adaptive statistical iterative reconstruction (ASIR), and model-based iterative reconstruction (MBIR). Standard-dose series were reconstructed with FBP (reference standard). Image noise was measured at multiple predefined sites. Two blinded abdominal radiologists interpreted randomly presented ultralow-dose images for multilevel subjective image quality (5-point scale) and depiction of organ-based focal lesions. Mean dose reduction relative to the standard series was 74% (median, 78%; range, 57-88%; mean effective dose, 1.90 mSv). Mean multiorgan image noise for low-dose MBIR was 14.7 ± 2.6 HU, significantly lower than standard-dose FBP (28.9 ± 9.9 HU), low-dose FBP (59.2 ± 23.3 HU), and ASIR (45.6 ± 14.1 HU) (p < 0.001). The mean subjective image quality score for low-dose MBIR (3.0 ± 0.5) was significantly higher than for low-dose FBP (1.6 ± 0.7) and ASIR (1.8 ± 0.7) (p < 0.001). Readers identified 213 focal noncalcific lesions with standard-dose FBP. Pooled lesion detection was higher for low-dose MBIR (79.3% [169/213]) compared with low-dose FBP (66.2% [141/213]) and ASIR (62.0% [132/213]) (p < 0.05). MBIR shows great potential for substantially reducing radiation doses at routine abdominal CT. Both FBP and ASIR are limited in this regard owing to reduced image quality and diagnostic capability. Further investigation is needed to determine the optimal dose level for MBIR that maintains adequate diagnostic performance. In general, objective and subjective image quality measurements do not necessarily correlate with diagnostic performance at ultralow-dose CT.

  11. Measurement of individual doses of radiation by personal dosimeter is important for the return of residents from evacuation order areas after nuclear disaster.

    PubMed

    Orita, Makiko; Hayashida, Naomi; Taira, Yasuyuki; Fukushima, Yoshiko; Ide, Juichi; Endo, Yuuko; Kudo, Takashi; Yamashita, Shunichi; Takamura, Noboru

    2015-01-01

    To confirm the availability of individual dose evaluation for the return of residents after the accident at the Fukushima Dai-ichi Nuclear Power Plant (FNPP), we evaluated individual doses of radiation as measured by personal dosimeters in residents who temporarily stayed in Evacuation Order Areas in Kawauchi village, which is partially located within a 20 km radius of the FNPP. We also compared individual doses with the external radiation doses estimated from the ambient dose rates and with doses estimated from the concentrations of radionuclides in the soil around each individual's house. Individual doses were significantly correlated with the ambient doses in front of the entrances to the houses (r = 0.90, p<0.01), in the backyards (r = 0.41, p<0.01) and in the nearby fields (r = 0.80, p<0.01). The maximum cumulative ambient doses in the backyards and fields around the houses were 6.38 and 9.27 mSv/y, respectively. The maximum cumulative individual dose was 3.28 mSv/y, and the median and minimum doses were 1.35 and 0.71 mSv/y. The estimated external effective doses from concentrations of artificial radionuclides in soil samples ranged from 0.03 to 23.42 mSv/y. The individual doses were moderately correlated with external effective doses in the backyards (r = 0.38, p<0.01) and in the fields (r = 0.36, p<0.01); however, the individual doses were not significantly correlated with the external effective doses in front of the entrances (r = 0.01, p = 0.92). Our study confirmed that individual doses are low levels even in the evacuation order area in Kawauchi village, and external effective dose levels are certainly decreasing due to the decay of artificial radionuclides and the decontamination of contaminated soil. Long-term follow-up of individual doses as well as internal-exposure doses, environmental monitoring and reconstruction of infrastructure are needed so that residents may return to their hometowns after a nuclear disaster.

  12. SU-F-T-157: Physics Considerations Regarding Dosimetric Accuracy of Analytical Dose Calculations for Small Field Proton Therapy: A Monte Carlo Study

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Geng, C; Nanjing University of Aeronautics and Astronautics, Nanjing; Daartz, J

    Purpose: To evaluate the accuracy of dose calculations by analytical dose calculation methods (ADC) for small field proton therapy in a gantry based passive scattering facility. Methods: 50 patients with intra-cranial disease were evaluated in the study. Treatment plans followed standard prescription and optimization procedures of proton stereotactic radiosurgery. Dose distributions calculated with the Monte Carlo (MC) toolkit TOPAS were used to represent delivered treatments. The MC dose was first adjusted using the output factor (OF) applied clinically. This factor is determined from the field size and the prescribed range. We then introduced a normalization factor to measure the differencemore » in mean dose between the delivered dose (MC dose with OF) and the dose calculated by ADC for each beam. The normalization was determined by the mean dose of the center voxels of the target area. We compared delivered dose distributions and those calculated by ADC in terms of dose volume histogram parameters and beam range distributions. Results: The mean target dose for a whole treatment is generally within 5% comparing delivered dose (MC dose with OF) and ADC dose. However, the differences can be as great as 11% for shallow and small target treated with a thick range compensator. Applying the normalization factor to the MC dose with OF can reduce the mean dose difference to less than 3%. Considering range uncertainties, the generally applied margins (3.5% of the prescribed range + 1mm) to cover uncertainties in range might not be sufficient to guarantee tumor coverage. The range difference for R90 (90% distal dose falloff) is affected by multiple factors, such as the heterogeneity index. Conclusion: This study indicates insufficient accuracy calculating proton doses using ADC. Our results suggest that uncertainties of target doses are reduced using MC techniques, improving the dosimetric accuracy for proton stereotactic radiosurgery. The work was supported by NIH/NCI under CA U19 021239. CG was partially supported by the Chinese Scholarship Council (CSC) and the National Natural Science Foundation of China (Grant No. 11475087).« less

  13. Dosimetric evaluation of high-dose-rate interstitial brachytherapy boost treatments for localized prostate cancer.

    PubMed

    Fröhlich, Georgina; Agoston, Péter; Lövey, József; Somogyi, András; Fodor, János; Polgár, Csaba; Major, Tibor

    2010-07-01

    To quantitatively evaluate the dose distributions of high-dose-rate (HDR) prostate implants regarding target coverage, dose homogeneity, and dose to organs at risk. Treatment plans of 174 implants were evaluated using cumulative dose-volume histograms (DVHs). The planning was based on transrectal ultrasound (US) imaging, and the prescribed dose (100%) was 10 Gy. The tolerance doses to rectum and urethra were 80% and 120%, respectively. Dose-volume parameters for target (V90, V100, V150, V200, D90, D(min)) and quality indices (DNR [dose nonuniformity ratio], DHI [dose homogeneity index], CI [coverage index], COIN [conformal index]) were calculated. Maximum dose in reference points of rectum (D(r)) and urethra (D(u)), dose to volume of 2 cm(3) of the rectum (D(2ccm)), and 0.1 cm(3) and 1% of the urethra (D(0.1ccm) and D1) were determined. Nonparametric correlation analysis was performed between these parameters. The median number of needles was 16, the mean prostate volume (V(p)) was 27.1 cm(3). The mean V90, V100, V150, and V200 were 99%, 97%, 39%, and 13%, respectively. The mean D90 was 109%, and the D(min) was 87%. The mean doses in rectum and urethra reference points were 75% and 119%, respectively. The mean volumetric doses were D(2ccm) = 49% for the rectum, D(0.1ccm) = 126%, and D1 = 140% for the urethra. The mean DNR was 0.37, while the DHI was 0.60. The mean COIN was 0.66. The Spearman rank order correlation coefficients for volume doses to rectum and urethra were R(D(r),D(2ccm)) = 0.69, R(D(u),D0.(1ccm)) = 0.64, R(D(u),D1) = 0.23. US-based treatment plans for HDR prostate implants based on the real positions of catheters provided acceptable dose distributions. In the majority of the cases, the doses to urethra and rectum were kept below the defined tolerance levels. For rectum, the dose in reference points correlated well with dose-volume parameters. For urethra dose characterization, the use of D1 volumetric parameter is recommended.

  14. Determination of the uncertainties in radiation doses from ingestion of strontium-90

    NASA Astrophysics Data System (ADS)

    Apostoaei, Andrei Iulian

    Quantification of the uncertainties in the internal dosimetry is important because it can impact the outcome of dose reconstruction, risk assessment or epidemiological studies. This research focused on determination of the uncertainties in the dose factors from a single ingestion of 90Sr by adults, and analyzed the changes with age and the effect of gender. The uncertainties in the estimated dose factors are a factor of 6 for the bone surface, 5 for the red bone marrow, 2.5 for bladder and stomach, 2.2 for the small intestine, 2.1 for the upper large intestine and 2.7 for the lower large intestine. For the rest of the organs the uncertainty is a factor of 3. Only four parameters of the biokinetic model showed an age-dependency within the adult age group: the fractional transfers of strontium from plasma to cortical and trabecular bone, and the removal rates from the cortical and trabecular bone, respectively. When age-dependent biokinetic parameters were used, the estimated dose-factors are very close to the dose factors obtained using age-independent kinetics (within 40%). Thus, the dose factors based on age-independent parameters should suffice for most practical purposes. The dose factors and the associated uncertainties were also calculated as a function of age-at-exposure and attained age. These age dependent curves can be used for estimating doses from continuous intakes, or doses delivered over a limited portion of time. In addition to the committed dose, an expected dose is also estimated in this work. The expected dose is calculated using the dose rate weighted by the probability of surviving up to the age when the dose-rate is delivered. For exposure at young ages the expected dose and the committed dose are similar, but the committed dose decreases to zero when exposure occurs close to age 70, while the expected dose has elevated values pass age 70. No gender differences were found for bone surface, for red bone marrow, and the large intestine. The doses to the soft tissues for females are larger by 20% than the doses for males, because of the differences in the whole-body mass between males and females.

  15. Organ dose measurement using Optically Stimulated Luminescence Detector (OSLD) during CT examination

    NASA Astrophysics Data System (ADS)

    Yusuf, Muhammad; Alothmany, Nazeeh; Abdulrahman Kinsara, Abdulraheem

    2017-10-01

    This study provides detailed information regarding the imaging doses to patient radiosensitive organs from a kilovoltage computed tomography (CT) scan procedure using OSLD. The study reports discrepancies between the measured dose and the calculated dose from the ImPACT scan, as well as a comparison with the dose from a chest X-ray radiography procedure. OSLDs were inserted in several organs, including the brain, eyes, thyroid, lung, heart, spinal cord, breast, spleen, stomach, liver and ovaries, of the RANDO phantom. Standard clinical scanning protocols were used for each individual site, including the brain, thyroid, lung, breast, stomach, liver and ovaries. The measured absorbed doses were then compared with the simulated dose obtained from the ImPACT scan. Additionally, the equivalent doses for each organ were calculated and compared with the dose from a chest X-ray radiography procedure. Absorbed organ doses measured by OSLD in the RANDO phantom of up to 17 mGy depend on the organ scanned and the scanning protocols used. A maximum 9.82% difference was observed between the target organ dose measured by OSLD and the results from the ImPACT scan. The maximum equivalent organ dose measured during this experiment was equal to 99.899 times the equivalent dose from a chest X-ray radiography procedure. The discrepancies between the measured dose with the OSLD and the calculated dose from the ImPACT scan were within 10%. This report recommends the use of OSLD for measuring the absorbed organ dose during CT examination.

  16. Underestimation of Low-Dose Radiation in Treatment Planning of Intensity-Modulated Radiotherapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jang, Si Young; Liu, H. Helen; Mohan, Radhe

    2008-08-01

    Purpose: To investigate potential dose calculation errors in the low-dose regions and identify causes of such errors for intensity-modulated radiotherapy (IMRT). Methods and Materials: The IMRT treatment plans of 23 patients with lung cancer and mesothelioma were reviewed. Of these patients, 15 had severe pulmonary complications after radiotherapy. Two commercial treatment-planning systems (TPSs) and a Monte Carlo system were used to calculate and compare dose distributions and dose-volume parameters of the target volumes and critical structures. The effect of tissue heterogeneity, multileaf collimator (MLC) modeling, beam modeling, and other factors that could contribute to the differences in IMRT dose calculationsmore » were analyzed. Results: In the commercial TPS-generated IMRT plans, dose calculation errors primarily occurred in the low-dose regions of IMRT plans (<50% of the radiation dose prescribed for the tumor). Although errors in the dose-volume histograms of the normal lung were small (<5%) above 10 Gy, underestimation of dose <10 Gy was found to be up to 25% in patients with mesothelioma or large target volumes. These errors were found to be caused by inadequate modeling of MLC transmission and leaf scatter in commercial TPSs. The degree of low-dose errors depends on the target volumes and the degree of intensity modulation. Conclusions: Secondary radiation from MLCs contributes a significant portion of low dose in IMRT plans. Dose underestimation could occur in conventional IMRT dose calculations if such low-dose radiation is not properly accounted for.« less

  17. Escalation to High-Dose Defibrotide in Patients with Hepatic Veno-Occlusive Disease.

    PubMed

    Triplett, Brandon M; Kuttab, Hani I; Kang, Guolian; Leung, Wing

    2015-12-01

    Hepatic veno-occlusive disease (VOD) is a serious complication of high-dose chemotherapy regimens, such as those used in hematopoietic cell transplantation recipients. Defibrotide is considered a safe and effective treatment when dosed at 25 mg/kg/day. However, patients who develop VOD still have increased mortality despite the use of defibrotide. Data are limited on the use of doses above 60 mg/kg/day for persistent VOD. In this prospective clinical trial 34 patients received escalating doses of defibrotide. For patients with persistent VOD despite doses of 60 mg/kg/day, doses were increased to a maximum of 110 mg/kg/day. Increased toxicity was not observed until doses rose beyond 100 mg/kg/day. Patients receiving doses between 10 and 100 mg/kg/day experienced an average of 3 bleeding episodes per 100 days of treatment, whereas those receiving doses >100 mg/kg/day experienced 13.2 bleeding episodes per 100 days (P = .008). Moreover, dose reductions due to toxicity were needed at doses of 110 mg/kg/day more often than at lower doses. Defibrotide may be safely escalated to doses well above the current standard without an increase in bleeding risk. However, the efficacy of this dose-escalation strategy remains unclear, because outcomes were similar to published cohorts of patients receiving standard doses of defibrotide for VOD. Copyright © 2015 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  18. Dosimetric verification of lung cancer treatment using the CBCTs estimated from limited-angle on-board projections

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, You; Yin, Fang-Fang; Ren, Lei, E-mail: lei.ren@duke.edu

    2015-08-15

    Purpose: Lung cancer treatment is susceptible to treatment errors caused by interfractional anatomical and respirational variations of the patient. On-board treatment dose verification is especially critical for the lung stereotactic body radiation therapy due to its high fractional dose. This study investigates the feasibility of using cone-beam (CB)CT images estimated by a motion modeling and free-form deformation (MM-FD) technique for on-board dose verification. Methods: Both digital and physical phantom studies were performed. Various interfractional variations featuring patient motion pattern change, tumor size change, and tumor average position change were simulated from planning CT to on-board images. The doses calculated onmore » the planning CT (planned doses), the on-board CBCT estimated by MM-FD (MM-FD doses), and the on-board CBCT reconstructed by the conventional Feldkamp-Davis-Kress (FDK) algorithm (FDK doses) were compared to the on-board dose calculated on the “gold-standard” on-board images (gold-standard doses). The absolute deviations of minimum dose (ΔD{sub min}), maximum dose (ΔD{sub max}), and mean dose (ΔD{sub mean}), and the absolute deviations of prescription dose coverage (ΔV{sub 100%}) were evaluated for the planning target volume (PTV). In addition, 4D on-board treatment dose accumulations were performed using 4D-CBCT images estimated by MM-FD in the physical phantom study. The accumulated doses were compared to those measured using optically stimulated luminescence (OSL) detectors and radiochromic films. Results: Compared with the planned doses and the FDK doses, the MM-FD doses matched much better with the gold-standard doses. For the digital phantom study, the average (± standard deviation) ΔD{sub min}, ΔD{sub max}, ΔD{sub mean}, and ΔV{sub 100%} (values normalized by the prescription dose or the total PTV) between the planned and the gold-standard PTV doses were 32.9% (±28.6%), 3.0% (±2.9%), 3.8% (±4.0%), and 15.4% (±12.4%), respectively. The corresponding values of FDK PTV doses were 1.6% (±1.9%), 1.2% (±0.6%), 2.2% (±0.8%), and 17.4% (±15.3%), respectively. In contrast, the corresponding values of MM-FD PTV doses were 0.3% (±0.2%), 0.9% (±0.6%), 0.6% (±0.4%), and 1.0% (±0.8%), respectively. Similarly, for the physical phantom study, the average ΔD{sub min}, ΔD{sub max}, ΔD{sub mean}, and ΔV{sub 100%} of planned PTV doses were 38.1% (±30.8%), 3.5% (±5.1%), 3.0% (±2.6%), and 8.8% (±8.0%), respectively. The corresponding values of FDK PTV doses were 5.8% (±4.5%), 1.6% (±1.6%), 2.0% (±0.9%), and 9.3% (±10.5%), respectively. In contrast, the corresponding values of MM-FD PTV doses were 0.4% (±0.8%), 0.8% (±1.0%), 0.5% (±0.4%), and 0.8% (±0.8%), respectively. For the 4D dose accumulation study, the average (± standard deviation) absolute dose deviation (normalized by local doses) between the accumulated doses and the OSL measured doses was 3.3% (±2.7%). The average gamma index (3%/3 mm) between the accumulated doses and the radiochromic film measured doses was 94.5% (±2.5%). Conclusions: MM-FD estimated 4D-CBCT enables accurate on-board dose calculation and accumulation for lung radiation therapy. It can potentially be valuable for treatment quality assessment and adaptive radiation therapy.« less

  19. Comparison of 2-Dose and 3-Dose 9-Valent Human Papillomavirus Vaccine Schedules in the United States: A Cost-effectiveness Analysis.

    PubMed

    Laprise, Jean-François; Markowitz, Lauri E; Chesson, Harrell W; Drolet, Mélanie; Brisson, Marc

    2016-09-01

    A recent clinical trial using the 9-valent human papillomavirus virus (HPV) vaccine has shown that antibody responses after 2 doses are noninferior to those after 3 doses, suggesting that 2 and 3 doses may have comparable vaccine efficacy. We used an individual-based transmission-dynamic model to compare the population-level effectiveness and cost-effectiveness of 2- and 3-dose schedules of 9-valent HPV vaccine in the United States. Our model predicts that if 2 doses of 9-valent vaccine protect for ≥20 years, the additional benefits of a 3-dose schedule are small as compared to those of 2-dose schedules, and 2-dose schedules are likely much more cost-efficient than 3-dose schedules. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  20. Meeting The Joint Commission's Dose Incident Identification and External Benchmarking Requirements Using the ACR's Dose Index Registry.

    PubMed

    Bohl, Michael A; Goswami, Roopa; Strassner, Brett; Stanger, Paula

    2016-08-01

    The purpose of this investigation was to evaluate the potential of using the ACR's Dose Index Registry(®) to meet The Joint Commission's requirements to identify incidents in which the radiation dose index from diagnostic CT examinations exceeded the protocol's expected dose index range. In total, 10,970 records in the Dose Index Registry were statistically analyzed to establish both an upper and lower expected dose index for each protocol. All 2015 studies to date were then retrospectively reviewed to identify examinations whose total examination dose index exceeded the protocol's defined upper threshold. Each dose incident was then logged and reviewed per the new Joint Commission requirements. Facilities may leverage their participation in the ACR's Dose Index Registry to fully meet The Joint Commission's dose incident identification review and external benchmarking requirements. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  1. Estimating peak skin and eye lens dose from neuroperfusion examinations: use of Monte Carlo based simulations and comparisons to CTDIvol, AAPM Report No. 111, and ImPACT dosimetry tool values.

    PubMed

    Zhang, Di; Cagnon, Chris H; Villablanca, J Pablo; McCollough, Cynthia H; Cody, Dianna D; Zankl, Maria; Demarco, John J; McNitt-Gray, Michael F

    2013-09-01

    CT neuroperfusion examinations are capable of delivering high radiation dose to the skin or lens of the eyes of a patient and can possibly cause deterministic radiation injury. The purpose of this study is to: (a) estimate peak skin dose and eye lens dose from CT neuroperfusion examinations based on several voxelized adult patient models of different head size and (b) investigate how well those doses can be approximated by some commonly used CT dose metrics or tools, such as CTDIvol, American Association of Physicists in Medicine (AAPM) Report No. 111 style peak dose measurements, and the ImPACT organ dose calculator spreadsheet. Monte Carlo simulation methods were used to estimate peak skin and eye lens dose on voxelized patient models, including GSF's Irene, Frank, Donna, and Golem, on four scanners from the major manufacturers at the widest collimation under all available tube potentials. Doses were reported on a per 100 mAs basis. CTDIvol measurements for a 16 cm CTDI phantom, AAPM Report No. 111 style peak dose measurements, and ImPACT calculations were performed for available scanners at all tube potentials. These were then compared with results from Monte Carlo simulations. The dose variations across the different voxelized patient models were small. Dependent on the tube potential and scanner and patient model, CTDIvol values overestimated peak skin dose by 26%-65%, and overestimated eye lens dose by 33%-106%, when compared to Monte Carlo simulations. AAPM Report No. 111 style measurements were much closer to peak skin estimates ranging from a 14% underestimate to a 33% overestimate, and with eye lens dose estimates ranging from a 9% underestimate to a 66% overestimate. The ImPACT spreadsheet overestimated eye lens dose by 2%-82% relative to voxelized model simulations. CTDIvol consistently overestimates dose to eye lens and skin. The ImPACT tool also overestimated dose to eye lenses. As such they are still useful as a conservative predictor of dose for CT neuroperfusion studies. AAPM Report No. 111 style measurements are a better predictor of both peak skin and eye lens dose than CTDIvol and ImPACT for the patient models used in this study. It should be remembered that both the AAPM Report No. 111 peak dose metric and CTDIvol dose metric are dose indices and were not intended to represent actual organ doses.

  2. Estimating peak skin and eye lens dose from neuroperfusion examinations: Use of Monte Carlo based simulations and comparisons to CTDIvol, AAPM Report No. 111, and ImPACT dosimetry tool values

    PubMed Central

    Zhang, Di; Cagnon, Chris H.; Villablanca, J. Pablo; McCollough, Cynthia H.; Cody, Dianna D.; Zankl, Maria; Demarco, John J.; McNitt-Gray, Michael F.

    2013-01-01

    Purpose: CT neuroperfusion examinations are capable of delivering high radiation dose to the skin or lens of the eyes of a patient and can possibly cause deterministic radiation injury. The purpose of this study is to: (a) estimate peak skin dose and eye lens dose from CT neuroperfusion examinations based on several voxelized adult patient models of different head size and (b) investigate how well those doses can be approximated by some commonly used CT dose metrics or tools, such as CTDIvol, American Association of Physicists in Medicine (AAPM) Report No. 111 style peak dose measurements, and the ImPACT organ dose calculator spreadsheet. Methods: Monte Carlo simulation methods were used to estimate peak skin and eye lens dose on voxelized patient models, including GSF's Irene, Frank, Donna, and Golem, on four scanners from the major manufacturers at the widest collimation under all available tube potentials. Doses were reported on a per 100 mAs basis. CTDIvol measurements for a 16 cm CTDI phantom, AAPM Report No. 111 style peak dose measurements, and ImPACT calculations were performed for available scanners at all tube potentials. These were then compared with results from Monte Carlo simulations. Results: The dose variations across the different voxelized patient models were small. Dependent on the tube potential and scanner and patient model, CTDIvol values overestimated peak skin dose by 26%–65%, and overestimated eye lens dose by 33%–106%, when compared to Monte Carlo simulations. AAPM Report No. 111 style measurements were much closer to peak skin estimates ranging from a 14% underestimate to a 33% overestimate, and with eye lens dose estimates ranging from a 9% underestimate to a 66% overestimate. The ImPACT spreadsheet overestimated eye lens dose by 2%–82% relative to voxelized model simulations. Conclusions: CTDIvol consistently overestimates dose to eye lens and skin. The ImPACT tool also overestimated dose to eye lenses. As such they are still useful as a conservative predictor of dose for CT neuroperfusion studies. AAPM Report No. 111 style measurements are a better predictor of both peak skin and eye lens dose than CTDIvol and ImPACT for the patient models used in this study. It should be remembered that both the AAPM Report No. 111 peak dose metric and CTDIvol dose metric are dose indices and were not intended to represent actual organ doses. PMID:24007152

  3. Survey of computed tomography scanners in Taiwan: Dose descriptors, dose guidance levels, and effective doses

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tsai, H. Y.; Tung, C. J.; Yu, C. C.

    2007-04-15

    The IAEA and the ICRP recommended dose guidance levels for the most frequent computed tomography (CT) examinations to promote strategies for the optimization of radiation dose to CT patients. A national survey, including on-site measurements and questionnaires, was conducted in Taiwan in order to establish dose guidance levels and evaluate effective doses for CT. The beam quality and output and the phantom doses were measured for nine representative CT scanners. Questionnaire forms were completed by respondents from facilities of 146 CT scanners out of 285 total scanners. Information on patient, procedure, scanner, and technique for the head and body examinationsmore » was provided. The weighted computed tomography dose index (CTDI{sub w}), the dose length product (DLP), organ doses and effective dose were calculated using measured data, questionnaire information and Monte Carlo simulation results. A cost-effective analysis was applied to derive the dose guidance levels on CTDI{sub w} and DLP for several CT examinations. The mean effective dose{+-}standard deviation distributes from 1.6{+-}0.9 mSv for the routine head examination to 13{+-}11 mSv for the examination of liver, spleen, and pancreas. The surveyed results and the dose guidance levels were provided to the national authorities to develop quality control standards and protocols for CT examinations.« less

  4. Radiation Dose Uncertainty and Correction for a Mouse Orthotopic and Xenograft Irradiation Model

    PubMed Central

    Gan, Gregory N.; Altunbas, Cem; Morton, John J.; Eagles, Justin; Backus, Jennifer; Dzingle, Wayne; Raben, David; Jimeno, Antonio

    2016-01-01

    Purpose In animal irradiation models, reported dose can vary significantly from the actual doses delivered. We describe an effective method for in vivo dose verification. Materials and Methods Mice bearing commercially-available cell line or patient-derived tumor cell orthotopic or flank xenografts were irradiated using a 160 kVp, 25 mA X-ray source. Entrance dose was evaluated using optically-stimulated luminescence dosimeters (OSLD) and exit dose was assessed using radiochromic film dosimetry. Results Tumor position within the irradiation field was validated using external fiducial markers. The average entrance dose in orthotopic tumors from 10 OSLDs placed on 2 different animal irradiation days was 514±37 cGy (range: 437–545). Exit dose measurements taken from 7 radiochromic films on two separate days were 341±21 cGy (a 34% attenuation). Flank tumor irradiation doses measured by OSLD were 368±9 cGy compared to exit doses of 330 cGy measured by radiochromic film. Conclusion Variations related to the irradiation model can lead to significant under or over- dosing in vivo which can affect tumor control and/or biologic endpoints that are dose dependent. We recommend that dose measurements be determined empirically based on the mouse model and irradiator used and dose compensation adjustments performed to ensure correct and appropriate doses. PMID:26689828

  5. Calculation of midplane dose for total body irradiation from entrance and exit dose MOSFET measurements.

    PubMed

    Satory, P R

    2012-03-01

    This work is the development of a MOSFET based surface in vivo dosimetry system for total body irradiation patients treated with bilateral extended SSD beams using PMMA missing tissue compensators adjacent to the patient. An empirical formula to calculate midplane dose from MOSFET measured entrance and exit doses has been derived. The dependency of surface dose on the air-gap between the spoiler and the surface was investigated by suspending a spoiler above a water phantom, and taking percentage depth dose measurements (PDD). Exit and entrances doses were measured with MOSFETs in conjunction with midplane doses measured with an ion chamber. The entrance and exit doses were combined using an exponential attenuation formula to give an estimate of midplane dose and were compared to the midplane ion chamber measurement for a range of phantom thicknesses. Having a maximum PDD at the surface simplifies the prediction of midplane dose, which is achieved by ensuring that the air gap between the compensator and the surface is less than 10 cm. The comparison of estimated midplane dose and measured midplane dose showed no dependence on phantom thickness and an average correction factor of 0.88 was found. If the missing tissue compensators are kept within 10 cm of the patient then MOSFET measurements of entrance and exit dose can predict the midplane dose for the patient.

  6. Dose and dose rate effects of whole-body gamma-irradiation: I. Lymphocytes and lymphoid organs

    NASA Technical Reports Server (NTRS)

    Pecaut, M. J.; Nelson, G. A.; Gridley, D. S.

    2001-01-01

    The major goal of part I of this study was to compare varying doses and dose rates of whole-body gamma-radiation on lymphoid cells and organs. C57BL/6 mice (n = 75) were exposed to 0, 0.5, 1.5, and 3.0 Gy gamma-rays (60Co) at 1 cGy/min (low-dose rate, LDR) and 80 cGy/min (high-dose rate, HDR) and euthanized 4 days later. A significant dose-dependent loss of spleen mass was observed with both LDR and HDR irradiation; for the thymus this was true only with HDR. Decreasing leukocyte and lymphocyte numbers occurred with increasing dose in blood and spleen at both dose rates. The numbers (not percentages) of CD3+ T lymphocytes decreased in the blood in a dose-dependent manner at both HDR and LDR. Splenic T cell counts decreased with dose only in HDR groups; percentages increased with dose at both dose rates. Dose-dependent decreases occurred in CD4+ T helper and CD8+ T cytotoxic cell counts at HDR and LDR. In the blood the percentages of CD4+ cells increased with increasing dose at both dose rates, whereas in the spleen the counts decreased only in the HDR groups. The percentages of the CD8+ population remained stable in both blood and spleen. CD19+ B cell counts and percentages in both compartments declined markedly with increasing HDR and LDR radiation. NK1.1+ natural killer cell numbers and proportions remained relatively stable. Overall, these data indicate that the observed changes were highly dependent on the dose, but not dose rate, and that cells in the spleen are more affected by dose rate than those in blood. The results also suggest that the response of lymphocytes in different body compartments may be variable.

  7. Three-Dimensional Radiobiologic Dosimetry: Application of Radiobiologic Modeling to Patient-Specific 3-Dimensional Imaging–Based Internal Dosimetry

    PubMed Central

    Prideaux, Andrew R.; Song, Hong; Hobbs, Robert F.; He, Bin; Frey, Eric C.; Ladenson, Paul W.; Wahl, Richard L.; Sgouros, George

    2010-01-01

    Phantom-based and patient-specific imaging-based dosimetry methodologies have traditionally yielded mean organ-absorbed doses or spatial dose distributions over tumors and normal organs. In this work, radiobiologic modeling is introduced to convert the spatial distribution of absorbed dose into biologically effective dose and equivalent uniform dose parameters. The methodology is illustrated using data from a thyroid cancer patient treated with radioiodine. Methods Three registered SPECT/CT scans were used to generate 3-dimensional images of radionuclide kinetics (clearance rate) and cumulated activity. The cumulated activity image and corresponding CT scan were provided as input into an EGSnrc-based Monte Carlo calculation: The cumulated activity image was used to define the distribution of decays, and an attenuation image derived from CT was used to define the corresponding spatial tissue density and composition distribution. The rate images were used to convert the spatial absorbed dose distribution to a biologically effective dose distribution, which was then used to estimate a single equivalent uniform dose for segmented volumes of interest. Equivalent uniform dose was also calculated from the absorbed dose distribution directly. Results We validate the method using simple models; compare the dose-volume histogram with a previously analyzed clinical case; and give the mean absorbed dose, mean biologically effective dose, and equivalent uniform dose for an illustrative case of a pediatric thyroid cancer patient with diffuse lung metastases. The mean absorbed dose, mean biologically effective dose, and equivalent uniform dose for the tumor were 57.7, 58.5, and 25.0 Gy, respectively. Corresponding values for normal lung tissue were 9.5, 9.8, and 8.3 Gy, respectively. Conclusion The analysis demonstrates the impact of radiobiologic modeling on response prediction. The 57% reduction in the equivalent dose value for the tumor reflects a high level of dose nonuniformity in the tumor and a corresponding reduced likelihood of achieving a tumor response. Such analyses are expected to be useful in treatment planning for radionuclide therapy. PMID:17504874

  8. SU-C-207-02: A Method to Estimate the Average Planar Dose From a C-Arm CBCT Acquisition

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Supanich, MP

    2015-06-15

    Purpose: The planar average dose in a C-arm Cone Beam CT (CBCT) acquisition had been estimated in the past by averaging the four peripheral dose measurements in a CTDI phantom and then using the standard 2/3rds peripheral and 1/3 central CTDIw method (hereafter referred to as Dw). The accuracy of this assumption has not been investigated and the purpose of this work is to test the presumed relationship. Methods: Dose measurements were made in the central plane of two consecutively placed 16cm CTDI phantoms using a 0.6cc ionization chamber at each of the 4 peripheral dose bores and in themore » central dose bore for a C-arm CBCT protocol. The same setup was scanned with a circular cut-out of radiosensitive gafchromic film positioned between the two phantoms to capture the planar dose distribution. Calibration curves for color pixel value after scanning were generated from film strips irradiated at different known dose levels. The planar average dose for red and green pixel values was calculated by summing the dose values in the irradiated circular film cut out. Dw was calculated using the ionization chamber measurements and film dose values at the location of each of the dose bores. Results: The planar average dose using both the red and green pixel color calibration curves were within 10% agreement of the planar average dose estimated using the Dw method of film dose values at the bore locations. Additionally, an average of the planar average doses calculated using the red and green calibration curves differed from the ionization chamber Dw estimate by only 5%. Conclusion: The method of calculating the planar average dose at the central plane of a C-arm CBCT non-360 rotation by calculating Dw from peripheral and central dose bore measurements is a reasonable approach to estimating the planar average dose. Research Grant, Siemens AG.« less

  9. Toward an organ based dose prescription method for the improved accuracy of murine dose in orthovoltage x-ray irradiators.

    PubMed

    Belley, Matthew D; Wang, Chu; Nguyen, Giao; Gunasingha, Rathnayaka; Chao, Nelson J; Chen, Benny J; Dewhirst, Mark W; Yoshizumi, Terry T

    2014-03-01

    Accurate dosimetry is essential when irradiating mice to ensure that functional and molecular endpoints are well understood for the radiation dose delivered. Conventional methods of prescribing dose in mice involve the use of a single dose rate measurement and assume a uniform average dose throughout all organs of the entire mouse. Here, the authors report the individual average organ dose values for the irradiation of a 12, 23, and 33 g mouse on a 320 kVp x-ray irradiator and calculate the resulting error from using conventional dose prescription methods. Organ doses were simulated in the Geant4 application for tomographic emission toolkit using the MOBY mouse whole-body phantom. Dosimetry was performed for three beams utilizing filters A (1.65 mm Al), B (2.0 mm Al), and C (0.1 mm Cu + 2.5 mm Al), respectively. In addition, simulated x-ray spectra were validated with physical half-value layer measurements. Average doses in soft-tissue organs were found to vary by as much as 23%-32% depending on the filter. Compared to filters A and B, filter C provided the hardest beam and had the lowest variation in soft-tissue average organ doses across all mouse sizes, with a difference of 23% for the median mouse size of 23 g. This work suggests a new dose prescription method in small animal dosimetry: it presents a departure from the conventional approach of assigninga single dose value for irradiation of mice to a more comprehensive approach of characterizing individual organ doses to minimize the error and uncertainty. In human radiation therapy, clinical treatment planning establishes the target dose as well as the dose distribution, however, this has generally not been done in small animal research. These results suggest that organ dose errors will be minimized by calibrating the dose rates for all filters, and using different dose rates for different organs.

  10. Toward an organ based dose prescription method for the improved accuracy of murine dose in orthovoltage x-ray irradiators

    PubMed Central

    Belley, Matthew D.; Wang, Chu; Nguyen, Giao; Gunasingha, Rathnayaka; Chao, Nelson J.; Chen, Benny J.; Dewhirst, Mark W.; Yoshizumi, Terry T.

    2014-01-01

    Purpose: Accurate dosimetry is essential when irradiating mice to ensure that functional and molecular endpoints are well understood for the radiation dose delivered. Conventional methods of prescribing dose in mice involve the use of a single dose rate measurement and assume a uniform average dose throughout all organs of the entire mouse. Here, the authors report the individual average organ dose values for the irradiation of a 12, 23, and 33 g mouse on a 320 kVp x-ray irradiator and calculate the resulting error from using conventional dose prescription methods. Methods: Organ doses were simulated in the Geant4 application for tomographic emission toolkit using the MOBY mouse whole-body phantom. Dosimetry was performed for three beams utilizing filters A (1.65 mm Al), B (2.0 mm Al), and C (0.1 mm Cu + 2.5 mm Al), respectively. In addition, simulated x-ray spectra were validated with physical half-value layer measurements. Results: Average doses in soft-tissue organs were found to vary by as much as 23%–32% depending on the filter. Compared to filters A and B, filter C provided the hardest beam and had the lowest variation in soft-tissue average organ doses across all mouse sizes, with a difference of 23% for the median mouse size of 23 g. Conclusions: This work suggests a new dose prescription method in small animal dosimetry: it presents a departure from the conventional approach of assigning a single dose value for irradiation of mice to a more comprehensive approach of characterizing individual organ doses to minimize the error and uncertainty. In human radiation therapy, clinical treatment planning establishes the target dose as well as the dose distribution, however, this has generally not been done in small animal research. These results suggest that organ dose errors will be minimized by calibrating the dose rates for all filters, and using different dose rates for different organs. PMID:24593746

  11. Comparison of two dosing schedules for subcutaneous injections of low-dose anti-CD20 veltuzumab in relapsed immune thrombocytopenia

    PubMed Central

    Liebman, Howard A.; Saleh, Mansoor N.; Bussel, James B.; Negrea, O. George; Horne, Heather; Wegener, William A.; Goldenberg, David M.

    2016-01-01

    We compared two dosing schedules for subcutaneous injections of a low-dose humanized anti-CD20 antibody, veltuzumab, in immune thrombocytopenia. Fifty adults with primary immune thrombocytopenia, in whom one or more lines of standard therapy had failed and who had a platelet count <30×109/L but no major bleeding, initially received escalating 80, 160, or 320 mg doses of subcutaneous veltuzumab administered twice, 2 weeks apart; the last group received once-weekly doses of 320 mg for 4 weeks. In all dose groups, injection reactions were transient and mild to moderate; there were no other safety issues. Forty-seven response-evaluable patients had 23 (49%) objective responses (platelet counts ≥30×109/L and ≥2 × baseline) including 15 (32%) complete responses (platelets ≥100×109/L). Responses (including complete responses) and bleeding reduction occurred in all dose groups and were not dose-dependent. In contrast, response duration increased progressively with total dose, reaching a median of 2.7 years with the four once-weekly 320-mg doses. Among nine responders retreated at relapse, three at higher dose levels responded again, including one patient who was retreated four times. In all dose groups, B-cell depletion occurred after the first dose until recovery starting 12 to 16 weeks after treatment. Veltuzumab serum levels increased with dose group according to total dose administered, but terminal half-life and clearance were comparable. Human anti-veltuzumab antibody titers developed without apparent dose dependence in nine patients, of whom six responded including five who had complete responses. Subcutaneous veltuzumab was convenient, well-tolerated, and active, without causing significant safety concerns. Platelet responses and bleeding reduction occurred in all dose groups, and response durability appeared to improve with higher doses. Clinicaltrials.gov identifier: NCT00547066 PMID:27515248

  12. Estimation of the Dose and Dose Rate Effectiveness Factor

    NASA Technical Reports Server (NTRS)

    Chappell, L.; Cucinotta, F. A.

    2013-01-01

    Current models to estimate radiation risk use the Life Span Study (LSS) cohort that received high doses and high dose rates of radiation. Transferring risks from these high dose rates to the low doses and dose rates received by astronauts in space is a source of uncertainty in our risk calculations. The solid cancer models recommended by BEIR VII [1], UNSCEAR [2], and Preston et al [3] is fitted adequately by a linear dose response model, which implies that low doses and dose rates would be estimated the same as high doses and dose rates. However animal and cell experiments imply there should be curvature in the dose response curve for tumor induction. Furthermore animal experiments that directly compare acute to chronic exposures show lower increases in tumor induction than acute exposures. A dose and dose rate effectiveness factor (DDREF) has been estimated and applied to transfer risks from the high doses and dose rates of the LSS cohort to low doses and dose rates such as from missions in space. The BEIR VII committee [1] combined DDREF estimates using the LSS cohort and animal experiments using Bayesian methods for their recommendation for a DDREF value of 1.5 with uncertainty. We reexamined the animal data considered by BEIR VII and included more animal data and human chromosome aberration data to improve the estimate for DDREF. Several experiments chosen by BEIR VII were deemed inappropriate for application to human risk models of solid cancer risk. Animal tumor experiments performed by Ullrich et al [4], Alpen et al [5], and Grahn et al [6] were analyzed to estimate the DDREF. Human chromosome aberration experiments performed on a sample of astronauts within NASA were also available to estimate the DDREF. The LSS cohort results reported by BEIR VII were combined with the new radiobiology results using Bayesian methods.

  13. SPECT-CT in routine clinical practice: increase in patient radiation dose compared with SPECT alone.

    PubMed

    Sharma, Punit; Sharma, Shekhar; Ballal, Sanjana; Bal, Chandrasekhar; Malhotra, Arun; Kumar, Rakesh

    2012-09-01

    To assess the patient radiation dose during routine clinical single-photon emission computed tomography-computed tomography (SPECT-CT) and measure the increase as compared with SPECT alone. Data pertaining to 357 consecutive patients who had undergone radioisotope imaging along with SPECT-CT of a selected volume were retrospectively evaluated. Dose of the injected radiopharmaceutical (MBq) was noted, and the effective dose (mSv) was calculated as per International Commission on Radiological Protection (ICRP) guidelines. The volume-weighted computed tomography dose index (CTDIvol) and dose length product of the CT were also assessed using standard phantoms. The effective dose (mSv) due to CT was calculated as the product of dose length product and a conversion factor depending on the region of investigation, using ICRP guidelines. The dose due to CT was compared among different investigations. The increase in effective dose was calculated as CT dose expressed as a percentage of radiopharmaceutical dose. The per-patient CT effective dose for different studies varied between 0.06 and 11.9 mSv. The mean CT effective dose was lowest for 99mTc-ethylene cysteine dimer brain SPECT-CT (0.9 ± 0.7) and highest for 99mTc-methylene diphosphonate bone SPECT-CT (4.2 ± 2.8). The increase in radiation dose (SPECT-CT vs. SPECT) varied widely (2.3-666.4% for 99mTc-tracers and 0.02-96.2% for 131I-tracers). However, the effective dose of CT in SPECT-CT was less than the values reported for conventional CT examinations of the same regions. Addition of CT to nuclear medicine imaging in the form of SPECT-CT increases the radiation dose to the patient, with the effective dose due to CT exceeding the effective dose of RP in many instances. Hence, appropriate utilization and optimization of the protocols of SPECT-CT is needed to maximize benefit to patients.

  14. Toward an organ based dose prescription method for the improved accuracy of murine dose in orthovoltage x-ray irradiators

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Belley, Matthew D.; Wang, Chu; Nguyen, Giao

    2014-03-15

    Purpose: Accurate dosimetry is essential when irradiating mice to ensure that functional and molecular endpoints are well understood for the radiation dose delivered. Conventional methods of prescribing dose in mice involve the use of a single dose rate measurement and assume a uniform average dose throughout all organs of the entire mouse. Here, the authors report the individual average organ dose values for the irradiation of a 12, 23, and 33 g mouse on a 320 kVp x-ray irradiator and calculate the resulting error from using conventional dose prescription methods. Methods: Organ doses were simulated in the Geant4 application formore » tomographic emission toolkit using the MOBY mouse whole-body phantom. Dosimetry was performed for three beams utilizing filters A (1.65 mm Al), B (2.0 mm Al), and C (0.1 mm Cu + 2.5 mm Al), respectively. In addition, simulated x-ray spectra were validated with physical half-value layer measurements. Results: Average doses in soft-tissue organs were found to vary by as much as 23%–32% depending on the filter. Compared to filters A and B, filter C provided the hardest beam and had the lowest variation in soft-tissue average organ doses across all mouse sizes, with a difference of 23% for the median mouse size of 23 g. Conclusions: This work suggests a new dose prescription method in small animal dosimetry: it presents a departure from the conventional approach of assigninga single dose value for irradiation of mice to a more comprehensive approach of characterizing individual organ doses to minimize the error and uncertainty. In human radiation therapy, clinical treatment planning establishes the target dose as well as the dose distribution, however, this has generally not been done in small animal research. These results suggest that organ dose errors will be minimized by calibrating the dose rates for all filters, and using different dose rates for different organs.« less

  15. Comparison of dose volume parameters evaluated using three forward planning – optimization techniques in cervical cancer brachytherapy involving two applicators

    PubMed Central

    Basu-Roy, Somapriya; Kar, Sanjay Kumar; Das, Sounik; Lahiri, Annesha

    2017-01-01

    Purpose This study is intended to compare dose-volume parameters evaluated using different forward planning- optimization techniques, involving two applicator systems in intracavitary brachytherapy for cervical cancer. It looks for the best applicator-optimization combination to fulfill recommended dose-volume objectives in different high-dose-rate (HDR) fractionation schedules. Material and methods We used tandem-ring and Fletcher-style tandem-ovoid applicator in same patients in two fractions of brachytherapy. Six plans were generated for each patient utilizing 3 forward optimization techniques for each applicator used: equal dwell weight/times (‘no optimization’), ‘manual dwell weight/times’, and ‘graphical’. Plans were normalized to left point A and dose of 8 Gy was prescribed. Dose volume and dose point parameters were compared. Results Without graphical optimization, maximum width and thickness of volume enclosed by 100% isodose line, dose to 90%, and 100% of clinical target volume (CTV); minimum, maximum, median, and average dose to both rectum and bladder are significantly higher with Fletcher applicator. Even if it is done, dose to both points B, minimum dose to CTV, and treatment time; dose to 2 cc (D2cc) rectum and rectal point etc.; D2cc, minimum, maximum, median, and average dose to sigmoid colon; D2cc of bladder remain significantly higher with this applicator. Dose to bladder point is similar (p > 0.05) between two applicators, after all optimization techniques. Conclusions Fletcher applicator generates higher dose to both CTV and organs at risk (2 cc volumes) after all optimization techniques. Dose restriction to rectum is possible using graphical optimization only during selected HDR fractionation schedules. Bladder always receives dose higher than recommended, and 2 cc sigmoid colon always gets permissible dose. Contrarily, graphical optimization with ring applicators fulfills all dose volume objectives in all HDR fractionations practiced. PMID:29204164

  16. Model-based Iterative Reconstruction: Effect on Patient Radiation Dose and Image Quality in Pediatric Body CT

    PubMed Central

    Dillman, Jonathan R.; Goodsitt, Mitchell M.; Christodoulou, Emmanuel G.; Keshavarzi, Nahid; Strouse, Peter J.

    2014-01-01

    Purpose To retrospectively compare image quality and radiation dose between a reduced-dose computed tomographic (CT) protocol that uses model-based iterative reconstruction (MBIR) and a standard-dose CT protocol that uses 30% adaptive statistical iterative reconstruction (ASIR) with filtered back projection. Materials and Methods Institutional review board approval was obtained. Clinical CT images of the chest, abdomen, and pelvis obtained with a reduced-dose protocol were identified. Images were reconstructed with two algorithms: MBIR and 100% ASIR. All subjects had undergone standard-dose CT within the prior year, and the images were reconstructed with 30% ASIR. Reduced- and standard-dose images were evaluated objectively and subjectively. Reduced-dose images were evaluated for lesion detectability. Spatial resolution was assessed in a phantom. Radiation dose was estimated by using volumetric CT dose index (CTDIvol) and calculated size-specific dose estimates (SSDE). A combination of descriptive statistics, analysis of variance, and t tests was used for statistical analysis. Results In the 25 patients who underwent the reduced-dose protocol, mean decrease in CTDIvol was 46% (range, 19%–65%) and mean decrease in SSDE was 44% (range, 19%–64%). Reduced-dose MBIR images had less noise (P > .004). Spatial resolution was superior for reduced-dose MBIR images. Reduced-dose MBIR images were equivalent to standard-dose images for lungs and soft tissues (P > .05) but were inferior for bones (P = .004). Reduced-dose 100% ASIR images were inferior for soft tissues (P < .002), lungs (P < .001), and bones (P < .001). By using the same reduced-dose acquisition, lesion detectability was better (38% [32 of 84 rated lesions]) or the same (62% [52 of 84 rated lesions]) with MBIR as compared with 100% ASIR. Conclusion CT performed with a reduced-dose protocol and MBIR is feasible in the pediatric population, and it maintains diagnostic quality. © RSNA, 2013 Online supplemental material is available for this article. PMID:24091359

  17. Multicentre evaluation of a novel vaginal dose reporting method in 153 cervical cancer patients.

    PubMed

    Westerveld, Henrike; de Leeuw, Astrid; Kirchheiner, Kathrin; Dankulchai, Pittaya; Oosterveld, Bernard; Oinam, Arun; Hudej, Robert; Swamidas, Jamema; Lindegaard, Jacob; Tanderup, Kari; Pötter, Richard; Kirisits, Christian

    2016-09-01

    Recently, a vaginal dose reporting method for combined EBRT and BT in cervical cancer patients was proposed. The current study was to evaluate vaginal doses with this method in a multicentre setting, wherein different applicators, dose rates and protocols were used. In a subset of patients from the EMBRACE study, vaginal doses were evaluated. Doses at the applicator surface left/right and anterior/posterior and at 5mm depth were measured. In addition, the dose at the Posterior-Inferior Border of Symphysis (PIBS) vaginal dose point and PIBS±2cm, corresponding to the mid and lower vagina, was measured. 153 patients from seven institutions were included. Large dose variations expressed in EQD2 with α/β=3Gy were seen between patients, in particular at the top left and right vaginal wall (median 195 (range 61-947)Gy/178 (61-980)Gy, respectively). At 5mm depth, doses were 98 (55-212)Gy/91 (54-227)Gy left/right, and 71 (51-145)Gy/67 (49-189)Gy anterior/posterior, respectively. The dose at PIBS and PIBS±2cm was 41 (3-81)Gy, 54 (32-109)Gy and 5 (1-51)Gy, respectively. At PIBS+2cm (mid vagina) dose variation was coming from BT. The variation at PIBS-2cm (lower vagina) was mainly dependent on EBRT field border location. This novel method for reporting vaginal doses coming from EBRT and BT through well-defined dose points gives a robust representation of the dose along the vaginal axis. In addition, it allows comparison of vaginal dose between patients from different centres. The doses at the PIBS points represent the doses at the mid and lower parts of the vagina. Large variations in dose throughout the vagina were observed between patients and centres. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Immunogenicity of 2 doses of HPV vaccine in younger adolescents vs 3 doses in young women: a randomized clinical trial.

    PubMed

    Dobson, Simon R M; McNeil, Shelly; Dionne, Marc; Dawar, Meena; Ogilvie, Gina; Krajden, Mel; Sauvageau, Chantal; Scheifele, David W; Kollmann, Tobias R; Halperin, Scott A; Langley, Joanne M; Bettinger, Julie A; Singer, Joel; Money, Deborah; Miller, Dianne; Naus, Monika; Marra, Fawziah; Young, Eric

    2013-05-01

    Global use of human papillomavirus (HPV) vaccines to prevent cervical cancer is impeded by cost. A 2-dose schedule for girls may be possible. To determine whether mean antibody levels to HPV-16 and HPV-18 among girls receiving 2 doses was noninferior to women receiving 3 doses. Randomized, phase 3, postlicensure, multicenter, age-stratified, noninferiority immunogenicity study of 830 Canadian females from August 2007 through February 2011. Follow-up blood samples were provided by 675 participants (81%). Girls (9-13 years) were randomized 1:1 to receive 3 doses of quadrivalent HPV vaccine at 0, 2, and 6 months (n = 261) or 2 doses at 0 and 6 months (n = 259). Young women (16-26 years) received 3 doses at 0, 2, and 6 months (n = 310). Antibody levels were measured at 0, 7, 18, 24, and 36 months. Primary outcome was noninferiority (95% CI, lower bound >0.5) of geometric mean titer (GMT) ratios for HPV-16 and HPV-18 for girls (2 doses) compared with young women (3 doses) 1 month after last dose. Secondary outcomes were noninferiority of GMT ratios of girls receiving 2 vs 3 doses of vaccine; and durability of noninferiority to 36 months. The GMT ratios were noninferior for girls (2 doses) to women (3 doses): 2.07 (95% CI, 1.62-2.65) for HPV-16 and 1.76 (95% CI, 1.41-2.19) for HPV-18. Girls (3 doses) had GMT responses 1 month after last vaccination for HPV-16 of 7736 milli-Merck units per mL (mMU/mL) (95% CI, 6651-8999) and HPV-18 of 1730 mMU/mL (95% CI, 1512-1980). The GMT ratios were noninferior for girls (2 doses) to girls (3 doses): 0.95 (95% CI, 0.73-1.23) for HPV-16 and 0.68 (95% CI, 0.54-0.85) for HPV-18. The GMT ratios for girls (2 doses) to women (3 doses) remained noninferior for all genotypes to 36 months. Antibody responses in girls were noninferior after 2 doses vs 3 doses for all 4 vaccine genotypes at month 7, but not for HPV-18 by month 24 or HPV-6 by month 36. Among girls who received 2 doses of HPV vaccine 6 months apart, responses to HPV-16 and HPV-18 one month after the last dose were noninferior to those among young women who received 3 doses of the vaccine within 6 months. Because of the loss of noninferiority to some genotypes at 24 to 36 months in girls given 2 doses vs 3 doses, more data on the duration of protection are needed before reduced-dose schedules can be recommended. clinicaltrials.gov Identifier: NCT00501137.

  19. 10 CFR 835.702 - Individual monitoring records.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... emergency exposures. (b) Recording of the non-uniform equivalent dose to the skin is not required if the... internal dose (committed effective dose or committed equivalent dose) is not required for any monitoring...: (i) The effective dose from external sources of radiation (equivalent dose to the whole body may be...

  20. 10 CFR 835.702 - Individual monitoring records.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... emergency exposures. (b) Recording of the non-uniform equivalent dose to the skin is not required if the... internal dose (committed effective dose or committed equivalent dose) is not required for any monitoring...: (i) The effective dose from external sources of radiation (equivalent dose to the whole body may be...

  1. 10 CFR 835.702 - Individual monitoring records.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... emergency exposures. (b) Recording of the non-uniform equivalent dose to the skin is not required if the... internal dose (committed effective dose or committed equivalent dose) is not required for any monitoring...: (i) The effective dose from external sources of radiation (equivalent dose to the whole body may be...

  2. 10 CFR 835.702 - Individual monitoring records.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... emergency exposures. (b) Recording of the non-uniform equivalent dose to the skin is not required if the... internal dose (committed effective dose or committed equivalent dose) is not required for any monitoring...: (i) The effective dose from external sources of radiation (equivalent dose to the whole body may be...

  3. 10 CFR 835.702 - Individual monitoring records.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... emergency exposures. (b) Recording of the non-uniform equivalent dose to the skin is not required if the... internal dose (committed effective dose or committed equivalent dose) is not required for any monitoring...: (i) The effective dose from external sources of radiation (equivalent dose to the whole body may be...

  4. Pretransplant Tacrolimus Dose Requirements Predict Early Posttransplant Dose Requirements in Blood Group AB0-Incompatible Kidney Transplant Recipients.

    PubMed

    Shuker, Nauras; de Man, Femke M; de Weerd, Annelies E; van Agteren, Madelon; Weimar, Willem; Betjes, Michiel G H; van Gelder, Teun; Hesselink, Dennis A

    2016-04-01

    The aim of this study was to investigate whether pretransplant tacrolimus (Tac) dose requirements of patients scheduled to undergo living donor kidney transplantation correlate with posttransplantation dose requirements. The predictive value of Tac dose requirements (defined as the ratio of the Tac predose concentration, C0, divided by the total daily Tac dose, D) pretransplantation on this same parameter posttransplantation was assessed retrospectively in a cohort of 57 AB0-incompatible kidney transplant recipients. These patients started immunosuppressive therapy 14 days before transplant surgery. All patients were using a stable dose of glucocorticoids and were at steady-state Tac exposure before transplantation. Tac dose requirements immediately before transplantation (C0/Dbefore) explained 63% of the Tac dose requirements on day 3 after transplantation: r = 0.633 [F (1, 44) = 75.97, P < 0.01]. No other clinical and demographic variables predicted Tac dose requirements early after transplantation. Steady-state Tac dose requirement before transplantation largely predicted posttransplantation Tac dose requirements in AB0-incompatible kidney transplant recipients. The importance of this finding is that the posttransplantation Tac dose can be individualized based on a patient's pretransplantation Tac concentration/dose ratio. Pretransplant Tac phenotyping therefore has the potential to improve transplantation outcomes.

  5. Dose rate effect of pulsed electron beam on micronucleus frequency in human peripheral blood lymphocytes.

    PubMed

    Acharya, Santhosh; Sanjeev, Ganesh; Bhat, Nagesh N; Narayana, Yerol

    2010-03-01

    The micronucleus assay in human peripheral blood lymphocytes is a sensitive indicator of radiation damage and could serve as a biological dosimeter in evaluating suspected overexposure to ionising radiation. Micronucleus (MN) frequency as a measure of chromosomal damage has also extensively been employed to quantify the effects of radiation dose rate on biological systems. Here we studied the effects of 8 MeV pulsed electron beam emitted by Microtron electron accelerator on MN induction at dose rates between 35 Gy min-1 and 352.5 Gy min-1. These dose rates were achieved by varying the pulse repetition rate (PRR). Fricke dosimeter was employed to measure the absorbed dose at different PRR and to ensure uniform dose distribution of the electron beam. To study the dose rate effect, blood samples were irradiated to an absorbed dose of (4.7+/-0.2) Gy at different rates and cytogenetic damage was quantified using the micronucleus assay. The obtained MN frequency showed no dose rate dependence within the studied dose rate range. Our earlier dose effect study using 8 MeV electrons revealed that the response of MN was linear-quadratic. Therefore, in the event of an accident, dose estimation can be made using linear-quadratic dose response parameters, without adding dose rate as a correction factor.

  6. Radiation dose uncertainty and correction for a mouse orthotopic and xenograft irradiation model.

    PubMed

    Gan, Gregory N; Altunbas, Cem; Morton, John J; Eagles, Justin; Backus, Jennifer; Dzingle, Wayne; Raben, David; Jimeno, Antonio

    2016-01-01

    In animal irradiation models, reported dose can vary significantly from the actual doses delivered. We describe an effective method for in vivo dose verification. Mice bearing commercially-available cell line or patient-derived tumor cell orthotopic or flank xenografts were irradiated using a 160 kVp, 25 mA X-ray source. Entrance dose was evaluated using optically-stimulated luminescence dosimeters (OSLD) and exit dose was assessed using radiochromic film dosimetry. Tumor position within the irradiation field was validated using external fiducial markers. The average entrance dose in orthotopic tumors from 10 OSLDs placed on two different animal irradiation days was 514 ± 37 cGy (range: 437-545). Exit dose measurements taken from seven radiochromic films on two separate days were 341 ± 21 cGy (a 34% attenuation). Flank tumor irradiation doses measured by OSLD were 368 ± 9 cGy compared to exit doses of 330 cGy measured by radiochromic film. Variations related to the irradiation model can lead to significant under or overdosing in vivo which can affect tumor control and/or biologic endpoints that are dose-dependent. We recommend that dose measurements be determined empirically based on the mouse model and irradiator used and dose compensation adjustments performed to ensure correct and appropriate doses.

  7. Evaluation of the effect of patient dose from cone beam computed tomography on prostate IMRT using Monte Carlo simulation.

    PubMed

    Chow, James C L; Leung, Michael K K; Islam, Mohammad K; Norrlinger, Bernhard D; Jaffray, David A

    2008-01-01

    The aim of this study is to evaluate the impact of the patient dose due to the kilovoltage cone beam computed tomography (kV-CBCT) in a prostate intensity-modulated radiation therapy (IMRT). The dose distributions for the five prostate IMRTs were calculated using the Pinnacle treatment planning system. To calculate the patient dose from CBCT, phase-space beams of a CBCT head based on the ELEKTA x-ray volume imaging system were generated using the Monte Carlo BEAMnr code for 100, 120, 130, and 140 kVp energies. An in-house graphical user interface called DOSCTP (DOSXYZnrc-based) developed using MATLAB was used to calculate the dose distributions due to a 360 degrees photon arc from the CBCT beam with the same patient CT image sets as used in Pinnacle. The two calculated dose distributions were added together by setting the CBCT doses equal to 1%, 1.5%, 2%, and 2.5% of the prescription dose of the prostate IMRT. The prostate plan and the summed dose distributions were then processed in the CERR platform to determine the dose-volume histograms (DVHs) of the regions of interest. Moreover, dose profiles along the x- and y-axes crossing the isocenter with and without addition of the CBCT dose were determined. It was found that the added doses due to CBCT are most significant at the femur heads. Higher doses were found at the bones for a relatively low energy CBCT beam such as 100 kVp. Apart from the bones, the CBCT dose was observed to be most concentrated on the anterior and posterior side of the patient anatomy. Analysis of the DVHs for the prostate and other critical tissues showed that they vary only slightly with the added CBCT dose at different beam energies. On the other hand, the changes of the DVHs for the femur heads due to the CBCT dose and beam energy were more significant than those of rectal and bladder wall. By analyzing the vertical and horizontal dose profiles crossing the femur heads and isocenter, with and without the CBCT dose equal to 2% of the prescribed dose, it was found that there is about a 5% increase of dose at the femur head. Still, such an increase in the femur head dose is well below the dose limit of the bone in our IMRT plans. Therefore, under these dose fractionation conditions, it is concluded that, though CBCT causes a higher dose deposited at the bones, there may be no significant effect in the DVHs of critical tissues in the prostate IMRT.

  8. Dose escalation in permanent brachytherapy for prostate cancer: dosimetric and biological considerations

    NASA Astrophysics Data System (ADS)

    Li, X. Allen; Wang, Jian Z.; Stewart, Robert D.; Di Biase, Steven J.

    2003-09-01

    No prospective dose escalation study for prostate brachytherapy (PB) with permanent implants has been reported. In this work, we have performed a dosimetric and biological analysis to explore the implications of dose escalation in PB using 125I and 103Pd implants. The concept of equivalent uniform dose (EUD), proposed originally for external-beam radiotherapy (EBRT), is applied to low dose rate brachytherapy. For a given 125I or 103Pd PB, the EUD for tumour that corresponds to a dose distribution delivered by EBRT is calculated based on the linear quadratic model. The EUD calculation is based on the dose volume histogram (DVH) obtained retrospectively from representative actual patient data. Tumour control probabilities (TCPs) are also determined in order to compare the relative effectiveness of different dose levels. The EUD for normal tissue is computed using the Lyman model. A commercial inverse treatment planning algorithm is used to investigate the feasibility of escalating the dose to prostate with acceptable dose increases in the rectum and urethra. The dosimetric calculation is performed for five representative patients with different prostate sizes. A series of PB dose levels are considered for each patient using 125I and 103Pd seeds. It is found that the PB prescribed doses (minimum peripheral dose) that give an equivalent EBRT dose of 64.8, 70.2, 75.6 and 81 Gy with a fraction size of 1.8 Gy are 129, 139, 150 and 161 Gy for 125I and 103, 112, 122 and 132 Gy for 103Pd implants, respectively. Estimates of the EUD and TCP for a series of possible prescribed dose levels (e.g., 145, 160, 170 and 180 Gy for 125I and 125, 135, 145 and 155 for 103Pd implants) are tabulated. The EUD calculation was found to depend strongly on DVHs and radiobiological parameters. The dosimetric calculations suggest that the dose to prostate can be escalated without a substantial increase in both rectal and urethral dose. For example, increasing the PB prescribed dose from 145 to 180 Gy increases EUD for the rectum by only 3%. Our studies indicate that the dose to urethra can be kept within 100-120% of the prescription dose for all the dose levels studied. In conclusion, dose escalation in permanent implant for localized prostate cancer may be advantageous. It is dosimetrically possible to increase dose to prostate without a substantial increase in the dose to the rectum and urethra. Based on the results of our studies, a prospective dose escalation trial for prostate permanent implants has been initiated at our institution.

  9. Direct dose mapping versus energy/mass transfer mapping for 4D dose accumulation: fundamental differences and dosimetric consequences.

    PubMed

    Li, Haisen S; Zhong, Hualiang; Kim, Jinkoo; Glide-Hurst, Carri; Gulam, Misbah; Nurushev, Teamour S; Chetty, Indrin J

    2014-01-06

    The direct dose mapping (DDM) and energy/mass transfer (EMT) mapping are two essential algorithms for accumulating the dose from different anatomic phases to the reference phase when there is organ motion or tumor/tissue deformation during the delivery of radiation therapy. DDM is based on interpolation of the dose values from one dose grid to another and thus lacks rigor in defining the dose when there are multiple dose values mapped to one dose voxel in the reference phase due to tissue/tumor deformation. On the other hand, EMT counts the total energy and mass transferred to each voxel in the reference phase and calculates the dose by dividing the energy by mass. Therefore it is based on fundamentally sound physics principles. In this study, we implemented the two algorithms and integrated them within the Eclipse treatment planning system. We then compared the clinical dosimetric difference between the two algorithms for ten lung cancer patients receiving stereotactic radiosurgery treatment, by accumulating the delivered dose to the end-of-exhale (EE) phase. Specifically, the respiratory period was divided into ten phases and the dose to each phase was calculated and mapped to the EE phase and then accumulated. The displacement vector field generated by Demons-based registration of the source and reference images was used to transfer the dose and energy. The DDM and EMT algorithms produced noticeably different cumulative dose in the regions with sharp mass density variations and/or high dose gradients. For the planning target volume (PTV) and internal target volume (ITV) minimum dose, the difference was up to 11% and 4% respectively. This suggests that DDM might not be adequate for obtaining an accurate dose distribution of the cumulative plan, instead, EMT should be considered.

  10. Evaluation of an iterative model-based CT reconstruction algorithm by intra-patient comparison of standard and ultra-low-dose examinations.

    PubMed

    Noël, Peter B; Engels, Stephan; Köhler, Thomas; Muenzel, Daniela; Franz, Daniela; Rasper, Michael; Rummeny, Ernst J; Dobritz, Martin; Fingerle, Alexander A

    2018-01-01

    Background The explosive growth of computer tomography (CT) has led to a growing public health concern about patient and population radiation dose. A recently introduced technique for dose reduction, which can be combined with tube-current modulation, over-beam reduction, and organ-specific dose reduction, is iterative reconstruction (IR). Purpose To evaluate the quality, at different radiation dose levels, of three reconstruction algorithms for diagnostics of patients with proven liver metastases under tumor follow-up. Material and Methods A total of 40 thorax-abdomen-pelvis CT examinations acquired from 20 patients in a tumor follow-up were included. All patients were imaged using the standard-dose and a specific low-dose CT protocol. Reconstructed slices were generated by using three different reconstruction algorithms: a classical filtered back projection (FBP); a first-generation iterative noise-reduction algorithm (iDose4); and a next generation model-based IR algorithm (IMR). Results The overall detection of liver lesions tended to be higher with the IMR algorithm than with FBP or iDose4. The IMR dataset at standard dose yielded the highest overall detectability, while the low-dose FBP dataset showed the lowest detectability. For the low-dose protocols, a significantly improved detectability of the liver lesion can be reported compared to FBP or iDose 4 ( P = 0.01). The radiation dose decreased by an approximate factor of 5 between the standard-dose and the low-dose protocol. Conclusion The latest generation of IR algorithms significantly improved the diagnostic image quality and provided virtually noise-free images for ultra-low-dose CT imaging.

  11. Immunogenicity to poliovirus type 2 following two doses of fractional intradermal inactivated poliovirus vaccine: A novel dose sparing immunization schedule.

    PubMed

    Anand, Abhijeet; Molodecky, Natalie A; Pallansch, Mark A; Sutter, Roland W

    2017-05-19

    The polio eradication endgame strategic plan calls for the sequential removal of Sabin poliovirus serotypes from the trivalent oral poliovirus vaccine (tOPV), starting with type 2, and the introduction of ≥1 dose of inactivated poliovirus vaccine (IPV), to maintain an immunity base against poliovirus type 2. The global removal of oral poliovirus type 2 was successfully implemented in May 2016. However, IPV supply constraints has prevented introduction in 21 countries and led to complete stock-out in >20 countries. We conducted a literature review and contacted corresponding authors of recent studies with fractional-dose IPV (fIPV), one-fifth of intramuscular dose administered intradermally, to conduct additional type 2 immunogenicity analyses of two fIPV doses compared with one full-dose IPV. Four studies were identified that assessed immunogenicity of two fIPV doses compared to one full-dose IPV. Two fractional doses are more immunogenic than 1 full-dose, with type 2 seroconversion rates improving between absolute 19-42% (median: 37%, p<0.001) and relative increase of 53-125% (median: 82%), and antibody titer to type 2 increasing by 2-32-fold (median: 10-fold). Early age of administration and shorter intervals between doses were associated with lower immunogenicity. Overall, two fIPV doses are more immunogenic than a single full-dose, associated with significantly increased seroconversion rates and antibody titers. Two fIPV doses together use two-fifth of the vaccine compared to one full-dose IPV. In response to the current IPV shortage, a schedule of two fIPV doses at ages 6 and 14weekshas been endorsed by technical oversight committees and has been introduced in some affected countries. Copyright © 2017. Published by Elsevier Ltd.

  12. Dose-distance metric that predicts late rectal bleeding in patients receiving radical prostate external-beam radiotherapy

    NASA Astrophysics Data System (ADS)

    Lee, Richard; Chan, Elisa K.; Kosztyla, Robert; Liu, Mitchell; Moiseenko, Vitali

    2012-12-01

    The relationship between rectal dose distribution and the incidence of late rectal complications following external-beam radiotherapy has been previously studied using dose-volume histograms or dose-surface histograms. However, they do not account for the spatial dose distribution. This study proposes a metric based on both surface dose and distance that can predict the incidence of rectal bleeding in prostate cancer patients treated with radical radiotherapy. One hundred and forty-four patients treated with radical radiotherapy for prostate cancer were prospectively followed to record the incidence of grade ≥2 rectal bleeding. Radiotherapy plans were used to evaluate a dose-distance metric that accounts for the dose and its spatial distribution on the rectal surface, characterized by a logistic weighting function with slope a and inflection point d0. This was compared to the effective dose obtained from dose-surface histograms, characterized by the parameter n which describes sensitivity to hot spots. The log-rank test was used to determine statistically significant (p < 0.05) cut-off values for the dose-distance metric and effective dose that predict for the occurrence of rectal bleeding. For the dose-distance metric, only d0 = 25 and 30 mm combined with a > 5 led to statistical significant cut-offs. For the effective dose metric, only values of n in the range 0.07-0.35 led to statistically significant cut-offs. The proposed dose-distance metric is a predictor of rectal bleeding in prostate cancer patients treated with radiotherapy. Both the dose-distance metric and the effective dose metric indicate that the incidence of grade ≥2 rectal bleeding is sensitive to localized damage to the rectal surface.

  13. Direct dose mapping versus energy/mass transfer mapping for 4D dose accumulation: fundamental differences and dosimetric consequences

    NASA Astrophysics Data System (ADS)

    Li, Haisen S.; Zhong, Hualiang; Kim, Jinkoo; Glide-Hurst, Carri; Gulam, Misbah; Nurushev, Teamour S.; Chetty, Indrin J.

    2014-01-01

    The direct dose mapping (DDM) and energy/mass transfer (EMT) mapping are two essential algorithms for accumulating the dose from different anatomic phases to the reference phase when there is organ motion or tumor/tissue deformation during the delivery of radiation therapy. DDM is based on interpolation of the dose values from one dose grid to another and thus lacks rigor in defining the dose when there are multiple dose values mapped to one dose voxel in the reference phase due to tissue/tumor deformation. On the other hand, EMT counts the total energy and mass transferred to each voxel in the reference phase and calculates the dose by dividing the energy by mass. Therefore it is based on fundamentally sound physics principles. In this study, we implemented the two algorithms and integrated them within the Eclipse treatment planning system. We then compared the clinical dosimetric difference between the two algorithms for ten lung cancer patients receiving stereotactic radiosurgery treatment, by accumulating the delivered dose to the end-of-exhale (EE) phase. Specifically, the respiratory period was divided into ten phases and the dose to each phase was calculated and mapped to the EE phase and then accumulated. The displacement vector field generated by Demons-based registration of the source and reference images was used to transfer the dose and energy. The DDM and EMT algorithms produced noticeably different cumulative dose in the regions with sharp mass density variations and/or high dose gradients. For the planning target volume (PTV) and internal target volume (ITV) minimum dose, the difference was up to 11% and 4% respectively. This suggests that DDM might not be adequate for obtaining an accurate dose distribution of the cumulative plan, instead, EMT should be considered.

  14. Dosimetric and Clinical Analysis of Spatial Distribution of the Radiation Dose in Gamma Knife Radiosurgery for Vestibular Schwannoma

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Massager, Nicolas, E-mail: nmassage@ulb.ac.be; Neurosurgery-Department, Hospital Erasme, Brussels; Lonneville, Sarah

    2011-11-15

    Objectives: We investigated variations in the distribution of radiation dose inside (dose inhomogeneity) and outside (dose falloff) the target volume during Gamma Knife (GK) irradiation of vestibular schwannoma (VS). We analyzed the relationship between some parameters of dose distribution and the clinical and radiological outcome of patients. Methods and Materials: Data from dose plans of 203 patients treated for a vestibular schwannoma by GK C using same prescription dose (12 Gy at the 50% isodose) were collected. Four different dosimetric indexes were defined and calculated retrospectively in all plannings on the basis of dose-volume histograms: Paddick conformity index (PI), gradientmore » index (GI), homogeneity index (HI), and unit isocenter (UI). The different measures related to distribution of the radiation dose were compared with hearing and tumor outcome of 203 patients with clinical and radiological follow-up of minimum 2 years. Results: Mean, median, SD, and ranges of the four indexes of dose distribution analyzed were calculated; large variations were found between dose plans. We found a high correlation between the target volume and PI, GI, and UI. No significant association was found between the indexes of dose distribution calculated in this study and tumor control, tumor volume shrinkage, hearing worsening, loss of functional hearing, or complete hearing loss at last follow-up. Conclusions: Parameters of distribution of the radiation dose during GK radiosurgery for VS can be highly variable between dose plans. The tumor and hearing outcome of patients treated is not significantly related to these global indexes of dose distribution inside and around target volume. In GK radiosurgery for VS, the outcome seems more to be influenced by local radiation dose delivered to specific structures or volumes than by global dose gradients.« less

  15. Botulinum Toxin Dosing Trends in Spasmodic Dysphonia Over a 20-year Period.

    PubMed

    Namin, Arya W; Christopher, Kara M; Eisenbeis, John F

    2017-01-01

    The study aims to (1) identify the botulinum toxin (BTX) dosing trend in a cohort of patients who received at least 20 injections for the treatment of adductor spasmodic dysphonia (ADSD), (2) describe two distinct BTX dosing trends in treating ADSD (a "classic" dosing trend that initially decreases before stabilizing, and a "fluctuating" dosing trend), and (3) determine if patients with the "classic" dosing trend differed in age or in dosing intervals from those with the "fluctuating" dosing trend. This is a retrospective case series. Of 149 patients who received a total of 2484 BTX injections for the treatment of spasmodic dysphonia in 1993-2013, 49 patients received at least 20 injections. The BTX dose and the interval between doses were recorded. The mean dose of injections 1-20 was determined. The age at initial injection, initial dose, and interval in days between treatments were compared for the "fluctuating" and "classic" groups. The cohort exhibits a significant decrease in dose during the first 10-15 injections. The "fluctuating" group had a significantly shorter interval between injections (mean interval = 97.09 days, SD = 29.41; mean interval = 136.90 days, SD = 43.76, P = 0.002). The mean age at initial dose was not significantly different between the "classic" and "fluctuating" groups. The average BTX dose of patients with ADSD who receive long-term injections significantly decreases during the initial 10-15 injections before stabilizing. Patients who exhibit the "fluctuating" dosing pattern have a significantly shorter interval between injections than those with the "classic" dosing pattern. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  16. The accuracy of the out-of-field dose calculations using a model based algorithm in a commercial treatment planning system

    NASA Astrophysics Data System (ADS)

    Wang, Lilie; Ding, George X.

    2014-07-01

    The out-of-field dose can be clinically important as it relates to the dose of the organ-at-risk, although the accuracy of its calculation in commercial radiotherapy treatment planning systems (TPSs) receives less attention. This study evaluates the uncertainties of out-of-field dose calculated with a model based dose calculation algorithm, anisotropic analytical algorithm (AAA), implemented in a commercial radiotherapy TPS, Varian Eclipse V10, by using Monte Carlo (MC) simulations, in which the entire accelerator head is modeled including the multi-leaf collimators. The MC calculated out-of-field doses were validated by experimental measurements. The dose calculations were performed in a water phantom as well as CT based patient geometries and both static and highly modulated intensity-modulated radiation therapy (IMRT) fields were evaluated. We compared the calculated out-of-field doses, defined as lower than 5% of the prescription dose, in four H&N cancer patients and two lung cancer patients treated with volumetric modulated arc therapy (VMAT) and IMRT techniques. The results show that the discrepancy of calculated out-of-field dose profiles between AAA and the MC depends on the depth and is generally less than 1% for in water phantom comparisons and in CT based patient dose calculations for static field and IMRT. In cases of VMAT plans, the difference between AAA and MC is <0.5%. The clinical impact resulting from the error on the calculated organ doses were analyzed by using dose-volume histograms. Although the AAA algorithm significantly underestimated the out-of-field doses, the clinical impact on the calculated organ doses in out-of-field regions may not be significant in practice due to very low out-of-field doses relative to the target dose.

  17. Measurement and comparison of skin dose using OneDose MOSFET and Mobile MOSFET for patients with acute lymphoblastic leukemia

    PubMed Central

    Mattar, Essam H.; Hammad, Lina F.; Al-Mohammed, Huda I.

    2011-01-01

    Summary Background Total body irradiation is a protocol used to treat acute lymphoblastic leukemia in patients prior to bone marrow transplant. It is involved in the treatment of the whole body using a large radiation field with extended source-skin distance. Therefore measuring and monitoring the skin dose during the treatment is important. Two kinds of metal oxide semiconductor field effect transistor (OneDose MOSFET and mobile MOSEFT) dosimeter are used during the treatment delivery to measure the skin dose to specific points and compare it with the target prescribed dose. The objective of this study was to compare the variation of skin dose in patients with acute lymphatic leukemia (ALL) treated with total body irradiation (TBI) using OneDose MOSFET detectors and Mobile MOSFET, and then compare both results with the target prescribed dose. Material/Methods The measurements involved 32 patient’s (16 males, 16 females), aged between 14–30 years, with an average age of 22.41 years. One-Dose MOSFET and Mobile MOSFET dosimetry were performed at 10 different anatomical sites on every patient. Results The results showed there was no variation between skin dose measured with OneDose MOSFET and Mobile MOSFET in all patients. Furthermore, the results showed for every anatomical site selected there was no significant difference in the dose delivered using either OneDose MOSFET detector or Mobile MOSFET as compared to the prescribed dose. Conclusions The study concludes that One-Dose MOSFET detectors and Mobile MOSFET both give a direct read-out immediately after the treatment; therefore both detectors are suitable options when measuring skin dose for total body irradiation treatment. PMID:21709641

  18. Measurement and comparison of skin dose using OneDose MOSFET and Mobile MOSFET for patients with acute lymphoblastic leukemia.

    PubMed

    Mattar, Essam H; Hammad, Lina F; Al-Mohammed, Huda I

    2011-07-01

    Total body irradiation is a protocol used to treat acute lymphoblastic leukemia in patients prior to bone marrow transplant. It is involved in the treatment of the whole body using a large radiation field with extended source-skin distance. Therefore measuring and monitoring the skin dose during the treatment is important. Two kinds of metal oxide semiconductor field effect transistor (OneDose MOSFET and mobile MOSEFT) dosimeter are used during the treatment delivery to measure the skin dose to specific points and compare it with the target prescribed dose. The objective of this study was to compare the variation of skin dose in patients with acute lymphatic leukemia (ALL) treated with total body irradiation (TBI) using OneDose MOSFET detectors and Mobile MOSFET, and then compare both results with the target prescribed dose. The measurements involved 32 patient's (16 males, 16 females), aged between 14-30 years, with an average age of 22.41 years. One-Dose MOSFET and Mobile MOSFET dosimetry were performed at 10 different anatomical sites on every patient. The results showed there was no variation between skin dose measured with OneDose MOSFET and Mobile MOSFET in all patients. Furthermore, the results showed for every anatomical site selected there was no significant difference in the dose delivered using either OneDose MOSFET detector or Mobile MOSFET as compared to the prescribed dose. The study concludes that One-Dose MOSFET detectors and Mobile MOSFET both give a direct read-out immediately after the treatment; therefore both detectors are suitable options when measuring skin dose for total body irradiation treatment.

  19. Correlation between measles vaccine doses: implications for the maintenance of elimination.

    PubMed

    McKee, A; Ferrari, M J; Shea, K

    2018-03-01

    Measles eradication efforts have been successful at achieving elimination in many countries worldwide. Such countries actively work to maintain this elimination by continuing to improve coverage of two routine doses of measles vaccine following measles elimination. While improving measles vaccine coverage is always beneficial, we show, using a steady-state analysis of a dynamical model, that the correlation between populations receiving the first and second routine dose also has a significant impact on the population immunity achieved by a specified combination of first and second dose coverage. If the second dose is administered to people independently of whether they had the first dose, high second-dose coverage improves the proportion of the population receiving at least one dose, and will have a large effect on population immunity. If the second dose is administered only to people who have had the first dose, high second-dose coverage reduces the rate of primary vaccine failure, but does not reach people who missed the first dose; this will therefore have a relatively small effect on population immunity. When doses are administered dependently, and assuming the first dose has higher coverage, increasing the coverage of the first dose has a larger impact on population immunity than does increasing the coverage of the second. Correlation between vaccine doses has a significant impact on the level of population immunity maintained by current vaccination coverage, potentially outweighing the effects of age structure and, in some cases, recent improvements in vaccine coverage. It is therefore important to understand the correlation between vaccine doses as such correlation may have a large impact on the effectiveness of measles vaccination strategies.

  20. Impact of Number of Human Papillomavirus Vaccine Doses on Genital Warts Diagnoses Among a National Cohort of U.S. Adolescents.

    PubMed

    Perkins, Rebecca B; Lin, Mengyun; Wallington, Sherrie F; Hanchate, Amresh

    2017-06-01

    The impact of fewer than 3 doses of human papillomavirus (HPV) vaccine on genital warts is uncertain. Using the Truven Health Analytics Marketscan administrative database, we compared rates of genital warts among women receiving 0, 1, 2, or 3 doses of HPV vaccine. Females aged 9 to 18 years on January 1, 2007, who were continuously enrolled in the database through December 31, 2013, were included. Patients were assigned an HPV dose state (0, 1, 2, or 3) based on the last recorded dose. The exposure period began on January 1, 2007, or the date of the final HPV dose, and lasted until the first diagnosis of genital warts or December 31, 2013. Multivariable Poisson regression was performed to determine the risk of genital warts associated with vaccine doses. Among 387,906 subjects, mean age and exposure period were 14.73 and 5.64 years, respectively. The proportions of doses received were: 52.1%, 7.8%, 9.4%, and 30.7% for 0, 1, 2, and 3 doses, respectively. The rate of genital warts was 1.97/1000 person-years. Receipt of 0 or 1 dose was associated with more genital warts than 3 doses. The effectiveness of 2 doses following current Centers for Disease Control and Prevention guidelines was similar to 3 doses. The risk of genital warts rose with age. Prevention of genital warts is higher with completion of 3 vaccine doses than with 1 dose, though 2-dose recommendations appear to provide similar protection. Prospective effectiveness studies of recommended 2-dose schedules against clinical endpoints including persistent infection, genital warts, and cervical dysplasia are necessary to ensure long-term protection of vaccinated cohorts.

  1. Occupational dose constraints in interventional cardiology procedures: the DIMOND approach

    NASA Astrophysics Data System (ADS)

    Tsapaki, Virginia; Kottou, Sophia; Vano, Eliseo; Komppa, Tuomo; Padovani, Renato; Dowling, Annita; Molfetas, Michael; Neofotistou, Vassiliki

    2004-03-01

    Radiation fields involved in angiographic suites are most uneven with intensity and gradient varying widely with projection geometry. The European Commission DIMOND III project addressed among others, the issues regarding optimization of staff doses with an attempt to propose preliminary occupational dose constraints. Two thermoluminescent dosemeters (TLD) were used to assess operators' extremity doses (left shoulder and left foot) during 20 coronary angiographies (CAs) and 20 percutaneous transluminal coronary angioplasties (PTCAs) in five European centres. X-ray equipment, radiation protection measures used and the dose delivered to the patient in terms of dose-area product (DAP) were recorded so as to subsequently associate them with operator's dose. The range of staff doses noted for the same TLD position, centre and procedure type emphasizes the importance of protective measures and technical characteristics of x-ray equipment. Correlation of patient's DAP with staff shoulder dose is moderate whereas correlation of patient's DAP with staff foot dose is poor in both CA and PTCA. Therefore, it is difficult to predict operator's dose from patient's DAP mainly due to the different use of protective measures. A preliminary occupational dose constraint value was defined by calculating cardiologists' annual effective dose and found to be 0.6 mSv.

  2. Field-size dependence of doses of therapeutic carbon beams.

    PubMed

    Kusano, Yohsuke; Kanai, Tatsuaki; Yonai, Shunsuke; Komori, Masataka; Ikeda, Noritoshi; Tachikawa, Yuji; Ito, Atsushi; Uchida, Hirohisa

    2007-10-01

    To estimate the physical dose at the center of spread-out Bragg peaks (SOBP) for various conditions of the irradiation system, a semiempirical approach was applied. The dose at the center of the SOBP depends on the field size because of large-angle scattering particles in the water phantom. For a small field of 5 x 5 cm2, the dose was reduced to 99.2%, 97.5%, and 96.5% of the dose used for the open field in the case of 290, 350, and 400 MeV/n carbon beams, respectively. Based on the three-Gaussian form of the lateral dose distributions of the carbon pencil beam, which has previously been shown to be effective for describing scattered carbon beams, we reconstructed the dose distributions of the SOBP beam. The reconstructed lateral dose distribution reproduced the measured lateral dose distributions very well. The field-size dependencies calculated using the reconstructed lateral dose distribution of the therapeutic carbon beam agreed with the measured dose dependency very well. The reconstructed beam was also used for irregularly shaped fields. The resultant dose distribution agreed with the measured dose distribution. The reconstructed beams were found to be applicable to the treatment-planning system.

  3. Evaluation of a new very low dose imaging protocol: feasibility and impact on X-ray dose levels in electrophysiology procedures

    PubMed Central

    Bourier, Felix; Reents, Tilko; Ammar-Busch, Sonia; Buiatti, Alessandra; Kottmaier, Marc; Semmler, Verena; Telishevska, Marta; Brkic, Amir; Grebmer, Christian; Lennerz, Carsten; Kolb, Christof; Hessling, Gabriele; Deisenhofer, Isabel

    2016-01-01

    Aims This study presents and evaluates the impact of a new lowest-dose fluoroscopy protocol (Siemens AG), especially designed for electrophysiology (EP) procedures, on X-ray dose levels. Methods and results From October 2014 to March 2015, 140 patients underwent an EP study on an Artis zee angiography system. The standard low-dose protocol was operated at 23 nGy (fluoroscopy) and at 120 nGy (cine-loop), the new lowest-dose protocol was operated at 8 nGy (fluoroscopy) and at 36 nGy (cine-loop). Procedural data, X-ray times, and doses were analysed in 100 complex left atrial and in 40 standard EP procedures. The resulting dose–area products were 877.9 ± 624.7 µGym² (n = 50 complex procedures, standard low dose), 199 ± 159.6 µGym² (n = 50 complex procedures, lowest dose), 387.7 ± 36.0 µGym² (n = 20 standard procedures, standard low dose), and 90.7 ± 62.3 µGym² (n = 20 standard procedures, lowest dose), P < 0.01. In the low-dose and lowest-dose groups, procedure times were 132.6 ± 35.7 vs. 126.7 ± 34.7 min (P = 0.40, complex procedures) and 72.3 ± 20.9 vs. 85.2 ± 44.1 min (P = 0.24, standard procedures), radiofrequency (RF) times were 53.8 ± 26.1 vs. 50.4 ± 29.4 min (P = 0.54, complex procedures) and 10.1 ± 9.9 vs. 12.2 ± 14.7 min (P = 0.60, standard procedures). One complication occurred in the standard low-dose and lowest-dose groups (P = 1.0). Conclusion The new lowest-dose imaging protocol reduces X-ray dose levels by 77% compared with the currently available standard low-dose protocol. From an operator standpoint, lowest X-ray dose levels create a different, reduced image quality. The new image quality did not significantly affect procedure or RF times and did not result in higher complication rates. Regarding radiological protection, operating at lowest-dose settings should become standard in EP procedures. PMID:26589627

  4. Timing of two versus three doses of quadrivalent HPV vaccine and associated effectiveness against condyloma in Sweden: a nationwide cohort study

    PubMed Central

    F, Lamb; E, Herweijer; A, Ploner; I, Uhnoo; K, Sundström; P, Sparén; L, Arnheim-Dahlström

    2017-01-01

    Objective To assess incidence of condyloma after two doses of quadrivalent human papillomavirus (qHPV) vaccine, by time since first vaccine dose, in girls and women initiating vaccination before age 20 years. Design Register-based nationwide open cohort study. Setting Sweden. Participants Girls and women initiating qHPV vaccination before age 20 years between 2006 and 2012. The study cohort included 264 498 girls, of whom 72 042 had received two doses of qHPV vaccine and 185 456 had received all three doses. Main outcome measure Incidence rate ratios (IRRs) of condyloma estimated by time between first and second doses of qHPV in months (m) and age at vaccination, adjusted for attained age. Results For girls first vaccinated with two doses before the age of 17 years, the IRR of condyloma for 0–3 months between the first and second doses was 1.96 (95% CI 1.43 to 2.68) as compared with the standard three-dose schedule. The IRRs were 1.27 (95% CI 0.63 to 2.58) and 4.36 (95% CI 2.05 to 9.28) after receipt of two doses with 4–7 months and 8+ months between doses, respectively. For women first vaccinated after the age of 17 years, vaccination with two doses of qHPV vaccine and 0–3 months between doses was associated with an IRR of 2.12 (95% CI 1.62 to 2.77). For an interval of 4–7 months between doses, the IRR did not statistically significantly differ to the standard three-dose schedule (IRR=0.81, 95% CI 0.36 to 1.84). For women with 8+ months between dose 1 and dose 2 the IRR was 3.16 (95% CI 1.40 to 7.14). Conclusion A two-dose schedule for qHPV vaccine with 4–7 months between the first and second doses may be as effective against condyloma in girls and women initiating vaccination under 20 years as a three-dose schedule. Results from this nationwide study support immunogenicity data from clinical trials. PMID:28600369

  5. Pulmonary nodules: effect of adaptive statistical iterative reconstruction (ASIR) technique on performance of a computer-aided detection (CAD) system-comparison of performance between different-dose CT scans.

    PubMed

    Yanagawa, Masahiro; Honda, Osamu; Kikuyama, Ayano; Gyobu, Tomoko; Sumikawa, Hiromitsu; Koyama, Mitsuhiro; Tomiyama, Noriyuki

    2012-10-01

    To evaluate the effects of ASIR on CAD system of pulmonary nodules using clinical routine-dose CT and lower-dose CT. Thirty-five patients (body mass index, 22.17 ± 4.37 kg/m(2)) were scanned by multidetector-row CT with tube currents (clinical routine-dose CT, automatically adjusted mA; lower-dose CT, 10 mA) and X-ray voltage (120 kVp). Each 0.625-mm-thick image was reconstructed at 0%-, 50%-, and 100%-ASIR: 0%-ASIR is reconstructed using only the filtered back-projection algorithm (FBP), while 100%-ASIR is reconstructed using the maximum ASIR and 50%-ASIR implies a blending of 50% FBP and ASIR. CAD output was compared retrospectively with the results of the reference standard which was established using a consensus panel of three radiologists. Data were analyzed using Bonferroni/Dunn's method. Radiation dose was calculated by multiplying dose-length product by conversion coefficient of 0.021. The consensus panel found 265 non-calcified nodules ≤ 30 mm (ground-glass opacity [GGO], 103; part-solid, 34; and solid, 128). CAD sensitivity was significantly higher at 100%-ASIR [clinical routine-dose CT, 71% (overall), 49% (GGO); lower-dose CT, 52% (overall), 67% (solid)] than at 0%-ASIR [clinical routine-dose CT, 54% (overall), 25% (GGO); lower-dose CT, 36% (overall), 50% (solid)] (p<0.001). Mean number of false-positive findings per examination was significantly higher at 100%-ASIR (clinical routine-dose CT, 8.5; lower-dose CT, 6.2) than at 0%-ASIR (clinical routine-dose CT, 4.6; lower-dose CT, 3.5; p<0.001). Effective doses were 10.77 ± 3.41 mSv in clinical routine-dose CT and 2.67 ± 0.17 mSv in lower-dose CT. CAD sensitivity at 100%-ASIR on lower-dose CT is almost equal to that at 0%-ASIR on clinical routine-dose CT. ASIR can increase CAD sensitivity despite increased false-positive findings. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  6. HADOC: a computer code for calculation of external and inhalation doses from acute radionuclide releases

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Strenge, D.L.; Peloquin, R.A.

    The computer code HADOC (Hanford Acute Dose Calculations) is described and instructions for its use are presented. The code calculates external dose from air submersion and inhalation doses following acute radionuclide releases. Atmospheric dispersion is calculated using the Hanford model with options to determine maximum conditions. Building wake effects and terrain variation may also be considered. Doses are calculated using dose conversion factor supplied in a data library. Doses are reported for one and fifty year dose commitment periods for the maximum individual and the regional population (within 50 miles). The fractional contribution to dose by radionuclide and exposure modemore » are also printed if requested.« less

  7. Antipsychotic treatment dosing profile in patients with schizophrenia evaluated with electronic monitoring (MEMS®).

    PubMed

    Acosta, Francisco J; Ramallo-Fariña, Yolanda; Bosch, Esperanza; Mayans, Teresa; Rodríguez, Carlos J; Caravaca, Ana

    2013-05-01

    Although the Medication Event Monitoring System (MEMS®) device offers accurate information on treatment dosing profile, such profile has never been studied in patients with schizophrenia. Enhancing our knowledge on this issue would help in developing intervention strategies to improve adherence to antipsychotic treatment in these patients. 74 outpatients with schizophrenia were monitored with the MEMS device for a 3-month period, for evaluation of antipsychotic treatment dosing profile, possible influence of medication schedule-related variables, adherence to treatment--considering dose intake within prescribed timeframes--and possible Hawthorne's effect of using the MEMS device. Dose-omission gaps occurred in 18.7% of monitoring days, most frequently during weekends, almost significantly. Almost one-third of prescribed doses were taken out of prescribed time. Neither the prescribed number of daily doses nor the indicated time of the day for dose intake (breakfast, dinner), were associated with correct antipsychotic dosing. Excess-dose was rare in general, and more frequent out of prescribed dose timeframe. No Hawthorne's effect was found for the MEMS device. Adherence reached only 35% according to a definition that included dose intake within prescribed timeframes. Antipsychotic treatment dosing was considerably irregular among patients with schizophrenia. Strategies to reduce dose-omission gaps and increase dosing within prescribed timeframes seem to be necessary. Gaining knowledge on precise oral antipsychotic dosing profiles or the influence of schedule-related variables may be useful to design strategies towards enhancing adherence. There appears to be no Hawthorne's effect associated with the use of MEMS devices in outpatients with schizophrenia. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Are two doses of human papillomavirus vaccine sufficient for girls aged 15-18 years? Results from a cohort study in India.

    PubMed

    Bhatla, Neerja; Nene, Bhagwan M; Joshi, Smita; Esmy, Pulikottil O; Poli, Usha Rani Reddy; Joshi, Geeta; Verma, Yogesh; Zomawia, Eric; Pimple, Sharmila; Prabhu, Priya R; Basu, Partha; Muwonge, Richard; Hingmire, Sanjay; Sauvaget, Catherine; Lucas, Eric; Pawlita, Michael; Gheit, Tarik; Jayant, Kasturi; Malvi, Sylla G; Siddiqi, Maqsood; Michel, Angelika; Butt, Julia; Sankaran, Subha; Kannan, Thiraviam Pillai Rameshwari Ammal; Varghese, Rintu; Divate, Uma; Willhauck-Fleckenstein, Martina; Waterboer, Tim; Müller, Martin; Sehr, Peter; Kriplani, Alka; Mishra, Gauravi; Jadhav, Radhika; Thorat, Ranjit; Tommasino, Massimo; Pillai, M Radhakrishna; Sankaranarayanan, Rengaswamy

    2018-06-01

    Extending two-dose recommendations of HPV vaccine to girls between 15 and 18 years will reduce program cost and improve compliance. Immunogenicity and vaccine targeted HPV infection outcomes were compared between 1795 girls aged 15-18 years receiving two (1-180 days) and 1515 girls of same age receiving three (1-60-180 days) doses. Immunogenicity outcomes in 15-18 year old two-dose recipients were also compared with the 10-14 year old three-dose (N = 2833) and two-dose (N = 3184) recipients. The 15-18 year old two-dose recipients had non-inferior L1-binding antibody titres at seven months against vaccine-targeted HPV types compared to three-dose recipients at 15-18 years and three-dose recipients at 10-14 years of age. Neutralizing antibody titres at 18 months in 15-18 year old two-dose recipients were non-inferior to same age three-dose recipients for all except HPV 18. The titres were inferior to those in the 10-14 year old three-dose recipients for all targeted types. Frequency of incident infections from vaccine-targeted HPV types in the 15-18 year old two-dose recipients was similar to the three dose recipients. None of the girls receiving two or three doses had persistent infection from vaccine-targeted types. These findings support that two doses of HPV vaccine can be extended to girls aged 15-18 years. Copyright © 2018. Published by Elsevier B.V.

  9. 198 AAAAI Survey on Immunotherapy Practice Patterns Concerning Dosing, Dose-Adjustment after Missed Doses and Duration of Immunotherapy

    PubMed Central

    Linnemann, Désirée Larenas; Gupta, Payel; Mithani, Sima; Ponda, Punita

    2012-01-01

    Background Several practical issues dealing with the exact application of allergen immunotherapy (AIT) among European and US allergists are not well known. Guidelines on AIT give recommendations and suggestions for only some of them. We present this unique survey with worldwide response. Methods The AAAAI immunotherapy committee conducted a web-based practice patterns survey (program: Survey Monkey) among all members in&outside US on dosing, dose-adjustment after missed doses and duration of AIT. Results 1201 Returned questionnaires (almost 25% response rate). 21% were non-US-Canada members. Maintenance doses in USCan are (mean/median): Dermatophagoides farinae (Df) combined with Dermatophagoides pteronyssinus (Dpt): 2155/1000AU; Df solo 2484/1000AU. Dpt when combined with Df 1937/1000AU; Dpt solo: 2183/1000AU.Cat 3224/2000BAU. Grass 11,410/4000BAU. 57-65% of the dosing falls within the recommended Practice Parameters recommended ranges. Non-USCan allergists expressed maintenance doses in many different units making analysis impossible. Dose-adjustment after missed doses is based on ‘time elapsed since the last applied dose’ by 77% of USCan and 58% of non-USCan allergists and on ‘time since missed scheduled dose’ by the rest. Doses are adjusted when a patient comes in more than 14 d/5 wk after the last administration at build-up/maintenance by both USCan and non-USCan colleagues. The mostly followed dose-adjustment schedules after 1, 2, 3 missed doses are: Build-up: repeat last dose, reduce by one dose, reduce by 2 doses; maintenance: reduce by one dose, reduce by 2 doses, reduce by 3 doses. 26% uses a different approach reducing doses by a certain percentage or volume. AIT is restarted after a gap in build-up of >30 days and of >12 weeks during maintenance in both groups (median). Outside USCan AIT is prescribed for 3 years (Median). However, 75% of USCan allergists prescribes AIT for 5 years. Main reasons why to continue AIT beyond 5 years: ‘symptoms came back after stopping’ or “patient afraid to relapse.” Conclusions These results show regional differences on some points (especially AIT duration) and they suggest in which direction to plan further research in 2 areas to establish universal dose-adjustment plans for missed applications and define the usefulness (or lack of) of long-term AIT. Moreover, there is still room for improvement in the way AIT is dosed.

  10. Different doses of prophylactic platelet transfusion for preventing bleeding in people with haematological disorders after myelosuppressive chemotherapy or stem cell transplantation

    PubMed Central

    Estcourt, Lise J; Stanworth, Simon; Doree, Carolyn; Trivella, Marialena; Hopewell, Sally; Blanco, Patricia; Murphy, Michael F

    2015-01-01

    Background Platelet transfusions are used in modern clinical practice to prevent and treat bleeding in people who are thrombocytopenic due to bone marrow failure. Although considerable advances have been made in platelet transfusion therapy in the last 40 years, some areas continue to provoke debate, especially concerning the use of prophylactic platelet transfusions for the prevention of thrombocytopenic bleeding. This is an update of a Cochrane review first published in 2004, and updated in 2012 that addressed four separate questions: prophylactic versus therapeutic-only platelet transfusion policy; prophylactic platelet transfusion threshold; prophylactic platelet transfusion dose; and platelet transfusions compared to alternative treatments. This review has now been split into four smaller reviews; this review compares different platelet transfusion doses. Objectives To determine whether different doses of prophylactic platelet transfusions (platelet transfusions given to prevent bleeding) affect their efficacy and safety in preventing bleeding in people with haematological disorders undergoing myelosuppressive chemotherapy with or without haematopoietic stem cell transplantation (HSCT). Search methods We searched for randomised controlled trials in the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library 2015, Issue 6), MEDLINE (from 1946), Embase (from 1974), CINAHL (from 1937), the Transfusion Evidence Library (from 1950), and ongoing trial databases to 23 July 2015. Selection criteria Randomised controlled trials involving transfusions of platelet concentrates, prepared either from individual units of whole blood or by apheresis, and given to prevent bleeding in people with malignant haematological disorders or undergoing HSCT that compared different platelet component doses (low dose 1.1 × 1011/m2 ± 25%, standard dose 2.2 × 1011/m2 ± 25%, high dose 4.4 × 1011/m2 ± 25%). Data collection and analysis We used the standard methodological procedures expected by The Cochrane Collaboration. Main results We included seven trials (1814 participants) in this review; six were conducted during one course of treatment (chemotherapy or HSCT). Overall the methodological quality of studies was low to moderate across different outcomes according to GRADE methodology. None of the included studies were at low risk of bias in every domain, and all the included studies had some threats to validity. Five studies reported the number of participants with at least one clinically significant bleeding episode within 30 days from the start of the study. There was no difference in the number of participants with a clinically significant bleeding episode between the low-dose and standard-dose groups (four studies; 1170 participants; risk ratio (RR) 1.04, 95% confidence interval (CI) 0.95 to 1.13; moderate-quality evidence); low-dose and high-dose groups (one study; 849 participants; RR 1.02, 95% CI 0.93 to 1.11; moderate-quality evidence); or high-dose and standard-dose groups (two studies; 951 participants; RR 1.02, 95% CI 0.93 to 1.11; moderate-quality evidence). Three studies reported the number of days with a clinically significant bleeding event per participant. There was no difference in the number of days of bleeding per participant between the low-dose and standard-dose groups (two studies; 230 participants; mean difference −0.17, 95% CI −0.51 to 0.17; low quality evidence). One study (855 participants) showed no difference in the number of days of bleeding per participant between high-dose and standard-dose groups, or between low-dose and high-dose groups (849 participants). Three studies reported the number of participants with severe or life-threatening bleeding. There was no difference in the number of participants with severe or life-threatening bleeding between a low-dose and a standard-dose platelet transfusion policy (three studies; 1059 participants; RR 1.33, 95% CI 0.91 to 1.92; low-quality evidence); low-dose and high-dose groups (one study; 849 participants; RR 1.20, 95% CI 0.82 to 1.77; low-quality evidence); or high-dose and standard-dose groups (one study; 855 participants; RR 1.11, 95% CI 0.73 to 1.68; low-quality evidence). Two studies reported the time to first bleeding episodes; we were unable to perform a meta-analysis. Both studies (959 participants) individually found that the time to first bleeding episode was either the same, or longer, in the low-dose group compared to the standard-dose group. One study (855 participants) found that the time to the first bleeding episode was the same in the high-dose group compared to the standard-dose group. Three studies reported all-cause mortality within 30 days from the start of the study. There was no difference in all-cause mortality between treatment arms (low-dose versus standard-dose: three studies; 1070 participants; RR 2.04, 95% CI 0.70 to 5.93; low-quality evidence; low-dose versus high-dose: one study; 849 participants; RR 1.33, 95% CI 0.50 to 3.54; low-quality evidence; and high-dose versus standard-dose: one study; 855 participants; RR 1.71, 95% CI 0.51 to 5.81; low-quality evidence). Six studies reported the number of platelet transfusions; we were unable to perform a meta-analysis. Two studies (959 participants) out of three (1070 participants) found that a low-dose transfusion strategy led to more transfusion episodes than a standard-dose. One study (849 participants) found that a low-dose transfusion strategy led to more transfusion episodes than a high-dose strategy. One study (855 participants) out of three (1007 participants) found no difference in the number of platelet transfusions between the high-dose and standard-dose groups. One study reported on transfusion reactions. This study’s authors suggested that a high-dose platelet transfusion strategy may lead to a higher rate of transfusion-related adverse events. None of the studies reported quality-of-life. Authors’ conclusions In haematology patients who are thrombocytopenic due to myelosuppressive chemotherapy or HSCT, we found no evidence to suggest that a low-dose platelet transfusion policy is associated with an increased bleeding risk compared to a standard-dose or high-dose policy, or that a high-dose platelet transfusion policy is associated with a decreased risk of bleeding when compared to a standard-dose policy. A low-dose platelet transfusion strategy leads to an increased number of transfusion episodes compared to a standard-dose strategy. A high-dose platelet transfusion strategy does not decrease the number of transfusion episodes per participant compared to a standard-dose regimen, and it may increase the number of transfusion-related adverse events. Findings from this review would suggest a change from current practice, with low-dose platelet transfusions used for people receiving in-patient treatment for their haematological disorder and high-dose platelet transfusion strategies not being used routinely. PMID:26505729

  11. 42 CFR 81.4 - Definition of terms used in this part.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...]. (e) Equivalent dose means the absorbed dose in a tissue or organ multiplied by a radiation weighting... dose means the portion of the equivalent dose that is received from radiation sources outside of the... pattern and level of radiation exposure. (h) Internal dose means the portion of the equivalent dose that...

  12. Investigation of dose characteristics in three-dimensional MAGAT-type polymer gel dosimetry with MSE MR imaging

    NASA Astrophysics Data System (ADS)

    Lee, Jason J. S.; Tsai, Chia-Jung; Lo, Man-Kuok; Huang, Yung-Hui; Chen, Chien-Chuan; Wu, Jay; Tyan, Yeu-Sheng; Wu, Tung-Hsin

    2008-05-01

    A new type of normoxic polymer gel dosimeter, named MAGAT responses well to absorbed dose even when manufacturing in the presence of normal levels of oxygen. The aim of this study was to evaluate dose response, diffusion effect and cumulated dose response under multiple fractional irradiations of the MAGAT gel dosimeter using Multiple Spin-Echo (MSE) Magnetic Resonance (MR) sequence. Dose response was performed by irradiating MAGAT-gel-filled testing vials with a 6 MV linear accelerator and a linear relationship was present with doses from 0 to 6 Gy, but gradually, a bi-exponential function result was obtained with given doses up to 20 Gy. No significant difference in dose response was present between single and cumulated doses (p > 0.05). For study of diffusion effect, edge sharpness of the R2 map imaging between two split doses was smaller than 1 cm of dose profile penumbra between 20% and 80%. In conclusion, the MAGAT polymer gel dosimeter with MSE MR imaging is a promising method for dose verification in clinical radiation therapy practice.

  13. Medición de los parámetros cosmológicos q0, ΩM, y ΩΛ, usando supernovas de Tipo Ia distantes

    NASA Astrophysics Data System (ADS)

    Clocchiatti, A.; High-Z Sne Search Team

    Las supernovas de tipo Ia son una herramienta de gran precisión para la medición de distancias de interés cosmológico. Los métodos recientes de calibración de su luminosidad intrínseca, que hacen uso de la forma de las curvas de luz en varios colores y permiten diferenciar entre supernovas distantes, intrínsecamente débiles, u oscurecidas por extinción, reducen la dispersión del método que las asume de magnitud absoluta constante de 0.50 mag a 0.15 mag, e incrementa el valor de la constante de Hubble de ~55 km s-1 Mpc-1, a 65 km s-1 Mpc-1. A partir de la calibración de las supernovas cercanas, con redshifts menores que 0.1, se pueden obtener distancias precisas a supernovas que explotan a alto redshift. Hemos aplicado estos métodos a 16 supernovas con 0.16 < Z < 0.97, encontrando que sus distancias son, en promedio, entre 10% y 13% (dependiendo del método empleado) mayores que las que uno esperaría en un universo con poca masa (Ω = 0.2), sin una constante cosmológica. Todos los métodos de ajuste de curvas de luz, y selección de subgrupos de la muestra de supernovas observadas, favorecen consistentemente modelos del universo que se expanden eternamente y que tienen una constante cosmológica positiva (ΩΛ > 0), y una aceleración de la expansión al presente (q0 < 0). Hay distintas fuentes de posibles errores sistemáticos que merecen ser analizadas, entre ellas: evolución de la metalicidad y estrellas progenitoras, extinción, bias en la elección de la muestra, amplificación por gravitational lensing, y contaminación de la muestra. Ninguno de estos efectos alcanza para reconciliar los datos con ΩΛ = 0, o q0 > 0.

  14. Sunspots and the Newcomb-Benford Law. (Spanish Title: Manchas Solares y la Ley de Newcomb-Benford.) Manchas Solares e a Lei de Newcomb-Benford

    NASA Astrophysics Data System (ADS)

    Alves, Mauro A.; Lyra, Cássia S.

    2008-12-01

    The Newcomb-Benford's Law (LNB) of first digits is introduced to high school students in an extracurricular activity through the study of sunspots. The LNB establishes that the first digits of various sets of data describing natural occurrences are not distributed uniformly, but according to a logarithmic distribution of probability. The LNB is counter-intuitive and is a good example of how mathematics applied to the study of natural phenomena can provide surprising and unexpected results serving also as a motivating agent in the study of physical sciences. En este trabajo se describe una actividad extracurricular donde se presenta a los estudiantes la ley de los primeros dígitos de Newcomb-Benford (LNB) con el estudio de manchas solares. La LNB establece que los primeros dígitos de algunos tipos de dados de ocurrencia natural no están distribuidos en manera uniforme, pero sí de acuerdo con una distribución logarítmica de probabilidad. La LNB es contra-intuitiva y es un excelente ejemplo de como las matemáticas aplicadas al estudio de fenómenos naturales pueden sorprender al estudiante, sirviendo también como elemento motivador en la educación de ciencias y de matemáticas. Este trabalho descreve uma atividade extracurricular na qual a lei dos primeiros dígitos de Newcomb-Benford (LNB) é introduzida a estudantes através do estudo de manchas solares. A LNB estabelece que os primeiros dígitos de vários tipos de conjunto de dados de ocorrência natural não são distribuídos de maneira uniforme, mas sim de acordo com uma distribuição logarítmica de probabilidade. A LNB é contra-intuitiva e é um ótimo exemplo de como a matemática aplicada ao estudo de fenômenos naturais pode fornecer resultados surpreendentes e inesperados, servindo também como um agente motivador no ensino de ciências e matemática.

  15. Nursing Taxonomies in Spain: Research Themes Presented at the AENTDE Conferences Over a 16-Year Period.

    PubMed

    Guirao-Goris, Silamani J Adolf; Lluch-Canut, Maria Teresa; Martín-Iglesias, Susana; Quero-Rufián, Aurora; Roldán Merino, Juan Francisco

    2017-10-01

    To identify the types of studies of nursing taxonomies and priority research themes presented at AENTDE conferences between 1996 and 2012. Four hundred oral communications and posters and 27 lectures presented at the AENTDE meetings were reviewed by means of a descriptive analysis of the types of studies conducted and a content analysis of priority research themes. The most commonly presented studies were descriptions of the implementation of nursing taxonomies, which accounted for 27.4% of the total over the 16-year period. However, their prevalence fell from 31.8% in 1996 to 9.1% in 2012. Basic research studies accounted for 17.4% of studies overall but were the most frequent in 2012, when their proportion had risen to 37.5%. The prevalence of basic research studies increased notably over the 16-year period. Content validity studies rose in number, while face validity studies fell. Studies of the practical implementation of taxonomies also declined. Identificar los tipos de estudios de taxonomías enfermeras y los temas de investigación prioritarios presentados en las convenciones de AENTDE desde 1996 a 2012. MÉTODO: Se revisaron 400 comunicaciones y 27 ponencias presentadas a 9 simposiums de AENTDE realizando un análisis del tipo de estudio y un análisis de contenido de los temas. Los estudios más frecuentes son las experiencias de implantación de las taxonomías enfermeras con un porcentaje medio de un 27.4% que partiendo de un 31.8% en 1996 disminuyó a un 9,1% en 2012. La investigación básica tienen un porcentaje medio del 17.4% obteniéndose el mayor porcentaje en 2012 con un 37,5%. CONCLUSIÓN: La prevalencia de los estudios de investigación básica se incrementó notablemente durante el período de 16 años. Los estudios de validez de contenido aumentaron en número, mientras que los estudios de validez aparente cayeron. Los estudios sobre la aplicación práctica de las taxonomías también disminuyeron. © 2016 NANDA International, Inc.

  16. Eye lens dosimetry in interventional cardiology: results of staff dose measurements and link to patient dose levels.

    PubMed

    Antic, V; Ciraj-Bjelac, O; Rehani, M; Aleksandric, S; Arandjic, D; Ostojic, M

    2013-01-01

    Workers involved in interventional cardiology procedures receive high eye lens dose if protection is not used. Currently, there is no suitable method for routine use for the measurement of eye dose. Since most angiography machines are equipped with suitable patient dosemeters, deriving factors linking staff eye doses to the patient doses can be helpful. In this study the patient kerma-area product, cumulative dose at an interventional reference point and eye dose in terms of Hp(3) of the cardiologists, nurses and radiographers for interventional cardiology procedures have been measured. Correlations between the patient dose and the staff eye dose were obtained. The mean eye dose was 121 µSv for the first operator, 33 µSv for the second operator/nurse and 12 µSv for radiographer. Normalised eye lens doses per unit kerma-area product were 0.94 µSv Gy⁻¹ cm⁻² for the first operator, 0.33 µSv Gy⁻¹ cm⁻² for the second operator/nurse and 0.16 µSv Gy⁻¹ cm⁻² for radiographers. Statistical analysis indicated that there is a weak but significant (p < 0.01) correlation between the eye dose and the kerma-area product for all three staff categories. These values are based on a local practice and may provide useful reference for other studies for validation and for wider utilisation in assessing the eye dose using patient dose values.

  17. Regulatory Forum Opinion Piece*: Retrospective Evaluation of Doses in the 26-week Tg.rasH2 Mice Carcinogenicity Studies: Recommendation to Eliminate High Doses at Maximum Tolerated Dose (MTD) in Future Studies.

    PubMed

    Paranjpe, Madhav G; Denton, Melissa D; Vidmar, Tom J; Elbekai, Reem H

    2015-07-01

    High doses in Tg.rasH2 carcinogenicity studies are usually set at the maximum tolerated dose (MTD), although this dose selection strategy has not been critically evaluated. We analyzed the body weight gains (BWGs), mortality, and tumor response in control and treated groups of 29 Tg.rasH2 studies conducted at BioReliance. Based on our analysis, it is evident that the MTD was exceeded at the high and/or mid-doses in several studies. The incidence of tumors in high doses was lower when compared to the low and mid-doses of both sexes. Thus, we recommend that the high dose in male mice should not exceed one-half of the estimated MTD (EMTD), as it is currently chosen, and the next dose should be one-fourth of the EMTD. Because females were less sensitive to decrements in BWG, the high dose in female mice should not exceed two-third of EMTD and the next dose group should be one-third of EMTD. If needed, a third dose group should be set at one-eighth EMTD in males and one-sixth EMTD in females. In addition, for compounds that do not show toxicity in the range finding studies, a limit dose should be applied for the 26-week carcinogenicity studies. © 2014 by The Author(s).

  18. Benchmarking pediatric cranial CT protocols using a dose tracking software system: a multicenter study.

    PubMed

    De Bondt, Timo; Mulkens, Tom; Zanca, Federica; Pyfferoen, Lotte; Casselman, Jan W; Parizel, Paul M

    2017-02-01

    To benchmark regional standard practice for paediatric cranial CT-procedures in terms of radiation dose and acquisition parameters. Paediatric cranial CT-data were retrospectively collected during a 1-year period, in 3 different hospitals of the same country. A dose tracking system was used to automatically gather information. Dose (CTDI and DLP), scan length, amount of retakes and demographic data were stratified by age and clinical indication; appropriate use of child-specific protocols was assessed. In total, 296 paediatric cranial CT-procedures were collected. Although the median dose of each hospital was below national and international diagnostic reference level (DRL) for all age categories, statistically significant (p-value < 0.001) dose differences among hospitals were observed. The hospital with lowest dose levels showed smallest dose variability and used age-stratified protocols for standardizing paediatric head exams. Erroneous selection of adult protocols for children still occurred, mostly in the oldest age-group. Even though all hospitals complied with national and international DRLs, dose tracking and benchmarking showed that further dose optimization and standardization is possible by using age-stratified protocols for paediatric cranial CT. Moreover, having a dose tracking system revealed that adult protocols are still applied for paediatric CT, a practice that must be avoided. • Significant differences were observed in the delivered dose between age-groups and hospitals. • Using age-adapted scanning protocols gives a nearly linear dose increase. • Sharing dose-data can be a trigger for hospitals to reduce dose levels.

  19. Dose in x-ray computed tomography

    NASA Astrophysics Data System (ADS)

    Kalender, Willi A.

    2014-02-01

    Radiation dose in x-ray computed tomography (CT) has become a topic of high interest due to the increasing numbers of CT examinations performed worldwide. This review aims to present an overview of current concepts for both scanner output metrics and for patient dosimetry and will comment on their strengths and weaknesses. Controversial issues such as the appropriateness of the CT dose index (CTDI) are discussed in detail. A review of approaches to patient dose assessment presently in practice, of the dose levels encountered and options for further dose optimization are also given and discussed. Patient dose assessment remains a topic for further improvement and for international consensus. All approaches presently in use are based on Monte Carlo (MC) simulations. Estimates for effective dose are established, but they are crude and not patient-specific; organ dose estimates are rarely available. Patient- and organ-specific dose estimates can be provided with adequate accuracy and independent of CTDI phantom measurements by fast MC simulations. Such information, in particular on 3D dose distributions, is important and helpful in optimization efforts. Dose optimization has been performed very successfully in recent years and even resulted in applications with effective dose values of below 1 mSv. In general, a trend towards lower dose values based on technical innovations has to be acknowledged. Effective dose values are down to clearly below 10 mSv on average, and there are a number of applications such as cardiac and pediatric CT which are performed routinely below 1 mSv on modern equipment.

  20. SU-E-J-93: Parametrisation of Dose to the Mucosa of the Anterior Rectal Wall in Transrectal Ultrasound Guided High-Dose-Rate Brachytherapy of the Prostate

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Aitkenhead, A; Hamlett, L; Wood, D

    2014-06-01

    Purpose: In high-dose-rate (HDR) brachytherapy of the prostate, radiation is delivered from a number of radioactive sources which are inserted via catheter into the target volume. The rectal mucosa also receives dose during the treatment, which may lead to late toxicity effects. To allow possible links between rectal dose and toxicity to be investigated, suitable methods of parametrising the rectal dose are needed. Methods: During treatment of a series of 95 patients, anatomy and catheter locations were monitored by transrectal ultrasound, and target volume positions were contoured on the ultrasound scan by the therapist. The anterior rectal mucosal wall wasmore » identified by contouring the transrectal ultrasound balloon within the ultrasound scan. Source positions and dwell times, along with the dose delivered to the patient were computed using the Oncentra Prostate treatment planning system (TPS). Data for the series of patients were exported from the TPS in Dicom format, and a series of parametrisation methods were developed in a Matlab environment to assess the rectal dose. Results: Contours of the anterior rectal mucosa were voxelised within Matlab to allow the dose to the rectal mucosa to be analysed directly from the 3D dose grid. Dose parametrisations based on dose-surface (DSH) and dose-line (DLH) histograms were obtained. Both lateral and longitudinal extents of the mucosal dose were parametrised using dose-line histograms in the relevant directions. Conclusion: We have developed a series of dose parametrisations for quantifying the dose to the rectal mucosa during HDR prostate brachytherapy which are suitable for future studies investigating potential associations between mucosal dose and late toxicity effects. The geometry of the transrectal probe standardises the rectal anatomy, making this treatment technique particularly suited to studies of this nature.« less

  1. Analysis of renal impairment in MM-003, a phase III study of pomalidomide + low - dose dexamethasone versus high - dose dexamethasone in refractory or relapsed and refractory multiple myeloma

    PubMed Central

    Weisel, Katja C.; Dimopoulos, Meletios A.; Moreau, Philippe; Lacy, Martha Q.; Song, Kevin W.; Delforge, Michel; Karlin, Lionel; Goldschmidt, Hartmut; Banos, Anne; Oriol, Albert; Alegre, Adrian; Chen, Christine; Cavo, Michele; Garderet, Laurent; Ivanova, Valentina; Martinez-Lopez, Joaquin; Knop, Stefan; Yu, Xin; Hong, Kevin; Sternas, Lars; Jacques, Christian; Zaki, Mohamed H.; Miguel, Jesus San

    2016-01-01

    Pomalidomide + low-dose dexamethasone is effective and well tolerated for refractory or relapsed and refractory multiple myeloma after bortezomib and lenalidomide failure. The phase III trial MM-003 compared pomalidomide + low-dose dexamethasone with high-dose dexamethasone. This subanalysis grouped patients by baseline creatinine clearance ≥ 30 − < 60 mL/min (n=93, pomalidomide + low-dose dexamethasone; n=56, high-dose dexamethasone) or ≥ 60 mL/min (n=205, pomalidomide + low-dose dexamethasone; n=93, high-dose dexamethasone). Median progression-free survival was similar for both subgroups and favored pomalidomide + low-dose dexamethasone versus high-dose dexamethasone: 4.0 versus 1.9 months in the group with baseline creatinine clearance ≥ 30 − < 60 mL/min (P<0.001) and 4.0 versus 2.0 months in the group with baseline creatinine clearance ≥ 60 mL/min (P<0.001). Median overall survival for pomalidomide + low-dose dexamethasone versus high-dose dexamethasone was 10.4 versus 4.9 months (P=0.030) and 15.5 versus 9.2 months (P=0.133), respectively. Improved renal function, defined as an increase in creatinine clearance from < 60 to ≥ 60 mL/min, was similar in pomalidomide + low-dose dexamethasone and high-dose dexamethasone patients (42% and 47%, respectively). Improvement in progression-free and overall survival in these patients was comparable with that in patients without renal impairment. There was no increase in discontinuations of therapy, dose modifications, and adverse events in patients with moderate renal impairment. Pomalidomide at a starting dose of 4 mg + low-dose dexamethasone is well tolerated in patients with refractory or relapsed and refractory multiple myeloma, and of comparable efficacy if moderate renal impairment is present. This trial was registered with clinicaltrials.gov identifier 01311687 and EudraCT identifier 2010-019820-30. PMID:27081177

  2. SimDoseCT: dose reporting software based on Monte Carlo simulation for a 320 detector-row cone-beam CT scanner and ICRP computational adult phantoms

    NASA Astrophysics Data System (ADS)

    Cros, Maria; Joemai, Raoul M. S.; Geleijns, Jacob; Molina, Diego; Salvadó, Marçal

    2017-08-01

    This study aims to develop and test software for assessing and reporting doses for standard patients undergoing computed tomography (CT) examinations in a 320 detector-row cone-beam scanner. The software, called SimDoseCT, is based on the Monte Carlo (MC) simulation code, which was developed to calculate organ doses and effective doses in ICRP anthropomorphic adult reference computational phantoms for acquisitions with the Aquilion ONE CT scanner (Toshiba). MC simulation was validated by comparing CTDI measurements within standard CT dose phantoms with results from simulation under the same conditions. SimDoseCT consists of a graphical user interface connected to a MySQL database, which contains the look-up-tables that were generated with MC simulations for volumetric acquisitions at different scan positions along the phantom using any tube voltage, bow tie filter, focal spot and nine different beam widths. Two different methods were developed to estimate organ doses and effective doses from acquisitions using other available beam widths in the scanner. A correction factor was used to estimate doses in helical acquisitions. Hence, the user can select any available protocol in the Aquilion ONE scanner for a standard adult male or female and obtain the dose results through the software interface. Agreement within 9% between CTDI measurements and simulations allowed the validation of the MC program. Additionally, the algorithm for dose reporting in SimDoseCT was validated by comparing dose results from this tool with those obtained from MC simulations for three volumetric acquisitions (head, thorax and abdomen). The comparison was repeated using eight different collimations and also for another collimation in a helical abdomen examination. The results showed differences of 0.1 mSv or less for absolute dose in most organs and also in the effective dose calculation. The software provides a suitable tool for dose assessment in standard adult patients undergoing CT examinations in a 320 detector-row cone-beam scanner.

  3. SimDoseCT: dose reporting software based on Monte Carlo simulation for a 320 detector-row cone-beam CT scanner and ICRP computational adult phantoms.

    PubMed

    Cros, Maria; Joemai, Raoul M S; Geleijns, Jacob; Molina, Diego; Salvadó, Marçal

    2017-07-17

    This study aims to develop and test software for assessing and reporting doses for standard patients undergoing computed tomography (CT) examinations in a 320 detector-row cone-beam scanner. The software, called SimDoseCT, is based on the Monte Carlo (MC) simulation code, which was developed to calculate organ doses and effective doses in ICRP anthropomorphic adult reference computational phantoms for acquisitions with the Aquilion ONE CT scanner (Toshiba). MC simulation was validated by comparing CTDI measurements within standard CT dose phantoms with results from simulation under the same conditions. SimDoseCT consists of a graphical user interface connected to a MySQL database, which contains the look-up-tables that were generated with MC simulations for volumetric acquisitions at different scan positions along the phantom using any tube voltage, bow tie filter, focal spot and nine different beam widths. Two different methods were developed to estimate organ doses and effective doses from acquisitions using other available beam widths in the scanner. A correction factor was used to estimate doses in helical acquisitions. Hence, the user can select any available protocol in the Aquilion ONE scanner for a standard adult male or female and obtain the dose results through the software interface. Agreement within 9% between CTDI measurements and simulations allowed the validation of the MC program. Additionally, the algorithm for dose reporting in SimDoseCT was validated by comparing dose results from this tool with those obtained from MC simulations for three volumetric acquisitions (head, thorax and abdomen). The comparison was repeated using eight different collimations and also for another collimation in a helical abdomen examination. The results showed differences of 0.1 mSv or less for absolute dose in most organs and also in the effective dose calculation. The software provides a suitable tool for dose assessment in standard adult patients undergoing CT examinations in a 320 detector-row cone-beam scanner.

  4. TU-H-CAMPUS-JeP3-02: Automated Dose Accumulation and Dose Accuracy Assessment for Online Or Offline Adaptive Replanning

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, G; Ahunbay, E; Li, X

    Purpose: With introduction of high-quality treatment imaging during radiation therapy (RT) delivery, e.g., MR-Linac, adaptive replanning of either online or offline becomes appealing. Dose accumulation of delivered fractions, a prerequisite for the adaptive replanning, can be cumbersome and inaccurate. The purpose of this work is to develop an automated process to accumulate daily doses and to assess the dose accumulation accuracy voxel-by-voxel for adaptive replanning. Methods: The process includes the following main steps: 1) reconstructing daily dose for each delivered fraction with a treatment planning system (Monaco, Elekta) based on the daily images using machine delivery log file and consideringmore » patient repositioning if applicable, 2) overlaying the daily dose to the planning image based on deformable image registering (DIR) (ADMIRE, Elekta), 3) assessing voxel dose deformation accuracy based on deformation field using predetermined criteria, and 4) outputting accumulated dose and dose-accuracy volume histograms and parameters. Daily CTs acquired using a CT-on-rails during routine CT-guided RT for sample patients with head and neck and prostate cancers were used to test the process. Results: Daily and accumulated doses (dose-volume histograms, etc) along with their accuracies (dose-accuracy volume histogram) can be robustly generated using the proposed process. The test data for a head and neck cancer case shows that the gross tumor volume decreased by 20% towards the end of treatment course, and the parotid gland mean dose increased by 10%. Such information would trigger adaptive replanning for the subsequent fractions. The voxel-based accuracy in the accumulated dose showed that errors in accumulated dose near rigid structures were small. Conclusion: A procedure as well as necessary tools to automatically accumulate daily dose and assess dose accumulation accuracy is developed and is useful for adaptive replanning. Partially supported by Elekta, Inc.« less

  5. SU-F-T-428: An Optimization-Based Commissioning Tool for Finite Size Pencil Beam Dose Calculations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, Y; Tian, Z; Song, T

    Purpose: Finite size pencil beam (FSPB) algorithms are commonly used to pre-calculate the beamlet dose distribution for IMRT treatment planning. FSPB commissioning, which usually requires fine tuning of the FSPB kernel parameters, is crucial to the dose calculation accuracy and hence the plan quality. Yet due to the large number of beamlets, FSPB commissioning could be very tedious. This abstract reports an optimization-based FSPB commissioning tool we have developed in MatLab to facilitate the commissioning. Methods: A FSPB dose kernel generally contains two types of parameters: the profile parameters determining the dose kernel shape, and a 2D scaling factors accountingmore » for the longitudinal and off-axis corrections. The former were fitted using the penumbra of a reference broad beam’s dose profile with Levenberg-Marquardt algorithm. Since the dose distribution of a broad beam is simply a linear superposition of the dose kernel of each beamlet calculated with the fitted profile parameters and scaled using the scaling factors, these factors could be determined by solving an optimization problem which minimizes the discrepancies between the calculated dose of broad beams and the reference dose. Results: We have commissioned a FSPB algorithm for three linac photon beams (6MV, 15MV and 6MVFFF). Dose of four field sizes (6*6cm2, 10*10cm2, 15*15cm2 and 20*20cm2) were calculated and compared with the reference dose exported from Eclipse TPS system. For depth dose curves, the differences are less than 1% of maximum dose after maximum dose depth for most cases. For lateral dose profiles, the differences are less than 2% of central dose at inner-beam regions. The differences of the output factors are within 1% for all the three beams. Conclusion: We have developed an optimization-based commissioning tool for FSPB algorithms to facilitate the commissioning, providing sufficient accuracy of beamlet dose calculation for IMRT optimization.« less

  6. SU-F-T-372: Surface and Peripheral Dose in Compensator-Based FFF Beam IMRT

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, D; Feygelman, V; Moros, E

    2016-06-15

    Purpose: Flattening filter free (FFF) beams produce higher dose rates. Combined with compensator IMRT techniques, the dose delivery for each beam can be much shorter compared to the flattened beam MLC-based or compensator-based IMRT. This ‘snap shot’ IMRT delivery is beneficial to patients for tumor motion management. Due to softer energy, surface doses in FFF beam treatment are usually higher than those from flattened beams. Because of less scattering due to no flattening filter, peripheral doses are usually lower in FFF beam treatment. However, in compensator-based IMRT using FFF beams, the compensator is in the beam pathway. Does it introducemore » beam hardening effects and scattering such that the surface dose is lower and peripheral dose is higher compared to FFF beam MLC-based IMRT? Methods: This study applied Monte Carlo techniques to investigate the surface and peripheral doses in compensator-based IMRT using FFF beams and compared it to the MLC-based IMRT using FFF beams and flattened beams. Besides various thicknesses of copper slabs to simulate various thicknesses of compensators, a simple cone-shaped compensator was simulated to mimic a clinical application. The dose distribution in water phantom by the cone-shaped compensator was then simulated by multiple MLC defined FFF and flattened beams with various openings. After normalized to Dmax, the surface and peripheral dose was compared between the FFF beam compensator-based IMRT and FFF/flattened beam MLC-based IMRT. Results: The surface dose at the central 0.5mm depth was close between the compensator and 6FFF MLC dose distributions, and about 8% (of Dmax) higher than the flattened 6MV MLC dose. At 8cm off axis at dmax, the peripheral dose between the 6FFF and flattened 6MV MLC demonstrated similar doses, while the compensator dose was about 1% higher. Conclusion: Compensator does not reduce the surface doses but slightly increases the peripheral doses due to scatter inside compensator.« less

  7. Keeping an eye on the ring: COMS plaque loading optimization for improved dose conformity and homogeneity.

    PubMed

    Gagne, Nolan L; Cutright, Daniel R; Rivard, Mark J

    2012-09-01

    To improve tumor dose conformity and homogeneity for COMS plaque brachytherapy by investigating the dosimetric effects of varying component source ring radionuclides and source strengths. The MCNP5 Monte Carlo (MC) radiation transport code was used to simulate plaque heterogeneity-corrected dose distributions for individually-activated source rings of 14, 16 and 18 mm diameter COMS plaques, populated with (103)Pd, (125)I and (131)Cs sources. Ellipsoidal tumors were contoured for each plaque size and MATLAB programming was developed to generate tumor dose distributions for all possible ring weighting and radionuclide permutations for a given plaque size and source strength resolution, assuming a 75 Gy apical prescription dose. These dose distributions were analyzed for conformity and homogeneity and compared to reference dose distributions from uniformly-loaded (125)I plaques. The most conformal and homogeneous dose distributions were reproduced within a reference eye environment to assess organ-at-risk (OAR) doses in the Pinnacle(3) treatment planning system (TPS). The gamma-index analysis method was used to quantitatively compare MC and TPS-generated dose distributions. Concentrating > 97% of the total source strength in a single or pair of central (103)Pd seeds produced the most conformal dose distributions, with tumor basal doses a factor of 2-3 higher and OAR doses a factor of 2-3 lower than those of corresponding uniformly-loaded (125)I plaques. Concentrating 82-86% of the total source strength in peripherally-loaded (131)Cs seeds produced the most homogeneous dose distributions, with tumor basal doses 17-25% lower and OAR doses typically 20% higher than those of corresponding uniformly-loaded (125)I plaques. Gamma-index analysis found > 99% agreement between MC and TPS dose distributions. A method was developed to select intra-plaque ring radionuclide compositions and source strengths to deliver more conformal and homogeneous tumor dose distributions than uniformly-loaded (125)I plaques. This method may support coordinated investigations of an appropriate clinical target for eye plaque brachytherapy.

  8. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Perko, Z; Bortfeld, T; Hong, T

    Purpose: The safe use of radiotherapy requires the knowledge of tolerable organ doses. For experimental fractionation schemes (e.g. hypofractionation) these are typically extrapolated from traditional fractionation schedules using the Biologically Effective Dose (BED) model. This work demonstrates that using the mean dose in the standard BED equation may overestimate tolerances, potentially leading to unsafe treatments. Instead, extrapolation of mean dose tolerances should take the spatial dose distribution into account. Methods: A formula has been derived to extrapolate mean physical dose constraints such that they are mean BED equivalent. This formula constitutes a modified BED equation where the influence of themore » spatial dose distribution is summarized in a single parameter, the dose shape factor. To quantify effects we analyzed 14 liver cancer patients previously treated with proton therapy in 5 or 15 fractions, for whom also photon IMRT plans were available. Results: Our work has two main implications. First, in typical clinical plans the dose distribution can have significant effects. When mean dose tolerances are extrapolated from standard fractionation towards hypofractionation they can be overestimated by 10–15%. Second, the shape difference between photon and proton dose distributions can cause 30–40% differences in mean physical dose for plans having the same mean BED. The combined effect when extrapolating proton doses to mean BED equivalent photon doses in traditional 35 fraction regimens resulted in up to 7–8 Gy higher doses than when applying the standard BED formula. This can potentially lead to unsafe treatments (in 1 of the 14 analyzed plans the liver mean dose was above its 32 Gy tolerance). Conclusion: The shape effect should be accounted for to avoid unsafe overestimation of mean dose tolerances, particularly when estimating constraints for hypofractionated regimens. In addition, tolerances established for a given treatment modality cannot necessarily be applied to other modalities with drastically different dose distributions.« less

  9. Older adults and high-risk medication administration in the emergency department.

    PubMed

    Kim, Mitchell; Mitchell, Steven H; Gatewood, Medley; Bennett, Katherine A; Sutton, Paul R; Crawford, Carol A; Bentov, Itay; Damodarasamy, Mamatha; Kaplan, Stephen J; Reed, May J

    2017-01-01

    Older adults are susceptible to adverse effects from opioids, nonsteroidal anti-inflammatory drugs (NSAIDs), and benzodiazepines (BZDs). We investigated factors associated with the administration of elevated doses of these medications of interest to older adults (≥65 years old) in the emergency department (ED). ED records were queried for the administration of medications of interest to older adults at two academic medical center EDs over a 6-month period. Frequency of recommended versus elevated ("High doses" were defined as doses that ranged between 1.5 and 3 times higher than the recommended starting doses; "very high doses" were defined as higher than high doses) starting doses of medications, as determined by geriatric pharmacy/medicine guidelines and expert consensus, was compared by age groups (65-69, 70-74, 75-79, 80-84, and ≥85 years), gender, and hospital. There were 17896 visits representing 11374 unique patients >65 years of age (55.3% men, 44.7% women). A total of 3394 doses of medications of interest including 1678 high doses and 684 very high doses were administered to 1364 different patients. Administration of elevated doses of medications was more common than that of recommended doses. Focusing on opioids and BZDs, the 65-69-year age group was much more likely to receive very high doses (1481 and 412 doses, respectively) than the ≥85-year age groups (relative risk [RR] 5.52, 95% CI 2.56-11.90), mainly reflecting elevated opioid dosing (RR 8.28, 95% CI 3.69-18.57). Men were more likely than women to receive very high doses (RR 1.47, 95% CI 1.26-1.72), primarily due to BZDs (RR 2.12, 95% CI 2.07-2.16). Administration of elevated doses of opioids and BZDs in the older population occurs frequently in the ED, especially to the 65-69-year age group and men. Further attention to potentially unsafe dosing of high-risk medications to older adults in the ED is warranted.

  10. Is Dose Deformation–Invariance Hypothesis Verified in Prostate IGRT?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Simon, Antoine, E-mail: antoine.simon@univ-rennes1.fr; Laboratoire Traitement du Signal et de l'Image, Université de Rennes 1, 35000 Rennes; Le Maitre, Amandine

    Purpose: To assess dose uncertainties resulting from the dose deformation–invariance hypothesis in prostate cone beam computed tomography (CT)–based image guided radiation therapy (IGRT), namely to evaluate whether rigidly propagated planned dose distribution enables good estimation of fraction dose distributions. Methods and Materials: Twenty patients underwent a CT scan for planning intensity modulated radiation therapy–IGRT delivering 80 Gy to the prostate, followed by weekly CT scans. Two methods were used to obtain the dose distributions on the weekly CT scans: (1) recalculating the dose using the original treatment plan; and (2) rigidly propagating the planned dose distribution. The cumulative doses were then estimatedmore » in the organs at risk for each dose distribution by deformable image registration. The differences between recalculated and propagated doses were finally calculated for the fraction and the cumulative dose distributions, by use of per-voxel and dose-volume histogram (DVH) metrics. Results: For the fraction dose, the mean per-voxel absolute dose difference was <1 Gy for 98% and 95% of the fractions for the rectum and bladder, respectively. The maximum dose difference within 1 voxel reached, however, 7.4 Gy in the bladder and 8.0 Gy in the rectum. The mean dose differences were correlated with gas volume for the rectum and patient external contour variations for the bladder. The mean absolute differences for the considered volume receiving greater than or equal to dose x (V{sub x}) of the DVH were between 0.37% and 0.70% for the rectum and between 0.53% and 1.22% for the bladder. For the cumulative dose, the mean differences in the DVH were between 0.23% and 1.11% for the rectum and between 0.55% and 1.66% for the bladder. The largest dose difference was 6.86%, for bladder V{sub 80Gy}. The mean dose differences were <1.1 Gy for the rectum and <1 Gy for the bladder. Conclusions: The deformation–invariance hypothesis was corroborated for the organs at risk in prostate IGRT except in cases of a large disappearance or appearance of rectal gas for the rectum and large external contour variations for the bladder.« less

  11. Evaluation of a new very low dose imaging protocol: feasibility and impact on X-ray dose levels in electrophysiology procedures.

    PubMed

    Bourier, Felix; Reents, Tilko; Ammar-Busch, Sonia; Buiatti, Alessandra; Kottmaier, Marc; Semmler, Verena; Telishevska, Marta; Brkic, Amir; Grebmer, Christian; Lennerz, Carsten; Kolb, Christof; Hessling, Gabriele; Deisenhofer, Isabel

    2016-09-01

    This study presents and evaluates the impact of a new lowest-dose fluoroscopy protocol (Siemens AG), especially designed for electrophysiology (EP) procedures, on X-ray dose levels. From October 2014 to March 2015, 140 patients underwent an EP study on an Artis zee angiography system. The standard low-dose protocol was operated at 23 nGy (fluoroscopy) and at 120 nGy (cine-loop), the new lowest-dose protocol was operated at 8 nGy (fluoroscopy) and at 36 nGy (cine-loop). Procedural data, X-ray times, and doses were analysed in 100 complex left atrial and in 40 standard EP procedures. The resulting dose-area products were 877.9 ± 624.7 µGym² (n = 50 complex procedures, standard low dose), 199 ± 159.6 µGym² (n = 50 complex procedures, lowest dose), 387.7 ± 36.0 µGym² (n = 20 standard procedures, standard low dose), and 90.7 ± 62.3 µGym² (n = 20 standard procedures, lowest dose), P < 0.01. In the low-dose and lowest-dose groups, procedure times were 132.6 ± 35.7 vs. 126.7 ± 34.7 min (P = 0.40, complex procedures) and 72.3 ± 20.9 vs. 85.2 ± 44.1 min (P = 0.24, standard procedures), radiofrequency (RF) times were 53.8 ± 26.1 vs. 50.4 ± 29.4 min (P = 0.54, complex procedures) and 10.1 ± 9.9 vs. 12.2 ± 14.7 min (P = 0.60, standard procedures). One complication occurred in the standard low-dose and lowest-dose groups (P = 1.0). The new lowest-dose imaging protocol reduces X-ray dose levels by 77% compared with the currently available standard low-dose protocol. From an operator standpoint, lowest X-ray dose levels create a different, reduced image quality. The new image quality did not significantly affect procedure or RF times and did not result in higher complication rates. Regarding radiological protection, operating at lowest-dose settings should become standard in EP procedures. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  12. Patient dose analysis in total body irradiation through in vivo dosimetry.

    PubMed

    Ganapathy, K; Kurup, P G G; Murali, V; Muthukumaran, M; Bhuvaneshwari, N; Velmurugan, J

    2012-10-01

    Total body irradiation (TBI) is a special radiotherapy technique, administered prior to bone marrow transplantation. Due to the complex nature of the treatment setup, in vivo dosimetry for TBI is mandatory to ensure proper delivery of the intended radiation dose throughout the body. Lithium fluoride (LiF) TLD-100 chips are used for the TBI in vivo dosimetry. Results obtained from the in vivo dosimetry of 20 patients are analyzed. Results obtained from forehead, abdomen, pelvis, and mediastinum showed a similar pattern with the average measured dose from 96 to 97% of the prescription dose. Extremities and chest received a dose greater than the prescription dose in many instances (more than 20% of measurements). Homogeneous dose delivery to the whole body is checked by calculating the mean dose with standard deviation for each fraction. Reasons for the difference between prescription dose and measured dose for each site are discussed. Dose homogeneity within ±10% is achieved using our in-house TBI protocol.

  13. Patient dose analysis in total body irradiation through in vivo dosimetry

    PubMed Central

    Ganapathy, K.; Kurup, P. G. G.; Murali, V.; Muthukumaran, M.; Bhuvaneshwari, N.; Velmurugan, J.

    2012-01-01

    Total body irradiation (TBI) is a special radiotherapy technique, administered prior to bone marrow transplantation. Due to the complex nature of the treatment setup, in vivo dosimetry for TBI is mandatory to ensure proper delivery of the intended radiation dose throughout the body. Lithium fluoride (LiF) TLD-100 chips are used for the TBI in vivo dosimetry. Results obtained from the in vivo dosimetry of 20 patients are analyzed. Results obtained from forehead, abdomen, pelvis, and mediastinum showed a similar pattern with the average measured dose from 96 to 97% of the prescription dose. Extremities and chest received a dose greater than the prescription dose in many instances (more than 20% of measurements). Homogeneous dose delivery to the whole body is checked by calculating the mean dose with standard deviation for each fraction. Reasons for the difference between prescription dose and measured dose for each site are discussed. Dose homogeneity within ±10% is achieved using our in-house TBI protocol. PMID:23293453

  14. Acute changes in the central nervous system of monkeys exposed to protons.

    NASA Technical Reports Server (NTRS)

    Haymaker, W.; Ibrahim, M. Z. M.; Miquel, J.; Call, N.; Noden, P.; Ashley, W.; Ballinger, E. R.; Ghidoni, J.; Lindsay, I. R.; Behar, A. J.

    1972-01-01

    Study of the changes occurring in simian brain exposed to protons of varied energy, given in wide dose and dose-rate ranges. Results show that inflammatory reaction and glycogen accumulation in astrocytes occurred practically in all animals. Cerebral cortical necrosis, granule cell pyknosis, and inflammatory reaction occurred at doses far lower than effective for high-energy gamma radiation given other series of monkeys at comparable dose rates. Metallic impregnation, carried out in virtually all the animals tested, revealed a wide variation in glial response even at equal doses and dose rates in the same proton energy series. Proton energy effect, dose effect, dose-time effect, and dose-rate effect were evident in the various morphological categories investigated, but inconsistencies were encountered.

  15. Absorbed dose thresholds and absorbed dose rate limitations for studies of electron radiation effects on polyetherimides

    NASA Technical Reports Server (NTRS)

    Long, Edward R., Jr.; Long, Sheila Ann T.; Gray, Stephanie L.; Collins, William D.

    1989-01-01

    The threshold values of total absorbed dose for causing changes in tensile properties of a polyetherimide film and the limitations of the absorbed dose rate for accelerated-exposure evaluation of the effects of electron radiation in geosynchronous orbit were studied. Total absorbed doses from 1 kGy to 100 MGy and absorbed dose rates from 0.01 MGy/hr to 100 MGy/hr were investigated, where 1 Gy equals 100 rads. Total doses less than 2.5 MGy did not significantly change the tensile properties of the film whereas doses higher than 2.5 MGy significantly reduced elongation-to-failure. There was no measurable effect of the dose rate on the tensile properties for accelerated electron exposures.

  16. Dose and risk in diagnostic radiology: How big How little Lecture Number 16

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Webster, E.W.

    1992-01-01

    This lecture is divided into two parts: dose and risk. The dose segment is technical and noncontroversial since it deals with straightforward measurements or calculations which do not depend on unproven hypotheses. Some conflicting contributions of low dose epidemiological studies to the appraisal of risk are briefly presented. Attention is focused on the following: dose reduction in radiography; dose reduction in fluoroscopy; limitations of dose reduction; estimated radiation risks for diagnostic radiology examinations; excess breast cancer following X-ray examinations for scoliosis; dose-response relation for human mammary cancer; lung cancer from protracted X-irradiation; leukemia and diagnostic X-ray exposure; and thyroid cancermore » after diagnostic dose of I-131.« less

  17. Efficacy of fewer than three doses of an HPV-16/18 AS04-adjuvanted vaccine: combined analysis of data from the Costa Rica Vaccine and PATRICIA Trials.

    PubMed

    Kreimer, Aimée R; Struyf, Frank; Del Rosario-Raymundo, Maria Rowena; Hildesheim, Allan; Skinner, S Rachel; Wacholder, Sholom; Garland, Suzanne M; Herrero, Rolando; David, Marie-Pierre; Wheeler, Cosette M; González, Paula; Jiménez, Silvia; Lowy, Douglas R; Pinto, Ligia A; Porras, Caroline; Rodriguez, Ana Cecilia; Safaeian, Mahboobeh; Schiffman, Mark; Schiller, John T; Schussler, John; Sherman, Mark E; Bosch, F Xavier; Castellsague, Xavier; Chatterjee, Archana; Chow, Song-Nan; Descamps, Dominique; Diaz-Mitoma, Francisco; Dubin, Gary; Germar, Maria Julieta; Harper, Diane M; Lewis, David J M; Limson, Genara; Naud, Paulo; Peters, Klaus; Poppe, Willy A J; Ramjattan, Brian; Romanowski, Barbara; Salmeron, Jorge; Schwarz, Tino F; Teixeira, Julio C; Tjalma, Wiebren A A

    2015-07-01

    There is some evidence to suggest that one or two doses of the HPV vaccine provides similar protection to the three-dose regimen. The main aim of the study was to ascertain HPV-16/18 vaccine efficacy in both full and naive cohorts and to explore protection conferred against non-vaccine HPV types, by number of doses received. Summary data from the Costa Rica Vaccine Trial (CVT; NCT00128661) and ~the PATRICIA trial (NCT001226810), two phase 3, double-blind, randomised controlled clinical trials of the HPV-16/18 AS04-adjuvanted vaccine in young women, were combined in a post-hoc analysis (GlaxoSmithKline [GSK] e-track number 202142) to investigate the efficacy of fewer than three doses of the HPV-16/18 vaccine after 4 years of follow-up. Women were randomly assigned to receive three doses of the HPV-16/18 vaccine or to a control vaccine; yet, some received fewer doses. After exclusion of women with less than 12 months of follow-up or those who were HPV-16/18 DNA-positive at enrolment (for the HPV-16/18 endpoint), we calculated vaccine efficacy against one-time detection of incident HPV infections after three, two, and one dose(s). The primary study endpoint was one-time detection of first incident HPV-16/18 infections accumulated during the follow-up phase. We assessed vaccine efficacy against incident HPV-16/18 infection in the modified total vaccinated cohort (22 327 received three doses, 1185 two doses, 543 one dose). Vaccine efficacy against incident HPV-16/18 infections for three doses was 77·0% (95% CI 74·7-79·1), two doses was 76·0% (62·0-85·3), and one dose was 85·7% (70·7-93·7). Vaccine efficacy against incident HPV-31/33/45 infections for three doses was 59·7% (56·0-63·0), two doses was 37·7% (12·4-55·9), and one dose was 36·6% (-5·4 to 62·2). Vaccine efficacy against incident HPV-16/18 infection for two-dose women who received their second dose at 1 month was 75·3% (54·2-87·5) and 82·6% (42·3-96·1) for those who received the second dose at 6 months (CVT data only). Vaccine efficacy against HPV-31/33/45 for two-dose women who received their second dose at 6 months (68·1%, 27·0-87·0; CVT data only), but not those receiving it at one month (10·1%, -42·0 to 43·3), was similar to the three-dose group. 4 years after vaccination of women aged 15-25 years, one and two doses of the HPV-16/18 vaccine seem to protect against cervical HPV-16/18 infections, similar to the protection provided by the three-dose schedule. Two doses separated by 6 months additionally provided some cross-protection. These data argue for a direct assessment of one-dose efficacy of the HPV-16/18 vaccine. US National Cancer Institute, National Institutes of Health Office of Research on Women's Health, and Ministry of Health of Costa Rica (CVT); GlaxoSmithKline Biologicals SA (PATRICIA). Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Comparison of internal dose estimates obtained using organ-level, voxel S value, and Monte Carlo techniques

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Grimes, Joshua, E-mail: grimes.joshua@mayo.edu; Celler, Anna

    2014-09-15

    Purpose: The authors’ objective was to compare internal dose estimates obtained using the Organ Level Dose Assessment with Exponential Modeling (OLINDA/EXM) software, the voxel S value technique, and Monte Carlo simulation. Monte Carlo dose estimates were used as the reference standard to assess the impact of patient-specific anatomy on the final dose estimate. Methods: Six patients injected with{sup 99m}Tc-hydrazinonicotinamide-Tyr{sup 3}-octreotide were included in this study. A hybrid planar/SPECT imaging protocol was used to estimate {sup 99m}Tc time-integrated activity coefficients (TIACs) for kidneys, liver, spleen, and tumors. Additionally, TIACs were predicted for {sup 131}I, {sup 177}Lu, and {sup 90}Y assuming themore » same biological half-lives as the {sup 99m}Tc labeled tracer. The TIACs were used as input for OLINDA/EXM for organ-level dose calculation and voxel level dosimetry was performed using the voxel S value method and Monte Carlo simulation. Dose estimates for {sup 99m}Tc, {sup 131}I, {sup 177}Lu, and {sup 90}Y distributions were evaluated by comparing (i) organ-level S values corresponding to each method, (ii) total tumor and organ doses, (iii) differences in right and left kidney doses, and (iv) voxelized dose distributions calculated by Monte Carlo and the voxel S value technique. Results: The S values for all investigated radionuclides used by OLINDA/EXM and the corresponding patient-specific S values calculated by Monte Carlo agreed within 2.3% on average for self-irradiation, and differed by as much as 105% for cross-organ irradiation. Total organ doses calculated by OLINDA/EXM and the voxel S value technique agreed with Monte Carlo results within approximately ±7%. Differences between right and left kidney doses determined by Monte Carlo were as high as 73%. Comparison of the Monte Carlo and voxel S value dose distributions showed that each method produced similar dose volume histograms with a minimum dose covering 90% of the volume (D90) agreeing within ±3%, on average. Conclusions: Several aspects of OLINDA/EXM dose calculation were compared with patient-specific dose estimates obtained using Monte Carlo. Differences in patient anatomy led to large differences in cross-organ doses. However, total organ doses were still in good agreement since most of the deposited dose is due to self-irradiation. Comparison of voxelized doses calculated by Monte Carlo and the voxel S value technique showed that the 3D dose distributions produced by the respective methods are nearly identical.« less

  19. Evaluation of the Pharmacokinetics and Efficacy of a Busulfan Test Dose in Adult Patients Undergoing Myeloablative Hematopoietic Cell Transplantation.

    PubMed

    Weil, Elizabeth; Zook, Felicia; Oxencis, Carolyn; Canadeo, Angela; Urmanski, Angela; Waggoner, Mindy; Eastwood, Daniel; Pasquini, Marcelo; Hamadani, Mehdi; Hari, Parameswaran

    2017-06-01

    Owing to interpatient variability in busulfan exposure, therapeutic monitoring of busulfan is often used in myeloablative allogeneic transplantation to ensure that patients are near the optimal steady-state goal of 900 ng/mL. One challenge in therapeutic monitoring of busulfan is the brief course of busulfan treatment, requiring prompt analysis and dose adjustments as needed. Pharmacokinetic evaluation of a busulfan test dose before the start of the conditioning regimen would allow for all conditioning regimen doses to be given at the calculated optimized dose. An observational study was completed to evaluate the effects of a busulfan test dose of 0.9 mg/kg administered before the start of a myeloablative intravenous busulfan-based conditioning regimen. Sixty adult patients who received a busulfan conditioning regimen were reviewed, including 30 patients prior to the implementation of the busulfan test dose (pretest dose group) and 30 patients who received the busulfan test dose (posttest dose group). The primary objective was a pharmacokinetic evaluation of the percentage of patients who achieved the desired steady-state goal using the test dose strategy. The safety and efficacy of the busulfan test dose were evaluated as well. The average busulfan steady-state level after the first dose of the conditioning regimen was significantly lower in the pre-test dose group compared with the post-test dose group (660 ng/mL versus 879.9 ng/mL; P < 0.001). Compared with the post-test dose group, significantly fewer patients in the pre-test dose group were within 10% of the busulfan steady-state goal (10% versus 73.3%; P < 0.001) or within 5% of the goal (0% versus 53%; P < 0.001). Requirements for parenteral nutrition and/or patient-controlled analgesia owing to mucositis and rates of veno-occlusive disease were not significantly different between the pre-test dose group and the post-test dose group. The rates of disease relapse, mortality, and acute graft-versus-host disease were similar in the two groups. A pretransplantation busulfan test dose of 0.9 mg/kg improved the patients' ability to reach therapeutic busulfan target levels after the first conditioning dose and resulted in fewer adjustments during conditioning. The use of a busulfan test dose did not significantly increase patients' risk of mucositis or other safety outcomes. Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  20. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shin, D; Kang, S; Kim, D

    Purpose: The dose difference between three-dimensional dose (3D dose) and 4D dose which considers motion due to respiratory can be varied according to geometrical relationship between planning target volume (PTV) and organ at risk (OAR). The purpose of the study is to investigate the dose difference between 3D and 4D dose using overlap volume histogram (OVH) which is an indicator that quantify geometrical relationship between a PTV and an OAR. Methods: Five liver cancer patients who previously treated stereotactic body radiotherapy (SBRT) were investigated. Four-dimensional computed tomography (4DCT) images were acquired for all patients. ITV-based treatment planning was performed. 3Dmore » dose was calculated on the end-exhale phase image as a reference phase image. 4D dose accumulation was implemented from all phase images using dose warping technique used deformable image registration (DIR) algorithm (Horn and Schunck optical flow) in DIRART. In this study OVH was used to quantify geometrical relationship between a PTV and an OAR. OVH between a PTV and a selected OAR was generated for each patient case and compared for all cases. The dose difference between 3D and 4D dose for normal organ was calculated and compared for all cases according to OVH. Results: The 3D and 4D dose difference for OAR was analyzed using dose-volume histogram (DVH). On the basis of a specific point which corresponds to 10% of OAR volume overlapped with expanded PTV, mean dose difference was 34.56% in minimum OVH distance case and 13.36% in maximum OVH distance case. As the OVH distance increased, mean dose difference between 4D and 3D dose was decreased. Conclusion: The tendency of dose difference variation was verified according to OVH. OVH is seems to be indicator that has a potential to predict the dose difference between 4D and 3D dose. This work was supported by the Radiation Technology R&D program (No. 2013M2A2A7043498) and the Mid-career Researcher Program (2014R1A2A1A10050270) through the National Research Foundation of Korea funded by the Ministry of Science, ICT&Future Planning.« less

  1. The effects of small field dosimetry on the biological models used in evaluating IMRT dose distributions

    NASA Astrophysics Data System (ADS)

    Cardarelli, Gene A.

    The primary goal in radiation oncology is to deliver lethal radiation doses to tumors, while minimizing dose to normal tissue. IMRT has the capability to increase the dose to the targets and decrease the dose to normal tissue, increasing local control, decrease toxicity and allow for effective dose escalation. This advanced technology does present complex dose distributions that are not easily verified. Furthermore, the dose inhomogeneity caused by non-uniform dose distributions seen in IMRT treatments has caused the development of biological models attempting to characterize the dose-volume effect in the response of organized tissues to radiation. Dosimetry of small fields can be quite challenging when measuring dose distributions for high-energy X-ray beams used in IMRT. The proper modeling of these small field distributions is essential in reproducing accurate dose for IMRT. This evaluation was conducted to quantify the effects of small field dosimetry on IMRT plan dose distributions and the effects on four biological model parameters. The four biological models evaluated were: (1) the generalized Equivalent Uniform Dose (gEUD), (2) the Tumor Control Probability (TCP), (3) the Normal Tissue Complication Probability (NTCP) and (4) the Probability of uncomplicated Tumor Control (P+). These models are used to estimate local control, survival, complications and uncomplicated tumor control. This investigation compares three distinct small field dose algorithms. Dose algorithms were created using film, small ion chamber, and a combination of ion chamber measurements and small field fitting parameters. Due to the nature of uncertainties in small field dosimetry and the dependence of biological models on dose volume information, this examination quantifies the effects of small field dosimetry techniques on radiobiological models and recommends pathways to reduce the errors in using these models to evaluate IMRT dose distributions. This study demonstrates the importance of valid physical dose modeling prior to the use of biological modeling. The success of using biological function data, such as hypoxia, in clinical IMRT planning will greatly benefit from the results of this study.

  2. Evaluation of nonrigid registration models for interfraction dose accumulation in radiotherapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Janssens, Guillaume; Orban de Xivry, Jonathan; Fekkes, Stein

    2009-09-15

    Purpose: Interfraction dose accumulation is necessary to evaluate the dose distribution of an entire course of treatment by adding up multiple dose distributions of different treatment fractions. This accumulation of dose distributions is not straightforward as changes in the patient anatomy may occur during treatment. For this purpose, the accuracy of nonrigid registration methods is assessed for dose accumulation based on the calculated deformations fields. Methods: A phantom study using a deformable cubic silicon phantom with implanted markers and a cylindrical silicon phantom with MOSFET detectors has been performed. The phantoms were deformed and images were acquired using a cone-beammore » CT imager. Dose calculations were performed on these CT scans using the treatment planning system. Nonrigid CT-based registration was performed using two different methods, the Morphons and Demons. The resulting deformation field was applied on the dose distribution. For both phantoms, accuracy of the registered dose distribution was assessed. For the cylindrical phantom, also measured dose values in the deformed conditions were compared with the dose values of the registered dose distributions. Finally, interfraction dose accumulation for two treatment fractions of a patient with primary rectal cancer has been performed and evaluated using isodose lines and the dose volume histograms of the target volume and normal tissue. Results: A significant decrease in the difference in marker or MOSFET position was observed after nonrigid registration methods (p<0.001) for both phantoms and with both methods, as well as a significant decrease in the dose estimation error (p<0.01 for the cubic phantom and p<0.001 for the cylindrical) with both methods. Considering the whole data set at once, the difference between estimated and measured doses was also significantly decreased using registration (p<0.001 for both methods). The patient case showed a slightly underdosed planning target volume and an overdosed bladder volume due to anatomical deformations. Conclusions: Dose accumulation using nonrigid registration methods is possible using repeated CT imaging. This opens possibilities for interfraction dose accumulation and adaptive radiotherapy to incorporate possible differences in dose delivered to the target volume and organs at risk due to anatomical deformations.« less

  3. SU-E-J-110: Dosimetric Analysis of Respiratory Motion Based On Four-Dimensional Dose Accumulation in Liver Stereotactic Body Radiotherapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kang, S; Kim, D; Kim, T

    2015-06-15

    Purpose: Respiratory motion in thoracic and abdominal region could lead to significant underdosing of target and increased dose to healthy tissues. The aim of this study is to evaluate the dosimetric effect of respiratory motion in conventional 3D dose by comparing 4D deformable dose in liver stereotactic body radiotherapy (SBRT). Methods: Five patients who had previously treated liver SBRT were included in this study. Four-dimensional computed tomography (4DCT) images with 10 phases for all patients were acquired on multi-slice CT scanner (Siemens, Somatom definition). Conventional 3D planning was performed using the average intensity projection (AIP) images. 4D dose accumulation wasmore » calculated by summation of dose distribution for all phase images of 4DCT using deformable image registration (DIR) . The target volume and normal organs dose were evaluated with the 4D dose and compared with those from 3D dose. And also, Index of achievement (IOA) which assesses the consistency between planned dose and prescription dose was used to compare target dose distribution between 3D and 4D dose. Results: Although the 3D dose calculation considered the moving target coverage, significant differences of various dosimetric parameters between 4D and 3D dose were observed in normal organs and PTV. The conventional 3D dose overestimated dose to PTV, however, there was no significant difference for GTV. The average difference of IOA which become ‘1’ in an ideal case was 3.2% in PTV. The average difference of liver and duodenum was 5% and 16% respectively. Conclusion: 4D dose accumulation which can provide dosimetric effect of respiratory motion has a possibility to predict the more accurate delivered dose to target and normal organs and improve treatment accuracy. This work was supported by the Radiation Technology R&D program (No. 2013M2A2A7043498) and the Mid-career Researcher Program (2014R1A2A1A10050270) through the National Research Foundation of Korea funded by the Ministry of Science, ICT&Future Planning (MSIP) of Korea.« less

  4. Dose to mass for evaluation and optimization of lung cancer radiation therapy.

    PubMed

    Tyler Watkins, William; Moore, Joseph A; Hugo, Geoffrey D; Siebers, Jeffrey V

    2017-11-01

    To evaluate potential organ at risk dose-sparing by using dose-mass-histogram (DMH) objective functions compared with dose-volume-histogram (DVH) objective functions. Treatment plans were retrospectively optimized for 10 locally advanced non-small cell lung cancer patients based on DVH and DMH objectives. DMH-objectives were the same as DVH objectives, but with mass replacing volume. Plans were normalized to dose to 95% of the PTV volume (PTV-D95v) or mass (PTV-D95m). For a given optimized dose, DVH and DMH were intercompared to ascertain dose-to-volume vs. dose-to-mass differences. Additionally, the optimized doses were intercompared using DVH and DMH metrics to ascertain differences in optimized plans. Mean dose to volume, D v ‾, mean dose to mass, D M ‾, and fluence maps were intercompared. For a given dose distribution, DVH and DMH differ by >5% in heterogeneous structures. In homogeneous structures including heart and spinal cord, DVH and DMH are nearly equivalent. At fixed PTV-D95v, DMH-optimization did not significantly reduce dose to OARs but reduced PTV-D v ‾ by 0.20±0.2Gy (p=0.02) and PTV-D M ‾ by 0.23±0.3Gy (p=0.02). Plans normalized to PTV-D95m also result in minor PTV dose reductions and esophageal dose sparing (D v ‾ reduced 0.45±0.5Gy, p=0.02 and D M ‾ reduced 0.44±0.5Gy, p=0.02) compared to DVH-optimized plans. Optimized fluence map comparisons indicate that DMH optimization reduces dose in the periphery of lung PTVs. DVH- and DMH-dose indices differ by >5% in lung and lung target volumes for fixed dose distributions, but optimizing DMH did not reduce dose to OARs. The primary difference observed in DVH- and DMH-optimized plans were variations in fluence to the periphery of lung target PTVs, where low density lung surrounds tumor. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. GTV-based prescription in SBRT for lung lesions using advanced dose calculation algorithms.

    PubMed

    Lacornerie, Thomas; Lisbona, Albert; Mirabel, Xavier; Lartigau, Eric; Reynaert, Nick

    2014-10-16

    The aim of current study was to investigate the way dose is prescribed to lung lesions during SBRT using advanced dose calculation algorithms that take into account electron transport (type B algorithms). As type A algorithms do not take into account secondary electron transport, they overestimate the dose to lung lesions. Type B algorithms are more accurate but still no consensus is reached regarding dose prescription. The positive clinical results obtained using type A algorithms should be used as a starting point. In current work a dose-calculation experiment is performed, presenting different prescription methods. Three cases with three different sizes of peripheral lung lesions were planned using three different treatment platforms. For each individual case 60 Gy to the PTV was prescribed using a type A algorithm and the dose distribution was recalculated using a type B algorithm in order to evaluate the impact of the secondary electron transport. Secondly, for each case a type B algorithm was used to prescribe 48 Gy to the PTV, and the resulting doses to the GTV were analyzed. Finally, prescriptions based on specific GTV dose volumes were evaluated. When using a type A algorithm to prescribe the same dose to the PTV, the differences regarding median GTV doses among platforms and cases were always less than 10% of the prescription dose. The prescription to the PTV based on type B algorithms, leads to a more important variability of the median GTV dose among cases and among platforms, (respectively 24%, and 28%). However, when 54 Gy was prescribed as median GTV dose, using a type B algorithm, the variability observed was minimal. Normalizing the prescription dose to the median GTV dose for lung lesions avoids variability among different cases and treatment platforms of SBRT when type B algorithms are used to calculate the dose. The combination of using a type A algorithm to optimize a homogeneous dose in the PTV and using a type B algorithm to prescribe the median GTV dose provides a very robust method for treating lung lesions.

  6. Efficacy of Single-Dose and Triple-Dose Albendazole and Mebendazole against Soil-Transmitted Helminths and Taenia spp.: A Randomized Controlled Trial

    PubMed Central

    Steinmann, Peter; Utzinger, Jürg; Du, Zun-Wei; Jiang, Jin-Yong; Chen, Jia-Xu; Hattendorf, Jan; Zhou, Hui; Zhou, Xiao-Nong

    2011-01-01

    Background The control of soil-transmitted helminth (STH) infections currently relies on the large-scale administration of single-dose oral albendazole or mebendazole. However, these treatment regimens have limited efficacy against hookworm and Trichuris trichiura in terms of cure rates (CR), whereas fecal egg reduction rates (ERR) are generally high for all common STH species. We compared the efficacy of single-dose versus triple-dose treatment against hookworm and other STHs in a community-based randomized controlled trial in the People's Republic of China. Methodology/Principal findings The hookworm CR and fecal ERR were assessed in 314 individuals aged ≥5 years who submitted two stool samples before and 3–4 weeks after administration of single-dose oral albendazole (400 mg) or mebendazole (500 mg) or triple-dose albendazole (3×400 mg over 3 consecutive days) or mebendazole (3×500 mg over 3 consecutive days). Efficacy against T. trichiura, Ascaris lumbricoides, and Taenia spp. was also assessed. Albendazole cured significantly more hookworm infections than mebendazole in both treatment regimens (single dose: respective CRs 69% (95% confidence interval [CI]: 55–81%) and 29% (95% CI: 20–45%); triple dose: respective CRs 92% (95% CI: 81–98%) and 54% (95% CI: 46–71%)). ERRs followed the same pattern (single dose: 97% versus 84%; triple dose: 99.7% versus 96%). Triple-dose regimens outperformed single doses against T. trichiura; three doses of mebendazole – the most efficacious treatment tested – cured 71% (95% CI: 57–82%). Both single and triple doses of either drug were highly efficacious against A. lumbricoides (CR: 93–97%; ERR: all >99.9%). Triple dose regimens cured all Taenia spp. infections, whereas single dose applications cured only half of them. Conclusions/Significance Single-dose oral albendazole is more efficacious against hookworm than mebendazole. To achieve high CRs against both hookworm and T. trichiura, triple-dose regimens are warranted. Trial Registration www.controlled-trials.com ISRCTN47375023 PMID:21980373

  7. SU-F-T-113: Inherent Functional Dependence of Spinal Cord Doses of Variable Irradiated Volumes in Spine SBRT

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ma, L; Braunstein, S; Chiu, J

    2016-06-15

    Purpose: Spinal cord tolerance for SBRT has been recommended for the maximum point dose level or at irradiated volumes such as 0.35 mL or 10% of contoured volumes. In this study, we investigated an inherent functional relationship that associates these dose surrogates for irradiated spinal cord volumes of up to 3.0 mL. Methods: A hidden variable termed as Effective Dose Radius (EDR) was formulated based on a dose fall-off model to correlate dose at irradiated spinal cord volumes ranging from 0 mL (point maximum) to 3.0 mL. A cohort of 15 spine SBRT cases was randomly selected to derive anmore » EDR-parameterized formula. The mean prescription dose for the studied cases was 21.0±8.0 Gy (range, 10–40Gy) delivered in 3±1 fractions with target volumes of 39.1 ± 70.6 mL. Linear regression and variance analysis were performed for the fitting parameters of variable EDR values. Results: No direct correlation was found between the dose at maximum point and doses at variable spinal cord volumes. For example, Pearson R{sup 2} = 0.643 and R{sup 2}= 0.491 were obtained when correlating the point maximum dose with the spinal cord dose at 1 mL and 3 mL, respectively. However, near perfect correlation (R{sup 2} ≥0.99) was obtained when corresponding parameterized EDRs. Specifically, Pearson R{sup 2}= 0.996 and R{sup 2} = 0.990 were obtained when correlating EDR (maximum point dose) with EDR (dose at 1 mL) and EDR(dose at 3 mL), respectively. As a result, high confidence level look-up tables were established to correlate spinal cord doses at the maximum point to any finite irradiated volumes. Conclusion: An inherent functional relationship was demonstrated for spine SBRT. Such a relationship unifies dose surrogates at variable cord volumes and proves that a single dose surrogate (e.g. point maximum dose) is mathematically sufficient in constraining the overall spinal cord dose tolerance for SBRT.« less

  8. EFFECT OF RADIATION DOSE LEVEL ON ACCURACY AND PRECISION OF MANUAL SIZE MEASUREMENTS IN CHEST TOMOSYNTHESIS EVALUATED USING SIMULATED PULMONARY NODULES

    PubMed Central

    Söderman, Christina; Johnsson, Åse Allansdotter; Vikgren, Jenny; Norrlund, Rauni Rossi; Molnar, David; Svalkvist, Angelica; Månsson, Lars Gunnar; Båth, Magnus

    2016-01-01

    The aim of the present study was to investigate the dependency of the accuracy and precision of nodule diameter measurements on the radiation dose level in chest tomosynthesis. Artificial ellipsoid-shaped nodules with known dimensions were inserted in clinical chest tomosynthesis images. Noise was added to the images in order to simulate radiation dose levels corresponding to effective doses for a standard-sized patient of 0.06 and 0.04 mSv. These levels were compared with the original dose level, corresponding to an effective dose of 0.12 mSv for a standard-sized patient. Four thoracic radiologists measured the longest diameter of the nodules. The study was restricted to nodules located in high-dose areas of the tomosynthesis projection radiographs. A significant decrease of the measurement accuracy and intraobserver variability was seen for the lowest dose level for a subset of the observers. No significant effect of dose level on the interobserver variability was found. The number of non-measurable small nodules (≤5 mm) was higher for the two lowest dose levels compared with the original dose level. In conclusion, for pulmonary nodules at positions in the lung corresponding to locations in high-dose areas of the projection radiographs, using a radiation dose level resulting in an effective dose of 0.06 mSv to a standard-sized patient may be possible in chest tomosynthesis without affecting the accuracy and precision of nodule diameter measurements to any large extent. However, an increasing number of non-measurable small nodules (≤5 mm) with decreasing radiation dose may raise some concerns regarding an applied general dose reduction for chest tomosynthesis examinations in the clinical praxis. PMID:26994093

  9. EFFECT OF RADIATION DOSE LEVEL ON ACCURACY AND PRECISION OF MANUAL SIZE MEASUREMENTS IN CHEST TOMOSYNTHESIS EVALUATED USING SIMULATED PULMONARY NODULES.

    PubMed

    Söderman, Christina; Johnsson, Åse Allansdotter; Vikgren, Jenny; Norrlund, Rauni Rossi; Molnar, David; Svalkvist, Angelica; Månsson, Lars Gunnar; Båth, Magnus

    2016-06-01

    The aim of the present study was to investigate the dependency of the accuracy and precision of nodule diameter measurements on the radiation dose level in chest tomosynthesis. Artificial ellipsoid-shaped nodules with known dimensions were inserted in clinical chest tomosynthesis images. Noise was added to the images in order to simulate radiation dose levels corresponding to effective doses for a standard-sized patient of 0.06 and 0.04 mSv. These levels were compared with the original dose level, corresponding to an effective dose of 0.12 mSv for a standard-sized patient. Four thoracic radiologists measured the longest diameter of the nodules. The study was restricted to nodules located in high-dose areas of the tomosynthesis projection radiographs. A significant decrease of the measurement accuracy and intraobserver variability was seen for the lowest dose level for a subset of the observers. No significant effect of dose level on the interobserver variability was found. The number of non-measurable small nodules (≤5 mm) was higher for the two lowest dose levels compared with the original dose level. In conclusion, for pulmonary nodules at positions in the lung corresponding to locations in high-dose areas of the projection radiographs, using a radiation dose level resulting in an effective dose of 0.06 mSv to a standard-sized patient may be possible in chest tomosynthesis without affecting the accuracy and precision of nodule diameter measurements to any large extent. However, an increasing number of non-measurable small nodules (≤5 mm) with decreasing radiation dose may raise some concerns regarding an applied general dose reduction for chest tomosynthesis examinations in the clinical praxis. © The Author 2016. Published by Oxford University Press.

  10. A comparison of skin and chest wall dose delivered with multicatheter, Contura multilumen balloon, and MammoSite breast brachytherapy.

    PubMed

    Cuttino, Laurie W; Todor, Dorin; Rosu, Mihaela; Arthur, Douglas W

    2011-01-01

    Skin and chest wall doses have been correlated with toxicity in patients treated with breast brachytherapy . This investigation compared the ability to control skin and chest wall doses between patients treated with multicatheter (MC), Contura multilumen balloon (CMLB), and MammoSite (MS) brachytherapy. 43 patients treated with the MC technique, 45 patients treated with the CMLB, and 83 patients treated with the MS were reviewed. The maximum doses delivered to the skin and chest wall were calculated for all patients. The mean maximum skin doses for the MC, CMLB, and MS were 2.3 Gy (67% of prescription dose), 2.8 Gy (82% of prescription dose), and 3.2 Gy per fraction (94% of prescription dose), respectively. Although the skin distances were similar (p = 0.23) for the two balloon techniques, the mean skin dose with the CMLB was significantly lower than with the MS (p = 0.05). The mean maximum rib doses for the MC, CMLB, and MS were 2.3 Gy (67% of prescription dose), 2.8 Gy (82% of prescription dose), and 3.6 Gy per fraction (105% of prescription dose), respectively. Again, the mean rib dose with the CMLB was significantly lower than with the MS (p = 0.002). The MC and CMLB techniques are associated with significantly lower mean skin and rib doses than is the MS. Treatment with the MS was associated with significantly more patients receiving doses to the skin or rib in excess of 125% of the prescription. Treatment with the CMLB may prove to yield less normal tissue toxicity than treatment with the MS. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Evaluation of clinical use of OneDose™ metal oxide semiconductor field-effect transistor detectors compared to thermoluminescent dosimeters to measure skin dose for adult patients with acute lymphoblastic leukemia

    PubMed Central

    Al-Mohammed, Huda Ibrahim

    2011-01-01

    Background: Total body irradiation is a protocol used to treat acute lymphoblastic leukemia in patients prior to their bone marrow transplant. It involves the treatment of the whole body using a large radiation field with extended source-skin distance. Therefore, it is important to measure and monitor the skin dose during the treatment. Thermoluminescent dosimeters (TLDs) and the OneDose™ metal oxide semiconductor field effect transistor (MOSFET) detectors are used during treatment delivery to measure the radiation dose and compare it with the target prescribed dose. Aims: The primary goal of this study was to measure the variation of skin dose using OneDose MOSFET detectors and TLD detectors, and compare the results with the target prescribed dose. The secondary aim was to evaluate the simplicity of use and determine if one system was superior to the other in clinical use. Material and Methods: The measurements involved twelve adult patients diagnosed with acute lymphoblastic leukemia. TLD and OneDose MOSFET dosimetry were performed at ten different anatomical sites of each patient. Results: The results showed that there was a variation between skin dose measured with OneDose MOSFET detectors and TLD in all patients. However, the variation was not significant. Furthermore, the results showed for every anatomical site there was no significant different between the prescribed dose and the dose measured by either TLD or OneDose MOSFET detectors. Conclusion: There were no significant differences between the OneDose MOSFET and TLDs in comparison to the target prescribed dose. However, OneDose MOSFET detectors give a direct read-out immediately after the treatment, and their simplicity of use to compare with TLD detectors may make them preferred for clinical use. PMID:22171243

  12. Clinical outcomes and cost minimization with an alternative dosing regimen for meropenem in a community hospital.

    PubMed

    Patel, Gita Wasan; Duquaine, Susan M; McKinnon, Peggy S

    2007-12-01

    To compare outcomes and cost for the traditional United States Food and Drug Administration-approved dosing regimen for meropenem versus an alternative dosing regimen providing similar pharmacodynamic exposure with a lower total daily dose. Retrospective cohort study with a cost-minimization analysis. A 417-bed, privately owned community hospital. One hundred patients who received meropenem 1 g every 8 or 12 hours (traditional dosing regimen) between January 1 and September 30, 2004 (historical controls), and 192 patients who received meropenem 500 mg every 6 or 8 hours (alternative dosing regimen) between October 1, 2004, and September 30, 2005. Demographic and clinical data were collected for all patients. Cost-minimization analysis was performed by using the drug acquisition cost for meropenem. Demographics, sources of infection, distributions of organisms, and Charlson Comorbidity Index scores were similar between patients in the traditionally and alternatively dosed groups. Concomitant therapy, duration of therapy, success rates, lengths of stay, and in-hospital mortality rates were also similar between groups. Median time to the resolution of symptoms was 3 days for traditional dosing and 1.5 days for alternative dosing (p<0.0001). A logistic regression model including the dosing strategy showed that only polymicrobial infections and sepsis were associated with increased failure rates. The median cost for antibiotics was $439.05/patient for traditional dosing and $234.08/patient for alternative dosing (p<0.0001). An alternative dosing regimen for meropenem with a lower total daily dose yielded patient outcomes, including success rates and duration of therapy, equivalent to those of the traditional dosing regimen. Alternative dosing decreased total drug exposure, costs for antibiotics, and time to the resolution of infections.

  13. Personalized Feedback on Staff Dose in Fluoroscopy-Guided Interventions: A New Era in Radiation Dose Monitoring.

    PubMed

    Sailer, Anna M; Vergoossen, Laura; Paulis, Leonie; van Zwam, Willem H; Das, Marco; Wildberger, Joachim E; Jeukens, Cécile R L P N

    2017-11-01

    Radiation safety and protection are a key component of fluoroscopy-guided interventions. We hypothesize that providing weekly personal dose feedback will increase radiation awareness and ultimately will lead to optimized behavior. Therefore, we designed and implemented a personalized feedback of procedure and personal doses for medical staff involved in fluoroscopy-guided interventions. Medical staff (physicians and technicians, n = 27) involved in fluoroscopy-guided interventions were equipped with electronic personal dose meters (PDMs). Procedure dose data including the dose area product and effective doses from PDMs were prospectively monitored for each consecutive procedure over an 8-month period (n = 1082). A personalized feedback form was designed displaying for each staff individually the personal dose per procedure, as well as relative and cumulative doses. This study consisted of two phases: (1) 1-5th months: Staff did not receive feedback (n = 701) and (2) 6-8th months: Staff received weekly individual dose feedback (n = 381). An anonymous evaluation was performed on the feedback and occupational dose. Personalized feedback was scored valuable by 76% of the staff and increased radiation dose awareness for 71%. 57 and 52% reported an increased feeling of occupational safety and changing their behavior because of personalized feedback, respectively. For technicians, the normalized dose was significantly lower in the feedback phase compared to the prefeedback phase: [median (IQR) normalized dose (phase 1) 0.12 (0.04-0.50) µSv/Gy cm 2 versus (phase 2) 0.08 (0.02-0.24) µSv/Gy cm 2 , p = 0.002]. Personalized dose feedback increases radiation awareness and safety and can be provided to staff involved in fluoroscopy-guided interventions.

  14. Measurements of the neutron dose equivalent for various radiation qualities, treatment machines and delivery techniques in radiation therapy

    NASA Astrophysics Data System (ADS)

    Hälg, R. A.; Besserer, J.; Boschung, M.; Mayer, S.; Lomax, A. J.; Schneider, U.

    2014-05-01

    In radiation therapy, high energy photon and proton beams cause the production of secondary neutrons. This leads to an unwanted dose contribution, which can be considerable for tissues outside of the target volume regarding the long term health of cancer patients. Due to the high biological effectiveness of neutrons in regards to cancer induction, small neutron doses can be important. This study quantified the neutron doses for different radiation therapy modalities. Most of the reports in the literature used neutron dose measurements free in air or on the surface of phantoms to estimate the amount of neutron dose to the patient. In this study, dose measurements were performed in terms of neutron dose equivalent inside an anthropomorphic phantom. The neutron dose equivalent was determined using track etch detectors as a function of the distance to the isocenter, as well as for radiation sensitive organs. The dose distributions were compared with respect to treatment techniques (3D-conformal, volumetric modulated arc therapy and intensity-modulated radiation therapy for photons; spot scanning and passive scattering for protons), therapy machines (Varian, Elekta and Siemens linear accelerators) and radiation quality (photons and protons). The neutron dose equivalent varied between 0.002 and 3 mSv per treatment gray over all measurements. Only small differences were found when comparing treatment techniques, but substantial differences were observed between the linear accelerator models. The neutron dose equivalent for proton therapy was higher than for photons in general and in particular for double-scattered protons. The overall neutron dose equivalent measured in this study was an order of magnitude lower than the stray dose of a treatment using 6 MV photons, suggesting that the contribution of the secondary neutron dose equivalent to the integral dose of a radiotherapy patient is small.

  15. SU-E-J-11: Measurement of Eye Lens Dose for Varian On-Board Imaging with Different CBCT Acquisition Techniques

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Deshpande, S; Dhote, D; Kumar, R

    Purpose: To measure actual patient eye lens dose for different cone beam computed tomography (CBCT) acquisition protocol of Varian’s On Board Imagining (OBI) system using Optically Stimulated Luminescence (OSL) dosimeter and study the eye lens dose with patient geometry and distance of isocenter to the eye lens Methods: OSL dosimeter was used to measure eye lens dose of patient. OSL dosimeter was placed on patient forehead center during CBCT image acquisition to measure eye lens dose. For three different cone beam acquisition protocol (standard dose head, low dose head and high quality head) of Varian On-Board Imaging, eye lens dosesmore » were measured. Measured doses were correlated with patient geometry and distance between isocenter to eye lens. Results: Measured eye lens dose for standard dose head was in the range of 1.8 mGy to 3.2 mGy, for high quality head protocol dose was in range of 4.5mGy to 9.9 mGy whereas for low dose head was in the range of 0.3mGy to 0.7mGy. Dose to eye lens is depends upon position of isocenter. For posterioraly located tumor eye lens dose is less. Conclusion: From measured doses it can be concluded that by proper selection of imagining protocol and frequency of imaging, it is possible to restrict the eye lens dose below the new limit set by ICRP. However, undoubted advantages of imaging system should be counter balanced by careful consideration of imaging protocol especially for very intense imaging sequences for Adoptive Radiotherapy or IMRT.« less

  16. A Comparison of Skin and Chest Wall Dose Delivered With Multicatheter, Contura Multilumen Balloon, and MammoSite Breast Brachytherapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cuttino, Laurie W., E-mail: lcuttino@mcvh-vcu.ed; Todor, Dorin; Rosu, Mihaela

    2011-01-01

    Purpose: Skin and chest wall doses have been correlated with toxicity in patients treated with breast brachytherapy . This investigation compared the ability to control skin and chest wall doses between patients treated with multicatheter (MC), Contura multilumen balloon (CMLB), and MammoSite (MS) brachytherapy. Methods and Materials: 43 patients treated with the MC technique, 45 patients treated with the CMLB, and 83 patients treated with the MS were reviewed. The maximum doses delivered to the skin and chest wall were calculated for all patients. Results: The mean maximum skin doses for the MC, CMLB, and MS were 2.3 Gy (67%more » of prescription dose), 2.8 Gy (82% of prescription dose), and 3.2 Gy per fraction (94% of prescription dose), respectively. Although the skin distances were similar (p = 0.23) for the two balloon techniques, the mean skin dose with the CMLB was significantly lower than with the MS (p = 0.05). The mean maximum rib doses for the MC, CMLB, and MS were 2.3 Gy (67% of prescription dose), 2.8 Gy (82% of prescription dose), and 3.6 Gy per fraction (105% of prescription dose), respectively. Again, the mean rib dose with the CMLB was significantly lower than with the MS (p = 0.002). Conclusion: The MC and CMLB techniques are associated with significantly lower mean skin and rib doses than is the MS. Treatment with the MS was associated with significantly more patients receiving doses to the skin or rib in excess of 125% of the prescription. Treatment with the CMLB may prove to yield less normal tissue toxicity than treatment with the MS.« less

  17. Perfusion CT of the Brain and Liver and of Lung Tumors: Use of Monte Carlo Simulation for Patient Dose Estimation for Examinations With a Cone-Beam 320-MDCT Scanner.

    PubMed

    Cros, Maria; Geleijns, Jacob; Joemai, Raoul M S; Salvadó, Marçal

    2016-01-01

    The purpose of this study was to estimate the patient dose from perfusion CT examinations of the brain, lung tumors, and the liver on a cone-beam 320-MDCT scanner using a Monte Carlo simulation and the recommendations of the International Commission on Radiological Protection (ICRP). A Monte Carlo simulation based on the Electron Gamma Shower Version 4 package code was used to calculate organ doses and the effective dose in the reference computational phantoms for an adult man and adult woman as published by the ICRP. Three perfusion CT acquisition protocols--brain, lung tumor, and liver perfusion--were evaluated. Additionally, dose assessments were performed for the skin and for the eye lens. Conversion factors were obtained to estimate effective doses and organ doses from the volume CT dose index and dose-length product. The sex-averaged effective doses were approximately 4 mSv for perfusion CT of the brain and were between 23 and 26 mSv for the perfusion CT body protocols. The eye lens dose from the brain perfusion CT examination was approximately 153 mGy. The sex-averaged peak entrance skin dose (ESD) was 255 mGy for the brain perfusion CT studies, 157 mGy for the lung tumor perfusion CT studies, and 172 mGy for the liver perfusion CT studies. The perfusion CT protocols for imaging the brain, lung tumors, and the liver performed on a 320-MDCT scanner yielded patient doses that are safely below the threshold doses for deterministic effects. The eye lens dose, peak ESD, and effective doses can be estimated for other clinical perfusion CT examinations from the conversion factors that were derived in this study.

  18. Measurements of the neutron dose equivalent for various radiation qualities, treatment machines and delivery techniques in radiation therapy.

    PubMed

    Hälg, R A; Besserer, J; Boschung, M; Mayer, S; Lomax, A J; Schneider, U

    2014-05-21

    In radiation therapy, high energy photon and proton beams cause the production of secondary neutrons. This leads to an unwanted dose contribution, which can be considerable for tissues outside of the target volume regarding the long term health of cancer patients. Due to the high biological effectiveness of neutrons in regards to cancer induction, small neutron doses can be important. This study quantified the neutron doses for different radiation therapy modalities. Most of the reports in the literature used neutron dose measurements free in air or on the surface of phantoms to estimate the amount of neutron dose to the patient. In this study, dose measurements were performed in terms of neutron dose equivalent inside an anthropomorphic phantom. The neutron dose equivalent was determined using track etch detectors as a function of the distance to the isocenter, as well as for radiation sensitive organs. The dose distributions were compared with respect to treatment techniques (3D-conformal, volumetric modulated arc therapy and intensity-modulated radiation therapy for photons; spot scanning and passive scattering for protons), therapy machines (Varian, Elekta and Siemens linear accelerators) and radiation quality (photons and protons). The neutron dose equivalent varied between 0.002 and 3 mSv per treatment gray over all measurements. Only small differences were found when comparing treatment techniques, but substantial differences were observed between the linear accelerator models. The neutron dose equivalent for proton therapy was higher than for photons in general and in particular for double-scattered protons. The overall neutron dose equivalent measured in this study was an order of magnitude lower than the stray dose of a treatment using 6 MV photons, suggesting that the contribution of the secondary neutron dose equivalent to the integral dose of a radiotherapy patient is small.

  19. SU-F-P-19: Fetal Dose Estimate for a High-Dose Fluoroscopy Guided Intervention Using Modern Data Tools

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Moirano, J

    Purpose: An accurate dose estimate is necessary for effective patient management after a fetal exposure. In the case of a high-dose exposure, it is critical to use all resources available in order to make the most accurate assessment of the fetal dose. This work will demonstrate a methodology for accurate fetal dose estimation using tools that have recently become available in many clinics, and show examples of best practices for collecting data and performing the fetal dose calculation. Methods: A fetal dose estimate calculation was performed using modern data collection tools to determine parameters for the calculation. The reference pointmore » air kerma as displayed by the fluoroscopic system was checked for accuracy. A cumulative dose incidence map and DICOM header mining were used to determine the displayed reference point air kerma. Corrections for attenuation caused by the patient table and pad were measured and applied in order to determine the peak skin dose. The position and depth of the fetus was determined by ultrasound imaging and consultation with a radiologist. The data collected was used to determine a normalized uterus dose from Monte Carlo simulation data. Fetal dose values from this process were compared to other accepted calculation methods. Results: An accurate high-dose fetal dose estimate was made. Comparison to accepted legacy methods were were within 35% of estimated values. Conclusion: Modern data collection and reporting methods ease the process for estimation of fetal dose from interventional fluoroscopy exposures. Many aspects of the calculation can now be quantified rather than estimated, which should allow for a more accurate estimation of fetal dose.« less

  20. Real-Time Patient and Staff Radiation Dose Monitoring in IR Practice

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sailer, Anna M., E-mail: karmanna@stanford.edu; Paulis, Leonie, E-mail: leonie.paulis@mumc.nl; Vergoossen, Laura

    PurposeKnowledge of medical radiation exposure permits application of radiation protection principles. In our center, the first dedicated real-time, automated patient and staff dose monitoring system (DoseWise Portal, Philips Healthcare) was installed. Aim of this study was to obtain insight in the procedural and occupational doses.Materials and MethodsAll interventional radiologists, vascular surgeons, and technicians wore personal dose meters (PDMs, DoseAware, Philips Healthcare). The dose monitoring system simultaneously registered for each procedure dose-related data as the dose area product (DAP) and effective staff dose (E) from PDMs. Use and type of shielding were recorded separately. All procedures were analyzed according to proceduremore » type; these included among others cerebral interventions (n = 112), iliac and/or caval venous recanalization procedures (n = 68), endovascular aortic repair procedures (n = 63), biliary duct interventions (n = 58), and percutaneous gastrostomy procedure (n = 28).ResultsMedian (±IQR) DAP doses ranged from 2.0 (0.8–3.1) (percutaneous gastrostomy) to 84 (53–147) Gy cm{sup 2} (aortic repair procedures). Median (±IQR) first operator doses ranged from 1.6 (1.1–5.0) μSv to 33.4 (12.1–125.0) for these procedures, respectively. The relative exposure, determined as first operator dose normalized to procedural DAP, ranged from 1.9 in biliary interventions to 0.1 μSv/Gy cm{sup 2} in cerebral interventions, indicating large variation in staff dose per unit DAP among the procedure types.ConclusionReal-time dose monitoring was able to identify the types of interventions with either an absolute or relatively high staff dose, and may allow for specific optimization of radiation protection.« less

  1. Dose Titration Algorithm Tuning (DTAT) should supersede 'the' Maximum Tolerated Dose (MTD) in oncology dose-finding trials.

    PubMed

    Norris, David C

    2017-01-01

    Background . Absent adaptive, individualized dose-finding in early-phase oncology trials, subsequent 'confirmatory' Phase III trials risk suboptimal dosing, with resulting loss of statistical power and reduced probability of technical success for the investigational therapy. While progress has been made toward explicitly adaptive dose-finding and quantitative modeling of dose-response relationships, most such work continues to be organized around a concept of 'the' maximum tolerated dose (MTD). The purpose of this paper is to demonstrate concretely how the aim of early-phase trials might be conceived, not as 'dose-finding', but as dose titration algorithm (DTA) -finding. Methods. A Phase I dosing study is simulated, for a notional cytotoxic chemotherapy drug, with neutropenia constituting the critical dose-limiting toxicity. The drug's population pharmacokinetics and myelosuppression dynamics are simulated using published parameter estimates for docetaxel. The amenability of this model to linearization is explored empirically. The properties of a simple DTA targeting neutrophil nadir of 500 cells/mm 3 using a Newton-Raphson heuristic are explored through simulation in 25 simulated study subjects. Results. Individual-level myelosuppression dynamics in the simulation model approximately linearize under simple transformations of neutrophil concentration and drug dose. The simulated dose titration exhibits largely satisfactory convergence, with great variance in individualized optimal dosing. Some titration courses exhibit overshooting. Conclusions. The large inter-individual variability in simulated optimal dosing underscores the need to replace 'the' MTD with an individualized concept of MTD i . To illustrate this principle, the simplest possible DTA capable of realizing such a concept is demonstrated. Qualitative phenomena observed in this demonstration support discussion of the notion of tuning such algorithms. Although here illustrated specifically in relation to cytotoxic chemotherapy, the DTAT principle appears similarly applicable to Phase I studies of cancer immunotherapy and molecularly targeted agents.

  2. Comparison of the Efficacy and Safety of 2 Acetaminophen Dosing Regimens in Febrile Infants and Children: A Report on 3 Legacy Studies.

    PubMed

    Temple, Anthony R; Zimmerman, Brenda; Gelotte, Cathy; Kuffner, Edwin K

    2017-01-01

    Compare efficacy and safety of 10 to 15 mg/kg with 20 to 30 mg/kg acetaminophen in febrile children 6 months to ≤ 11 years from 3 double-blind, randomized, single or multiple dose studies. Doses were compared on sum of the temperature differences (SUMDIFF), maximum temperature difference (MAXDIFF), temperature differences at each time point, and dose by time interactions. Alanine aminotransferase (ALT) was evaluated in the 72-hour duration study. A single dose of acetaminophen 20 to 30 mg/kg produced a greater effect on temperature decrement and duration of antipyretic effect over 8 hours than a single dose of 10 to 15 mg/kg. When equivalent total doses (i.e., 2 doses of 10 to 15 mg/kg given at 4-hour intervals and 1 dose of 20 to 30 mg/kg) were given over the initial 8-hour period, there were no significant temperature differences. Over a 72-hour period, 10 to 15 mg/kg acetaminophen administered every 4 hours maintained a more consistent temperature decrement than 20 to 30 mg/kg acetaminophen administered every 8 hours. Following doses of 60 to 90 mg/kg/day for up to 72 hours, no child had a clinically important increase in ALT from baseline. The number of children with reported adverse events was similar between doses. Data demonstrate the antipyretic effect of acetaminophen is dependent on total dose over a given time interval. These 3 studies provide clinical evidence that the recommended standard acetaminophen dose of 10 to 15 mg/kg is a safe and effective dose for treating fever in pediatric patients when administered as a single dose or as multiple doses for up to 72 hours.

  3. Pharmacokinetic Dashboard-Recommended Dosing Is Different than Standard of Care Dosing in Infliximab-Treated Pediatric IBD Patients.

    PubMed

    Dubinsky, Marla C; Phan, Becky L; Singh, Namita; Rabizadeh, Shervin; Mould, Diane R

    2017-01-01

    Standard of care (SOC; combination of 5-10 mg/kg and an interval every 6-8 weeks) dosing of infliximab (IFX) is associated with significant loss of response. Dashboards using covariates that influence IFX pharmacokinetics (PK) may be a more precise way of optimizing anti-TNF dosing. We tested a prototype dashboard to compare forecasted dosing regimens with actual administered regimens and SOC. Fifty IBD patients completing IFX induction were monitored during maintenance (weeks 14-54). Clinical and laboratory data were collected at each infusion; serum was analyzed for IFX concentrations and anti-drug antibodies (ADA) at weeks 14 and 54 (Prometheus Labs, San Diego). Dosing was blinded to PK data. Dashboard-based assessments were conducted on de-identified clinical, laboratory, and PK data. Bayesian algorithms were used to forecast individualized troughs and determine optimal dosing to maintain target trough concentrations (3 μg/mL). Dashboard forecasted dosing post-week 14 was compared to actual administered dose and frequency and SOC. Using week 14 clinical data only, the dashboard recommended either a dose or an interval change (<0.5 mg/kg or <1 week difference) in 43/50 patients; only 44% recommended to have SOC dosing. When IFX14 concentration and ADA status were added to clinical data, dose and/or interval changes based on actual dosing were recommended in 48/50 (96%) patients; SOC dosing was recommended in only 11/50 (22%). Dashboard recommended SOC IFX dosing in a minority of patients. Dashboards will be an important tool to individualize IFX dosing to improve treatment durability.

  4. A 3D isodose manipulation tool for interactive dose shaping

    NASA Astrophysics Data System (ADS)

    Kamerling, C. P.; Ziegenhein, P.; Heinrich, H.; Oelfke, U.

    2014-03-01

    The interactive dose shaping (IDS) planning paradigm aims to perform interactive local dose adaptations of an IMRT plan without compromising already established valuable dose features in real-time. In this work we introduce an interactive 3D isodose manipulation tool which enables local modifications of a dose distribution intuitively by direct manipulation of an isodose surface. We developed an in-house IMRT TPS framework employing an IDS engine as well as a 3D GUI for dose manipulation and visualization. In our software an initial dose distribution can be interactively modified through an isodose surface manipulation tool by intuitively clicking on an isodose surface. To guide the user interaction, the position of the modification is indicated by a sphere while the mouse cursor hovers the isodose surface. The sphere's radius controls the locality of the modification. The tool induces a dose modification as a direct change of dose in one or more voxels, which is incrementally obtained by fluence adjustments. A subsequent recovery step identifies voxels with violated dose features and aims to recover their original dose. We showed a proof of concept study for the proposed tool by adapting the dose distribution of a prostate case (9 beams, coplanar). Single dose modifications take less than 2 seconds on an actual desktop PC.

  5. Can reduction of uncertainties in cervix cancer brachytherapy potentially improve clinical outcome?

    PubMed

    Nesvacil, Nicole; Tanderup, Kari; Lindegaard, Jacob C; Pötter, Richard; Kirisits, Christian

    2016-09-01

    The aim of this study was to quantify the impact of different types and magnitudes of dosimetric uncertainties in cervix cancer brachytherapy (BT) on tumour control probability (TCP) and normal tissue complication probability (NTCP) curves. A dose-response simulation study was based on systematic and random dose uncertainties and TCP/NTCP models for CTV and rectum. Large patient cohorts were simulated assuming different levels of dosimetric uncertainties. TCP and NTCP were computed, based on the planned doses, the simulated dose uncertainty, and an underlying TCP/NTCP model. Systematic uncertainties of 3-20% and random uncertainties with a 5-30% standard deviation per BT fraction were analysed. Systematic dose uncertainties of 5% lead to a 1% decrease/increase of TCP/NTCP, while random uncertainties of 10% had negligible impact on the dose-response curve at clinically relevant dose levels for target and OAR. Random OAR dose uncertainties of 30% resulted in an NTCP increase of 3-4% for planned doses of 70-80Gy EQD2. TCP is robust to dosimetric uncertainties when dose prescription is in the more flat region of the dose-response curve at doses >75Gy. For OARs, improved clinical outcome is expected by reduction of uncertainties via sophisticated dose delivery and treatment verification. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Dependence of normal brain integral dose and normal tissue complication probability on the prescription isodose values for γ-knife radiosurgery

    NASA Astrophysics Data System (ADS)

    Ma, Lijun

    2001-11-01

    A recent multi-institutional clinical study suggested possible benefits of lowering the prescription isodose lines for stereotactic radiosurgery procedures. In this study, we investigate the dependence of the normal brain integral dose and the normal tissue complication probability (NTCP) on the prescription isodose values for γ-knife radiosurgery. An analytical dose model was developed for γ-knife treatment planning. The dose model was commissioned by fitting the measured dose profiles for each helmet size. The dose model was validated by comparing its results with the Leksell gamma plan (LGP, version 5.30) calculations. The normal brain integral dose and the NTCP were computed and analysed for an ensemble of treatment cases. The functional dependence of the normal brain integral dose and the NCTP versus the prescribing isodose values was studied for these cases. We found that the normal brain integral dose and the NTCP increase significantly when lowering the prescription isodose lines from 50% to 35% of the maximum tumour dose. Alternatively, the normal brain integral dose and the NTCP decrease significantly when raising the prescribing isodose lines from 50% to 65% of the maximum tumour dose. The results may be used as a guideline for designing future dose escalation studies for γ-knife applications.

  7. Radiation Hormesis: Historical Perspective and Implications for Low-Dose Cancer Risk Assessment

    PubMed Central

    Vaiserman, Alexander M.

    2010-01-01

    Current guidelines for limiting exposure of humans to ionizing radiation are based on the linear-no-threshold (LNT) hypothesis for radiation carcinogenesis under which cancer risk increases linearly as the radiation dose increases. With the LNT model even a very small dose could cause cancer and the model is used in establishing guidelines for limiting radiation exposure of humans. A slope change at low doses and dose rates is implemented using an empirical dose and dose rate effectiveness factor (DDREF). This imposes usually unacknowledged nonlinearity but not a threshold in the dose-response curve for cancer induction. In contrast, with the hormetic model, low doses of radiation reduce the cancer incidence while it is elevated after high doses. Based on a review of epidemiological and other data for exposure to low radiation doses and dose rates, it was found that the LNT model fails badly. Cancer risk after ordinarily encountered radiation exposure (medical X-rays, natural background radiation, etc.) is much lower than projections based on the LNT model and is often less than the risk for spontaneous cancer (a hormetic response). Understanding the mechanistic basis for hormetic responses will provide new insights about both risks and benefits from low-dose radiation exposure. PMID:20585444

  8. Mathematical optimization of high dose-rate brachytherapy—derivation of a linear penalty model from a dose-volume model

    NASA Astrophysics Data System (ADS)

    Morén, B.; Larsson, T.; Carlsson Tedgren, Å.

    2018-03-01

    High dose-rate brachytherapy is a method for cancer treatment where the radiation source is placed within the body, inside or close to a tumour. For dose planning, mathematical optimization techniques are being used in practice and the most common approach is to use a linear model which penalizes deviations from specified dose limits for the tumour and for nearby organs. This linear penalty model is easy to solve, but its weakness lies in the poor correlation of its objective value and the dose-volume objectives that are used clinically to evaluate dose distributions. Furthermore, the model contains parameters that have no clear clinical interpretation. Another approach for dose planning is to solve mixed-integer optimization models with explicit dose-volume constraints which include parameters that directly correspond to dose-volume objectives, and which are therefore tangible. The two mentioned models take the overall goals for dose planning into account in fundamentally different ways. We show that there is, however, a mathematical relationship between them by deriving a linear penalty model from a dose-volume model. This relationship has not been established before and improves the understanding of the linear penalty model. In particular, the parameters of the linear penalty model can be interpreted as dual variables in the dose-volume model.

  9. Immunogenicity of a three dose and five dose oral human rotavirus vaccine (RIX4414) schedule in south Indian infants.

    PubMed

    Kompithra, Rajeev Zachariah; Paul, Anu; Manoharan, Divya; Babji, Sudhir; Sarkar, Rajiv; Mathew, Leni G; Kang, Gagandeep

    2014-08-11

    This study was undertaken to compare the immunogenicity of a three dose and five dose schedule of an oral live-attenuated human rotavirus vaccine, Rotarix in south Indian infants. Healthy infants (N=90), six to seven weeks of age were enrolled to receive three doses (n=45) or five doses of Rotarix vaccine (n=45) along with other scheduled vaccines, each dose separated by a four week interval. Blood samples were taken before vaccination and one month post-dose three in the Rotarix three dose group and one month post-dose five in the Rotarix five dose group; all were tested for anti-rotavirus IgA by an antibody sandwich enzyme immunoassay. At baseline, >50% of infants had >20 units of anti-rotavirus IgA. The seroconversion rates after three and five doses were low and not significantly different in the two groups. However, among vaccine responders, children seropositive at baseline showed a much greater absolute increase in IgA antibody levels than children seronegative at baseline. Rotarix vaccine showed low immunogenicity in south Indian children and increasing the number of doses did not increase the proportion of infants seroconverting after vaccination. Copyright © 2014. Published by Elsevier Ltd.

  10. Quantification of dose uncertainties for the bladder in prostate cancer radiotherapy based on dominant eigenmodes

    NASA Astrophysics Data System (ADS)

    Rios, Richard; Acosta, Oscar; Lafond, Caroline; Espinosa, Jairo; de Crevoisier, Renaud

    2017-11-01

    In radiotherapy for prostate cancer the dose at the treatment planning for the bladder may be a bad surrogate of the actual delivered dose as the bladder presents the largest inter-fraction shape variations during treatment. This paper presents PCA models as a virtual tool to estimate dosimetric uncertainties for the bladder produced by motion and deformation between fractions. Our goal is to propose a methodology to determine the minimum number of modes required to quantify dose uncertainties of the bladder for motion/deformation models based on PCA. We trained individual PCA models using the bladder contours available from three patients with a planning computed tomography (CT) and on-treatment cone-beam CTs (CBCTs). Based on the above models and via deformable image registration (DIR), we estimated two accumulated doses: firstly, an accumulated dose obtained by integrating the planning dose over the Gaussian probability distribution of the PCA model; and secondly, an accumulated dose obtained by simulating treatment courses via a Monte Carlo approach. We also computed a reference accumulated dose for each patient using his available images via DIR. Finally, we compared the planning dose with the three accumulated doses, and we calculated local dose variability and dose-volume histogram uncertainties.

  11. Immunogenicity Following One, Two, or Three Doses of the 7-valent Pneumococcal Conjugate Vaccine

    PubMed Central

    Russell, FM; Balloch, A; Tang, MLK; Carapetis, JR; Licciardi, P; Nelson, J; Jenney, AWJ; Tikoduadua, L; Waqatakirewa, L; Pryor, J; Byrnes, GB; Cheung, YB; Mulholland, EK

    2009-01-01

    The aim was to identify an appropriate infant pneumococcal vaccination strategy for resource poor countries. Fijian infants received 0, 1, 2, or 3 doses of 7-valent pneumococcal conjugate vaccine (PCV) in early infancy. Following 3 PCV doses, geometric mean concentration (GMC) to all 7 serotypes were ≥ 1.0μg/mL, and >85% of children achieved antibody levels ≥0.35μg/mL at 18 weeks. Following 2 doses, GMC were lower for 6B, 14, and 23F, but higher for 19F compared with 3 doses. Following a single dose, significant responses were seen for all serotypes post primary series compared with the unvaccinated. By 12 months, differences between 2 and 3 doses persisted for serotype 14 only. Although GMC following 3 doses are higher than after 2 doses, the differences were small. A single dose may offer some protection for most serotypes. PMID:19616498

  12. A practical approach to determine dose metrics for nanomaterials.

    PubMed

    Delmaar, Christiaan J E; Peijnenburg, Willie J G M; Oomen, Agnes G; Chen, Jingwen; de Jong, Wim H; Sips, Adriënne J A M; Wang, Zhuang; Park, Margriet V D Z

    2015-05-01

    Traditionally, administered mass is used to describe doses of conventional chemical substances in toxicity studies. For deriving toxic doses of nanomaterials, mass and chemical composition alone may not adequately describe the dose, because particles with the same chemical composition can have completely different toxic mass doses depending on properties such as particle size. Other dose metrics such as particle number, volume, or surface area have been suggested, but consensus is lacking. The discussion regarding the most adequate dose metric for nanomaterials clearly needs a systematic, unbiased approach to determine the most appropriate dose metric for nanomaterials. In the present study, the authors propose such an approach and apply it to results from in vitro and in vivo experiments with silver and silica nanomaterials. The proposed approach is shown to provide a convenient tool to systematically investigate and interpret dose metrics of nanomaterials. Recommendations for study designs aimed at investigating dose metrics are provided. © 2015 SETAC.

  13. High dose-per-pulse electron beam dosimetry - A model to correct for the ion recombination in the Advanced Markus ionization chamber.

    PubMed

    Petersson, Kristoffer; Jaccard, Maud; Germond, Jean-François; Buchillier, Thierry; Bochud, François; Bourhis, Jean; Vozenin, Marie-Catherine; Bailat, Claude

    2017-03-01

    The purpose of this work was to establish an empirical model of the ion recombination in the Advanced Markus ionization chamber for measurements in high dose rate/dose-per-pulse electron beams. In addition, we compared the observed ion recombination to calculations using the standard Boag two-voltage-analysis method, the more general theoretical Boag models, and the semiempirical general equation presented by Burns and McEwen. Two independent methods were used to investigate the ion recombination: (a) Varying the grid tension of the linear accelerator (linac) gun (controls the linac output) and measuring the relative effect the grid tension has on the chamber response at different source-to-surface distances (SSD). (b) Performing simultaneous dose measurements and comparing the dose-response, in beams with varying dose rate/dose-per-pulse, with the chamber together with dose rate/dose-per-pulse independent Gafchromic™ EBT3 film. Three individual Advanced Markus chambers were used for the measurements with both methods. All measurements were performed in electron beams with varying mean dose rate, dose rate within pulse, and dose-per-pulse (10 -2  ≤ mean dose rate ≤ 10 3 Gy/s, 10 2  ≤ mean dose rate within pulse ≤ 10 7  Gy/s, 10 -4  ≤ dose-per-pulse ≤ 10 1  Gy), which was achieved by independently varying the linac gun grid tension, and the SSD. The results demonstrate how the ion collection efficiency of the chamber decreased as the dose-per-pulse increased, and that the ion recombination was dependent on the dose-per-pulse rather than the dose rate, a behavior predicted by Boag theory. The general theoretical Boag models agreed well with the data over the entire investigated dose-per-pulse range, but only for a low polarizing chamber voltage (50 V). However, the two-voltage-analysis method and the Burns & McEwen equation only agreed with the data at low dose-per-pulse values (≤ 10 -2 and ≤ 10 -1  Gy, respectively). An empirical model of the ion recombination in the chamber was found by fitting a logistic function to the data. The ion collection efficiency of the Advanced Markus ionization chamber decreases for measurements in electron beams with increasingly higher dose-per-pulse. However, this chamber is still functional for dose measurements in beams with dose-per-pulse values up toward and above 10 Gy, if the ion recombination is taken into account. Our results show that existing models give a less-than-accurate description of the observed ion recombination. This motivates the use of the presented empirical model for measurements with the Advanced Markus chamber in high dose-per-pulse electron beams, as it enables accurate absorbed dose measurements (uncertainty estimation: 2.8-4.0%, k = 1). The model depends on the dose-per-pulse in the beam, and it is also influenced by the polarizing chamber voltage, with increasing ion recombination with a lowering of the voltage. © 2017 American Association of Physicists in Medicine.

  14. The value of fixed rasburicase dosing versus weight-based dosing in the treatment and prevention of tumor lysis syndrome.

    PubMed

    Boutin, Alyssa; Blackman, Alison; O'Sullivan, David M; Forcello, Nicholas

    2018-01-01

    Background Rasburicase is a recombinant urate oxidase enzyme used for the treatment and prevention of tumor lysis syndrome. Our objective was to assess the efficacy of indication-based, low-dose rasburicase administration compared to the Food and Drug Administration-approved weight-based dosing. Methods This was a retrospective cohort study utilizing data from a tertiary medical center including patients admitted from 2012 to 2016, who received at least one dose of rasburicase. The primary outcome was achieving a uric acid level less than 7.5 mg/dl after a single dose of rasburicase in the preprotocol (Food and Drug Administration-approved weight-based dosing) and postprotocol (indication-based, low-dose) groups. Secondary outcomes included the change in uric acid levels between the pre- and postprotocol groups, adherence to the new institutional protocol, need for repeat rasburicase doses, and a cost analysis. Results Sixty-four patients received at least one dose of rasburicase between 1 January 2012 and 1 December 2016. Twenty-seven (79.4%) doses in the preprotocol group and 28 (82.4%) doses in the postprotocol group successfully achieved a uric acid level less than 7.5 mg/dl after a single dose of rasburicase (p=1.000). The average total monthly cost of rasburicase was reduced by 59.9% after adoption of the new protocol. Conclusions Indication-based, low-dose rasburicase displayed significantly more value when compared to weight-based dosing as shown by achieving cost savings without compromising clinical efficacy.

  15. Effect of Admission Oral Diuretic Dose on Response to Continuous versus Bolus Intravenous Diuretics in Acute Heart Failure: An Analysis from DOSE-AHF

    PubMed Central

    Shah, Ravi V.; McNulty, Steven; O'Connor, Christopher M.; Felker, G. Michael; Braunwald, Eugene; Givertz, Michael M.

    2014-01-01

    Background Results from the Diuretic Optimization Strategies in Acute Heart Failure (DOSE-AHF) study suggest that an initial continuous infusion of loop diuretics is not superior to bolus dosing with regard to clinical endpoints in AHF. We hypothesized that outpatient furosemide dose was associated with congestion and poorer renal function, and explored the hypothesis that a continuous infusion may be more effective in patients on higher outpatient diuretic doses. Methods DOSE-AHF randomized 308 patients within 24 hours of admission to high vs. low initial intravenous diuretic dose given as either a continuous infusion or bolus. We compared baseline characteristics and assessed associations between mode of administration (bolus vs. continuous) and outcomes in patients receiving high-dose (≥120 mg furosemide equivalent, n=177) versus low-dose (<120 mg furosemide equivalent, n=131) outpatient diuretics. Results Patients on higher doses of furosemide were less frequently on renin-angiotensin system inhibitors (P=.01), and had worse renal function and more advanced symptoms. There was a significant interaction between outpatient dose and mode of therapy (P=0.01) with respect to net fluid loss at 72 hours after adjusting for creatinine and intensification strategy. Admission diuretic dose was associated with an increased risk of death or rehospitalization at 60 days (adjusted HR=1.08 per 20-mg increment in dose, 95% CI 1.01–1.16, P=.03). Conclusions In acute HF, patients on higher diuretic doses have greater disease severity, and may benefit from an initial bolus strategy. PMID:23194486

  16. Dose Monitoring in Radiology Departments: Status Quo and Future Perspectives.

    PubMed

    Boos, J; Meineke, A; Bethge, O T; Antoch, G; Kröpil, P

    2016-05-01

    The number of computed tomography examinations has continuously increased over the last decades and accounts for a major part of the collective radiation dose from medical investigations. For purposes of quality assurance in modern radiology a systematic monitoring and analysis of dose related data from radiological examinations is mandatory. Various ways of collecting dose data are available today, for example the Digital Imaging and Communication in Medicine - Structured Report (DICOM-SR), optical character recognition and DICOM-modality performed procedure steps (MPPS). The DICOM-SR is part of the DICOM-standard and provides the DICOM-Radiation Dose Structured Report, which is an easily applicable and comprehensive solution to collect radiation dose parameters. This standard simplifies the process of data collection and enables comprehensive dose monitoring. Various commercial dose monitoring software devices with varying characteristics are available today. In this article, we discuss legal obligations, various ways to monitor dose data, current dose monitoring software solutions and future perspectives in regard to the EU Council Directive 2013/59/EURATOM. • Automated, systematic dose monitoring is an important element in quality assurance of radiology departments. • DICOM-RDSR-capable CT scanners facilitate the monitoring of dose data. • A variety of commercial and non-commercial dose monitoring software tools are available today. • Successful dose monitoring requires comprehensive infrastructure for monitoring, analysing and optimizing radiation exposure. Citation Format: • Boos J, Meineke A, Bethge OT et al. Dose Monitoring in Radiology Departments: Status Quo and Future Perspectives. Fortschr Röntgenstr 2016; 188: 443 - 450. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Nodule Classification on Low-Dose Unenhanced CT and Standard-Dose Enhanced CT: Inter-Protocol Agreement and Analysis of Interchangeability.

    PubMed

    Lee, Kyung Hee; Lee, Kyung Won; Park, Ji Hoon; Han, Kyunghwa; Kim, Jihang; Lee, Sang Min; Park, Chang Min

    2018-01-01

    To measure inter-protocol agreement and analyze interchangeability on nodule classification between low-dose unenhanced CT and standard-dose enhanced CT. From nodule libraries containing both low-dose unenhanced and standard-dose enhanced CT, 80 solid and 80 subsolid (40 part-solid, 40 non-solid) nodules of 135 patients were selected. Five thoracic radiologists categorized each nodule into solid, part-solid or non-solid. Inter-protocol agreement between low-dose unenhanced and standard-dose enhanced images was measured by pooling κ values for classification into two (solid, subsolid) and three (solid, part-solid, non-solid) categories. Interchangeability between low-dose unenhanced and standard-dose enhanced CT for the classification into two categories was assessed using a pre-defined equivalence limit of 8 percent. Inter-protocol agreement for the classification into two categories {κ, 0.96 (95% confidence interval [CI], 0.94-0.98)} and that into three categories (κ, 0.88 [95% CI, 0.85-0.92]) was considerably high. The probability of agreement between readers with standard-dose enhanced CT was 95.6% (95% CI, 94.5-96.6%), and that between low-dose unenhanced and standard-dose enhanced CT was 95.4% (95% CI, 94.7-96.0%). The difference between the two proportions was 0.25% (95% CI, -0.85-1.5%), wherein the upper bound CI was markedly below 8 percent. Inter-protocol agreement for nodule classification was considerably high. Low-dose unenhanced CT can be used interchangeably with standard-dose enhanced CT for nodule classification.

  18. Booster and higher antigen doses of inactivated influenza vaccine in HIV-infected patients.

    PubMed

    Johnston, Jessica A; Tincher, Lindsey B; Lowe, Denise K

    2013-12-01

    To review the literature regarding booster or higher doses of influenza antigen for increasing immunogenicity of inactivated influenza vaccine (IIV) in HIV-infected patients. MEDLINE (1966 to September 2013) was searched using the terms immunize, influenza, vaccine, and HIV or AIDS in combination with two-dose, booster-dose, increased antigen, or high-dose. One trial of booster dosing with standard doses (SDs) of IIV, trivalent (IIV3); 2 trials of booster dosing with intermediate doses (ID) of H1N1 IIV or IIV3; and 1 trial of high-dose (HD) IIV3 were identified. Trials administering 2-dose, booster-dose, or increased antigen of influenza vaccine to patients with HIV were reviewed. Because adjuvanted IIV is not available and IIV, quadrivalent was recently approved in the United States, studies evaluating these vaccines were excluded. HIV-infected individuals are at high risk for influenza-related complications; however, vaccination with SD IIV may not confer optimal protection. It has been postulated that booster or higher doses of influenza antigen may lead to increased immunogenicity. When ID and SD or ID with boosters were evaluated in HIV-infected patients, significant increases in surrogate markers for influenza protection were not achieved. However, HD IIV3 did result in significant increases in seroprotective antibody levels, though 'clinical' influenza was not evaluated. Currently, evidence is insufficient to reach conclusions about the efficacy of booster dosing, ID, or HD influenza vaccine in HIV-infected patients. Trials evaluating booster or higher-antigen doses of IIV for 'clinical' influenza are necessary before routinely recommending for HIV-infected patients.

  19. Novel Approaches for Visualizing and Analyzing Dose-Timing Data from Electronic Drug Monitors, or "How the 'Broken Window' Theory Pertains to ART Adherence".

    PubMed

    Gill, Christopher J; DeSilva, Mary Bachman; Hamer, Davidson H; Keyi, Xu; Wilson, Ira B; Sabin, Lora

    2015-11-01

    Adherence to antiretroviral medications is usually expressed in terms of the proportion of doses taken. However, the timing of doses taken may also be an important dimension to overall adherence. Little is known about whether patients who mistime doses are also more likely to skip doses. Using data from the completed Adherence for Life randomized controlled trial, we created visual and statistical models to capture and analyze dose timing data collected longitudinally with electronic drug monitors (EDM). From scatter plots depicting dose time versus calendar date, we identified dominant patterns of dose taking and calculated key features [slope of line over calendar date; residual mean standard error (RMSE)]. Each was assessed for its ability to categorize subjects with 'sub-optimal' (<95 % of doses taken) using area under the receiver operating characteristic (AROC) curve analysis. Sixty eight subjects contributed EDM data, with ~300 to 400 observations/subject. While regression line slopes did not predict 'sub-optimal' adherence (AROC 0.51, 95 % CI 0.26-0.75), the variability in dose timing (RMSE) was strongly predictive (AROC 0.79, 95 % CI 0.62-0.97). Compared with the lowest quartile of RMSE (minimal dose time variability), each successive quartile roughly doubled the odds of 'sub-optimal' adherence (OR 2.1, 95 % CI 1.3-3.4). Patterns of dose timing and mistiming are strongly related to overall adherence behavior. Notably, individuals who skip doses are more likely to mistime doses, with the degree of risk positively correlated with the extent of dose timing variability.

  20. Poster — Thur Eve — 27: Flattening Filter Free VMAT Quality Assurance: Dose Rate Considerations for Detector Response

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Viel, Francis; Duzenli, Cheryl; British Columbia Cancer Agency, Department of Medical Physics, Vancouver Centre

    2014-08-15

    Introduction: Radiation detector responses can be affected by dose rate. Due to higher dose per pulse and wider range of mu rates in FFF beams, detector responses should be characterized prior to implementation of QA protocols for FFF beams. During VMAT delivery, the MU rate may also vary dramatically within a treatment fraction. This study looks at the dose per pulse variation throughout a 3D volume for typical VMAT plans and the response characteristics for a variety of detectors, and makes recommendations on the design of QA protocols for FFF VMAT QA. Materials and Methods: Linac log file data andmore » a simplified dose calculation algorithm are used to calculate dose per pulse for a variety of clinical VMAT plans, on a voxel by voxel basis, as a function of time in a cylindrical phantom. Diode and ion chamber array responses are characterized over the relevant range of dose per pulse and dose rate. Results: Dose per pulse ranges from <0.1 mGy/pulse to 1.5 mGy/pulse in a typical VMAT treatment delivery using the 10XFFF beam. Diode detector arrays demonstrate increased sensitivity to dose (+./− 3%) with increasing dose per pulse over this range. Ion chamber arrays demonstrate decreased sensitivity to dose (+/− 1%) with increasing dose rate over this range. Conclusions: QA protocols should be designed taking into consideration inherent changes in detector sensitivity with dose rate. Neglecting to account for changes in detector response with dose per pulse can lead to skewed QA results.« less

  1. The effect of pre-dose on thermally and optically stimulated luminescence from α-Al2O3:C,Mg and α-Al2O3:C.

    PubMed

    Kalita, J M; Chithambo, M L

    2018-06-15

    We report the effect of pre-dose on the thermoluminescence (TL) and optically stimulated luminescence (OSL) dose response of α-Al 2 O 3 :C,Mg and α-Al 2 O 3 :C. Before any luminescence measurement, the samples were irradiated with different doses, namely 100, 500 and 1000 Gy to populate the deep electron traps. This is the pre-dose. The results from TL and OSL studies are compared with results from samples used without any pre-measurement dose. The TL glow curves and OSL decay curves of α-Al 2 O 3 :C,Mg recorded after pre-doses of 100, 500 and 1000 Gy are identical to those from a sample used without any pre-dose. Further, the TL and OSL dose response of all α-Al 2 O 3 :C,Mg samples are similar regardless of pre-dose. In comparison, the TL glow curves and OSL decay curves of α-Al 2 O 3 :C are influenced by pre-dose. We conclude that the differences in the TL and OSL dose response of various pre-dosed samples of α-Al 2 O 3 :C are due to the concentration of charge in the deep traps. On the other hand, owing to the lower concentration of such deep traps in α-Al 2 O 3 :C,Mg, the TL or OSL dose responses are not affected by pre-dose in this material. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. The Model Averaging for Dichotomous Response Benchmark Dose (MADr-BMD) Tool

    EPA Pesticide Factsheets

    Providing quantal response models, which are also used in the U.S. EPA benchmark dose software suite, and generates a model-averaged dose response model to generate benchmark dose and benchmark dose lower bound estimates.

  3. The Impact of Monte Carlo Dose Calculations on Intensity-Modulated Radiation Therapy

    NASA Astrophysics Data System (ADS)

    Siebers, J. V.; Keall, P. J.; Mohan, R.

    The effect of dose calculation accuracy for IMRT was studied by comparing different dose calculation algorithms. A head and neck IMRT plan was optimized using a superposition dose calculation algorithm. Dose was re-computed for the optimized plan using both Monte Carlo and pencil beam dose calculation algorithms to generate patient and phantom dose distributions. Tumor control probabilities (TCP) and normal tissue complication probabilities (NTCP) were computed to estimate the plan outcome. For the treatment plan studied, Monte Carlo best reproduces phantom dose measurements, the TCP was slightly lower than the superposition and pencil beam results, and the NTCP values differed little.

  4. Patient Dose In Diagnostic Radiology: When & How?

    NASA Astrophysics Data System (ADS)

    Lassen, Margit; Gorson, Robert O.

    1980-08-01

    Different situations are discussed in which it is of value to know radiation dose to the patient in diagnostic radiology. Radiation dose to specific organs is determined using the Handbook on Organ Doses published by the Bureau of Radiological Health of the Food and Drug Administration; the method is applied to a specific case. In this example dose to an embryo is calculated in examinations involving both fluoroscopy and radiography. In another example dose is determined to a fetus in late pregnancy using tissue air ratios. Patient inquiries about radiation dose are discussed, and some answers are suggested. The reliability of dose calculations is examined.

  5. Leuco-crystal-violet micelle gel dosimeters: Component effects on dose-rate dependence

    NASA Astrophysics Data System (ADS)

    Xie, J. C.; Katz, E. A. B.; Alexander, K. M.; Schreiner, L. J.; McAuley, K. B.

    2017-05-01

    Designed experiments were performed to produce empirical models for the dose sensitivity, initial absorbance, and dose-rate dependence respectively for leucocrystal violet (LCV) micelle gel dosimeters containing cetyltrimethylammonium bromide (CTAB) and 2,2,2-trichloroethanol (TCE). Previous gels of this type showed dose-rate dependent behaviour, producing an ˜18% increase in dose sensitivity between dose rates of 100 and 600 cGy min-1. Our models predict that the dose rate dependence can be reduced by increasing the concentration of TCE, CTAB and LCV. Increasing concentrations of LCV and CTAB produces a significant increase in dose sensitivity with a corresponding increase in initial absorbance. An optimization procedure was used to determine a nearly dose-rate independent gel which maintained high sensitivity and low initial absorbance. This gel which contains 33 mM CTAB, 1.25 mM LCV, and 96 mM TCE in 25 mM trichloroacetic acid and 4 wt% gelatin showed an increase in dose sensitivity of only 4% between dose rates of 100 and 600 cGy min-1, and provides an 80% greater dose sensitivity compared to Jordan’s standard gels with similar initial absorbance.

  6. Monte Carlo evaluation of RapidArc™ oropharynx treatment planning strategies for sparing of midline structures

    NASA Astrophysics Data System (ADS)

    Bush, K.; Zavgorodni, S.; Gagne, I.; Townson, R.; Ansbacher, W.; Beckham, W.

    2010-08-01

    The aim of the study was to perform the Monte Carlo (MC) evaluation of RapidArc™ (Varian Medical Systems, Palo Alto, CA) dose calculations for four oropharynx midline sparing planning strategies. Six patients with squamous cell cancer of the oropharynx were each planned with four RapidArc head and neck treatment strategies consisting of single and double photon arcs. In each case, RTOG0522 protocol objectives were used during planning optimization. Dose calculations performed with the analytical anisotropic algorithm (AAA) are compared against BEAMnrc/DOSXYZnrc dose calculations for the 24-plan dataset. Mean dose and dose-to-98%-of-structure-volume (D98%) were used as metrics in the evaluation of dose to planning target volumes (PTVs). Mean dose and dose-to-2%-of-structure-volume (D2%) were used to evaluate dose differences within organs at risk (OAR). Differences in the conformity index (CI) and the homogeneity index (HI) as well as 3D dose distributions were also observed. AAA calculated PTV mean dose, D98%, and HIs showed very good agreement with MC dose calculations within the 0.8% MC (statistical) calculation uncertainty. Regional node volume (PTV-80%) mean dose and D98% were found to be overestimated (1.3%, σ = 0.8% and 2.3%, σ = 0.8%, respectively) by the AAA with respect to MC calculations. Mean dose and D2% to OAR were also observed to be consistently overestimated by the AAA. Increasing dose calculation differences were found in planning strategies exhibiting a higher overall fluence modulation. From the plan dataset, the largest local dose differences were observed in heavily shielded regions and within the esophageal and sinus cavities. AAA dose calculations as implemented in RapidArc™ demonstrate excellent agreement with MC calculations in unshielded regions containing moderate inhomogeneities. Acceptable agreement is achieved in regions of increased MLC shielding. Differences in dose are attributed to inaccuracies in the AAA-modulated fluence modeling, modeling of material inhomogeneities and dose deposition within low-density materials. The use of MC dose calculations leads to the same general conclusion as using AAA that a two arc delivery with limited collimator opening can provide the greatest amount of midline sparing compared to the other techniques investigated.

  7. SU-F-P-27: The Study of Actual DVH for Target and OARs During the Radiotherapy of Non-Small Cell Lung Cancer

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ma, C; Yin, Y

    2016-06-15

    Purpose: To analyze the changes of the volume and dosimetry of target and organs at risk (OARs) by comparing the daily CBCT images and planning CT images of the patients with Non-Small Cell Lung Cancer (NSCLC) and analyze the difference between planned dose and accumulated dose. Methods: This study retrospectively analyzed eight cases of non-small cell lung cancer patients who accepted CRT or IMRT treatment and KV-CBCT. For each patient, the prescription dose was 60Gy and the fraction dose was 2Gy. Deform the daily CBCT images to planning CT images by the mapping of registration to compare the planning dosemore » with cumulative dose of targets and organs at risk in RayStation. Results: The average volume of GTV of 8 patients with CBCT was 88.26% of the original volume. The average plan dose of GTV was 64.49±2.40Gy. The accumulated dose of GTV was 60.13±2.70Gy (P≤0.05). The average volume of PTV to reach the prescription dose was 95.59% for original plan and 81.47% for accumulated plan (P≤0.05). The volume changes of the left and right lung of the original volume was 88.95% and 80.32%, respectively. The average dose of the left and right lung of original plan was 9.31±1.75Gy and 4.33±1.10Gy, respectively(P≥0.05). The average accumulated dose was 9.63±1.96Gy and 4.63±1.36Gy, respectively(P≥0.05). The average plan dose and accumulated dose of heart was 6.88±1.70Gy and 6.38±0.91Gy, respectively (P≥0.05). The average plan maximum dose and accumulated dose for spinal cord was 24.62±5.91Gy and 26.00±5.14Gy, respectively (P≥0.05). Conclusion: The changes of target anatomical structure with NSCLC make difference between the planned dose and cumulative dose. With the dose deformation method, the dose gap can be found between planning dose and delivery dose.« less

  8. Feasibility study on inverse four-dimensional dose reconstruction using the continuous dose-image of EPID

    PubMed Central

    Yeo, Inhwan Jason; Jung, Jae Won; Yi, Byong Yong; Kim, Jong Oh

    2013-01-01

    Purpose: When an intensity-modulated radiation beam is delivered to a moving target, the interplay effect between dynamic beam delivery and the target motion due to miss-synchronization can cause unpredictable dose delivery. The portal dose image in electronic portal imaging device (EPID) represents radiation attenuated and scattered through target media. Thus, it may possess information about delivered radiation to the target. Using a continuous scan (cine) mode of EPID, which provides temporal dose images related to target and beam movements, the authors’ goal is to perform four-dimensional (4D) dose reconstruction. Methods: To evaluate this hypothesis, first, the authors have derived and subsequently validated a fast method of dose reconstruction based on virtual beamlet calculations of dose responses using a test intensity-modulated beam. This method was necessary for processing a large number of EPID images pertinent for four-dimensional reconstruction. Second, cine mode acquisition after summation over all images was validated through comparison with integration mode acquisition on EPID (IAS3 and aS1000) for the test beam. This was to confirm the agreement of the cine mode with the integrated mode, specifically for the test beam, which is an accepted mode of image acquisition for dosimetry with EPID. Third, in-phantom film and exit EPID dosimetry was performed on a moving platform using the same beam. Heterogeneous as well as homogeneous phantoms were used. The cine images were temporally sorted at 10% interval. The authors have performed dose reconstruction to the in-phantom plane from the sorted cine images using the above validated method of dose reconstruction. The reconstructed dose from each cine image was summed to compose a total reconstructed dose from the test beam delivery, and was compared with film measurements. Results: The new method of dose reconstruction was validated showing greater than 95.3% pass rates of the gamma test with the criteria of dose difference of 3% and distance to agreement of 3 mm. The dose comparison of the reconstructed dose with the measured dose for the two phantoms showed pass rates higher than 96.4% given the same criteria. Conclusions: Feasibility of 4D dose reconstruction was successfully demonstrated in this study. The 4D dose reconstruction demonstrated in this study can be a promising dose validation method for radiation delivery on moving organs. PMID:23635250

  9. Accumulated Delivered Dose Response of Stereotactic Body Radiation Therapy for Liver Metastases

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Swaminath, Anand; Massey, Christine; Brierley, James D.

    2015-11-01

    Purpose: To determine whether the accumulated dose using image guided radiation therapy is a stronger predictor of clinical outcomes than the planned dose in stereotactic body radiation therapy (SBRT) for liver metastases. Methods and Materials: From 2003 to 2009, 81 patients with 142 metastases were treated in institutional review board–approved SBRT studies (5-10 fractions). Patients were treated during free breathing (with or without abdominal compression) or with controlled exhale breath-holding. SBRT was planned on a static exhale computed tomography (CT) scan, and the minimum planning target volume dose to 0.5 cm{sup 3} (minPTV) was recorded. The accumulated minimum dose to themore » 0.5 cm{sup 3} gross tumor volume (accGTV) was calculated after performing dose accumulation from exported image guided radiation therapy data sets registered to the planning CT using rigid (2-dimensional MV/kV orthogonal) or deformable (3-dimensional/4-dimensional cone beam CT) image registration. Univariate and multivariate Cox regression models assessed the factors influencing the time to local progression (TTLP). Hazard ratios for accGTV and minPTV were compared using model goodness-of-fit and bootstrapping. Results: Overall, the accGTV dose exceeded the minPTV dose in 98% of the lesions. For 5 to 6 fractions, accGTV doses of >45 Gy were associated with 1-year local control of 86%. On univariate analysis, the cancer subtype (breast), smaller tumor volume, and increased dose were significant predictors for improved TTLP. The dose and volume were uncorrelated; the accGTV dose and minPTV dose were correlated and were tested separately on multivariate models. Breast cancer subtype, accGTV dose (P<.001), and minPTV dose (P=.02) retained significance in the multivariate models. The univariate hazard ratio for TTLP for 5-Gy increases in accGTV versus minPTV was 0.67 versus 0.74 (all patients; 95% confidence interval of difference 0.03-0.14). Goodness-of-fit testing confirmed the accGTV dose as a stronger dose–response predictor than the minPTV dose. Conclusions: The accGTV dose is a better predictor of TTLP than the minPTV dose for liver metastasis SBRT. The use of modern image guided radiation therapy in future analyses of dose–response outcomes should increase the concordance between the planned and delivered doses.« less

  10. Adaptive radiation therapy of prostate cancer

    NASA Astrophysics Data System (ADS)

    Wen, Ning

    ART is a close-loop feedback algorithm which evaluates the organ deformation and motion right before the treatment and takes into account dose delivery variation daily to compensate for the difference between planned and delivered dose. It also has potential to allow further dose escalation and margin reduction to improve the clinical outcome. This retrospective study evaluated ART for prostate cancer treatment and radiobiological consequences. An IRB approved protocol has been used to evaluate actual dose delivery of patients with prostate cancer undergoing treatment with daily CBCT. The dose from CBCT was measured in phantom using TLD and ion chamber techniques in the pelvic scan setting. There were two major findings from the measurements of CBCT dose: (1) the lateral dose distribution was not symmetrical, with Lt Lat being ˜40% higher than Rt Lat and (2) AP skin dose varies with patient size, ranging 3.2--6.1 cGy for patient's AP separation of 20--33 cm (the larger the separation, the less the skin dose) but lateral skin doses depend little on separations. Dose was recalculated on each CBCT set under the same treatment plan. DIR was performed between SIM-CT and evaluated for each CT sets. Dose was reconstructed and accumulated to reflect the actual dose delivered to the patient. Then the adaptive plans were compared to the original plan to evaluate tumor control and normal tissue complication using radiobiological model. Different PTV margins were also studied to access margin reduction techniques. If the actual dose delivered to the PTV deviated significantly from the prescription dose for the given fractions or the OAR received higher dose than expected, the treatment plan would be re-optimized based on the previously delivered dose. The optimal schedule was compared based on the balance of PTV dose coverage and inhomogeneity, OAR dose constraints and labor involved. DIR was validated using fiducial marker position, visual comparison and UE. The mean and standard deviation of markers after rigid registration in L-R direction was 0 and 1 mm. But the mean was 2--4 mm in the A-P and S-I direction and standard deviation was about 2 mm. After DIR, the mean in all three directions became 0 and standard deviation was within sub millimeter. UE images were generated for each CT set and carefully reviewed in the prostate region. DIR provided accurate transformation matrix to be used for dose reconstruction. The delivered dose was evaluated with radiobiological models. TCP for the CTV was calculated to evaluate tumor control in different margin settings. TCP calculated from the reconstructed dose agreed within 5% of the value in the plan for all patients with three different margins. EUD and NTCP were calculated to evaluate reaction of rectum to radiation. Similar biological evaluation was performed for bladder. EUD of actual dose was 3%--9% higher than that of planned dose of patient 1--3, 11%--20% higher of patient 4--5. Smaller margins could not reduce late GU toxicity effectively since bladder complication was directly related to Dmax which was at the same magnitude in the bladder no matter which margin was applied. Re-optimization was performed at the 10th, 20th , 30th, and 40th fraction to evaluate the effectiveness to limit OAR dose while maintaining the target coverage. Reconstructed dose was added to dose from remaining fractions after optimization to show the total dose patient would receive. It showed that if the plan was re-optimized at 10th or 20th fraction, total dose to rectum and bladder were very similar to planned dose with minor deviations. If the plan was re-optimized at the 30th fraction, since there was a large deviation between reconstructed dose and planned dose to OAR, optimization could not limit the OAR dose to the original plan with only 12 fractions left. If the re-optimization was done at the 40th fraction, it was impossible to compensate in the last 2 fractions. Large deviations of total dose to bladder and rectum still existed while dose inhomogeneity to PTV was significantly increased due to hard constraints set in the optimization to reduce OAR dose. In summary, ART did not show improvements in TCP if the patient was setup with CBCT. However, EUD of rectum and bladder was increased significantly due to tissue deformation which varied daily. With the power of ART, margins added to the CTV could be further reduced to preserve critical organs surrounding the target. (Abstract shortened by UMI.)

  11. Modeling adverse event counts in phase I clinical trials of a cytotoxic agent.

    PubMed

    Muenz, Daniel G; Braun, Thomas M; Taylor, Jeremy Mg

    2018-05-01

    Background/Aims The goal of phase I clinical trials for cytotoxic agents is to find the maximum dose with an acceptable risk of severe toxicity. The most common designs for these dose-finding trials use a binary outcome indicating whether a patient had a dose-limiting toxicity. However, a patient may experience multiple toxicities, with each toxicity assigned an ordinal severity score. The binary response is then obtained by dichotomizing a patient's richer set of data. We contribute to the growing literature on new models to exploit this richer toxicity data, with the goal of improving the efficiency in estimating the maximum tolerated dose. Methods We develop three new, related models that make use of the total number of dose-limiting and low-level toxicities a patient experiences. We use these models to estimate the probability of having at least one dose-limiting toxicity as a function of dose. In a simulation study, we evaluate how often our models select the true maximum tolerated dose, and we compare our models with the continual reassessment method, which uses binary data. Results Across a variety of simulation settings, we find that our models compare well against the continual reassessment method in terms of selecting the true optimal dose. In particular, one of our models which uses dose-limiting and low-level toxicity counts beats or ties the other models, including the continual reassessment method, in all scenarios except the one in which the true optimal dose is the highest dose available. We also find that our models, when not selecting the true optimal dose, tend to err by picking lower, safer doses, while the continual reassessment method errs more toward toxic doses. Conclusion Using dose-limiting and low-level toxicity counts, which are easily obtained from data already routinely collected, is a promising way to improve the efficiency in finding the true maximum tolerated dose in phase I trials.

  12. Immunogenicity and safety of a live attenuated shingles (herpes zoster) vaccine (Zostavax®) in individuals aged ≥ 70 years: a randomized study of a single dose vs. two different two-dose schedules.

    PubMed

    Vesikari, Timo; Hardt, Roland; Rümke, Hans C; Icardi, Giancarlo; Montero, Jordi; Thomas, Stéphane; Sadorge, Christine; Fiquet, Anne

    2013-04-01

    Disease protection provided by herpes zoster (HZ) vaccination tends to reduce as age increases. This study was designed to ascertain whether a second dose of the HZ vaccine, Zostavax(®), would increase varicella zoster virus (VZV)-specific immune response among individuals aged ≥ 70 y. Individuals aged ≥ 70 y were randomized to receive HZ vaccine in one of three schedules: a single dose (0.65 mL), two doses at 0 and 1 mo, or two doses at 0 and 3 mo. VZV antibody titers were measured at baseline, 4 weeks after each vaccine dose, and 12 mo after the last dose. In total, 759 participants (mean age 76.1 y) were randomized to receive vaccination. Antibody responses were similar after a single dose or two doses of HZ vaccine [post-dose 2/post-dose 1 geometric mean titer (GMT) ratios for the 1-mo or 3-mo schedules were 1.11, 95% confidence interval (CI) 1.02-1.22 and 0.78, 95% CI 0.73-0.85], respectively). The 12-mo post-dose 2/12-mo post-dose 1 GMT ratio was similar for the 1-mo schedule and for the 3-mo schedule (1.06, 95% CI 0.96-1.17 and 1.08, 95% CI 0.98-1.19, respectively). Similar immune responses were observed in participants aged 70-79 y and those aged ≥ 80 y. HZ vaccine was generally well tolerated, with no evidence of increased adverse event incidence after the second dose with either schedule. Compared with a single-dose regimen, two-dose vaccination did not increase VZV antibody responses among individuals aged ≥ 70 y. Antibody persistence after 12 mo was similar with all three schedules.

  13. Decorporation Approach after Rat Lung Contamination with Plutonium: Evaluation of the Key Parameters Influencing the Efficacy of a Protracted Chelation Treatment.

    PubMed

    Grémy, Olivier; Coudert, Sylvie; Renault, Daniel; Miccoli, Laurent

    2017-11-01

    While the efficacy of a protracted zinc (Zn)- or calcium (Ca)-diethylenetriaminepentaacetic acid (DTPA) treatment in reducing transuranic body burden has already been demonstrated, questions about therapeutic variables remain. In response to this, we designed animal experiments primarily to assess both the effect of fractionation of a given dose and the effect of the frequency of dose fraction, with the same total dose. In our study, rats were contaminated intravenously with plutonium (Pu) then treated several days later with Ca-DTPA given at once or in various split-dose regimens cumulating to the same total dose and spread over several days. Similar efficacies were induced by the injection of the total dose or by splitting the dose in several smaller doses, independent of the number of doses and the dose level per injection. In a second study, rats were pulmonary contaminated, and three weeks later they received a Ca-DTPA dose 11-fold higher than the maximal daily recommended dose, administered either as a single bolus or as numerous multiple injections cumulating to the same dose, based on different injection frequency schedules. Independent of frequency schedule, the various split-dose regimens spread over weeks/months were as efficient as single delivery of the total dose in mobilizing lung plutonium, and had a therapeutic advantage for removal of retained hepatic and bone plutonium burdens. We concluded that cumulative dose level was a therapeutic variable of greater importance than the distribution of split doses for the success of a repeated treatment regimen on retained tissue plutonium. In addition, pulmonary administration of clodronate, which aims at killing alveolar macrophages and subsequently releasing their plutonium content, and which is associated with a continuous Ca-DTPA infusion regimen, suggested that the efficacy of injected Ca-DTPA in decorporating lung deposit is limited, due to its restricted penetration into alveolar macrophages and not because plutonium, as a physicochemical form, is unavailable for chelation.

  14. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dogan, N; Padgett, K; Evans, J

    Purpose: Adaptive Radiotherapy (ART) with frequent CT imaging has been used to improve dosimetric accuracy by accounting for anatomical variations, such as primary tumor shrinkage and/or body weight loss, in Head and Neck (H&N) patients. In most ART strategies, the difference between the planned and the delivered dose is estimated by generating new plans on repeated CT scans using dose-volume constraints used with the initial planning CT without considering already delivered dose. The aim of this study was to assess the dosimetric gains achieved by re-planning based on prior dose by comparing them to re-planning not based-on prior dose formore » H&N patients. Methods: Ten locally-advanced H&N cancer patients were selected for this study. For each patient, six weekly CT imaging were acquired during the course of radiotherapy. PTVs, parotids, cord, brainstem, and esophagus were contoured on both planning and six weekly CT images. ART with weekly re-plans were done by two strategies: 1) Generating a new optimized IMRT plan without including prior dose from previous fractions (NoPriorDose) and 2) Generating a new optimized IMRT plan based on the prior dose given from previous fractions (PriorDose). Deformable image registration was used to accumulate the dose distributions between planning and six weekly CT scans. The differences in accumulated doses for both strategies were evaluated using the DVH constraints for all structures. Results: On average, the differences in accumulated doses for PTV1, PTV2 and PTV3 for NoPriorDose and PriorDose strategies were <2%. The differences in Dmean to the cord and brainstem were within 3%. The esophagus Dmean was reduced by 2% using PriorDose. PriorDose strategy, however, reduced the left parotid D50 and Dmean by 15% and 14% respectively. Conclusion: This study demonstrated significant parotid sparing, potentially reducing xerostomia, by using ART with IMRT optimization based on prior dose for weekly re-planning of H&N cancer patients.« less

  15. Eye lens dose correlations with personal dose equivalent and patient exposure in paediatric interventional cardiology performed with a fluoroscopic biplane system.

    PubMed

    Alejo, L; Koren, C; Corredoira, E; Sánchez, F; Bayón, J; Serrada, A; Guibelalde, E

    2017-04-01

    To analyse the correlations between the eye lens dose estimates performed with dosimeters placed next to the eyes of paediatric interventional cardiologists working with a biplane system, the personal dose equivalent measured on the thorax and the patient dose. The eye lens dose was estimated in terms of H p (0.07) on a monthly basis, placing optically stimulated luminescence dosimeters (OSLDs) on goggles. The H p (0.07) personal dose equivalent was measured over aprons with whole-body OSLDs. Data on patient dose as recorded by the kerma-area product (P KA ) were collected using an automatic dose management system. The 2 paediatric cardiologists working in the facility were involved in the study, and 222 interventions in a 1-year period were evaluated. The ceiling-suspended screen was often disregarded during interventions. The annual eye lens doses estimated on goggles were 4.13±0.93 and 4.98±1.28mSv. Over the aprons, the doses obtained were 10.83±0.99 and 11.97±1.44mSv. The correlation between the goggles and the apron dose was R 2 =0.89, with a ratio of 0.38. The correlation with the patient dose was R 2 =0.40, with a ratio of 1.79μSvGy -1 cm -2 . The dose per procedure obtained over the aprons was 102±16μSv, and on goggles 40±9μSv. The eye lens dose normalized to P KA was 2.21±0.58μSvGy -1 cm -2 . Measurements of personal dose equivalent over the paediatric cardiologist's apron are useful to estimate eye lens dose levels if no radiation protection devices are typically used. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  16. Dose, image quality and spine modeling assessment of biplanar EOS micro-dose radiographs for the follow-up of in-brace adolescent idiopathic scoliosis patients.

    PubMed

    Morel, Baptiste; Moueddeb, Sonia; Blondiaux, Eleonore; Richard, Stephen; Bachy, Manon; Vialle, Raphael; Ducou Le Pointe, Hubert

    2018-05-01

    The aim of this study was to compare the radiation dose, image quality and 3D spine parameter measurements of EOS low-dose and micro-dose protocols for in-brace adolescent idiopathic scoliosis (AIS) patients. We prospectively included 25 consecutive patients (20 females, 5 males) followed for AIS and undergoing brace treatment. The mean age was 12 years (SD 2 years, range 8-15 years). For each patient, in-brace biplanar EOS radiographs were acquired in a standing position using both the conventional low-dose and micro-dose protocols. Dose area product (DAP) was systematically recorded. Diagnostic image quality was qualitatively assessed by two radiologists for visibility of anatomical structures. The reliability of 3D spine modeling between two operators was quantitatively evaluated for the most clinically relevant 3D radiological parameters using intraclass correlation coefficient (ICC). The mean DAP for the posteroanterior and lateral acquisitions was 300 ± 134 and 433 ± 181 mGy cm 2 for the low-dose radiographs, and 41 ± 19 and 81 ± 39 mGy cm 2 for micro-dose radiographs. Image quality was lower with the micro-dose protocol. The agreement was "good" to "very good" for all measured clinical parameters when comparing the low-dose and micro-dose protocols (ICC > 0.73). The micro-dose protocol substantially reduced the delivered dose (by a factor of 5-7 compared to the low-dose protocol) in braced children with AIS. Although image quality was reduced, the micro-dose protocol proved to be adapted to radiological follow-up, with adequate image quality and reliable clinical measurements. These slides can be retrieved under Electronic Supplementary Material.

  17. Does initial dosing of levothyroxine in infants with congenital hypothyroidism lead to frequent dose adjustments secondary to iatrogenic hyperthyroidism on follow-up?

    PubMed

    Craven, Meghan; Frank, Graeme R

    2018-06-27

    Congenital hypothyroidism (CH) is the most common preventable cause of intellectual disability. The recommended starting dose of levothyroxine (LT4) is between 10 and 15 μg/kg, an extremely wide range. We hypothesized that a sizable proportion of newborns treated for CH at the higher end of the dosage range become biochemically hyperthyroid at a follow-up visit. This study is a retrospective chart review of infants with CH between 2002 and 2012. Of the 104 patients included in this analysis, the average age at diagnosis was 11 days and the average starting dose of LT4 was 12±2.5 μg/kg. At follow-up, 36.5% required a dose reduction because of iatrogenic hyperthyroxinemia, 51% required no dose adjustment and 12.5% required a dose increase due to an elevated thyroid stimulating hormone (TSH). The starting doses of LT4 for those requiring a dose reduction, those not requiring an adjustment and those requiring an increase in the dose were 13.2±2.4, 11.5±2.1 and 10.3±2.6 μg/kg/day, respectively (p≤0.0001). Of the 34% of infants treated with an initial dose of >12.5 μg/day, 57.1% required a dose reduction at follow-up, compared to 26.1% of those whose initial starting dose was ≤12.5 μg/kg/day (p=0.007). Following the guidelines for initiating therapy for CH, 36.5% of the infants required a dose reduction for iatrogenic hyperthyroxinemia. These infants received a higher dose of LT4 than the infants who either required no adjustment or required an increase in the dose. A narrower range for initial dosing in CH may be appropriate.

  18. Effect of pill burden on dosing preferences, willingness to pay, and likely adherence among patients with type 2 diabetes

    PubMed Central

    Hauber, A Brett; Han, Steven; Yang, Jui-Chen; Gantz, Ira; Tunceli, Kaan; Gonzalez, Juan Marcos; Brodovicz, Kimberly; Alexander, Charles M; Davies, Michael; Iglay, Kristy; Zhang, Qiaoyi; Radican, Larry

    2013-01-01

    Purpose To quantify willingness-to-pay (WTP) for reducing pill burden and dosing frequency among patients with type 2 diabetes mellitus (T2DM), and to examine the effect of dosing frequency and pill burden on likely medication adherence. Patients and methods Participants were US adults with T2DM on oral antihyperglycemic therapy. Each patient completed an online discrete-choice experiment (DCE) with eight choice questions, each including a pair of hypothetical medication profiles. Each profile was defined by reduction in average glucose (AG), daily dosing, chance of mild-to-moderate stomach problems, frequency of hypoglycemia, weight change, incremental risk of congestive heart failure (CHF), and cost. Patients were asked to rate their likely adherence to the profiles presented in each question. Choice questions were based on a predetermined experimental design. Choice data were analyzed using random-parameters logit. Likely treatment adherence was analyzed using a Heckman two-stage model. Results Of the 1,114 patients who completed the survey, 90 had lower dosing burden (<5 pills/day taken once/day or as needed) for all medications, and 1,024 had higher dosing burden (≥5 pills/day or more than once/day). Reduction in AG was valued most highly by patients. Hypoglycemia, chance of mild-to-moderate stomach problems, weight change, incremental risk of CHF, and daily dosing were less valued. Patients with higher current dosing burden had lower WTP for more convenient dosing schedules than patients with lower current dosing burden. Changes in dosing and cost impacted likely adherence. The magnitude of the impact of dosing on likely adherence was higher for patients with lower current dosing burden than for patients with higher current dosing burden. Conclusion Patients with T2DM were willing to pay for improvements in efficacy, side effects, and dosing. Patients’ WTP for more convenient dosing depended on current dosing burden, as did the effect of these attributes on likely adherence. PMID:24086104

  19. Chernobyl accident: reconstruction of thyroid dose for inhabitants of the Republic of Belarus.

    PubMed

    Gavrilin, Y I; Khrouch, V T; Shinkarev, S M; Krysenko, N A; Skryabin, A M; Bouville, A; Anspaugh, L R

    1999-02-01

    The Chernobyl accident in April 1986 resulted in widespread contamination of the environment with radioactive materials, including (131)I and other radioiodines. This environmental contamination led to substantial radiation doses in the thyroids of many inhabitants of the Republic of Belarus. The reconstruction of thyroid doses received by Belarussians is based primarily on exposure rates measured against the neck of more than 200,000 people in the more contaminated territories; these measurements were carried out within a few weeks after the accident and before the decay of (131)I to negligible levels. Preliminary estimates of thyroid dose have been divided into 3 classes: Class 1 ("measured" doses), Class 2 (doses "derived by affinity"), and Class 3 ("empirically-derived" doses). Class 1 doses are estimated directly from the measured thyroidal (131)I content of the person considered, plus information on lifestyle and dietary habits. Such estimates are available for about 130,000 individuals from the contaminated areas of the Gomel and Mogilev Oblasts and from the city of Minsk. Maximum individual doses are estimated to range up to about 60 Gy. For every village with a sufficient number of residents with Class 1 doses, individual thyroid dose distributions are determined for several age groups and levels of milk consumption. These data are used to derive Class 2 thyroid dose estimates for unmeasured inhabitants of these villages. For any village where the number of residents with Class 1 thyroid doses is small or equal to zero, individual thyroid doses of Class 3 are derived from the relationship obtained between the mean adult thyroid dose and the deposition density of (131)I or 137Cs in villages with Class 2 thyroid doses presenting characteristics similar to those of the village considered. In order to improve the reliability of the Class 3 thyroid doses, an extensive program of measurement of (129)I in soils is envisaged.

  20. Knowledge-based iterative model reconstruction: comparative image quality and radiation dose with a pediatric computed tomography phantom.

    PubMed

    Ryu, Young Jin; Choi, Young Hun; Cheon, Jung-Eun; Ha, Seongmin; Kim, Woo Sun; Kim, In-One

    2016-03-01

    CT of pediatric phantoms can provide useful guidance to the optimization of knowledge-based iterative reconstruction CT. To compare radiation dose and image quality of CT images obtained at different radiation doses reconstructed with knowledge-based iterative reconstruction, hybrid iterative reconstruction and filtered back-projection. We scanned a 5-year anthropomorphic phantom at seven levels of radiation. We then reconstructed CT data with knowledge-based iterative reconstruction (iterative model reconstruction [IMR] levels 1, 2 and 3; Philips Healthcare, Andover, MA), hybrid iterative reconstruction (iDose(4), levels 3 and 7; Philips Healthcare, Andover, MA) and filtered back-projection. The noise, signal-to-noise ratio and contrast-to-noise ratio were calculated. We evaluated low-contrast resolutions and detectability by low-contrast targets and subjective and objective spatial resolutions by the line pairs and wire. With radiation at 100 peak kVp and 100 mAs (3.64 mSv), the relative doses ranged from 5% (0.19 mSv) to 150% (5.46 mSv). Lower noise and higher signal-to-noise, contrast-to-noise and objective spatial resolution were generally achieved in ascending order of filtered back-projection, iDose(4) levels 3 and 7, and IMR levels 1, 2 and 3, at all radiation dose levels. Compared with filtered back-projection at 100% dose, similar noise levels were obtained on IMR level 2 images at 24% dose and iDose(4) level 3 images at 50% dose, respectively. Regarding low-contrast resolution, low-contrast detectability and objective spatial resolution, IMR level 2 images at 24% dose showed comparable image quality with filtered back-projection at 100% dose. Subjective spatial resolution was not greatly affected by reconstruction algorithm. Reduced-dose IMR obtained at 0.92 mSv (24%) showed similar image quality to routine-dose filtered back-projection obtained at 3.64 mSv (100%), and half-dose iDose(4) obtained at 1.81 mSv.

  1. SU-G-BRB-14: Uncertainty of Radiochromic Film Based Relative Dose Measurements

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Devic, S; Tomic, N; DeBlois, F

    2016-06-15

    Purpose: Due to inherently non-linear dose response, measurement of relative dose distribution with radiochromic film requires measurement of absolute dose using a calibration curve following previously established reference dosimetry protocol. On the other hand, a functional form that converts the inherently non-linear dose response curve of the radiochromic film dosimetry system into linear one has been proposed recently [Devic et al, Med. Phys. 39 4850–4857 (2012)]. However, there is a question what would be the uncertainty of such measured relative dose. Methods: If the relative dose distribution is determined going through the reference dosimetry system (conversion of the response bymore » using calibration curve into absolute dose) the total uncertainty of such determined relative dose will be calculated by summing in quadrature total uncertainties of doses measured at a given and at the reference point. On the other hand, if the relative dose is determined using linearization method, the new response variable is calculated as ζ=a(netOD)n/ln(netOD). In this case, the total uncertainty in relative dose will be calculated by summing in quadrature uncertainties for a new response function (σζ) for a given and the reference point. Results: Except at very low doses, where the measurement uncertainty dominates, the total relative dose uncertainty is less than 1% for the linear response method as compared to almost 2% uncertainty level for the reference dosimetry method. The result is not surprising having in mind that the total uncertainty of the reference dose method is dominated by the fitting uncertainty, which is mitigated in the case of linearization method. Conclusion: Linearization of the radiochromic film dose response provides a convenient and a more precise method for relative dose measurements as it does not require reference dosimetry and creation of calibration curve. However, the linearity of the newly introduced function must be verified. Dave Lewis is inventor and runs a consulting company for radiochromic films.« less

  2. SU-F-T-325: On the Use of Bolus in Dosimetry and Dose Reduction for Pacemaker and Defibrillator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, W; Kenneth, R; Higgins, S

    Purpose: Special attention is required in planning and administering radiation therapy to patients with cardiac implantable electronic devices (CIEDs), such as pacemaker and defibrillator. The range of dose to CIEDs that can induce malfunction is very large among CIEDs. Significant defects have been reported at dose as low as 0.15Gy. Failures causing discomfort have been reported at dose as low as 0.05Gy. Therefore, accurate estimation of dose to CIED and dose reduction are both important even if the dose is expected to be less than the often-used 2Gy limit. We investigate the use of bolus in in vivo dosimetry formore » CIEDs. Methods: In our clinic, high-energy beams (>10MV) are not used for patients with CIED due to neutron production. Solid water phantom measurements of out-of-field dose for a 6MV beam were performed using parallel plate chamber at different depth with and without 2cm bolus covering the chamber. In vivo dosimetry at skin surface above the pacemaker was performed with and without bolus for 3 patients with pacemaker <5cm from the field edge. Results: Chamber measured dose at depth ∼1 to 1.5cm below the skin surface, where the CIED is normally located, was reduced by ∼6% – 20% with bolus. The dose reduction became smaller at deeper depth. In vivo dosimetry at skin surface also yielded ∼20% – 60% lower dose when using bolus for the 3 patients. In general, TPS calculation underestimated the dose. The dose measured with bolus is closer to the dose at the depth of the pacemaker and less affected by contaminant electrons and linac head leakage. Conclusion: In vivo CIED dose measurements should be performed with 1 to 2cm bolus covering the dosimeter on the skin above the CIED for more accurate CIED dose estimation. The use of bolus also reduces the dose delivered to CIED.« less

  3. A dosimetry technique for measuring kilovoltage cone‐beam CT dose on a linear accelerator using radiotherapy equipment

    PubMed Central

    Lawford, Catherine E.

    2014-01-01

    This work develops a technique for kilovoltage cone‐beam CT (CBCT) dosimetry that incorporates both point dose and integral dose in the form of dose length product, and uses readily available radiotherapy equipment. The dose from imaging protocols for a range of imaging parameters and treatment sites was evaluated. Conventional CT dosimetry using 100 mm long pencil chambers has been shown to be inadequate for the large fields in CBCT and has been replaced in this work by a combination of point dose and integral dose. Absolute dose measurements were made with a small volume ion chamber at the central slice of a radiotherapy phantom. Beam profiles were measured using a linear diode array large enough to capture the entire imaging field. These profiles were normalized to absolute dose to form dose line integrals, which were then weighted with radial depth to form the DLPCBCT. This metric is analogous to the standard dose length product (DLP), but derived differently to suit the unique properties of CBCT. Imaging protocols for head and neck, chest, and prostate sites delivered absolute doses of 0.9, 2.2, and 2.9 cGy to the center of the phantom, and DLPCBCT of 28.2, 665.1, and 565.3 mGy.cm, respectively. Results are displayed as dose per 100 mAs and as a function of key imaging parameters such as kVp, mAs, and collimator selection in a summary table. DLPCBCT was found to correlate closely with the dimension of the imaging region and provided a good indication of integral dose. It is important to assess integral dose when determining radiation doses to patients using CBCT. By incorporating measured beam profiles and DLP, this technique provides a CBCT dosimetry in radiotherapy phantoms and allows the prediction of imaging dose for new CBCT protocols. PACS number: 87.57.uq PMID:25207398

  4. Will X-ray Safety Glasses Become Mandatory for Radiological Vascular Interventions?

    PubMed

    Thomas, Rohit Philip; Grau, Mathias; Eldergash, Osama; Kowald, Tobias; Schnabel, Johannes; Szczechowicz, Marcin; Chavan, Ajay

    2018-07-01

    The annual permissible radiation ocular lens dose has been reduced to 20 millisieverts (mSv) in the current European directive 2013/59/Euratom. The aim of this study was to evaluate the personal radiation dose for vascular interventions with special focus on ocular lens dose. From May 2016 to October 2016, the personal radiation doses of two interventionists and four technicians were prospectively recorded during 206 vascular interventions. The position of personnel, intervention type and fluoroscopy time were recorded. Parameters evaluated were total body dose measured by film dosimeter, hand dose measured by ring thermoluminescent dosimeter (TLD) and ocular lens dose measured by TLD placed in front of the safety glasses. Linear regression analysis was used to estimate the dose at 2 and 5 years. The ocular lens dose, hand and total body dose of the two interventionists were 11/5, 56/47 and 0.6 mSv each, respectively. The estimated 5-year ocular dose was 113.08 mSv (95% CI 38.2-187.97)/40.95 (95% CI 16.9-64.7). Similarly, hand dose was 608.4 mSv (95% CI 442.78-774.38)/514.47 (95% CI 329.83-699.10) and body dose 6.07 mSv (95% CI 4.70-8.22)/5.12 (95% CI 3.65-6.59), respectively. Amongst four technicians, only the first assistant showed recordings of 0.3 mSv body dose, 2 mSv ocular lens dose and 5 mSv hand dose. The yearly ocular lens dose, particularly for interventionists dealing with complex interventions, could cross the permitted yearly limit set by the new Euratom directive. Therefore, X-ray safety glasses would become mandatory for complex radiological vascular interventions. Level III, non-randomized controlled cohort/follow-up study.

  5. SU-F-19A-10: Recalculation and Reporting Clinical HDR 192-Ir Head and Neck Dose Distributions Using Model Based Dose Calculation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Carlsson Tedgren, A; Persson, M; Nilsson, J

    Purpose: To retrospectively re-calculate dose distributions for selected head and neck cancer patients, earlier treated with HDR 192Ir brachytherapy, using Monte Carlo (MC) simulations and compare results to distributions from the planning system derived using TG43 formalism. To study differences between dose to medium (as obtained with the MC code) and dose to water in medium as obtained through (1) ratios of stopping powers and (2) ratios of mass energy absorption coefficients between water and medium. Methods: The MC code Algebra was used to calculate dose distributions according to earlier actual treatment plans using anonymized plan data and CT imagesmore » in DICOM format. Ratios of stopping power and mass energy absorption coefficients for water with various media obtained from 192-Ir spectra were used in toggling between dose to water and dose to media. Results: Differences between initial planned TG43 dose distributions and the doses to media calculated by MC are insignificant in the target volume. Differences are moderate (within 4–5 % at distances of 3–4 cm) but increase with distance and are most notable in bone and at the patient surface. Differences between dose to water and dose to medium are within 1-2% when using mass energy absorption coefficients to toggle between the two quantities but increase to above 10% for bone using stopping power ratios. Conclusion: MC predicts target doses for head and neck cancer patients in close agreement with TG43. MC yields improved dose estimations outside the target where a larger fraction of dose is from scattered photons. It is important with awareness and a clear reporting of absorbed dose values in using model based algorithms. Differences in bone media can exceed 10% depending on how dose to water in medium is defined.« less

  6. Online dose reconstruction for tracked volumetric arc therapy: Real-time implementation and offline quality assurance for prostate SBRT.

    PubMed

    Kamerling, Cornelis Ph; Fast, Martin F; Ziegenhein, Peter; Menten, Martin J; Nill, Simeon; Oelfke, Uwe

    2017-11-01

    Firstly, this study provides a real-time implementation of online dose reconstruction for tracked volumetric arc therapy (VMAT). Secondly, this study describes a novel offline quality assurance tool, based on commercial dose calculation algorithms. Online dose reconstruction for VMAT is a computationally challenging task in terms of computer memory usage and calculation speed. To potentially reduce the amount of memory used, we analyzed the impact of beam angle sampling for dose calculation on the accuracy of the dose distribution. To establish the performance of the method, we planned two single-arc VMAT prostate stereotactic body radiation therapy cases for delivery with dynamic MLC tracking. For quality assurance of our online dose reconstruction method we have also developed a stand-alone offline dose reconstruction tool, which utilizes the RayStation treatment planning system to calculate dose. For the online reconstructed dose distributions of the tracked deliveries, we could establish strong resemblance for 72 and 36 beam co-planar equidistant beam samples with less than 1.2% deviation for the assessed dose-volume indicators (clinical target volume D98 and D2, and rectum D2). We could achieve average runtimes of 28-31 ms per reported MLC aperture for both dose computation and accumulation, meeting our real-time requirement. To cross-validate the offline tool, we have compared the planned dose to the offline reconstructed dose for static deliveries and found excellent agreement (3%/3 mm global gamma passing rates of 99.8%-100%). Being able to reconstruct dose during delivery enables online quality assurance and online replanning strategies for VMAT. The offline quality assurance tool provides the means to validate novel online dose reconstruction applications using a commercial dose calculation engine. © 2017 The Authors. Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  7. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Brady, S; Shulkin, B

    Purpose: To develop ultra-low dose computed tomography (CT) attenuation correction (CTAC) acquisition protocols for pediatric positron emission tomography CT (PET CT). Methods: A GE Discovery 690 PET CT hybrid scanner was used to investigate the change to quantitative PET and CT measurements when operated at ultra-low doses (10–35 mAs). CT quantitation: noise, low-contrast resolution, and CT numbers for eleven tissue substitutes were analyzed in-phantom. CT quantitation was analyzed to a reduction of 90% CTDIvol (0.39/3.64; mGy) radiation dose from baseline. To minimize noise infiltration, 100% adaptive statistical iterative reconstruction (ASiR) was used for CT reconstruction. PET images were reconstructed withmore » the lower-dose CTAC iterations and analyzed for: maximum body weight standardized uptake value (SUVbw) of various diameter targets (range 8–37 mm), background uniformity, and spatial resolution. Radiation organ dose, as derived from patient exam size specific dose estimate (SSDE), was converted to effective dose using the standard ICRP report 103 method. Effective dose and CTAC noise magnitude were compared for 140 patient examinations (76 post-ASiR implementation) to determine relative patient population dose reduction and noise control. Results: CT numbers were constant to within 10% from the non-dose reduced CTAC image down to 90% dose reduction. No change in SUVbw, background percent uniformity, or spatial resolution for PET images reconstructed with CTAC protocols reconstructed with ASiR and down to 90% dose reduction. Patient population effective dose analysis demonstrated relative CTAC dose reductions between 62%–86% (3.2/8.3−0.9/6.2; mSv). Noise magnitude in dose-reduced patient images increased but was not statistically different from pre dose-reduced patient images. Conclusion: Using ASiR allowed for aggressive reduction in CTAC dose with no change in PET reconstructed images while maintaining sufficient image quality for co-localization of hybrid CT anatomy and PET radioisotope uptake.« less

  8. SU-F-T-441: Dose Calculation Accuracy in CT Images Reconstructed with Artifact Reduction Algorithm

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ng, C; Chan, S; Lee, F

    Purpose: Accuracy of radiotherapy dose calculation in patients with surgical implants is complicated by two factors. First is the accuracy of CT number, second is the dose calculation accuracy. We compared measured dose with dose calculated on CT images reconstructed with FBP and an artifact reduction algorithm (OMAR, Philips) for a phantom with high density inserts. Dose calculation were done with Varian AAA and AcurosXB. Methods: A phantom was constructed with solid water in which 2 titanium or stainless steel rods could be inserted. The phantom was scanned with the Philips Brillance Big Bore CT. Image reconstruction was done withmore » FBP and OMAR. Two 6 MV single field photon plans were constructed for each phantom. Radiochromic films were placed at different locations to measure the dose deposited. One plan has normal incidence on the titanium/steel rods. In the second plan, the beam is at almost glancing incidence on the metal rods. Measurements were then compared with dose calculated with AAA and AcurosXB. Results: The use of OMAR images slightly improved the dose calculation accuracy. The agreement between measured and calculated dose was best with AXB and image reconstructed with OMAR. Dose calculated on titanium phantom has better agreement with measurement. Large discrepancies were seen at points directly above and below the high density inserts. Both AAA and AXB underestimated the dose directly above the metal surface, while overestimated the dose below the metal surface. Doses measured downstream of metal were all within 3% of calculated values. Conclusion: When doing treatment planning for patients with metal implants, care must be taken to acquire correct CT images to improve dose calculation accuracy. Moreover, great discrepancies in measured and calculated dose were observed at metal/tissue interface. Care must be taken in estimating the dose in critical structures that come into contact with metals.« less

  9. SU-E-T-169: Characterization of Pacemaker/ICD Dose in SAVI HDR Brachytherapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kalavagunta, C; Lasio, G; Yi, B

    2015-06-15

    Purpose: It is important to estimate dose to pacemaker (PM)/Implantable Cardioverter Defibrillator (ICD) before undertaking Accelerated Partial Breast Treatment using High Dose Rate (HDR) brachytherapy. Kim et al. have reported HDR PM/ICD dose using a single-source balloon applicator. To the authors knowledge, there have so far not been any published PM/ICD dosimetry literature for the Strut Adjusted Volume Implant (SAVI, Cianna Medical, Aliso Viejo, CA). This study aims to fill this gap by generating a dose look up table (LUT) to predict maximum dose to the PM/ICD in SAVI HDR brachytherapy. Methods: CT scans for 3D dosimetric planning were acquiredmore » for four SAVI applicators (6−1-mini, 6−1, 8−1 and 10−1) expanded to their maximum diameter in air. The CT datasets were imported into the Elekta Oncentra TPS for planning and each applicator was digitized in a multiplanar reconstruction window. A dose of 340 cGy was prescribed to the surface of a 1 cm expansion of the SAVI applicator cavity. Cartesian coordinates of the digitized applicator were determined in the treatment leading to the generation of a dose distribution and corresponding distance-dose prediction look up table (LUT) for distances from 2 to 15 cm (6-mini) and 2 to 20 cm (10–1).The deviation between the LUT doses and the dose to the cardiac device in a clinical case was evaluated. Results: Distance-dose look up table were compared to clinical SAVI plan and the discrepancy between the max dose predicted by the LUT and the clinical plan was found to be in the range (−0.44%, 0.74%) of the prescription dose. Conclusion: The distance-dose look up tables for SAVI applicators can be used to estimate the maximum dose to the ICD/PM, with a potential usefulness for quick assessment of dose to the cardiac device prior to applicator placement.« less

  10. Four-Dimensional Patient Dose Reconstruction for Scanned Ion Beam Therapy of Moving Liver Tumors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Richter, Daniel; TU Darmstadt, Darmstadt; Saito, Nami

    2014-05-01

    Purpose: Estimation of the actual delivered 4-dimensional (4D) dose in treatments of patients with mobile hepatocellular cancer with scanned carbon ion beam therapy. Methods and Materials: Six patients were treated with 4 fractions to a total relative biological effectiveness (RBE)–weighted dose of 40 Gy (RBE) using a single field. Respiratory motion was addressed by dedicated margins and abdominal compression (5 patients) or gating (1 patient). 4D treatment dose reconstructions based on the treatment records and the measured motion monitoring data were performed for the single-fraction dose and a total of 17 fractions. To assess the impact of uncertainties in the temporalmore » correlation between motion trajectory and beam delivery sequence, 3 dose distributions for varying temporal correlation were calculated per fraction. For 3 patients, the total treatment dose was formed from the fractional distributions using all possible combinations. Clinical target volume (CTV) coverage was analyzed using the volumes receiving at least 95% (V{sub 95}) and 107% (V{sub 107}) of the planned doses. Results: 4D dose reconstruction based on daily measured data is possible in a clinical setting. V{sub 95} and V{sub 107} values for the single fractions ranged between 72% and 100%, and 0% and 32%, respectively. The estimated total treatment dose to the CTV exhibited improved and more robust dose coverage (mean V{sub 95} > 87%, SD < 3%) and overdose (mean V{sub 107} < 4%, SD < 3%) with respect to the single-fraction dose for all analyzed patients. Conclusions: A considerable impact of interplay effects on the single-fraction CTV dose was found for most of the analyzed patients. However, due to the fractionated treatment, dose heterogeneities were substantially reduced for the total treatment dose. 4D treatment dose reconstruction for scanned ion beam therapy is technically feasible and may evolve into a valuable tool for dose assessment.« less

  11. Gating window dependency on scanned carbon-ion beam dose distribution and imaging dose for thoracoabdominal treatment.

    PubMed

    Mori, Shinichiro; Karube, Masataka; Yasuda, Shigeo; Yamamoto, Naoyoshi; Tsuji, Hiroshi; Kamada, Tadashi

    2017-06-01

    To explore the trade-off between dose assessment and imaging dose in respiratory gating with radiographic fluoroscopic imaging, we evaluated the relationship between dose assessment and fluoroscopic imaging dose in various gating windows, retrospectively. Four-dimensional (4D) CT images acquired for 10 patients with lung and liver tumours were used for 4D treatment planning for scanned carbon ion beam. Imaging dose from two oblique directions was calculated by the number of images multiplied by the air kerma per image. Necessary beam-on time was calculated from the treatment log file. Accumulated dose distribution was calculated. The gating window was defined as tumour position not respiratory phase and changed from 0-100% duty cycle on 4DCT. These metrics were individually evaluated for every case. For lung cases, sufficient dose conformation was achieved in respective gating windows [D 95 -clinical target volume (CTV) > 99%]. V 20 -lung values for 50%- and 30%-duty cycles were 2.5% and 6.0% of that for 100%-duty cycle. Maximum doses (cord/oesophagus) for 30%-duty cycle decreased 6.8%/7.4% to those for 100%-duty cycle. For liver cases, V 10 -liver values for 50%- and 30%-duty cycles were 9.4% and 12.8% of those for 100%-duty cycle, respectively. Maximum doses (cord/oesophagus) for 50%- and 30%-duty cycles also decreased 17.2%/19.3% and 24.6%/29.8% to those for 100%-duty cycle, respectively. Total imaging doses increased 43.5% and 115.8% for 50%- and 30%-duty cycles to that for the 100%-duty cycle. When normal tissue doses are below the tolerance level, the gating window should be expanded to minimize imaging dose and treatment time. Advances in knowledge: The skin dose from imaging might not be counterbalanced to the OAR dose; however, imaging dose is a particularly important factor.

  12. Isobio software: biological dose distribution and biological dose volume histogram from physical dose conversion using linear-quadratic-linear model.

    PubMed

    Jaikuna, Tanwiwat; Khadsiri, Phatchareewan; Chawapun, Nisa; Saekho, Suwit; Tharavichitkul, Ekkasit

    2017-02-01

    To develop an in-house software program that is able to calculate and generate the biological dose distribution and biological dose volume histogram by physical dose conversion using the linear-quadratic-linear (LQL) model. The Isobio software was developed using MATLAB version 2014b to calculate and generate the biological dose distribution and biological dose volume histograms. The physical dose from each voxel in treatment planning was extracted through Computational Environment for Radiotherapy Research (CERR), and the accuracy was verified by the differentiation between the dose volume histogram from CERR and the treatment planning system. An equivalent dose in 2 Gy fraction (EQD 2 ) was calculated using biological effective dose (BED) based on the LQL model. The software calculation and the manual calculation were compared for EQD 2 verification with pair t -test statistical analysis using IBM SPSS Statistics version 22 (64-bit). Two and three-dimensional biological dose distribution and biological dose volume histogram were displayed correctly by the Isobio software. Different physical doses were found between CERR and treatment planning system (TPS) in Oncentra, with 3.33% in high-risk clinical target volume (HR-CTV) determined by D 90% , 0.56% in the bladder, 1.74% in the rectum when determined by D 2cc , and less than 1% in Pinnacle. The difference in the EQD 2 between the software calculation and the manual calculation was not significantly different with 0.00% at p -values 0.820, 0.095, and 0.593 for external beam radiation therapy (EBRT) and 0.240, 0.320, and 0.849 for brachytherapy (BT) in HR-CTV, bladder, and rectum, respectively. The Isobio software is a feasible tool to generate the biological dose distribution and biological dose volume histogram for treatment plan evaluation in both EBRT and BT.

  13. Using RADFET for the real-time measurement of gamma radiation dose rate

    NASA Astrophysics Data System (ADS)

    Andjelković, Marko S.; Ristić, Goran S.; Jakšić, Aleksandar B.

    2015-02-01

    RADFETs (RADiation sensitive Field Effect Transistors) are integrating ionizing radiation dosimeters operating on the principle of conversion of radiation-induced threshold voltage shift into absorbed dose. However, one of the major drawbacks of RADFETs is the inability to provide the information on the dose rate in real-time using the conventional absorbed dose measurement technique. The real-time monitoring of dose rate and absorbed dose can be achieved with the current mode dosimeters such as PN and PIN diodes/photodiodes, but these dosimeters have some limitations as absorbed dose meters and hence they are often not a suitable replacement for RADFETs. In that sense, this paper investigates the possibility of using the RADFET as a real-time dose rate meter so that it could be applied for simultaneous online measurement of the dose rate and absorbed dose. A RADFET sample, manufactured by Tyndall National Institute, Cork, Ireland, was tested as a dose rate meter under gamma irradiation from a Co-60 source. The RADFET was configured as a PN junction, such that the drain, gate and source terminals were grounded, while the radiation-induced current was measured at the bulk terminal, whereby the bulk was successively biased with 0 , 10 , 20  and 30 V. In zero-bias mode the radiation-induced current was unstable, but in the biased mode the current response was stable for the investigated dose rates from 0.65  to 32.1 Gy h-1 and up to the total absorbed dose of 25 Gy. The current increased with the dose rate in accordance with the power law, whereas the sensitivity of the current read-out was linear with respect to the applied bias voltage. Comparison with previously analyzed PIN photodiodes has shown that the investigated RADFET is competitive with PIN photodiodes as a gamma radiation dose rate meter and therefore has the potential to be employed for the real-time monitoring of the dose rate and absorbed dose.

  14. Efficacy of sacubitril/valsartan vs. enalapril at lower than target doses in heart failure with reduced ejection fraction: the PARADIGM-HF trial.

    PubMed

    Vardeny, Orly; Claggett, Brian; Packer, Milton; Zile, Michael R; Rouleau, Jean; Swedberg, Karl; Teerlink, John R; Desai, Akshay S; Lefkowitz, Martin; Shi, Victor; McMurray, John J V; Solomon, Scott D

    2016-10-01

    In this analysis, we utilized data from PARADIGM-HF to test the hypothesis that participants who exhibited any dose reduction during the trial would have similar benefits from lower doses of sacubitril/valsartan relative to lower doses of enalapril. In a post-hoc analysis from PARADIGM-HF, we characterized patients by whether they received the maximal dose (200 mg sacubitril/valsartan or 10 mg enalapril twice daily) throughout the trial or had any dose reduction to lower doses (100/50/0 mg sacubitril/valsartan or 5/2.5/0 mg enalapril twice daily). The treatment effect for the primary outcome was estimated, stratified by dose level using time-updated Cox regression models. In the two treatment arms, participants with a dose reduction (43% of those randomized to enalapril and 42% of those randomized to sacubitril/valsartan) had similar baseline characteristics and similar baseline predictors of the need for dose reduction. In a time-updated analysis, any dose reduction was associated with a higher subsequent risk of the primary event [hazard ratio (HR) 2.5, 95% confidence interval (CI) 2.2-2.7]. However, the treatment benefit of sacubitril/valsartan over enalapril following a dose reduction was similar (HR 0.80, 95% CI 0.70-0.93, P < 0.001) to that observed in patients who had not experienced any dose reduction (HR 0.79, 95% CI 0.71-0.88, P < 0.001). In PARADIGM-HF, study medication dose reduction identified patients at higher risk of a major cardiovascular event. The magnitude of benefit for patients on lower doses of sacubitril/valsartan relative to those on lower doses of enalapril was similar to that of patients who remained on target doses of both drugs. © 2016 The Authors. European Journal of Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.

  15. A dosimetry technique for measuring kilovoltage cone-beam CT dose on a linear accelerator using radiotherapy equipment.

    PubMed

    Scandurra, Daniel; Lawford, Catherine E

    2014-07-08

    This work develops a technique for kilovoltage cone-beam CT (CBCT) dosimetry that incorporates both point dose and integral dose in the form of dose length product, and uses readily available radiotherapy equipment. The dose from imaging protocols for a range of imaging parameters and treatment sites was evaluated. Conventional CT dosimetry using 100 mm long pencil chambers has been shown to be inadequate for the large fields in CBCT and has been replaced in this work by a combination of point dose and integral dose. Absolute dose measurements were made with a small volume ion chamber at the central slice of a radiotherapy phantom. Beam profiles were measured using a linear diode array large enough to capture the entire imaging field. These profiles were normalized to absolute dose to form dose line integrals, which were then weighted with radial depth to form the DLPCBCT. This metric is analogous to the standard dose length product (DLP), but derived differently to suit the unique properties of CBCT. Imaging protocols for head and neck, chest, and prostate sites delivered absolute doses of 0.9, 2.2, and 2.9 cGy to the center of the phantom, and DLPCBCT of 28.2, 665.1, and 565.3mGy.cm, respectively. Results are displayed as dose per 100 mAs and as a function of key imaging parameters such as kVp, mAs, and collimator selection in a summary table. DLPCBCT was found to correlate closely with the dimension of the imaging region and provided a good indication of integral dose. It is important to assess integral dose when determining radiation doses to patients using CBCT. By incorporating measured beam profiles and DLP, this technique provides a CBCT dosimetry in radiotherapy phantoms and allows the prediction of imaging dose for new CBCT protocols.

  16. Organ dose conversions from ESR measurements using tooth enamel of atomic bomb survivors.

    PubMed

    Takahashi, Fumiaki; Sato, Kaoru

    2012-03-01

    Dose conversions were studied for dosimetry of atomic bomb survivors based upon electron spin resonance (ESR) measurements of tooth enamel. Previously analysed data had clarified that the tooth enamel dose could be much larger than other organ doses from a low-energy photon exposure. The radiation doses to other organs or whole-body doses, however, are assumed to be near the tooth enamel dose for photon energies which are dominant in the leakage spectrum of the Hiroshima atomic bomb assumed in DS02. In addition, the thyroid can be a candidate for a surrogate organ in cases where the tooth enamel dose is not available in organ dosimetry. This paper also suggests the application of new Japanese voxel phantoms to derive tooth enamel doses by numerical analyses.

  17. Hepatitis B vaccine booster dose: low-dose recombinant hepatitis B vaccines as a booster dose.

    PubMed

    Bryan, J P; MacArthy, P; Rudock, A; Fogarty, J P; Dowd, H; Legters, L J; Perine, P L

    1997-06-01

    The timing and best regimen for a booster dose of hepatitis B vaccine have not been determined. Two studies were conducted to determine the response to a booster dose of 5 micrograms recombinant hepatitis B vaccine. In the first study, a 5 micrograms (0.5 ml) dose of Recombivax HB was administered intramuscularly 38 months after the initial dose to 71 volunteers. In a second study, we offered a 5 micrograms dose recombinant hepatitis B vaccine, either Recombivax HB (0.5 ml) or Engerix B (0.25 ml), to students who had previously been immunized with three doses of vaccine. In the first study, among the 44 persons for whom postbooster sera were available, the geometric mean concentration of anti-hepatitis B surface antigens increased from 42 to 2090 mIU/ml after the 5 micrograms (0.5 ml) dose of Recombivax. In the second study, after a 5 micrograms (0.5 ml) dose of Recombivax, the geometric mean concentration increased from 43 to 990 mIU/ml (n = 48), and in the group that received a 5 micrograms (0.25 ml) dose of Engerix B, the concentration increased from 83 to 2337 mIU/ml (n = 45) (p = 0.18 for postdose concentrations). A 5 micrograms dose of recombinant vaccine results in an excellent booster response at a cost one fourth to one half that of a full 1 ml dose of vaccine.

  18. Effective Dose of CT- and Fluoroscopy-Guided Perineural/Epidural Injections of the Lumbar Spine: A Comparative Study

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schmid, Gebhard; Schmitz, Alexander; Borchardt, Dieter

    The objective of this study was to compare the effective radiation dose of perineural and epidural injections of the lumbar spine under computed tomography (CT) or fluoroscopic guidance with respect to dose-reduced protocols. We assessed the radiation dose with an Alderson Rando phantom at the lumbar segment L4/5 using 29 thermoluminescence dosimeters. Based on our clinical experience, 4-10 CT scans and 1-min fluoroscopy are appropriate. Effective doses were calculated for CT for a routine lumbar spine protocol and for maximum dose reduction; as well as for fluoroscopy in a continuous and a pulsed mode (3-15 pulses/s). Effective doses under CTmore » guidance were 1.51 mSv for 4 scans and 3.53 mSv for 10 scans using a standard protocol and 0.22 mSv and 0.43 mSv for the low-dose protocol. In continuous mode, the effective doses ranged from 0.43 to 1.25 mSv for 1-3 min of fluoroscopy. Using 1 min of pulsed fluoroscopy, the effective dose was less than 0.1 mSv for 3 pulses/s. A consequent low-dose CT protocol reduces the effective dose compared to a standard lumbar spine protocol by more than 85%. The latter dose might be expected when applying about 1 min of continuous fluoroscopy for guidance. A pulsed mode further reduces the effective dose of fluoroscopy by 80-90%.« less

  19. Fetal radiation monitoring and dose minimization during intensity modulated radiation therapy for glioblastoma in pregnancy.

    PubMed

    Horowitz, David P; Wang, Tony J C; Wuu, Cheng-Shie; Feng, Wenzheng; Drassinower, Daphnie; Lasala, Anita; Pieniazek, Radoslaw; Cheng, Simon; Connolly, Eileen P; Lassman, Andrew B

    2014-11-01

    We examined the fetal dose from irradiation of glioblastoma during pregnancy using intensity modulated radiation therapy (IMRT), and describe fetal dose minimization using mobile shielding devices. A case report is described of a pregnant woman with glioblastoma who was treated during the third trimester of gestation with 60 Gy of radiation delivered via a 6 MV photon IMRT plan. Fetal dose without shielding was estimated using an anthropomorphic phantom with ion chamber and diode measurements. Clinical fetal dose with shielding was determined with optically stimulated luminescent dosimeters and ion chamber. Clinical target volume (CTV) and planning target volume (PTV) coverage was 100 and 98 % receiving 95 % of the prescription dose, respectively. Normal tissue tolerances were kept below quantitative analysis of normal tissue effects in the clinic (QUANTEC) recommendations. Without shielding, anthropomorphic phantom measurements showed a cumulative fetal dose of 0.024 Gy. In vivo measurements with shielding in place demonstrated a cumulative fetal dose of 0.016 Gy. The fetal dose estimated without shielding was 0.04 % and with shielding was 0.026 % of the target dose. In vivo estimation of dose equivalent received by the fetus was 24.21 mSv. Using modern techniques, brain irradiation can be delivered to pregnant patients in the third trimester with very low measured doses to the fetus, without compromising target coverage or normal tissue dose constraints. Fetal dose can further be reduced with the use of shielding devices, in keeping with the principle of as low as reasonably achievable.

  20. Three different up-titration regimens of ponesimod, an S1P1 receptor modulator, in healthy subjects.

    PubMed

    Scherz, Michael W; Brossard, Patrick; D'Ambrosio, Daniele; Ipek, Murat; Dingemanse, Jasper

    2015-06-01

    Ponesimod is a selective S1P1 receptor modulator, and induces dose-dependent reduction of circulating lymphocytes upon oral dosing. Previous studies showed that single doses up to 75 mg or multiple doses up to 40 mg once daily are well tolerated, and heart rate (HR) reduction and atrio-ventricular conduction delays upon treatment initiation are reduced by gradual up-titration to the maintenance dose. This single-center, open-label, randomized, multiple-dose, 3-treatment, 3-way crossover study compared the tolerability, safety, pharmacokinetics, cardiodynamics, and effects on lymphocytes of 3 different up-titration regimens of ponesimod in healthy male and female subjects. Up-titration regimens comprised escalating periods of b.i.d. dosing (2.5 or 5 mg) and q.d. dosing (10 or 20 mg or both). After the third up-titration period a variable-duration washout period of 1-3 days was followed by re-challenge with a single 20-mg dose of ponesimod. Adverse events were transient and mild to moderate in intensity, not different between regimens. HR decrease after the first dose was greater than after all subsequent doses, including up-titration doses. Little or no HR change was observed with morning doses of b.i.d. regimens, suggesting that 2.5 and 5 mg b.i.d. are sufficient to sustain cardiac desensitization for the 12-hours dosing interval. © 2015, The American College of Clinical Pharmacology.

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