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Sample records for 17d yf vaccines

  1. Vaccination with Replication Deficient Adenovectors Encoding YF-17D Antigens Induces Long-Lasting Protection from Severe Yellow Fever Virus Infection in Mice.

    PubMed

    Bassi, Maria R; Larsen, Mads A B; Kongsgaard, Michael; Rasmussen, Michael; Buus, Søren; Stryhn, Anette; Thomsen, Allan R; Christensen, Jan P

    2016-02-01

    The live attenuated yellow fever vaccine (YF-17D) has been successfully used for more than 70 years. It is generally considered a safe vaccine, however, recent reports of serious adverse events following vaccination have raised concerns and led to suggestions that even safer YF vaccines should be developed. Replication deficient adenoviruses (Ad) have been widely evaluated as recombinant vectors, particularly in the context of prophylactic vaccination against viral infections in which induction of CD8+ T-cell mediated immunity is crucial, but potent antibody responses may also be elicited using these vectors. In this study, we present two adenobased vectors targeting non-structural and structural YF antigens and characterize their immunological properties. We report that a single immunization with an Ad-vector encoding the non-structural protein 3 from YF-17D could elicit a strong CD8+ T-cell response, which afforded a high degree of protection from subsequent intracranial challenge of vaccinated mice. However, full protection was only observed using a vector encoding the structural proteins from YF-17D. This vector elicited virus-specific CD8+ T cells as well as neutralizing antibodies, and both components were shown to be important for protection thus mimicking the situation recently uncovered in YF-17D vaccinated mice. Considering that Ad-vectors are very safe, easy to produce and highly immunogenic in humans, our data indicate that a replication deficient adenovector-based YF vaccine may represent a safe and efficient alternative to the classical live attenuated YF vaccine and should be further tested.

  2. The yellow fever 17D virus as a platform for new live attenuated vaccines.

    PubMed

    Bonaldo, Myrna C; Sequeira, Patrícia C; Galler, Ricardo

    2014-01-01

    The live-attenuated yellow fever 17D virus is one of the most outstanding human vaccines ever developed. It induces efficacious immune responses at a low production cost with a well-established manufacture process. These advantages make the YF17D virus attractive as a vector for the development of new vaccines. At the beginning of vector development studies, YF17D was genetically manipulated to express other flavivirus prM and E proteins, components of the viral envelope. While these 17D recombinants are based on the substitution of equivalent YF17D genes, other antigens from unrelated pathogens have also been successfully expressed and delivered by recombinant YF17D viruses employing alternative strategies for genetic manipulation of the YF17D genome. Herein, we discuss these strategies in terms of possibilities of single epitope or larger sequence expression and the main properties of these replication-competent viral platforms.

  3. 17DD and 17D-213/77 Yellow Fever Substrains Trigger a Balanced Cytokine Profile in Primary Vaccinated Children

    PubMed Central

    Luiza-Silva, Maria; Batista, Maurício Azevedo; Martins, Marina Angela; Sathler-Avelar, Renato; da Silveira-Lemos, Denise; Camacho, Luiz Antonio Bastos; de Menezes Martins, Reinaldo; de Lourdes de Sousa Maia, Maria; Farias, Roberto Henrique Guedes; da Silva Freire, Marcos; Galler, Ricardo; Homma, Akira; Ribeiro, José Geraldo Leite; Lemos, Jandira Aparecida Campos; Auxiliadora-Martins, Maria; Caldas, Iramaya Rodrigues; Elói-Santos, Silvana Maria; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis

    2012-01-01

    Background This study aimed to compare the cytokine-mediated immune response in children submitted to primary vaccination with the YF-17D-213/77 or YF-17DD yellow fever (YF) substrains. Methods A non-probabilistic sample of eighty healthy primary vaccinated (PV) children was selected on the basis of their previously known humoral immune response to the YF vaccines. The selected children were categorized according to their YF-neutralizing antibody titers (PRNT) and referred to as seroconverters (PV-PRNT+) or nonseroconverters (PV-PRNT−). Following revaccination with the YF-17DD, the PV-PRNT− children (YF-17D-213/77 and YF-17DD groups) seroconverted and were referred as RV-PRNT+. The cytokine-mediated immune response was investigated after short-term in vitro cultures of whole blood samples. The results are expressed as frequency of high cytokine producers, taking the global median of the cytokine index (YF-Ag/control) as the cut-off. Results The YF-17D-213/77 and the YF-17DD substrains triggered a balanced overall inflammatory/regulatory cytokine pattern in PV-PRNT+, with a slight predominance of IL-12 in YF-17DD vaccinees and a modest prevalence of IL-10 in YF-17D-213/77. Prominent frequency of neutrophil-derived TNF-α and neutrophils and monocyte-producing IL-12 were the major features of PV-PRNT+ in the YF-17DD, whereas relevant inflammatory response, mediated by IL-12+CD8+ T cells, was the hallmark of the YF-17D-213/77 vaccinees. Both substrains were able to elicit particular but relevant inflammatory events, regardless of the anti-YF PRNT antibody levels. PV-PRNT− children belonging to the YF-17DD arm presented gaps in the inflammatory cytokine signature, especially in terms of the innate immunity, whereas in the YF-17D-213/77 arm the most relevant gap was the deficiency of IL-12-producing CD8+T cells. Revaccination with YF-17DD prompted a balanced cytokine profile in YF-17DD nonresponders and a robust inflammatory profile in YF-17D-213/77 nonresponders

  4. 17D yellow fever vaccines: new insights. A report of a workshop held during the World Congress on medicine and health in the tropics, Marseille, France, Monday 12 September 2005.

    PubMed

    Barrett, Alan D T; Monath, Thomas P; Barban, Veronique; Niedrig, Matthias; Teuwen, Dirk E

    2007-04-12

    Yellow fever (YF) is a major health problem in endemic regions of Africa and South America. It also poses a serious health risk to travellers to areas with endemic disease. Currently, there is no effective drug treatment for YF; however, 17D YF vaccines have demonstrated high rates of effectiveness and good safety profiles. This workshop was organized to review key data and issues about YF disease and currently available 17D YF vaccines. Starting with an overview of the current disease epidemiology in Africa and South America and a review of the safety data of 17D YF vaccines, data were then presented demonstrating the genetic stability of multiple production lots of a 17D YF vaccine, the immunological responses of healthy subjects post-vaccination and the long-term immunogenicity of 17D YF vaccines. Finally, the findings of the molecular characterization of 17D YF virus sub-strains recovered from rare, fatal cases of post-vaccination serious adverse events were presented. There was unanimous agreement that current 17D YF vaccines have a highly favourable benefit-risk profile when used in persons at risk of exposure to the YF virus, and that appropriate use of 17D YF vaccines will minimize the occurrence of serious adverse events post-vaccination.

  5. Yellow fever 17D-vectored vaccines expressing Lassa virus GP1 and GP2 glycoproteins provide protection against fatal disease in guinea pigs.

    PubMed

    Jiang, Xiaohong; Dalebout, Tim J; Bredenbeek, Peter J; Carrion, Ricardo; Brasky, Kathleen; Patterson, Jean; Goicochea, Marco; Bryant, Joseph; Salvato, Maria S; Lukashevich, Igor S

    2011-02-01

    Yellow Fever (YF) and Lassa Fever (LF) are two prevalent hemorrhagic fevers co-circulating in West Africa and responsible for thousands of deaths annually. The YF vaccine 17D has been used as a vector for the Lassa virus glycoprotein precursor (LASV-GPC) or their subunits, GP1 (attachment glycoprotein) and GP2 (fusion glycoprotein). Cloning shorter inserts, LASV-GP1 and -GP2, between YF17D E and NS1 genes enhanced genetic stability of recombinant viruses, YF17D/LASV-GP1 and -GP2, in comparison with YF17D/LASV-GPC recombinant. The recombinant viruses were replication competent and properly processed YF proteins and LASV GP antigens in infected cells. YF17D/LASV-GP1 and -GP2 induced specific CD8+ T cell responses in mice and protected strain 13 guinea pigs against fatal LF. Unlike immunization with live attenuated reassortant vaccine ML29, immunization with YF17D/LASV-GP1 and -GP2 did not provide sterilizing immunity. This study demonstrates the feasibility of YF17D-based vaccine to control LF in West Africa.

  6. Yellow fever 17D-vectored vaccines expressing Lassa virus GP1 and GP2 glycoproteins provide protection against fatal disease in guinea pigs

    PubMed Central

    Jiang, Xiaohong; Dalebout, Tim J.; Bredenbeek, Peter J.; Carrion, Ricardo; Brasky, Kathleen; Patterson, Jean; Goicochea, Marco; Bryant, Joseph; Salvato, Maria S.; Lukashevich, Igor S.

    2010-01-01

    Yellow Fever (YF) and Lassa Fever (LF) are two prevalent hemorrhagic fevers co-circulating in West Africa and responsible for thousands of deaths annually. The YF vaccine 17D has been used as a vector for the Lassa virus glycoprotein precursor (LASV-GPC) or their subunits, GP1 (attachment glycoprotein) and GP2 (fusion glycoprotein). Cloning shorter inserts, LASV GP1 and GP2, between YF17D E and NS1 genes enhanced genetic stability of recombinant viruses, YF17D/LASV-GP1 and –GP2, in comparison with YF17D/LASV-GPC recombinant. The recombinant viruses were replication competent and properly processed YF and LASV GP proteins in infected cells. YF17D/LASV-GP1&GP2 induced specific CD8+ T cell responses in mice and protected strain 13 guinea pigs against fatal LF. Unlike immunization with live attenuated reassortant vaccine ML29, immunization with YF17D/LASV-GP1&GP2 did not provide sterilizing immunity. This study demonstrates the feasibility of YF17D-based vaccine to control LF in West Africa. PMID:21145373

  7. The live-attenuated yellow fever vaccine 17D induces broad and potent T cell responses against several viral proteins in Indian rhesus macaques – implications for recombinant vaccine design

    PubMed Central

    Mudd, Philip A.; Piaskowski, Shari M.; Neves, Patricia C. Costa; Rudersdorf, Richard; Kolar, Holly L.; Eernisse, Christopher M.; Weisgrau, Kim L.; Veloso de Santana, Marlon G.; Wilson, Nancy A.; Bonaldo, Myrna C.; Galler, Ricardo; Rakasz, Eva G.; Watkins, David I.

    2011-01-01

    The yellow fever vaccine 17D (YF17D) is one of the most effective vaccines. Its wide use and favorable safety profile make it a prime candidate for recombinant vaccines. It is believed that neutralizing antibodies account for a large measure of the protection afforded to YF17D-vaccinated individuals, however cytotoxic T lymphocyte (CTL) responses have been described in the setting of YF17D vaccination. YF17D is an ssRNA flavivirus that is translated as a full-length polyprotein, several domains of which pass into the lumen of the endoplasmic reticulum (ER). The processing and presentation machinery for MHC class I-restricted CTL responses favor cytoplasmic peptides that are transported into the ER by the transporter associated with antigen presentation (TAP) proteins. In order to inform recombinant vaccine design, we sought to determine if YF17D-induced CTL responses preferentially targeted viral domains that remain within the cytoplasm. We performed whole YF17D proteome mapping of CTL responses in 6 Indian rhesus macaques vaccinated with YF17D using overlapping YF17D peptides. We found that the ER luminal E protein was the most immunogenic viral protein followed closely by the cytoplasmic NS3 and NS5 proteins. These results suggest that antigen processing and presentation in this model system is not preferentially affected by the subcellular location of the viral proteins that are the source of CTL epitopes. The data also suggest potential immunogenic regions of YF17D that could serve as the focus of recombinant T cell vaccine development. PMID:20607226

  8. Randomized Double-Blind Phase III Pivotal Field Trial of the Comparative Immunogenicity Safety and Tolerability of Two Yellow Fever 17D Vaccines (ARILVAX(Trademark) and YF-VAX(Trademark)) in Healthy Infants and Children in Peru

    DTIC Science & Technology

    2004-08-17

    ARILVAX™ AND YF-VAX) IN HEALTHY INFANTS AND CHILDREN IN PERU VIVIAN E. BELMUSTO-WORN, JOSE L. SANCHEZ, KAREN MCCARTHY, RICHARD NICHOLS, CHRISTIAN T...34031-3800, Telephone: 51-1-561-2882/3848, Fax: 51-1-561-3042, E-mail: worn@nmrcd.med.navy.mil. Jose L. Sanchez, Department of Epidemiology and Threat...upch.edu.pe. Carlos Echevarria, PRA International, Pasaje San Jose 120, Magdalena, Lima, Peru, Telephone: 51-1- 263-7231, Cell Phone: 51- 1-9992-4422, E-mail

  9. Suspected YF-AND after yellow fever vaccination in Finland.

    PubMed

    Jääskeläinen, Anne J; Huhtamo, Eili; Kivioja, Reetta; Domingo, Cristina; Vene, Sirkka; Kallio-Kokko, Hannimari; Niedrig, Matthias; Tienari, Pentti J; Vapalahti, Olli

    2014-11-01

    Yellow fever (YF) vaccine is considered safe but vaccine-associated complications have also been encountered. We report neurological symptoms after YF-vaccination in a previously healthy Finnish male. Other concomitant infections or causes for the symptoms could not be identified.

  10. A recombinant Yellow Fever 17D vaccine expressing Lassa virus glycoproteins.

    PubMed

    Bredenbeek, Peter J; Molenkamp, Richard; Spaan, Willy J M; Deubel, Vincent; Marianneau, Phillippe; Salvato, Maria S; Moshkoff, Dmitry; Zapata, Juan; Tikhonov, Ilia; Patterson, Jean; Carrion, Ricardo; Ticer, Anysha; Brasky, Kathleen; Lukashevich, Igor S

    2006-02-20

    The Yellow Fever Vaccine 17D (YFV17D) has been used as a vector for the Lassa virus glycoprotein precursor (LASV-GPC) resulting in construction of YFV17D/LASV-GPC recombinant virus. The virus was replication-competent and processed the LASV-GPC in cell cultures. The recombinant replicated poorly in guinea pigs but still elicited specific antibodies against LASV and YFV17D antigens. A single subcutaneous injection of the recombinant vaccine protected strain 13 guinea pigs against fatal Lassa Fever. This study demonstrates the potential to develop an YFV17D-based bivalent vaccine against two viruses that are endemic in the same area of Africa.

  11. A randomised double-blind clinical trial of two yellow fever vaccines prepared with substrains 17DD and 17D-213/77 in children nine-23 months old

    PubMed Central

    2015-01-01

    This randomised, double-blind, multicentre study with children nine-23 months old evaluated the immunogenicity of yellow fever (YF) vaccines prepared with substrains 17DD and 17D-213/77. YF antibodies were tittered before and 30 or more days after vaccination. Seropositivity and seroconversion were analysed according to the maternal serological status and the collaborating centre. A total of 1,966 children were randomised in the municipalities of the states of Mato Grosso do Sul, Minas Gerais and São Paulo and blood samples were collected from 1,714 mothers. Seropositivity was observed in 78.6% of mothers and 8.9% of children before vaccination. After vaccination, seropositivity rates of 81.9% and 83.2%, seroconversion rates of 84.8% and 85.8% and rates of a four-fold increase over the pre-vaccination titre of 77.6% and 81.8% were observed in the 17D-213/77 and 17DD subgroups, respectively. There was no association with maternal immunity. Among children aged 12 months or older, the seroconversion rates of 69% were associated with concomitant vaccination against measles, mumps and rubella. The data were not conclusive regarding the interference of maternal immunity in the immune response to the YF vaccine, but they suggest interference from other vaccines. The failures in seroconversion after vaccination support the recommendation of a booster dose in children within 10 years of the first dose. PMID:26517656

  12. A randomised double-blind clinical trial of two yellow fever vaccines prepared with substrains 17DD and 17D-213/77 in children nine-23 months old.

    PubMed

    2015-09-01

    This randomised, double-blind, multicentre study with children nine-23 months old evaluated the immunogenicity of yellow fever (YF) vaccines prepared with substrains 17DD and 17D-213/77. YF antibodies were titered before and 30 or more days after vaccination. Seropositivity and seroconversion were analysed according to the maternal serological status and the collaborating centre. A total of 1,966 children were randomised in the municipalities of the states of Mato Grosso do Sul, Minas Gerais and São Paulo and blood samples were collected from 1,714 mothers. Seropositivity was observed in 78.6% of mothers and 8.9% of children before vaccination. After vaccination, seropositivity rates of 81.9% and 83.2%, seroconversion rates of 84.8% and 85.8% and rates of a four-fold increase over the pre-vaccination titre of 77.6% and 81.8% were observed in the 17D-213/77 and 17DD subgroups, respectively. There was no association with maternal immunity. Among children aged 12 months or older, the seroconversion rates of 69% were associated with concomitant vaccination against measles, mumps and rubella. The data were not conclusive regarding the interference of maternal immunity in the immune response to the YF vaccine, but they suggest interference from other vaccines. The failures in seroconversion after vaccination support the recommendation of a booster dose in children within 10 years of the first dose.

  13. [Effectiveness of the yellow fever vaccine 17D: an epidemiologic evaluation in health services].

    PubMed

    Guerra, H L; Sardinha, T M; da Rosa, A P; Lima e Costa, M F

    1997-08-01

    The purpose of this study was to evaluate the efficacy of the 17D yellow fever vaccine in the conditions under which it is used in public health services. In 1989, a nonconcurrent prospective study was carried out in Bocaiúva, Minas Gerais State, Brazil, 6 months after mass vaccination of the population. The study population was made up of first-grade students from all the schools in Bocaiúva. The exposed group consisted of a simple random sample of vaccinated students (n = 173) and the unexposed group consisted of all those who had not been vaccinated (n = 55). Serum samples were examined with the neutralization test in mice; these tests were conducted blind, that is, the examiner did not know the vaccination status of the subject. The serology results were as follows: of those vaccinated, 75% were seropositive, 17% were seronegative, and 7% showed an inconclusive result; in the unvaccinated children, these results were 9%, 87%, and 4%, respectively. The age-adjusted seropositivity ratio between vaccinated and unvaccinated children was 7.6 (95% CI: 3.4 to 16.7). The proportion of seropositivity attributable to vaccination, adjusted for age, was 86.8% (95% CI: 70.6 to 94.0). The results showed that the efficacy of the vaccine, defined by means of seropositivity for the virus, was below the levels expected for the 17D vaccine. This may have been due to operational failures in the conservation or application of the vaccine. The results point to the need for routine systematic evaluations by the health services after mass utilization of the vaccine.

  14. Booster dose after 10 years is recommended following 17DD-YF primary vaccination

    PubMed Central

    Campi-Azevedo, Ana Carolina; Costa-Pereira, Christiane; Antonelli, Lis R; Fonseca, Cristina T; Teixeira-Carvalho, Andréa; Villela-Rezende, Gabriela; Santos, Raiany A; Batista, Maurício A; Campos, Fernanda M; Pacheco-Porto, Luiza; Melo Júnior, Otoni A; Hossell, Débora MSH; Coelho-dos-Reis, Jordana G; Peruhype-Magalhães, Vanessa; Costa-Silva, Matheus F; de Oliveira, Jaquelline G; Farias, Roberto H; Noronha, Tatiana G; Lemos, Jandira A; von Doellinger, Vanessa dos R; Simões, Marisol; de Souza, Mirian M; Malaquias, Luiz C; Persi, Harold R; Pereira, Jorge M; Martins, José A; Dornelas-Ribeiro, Marcos; Vinhas, Aline de A; Alves, Tatiane R; Maia, Maria de L; Freire, Marcos da S; Martins, Reinaldo de M; Homma, Akira; Romano, Alessandro PM; Domingues, Carla M; Tauil, Pedro L; Vasconcelos, Pedro F; Rios, Maria; Caldas, Iramaya R; Camacho, Luiz A; Martins-Filho, Olindo Assis

    2016-01-01

    A single vaccination of Yellow Fever vaccines is believed to confer life-long protection. In this study, results of vaccinees who received a single dose of 17DD-YF immunization followed over 10 y challenge this premise. YF-neutralizing antibodies, subsets of memory T and B cells as well as cytokine-producing lymphocytes were evaluated in groups of adults before (NVday0) and after (PVday30-45, PVyear1-4, PVyear5-9, PVyear10-11, PVyear12-13) 17DD-YF primary vaccination. YF-neutralizing antibodies decrease significantly from PVyear1-4 to PVyear12-13 as compared to PVday30-45, and the seropositivity rates (PRNT≥2.9Log10mIU/mL) become critical (lower than 90%) beyond PVyear5-9. YF-specific memory phenotypes (effector T-cells and classical B-cells) significantly increase at PVday30-45 as compared to naïve baseline. Moreover, these phenotypes tend to decrease at PVyear10-11 as compared to PVday30-45. Decreasing levels of TNF-α+ and IFN-γ+ produced by CD4+ and CD8+ T-cells along with increasing levels of IL-10+CD4+T-cells were characteristic of anti-YF response over time. Systems biology profiling represented by hierarchic networks revealed that while the naïve baseline is characterized by independent micro-nets, primary vaccinees displayed an imbricate network with essential role of central and effector CD8+ memory T-cell responses. Any putative limitations of this cross-sectional study will certainly be answered by the ongoing longitudinal population-based investigation. Overall, our data support the current Brazilian national immunization policy guidelines that recommend one booster dose 10 y after primary 17DD-YF vaccination. PMID:26360663

  15. Antibody response to 17D yellow fever vaccine in Ghanaian infants.

    PubMed Central

    Osei-Kwasi, M.; Dunyo, S. K.; Koram, K. A.; Afari, E. A.; Odoom, J. K.; Nkrumah, F. K.

    2001-01-01

    OBJECTIVES: To assess the seroresponses to yellow fever vaccination at 6 and 9 months of age; assess any possible adverse effects of immunization with the 17D yellow fever vaccine in infants, particularly at 6 months of age. METHODS: Four hundred and twenty infants who had completed BCG, OPV and DPT immunizations were randomized to receive yellow fever immunization at either 6 or 9 months. A single dose of 0.5 ml of the reconstituted vaccine was administered to each infant by subcutaneous injection. To determine the yellow fever antibody levels of the infants, each donated 1 ml whole blood prior to immunization and 3 months post-immunization. Each serum sample was titred on Vero cells against the vaccine virus. FINDINGS: The most common adverse reactions reported were fever, cough, diarrhoea and mild reactions at the inoculation site. The incidences of adverse reactions were not statistically different in both groups. None of the pre-immunization sera in both age groups had detectable yellow fever antibodies. Infants immunized at 6 months recorded seroconversion of 98.6% and those immunized at 9 months recorded 98% seroconversion. The GMT of their antibodies were 158.5 and 129.8, respectively. CONCLUSIONS: The results indicate that seroresponses to yellow fever immunization at 6 and 9 months as determined by seroconversion and GMTs of antibodies are similar. The findings of good seroresponses at 6 months without significant adverse effects would suggest that the 17D yellow fever vaccine could be recommended for use in children at 6 months in outbreak situations or in high risk endemic areas. PMID:11731813

  16. Immunogenicity of a purified fragment of 17D yellow fever envelope protein.

    PubMed

    Brandriss, M W; Schlesinger, J J; Walsh, E E

    1990-06-01

    Information on the immunogenic properties of purified flavivirus proteins may be useful in the development of recombinant or synthetic peptide vaccines. Using a monoclonal antibody, an attempt was made to purify the envelope (E) protein of 17D yellow fever virus (17D YF) by affinity chromatography. The purified material could not be identified as intact E protein but it did bear antigenic determinants of E as determined by selective reactivity with anti-E monoclonal antibodies. Rabbits immunized with this material produced antibodies that neutralized 17D YF and dengue-2 viruses in comparable titers, indicating that cross-reactive antigenic determinants were preserved. Immunization of mice resulted in protection against intracerebral challenge with 17D YF.

  17. Neutralizing antibody response to booster vaccination with the 17d yellow fever vaccine.

    PubMed

    Hepburn, M J; Kortepeter, M G; Pittman, P R; Boudreau, E F; Mangiafico, J A; Buck, P A; Norris, S L; Anderson, E L

    2006-04-05

    A retrospective review was conducted of yellow fever vaccination among laboratory workers receiving annual serologic assessment to determine the initial and long-term response after boosting. Patients were divided into three groups based on pre-vaccination serology: Group 1, 1:10; Group 2, 1:20-1:40 and Group 3, >1:40. The percent with > or = four-fold increase in titers after booster vaccination were: 78% (646/829, Group 1), 65% (79/121, Group 2) and 10% (8/79, Group 3) (p<0.0001). The median times to titer failure (<1:40) were 798 days (Group 1), 3340 days (Group 2) and 7709 days (Group 3) (p<0.0001). Pre-vaccination serology influenced the initial and long-term response to yellow fever booster vaccination.

  18. WHO Working Group on Technical Specifications for Manufacture and Evaluation of Yellow Fever Vaccines, Geneva, Switzerland, 13-14 May 2009.

    PubMed

    Ferguson, Morag; Shin, Jinho; Knezevic, Ivana; Minor, Philip; Barrett, Alan

    2010-12-06

    In May 2009, WHO convened a meeting of Working Group on Technical Specifications for Manufacturing and Evaluating Yellow Fever (YF) Vaccines, Geneva, Switzerland to initiate revision of the WHO Recommendations (formerly, Requirements) for YF vaccine published in WHO Technical Report Series number 872 (1998). The Working Group, consisting of experts from academia, industry, national regulatory authorities and national control laboratories, reviewed the latest issues of safety, efficacy and quality of YF vaccines and agreed that (i) the revision should focus on live attenuated YF vaccine virus 17D lineage; and that (ii) nonclinical and clinical guidelines for new vaccines prepared from 17D lineage be developed.

  19. Molecular and immunological characterization of a DNA-launched yellow fever virus 17D infectious clone.

    PubMed

    Jiang, Xiaohong; Dalebout, Tim J; Lukashevich, Igor S; Bredenbeek, Peter J; Franco, David

    2015-04-01

    Yellow fever virus (YFV)-17D is an empirically developed, highly effective live-attenuated vaccine that has been administered to human beings for almost a century. YFV-17D has stood as a paradigm for a successful viral vaccine, and has been exploited as a potential virus vector for the development of recombinant vaccines against other diseases. In this study, a DNA-launched YFV-17D construct (pBeloBAC-FLYF) was explored as a new modality to the standard vaccine to combine the commendable features of both DNA vaccine and live-attenuated viral vaccine. The DNA-launched YFV-17D construct was characterized extensively both in cell culture and in mice. High titres of YFV-17D were generated upon transfection of the DNA into cells, whereas a mutant with deletion in the capsid-coding region (pBeloBAC-YF/ΔC) was restricted to a single round of infection, with no release of progeny virus. Homologous prime-boost immunization of AAD mice with both pBeloBAC-FLYF and pBeloBAC-YF/ΔC elicited specific dose-dependent cellular immune response against YFV-17D. Vaccination of A129 mice with pBeloBAC-FLYF resulted in the induction of YFV-specific neutralizing antibodies in all vaccinated subjects. These promising results underlined the potential of the DNA-launched YFV both as an alternative to standard YFV-17D vaccination and as a vaccine platform for the development of DNA-based recombinant YFV vaccines.

  20. Comparison of the Live Attenuated Yellow Fever Vaccine 17D-204 Strain to Its Virulent Parental Strain Asibi by Deep Sequencing

    PubMed Central

    Beck, Andrew; Tesh, Robert B.; Wood, Thomas G.; Widen, Steven G.; Ryman, Kate D.; Barrett, Alan D. T.

    2014-01-01

    Background. The first comparison of a live RNA viral vaccine strain to its wild-type parental strain by deep sequencing is presented using as a model the yellow fever virus (YFV) live vaccine strain 17D-204 and its wild-type parental strain, Asibi. Methods. The YFV 17D-204 vaccine genome was compared to that of the parental strain Asibi by massively parallel methods. Variability was compared on multiple scales of the viral genomes. A modeled exploration of small-frequency variants was performed to reconstruct plausible regions of mutational plasticity. Results. Overt quasispecies diversity is a feature of the parental strain, whereas the live vaccine strain lacks diversity according to multiple independent measurements. A lack of attenuating mutations in the Asibi population relative to that of 17D-204 was observed, demonstrating that the vaccine strain was derived by discrete mutation of Asibi and not by selection of genomes in the wild-type population. Conclusions. Relative quasispecies structure is a plausible correlate of attenuation for live viral vaccines. Analyses such as these of attenuated viruses improve our understanding of the molecular basis of vaccine attenuation and provide critical information on the stability of live vaccines and the risk of reversion to virulence. PMID:24141982

  1. The dissemination of 17D yellow fever vaccine in Africans in Kenya in relation to the interpretation of results of protection-test surveys

    PubMed Central

    Lumsden, W. H. R.

    1954-01-01

    The extent of dissemination of 17D yellow fever vaccine among the population of Kenya, especially among Africans, is estimated, largely from information in the records of the Kenya Medical Department. The total recorded vaccinations of Africans between 1941 and 1951 amount to about 379,000, representing 7.2% of the African population in 1948; it is, however, possible that the actual number of vaccinations is considerably higher. At Mombasa, 78,000 persons of races other than Africans were given routine inoculation over the same period. After a study of the economy of use of vaccine, the author discusses the protection-test surveys performed before 1951 and during that year in relation to the dissemination of vaccine. It is tentatively concluded that natural infection of man with yellow fever is rare in both Kenya and Tanganyika. PMID:13209303

  2. The 17D-204 Vaccine Strain-Induced Protection against Virulent Yellow Fever Virus Is Mediated by Humoral Immunity and CD4+ but not CD8+ T Cells

    PubMed Central

    Lam, L. K. Metthew; Klimstra, William B.

    2016-01-01

    A gold standard of antiviral vaccination has been the safe and effective live-attenuated 17D-based yellow fever virus (YFV) vaccines. Among more than 500 million vaccinees, only a handful of cases have been reported in which vaccinees developed a virulent wild type YFV infection. This efficacy is presumed to be the result of both neutralizing antibodies and a robust T cell response. However, the particular immune components required for protection against YFV have never been evaluated. An understanding of the immune mechanisms that underlie 17D-based vaccine efficacy is critical to the development of next-generation vaccines against flaviviruses and other pathogens. Here we have addressed this question for the first time using a murine model of disease. Similar to humans, vaccination elicited long-term protection against challenge, characterized by high neutralizing antibody titers and a robust T cell response that formed long-lived memory. Both CD4+ and CD8+ T cells were polyfunctional and cytolytic. Adoptive transfer of immune sera or CD4+ T cells provided partial protection against YFV, but complete protection was achieved by transfer of both immune sera and CD4+ T cells. Thus, robust CD4+ T cell activity may be a critical contributor to protective immunity elicited by highly effective live attenuated vaccines. PMID:27463517

  3. A case suspected for yellow fever vaccine-associated viscerotropic disease in the Netherlands.

    PubMed

    van de Pol, Eva M; Gisolf, Elizabeth H; Richter, Clemens

    2014-01-01

    Yellow fever (YF) 17D vaccine is one of the most successful vaccines ever developed. Since 2001, 56 cases of yellow fever vaccine-associated viscerotropic disease (YEL-AVD) have been published in the peer-reviewed literature. Here, we report a new case suspected for YEL-AVD in the Netherlands. Further research is needed to determine the true incidence of YEL-AVD and to clarify host and vaccine-associated factors in the pathogenesis of YEL-AVD. Because of the potential adverse events, healthcare providers should carefully consider vaccination only in people who are truly at risk for YF infection, especially in primary vaccine recipients.

  4. Plasmid DNA initiates replication of yellow fever vaccine in vitro and elicits virus-specific immune response in mice

    SciTech Connect

    Tretyakova, Irina; Nickols, Brian; Hidajat, Rachmat; Jokinen, Jenny; Lukashevich, Igor S.; Pushko, Peter

    2014-11-15

    Yellow fever (YF) causes an acute hemorrhagic fever disease in tropical Africa and Latin America. To develop a novel experimental YF vaccine, we applied iDNA infectious clone technology. The iDNA represents plasmid that encodes the full-length RNA genome of 17D vaccine downstream from a cytomegalovirus (CMV) promoter. The vaccine was designed to transcribe the full-length viral RNA and to launch 17D vaccine virus in vitro and in vivo. Transfection with 10 ng of iDNA plasmid was sufficient to start replication of vaccine virus in vitro. Safety of the parental 17D and iDNA-derived 17D viruses was confirmed in AG129 mice deficient in receptors for IFN-α/β/γ. Finally, direct vaccination of BALB/c mice with a single 20 μg dose of iDNA plasmid resulted in seroconversion and elicitation of virus-specific neutralizing antibodies in animals. We conclude that iDNA immunization approach combines characteristics of DNA and attenuated vaccines and represents a promising vaccination strategy for YF. - Highlights: • The iDNA{sup ®} platform combines advantages of DNA and live attenuated vaccines. • Yellow fever (YF) 17D vaccine was launched from iDNA plasmid in vitro and in vivo. • Safety of iDNA-generated 17D virus was confirmed in AG129 mice. • BALB/c mice seroconverted after a single-dose vaccination with iDNA. • YF virus-neutralizing response was elicited in iDNA-vaccinated mice.

  5. Limited replication of yellow fever 17DD and 17D-Dengue recombinant viruses in rhesus monkeys.

    PubMed

    Trindade, Gisela F; Marchevsky, Renato S; Fillipis, Ana M B de; Nogueira, Rita M R; Bonaldo, Myrna C; Acero, Pedro C; Caride, Elena; Freire, Marcos S; Galler, Ricardo

    2008-06-01

    For the development of safe live attenuated flavivirus vaccines one of the main properties to be established is viral replication. We have used real-time reverse transcriptase-polymerase chain reaction and virus titration by plaque assay to determine the replication of yellow fever 17DD virus (YFV 17DD) and recombinant yellow fever 17D viruses expressing envelope proteins of dengue virus serotypes 2 and 4 (17D-DENV-2 and 17D-DENV-4). Serum samples from rhesus monkeys inoculated with YFV 17DD and 17D-DENV chimeras by intracerebral or subcutaneous route were used to determine and compare the viremia induced by these viruses. Viral load quantification in samples from monkeys inoculated by either route with YFV 17DD virus suggested a restricted capability of the virus to replicate reaching not more than 2.0 log10 PFU mL(-1) or 3.29 log10 copies mL(-1). Recombinant 17D-dengue viruses were shown by plaquing and real-time PCR to be as attenuated as YF 17DD virus with the highest mean peak titer of 1.97 log10 PFU mL(-1) or 3.53 log10 copies mL(-1). These data serve as a comparative basis for the characterization of other 17D-based live attenuated candidate vaccines against other diseases.

  6. Yellow Fever 17DD Vaccine Virus Infection Causes Detectable Changes in Chicken Embryos

    PubMed Central

    Manso, Pedro Paulo de Abreu; Dias de Oliveira, Barbara C. E. P.; de Sequeira, Patrícia Carvalho; Maia de Souza, Yuli Rodrigues; Ferro, Jessica Maria dos Santos; da Silva, Igor José; Caputo, Luzia Fátima Gonçalves; Guedes, Priscila Tavares; dos Santos, Alexandre Araujo Cunha; Freire, Marcos da Silva; Bonaldo, Myrna Cristina; Pelajo-Machado, Marcelo

    2015-01-01

    The yellow fever (YF) 17D vaccine is one of the most effective human vaccines ever created. The YF vaccine has been produced since 1937 in embryonated chicken eggs inoculated with the YF 17D virus. Yet, little information is available about the infection mechanism of YF 17DD virus in this biological model. To better understand this mechanism, we infected embryos of Gallus gallus domesticus and analyzed their histopathology after 72 hours of YF infection. Some embryos showed few apoptotic bodies in infected tissues, suggesting mild focal infection processes. Confocal and super-resolution microscopic analysis allowed us to identify as targets of viral infection: skeletal muscle cells, cardiomyocytes, nervous system cells, renal tubular epithelium, lung parenchyma, and fibroblasts associated with connective tissue in the perichondrium and dermis. The virus replication was heaviest in muscle tissues. In all of these specimens, RT-PCR methods confirmed the presence of replicative intermediate and genomic YF RNA. This clearer characterization of cell targets in chicken embryos paves the way for future development of a new YF vaccine based on a new cell culture system. PMID:26371874

  7. Yellow fever vaccine: comparison of the neurovirulence of new 17D-204 Stamaril™ seed lots and RK 168-73 strain.

    PubMed

    Moulin, Jean-Claude; Silvano, Jérémy; Barban, Véronique; Riou, Patrice; Allain, Caroline

    2013-07-01

    The neurovirulence of two new candidate 17D-204 Stamaril™ working seed lots and that of two reference preparations were compared. The Stamaril™ working seed lots have been used for more than twenty years for the manufacturing of vaccines of acceptable safety and efficacy. The preparation designated RK 168-73 and provided by the Robert Koch Institute was used as a reference. It was confirmed that RK 168-73 strain was not a good virus control in our study because it has a very low neurovirulence regarding both the clinical and histopathological scores in comparison with Stamaril™ strain and is not representative of a vaccine known to be satisfactory in use. The results were reinforced by the phenotypic characterization by plaque assay demonstrating that RK 168-73 was very different from the Stamaril™ vaccine, and by sequencing results showing 4 mutations between Stamaril™ and RK 168-73 viruses leading to amino acid differences in the NS4B and envelop proteins.

  8. Advances and controversies in yellow fever vaccination.

    PubMed

    Jonker, Emile F F; Visser, Leonardus G; Roukens, Anna H

    2013-11-01

    Ever since its development in 1937, the live-attenuated 17D yellow fever (YF) vaccine has been one of the most effective vaccines available to man. In this review we highlight the major steps in the development of 17D YF vaccine. We discuss the use of neutralizing antibodies as a surrogate marker for protection, and explore the strengths and weaknesses of the current plaque reduction neutralization test (PRNT), a technique developed in the 1960s that continues to be superior to every modern test in both sensitivity and specificity. The neutralizing antibodies demonstrated by the PRNT can be detected for several decades after vaccination, possibly even for the remainder of the recipient's natural life. We review the available evidence on the duration of protection after primary vaccination, a topic that has been the subject of controversy over the last few months. For persons who are immunocompromised due to disease, medication or advancing age, the duration of protection may be shorter: they should always have their vaccine response checked by PRNT. Due to the higher risk of severe adverse events after vaccination with 17D YF in this group, the development of a new, inactivated vaccine will have substantial benefits in this population.

  9. Immunogenicity of Yellow Fever Vaccine Coadministered With MenAfriVac in Healthy Infants in Ghana and Mali

    PubMed Central

    Roy Chowdhury, Panchali; Meier, Christian; Laraway, Hewad; Tang, Yuxiao; Hodgson, Abraham; Sow, Samba O.; Enwere, Godwin C.; Plikaytis, Brian D.; Kulkarni, Prasad S.; Preziosi, Marie-Pierre; Niedrig, Matthias

    2015-01-01

    Background. Yellow fever (YF) is still a major public health problem in endemic regions of Africa and South America. In Africa, one of the main control strategies is routine vaccination within the Expanded Programme on Immunization (EPI). A new meningococcal A conjugate vaccine (PsA-TT) is about to be introduced in the EPI of countries in the African meningitis belt, and this study reports on the immunogenicity of the YF-17D vaccines in infants when administered concomitantly with measles vaccine and PsA-TT. Methods. Two clinical studies were conducted in Ghana and in Mali among infants who received PsA-TT concomitantly with measles and YF vaccines at 9 months of age. YF neutralizing antibody titers were measured using a microneutralization assay. Results. In both studies, the PsA-TT did not adversely affect the immune response to the concomitantly administered YF vaccine at the age of 9 months. The magnitude of the immune response was different between the 2 studies, with higher seroconversion and seroprotection rates found in Mali vs Ghana. Conclusions. Immunogenicity to YF vaccine is unaffected when coadministered with PsA-TT at 9 months of age. Further studies are warranted to better understand the determinants of the immune response to YF vaccine in infancy. Clinical Trials Registration. ISRCTN82484612 (PsA-TT-004); PACTR201110000328305 (PsA-TT-007). PMID:26553692

  10. Plasmid DNA Initiates Replication of Yellow Fever Vaccine In Vitro and Elicits Virus-Specific Immune Response in Mice

    PubMed Central

    Tretyakova, Irina; Nickols, Brian; Hidajat, Rachmat; Jokinen, Jenny; Lukashevich, Igor S.; Pushko, Peter

    2014-01-01

    Yellow fever (YF) causes an acute hemorrhagic fever disease in tropical Africa and Latin America. To develop a novel experimental YF vaccine, we applied iDNA infectious clone technology. The iDNA represents plasmid that encodes the full-length RNA genome of 17D vaccine downstream from a cytomegalovirus (CMV) promoter. The vaccine was designed to transcribe the full-length viral RNA and to launch 17D vaccine virus in vitro and in vivo. Transfection with 10ng of iDNA plasmid was sufficient to start replication of vaccine virus in vitro. Safety of the parental 17D and iDNA-derived 17D viruses was confirmed in AG129 mice deficient in receptors for IFN-α/β/γ. Finally, direct vaccination of BALB/c mice with a single 20µg dose of iDNA plasmid resulted in seroconversion and elicitation of virus-specific neutralizing antibodies in animals. We conclude that iDNA immunization approach combines characteristics of DNA and attenuated vaccines and represents a promising vaccination strategy for YF. PMID:25129436

  11. Plasmid DNA initiates replication of yellow fever vaccine in vitro and elicits virus-specific immune response in mice.

    PubMed

    Tretyakova, Irina; Nickols, Brian; Hidajat, Rachmat; Jokinen, Jenny; Lukashevich, Igor S; Pushko, Peter

    2014-11-01

    Yellow fever (YF) causes an acute hemorrhagic fever disease in tropical Africa and Latin America. To develop a novel experimental YF vaccine, we applied iDNA infectious clone technology. The iDNA represents plasmid that encodes the full-length RNA genome of 17D vaccine downstream from a cytomegalovirus (CMV) promoter. The vaccine was designed to transcribe the full-length viral RNA and to launch 17D vaccine virus in vitro and in vivo. Transfection with 10 ng of iDNA plasmid was sufficient to start replication of vaccine virus in vitro. Safety of the parental 17D and iDNA-derived 17D viruses was confirmed in AG129 mice deficient in receptors for IFN-α/β/γ. Finally, direct vaccination of BALB/c mice with a single 20 μg dose of iDNA plasmid resulted in seroconversion and elicitation of virus-specific neutralizing antibodies in animals. We conclude that iDNA immunization approach combines characteristics of DNA and attenuated vaccines and represents a promising vaccination strategy for YF.

  12. Vaccine Platforms to Control Arenaviral Hemorrhagic Fevers

    PubMed Central

    Carrion, Ricardo; Bredenbeek, Peter; Jiang, Xiaohong; Tretyakova, Irina; Pushko, Peter; Lukashevich, Igor S.

    2013-01-01

    Arenaviruses are rodent-borne emerging human pathogens. Diseases caused by these viruses, e.g., Lassa fever (LF) in West Africa and South American hemorrhagic fevers (HFs), are serious public health problems in endemic areas. We have employed replication-competent and replication-deficient strategies to design vaccine candidates potentially targeting different groups “at risk”. Our leader LF vaccine candidate, the live reassortant vaccine ML29, is safe and efficacious in all tested animal models including non-human primates. In this study we showed that treatment of fatally infected animals with ML29 two days after Lassa virus (LASV) challenge protected 80% of the treated animals. In endemic areas, where most of the target population is poor and many live far from health care facilities, a single-dose vaccination with ML29 would be ideal solution. Once there is an outbreak, a fast-acting vaccine or post-exposure prophylaxis would be best. The 2nd vaccine technology is based on Yellow Fever (YF) 17D vaccine. We designed YF17D-based recombinant viruses expressing LASV glycoproteins (GP) and showed protective efficacy of these recombinants. In the current study we developed a novel technology to clone LASV nucleocapsid within YF17D C gene. Low immunogenicity and stability of foreign inserts must be addressed to design successful LASV/YFV bivalent vaccines to control LF and YF in overlapping endemic areas of West Africa. The 3rd platform is based on the new generation of alphavirus replicon virus-like-particle vectors (VLPV). Using this technology we designed VLPV expressing LASV GP with enhanced immunogenicity and bivalent VLPV expressing cross-reactive GP of Junin virus (JUNV) and Machupo virus (MACV), causative agents of Argentinian and Bolivian HF, respectively. A prime-boost regimen required for VLPV immunization might be practical for medical providers, military, lab personnel, and visitors in endemic areas. PMID:23420494

  13. Vaccine Platforms to Control Arenaviral Hemorrhagic Fevers.

    PubMed

    Carrion, Ricardo; Bredenbeek, Peter; Jiang, Xiaohong; Tretyakova, Irina; Pushko, Peter; Lukashevich, Igor S

    2012-11-20

    Arenaviruses are rodent-borne emerging human pathogens. Diseases caused by these viruses, e.g., Lassa fever (LF) in West Africa and South American hemorrhagic fevers (HFs), are serious public health problems in endemic areas. We have employed replication-competent and replication-deficient strategies to design vaccine candidates potentially targeting different groups "at risk". Our leader LF vaccine candidate, the live reassortant vaccine ML29, is safe and efficacious in all tested animal models including non-human primates. In this study we showed that treatment of fatally infected animals with ML29 two days after Lassa virus (LASV) challenge protected 80% of the treated animals. In endemic areas, where most of the target population is poor and many live far from health care facilities, a single-dose vaccination with ML29 would be ideal solution. Once there is an outbreak, a fast-acting vaccine or post-exposure prophylaxis would be best. The 2(nd) vaccine technology is based on Yellow Fever (YF) 17D vaccine. We designed YF17D-based recombinant viruses expressing LASV glycoproteins (GP) and showed protective efficacy of these recombinants. In the current study we developed a novel technology to clone LASV nucleocapsid within YF17D C gene. Low immunogenicity and stability of foreign inserts must be addressed to design successful LASV/YFV bivalent vaccines to control LF and YF in overlapping endemic areas of West Africa. The 3(rd) platform is based on the new generation of alphavirus replicon virus-like-particle vectors (VLPV). Using this technology we designed VLPV expressing LASV GP with enhanced immunogenicity and bivalent VLPV expressing cross-reactive GP of Junin virus (JUNV) and Machupo virus (MACV), causative agents of Argentinian and Bolivian HF, respectively. A prime-boost regimen required for VLPV immunization might be practical for medical providers, military, lab personnel, and visitors in endemic areas.

  14. Live virus vaccines based on a yellow fever vaccine backbone: standardized template with key considerations for a risk/benefit assessment.

    PubMed

    Monath, Thomas P; Seligman, Stephen J; Robertson, James S; Guy, Bruno; Hayes, Edward B; Condit, Richard C; Excler, Jean Louis; Mac, Lisa Marie; Carbery, Baevin; Chen, Robert T

    2015-01-01

    The Brighton Collaboration Viral Vector Vaccines Safety Working Group (V3SWG) was formed to evaluate the safety of live, recombinant viral vaccines incorporating genes from heterologous viruses inserted into the backbone of another virus (so-called "chimeric virus vaccines"). Many viral vector vaccines are in advanced clinical trials. The first such vaccine to be approved for marketing (to date in Australia, Thailand, Malaysia, and the Philippines) is a vaccine against the flavivirus, Japanese encephalitis (JE), which employs a licensed vaccine (yellow fever 17D) as a vector. In this vaccine, two envelope proteins (prM-E) of YF 17D virus were exchanged for the corresponding genes of JE virus, with additional attenuating mutations incorporated into the JE gene inserts. Similar vaccines have been constructed by inserting prM-E genes of dengue and West Nile into YF 17D virus and are in late stage clinical studies. The dengue vaccine is, however, more complex in that it requires a mixture of four live vectors each expressing one of the four dengue serotypes. This vaccine has been evaluated in multiple clinical trials. No significant safety concerns have been found. The Phase 3 trials met their endpoints in terms of overall reduction of confirmed dengue fever, and, most importantly a significant reduction in severe dengue and hospitalization due to dengue. However, based on results that have been published so far, efficacy in preventing serotype 2 infection is less than that for the other three serotypes. In the development of these chimeric vaccines, an important series of comparative studies of safety and efficacy were made using the parental YF 17D vaccine virus as a benchmark. In this paper, we use a standardized template describing the key characteristics of the novel flavivirus vaccine vectors, in comparison to the parental YF 17D vaccine. The template facilitates scientific discourse among key stakeholders by increasing the transparency and comparability of

  15. Cell-mediated immunity induced by chimeric tetravalent dengue vaccine in naive or flavivirus-primed subjects.

    PubMed

    Guy, Bruno; Nougarede, Nolwenn; Begue, Sarah; Sanchez, Violette; Souag, Nadia; Carre, Murielle; Chambonneau, Laurent; Morrisson, Dennis N; Shaw, David; Qiao, Ming; Dumas, Rafaele; Lang, Jean; Forrat, Remi

    2008-10-23

    Three independent, phase 1 clinical trials were conducted in Australia and in USA to assess the safety and immunogenicity of sanofi pasteur dengue vaccine candidates. In this context, Dengue 1-4 and Yellow Fever 17D-204 (YF 17D)-specific CD4 and CD8 cellular responses induced by tetravalent chimeric dengue vaccines (CYD) were analyzed in flavivirus-naive or flavivirus-immune patients. Tetravalent CYD vaccine did not trigger detectable changes in serum pro-inflammatory cytokines, whatever the vaccinees immune status, while inducing significant YF 17D NS3-specific CD8 responses and dengue serotype-specific T helper responses. These responses were dominated by serotype 4 in naive individuals, but a booster vaccination (dose #2) performed 4 months following dose #1 broadened serotype-specific responses. A similar, broader response was seen after primary tetravalent immunization in subjects with pre-existing dengue 1 or 2 immunity caused by prior monovalent live-attenuated dengue vaccination. In all three trials, the profile of induced response was similar, whatever the subjects' immune status, i.e. an absence of Th2 response, and an IFN-gamma/TNF-alpha ratio dominated by IFN-gamma, for both CD4 and CD8 responses. Our results also showed an absence of cross-reactivity between YF 17D or Dengue NS3-specific CD8 responses, and allowed the identification of 3 new CD8 epitopes in the YF 17D NS3 antigen. These data are consistent with the previously demonstrated excellent safety of these dengue vaccines in flavivirus-naive and primed individuals.

  16. Live Virus Vaccines Based on a Yellow Fever Vaccine Backbone: Standardized Template with Key Considerations for a Risk/Benefit Assessment*

    PubMed Central

    Monath, Thomas P.; Seligman, Stephen J.; Robertson, James S.; Guy, Bruno; Hayes, Edward B.; Condit, Richard C.; Excler, Jean Louis; Mac, Lisa Marie; Carbery, Baevin; Chen, Robert T

    2015-01-01

    The Brighton Collaboration Viral Vector Vaccines Safety Working Group (V3SWG) was formed to evaluate the safety of live, recombinant viral vaccines incorporating genes from heterologous viruses inserted into the backbone of another virus (so-called “chimeric virus vaccines”). Many viral vector vaccines are in advanced clinical trials. The first such vaccine to be approved for marketing (to date in Australia, Thailand, Malaysia, and the Philippines) is a vaccine against the flavivirus Japanese encephalitis (JE), which employs a licensed vaccine (yellow fever 17D) as a vector. In this vaccine, two envelope proteins (prM-E) of YF 17D virus were replaced by the corresponding genes of JE virus, with additional attenuating mutations incorporated into the JE gene inserts. Similar vaccines have been constructed by inserting prM-E genes of dengue and West Nile into YF 17D virus and are in late stage clinical studies. The dengue vaccine is, however, more complex in that it requires a mixture of four live vectors each expressing one of the four dengue serotypes. This vaccine has been evaluated in multiple clinical trials. No significant safety concerns have been found. The Phase 3 trials met their endpoints in terms of overall reduction of confirmed dengue fever, and, most importantly a significant reduction in severe dengue and hospitalization due to dengue. However, based on results that have been published so far, efficacy in preventing serotype 2 infection is less than that for the other three serotypes. In the development of these chimeric vaccines, an important series of comparative studies of safety and efficacy were made using the parental YF 17D vaccine virus as a benchmark. In this paper, we use a standardized template describing the key characteristics of the novel flavivirus vaccine vectors, in comparison to the parental YF 17D vaccine. The template facilitates scientific discourse among key stakeholders by increasing the transparency and comparability of

  17. A DNA vaccine against yellow fever virus: development and evaluation.

    PubMed

    Maciel, Milton; Cruz, Fábia da Silva Pereira; Cordeiro, Marli Tenório; da Motta, Márcia Archer; Cassemiro, Klécia Marília Soares de Melo; Maia, Rita de Cássia Carvalho; de Figueiredo, Regina Célia Bressan Queiroz; Galler, Ricardo; Freire, Marcos da Silva; August, Joseph Thomas; Marques, Ernesto T A; Dhalia, Rafael

    2015-04-01

    Attenuated yellow fever (YF) virus 17D/17DD vaccines are the only available protection from YF infection, which remains a significant source of morbidity and mortality in the tropical areas of the world. The attenuated YF virus vaccine, which is used worldwide, generates both long-lasting neutralizing antibodies and strong T-cell responses. However, on rare occasions, this vaccine has toxic side effects that can be fatal. This study presents the design of two non-viral DNA-based antigen formulations and the characterization of their expression and immunological properties. The two antigen formulations consist of DNA encoding the full-length envelope protein (p/YFE) or the full-length envelope protein fused to the lysosomal-associated membrane protein signal, LAMP-1 (pL/YFE), aimed at diverting antigen processing/presentation through the major histocompatibility complex II precursor compartments. The immune responses triggered by these formulations were evaluated in H2b and H2d backgrounds, corresponding to the C57Bl/6 and BALB/c mice strains, respectively. Both DNA constructs were able to induce very strong T-cell responses of similar magnitude against almost all epitopes that are also generated by the YF 17DD vaccine. The pL/YFE formulation performed best overall. In addition to the T-cell response, it was also able to stimulate high titers of anti-YF neutralizing antibodies comparable to the levels elicited by the 17DD vaccine. More importantly, the pL/YFE vaccine conferred 100% protection against the YF virus in intracerebrally challenged mice. These results indicate that pL/YFE DNA is an excellent vaccine candidate and should be considered for further developmental studies.

  18. Yellow fever vaccine-associated adverse events following extensive immunization in Argentina.

    PubMed

    Biscayart, Cristián; Carrega, María Eugenia Pérez; Sagradini, Sandra; Gentile, Angela; Stecher, Daniel; Orduna, Tomás; Bentancourt, Silvia; Jiménez, Salvador García; Flynn, Luis Pedro; Arce, Gabriel Pirán; Uboldi, María Andrea; Bugna, Laura; Morales, María Alejandra; Digilio, Clara; Fabbri, Cintia; Enría, Delia; Diosque, Máximo; Vizzotti, Carla

    2014-03-05

    As a consequence of YF outbreaks that hit Brazil, Argentina, and Paraguay in 2008-2009, a significant demand for YF vaccination was subsequently observed in Argentina, a country where the usual vaccine recommendations are restricted to provinces that border Brazil, Paraguay, and Bolivia. The goal of this paper is to describe the adverse events following immunization (AEFI) against YF in Argentina during the outbreak in the northeastern province of Misiones, which occurred from January 2008 to January 2009. During this time, a total of nine cases were reported, almost two million doses of vaccine were administered, and a total of 165 AEFI were reported from different provinces. Case study analyses were performed using two AEFI classifications. Forty-nine events were classified as related to the YF vaccine (24 serious and 1 fatal case), and 12 events were classified as inconclusive. As the use of the YF 17D vaccine can be a challenge to health systems of countries with different endemicity patterns, a careful clinical and epidemiological evaluation should be performed before its prescription to minimize serious adverse events.

  19. The Safety of Yellow Fever Vaccine 17D or 17DD in Children, Pregnant Women, HIV+ Individuals, and Older Persons: Systematic Review

    PubMed Central

    Thomas, Roger E.; Lorenzetti, Diane L.; Spragins, Wendy; Jackson, Dave; Williamson, Tyler

    2012-01-01

    Yellow fever vaccine provides long-lasting immunity. Rare serious adverse events after vaccination include neurologic or viscerotropic syndromes or anaphylaxis. We conducted a systematic review of adverse events associated with yellow fever vaccination in vulnerable populations. Nine electronic bibliographic databases and reference lists of included articles were searched. Electronic databases identified 2,415 abstracts for review, and 32 abstracts were included in this review. We identified nine studies of adverse events in infants and children, eight studies of adverse events in pregnant women, nine studies of adverse events in human immunodeficiency virus-positive patients, five studies of adverse events in persons 60 years and older, and one study of adverse events in individuals taking immunosuppressive medications. Two case studies of maternal–neonate transmission resulted in serious adverse events, and the five passive surveillance databases identified very small numbers of cases of yellow fever vaccine-associated viscerotropic disease, yellow fever vaccine-associated neurotropic disease, and anaphylaxis in persons ≥ 60 years. No other serious adverse events were identified in the other studies of vulnerable groups. PMID:22302874

  20. Clinical and Immunological Insights on Severe, Adverse Neurotropic and Viscerotropic Disease following 17D Yellow Fever Vaccination▿

    PubMed Central

    Silva, Maria Luiza; Espírito-Santo, Luçandra Ramos; Martins, Marina Angela; Silveira-Lemos, Denise; Peruhype-Magalhães, Vanessa; Caminha, Ricardo Carvalho; de Andrade Maranhão-Filho, Péricles; Auxiliadora-Martins, Maria; de Menezes Martins, Reinaldo; Galler, Ricardo; da Silva Freire, Marcos; Marcovistz, Rugimar; Homma, Akira; Teuwen, Dirk E.; Elói-Santos, Silvana Maria; Andrade, Mariléia Chaves; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis

    2010-01-01

    Yellow fever (YF) vaccines (17D-204 and 17DD) are well tolerated and cause very low rates of severe adverse events (YEL-SAE), such as serious allergic reactions, neurotropic adverse diseases (YEL-AND), and viscerotropic diseases (YEL-AVD). Viral and host factors have been postulated to explain the basis of YEL-SAE. However, the mechanisms underlying the occurrence of YEL-SAE remain unknown. The present report provides a detailed immunological analysis of a 23-year-old female patient. The patient developed a suspected case of severe YEL-AVD with encephalitis, as well as with pancreatitis and myositis, following receipt of a 17D-204 YF vaccination. The patient exhibited a decreased level of expression of Fc-γR in monocytes (CD16, CD32, and CD64), along with increased levels of NK T cells (an increased CD3+ CD16+/− CD56+/−/CD3+ ratio), activated T cells (CD4+ and CD8+ cells), and B lymphocytes. Enhanced levels of plasmatic cytokines (interleukin-6 [IL-6], IL-17, IL-4, IL-5, and IL-10) as well as an exacerbated ex vivo intracytoplasmic cytokine pattern, mainly observed within NK cells (gamma interferon positive [IFN-γ+], tumor necrosis factor alpha positive [TNF-α+], and IL-4 positive [IL-4+]), CD8+ T cells (IL-4+ and IL-5+), and B lymphocytes (TNF-α+, IL-4+, and IL-10+). The analysis of CD4+ T cells revealed a complex profile that consisted of an increased frequency of IL-12+ and IFN-γ+ cells and a decreased percentage of TNF-α+, IL-4+, and IL-5+ cells. Depressed cytokine synthesis was observed in monocytes (TNF-α+) following the provision of antigenic stimuli in vitro. These results support the hypothesis that a strong adaptive response and abnormalities in the innate immune system may be involved in the establishment of YEL-AND and YEL-AVD. PMID:19906894

  1. Yellow fever vaccine: an effective vaccine for travelers.

    PubMed

    Verma, Ramesh; Khanna, Pardeep; Chawla, Suraj

    2014-01-01

    Yellow fever (YF) is an acute viral communicable disease transmitted by an arbovirus of the Flavivirus genus. It is primarily a zoonotic disease, especially the monkeys. Worldwide, an estimated 200,000 cases of yellow fever occurred each year, and the case-fatality rate is ~15%. Forty-five endemic countries in Africa and Latin America, with a population of close to 1 billion, are at risk. Up to 50% of severely affected persons from YF die without treatment. During 2009, 55 cases and 18 deaths were reported from Brazil, Colombia, and Peru. Brazil reported the maximum number of cases and death, i.e., 42 cases with 11 deaths. From January 2010 to March 2011, outbreaks of YF were reported to the WHO by Cameroon, Democratic Republic of Congo, Cote d'Ivoire, Guinea, Sierra Leone, Senegal, and Uganda. Cases were also reported in three northern districts of Abim, Agago, and Kitugun near the border with South Sudan. YF usually causes fever, muscle pain with prominent backache, headache, shivers, loss of appetite, and nausea or vomiting. Most patients improve, and their symptoms disappear after 3 to 4 d. Half of the patients who enter the toxic phase die within 10-14 d, while the rest recover without significant organ damage. Vaccination has been the single most important measure for preventing YF. The 17D-204 YF vaccine is a freeze-dried, live attenuated, highly effective vaccine. It is available in single-dose or multi-dose vials and should be stored at 2-8 °C. It is reconstituted with normal saline and should be used within 1 h of reconstitution. The 0.5 mL dose is delivered subcutaneously. Revaccination is recommended every 10 y for people at continued risk of exposure to yellow fever virus (YFV). This vaccine is available worldwide. Travelers, especially to Africa or Latin America from Asia, must have a certificate documenting YF vaccination, which is required by certain countries for entry under the International Health Regulations (IHR) of the WHO.

  2. The synergistic effect of combined immunization with a DNA vaccine and chimeric yellow fever/dengue virus leads to strong protection against dengue.

    PubMed

    Azevedo, Adriana S; Gonçalves, Antônio J S; Archer, Marcia; Freire, Marcos S; Galler, Ricardo; Alves, Ada M B

    2013-01-01

    The dengue envelope glycoprotein (E) is the major component of virion surface and its ectodomain is composed of domains I, II and III. This protein is the main target for the development of a dengue vaccine with induction of neutralizing antibodies. In the present work, we tested two different vaccination strategies, with combined immunizations in a prime/booster regimen or simultaneous inoculation with a DNA vaccine (pE1D2) and a chimeric yellow fever/dengue 2 virus (YF17D-D2). The pE1D2 DNA vaccine encodes the ectodomain of the envelope DENV2 protein fused to t-PA signal peptide, while the YF17D-D2 was constructed by replacing the prM and E genes from the 17D yellow fever vaccine virus by those from DENV2. Balb/c mice were inoculated with these two vaccines by different prime/booster or simultaneous immunization protocols and most of them induced a synergistic effect on the elicited immune response, mainly in neutralizing antibody production. Furthermore, combined immunization remarkably increased protection against a lethal dose of DENV2, when compared to each vaccine administered alone. Results also revealed that immunization with the DNA vaccine, regardless of the combination with the chimeric virus, induced a robust cell immune response, with production of IFN-γ by CD8+ T lymphocytes.

  3. Chimeric yellow fever/dengue virus as a candidate dengue vaccine: quantitation of the dengue virus-specific CD8 T-cell response.

    PubMed

    van Der Most, R G; Murali-Krishna, K; Ahmed, R; Strauss, J H

    2000-09-01

    We have constructed a chimeric yellow fever/dengue (YF/DEN) virus, which expresses the premembrane (prM) and envelope (E) genes from DEN type 2 (DEN-2) virus in a YF virus (YFV-17D) genetic background. Immunization of BALB/c mice with this chimeric virus induced a CD8 T-cell response specific for the DEN-2 virus prM and E proteins. This response protected YF/DEN virus-immunized mice against lethal dengue encephalitis. Control mice immunized with the parental YFV-17D were not protected against DEN-2 virus challenge, indicating that protection was mediated by the DEN-2 virus prM- and E-specific immune responses. YF/DEN vaccine-primed CD8 T cells expanded and were efficiently recruited into the central nervous systems of DEN-2 virus challenged mice. At 5 days after challenge, 3 to 4% of CD8 T cells in the spleen were specific for the prM and E proteins, and 34% of CD8 T cells in the central nervous system recognized these proteins. Depletion of either CD4 or CD8 T cells, or both, strongly reduced the protective efficacy of the YF/DEN virus, stressing the key role of the antiviral T-cell response.

  4. YF-12 in flight

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The Flight Research Center's involvement with the YF-12A, an interceptor version of the Lockheed A-12, began in 1967. Ames Research Center was interested in using wind tunnel data that had been generated at Ames under extreme secrecy. Also, the Office of Advanced Research and Technology (OART) saw the YF-12A as a means to advance high-speed technology, which would help in designing the Supersonic Transport (SST). The Air Force needed technical assistance to get the latest reconnaissance version of the A-12 family, the SR-71A, fully operational. Eventually, the Air Force offered NASA the use of two YF-12A aircraft, 60-6935 and 60-6936. A joint NASA-USAF program was mapped out in June 1969. NASA and Air Force technicians spent three months readying 935 for flight. On 11 December 1969, the flight program got underway with a successful maiden flight piloted by Col. Joe Rogers and Maj. Gary Heidelbaugh of the SR-71/F-12 Test Force. During the program, the Air Force concentrated on military applications, and NASA pursued a loads research program. NASA studies included inflight heating, skin-friction cooling, 'coldwall' research (a heat transfer experiment), flowfield studies, shaker vane research, and tests in support of the Space Shuttle landing program. Ultimately, 935 became the workhorse of the program, with 146 flights between 11 December 1969 and 7 November 1979. The second YF-12A, 936, made 62 flights. It was lost in a non-fatal crash on 24 June 1971. It was replaced by the so-called YF-12C (SR-71A 61-7951, modified with YF-12A inlets and engines and a bogus tail number 06937). The Lockheed A-12 family, known as the Blackbirds, were designed by Clarence 'Kelly' Johnson. They were constructed mostly of titanium to withstand aerodynamic heating. Fueled by JP-7, the Blackbirds were capable of cruising at Mach 3.2 and attaining altitudes in excess of 80,000 feet. The first version, a CIA reconnaissance aircraft that first flew in April 1962 was called the A-12. An

  5. YF-17 in Flight

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The Northrop Aviation YF-17 technology demonstrator aircraft in flight during a 1976 flight research program at NASA's Dryden Flight Research Center, Edwards, California. From May 27 to July 14, 1976, the Dryden Flight Research Center, Edwards, California, flew the Northrop Aviation YF-17 technology demonstrator to test the high-performance U.S. Air Force fighter at transonic speeds. The objectives of the seven-week flight test program included the study of maneuverability of this aircraft at transonic speeds and the collection of in-flight pressure data from around the afterbody of the aircraft to improve wind-tunnel predictions for future fighter aircraft. Also studied were stability and control and buffeting at high angles of attack as well as handling qualities at high load factors. Another objective of this program was to familiarize center pilots with the operation of advanced high-performance fighter aircraft. During the seven-week program, all seven of the center's test pilots were able to fly the aircraft with Gary Krier serving as project pilot. In general the pilots reported no trouble adapting to the aircraft and reported that it was easy to fly. There were no familiarization flights. All 25 research flights were full-data flights. They obtained data on afterbody pressures, vertical-fin dynamic loads, agility, pilot physiology, and infrared signatures. Average flight time was 45 minutes, although two flights involving in-flight refueling lasted approximately one hour longer than usual. Dryden Project Manager Roy Bryant considered the program a success. Center pilots felt that the aircraft was generations ahead of then current active military aircraft. Originally built for the Air Force's lightweight fighter program, the YF-17 Cobra left Dryden to support the Northrop/Navy F-18 Program. The F-18 Hornet evolved from the YF-17.

  6. YF-12C on ramp

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The so-called YF-12C on the NASA Flight Research Center ramp. Following the loss of a YF-12A in a non-fatal accident in June 1971, NASA acquired the second production SR-71A (61-7951) from the Air Force. Because the SR-71 program was shrouded in the highest secrecy, the Air Force restricted NASA to using the aircraft solely for propulsion testing with YF-12A inlets and engines. It was designated the YF-12C, and given a bogus tail number (06937). The two YF-12As in the program had actual tail numbers 06935 and 06936. The first NASA flight of the YF-12C took place on 24 May 1972. The Flight Research Center's involvement with the YF-12A, an interceptor version of the Lockheed A-12, began in 1967. Ames Research Center was interested in using wind tunnel data that had been generated at Ames under extreme secrecy. Also, the Office of Advanced Research and Technology (OART) saw the YF-12A as a means to advance high-speed technology, which would help in designing the Supersonic Transport (SST). The Air Force needed technical assistance to get the latest reconnaissance version of the A-12 family, the SR-71A, fully operational. Eventually, the Air Force offered NASA the use of two YF-12A aircraft, 60-6935 and 606936. A joint NASA-USAF program was mapped out in June 1969. NASA and Air Force technicians spent three months readying 935 for flight. On 11 December 1969, the flight program got underway with a successful maiden flight piloted by Col. Joe Rogers and Maj. Gary Heidelbaugh of the SR-71/F-12 Test Force. During the program, the Air Force concentrated on military applications, and NASA pursued a loads research program. NASA studies included inflight heating, skin-friction cooling, 'coldwall' research (a heat transfer experiment), flowfield studies, shaker vane research, and tests in support of the Space Shuttle landing program. Ultimately, 935 became the workhorse of the program, with 146 flights between 11 December 1969 and 7 November 1979. The second YF-12A, 936, made

  7. Persistence of Yellow Fever vaccine-induced antibodies after cord blood stem cell transplant

    PubMed Central

    Avelino-Silva, Vivian Iida; Freire, Marcos da Silva; Rocha, Vanderson; Rodrigues, Celso Arrais; Novis, Yana Sarkis; Sabino, Ester C.; Kallas, Esper Georges

    2016-01-01

    ABSTRACT We report the case of a cord blood haematopoietic stem cell transplant recipient who was vaccinated for Yellow Fever (YF) 7 days before initiating chemotherapy and had persistent YF antibodies more than 3 years after vaccination. Since the stem cell donor was never exposed to wild YF or to the YF vaccine, and our patient was not exposed to YF or revaccinated, this finding strongly suggests the persistence of recipient immunity. We briefly discuss potential consequences of incomplete elimination of recipient's leukocytes following existing haematopoietic cancer treatments. PMID:26618995

  8. YF-17/ADEN system study

    NASA Technical Reports Server (NTRS)

    Gowadia, N. S.; Bard, W. D.; Wooten, W. H.

    1979-01-01

    The YF-17 aircraft was evaluated as a candidate nonaxisymmetric nozzle flight demonstrator. Configuration design modifications, control system design, flight performance assessment, and program plan and cost we are summarized. Two aircraft configurations were studied. The first was modified as required to install only the augmented deflector exhaust nozzle (ADEN). The second one added a canard installation to take advantage of the full (up to 20 deg) nozzle vectoring capability. Results indicate that: (1) the program is feasible and can be accomplished at reasonable cost and low risk; (2) installation of ADEN increases the aircraft weight by 600 kg (1325 lb); (3) the control system can be modified to accomplish direct lift, pointing capability, variable static margin and deceleration modes of operation; (4) unvectored thrust-minus-drag is similar to the baseline YF-17; and (5) vectoring does not improve maneuvering performance. However, some potential benefits in direct lift, aircraft pointing, handling at low dynamic pressure and takeoff/landing ground roll are available. A 27 month program with 12 months of flight test is envisioned, with the cost estimated to be $15.9 million for the canard equipped aircraft and $13.2 million for the version without canard. The feasiblity of adding a thrust reverser to the YF-17/ADEN was investigated.

  9. Active assessment of adverse events following yellow fever vaccination of persons aged 60 years and more

    PubMed Central

    Miyaji, Karina Takesaki; Luiz, André Machado; Lara, Amanda Nazareth; do Socorro Souza Chaves, Tania; Piorelli, Roberta de Oliveira; Lopes, Marta Heloisa; Sartori, Ana Marli Christovam

    2013-01-01

    Introduction: Older age has been associated to serious adverse events (AE) following yellow fever (YF) vaccination in passive surveillance studies, but few prospective studies involving seniors have been published. Results: A total of 906 persons were evaluated; 78 were not vaccinated and 828 received the vaccine; 700 (84.7%) were interviewed after vaccination: 593 (84.7%) did not report any symptoms or signs following YF vaccine; 107 (15.3%) reported at least one AE temporally associated to YF vaccination: 97 (13.9%) had systemic AE and 17 (2.4%) reported AE at the injection site (7 had both systemic and local AE). Data regarding previous vaccination was available for 655 subjects. Statistically significant higher rates of systemic AE were observed among subjects who received the first YF vaccination (17.5%) in comparison to persons who had been previously vaccinated (9.5%). Methods: This observational prospective study aimed to describe AE following YF vaccination in persons aged ≥ 60 y. From March 2009 to April 2010, seniors who sought YF vaccination at a reference Immunization Center in São Paulo city, Brazil, were included. Demographic and clinical data, previous YF vaccination, travel destination and the final decision regarding YF vaccination or not were collected from standardized medical records. Active AE assessment was done through telephone or electronic mail interview performed approximately 14 d after immunization. Conclusion: Most persons aged ≥ 60 y may be safely vaccinated against YF. Before vaccination, they must be carefully screened for conditions associated to altered immunocompetence and for risk of exposure to YF. PMID:23291944

  10. YF-12C in flight at sunset

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The so-called YF-12C in flight at sunset. The YF-12C was the second production SR-71A (61-7951), modified with YF-12A inlets and engines, and given a bogus tail number (06937). It replaced a YF-12A (60-6936) that crashed during a joint USAF-NASA research program. The Flight Research Center's involvement with the YF-12A, an interceptor version of the Lockheed A-12, began in 1967. Ames Research Center was interested in using wind tunnel data that had been generated at Ames under extreme secrecy. Also, the Office of Advanced Research and Technology (OART) saw the YF-12A as a means to advance high-speed technology, which would help in designing the Supersonic Transport (SST). The Air Force needed technical assistance to get the latest reconnaissance version of the A-12 family, the SR-71A, fully operational. Eventually, the Air Force offered NASA the use of two YF-12A aircraft, 60-6935 and 60-6936. A joint NASA-USAF program was mapped out in June 1969. NASA and Air Force technicians spent three months readying 935 for flight. On 11 December 1969, the flight program got underway with a successful maiden flight piloted by Col. Joe Rogers and Maj. Gary Heidelbaugh of the SR-71/F-12 Test Force. During the program, the Air Force concentrated on military applications, and NASA pursued a loads research program. NASA studies included inflight heating, skin-friction cooling, 'coldwall' research (a heat transfer experiment), flowfield studies, shaker vane research, and tests in support of the Space Shuttle landing program. Ultimately, 935 became the workhorse of the program, with 146 flights between 11 December 1969 and 7 November 1979. The second YF-12A, 936, made 62 flights. It was lost in a non-fatal crash on 24 June 1971. It was replaced by the YF-12C. The YF-12C was delivered to NASA on 16 July 1971. From then until 22 December 1978, it made 90 flights. The Lockheed A-12 family, known as the Blackbirds, were designed by Clarence 'Kelly' Johnson. They were constructed mostly

  11. An unusual case of influenza-like illness after yellow fever vaccination.

    PubMed

    Lamson, Daryl M; Ramani, Rama; Kleabonas, Matthew; Metcalfe, Maureen; Humphrey, Charles; St George, Kirsten

    2014-05-01

    Yellow fever (YF) is an important public health concern in areas where the disease is endemic. For more than 60 years a highly effective live attenuated vaccine has been available, its widespread use resulting in a dramatic decrease in the number of cases. On rare occasions, YF vaccine can cause mild to severe disease and rare adverse vaccine-associated events have been reported. Additionally, an average viremia of 3-5 days after administration of the YF vaccine has been published. Here we present a case where YF vaccine was isolated in cell culture from a respiratory swab collected from a patient presenting with influenza-like illness. To the best of our knowledge, this is the first report finding replicating YF vaccine in the respiratory sample of a post inoculated individual.

  12. Two YF-12 aircraft in flight

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The YF-12A (60-6935) carries the 'coldwall' heat transfer pod on a pylon beneath the forward fuselage. The pod is seen with its insulating coating intact. In the foreground, the YF-12C flies photo chase. The coldwall project, supported by Langley Research Center, consisted of a stainless steel tube equipped with thermocouples and pressure-sensors. A special insulating coating covered the tube, which was chilled with liquid nitrogen. At Mach 3, the insulation could be pyrotechnically blown away from the tube, instantly exposing it to the thermal environment. The experiment caused many inflight difficulties, such as engine unstarts, but eventually researchers got a successful flight. The Flight Research Center's involvement with the YF-12A, an interceptor version of the Lockheed A-12, began in 1967. Ames Research Center was interested in using wind tunnel data that had been generated at Ames under extreme secrecy. Also, the Office of Advanced Research and Technology (OART) saw the YF-12A as a means to advance high-speed technology, which would help in designing the Supersonic Transport (SST). The Air Force needed technical assistance to get the latest reconnaissance version of the A-12 family, the SR-71A, fully operational. Eventually, the Air Force offered NASA the use of two YF-12A aircraft, 60-6935 and 60-6936. A joint NASA-USAF program was mapped out in June 1969. NASA and Air Force technicians spent three months readying 935 for flight. On 11 December 1969, the flight program got underway with a successful maiden flight piloted by Col. Joe Rogers and Maj. Gary Heidelbaugh of the SR-71/F-12 Test Force. During the program, the Air Force concentrated on military applications, and NASA pursued a loads research program. NASA studies included inflight heating, skin-friction cooling, 'coldwall' research (a heat transfer experiment), flowfield studies, shaker vane research, and tests in support of the Space Shuttle landing program. Ultimately, 935 became the workhorse

  13. YF-12A #935 on ramp

    NASA Technical Reports Server (NTRS)

    1971-01-01

    A front, overhead view of the number two YF-12A (60-6935) on the ramp at the NASA Flight Research Center (now NASA Dryden), Edwards, California. Notice how the chines end abruptly, just aft of the nose radome. The aircraft was originally designed as an interceptor. The large radome housed a radar for the Hughes ASG-18 missile fire control system. The Flight Research Center's involvement with the YF-12A, an interceptor version of the Lockheed A-12, began in 1967. Ames Research Center was interested in using wind tunnel data that had been generated at Ames under extreme secrecy. Also, the Office of Advanced Research and Technology (OART) saw the YF-12A as a means to advance high-speed technology, which would help in designing the Supersonic Transport (SST). The Air Force needed technical assistance to get the latest reconnaissance version of the A-12 family, the SR-71A, fully operational. Eventually, the Air Force offered NASA the use of two YF-12A aircraft, 60-6935 and 60-6936. A joint NASA-USAF program was mapped out in June 1969. NASA and Air Force technicians spent three months readying 935 for flight. On 11 December 1969, the flight program got underway with a successful maiden flight piloted by Col. Joe Rogers and Maj. Gary Heidelbaugh of the SR-71/F-12 Test Force. During the program, the Air Force concentrated on military applications, and NASA pursued a loads research program. NASA studies included inflight heating, skin-friction cooling, 'coldwall' research (a heat transfer experiment), flowfield studies, shaker vane research, and tests in support of the Space Shuttle landing program. Ultimately, 935 became the workhorse of the program, with 146 flights between 11 December 1969 and 7 November 1979. The second YF-12A, 936, made 62 flights. It was lost in a non-fatal crash on 24 June 1971. It was replaced by the so-called YF-12C (SR-71A 61-7951, modified with YF-12A inlets and engines and a bogus tail number 06937). The Lockheed A-12 family, known as the

  14. Vaccinations

    MedlinePlus

    ... vaccinated? For many years, a set of annual vaccinations was considered normal and necessary for dogs and ... to protect for a full year. Consequently, one vaccination schedule will not work well for all pets. ...

  15. Overview of the NASA YF-12 program

    NASA Technical Reports Server (NTRS)

    Kock, B. M.

    1978-01-01

    The history of NASA's interest in supersonic research and the agency's contribution to the development of the YF 12 aircraft is reviewed as well as the program designed to use that aircraft as a test bed for supersonic cruise research. Topics cover elements of the program, project organization, and major accomplishments.

  16. YF-12 Experiments Symposium, Volume 1

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Papers presented by personnel from the Dryden Flight Research Center, the Lewis Research Center, and the Ames Research Center are presented. Topics cover propulsion system performance, inlet time varying distortion, structures, aircraft controls, propulsion controls, and aerodynamics. The reports were based on analytical studies, laboratory experiments, wind tunnel tests, and extensive flight research with two YF-12 airplanes.

  17. Vaccines and vaccination against yellow fever: WHO Position Paper, June 2013--recommendations.

    PubMed

    2015-01-01

    This article presents the World Health Organizations (WHO) evidence and recommendations for the use of yellow fever (YF) vaccination from "Vaccines and vaccination against yellow fever: WHO Position Paper - June 2013" published in the Weekly Epidemiological Record. This position paper summarizes the WHO position on the use of YF vaccination, in particular that a single dose of YF vaccine is sufficient to confer sustained life-long protective immunity against YF disease. A booster dose is not necessary. The current document replaces the position paper on the use of yellow fever vaccines and vaccination published in 2003. Footnotes to this paper provide a number of core references. In accordance with its mandate to provide guidance to Member States on health policy matters, WHO issues a series of regularly updated position papers on vaccines and combinations of vaccines against diseases that have an international public health impact. These papers are concerned primarily with the use of vaccines in large-scale immunization programmes; they summarize essential background information on diseases and vaccines, and conclude with WHO's current position on the use of vaccines in the global context. This paper reflects the recommendations of WHO's Strategic Advisory Group of Experts (SAGE) on immunization. These recommendations were discussed by SAGE at its April 2013 meeting. Evidence presented at the meeting can be accessed at http://www.who.int/immunization/sage/previous/en/index.html.

  18. YF-12A #936 on ramp

    NASA Technical Reports Server (NTRS)

    1969-01-01

    The arrival of YF-12A (60-6936) at the NASA Flight Research Center. This aircraft was used by the Air Force crews during the joint USAF-NASA research program. This aircraft, 936, was the third YF-12A built. The first YF-12A (60-6934) flew in August 1963. Lockheed test pilot Robert Gilliland made the first flight in 936 on 13 March 1964. It later set nine world absolute speed and altitude records on 1 May 1965. Aircraft 936 participated in AIM-47 missile firing tests at Eglin AFB, Florida in 1966. It joined the USAF-NASA F-12 Test Force in 1969, and made 62 successful flights. On 24 June 1971, it was lost in an accident during the 63rd flight. A fuel line failed, causing a fire in the right engine. As the aircraft approached Rogers Dry Lake for an emergency landing, the intensity of the fire increased. Lt. Col. Ronald 'Jack' Layton and Maj. Billy Curtis decided to eject, and the YF-12A nosed in and exploded. The Flight Research Center's involvement with the YF-12A, an interceptor version of the Lockheed A-12, began in 1967. Ames Research Center was interested in using wind tunnel data that had been generated at Ames under extreme secrecy. Also, the Office of Advanced Research and Technology (OART) saw the YF-12A as a means to advance high-speed technology, which would help in designing the Supersonic Transport (SST). The Air Force needed technical assistance to get the latest reconnaissance version of the A-12 family, the SR-71A, fully operational. Eventually, the Air Force offered NASA the use of two YF-12A aircraft, 60-6935 and 60-6936. A joint NASA-USAF program was mapped out in June 1969. NASA and Air Force technicians spent three months readying 935 for flight. On 11 December 1969, the flight program got underway with a successful maiden flight piloted by Col. Joe Rogers and Maj. Gary Heidelbaugh of the SR-71/F-12 Test Force. During the program, the Air Force concentrated on military applications, and NASA pursued a loads research program. NASA studies included

  19. YF-12A and YF-12C in flight formation at dawn

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The YF-12A (60-6935) carries the 'coldwall' heat transfer pod on a pylon beneath the forward fuselage. The pod is seen with its insulating coating intact. In the background, the YF-12C flies photo chase. The coldwall project, supported by Langley Research Center, consisted of a stainless steel tube equipped with thermocouples and pressure-sensors. A special insulating coating covered the tube, which was chilled with liquid nitrogen. At Mach 3, the insulation could be pyrotechnically blown away from the tube, instantly exposing it to the thermal environment. The experiment caused many inflight difficulties, such as engine unstarts, but eventually researchers got a successful flight. The Flight Research Center's involvement with the YF-12A, an interceptor version of the Lockheed A-12, began in 1967. Ames Research Center was interested in using wind tunnel data that had been generated at Ames under extreme secrecy. Also, the Office of Advanced Research and Technology (OART) saw the YF-12A as a means to advance high-speed technology, which would help in designing the Supersonic Transport (SST). The Air Force needed technical assistance to get the latest reconnaissance version of the A-12 family, the SR-71A, fully operational. Eventually, the Air Force offered NASA the use of two YF-12A aircraft, 60-6935 and 60-6936. A joint NASA-USAF program was mapped out in June 1969. NASA and Air Force technicians spent three months readying 935 for flight. On 11 December 1969, the flight program got underway with a successful maiden flight piloted by Col. Joe Rogers and Maj. Gary Heidelbaugh of the SR-71/F-12 Test Force. During the program, the Air Force concentrated on military applications, and NASA pursued a loads research program. NASA studies included inflight heating, skin-friction cooling, 'coldwall' research (a heat transfer experiment), flowfield studies, shaker vane research, and tests in support of the Space Shuttle landing program. Ultimately, 935 became the workhorse

  20. YF-16 flight flutter test procedures

    NASA Technical Reports Server (NTRS)

    Brignac, W. J.; Ness, H. B.; Johnson, M. K.; Smith, L. M.

    1976-01-01

    The Random Decrement technique (Randomdec) was incorporated in procedures for flight testing of the YF-16 lightweight fighter prototype. Damping values obtained substantiate the adequacy of the flutter margin of safety. To confirm the structural modes which were being excited, a spectral analysis of each channel was performed using the AFFTC time/data 1923/50 time series analyzer. Inflight test procedure included the careful monitoring of strip charts, three axis pulses, rolls, and pullups.

  1. Precision controllability of the YF-17 airplane

    NASA Technical Reports Server (NTRS)

    Sisk, T. R.; Mataeny, N. W.

    1980-01-01

    A flying qualities evaluation conducted on the YF-17 airplane permitted assessment of its precision controllability in the transonic flight regime over the allowable angle of attack range. The precision controllability (tailchase tracking) study was conducted in constant-g and windup turn tracking maneuvers with the command augmentation system (CAS) on, automatic maneuver flaps, and the caged pipper gunsight depressed 70 mils. This study showed that the YF-17 airplane tracks essentially as well at 7 g's to 8 g's as earlier fighters did at 4 g's to 5 g's before they encountered wing rock. The pilots considered the YF-17 airplane one of the best tracking airplanes they had flown. Wing rock at the higher angles of attack degraded tracking precision, and lack of control harmony made precision controllability more difficult. The revised automatic maneuver flap schedule incorporated in the airplane at the time of the tests did not appear to be optimum. The largest tracking errors and greatest pilot workload occurred at high normal load factors at low angles of attack. The pilots reported that the high-g maneuvers caused some tunnel vision and that they found it difficult to think clearly after repeated maneuvers.

  2. Tuning NaYF4 Nanoparticles through Alkaline Earth Doping

    PubMed Central

    Chen, Xian; Peng, Dengfeng; Wang, Feng

    2013-01-01

    Phase and size of lanthanide-doped nanoparticles are the most important characteristics that dictate optical properties of these nanoparticles and affect their technological applications. Herein, we present a systematic study to examine the effect of alkaline earth doping on the formation of NaYF4 upconversion nanoparticles. We show that alkaline earth doping has a dual function of tuning particle size of hexagonal phase NaYF4 nanoparticles and stabilizing cubic phase NaYF4 nanoparticles depending on composition and concentration of the dopant ions. The study described here represents a facile and general strategy to tuning the properties of NaYF4 upconversion nanoparticles. PMID:28348353

  3. Vaccines

    MedlinePlus Videos and Cool Tools

    Vaccinations are injections of antigens into the body. Once the antigens enter the blood, they circulate along ... suppressor T cells stop the attack. After a vaccination, the body will have a memory of an ...

  4. Current status and future prospects of yellow fever vaccines.

    PubMed

    Beck, Andrew S; Barrett, Alan D T

    2015-01-01

    Yellow fever 17D vaccine is one of the oldest live-attenuated vaccines in current use that is recognized historically for its immunogenic and safe properties. These unique properties of 17D are presently exploited in rationally designed recombinant vaccines targeting not only flaviviral antigens but also other pathogens of public health concern. Several candidate vaccines based on 17D have advanced to human trials, and a chimeric recombinant Japanese encephalitis vaccine utilizing the 17D backbone has been licensed. The mechanism(s) of attenuation for 17D are poorly understood; however, recent insights from large in silico studies have indicated particular host genetic determinants contributing to the immune response to the vaccine, which presumably influences the considerable durability of protection, now in many cases considered to be lifelong. The very rare occurrence of severe adverse events for 17D is discussed, including a recent fatal case of vaccine-associated viscerotropic disease.

  5. Travel characteristics and yellow fever vaccine usage among US Global TravEpiNet travelers visiting countries with risk of yellow fever virus transmission, 2009-2011.

    PubMed

    Jentes, Emily S; Han, Pauline; Gershman, Mark D; Rao, Sowmya R; LaRocque, Regina C; Staples, J Erin; Ryan, Edward T

    2013-05-01

    Yellow fever (YF) vaccine-associated serious adverse events and changing YF epidemiology have challenged healthcare providers to vaccinate only travelers whose risk of YF during travel is greater than their risk of adverse events. We describe the travel characteristics and YF vaccine use among US travelers visiting Global TravEpiNet clinics from January of 2009 to March of 2011. Of 16,660 travelers, 5,588 (34%) had itineraries to areas with risk of YF virus transmission. Of those travelers visiting one country with YF risk (N = 4,517), 71% were vaccinated at the visit, and 20% were presumed to be immune from prior vaccination. However, travelers visiting friends and relatives (odds ratio [OR] = 2.57, 95% confidence interval [95% CI] = 1.27-5.22) or going to Nigeria (OR = 3.01, 95% CI = 1.37-6.62) were significantly more likely to decline vaccination. To optimize YF vaccine use, clinicians should discuss an individual's risk-benefit assessment of vaccination and close knowledge gaps regarding vaccine use among at-risk populations.

  6. Yellow fever vaccine-associated viscerotropic disease: current perspectives

    PubMed Central

    Thomas, Roger E

    2016-01-01

    Purpose To assess those published cases of yellow fever (YF) vaccine-associated viscerotropic disease that meet the Brighton Collaboration criteria and to assess the safety of YF vaccine with respect to viscerotropic disease. Literature search Ten electronic databases were searched with no restriction of date or language and reference lists of retrieved articles. Methods All abstracts and titles were independently read by two reviewers and data independently entered by two reviewers. Results All serious adverse events that met the Brighton Classification criteria were associated with first YF vaccinations. Sixty-two published cases (35 died) met the Brighton Collaboration viscerotropic criteria, with 32 from the US, six from Brazil, five from Peru, three from Spain, two from the People’s Republic of China, one each from Argentina, Australia, Belgium, Ecuador, France, Germany, Ireland, New Zealand, Portugal, and the UK, and four with no country stated. Two cases met both the viscerotropic and YF vaccine-associated neurologic disease criteria. Seventy cases proposed by authors as viscerotropic disease did not meet any Brighton Collaboration viscerotropic level of diagnostic certainty or any YF vaccine-associated viscerotropic disease causality criteria (37 died). Conclusion Viscerotropic disease is rare in the published literature and in pharmacovigilance databases. All published cases were from developing countries. Because the symptoms are usually very severe and life threatening, it is unlikely that cases would not come to medical attention (but might not be published). Because viscerotropic disease has a highly predictable pathologic course, it is likely that viscerotropic disease post-YF vaccine occurs in low-income countries with the same incidence as in developing countries. YF vaccine is a very safe vaccine that likely confers lifelong immunity. PMID:27784992

  7. SR-71A/YF-12A takeoff and flight

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The YF-12 'Blackbird' was an experimental fighter-interceptor version of the Lockheed A-12 aircraft. In Air Force flight tests on May 1, 1965, the YF-12 set a speed record of 2,070.101 miles per hour and an altitude record of 80,258 feet. First publicly displayed at Edwards Air Force Base, California, in 1964, the YF-12 was never adopted by the military as an operational aircraft. It was, however, a precursor to the SR-71 Blackbird reconnaissance plane. Two YF-12 aircraft were flown in a joint Air Force-NASA research program at the NASA Flight Research Center (now the NASA Dryden Flight Research Center) between 1969 and 1979, although the second plane, piloted primarily by the Air Force, was lost to an inflight fire in 1971. The two YF-12 aircraft bore the serial numbers 60-6935 and 60-6936. This clip, which runs 36 seconds in length, begins with shots of the crew boarding and takeoff of an SR-71A (serial no. 61-7951) flown at NASA Dryden but designated as a YF-12C. The clip ends with air-to-air footage of a true YF-12A (serial no. 60-6935) identified by its distinctive radome that housed a powerful search and attack radar.

  8. Surveillance for Yellow Fever Virus in Non-Human Primates in Southern Brazil, 2001–2011: A Tool for Prioritizing Human Populations for Vaccination

    PubMed Central

    Almeida, Marco A. B.; Cardoso, Jader da C.; dos Santos, Edmilson; da Fonseca, Daltro F.; Cruz, Laura L.; Faraco, Fernando J. C.; Bercini, Marilina A.; Vettorello, Kátia C.; Porto, Mariana A.; Mohrdieck, Renate; Ranieri, Tani M. S.; Schermann, Maria T.; Sperb, Alethéa F.; Paz, Francisco Z.; Nunes, Zenaida M. A.; Romano, Alessandro P. M.; Costa, Zouraide G.; Gomes, Silvana L.; Flannery, Brendan

    2014-01-01

    In Brazil, epizootics among New World monkey species may indicate circulation of yellow fever (YF) virus and provide early warning of risk to humans. Between 1999 and 2001, the southern Brazilian state of Rio Grande do Sul initiated surveillance for epizootics of YF in non-human primates to inform vaccination of human populations. Following a YF outbreak, we analyzed epizootic surveillance data and assessed YF vaccine coverage, timeliness of implementation of vaccination in unvaccinated human populations. From October 2008 through June 2009, circulation of YF virus was confirmed in 67 municipalities in Rio Grande do Sul State; vaccination was recommended in 23 (34%) prior to the outbreak and in 16 (24%) within two weeks of first epizootic report. In 28 (42%) municipalities, vaccination began more than two weeks after first epizootic report. Eleven (52%) of 21 laboratory-confirmed human YF cases occurred in two municipalities with delayed vaccination. By 2010, municipalities with confirmed YF epizootics reported higher vaccine coverage than other municipalities that began vaccination. In unvaccinated human populations timely response to epizootic events is critical to prevent human yellow fever cases. PMID:24625681

  9. Surveillance for yellow Fever virus in non-human primates in southern Brazil, 2001-2011: a tool for prioritizing human populations for vaccination.

    PubMed

    Almeida, Marco A B; Cardoso, Jader da C; Dos Santos, Edmilson; da Fonseca, Daltro F; Cruz, Laura L; Faraco, Fernando J C; Bercini, Marilina A; Vettorello, Kátia C; Porto, Mariana A; Mohrdieck, Renate; Ranieri, Tani M S; Schermann, Maria T; Sperb, Alethéa F; Paz, Francisco Z; Nunes, Zenaida M A; Romano, Alessandro P M; Costa, Zouraide G; Gomes, Silvana L; Flannery, Brendan

    2014-03-01

    In Brazil, epizootics among New World monkey species may indicate circulation of yellow fever (YF) virus and provide early warning of risk to humans. Between 1999 and 2001, the southern Brazilian state of Rio Grande do Sul initiated surveillance for epizootics of YF in non-human primates to inform vaccination of human populations. Following a YF outbreak, we analyzed epizootic surveillance data and assessed YF vaccine coverage, timeliness of implementation of vaccination in unvaccinated human populations. From October 2008 through June 2009, circulation of YF virus was confirmed in 67 municipalities in Rio Grande do Sul State; vaccination was recommended in 23 (34%) prior to the outbreak and in 16 (24%) within two weeks of first epizootic report. In 28 (42%) municipalities, vaccination began more than two weeks after first epizootic report. Eleven (52%) of 21 laboratory-confirmed human YF cases occurred in two municipalities with delayed vaccination. By 2010, municipalities with confirmed YF epizootics reported higher vaccine coverage than other municipalities that began vaccination. In unvaccinated human populations timely response to epizootic events is critical to prevent human yellow fever cases.

  10. Persistence of Th1/Tc1 responses one year after tetravalent dengue vaccination in adults and adolescents in Singapore.

    PubMed

    Harenberg, Anke; Begue, Sarah; Mamessier, Audrey; Gimenez-Fourage, Sophie; Ching Seah, Ching; Wei Liang, Ai; Li Ng, Jun; Yun Toh, Xue; Archuleta, Sophia; Wilder-Smith, Annelies; Shek, Lynette P; Wartel-Tram, Anh; Bouckenooghe, Alain; Lang, Jean; Crevat, Denis; Caillet, Catherine; Guy, Bruno

    2013-11-01

    To characterize the cell mediated immunity (CMI) induced by the investigational CYD tetravalent dengue vaccine (TDV), we developed a whole-blood, intracellular cytokine staining (ICS) assay and a multiplex assay, each requiring 3 mL of blood. We assessed CMI before and 28 d after a first and third injection of CYD-TDV and one year after the third injection in a subset of 80 adolescents and adults enrolled in a phase II trial in Singapore (ClinicalTrial.gov NCT NCT00880893). CD4/IFNγ/TNFα responses specific to dengue NS3 were detected before vaccination. Vaccination induced YF-17D-NS3-specific CD8/IFNγ responses, without significant TNFα, and a CYD-specific Th1/Tc1 cellular response in all participants, which was characterized by predominant IFNγ secretion compared with TNFα, associated with low level IL-13 secretion in multiplex analysis of peripheral blood mononuclear cells (PBMC) supernatants after restimulation with each the CYD vaccine viruses. Responses were directed mainly against CYD-4 after the first vaccination, and were more balanced against all four serotypes after the third vaccination. The same qualitative profile was observed one year after the third vaccination, with approximately 2-fold lower NS3-specific responses, and 3-fold lower serotype-specific cellular responses. These findings confirm previous observations regarding both the nature and specificity of cellular responses induced by CYD-TDV, and for the first time demonstrate the persistence of cellular responses after one year. We also established the feasibility of analyzing CMI with small blood samples, allowing such analysis to be considered for pediatric trials.

  11. Advanced age a risk factor for illness temporally associated with yellow fever vaccination.

    PubMed Central

    Martin, M.; Weld, L. H.; Tsai, T. F.; Mootrey, G. T.; Chen, R. T.; Niu, M.; Cetron, M. S.

    2001-01-01

    In 1998, the Centers for Disease Control and Prevention was notified of severe illnesses and one death, temporally associated with yellow fever (YF) vaccination, in two elderly U.S. residents. Because the cases were unusual and adverse events following YF vaccination had not been studied, we estimated age-related reporting rates for systemic illness following YF vaccination. We found that the rate of reported adverse events among elderly vaccinees was higher than among vaccinees 25 to 44 years of age. We also found two additional deaths among elderly YF vaccinees. These data signal a potential problem but are not sufficient to reliably estimate incidence rates or to understand potential underlying mechanisms; therefore, enhanced surveillance is needed. YF remains an important cause of severe illness and death, and travel to disease-endemic regions is increasing. For elderly travelers, the risk for severe illness and death due to YF infection should be balanced against the risk for systemic illness due to YF vaccine. PMID:11747720

  12. Recent Load Calibrations Experience with the YF-12 Airplane

    NASA Technical Reports Server (NTRS)

    Jenkins, J. M.; Kuhl, A. E.

    1978-01-01

    The use of calibrated strain gages to measure wing loads on the YF-12A airplane is discussed as well as structural configurations relative to the thermal environment and resulting thermal stresses. A thermal calibration of the YF-12A is described to illustrate how contaminating thermal effects can be removed from loads equations. The relationship between ground load calibrations and flight measurements is examined for possible errors, and an analytical approach to accommodate such errors is presented.

  13. Feasibility study of inlet shock stability system of YF-12

    NASA Technical Reports Server (NTRS)

    Blausey, G. C.; Coleman, D. M.; Harp, D. S.

    1972-01-01

    The feasibility of self actuating bleed valves as a shock stabilization system in the inlet of the YF-12 is considered for vortex valves, slide valves, and poppet valves. Analytical estimation of valve performance indicates that only the slide and poppet valves located in the inlet cowl can meet the desired steady state stabilizing flows, and of the two the poppet valve is substantially faster in response to dynamic disturbances. The poppet valve is, therefore, selected as the best shock stability system for the YF-12 inlet.

  14. Status of the NASA YF-12 Propulsion Research Program

    NASA Technical Reports Server (NTRS)

    Albers, J. A.

    1976-01-01

    The YF-12 research program was initiated to establish a technology base for the design of an efficient propulsion system for supersonic cruise aircraft. The major technology areas under investigation in this program are inlet design analysis, propulsion system steady-state performance, propulsion system dynamic performance, inlet and engine control systems, and airframe/propulsion system interactions. The objectives, technical approach, and status of the YF-12 propulsion program are discussed. Also discussed are the results obtained to date by the NASA Ames, Lewis, and Dryden research centers. The expected technical results and proposed future programs are also given. Propulsion system configurations are shown.

  15. Antitumor Action of a Novel Histone Deacetylase Inhibitor, YF479, in Breast Cancer1

    PubMed Central

    Zhang, Tao; Chen, Yihua; Li, Jingjie; Yang, Feifei; Wu, Haigang; Dai, Fujun; Hu, Meichun; Lu, Xiaoling; Peng, Yi; Liu, Mingyao; Zhao, Yongxiang; Yi, Zhengfang

    2014-01-01

    Accumulating evidence demonstrates important roles for histone deacetylase in tumorigenesis (HDACs), highlighting them as attractive targets for antitumor drug development. Histone deactylase inhibitors (HDACIs), which have shown favorable anti-tumor activity with low toxicity in clinical investigations, are a promising class of anticancer therapeutics. Here, we screened our compound library to explore small molecules that possess anti-HDAC activity and identified a novel HDACI, YF479. Suberoylanilide hydroxamic acid (SAHA), which was the first approved HDAC inhibitor for clinical treatment by the FDA, was as positive control in our experiments. We further demonstrated YF479 abated cell viability, suppressed colony formation and tumor cell motility in vitro. To investigate YF479 with superior pharmacodynamic properties, we developed spontaneous and experimental breast cancer animal models. Our results showed YF479 significantly inhibited breast tumor growth and metastasis in vivo. Further study indicated YF479 suppressed both early and end stages of metastatic progression. Subsequent adjuvant chemotherapy animal experiment revealed the elimination of local-regional recurrence (LRR) and distant metastasis by YF479. More important, YF479 remarkably prolonged the survival of tumor-bearing mice. Intriguingly, YF479 displayed more potent anti-tumor activity in vitro and in vivo compared with SAHA. Together, our results suggest that YF479, a novel HDACI, inhibits breast tumor growth, metastasis and recurrence. In light of these results, YF479 may be an effective therapeutic option in clinical trials for patients burdened by breast cancer. PMID:25220594

  16. 17 CFR 240.17d-2 - Program for allocation of regulatory responsibility.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Program for allocation of regulatory responsibility. 240.17d-2 Section 240.17d-2 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) GENERAL RULES AND REGULATIONS, SECURITIES EXCHANGE ACT OF 1934 Rules...

  17. 17 CFR 240.17d-1 - Examination for compliance with applicable financial responsibility rules.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Examination for compliance with applicable financial responsibility rules. 240.17d-1 Section 240.17d-1 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) GENERAL RULES AND REGULATIONS, SECURITIES...

  18. A public health risk assessment for yellow fever vaccination: a model exemplified by an outbreak in the state of São Paulo, Brazil

    PubMed Central

    Ribeiro, Ana Freitas; Tengan, Ciléa; Sato, Helena Keico; Spinola, Roberta; Mascheretti, Melissa; França, Ana Cecilia Costa; Port-Carvalho, Marcio; Pereira, Mariza; de Souza, Renato Pereira; Amaku, Marcos; Burattini, Marcelo Nascimento; Coutinho, Francisco Antonio Bezerra; Lopez, Luis Fernandez; Massad, Eduardo

    2015-01-01

    We propose a method to analyse the 2009 outbreak in the region of Botucatu in the state of São Paulo (SP), Brazil, when 28 yellow fever (YF) cases were confirmed, including 11 deaths. At the time of the outbreak, the Secretary of Health of the State of São Paulo vaccinated one million people, causing the death of five individuals, an unprecedented number of YF vaccine-induced fatalities. We apply a mathematical model described previously to optimise the proportion of people who should be vaccinated to minimise the total number of deaths. The model was used to calculate the optimum proportion that should be vaccinated in the remaining, vaccine-free regions of SP, considering the risk of vaccine-induced fatalities and the risk of YF outbreaks in these regions. PMID:25946247

  19. A public health risk assessment for yellow fever vaccination: a model exemplified by an outbreak in the state of São Paulo, Brazil.

    PubMed

    Ribeiro, Ana Freitas; Tengan, Ciléa; Sato, Helena Keico; Spinola, Roberta; Mascheretti, Melissa; França, Ana Cecilia Costa; Port-Carvalho, Marcio; Pereira, Mariza; Souza, Renato Pereira de; Amaku, Marcos; Burattini, Marcelo Nascimento; Coutinho, Francisco Antonio Bezerra; Lopez, Luis Fernandez; Massad, Eduardo

    2015-04-01

    We propose a method to analyse the 2009 outbreak in the region of Botucatu in the state of São Paulo (SP), Brazil, when 28 yellow fever (YF) cases were confirmed, including 11 deaths. At the time of the outbreak, the Secretary of Health of the State of São Paulo vaccinated one million people, causing the death of five individuals, an unprecedented number of YF vaccine-induced fatalities. We apply a mathematical model described previously to optimise the proportion of people who should be vaccinated to minimise the total number of deaths. The model was used to calculate the optimum proportion that should be vaccinated in the remaining, vaccine-free regions of SP, considering the risk of vaccine-induced fatalities and the risk of YF outbreaks in these regions.

  20. Yellow Fever Vaccination of a Primary Vaccinee During Adalimumab Therapy.

    PubMed

    Nash, Esther R; Brand, Myron; Chalkias, Spyridon

    2015-01-01

    In this case report, we describe a 63-year-old female with Crohn's disease since age 16 years, and on adalimumab therapy, who inadvertently received a yellow fever vaccine (YFV) 4 days before her next dose of adalimumab. She had never received YFV. Her next dose of tumor necrosis factor (TNF) antagonist was held. She did not report any adverse effects referable to the vaccine. Reverse transcriptase-polymerase chain reaction (RT-PCR) for yellow fever (YF) viral RNA on days 12 and 18 postvaccination was negative. Neutralizing antibody to YF virus vaccine was immunoprotective on day 18 following vaccination, which further increased by day 26. A neutralizing antibody obtained 2 years following vaccination also remained immunoprotective.

  1. Development and validation of an ELISA kit (YF MAC-HD) to detect IgM to yellow fever virus

    PubMed Central

    Basile, Alison Jane; Goodman, Christin; Horiuchi, Kalanthe; Laven, Janeen; Panella, Amanda J; Kosoy, Olga; Lanciotti, Robert S.; Johnson, Barbara W.

    2015-01-01

    Yellow fever virus (YFV) is endemic in tropical and sub-tropical regions of the world, with around 180,000 human infections a year occurring in Africa. Serologic testing is the chief laboratory diagnostic means of identifying an outbreak and to inform the decision to commence a vaccination campaign. The World Health Organization disseminates the reagents for YFV testing to African reference laboratories, and the US Centers for Disease Control and Prevention (CDC) is charged with producing and providing these reagents. The CDC M-antibody capture ELISA is a 2-day test, requiring titration of reagents when new lots are received, which leads to inconsistency in testing and wastage of material. Here we describe the development of a kit-based assay (YF MAC-HD) based upon the CDC method, that is completed in approximately 3.5 h, with equivocal samples being reflexed to an overnight protocol. The kit exhibits >90% accuracy when compared to the 2-day test. The kits were designed for use with a minimum of equipment and are stored at 4 °C, removing the need for freezing capacity. This kit is capable of tolerating temporary sub-optimal storage conditions which will ease shipping or power outage concerns, and a shelf life of >6 months was demonstrated with no deterioration in accuracy. All reagents necessary to run the YF MAC-HD are included in the kit and are single-use, with 8 or 24 sample options per kit. Field trials are envisioned for the near future, which will enable refinement of the method. The use of the YF MAC-HD is anticipated to reduce materials wastage, and improve the quality and consistency of YFV serologic testing in endemic areas. PMID:26342907

  2. Risk of fatal adverse events associated with 17DD yellow fever vaccine.

    PubMed Central

    Struchiner, C. J.; Luz, P. M.; Dourado, I.; Sato, H. K.; Aguiar, S. G.; Ribeiro, J. G. L.; Soares, R. C. R.; Codeço, C. T.

    2004-01-01

    Yellow fever (YF), an acute infectious disease, is endemic in the north and central-west of Brazil. This disease can be prevented by the use of a vaccine. In Brazil, four fatal adverse events have been associated with the YF vaccine used in the country (17DD vaccine). We briefly describe the last two fatalities, and estimate the risk of 17DD-associated fatal adverse events under different epidemiological scenarios. Controversies regarding the appropriate denominator that enters the estimation of risk serve as a motivation for each proposed scenario. The statistical procedures used show optimum behaviour when assessing the risk of rare events. Risk estimates vary from 0.043 (95 % CI 0.017-0.110) to 2.131 (95 % CI 0.109-12.071) fatalities per million doses administered. The robust estimates of the risk of fatal adverse events we present constitute an important element in future risk-benefit analysis and point to the need for good quality vaccine coverage and adverse-events surveillance data to assess the risk of vaccination. Although vaccination of YF endemic regions is necessary to maintain low disease prevalence, preventive administration of YF vaccine to the entire population should be cautiously analysed. PMID:15473158

  3. Draft Genome Sequence of Lactococcus lactis subsp. lactis Strain YF11

    PubMed Central

    Du, Yuhui; Song, Lifu; Feng, Wenjing; Pei, Guangsheng; Zheng, Ping; Yu, Zhichao; Sun, Jibin

    2013-01-01

    Lactococcus lactis subsp. lactis strain YF11 is a food preservative bacterium with a high capacity to produce nisin. Here, we announce the draft genome sequence of Lactococcus lactis subsp. lactis YF11 (2,527,433 bp with a G+C content of 34.81%). PMID:23929487

  4. Controlled synthesis of NaYF4 nanoparticles and upconversion properties of NaYF4:Yb, Er (Tm)/FC transparent nanocomposite thin films.

    PubMed

    Huang, Wenjuan; Lu, Chunhua; Jiang, Chenfei; Wang, Wei; Song, Jianbin; Ni, Yaru; Xu, Zhongzi

    2012-06-15

    Monodisperse oleic acid stabilized pure NaYF(4) nanoparticles with controlled size and shape have been successfully synthesized by changing the initial reaction temperature. Transparent nanocomposite thin films consisting of NaYF(4):Yb, Er (Tm) upconverting nanoparticles (UCNPs) and fluorocarbon resin (FC) are deposited on the slide glass by dip-coating method. The results show that these nanocomposite thin films exhibit intense green and blue upconversion photoluminescence under 980 nm laser excitation and higher transparency than blank substrate. The NaYF(4):Yb,Er (Tm) nanoparticles and NaYF(4):Yb,Er (Tm)/FC nanocomposite thin films have been characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), scanning electron microscopy (SEM), SEM/back-scattered electron (BSE), atomic force microscopy (AFM), UV-Vis spectrophotometer (UVPC), and photoluminescence (PL) spectra. These nanocomposite thin films can be potentially used in solar cells field.

  5. Core noise measurements on a YF-102 turbofan engine

    NASA Technical Reports Server (NTRS)

    Reshotko, M.; Karchmer, A. M.; Penko, P. F.; Mcardle, J. G.

    1977-01-01

    Core noise from a YF-102 high bypass ratio turbofan engine was investigated through the use of simultaneous measurements of internal fluctuating pressures and far field noise. Acoustic waveguide probes, located in the engine at the compressor exit, in the combustor, at the turbine exit, and in the core nozzle, were employed to measure internal fluctuating pressures. Spectra showed that the internal signals were free of tones, except at high frequency where machinery noise was present. Data obtained over a wide range of engine conditions suggest that below 60% of maximum fan speed the low frequency core noise contributes significantly to the far field noise.

  6. Power scaling of cryogenic Yb:LiYF(4) lasers.

    PubMed

    Zapata, Luis E; Ripin, Daniel J; Fan, Tso Yee

    2010-06-01

    We demonstrate a cryogenically cooled Yb:LiYF(4) (Yb:YLF) laser with 224W linearly polarized output power (pump-power limited) and a slope efficiency of 68%. The beam quality is characterized by an M(2) approximately 1.1 at 60W output and M(2) approximately 2.6 at 180W output. This level of average laser power is approximately 2 orders of magnitude higher than demonstrated previously in cryogenic Yb:YLF. Yb:YLF is attractive for femtosecond pulse generation because of its wide gain bandwidth, and this demonstration shows the potential for high-average-power subpicosecond pulse lasers.

  7. Description of a Prospective 17DD Yellow Fever Vaccine Cohort in Recife, Brazil

    PubMed Central

    de Melo, Andréa Barbosa; da Silva, Maria da Paz C.; Magalhães, Maria Cecília F.; Gonzales Gil, Laura Helena Vega; Freese de Carvalho, Eduardo M.; Braga-Neto, Ulisses M.; Bertani, Giovani Rota; Marques, Ernesto T. A.; Cordeiro, Marli Tenório

    2011-01-01

    From September 2005 to March 2007, 238 individuals being vaccinated for the first time with the yellow fever (YF) -17DD vaccine were enrolled in a cohort established in Recife, Brazil. A prospective study indicated that, after immunization, anti-YF immunoglobulin M (IgM) and anti-YF IgG were present in 70.6% (IgM) and 98.3% (IgG) of the vaccinated subjects. All vaccinees developed protective immunity, which was detected by the plaque reduction neutralization test (PRNT) with a geometric mean titer of 892. Of the 238 individuals, 86.6% had IgG antibodies to dengue virus; however, the presence of anti-dengue IgG did not interfere significantly with the development of anti-YF neutralizing antibodies. In a separate retrospective study of individuals immunized with the 17DD vaccine, the PRNT values at 5 and 10 years post-vaccination remained positive but showed a significant decrease in neutralization titer (25% with PRNT titers < 100 after 5 years and 35% after 10 years). PMID:21976581

  8. Risk of yellow fever vaccine-associated viscerotropic disease among the elderly: a systematic review.

    PubMed

    Rafferty, Ellen; Duclos, Philippe; Yactayo, Sergio; Schuster, Melanie

    2013-12-02

    Yellow fever vaccine-associated viscerotropic disease (YEL-AVD) is a rare and serious adverse event of the yellow fever (YF) vaccine that mimics wild-type YF. Research shows there may be an increased risk of YEL-AVD among the elderly population (≥ 60-65 years old), however this research has yet to be accumulated and reviewed in order to make policy recommendations to countries currently administering the YF vaccine. This paper systematically reviewed all information available on YEL-AVD to determine if there is an increased risk among the elderly, for both travelers and endemic populations. Age-specific reporting rates (RRs) were re-calculated from the literature using the Brighton Collaboration case definition for YEL-AVD and were then analyzed to determine if there was a significant difference between the RRs of younger and older age groups. Two out of the five studies found a significantly higher rate of YEL-AVD among the elderly population. Our findings suggest unexposed elders may be at an increased risk of developing YEF-AVD, however the evidence remains limited. Therefore, our findings for YF vaccination of elderly populations support the recommendations made by the Strategic Advisory Group of Experts (SAGE) in their April 2013 meeting, mainly vaccination of the elderly should be based on a careful risk-benefit analysis.

  9. Fabrication research for supersonic cruise aircraft. [YF-12 skin structures

    NASA Technical Reports Server (NTRS)

    Hoffman, E. L.; Bales, T. T.; Payne, L.

    1979-01-01

    Advanced fabrication and joining processes for titanium and composite materials are being investigated by NASA to develop technology for the Supersonic Cruise Research (SCR) Program. Full-scale structural panels are being designed and fabricated to meet the criteria of an existing integrally stiffened shear panel on the upper wing surface of the NASA YF-12 aircraft. The program consists of laboratory testing and Mach 3 flight service of full-scale structural panels and laboratory testing of representative structural element specimens. Borsic/aluminum honeycomb-core, titanium clad Borsic/aluminum skin-stringer, graphite/PMR-15 polyimide honeycomb-core, and titanium superplastically formed/diffusion bonded panels have been designed, fabricated, and tested. Graphite/LARC-160 polyimide skin-stringer panels have been designed, and fabrication methods are being developed.

  10. Ionic-liquid-assisted synthesis of YF{sub 3} with different crystalline phases and morphologies

    SciTech Connect

    Zhong Haoxiang; Hong Jianming; Cao Xiaofeng; Chen Xuetai Xue Ziling

    2009-03-05

    YF{sub 3} with different crystalline phases and morphologies have been prepared via a facile hydrothermal route assisted by imidazolium ionic liquids 1-butyl-3-methylimidazolium tetrafluoroborate (C{sub 4}mimBF{sub 4}) or 1-butyl-3-methylimidazolium hexafluorophosphate (C{sub 4}mimPF{sub 6}). The microstructures and morphologies of YF{sub 3} particles were characterized by X-ray powder diffraction, X-ray photoelectron spectra (XPS), transmission electron microscopy (TEM), high resolution electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM). Cubic and orthorhombic YF{sub 3} were selectively synthesized by adjusting the molar ratio of the reagents and using C{sub 4}mimBF{sub 4} as the fluoride source, while only orthorhombic YF{sub 3} was obtained using C{sub 4}mimPF{sub 6}, indicating that the crystalline phases and morphologies of the products were significantly influenced by fluoride source and reaction media.

  11. Biotransformation of 2,3,3,3-tetrafluoropropene (HFO-1234yf) in rabbits

    SciTech Connect

    Schuster, Paul; Bertermann, Ruediger; Rusch, Georg M.; Dekant, Wolfgang

    2010-05-01

    2,3,3,3-Tetrafluoropropene (HFO-1234yf) is a non-ozone-depleting fluorocarbon replacement with a low global warming potential and is developed as refrigerant. Due to lethality observed after high concentration inhalation exposures of HFO-1234yf in a developmental toxicity study with rabbits, the biotransformation of HFO-1234yf was investigated in this species. Female New Zealand White rabbits were exposed to air containing 2000; 10,000; or 50,000 ppm (n = 3/concentration) HFO234yf. All inhalation exposures were conducted for 6 h in a dynamic exposure chamber. Animals were individually housed in metabolic cages after the end of the exposures and urines were collected at 12 h intervals for 60 h. For metabolite identification, urine samples were analyzed by {sup 1}H-coupled and {sup 1}H-decoupled {sup 19}F-NMR and by LC/MS-MS or GC/MS. Metabolites were identified by {sup 19}F-NMR chemical shifts, signal multiplicity, {sup 1}H-{sup 19}F coupling constants and by comparison with synthetic reference compounds. In urine samples of rabbits exposed to 2000; 10,000; or 50,000 ppm HFO-1234yf, the predominant metabolite was N-acetyl-S-(3,3,3-trifluoro-2-hydroxypropanyl)-L-cysteine and accounted for app. 48% of total {sup 19}F-NMR signal intensities. S-(3,3,3-Trifluoro-2-hydroxypropanyl)mercaptolactic acid, 3,3,3-trifluoro-1,2-dihydroxypropane, 3,3,3-trifluoro-2-propanol and inorganic fluoride were also present as urinary metabolites. In incubations of rabbit liver S9 fractions containing glutathione, NADPH and HFO-1234yf, 3,3,3-trifluoro-1,2-dihydroxypropane, S-(3,3,3-trifluoro-2-hydroxypropanyl)glutathione, 3,3,3-trifluoro-2-propanol and inorganic fluoride were identified as metabolites of HFO-1234yf by {sup 19}F-NMR. The quantity of recovered metabolites in urine suggest a low extent (< 0.1% of dose received) of biotransformation of HFO-1234yf in rabbits, and 95% of all metabolites were excreted within 12 h after the end of the exposures (t{sub 1/2} app. 9.5 h). The obtained

  12. Biotransformation of 2,3,3,3-tetrafluoropropene (HFO-1234yf) in rabbits.

    PubMed

    Schuster, Paul; Bertermann, Rüdiger; Rusch, Georg M; Dekant, Wolfgang

    2010-05-01

    2,3,3,3-Tetrafluoropropene (HFO-1234yf) is a non-ozone-depleting fluorocarbon replacement with a low global warming potential and is developed as refrigerant. Due to lethality observed after high concentration inhalation exposures of HFO-1234yf in a developmental toxicity study with rabbits, the biotransformation of HFO-1234yf was investigated in this species. Female New Zealand White rabbits were exposed to air containing 2000; 10,000; or 50,000 ppm (n=3/concentration) HFO234yf. All inhalation exposures were conducted for 6 h in a dynamic exposure chamber. Animals were individually housed in metabolic cages after the end of the exposures and urines were collected at 12 h intervals for 60 h. For metabolite identification, urine samples were analyzed by (1)H-coupled and (1)H-decoupled (19)F-NMR and by LC/MS-MS or GC/MS. Metabolites were identified by (19)F-NMR chemical shifts, signal multiplicity, (1)H-(19)F coupling constants and by comparison with synthetic reference compounds. In urine samples of rabbits exposed to 2000; 10,000; or 50,000 ppm HFO-1234yf, the predominant metabolite was N-acetyl-S-(3,3,3-trifluoro-2-hydroxypropanyl)-l-cysteine and accounted for app. 48% of total (19)F-NMR signal intensities. S-(3,3,3-Trifluoro-2-hydroxypropanyl)mercaptolactic acid, 3,3,3-trifluoro-1,2-dihydroxypropane, 3,3,3-trifluoro-2-propanol and inorganic fluoride were also present as urinary metabolites. In incubations of rabbit liver S9 fractions containing glutathione, NADPH and HFO-1234yf, 3,3,3-trifluoro-1,2-dihydroxypropane, S-(3,3,3-trifluoro-2-hydroxypropanyl)glutathione, 3,3,3-trifluoro-2-propanol and inorganic fluoride were identified as metabolites of HFO-1234yf by (19)F-NMR. The quantity of recovered metabolites in urine suggest a low extent (<0.1% of dose received) of biotransformation of HFO-1234yf in rabbits, and 95% of all metabolites were excreted within 12 h after the end of the exposures (t(1/2) app. 9.5 h). The obtained results indicate that HFO-1234yf is

  13. YF-12 Lockalloy ventral fin program, volume 1. [design analysis, fabrication, and manufacturing of aircraft structures using aluminum and beryllium alloys for the lockheed YF-12 aircraft

    NASA Technical Reports Server (NTRS)

    Duba, R. J.; Haramis, A. C.; Marks, R. F.; Payne, L.; Sessing, R. C.

    1976-01-01

    Results are presented of the YF-12 Lockalloy Ventral Fin Program which was carried out by Lockheed Aircraft Corporation - Advanced Development Projects for the joint NASA/USAF YF-12 Project. The primary purpose of the program was to redesign and fabricate the ventral fin of the YF-12 research airplane (to reduce flutter) using Lockalloy, and alloy of beryllium and aluminum, as a major structural material. A secondary purpose, was to make a material characterization study (thermodynamic properties, corrosion; fatigue tests, mechanical properties) of Lockalloy to validate the design of the ventral fin and expand the existing data base on this material. All significant information pertinent to the design and fabrication of the ventral fin is covered. Emphasis throughout is given to Lockalloy fabrication and machining techniques and attendant personnel safety precautions. Costs are also examined. Photographs of tested alloy specimens are shown along with the test equipment used.

  14. 17DD yellow fever vaccine

    PubMed Central

    Martins, Reinaldo M.; Maia, Maria de Lourdes S.; Farias, Roberto Henrique G.; Camacho, Luiz Antonio B.; Freire, Marcos S.; Galler, Ricardo; Yamamura, Anna Maya Yoshida; Almeida, Luiz Fernando C.; Lima, Sheila Maria B.; Nogueira, Rita Maria R.; Sá, Gloria Regina S.; Hokama, Darcy A.; de Carvalho, Ricardo; Freire, Ricardo Aguiar V.; Filho, Edson Pereira; Leal, Maria da Luz Fernandes; Homma, Akira

    2013-01-01

    Objective: To verify if the Bio-Manguinhos 17DD yellow fever vaccine (17DD-YFV) used in lower doses is as immunogenic and safe as the current formulation. Results: Doses from 27,476 IU to 587 IU induced similar seroconversion rates and neutralizing antibodies geometric mean titers (GMTs). Immunity of those who seroconverted to YF was maintained for 10 mo. Reactogenicity was low for all groups. Methods: Young and healthy adult males (n = 900) were recruited and randomized into 6 groups, to receive de-escalating doses of 17DD-YFV, from 27,476 IU to 31 IU. Blood samples were collected before vaccination (for neutralization tests to yellow fever, serology for dengue and clinical chemistry), 3 to 7 d after vaccination (for viremia and clinical chemistry) and 30 d after vaccination (for new yellow fever serology and clinical chemistry). Adverse events diaries were filled out by volunteers during 10 d after vaccination. Volunteers were retested for yellow fever and dengue antibodies 10 mo later. Seropositivity for dengue was found in 87.6% of volunteers before vaccination, but this had no significant influence on conclusions. Conclusion: In young healthy adults Bio-Manguinhos/Fiocruz yellow fever vaccine can be used in much lower doses than usual. International Register ISRCTN 38082350. PMID:23364472

  15. Praseodymium doped NaYF4 nanocrystals in oxyfluoride glass-ceramics; morphological and spectroscopic studies.

    PubMed

    Dominiak-Dzik, G

    2009-04-01

    The synthesis, morphology, optical properties and excited state dynamics of the Pr-doped NaYF4 nanocrystals in glass-ceramics are presented. The crystalline cubic NaYF4:Pr were synthesized by the controlled heat-treatment of multicomponent oxyfluoride glass based on silica and YF3. A series of the two-hour heat treatments at 620-660 degrees C were carried out yielding visually transparent materials. Above 660 degrees C an opaque material was obtained. The crystalline phase was characterized by the X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (TEM) and selected area electron diffraction (SAED). The effect of ceramming temperature on the NaYF4:Pr cell parameter (a = 5.470 A for NaYF4 and 5.4899 A, 5.4979 A and 5.5378 A in glass-ceramics) and particle average size (15-40 nm) was observed. Optical characteristics of formed glass-ceramics were favorably affected by the Pr3+ ions in well-defined sites of NaYF4; emission intensities increased and luminescence decay curves become single exponential with the longer corresponding lifetimes.

  16. 17 CFR 270.17d-3 - Exemption relating to certain joint enterprises or arrangements concerning payment for...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... management investment company. 270.17d-3 Section 270.17d-3 Commodity and Securities Exchanges SECURITIES AND... registered open-end management investment company. An affiliated person of, or principal underwriter for, a registered open-end management investment company and an affiliated person of such a person or...

  17. 17 CFR 270.17d-3 - Exemption relating to certain joint enterprises or arrangements concerning payment for...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... management investment company. 270.17d-3 Section 270.17d-3 Commodity and Securities Exchanges SECURITIES AND... registered open-end management investment company. An affiliated person of, or principal underwriter for, a registered open-end management investment company and an affiliated person of such a person or...

  18. 75 FR 28080 - Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Order Approving and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-19

    ... COMMISSION Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Order Approving and Declaring Effective a Plan for the Allocation of Regulatory Responsibilities Between the Financial Industry... allocation of regulatory responsibilities, dated March 31, 2010 (``17d- 2 Plan'' or the ``Plan''). The...

  19. 75 FR 28078 - Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Order Approving and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-19

    ... COMMISSION Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Order Approving and Declaring Effective a Plan for the Allocation of Regulatory Responsibilities Between the Financial Industry... allocation of regulatory responsibilities, dated March 31, 2010 (``17d- 2 Plan'' or the ``Plan''). The...

  20. YF-12A #935 with test pilot Donald L. Mallick

    NASA Technical Reports Server (NTRS)

    1972-01-01

    NASA test pilot Don Mallick, in full pressure suit, stands in front of the YF-12A (60-6935). Don is ready for a flight across the Western United States. Donald L. Mallick joined the National Advisory Committee for Aeronautics' Langley Aeronautical Laboratory at Hampton, Virginia, as a research pilot, in June 1957. He transferred to the National Aeronautics and Space Administration's Flight Research Center, Edwards, California, in February 1963. Mallick attended Pennsylvania State University, University Park, Pennsylvania, for the period 1948-1949, studying Mechanical Engineering before entering the U.S. Navy for pilot training. Don served during the Korean War period, 1950-1954, flying F2H-2 Banshee jets from the carriers, USS F.D. Roosevelt and the USS Wasp. Later in 1954 he returned to school at the University of Florida, Gainesville, Florida, graduating with Honors in June 1957 and earning his degree in aeronautical engineering. Don joined the Naval Reserves and served in almost all categories of Reserve operations before retiring in 1970 as a Lieutenant Commander. As a research pilot at NACA-NASA Langley Don flew quantitative stability-&-control and handling-qualities tests on modified helicopters. On the Vertol VZ-2 Vertical Short Take-off and Landing research aircraft, he performed qualitative evaluation flights. Other aircraft flown for flight tests were: F2H-1 Banshee, F-86D, F9F-2 and F8U-3, F11F-1 Tigercat, and F-100C. Don also flew support and photo flights. In his capacity as research pilot at the NASA Flight Research Center Don was assigned to NASA's Lockheed Jetstar General Purpose Airborne Simulator (GPAS). He flew all of the tests, with the majority being as project pilot. Mallick made a flight in the lightweight M2-F1 lifting body on January 30, 1964. In 1964, Don was assigned to and completed the USAF Test pilot school, Class 64A. Later in 1964, he flew as the co-project pilot on the Lunar Landing Research Vehicle (LLRV) making over seventy

  1. Adaptation of yellow fever virus 17D to Vero cells is associated with mutations in structural and non-structural protein genes.

    PubMed

    Beasley, David W C; Morin, Merribeth; Lamb, Ashley R; Hayman, Edward; Watts, Douglas M; Lee, Cynthia K; Trent, Dennis W; Monath, Thomas P

    2013-09-01

    Serial passaging of yellow fever virus 17D in Vero cells was employed to derive seed material for a novel inactivated vaccine, XRX-001. Two independent passaging series identified a novel lysine to arginine mutation at amino acid 160 of the envelope protein, a surface-exposed residue in structural domain I. A third passage series resulted in an isoleucine to methionine mutation at residue 113 of the NS4B protein, a central membrane spanning region of the protein which has previously been associated with Vero cell adaptation of other mosquito-borne flaviviruses. These studies confirm that flavivirus adaptation to growth in Vero cells can be mediated by structural or non-structural protein mutations.

  2. Fabrication of Au-Ag nanocage@NaYF4@NaYF4:Yb,Er Core-Shell Hybrid and its Tunable Upconversion Enhancement

    PubMed Central

    Chen, Xu; Zhou, Donglei; Xu, Wen; Zhu, Jinyang; Pan, Gencai; Yin, Ze; Wang, He; Zhu, Yongsheng; Shaobo, Cui; Song, Hongwei

    2017-01-01

    Localized electric filed enhancement by surface plasmon resonance (SPR) of noble metal nanoparticles is an effective method to amplify the upconversion luminescence (UCL) strength of upconversion nanoparticles (UCNPs), whereas the highly effective UCL enhancement of UCNPs in colloids has not been realized until now. Here, we designed and fabricated the colloidal Au-Ag nanocage@NaYF4@NaYF4:Yb,Er core-shell hybrid with different intermediate thickness (NaYF4) and tunable SPR peaks from visible wavelength region to NIR region. After the optimization of the intermediate spacer thickness (~7.5 nm) of NaYF4 NPs and the SPR peak (~950 nm) of noble metal nanoparticles, an optimum enhancement as high as ~25 folds was obtained. Systematic investigation indicates that UCL enhancement mainly originates from the influence of the intermediate spacer and the coupling of Au-Ag nanocages with the excitation electromagnetic field of the UCNPs. Our findings may provide a new thinking on designing highly effective metal@UCNPs core-shell hybrid in colloids. PMID:28106128

  3. Fabrication of Au-Ag nanocage@NaYF4@NaYF4:Yb,Er Core-Shell Hybrid and its Tunable Upconversion Enhancement

    NASA Astrophysics Data System (ADS)

    Chen, Xu; Zhou, Donglei; Xu, Wen; Zhu, Jinyang; Pan, Gencai; Yin, Ze; Wang, He; Zhu, Yongsheng; Shaobo, Cui; Song, Hongwei

    2017-01-01

    Localized electric filed enhancement by surface plasmon resonance (SPR) of noble metal nanoparticles is an effective method to amplify the upconversion luminescence (UCL) strength of upconversion nanoparticles (UCNPs), whereas the highly effective UCL enhancement of UCNPs in colloids has not been realized until now. Here, we designed and fabricated the colloidal Au-Ag nanocage@NaYF4@NaYF4:Yb,Er core-shell hybrid with different intermediate thickness (NaYF4) and tunable SPR peaks from visible wavelength region to NIR region. After the optimization of the intermediate spacer thickness (~7.5 nm) of NaYF4 NPs and the SPR peak (~950 nm) of noble metal nanoparticles, an optimum enhancement as high as ~25 folds was obtained. Systematic investigation indicates that UCL enhancement mainly originates from the influence of the intermediate spacer and the coupling of Au-Ag nanocages with the excitation electromagnetic field of the UCNPs. Our findings may provide a new thinking on designing highly effective metal@UCNPs core-shell hybrid in colloids.

  4. HPV vaccine

    MedlinePlus

    Vaccine - HPV; Immunization - HPV; Gardasil; HPV2; HPV4; Vaccine to prevent cervical cancer; Genital warts - HPV vaccine; Cervical dysplasia - HPV vaccine; Cervical cancer - HPV vaccine; Cancer of the cervix - HPV vaccine; Abnormal ...

  5. Controllable Phase Transformation and Mid-infrared Emission from Er3+-Doped Hexagonal-/Cubic-NaYF4 Nanocrystals

    PubMed Central

    Yang, Dandan; Chen, Dongdan; He, Huilin; Pan, Qiwen; Xiao, Quanlan; Qiu, Jianrong; Dong, Guoping

    2016-01-01

    The morphology of hexagonal phase NaYF4:Er3+ nanorods synthesized by hydrothermal method changed greatly after a continuing calcination, along with a phase transformation to cubic phase. Photoluminescence (PL) spectra indicated that mid-infrared (MIR) emission was obtained in both hexagonal and cubic phase NaYF4:Er3+ nanocrystals for the first time. And the MIR emission of NaYF4:Er3+ nanocrystals enhanced remarkably at higher calcination temperature. To prevent uncontrollable morphology from phase transformation, the cubic phase NaYF4:Er3+ nanospheres with an average size of ~100 nm were prepared via a co-precipitation method directly. In contrast, the results showed better morphology and size of cubic phase NaYF4:Er3+ nanocrystals have realized when calcined at different temperatures. And PL spectra demonstrated a more intense MIR emission in the cubic phase NaYF4:Er3+ nanocrystals with an increasing temperature. Besides, the MIR emission peak of Er3+ ions had an obvious splitting in cubic phase NaYF4. Therefore, cubic phase NaYF4:Er3+ nanospheres with more excellent MIR luminescent properties seems to provide a new material for nanocrystal-glass composites, which is expected to open a broad new field for the realization of MIR lasers gain medium. PMID:27453150

  6. Japanese encephalitis vaccines: current vaccines and future prospects.

    PubMed

    Monath, T P

    2002-01-01

    Vaccination against JE ideally should be practiced in all areas of Asia where the virus is responsible for human disease. The WHO has placed a high priority on the development of a new vaccine for prevention of JE. Some countries in Asia (Japan, South Korea, North Korea, Taiwan, Vietnam, Thailand, and the PRC) manufacture JE vaccines and practice childhood immunization, while other countries suffering endemic or epidemic disease (India, Nepal, Laos, Cambodia, Bangladesh, Myanmar, Malaysia, Indonesia and the Philippines) have no JE vaccine manufacturing or policy for use. With the exception of the PRC, all countries practicing JE vaccination use formalin inactivated mouse brain vaccines, which are relatively expensive and are associated with rare but clinically significant allergic and neurological adverse events. New inactivated JE vaccines manufactured in Vero cells are in advanced preclinical or early clinical development in Japan, South Korea, Taiwan, and the PRC. An empirically derived, live attenuated vaccine (SA14-14-2) is widely used in the PRC. Trials in the PRC have shown SA14-14-2 to be safe and effective when administered in a two-dose regimen, but regulatory concerns over manufacturing and control have restricted international distribution. The genetic basis of attenuation of SA14-14-2 has been partially defined. A new live attenuated vaccine (ChimeriVax-JE) that uses a reliable flavivirus vaccine--yellow fever 17D--as a live vector for the envelope genes of SA14-14-2 virus is in early clinical trials and appears to be well tolerated and immunogenic after a single dose. Vaccinia and avipox vectored vaccines have also been tested clinically, but are no longer being pursued due to restricted effectiveness mediated by anti-vector immunity. Other approaches to JE vaccines--including naked DNA, oral vaccination, and recombinant subunit vaccines--have been reviewed.

  7. PHOTONIC CRYSTAL SURFACE ENHANCED UPCONVERSION EMISSION OF YF3:Yb3+, Er3+ NANOPARTICLES

    NASA Astrophysics Data System (ADS)

    Shao, Bo; Yang, Zhengwen; Li, Jun; Liao, Jiayan; Lai, Shenfeng; Qiu, Jianbei; Song, Zhiguo; Yang, Yong; Zhou, Dacheng

    2015-11-01

    The opal photonic crystals made of polystyrene microspheres with 155, 230, 270 or 410 nm in diameter were used to enhance upconversion (UC) emission of YF3:Yb3+, Er3+ nanoparticles, respectively. The red or green UC emission of YF3:Yb3+, Er3+ nanoparticles can be selectively enhanced when the red or green UC emission wavelength overlapped with the photonic bandgaps of opals, which is attributed to Bragg reflection of photonic bandgap. In addition, when the 980 nm excitation light wavelength was in the region of the photonic bandgap, red and green UC emissions of YF3:Yb3+, Er3+ nanoparticles were enhanced due to the enhancement of excitation field.

  8. Aerodynamic and acoustic behavior of a YF-12 inlet at static conditions

    NASA Technical Reports Server (NTRS)

    Bangert, L. H.; Feltz, E. P.; Godby, L. A.; Miller, L. D.

    1981-01-01

    An aeroacoustic test program to determine the cause of YF-12 inlet noise suppression was performed with a YF-12 aircraft at ground static conditions. Data obtained over a wide range of engine speeds and inlet configurations are reported. Acoustic measurements were made in the far field and aerodynamic and acoustic measurements were made inside the inlet. The J-58 test engine was removed from the aircraft and tested separately with a bellmouth inlet. The far field noise level was significantly lower for the YF-12 inlet than for the bellmouth inlet at engine speeds above 5500 rpm. There was no evidence that noise suppression was caused by flow choking. Multiple pure tones were reduced and the spectral peak near the blade passing frequency disappeared in the region of the spike support struts at engine speeds between 6000 and 6600 rpm.

  9. Thermoluminescence response of K2YF5:Tb3+ crystals to photon radiation fields.

    PubMed

    Faria, L O; Lo, D; Kui, H W; Khaidukov, N M; Nogueira, M S

    2004-01-01

    This investigation has been performed to test the feasibility of using K2YF5:Tb3+ crystals as thermoluminescence dosemeters (TLD). K2YF5 single crystals doped with 0.2, 10.0 and 50.0 at.% of trivalent optically active Tb3+ ions as well as K2TbF5 and undoped K2YF5 crystals have been synthesized under hydrothermal conditions. Polished crystal platelets with thickness of about 1 mm have been irradiated with X and gamma rays in order to study thermoluminescent (TL) sensitivity as well as dose and energy response in terms of the Tb3+ concentration in K2YF5. Within this concentration series, K2YF5 crystals doped with 10.0 at.% Tb3+ have been found to have maximum TL response due to a broad asymmetric TL glow peak at 269 degrees C with good linearity of dose response and reproducibility of dose measurements. After deconvolution, the main dosimetric peak has been revealed to be composed of two individual peaks, both with linear TL response behaviour, centered at 210 and 269 degrees C. As it has been proved, the linear TL signal coefficient for K2Y0.9Tb0.1F5 is almost 10 times greater than that for commercial TLD-100 (LiF:Mg,Ti), irradiated with a 137Cs gamma radiation source at the same conditions. The reported results indicate that K2YF5 crystals doped with Tb3+ have potential as promising materials for radiation dosemeters.

  10. Temporal dynamics of the primary human T cell response to yellow fever virus 17D as it matures from an effector- to a memory-type response.

    PubMed

    Blom, Kim; Braun, Monika; Ivarsson, Martin A; Gonzalez, Veronica D; Falconer, Karolin; Moll, Markus; Ljunggren, Hans-Gustaf; Michaëlsson, Jakob; Sandberg, Johan K

    2013-03-01

    The live attenuated yellow fever virus (YFV) 17D vaccine provides a good model to study immune responses to an acute viral infection in humans. We studied the temporal dynamics, composition, and character of the primary human T cell response to YFV. The acute YFV-specific effector CD8 T cell response was broad and complex; it was composed of dominant responses that persisted into the memory population, as well as of transient subdominant responses that were not detected at the memory stage. Furthermore, HLA-A2- and HLA-B7-restricted YFV epitope-specific effector cells predominantly displayed a CD45RA(-)CCR7(-)PD-1(+)CD27(high) phenotype, which transitioned into a CD45RA(+)CCR7(-)PD-1(-)CD27(low) memory population phenotype. The functional profile of the YFV-specific CD8 T cell response changed in composition as it matured from an effector- to a memory-type response, and it tended to become less polyfunctional during the course of this transition. Interestingly, activation of CD4 T cells, as well as FOXP3(+) T regulatory cells, in response to YFV vaccination preceded the kinetics of the CD8 T cell response. The present results contribute to our understanding of how immunodominance patterns develop, as well as the phenotypic and functional characteristics of the primary human T cell response to a viral infection as it evolves and matures into memory.

  11. Gold decorated NaYF4:Yb,Er/NaYF4/silica (core/shell/shell) upconversion nanoparticles for photothermal destruction of BE(2)-C neuroblastoma cells

    NASA Astrophysics Data System (ADS)

    Qian, Li Peng; Zhou, Li Han; Too, Heng-Phon; Chow, Gan-Moog

    2011-02-01

    Gold decorated NaYF4:Yb,Er/NaYF4/silica (core/shell/shell) upconversion (UC) nanoparticles ( 70-80 nm) were synthesized using tetraethyl orthosilicate and chloroauric acid in a one-step reverse microemulsion method. Gold nanoparticles ( 6 nm) were deposited on the surface of silica shell of these core/shell/shell nanoparticles. The total upconversion emission intensity (green, red, and blue) of the core/shell/shell nanoparticles decreased by 31% after Au was deposited on the surface of silica shell. The upconverted green light was coupled with the surface plasmon of Au leading to rapid heat conversion. These UC/silica/Au nanoparticles were very efficient to destroy BE(2)-C cancer cells and showed strong potential in photothermal therapy.

  12. Uniform NaYF{sub 4}:Yb, Tm hexagonal submicroplates: Controlled synthesis and enhanced UV and blue upconversion luminescence

    SciTech Connect

    Huang, Wenjuan; Ding, Mingye; Huang, Hengming; Jiang, Chenfei; Song, Yan; Ni, Yaru; Lu, Chunhua; Xu, Zhongzi

    2013-02-15

    Graphical abstract: Display Omitted Highlights: ► β-NaYF{sub 4} phosphors as an excellent upconversion materials. ► Oleic acid can promote the transformation of α → β phase NaYF{sub 4}. ► The shape and size of β-NaYF{sub 4} submicroplate can be tuned by reactant concentration. ► Enhanced UV and blue peaks can be obtained by varying Yb{sup 3+} and Tm{sup 3+} concentration. -- Abstract: We reported the preparation of cubic (α-) and hexagonal (β-) NaYF{sub 4} particles in high boiling organic solvents 1-octadecene (ODE) and oleic acid (OA), through a thermal decomposition synthesis route. The as-prepared products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), photoluminescence (PL) spectra. By tuning the OA/ODE volume ratio and reactant concentration, we could manipulate the morphology, size, and crystal structure of the products. Highly uniform β-NaYF{sub 4} submicroplates were obtained from α-NaYF{sub 4} nanoparticles by increasing the OA/ODE volume ratio, while the phase kept unchanged with the increasing of reactant concentration. Upconversion emissions from UV to NIR emissions were observed in β-NaYF{sub 4} hexagonal submicroplates under 980 nm laser diode excitation. In addition, the enhanced UV and blue upconversion emissions were obtained by varying Tm{sup 3+} and Yb{sup 3+} ion concentration.

  13. Active controls for flutter suppression and gust alleviation in supersonic aircraft. [YF-17 flutter model

    NASA Technical Reports Server (NTRS)

    Nissim, E.

    1980-01-01

    Results of work done on active controls on the modified YF-17 flutter model are summarized. The basic derivation of a suitable control law is discussed. It is shown that discrepencies found between analysis and wind tunnel tests originate from the lack of proper implementation of the desired control law. Program capabilities are described.

  14. Long-lasting stem cell-like memory CD8+ T cells with a naïve-like profile upon yellow fever vaccination.

    PubMed

    Fuertes Marraco, Silvia A; Soneson, Charlotte; Cagnon, Laurène; Gannon, Philippe O; Allard, Mathilde; Abed Maillard, Samia; Montandon, Nicole; Rufer, Nathalie; Waldvogel, Sophie; Delorenzi, Mauro; Speiser, Daniel E

    2015-04-08

    Efficient and persisting immune memory is essential for long-term protection from infectious and malignant diseases. The yellow fever (YF) vaccine is a live attenuated virus that mediates lifelong protection, with recent studies showing that the CD8(+) T cell response is particularly robust. Yet, limited data exist regarding the long-term CD8(+) T cell response, with no studies beyond 5 years after vaccination. We investigated 41 vaccinees, spanning 0.27 to 35 years after vaccination. YF-specific CD8(+) T cells were readily detected in almost all donors (38 of 41), with frequencies decreasing with time. As previously described, effector cells dominated the response early after vaccination. We detected a population of naïve-like YF-specific CD8(+) T cells that was stably maintained for more than 25 years and was capable of self-renewal ex vivo. In-depth analyses of markers and genome-wide mRNA profiling showed that naïve-like YF-specific CD8(+) T cells in vaccinees (i) were distinct from genuine naïve cells in unvaccinated donors, (ii) resembled the recently described stem cell-like memory subset (Tscm), and (iii) among all differentiated subsets, had profiles closest to naïve cells. Our findings reveal that CD8(+) Tscm are efficiently induced by a vaccine in humans, persist for decades, and preserve a naïveness-like profile. These data support YF vaccination as an optimal mechanistic model for the study of long-lasting memory CD8(+) T cells in humans.

  15. Additives and solvents-induced phase and morphology modification of NaYF{sub 4} for improving up-conversion emission

    SciTech Connect

    Zhuang, Jianle; Yang, Xianfeng; Wang, Jing; Lei, Bingfu; Liu, Yingliang; Wu, Mingmei

    2016-01-15

    Both cubic and hexagonal NaYF{sub 4} were synthesized in different reaction systems via hydro/solvo-thermal route. The effects of reaction temperature, solvents, and additives on the synthesis of NaYF{sub 4} have been studied in detail. It has been shown that phase transformation from cubic NaYF{sub 4} to hexagonal NaYF{sub 4} always occurred. The sequence of the ability for inducing the phase transformation was ethanol>H{sub 2}O>acetic acid. It is found that ethanol can not only facilitate the formation of hexagonal NaYF{sub 4} but also control the growth of the crystal. This is quite unusual for the growth of H-NaYF{sub 4}. The up-conversion emission properties of Yb/Er co-doped NaYF{sub 4} have also been investigated and the results demonstrated some general principles for improving up-conversion emission. - Graphical abstract: Additives and solvents can induce the phase transformation of NaYF{sub 4}, typically the use of organic sodium salt and ethanol. - Highlights: • The effect of additives and solvents on the synthesis of NaYF{sub 4} was studied in detail. • Ethanol can facilitate the formation of H-NaYF{sub 4} while acetic acid restrain it. • Three general principles for improving up-conversion emission were summarized.

  16. Energy transfer processes between Tm(3+) and Ho(3+) in LiYF4. Ph.D. Thesis Final Report

    NASA Technical Reports Server (NTRS)

    Oezen, Goenuel

    1991-01-01

    The spectroscopic properties of the crystal LiYF4 doped with Thulium (Tm) and Holmium (Ho) ions are studied. The basic processes are discussed that regulate the transfer of energy between these two ions in this crystal. In this system Tm is considered the donor ion and the Ho the acceptor ion. Spectral data were obtained on three samples available: LiYF4:Tm(3+) (0.5 percent), LiYF4:Ho(3+) (1 percent), and LiYF4:Tm(3+) (5 percent), Ho(3+) (0.2 percent). Spectral data, which include absorption, luminescence, excitation, and the response to pulsed excitation in a wide range of temperatures, allowed to look at the energy transfer processes by considering the kinetic evolution of the emission of the two ions (donor and acceptor) involved in the process and the basic spectroscopic properties related to them. This inclusive approach has led to the validation of the physical model.

  17. Controlled synthesis and temperature-dependent spectra of NaYF4:Yb3+, Re3+@NaYF4@SiO2 (RE = Er, Tm) core-shell-shell nanophosphors

    NASA Astrophysics Data System (ADS)

    Bu, Y. Y.; Yan, X. H.

    2017-02-01

    The NaYF4 Yb3+, Re3+@NaYF4@SiO2 (RE = Er, Tm) core-shell-shell nanophosphors were synthesized by thermal decomposition of lanthanide trifluoroacetate precursors and subsequent hydrolysis coating process. Structures of resulting nanophosphors are studied by the X-ray diffraction and high-resolution transmission electron microscopy. Temperature-dependent photoluminescence spectra, thermal quenching ratios, fluorescence intensity ratios, and temperature sensitivity of resulting nanoparticles are studied in the temperature range from 298 to 623 K. The results suggest that the NaYF4:Yb3+, Er3+@NaYF4@SiO2 is a suitable candidate for making a low temperature sensor up to 450 K with a maximum sensitivity of 24 × 10-4 K-1, and the NaYF4:Yb3+, Tm3+@NaYF4@SiO2 is an excellent candidate for temperature sensors at high temperature. This work presents a new method to use the fluoride nanocrystals as the optical thermometry at high temperature.

  18. Sequential growth of sandwiched NaYF4:Yb/Er@NaYF4:Yb@NaNdF4:Yb core-shell-shell nanoparticles for photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Peng, Huang-Yong; Ding, Bin-Bin; Ma, Yin-Chu; Sun, Shi-Qi; Tao, Wei; Guo, Yan-Chuan; Guo, Hui-Chen; Yang, Xian-Zhu; Qian, Hai-Sheng

    2015-12-01

    Upconversion (UC) nanostructures have attracted much interest for their extensive biological applications. In this work, we describe a sequential synthetic route to prepare sandwiched NaYF4:Yb/Er@NaYF4:Yb@NaNdF4:Yb core-shell upconversion nanoparticles. The as-prepared products were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM, JEM 2100F), respectively. The as-prepared core-shell nanoparticles of NaYF4:Yb/Er@NaYF4:Yb@NaNdF4:Yb are composed of elliptical nanoparticles with a length of 80 nm and width of 42 nm, which show efficient upconversion fluorescence excited at 808 nm indicating the formation of core-shell-shell sandwiched nanostructures. In addition, the as-prepared sandwiched NaYF4:Yb/Er@NaYF4:Yb@NaNdF4:Yb core-shell upconversion nanoparticles also show strong upconversion fluorescence excited at 980 nm. Amphiphilic mPEG2k-b-PEBEP6K copolymers (denoted as PPE) were chosen to transfer these hydrophobic UCNPs into the aqueous phase for biological application. In vitro photodynamic therapy of cancer cells show that the viability of cells incubated with the nanoparticles loaded with MC 540 was significantly lower as compared to the nanoparticles without photosensitizers exposed to NIR laser.

  19. Evaluation of two yellow fever vaccines for routine immunization programs in Argentina.

    PubMed

    Ripoll, Carlos; Ponce, Amalia; Wilson, Mario M; Sharif, Norma; Vides, José B; Armoni, Judith; Teuwen, Dirk E

    2008-01-01

    Although highly effective vaccines have been available for almost 70 years, an estimated 200,000 cases of YF, including 30,000 deaths, still occur annually. This study evaluated the safety of two yellow fever (YF) vaccines [Stamaril and Vacina Contra Febre Amarela (VCFA)]. A total of 2,514 subjects were randomized equally to receive Stamaril or VCFA. Immediate reactions occurring within 30 minutes after vaccination, and solicited local and systemic reactions occurring within eight days, were monitored. Unsolicited local, systemic adverse events and serious adverse events (SAE) were recorded for 21 days after vaccination. Solicited local and systemic adverse reactions were reported by 15.3-17.6% and 30.4-31.6% of the Stamaril and VCFA groups, respectively. Only 56 of the 2,514 study subjects (2.2%) reported a severe solicited adverse reaction, 25 in the Stamaril group (1.99%) and 31 in the VFCA group (2.49%), (p=0.403). Ten subjects (0.8%) in each group reported at least one severe solicited local reaction (p = 0.988). A total of 18 Stamaril subjects (1.43%) and 21 VCFA subjects (1.68%) reported at least one severe solicited systemic reaction (p = 0.617) One SAE considered related to vaccination occurred, polymyalgia in the VCFA group. No immediate reactions to vaccination were seen. Vaccine-related unsolicited events were infrequent, 1.4% in the Stamaril group and 2.0% VCFA group, generally of mild or moderate intensity. We conclude that the safety profiles of Stamaril and VCFA support routine vaccination to prevent YF in residents of and travelers to endemic areas of South America and Africa.

  20. Future emissions and atmospheric fate of HFC-1234yf from mobile air conditioners in Europe.

    PubMed

    Henne, Stephan; Shallcross, Dudley E; Reimann, Stefan; Xiao, Ping; Brunner, Dominik; O'Doherty, Simon; Buchmann, Brigitte

    2012-02-07

    HFC-1234yf (2,3,3,3-tetrafluoropropene) is under discussion for replacing HFC-134a (1,1,1,2-tetrafluoroethane) as a cooling agent in mobile air conditioners (MACs) in the European vehicle fleet. Some HFC-1234yf will be released into the atmosphere, where it is almost completely transformed to the persistent trifluoroacetic acid (TFA). Future emissions of HFC-1234yf after a complete conversion of the European vehicle fleet were assessed. Taking current day leakage rates and predicted vehicle numbers for the year 2020 into account, European total HFC-1234yf emissions from MACs were predicted to range between 11.0 and 19.2 Gg yr(-1). Resulting TFA deposition rates and rainwater concentrations over Europe were assessed with two Lagrangian chemistry transport models. Mean European summer-time TFA mixing ratios of about 0.15 ppt (high emission scenario) will surpass previously measured levels in background air in Germany and Switzerland by more than a factor of 10. Mean deposition rates (wet + dry) of TFA were estimated to be 0.65-0.76 kg km(-2) yr(-1), with a maxium of ∼2.0 kg km(-2) yr(-1) occurring in Northern Italy. About 30-40% of the European HFC-1234yf emissions were deposited as TFA within Europe, while the remaining fraction was exported toward the Atlantic Ocean, Central Asia, Northern, and Tropical Africa. Largest annual mean TFA concentrations in rainwater were simulated over the Mediterranean and Northern Africa, reaching up to 2500 ng L(-1), while maxima over the continent of about 2000 ng L(-1) occurred in the Czech Republic and Southern Germany. These highest annual mean concentrations are at least 60 times lower than previously determined to be a safe level for the most sensitive aquatic life-forms. Rainwater concentrations during individual rain events would still be 1 order of magnitude lower than the no effect level. To verify these results future occasional sampling of TFA in the atmospheric environment should be considered. If future HFC-1234yf

  1. HPV Vaccine

    MedlinePlus

    ... Surgery? A Week of Healthy Breakfasts Shyness HPV Vaccine KidsHealth > For Teens > HPV Vaccine Print A A ... starting at age 9. continue How Does the Vaccine Work? The HPV vaccine is approved for people ...

  2. HPV Vaccine

    MedlinePlus

    ... Surgery? A Week of Healthy Breakfasts Shyness HPV Vaccine KidsHealth > For Teens > HPV Vaccine A A A ... starting at age 9. continue How Does the Vaccine Work? The HPV vaccine is approved for people ...

  3. Occurrence of Autoimmune Diseases Related to the Vaccine against Yellow Fever

    PubMed Central

    Oliveira, Ana Cristina Vanderley; Maria Henrique da Mota, Licia; dos Santos-Neto, Leopoldo Luiz; De Carvalho, Jozélio Freire; Caldas, Iramaya Rodrigues; Martins Filho, Olindo Assis; Tauil, Pedro Luis

    2014-01-01

    Yellow fever is an infectious disease, endemic in South America and Africa. This is a potentially serious illness, with lethality between 5 and 40% of cases. The most effective preventive vaccine is constituted by the attenuated virus strain 17D, developed in 1937. It is considered safe and effective, conferring protection in more than 90% in 10 years. Adverse effects are known as mild reactions (allergies, transaminases transient elevation, fever, headache) and severe (visceral and neurotropic disease related to vaccine). However, little is known about its potential to induce autoimmune responses. This systematic review aims to identify the occurrence of autoinflammatory diseases related to 17D vaccine administration. Six studies were identified describing 13 possible cases. The diseases were Guillain-Barré syndrome, multiple sclerosis, multiple points evanescent syndrome, acute disseminated encephalomyelitis, autoimmune hepatitis, and Kawasaki disease. The data suggest that 17D vaccination may play a role in the mechanism of loss of self-tolerance. PMID:25405025

  4. 17 CFR 270.17d-1 - Applications regarding joint enterprises or arrangements and certain profit-sharing plans.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Applications regarding joint... Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.17d-1 Applications regarding joint enterprises or arrangements and certain...

  5. 75 FR 25004 - Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Order Approving and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-06

    ... ISE and FINRA. Accordingly, the proposed Plan promotes efficiency by reducing costs to Ballista... ``Inbound Router Member.'' Under the 17d-2 Plan, ISE would retain full responsibility for surveillance... member that acts as an inbound router for ISE and is a member of both ISE and FINRA (``Inbound...

  6. 75 FR 57998 - Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Notice of Filing of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-23

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE... Authority, Inc. and BATS-Y Exchange, Inc. September 17, 2010. Pursuant to Section 17(d) of the Securities...'') (together with BYX, the ``Parties'') filed with the Securities and Exchange Commission (``Commission''...

  7. 78 FR 46656 - Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Notice of Filing of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-01

    ... Authority, Inc. and Topaz Exchange, LLC July 26, 2013. Pursuant to Section 17(d) of the Securities Exchange..., Topaz Exchange, LLC (``Topaz'') and the Financial Industry Regulatory Authority, Inc. (``FINRA'') (together with Topaz, the ``Parties'') filed with the Securities and Exchange Commission (``Commission''...

  8. Synthesis of β-NaYF4: Yb3+, Tm3+ @ TiO2 and β-NaYF4: Yb3+, Tm3+ @ TiO2 @ Au nanocomposites and effective upconversion-driven photocatalytic properties

    NASA Astrophysics Data System (ADS)

    Duo, Shuwang; Zhang, JieJun; Zhang, Hao; Chen, Zhong; Zhong, Cuiping; Liu, Tingzhi

    2016-12-01

    The β-NaYF4: Yb3+, Tm3+ @ TiO2 nanocomposite has been prepared by a facile hydrothermal method followed by the hydrolysis of TBOT, and then NaYF4: Yb3+, Tm3+ @ TiO2, HAuCl4 and sodium citrate were put into an oil bath for reaction to obtain the β-NaYF4: Yb3+, Tm3+ @ TiO2 @ Au core-shell nanocomposite. XRD and HRTEM show that the samples exhibit the hexagonal phase NaYF4, anatase TiO2 and cubic Au, indicating that the core-shell phases of NaYF4-TiO2 or NaYF4-TiO2-Au coexist in these samples. EDS and XPS results show the presence of Na, Y, F, Ti, O and Au elements. When TiO2 was coated on the surface of upconversion nanomaterials of NaYF4: Yb3+, Tm3+, the photocatalytic activity was improved significantly, and the β-NaYF4: Yb3+, Tm3+ @ TiO2 nanocomposite gives the highest photodegradation efficiency for MB and RhB, and decomposes about 73% of MB or 80% of RhB within 4.5 h under simulated solar light irradiation respectively. When the ultraviolet light from simulated sunlight irradiation was removed by the addition of a UV filter, the β-NaYF4: Yb3+, Tm3+ @ TiO2 nanocomposite decomposes about 42% of MB or 48% of RhB within 4.5 h. It means that the upconversion-driven photocatalytic performance (decomposes 42% of MB or 48% of RhB) is more effective than UV light-driven photocatalytic performance (31% of MB or 32% of RhB) in the photodegradation process. In addition, the β-NaYF4: Yb3+, Tm3+ @ TiO2 @ Au core-shell nanocomposite does not exhibit the better photocatalytic activity, and the optimal research will be carried out in the future.

  9. Biotransformation of 2,3,3,3-tetrafluoropropene (HFO-1234yf)

    SciTech Connect

    Schuster, Paul; Bertermann, Ruediger; Snow, Timothy A.; Han Xing; Rusch, George M.; Jepson, Gary W.; Dekant, Wolfgang

    2008-12-01

    2,3,3,3-Tetrafluoropropene (HFO-1234yf) is a non-ozone-depleting fluorocarbon replacement with a low global warming potential which has been developed as refrigerant. The biotransformation of HFO-1234yf was investigated after inhalation exposure. Male Sprague-Dawley rats were exposed to air containing 2000, 10,000, or 50,000 ppm HFO-1234yf for 6 h and male B6C3F1 mice were exposed to 50,000 ppm HFO-1234yf for 3.5 h in a dynamic exposure chamber (n = 5/concentration). After the end of the exposure, animals were individually housed in metabolic cages and urines were collected at 6 or 12-hour intervals for 48 h. For metabolite identification, urine samples were analyzed by {sup 1}H-coupled and decoupled {sup 19}F-NMR and by LC/MS-MS or GC/MS. Metabolites were identified by {sup 19}F-NMR chemical shifts, signal multiplicity, {sup 1}H-{sup 19}F coupling constants and by comparison with synthetic reference compounds. In all urine samples, the predominant metabolites were two diastereomers of N-acetyl-S-(3,3,3-trifluoro-2-hydroxy-propyl)-L-cysteine. In {sup 19}F-NMR, the signal intensity of these metabolites represented more than 85% (50,000 ppm) of total {sup 19}F related signals in the urine samples. Trifluoroacetic acid, 3,3,3-trifluorolactic acid, 3,3,3-trifluoro-1-hydroxyacetone, 3,3,3-trifluoroacetone and 3,3,3-trifluoro-1,2-dihydroxypropane were present as minor metabolites. Quantification of N-acetyl-S-(3,3,3-trifluoro-2-hydroxy-propyl)-L-cysteine by LC/MS-MS showed that most of this metabolite (90%) was excreted within 18 h after the end of exposure (t{sub 1/2} app. 6 h). In rats, the recovery of N-acetyl-S-(3,3,3-trifluoro-2-hydroxy-propyl)-L-cysteine excreted within 48 h in urine was determined as 0.30 {+-} 0.03, 0.63 {+-} 0.16, and 2.43 {+-} 0.86 {mu}mol at 2000, 10,000 and 50,000 ppm, respectively suggesting only a low extent (<< 1% of dose received) of biotransformation of HFO-1234yf. In mice, the recovery of this metabolite was 1.774 {+-} 0.4 {mu

  10. Flight and analytical investigations of a structural mode excitation system on the YF-12A airplane

    NASA Technical Reports Server (NTRS)

    Goforth, E. A.; Murphy, R. C.; Beranek, J. A.; Davis, R. A.

    1987-01-01

    A structural excitation system, using an oscillating canard vane to generate force, was mounted on the forebody of the YF-12A airplane. The canard vane was used to excite the airframe structural modes during flight in the subsonic, transonic, and supersonic regimes. Structural modal responses generated by the canard vane forces were measured at the flight test conditions by airframe-mounted accelerometers. Correlations of analytical and experimental aeroelastic results were made. Doublet lattice, steady state double lattice with uniform lag, Mach box, and piston theory all produced acceptable analytical aerodynamic results within the restrictions that apply to each. In general, the aerodynamic theory methods, carefully applied, were found to predict the dynamic behavior of the YF-12A aircraft adequately.

  11. Mathematical study of the thermoluminescence process in K2YF5:Tb(3+).

    PubMed

    Kadari, Ahmed; Mostefa, Rabah; Marcazzó, Julián; Kadri, Dahane

    2015-12-01

    This paper presents results of studying the simulated thermoluminescence (TL) glow curve in potassium-yttrium double fluoride doped with trivalent optically active Tb(3+) ions (K2YF5:Tb(3+)). Samples have been irradiated with different doses (0.24, 2.4 and 24 Gy) of beta particles. Four trapping states and one kind of recombination-centre model have been used in this simulation. The activation energy and order of kinetics are determined using the general-order kinetic model. The results obtained using the authors' proposed models were tested and compared with the experimental glow curve of K2YF5:Tb(3+). The comparison has shown that the proposed model can predict more accurately and easily the behaviour of the TL glow curve at three different doses.

  12. Biotransformation of 2,3,3,3-tetrafluoropropene (HFO-1234yf).

    PubMed

    Schuster, Paul; Bertermann, Rüdiger; Snow, Timothy A; Han, Xing; Rusch, George M; Jepson, Gary W; Dekant, Wolfgang

    2008-12-01

    2,3,3,3-Tetrafluoropropene (HFO-1234yf) is a non-ozone-depleting fluorocarbon replacement with a low global warming potential which has been developed as refrigerant. The biotransformation of HFO-1234yf was investigated after inhalation exposure. Male Sprague-Dawley rats were exposed to air containing 2000, 10,000, or 50,000 ppm HFO-1234yf for 6 h and male B6C3F1 mice were exposed to 50,000 ppm HFO-1234yf for 3.5 h in a dynamic exposure chamber (n=5/concentration). After the end of the exposure, animals were individually housed in metabolic cages and urines were collected at 6 or 12-hour intervals for 48 h. For metabolite identification, urine samples were analyzed by (1)H-coupled and decoupled (19)F-NMR and by LC/MS-MS or GC/MS. Metabolites were identified by (19)F-NMR chemical shifts, signal multiplicity, (1)H-(19)F coupling constants and by comparison with synthetic reference compounds. In all urine samples, the predominant metabolites were two diastereomers of N-acetyl-S-(3,3,3-trifluoro-2-hydroxy-propyl)-l-cysteine. In (19)F-NMR, the signal intensity of these metabolites represented more than 85% (50,000 ppm) of total (19)F related signals in the urine samples. Trifluoroacetic acid, 3,3,3-trifluorolactic acid, 3,3,3-trifluoro-1-hydroxyacetone, 3,3,3-trifluoroacetone and 3,3,3-trifluoro-1,2-dihydroxypropane were present as minor metabolites. Quantification of N-acetyl-S-(3,3,3-trifluoro-2-hydroxy-propyl)-l-cysteine by LC/MS-MS showed that most of this metabolite (90%) was excreted within 18 h after the end of exposure (t(1/2) app. 6 h). In rats, the recovery of N-acetyl-S-(3,3,3-trifluoro-2-hydroxy-propyl)-l-cysteine excreted within 48 h in urine was determined as 0.30+/-0.03, 0.63+/-0.16, and 2.43+/-0.86 micromol at 2000, 10,000 and 50,000 ppm, respectively suggesting only a low extent (<1% of dose received) of biotransformation of HFO-1234yf. In mice, the recovery of this metabolite was 1.774+/-0.4 mumol. Metabolites identified after in vitro incubations of

  13. High-resolution spectra of LiYF4:Ho3+ in a magnetic field

    NASA Astrophysics Data System (ADS)

    Popova, M. N.; Boldyrev, K. N.

    2017-01-01

    We report on the first high-resolution optical spectroscopy study of LiYF4:Ho in an external magnetic field. Peculiarities in the hyperfine structure of holmium spectral lines are discussed for the cases H||c and H⊥c (H = 0.53 and 0.87 T). The spectra reveal a strong interaction between crystal-field levels, mediated by Zeeman and hyperfine terms in the Hamiltonian. A study of the magnetic-field-dependent isotope shifts in 7Li0.16Li0.9YF4:Ho (0.1 at.%) single crystals delivers an estimate of the difference in magnetic g factors for holmium centers with all 6Li isotopes in the nearest surrounding of Ho3+ (g(0)) and the centers having one 7Li isotope there (g(1)):g(1) - g(0) = 0.01 ± 0.005.

  14. A Strategy to enhance Eu3+ emission from LiYF4:Eu nanophosphors and green-to-orange multicolor tunable, transparent nanophosphor-polymer composites.

    PubMed

    Kim, Su Yeon; Won, Yu-Ho; Jang, Ho Seong

    2015-01-19

    LiYF4:Eu nanophosphors with a single tetragonal phase are synthesized, and various strategies to enhance the Eu(3+) emission from the nanophosphors are investigated. The optimized Eu(3+) concentration is 35 mol%, and the red emission peaks due to the (5)D0 →(7)FJ (J = 1 and 2) transitions of Eu(3+) ions are further enhanced by energy transfer from a sensitizer pair of Ce(3+) and Tb(3+). The triple doping of Ce, Tb, and Eu into the LiYF4 host more effectively enhances the Eu(3+) emission than the core/shell strategies of LiYF4:Eu(35%)/LiYF4:Ce(15%), Tb(15%) and LiYF4:Ce(15%), Tb(15%)/LiYF4:Eu(35%) architectures. Efficient energy transfer from Ce(3+) to Eu(3+) through Tb(3+) results in three times higher Eu(3+) emission intensity from LiYF4:Ce(15%), Tb(15%), Eu(1%) nanophosphors compared with LiYF4:Eu(35%), which contains the optimized Eu(3+) concentration. Owing to the energy transfer of Ce(3+) → Tb(3+) and Ce(3+) → Tb(3+) → Eu(3+), intense green and red emission peaks are observed from LiYF4:Ce(13%), Tb(14%), Eu(1-5%) (LiYF4:Ce, Tb, Eu) nanophosphors, and the intensity ratio of green to red emission is controlled by adjusting the Eu(3+) concentration. With increasing Eu(3+) concentration, the LiYF4:Ce, Tb, Eu nanophosphors exhibit multicolor emission from green to orange. In addition, the successful incorporation of LiYF4:Ce, Tb, Eu nanophosphors into polydimethylsiloxane (PDMS) facilitates the preparation of highly transparent nanophosphor-PDMS composites that present excellent multicolor tunability.

  15. A Strategy to enhance Eu3+ emission from LiYF4:Eu nanophosphors and green-to-orange multicolor tunable, transparent nanophosphor-polymer composites

    NASA Astrophysics Data System (ADS)

    Kim, Su Yeon; Won, Yu-Ho; Jang, Ho Seong

    2015-01-01

    LiYF4:Eu nanophosphors with a single tetragonal phase are synthesized, and various strategies to enhance the Eu3+ emission from the nanophosphors are investigated. The optimized Eu3+ concentration is 35 mol%, and the red emission peaks due to the 5D0 -->7FJ (J = 1 and 2) transitions of Eu3+ ions are further enhanced by energy transfer from a sensitizer pair of Ce3+ and Tb3+. The triple doping of Ce, Tb, and Eu into the LiYF4 host more effectively enhances the Eu3+ emission than the core/shell strategies of LiYF4:Eu(35%)/LiYF4:Ce(15%), Tb(15%) and LiYF4:Ce(15%), Tb(15%)/LiYF4:Eu(35%) architectures. Efficient energy transfer from Ce3+ to Eu3+ through Tb3+ results in three times higher Eu3+ emission intensity from LiYF4:Ce(15%), Tb(15%), Eu(1%) nanophosphors compared with LiYF4:Eu(35%), which contains the optimized Eu3+ concentration. Owing to the energy transfer of Ce3+ --> Tb3+ and Ce3+ --> Tb3+ --> Eu3+, intense green and red emission peaks are observed from LiYF4:Ce(13%), Tb(14%), Eu(1-5%) (LiYF4:Ce, Tb, Eu) nanophosphors, and the intensity ratio of green to red emission is controlled by adjusting the Eu3+ concentration. With increasing Eu3+ concentration, the LiYF4:Ce, Tb, Eu nanophosphors exhibit multicolor emission from green to orange. In addition, the successful incorporation of LiYF4:Ce, Tb, Eu nanophosphors into polydimethylsiloxane (PDMS) facilitates the preparation of highly transparent nanophosphor-PDMS composites that present excellent multicolor tunability.

  16. YF-12 cooperative airframe/propulsion control system program, volume 1

    NASA Technical Reports Server (NTRS)

    Anderson, D. L.; Connolly, G. F.; Mauro, F. M.; Reukauf, P. J.; Marks, R. (Editor)

    1980-01-01

    Several YF-12C airplane analog control systems were converted to a digital system. Included were the air data computer, autopilot, inlet control system, and autothrottle systems. This conversion was performed to allow assessment of digital technology applications to supersonic cruise aircraft. The digital system was composed of a digital computer and specialized interface unit. A large scale mathematical simulation of the airplane was used for integration testing and software checkout.

  17. Physiologic and anti-G suit performance data from YF-16 flight tests

    NASA Technical Reports Server (NTRS)

    Gillingham, K. K.; Winter, W. R.

    1976-01-01

    Biomedical data were collected during high-G portions of 11 YF-16 test flights. Test pilots monitored revealed increased respiratory rate and volume, decreased tidal volume, and increased heart rate at higher G levels, with one pilot exhibiting various cardiac arrhythmias. Anti-G suit inflation and pressurization lags varied inversely with G-onset rate, and suit pressurization slope was near the design value.

  18. YF 102 in-duct combustor noise measurements with a turbine nozzle, volume 1

    NASA Technical Reports Server (NTRS)

    Wilson, C. A.; Oconnell, J. M.

    1981-01-01

    The internal noise generated by an Avco Lycoming YF-102 engine combustor installed in a test rig was recorded. Two configurations were tested one with and one without the first stage turbine nozzle installed. Acoustic probes and accessories were used. Internal dynamic pressure level measurements were made at ten locations within the combustor. The combustor rig, the test procedures, and data acquisition and reduction systems are described. Tables and plots of narrow band and one third octave band pressure level spectra are included.

  19. Metastable NaYF 4 fluorite at high pressures and high temperatures

    NASA Astrophysics Data System (ADS)

    Grzechnik, Andrzej; Bouvier, Pierre; Crichton, Wilson A.; Farina, Luca; Köhler, Jürgen

    2002-06-01

    High-pressure high-temperature behavior of metastable NaYF 4 fluorite (Fm 3¯m, Z=4), with the Na and Y atoms randomly distributed in the cationic sublattice, is studied with synchrotron angle-dispersive powder X-ray diffraction in diamond anvil (DAC) and large-volume Paris-Edinburgh cells and synthesis in a multi-anvil apparatus. The onset of a pressure-induced phase transition at room temperature takes place above 10 GPa as observed in DACs loaded with different hydrostatic and non-hydrostatic pressure media (nitrogen, paraffin oil, or ethanol:methanol media). In situ powder X-ray diffraction measurements in the Paris-Edinburgh cell and syntheses using the multi-anvil apparatus at high pressures and high temperatures show that the new polymorph is of the gagarinite-type (P6 3/m, Z=1) with partially ordered cations, the formula being Na 1.5Y 1.5F 6. This phase is structurally related to the Na 1.5Y 1.5F 6 modification (P 6¯, Z=1) stable at ambient conditions. At higher temperatures, the new pressure-induced hexagonal variant of NaYF 4 eventually decomposes into a non-stoichiometric gagarinite-like phase and yttrium fluoride YF 3 (Pnma, Z=4).

  20. Enhancement of the up-conversion luminescence from NaYF4:Yb3+,Tb3+

    NASA Astrophysics Data System (ADS)

    Hölsä, Jorma; Laihinen, Tero; Laamanen, Taneli; Lastusaari, Mika; Pihlgren, Laura; Rodrigues, Lucas C. V.; Soukka, Tero

    2014-04-01

    The synthesis conditions of the Yb3+ and Tb3+ co-doped NaYF4 were optimized by reducing the number of washings to include only ethanol. The avoidance of the loss of amorphous NaF prior to post-annealing of the as-prepared materials resulted in the enhancement of the otherwise rather weak up-conversion from Tb3+ by 1-2 orders of magnitude. At the same time, the temperature of formation of the hexagonal NaRF4 phase with high up-conversion could be lowered by 100 °C down to 350 °C. This improvement in up-conversion was concluded to result from the better stoichiometry of the material without washing with water. The deficit of Na+ would result in the excess of fluoride which, although not as fatal to the luminescence as the fluoride vacancies, has serious implications to the up-conversion intensity. A further enhancement in the up-conversion luminescence was observed to be due to the Er3+ ion impurity frequently associated with high-concentration Yb3+ materials. The mechanism involving the unintentional Er3+ sensitizer and the resonance energy transfer in the Yb3+-Er3+-Tb3+ co-doped NaYF4 were discussed based on the energy level schemes of the Yb3+, Er3+, and Tb3+ ions in NaYF4.

  1. Synthesis and characterization of α-NaYF4: Yb, Er nanoparticles by reverse microemulsion method

    NASA Astrophysics Data System (ADS)

    Gunaseelan, M.; Senthilselvan, J.

    2016-05-01

    A simple and cost effective reverse microemulsion system was newly designed to synthesis NaYF4:20%Yb,2%Er upconverting luminescent nanoparticles. XRD results confirms the cubic structure of NaYF4 nanophosphor in the as prepared condition without any other impurity phases. The as-prepared sample itself having highly crystalline nanoparticle with well dispersed uniform morphology is the advantage of this reverse microemulsion process. HRTEM images of as prepared and calcined samples revealed spherical nanoclusters morphology with size of ~210 nm and ~245 nm respectively. The characteristic absorption wavelength that occurs at 980 nm due to transition of energy levels 2F5/2 to 2F7/2 for Yb3+ rare earth ion in as prepared and calcined upconversion nanoparticle confirms the presence of Yb3+ by UV-Visible spectroscopy which can act as a sensitizer for photonic upconversion. Therefore the absorption at NIR region and emission spectrum at visible region suggests that NaYF4:20%Yb,2%Er is suitable for upcoversion process, due to its optical property and chemical stability this material also be useful for bio imaging applications.

  2. Vaccine hesitancy

    PubMed Central

    Dubé, Eve; Laberge, Caroline; Guay, Maryse; Bramadat, Paul; Roy, Réal; Bettinger, Julie A.

    2013-01-01

    Despite being recognized as one of the most successful public health measures, vaccination is perceived as unsafe and unnecessary by a growing number of individuals. Lack of confidence in vaccines is now considered a threat to the success of vaccination programs. Vaccine hesitancy is believed to be responsible for decreasing vaccine coverage and an increasing risk of vaccine-preventable disease outbreaks and epidemics. This review provides an overview of the phenomenon of vaccine hesitancy. First, we will characterize vaccine hesitancy and suggest the possible causes of the apparent increase in vaccine hesitancy in the developed world. Then we will look at determinants of individual decision-making about vaccination. PMID:23584253

  3. Inactivation of mouse liver glutathione S-transferase YfYf (Pi class) by ethacrynic acid and 5,5'-dithiobis-(2-nitrobenzoic acid).

    PubMed Central

    Phillips, M F; Mantle, T J

    1993-01-01

    Mouse liver glutathione S-transferase YfYf (Pi class) reacts with [14C]ethacrynic acid to form a covalent adduct with a stoichiometry of 1 mol per mol of subunit. Proteolytic digestion of the enzyme-[14C]ethacrynic acid adduct with V8 protease produced an 11 kDa fragment containing radioactivity. Sequencing revealed this to be an N-terminal peptide (minus the first 15 residues, terminating at Glu-112) which contains only one cysteine residue (Cys-47). This is tentatively identified as the site of ethacrynic attachment. Kinetic studies reveal that glutathione S-conjugates protect against inactivation by ethacrynic acid, but the level of protection is not consistent with their potency as product inhibitors. A model is proposed in which glutathione S-conjugates and ethacrynic acid compete for the free enzyme, and a second molecule of ethacrynic acid reacts covalently with the enzyme-ethacrynic acid complex. The native protein contains one thiol reactive with 5,5'-dithiobis-(2-nitrobenzoic acid) at neutral pH. The resultant mixed disulphide, like the ethacrynic acid adduct, is inactive, but treatment with cyanide (which incorporates on a mol for mol basis) restores activity to 35% of that of the native enzyme. Images Figure 4 PMID:8363586

  4. A Meta-Analysis of Serological Response Associated with Yellow Fever Vaccination

    PubMed Central

    Jean, Kévin; Donnelly, Christl A.; Ferguson, Neil M.; Garske, Tini

    2016-01-01

    Despite previous evidence of high level of efficacy, no synthetic metric of yellow fever (YF) vaccine efficacy is currently available. Based on the studies identified in a recent systematic review, we conducted a random-effects meta-analysis of the serological response associated with YF vaccination. Eleven studies conducted between 1965 and 2011 representing 4,868 individual observations were included in the meta-analysis. The pooled estimate of serological response was 97.5% (95% confidence interval [CI] = 82.9–99.7%). There was evidence of between-study heterogeneity (I2 = 89.1%), but this heterogeneity did not appear to be related to study size, study design, or seroconversion measurement or definition. Pooled estimates were significantly higher (P < 0.0001) among studies conducted in nonendemic settings (98.9%, 95% CI = 98.2–99.4%) than among those conducted in endemic settings (94.2%, 95% CI = 83.8–98.1%). These results provide background information against which to evaluate the efficacy of fractional doses of YF vaccine that may be used in outbreak situations. PMID:27928091

  5. 3D assembly of upconverting NaYF4 nanocrystals by AFM nanoxerography: creation of anti-counterfeiting microtags

    NASA Astrophysics Data System (ADS)

    Sangeetha, Neralagatta M.; Moutet, Pierre; Lagarde, Delphine; Sallen, Gregory; Urbaszek, Bernhard; Marie, Xavier; Viau, Guillaume; Ressier, Laurence

    2013-09-01

    Formation of 3D close-packed assemblies of upconverting NaYF4 colloidal nanocrystals (NCs) on surfaces, by Atomic Force Microscopy (AFM) nanoxerography is presented. The surface potential of the charge patterns, the NC concentration, the polarizability of the NCs and the polarity of the dispersing solvent are identified as the key parameters controlling the assembly of NaYF4 NCs into micropatterns of the desired 3D architecture. This insight allowed us to fabricate micrometer sized Quick Response (QR) codes encoded in terms of upconversion luminescence intensity or color. Topographically hidden messages could also be readily incorporated within these microtags. This work demonstrates that AFM nanoxerography has enormous potential for generating high-security anti-counterfeiting microtags.Formation of 3D close-packed assemblies of upconverting NaYF4 colloidal nanocrystals (NCs) on surfaces, by Atomic Force Microscopy (AFM) nanoxerography is presented. The surface potential of the charge patterns, the NC concentration, the polarizability of the NCs and the polarity of the dispersing solvent are identified as the key parameters controlling the assembly of NaYF4 NCs into micropatterns of the desired 3D architecture. This insight allowed us to fabricate micrometer sized Quick Response (QR) codes encoded in terms of upconversion luminescence intensity or color. Topographically hidden messages could also be readily incorporated within these microtags. This work demonstrates that AFM nanoxerography has enormous potential for generating high-security anti-counterfeiting microtags. Electronic supplementary information (ESI) available: Detailed experimental procedures for the synthesis of upconverting NaYF4 nanocrystals and their transmission electron microscopy images. KFM and AFM images corresponding to the assembly of positively charged β-NaYF4:Er3+,Yb3+ nanocrystals from water suspensions by AFM nanoxerography. Photoluminescence spectra of β-NaYF4:Er3+,Yb3+ nanocrystals

  6. [Travelers' vaccines].

    PubMed

    Ouchi, Kazunobu

    2011-09-01

    The number of Japanese oversea travelers has gradually increased year by year, however they usually pay less attention to the poor physical condition at the voyage place. Many oversea travelers caught vaccine preventable diseases in developing countries. The Vaccine Guideline for Oversea Travelers 2010 published by Japanese Society of Travel Health will be helpful for spreading the knowledge of travelers' vaccine and vaccine preventable diseases in developing countries. Many travelers' vaccines have not licensed in Japan. I hope these travelers' vaccines, such as typhoid vaccine, meningococcal vaccine, cholera vaccine and so on will be licensed in the near future.

  7. Leptospirosis vaccines

    PubMed Central

    Wang, Zhijun; Jin, Li; Węgrzyn, Alicja

    2007-01-01

    Leptospirosis is a serious infection disease caused by pathogenic strains of the Leptospira spirochetes, which affects not only humans but also animals. It has long been expected to find an effective vaccine to prevent leptospirosis through immunization of high risk humans or animals. Although some leptospirosis vaccines have been obtained, the vaccination is relatively unsuccessful in clinical application despite decades of research and millions of dollars spent. In this review, the recent advancements of recombinant outer membrane protein (OMP) vaccines, lipopolysaccharide (LPS) vaccines, inactivated vaccines, attenuated vaccines and DNA vaccines against leptospirosis are reviewed. A comparison of these vaccines may lead to development of new potential methods to combat leptospirosis and facilitate the leptospirosis vaccine research. Moreover, a vaccine ontology database was built for the scientists working on the leptospirosis vaccines as a starting tool. PMID:18072968

  8. Preparation and characterization of upconversion luminescent NaYF4:Yb, Er (Tm)/PS bulk transparent nanocomposites through in situ polymerization.

    PubMed

    Chai, Ruitao; Lian, Hongzhou; Cheng, Ziyong; Zhang, Cuimiao; Hou, Zhiyao; Xu, Zhenhe; Lin, Jun

    2010-05-15

    The in situ polymerization method was applied to synthesize bulk nanocomposites consisting of hydrophobic NaYF(4):Yb, Er (Tm) nanoparticles as the filler and polystyrene (PS) as the host material. The oleic acid stabilized NaYF(4):Yb, Er (Tm) nanoparticles and NaYF(4):Yb, Er (Tm)/PS nanocomposites have been well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), the thermogravimetric analysis (TGA), upconversion photoluminescence spectra and luminescence decays. The well-crystallized NaYF(4):Yb, Er (Tm) nanoparticles are spherical with a mean diameter of 40 nm. NaYF(4):Yb, Er/PS and NaYF(4):Yb, Tm/PS nanocomposites exhibit strong green and blue upconversion photoluminescence upon 980 nm laser excitation, due to the integration of luminescent NaYF(4):Yb, Er and NaYF(4):Yb, Tm nanoparticles, respectively. These nanocomposites can be potentially used as 3D display materials.

  9. Vaccine Hesitancy.

    PubMed

    Jacobson, Robert M; St Sauver, Jennifer L; Finney Rutten, Lila J

    2015-11-01

    Vaccine refusal received a lot of press with the 2015 Disneyland measles outbreak, but vaccine refusal is only a fraction of a much larger problem of vaccine delay and hesitancy. Opposition to vaccination dates back to the 1800 s, Edward Jenner, and the first vaccine ever. It has never gone away despite the public's growing scientific sophistication. A variety of factors contribute to modern vaccine hesitancy, including the layperson's heuristic thinking when it comes to balancing risks and benefits as well as a number of other features of vaccination, including falling victim to its own success. Vaccine hesitancy is pervasive, affecting a quarter to a third of US parents. Clinicians report that they routinely receive requests to delay vaccines and that they routinely acquiesce. Vaccine rates vary by state and locale and by specific vaccine, and vaccine hesitancy results in personal risk and in the failure to achieve or sustain herd immunity to protect others who have contraindications to the vaccine or fail to generate immunity to the vaccine. Clinicians should adopt a variety of practices to combat vaccine hesitancy, including a variety of population health management approaches that go beyond the usual call to educate patients, clinicians, and the public. Strategies include using every visit to vaccinate, the creation of standing orders or nursing protocols to provide vaccination without clinical encounters, and adopting the practice of stating clear recommendations. Up-to-date, trusted resources exist to support clinicians' efforts in adopting these approaches to reduce vaccine hesitancy and its impact.

  10. Half opened microtubes of NaYF 4:Yb,Er synthesized in reverse microemulsion under solvothermal condition

    NASA Astrophysics Data System (ADS)

    Huang, Yeju; You, Hongpeng; Song, Yanhua; Jia, Guang; Yang, Mei; Zheng, Yuhua; Zhang, Lihui; Liu, Kai

    2010-10-01

    NaYF 4:Yb,Er micro/nanocrystals with different sizes and morphologies such as nanospheres, short flexural nanorods, and half opened microtubes, were synthesized in reverse microemulsion under solvothermal condition using the quaternary reverse microemulsion system, CTAB/1-butanol/cyclohexane/aqueous solution. The X-ray diffraction analysis confirmed that cubic phase NaYF 4:Yb,Er can completely transform to hexagonal phase with increasing reaction time. The scanning electron microscope and transmission electron microscope images revealed that the morphology of the product can be tailored by varying the reaction time. A possible crystalline growth process of the NaYF 4:Yb,Er micro/nanocrystals was discussed. The obtained half opened microtubes exhibited an intense green upconversion luminescence, which may be attractive in novel optoelectronic devices.

  11. MOLTEN SALT SYNTHESIS OF YF3:Yb3+/Ln3+(Ln = Er3+, Tm3+) MICROSHEETS WITH MULTICOLOR UPCONVERSION LUMINESCENCE

    NASA Astrophysics Data System (ADS)

    Ding, Mingye; Lu, Chunhua; Cao, Linhai; Ni, Yaru; Xu, Zhongzi

    2013-09-01

    In this paper, highly crystalline YF3:Yb3+/Ln3+(Ln = Er3+, Tm3+) microsheets were successfully synthesized by a surfactant-free molten salt method for the first time. The results indicated that the as-obtained samples belonged to orthorhombic system and exhibited microsheets morphology with side lengths of 30 to 80 μm and wall thickness from 1 to 1.5 μm. By changing the dopant's species (Ln3+), multicolor (yellow and blue) upconversion emission can be observed in YF3:Yb3+/Ln3+ microsheets under 980 nm laser diode (LD) excitation. The upconversion mechanisms in co-doping YF3 samples were analyzed in detail based on the emission spectra. Importantly, this approach not only proposes a new alternative in synthesizing such materials, but also opens the possibility to meet the increasing commercial demand.

  12. Hydrothermal synthesis and the enhanced blue upconversion luminescence of NaYF 4:Nd 3+,Tm 3+,Yb 3+

    NASA Astrophysics Data System (ADS)

    Sun, Jiayue; Zhang, Weihang; Du, Haiyan; Yang, Zhiping

    2010-09-01

    Nd 3+, Tm 3+ and Yb 3+ co-doped NaYF 4 upconversion (UC) material was synthesized by the hydrothermal method. The structure of the sample was characterized by the X-ray diffraction, and its UC luminescence properties were investigated in detail. Under the 980 nm semiconductor laser excitation, its UC spectra exhibited distinct emission peaks at 451 nm, 475 nm and 646 nm respectively. On the basis of the comparison of UC spectra between NaYF 4:Nd 3+,Tm 3+,Yb 3+ and NaYF 4:Tm 3+,Yb 3+, it was indicated that the existence of Nd 3+ ion enhanced the blue emission intensity. The law of luminescence intensity versus pump power proved that the blue emission at 475 nm, and the red emission at 646 nm were the two-photon processes, while the blue emission at 451 nm was a three-photon process.

  13. Yellow fever vaccination in the Americas.

    PubMed

    1984-01-01

    Outbreaks of yellow fever in recent years in the Americas have prompted concern about the possible urbanization of jungle fever. Vaccination, using the 17D strain of yellow fever virus, provides an effective, practical method of large scale protection against the disease. Because yellow fever can reappear in certain areas after a 2-year dormancy period, some countries maintain routine vaccination programs in areas where jungle yellow fever is endemic. The size of the endemic area (approximately half of South America), transportation and communication difficulties, and the inability to ensure a reliable cold chain are problems facing these programs. In addition, the problem of reaching dispersed and isolated populations has been addressed by the use of mobile teams, radio monitoring, and educational methods. During yellow fever outbreaks, many countries institute massive vaccination campaigns, targeted at temporary workers and migrants. Because epidemics in South America may involve extensive areas, these campaigns may not effectively address the problem. The ped-o-jet injector method, used in Brazil and Colombia, should be used in outbreak situations, as it is effective for large-scale vaccination. Vaccine by needle, suggested for maintenance programs, should be administered to those above 1 year of age. An efficient monitoring method to avoid revaccination, and to assess immunity, should be developed. The 17D strain produces seroconversion in 95% of recipients, and most is prepared in Brazil and Colombia. But, problems with storage methods, instability in seed lots, and difficulties in large-scale production were identified in 1981 by the Pan American Health Organization and WHO. The group recommended modernization of current production techniques and further research to develop a vaccine that could be produced in cell cultures. Brazil and Colombia have acted on these recommendations, modernizing vaccine production and researching thermostabilizing media for

  14. UVC upconversion material under sunlight excitation: LiYF(4): Pr(3+).

    PubMed

    Wu, Jianhong; Zheng, Haolin; Liu, Xinghua; Han, Boning; Wei, Jun; Yang, Yanmin

    2016-02-15

    UVC upconversion emission is observed in a LiYF4:Pr3+ microcrystal under sunlight excitation. The dependence of UVC UC emission intensity on the excitation density of a 488 nm laser and sunlight is investigated. The obtained data indicates that two-photon processes play an important role in UVC UC emission. The UVC UC mechanisms of Pr3+ under the excitation of a laser and sunlight are presented and discussed. The UVC emission under sunlight excitation has broad prospects for application.

  15. Status of a digital integrated propulsion/flight control system for the YF-12 airplane

    NASA Technical Reports Server (NTRS)

    Reukauf, P. J.; Burcham, F. W., Jr.; Holzman, J. K.

    1975-01-01

    The NASA Flight Research Center is engaged in a program with the YF-12 airplane to study the control of interactions between the airplane and the propulsion system. The existing analog air data computer, autothrottle, autopilot, and inlet control system are to be converted to digital systems by using a general purpose airborne computer and interface unit. First, the existing control laws will be programmed in the digital computer and flight tested. Then new control laws are to be derived from a dynamic propulsion model and a total force and moment aerodynamic model to integrate the systems. These control laws are to be verified in a real time simulation and flight tested.

  16. UPCONVERSION LUMINESCENCE ENHANCEMENT OF NaYF4:Yb3+, Er3+ NANOPARTICLES ON INVERSE OPAL SURFACE

    NASA Astrophysics Data System (ADS)

    Liao, Jiayan; Yang, Zhengwen; Wu, Hangjun; Lai, Shenfeng; Qiu, Jianbei; Song, Zhiguo; Yang, Yong; Zhou, Dacheng; Yin, Zhaoyi

    2014-01-01

    LaPO4 inverse opal photonic crystals with different photonic band gaps were fabricated by template-assisted method. The Yb3+/Er3+ co-doped NaYF4 nanoparticles were deposited on the surfaces of the inverse opals, and their up-conversion emission properties were investigated. The upconversion emissions of Yb3+/Er3+ co-doped NaYF4 nanoparticles on the inverse opal surfaces have been enhanced when the upconversion emission bands of the nanoparticles are in the range of photonic band gaps of the inverse opals, which is attributed to an efficient and selective reflection of photonic band gaps.

  17. Edible vaccines.

    PubMed

    Meloen, R H; Hamilton, W D; Casal, J I; Dalsgaard, K; Langeveld, J P

    1998-01-01

    The ultimate vaccine is an oral vaccine which given once protects against a multitude of diseases. Furthermore this ultimate vaccine needs to be very stable and inexpensive to produce. Probably this latter condition can be met only if the vaccines are produced in plants. Such vaccines are called 'edible vaccines'. Edible vaccines can be produced in plants in many ways. Using recombinant plantvirus, CPMV, it was shown that plants can produce massive amounts of chimaeric virus particles which protect after a single injection the target animal against disease. The final step, oral administration, is being addressed at present. Preliminary experiments by others suggest that this step may be solved sooner than expected.

  18. Case Study of R-1234yf Refrigerant: Implications for the Framework for Responsible Innovation.

    PubMed

    Wodzisz, Rafał

    2015-12-01

    Safety and care for the natural environment are two of the most important values that drive scientific enterprise in twentieth century. Researchers and innovators often develop new technologies aimed at pollution reduction, and therefore satisfy the strive for fulfilment of these values. This work is often incentivized by policy makers. According to EU directive 2006/40/EC on mobile air conditioning since 2013 all newly approved vehicles have to be filled with refrigerant with low global warming potential (GWP). Extensive and expensive research financed by leading car manufacturers led to invention of R-1234yf refrigerant with GWP < 1, which was huge improvement. For the proper understanding of this case it will be useful to refer it to the idea of responsible innovation (RI), which is now being developed and quickly attracts attention. I proceed in the following order. Firstly, I present the relevant properties of R-1234yf and discuss the controversy associated with its marketing. Secondly, I examine framework for responsible innovation. In greater detail I discuss the notions of care for future generations and collective responsibility. Thirdly, I apply the offered framework to the case study at hand. Finally, I draw some conclusions which go in two directions: one is to make some suggestions for improving the framework of RI, and the second is to identify missed opportunities for developing truly responsible refrigerant.

  19. Secretory expression of nattokinase from Bacillus subtilis YF38 in Escherichia coli.

    PubMed

    Liang, Xiaobo; Jia, Shifang; Sun, Yufang; Chen, Meiling; Chen, Xiuzhu; Zhong, Jin; Huan, Liandong

    2007-11-01

    Nattokinase producing bacterium, B. subtilis YF38, was isolated from douchi, using the fibrin plate method. The gene encoding this enzyme was cloned by polymerase chain reaction (PCR). Cytoplasmic expression of this enzyme in E. coli resulted in inactive inclusion bodies. But with the help of two different signal peptides, the native signal peptide of nattokinase and the signal peptide of PelB, active nattokinase was successfully expressed in E. coli with periplasmic secretion, and the nattokinase in culture medium displayed high fibrinolytic activity. The fibrinolytic activity of the expressed enzyme in the culture was determined to reach 260 urokinase units per micro-liter when the recombinant strain was induced by 0.7 mmol l(-1) isopropyl-beta-D- thiogalactopyranoside (IPTG) at 20 degrees C for 20 h, resulting 49.3 mg active enzyme per liter culture. The characteristic of this recombinant nattokinase is comparable to the native nattokinase from B. subtilis YF38. Secretory expression of nattokinase in E. coli would facilitate the development of this enzyme into a therapeutic product for the control and prevention of thrombosis diseases.

  20. A historical perspective of the YF-12A thermal loads and structures program

    NASA Technical Reports Server (NTRS)

    Jenkins, Jerald M.; Quinn, Robert D.

    1996-01-01

    Around 1970, the Y-F-12A loads and structures efforts focused on numerous technological issues that needed defining with regard to aircraft that incorporate hot structures in the design. Laboratory structural heating test technology with infrared systems was largely created during this program. The program demonstrated the ability to duplicate the complex flight temperatures of an advanced supersonic airplane in a ground-based laboratory. The ability to heat and load an advanced operational aircraft in a laboratory at high temperatures and return it to flight status without adverse effects was demonstrated. The technology associated with measuring loads with strain gages on a hot structure was demonstrated with a thermal calibration concept. The results demonstrated that the thermal stresses were significant although the airplane was designed to reduce thermal stresses. Considerable modeling detail was required to predict the heat transfer and the corresponding structural characteristics. The overall YF-12A research effort was particularly productive, and a great deal of flight, laboratory, test and computational data were produced and cross-correlated.

  1. Edible vaccines.

    PubMed

    Artnzen, C J

    1997-01-01

    Vaccines were the result of trial and error research until molecular biology and genetic engineering made possible the creation of of many new and improved vaccines. New vaccines need to be inexpensive, easily administered, and capable of being stored and transported without refrigeration; without these characteristics, developing countries find it difficult to adopt vaccination as the central strategy for preventing their most devastating diseases. The authors describe a promising approach to inexpensive and effective vaccines: producing them in plants we commonly consume.

  2. Vaccine safety.

    PubMed

    Jacobson, Robert M

    2003-11-01

    Rates of reported adverse events are remarkably low. VAERS identifies an adverse event rate approximating 11.4 reports per 100,000 vaccine doses. Approximately 15% of these reports represent SAEs, but less than 2% involve death; in most cases, reviews have shown no causal relation between the events and the vaccine. Across the spectrum of vaccines in use (including those directed against influenza and hepatitis B virus), many claims of adverse events regarding vaccines represent typical reactions to vaccinations. These reactions can be thought of as foreign-body reactions and predominate among the inactivated vaccines. In controlled studies, the adverse event rates that occur with vaccination resemble those that occur with placebo injections. Typical reactions associated with live viral and bacterial vaccines, such as MMR and varicella vaccines, may resemble attenuated forms of the disease for which the vaccine is directed. Other claims against vaccines represent chance-coincidence or misunderstood data; further studies of claims have vindicated the overall safety of the vaccines in most cases. Two documented safety concerns with vaccines, however, have demonstrated that vaccines (like other biologics and pharmacologic) can result in harm (eg, rotavirus and OPV vaccines). The denouement with these vaccines indicates the broad postmarketing data collection and evaluation that extends efforts made with prelicensure study to balance the benefits from vaccination with the risk for harm. Overall, measures including prelicensure study and postlicensure surveillance, such as VAERS, the Vaccine Safety Datalink Project, and the Clinical Immunization Safety Assessment Centers, have resulted in an exceptional safety profile for the vaccines in use.

  3. Mn(2+)-doped NaYF4:Yb/Er upconversion nanoparticle-based electrochemiluminescent aptasensor for bisphenol A.

    PubMed

    Guo, Xiaofei; Wu, Shijia; Duan, Nuo; Wang, Zhouping

    2016-05-01

    A novel aptasensor labeled with Mn(2+)-doped NaYF4:Yb/Er upconversion nanoparticles (NaYF4:Yb,Er/Mn UCNPs) was employed in electrogenerated chemiluminescence (ECL) for the sensitive detection of bisphenol A (BPA). The ECL aptasensor was assembled by immobilizing the thiolated aptamers of BPA covalently on a gold nanoparticle (AuNPs)-modified electrode and pairing with complementary DNA labeled with NaYF4:Yb,Er/Mn UCNPs. The ECL aptasensor can not only rapidly and accurately detect BPA concentrations from 0.05 to 100 ng/mL with a detection limit of 0.037 ng/mL but also provides a new platform for ECL applications based on the use of upconversion nanoparticles as a promising alternative material. Graphical Abstract The NaYF4:Yb,Er/Mn UCNPs combining with the BPA aptamer serving as recognition elements create a ECL platform for the sensitive detection of bisphenol A. The change in ECL signals induced by aptamer-target interactions was measured and a significant decrease in intensity was found on interaction with BPA in the concentration range of 0.05 to 100 ng/mL.

  4. Response to comment on "Environmental fate of the next generation refrigerant 2,3,3,3-tetrafluoropropene (HFO-1234yf)

    DOE PAGES

    Im, Jeongdae; Walshe-Langford, Gillian E.; Moon, Ji Won; ...

    2015-06-11

    In this study, refrigerant 2,3,3,3-tetrafluoropropene (HFO-1234yf) has been developed for use in mobile air conditioning systems to replace 1,1,1,2-tetrafluoroethane (HFC-134a), which has a much greater global warming potential.

  5. Synthesis and upconversion emission of rare earth-doped olive-like YF{sub 3} micro-particles

    SciTech Connect

    Lin, Hang; Chen, Daqin; Niu, Mutong; Yu, Yunlong; Huang, Ping; Wang, Yuansheng

    2010-01-15

    The olive-like YF{sub 3} micro-particles were fabricated via a two-step route. The precursor NH{sub 4}Y{sub 3}F{sub 10} nano-cages sized 8 nm with hollow interiors were first synthesized in a solid reaction at room temperature. In the course of subsequent hydrothermal treating, the unstable NH{sub 4}Y{sub 3}F{sub 10} nano-cages were decomposed, resulted in the formation of Y(OH){sub 1.63}F{sub 1.37} micro-tubes. Prolonging the hydrothermal reaction induced the further decomposition of Y(OH){sub 1.63}F{sub 1.37} to produce YF{sub 3} nano-crystals, which then aggregated together forming the final olive-like YF{sub 3} micro-particles. For the Er{sup 3+}/Yb{sup 3+} co-doped olive-like YF{sub 3} micro-particles, intense visible upconversion emissions were measured under 976 nm excitation owing to the partition of rare earth ions in the lattice, indicating this material a promising luminescent host.

  6. Dual functions of YF3:Eu3+ for improving photovoltaic performance of dye-sensitized solar cells

    PubMed Central

    Wu, Jihuai; Wang, Jiangli; Lin, Jianming; Xiao, Yaoming; Yue, Gentian; Huang, Miaoliang; Lan, Zhang; Huang, Yunfang; Fan, Leqing; Yin, Shu; Sato, Tsugio

    2013-01-01

    In order to enhance the photovoltaic performance of dye-sensitized solar cell (DSSC), a novel design is demonstrated by introducing rare-earth compound europium ion doped yttrium fluoride (YF3:Eu3+) in TiO2 film in the DSSC. As a conversion luminescence medium, YF3:Eu3+ transfers ultraviolet light to visible light via down-conversion, and increases incident harvest and photocurrent of DSSC. As a p-type dopant, Eu3+ elevates the Fermi level of TiO2 film and thus heightens photovoltage of the DSSC. The conversion luminescence and p-type doping effect are demonstrated by photoluminescence spectra and Mott-Schottky plots. When the ratio of YF3:Eu3+/TiO2 in the doping layer is optimized as 5 wt.%, the light-to-electric energy conversion efficiency of the DSSC reaches 7.74%, which is increased by 32% compared to that of the DSSC without YF3:Eu3+ doping. Double functions of doped rare-earth compound provide a new route for enhancing the photovoltaic performance of solar cells. PMID:23792787

  7. Dual functions of YF3:Eu3+ for improving photovoltaic performance of dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Wu, Jihuai; Wang, Jiangli; Lin, Jianming; Xiao, Yaoming; Yue, Gentian; Huang, Miaoliang; Lan, Zhang; Huang, Yunfang; Fan, Leqing; Yin, Shu; Sato, Tsugio

    2013-06-01

    In order to enhance the photovoltaic performance of dye-sensitized solar cell (DSSC), a novel design is demonstrated by introducing rare-earth compound europium ion doped yttrium fluoride (YF3:Eu3+) in TiO2 film in the DSSC. As a conversion luminescence medium, YF3:Eu3+ transfers ultraviolet light to visible light via down-conversion, and increases incident harvest and photocurrent of DSSC. As a p-type dopant, Eu3+ elevates the Fermi level of TiO2 film and thus heightens photovoltage of the DSSC. The conversion luminescence and p-type doping effect are demonstrated by photoluminescence spectra and Mott-Schottky plots. When the ratio of YF3:Eu3+/TiO2 in the doping layer is optimized as 5 wt.%, the light-to-electric energy conversion efficiency of the DSSC reaches 7.74%, which is increased by 32% compared to that of the DSSC without YF3:Eu3+ doping. Double functions of doped rare-earth compound provide a new route for enhancing the photovoltaic performance of solar cells.

  8. 77 FR 16988 - Protection of Stratospheric Ozone: Amendment to HFO-1234yf SNAP Rule for Motor Vehicle Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-23

    ... procedure, Air pollution control, Reporting and recordkeeping requirements, Stratospheric ozone layer. Dated... AGENCY 40 CFR Part 82 RIN 2060-AR20 Protection of Stratospheric Ozone: Amendment to HFO-1234yf SNAP Rule... substitute for ozone- depleting substances (ODSs) in the motor vehicle air conditioning end- use within...

  9. 77 FR 17344 - Protection of Stratospheric Ozone: Amendment to HFO-1234yf SNAP Rule for Motor Vehicle Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-26

    ... control, Incorporation by reference, Reporting and recordkeeping requirements, Stratospheric ozone layer... AGENCY 40 CFR Part 82 RIN-2060-AR20 Protection of Stratospheric Ozone: Amendment to HFO-1234yf SNAP Rule...-tetrafluoroprop-1-ene), a substitute for ozone-depleting substances (ODSs) in the motor vehicle air...

  10. Solvothermal synthesis and tunable luminescence of Tb{sup 3+}, Eu{sup 3+} codoped YF{sub 3} nano- and micro-crystals with uniform morphologies

    SciTech Connect

    Tian, Yue; Chen, Baojiu; Li, Xiangping; Zhang, Jinsu; Tian, Bining; Sun, Jiashi; Cheng, Lihong; Zhong, Haiyang; Zhong, Hua; Hua, Ruinian

    2012-12-15

    Tb{sup 3+}, Eu{sup 3+} codoped YF{sub 3} nano- and micro-crystals with the morphologies of ellipsoid-like nanoplate, spindle, sandwich-structural rhombus and nanoaggregate were synthesized through a solvothermal method. The morphologies of the prepared products can be tailored by controlling the volume ratio of ethylene glycol (EG) to H{sub 2}O, solvent type or the reaction time. A possible formation mechanism of the sandwich-structural rhombus like YF{sub 3} phosphor was proposed. The emitting colors of YF{sub 3}:Tb{sup 3+},Eu{sup 3+} phosphors can be easily tuned from yellowish green, yellow to orange by increasing Eu{sup 3+} concentration. The energy transfer from Tb{sup 3+} to Eu{sup 3+} in YF{sub 3} phosphors was studied. It was found that the interaction type between Tb{sup 3+} and Eu{sup 3+} is electric dipole-dipole interaction. - Graphical abstract: Sandwich-structural rhombus like YF{sub 3}:Tb{sup 3+}, Eu{sup 3+} phosphors were synthesized through a solvothermal process. The formation mechanism of the sandwich-structural rhombus like YF{sub 3}:Tb{sup 3+}, Eu{sup 3+} phosphors was studied. Highlights: Black-Right-Pointing-Pointer YF{sub 3} nano- and micro-crystals were synthesized through solvothermal route. Black-Right-Pointing-Pointer A formation mechanism of the sandwich-structural rhombus like YF{sub 3} was proposed. Black-Right-Pointing-Pointer The emitting colors of YF{sub 3}:Tb{sup 3+},Eu{sup 3+} phosphors can be tuned. Black-Right-Pointing-Pointer Energy transfer from Tb{sup 3+} to Eu{sup 3+} is confirmed as electric dipole-dipole interaction.

  11. CD8+ T cells complement antibodies in protecting against yellow fever virus.

    PubMed

    Bassi, Maria R; Kongsgaard, Michael; Steffensen, Maria A; Fenger, Christina; Rasmussen, Michael; Skjødt, Karsten; Finsen, Bente; Stryhn, Anette; Buus, Søren; Christensen, Jan P; Thomsen, Allan R

    2015-02-01

    The attenuated yellow fever (YF) vaccine (YF-17D) was developed in the 1930s, yet little is known about the protective mechanisms underlying its efficiency. In this study, we analyzed the relative contribution of cell-mediated and humoral immunity to the vaccine-induced protection in a murine model of YF-17D infection. Using different strains of knockout mice, we found that CD4(+) T cells, B cells, and Abs are required for full clinical protection of vaccinated mice, whereas CD8(+) T cells are dispensable for long-term survival after intracerebral challenge. However, by analyzing the immune response inside the infected CNS, we observed an accelerated T cell influx into the brain after intracerebral challenge of vaccinated mice, and this T cell recruitment correlated with improved virus control in the brain. Using mice deficient in B cells we found that, in the absence of Abs, YF vaccination can still induce some antiviral protection, and in vivo depletion of CD8(+) T cells from these animals revealed a pivotal role for CD8(+) T cells in controlling virus replication in the absence of a humoral response. Finally, we demonstrated that effector CD8(+) T cells also contribute to viral control in the presence of circulating YF-specific Abs. To our knowledge, this is the first time that YF-specific CD8(+) T cells have been demonstrated to possess antiviral activity in vivo.

  12. Rotavirus vaccines

    PubMed Central

    Yen, Catherine; Tate, Jacqueline E; Hyde, Terri B; Cortese, Margaret M; Lopman, Benjamin A; Jiang, Baoming; Glass, Roger I; Parashar, Umesh D

    2016-01-01

    Rotavirus is the leading cause of severe diarrhea among children <5 years worldwide. Currently licensed rotavirus vaccines have been efficacious and effective, with many countries reporting substantial declines in diarrheal and rotavirus-specific morbidity and mortality. However, the full public health impact of these vaccines has not been realized. Most countries, including those with the highest disease burden, have not yet introduced rotavirus vaccines into their national immunization programs. Research activities that may help inform vaccine introduction decisions include (1) establishing effectiveness, impact, and safety for rotavirus vaccines in low-income settings; (2) identifying potential strategies to improve performance of oral rotavirus vaccines in developing countries, such as zinc supplementation; and (3) pursuing alternate approaches to oral vaccines, such as parenteral immunization. Policy- and program-level barriers, such as financial implications of new vaccine introductions, should be addressed to ensure that countries are able to make informed decisions regarding rotavirus vaccine introduction. PMID:24755452

  13. Mutual interference on the immune response to yellow fever vaccine and a combined vaccine against measles, mumps and rubella.

    PubMed

    Nascimento Silva, Juliana Romualdo; Camacho, Luiz Antonio B; Siqueira, Marilda M; Freire, Marcos de Silva; Castro, Yvone P; Maia, Maria de Lourdes S; Yamamura, Anna Maya Y; Martins, Reinaldo M; Leal, Maria de Luz F

    2011-08-26

    A randomized trial was conducted to assess the immunogenicity and reactogenicity of yellow fever vaccines (YFV) given either simultaneously in separate injections, or 30 days or more after a combined measles-mumps-rubella (MMR) vaccine. Volunteers were also randomized to YFV produced from 17DD and WHO-17D-213 substrains. The study group comprised 1769 healthy 12-month-old children brought to health care centers in Brasilia for routine vaccination. The reactogenicity was of the type and frequency expected for the vaccines and no severe adverse event was associated to either vaccine. Seroconversion and seropositivity 30 days or more after vaccination against yellow fever was similar across groups defined by YFV substrain. Subjects injected YFV and MMR simultaneously had lower seroconversion rates--90% for rubella, 70% for yellow fever and 61% for mumps--compared with those vaccinated 30 days apart--97% for rubella, 87% for yellow fever and 71% for mumps. Seroconversion rates for measles were higher than 98% in both comparison groups. Geometric mean titers for rubella and for yellow fever were approximately three times higher among those who got the vaccines 30 days apart. For measles and mumps antibodies GMTs were similar across groups. MMR's interference in immune response of YFV and YFV's interference in immune response of rubella and mumps components of MMR had never been reported before but are consistent with previous observations from other live vaccines. These results may affect the recommendations regarding primary vaccination with yellow fever vaccine and MMR.

  14. The CCK(2) receptor antagonist, YF476, inhibits Mastomys ECL cell hyperplasia and gastric carcinoid tumor development.

    PubMed

    Kidd, M; Siddique, Z-L; Drozdov, I; Gustafsson, B I; Camp, R L; Black, J W; Boyce, M; Modlin, I M

    2010-06-08

    YF476 is a potent and highly selective cholecystokin 2 (CCK(2)) receptor antagonist of the benzodiazepine class. It inhibits gastric neuroendocrine enterochromaffin-like (ECL) cell secretion, proliferation and spontaneous formation of gastric neuroendocrine tumors (carcinoids) in cotton rats. The Mastomys rodent species exhibits a genetic predisposition to gastric ECL neuroendocrine tumor formation which can be accelerated by acid suppression and induction of hypergastrinemia. In this respect, it mimics the human condition of atrophic gastritis, hypergastrinemia and gastric carcinoid development. We investigated whether YF476 could inhibit acid suppression-induced ECL cell hyperplasia and neoplasia in this model. In addition, we examined whether YF476 could reverse established ECL cell hyperplasia and neoplasia. Targeting the CCK(2) receptor during Loxtidine-induced hypergastrinemia resulted in a reduction in ECL cell secretion (plasma and mucosal histamine, and histidine decarboxylase (HDC) transcripts, p<0.05) and proliferation (numbers of HDC-positive cells, connective tissue growth factor (CTGF) and cyclin D1 transcription). This was associated with a decrease in ECL cell hyperplasia and a 60% reduction in gastric ECL cell microcarcinoid (tumors <0.3mm in size) formation. YF476 inhibited ECL cell neoplasia (gastric carcinoid) in animals with hyperplasia, inhibited the formation of ECL cell tumors when co-administered with Loxtidine and reversed the growth and developement of gastric ECL cell carcinoids in long-term acid suppressed Mastomys. Variable importance analysis using a logistic multinomial regression model indicated the effects of YF476 were specific to the ECL cell and alterations in ECL cell function reflected inhibition of transcripts for HDC, Chromogranin A (CgA), CCK(2) and the autocrine growth factor, CTGF. We conclude that specifically targeting the CCK(2) receptor inhibits gastrin-mediated ECL cell secretion and ECL cell proliferation and tumor

  15. Deposition and rainwater concentrations of trifluoroacetic acid in the United States from the use of HFO-1234yf

    NASA Astrophysics Data System (ADS)

    Kazil, J.; McKeen, S.; Kim, S.-W.; Ahmadov, R.; Grell, G. A.; Talukdar, R. K.; Ravishankara, A. R.

    2014-12-01

    Currently, HFC-134a (1,1,1,2-tetrafluoroethane) is the most common refrigerant in automobile air conditioners. This high global warming potential substance (100 year GWP of 1370) will likely be phased out and replaced with HFO-1234yf (2,3,3,3-tetrafluoropropene) that has a 100 year GWP of 4. HFO-1234yf will be oxidized to produce trifluoroacetic acid (TFA) in clouds. TFA, a mildly toxic substance with detrimental effects on some aquatic organisms at high concentrations (≥100μgL-1), would be transported by rain to the surface and enter bodies of water. We investigated the dry and wet deposition of TFA from HFO-1234yf over the contiguous USA using the Advanced Research Weather Research and Forecasting model (ARW) with interactive chemical, aerosol, and cloud processes (WRF/Chem) model. Special focus was placed on emissions from three continental USA regions with different meteorological characteristics. WRF/Chem simulated meteorology, cloud processes, gas and aqueous phase chemistry, and dry and wet deposition between May and September 2006. The model reproduced well the multimonth total sulfate wet deposition (4% bias) and its spatial variability (r = 0.86) observed by the National Atmospheric Deposition Program. HFO-1234yf emissions were obtained by assuming the number of automobile air conditioners to remain unchanged, and substituting HFO-1234yf, mole-per-mole for HFC-134a. Our estimates of current HFC-134a emissions were in agreement with field data. Average TFA rainwater concentration was 0.89μgL-1, with peak values of 7.8μgL-1, for the May-September 2006 period over the contiguous USA. TFA rainwater concentrations over the dry western USA were often significantly higher, but wet-deposited TFA amounts remained relatively low at such locations.

  16. DENGUE VACCINES.

    PubMed

    Thisyakorn, Usa; Thisyakorn, Chule

    2015-01-01

    The uniqueness of the dengue viruses (DENVs) and the spectrum of disease resulting from infection have made dengue vaccine development difficult. Several vaccine candidates are currently being evaluated in clinical studies. The candidate currently at the most advanced clinical development stage, a live-attenuated tetravalent vaccine based on the chimeric yellow fever-dengue virus (CYD-TDV), has progressed to Phase 3 efficacy studies. Several other live-attenuated vaccines, as well as subunit, DNA, and purified inactivated vaccine candidates are at earlier stages of clinical development. Additional technological approaches, such as virus-vectored and Virus-Like Particles (VLP)-based vaccines are under evaluation in preclinical studies.

  17. Vaccines (immunizations) - overview

    MedlinePlus

    ... diphtheria, mumps, measles, pertussis (whooping cough), meningitis, and polio. Many of these infections can cause serious or ... MMR - vaccine Pneumococcal conjugate vaccine Pneumococcal polysaccharide ... (vaccine) Rotavirus vaccine Tdap vaccine Tetanus - vaccine

  18. Peritoneal bacterial infection repressed the expression of IL17D in Siberia sturgeon a chondrostean fish in the early immune response.

    PubMed

    Zhu, Hua; Song, Ruxing; Wang, Xiaowen; Hu, Hongxia; Zhang, Zuobing

    2017-03-06

    IL17s are pro-inflammatory cytokines that play important roles in host fighting against extracellular bacteria and auto-immune and allergic diseases. IL17D is believed to be the most ancient IL17 member and its functions are far from clarity. Although it has been found in invertebrates, jawless fish, teleosts, and tetrapods, it has not been described in chondrostean fish. Moreover, there are discrepancies concerning its expression pattern in these animals. In this study, we cloned and characterized the cDNA of il17d in Siberia sturgeon (Acipenser baerii), a chondrostean fish and commercially important species in aquaculture. The sturgeon il17d cDNA encodes a deduced protein of 210aa. The classical characteristics of IL17, such as IL17 domain, cysteine and serine residues importantly for cystine-knot formation, and signal peptide, were observed in sturgeon IL17D. Phylogenetic analysis and multiple alignment suggest it is a counterpart of mammalian IL17D. However, in vivo studies demonstrated that the expression pattern of sturgeon il17d mRNA is different from that of other teleosts and jawless fish, and in most cases its expression was down-regulated at the early time points and gradually increasing at late time points when sturgeon were challenged with bacteria (Aernomas hydrophila or Staphylococcus aureus). The In vitro study by using primary spleen cells stimulated with polyI:C revealed a similar expression pattern to that in vivo studies, while the stimulation with β-glucan or LPS, which normally induced expression of il17d mRNA in target cells in vitro in other animals, did not show apparent changes in the expression of il17d mRNA. The results of present study indicated sturgeon IL17D may possess some different characteristics from its counterparts of other fish and invertebrates in the immune response, and may contribute to the understanding of IL17D functions in evolution as well as the potential use in sturgeon aquaculture.

  19. Vaccine Safety

    MedlinePlus

    ... FAQs about Vaccine Safety Research Publications HDM Reports ISO Scientific Agenda Ensuring Safety History Understanding Side Effects ... Datalink Publications Emergency Preparedness Vaccine Safety Partners About ISO File Formats Help: How do I view different ...

  20. Fabrication methods for YF-12 wing panels for the Supersonic Cruise Aircraft Research Program

    NASA Technical Reports Server (NTRS)

    Hoffman, E. L.; Payne, L.; Carter, A. L.

    1975-01-01

    Advanced fabrication and joining processes for titanium and composite materials are being investigated by NASA to develop technology for the Supersonic Cruise Aircraft Research (SCAR) Program. With Lockheed-ADP as the prime contractor, full-scale structural panels are being designed and fabricated to replace an existing integrally stiffened shear panel on the upper wing surface of the NASA YF-12 aircraft. The program involves ground testing and Mach 3 flight testing of full-scale structural panels and laboratory testing of representative structural element specimens. Fabrication methods and test results for weldbrazed and Rohrbond titanium panels are discussed. The fabrication methods being developed for boron/aluminum, Borsic/aluminum, and graphite/polyimide panels are also presented.

  1. Enhanced upconversion luminescence of NaYF4:Yb, Er microprisms via La3+ doping

    NASA Astrophysics Data System (ADS)

    Fu, Junxiang; Zhang, Xiaozeng; Chao, Zhicong; Li, Zibo; Liao, Jinsheng; Hou, Dejian; Wen, Herui; Lu, Xiaoneng; Xie, Xinrong

    2017-02-01

    A series of β-NaYF4: Yb, Er micro-prisms codoped with La3+(0-30 at%) were synthesized via hydrothermal process. Upon 980 nm excitation at room temperature, 20 mol% La3+ codoped sample shows a maximum upconversion emission intensity. Excitation power density dependencies of UC luminescence and the decay curves were investigated. The UCPL decay is evidently monoexponential for all samples and La3+ doping did not significantly change the decay time. In this particular case, we found the napierian logarithm of the UC emission intensity (lnI) had a good linear relationship with the cell lattice parameters. This correlation may be helpful for design and fabrication of high performance upconversion materials.

  2. Mechanical characteristics of stability-bleed valves for a supersonic inlet. [for the YF-12 aircraft

    NASA Technical Reports Server (NTRS)

    Neiner, G. H.; Dustin, M. O.; Cole, G. L.

    1977-01-01

    Mechanical characteristics of a set of direct-operated relief valves used in a throat-bypass stability-bleed system designed for the YF-12 aircraft inlet are described. A comparison of data taken before and after the windtunnel tests (at room temperature) showed that both the effective spring rate and the piston friction had decreased during the wind tunnel tests. In neither the effective spring rate nor the piston friction was the magnitude of change great enough to cause significant impairment of overall system effectiveness. No major valve mechanical problems were encountered in any of the tests. During high temperature bench tests, piston frictional drag increased. The friction returned to its initial room temperature value when the stability-bleed valve was disassembled and reassembled. The problem might be solved by using a different material for the piston sleeve bearing and the piston rings.

  3. Geometry modulated upconversion photoluminescence of individual NaYF4: Yb3+, Er3+ microcrystals

    NASA Astrophysics Data System (ADS)

    Wang, Bing; Wang, Jiao; Mei, Yongfeng

    2017-02-01

    Upconversion (UC) photoluminescence (PL) properties of individual β-NaYF4: Yb3+, Er3+ microcrystals are investigated on their crystal orientation and size by a confocal micro-photoluminescence (μ-PL) system. The UC PL intensities including red and green bands of individual microcrystals change nearly lineally with their diameter but in different slopes. The ratio of integrated PL intensities between red and green bands (R/G) of individual microcrystals can be modulated by the crystal geometry, which is attributed to the optical propagation path and optical loss coefficient α. PL emission mapping along the crystal surface reveals a typical characteristic of optical waveguide in our UC microcrystals. Importantly, the variation of anisotropy in (100) and (001) crystal plane influences the UC PL spectra in the single microcrystals. Our finding could help the basic understanding of UC luminescence in micro/nanocrystals and hint their optimized fabrication for enhanced light emission.

  4. Tailoring Plasmonic Enhanced Upconversion in Single NaYF4:Yb3+/Er3+ Nanocrystals

    PubMed Central

    Wang, Ya-Lan; Mohammadi Estakhri, Nasim; Johnson, Amber; Li, Hai-Yang; Xu, Li-Xiang; Zhang, Zhenyu; Alù, Andrea; Wang, Qu-Quan; Shih, Chih-Kang (Ken)

    2015-01-01

    By using silver nanoplatelets with a widely tunable localized surface plasmon resonance (LSPR), and their corresponding local field enhancement, here we show large manipulation of plasmonic enhanced upconversion in NaYF4:Yb3+/Er3+ nanocrystals at the single particle level. In particular, we show that when the plasmonic resonance of silver nanolplatelets is tuned to 656 nm, matching the emission wavelength, an upconversion enhancement factor ~5 is obtained. However, when the plasmonic resonance is tuned to 980 nm, matching the nanocrystal absorption wavelength, we achieve an enhancement factor of ~22 folds. The precise geometric arrangement between fluorescent nanoparticles and silver nanoplatelets allows us to make, for the first time, a comparative analysis between experimental results and numerical simulations, yielding a quantitative agreement at the single particle level. Such a comparison lays the foundations for a rational design of hybrid metal-fluorescent nanocrystals to harness the upconversion enhancement for biosensing and light harvesting applications. PMID:25976870

  5. TFA from HFO-1234yf: accumulation and aquatic risk in terminal water bodies.

    PubMed

    Russell, Mark H; Hoogeweg, Gerco; Webster, Eva M; Ellis, David A; Waterland, Robert L; Hoke, Robert A

    2012-09-01

    A next-generation mobile automobile air-conditioning (MAC) refrigerant, HFO-1234yf (CF(3) CF = CH(2)), is being developed with improved environmental characteristics. In the atmosphere, it ultimately forms trifluoroacetic acid (TFA(A); CF(3)COOH), which is subsequently scavenged by precipitation and deposited on land and water as trifluoroacetate (TFA; CF(3)COO(-)). Trifluoroacetate is environmentally stable and has the potential to accumulate in terminal water bodies, that is, aquatic systems receiving inflow but with little or no outflow and with high rates of evaporation. Previous studies have estimated the emission rates of HFO-1234yf and have modeled the deposition concentrations and rates of TFA across North America. The present study uses multimedia modeling and geographic information system (GIS)-based modeling to assess the potential concentrations of TFA in terminal water bodies over extended periods. After 10 years of emissions, predicted concentrations of TFA in terminal water bodies across North America are estimated to range between current background levels (i.e., 0.01-0.22 µg/L) and 1 to 6 µg/L. After 50 years of continuous emissions, aquatic concentrations of 1 to 15 µg/L are predicted, with extreme concentrations of up to 50 to 200 µg/L in settings such as the Sonoran Desert along the California/Arizona (USA) border. Based on the relative insensitivity of aquatic organisms to TFA, predicted concentrations of TFA in terminal water bodies are not expected to impair aquatic systems, even considering potential emissions over extended periods.

  6. Immunogenicity and safety of tetravalent dengue vaccine in 2-11 year-olds previously vaccinated against yellow fever: randomized, controlled, phase II study in Piura, Peru.

    PubMed

    Lanata, Claudio F; Andrade, Teresa; Gil, Ana I; Terrones, Cynthia; Valladolid, Omar; Zambrano, Betzana; Saville, Melanie; Crevat, Denis

    2012-09-07

    In a randomized, placebo-controlled, monocenter, observer blinded study conducted in an area where dengue is endemic, we assessed the safety and immunogenicity of a recombinant, live, attenuated, tetravalent dengue vaccine candidate (CYD-TDV) in 2-11 year-olds with varying levels of pre-existing yellow-fever immunity due to vaccination 1-7 years previously. 199 children received 3 injections of CYD-TDV (months 0, 6 and 12) and 99 received placebo (months 0 and 6) or pneumococcal polysaccharide vaccine (month 12). One month after the third dengue vaccination, serotype specific neutralizing antibody GMTs were in the range of 178-190 (1/dil) (versus 16.7-38.1 in the control group), a 10-20 fold-increase from baseline, and 94% of vaccines were seropositive to all four serotypes (versus 39% in the control group). There were no vaccine-related SAEs. The observed reactogenicity profile was consistent with phase I studies, with severity grade 1-2 injection site pain, headache, malaise and fever most frequently reported and no increase after subsequent vaccinations. Virologically confirmed dengue cases were seen after completion of the 3 doses: 1 in the CYD-TDV group (N=199), and 3 in the control group (N=99). A 3-dose regimen of CYD-TDV had a good safety profile in 2-11 year olds with a history of YF vaccination and elicited robust antibody responses that were balanced against the four serotypes.

  7. Study of optical and luminescent properties of nanocrystals NaYF4:Tm3+, Yb3+ in the UV range in the application of integrated optics

    NASA Astrophysics Data System (ADS)

    Asharchuk, I. M.; Molchanova, S. I.; Rocheva, V. V.; Baranov, M. S.; Sarycheva, M. E.; Khaydukov, K. V.

    2016-12-01

    Studied the photoluminescence properties of synthesized nanocrystals doped with rare-earth ions NaYF4:Tm3+, Yb3+, measured luminescence spectra and absorption in the visible and near infrared regions of 300-1000 nm. Were measured the energy of phonons these nanocrystals, the average phonon energy was 332cm-1. Made optical waveguide impregnated with nanoparticles NaYF4: Yb3+, Tm3+ as the prospect of a compact source of radiation in the visible and UV range.

  8. Edible vaccines.

    PubMed Central

    Artnzen, C J

    1997-01-01

    Vaccines were the result of trial and error research until molecular biology and genetic engineering made possible the creation of of many new and improved vaccines. New vaccines need to be inexpensive, easily administered, and capable of being stored and transported without refrigeration; without these characteristics, developing countries find it difficult to adopt vaccination as the central strategy for preventing their most devastating diseases. The authors describe a promising approach to inexpensive and effective vaccines: producing them in plants we commonly consume. Images p190-a p191-a p193-a p196-a PMID:9182305

  9. Fabrication and evaluation of chitosan/NaYF4:Yb(3+)/Tm(3+) upconversion nanoparticles composite beads based on the gelling of Pickering emulsion droplets.

    PubMed

    Yan, Huiqiong; Chen, Xiuqiong; Shi, Jia; Shi, Zaifeng; Sun, Wei; Lin, Qiang; Wang, Xianghui; Dai, Zihao

    2017-02-01

    The rare earth ion doped upconversion nanoparticles (UCNPs) synthesized by hydrophobic organic ligands possess poor solubility and low fluorescence quantum yield in aqueous media. To conquer this issue, NaYF4:Yb(3+)/Tm(3+) UCNPs, synthesized by a hydrothermal method, were coated with F127 and then assembled with chitosan to fabricate the chitosan/NaYF4:Yb(3+)/Tm(3+) composite beads (CS/NaYF4:Yb(3+)/Tm(3+) CBs) by Pickering emulsion system. The characterization results revealed that the as-synthesized NaYF4:Yb(3+)/Tm(3+) UCNPs with an average size of 20nm exhibited spherical morphology, high crystallinity and characteristic emission upconversion fluorescence with an overall blue color output. The NaYF4:Yb(3+)/Tm(3+) UCNPs were successfully conjugated on the surface of chitosan beads by the gelling of emulsion droplets. The resultant CS/NaYF4:Yb(3+)/Tm(3+) CBs showed good upconversion luminescent property, drug-loading capacity, release performance and excellent biocompatibility, exhibiting great potentials in targeted drug delivery and tissue engineering with potential tracking capability and lasting release performance.

  10. Bifunctional NaYF4:Er3+/Yb3+ submicron rods, implemented in quantum dot sensitized solar cell(Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Guerrero, J. Pablo; Cerdán Pasarán, Andrea; López-Luke, Tzarara; Ramachari, D.; Esparza, Diego; De la Rosa Cruz, Elder; Romero Arellano, Victor Hugo

    2016-09-01

    In this work are presented the results obtained with solar cells sensitized with quantum dots of cadmium sulphide (CdS) incorporating luminescent materials (NaYF4:Yb/Er). The study revealed that through using a bifunctional layer of NaYF4:Yb/Er submicron rods, the infrared radiation is absorbed in 980nm to generate luminescence in the visible region to 530nm, under the UP-conversion process, in the same way simultaneously, NaYF4:Yb/Er layer causes scattering toward the quantum dots, the emission and scattering generated by this material is reabsorbed by the QD-CdS, and these in turn are absorbing in its range of solar radiation absorption, Thus generates an increase in the electron injection into the semiconductor of TiO2. The results of a cell incorporating NaYF4: Yb/Er at 0.07M shown photoconversion efficiencies of 3.39% improving efficiency with respect to the reference solar cell without using NaYF4: Yb/Er of 1.99%. The obtained values of current and voltage showed a strong dependence of the percentage of NaYF4 Yb/Er, and the mechanism of incorporation of this material.

  11. Controllable synthesis and up-conversion properties of tetragonal BaYF5:Yb/Ln (Ln=Er, Tm, and Ho) nanocrystals.

    PubMed

    Niu, Na; Yang, Piaoping; Liu, Yanchao; Li, Chunxia; Wang, Dong; Gai, Shili; He, Fei

    2011-10-15

    The nanocrystals (NCs) of tetragonal barium yttrium fluoride (BaYF(5)) doped 1 mol% Ln(3+) (Ln=Er, Tm, Ho) and 20 mol% Yb(3+) with different morphologies and sizes have been successfully synthesized through a facile hydrothermal method. The influences of pH values of the initial solution and fluorine sources on the final structure and morphology of the products have been well investigated. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM) were used to characterize the size, structure and morphology of these samples prepared at different conditions. And it is found that BaYF(5):Yb/Ln NCs prepared at pH value of 10 using NaBF(4) as F(-) source have a uniform spherical morphology with average diameter of 25 nm. Additionally, the up-conversion (UC) properties of Yb/Er, Yb/Tm, and Yb/Ho doped BaYF(5) nanoparticles were also discussed. Under 980 nm laser excitation, the BaYF(5):Yb/Er, BaYF(5):Yb/Tm, and BaYF(5):Yb/Ho NCs exhibit green, whitish blue, and yellow green UC luminescence, respectively. The luminescence mechanisms for the doped lanthanide ions were thoroughly analyzed.

  12. DNA vaccines

    NASA Astrophysics Data System (ADS)

    Gregersen, Jens-Peter

    2001-12-01

    Immunization by genes encoding immunogens, rather than with the immunogen itself, has opened up new possibilities for vaccine research and development and offers chances for new applications and indications for future vaccines. The underlying mechanisms of antigen processing, immune presentation and regulation of immune responses raise high expectations for new and more effective prophylactic or therapeutic vaccines, particularly for vaccines against chronic or persistent infectious diseases and tumors. Our current knowledge and experience of DNA vaccination is summarized and critically reviewed with particular attention to basic immunological mechanisms, the construction of plasmids, screening for protective immunogens to be encoded by these plasmids, modes of application, pharmacokinetics, safety and immunotoxicological aspects. DNA vaccines have the potential to accelerate the research phase of new vaccines and to improve the chances of success, since finding new immunogens with the desired properties is at least technically less demanding than for conventional vaccines. However, on the way to innovative vaccine products, several hurdles have to be overcome. The efficacy of DNA vaccines in humans appears to be much less than indicated by early studies in mice. Open questions remain concerning the persistence and distribution of inoculated plasmid DNA in vivo, its potential to express antigens inappropriately, or the potentially deleterious ability to insert genes into the host cell's genome. Furthermore, the possibility of inducing immunotolerance or autoimmune diseases also needs to be investigated more thoroughly, in order to arrive at a well-founded consensus, which justifies the widespread application of DNA vaccines in a healthy population.

  13. [Antiviral vaccines].

    PubMed

    Girard, M

    1999-01-01

    Vaccination has been successful in controlling numerous diseases in man and animals. Smallpox has been eradicated and poliomyelitis is on the verge of being eradicated. The traditional immunization arsenal includes vaccines using live, attenuated, and inactivated organisms. DNA recombinant technology has added two new types of vaccines, i.e. subunit vaccines based on purified antigens produced by genetic engineering in bacterial, yeast, or animal-cell cultures and live recombinant vaccines based on attenuated bacterial or viral vectors. Currently the best known examples of these new vaccines are those using poxvirus vectors (vaccinia virus, canarypox virus, or fowlpox virus) but new vectors are under development. Another application for genetic engineering in the field of vaccinology is the development of DNA vaccines using naked plasmid DNA. This technique has achieved remarkable results in small rodents but its efficacy, safety, and feasibility in man has yet to be demonstrated. Numerous studies are now under way to improve the process. In the field of synthetic vaccines, lipopeptides have shown promise for induction of cell immune response. Development of vaccines for administration by the oral or nasal route may one day revolutionize vaccination techniques. However, effective vaccines against hepatitis C and HIV have stalled in the face of the complexity and pathophysiology of these diseases. These are the greatest challenges confronting scientists at the dawn of the new millennium.

  14. Characterization of a new selective antagonist for angiotensin-(1-7), D-pro7-angiotensin-(1-7).

    PubMed

    Santos, Robson A S; Haibara, Andréa S; Campagnole-Santos, Maria José; Simões e Silva, Ana C; Paula, Renata D; Pinheiro, Sérgio V B; Leite, Maria Fátima; Lemos, Virginia S; Silva, Denise M R; Guerra, Mateus T; Khosla, Mahesh C

    2003-03-01

    Angiotensin-(1-7) [Ang-(1-7)] has biological actions that can often be distinguished from those of angiotensin II (Ang II). Recent studies indicate that the effects of Ang-(1-7) are mediated by specific receptor(s). We now report the partial characterization of a new antagonist selective for Ang-(1-7), D-Pro7-Ang-(1-7). D-Pro7-Ang-(1-7) (50 pmol) inhibited the hypertensive effect induced by microinjection of Ang-(1-7) [4+/-1 vs 21+/-2 mm Hg, 25 pmol Ang-(1-7) alone] into the rostral ventrolateral medulla without changing the effect of Ang II (16+/-2.5 vs 19+/-2.5 mm Hg after 25 pmol Ang II alone). At 10(-7) mol/L concentration, it completely blocked the endothelium-dependent vasorelaxation produced by Ang-(1-7) (10(-10) to 10(-6) mol/L) in the mouse aorta. The antidiuresis produced by Ang-(1-7) (40 pmol/100 g body weight) in water-loaded rats was also blocked by its analog [1 microg/100 g body weight; 3.08+/-0.8 vs 1.27+/-0.33 mL in Ang-(1-7)-treated rats]. D-Pro7-Ang-(1-7) at a molar ratio of 40:1 did not change the hypotensive effect of bradykinin. Moreover, D-Pro7-Ang-(1-7) did not affect the dipsogenic effect produced by intracerebroventricular administration of Ang II (11.4+/-1.15 vs 8.8+/-1.2 mL/h after Ang II) and did not show any demonstrable angiotensin-converting enzyme inhibitory activity in assays with the synthetic substrate Hip-His-Leu and rat plasma as a source of enzyme. Autoradiography studies with 125I-Ang-(1-7) in mouse kidney slices showed that D-Pro7-Ang-(1-7) competed for the binding of Ang-(1-7) to the cortical supramedullary region. In Chinese hamster ovary cells stably transfected with the AT1 receptor subtype, D-Pro7-Ang-(1-7) did not compete for the specific binding of 125I-Ang-II in concentrations up to 10(-6) mol/L. There was also no significant displacement of Ang II binding to angiotensin type 2 receptors in membrane preparations of adrenal medulla. These data indicate that D-Pro7-Ang-(1-7) is a selective antagonist for Ang-(1-7), which can be useful to clarify the functional role of this heptapeptide.

  15. Mechanochemical preparation of nanocrystalline NaYF4:Gd3+/Yb3+/Tm3+: An efficient upconversion phosphor

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Riesen, Hans

    2015-11-01

    We report on a mechanochemical preparation route for NaYF4:Gd3+/Yb3+/Tm3+ nanoparticles by ball-milling NaF, YF3, GdF3, YbF3 and TmF3 at room temperature. An analysis by XRD and TEM demonstrates that the resulting materials are mainly (∼88% after 4 h ball-milling) in the hexagonal phase and are on the nanoscale with an average crystallite size of ∼20 nm. The prepared nanoparticles display efficient upconversion emission; upon excitation by a 980 nm laser diode, bright visible blue light emission can be observed. However, in accord with previous results, the strongest emission is observed in the NIR at 800 nm.

  16. Laser performance of in-band pumped Er : LiYF4 and Er : LiLuF4 crystals

    NASA Astrophysics Data System (ADS)

    Gorbachenya, K. N.; Kurilchik, S. V.; Kisel, V. E.; Yasukevich, A. S.; Kuleshov, N. V.; Nizamutdinov, A. S.; Korableva, S. L.; Semashko, V. V.

    2016-02-01

    Spectroscopic properties of Er : LiLuF4 and Er : LiYF4 crystals in the spectral region near 1.5 μm and the lasing characteristics of these crystals under in-band pumping at a wavelength of 1522 nm are studied. With the Er : LiLuF4 crystal, the maximum slope efficiency with respect to the absorbed pump power was 44% at a wavelength of 1609 nm. Continuous-wave operation of an inband pumped Er : LiYF4 laser is obtained for the first time. The output power at a wavelength of 1606 nm was 58 mW with a slope efficiency of 21%.

  17. High-power GaN diode-pumped continuous wave Pr3+-doped LiYF4 laser.

    PubMed

    Hashimoto, Kohei; Kannari, Fumihiko

    2007-09-01

    A cw Pr(3+):LiYF(4) laser at 639 nm pumped by a high-power GaN laser diode (444 nm) is demonstrated. The highest laser power of 112 mW is achieved with an optical-optical conversion efficiency of 33.5%. Characteristics of this laser at elevated temperatures are also investigated for practical applications such as a laser projector.

  18. Hepatitis Vaccines

    PubMed Central

    Ogholikhan, Sina; Schwarz, Kathleen B.

    2016-01-01

    Viral hepatitis is a serious health problem all over the world. However, the reduction of the morbidity and mortality due to vaccinations against hepatitis A and hepatitis B has been a major component in the overall reduction in vaccine preventable diseases. We will discuss the epidemiology, vaccine development, and post-vaccination effects of the hepatitis A and B virus. In addition, we discuss attempts to provide hepatitis D vaccine for the 350 million individuals infected with hepatitis B globally. Given the lack of a hepatitis C vaccine, the many challenges facing the production of a hepatitis C vaccine will be shown, along with current and former vaccination trials. As there is no current FDA-approved hepatitis E vaccine, we will present vaccination data that is available in the rest of the world. Finally, we will discuss the existing challenges and questions facing future endeavors for each of the hepatitis viruses, with efforts continuing to focus on dramatically reducing the morbidity and mortality associated with these serious infections of the liver. PMID:26978406

  19. Is the absence or intermittent YF vaccination the major contributor to its persistent outbreaks in eastern Africa?

    PubMed

    Baba, Marycelin Mandu; Ikusemoran, Mayomi

    2017-01-18

    The Europe 2020 strategy and recently ratified Paris agreement are the main documents in the European Union (EU) involving energy and climate policy. Therefore, the aim of this paper is to reveal the possibilities of EU countries to achieve the Europe 2020 strategy and Paris agreement targets. Referring to the regression analysis, the results showed that the growth of economy and primary energy consumption stimulate GHG emissions in EU-28; meanwhile, the increase of RES share decreased them. Moreover, the paper revealed that if the EU will achieve its targets committed in the Europe 2020 strategy, even assuming fast economic growth, the target to reduce GHG emission by 20% by 2020 compared to 1990 will be achieved. According to different tendencies of economic growth, energy consumption and share of RES changes, the results showed that only recent (2005 - 2012) tendencies are the most suitable for the implementation of GHG emissions targets of Europe 2020 strategy but not of the Paris agreement. Therefore, the EU countries should attempt more to reduce energy consumption and to increase the share of RES seeking to implement the target of GHG emissions committed in Paris agreement.

  20. Enhanced photoelectric conversion efficiency of dye-sensitized solar cells by the incorporation of dual-mode luminescent NaYF4:Yb3+/Er3+.

    PubMed

    Li, Ying; Pan, Kai; Wang, Guofeng; Jiang, Baojiang; Tian, Chungui; Zhou, Wei; Qu, Yang; Liu, Shuai; Feng, Li; Fu, Honggang

    2013-06-14

    This work focuses on the design of composite photoanodes with dual-mode luminescent function as well as the effects of luminescent phosphors on the photoelectric properties of dye-sensitized solar cells. Specifically, hexagonal phase NaYF4:Yb(3+)/Er(3+) microcrystals were prepared by a hydrothermal method and added to the TiO2 photoanodes of dye-sensitized solar cells. The results indicated that the TiO2-NaYF4:Yb(3+)/Er(3+) composite photoanodes can emit visible light under 495 or 980 nm excitation, and then the visible light can be absorbed by dye N719 to improve light harvesting and thereby the efficiency of the solar cell. Under simulated solar radiation in the wavelength range of λ≥ 400 nm, the photoelectric conversion efficiency of TiO2-NaYF4:Yb(3+)/Er(3+) cell was increased by 10% compared to pure TiO2 cell. For the electrodes with the same thickness, the amount of dye adsorption of the photoanodes decreased a little after adding NaYF4:Yb(3+)/Er(3+), which was attributed to the decrease of TiO2 in the photoanodes. The electron transport and interfacial recombination kinetics were investigated by the electrochemical impedance spectroscopy and intensity-modulated photocurrent/photovoltage spectroscopy. The TiO2-NaYF4:Yb(3+)/Er(3+) cell has longer electron recombination time as well as electron transport time than pure TiO2 cell. The charge collection efficiency of TiO2-NaYF4:Yb(3+)/Er(3+) cell was little lower than that of pure TiO2 cell. In addition, the interfacial resistance of the TiO2-dye|I3(-)/I(-) electrolyte interface of TiO2-NaYF4:Yb(3+)/Er(3+) cell was much bigger than that of pure TiO2 cell. All these results indicated that the charge transport cannot be improved by adding NaYF4:Yb(3+)/Er(3+). And thus, the enhanced photoelectric conversion efficiencies of TiO2-NaYF4:Yb(3+)/Er(3+) cells were closely related to the dual-mode luminescent function of NaYF4:Yb(3+)/Er(3+).

  1. Vaccines licensed and in clinical trials for the prevention of dengue.

    PubMed

    Torresi, J; Ebert, G; Pellegrini, M

    2017-02-14

    Dengue has become a major global public health threat with almost half of the world's population living in at-risk areas. Vaccination would likely represent an effective strategy for the management of dengue disease in endemic regions, however to date there is only one licensed preventative vaccine for dengue infection. The development of a vaccine against dengue virus (DENV) has been hampered by an incomplete understanding of protective immune responses against DENV. The most clinically advanced dengue vaccine is the chimeric yellow fever-dengue vaccine (CYD) that employs the yellow fever virus 17D strain as the replication backbone (Chimerivax-DEN; CYD-TDV). This vaccine had an overall pooled protective efficacy of 65.6% but was substantially more effective against severe dengue and dengue hemorrhagic fever. Several other vaccine approaches have been developed including live attenuated chimeric dengue vaccines (DENVax and LAV Delta 30), DEN protein subunit V180 vaccine (DEN1-80E) and DENV DNA vaccines. These vaccines have been shown to be immunogenic in animals and also safe and immunogenic in humans. However, these vaccines are yet to progress to phase III trials to determine their protective efficacy against dengue. This review will summarize the details of vaccines that have progressed to clinical trials in humans.

  2. Vaccine Adverse Events

    MedlinePlus

    ... Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products Vaccines, Blood & Biologics Home Vaccines, Blood & Biologics Safety & Availability ( ... Center for Biologics Evaluation & Research Vaccine Adverse Events Vaccine Adverse Events Share Tweet Linkedin Pin it More ...

  3. Vaccines.gov

    MedlinePlus

    ... Statements Vaccine Approvals Features: News & Video Free Resources Vaccines are safe, effective, and save lives. Find answers ... by science, on vaccine safety. Are your child’s vaccines up to date? Getting all recommended vaccines on ...

  4. [HPV vaccination].

    PubMed

    Stronski Huwiler, Susanne; Spaar, Anne

    2016-01-01

    Human Papilloma Viruses are associated with genital carcinoma (of the cervix, anus, vulva, vagina and the penis) as well as with non-genital carcinoma (oropharyngeal carcinoma) and genital warts. In Switzerland two highly efficient and safe vaccines are available. The safety of these vaccines has been repeatedly subject of controversial discussions, however so far post marketing surveillance has always been able to confirm the safety. In Switzerland girls and young women have been offered the HPV vaccination within cantonal programmes since 2008. 2015 the recommendation for the HPV-vaccination for boys and young men was issued, and starting July 1, 2016 they as well will be offered vaccination free of charge within the cantonal programmes. This article discusses the burden of disease, efficacy and safety of the vaccines and presents facts which are important for vaccinating these young people. Specifically, aspects of the decisional capacity of adolescents to consent to the vaccination are presented. Finally, the future perspective with a focus on a new vaccine with an enlarged spectrum of HPV-types is discussed.

  5. Tunable multicolor and white-light upconversion luminescence in Yb3+/Tm3+/Ho3+ tri-doped NaYF4 micro-crystals.

    PubMed

    Lin, Hao; Xu, Dekang; Teng, Dongdong; Yang, Shenghong; Zhang, Yueli

    2015-09-01

    NaYF4 micro-crystals with various concentrations of Yb(3+) /Tm(3+) /Ho(3+) were prepared successfully via a simple and reproducible hydrothermal route using EDTA as the chelating agent. Their phase structure and surface morphology were studied using powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD patterns revealed that all the samples were pure hexagonal phase NaYF4. SEM images showed that Yb(3+)/Tm(3+)/Ho(3+) tri-doped NaYF4 were hexagonal micro-prisms. Upconversion photoluminescence spectra of Yb(3+)/Tm(3+)/Ho(3+) tri-doped NaYF4 micro-crystals with various dopant concentrations under 980 nm excitation with a 665 mW pump power were studied. Tunable multicolor (purple, purplish blue, yellowish green, green) and white light were achieved by simply adjusting the Ho(3+) concentration in 20%Yb(3+)/1%Tm(3+)/xHo(3+) tri-doped NaYF4 micro-crystals. Furthermore, white-light emissions could be obtained using different pump powers in 20%Yb(3+)/1%Tm(3+)/1%Ho(3+) tri-doped NaYF4 micro-crystals at 980 nm excitation. The pump power-dependent intensity relationship was studied and relevant energy transfer processes were discussed in detail. The results suggest that Yb(3+)/Tm(3+) Ho(3+) tri-doped NaYF4 micro-crystals have potential applications in optoelectronic devices such as photovoltaic, plasma display panel and white-light-emitting diodes.

  6. [Crystal structure and upconversion emission of Yb3+/Er(3+) -co-doped NaYF4 nanocrystals].

    PubMed

    Yao, Li-Li; Luo, Li; Dong, Guo-Shuai; Wang, Yin-Hai

    2013-11-01

    Yb3+/EP(3+) -co-doped cubic NaYF4 and Yb3+/Er3+/Gd(3+) -tri-doped hexagonal NaYF4 nanocrystals were synthesized by a modified coprecipitation method with ethylenediamine tetraacetic acid (EDTA) as chelating agent. The samples' morphology, crystal phase and upconversion emission were measured with transmission electron microscope (TEM), X-ray diffraction patterns (XRD) and upconversion luminescence spectrum. TEM and XRD results showed that the phase transition from cubic to hexagonal was promoted through Gd3+ doping. It has been reported that the upconversion efficiency of hexagonal NaYF4 is higher than that of cubic NaYF4, however, the effect of crystal phase on upconversion luminescence has not been well understood. This work focuses analysis of measurement results to compare the effect of, crystal phase on the crystal field energy splitting and upconversion emission intensity as well as emission color, and a mechanism of luminescence enhancement and color tunability are revealed. Strong visible upconversion luminescence can be seen clearly by the naked eyes in both cubic phase and hexagonal phase samples upon excitation by a 980 nm laser diode with power of 10 mW, consisting of green emissions centered at around 525/550 nm originating from the transitions of 2H11/2/4 S3/2 --> 4 I15/2 and red emission at about 657 nm from 4F9/2 to 4 I15/2 of Er3+ ions respectively. In comparison to cubic sample, the hexagonal phase sample presented much stronger and sharper upconversion luminescence, whose emission efficiency was enhanced 10 times with an additional transition of 2 H9/2 --> 4I13/2 at 557 nm, furthermore, the intensity ratio of red to green emission increased from 2 :1 to 3 : 1. Doping NaYF4 nanocrystals with Gd3+ ions induced the hexagonal-to-cubic phase transition and thus decreased the crystal symmetry, consequently increased absorption cross-section and 4f-4f transition probabilities by relaxing forbidden selection rules, resulting in stronger emission. In the

  7. White up-conversion luminescence of NaYF4:Yb3+,Pr3+,Er3+

    NASA Astrophysics Data System (ADS)

    Hölsä, Jorma; Laamanen, Taneli; Laihinen, Tero; Lastusaari, Mika; Pihlgren, Laura; Rodrigues, Lucas C. V.

    2014-08-01

    Photon up-conversion which yields higher energy emission by stacking lower energy photons is possible only with specific rare earth ions. Despite this, it has several potential applications. NaYF4 with Yb3+,Er3+ co-doping has been recognized as one of the most feasible materials for efficient up-conversion luminescence. In this work, the up-conversion luminescence of the Pr3+-Er3+ combination was studied using sensitization by Yb3+. Emission was observed in the visible including blue, green, yellow, orange and red. These are due to the 3P0,1 → 3H4-6,3F2-4 and 1D2 → 3H4 (Pr3+) as well as 2H11/2,4S3/2,4F9/2 → 4I15/2 (Er3+) transitions. Concentration quenching of the Pr3+ luminescence was observed already with 1 mol-% due to many cross-relaxation processes. With naked eye, the up-conversion luminescence was seen as white light. The CIE chromaticity coordinates are close to those of the standard illuminant F4 which represents warm white.

  8. Luminescent properties of Tm3+/ Ho3+ co-doped LiYF4 crystals

    NASA Astrophysics Data System (ADS)

    Li, Shan-shan; Xia, Hai-ping; Dong, Yan-ming; Fu, Li; Gu, Xue-mei; Zhang, Jian-li; Wang, Dong-jie; Jiang, Hao-chuan; Chen, Bao-jiu

    2014-11-01

    Ho3+ with various concentrations and Tm3+ with molar concentration of 1.28% are co-doped in LiYF4 (YLF) single crystals. The luminescent properties of the crystals are investigated through emission spectra, emission cross section and decay curves under the excitation of 808 nm. The energy transfer from Tm3+ to Ho3+ and the optimum fluorescence emission of Ho3+ around 2.05 μm are investigated. The emission intensity at 2.05 μm keeps increasing with the molar concentration of Ho3+ improved from 0.50% to 1.51% when the molar concentration of Tm3+ is kept at 1.28%. Moreover, for the co-doped crystals in which the molar concentrations of Tm3+ and Ho3+ are 1.28% and 1.51%, respectively, the maximum emission cross section reaches 0.760×10-20 cm2 and the maximum fluorescence lifetime is 21.98 ms. All the parameters suggest that these materials have more advantages in the future 2.0 μm laser applications.

  9. From research to phase III: preclinical, industrial and clinical development of the Sanofi Pasteur tetravalent dengue vaccine.

    PubMed

    Guy, Bruno; Barrere, Beatrice; Malinowski, Claire; Saville, Melanie; Teyssou, Remy; Lang, Jean

    2011-09-23

    Dengue vaccine development has reached a major milestone with the initiation, in 2010, of the first phase III clinical trial to investigate the Sanofi Pasteur CYD tetravalent dengue vaccine (TDV). The CYD TDV candidate is composed of four recombinant, live, attenuated vaccines (CYD-1-4) based on a yellow fever vaccine 17D (YFV 17D) backbone, each expressing the pre-membrane and envelope genes of one of the four dengue virus serotypes. The vaccine is genetically and phenotypically stable, non-hepatotropic, less neurovirulent than YFV 17D, and does not infect mosquitoes by the oral route. In vitro and in vivo preclinical studies showed that CYD TDV induces controlled stimulation of human dendritic cells, and significant immune responses in monkeys. Scale up and industrialization are being conducted in parallel with preclinical and clinical development to fulfill the needs of phase II/III trials, and to anticipate and facilitate supply and access to vaccine in the countries where the dengue disease burden makes it an urgent public health priority. The vaccine has now been administered to more than 6000 children and adults from dengue endemic and non-endemic areas and no safety concerns have arisen in any of the completed or ongoing trials. A three-dose vaccination regimen induces an immune response against all four serotypes in the large majority of vaccinees. Preexisting flavivirus immunity favors quicker and higher immune responses to CYD TDV, without adversely effecting clinical safety or increasing vaccine viremia. The observed level and nature of the cellular immune responses in humans are consistent with the good safety and immunogenicity profile of the vaccine. Preliminary results of an ongoing, proof-of-concept efficacy and large scale safety study in Thai children are expected by the end of 2012. Here we discuss the different steps and challenges of developing CYD TDV, from research to industrialization, and summarize some of the challenges to the successful

  10. Paramagnetism and improved upconversion luminescence properties of NaYF4:Yb,Er/NaGdF4 nanocomposites synthesized by a boiling water seed-mediated route

    NASA Astrophysics Data System (ADS)

    Yang, Chao-Qing; Li, Ao-Ju; Guo, Wei; Tian, Peng-Hua; Yu, Xiao-Long; Liu, Zhong-Xin; Cao, Yang; Sun, Zhong-Liang

    2016-03-01

    In a route boiling water served as reaction medium, a stoichiometric amount of rare-earth compound and fluoride are put into this system to form α-NaYF4:Yb, Er nuclei. Then prepared sample is heated at elevated temperature to improve the fluorescence intensity, and next a NaGdF4 shell grows on the surface of NaYF4 nuclei. NaYF4:Yb,Er/NaGdF4 core-shell structured upconversion nanoparticles (CSUCNPs) have been successfully synthesized by above route. The use of boiling water decreases the cubic-to-hexagonal phase transition temperature of NaYF4:Yb,Er to 350°C and increases its upconversion (UC) luminescence intensity. A heterogeneous NaGdF4 epitaxially growing on the surface of Ln3+-doped NaYF4 not only improves UC luminescence, but also creates a paramagnetic shell, which can be used as contrast agents in magnetic resonance imaging (MRI). The solution of CSUCNPs shows bright green UC fluorescence under the excitation at 980 nm in a power density only about 50 mW·cm-2. A broad spectrum with a dominant resonance at g of about 2 is observed by the electron paramagnetic resonance (EPR) spectrum of CSUCNPs. Above properties suggest that the obtained CSUCNPs could be potential candidates for dual-mode optical/magnetic bioapplications.

  11. Simultaneous size and luminescence control of NaYF4:Yb3+/RE3+ (RE = Tm, Ho) microcrystals via Li+ doping

    NASA Astrophysics Data System (ADS)

    Lin, Hao; Xu, Dekang; Teng, Dongdong; Yang, Shenghong; Zhang, Yueli

    2015-07-01

    Enhancement of upconversion (UC) luminescence is imperative for the applications of UC microcrystals (MCs). In this work, NaYF4:Yb3+/RE3+ (RE = Tm, Ho) MCs via Li+ doping were successfully prepared by a simple hydrothermal process with the assistance of citric acid. The UC luminescence intensities of NaYF4:Yb3+/RE3+ (RE = Tm, Ho) are significantly enhanced via Li+ doping at different concentrations. Compared to Li+-absent sample, UC luminescence intensities of blue emission (477 nm) and red emission (649 nm) in NaYF4:Yb3+/Tm3+ MCs via 15 mol% Li+ doping are improved by 10 and 9 times, respectively; UC luminescence intensities of green emission (538 nm) and red emission (644 nm) in NaYF4:Yb3+/Ho3+ MCs via 15 mol% Li+ doping are improved by 12 and 3 times, respectively. The mechanism of the enhancement via Li+ doping is discussed in details, which may be attributed to the fact that Li+ doping can cause the distortion of the local symmetry around RE ions. Our results indicate that the enhanced UC luminescence of NaYF4:Yb3+/RE3+ (RE = Tm, Ho) MCs via Li+ doping may have potential applications in optoelectronic devices such as solar cells and plasma display panel.

  12. Semi-emprical and ab initio study of lanthanide and transition metal ions doped in hexagonol beta-NaYF4

    NASA Astrophysics Data System (ADS)

    Yao, Ge

    Lanthanide and transition metal doped hexagonal beta-NaYF4 nanocrystals have a wide variety of applications in bioimaging, solar concentrators, display panel technology, photodynamic therapy, and security printing. This dissertation research employed two complementary approaches to characterizing the photoactive properties of lanthanides and transition metals doped in beta-NaYF 4. One approach was a semi-empirical method, based on Judd-Ofelt theory, used to calculate the optical transition intensity parameters for Er 3+ doped in beta-phase NaYF4:Yb3+ from measured emission intensity ratios and the diffuse reflectance spectrum. The second approach was based on first-principles density functional theory, investigating the effect of doping on the electronic structure of the materials of interest. In this latter approach, models of beta-NaYF4 with different numbers of atoms in supercells were built, where supercells were reproduced through translational symmetry creating periodic boundary conditions. The models were tested for convergence of local structure and energy as a function of supercell size. First, a converged model for the un-doped "parent" structure of the host material was developed using the Perdew-Burke-Ernzerhof (PBE) functional. Then, a systematic investigation of the optimized geometry and electronic structure of the doped beta-NaYF4: Ln3+ nanocrystals, was conducted using both spin-polarized DFT and non-collinear-spin DFT. For transition metal doping, the relationship between site symmetry and spin state with different doping concentrations was also demonstrated.

  13. Licensed Dengue Vaccine: Public Health Conundrum and Scientific Challenge

    PubMed Central

    Halstead, Scott B.

    2016-01-01

    A tetravalent live attenuated vaccine composed of chimeras of yellow fever 17D and the four dengue viruses (chimeric yellow fever dengue [CYD]) manufactured by Sanofi Pasteur has completed phase III clinical testing in over 35,000 children 2–16 years of age. The vaccine was recently licensed in four countries. During the first 2 years of observation, CYD vaccine efficacy ranged between 30% and 79% in 10 different countries with an overall efficacy of 56.8%. During year 3, there was an overall efficacy against hospitalization of 16.7%, but a relative risk of hospitalization of 1.6 among children younger than 9 years and 4.95 in children 5 years of age and younger. Vaccination of seronegative children resulted in universal broad dengue neutralizing antibody responses, but poor protection against breakthrough dengue cases. Unless proven otherwise, such breakthrough cases in vaccinated subjects should be regarded as vaccine antibody-enhanced (ADE). The provenance of these cases can be studied serologically using original antigenic sin immune responses in convalescent sera. In conventional dengue vaccine efficacy clinical trials, persons vaccinated as seronegatives may be hospitalized with breakthrough ADE infections, whereas in the placebo group, dengue infection of monotypic immunes results in hospitalization. Vaccine efficacy trial design must identify dengue disease etiology by separately measuring efficacy in seronegatives and seropositives. The reason(s) why CYD vaccine failed to raise protective dengue virus immunity are unknown. To achieve a safe and protective dengue vaccine, careful studies of monotypic CYD vaccines in humans should precede field trials of tetravalent formulations. PMID:27352870

  14. Tuning the Energy Transfer Efficiency between Ce(3+) and Ln(3+) Ions (Ln=Tm, Sm, Tb, Dy) by Controlling the Crystal Phase of NaYF4 Nanocrystals.

    PubMed

    Adusumalli, Venkata N K B; Koppisetti, Heramba V S R M; Ganguli, Sagar; Sarkar, Shyam; Mahalingam, Venkataramanan

    2017-01-23

    NaYF4 is a superior host matrix to study the luminescence properties of lanthanide (Ln(3+) ) ions. Ln(3+) ions in hexagonal-phase NaYF4 (β-phase) nanocrystals (NCs) exhibit strong luminescence via an upconversion process compared to cubic NaYF4 (α-phase) NCs. However, in Ce(3+) /Ln(3+) -doped NaYF4 NCs (Ln=Tm, Tb, Sm, Dy) the α-phase NaYF4 NCs shows strong luminescence compared to their counterpart β-phase NCs despite the latter being much larger in size. This is attributed to comparatively large overlap between Ce(3+) ions emission band with excited energy levels of those Ln(3+) ions in α-phase compared to β-phase NCs. This difference is attributed to different crystal-field splitting of Ce(3+) ions 4f-5d band in different crystal environments of the α-phase (cubic crystal field environment) and β-phase (trigonal prismatic with equatorials crystal field environment) NaYF4 NCs with respect to their barycenter. The enhanced luminescence from α-phase NaYF4 NCs is advantageous as they are prepared at a relatively lower temperature and shorter reaction times compared to β-NaYF4 NCs.

  15. Highly efficient Yb3+/Tm3+ co-doped NaYF4 nanotubes: Synthesis and intense ultraviolet to infrared up-conversion luminescence

    NASA Astrophysics Data System (ADS)

    Zhang, Y. Y.; Wang, Y.; Deng, J. Q.; Wang, J.; Ni, S. C.

    2014-02-01

    Nanocrystals of up-conversion (UC) phosphor Yb3+/Tm3+ co-doped NaYF4 are prepared by a facile hydrothermal method using oleic acid as a stabilizing agent. The as-prepared nanocrystals are of hexagonal phase, and have tube-like morphology and strong ultraviolet (UV) and blue UC fluorescence intensity, which have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and luminescence spectroscopy. The effect of Yb3+ concentration on the UC emission properties is also analyzed. Our results reveal that the intensity of emission peaks can be controlled by varying the Yb3+ concentration and these NaYF4 nanotubes are highly efficient host material. The as-prepared NaYF4 nanotubes show potential applications in UV compact solid state lasers and multi-channel fluorescent label.

  16. Design and flight testing actuator failure accommodation controllers on WVU YF-22 research UAVs

    NASA Astrophysics Data System (ADS)

    Gu, Yu

    This dissertation describes the design, development, and flight testing of a Neural Network (NN) based Fault Tolerant Flight Control System (FTFCS) with the ability to accommodate for actuator failures. The goal of this research was to demonstrate the ability of a specific set of control laws to maintain aircraft handling qualities in the presence of failures in the actuator channels. In this study, two-failure scenarios have been investigated: aileron failure (locking of the right aileron at a trim position) and elevator failure (locking of the right elevator at a trim position). A fleet of WVU YF-22 research aircraft test-beds were manufactured and instrumented for developing and testing of flight control software. An on-board payload with a PC-104 format computer system, sensors, and custom made circuit boards were designed and developed for these aircraft test-beds. The fault tolerant flight control systems for this study were designed to recover the aircraft with damaged actuators. On-board real-time data acquisition and control software was developed to achieve the Actuator Failure Accommodation (AFA) flight demonstration. For the purposes of this research, control laws were required to be adaptive to changing aircraft dynamics during a failure scenario. On-line learning NNs---with their non-linearity and learning abilities---were used in the design of the on-board aircraft control scheme. The on-line training reduced the criticality of an extensive on-line Parameter IDentification (PID) during the failure and gives an on-board flight controller the capability to adjust to maintain the best possible flight performance during an unexpected failure. This document will outline and describe the design and building of the flight controller, aircraft test-beds, on-board payload systems, and software in detail. Flight test results will be presented and documented to demonstrate the performance of a NN based FTFCS under failure conditions.

  17. Experimental Performance of R-1234yf and R-1234ze as Drop-in Replacements for R-134a in Domestic Refrigerators

    SciTech Connect

    Karber, Kyle M; Abdelaziz, Omar; Vineyard, Edward Allan

    2012-01-01

    Concerns about anthropogenic climate change have generated an interest in low global warming potential (GWP) refrigerants and have spawned policies and regulations that encourage the transition to low GWP refrigerants. Recent research has largely focused on hydrofluoroolefins (HFOs), including R-1234yf (GWP = 4) as a replacement for R-134a (GWP = 1430) in automotive air-conditioning applications. While R-1234yf and R-1234ze (GWP = 6) have been investigated theoretically as a replacements for R-134a in domestic refrigeration, there is a lack of experimental evidence. This paper gives experimental performance data for R-1234yf and R-1234ze as drop-in replacements for R134a in two household refrigerators one baseline and one advanced technology. An experiment was conducted to evaluate and compare the performance of R-134a to R-1234yf and R-1234ze, using AHAM standard HRF-1 to evaluate energy consumption. These refrigerants were tested as drop-in replacements, with no performance enhancing modifications to the refrigerators. In Refrigerator 1 and 2, R-1234yf had 2.7% and 1.3% higher energy consumption than R-134a, respectively. This indicates that R-1234yf is a suitable drop-in replacement for R-134a in domestic refrigeration applications. In Refrigerator 1 and 2, R-1234ze had 16% and 5.4% lower energy consumption than R-134a, respectively. In order to replace R-134a with R-1234ze in domestic refrigerators the lower capacity would need to be addressed, thus R-1234ze might not be suitable for drop-in replacement.

  18. Evaluation by step response tests of prototype relief valves designed for YF-12 inlet stability bleed system

    NASA Technical Reports Server (NTRS)

    Dustin, M. O.; Neiner, G. H.

    1975-01-01

    Two stability bleed system relief valves were tested in a special dynamic test facility. These poppet valves are prototypes for a stability bleed system designed for use in a YF-12 flight inlet. One valve is unshielded, while the other has a special shield to eliminate the flow effect pressures on the piston. The tests determined the size of a damping orifice to be used during wind tunnel tests of the bleed system and verified an analog simulation of the valves. The effects of initial pressure level, pressure step size, and spring rate were investigated.

  19. Optical characterization of Tm3+ in LiYF4 and LiLuF4 crystals

    NASA Astrophysics Data System (ADS)

    Xiong, Jing; Peng, HaiYan; Hu, Pengchao; Hang, Yin; Zhang, Lianhan

    2010-05-01

    A comparative study of the optical properties of Tm3+ in LiYF4 (YLF) and LiLuF4 (LLF) crystals is presented. Room temperature polarized absorption spectra and fluorescence spectra for Tm3+ in LYF and LLF were measured and analysed. By applying the Judd-Ofelt approach, the intensity parameters Ω2,4,6 were calculated. The radiative transition rates, branching ratios and radiative lifetimes were also obtained. The results were analysed and compared between these two samples, indicating that both of them are favourable laser media.

  20. An ab initio density functional theory calculations on the K2YF5 crystal containing hydroxyl impurities

    NASA Astrophysics Data System (ADS)

    Gallegos-Cuellar, A. A.; Licona-Ibarra, R.; Rivas-Silva, J. F.; Flores-Riveros, A.; Azorín Nieto, J.; Casco-Vásquez, J. F.

    2013-11-01

    High frequency absorption spectral lines not matching any of the chemical constituents were observed while analyzing the infrared experimental spectrum of a K2YF5:Tb+3 sample. We ascribe these lines to the presence of impurities that inadvertently contaminated the crystal compound during synthesis, whose mass and electronegativity apparently indicate OH substitutional ions occupying fluorine sites. In this report we have performed ab initio calculations by means of a solid state computational code, applied to a model consisting of a potassium-yttrium-double fluoride structure where OH ion aggregates are introduced on F sites, which indeed confirm such assignment.

  1. Sequential three-step three-photon near-infrared quantum splitting in β-NaYF4:Tm3+

    NASA Astrophysics Data System (ADS)

    Yu, D. C.; Ye, S.; Peng, M. Y.; Zhang, Q. Y.; Wondraczek, L.

    2012-05-01

    We report on sequential three-step three-photon near-infrared (NIR) quantum splitting in Tm3+-doped β-NaYF4, where an incident blue photon around 470 nm is split into three NIR photons (1165, 1466, and 1800 nm). The underlying mechanism is analyzed by means of static and dynamic photoemission spectroscopy. Here, an experimental total quantum yield of ˜32% is obtained. When quenching due to residual hydroxyl groups and other defect species can be overcome, numerical analyses indicate a theoretical maximum quantum yield of 158%, suggesting application in efficient spectral converters.

  2. Broadband-tunable CW laser operation of Pr(3+):LiYF(4) around 900  nm.

    PubMed

    Qu, Biao; Moncorgé, Richard; Cai, Zhiping; Doualan, Jean-Louis; Xu, Bin; Xu, Huiying; Braud, Alain; Camy, Patrice

    2015-07-01

    We present here the first broadband-tunable CW laser operation of a Pr(3+)-doped LiYF(4) crystal in the 900-nm spectral range after pumping with an optically pumped semiconductor laser at 479 nm. It is confirmed that the entire emission band can be assigned to the same set of thermalized emitting levels (I(6)1,P3(0,1)). It is also demonstrated that laser performance could be improved up to laser slope efficiencies of about 33% with threshold absorbed pump powers not exceeding 100 mW.

  3. Typhoid Vaccine

    MedlinePlus

    ... serious disease. It is caused by bacteria called Salmonella Typhi. Typhoid causes a high fever, fatigue, weakness, stomach ... a typhoid carrier. Laboratory workers who work with Salmonella Typhi bacteria. Inactivated typhoid vaccine (shot)One dose provides ...

  4. Typhoid Vaccine

    MedlinePlus

    ... serious disease. It is caused by bacteria called Salmonella Typhi. Typhoid causes a high fever, fatigue, weakness, ... a typhoid carrier. • Laboratory workers who work with Salmonella Typhi bacteria. Inactivated typhoid vaccine (shot) • One dose ...

  5. An infrared pump-probe measurement of the Sm3+6H7/2 lifetime in LiYF4

    NASA Astrophysics Data System (ADS)

    Horvath, Sebastian P.; Wells, Jon-Paul R.; van der Meer, Alexander F. G.; Reid, Michael F.

    2017-04-01

    We report a pump-probe measurement of the lifetime of the 6H7/2 multiplet of Sm3+:LiYF4. A lifetime of 3.1 ± 0.3 ps was inferred for the Y2 level of the 6H7/2 multiplet. This lifetime is two orders of magnitude faster than for a similar energy gap in Nd3+:LiYF4, and does not follow the prediction of a simple exponential energy-gap law for non-radiative relaxation in this material.

  6. Optical spectroscopy and diode-pumped laser characteristics of codoped Tm-Ho:YLF and Tm-Ho:BaYF: a comparative analysis

    NASA Astrophysics Data System (ADS)

    Cornacchia, F.; Sani, E.; Toncelli, A.; Tonelli, M.; Marano, M.; Taccheo, S.; Galzerano, G.; Laporta, P.

    Single crystals of monoclinic BaY2F8 and tetragonal LiYF4 codoped with the same Tm3+ and Ho3+ concentrations were successfully grown by the Czochralski method. Here we present a comparative analysis of the two hosts including spectroscopic characterization and cw diode-pumped laser experiments in the 2-μm wavelength region at room temperature. The main differences between the two hosts are a lower slope efficiency associated with a much wider tuning range (2005-2094 nm) of BaY2F8 with respect to LiYF4.

  7. Ear Infection and Vaccines

    MedlinePlus

    ... an ENT Doctor Near You Ear Infection and Vaccines Ear Infection and Vaccines Patient Health Information News ... or may need reinsertion over time. What about vaccines? A vaccine is a preparation administered to stimulate ...

  8. Adults Need Vaccines, Too!

    MedlinePlus

    ... turn JavaScript on. Feature: Adult Vaccinations Adults Need Vaccines, Too! Past Issues / Summer 2015 Table of Contents ... of the millions of adults not receiving the vaccines you need? What vaccines do you need? All ...

  9. Smallpox Vaccine Overview

    MedlinePlus

    ... Facebook Tweet Share Compartir SMALLPOX FACT SHEET The Smallpox Vaccine The smallpox vaccine helps the body develop ... disease or may modify the severity of disease. Smallpox Vaccine Safety The smallpox vaccine is the best ...

  10. Influenza Vaccine, Live Intranasal

    MedlinePlus

    ... the recombinant influenza vaccine (RIV). The nasal spray flu vaccine (live attenuated influenza vaccine or LAIV) should NOT ... to your doctor or pharmacist about the best flu vaccine option for you or your family.

  11. Deep, high contrast microscopic cell imaging using three-photon luminescence of β-(NaYF4:Er3+/NaYF4) nanoprobe excited by 1480-nm CW laser of only 1.5-mW

    PubMed Central

    Liu, Jing; Wu, Ruitao; Li, Nana; Zhang, Xin; Zhan, Qiuqiang; He, Sailing

    2015-01-01

    It is challenging to achieve deep microscopic imaging for the strong scattering in biotissue. An efficient three-photon luminescence can effectively increase the penetration depth. Here we report that β-NaYF4: Er3+/NaYF4 UCNPs were excited by a 1480-nm CW-laser and emitted 543/653-nm light through a three-photon process. With the merit of the hexagonal crystal phase, sub-milliwatt laser power was utilized to excite the UCNP-probed cells to minimize the heating effect. The polymer-coated UCNPs were shown to be harmless to cells. The deep, high contrast in vitro microscopic imaging was implemented through an artificial phantom. Imaging depth of 800 μm was achieved using only 1.5 mW excitation and a 0.7 NA objective. The green/red emission intensities ratio after penetrating the phantom was studied, indicating that longer emission wavelength is preferred for deep multiphoton microscopy. The proposed and demonstrated β-UCNPs would have great potential in three-photon microscopy. PMID:26137385

  12. Deep, high contrast microscopic cell imaging using three-photon luminescence of β-(NaYF4:Er(3+)/NaYF4) nanoprobe excited by 1480-nm CW laser of only 1.5-mW.

    PubMed

    Liu, Jing; Wu, Ruitao; Li, Nana; Zhang, Xin; Zhan, Qiuqiang; He, Sailing

    2015-05-01

    It is challenging to achieve deep microscopic imaging for the strong scattering in biotissue. An efficient three-photon luminescence can effectively increase the penetration depth. Here we report that β-NaYF4: Er(3+)/NaYF4 UCNPs were excited by a 1480-nm CW-laser and emitted 543/653-nm light through a three-photon process. With the merit of the hexagonal crystal phase, sub-milliwatt laser power was utilized to excite the UCNP-probed cells to minimize the heating effect. The polymer-coated UCNPs were shown to be harmless to cells. The deep, high contrast in vitro microscopic imaging was implemented through an artificial phantom. Imaging depth of 800 μm was achieved using only 1.5 mW excitation and a 0.7 NA objective. The green/red emission intensities ratio after penetrating the phantom was studied, indicating that longer emission wavelength is preferred for deep multiphoton microscopy. The proposed and demonstrated β-UCNPs would have great potential in three-photon microscopy.

  13. Human vaccines & immunotherapeutics: news.

    PubMed

    Riedmann, Eva M

    2013-10-01

    Infant rotavirus vaccination provides for herd immunity Nonreplicating sporozoite vaccine protects humans against malaria Personalized brain cancer vaccine enters phase 2 trial Novel implantable therapeutic cancer vaccine to be tested in humans Clostridium difficile vaccine candidate successful in phase 1 CDC reports strong uptake of HPV vaccine in boys Whooping cough outbreak in Texas.

  14. EPR, ENDOR and HYSCORE study of X-ray induced centres in K2YF5 thermoluminescent phosphors.

    PubMed

    Zverev, Dmitry; Vrielinck, Henk; Callens, Freddy; Matthys, Paul; Van Doorslaer, Sabine; Khaidukov, Nicholas M

    2008-04-07

    X-Ray irradiation at room temperature produces several paramagnetic centres in rare-earth activated K2YF5 crystals, whose thermal annealing behaviour can be linked with the occurrence of thermoluminescence (TL) glow peaks. In this paper, continuous wave (CW) and pulsed paramagnetic resonance techniques are used to study the structure of a very stable radiation-induced centre, which may be involved in the TL peak at approximately 390 degrees C reported for Ce- and Tb-activated crystals. From the spectra the centre's g tensor and hyperfine (nuclear quadrupole) tensors for several 19F and 39K neighbouring nuclei are extracted, but no self-hyperfine interaction could be detected. Based on the analysis of the interaction tensors, a model is constructed consisting of an oxygen-related radical (e.g. O(-) or O2(-)) on a substitutional F(-) position in the mirror plane of the YF7 polyhedra. Such a centre most probably corresponds to a trapped-hole state.

  15. Infrared spectral properties for α-NaYF4 single crystal of various Er3+doping concentrations

    NASA Astrophysics Data System (ADS)

    Wang, Cheng; Xia, Haiping; Feng, Zhigang; Zhang, Zhixiong; Jiang, Dongsheng; Zhang, Jian; He, Shinan; Tang, Qingyang; sheng, Qiguo; Gu, Xuemei; Zhang, Yuepin; Chen, Baojiu; Jiang, Haochuan

    2016-08-01

    The α-NaYF4 single crystals doped with 0.2 mol%, 0.5 mol%, 1 mol%, 2 mol% and 3 mol% Er3+ ions were fabricated by an improved Bridgman method. The ~1.5 μm and ~2.7 μm emission properties were investigated in detail through the measured absorption and emission spectra. A Judd-Ofelt analysis of Er3+in α-NaYF4 samples is performed. The Judd-Ofelt parameters are obtained (Ω2=2.71×10-20 cm2, Ω4=2.28×10-20 cm2, Ω6=0.84×10-20 cm2) and the radiative lifetimes of Er3+energy levels and the branching ratios of Er3+transitions are calculated. The calculated maximum emission cross section by McCumber theory for ~1.5 μm and ~2.7 μm reached 1.35×10-20 cm2 and 2.2×10-20 cm2, respectively. The gain cross section spectra were calculated based on the absorption and emission cross section spectra. All these spectral properties indicated that this kind of fluoride crystal has potential application as host material for infrared lasers.

  16. Solvothermal synthesis and upconversion properties of YF3:Ln (Ln = Yb/Er,Yb/Tm,Yb/Ho) nanoparticles.

    PubMed

    He, Fei; Wang, Lin; Niu, Na; Gai, Shili; Wang, Yan; Yang, Piaoping

    2014-05-01

    YF3 nanoparticles with different morphology, dimension, and dispersity have been synthesized through a simple solvothermal method by using n-octanol and n-octylamine as a mixed solvent and lanthanide acetylacetonate as the RE3+ source. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectrum (EDS) and up-conversion (UC) photoluminescence spectra were used to characterize the samples. The results reveal that the morphology and dimension of the as-prepared nanoparticles can be regulated by adjusting n-octanol/ n-octylamine volume ratio in the initial system. Besides, by doping with different rare-earth elements (Yb/Er, Yb/Tm, Yb/Ho), the as-prepared YF3 samples can emit characteristic green, blue, and yellow light under 980 nm laser excitation. Additionally, when being co-doped with the activator ion-pairs Tm/Er and Tm/Ho, the color of the emission light can be further modified by adjusting the Yb3+ ion content.

  17. Structural investigations of sol-gel-derived LiYF{sub 4} and LiGdF{sub 4} powders

    SciTech Connect

    Lepoutre, S.; Boyer, D. Potdevin, A.; Dubois, M.; Briois, V.; Mahiou, R.

    2007-11-15

    A soft synthesis route based on the sol-gel process was used for preparing rare-earth tetrafluoride powders from alkoxide precursors. In-situ fluorination was performed by decomposition of a fluorine containing organic compound named 1,1,1-trifluoro-5-methyl-2,4-hexanedione when sintering the as-prepared xerogel to produce crystallized samples. Both to insure complete departure of organic residues as well as to avoid any oxidation into oxyfluoride, annealing treatment was carried out under fluorine atmosphere. Free-oxygen content of resulting samples was evidenced by infrared and Raman spectroscopies. X-ray absorption spectroscopies (XAS) and {sup 19}F nuclear magnetic resonance (NMR) studies showed that samples heat treated at 300 deg. C are already crystallized but for a full crystallization in LiGdF{sub 4} and LiYF{sub 4} a thermal treatment at 550 deg. C is needed. Temperature dependence of powder morphology was analyzed by scanning electron microscopy (SEM). - Graphical abstract: The sol-gel route is a soft process, which allows developing versatile-shaped compounds. A fluorine organic compound named 1,1,1-trifluoro-5-methyl-2,4-hexadione was used to synthesis LiGdF{sub 4} and LiYF{sub 4} powders based on the sol-gel method. These materials can be used as host lattices for rare-earth ions to provide phosphors.

  18. HIV Infection and Adult Vaccination

    MedlinePlus

    ... conjugate vaccine series which protects against meningococcal disease Hepatitis B vaccine series to protect against hepatitis B HPV vaccine ... conjugate vaccine series which protects against meningococcal disease Hepatitis B vaccine series to protect against hepatitis B HPV vaccine ...

  19. Cancer vaccines.

    PubMed

    Butterfield, Lisa H

    2015-04-22

    Cancer vaccines are designed to promote tumor specific immune responses, particularly cytotoxic CD8 positive T cells that are specific to tumor antigens. The earliest vaccines, which were developed in 1994-95, tested non-mutated, shared tumor associated antigens that had been shown to be immunogenic and capable of inducing clinical responses in a minority of people with late stage cancer. Technological developments in the past few years have enabled the investigation of vaccines that target mutated antigens that are patient specific. Several platforms for cancer vaccination are being tested, including peptides, proteins, antigen presenting cells, tumor cells, and viral vectors. Standard of care treatments, such as surgery and ablation, chemotherapy, and radiotherapy, can also induce antitumor immunity, thereby having cancer vaccine effects. The monitoring of patients' immune responses at baseline and after standard of care treatment is shedding light on immune biomarkers. Combination therapies are being tested in clinical trials and are likely to be the best approach to improving patient outcomes.

  20. Nanoparticle vaccines.

    PubMed

    Zhao, Liang; Seth, Arjun; Wibowo, Nani; Zhao, Chun-Xia; Mitter, Neena; Yu, Chengzhong; Middelberg, Anton P J

    2014-01-09

    Nanotechnology increasingly plays a significant role in vaccine development. As vaccine development orientates toward less immunogenic "minimalist" compositions, formulations that boost antigen effectiveness are increasingly needed. The use of nanoparticles in vaccine formulations allows not only improved antigen stability and immunogenicity, but also targeted delivery and slow release. A number of nanoparticle vaccines varying in composition, size, shape, and surface properties have been approved for human use and the number of candidates is increasing. However, challenges remain due to a lack of fundamental understanding regarding the in vivo behavior of nanoparticles, which can operate as either a delivery system to enhance antigen processing and/or as an immunostimulant adjuvant to activate or enhance immunity. This review provides a broad overview of recent advances in prophylactic nanovaccinology. Types of nanoparticles used are outlined and their interaction with immune cells and the biosystem are discussed. Increased knowledge and fundamental understanding of nanoparticle mechanism of action in both immunostimulatory and delivery modes, and better understanding of in vivo biodistribution and fate, are urgently required, and will accelerate the rational design of nanoparticle-containing vaccines.

  1. Synthesis, Characterization, and Application of Core–Shell Co0.16Fe2.84O4@NaYF4(Yb, Er) and Fe3O4@NaYF4(Yb, Tm) Nanoparticle as Trimodal (MRI, PET/SPECT, and Optical) Imaging Agents

    PubMed Central

    2015-01-01

    Multimodal nanoparticulate materials are described, offering magnetic, radionuclide, and fluorescent imaging capabilities to exploit the complementary advantages of magnetic resonance imaging (MRI), positron emission tomography/single-photon emission commuted tomography (PET/SPECT), and optical imaging. They comprise Fe3O4@NaYF4 core/shell nanoparticles (NPs) with different cation dopants in the shell or core, including Co0.16Fe2.84O4@NaYF4(Yb, Er) and Fe3O4@NaYF4(Yb, Tm). These NPs are stabilized by bisphosphonate polyethylene glycol conjugates (BP-PEG), and then show a high transverse relaxivity (r2) up to 326 mM–1 s–1 at 3T, a high affinity to [18F]-fluoride or radiometal-bisphosphonate conjugates (e.g., 64Cu and 99mTc), and fluorescent emissions from 500 to 800 nm under excitation at 980 nm. The biodistribution of intravenously administered particles determined by PET/MR imaging suggests that negatively charged Co0.16Fe2.84O4@NaYF4(Yb, Er)-BP-PEG (10K) NPs cleared from the blood pool more slowly than positively charged NPs Fe3O4@NaYF4(Yb, Tm)-BP-PEG (2K). Preliminary results in sentinel lymph node imaging in mice indicate the advantages of multimodal imaging. PMID:26172432

  2. Enhanced photovoltaic performance of dye-sensitized solar cells based on NaYF4:Yb(3+), Er(3+)-incorporated nanocrystalline TiO2 electrodes.

    PubMed

    Zhu, Guang; Wang, Hongyan; Zhang, Quanxin; Zhang, Li

    2015-08-01

    Near infrared to visible up-conversion of light by rare earth ion-doped phosphors (NaYF4:Yb(3+), Er(3+)) that convert multiple photons of lower energy to higher energy photons offer new possibilities for improved performance of photovoltaic devices. Here, up-conversion phosphor NaYF4:Yb(3+), Er(3+) doped nanocrystalline TiO2 films are designed and used as a electrode for dye-sensitized solar cells, and the photovoltaic performance of DSSCs based on composite electrodes are investigated. The results show the cell with NaYF4:Yb(3+), Er(3+) achieves a power conversion efficiency of 7.65% under one sun illumination (AM 1.5G, 100mWcm(-2)), which is an increase of 14% compared to the cell without NaYF4:Yb(3+), Er(3+) (6.71%). The performance improvement is attributed to the dual effects of enhanced light harvesting from extended light absorption range and increased light scattering, and lower electron transfer resistance.

  3. Synthesis of Upconversion β-NaYF4:Nd3+/Yb3+/Er3+ Particles with Enhanced Luminescent Intensity through Control of Morphology and Phase

    PubMed Central

    Shang, Yunfei; Hao, Shuwei; Liu, Jing; Tan, Meiling; Wang, Ning; Yang, Chunhui; Chen, Guanying

    2015-01-01

    Hexagonal NaYF4:Nd3+/Yb3+/Er3+ microcrystals and nanocrystals with well-defined morphologies and sizes have been synthesized via a hydrothermal route. The rational control of initial reaction conditions can not only result in upconversion (UC) micro and nanocrystals with varying morphologies, but also can produce enhanced and tailored upconversion emissions from the Yb3+/Er3+ ion pairs sensitized by the Nd3+ ions. The increase of reaction time converts the phase of NaYF4:Nd3+/Yb3+/Er3+ particles from the cubic to the hexagonal structure. The added amount of oleic acid plays a critical role in the shape evolution of the final products due to their preferential attachment to some crystal planes. The adjustment of the molar ratio of F−/Ln3+ can range the morphologies of the β-NaYF4:Nd3+/Yb3+/Er3+ microcrystals from spheres to nanorods. When excited by 808 nm infrared laser, β-NaYF4:Nd3+/Yb3+/Er3+ microplates exhibit a much stronger UC emission intensity than particles with other morphologies. This phase- and morphology-dependent UC emission holds promise for applications in photonic devices and biological studies.

  4. Intense 2.7 μm mid-infrared emission of Er{sup 3+} in oxyfluoride glass ceramic containing NaYF{sub 4} nanocrystals

    SciTech Connect

    Liu, Yin; Liu, Xueyun; Wang, Weichao; Yu, Ting; Zhang, Qinyuan

    2016-04-15

    Highlights: • Transparent oxyfluoride glass-ceramics containing NaYF{sub 4}:Er{sup 3+} nanocrystals have been prepared. • Intense 2.7 μm emission of the glass-ceramics has been demonstrated. • Prolonged decay lifetimes of Er{sup 3+}:{sup 4}I{sub 11/2} and {sup 4}I{sub 13/2} levels have been achieved. - Abstract: Transparent oxyfluoride glass ceramics containing NaYF{sub 4}:Er{sup 3+} nanocrystals have been prepared by melt quenching and subsequent thermal treatment. X-ray diffraction and high-resolution transmission electron microscopy analysis confirmed the precipitation of NaYF{sub 4} nanocrystals in glass. Energy dispersive spectrometer results evidenced the preferential concentration of Er{sup 3+} ions in nanocrystals. Mid-infrared, upconversion, and near-infrared emissions were measured upon excitation with 980 nm laser diode and the luminescence mechanisms were discussed. Intense 2.7 μm emission originating from the Er{sup 3+}:{sup 4}I{sub 11/2} → {sup 4}I{sub 13/2} transition was achieved due to the incorporation of Er{sup 3+} ions into the precipitated low phonon energy fluoride nanocrystals. The results indicate that oxyfluoride glass ceramic containing NaYF{sub 4}:Er{sup 3+} nanocrystals is a promising candidate material for 2.7 μm laser.

  5. Fabrication of NaYF4:Yb,Er Nanoprobes for Cell Imaging Directly by Using the Method of Hydrion Rivalry Aided by Ultrasonic

    NASA Astrophysics Data System (ADS)

    Li, Zhihua; Miao, Haixia; Fu, Ying; Liu, Yuxiang; Zhang, Ran; Tang, Bo

    2016-10-01

    A novel method of fabricating water-soluble bio-probes with ultra-small size such as NaYF4:Yb,Er (18 nm), NaGdF4:Yb,Er (8 nm), CaF2:Yb,Er (10 nm), PbS (7 nm), and ZnS (12 nm) has been developed to provide for the solubility switch of nanoparticles from oil-soluble to water-soluble in terms of hydrion rivalry aided by ultrasonic. Using NaYF4:Yb,Er (18 nm) as an example, we evaluate the properties of as-prepared water-soluble nanoparticles (NPs) by using thermogravimetric analyses (TGA), Fourier transform infrared spectroscopy (FTIR), zeta potential ( ζ) testing, and 1H nuclear magnetic resonance (1HNMR). The measured ζ value shows that the newly prepared hydrophilic NaYF4:Yb,Er NPs are the positively charged particles. Acting as reactive electrophilic moiety, the freshly prepared hydrophilic NaYF4:Yb,Er NPs have carried out the coupling with amino acids and fluorescence labeling and imaging of HeLa cells directly. Experiments indicate that the method of hydrion rivalry aided by ultrasonic provides a simple and novel opportunity to transform hydrophobic NPs into hydrophilic NPs with good reactivity, which can be imaging some specific biological targets directly.

  6. Mucosal vaccines

    PubMed Central

    Nizard, Mevyn; Diniz, Mariana O; Roussel, Helene; Tran, Thi; Ferreira, Luis CS; Badoual, Cecile; Tartour, Eric

    2014-01-01

    The mucosal immune system displays several adaptations reflecting the exposure to the external environment. The efficient induction of mucosal immune responses also requires specific approaches, such as the use of appropriate administration routes and specific adjuvants and/or delivery systems. In contrast to vaccines delivered via parenteral routes, experimental, and clinical evidences demonstrated that mucosal vaccines can efficiently induce local immune responses to pathogens or tumors located at mucosal sites as well as systemic response. At least in part, such features can be explained by the compartmentalization of mucosal B and T cell populations that play important roles in the modulation of local immune responses. In the present review, we discuss molecular and cellular features of the mucosal immune system as well as novel immunization approaches that may lead to the development of innovative and efficient vaccines targeting pathogens and tumors at different mucosal sites. PMID:25424921

  7. Development and Characterization of Monoclonal Antibodies to Yellow Fever Virus and Application in Antigen Detection and IgM Capture Enzyme-Linked Immunosorbent Assay

    PubMed Central

    Adungo, Ferdinard; Kamau, David; Inoue, Shingo; Hayasaka, Daisuke; Posadas-Herrera, Guillermo; Sang, Rosemary; Mwau, Matilu

    2016-01-01

    Yellow fever (YF) is an acute hemorrhagic viral infection transmitted by mosquitoes in Africa and South America. The major challenge in YF disease detection and confirmation of outbreaks in Africa is the limited availability of reference laboratories and the persistent lack of access to diagnostic tests. We used wild-type YF virus sequences to generate recombinant envelope protein in an Escherichia coli expression system. Both the recombinant protein and sucrose gradient-purified YF vaccine virus 17D (YF-17D) were used to immunize BALB/c mice to generate monoclonal antibodies (MAbs). Eight MAbs were established and systematically characterized by indirect enzyme-linked immunosorbent assay (ELISA), Western blot analysis, and immunofluorescence assay (IFA). The established MAbs showed strong reactivity with wild-type YF virus and recombinant protein with no detectable cross-reactivity to dengue virus or Japanese encephalitis virus. Epitope mapping showed strong binding of three MAbs to amino acid positions 1 to 51, while two MAbs mapped to amino acid positions 52 to 135 of the envelope protein. The remaining three MAbs did not show reactivity to envelope fragments. The established MAbs exert no neutralization against wild-type YF and 17D viruses (titer of <10 for both strains). The applicability of MAbs 8H3 and 3F4 was further evaluated using IgM capture ELISA. A total of 49 serum samples were analyzed, among which 12 positive patient and vaccinee samples were correctly identified. Using serum samples that were 2-fold serially diluted, the IgM capture ELISA was able to detect all YF-positive samples. Furthermore, MAb-based antigen detection ELISA enabled the detection of virus in culture supernatants containing titers of about 1,000 focus-forming units. PMID:27307452

  8. Immune Interference After Sequential Alphavirus Vaccine Vaccinations

    DTIC Science & Technology

    2009-01-01

    REPORT DATE 11 MAR 2009 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Immune interference after sequential alphavirus ...of administration of investigational alphavirus vaccines on neutralizing antibody response. Volunteers who received the inactivated eastern and...vaccine strategy among those receiving multiple alphavirus vaccines and those developing next generation vaccines for these threats. 15. SUBJECT TERMS

  9. 2.0-μm emission and energy transfer of Ho3+/Yb3+ co-doped LiYF4 single crystal excited by 980 nm

    NASA Astrophysics Data System (ADS)

    Yang, Shuo; Xia, Hai-Ping; Jiang, Yong-Zhang; Zhang, Jia-Zhong; Jiang, Dong-Sheng; Wang, Cheng; Feng, Zhi-Gang; Zhang, Jian; Gu, Xue-Mei; Zhang, Jian-Li; Jiang, Hao-Chuan; Chen, Bao-Jiu

    2015-06-01

    Ho3+/Yb3+ co-doped LiYF4 single crystals with various Yb3+ concentrations and ˜ 0.98 mol% Ho3+ concentration are grown by the Bridgman method under the conditions of taking LiF and YF3 as raw materials and a temperature gradient (40 °C/cm-50 °C/cm) for the solid-liquid interface. The luminescent performances of the crystals are investigated through emission spectra, infrared transmittance spectrum, emission cross section, and decay curves under excitation by 980 nm. Compared with the Ho3+ single-doped LiYF4 crystal, the Ho3+/Yb3+ co-doped LiYF4 single crystal has an obviously enhanced emission band from 1850 nm to 2150 nm observed when excited by a 980-nm diode laser. The energy transfer from Yb3+ to Ho3+ and the optimum fluorescence emission around 2.0 μm of Ho3+ ions are investigated. The maximum emission cross section of the above sample at 2.0 μm is calculated to be 1.08×10-20 cm2 for the LiYF4 single crystal of 1-mol% Ho3+ and 6-mol% Yb3+ according to the measured absorption spectrum. The high energy transfer efficiency of 88.9% from Yb3+ to Ho3+ ion in the sample co-doped by Ho3+ (1 mol%) and Yb3+ (8 mol%) demonstrates that the Yb3+ ions can efficiently sensitize the Ho3+ ions. Project supported by the National Natural Science Foundation of China (Grant Nos. 51472125 and 51272109) and the K.C. Wong Magna Fund in Ningbo University, China (Grant No. NBUWC001).

  10. Replicating vaccines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early work on fish immunology and disease resistance demonstrated fish (like animals and humans) that survived infection were typically resistant to re-infection with the same pathogen. The concepts of resistance upon reinfection lead to the research and development of replicating (live) vaccines in...

  11. AIDS Vaccines.

    ERIC Educational Resources Information Center

    Matthews, Thomas J.; Bolognesi, Dani P.

    1988-01-01

    Reveals that success of discovering vaccines is far from being assured although several candidates are being tested. States that the devious nature of the virus, the lack of a good animal model for the disease, and the difficulties of clinical trials inhibit the efforts of researchers. (RT)

  12. Polio Vaccine

    MedlinePlus

    ... workers who might handle polio virus, and healthcare workers treating patients who could have polio. These higher-risk adults may need 1 to 3 doses of IPV, depending on how many doses they have had in the past.There are no known risks to getting IPV at the same time as other vaccines.

  13. Rotavirus Vaccine

    MedlinePlus

    ... including a severe allergy to latex. Babies with "severe combined immunodeficiency" (SCID) should not get rotavirus vaccine. Babies who have had a type of bowel blockage called "intussusception" should not get ... with moderate or severe diarrhea or vomiting. Check with your doctor if ...

  14. Malaria vaccine.

    PubMed

    1994-05-01

    Some have argued that the vaccine against malaria developed by Manuel Pattaroyo, a Colombian scientist, is being tested prematurely in humans and that it is unlikely to be successful. While the Pattaroyo vaccine has been shown to confer protection against the relatively mild malaria found in Colombia, doubts exist over whether it will be effective in Africa. Encouraging first results, however, are emerging from field tests in Tanzania. The vaccine triggered a strong new immune response, even in individuals previously exposed to malaria. Additional steps must be taken to establish its impact upon mortality and morbidity. Five major trials are underway around the world. The creator estimates that the first ever effective malaria vaccine could be available for widespread use within five years and he has no intention of securing a patent for the discovery. In another development, malaria specialists from 35 African countries convened at an international workshop in Zimbabwe to compare notes. Participants disparaged financial outlays for the fight against malaria equivalent to 2% of total AIDS funding as insufficient; noted intercountry differences in prevention, diagnosis, and treatment; and found information exchange between anglophone and francophone doctors to be generally poor.

  15. Valuing vaccination

    PubMed Central

    Bärnighausen, Till; Bloom, David E.; Cafiero-Fonseca, Elizabeth T.; O’Brien, Jennifer Carroll

    2014-01-01

    Vaccination has led to remarkable health gains over the last century. However, large coverage gaps remain, which will require significant financial resources and political will to address. In recent years, a compelling line of inquiry has established the economic benefits of health, at both the individual and aggregate levels. Most existing economic evaluations of particular health interventions fail to account for this new research, leading to potentially sizable undervaluation of those interventions. In line with this new research, we set forth a framework for conceptualizing the full benefits of vaccination, including avoided medical care costs, outcome-related productivity gains, behavior-related productivity gains, community health externalities, community economic externalities, and the value of risk reduction and pure health gains. We also review literature highlighting the magnitude of these sources of benefit for different vaccinations. Finally, we outline the steps that need to be taken to implement a broad-approach economic evaluation and discuss the implications of this work for research, policy, and resource allocation for vaccine development and delivery. PMID:25136129

  16. Nanotoxoid Vaccines

    PubMed Central

    Hu, Che-Ming J.; Zhang, Liangfang

    2014-01-01

    To improve innate defense against diseases, vaccine formulations are routinely administered to mount immune responses against disease-causing organisms or their associated toxins. These formulations are typically prepared with weakened forms of microbes, their surface proteins, or their virulence factors, which can train the immune system to recognize and neutralize similar infectious threats in later exposures. Owing to many unique properties of nanoparticles in enhancing vaccine potency, nanoscale carriers are drawing increasing interest as a platform for developing safer and more effective vaccine formulations. Notably, a nanoparticle-based strategy was recently demonstrated to safely deliver intact, non-denatured protein toxins to mount a potent anti-toxin immune response. A biomimetic nanoparticle cloaked in biological membranes was used to sequester membrane-active toxins. Upon interaction with the nanoparticles, the toxins become retrained and lose their toxicity as they are precluded from interacting with cellular targets. The resulting particle/toxin complex adopts a nanoparticulate morphology that facilitates the toxins’ intracellular delivery. This sequestration approach has immense immunological implications owing to its ability in enabling structurally preserved toxins for immune processing. This technique offers opportunities in novel toxoid vaccine designs that promise more effective anti-toxin immune responses and contrasts the existing paradigm in toxoid preparation, in which toxins are antigenically altered to ensure virulence removal. The potent nanotoxoid formulations provide a viable anti-virulence measure in combating microbial infections that involve membrane-damaging toxins, including methicillin-resistant Staphylococcus aureus (MRSA) and Group A streptococcal infections. PMID:25285152

  17. Vexing Vaccines

    ERIC Educational Resources Information Center

    Bowman, Darcia Harris

    2004-01-01

    Schools play a key role in ensuring that children are being immunized against diseases, but conflicting research is making enforcement difficult. This article discusses a growing trend of vaccine avoidance and the endless supply of conflicting information and research about immunization safety. Despite the controversy, many people appear to accept…

  18. Vaccine chronicle in Japan.

    PubMed

    Nakayama, Tetsuo

    2013-10-01

    The concept of immunization was started in Japan in 1849 when Jenner's cowpox vaccine seed was introduced, and the current immunization law was stipulated in 1948. There have been two turning points for amendments to the immunization law: the compensation remedy for vaccine-associated adverse events in 1976, and the concept of private vaccination in 1994. In 1992, the regional Court of Tokyo, not the Supreme Court, decided the governmental responsibility on vaccine-associated adverse events, which caused the stagnation of vaccine development. In 2010, many universal vaccines became available as the recommended vaccines, but several vaccines, including mumps, zoster, hepatitis B, and rota vaccines, are still voluntary vaccines, not universal routine applications. In this report, immunization strategies and vaccine development are reviewed for each vaccine item and future vaccine concerns are discussed.

  19. Varicella (Chickenpox) Vaccine

    MedlinePlus

    ProQuad® (as a combination product containing Measles Vaccine, Mumps Vaccine, Rubella Vaccine, Varicella Vaccine) ... up to about 1 person in 5) and measles-like rash (about 1 person in 20) than MMR and varicella vaccines given separately. Moderate Problems:Seizure (jerking or staring) ...

  20. Optical gain at 1550 nm from colloidal solution of Er3+-Yb3+ codoped NaYF4 nanocubes.

    PubMed

    Liu, Xiaofeng; Chi, Yingzhi; Dong, Guoping; Wu, E; Qiao, Yanbo; Zeng, Heping; Qiu, Jianrong

    2009-03-30

    We demonstrated optical amplification at 1550 nm with a carbon tetrachloride solution of Er(3+)-Yb(3+) codoped NaYF(4) nanocubes synthesized with solvo-thermal route. Upon excitation with a 980 nm laser diode, the nanocube solution exhibited strong near-infrared emission by the (4)I(13/2)-->(4)I(15/2) transition of Er(3+) ions due to energy transfer from Yb(3+) ions. We obtained the highest optical gain coefficient at 1550 nm of 0.58 cm(-1) for the solution with the pumping power of 200 mW. This colloidal solution might be a promising candidate as a liquid medium for optical amplifier and laser at the optical communication wavelength.

  1. Characterization of conjugates of NaYF4:Yb,Er,Gd upconversion nanoparticle with aluminium phthalocyanines

    NASA Astrophysics Data System (ADS)

    Watkins, Zane; Uddin, Imran; Britton, Jonathan; Nyokong, Tebello

    2017-02-01

    NaYF4:Er/Yb/Gd upconversion nanoparticles (UCNP) capped with amino groups were covalently attached to chloro aluminium tetrasulphonated phthalocyanine (ClAlTSPc) and chloro aluminium tetracarboxy phthalocyanine (ClAlTCPc). The conjugates were characterized using different techniques such as infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). There was a decrease in the intensity of fluorescence emission spectra of the UCNPs at 658 nm in the presence of the phthalocyanines. This decrease indicates an energy transfer between the donor UCNP and conjugated accepting phthalocyanine (Pc), due to Förster resonance energy transfer (FRET). FRET efficiencies of 18% and 21% for ClAlTSPc and ClAlTCPc, respectively, were obtained. Oxygen generation by ClAlTSPc following FRET was proved.

  2. Cooperative effects of immune enhancer TPPPS and different adjuvants on antibody responses induced by recombinant ALV-J gp85 subunit vaccines in SPF chickens.

    PubMed

    Li, Yang; Meng, Fanfeng; Cui, Shuai; Fu, Jiayuan; Wang, Yixin; Cui, Zhizhong; Chang, Shuang; Zhao, Peng

    2017-03-14

    To explore the antibody responses and protective effects induced by subgroup J avian leukosis virus (ALV-J) gp85 protein vaccine plus different adjuvants (CpG and white oil adjuvant YF01) combined with the immune enhancer Taishan Pinus massoniana pollen polysaccharide (TPPPS), we immunized SPF chickens with the recombinant ALV-J gp85 protein, along with different adjuvants and immune enhancer, which protected the chickens by inducing different levels of protective antibodies. Results showed that a single injection of gp85 recombinant protein could only produce low-titre antibodies that were maintained over a short time in few chickens. When combined with YF01 or CpG adjuvants, the recombinant protein could induce high-titre antibodies in most of the immunized chickens. Moreover, when the immune enhancer TPPPS was used with the two adjuvants, it further elevated the antibody levels for a longer duration. The eggs from four groups with the highest levels of ALV-J antibodies were collected, hatched, and examined for maternal antibodies. The protection by the maternal antibodies against ALV-J infection in the TPPPS-immunized group was higher than that in the group without TPPPS, which was consistent with the observations in the parents. This study shows that the immune enhancer TPPPS, combined with YF01 or CpG adjuvants, can enhance the immunogenicity of gp85 recombinant proteins, and provide a better immuno-protection. It provides a powerful experimental basis for the development of ALV-J subunit vaccine. Efficient subunit vaccine development will also accelerate the process of purification of ALV-J.

  3. Up-conversion luminescence of the NaYF4:Yb3+,Er3+ nanomaterials prepared with the solvothermal synthesis

    NASA Astrophysics Data System (ADS)

    Palo, Emilia; Pihlgren, Laura; Tuomisto, Minnea; Laihinen, Tero; Hyppänen, Iko; Kankare, Jouko; Lastusaari, Mika; Soukka, Tero; Swart, Hendrik C.; Hölsä, Jorma

    2016-09-01

    Up-converting NaYF4:Yb3+,Er3+ (xYb: 0.20, xEr: 0.02) nanomaterials were prepared with a microwave assisted solvothermal synthesis to study how the synthesis parameters affect the structure and up-conversion luminescence of the materials and thus their usability as labels in biomedical applications. The purity of the materials was studied with Fourier transform infra-red (FT-IR) spectroscopy and the particle size and morphology with transmission electron microscopy (TEM). The crystal structure was characterized with X-ray powder diffraction (XPD) and the crystallite sizes were calculated with the Scherrer formula. Up-conversion luminescence and luminescence decays were studied with near infra-red (NIR) laser excitation at 970 nm. The presence of the oleic acid was observed in the FT-IR spectra. The TEM images showed small quasi-spherical nanoparticles as well as long nanorods. The XPD measurements revealed that both cubic and hexagonal forms of NaYF4 were present in the materials. The crystallite sizes ranged from ca. 20 to over 150 nm for the cubic and hexagonal phases, respectively. The characteristic up-conversion luminescence of Er3+ in red (640-685 nm; 4F9/2 → 4I15/2) and green (515-560 nm; 2H11/2, 4S3/2 → 4I15/2 transitions) wavelengths was observed. The most intense luminescence and the longest luminescence emission lifetime were obtained with the material annealed for 12 h at 177 °C with 1.8 MPa pressure due to the predominance of the well-crystallized hexagonal form of NaRF4 (R: Y, Yb, Er).

  4. Immune interference after sequential alphavirus vaccine vaccinations.

    PubMed

    Pittman, Phillip R; Liu, Ching-Tong; Cannon, Timothy L; Mangiafico, Joseph A; Gibbs, Paul H

    2009-08-06

    We compared the effect of order of administration of investigational alphavirus vaccines on neutralizing antibody response. Volunteers who received the inactivated eastern and western equine encephalitis (EEE and WEE) vaccines before live attenuated Venezuelan (VEE) vaccine had significantly lower rates of antibody response than those receiving VEE vaccine before EEE and WEE vaccines (66.7% vs. 80.6%; p=0.026). The odds of having a VEE antibody non-response among those initially receiving EEE and WEE vaccines, adjusted for gender, were significant (odds ratio [OR]=2.20; 95% CI=1.2-4.1 [p=0.0145]) as were the odds of non-response among females adjusted for group (OR=1.81; 95% CI=1.2-2.7 [p=0.0037]). Antibody interference and gender effect have major implications for vaccine strategy among those receiving multiple alphavirus vaccines and those developing next generation vaccines for these threats.

  5. Human Papillomavirus (HPV) Vaccines

    MedlinePlus

    ... Directory Cancer Prevention Overview Research Human Papillomavirus (HPV) Vaccines On This Page What are human papillomaviruses? Which ... infections? Can HPV infections be prevented? What HPV vaccines are available? Who should get the HPV vaccines? ...

  6. Meningococcal Vaccine (For Parents)

    MedlinePlus

    ... to 2-Year-Old Your Child's Immunizations: Meningococcal Vaccines KidsHealth > For Parents > Your Child's Immunizations: Meningococcal Vaccines ... or her parents, and the doctor. Why the Vaccines Are Recommended Meningococcal disease is caused by a ...

  7. Your Baby's First Vaccines

    MedlinePlus

    ... Link Vaccines & Immunizations Immunization Schedules Your Child's First Vaccines Format: Select one PDF [335 KB] RTF [260 ... child will get one or more of these vaccines today: DTaP Hib Hepatitis B Polio PCV13 Why ...

  8. Vaccines Stop Illness

    MedlinePlus

    Skip Navigation Bar Home Current Issue Past Issues Vaccines Stop Illness Past Issues / Spring 2008 Table of ... meningitis won't infect, cripple, or kill children. Vaccine Safety In light of recent questions about vaccine ...

  9. Vaccines and Thimerosal

    MedlinePlus

    ... this? Submit What's this? Submit Button Thimerosal in Vaccines Recommend on Facebook Tweet Share Compartir Thimerosal is ... harm. Thimerosal prevents the growth of bacteria in vaccines. Thimerosal is added to vials of vaccine that ...

  10. Childhood Vaccine Schedule

    MedlinePlus

    ... Navigation Bar Home Current Issue Past Issues Childhood Vaccine Schedule Past Issues / Spring 2008 Table of Contents ... please turn Javascript on. When to Vaccinate What Vaccine Why Birth (or any age if not previously ...

  11. Meningococcal Vaccine (For Parents)

    MedlinePlus

    ... Your 1- to 2-Year-Old Your Child's Immunizations: Meningococcal Vaccines KidsHealth > For Parents > Your Child's Immunizations: ... who are at increased risk for meningococcal disease. Immunization Schedule Vaccination with meningococcal conjugate vaccine is recommended: ...

  12. Human Papillomavirus (HPV) Vaccine

    MedlinePlus

    Why get vaccinated?HPV vaccine prevents infection with human papillomavirus (HPV) types that are associated with cause ... at http://www.cdc.gov/hpv. HPV Vaccine (Human Papillomavirus) Information Statement. U.S. Department of Health and ...

  13. Vaccinations during Pregnancy

    MedlinePlus

    ... get is safe. Make sure your vaccinations are up to date before you get pregnant. What is a vaccination? ... are recommended before pregnancy? It’s best to be up to date on all your routine adult vaccinations before you ...

  14. Vaccine-Preventable Disease Photos

    MedlinePlus

    Home | About | A-Z | Contact | Follow Vaccine Information You Need VACCINE BASICS Evaluating Online Health Information FAQs How Vaccines Work Importance of Vaccines Paying for Vaccines State Immunization Programs ...

  15. Colloidal synthesis and blue based multicolor upconversion emissions of size and composition controlled monodisperse hexagonal NaYF4:Yb,Tm nanocrystals.

    PubMed

    Yin, Anxiang; Zhang, Yawen; Sun, Lingdong; Yan, Chunhua

    2010-06-01

    Monodisperse beta-NaYF4:Yb,Tm nanocrystals with controlled size (25-150 nm), shape (sphere, hexagonal prism, and hexagonal plate), and composition (Yb: 20-40%, Tm: 0.2-5%) were synthesized from the thermolysis of metal trifluoroacetates in hot surfactant solutions. The upconversion (UC) of near-infrared light (980 nm) to ultra-violet (360 nm), blue (450 and 475 nm), red (650 and 695 nm) and infrared (800 nm) light in the beta-NaYF4:Yb,Tm nanocrystals has been studied by UC spectroscopy. Both the total intensity of UC emissions and the relative intensities of emissions at different wavelengths have shown a strong dependence on different particle sizes and different Tm3+ and Yb3+ concentrations. As a result, different overall output colors of UC emissions can be achieved by altering sizes and Yb3+/Tm3+ doping concentrations of the beta-NaYF4:Yb,Tm nanocrystals. The intensity-power curves of a series of samples have proved that emissions at 360 and 450 nm can be ascribed to four-photon process (1D2 to 3H6 and 1D2 to 3H4, respectively), while emissions at 475 and 650 nm are three-photon processes (1G4 to 3H6 and 1G4 to 3H4, respectively) and emissions at 695 and 800 nm are two-photon ones (3F2 to 3H6 and 3F4 to 3H6, respectively). A UC saturation effect would occur under a certain excitation intensity of the 980 nm CW diode laser for the as-obtained beta-NaYF4:Yb,Tm nanocrystals, leading to the decrease of the slopes of the I-P curves. The results of our study also revealed that the successive transfer model instead of the cooperative sensitization model can be applied to explain the UC behaviors of the beta-NaYF4:Yb,Tm nanocrystals. Further, an unexpected stronger emissions of four-photon process at 360 and 450 nm for approximately 50 nm beta-NaYF4:Yb,Tm nanocrystals than those for the bigger (approximately 150 nm) nanocrystals was observed and explained in terms of the effects of crystallite size, surface-to-volume ratio and homogeneity of the doping cations.

  16. Safety and immunogenicity of a live attenuated Japanese encephalitis chimeric virus vaccine (IMOJEV®) in children.

    PubMed

    Chokephaibulkit, K; Houillon, G; Feroldi, E; Bouckenooghe, A

    2016-01-01

    JE-CV (IMOJEV®, Sanofi Pasteur, France) is a live attenuated virus vaccine constructed by inserting coding sequences of the prM and E structural proteins of the Japanese encephalitis SA14-14-2 virus into the genome of yellow fever 17D virus. Primary immunization with JE-CV requires a single dose of the vaccine. This article reviews clinical trials of JE-CV in children aged up to 6 years conducted in countries across South-East Asia. Strong and persistent antibody responses were observed after single primary and booster doses, with 97% of children seroprotected up to five years after booster vaccination. Models of long-term antibody persistence predict a median duration of protection of approximately 30 years after a booster dose. The safety and reactogenicity profiles of JE-CV primary and booster doses are comparable to other widely used childhood vaccines.

  17. Subviral Particle as Vaccine and Vaccine Platform

    PubMed Central

    Tan, Ming; Jiang, Xi

    2014-01-01

    Recombinant subvirual particles retain similar antigenic features of their authentic viral capsids and thus have been applied as nonreplicating subunit vaccines against viral infection and illness. Additionally, the self-assembled, polyvalent subviral particles are excellent platforms to display foreign antigens for immune enhancement for vaccine development. These subviral particle-based vaccines are noninfectious and thus safer than the conventional live attenuated and inactivated vaccines. While several VLP vaccines are available in the markets, numerous others, including dual vaccines against more than one pathogen, are under clinical or preclinical development. This article provides an update of these efforts. PMID:24662314

  18. [Vaccination against mouse pox].

    PubMed

    Mahnel, H

    1985-01-01

    Attenuated MVA-strain of vaccinia virus has been efficient in the control of enzootic mousepox and in prophylactic vaccination. The virus has been used as a live vaccine for prophylactic and emergency vaccinations as well as for sanitation of populations. More than 100 000 vaccinations were carried out safely. Even after suspension of the obligatory vaccination of humans against smallpox the MVA-vaccine can be employed without risk and danger.

  19. Engineered human vaccines

    SciTech Connect

    Sandhu, J.S. . Div. of Immunology and Neurobiology)

    1994-01-01

    The limitations of human vaccines in use at present and the design requirements for a new generation of human vaccines are discussed. The progress in engineering of human vaccines for bacteria, viruses, parasites, and cancer is reviewed, and the data from human studies with the engineered vaccines are discussed, especially for cancer and AIDS vaccines. The final section of the review deals with the possible future developments in the field of engineered human vaccines and the requirement for effective new human adjuvants.

  20. Human Vaccines & Immunotherapeutics

    PubMed Central

    Riedmann, Eva M

    2014-01-01

    Measles vaccination: Targeted and non-targeted benefits CDC reports: 2-dose regimen of chickenpox vaccine is a success Positive preliminary results from the CAPiTA study Seasonal flu vaccine associate with reduced stroke risk HPV vaccine shown to halve cervical abnormalities Global prize for mobile mast vaccine storage project Developmental pathway of potent HIV-neutralizing antibodies Burkholderia vaccine: US Dep of Defense collaborates with Bavarian Nordic

  1. Hepatitis B Vaccine

    MedlinePlus

    ... a combination product containing Haemophilus influenzae type b, Hepatitis B Vaccine) ... combination product containing Diphtheria, Tetanus Toxoids, Acellular Pertussis, Hepatitis B, Polio Vaccine)

  2. Colloidal synthesis and blue based multicolor upconversion emissions of size and composition controlled monodisperse hexagonal NaYF4 : Yb,Tm nanocrystals

    NASA Astrophysics Data System (ADS)

    Yin, Anxiang; Zhang, Yawen; Sun, Lingdong; Yan, Chunhua

    2010-06-01

    Monodisperse β-NaYF4 : Yb,Tm nanocrystals with controlled size (25-150 nm), shape (sphere, hexagonal prism, and hexagonal plate), and composition (Yb: 20-40%, Tm: 0.2-5%) were synthesized from the thermolysis of metal trifluoroacetates in hot surfactant solutions. The upconversion (UC) of near-infrared light (980 nm) to ultra-violet (360 nm), blue (450 and 475 nm), red (650 and 695 nm) and infrared (800 nm) light in the β-NaYF4 : Yb,Tm nanocrystals has been studied by UC spectroscopy. Both the total intensity of UC emissions and the relative intensities of emissions at different wavelengths have shown a strong dependence on different particle sizes and different Tm3+ and Yb3+ concentrations. As a result, different overall output colors of UC emissions can be achieved by altering sizes and Yb3+/Tm3+ doping concentrations of the β-NaYF4 : Yb,Tm nanocrystals. The intensity-power curves of a series of samples have proved that emissions at 360 and 450 nm can be ascribed to four-photon process (1D2 to 3H6 and 1D2 to 3H4, respectively), while emissions at 475 and 650 nm are three-photon processes (1G4 to 3H6 and 1G4 to 3H4, respectively) and emissions at 695 and 800 nm are two-photon ones (3F2 to 3H6 and 3F4 to 3H6, respectively). A UC saturation effect would occur under a certain excitation intensity of the 980 nm CW diode laser for the as-obtained β-NaYF4 : Yb,Tm nanocrystals, leading to the decrease of the slopes of the I-P curves. The results of our study also revealed that the successive transfer model instead of the cooperative sensitization model can be applied to explain the UC behaviors of the β-NaYF4 : Yb,Tm nanocrystals. Further, an unexpected stronger emissions of four-photon process at 360 and 450 nm for ~50 nm β-NaYF4 : Yb,Tm nanocrystals than those for the bigger (~150 nm) nanocrystals was observed and explained in terms of the effects of crystallite size, surface-to-volume ratio and homogeneity of the doping cations.Monodisperse β-NaYF4 : Yb

  3. Designed Er3+-singly doped NaYF4 with double excitation bands for simultaneous deep macroscopic and microscopic upconverting bioimaging

    PubMed Central

    Wen, Xuanyuan; Wang, Baoju; Wu, Ruitao; Li, Nana; He, Sailing; Zhan, Qiuqiang

    2016-01-01

    Simultaneous deep macroscopic imaging and microscopic imaging is in urgent demand, but is challenging to achieve experimentally due to the lack of proper fluorescent probes. Herein, we have designed and successfully synthesized simplex Er3+-doped upconversion nanoparticles (UCNPs) with double excitation bands for simultaneous deep macroscopic and microscopic imaging. The material structure and the excitation wavelength of Er3+-singly doped UCNPs were further optimized to enhance the upconversion emission efficiency. After optimization, we found that NaYF4:30%Er3+@NaYF4:2%Er3+ could simultaneously achieve efficient two-photon excitation (2PE) macroscopic tissue imaging and three-photon excitation (3PE) deep microscopic when excited by 808 nm continuous wave (CW) and 1480 nm CW lasers, respectively. In vitro cell imaging and in vivo imaging have also been implemented to demonstrate the feasibility and potential of the proposed simplex Er3+-doped UCNPs as bioprobe. PMID:27375936

  4. Transport Properties of Aliovalent Substitution Solid Solutions of the System (1-x)PbF2-x YF3-SnF2

    NASA Astrophysics Data System (ADS)

    Pogorenko, Y. V.; Pshenychnyi, R. M.; Lutsyk, V. I.; Omel’chuk, A. O.

    2017-02-01

    In polycrystalline solid solution of Pb1-x Y x SnF4+x (0 < x ≤ 0,17) with a structure of β-PbSnF4 in temperature 293 – 523 K the fluorine anions occupy three structurally nonequivalent positions which differ in the local environment and mobility. The concentration of mobility fluoride anions at 300 K is almost independent of the content of heterovalent substituent on YF3 and at temperatures above 430 K increases with grow concentration of the YF3. Fluoride ion exchange between nonequivalent subsystems increases with raising temperature, which causes an increase in conductivity. The electronic component of conductivity the synthesized samples by 2 orders of magnitude lower than the ion.

  5. α-NaYF4:Yb3+-Tm3+@CaF2 nanocrystals for NIR-to-NIR temperature sensing

    NASA Astrophysics Data System (ADS)

    Wu, Ruozhen; Zhou, Jiajia; Lei, Lei; Zhang, Shengjun; Xiao, Zhen; Zhang, Junjie; Xu, Shiqing

    2017-01-01

    The approach of lanthanides doping upconversion temperature sensing exhibits high superiority in bioscience. However, most of the upconversion nanothermometers show their fluorescences temperature sensing beyond biological transparent window (650-950 nm) while suffering from the interference of surrounding environment. Here we report a nanoprobe with ultrasmall size, i.e. α-NaYF4:Yb-Tm@CaF2 nanocrystal, which has a sensitive capability to realize NIR-to-NIR temperature sensing. Temperature sensing sensitivities through 3H4 → 3H6 and 1G4 → 3H6 transitions of Tm3+ ions are evaluated in temperature region of 313-373 K. The results indicate that α-NaYF4:Yb-Tm@CaF2 nanocrystal is a promising candidate for biological temperature sensing.

  6. Laser performance of in-band pumped Er : LiYF{sub 4} and Er : LiLuF{sub 4} crystals

    SciTech Connect

    Gorbachenya, K N; Kisel, V E; Yasukevich, A S; Kuleshov, N V; Kurilchik, S V; Nizamutdinov, A S; Korableva, S L; Semashko, V V

    2016-02-28

    Spectroscopic properties of Er : LiLuF{sub 4} and Er : LiYF{sub 4} crystals in the spectral region near 1.5 μm and the lasing characteristics of these crystals under in-band pumping at a wavelength of 1522 nm are studied. With the Er : LiLuF{sub 4} crystal, the maximum slope efficiency with respect to the absorbed pump power was 44% at a wavelength of 1609 nm. Continuous-wave operation of an inband pumped Er : LiYF{sub 4} laser is obtained for the first time. The output power at a wavelength of 1606 nm was 58 mW with a slope efficiency of 21%. (lasers)

  7. Vaccines and vaccinations. The strategic issues.

    PubMed

    Ford, R B

    2001-05-01

    The rapid proliferation of companion animal vaccines, advances in diagnostic and vaccine technology, and concerns over vaccine safety are clearly among the most important issues practicing veterinarians face as we enter the 21st century. Although many would argue that these are already issues, the future promises to be especially challenging as the vaccines we currently use and the protocols we recommend undergo unprecedented review.

  8. Avian influenza vaccines and vaccination for poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccines against avian influenza (AI) have had more limited use in poultry than vaccines against other poultry diseases such as Newcastle disease (ND) and infectious bronchitis, and have been used more commonly in the developing world. Over the past 40 years, AI vaccines have been primarily based o...

  9. Feasibility study for the use of a YF-12 aircraft as a scientific instrument platform for observing the 1970 solar eclipse

    NASA Technical Reports Server (NTRS)

    Mercer, R. D.

    1973-01-01

    The scientific and engineering findings are presented of the feasibility study for the use of a YF-12 aircraft as a scientific instrument platform for observing the 1970 solar eclipse. Included in the report is the computer program documentation of the solar eclipse determination; summary data on SR-71A type aircraft capabilities and limitations as an observing platform for solar eclipses; and the recordings of an informal conference on observations of solar eclipses using SR-71A type aircraft.

  10. Luminescence energy transfer detection of PSA in red region based on Mn2+-enhanced NaYF4:Yb, Er upconversion nanorods.

    PubMed

    Zhang, Jianguo; Wang, Shaozhen; Gao, Ni; Feng, Dexiang; Wang, Lun; Chen, Hongqi

    2015-10-15

    A new turn-on luminescence energy transfer (LET) system has been designed for the detection of prostate specific antigen (PSA, a cancer marker) that utilizes Mn(2+)-enhanced long wavelength luminescence NaYF4:Yb, Er upconversion nanorods as the donor and gold nanorods as the acceptor. The Mn(2+)-doped NaYF4:Yb,Er upconversion luminescence nanorods with an emission peak located in the red region were synthesized. The presence of Mn(2+) markedly increased the luminescence intensity over that of the NaYF4:Yb, Er upconversion nanomaterials (excited by a 980 nm continuous wavelength laser). The surfaces of Mn(2+)-doped NaYF4:Yb, Er upconversion nanorods were modified with poly(acrylic acid). Antibodies against prostate specific antigen were bound to the surface of the carboxyl-functionalized upconversion nanorods, which acted as the energy donor in this LET system. Gold nanorods with an absorption band at ~666 nm were synthesized by the seed growth method, acted as the energy acceptor. The emission band of the upconversion nanorods overlapped well with the absorption band of the gold nanorods. The luminescence was quenched because of the electrostatic interactions that shortened the distance between the donor (negatively charged) and the accepter (positively charged).When the PSA antigen was added into the system, the energy acceptor and the energy donors were separated because the binding affinity between PSA and anti-PSA was greater than the electrostatic interactions, and thereby the luminescence was recovered. The linear range of detecting PSA was from 0.1172 to 18.75 ng/mL (R=0.995), with a limit of detection for PSA as low as 0.1129 ng/mL. The method was successfully applied to the sensing of PSA in human serum samples.

  11. Aptamer biosensor for Salmonella typhimurium detection based on luminescence energy transfer from Mn2 +-doped NaYF4:Yb, Tm upconverting nanoparticles to gold nanorods

    NASA Astrophysics Data System (ADS)

    Cheng, Keyi; Zhang, Jianguo; Zhang, Liping; Wang, Lun; Chen, Hongqi

    2017-01-01

    A highly sensitive luminescent bioassay for the detection of Salmonella typhimurium was fabricated using Mn2 +-doped NaYF4:Yb,Tm upconversion nanoparticles (UCNPs) as the donor and gold nanorods (Au NRs) as the acceptor and utilizing an energy transfer (LET) system. Mn2 +-doped NaYF4:Yb,Tm UCNPs with a strong emission peak at 807 nm were obtained by changing the doped ion ratio. Carboxyl-terminated Mn2 +-doped NaYF4:Yb,Tm UCNPs were coupled with S. typhimurium aptamers, which were employed to capture and concentrate S. typhimurium. The electrostatic interactions shorten the distance between the negatively charged donor and the positively charged acceptor, which results in luminescence quenching. The added S. typhimurium leads to the restoration of luminescence due to the formation of UCNPs-aptamers-S. typhimurium, which repels the UCNPs-aptamers from the Au NRs. The LET system does not occur because of the nonexistence of the luminescence emission band of Mn2 +-doped NaYF4:Yb,Tm UCNPs, which had large spectral overlap with the absorption band of Au NRs. Under optimal conditions, the linear range of detecting S. typhimurium was 12 to 5 × 105 cfu/mL (R = 0.99). The limit of detection for S. typhimurium was as low as 11 cfu/mL in an aqueous buffer. The measurement of S. typhimurium in milk samples was satisfied in accordance with the plate-counting method, suggesting that the proposed method was of practical value in the application of food security.

  12. Safety and Biodistribution Evaluation in Cynomolgus Macaques of rAAV2tYF-CB-hRS1, a Recombinant Adeno-Associated Virus Vector Expressing Retinoschisin.

    PubMed

    Ye, Guo-Jie; Budzynski, Ewa; Sonnentag, Peter; Miller, Paul E; Sharma, Alok K; Ver Hoeve, James N; Howard, Kellie; Knop, David R; Neuringer, Martha; McGill, Trevor; Stoddard, Jonathan; Chulay, Jeffrey D

    2015-09-01

    Applied Genetic Technologies Corporation is developing rAAV2tYF-CB-hRS1, a recombinant adeno-associated virus (rAAV) vector for treatment of X-linked retinoschisis (XLRS), an inherited retinal disease characterized by splitting (schisis) of retinal layers causing poor vision. We report here results of a study evaluating the safety and biodistribution of rAAV2tYF-CB-hRS1 in normal cynomolgus macaques. Three groups of male animals (n = 6 per group) received an intravitreal injection in one eye of either vehicle, or rAAV2tYF-CB-hRS1 at one of two dose levels (4 × 10(10) or 4 × 10(11) vg/eye). Half the animals were sacrificed after 14 days and the others after 91 or 115 days. The intravitreal injection procedure was well tolerated in all groups. Serial ophthalmic examinations demonstrated a dose-related anterior and posterior segment inflammatory response that improved over time. There were no test article-related effects on intraocular pressure, electroretinography, visual evoked potential, hematology, coagulation, clinical chemistry, or gross necropsy observations. Histopathological examination demonstrated minimal or moderate mononuclear infiltrates in 6 of 12 vector-injected eyes. Immunohistochemical staining showed RS1 labeling of the ganglion cell layer at the foveal slope in vector-injected eyes at both dose levels. Serum anti-AAV antibodies were detected in 4 of 6 vector-injected animals at the day 15 sacrifice and all vector-injected animals at later time points. No animals developed antibodies to RS1. Biodistribution studies demonstrated high levels of vector DNA in the injected eye but minimal or no vector DNA in any other tissue. These results support the use of rAAV2tYF-CB-hRS1 in clinical studies in patients with XLRS.

  13. Immune response after an experimental intramammary challenge with killed Staphylococcus aureus in cows and heifers vaccinated and not vaccinated with Startvac, a polyvalent mastitis vaccine.

    PubMed

    Piepers, S; Prenafeta, A; Verbeke, J; De Visscher, A; March, Ricard; De Vliegher, S

    2017-01-01

    An experimental trial was conducted to explore the effect of vaccination with a polyvalent vaccine against mastitis (Startvac) on the early immune response after experimental intramammary challenge with a heterologous killed Staphylococcus aureus strain. The effect of vaccination on milk production, clinical signs, quarter milk somatic cell count, milk polymorphonuclear neutrophilic leukocyte (PMN) concentration and viability, the concentration of antigen-specific antibodies [slime associated antigenic complex (SAAC) and J5] and their IgG1 and IgG2 subtypes in both serum and whey, and the antigen-specific IFN-γ, IL-4, and IL-17 production by blood lymphocytes after in vitro stimulation with S. aureus and Escherichia coli extracts were determined. A cohort of 8 clinically healthy end-term cows and heifers were conveniently selected, of which half was vaccinated with Startvac at 45 and 10 d before the expected calving date and half served as nonvaccinated control animals. At 15 d in milk, 2 contralateral quarters of each of the 8 animals were challenged with 2×10(9) cfu/mL of the formaldehyde-killed S. aureusC195strain. The 2 other quarters were infused with phosphate-buffered saline and served as control quarters. The increase in both quarter milk somatic cell count and PMN concentration and the drop in milk production after S. aureus inoculation was less pronounced in the vaccinates than in the nonvaccinates, reflecting a less severe inflammatory response. No significant differences in PMN viability between vaccinates and nonvaccinates could be demonstrated. The serum SAAC- and J5-specific antibody concentration significantly increased across the dry period in the vaccinated animals only. The whey concentration of SAAC-specific antibodies was significantly higher in vaccinates than in nonvaccinates at both 15 and 17 d in milk, independent from the challenge status of the quarters. No significant differences in the whey J5-specific antibody concentration were

  14. Diode-pumped LiY0.3Lu0.7F4:Pr and LiYF4:Pr red lasers

    NASA Astrophysics Data System (ADS)

    Lyapin, A. A.; Gorieva, V. G.; Korableva, S. L.; Artemov, S. A.; Ryabochkina, P. A.; Semashko, V. V.

    2016-12-01

    The laser quality LiY0.3Lu0.7F4:Pr and LiYF4:Pr fluoride single crystals were grown in Kazan University by the Bridgeman technique. Spectral-kinetic properties of LiY0.3Lu0.7F4:Pr and LiYF4:Pr crystals have been investigated. For the first time, laser oscillations of LiY0.3Lu0.7F4:Pr crystal have been obtained on 3P0  →  3F2 transitions (λ  =  640 nm) under multimode diode pumping at 442 nm, with a slope efficiency of 9 %. Also, continuous-wave lasing has been obtained for LiYF4:Pr crystal at 640 nm under the same pumping condition with a slope efficiency of 8.5%. The maximum output power of 340 mW has been achieved for both crystals.

  15. Comparative study of the electronic structure of two laser crystals: BeAl2O4 and LiYF4

    NASA Astrophysics Data System (ADS)

    Ching, W. Y.; Xu, Yong-Nian; Brickeen, B. K.

    2001-03-01

    The ground-state electronic structure and bonding of two important laser crystals, BeAl2O4 and LiYF4, were calculated using a first-principles method based the local approximation of the density-functional theory. The results were compared with similar calculations on several other laser crystals including yttrium aluminum garnet (Y3Al5O12). The geometry of each crystal was optimized first with all internal parameters relaxed. The bulk moduli B were obtained by fitting the calculated total energies at different volumes to the Murnaghan equation of state. It was found that LiYF4 (B=90.0 GPa) is much softer than BeAl2O4 (B=217.3 GPa). In BeAl2O4, Be and Al atoms have very similar local electronic structure and the crystal resembles that of α-Al2O3 (sapphire). LiYF4 is a highly ionic crystal while BeAl2O4 has a significant amount of covalent mixing. The density of states, their atomic and orbital decompositions, the effective charges, the bond order, and the charge distributions in these two crystals are presented and contrasted.

  16. Toward NIR driven photocatalyst: Fabrication, characterization, and photocatalytic activity of β-NaYF4:Yb(3+),Tm(3+)/g-C3N4 nanocomposite.

    PubMed

    Huang, Min-Zhong; Yuan, Baoling; Dai, Leyang; Fu, Ming-Lai

    2015-12-15

    The β-NaYF4:Yb(3+),Tm(3+)/g-C3N4 (NYT/C3N4) photocatalyst has been successfully fabricated by a stepwise method. Firstly, the advanced near-infrared (NIR) driven photocatalyst was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and UV-Vis-NIR diffuse reflectance spectroscopy. It was found that NYT/C3N4 photocatalyst consisted of uniform hexagonal phase NaYF4 nanocrystals with about 20nm diameter distributed on surface of g-C3N4 sheets, and the NYT/C3N4 composite exhibited strong near-infrared light absorption and the energy transfer from β-NaYF4:Yb(3+),Tm(3+) to g-C3N4 was confirmed. Secondly, the photocatalytic activities of the catalysts were evaluated by the degradation of methyl blue dye and colorless phenol under the irradiation of 980nm laser. The results suggested that NYT/C3N4 nanocomposite is an advanced NIR-driven photocatalyst. Moreover the NYT/C3N4 photocatalyst showed good stability for photocatalytic decoloration of dye in the recycled tests. This study suggested a promising system to utilize the NIR energy of sunlight for photochemical and photoelectrical applications based on g-C3N4, which will contribute to the utilization of solar energy in the future.

  17. Simultaneous morphology manipulation and upconversion luminescence enhancement of β-NaYF4:Yb3+/Er3+ microcrystals by simply tuning the KF dosage

    PubMed Central

    Ding, Mingye; Chen, Daqin; Yin, Shilong; Ji, Zhenguo; Zhong, Jiasong; Ni, Yaru; Lu, Chunhua; Xu, Zhongzi

    2015-01-01

    A strategy has been adopted for simultaneous morphology manipulation and upconversion luminescence enhancement of β-NaYF4:Yb3+/Er3+ microcrystals by simply tuning the KF dosage. X-ray power diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and photoluminescence spectra (PL) were used to characterize the samples. The influence of molar ratio of KF to Y3+ on the crystal phase and morphology has been systematically investigated and discussed. It is found that the molar ratio of KF to Y3+ can strongly control the morphology of the as-synthesized β-NaYF4 samples because of the different capping effect of F− ions on the different crystal faces. The possible formation mechanism has been proposed on the basis of a series of time-dependent experiments. More importantly, the upconversion luminescence of β-NaYF4:Yb3+/Er3+ was greatly enhanced by increasing the molar ratio of KF to RE3+ (RE = Y, Yb, Er), which is attributed to the distortion of local crystal field symmetry around lanthanide ions through K+ ions doping. This synthetic methodology is expected to provide a new strategy for simultaneous morphology control and remarkable upconversion luminescence enhancement of yttrium fluorides, which may be applicable for other rare earth fluorides. PMID:26235808

  18. Coupling of Ag Nanoparticle with Inverse Opal Photonic Crystals as a Novel Strategy for Upconversion Emission Enhancement of NaYF4: Yb(3+), Er(3+) Nanoparticles.

    PubMed

    Shao, Bo; Yang, Zhengwen; Wang, Yida; Li, Jun; Yang, Jianzhi; Qiu, Jianbei; Song, Zhiguo

    2015-11-18

    Rare-earth-ion-doped upconversion (UC) nanoparticles have generated considerable interest because of their potential application in solar cells, biological labeling, therapeutics, and imaging. However, the applications of UC nanoparticles were still limited because of their low emission efficiency. Photonic crystals and noble metal nanoparticles are applied extensively to enhance the UC emission of rare earth ions. In the present work, a novel substrate consisting of inverse opal photonic crystals and Ag nanoparticles was prepared by the template-assisted method, which was used to enhance the UC emission of NaYF4: Yb(3+), Er(3+) nanoparticles. The red or green UC emissions of NaYF4: Yb(3+), Er(3+) nanoparticles were selectively enhanced on the inverse opal substrates because of the Bragg reflection of the photonic band gap. Additionally, the UC emission enhancement of NaYF4: Yb(3+), Er(3+) nanoparticles induced by the coupling of metal nanoparticle plasmons and photonic crystal effects was realized on the Ag nanoparticles included in the inverse opal substrate. The present results demonstrated that coupling of Ag nanoparticle with inverse opal photonic crystals provides a useful strategy to enhance UC emission of rare-earth-ion-doped nanoparticles.

  19. Multifunctional MnO2 nanosheet-modified Fe3O4@SiO2/NaYF4:Yb, Er nanocomposites as novel drug carriers.

    PubMed

    Zhao, Peng; Zhu, Yihua; Yang, Xiaoling; Shen, Jianhua; Jiang, Xin; Zong, Jie; Li, Chunzhong

    2014-01-14

    We report on a novel drug carrier which is based on the combination of magnetic and upconversion (UC) emission of Fe3O4@SiO2/NaYF4:Yb, Er (MSU) hybrids modified with MnO2 nanosheets (MSU/MnO2). The MSU hybrids were fabricated by covalently linking amino-modified Fe3O4@SiO2 particles with carboxyl-functionalized NaYF4:Yb, Er particles. The Fe3O4 core and the NaYF4:Yb, Er shell functioned successfully for magnetic targeting and fluorescence imaging, respectively. MnO2 nanosheets served as drug carriers and UC luminescence quenchers. The drug can be released by introducing glutathione (GSH) which reduces MnO2 to Mn(2+), and at the same time, UC luminescence can be turned on. These results clearly show that these MSU/MnO2 nanocomposites are promising platforms which can be applied to construct a smart drug delivery system with magnetic targeting and GSH-stimulation, as well as tracking by UC luminescence.

  20. History of vaccination

    PubMed Central

    Plotkin, Stanley

    2014-01-01

    Vaccines have a history that started late in the 18th century. From the late 19th century, vaccines could be developed in the laboratory. However, in the 20th century, it became possible to develop vaccines based on immunologic markers. In the 21st century, molecular biology permits vaccine development that was not possible before. PMID:25136134

  1. History of vaccination.

    PubMed

    Plotkin, Stanley

    2014-08-26

    Vaccines have a history that started late in the 18th century. From the late 19th century, vaccines could be developed in the laboratory. However, in the 20th century, it became possible to develop vaccines based on immunologic markers. In the 21st century, molecular biology permits vaccine development that was not possible before.

  2. Vaccines today, vaccines tomorrow: a perspective

    PubMed Central

    2013-01-01

    Vaccines are considered as one of the major contributions of the 20th century and one of the most cost effective public health interventions. The International Vaccine Institute has as a mission to discover, develop and deliver new and improved vaccines against infectious diseases that affects developing nations. If Louis Pasteur is known across the globe, vaccinologists like Maurice Hilleman, Jonas Salk and Charles Mérieux are known among experts only despite their contribution to global health. Thanks to a vaccine, smallpox has been eradicated, polio has nearly disappeared, Haemophilus influenzae B, measles and more recently meningitis A are controlled in many countries. While a malaria vaccine is undergoing phase 3, International Vaccine Institute, in collaboration with an Indian manufacturer has brought an oral inactivated cholera vaccine to pre-qualification. The field of vaccinology has undergone major changes thanks to philanthropists such as Bill and Melinda Gates, initiatives like the Decade of Vaccines and public private partnerships. Current researches on vaccines have more challenging targets like the dengue viruses, malaria, human immunodeficiency virus, the respiratory syncytial virus and nosocomial diseases. Exciting research is taking place on new adjuvants, nanoparticles, virus like particles and new route of administration. An overcrowded infant immunization program, anti-vaccine groups, immunizing a growing number of elderlies and delivering vaccines to difficult places are among challenges faced by vaccinologists and global health experts. PMID:23596584

  3. Vaccine Policy Issues

    DTIC Science & Technology

    2005-05-19

    evidence “favors rejection” of the idea that either the measles- mumps-rubella vaccine or thimerosal-containing vaccines cause autism (IOM...Immunization Safety Review: Vaccines and Autism , Washington, D.C., National Academies Press, 2004). 46ACIP’s rotavirus vaccine fact sheet is at [http...that the vaccines or preservatives or packaging might cause autism and other neurodevelopmental disorders. One focus has been on thimerosal, a mercury

  4. Hydrothermal synthesis of superparamagnetic and red luminescent bifunctional Fe3O4@Mn2+-doped NaYF4:Yb/Er core@shell monodisperse nanoparticles and their subsequent ligand exchange in water

    NASA Astrophysics Data System (ADS)

    Qin, Zhenli; Du, Sinan; Luo, Yang; Liao, Zhijian; Zuo, Fang; Luo, Jianbin; Liu, Dong

    2016-08-01

    We report the use of an efficient hydrothermal method to synthesize superparamagnetic and red luminescent bifunctional Fe3O4@Mn2+-doped NaYF4:Yb/Er nanoparticles (NPs) with core@shell structures via a seed-growth procedure. Oleic acid coated Fe3O4 (OA-Fe3O4) NPs were initially synthesized using a coprecipitation method. The as-synthesized OA-Fe3O4 NPs were then used as seeds, on which the red upconversion luminescent shell (Mn2+-doped NaYF4:Yb/Er) was formed. Furthermore, hydrophobic to hydrophilic surface modification of the Fe3O4@Mn2+-doped NaYF4:Yb/Er NPs was achieved via a ligand exchange method where oleic acid was displaced by a PEG phosphate ligand [PEG = poly(ethylene glycol)]. These materials were characterized by means of transmission electron microscopy (TEM), X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, and vibrating sample magnetometry (VSM). The Fe3O4 cores were uniformly coated with a Mn2+-doped NaYF4:Yb/Er shell, and the bifunctional Fe3O4@Mn2+-doped NaYF4:Yb/Er NPs were monodispersed. Furthermore, the Fe3O4@Mn2+-doped NaYF4:Yb/Er NPs exhibited a saturated magnetization value of 6.2 emu/g and emitted red luminescence under a 980 nm laser. The obtained bifunctional Fe3O4@Mn2+-doped NaYF4:Yb/Er NPs may find potential applications in drug targeting, bioseparation, and diagnostic analysis. The synthetic method may be employed for the preparation of other bifunctional nanomaterials.

  5. Typhoid fever vaccination strategies.

    PubMed

    Date, Kashmira A; Bentsi-Enchill, Adwoa; Marks, Florian; Fox, Kimberley

    2015-06-19

    Typhoid vaccination is an important component of typhoid fever prevention and control, and is recommended for public health programmatic use in both endemic and outbreak settings. We reviewed experiences with various vaccination strategies using the currently available typhoid vaccines (injectable Vi polysaccharide vaccine [ViPS], oral Ty21a vaccine, and injectable typhoid conjugate vaccine [TCV]). We assessed the rationale, acceptability, effectiveness, impact and implementation lessons of these strategies to inform effective typhoid vaccination strategies for the future. Vaccination strategies were categorized by vaccine disease control strategy (preemptive use for endemic disease or to prevent an outbreak, and reactive use for outbreak control) and vaccine delivery strategy (community-based routine, community-based campaign and school-based). Almost all public health typhoid vaccination programs used ViPS vaccine and have been in countries of Asia, with one example in the Pacific and one experience using the Ty21a vaccine in South America. All vaccination strategies were found to be acceptable, feasible and effective in the settings evaluated; evidence of impact, where available, was strongest in endemic settings and in the short- to medium-term. Vaccination was cost-effective in high-incidence but not low-incidence settings. Experience in disaster and outbreak settings remains limited. TCVs have recently become available and none are WHO-prequalified yet; no program experience with TCVs was found in published literature. Despite the demonstrated success of several typhoid vaccination strategies, typhoid vaccines remain underused. Implementation lessons should be applied to design optimal vaccination strategies using TCVs which have several anticipated advantages, such as potential for use in infant immunization programs and longer duration of protection, over the ViPS and Ty21a vaccines for typhoid prevention and control.

  6. Obesity vaccines.

    PubMed

    Monteiro, Mariana P

    2014-01-01

    Obesity is one of the largest and fastest growing public health problems in the world. Last century social changes have set an obesogenic milieu that calls for micro and macro environment interventions for disease prevention, while treatment is mandatory for individuals already obese. The cornerstone of overweight and obesity treatment is diet and physical exercise. However, many patients find lifestyle modifications difficult to comply and prone to failure in the long-term; therefore many patients consider anti-obesity drugs an important adjuvant if not a better alternative to behavioral approach or obesity surgery. Since the pharmacological options for obesity treatment remain quite limited, this is an exciting research area, with new treatment targets and strategies on the horizon. This review discusses the development of innovative therapeutic agents, focusing in energy homeostasis regulation and the use of molecular vaccines, targeting hormones such as somatostatin, GIP and ghrelin, to reduce body weight.

  7. Boundary layer, skin friction, and boattail pressure measurements from the YF-12 airplane at Mach numbers up to 3

    NASA Technical Reports Server (NTRS)

    Fisher, D. F.

    1978-01-01

    In-flight measurements of boundary layer and skin friction data were made on YF-12 airplanes for Mach numbers between 2.0 and 3.0. Boattail pressures were also obtained for Mach numbers between 0.7 and 3.0 with Reynolds numbers up to four hundred million. Boundary layer data measured along the lower fuselage centerline indicate local displacement and momentum thicknesses can be much larger than predicted. Skin friction coefficients measured at two of five lower fuselage stations were significantly less than predicted by flat plate theory. The presence of large differences between measured boattail pressure drag and values calculated by a potential flow solution indicates the presence of vortex effects on the upper boattail surface. At both subsonic and supersonic speeds, pressure drag on the longer of two boattail configurations was equal to or less than the pressure drag on the shorter configuration. At subsonic and transonic speeds, the difference in the drag coefficient was on the order of 0.0008 to 0.0010. In the supersonic cruise range, the difference in the drag coefficient was on the order of 0.002. Boattail drag coefficients are based on wing reference area.

  8. Optical properties and size distribution of the nanocolloids made of rare-earth ion-doped NaYF4

    NASA Astrophysics Data System (ADS)

    Patel, Darayas N.; Lewis, Ashley; Wright, Donald M.; Lewis, Danielle; Valentine, Rueben; Valentine, Maucus; Wessley, Dennis; Sarkisov, Sergey; Darwish, Abdalla M.

    2015-03-01

    In this paper we investigate optical properties and size distribution of the nano-colloids made of trivalent rare-earth ion doped fluorides: holmium and ytterbium, thulium and ytterbium, and erbium and ytterbium co-doped NaYF4. These materials were synthesized by using simple co-precipitation synthetic method. The initially prepared micro-crystals had very weak or no visible upconversion fluorescence signals when being pumped with a 980-nm laser. The fluorescence intensity significantly increased after the crystals were annealed at a temperature of 400°C - 600°C undergoing the transition from cubic alpha to hexagonal beta phase of the fluoride host. Nano-colloids of the crystals were made in polar solvents using the laser ablation and ball milling methods. Size analyses of the prepared nano-colloids were conducted using a dynamic light scatterometer and atomic force microscope. The nano-colloids were filled in holey PCFs and their fluorescent properties were studied and the feasibility of new a type of fiber amplifier/laser was evaluated.

  9. R1234yf vs. R134a Flow Boiling Heat Transfer Inside a 3.4 mm ID Microfin Tube

    NASA Astrophysics Data System (ADS)

    Diani, A.; Mancin, S.; Rossetto, L.

    2014-11-01

    The refrigerant charge minimization as well as the use of eco-friendly fluids can be considered two of the most important targets for these applications to cope with the new environmental challenges. This paper compares the R1234yf and R134a flow boiling heat transfer and pressure drop measurements inside a small microfin tube with internal diameter at the fin tip of 3.4 mm. This study is carried out in an experimental facility built at the Dipartimento di Ingegneria Industriale of the University of Padova especially designed to study both single and two phase heat transfer processes. The microfin tube is brazed inside a copper plate and electrically heated from the bottom. Several T -type thermocouples are inserted in the wall to measure the temperature distribution during the phase change process. In particular, the experimental measurements were carried out at constant saturation temperature of 30 °C, by varying the refrigerant mass velocity between 190 kg m-2 s-1 and 940 kg m-2 s-1, the vapour quality from 0.2 to 0.99, at different imposed heat fluxes. The two refrigerants are compared considering the values of the two-phase heat transfer coefficient and pressure drop.

  10. Experimental demonstration of plasmon enhanced energy transfer rate in NaYF4:Yb3+,Er3+ upconversion nanoparticles

    PubMed Central

    Lu, Dawei; Mao, Chenchen; Cho, Suehyun K.; Ahn, Sungmo; Park, Wounjhang

    2016-01-01

    Energy transfer upconversion (ETU) is known to be the most efficient frequency upconversion mechanism. Surface plasmon can further enhance the upconversion process, opening doors to many applications. However, ETU is a complex process involving competing transitions between multiple energy levels and it has been difficult to precisely determine the enhancement mechanisms. In this paper, we report a systematic study on the dynamics of the ETU process in NaYF4:Yb3+,Er3+ nanoparticles deposited on plasmonic nanograting structure. From the transient near-infrared photoluminescence under various excitation power densities, we observed faster energy transfer rates under stronger excitation conditions until it reached saturation where the highest internal upconversion efficiency was achieved. The experimental data were analyzed using the complete set of rate equations. The internal upconversion efficiency was found to be 56% and 36%, respectively, with and without the plasmonic nanograting. We also analyzed the transient green emission and found that it is determined by the infrared transition rate. To our knowledge, this is the first report of experimentally measured internal upconversion efficiency in plasmon enhanced upconversion material. Our work decouples the internal upconversion efficiency from the overall upconverted luminescence efficiency, allowing more targeted engineering for efficiency improvement. PMID:26739230

  11. Experimental demonstration of plasmon enhanced energy transfer rate in NaYF4:Yb3+,Er3+ upconversion nanoparticles

    NASA Astrophysics Data System (ADS)

    Lu, Dawei; Mao, Chenchen; Cho, Suehyun K.; Ahn, Sungmo; Park, Wounjhang

    2016-01-01

    Energy transfer upconversion (ETU) is known to be the most efficient frequency upconversion mechanism. Surface plasmon can further enhance the upconversion process, opening doors to many applications. However, ETU is a complex process involving competing transitions between multiple energy levels and it has been difficult to precisely determine the enhancement mechanisms. In this paper, we report a systematic study on the dynamics of the ETU process in NaYF4:Yb3+,Er3+ nanoparticles deposited on plasmonic nanograting structure. From the transient near-infrared photoluminescence under various excitation power densities, we observed faster energy transfer rates under stronger excitation conditions until it reached saturation where the highest internal upconversion efficiency was achieved. The experimental data were analyzed using the complete set of rate equations. The internal upconversion efficiency was found to be 56% and 36%, respectively, with and without the plasmonic nanograting. We also analyzed the transient green emission and found that it is determined by the infrared transition rate. To our knowledge, this is the first report of experimentally measured internal upconversion efficiency in plasmon enhanced upconversion material. Our work decouples the internal upconversion efficiency from the overall upconverted luminescence efficiency, allowing more targeted engineering for efficiency improvement.

  12. Enhancement of single particle rare earth doped NaYF4: Yb, Er emission with a gold shell

    NASA Astrophysics Data System (ADS)

    Li, Ling; Green, Kory; Hallen, Hans; Lim, Shuang Fang

    2015-01-01

    Upconversion of infrared light to visible light has important implications for bioimaging. However, the small absorption cross-section of rare earth dopants has limited the efficiency of these anti-Stokes nanomaterials. We present enhanced excitation absorption and single particle fluorescent emission of sodium yttrium fluoride, NaYF4: Yb, Er based upconverting nanoparticles coated with a gold nanoshell through surface plasmon resonance. The single gold-shell coated nanoparticles show enhanced absorption in the near infrared, enhanced total emission intensity, and increased green relative to red emission. We also show differences in enhancement between single and aggregated gold shell nanoparticles. The surface plasmon resonance of the gold-shell coated nanoparticle is shown to be dependent on the shell thickness. In contrast to other reported results, our single particle experimental observations are corroborated by finite element calculations that show where the green/red emission enhancement occurs, and what portion of the enhancement is due to electromagnetic effects. We find that the excitation enhancement and green/red emission ratio enhancement occurs at the corners and edges of the doped emissive core.

  13. Spectroscopy and excitation dynamics of the trivalent lanthanides Tm(3+) and Ho(3+) in LiYF4

    NASA Technical Reports Server (NTRS)

    Walsh, Brian M.

    1995-01-01

    A detailed study of the spectroscopy and excitation dynamics Tm3+ and Ho3+ in yttrium lithium fluoride, LiYF4 (YLF), has been done. Absorption spectroscopy is utilized in the Judd-Ofelt theory to determine radiative transition rates of spontaneous emission. Luminescence spectroscopy is studied under cw diode laser excitation at 785nm. The effect of dopant ion concentration and excitation power on the observed luminescence are considered in these measurements. An analysis of these measurements have been used to determine channels of energy transfer between Tm3+ and Ho3+ ions. The temporal response of Tm and Ho in singly and co-doped YLF to pulsed laser excitation with a Ti:Al2O3 laser and a CoMgF2 laser turned to various wavelengths have also been studied. The energy transfer mechanisms of cross relaxation, upconversion, and resonant energy transfer between Tm3+ and Ho3+ ions have been modeled, and the model parameters extracted by a fitting procedure to the measured temporal response curves. Rate equation approaches to modeling are presented that result in predictions of rate constants for energy transfer processes, as well as more conventional approaches to modeling such as the Forster-Dexter models, which give the interaction strengths in terms of microscopic interaction parameters.

  14. Controlled synthesis and upconversion luminescence properties of LiYF4:Yb0.2Er0.02 nanoparticles

    NASA Astrophysics Data System (ADS)

    Zhang, Dan; De, Gejihu; Zi, Lu; Xu, Yueshan; Liu, Songtao

    2016-07-01

    A series of high quality tetragonal LiYF4:Yb0.2Er0.02 nanoparticles were synthesized via thermal decomposition method. The influence of reaction conditions on final products has been investigated in detail. The TEM and XRD data show that the size, shape and crystallization of the samples depend on the reaction time and concentration. The upconversion luminescence (UCL) intensity gradually enhanced along with the sizes of the samples increasing. And when the reaction solvent system is oleic acid/1-octadecence (OA/ODE), the samples show smaller size and stronger emission compared with oleic acid/oleylamine/1-octadecence (OA/OM/ODE). Under 980 nm NIR laser diode excitation, all the samples show intense green emission between 510 and 570 nm wavelength from 4S3/2 → 4I15/2 and 2H11/2 → 4I15/2 transitions of Er3+ and intense red emission between 640 and 690 nm attributed to 2F11/2 → 4I15/2 transition of Er3+, both of the processes belong to two-photon energy absorption.

  15. DNA Vaccination in Chickens.

    PubMed

    Gupta, Shishir Kumar; Dey, Sohini; Chellappa, Madhan Mohan

    2016-01-01

    Robust and sustainable development of poultry industry requires prevention of deadly infectious diseases. Vigorous vaccination of the birds is a routine practice; however, the live and inactivated vaccines that are used have inherent disadvantages. New-generation vaccines such as DNA vaccines offer several advantages over conventional vaccines. DNA vaccines, which encode an antigen of interest or multiple antigens in the target host, are stable, easy to produce and administer, do not require cold chain maintenance, and are not affected by the maternal antibodies. In addition, DNA vaccines can also be administered in ovo, and thus, mass vaccination and early induction of immune response can effectively be achieved. In this chapter, we focus on the development of DNA vaccines against important infectious viral as well as parasitic diseases of poultry.

  16. Neurologic complications of vaccinations.

    PubMed

    Miravalle, Augusto A; Schreiner, Teri

    2014-01-01

    This chapter reviews the most common neurologic disorders associated with common vaccines, evaluates the data linking the disorder with the vaccine, and discusses the potential mechanism of disease. A literature search was conducted in PubMed using a combination of the following terms: vaccines, vaccination, immunization, and neurologic complications. Data were also gathered from publications of the American Academy of Pediatrics Committee on Infectious Diseases, the World Health Organization, the US Centers for Disease Control and Prevention, and the Vaccine Adverse Event Reporting System. Neurologic complications of vaccination are rare. Many associations have been asserted without objective data to support a causal relationship. Rarely, patients with a neurologic complication will have a poor outcome. However, most patients recover fully from the neurologic complication. Vaccinations have altered the landscape of infectious disease. However, perception of risk associated with vaccinations has limited the success of disease eradication measures. Neurologic complications can be severe, and can provoke fear in potential vaccines. Evaluating whether there is causal link between neurologic disorders and vaccinations, not just temporal association, is critical to addressing public misperception of risk of vaccination. Among the vaccines available today, the cost-benefit analysis of vaccinations and complications strongly argues in favor of vaccination.

  17. Vaccinations for Adults with Diabetes

    MedlinePlus

    Vaccinations for Adults with Diabetes The table below shows which vaccinations you should have to protect your health if ... sure you and your healthcare provider keep your vaccinations up to date. Vaccine Do you need it? ...

  18. Diabetes and Hepatitis B Vaccination

    MedlinePlus

    ... monitoring in close succession. CDC now recommends the hepatitis B vaccine for adults with diabetes. What is the recommendation ... As with other vaccines, the effectiveness of the hepatitis B vaccine decreases with age. Decisions to vaccinate should include ...

  19. Nasal spray flu vaccine (image)

    MedlinePlus

    The flu vaccine can also be administered as a nasal spray instead of the usual injection method. It can be ... the recombinant influenza vaccine (RIV). The nasal spray flu vaccine (live attenuated influenza vaccine or LAIV) should not ...

  20. 42 CFR 410.57 - Pneumococcal vaccine and flu vaccine.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 2 2012-10-01 2012-10-01 false Pneumococcal vaccine and flu vaccine. 410.57... § 410.57 Pneumococcal vaccine and flu vaccine. (a) Medicare Part B pays for pneumococcal vaccine and its administration when reasonable and necessary for the prevention of disease, if the vaccine is ordered by a...

  1. 42 CFR 410.57 - Pneumococcal vaccine and flu vaccine.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 2 2013-10-01 2013-10-01 false Pneumococcal vaccine and flu vaccine. 410.57... § 410.57 Pneumococcal vaccine and flu vaccine. (a) Medicare Part B pays for pneumococcal vaccine and its administration when reasonable and necessary for the prevention of disease, if the vaccine is ordered by a...

  2. 42 CFR 410.57 - Pneumococcal vaccine and flu vaccine.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 2 2014-10-01 2014-10-01 false Pneumococcal vaccine and flu vaccine. 410.57... § 410.57 Pneumococcal vaccine and flu vaccine. (a) Medicare Part B pays for pneumococcal vaccine and its administration when reasonable and necessary for the prevention of disease, if the vaccine is ordered by a...

  3. 42 CFR 410.57 - Pneumococcal vaccine and flu vaccine.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false Pneumococcal vaccine and flu vaccine. 410.57... § 410.57 Pneumococcal vaccine and flu vaccine. (a) Medicare Part B pays for pneumococcal vaccine and its administration when reasonable and necessary for the prevention of disease, if the vaccine is ordered by a...

  4. 42 CFR 410.57 - Pneumococcal vaccine and flu vaccine.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Pneumococcal vaccine and flu vaccine. 410.57... § 410.57 Pneumococcal vaccine and flu vaccine. (a) Medicare Part B pays for pneumococcal vaccine and its administration when reasonable and necessary for the prevention of disease, if the vaccine is ordered by a...

  5. Vaccines against poverty

    PubMed Central

    MacLennan, Calman A.; Saul, Allan

    2014-01-01

    With the 2010s declared the Decade of Vaccines, and Millennium Development Goals 4 and 5 focused on reducing diseases that are potentially vaccine preventable, now is an exciting time for vaccines against poverty, that is, vaccines against diseases that disproportionately affect low- and middle-income countries (LMICs). The Global Burden of Disease Study 2010 has helped better understand which vaccines are most needed. In 2012, US$1.3 billion was spent on research and development for new vaccines for neglected infectious diseases. However, the majority of this went to three diseases: HIV/AIDS, malaria, and tuberculosis, and not neglected diseases. Much of it went to basic research rather than development, with an ongoing decline in funding for product development partnerships. Further investment in vaccines against diarrheal diseases, hepatitis C, and group A Streptococcus could lead to a major health impact in LMICs, along with vaccines to prevent sepsis, particularly among mothers and neonates. The Advanced Market Commitment strategy of the Global Alliance for Vaccines and Immunisation (GAVI) Alliance is helping to implement vaccines against rotavirus and pneumococcus in LMICs, and the roll out of the MenAfriVac meningococcal A vaccine in the African Meningitis Belt represents a paradigm shift in vaccines against poverty: the development of a vaccine primarily targeted at LMICs. Global health vaccine institutes and increasing capacity of vaccine manufacturers in emerging economies are helping drive forward new vaccines for LMICs. Above all, partnership is needed between those developing and manufacturing LMIC vaccines and the scientists, health care professionals, and policy makers in LMICs where such vaccines will be implemented. PMID:25136089

  6. Vaccines against poverty.

    PubMed

    MacLennan, Calman A; Saul, Allan

    2014-08-26

    With the 2010s declared the Decade of Vaccines, and Millennium Development Goals 4 and 5 focused on reducing diseases that are potentially vaccine preventable, now is an exciting time for vaccines against poverty, that is, vaccines against diseases that disproportionately affect low- and middle-income countries (LMICs). The Global Burden of Disease Study 2010 has helped better understand which vaccines are most needed. In 2012, US$1.3 billion was spent on research and development for new vaccines for neglected infectious diseases. However, the majority of this went to three diseases: HIV/AIDS, malaria, and tuberculosis, and not neglected diseases. Much of it went to basic research rather than development, with an ongoing decline in funding for product development partnerships. Further investment in vaccines against diarrheal diseases, hepatitis C, and group A Streptococcus could lead to a major health impact in LMICs, along with vaccines to prevent sepsis, particularly among mothers and neonates. The Advanced Market Commitment strategy of the Global Alliance for Vaccines and Immunisation (GAVI) Alliance is helping to implement vaccines against rotavirus and pneumococcus in LMICs, and the roll out of the MenAfriVac meningococcal A vaccine in the African Meningitis Belt represents a paradigm shift in vaccines against poverty: the development of a vaccine primarily targeted at LMICs. Global health vaccine institutes and increasing capacity of vaccine manufacturers in emerging economies are helping drive forward new vaccines for LMICs. Above all, partnership is needed between those developing and manufacturing LMIC vaccines and the scientists, health care professionals, and policy makers in LMICs where such vaccines will be implemented.

  7. Narcolepsy Following Yellow Fever Vaccination: A Case Report

    PubMed Central

    Rosch, Richard E.; Farquhar, Michael; Gringras, Paul; Pal, Deb K.

    2016-01-01

    Narcolepsy with cataplexy is a rare, but important differential diagnosis for daytime sleepiness and atonic paroxysms in an adolescent. A recent increase in incidence in the pediatric age group probably linked to the use of the Pandemrix influenza vaccine in 2009, has increased awareness that different environmental factors can “trigger” narcolepsy with cataplexy in a genetically susceptible population. Here, we describe the case of a 13-year-old boy with narcolepsy following yellow fever vaccination. He carries the HLA DQB1*0602 haplotype strongly associated with narcolepsy and cataplexy. Polysomnography showed rapid sleep onset with rapid eye movement (REM) latency of 47 min, significant sleep fragmentation and a mean sleep latency of 1.6 min with sleep onset REM in four out of four nap periods. Together with the clinical history, these findings are diagnostic of narcolepsy type 1. The envelope protein E of the yellow fever vaccine strain 17D has significant amino acid sequence overlap with both hypocretin and the hypocretin receptor 2 receptors in protein regions that are predicted to act as epitopes for antibody production. These findings raise the question whether the yellow fever vaccine strain may, through a potential molecular mimicry mechanism, be another infectious trigger for this neuro-immunological disorder. PMID:27559330

  8. Vaccines and Immunization Practice.

    PubMed

    Hogue, Michael D; Meador, Anna E

    2016-03-01

    Vaccines are among most cost-effective public health strategies. Despite effective vaccines for many bacterial and viral illnesses, tens of thousands of adults and hundreds of children die each year in the United States from vaccine-preventable diseases. Underutilization of vaccines requires rethinking the approach to incorporating vaccines into practice. Arguably, immunizations could be a part all health care encounters. Shared responsibility is paramount if deaths are to be reduced. This article reviews the available vaccines in the US market, as well as practice recommendations of the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices.

  9. Universal fungal vaccines

    PubMed Central

    Hamad, Mawieh

    2012-01-01

    The complex nature of fungal pathogens, the intricate host-pathogen relationship and the health status of subjects in need of antifungal vaccination continue to hamper efforts to develop fungal vaccines for clinical use. That said, the rise of the universal vaccine concept is hoped to revive fungal vaccine research by expanding the pool of vaccine candidates worthy of clinical evaluation. It can do so through antigenic commonality-based screening for vaccine candidates from a wide range of pathogens and by reassessing the sizable collection of already available experimental and approved vaccines. Development of experimental vaccines protective against multiple fungal pathogens is evidence of the utility of this concept in fungal vaccine research. However, universal fungal vaccines are not without difficulties; for instance, development of vaccines with differential effectiveness is an issue that should be addressed. Additionally, rationalizing the development of universal fungal vaccines on health or economic basis could be contentious. Herein, universal fungal vaccines are discussed in terms of their potential usefulness and possible drawbacks. PMID:22922769

  10. Vaccine Safety Datalink

    Cancer.gov

    The Vaccine Safety Datalink is part of the National Immunization Program within the Centers for Disease Control and Prevention and was started in recognition of gaps in the scientific knowledge of rare vaccine side effects.

  11. Pneumococcal Vaccines (PCV, PPSV)

    MedlinePlus

    ... to 2-Year-Old Your Child's Immunizations: Pneumococcal Vaccines (PCV, PPSV) KidsHealth > For Parents > Your Child's Immunizations: ... or HIV infection); or cochlear implants. Why the Vaccines Are Recommended Children younger than 2 years old, ...

  12. Vaccines and Pregnancy

    MedlinePlus

    ... best live chat Live Help Fact Sheets Share Vaccines and Pregnancy Thursday, 01 September 2016 In every ... risk. This sheet talks about whether exposure to vaccines may increase the risk for birth defects over ...

  13. National Vaccine Program Office

    MedlinePlus

    ... Track Your Community Vaccine Safety Scientific Agenda Newsletter Sign Up Subscribe to newsletter updates for the latest information ... National Vaccine Program Office. Email Connect With NVPO Sign Up for NVPO Updates To sign up for updates ...

  14. China's emerging vaccine industry.

    PubMed

    Hendriks, Jan; Liang, Yan; Zeng, Bing

    2010-07-01

    The Chinese vaccine industry is developing rapidly due to an emerging and large market for current and new vaccines, a large potential for local vaccine manufacturing both in the public and private domain, and a governmental orientation towards national vaccine self-sufficiency. There are currently over 40 companies and institutions manufacturing a large variety of traditional (EPI) and some new vaccines. The innovative development capacity of state vaccine institutions is stimulated by significant government investments. Various Chinese influenza manufacturers were in 2009 among the first worldwide to obtain national license for their pandemic H1N1 flu vaccines. It is of interest to note that private but also governmental entities are committed to raise manufacturing quality standards to reach WHO prequalification. It is expected that WHO prequalification for at least one product from a Chinese manufacturer will have been obtained by 2011. This will open the door to the global market for Chinese vaccines.

  15. Live Virus Smallpox Vaccine

    MedlinePlus

    ... Submit What's this? Submit Button The Live Virus Smallpox Vaccine Language: English Español (Spanish) Recommend on Facebook ... the vaccinia virus. Who should NOT get the smallpox vaccine? People most likely to have side effects ...

  16. Screening Tests and Vaccines

    MedlinePlus

    ... Contact Us Text size | Print | Screening Tests and Vaccines This information in Spanish ( en español ) Getting important screening tests and vaccines can save your life. Check this section of ...

  17. The HPV Vaccination Crisis

    Cancer.gov

    Following the release of a consensus statement from the NCI-Designated Cancer Centers urging HPV vaccination in the United States, Dr. Noel Brewer discusses the country’s low vaccination rates and how clinicians can help to improve them.

  18. Clinical vaccine development

    PubMed Central

    2015-01-01

    Vaccination is regarded as one of the biggest triumphs in the history of medicine. We are living in the most successful period of vaccine development. The accumulation of multidisciplinary knowledge and the investment of massive funding have enabled the development of vaccines against many infectious diseases as well as other diseases including malignant tumors. The paradigm of clinical vaccine evaluation and licensure has also been modernized based on scientific improvements and historical experience. However, there remain a number of hurdles to overcome. Continuous efforts are focused on increasing the efficacy and reducing the risks related to vaccine use. Cutting-edge knowledge about immunology and microbiology is being rapidly translated to vaccine development. Thus, physicians and others involved in the clinical development of vaccines should have sufficient understanding of the recent developmental trends in vaccination and the diseases of interest. PMID:25648742

  19. Vaccines in Multiple Sclerosis.

    PubMed

    Williamson, Eric M L; Chahin, Salim; Berger, Joseph R

    2016-04-01

    Vaccinations help prevent communicable disease. To be valuable, a vaccine's ability to prevent disease must exceed the risk of adverse effects from administration. Many vaccines present no risk of infection as they are comprised of killed or non-infectious components while other vaccines consist of live attenuated microorganisms which carry a potential risk of infection-particularly, in patients with compromised immunity. There are several unique considerations with respect to vaccination in the multiple sclerosis (MS) population. First, there has been concern that vaccination may trigger or aggravate the disease. Second, disease-modifying therapies (DMTs) employed in the treatment of MS may increase the risk of infectious complications from vaccines or alter their efficacy. Lastly, in some cases, vaccination strategies may be part of the treatment paradigm in attempts to avoid complications of therapy.

  20. Vaccines against malaria.

    PubMed

    Ouattara, Amed; Laurens, Matthew B

    2015-03-15

    Despite global efforts to control malaria, the illness remains a significant public health threat. Currently, there is no licensed vaccine against malaria, but an efficacious vaccine would represent an important public health tool for successful malaria elimination. Malaria vaccine development continues to be hindered by a poor understanding of antimalarial immunity, a lack of an immune correlate of protection, and the genetic diversity of malaria parasites. Current vaccine development efforts largely target Plasmodium falciparum parasites in the pre-erythrocytic and erythrocytic stages, with some research on transmission-blocking vaccines against asexual stages and vaccines against pregnancy-associated malaria. The leading pre-erythrocytic vaccine candidate is RTS,S, and early results of ongoing Phase 3 testing show overall efficacy of 46% against clinical malaria. The next steps for malaria vaccine development will focus on the design of a product that is efficacious against the highly diverse strains of malaria and the identification of a correlate of protection against disease.

  1. Mathematical models of vaccination.

    PubMed

    Scherer, Almut; McLean, Angela

    2002-01-01

    Mathematical models of epidemics have a long history of contributing to the understanding of the impact of vaccination programmes. Simple, one-line models can predict target vaccination coverage that will eradicate an infectious agent, whilst other questions require complex simulations of stochastic processes in space and time. This review introduces some simple ordinary differential equation models of mass vaccination that can be used to address important questions about the predicted impact of vaccination programmes. We show how to calculate the threshold vaccination coverage rate that will eradicate an infection, explore the impact of vaccine-induced immunity that wanes through time, and study the competitive interactions between vaccine susceptible and vaccine resistant strains of infectious agent.

  2. Selectively enhanced red upconversion luminescence and phase/size manipulation via Fe3+ doping in NaYF4:Yb,Er nanocrystals

    NASA Astrophysics Data System (ADS)

    Tang, Jing; Chen, Li; Li, Jing; Wang, Zhe; Zhang, Jiahua; Zhang, Ligong; Luo, Yongshi; Wang, Xiaojun

    2015-08-01

    Red upconversion luminescence (UCL) is selectively enhanced by about 7 times via Fe3+ codoping into a NaYF4:Yb,Er nanocrystalline lattice. The maximum red-to-green ratio (R/G) as well as the overall integrated UCL intensity features at an Fe3+ content of 20 mol%. The size and phase of nanocrystals are simultaneously manipulated via Fe3+ doping with various concentrations by a facile hydrothermal method. Contrary to the literature, the pure hexagonal phase appears when Fe3+ concentrations are from 5 to 20 mol%, meanwhile, the size of NaYF4:Yb,Er nanocrystals reaches its maximum at 10 mol%. The intensified visible UCL especially the dominant red emission is mainly ascribed to the energy transfer (ET) from |2F7/2, 4T1g > (Yb3+-Fe3+ dimer) to 4F9/2 (Er3+) states as well as the distortion of the crystalline field symmetry upon Fe3+ codoping. Dynamic investigation of 4S3/2 and 4F9/2 states under the pulsed laser excitation of 980 nm along with the diffuse reflectance data further supports the proposed mechanism of UC processes. The results show the remarkable promise of Fe3+-codoped NaYF4:Yb,Er nanocrystals as upconverting nanoprobes with high sensitivity and penetrability in deeper tissue for multimodal biomedical imaging.Red upconversion luminescence (UCL) is selectively enhanced by about 7 times via Fe3+ codoping into a NaYF4:Yb,Er nanocrystalline lattice. The maximum red-to-green ratio (R/G) as well as the overall integrated UCL intensity features at an Fe3+ content of 20 mol%. The size and phase of nanocrystals are simultaneously manipulated via Fe3+ doping with various concentrations by a facile hydrothermal method. Contrary to the literature, the pure hexagonal phase appears when Fe3+ concentrations are from 5 to 20 mol%, meanwhile, the size of NaYF4:Yb,Er nanocrystals reaches its maximum at 10 mol%. The intensified visible UCL especially the dominant red emission is mainly ascribed to the energy transfer (ET) from |2F7/2, 4T1g > (Yb3+-Fe3+ dimer) to 4F9/2 (Er3

  3. Ongoing pharmacovigilance on vaccines.

    PubMed

    Santuccio, Carmela; Trotta, Francesco; Felicetti, Patrizia

    2015-02-01

    Vaccines have peculiar characteristics as well as their surveillance. Specific requirements, needs and challenges for the vaccine vigilance are discussed in the perspective to improve the whole system in order to guarantee a safer vaccine use and the keeping of the public confidence in vaccinations. Key elements for the routine safety monitoring, new regulations and some available tools are taken into account. Finally, the Italian experience is shortly described.

  4. NaYF4:Er(3+),Yb(3+)/SiO2 Core/Shell Upconverting Nanocrystals for Luminescence Thermometry up to 900 K.

    PubMed

    Geitenbeek, Robin G; Prins, P Tim; Albrecht, Wiebke; van Blaaderen, Alfons; Weckhuysen, Bert M; Meijerink, Andries

    2017-02-16

    The rapid development of nanomaterials with unique size-tunable properties forms the basis for a variety of new applications, including temperature sensing. Luminescent nanoparticles (NPs) have demonstrated potential as sensitive nanothermometers, especially in biological systems. Their small size offers the possibility of mapping temperature profiles with high spatial resolution. The temperature range is however limited, which prevents use in high-temperature applications such as, for example, nanoelectronics, thermal barrier coatings, and chemical reactors. In this work, we extend the temperature range for nanothermometry beyond 900 K using silica-coated NaYF4 nanoparticles doped with the lanthanide ions Yb(3+) and Er(3+). Monodisperse ∼20 nm NaYF4:Yb,Er nanocrystals were coated with a ∼10 nm silica shell. Upon excitation with infrared radiation, bright green upconversion (UC) emission is observed. From the intensity ratio between (2)H11/2 and (4)S3/2 UC emission lines at 520 and 550 nm, respectively, the temperature can be determined up to at least 900 K with an accuracy of 1-5 K for silica-coated NPs. For bare NaYF4:Yb,Er NPs, the particles degrade above 600 K. Repeated thermal cycling experiments demonstrate the high durability and reproducibility of the silica-coated nanocrystals as temperature probes without any loss of performance. The present results open avenues for the development of a new class of highly stable nanoprobes by applying a silica coating around a wide variety of lanthanide-doped NPs.

  5. NaYF4:Er3+,Yb3+/SiO2 Core/Shell Upconverting Nanocrystals for Luminescence Thermometry up to 900 K

    PubMed Central

    2017-01-01

    The rapid development of nanomaterials with unique size-tunable properties forms the basis for a variety of new applications, including temperature sensing. Luminescent nanoparticles (NPs) have demonstrated potential as sensitive nanothermometers, especially in biological systems. Their small size offers the possibility of mapping temperature profiles with high spatial resolution. The temperature range is however limited, which prevents use in high-temperature applications such as, for example, nanoelectronics, thermal barrier coatings, and chemical reactors. In this work, we extend the temperature range for nanothermometry beyond 900 K using silica-coated NaYF4 nanoparticles doped with the lanthanide ions Yb3+ and Er3+. Monodisperse ∼20 nm NaYF4:Yb,Er nanocrystals were coated with a ∼10 nm silica shell. Upon excitation with infrared radiation, bright green upconversion (UC) emission is observed. From the intensity ratio between 2H11/2 and 4S3/2 UC emission lines at 520 and 550 nm, respectively, the temperature can be determined up to at least 900 K with an accuracy of 1–5 K for silica-coated NPs. For bare NaYF4:Yb,Er NPs, the particles degrade above 600 K. Repeated thermal cycling experiments demonstrate the high durability and reproducibility of the silica-coated nanocrystals as temperature probes without any loss of performance. The present results open avenues for the development of a new class of highly stable nanoprobes by applying a silica coating around a wide variety of lanthanide-doped NPs. PMID:28303168

  6. Tunable upconversion emission in Ba{sub 2}YF{sub 7}:Yb{sup 3+}/Er{sup 3+} nanocrystals with different Yb{sup 3+} concentration

    SciTech Connect

    Chuai, Xiaohong; Yin, Feixiang; Liu, Zhenyu; Shi, Feng; Wang, Jianshuo; Wang, Lili; Zheng, Kezhi; He, Chunfeng; Qin, Weiping

    2013-06-01

    Graphical abstract: The emission intensity at 520 nm and 540 nm can be tuned by Yb{sup 3+} concentration. - Highlights: • High concentration of Yb{sup 3+} can be doped into Ba{sub 2}YF{sub 7} without a phase change. • The emission intensity at 520 nm and 540 nm can be tuned by Yb{sup 3+} concentration. • The long lifetime of {sup 4}F{sub 9/2} level makes its populating effective. - Abstract: Ba{sub 2}YF{sub 7}:xYb{sup 3+},0.02Er{sup 3+} nanocrystals with different Yb{sup 3+} concentration (x = 0.2, 0.4, 0.6, 0.8, 0.98) were synthesized via a solvothermal method. Their X-ray diffraction patterns reveal that all the samples are cubic phase without phase change at arbitrary Yb{sup 3+} concentration. Upon excitation of 980 nm laser, these nanocrystals display upconversion emission in the green and red spectral regions. The relative emission intensity at these two regions can be tuned by Yb{sup 3+} concentration. To investigate the effect of Yb{sup 3+} ion, the decay times of 650 nm emission were measured and analyzed. Ba{sub 2}YF{sub 7}:0.6Yb{sup 3+},0.02Er{sup 3+} nanocrystals have the longest lifetime and highest emission intensity among all the samples. We concluded the lifetime of {sup 4}F{sub 9/2} level has an effect on its own population and intensity ratio of red and green emission. Our results show Yb{sup 3+} ion can tune the upconversion emission and improve upconverison emission intensity.

  7. Synthesis-driven, structure-dependent optical behavior in phase-tunable NaYF4:Yb,Er-based motifs and associated heterostructures

    DOE PAGES

    Liu, Haiqing; Han, Jinkyu; McBean, Coray; ...

    2017-01-03

    Understanding the key parameters necessary for generating uniform Er,Yb co-activated NaYF4 possessing various selected phases (i.e. cubic or hexagonal) represents an important chemical strategy towards tailoring optical behavior in these systems. In this paper, we report on a straightforward hydrothermal synthesis in which the separate effects of reaction temperature, reaction time, and precursor stoichiometry in the absence of any surfactant were independently investigated. Interestingly, the presence and the concentration of NH4OH appear to be the most critical determinants of the phase and morphology. For example, with NH4OH as an additive, we have observed the formation of novel hierarchical nanowire bundlesmore » which possess overall lengths of ~5 μm and widths of ~1.5 μm but are composed of constituent component sub-units of long, ultrathin (~5 nm) nanowires. These motifs have yet to be reported as distinctive morphological manifestations of fluoride materials. The optical properties of as-generated structures have also been carefully analyzed. Specifically, we have observed tunable, structure-dependent energy transfer behavior associated with the formation of a unique class of NaYF4–CdSe quantum dot (QD) heterostructures, incorporating zero-dimensional (0D), one-dimensional (1D), and three-dimensional (3D) NaYF4 structures. Our results have demonstrated the key roles of the intrinsic morphology-specific physical surface area and porosity as factors in governing the resulting opto-electronic behavior. Finally and specifically, the trend in energy transfer efficiency correlates well with the corresponding QD loading within these heterostructures, thereby implying that the efficiency of FRET appears to be directly affected by the amount of QDs immobilized onto the external surfaces of the underlying fluoride host materials.« less

  8. Vaccine against herpes zoster.

    PubMed

    Pasternak, Jacyr

    2013-01-01

    The herpes zoster vaccine is made using high doses of live attenuated varicella/zoster virus. The vaccine is well tolerated and has few adverse effects: the most common one is pain at the injection site. Complications can occur mainly in persons who had prior zoster keratitis or uveitis. The vaccine can prevent this disease with low mortality but high morbidity.

  9. [Improving vaccination measures].

    PubMed

    Iannazzo, S

    2014-01-01

    Despite the benefits of routine vaccination of newborns are known and widely documented, in recent years we are observing a gradual increase in the number of parents who express doubts and concerns about the safety of vaccines and the real need to submit their children to vaccinations included in the national recommendations. This attitude is reinforced by the current epidemiological profile, in Western countries, of many vaccine preventable diseases, accompanied by a low risk perception among parents. Institutions and all the actors involved in vaccination programs have a duty to investigate the reasons for the loss of confidence in vaccination among the population in order to identify and implement appropriate and effective interventions. The improvement of vaccination should, theoretically, goes on a double track, placing side by side the provision of effective vaccines, safe and necessary, and interventions designed to increase demand for vaccination among the population, improve access to vaccination services, improve the system as a whole. But to actually improve the vaccinations' offer it is necessary also to provide interventions aimed at regaining the confidence of the population in relation to vaccination and the institutions that promote them. Particular attention should be given to the aspects of communication and risk communication.

  10. Yellow Fever Vaccine

    MedlinePlus

    What is yellow fever?Yellow fever is a serious disease caused by the yellow fever virus. It is found in certain parts of Africa ... How can I prevent yellow fever?Yellow fever vaccine can prevent yellow fever. ... only at designated vaccination centers. After getting the vaccine, you ...

  11. A Dengue Vaccine.

    PubMed

    Durbin, Anna P

    2016-06-30

    Denvaxia is the first licensed vaccine for the prevention of dengue. It is a live vaccine developed using recombinant DNA technology. The vaccine is given as three doses over the course of a year and has the potential to prevent hundreds of thousands of hospitalizations each year.

  12. Polysaccharide-Based Vaccines

    NASA Astrophysics Data System (ADS)

    Santana, Violeta Fernández; Balbin, Yury Valdés; Calderón, Janoi Chang; Icart, Luis Peña; Verez-Bencomo, Vicente

    Capsular polysaccharides (CPS) and lipopolysaccharides from bacteria are employed for the production of vaccines against human diseases. Initial development of CPS as a vaccine was followed by the development and introduction of conjugate polysaccharide-protein vaccines. The principles leading to both developments are reviewed.

  13. Dengue vaccines for travelers.

    PubMed

    Wilder-Smith, Annelies; Deen, Jacqueline L

    2008-07-01

    Dengue is an arthropod-borne infection caused by a flavivirus and spread by the Aedes mosquitoes. Many of the countries where dengue is endemic are popular tourist destinations and the disease is an increasingly important problem encountered by international travelers. Personal protection against the day-feeding dengue vectors is problematic, indicating the urgent need for a dengue vaccine. This review discusses the challenges of vaccine development, current vaccine strategies and the prospects for the availability of a vaccine for travelers in the future. Cost-effectiveness studies will need to take into account many factors, including the attack rate of dengue in travelers, the proportion of travelers who will need hospitalization, the cost of altered travel itineraries, the cost of the vaccine, duration of travel, destination and season. To be licensed as a travelers' vaccine, vaccine trials must address safety, immunogenicity, duration of protection, schedules and boosters in adults (in particular in immunologically naive adults), trials that may differ from those conducted in endemic countries. Vaccine schedules with long intervals would be a major obstacle to the uptake of the vaccine by travelers. Enhanced reactogenicity or interference with immunization must be effectively excluded for travelers with prior or concurrent vaccination against other flaviviruses, such as yellow fever or Japanese encephalitis. Licensing dengue as a travelers' vaccine poses unique challenges beyond the development of a vaccine for the endemic population.

  14. Improving newcastle disease vaccination with homologous vaccines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    All Newcastle disease viruses (NDVs) belong to a single serotype; however, current vaccine strains display important amino acid differences at the F and HN protein compared with virulent outbreak strains (vNDV). Previous studies have shown decreased viral shedding after challenge when vaccines were...

  15. Biotransformation of 2,3,3,3-tetrafluoropropene (HFO-1234yf) in male, pregnant and non-pregnant female rabbits after single high dose inhalation exposure

    SciTech Connect

    Schmidt, Tobias; Bertermann, Rüdiger; Rusch, George M.; Hoffman, Gary M.; Dekant, Wolfgang

    2012-08-15

    2,3,3,3-Tetrafluoropropene (HFO-1234yf) is a novel refrigerant intended for use in mobile air conditioning. It showed a low potential for toxicity in rodents studies with most NOAELs well above 10,000 ppm in guideline compliant toxicity studies. However, a developmental toxicity study in rabbits showed mortality at exposure levels of 5,500 ppm and above. No lethality was observed at exposure levels of 2,500 and 4,000 ppm. Nevertheless, increased subacute inflammatory heart lesions were observed in rabbits at all exposure levels. Since the lethality in pregnant animals may be due to altered biotransformation of HFO-1234yf and to evaluate the potential risk to pregnant women facing a car crash, this study compared the acute toxicity and biotransformation of HFO-1234yf in male, female and pregnant female rabbits. Animals were exposed to 50,000 ppm and 100,000 ppm for 1 h. For metabolite identification by {sup 19}F NMR and LC/MS-MS, urine was collected for 48 h after inhalation exposure. In all samples, the predominant metabolites were S-(3,3,3-trifluoro-2-hydroxypropanyl)-mercaptolactic acid and N-acetyl-S-(3,3,3-trifluoro-2-hydroxypropanyl)-L-cysteine. Since no major differences in urinary metabolite pattern were observed between the groups, only N-acetyl-S-(3,3,3-trifluoro-2-hydroxypropanyl)-L-cysteine excretion was quantified. No significant differences in recovery between non-pregnant (43.10 ± 22.35 μmol) and pregnant female (50.47 ± 19.72 μmol) rabbits were observed, male rabbits exposed to 100,000 ppm for one hour excreted 86.40 ± 38.87 μmol. Lethality and clinical signs of toxicity were not observed in any group. The results suggest that the lethality of HFO-1234yf in pregnant rabbits unlikely is due to changes in biotransformation patterns or capacity in pregnant rabbits. -- Highlights: ► No lethality and clinical signs were observed. ► No differences in metabolic pattern between pregnant and non-pregnant rabbits. ► Rapid and similar metabolite

  16. Synthesis of stable carboxy-terminated NaYF4: Yb3+, Er3+@SiO2 nanoparticles with ultrathin shell for biolabeling applications

    NASA Astrophysics Data System (ADS)

    Liu, Fuyao; Zhao, Qi; You, Hongpeng; Wang, Zhenxin

    2013-01-01

    Here, a two-step method has been developed for synthesizing carboxy-terminated NaYF4: Yb3+, Er3+@SiO2 core@shell nanoparticles (UCNP@SiO2) with ultrathin shell (1.5 nm). First, the NaYF4: Yb3+, Er3+ upconverting nanoparticles (UCNPs) were prepared using solvothermal technology; then, silica shells (SiO2) were deposited on the nanocrystals to form core-shell structures by the hydrolysis of tetraethylorthosilicate (TEOS). The ultrathin SiO2 shell was obtained by increasing surfactant amount and decreasing TEOS amount in the reaction mixture. Carboxyethylsilanetriol (CTES) was used to generate the carboxy group on the particle surface. The carboxy-terminated UCNP@SiO2 are ideally suited for biolabeling and bioimaging applications because the as-prepared nanoparticles have extreme colloidal and optical stabilities, and the carboxy groups on the particle surface easily react with amino residues of biomolecules. As an example, we reported on the interactions of Ricinus Communis Agglutinin (RCA 120) conjugated UCNP@SiO2 with HeLa cells. The excellent performance of the RCA 120 conjugated UCNP@SiO2 in cellular fluorescence imaging was demonstrated.Here, a two-step method has been developed for synthesizing carboxy-terminated NaYF4: Yb3+, Er3+@SiO2 core@shell nanoparticles (UCNP@SiO2) with ultrathin shell (1.5 nm). First, the NaYF4: Yb3+, Er3+ upconverting nanoparticles (UCNPs) were prepared using solvothermal technology; then, silica shells (SiO2) were deposited on the nanocrystals to form core-shell structures by the hydrolysis of tetraethylorthosilicate (TEOS). The ultrathin SiO2 shell was obtained by increasing surfactant amount and decreasing TEOS amount in the reaction mixture. Carboxyethylsilanetriol (CTES) was used to generate the carboxy group on the particle surface. The carboxy-terminated UCNP@SiO2 are ideally suited for biolabeling and bioimaging applications because the as-prepared nanoparticles have extreme colloidal and optical stabilities, and the carboxy

  17. Passive Q-switching of Pr:LiYF4 orange laser at 604 nm using topological insulators Bi2Se3 as saturable absorber

    NASA Astrophysics Data System (ADS)

    Cheng, Yongjie; Peng, Jian; Bin, Xu; Xu, Huiying; Cai, Zhiping; Weng, Jian

    2017-02-01

    Q-switched laser operation of a laser diode pumped Pr:LiYF4 laser is reported at 604 nm using a topological insulator (TI) Bi2Se3 nanosheet material as saturable absorbers (SAs), for the first time to our knowledge. Stable Q-switched laser operation is obtained with shortest pulse width of about 802 ns, a maximum pulse repetition rate of 130 kHz, pulse energy of about 0.2 μJ and a maximum average output power of 26 mW. This work further extends the working wavelength of Bi2Se3 as saturable absorbers to visible domain.

  18. NaYF4:Yb/Er@PPy core-shell nanoplates: an imaging-guided multimodal platform for photothermal therapy of cancers

    NASA Astrophysics Data System (ADS)

    Huang, Xiaojuan; Li, Bo; Peng, Chen; Song, Guosheng; Peng, Yuxuan; Xiao, Zhiyin; Liu, Xijian; Yang, Jianmao; Yu, Li; Hu, Junqing

    2015-12-01

    Imaging guided photothermal agents have attracted great attention for accurate diagnosis and treatment of tumors. Herein, multifunctional NaYF4:Yb/Er@polypyrrole (PPy) core-shell nanoplates are developed by combining a thermal decomposition reaction and a chemical oxidative polymerization reaction. Within such a composite nanomaterial, the core of the NaYF4:Yb/Er nanoplate can serve as an efficient nanoprobe for upconversion luminescence (UCL)/X-ray computed tomography (CT) dual-modal imaging, the shell of the PPy shows strong near infrared (NIR) region absorption and makes it effective in photothermal ablation of cancer cells and infrared thermal imaging in vivo. Thus, this platform can be simultaneously used for cancer diagnosis and photothermal therapy, and compensates for the deficiencies of individual imaging modalities and satisfies the higher requirements on the efficiency and accuracy for diagnosis and therapy of cancer. The results further provide some insight into the exploration of multifunctional nanocomposites in the photothermal theragnosis therapy of cancers.Imaging guided photothermal agents have attracted great attention for accurate diagnosis and treatment of tumors. Herein, multifunctional NaYF4:Yb/Er@polypyrrole (PPy) core-shell nanoplates are developed by combining a thermal decomposition reaction and a chemical oxidative polymerization reaction. Within such a composite nanomaterial, the core of the NaYF4:Yb/Er nanoplate can serve as an efficient nanoprobe for upconversion luminescence (UCL)/X-ray computed tomography (CT) dual-modal imaging, the shell of the PPy shows strong near infrared (NIR) region absorption and makes it effective in photothermal ablation of cancer cells and infrared thermal imaging in vivo. Thus, this platform can be simultaneously used for cancer diagnosis and photothermal therapy, and compensates for the deficiencies of individual imaging modalities and satisfies the higher requirements on the efficiency and accuracy for

  19. Importance of vaccination habit and vaccine choice on influenza vaccination among healthy working adults.

    PubMed

    Lin, Chyongchiou J; Nowalk, Mary Patricia; Toback, Seth L; Rousculp, Matthew D; Raymund, Mahlon; Ambrose, Christopher S; Zimmerman, Richard K

    2010-11-10

    This randomized cluster trial was designed to improve workplace influenza vaccination rates using enhanced advertising, choice of vaccine type (intranasal or injectable) and an incentive. Workers aged 18-49 years were surveyed immediately following vaccination to determine factors associated with vaccination behavior and choice. The questionnaire assessed attitudes, beliefs and social support for influenza vaccine, demographics, and historical, current, and intentional vaccination behavior. Of the 2389 vaccinees, 83.3% received injectable vaccine and 16.7% received intranasal vaccine. Factors associated with previous influenza vaccination were older age, female sex, higher education and greater support for injectable vaccine (all P<.02). Current influenza vaccination with intranasal vaccine vs. injectable vaccine was associated with higher education, the study interventions, greater support for the intranasal vaccine and nasal sprays, less support of injectable vaccine, more negative attitudes about influenza vaccine, and a greater likelihood of reporting that the individual would not have been vaccinated had only injectable vaccine been offered (all P<.01). Intentional vaccine choice was most highly associated with previous vaccination behavior (P<.001). A key to long term improvements in workplace vaccination is to encourage first time influenza vaccination through interventions that include incentives, publicity and vaccine choice.

  20. Brucellosis vaccines for livestock.

    PubMed

    Goodwin, Zakia I; Pascual, David W

    2016-11-15

    Brucellosis is a livestock disease responsible for fetal loss due to abortions. Worldwide, this disease has profound economic and social impact by reducing the ability of livestock producers to provide an adequate supply of disease-free meat and dairy products. In addition to its presence in domesticated animals, brucellosis is harbored in a number of wildlife species creating new disease reservoirs, which adds to the difficulty of eradicating this disease. Broad and consistent use of the available vaccines would contribute in reducing the incidence of brucellosis. Unfortunately, this practice is not common. In addition, the current brucellosis vaccines cannot provide sterilizing immunity, and in certain circumstances, vaccinated livestock are not protected against co-mingling Brucella-infected wildlife. Given that these vaccines are inadequate for conferring complete protection for some vaccinated livestock, alternatives are being sought, and these include genetic modifications of current vaccines or their reformulations. Alternatively, many groups have sought to develop new vaccines. Subunit vaccines, delivered as a combination of soluble vaccine plus adjuvant or the heterologous expression of Brucella epitopes by different vaccine vectors are currently being tested. New live attenuated Brucella vaccines are also being developed and tested in their natural hosts. Yet, what is rarely considered is the route of vaccination which could improve vaccine efficacy. Since Brucella infections are mostly transmitted mucosally, mucosal delivery of a vaccine has the potential of eliciting a more robust protective immune response for improved efficacy. Hence, this review will examine these questions and provide the status of new vaccines for livestock brucellosis.

  1. CD4/CD8 Ratio and KT Ratio Predict Yellow Fever Vaccine Immunogenicity in HIV-Infected Patients

    PubMed Central

    Hunt, Peter W.; Huang, Yong; Simoes, Marisol; Lima, Sheila B.; Freire, Marcos S.; Caiaffa-Filho, Helio H.; Hong, Marisa A.; Costa, Dayane Alves; Dias, Juliana Zanatta C.; Cerqueira, Natalia B.; Nishiya, Anna Shoko; Sabino, Ester Cerdeira; Sartori, Ana M.; Kallas, Esper G.

    2016-01-01

    Background HIV-infected individuals have deficient responses to Yellow Fever vaccine (YFV) and may be at higher risk for adverse events (AE). Chronic immune activation–characterized by low CD4/CD8 ratio or high indoleamine 2,3-dioxygenase-1 (IDO) activity—may influence vaccine response in this population. Methods We prospectively assessed AE, viremia by the YFV virus and YF-specific neutralizing antibodies (NAb) in HIV-infected (CD4>350) and -uninfected adults through 1 year after vaccination. The effect of HIV status on initial antibody response to YFV was measured during the first 3 months following vaccination, while the effect on persistence of antibody response was measured one year following vaccination. We explored CD4/CD8 ratio, IDO activity (plasma kynurenine/tryptophan [KT] ratio) and viremia by Human Pegivirus as potential predictors of NAb response to YFV among HIV-infected participants with linear mixed models. Results 12 HIV-infected and 45-uninfected participants were included in the final analysis. HIV was not significantly associated with AE, YFV viremia or NAb titers through the first 3 months following vaccination. However, HIV–infected participants had 0.32 times the NAb titers observed for HIV-uninfected participants at 1 year following YFV (95% CI 0.13 to 0.83, p = 0.021), independent of sex, age and prior vaccination. In HIV-infected participants, each 10% increase in CD4/CD8 ratio predicted a mean 21% higher post-baseline YFV Nab titer (p = 0.024). Similarly, each 10% increase in KT ratio predicted a mean 21% lower post-baseline YFV Nab titer (p = 0.009). Viremia by Human Pegivirus was not significantly associated with NAb titers. Conclusions HIV infection appears to decrease the durability of NAb responses to YFV, an effect that may be predicted by lower CD4/CD8 ratio or higher KT ratio. PMID:27941965

  2. Diagnostic and vaccine chapter.

    PubMed

    Wolfram, J H; Kokanov, S K; Verkhovsky, O A

    2010-10-01

    The first report in this chapter describes the development of a killed composite vaccine. This killed vaccine is non-infectious to humans, other animals, and the environment. The vaccine has low reactivity, is non-abortive, and does not induce pathomorphological alterations to the organs of vaccinated animals. The second report of this chapter describes the diagnostic value of a competitive enzyme-linked immunosorbent assay for detecting Brucella-specific antibodies and its ability to discriminate vaccinated cattle from infected cattle. The results indicated that the competitive enzyme-linked immunosorbent assay is more sensitive than traditional tests for detecting antibodies to Brucella abortus in naturally and experimentally infected cattle.

  3. Patenting malarial vaccine.

    PubMed

    Wiwanitkit, Viroj

    2008-01-01

    Malaria is an important tropical infection affecting millions of world population each year. Malarial vaccine development is the hope for successful control of malaria. Knowledge on malaria vaccine has been considered patentable subject for decades. Due to the present advance biotechnology, the number of patent applications related to malarial vaccine is growing exponentially. Several malarial vaccine candidates have been recently identified and the genetic manipulation of these candidates is becoming more efficient with the advancement of new biotechnologies. This review summarizes some of the recent published patents on malarial vaccines covering antigens, candidate epitopes and recombinant processing.

  4. Vaccination for Disease

    NASA Astrophysics Data System (ADS)

    Oehen, Stephan; Hengartner, Hans; Zinkernagel, Rolf M.

    1991-01-01

    Recombinant virus vaccines that express a limited number of epitopes are currently being developed to prevent disease by changing the relative balance between viral spread and the immune response. Some circumstances, however, were found in infections with a noncytopathic virus in which vaccination caused disease; sensitive parameters included the genetic background of the host, the time or dose of infection, and the constituents of the vaccine. Thus, immunopathologic damage by T cells may be an unwanted consequence of vaccination with the new types of peptide or recombinant vaccines that are being investigated for the human immunodeficiency viruses and other pathogens.

  5. Emerging Vaccine Informatics

    PubMed Central

    He, Yongqun; Rappuoli, Rino; De Groot, Anne S.; Chen, Robert T.

    2010-01-01

    Vaccine informatics is an emerging research area that focuses on development and applications of bioinformatics methods that can be used to facilitate every aspect of the preclinical, clinical, and postlicensure vaccine enterprises. Many immunoinformatics algorithms and resources have been developed to predict T- and B-cell immune epitopes for epitope vaccine development and protective immunity analysis. Vaccine protein candidates are predictable in silico from genome sequences using reverse vaccinology. Systematic transcriptomics and proteomics gene expression analyses facilitate rational vaccine design and identification of gene responses that are correlates of protection in vivo. Mathematical simulations have been used to model host-pathogen interactions and improve vaccine production and vaccination protocols. Computational methods have also been used for development of immunization registries or immunization information systems, assessment of vaccine safety and efficacy, and immunization modeling. Computational literature mining and databases effectively process, mine, and store large amounts of vaccine literature and data. Vaccine Ontology (VO) has been initiated to integrate various vaccine data and support automated reasoning. PMID:21772787

  6. Vaccinations for pregnant women.

    PubMed

    Swamy, Geeta K; Heine, R Phillips

    2015-01-01

    In the United States, eradication and reduction of vaccine-preventable diseases through immunization has directly increased life expectancy by reducing mortality. Although immunization is a public priority, vaccine coverage among adult Americans is inadequate. The Institute of Medicine, the Community Preventive Services Task Force, and other public health entities have called for the development of innovative programs to incorporate adult vaccination into routine clinical practice. Obstetrician-gynecologists are well suited to serve as vaccinators of women in general and more specifically pregnant women. Pregnant women are at risk for vaccine-preventable disease-related morbidity and mortality and adverse pregnancy outcomes, including congenital anomalies, spontaneous abortion, preterm birth, and low birth weight. In addition to providing direct maternal benefit, vaccination during pregnancy likely provides direct fetal and neonatal benefit through passive immunity (transplacental transfer of maternal vaccine-induced antibodies). This article reviews: 1) types of vaccines; 2) vaccines specifically recommended during pregnancy and postpartum; 3) vaccines recommended during pregnancy and postpartum based on risk factors and special circumstances; 4) vaccines currently under research and development for licensure for maternal-fetal immunization; and 5) barriers to maternal immunization and available patient and health care provider resources.

  7. Vaccination against Klebsiella aerogenes.

    PubMed Central

    Roe, E. A.; Jones, R. J.

    1984-01-01

    Klebsiella vaccine was prepared from strains of Klebsiella aerogenes with capsular types K1, K36, K44 and K Cross (a type which cross-reacts in vitro with sera from many klebsiella capsular types). The vaccine was extracted by dialysis and ultrafiltration from capsular material released during growth of the bacteria in a five-day batch culture. Mice given one dose of vaccine from K1a (1.0 microgram/mouse) survived lethal intraperitoneal challenge of 11/11 homologous klebsiella strains four days after vaccination; 14 days after vaccination protection against the same challenge strains had declined to 5/11 strains. Vaccines from K1a, b, c, K36, K44 and K Cross induced homologous protection and protected mice against different ranges of heterologous klebsiella capsular types. The protective response of the mice was greatly enhanced by administering three doses of the vaccines. Vaccines from K1, K36, K44 and K Cross protected mice against 14/20, 11/20, 10/20 and 9/20 homologous and heterologous klebsiella challenge strains respectively. None of the klebsiella vaccines was toxic for mice at the immunizing dose (1.0 microgram/mouse). Vaccine from K36 was the most lethal, killing mice at 10(3) immunizing doses. The least toxic vaccine was from K44, which killed mice at 10(4) immunizing doses. PMID:6389699

  8. [Vaccinations for international travelers].

    PubMed

    Berens-Riha, N; Alberer, M; Löscher, T

    2014-03-01

    Vaccinations are a prominent part of health preparations before international travel. They can avoid or significantly reduce the risk of numerous infectious diseases. Until recently, vaccination against yellow fever was the only obligatory vaccination. However, according to updated international health regulations, other vaccinations and prophylactic measures may be required at entry from certain countries. For all routine vaccinations as recommended in Germany, necessary revaccination and catch-up of missed vaccinations should be administered before travel. At most destinations the risk of infection is higher than in Germany. Hepatitis A vaccine is generally recommended for travelers to areas of increased risk, polio vaccine for all destinations where eradication is not yet confirmed (Asia and Africa). The indications for other travel vaccines must take into consideration travel destination and itinerary, type and duration of travel, individual risk of exposure as well as the epidemiology of the disease to be prevented. Several vaccines of potential interest for travel medicine, e.g., new vaccines against malaria and dengue fever, are under development.

  9. Endotoxins in commercial vaccines.

    PubMed Central

    Geier, M R; Stanbro, H; Merril, C R

    1978-01-01

    Twenty samples of commercial vaccines intended for administration to humans were assayed for the presence of bacterial endotoxins by using the Limulus amebocyte lysate test. Sixteen of the vaccines contained more than 0.1 ng of endotoxin per ml (which corresponds to 103 bacterial cell wall equivalents per ml in the undiluted vaccines). These results suggest that at some stage of preparation, the vaccines have contained varying amounts of gram-negative bacteria and may indicate the presence of other bacterial products as well. It might be useful to list the level of endotoxins, phage, and other contaminants on each vaccine lot to facilitate studies on any side effects of these contaminants. Selection of vaccine lots with the least endotoxin might reduce some of the adverse effects of vaccinations. PMID:727776

  10. Vaccines for allergy

    PubMed Central

    Linhart, Birgit; Valenta, Rudolf

    2012-01-01

    Vaccines aim to establish or strengthen immune responses but are also effective for the treatment of allergy. The latter is surprising because allergy represents a hyper-immune response based on immunoglobulin E production against harmless environmental antigens, i.e., allergens. Nevertheless, vaccination with allergens, termed allergen-specific immunotherapy is the only disease-modifying therapy of allergy with long-lasting effects. New forms of allergy diagnosis and allergy vaccines based on recombinant allergen-derivatives, peptides and allergen genes have emerged through molecular allergen characterization. The molecular allergy vaccines allow sophisticated targeting of the immune system and may eliminate side effects which so far have limited the use of traditional allergen extract-based vaccines. Successful clinical trials performed with the new vaccines indicate that broad allergy vaccination is on the horizon and may help to control the allergy pandemic. PMID:22521141

  11. Vaccine epidemiology: A review

    PubMed Central

    Lahariya, Chandrakant

    2016-01-01

    This review article outlines the key concepts in vaccine epidemiology, such as basic reproductive numbers, force of infection, vaccine efficacy and effectiveness, vaccine failure, herd immunity, herd effect, epidemiological shift, disease modeling, and describes the application of this knowledge both at program levels and in the practice by family physicians, epidemiologists, and pediatricians. A case has been made for increased knowledge and understanding of vaccine epidemiology among key stakeholders including policy makers, immunization program managers, public health experts, pediatricians, family physicians, and other experts/individuals involved in immunization service delivery. It has been argued that knowledge of vaccine epidemiology which is likely to benefit the society through contributions to the informed decision-making and improving vaccination coverage in the low and middle income countries (LMICs). The article ends with suggestions for the provision of systematic training and learning platforms in vaccine epidemiology to save millions of preventable deaths and improve health outcomes through life-course. PMID:27453836

  12. Principles of Vaccination.

    PubMed

    Zepp, Fred

    2016-01-01

    While many of the currently available vaccines have been developed empirically, with limited understanding on how they activate the immune system and elicit protective immunity, the recent progress in basic sciences like immunology, microbiology, genetics, and molecular biology has fostered our understanding on the interaction of microorganisms with the human immune system. In consequence, modern vaccine development strongly builds on the precise knowledge of the biology of microbial pathogens, their interaction with the human immune system, as well as their capacity to counteract and evade innate and adaptive immune mechanisms. Strategies engaged by pathogens strongly determine how a vaccine should be formulated to evoke potent and efficient protective immune responses. The improved knowledge of immune response mechanisms has facilitated the development of new vaccines with the capacity to defend against challenging pathogens and can help to protect individuals particular at risk like immunocompromised and elderly populations. Modern vaccine development technologies include the production of highly purified antigens that provide a lower reactogenicity and higher safety profile than the traditional empirically developed vaccines. Attempts to improve vaccine antigen purity, however, may result in impaired vaccine immunogenicity. Some of such disadvantages related to highly purified and/or genetically engineered vaccines yet can be overcome by innovative technologies, such as live vector vaccines, and DNA or RNA vaccines. Moreover, recent years have witnessed the development of novel adjuvant formulations that specifically focus on the augmentation and/or control of the interplay between innate and adaptive immune systems as well as the function of antigen-presenting cells. Finally, vaccine design has become more tailored, and in turn has opened up the potential of extending its application to hitherto not accessible complex microbial pathogens plus providing new

  13. Influenza vaccines and vaccination strategies in birds.

    PubMed

    van den Berg, Thierry; Lambrecht, Bénédicte; Marché, Sylvie; Steensels, Mieke; Van Borm, Steven; Bublot, Michel

    2008-03-01

    Although it is well accepted that the present Asian H5N1 panzootic is predominantly an animal health problem, the human health implications and the risk of human pandemic have highlighted the need for more information and collaboration in the field of veterinary and human health. H5 and H7 avian influenza (AI) viruses have the unique property of becoming highly pathogenic (HPAI) during circulation in poultry. Therefore, the final objective of poultry vaccination against AI must be eradication of the virus and the disease. Actually, important differences exist in the control of avian and human influenza viruses. Firstly, unlike human vaccines that must be adapted to the circulating strain to provide adequate protection, avian influenza vaccination provides broader protection against HPAI viruses. Secondly, although clinical protection is the primary goal of human vaccines, poultry vaccination must also stop transmission to achieve efficient control of the disease. This paper addresses these differences by reviewing the current and future influenza vaccines and vaccination strategies in birds.

  14. Highly Efficient LiYF4:Yb(3+), Er(3+) Upconversion Single Crystal under Solar Cell Spectrum Excitation and Photovoltaic Application.

    PubMed

    Chen, Xu; Xu, Wen; Song, Hongwei; Chen, Cong; Xia, Haiping; Zhu, Yongsheng; Zhou, Donglei; Cui, Shaobo; Dai, Qilin; Zhang, Jiazhong

    2016-04-13

    Luminescent upconversion is a promising way to harvest near-infrared (NIR) sunlight and transforms it into visible light that can be directly absorbed by active materials of solar cells and improve their power conversion efficiency (PCE). However, it is still a great challenge to effectively improve the PCE of solar cells with the assistance of upconversion. In this work, we demonstrate the application of the transparent LiYF4:Yb(3+), Er(3+) single crystal as an independent luminescent upconverter to improve the PCE of perovskite solar cells. The LiYF4:Yb(3+), Er(3+) single crystal is prepared by an improved Bridgman method, and its internal quantum efficiency approached to 5.72% under 6.2 W cm(-2) 980 nm excitation. The power-dependent upconversion luminescence indicated that under the excitation of simulated sunlight the (4)F(9/2)-(4)I(15/2) red emission originally results from the cooperation of a 1540 nm photon and a 980 nm photon. Furthermore, when the single crystal is placed in front of the perovskite solar cells, the PCE is enhanced by 7.9% under the irradiation of simulated sunlight by 7-8 solar constants. This work implies the upconverter not only can serve as proof of principle for improving PCE of solar cells but also is helpful to practical application.

  15. Phase Transformation and Intense 2.7 μm Emission from Er3+ Doped YF3/YOF Submicron-crystals

    PubMed Central

    Chai, Guanqi; Dong, Guoping; Qiu, Jianrong; Zhang, Qinyuan; Yang, Zhongmin

    2013-01-01

    Yttrium fluoride YF3:Er3+ and yttrium oxyfluoride YOF:Er3+ submicron-crystals with mid-infrared fluorescent emissions were synthesized for the first time. The rhombohedral phase YOF submicron-crystals were synthesized by the crystalline phase transformation from pure orthorhombic YF3 submicron-crystals, which were prepared by co-precipitation method. The composition and morphology were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM), which showed that submicron-crystals were quasi-spherical with the particle size of ~400 nm. A novel formation mechanism of YOF submicron-crystals was proposed. Photoluminescence (PL) spectra indicated the 2.7 μm emission of Er3+ has remarkably enhanced with the increase of Er3+ doping concentration, and a novel dynamic circulatory energy transfer mechanism was proposed. Fourier transform infrared spectra (FTIR) were used to demonstrate the change of hydroxyl content. These oxyfluoride submicron-crystals provide a new material for nano/submicron-crystals-glass composites, and open a brand new field for the realization of mid-infrared micro/nano-lasers. PMID:23604234

  16. Crystal structure and vibrational properties of new luminescent hosts K{sub 3}YF{sub 6} and K{sub 3}GdF{sub 6}

    SciTech Connect

    Gusowski, Marek Adam . E-mail: marek.gusowski@wp.pl; Gagor, Anna; Trzebiatowska-Gusowska, Monika; Ryba-Romanowski, Witold

    2006-10-15

    The luminescence hosts K{sub 3}YF{sub 6} and K{sub 3}GdF{sub 6} were obtained in a single-crystal form. Their crystal structure was determined from single-crystal X-ray diffraction data. Both crystals adopt monoclinic system with space group P2{sub 1}/n, Z=2. Lattice parameters for K{sub 3}YF{sub 6} are refined to the following values a=6.3376(13)A, b=6.5435(13)A, c=9.0390(18)A, {beta}=90.65(3) and for K{sub 3}GdF{sub 6}a=6.3759(13)A, b=6.5922(13)A, c=9.1200(18)A, {beta}=90.80(3). The vibrational analysis, IR and Raman spectroscopy at room temperature, was applied to these compounds in order to study the site symmetry of Y{sup 3+} and Gd{sup 3+} ions.

  17. Gain Characteristics of Polymer Waveguide Amplifiers Based on NaYF4:Ybl+, Er3+ Nanocrystals at 0.54 µm Wavelength.

    PubMed

    Zhang, Meiling; Yin, Jiao; Jia, Zhixu; Song, Weiye; Wang, Xibin; Qin, Guanshi; Zhao, Dan; Qin, Weiping; Wang, Fei; Zhang, Daming

    2016-04-01

    Gain characteristics of polymer waveguide amplifiers based on NaYF4:Yb3+, Er3+ nanocrystals (NCs) at 0.54 µm wavelength were investigated through numerical simulations. NaYF4:18%Yb3+, 1 0%Er3+ NCs were doped into SU-8 2005 polymer matrix as the core of a polymer waveguide. The absorption spectrum and photoluminescence spectrum of the NCs were recorded and analyzed. The Judd-Ofelt parameters were achieved by means of Judd-Ofelt theory: Ω2 = 6.302 x 10(-20) cm2, Ω4 = 0.69 x 10(-20) cm2, Ω6 =7.572 x 10(-20) cm2. We simulated the gain characteristics of the waveguide amplifier at 0.54 µm wavelength by combining the atomic rate equations with power propaga- tion equations. The gain curves had the saturation effects. A maximum gain -4.3 dB for the 5 cm waveguide with the Er3+ concentration of ~7.5 x 1025 m-3 was obtained.

  18. Wind tunnel evaluation of YF-12 inlet response to internal airflow disturbances with and without control. [Lewis 10 by 10 ft supersonic wind tunnel tests

    NASA Technical Reports Server (NTRS)

    Cole, G. L.; Neiner, G. H.; Dustin, M. O.

    1978-01-01

    The response of terminal-shock position and static pressures in the subsonic duct of a YF-12 aircraft flight-hardware inlet to perturbations in simulated engine corrected airflow were obtained with and without inlet control. Frequency response data, obtained with inlet controls inactive, indicated the general nature of the inherent inlet dynamics, assisted in the design of controls, and provided a baseline reference for responses with active controls. All the control laws were implemented by means of a digital computer that could be programmed to behave like the flight inlet's existing analog control. The experimental controls were designed using an analytical optimization technique. The capabilities of the controls were limited primarily by the actuation hardware. The experimental controls provided somewhat better attenuation of terminal shock excursions than did the YF-13 inlet control. Controls using both the forward and aft bypass systems also provided somewhat better attenuation than those using just the forward bypass. The main advantage of using both bypasses is in the greater control flexibility that is achieved.

  19. Highly sensitive and selective cartap nanosensor based on luminescence resonance energy transfer between NaYF4:Yb,Ho nanocrystals and gold nanoparticles.

    PubMed

    Wang, Zhijiang; Wu, Lina; Shen, Baozhong; Jiang, Zhaohua

    2013-09-30

    Fluorescent detection is an attractive method for the detection of toxic chemicals. However, most chemosensors that are currently utilized in fluorescent detection are based on organic dyes or quantum dots, which suffer from instability, high background noise and interference from organic impurities in solution, which can also be excited by UV radiation. In the present research, we developed a novel NaYF4:Yb,Ho/Au nanocomposite-based chemosensor with high sensitivity (10 ppb) and selectivity over competing analytes for the detection of the insecticide cartap. This nanosensor is excited with a 970-nm laser instead of UV radiation to give an emission peak at 541 nm. In the presence of cartap, the nanocomposites aggregate, resulting in enhanced luminescence resonance energy transfer between the NaYF4:Yb,Ho nanocrystals and the gold nanoparticles, which decreases the emission intensity at 541 nm. The relative luminescence intensity at 541 nm has a linear relationship with the concentration of cartap in the solution. Based on this behavior, the developed nanosensor successfully detected cartap in farm produce and water samples with satisfactory results.

  20. Comparing the luminescence processes of YVO4:Eu and core-shell YVO4@YF3 nanocrystals with bulk-YVO4:Eu

    NASA Astrophysics Data System (ADS)

    Shirmane, L.; Feldmann, C.; Pankratov, V.

    2017-01-01

    Comparative analysis of bulk, non-coated and core-shelled nanocrystalline YVO4:Eu was performed by means of time-resolved luminescence and VUV excitation luminescence spectroscopy techniques. Nanocrystalline YVO4:Eu samples - both as-prepared and YF3 core-shelled - have been synthesized by means of a microwave-assisted synthesis in ionic liquids, which allows to obtain 10-12 nm nanoparticles with high crystallinity. The results show noticeable differences between bulk and nanocrystalline YVO4:Eu in photoluminescence experimental data, which explains by influence of the nanocrystal surface. A YF3 core-shell layer around YVO4:Eu nanoparticles partially recovers the intensity of the Eu3+ emission. It is demonstrated that the Eu3+ luminescence recovery is achieved at the expense of the suppression of the intrinsic emission but not due to the passivation of surface loss centers in core-shelled nanocrystals. It is also shown that surface loss processes are the reason of the degradation of energy transfer efficiency from the host lattice to Eu3+ under high-energy excitations in vacuum ultraviolet spectral range.

  1. Influenza Vaccines: Challenges and Solutions

    PubMed Central

    Houser, Katherine; Subbarao, Kanta

    2015-01-01

    Vaccination is the best method for the prevention and control of influenza. Vaccination can reduce illness and lessen severity of infection. This review focuses on how currently licensed influenza vaccines are generated in the U.S., why the biology of influenza poses vaccine challenges, and vaccine approaches on the horizon that address these challenges. PMID:25766291

  2. Human Papillomavirus (HPV) Vaccine (Cervarix)

    MedlinePlus

    ... a previous dose of HPV vaccine, should not get the vaccine. Tell your doctor if the person getting vaccinated has any severe allergies, including an allergy to latex. HPV vaccine is not recommended for pregnant women. However, receiving HPV vaccine when pregnant is ...

  3. Human Papillomavirus (HPV) Vaccine (Gardasil)

    MedlinePlus

    ... a previous dose of HPV vaccine, should not get the vaccine. Tell your doctor if the person getting vaccinated has any severe allergies, including an allergy to yeast. HPV vaccine is not recommended for pregnant women. However, receiving HPV vaccine when pregnant is ...

  4. [Mercury in vaccines].

    PubMed

    Hessel, Luc

    2003-01-01

    Thiomersal, also called thimerosal, is an ethyl mercury derivative used as a preservative to prevent bacterial contamination of multidose vaccine vials after they have been opened. Exposure to low doses of thiomersal has essentially been associated with hypersensitivity reactions. Nevertheless there is no evidence that allergy to thiomersal could be induced by thiomersal-containing vaccines. Allergy to thiomersal is usually of delayed-hypersensitivity type, but its detection through cutaneous tests is not very reliable. Hypersensitivity to thiomersal is not considered as a contraindication to the use of thiomersal-containing vaccines. In 1999 in the USA, thiomersal was present in approximately 30 different childhood vaccines, whereas there were only 2 in France. Although there were no evidence of neurological toxicity in infants related to the use of thiomersal-containing vaccines, the FDA considered that the cumulative dose of mercury received by young infants following vaccination was high enough (although lower than the FDA threshold for methyl mercury) to request vaccine manufacturers to remove thiomersal from vaccine formulations. Since 2002, all childhood vaccines used in Europe and the USA are thiomersal-free or contain only minute amounts of thiomersal. Recently published studies have shown that the mercury levels in the blood, faeces and urine of children who had received thiomersal-containing vaccines were much lower than those accepted by the American Environmental Protection Agency. It has also been demonstrated that the elimination of mercury in children was much faster than what was expected on the basis of studies conducted with methyl mercury originating from food. Recently, the hypothesis that mercury contained in vaccines could be the cause of autism and other neurological developmental disorders created a new debate in the medical community and the general public. To date, none of the epidemiological studies conducted in Europe and elsewhere

  5. Vaccine strategies: Optimising outcomes.

    PubMed

    Hardt, Karin; Bonanni, Paolo; King, Susan; Santos, Jose Ignacio; El-Hodhod, Mostafa; Zimet, Gregory D; Preiss, Scott

    2016-12-20

    Successful immunisation programmes generally result from high vaccine effectiveness and adequate uptake of vaccines. In the development of new vaccination strategies, the structure and strength of the local healthcare system is a key consideration. In high income countries, existing infrastructures are usually used, while in less developed countries, the capacity for introducing new vaccines may need to be strengthened, particularly for vaccines administered beyond early childhood, such as the measles or human papillomavirus (HPV) vaccine. Reliable immunisation service funding is another important factor and low income countries often need external supplementary sources of finance. Many regions also obtain support in generating an evidence base for vaccination via initiatives created by organisations including World Health Organization (WHO), the Pan American Health Organization (PAHO), the Agence de Médecine Préventive and the Sabin Vaccine Institute. Strong monitoring and surveillance mechanisms are also required. An example is the efficient and low-cost approaches for measuring the impact of the hepatitis B control initiative and evaluating achievement of goals that have been established in the WHO Western Pacific region. A review of implementation strategies reveals differing degrees of success. For example, in the Americas, PAHO advanced a measles-mumps-rubella vaccine strategy, targeting different population groups in mass, catch-up and follow-up vaccination campaigns. This has had much success but coverage data from some parts of the region suggest that children are still not receiving all appropriate vaccines, highlighting problems with local service infrastructures. Stark differences in coverage levels are also observed among high income countries, as is the case with HPV vaccine implementation in the USA versus the UK and Australia, reflecting differences in delivery settings. Experience and research have shown which vaccine strategies work well and the

  6. Seasonal influenza vaccines.

    PubMed

    Fiore, Anthony E; Bridges, Carolyn B; Cox, Nancy J

    2009-01-01

    Influenza vaccines are the mainstay of efforts to reduce the substantial health burden from seasonal influenza. Inactivated influenza vaccines have been available since the 1940s and are administered via intramuscular injection. Inactivated vaccines can be given to anyone six months of age or older. Live attenuated, cold-adapted influenza vaccines (LAIV) were developed in the 1960s but were not licensed in the United States until 2003, and are administered via nasal spray. Both vaccines are trivalent preparations grown in eggs and do not contain adjuvants. LAIV is licensed for use in the United States for healthy nonpregnant persons 2-49 years of age.Influenza vaccination induces antibodies primarily against the major surface glycoproteins hemagglutinin (HA) and neuraminidase (NA); antibodies directed against the HA are most important for protection against illness. The immune response peaks at 2-4 weeks after one dose in primed individuals. In previously unvaccinated children <9 years of age, two doses of influenza vaccine are recommended, as some children in this age group have limited or no prior infections from circulating types and subtypes of seasonal influenza. These children require both an initial priming dose and a subsequent booster dose of vaccine to mount a protective antibody response.The most common adverse events associated with inactivated vaccines are sore arm and redness at the injection site; systemic symptoms such as fever or malaise are less commonly reported. Guillian-Barré Syndrome (GBS) was identified among approximately 1 per 100,000 recipients of the 1976 swine influenza vaccine. The risk of influenza vaccine-associated GBS from seasonal influenza vaccine is thought to be at most approximately 1-2 cases per 1 million vaccinees, based on a few studies that have found an association; other studies have found no association.The most common adverse events associated with LAIV are nasal congestion, headache, myalgias or fever. Studies of the

  7. Vaccine process technology.

    PubMed

    Josefsberg, Jessica O; Buckland, Barry

    2012-06-01

    The evolution of vaccines (e.g., live attenuated, recombinant) and vaccine production methods (e.g., in ovo, cell culture) are intimately tied to each other. As vaccine technology has advanced, the methods to produce the vaccine have advanced and new vaccine opportunities have been created. These technologies will continue to evolve as we strive for safer and more immunogenic vaccines and as our understanding of biology improves. The evolution of vaccine process technology has occurred in parallel to the remarkable growth in the development of therapeutic proteins as products; therefore, recent vaccine innovations can leverage the progress made in the broader biotechnology industry. Numerous important legacy vaccines are still in use today despite their traditional manufacturing processes, with further development focusing on improving stability (e.g., novel excipients) and updating formulation (e.g., combination vaccines) and delivery methods (e.g., skin patches). Modern vaccine development is currently exploiting a wide array of novel technologies to create safer and more efficacious vaccines including: viral vectors produced in animal cells, virus-like particles produced in yeast or insect cells, polysaccharide conjugation to carrier proteins, DNA plasmids produced in E. coli, and therapeutic cancer vaccines created by in vitro activation of patient leukocytes. Purification advances (e.g., membrane adsorption, precipitation) are increasing efficiency, while innovative analytical methods (e.g., microsphere-based multiplex assays, RNA microarrays) are improving process understanding. Novel adjuvants such as monophosphoryl lipid A, which acts on antigen presenting cell toll-like receptors, are expanding the previously conservative list of widely accepted vaccine adjuvants. As in other areas of biotechnology, process characterization by sophisticated analysis is critical not only to improve yields, but also to determine the final product quality. From a regulatory

  8. Ion-redistribution induced efficient upconversion in β-NaYF4:20%Yb3+,2%Er3+ microcrystals with well controlled morphology and size.

    PubMed

    Fan, Shaohua; Wang, Shikai; Yu, Lu; Sun, Hongtao; Gao, Guojun; Hu, Lili

    2017-01-09

    We develop an efficient green upconversion (UC) β-NaYF4:20%Yb3+,2%Er3+ microcrystal with well controlled morphology and size by hydrothermal method using two different chelating agents of CIT and EDTA-2Na via a simple ion-exchange reaction. Importantly, the UC emission efficiency of newly developed CIT and EDTA-2Na β-NaYF4:20%Yb3+,2%Er3+ microcrystals is almost as strong as that of commercial counterpart by solid-state method. A proof-of-concept β-NaYF4:20%Yb3+,2%Er3+ microcrystal waveguide is demonstrated to extend their applications in modern micro-optoelectronics. The local ion-redistribution process during the ion-exchange reaction, which effectively disperses the locally clustered Yb3+, accounts for the enormously enhanced UC emission in β-NaYF4:20%Yb3+,2%Er3+ microcrystals.

  9. Up-conversion in sol-gel derived nano-glass-ceramics comprising NaYF 4 nano-crystals doped with Yb 3+, Ho 3+ and Tm 3+

    NASA Astrophysics Data System (ADS)

    Santana-Alonso, A.; Méndez-Ramos, J.; Yanes, A. C.; del-Castillo, J.; Rodríguez, V. D.

    2010-07-01

    NaYF 4 is an excellent host material for rare-earth ions presenting very high efficiencies in up-conversion processes. Thus, nano-glass-ceramics containing NaYF 4 nano-crystals emerge as promising candidates for general lighting appliances and integrated optical devices. Here we report highly transparent sol-gel derived nano-glass-ceramics comprising Yb 3+-Ho 3+ and Yb 3+-Ho 3+-Tm 3+ co-doped NaYF 4 nano-crystals. A structural analysis by means of X-ray diffraction measurements confirmed the formation of NaYF 4 nano-crystals during thermal treatment. Luminescence features have been related to the crystallinity degree of the samples. Violet, blue, green and red up-conversion emissions were obtained under infrared excitation at 980 nm and corresponding mechanisms involved have been analysed. Additionally, the total visible up-conversion emission has been quantified in terms of the standard chromaticity coordinates. In particular, an overall colour emission, very close to the standard equal energy white-light illumination point of the chromaticity diagram, was obtained in the Yb 3+-Ho 3+-Tm 3+ triply-doped samples.

  10. The action mechanism of TiO{sub 2}:NaYF{sub 4}:Yb{sup 3+},Tm{sup 3+} cathode buffer layer in highly efficient inverted organic solar cells

    SciTech Connect

    Liu, Chunyu; Chen, Huan; Zhao, Dan; Shen, Liang; He, Yeyuan; Guo, Wenbin E-mail: chenwy@jlu.edu.cn; Chen, Weiyou E-mail: chenwy@jlu.edu.cn

    2014-08-04

    We report the fabrication and characteristics of organic solar cells with 6.86% power conversion efficiency (PCE) by doping NaYF{sub 4}:Yb{sup 3+},Tm{sup 3+} into TiO{sub 2} cathode buffer layer. The dependence of devices performance on doping concentration of NaYF{sub 4}:Yb{sup 3+},Tm{sup 3+} is investigated. Results indicate that short-circuit current density (J{sub sc}) has an apparent improvement, leading to an enhancement of 22.7% in PCE for the optimized doping concentration of 0.05 mmol ml{sup −1} compared to the control devices. NaYF{sub 4}:Yb{sup 3+},Tm{sup 3+} nanoparticles (NPs) can play threefold roles, one is that the incident light in visible region can be scattered by NaYF{sub 4} NPs, the second is that solar irradiation in infrared region can be better utilized by Up-conversion effect of Yb{sup 3+} and Tm{sup 3+} ions, the third is that electron transport property in TiO{sub 2} thin film can be greatly improved.

  11. Systems immunogenetics of vaccines.

    PubMed

    Mooney, Michael; McWeeney, Shannon; Sékaly, Rafick-Pierre

    2013-04-01

    Vaccines are the most cost effective public health measure for preventing viral infection and limiting epidemic spread within susceptible populations. However, the efficacy of current protective vaccines is highly variable, particularly in aging populations. In addition, there have been a number of challenges in the development of new vaccines due to a lack of detailed understanding of the immune correlates of protection. To identify the mechanisms underlying the variability of the immune response to vaccines, system-level tools need to be developed that will further our understanding of virus-host interactions and correlates of vaccine efficacy. This will provide critical information for rational vaccine design and allow the development of an analog to the "precision medicine" framework (already acknowledged as a powerful approach in medicine and therapeutics) to be applied to vaccinology.

  12. Herpes zoster virus vaccine.

    PubMed

    Woolery, William Alan

    2008-10-01

    Varicella zoster virus (VZV) is the etiologic agent of varicella and herpes zoster (HZ) in humans. Herpes zoster is the result of reactivation of VZV within certain sensory ganglia. The burden of illness from HZ and post-herpetic neuralgia (PHN) is high. Herpes-zoster vaccine contains live attenuated varicella-zoster virus in an amount approximately 14 times greater than that found in the varicella virus vaccine. Herpes zoster vaccine is approved for the prevention of shingles in appropriate persons aged 60 and older. The vaccine is administered in a single subcutaneous dose. Reported side effects are mild and generally limited to localized injection site findings. Herpes-zoster vaccine reportedly decreases the occurrence of herpes zoster by approximately 50 percent and prevents the development of PHN by two thirds. The vaccine appears to be minimally effective in those individuals over the age of 80 and is not recommended in this age group.

  13. [Vaccination for international travelers].

    PubMed

    Arrazola, M Pilar; Serrano, Almudena; López-Vélez, Rogelio

    2016-05-01

    Traveler's vaccination is one of the key strategies for the prevention of infectious diseases during international travel. The risk of acquiring an infectious disease is determined in each case by the characteristics of the traveler and the travel, so the pre-departure medical advice of the traveler must be individualized. The World Health Organization classifies travelerś vaccines into three groups. - Vaccines for routine use in national immunization programs: Haemophilus influenzae type b, hepatitis B, polio, measles-mumps-rubella, tetanus-diphtheria-whooping a cough, and chickenpox. - Vaccinations required by law in certain countries before to enter them: yellow fever, meningococcal disease and poliomyelitis. - Vaccines recommended depending on the circumstances: cholera, japanese encephalitis, tick-borne encephalitis, meningococcal disease, typhoid fever, influenza, hepatitis A, hepatitis B, rabies and BCG. This review is intended to introduce the reader to the field of international vaccination.

  14. Ricin vaccine development.

    PubMed

    Smallshaw, Joan E; Vitetta, Ellen S

    2012-01-01

    In this chapter we discuss vaccines to protect against the highly toxic plant-derived toxin, ricin. Due to its prevalence, ease of use, and stability it has been used in sporadic incidents of espionage. There is also concern that it will be used as an agent of bioterrorism. As a result there has been a great deal of interest in developing a safe vaccine or antidote to protect humans, and in particular soldiers and first responders. Although multiple types of vaccines have been tested, at this time two recombinant vaccines are the leading candidates for the national vaccine stockpile. In terms of passive post-exposure protection, monoclonal neutralizing antibodies that passively protect animals are also under development. These vaccines and antibodies are discussed in the context of the toxicity and structure of ricin.

  15. Vaccines and Kawasaki disease.

    PubMed

    Esposito, Susanna; Bianchini, Sonia; Dellepiane, Rosa Maria; Principi, Nicola

    2016-01-01

    The distinctive immune system characteristics of children with Kawasaki disease (KD) could suggest that they respond in a particular way to all antigenic stimulations, including those due to vaccines. Moreover, treatment of KD is mainly based on immunomodulatory therapy. These factors suggest that vaccines and KD may interact in several ways. These interactions could be of clinical relevance because KD is a disease of younger children who receive most of the vaccines recommended for infectious disease prevention. This paper shows that available evidence does not support an association between KD development and vaccine administration. Moreover, it highlights that administration of routine vaccines is mandatory even in children with KD and all efforts must be made to ensure the highest degree of protection against vaccine-preventable diseases for these patients. However, studies are needed to clarify currently unsolved issues, especially issues related to immunologic interference induced by intravenous immunoglobulin and biological drugs.

  16. Immunizations: vaccinations in general.

    PubMed

    Wiley, Catherine C

    2015-06-01

    The childhood immunization schedule is complex and nuanced. Although serious adverse reactions to immunizations are uncommon, clinicians must be well-versed in these reactions as well as the contraindications and precautions to each vaccine. • Conjugate vaccine technology links polysaccharide antigens to carrier proteins, triggering T-cell-dependent immunity to polysaccharides, thereby strengthening immune memory. • On the basis of some research evidence and consensus, live vaccines are generally contraindicated in immunocompromised patients and in pregnancy. Most live vaccines can be administered to household contacts of immunocompromised patients. • On the basis of some research and consensus, modified administration of meningococcal, pneumococcal, and less commonly, other vaccines may be indicated to protect immunocompromised patients. • On the basis of disease epidemiology and consensus, international travelers should be up-to-date with all routine immunizations; depending on destination, additional vaccines or immune globulin may be required.

  17. Chikungunya vaccines in development

    PubMed Central

    Schwameis, Michael; Buchtele, Nina; Wadowski, Patricia Pia; Schoergenhofer, Christian; Jilma, Bernd

    2016-01-01

    ABSTRACT Chikungunya virus has become a global health threat, spreading to the industrial world of Europe and the Americas; no treatment or prophylactic vaccine is available. Since the late 1960s much effort has been put into the development of a vaccine, and several heterogeneous strategies have already been explored. Only two candidates have recently qualified to enter clinical phase II trials, a chikungunya virus-like particle-based vaccine and a recombinant live attenuated measles virus-vectored vaccine. This review focuses on the current status of vaccine development against chikungunya virus in humans and discusses the diversity of immunization strategies, results of recent human trials and promising vaccine candidates. PMID:26554522

  18. Vaccine herd effect.

    PubMed

    Kim, Tae Hyong; Johnstone, Jennie; Loeb, Mark

    2011-09-01

    Vaccination ideally protects susceptible populations at high risk for complications of the infection. However, vaccines for these subgroups do not always provide sufficient effectiveness. The herd effect or herd immunity is an attractive way to extend vaccine benefits beyond the directly targeted population. It refers to the indirect protection of unvaccinated persons, whereby an increase in the prevalence of immunity by the vaccine prevents circulation of infectious agents in susceptible populations. The herd effect has had a major impact in the eradication of smallpox, has reduced transmission of pertussis, and protects against influenza and pneumococcal disease. A high uptake of vaccines is generally needed for success. In this paper we aim to provide an update review on the herd effect, focusing on the clinical benefit, by reviewing data for specific vaccines.

  19. Therapeutic cancer vaccines

    PubMed Central

    Melief, Cornelis J.M.; van Hall, Thorbald; Arens, Ramon; Ossendorp, Ferry; van der Burg, Sjoerd H.

    2015-01-01

    The clinical benefit of therapeutic cancer vaccines has been established. Whereas regression of lesions was shown for premalignant lesions caused by HPV, clinical benefit in cancer patients was mostly noted as prolonged survival. Suboptimal vaccine design and an immunosuppressive cancer microenvironment are the root causes of the lack of cancer eradication. Effective cancer vaccines deliver concentrated antigen to both HLA class I and II molecules of DCs, promoting both CD4 and CD8 T cell responses. Optimal vaccine platforms include DNA and RNA vaccines and synthetic long peptides. Antigens of choice include mutant sequences, selected cancer testis antigens, and viral antigens. Drugs or physical treatments can mitigate the immunosuppressive cancer microenvironment and include chemotherapeutics, radiation, indoleamine 2,3-dioxygenase (IDO) inhibitors, inhibitors of T cell checkpoints, agonists of selected TNF receptor family members, and inhibitors of undesirable cytokines. The specificity of therapeutic vaccination combined with such immunomodulation offers an attractive avenue for the development of future cancer therapies. PMID:26214521

  20. Vaccine Treatment for Prostate Cancer

    MedlinePlus

    ... Back After Treatment Prostate Cancer Treating Prostate Cancer Vaccine Treatment for Prostate Cancer Sipuleucel-T (Provenge) is ... less advanced prostate cancer. Possible side effects of vaccine treatment Side effects from the vaccine tend to ...

  1. What Vaccines Do You Need?

    MedlinePlus

    ... Why Immunize? Vaccines: The Basics Adolescent and Adult Vaccine Quiz Recommend on Facebook Tweet Share Compartir Españ ... adolescentes y adultos Did you know that certain vaccines are recommended for adults and adolescents?* Take this ...

  2. Renal Disease and Adult Vaccination

    MedlinePlus

    ... Resources for Healthcare Professionals Renal Disease and Adult Vaccination Recommend on Facebook Tweet Share Compartir Vaccines are ... have immunity to this disease Learn about adult vaccination and other health conditions Asplenia Diabetes Type 1 ...

  3. Liver Disease and Adult Vaccination

    MedlinePlus

    ... Vaccination Recommendations Adult Vaccination Resources for Healthcare Professionals Liver Disease and Adult Vaccination Recommend on Facebook Tweet ... critical for people with health conditions such as liver disease. If you have chronic liver disease, talk ...

  4. Influenza Vaccine, Inactivated or Recombinant

    MedlinePlus

    ... die from flu, and many more are hospitalized.Flu vaccine can:keep you from getting flu, make flu ... inactivated or recombinant influenza vaccine?A dose of flu vaccine is recommended every flu season. Children 6 months ...

  5. Existing antibacterial vaccines.

    PubMed

    Mendoza, Natalia; Ravanfar, Parisa; Satyaprakash, Anita; Satyaprakah, Anita; Pillai, Sivaprabha; Creed, Rosella

    2009-01-01

    There are countless bacterial pathogens that cause disease in humans. Many of these bacterial infections not only cause significant morbidity and mortality in the human population but also cause a significant economic impact on society. Vaccines allow for reduction and potential eradication of such diseases. This article will review the currently approved antibacterial vaccines, which are vaccines for pertussis, tetanus, diphtheria, meningococcus, pneumococcus, Haemophilus influenza, cholera, typhoid, and anthrax.

  6. Emerging Vaccine Technologies

    PubMed Central

    Loomis, Rebecca J.; Johnson, Philip R.

    2015-01-01

    Vaccination has proven to be an invaluable means of preventing infectious diseases by reducing both incidence of disease and mortality. However, vaccines have not been effectively developed for many diseases including HIV-1, hepatitis C virus (HCV), tuberculosis and malaria, among others. The emergence of new technologies with a growing understanding of host-pathogen interactions and immunity may lead to efficacious vaccines against pathogens, previously thought impossible. PMID:26343196

  7. Myopericarditis following Smallpox Vaccination

    DTIC Science & Technology

    2004-04-20

    smallpox vaccinations with this strain of vaccinia virus . Fifty-eight males and one female aged 21–43 years with confirmed or probable acute...or unrecognized event after smallpox vaccinations with the New York City Board of Health strain of vaccinia virus (Dryvax; Wyeth Laboratories, Marietta...respectively). military personnel; myocarditis; pericarditis; smallpox; vaccination; vaccinia virus Abbreviations: CDC, Centers for Disease Control and

  8. [Does vaccination cause disease?].

    PubMed

    Zingg, W

    2005-10-01

    Not many inventions in medical history have influenced our society as much as vaccination. The concept is old and simple. When Edward Jenner published his work on cowpox, "variolation" was quite common. In this procedure, pus of patients with mild smallpox was transferred to healthy individuals. Meanwhile smallpox has been eradicated worldwide. Diseases such as poliomyelitis, diphtheria or tetanus almost disappeared in industrialized countries. The same happened with epiglottitis and meningitis due to Haemophilus influenzae type b (Hib) after vaccination against Hib was introduced in Switzerland in 1990. This success was possible because of routine vaccination. Immunization is a save procedure and adverse events are much lower than complications in the natural course of the prevented diseases. However vaccinations were accused to cause diseases themselves such as asthma, multiple sclerosis, diabetes mellitus, chronic arthritis or autism. Hitherto no large cohort study or case-control-study was able to proof responsibility of vaccines in any of these diseases. Public media are eager to publish early data from surveillance reports or case reports which are descriptive and never a principle of cause and effect. In large controlled trials there was no proof that vaccination causes asthma, hepatitis-B-vaccination causes multiple sclerosis or macrophagic myofasciitis, Hib-vaccination causes diabetes mellitus, rubella-vaccination causes chronic arthritis, measles-mumps-rubella-vaccination causes gait disturbance or thiomersal causes autism. These results are rarely published in newspapers or television. Thus, many caring parents are left with negative ideas about immunization. Looking for the best for their children they withhold vaccination and give way to resurgence of preventable diseases in our communities. This must be prevented. There is more evidence than expected that vaccination is safe and this can and must be told to parents.

  9. Rift Valley fever vaccines

    PubMed Central

    Ikegami, Tetsuro; Makino, Shinji

    2009-01-01

    Rift Valley fever virus (RVFV), which belongs to the genus Phlebovirus, family Bunyaviridae, is a negative-stranded RNA virus carrying a tripartite RNA genome. RVFV is transmitted by mosquitoes and causes large outbreaks among ruminants and humans in Africa and the Arabian Peninsula. Human patients develop an acute febrile illness, followed by a fatal hemorrhagic fever, encephalitis or ocular diseases, whereas ruminants experience abortions during outbreak. Effective vaccination of both humans and ruminants is the best approach to control Rift Valley fever. This article summarizes the development of inactivated RVFV vaccine, live attenuated vaccine, and other new generation vaccines. PMID:19837291

  10. Vaccines, our shared responsibility.

    PubMed

    Pagliusi, Sonia; Jain, Rishabh; Suri, Rajinder Kumar

    2015-05-05

    The Developing Countries Vaccine Manufacturers' Network (DCVMN) held its fifteenth annual meeting from October 27-29, 2014, New Delhi, India. The DCVMN, together with the co-organizing institution Panacea Biotec, welcomed over 240 delegates representing high-profile governmental and nongovernmental global health organizations from 36 countries. Over the three-day meeting, attendees exchanged information about their efforts to achieve their shared goal of preventing death and disability from known and emerging infectious diseases. Special praise was extended to all stakeholders involved in the success of polio eradication in South East Asia and highlighted challenges in vaccine supply for measles-rubella immunization over the coming decades. Innovative vaccines and vaccine delivery technologies indicated creative solutions for achieving global immunization goals. Discussions were focused on three major themes including regulatory challenges for developing countries that may be overcome with better communication; global collaborations and partnerships for leveraging investments and enable uninterrupted supply of affordable and suitable vaccines; and leading innovation in vaccines difficult to develop, such as dengue, Chikungunya, typhoid-conjugated and EV71, and needle-free technologies that may speed up vaccine delivery. Moving further into the Decade of Vaccines, participants renewed their commitment to shared responsibility toward a world free of vaccine-preventable diseases.

  11. Polyvalent AIDS Vaccines

    PubMed Central

    Lu, Shan; Grimes Serrano, Jill M.; Wang, Shixia

    2013-01-01

    A major hurdle in the development of a global HIV-1 vaccine is viral diversity. For close to three decades, HIV vaccine development has focused on either the induction of T cell immune responses or antibody responses, and only rarely on both components. After the failure of the STEP trial, the scientific community concluded that a T cell-based vaccine would likely not be protective if the T cell immune responses were elicited against only a few dominant epitopes. Similarly, for vaccines focusing on antibody responses, one of the main criticisms after VaxGen’s failed Phase III trials was on the limited antigen breadth included in the two formulations used. The successes of polyvalent vaccine approaches against other antigenically variable pathogens encourage implementation of the same approach for the design of HIV-1 vaccines. A review of the existing HIV-1 vaccination approaches based on the polyvalent principle is included here to provide a historical perspective for the current effort of developing a polyvalent HIV-1 vaccine. Results summarized in this review provide a clear indication that the polyvalent approach is a viable one for the future development of an effective HIV vaccine. PMID:21054250

  12. Vaccines: Shaping global health.

    PubMed

    Pagliusi, Sonia; Ting, Ching-Chia; Lobos, Fernando

    2017-03-14

    The Developing Countries Vaccine Manufacturers' Network (DCVMN) gathered leaders in immunization programs, vaccine manufacturing, representatives of the Argentinean Health Authorities and Pan American Health Organization, among other global health stakeholders, for its 17th Annual General Meeting in Buenos Aires, to reflect on how vaccines are shaping global health. Polio eradication and elimination of measles and rubella from the Americas is a result of successful collaboration, made possible by timely supply of affordable vaccines. After decades of intense competition for high-value markets, collaboration with developing countries has become critical, and involvement of multiple manufacturers as well as public- and private-sector investments are essential, for developing new vaccines against emerging infectious diseases. The recent Zika virus outbreak and the accelerated Ebola vaccine development exemplify the need for international partnerships to combat infectious diseases. A new player, Coalition for Epidemic Preparedness Innovations (CEPI) has made its entrance in the global health community, aiming to stimulate research preparedness against emerging infections. Face-to-face panel discussions facilitated the dialogue around challenges, such as risks of viability to vaccine development and regulatory convergence, to improve access to sustainable vaccine supply. It was discussed that joint efforts to optimizing regulatory pathways in developing countries, reducing registration time by up to 50%, are required. Outbreaks of emerging infections and the global Polio eradication and containment challenges are reminders of the importance of vaccines' access, and of the importance of new public-private partnerships.

  13. Dengue virus vaccine development.

    PubMed

    Yauch, Lauren E; Shresta, Sujan

    2014-01-01

    Dengue virus (DENV) is a significant cause of morbidity and mortality in tropical and subtropical regions, causing hundreds of millions of infections each year. Infections range from asymptomatic to a self-limited febrile illness, dengue fever (DF), to the life-threatening dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). The expanding of the habitat of DENV-transmitting mosquitoes has resulted in dramatic increases in the number of cases over the past 50 years, and recent outbreaks have occurred in the United States. Developing a dengue vaccine is a global health priority. DENV vaccine development is challenging due to the existence of four serotypes of the virus (DENV1-4), which a vaccine must protect against. Additionally, the adaptive immune response to DENV may be both protective and pathogenic upon subsequent infection, and the precise features of protective versus pathogenic immune responses to DENV are unknown, complicating vaccine development. Numerous vaccine candidates, including live attenuated, inactivated, recombinant subunit, DNA, and viral vectored vaccines, are in various stages of clinical development, from preclinical to phase 3. This review will discuss the adaptive immune response to DENV, dengue vaccine challenges, animal models used to test dengue vaccine candidates, and historical and current dengue vaccine approaches.

  14. Vaccination against Brucella.

    PubMed

    Nicoletti, P

    1990-01-01

    Vaccination has played an enormous role in reducing brucellosis in many countries. It is certain to continue to be the preeminent factor in control of the disease in others. The search for an ideal vaccine continues. Live vaccines have proved to be superior to inactivated products. They are effective, inexpensive, and immunity is more persistent. The disadvantages of postvaccinal antibodies can be minimized by reduction of previously recommended doses and through use of supplemental diagnostic tests. These procedures now make entire population vaccination of great practical significance with many advantages over limited use of the strains 19 and Rev. 1. Adult animal vaccination should be much more extensive in many countries. A live B. suis strain 2 vaccine developed in China deserves much additional evaluation, including use in swine, for which no satisfactory vaccine exists. It is generally agreed that cell-mediated responses are the dominant aspect of immunogenesis. However, the correlates that have frequently been used--dermal hypersensitivity and lymphocyte stimulation in vitro--appear to be poor indices of cell-mediated immunity in brucellosis. Many studies have shown that postvaccinal antibodies do not predict subsequent immunity. There is a great need for simple in vivo or in vitro methods to measure CMI. While vaccination of humans may be useful in control of brucellosis in some high-risk occupations, the ultimate success is dependent upon reduction of this very important zoonosis in natural hosts. This is most effectively accomplished by widespread use of vaccination.

  15. Vaccination in elite athletes.

    PubMed

    Gärtner, Barbara C; Meyer, Tim

    2014-10-01

    Public health vaccination guidelines cannot be easily transferred to elite athletes. An enhanced benefit from preventing even mild diseases is obvious but stronger interference from otherwise minor side effects has to be considered as well. Thus, special vaccination guidelines for adult elite athletes are required. In most of them, protection should be strived for against tetanus, diphtheria, pertussis, influenza, hepatitis A, hepatitis B, measles, mumps and varicella. When living or traveling to endemic areas, the athletes should be immune against tick-borne encephalitis, yellow fever, Japanese encephalitis, poliomyelitis, typhoid fever, and meningococcal disease. Vaccination against pneumococci and Haemophilus influenzae type b is only relevant in athletes with certain underlying disorders. Rubella and papillomavirus vaccination might be considered after an individual risk-benefit analysis. Other vaccinations such as cholera, rabies, herpes zoster, and Bacille Calmette-Guérin (BCG) cannot be universally recommended for athletes at present. Only for a very few diseases, a determination of antibody titers is reasonable to avoid unnecessary vaccinations or to control efficacy of an individual's vaccination (especially for measles, mumps, rubella, varicella, hepatitis B and, partly, hepatitis A). Vaccinations should be scheduled in a way that possible side effects are least likely to occur in periods of competition. Typically, vaccinations are well tolerated by elite athletes, and resulting antibody titers are not different from the general population. Side effects might be reduced by an optimal selection of vaccines and an appropriate technique of administration. Very few discipline-specific considerations apply to an athlete's vaccination schedule mainly from the competition and training pattern as well as from the typical geographical distribution of competitive sites.

  16. History of polio vaccination

    PubMed Central

    Baicus, Anda

    2012-01-01

    Poliomyelitis is an acute paralytic disease caused by three poliovirus (PV) serotypes. Less than 1% of PV infections result in acute flaccid paralysis. The disease was controlled using the formalin-inactivated Salk polio vaccine (IPV) and the Sabin oral polio vaccine (OPV). Global poliomyelitis eradication was proposed in 1988 by the World Health Organization to its member states. The strategic plan established the activities required for polio eradication, certification for regions, OPV cessation phase and post-OPV phase. OPV is the vaccine of choice for the poliomyelitis eradication program because it induces both a systemic and mucosal immune response. The major risks of OPV vaccination are the appearance of Vaccine-Associated Paralytic Poliomyelitis cases (VAPP) and the emergence of Vaccine Derived Polioviruses strains. The supplementary immunization with monovalent strains of OPV type 1 or type 3 or with a new bivalent oral polio vaccine bOPV (containing type 1 and type 3 PV) has been introduced in those regions where the virus has been difficult to control. Most countries have switched the schedule of vaccination by using IPV instead of OPV because it poses no risk of vaccine-related disease. Until 2008, poliomyelitis was controlled in Romania, an Eastern European country, predominantly using OPV. The alternative vaccination schedule (IPV/OPV) was implemented starting in September 2008, while beginning in 2009, the vaccination was IPV only. The risk of VAPP will disappear worldwide with the cessation of use of OPV. The immunization for polio must be maintained for at least 5 to 10 years using IPV. PMID:24175215

  17. Human Papillomavirus Vaccine

    PubMed Central

    Savas, Lara S.; Fernández, Maria E.; Jobe, David; Carmack, Chakema C.

    2012-01-01

    Background Research is needed to understand parental factors influencing human papillomavirus (HPV) vaccination, particularly in groups with a higher burden of cervical cancer. Purpose To determine correlates of HPV vaccination among a sample of low-income parents of age-eligible daughters (aged 9–17 years) who called the 2-1-1 Helpline. Secondary analyses describe potential differences in HPV vaccination correlates by Hispanic and black parent groups, specifically. Methods This 2009 cross-sectional feasibility survey of cancer prevention needs was conducted in Houston at the 2-1-1 Texas/United Way Helpline. In 2012, to examine the association between parental psychosocial, cognitive, and decisional factors and HPV vaccination uptake (one or two doses), bivariate and multivariable logistic regression analyses were conducted for minority parents and for Hispanic and black parent groups, separately. Results Lower rates of HPV vaccination uptake were reported among minority daughters of 2-1-1 callers (29% overall) compared with national and Texas rates. In final adjusted analysis, factors positively associated with HPV vaccination uptake included being offered the vaccination by a doctor or nurse, belief that the vaccine would prevent cervical cancer, and Hispanic ethnicity. Secondary analyses detected differences in factors associated with vaccination in Hispanic and black groups. Conclusions Findings indicate low levels of vaccination among 2-1-1 callers. Increased understanding of determinants of HPV vaccination in low-income minority groups can guide interventions to increase coverage. Because 2-1-1 informational and referral services networks reach populations considered medically underserved, 2-1-1 can serve as a community hub for informing development of and implementing approaches aimed at hard-to-reach groups. PMID:23157770

  18. Adverse reactions to vaccines.

    PubMed

    Martin, Bryan L; Nelson, Michael R; Hershey, Joyce N; Engler, Renata J M

    2003-06-01

    (The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense.) Immunization healthcare is becoming increasingly complex as the number and types of vaccines have continued to expand. Like all prescription drugs, vaccines may be associated with adverse events. The majority of these reactions are self-limited and not associated with prolonged disability. The media, Internet and public advocacy groups have focused on potentially serious vaccine-associated adverse events with questions raised about causal linkages to increasing frequencies of diseases such as autism and asthma. Despite a lack of evidence of a causal relationship to a variety of vaccine safety concerns, including extensive reviews by the Institute of Medicine, questions regarding vaccine safety continue to threaten the success of immunization programs. Risk communication arid individual risk assessment is further challenged by the public health success of vaccine programs creating the perception that certain vaccines are no longer necessary or justified because of the rare reaction risk. There is a need for improved understanding of true vaccine contraindications and precautions as well as host factors and disease threat in order to develop a patient specific balanced risk communication intervention. When they occur, vaccine related adverse events must be treated, documented and reported through the VAERS system. The increasing complexity of vaccination health care has led the Center of Disease Control and Prevention (CDC) to identify Vaccine Safety Assessment and Evaluation as a potential new specialty.

  19. Clinical development of Ebola vaccines

    PubMed Central

    Sridhar, Saranya

    2015-01-01

    The ongoing outbreak of Ebola virus disease in West Africa highlighted the lack of a licensed drug or vaccine to combat the disease and has renewed the urgency to develop a pipeline of Ebola vaccines. A number of different vaccine platforms are being developed by assessing preclinical efficacy in animal models and expediting clinical development. Over 15 different vaccines are in preclinical development and 8 vaccines are now in different stages of clinical evaluation. These vaccines include DNA vaccines, virus-like particles and viral vectors such as live replicating vesicular stomatitis virus (rVSV), human and chimpanzee adenovirus, and vaccinia virus. Recently, in preliminary results reported from the first phase III trial of an Ebola vaccine, the rVSV-vectored vaccine showed promising efficacy. This review charts this rapidly advancing area of research focusing on vaccines in clinical development and discusses the future opportunities and challenges faced in the licensure and deployment of Ebola vaccines. PMID:26668751

  20. YF-17A

    NASA Video Gallery

    the 1976 flight test program included the study of maneuverability of this aircraft at transonic speeds and the collection of in-flight pressure data from around the afterbody of the aircraft to im...

  1. Pricing of new vaccines.

    PubMed

    Lee, Bruce Y; McGlone, Sarah M

    2010-08-01

    New vaccine pricing is a complicated process that could have substantial long-standing scientific, medical, and public health ramifications. Pricing can have a considerable impact on new vaccine adoption and, thereby, either culminate or thwart years of research and development and public health efforts. Typically, pricing strategy consists of the following ten components: 1. Conduct a target population analysis; 2. Map potential competitors and alternatives; 3. Construct a vaccine target product profile (TPP) and compare it to projected or actual TPPs of competing vaccines; 4. Quantify the incremental value of the new vaccine's characteristics; 5. Determine vaccine positioning in the marketplace; 6. Estimate the vaccine price-demand curve; 7. Calculate vaccine costs (including those of manufacturing, distribution, and research and development); 8. Account for various legal, regulatory, third party payer, and competitor factors; 9. Consider the overall product portfolio; 10. Set pricing objectives; 11. Select pricing and pricing structure. While the biomedical literature contains some studies that have addressed these components, there is still considerable room for more extensive evaluation of this important area.

  2. Argentine hemorrhagic fever vaccines.

    PubMed

    Ambrosio, Ana; Saavedra, Maria; Mariani, Mauricio; Gamboa, Graciela; Maiza, Andrea

    2011-06-01

    Argentine hemorrhagic fever (AHF), an acute disease caused by Junin virus (JUNV, Arenaviridae), has been an important issue to public health in Argentina since the early 1950s. The field rodent Calomys musculinus is JUNV natural reservoir and human disease is a consequence of contact with infected rodents. A steady extention of AHF endemic area is being observed since the first reports of the disease. Important achievements have been made in: (a) improvement of methods for the etiological diagnosis; (b) implementation and validation of therapeutical measures; (c) development of vaccines to protect against AHF. Reference is made to different research strategies used to obtain anti-AHF vaccines in the past and anti-arenaviral diseases in the present. Information is updated on features and field performance of Candid #1 vaccine, a live attenuted vaccine currently used to prevent AHF. This vaccine was developed through a joint international effort that envisioned it as an orphan drug. With transferred technology, Argentine government was committed to be Candid #1 manufacturer and to register this vaccine as a novel medical product under the Argentine regulatory authority. Candid #1 vaccine is the first one used to control an arenaviral hemorrhagic fever, the first live viral vaccine to be manufactured and registered in Argentina, reaching its target population through governmental effort.

  3. The Human Hookworm Vaccine.

    PubMed

    Hotez, Peter J; Diemert, David; Bacon, Kristina M; Beaumier, Coreen; Bethony, Jeffrey M; Bottazzi, Maria Elena; Brooker, Simon; Couto, Artur Roberto; Freire, Marcos da Silva; Homma, Akira; Lee, Bruce Y; Loukas, Alex; Loblack, Marva; Morel, Carlos Medicis; Oliveira, Rodrigo Correa; Russell, Philip K

    2013-04-18

    Hookworm infection is one of the world's most common neglected tropical diseases and a leading cause of iron deficiency anemia in low- and middle-income countries. A Human Hookworm Vaccine is currently being developed by the Sabin Vaccine Institute and is in phase 1 clinical testing. The candidate vaccine is comprised of two recombinant antigens known as Na-GST-1 and Na-APR-1, each of which is an important parasite enzyme required for hookworms to successfully utilize host blood as a source of energy. The recombinant proteins are formulated on Alhydrogel(®) and are being tested in combination with a synthetic Toll-like receptor 4 agonist. The aim of the vaccine is to induce anti-enzyme antibodies that will reduce both host blood loss and the number of hookworms attached to the gut. Transfer of the manufacturing technology to the Oswaldo Cruz Foundation (FIOCRUZ)/Bio-Manguinhos (a Brazilian public sector developing country vaccine manufacturer) is planned, with a clinical development plan that could lead to registration of the vaccine in Brazil. The vaccine would also need to be introduced in the poorest regions of Africa and Asia, where hookworm infection is highly endemic. Ultimately, the vaccine could become an essential tool for achieving hookworm control and elimination, a key target in the 2012 London Declaration on Neglected Tropical Diseases.

  4. Herpes zoster vaccine (Zostavax).

    PubMed

    2006-09-11

    A live attenuated varicella-zoster vaccine (Zostavax--Merck) has been approved by the FDA for prevention of herpes zoster (HZ; zoster; shingles) in persons > or = 60 years old. Each dose of Zostavax contains about 14 times as much varicella-zoster virus (VZV) as Varivax, which has been used in the US since 1995 to vaccinate against varicella (chicken pox).

  5. Vaccines Against Malaria

    PubMed Central

    Ouattara, Amed; Laurens, Matthew B.

    2015-01-01

    Despite global efforts to control malaria, the illness remains a significant public health threat. Currently, there is no licensed vaccine against malaria, but an efficacious vaccine would represent an important public health tool for successful malaria elimination. Malaria vaccine development continues to be hindered by a poor understanding of antimalarial immunity, a lack of an immune correlate of protection, and the genetic diversity of malaria parasites. Current vaccine development efforts largely target Plasmodium falciparum parasites in the pre-erythrocytic and erythrocytic stages, with some research on transmission-blocking vaccines against asexual stages and vaccines against pregnancy-associated malaria. The leading pre-erythrocytic vaccine candidate is RTS,S, and early results of ongoing Phase 3 testing show overall efficacy of 46% against clinical malaria. The next steps for malaria vaccine development will focus on the design of a product that is efficacious against the highly diverse strains of malaria and the identification of a correlate of protection against disease. PMID:25452593

  6. Pricing of new vaccines

    PubMed Central

    McGlone, Sarah M

    2010-01-01

    New vaccine pricing is a complicated process that could have substantial long-standing scientific, medical and public health ramifications. Pricing can have a considerable impact on new vaccine adoption and, thereby, either culminate or thwart years of research and development and public health efforts. Typically, pricing strategy consists of the following eleven components: (1) Conduct a target population analysis; (2) Map potential competitors and alternatives; (3) Construct a vaccine target product profile (TPP) and compare it to projected or actual TPPs of competing vaccines; (4) Quantify the incremental value of the new vaccine's characteristics; (5) Determine vaccine positioning in the marketplace; (6) Estimate the vaccine price-demand curve; (7) Calculate vaccine costs (including those of manufacturing, distribution, and research and development); (8) Account for various legal, regulatory, third party payer and competitor factors; (9) Consider the overall product portfolio; (10) Set pricing objectives; (11) Select pricing and pricing structure. While the biomedical literature contains some studies that have addressed these components, there is still considerable room for more extensive evaluation of this important area. PMID:20861678

  7. Emerging human papillomavirus vaccines

    PubMed Central

    Ma, Barbara; Maraj, Bharat; Tran, Nam Phuong; Knoff, Jayne; Chen, Alexander; Alvarez, Ronald D; Hung, Chien-Fu; Wu, T.-C.

    2013-01-01

    Introduction Identification of human papillomavirus (HPV) as the etiologic factor of cervical, anogenital, and a subset of head and neck cancers has stimulated the development of preventive and therapeutic HPV vaccines to control HPV-associated malignancies. Excitement has been generated by the commercialization of two preventive L1-based vaccines, which use HPV virus-like particles (VLPs) to generate capsid-specific neutralizing antibodies. However, factors such as high cost and requirement for cold chain have prevented widespread implementation where they are needed most. Areas covered Next generation preventive HPV vaccine candidates have focused on cost-effective stable alternatives and generating broader protection via targeting multivalent L1 VLPs, L2 capsid protein, and chimeric L1/L2 VLPs. Therapeutic HPV vaccine candidates have focused on enhancing T cell-mediated killing of HPV-transformed tumor cells, which constitutively express HPV-encoded proteins, E6 and E7. Several therapeutic HPV vaccines are in clinical trials. Expert opinion Although progress is being made, cost remains an issue inhibiting the use of preventive HPV vaccines in countries that carry the majority of the cervical cancer burden. In addition, progression of therapeutic HPV vaccines through clinical trials may require combination strategies employing different therapeutic modalities. As research in the development of HPV vaccines continues, we may generate effective strategies to control HPV-associated malignancies. PMID:23163511

  8. Conscientious Objection to Vaccination.

    PubMed

    Clarke, Steve; Giubilini, Alberto; Walker, Mary Jean

    2017-03-01

    Vaccine refusal occurs for a variety of reasons. In this article we examine vaccine refusals that are made on conscientious grounds; that is, for religious, moral, or philosophical reasons. We focus on two questions: first, whether people should be entitled to conscientiously object to vaccination against contagious diseases (either for themselves or for their children); second, if so, to what constraints or requirements should conscientious objection (CO) to vaccination be subject. To address these questions, we consider an analogy between CO to vaccination and CO to military service. We argue that conscientious objectors to vaccination should make an appropriate contribution to society in lieu of being vaccinated. The contribution to be made will depend on the severity of the relevant disease(s), its morbidity, and also the likelihood that vaccine refusal will lead to harm. In particular, the contribution required will depend on whether the rate of CO in a given population threatens herd immunity to the disease in question: for severe or highly contagious diseases, if the population rate of CO becomes high enough to threaten herd immunity, the requirements for CO could become so onerous that CO, though in principle permissible, would be de facto impermissible.

  9. Conscientious Objection to Vaccination

    PubMed Central

    Clarke, Steve; Giubilini, Alberto

    2016-01-01

    ABSTRACT Vaccine refusal occurs for a variety of reasons. In this article we examine vaccine refusals that are made on conscientious grounds; that is, for religious, moral, or philosophical reasons. We focus on two questions: first, whether people should be entitled to conscientiously object to vaccination against contagious diseases (either for themselves or for their children); second, if so, to what constraints or requirements should conscientious objection (CO) to vaccination be subject. To address these questions, we consider an analogy between CO to vaccination and CO to military service. We argue that conscientious objectors to vaccination should make an appropriate contribution to society in lieu of being vaccinated. The contribution to be made will depend on the severity of the relevant disease(s), its morbidity, and also the likelihood that vaccine refusal will lead to harm. In particular, the contribution required will depend on whether the rate of CO in a given population threatens herd immunity to the disease in question: for severe or highly contagious diseases, if the population rate of CO becomes high enough to threaten herd immunity, the requirements for CO could become so onerous that CO, though in principle permissible, would be de facto impermissible. PMID:28008636

  10. HPV Vaccine and Pregnancy

    MedlinePlus

    ... vaccines are given as an injection in a series of three doses at three different times. They are licensed for males and females between ... pregnancy to complete any remaining shots in the series. Can I receive ... baby received the HPV vaccine around the time that I got pregnant. Is there a risk ...

  11. Vaccines and autoimmunity.

    PubMed

    De Martino, M; Chiappini, E; Galli, L

    2013-01-01

    Vaccines have eradicated or controlled many infectious diseases, saving each year millions of lives and quality of life of many other millions of people. In spite of the success of vaccines over the last two centuries, parents (and also some health care workers) gloss over the devastating consequences of diseases, which are now avoided thanks to vaccines, and direct their attention to possible negative effects of immunization. Three immunological objections are raised: vaccines cause antigenic overload, natural immunity is safer and better than vaccine-induced immunity, and vaccines induce autoimmunity. The last point is examined in this review. Theoretically, vaccines could trigger autoimmunity by means of cytokine production, anti-idiotypic network, expression of human histocompatibility leukocyte antigens, modification of surface antigens and induction of novel antigens, molecular mimicry, bystander activation, epitope spreading, and polyclonal activation of B cells. There is strong evidence that none of these mechanisms is really effective in causing autoimmune diseases. Vaccines are not a source of autoimmune diseases. By contrast, absolute evidence exists that infectious agents can trigger autoimmune mechanisms and that they do cause autoimmune diseases.

  12. Chimeric Pestivirus Experimental Vaccines.

    PubMed

    Reimann, Ilona; Blome, Sandra; Beer, Martin

    2016-01-01

    Chimeric pestiviruses have shown great potential as marker vaccine candidates against pestiviral infections. Exemplarily, we describe here the construction and testing of the most promising classical swine fever vaccine candidate "CP7_E2alf" in detail. The description is focused on classical cloning technologies in combination with reverse genetics.

  13. Flight-determined lag of angle-of-attack and angle-of-sideslip sensors in the YF-12A airplane from analysis of dynamic maneuvers

    NASA Technical Reports Server (NTRS)

    Gilyard, G. B.; Belte, D.

    1974-01-01

    Magnitudes of lags in the pneumatic angle-of-attack and angle-of-sideslip sensor systems of the YF-12A airplane were determined for a variety of flight conditions by analyzing stability and control data. The three analysis techniques used are described. An apparent trend with Mach number for measurements from both of the differential-pressure sensors showed that the lag ranged from approximately 0.15 second at subsonic speed to 0.4 second at Mach 3. Because Mach number was closely related to altitude for the available flight data, the individual effects of Mach number and altitude on the lag could not be separated clearly. However, the results indicated the influence of factors other than simple pneumatic lag.

  14. Measurements in Flight of the Longitudinal-Stability Characteristics of a Republic YF-84A Airplane (Army Serial No. 45-59488) at High Subsonic Mach Numbers

    NASA Technical Reports Server (NTRS)

    Turner, Howard L.; Cooper, George E.

    1948-01-01

    A brief investigation was made of the longitudinal-stability characteristics of a YF-84A airplane (Army Serial No. 45-79488). The airplane developed a pitching-up tendency at approximately 0.80 Mach number which necessitated large push forces and down-elevator deflections for further increases in speed. In steady turns at 35,000 feet with the center of gravity at 28.3 percent mean aerodynamic chord for normal accelerations up to the maximum test value, the control-force gradients were excessive at Mach numbers over 0.78. Airplane buffeting did not present a serious problem in accelerated or unaccelerated flight at 15,000 and 35,000 feet up to the maximum test Mach number of 0.84. It is believed that excessive control force would be the limiting factor in attaining speeds in excess of 0.84 Mach number, especially at altitudes below 35,000 feet.

  15. Efficient green continuous-wave lasing of blue-diode-pumped solid-state lasers based on praseodymium-doped LiYF4.

    PubMed

    Hansen, Nils-Owe; Bellancourt, Aude-Reine; Weichmann, Ulrich; Huber, Günter

    2010-07-10

    We report highly efficient laser operation of praseodymium-doped LiYF(4) in the green spectral range. The influence of the crystal length and pump light focusing on the laser performance has been studied. The pump radiation was delivered by InGaN laser diodes. Optimizing the setup for a 2.9 mm long crystal with a doping concentration of 0.5% led to an electric to green laser power conversion efficiency as high as 7.4%. With 500 and 1000 mW of pump light power, output powers of 179 and 358 mW have been reached, respectively. With respect to absorbed power, slope efficiencies of up to approximately 60% have been achieved.

  16. Fabrication of freestanding silk fibroin films containing Ag nanowires/NaYF4:Yb,Er nanocomposites with metal-enhanced fluorescence behavior.

    PubMed

    Zhao, Bing; Qi, Ning; Zhang, Ke-Qin; Gong, Xiao

    2016-06-01

    Solar cells containing upconversion nanoparticles (UCNPs) used as a power source in biomedical nanosystems have attracted great interest. However, such solar cells further need to be developed because their substrate materials should be biocompatible, flexible and highly luminescent. Here, we report that freestanding silk fibroin (SF) films containing a mesh of silver nanowires (AgNWs) and β-NaYF4:Yb,Er nanocrystals with metal-enhanced fluorescence behavior can be fabricated. The freestanding composite films exhibit properties such as good optical transparency, conductivity and flexibility. Furthermore, they show significantly enhanced upconversion fluorescence due to surface plasmon polaritons (SPPs) of AgNWs compared to the SF-UCNP films without AgNWs. The freestanding composite films with metal-enhanced fluorescence behavior show great promise for future applications in self-powered nanodevices such as cardiac pacemakers, biosensors and nanorobots.

  17. Spectroscopy and visible laser operations of a μ-PD grown Pr3+ :LiYF4 single-crystal fiber

    NASA Astrophysics Data System (ADS)

    Damiano, Eugenio; Shu, Jun; Sottile, Alberto; Tonelli, Mauro

    2017-04-01

    We report on the growth and visible laser operations of a single-crystal fiber of Pr3+ :LiYF4 (Pr:YLF), grown by the micro-pulling-down method (μ-PD). We performed spectroscopic analyses on the crystal and compared the results with a Czochralski-grown sample of the same material. These analyses proved the high optical quality of the fiber. Using a hemispherical cavity and pumping the crystal with an InGaN-based laser diode, we achieved laser emission in the orange, red and deep red regions. We measured the slope efficiencies of three transitions and studied the propagation of output beams. To the best of our knowledge, these are the first laser operations in a Pr:YLF single-crystal fiber grown by this method.

  18. An experimental design approach for hydrothermal synthesis of NaYF4: Yb3+, Tm3+ upconversion microcrystal: UV emission optimization

    NASA Astrophysics Data System (ADS)

    Kaviani Darani, Masoume; Bastani, Saeed; Ghahari, Mehdi; Kardar, Pooneh

    2015-11-01

    Ultraviolet (UV) emissions of hydrothermally synthesized NaYF4: Yb3+, Tm3+ upconversion crystals were optimized using the response surface methodology experimental design. In these experimental designs, 9 runs, two factors namely (1) Tm3+ ion concentration, and (2) pH value were investigated using 3 different ligands. Introducing UV upconversion emissions as responses, their intensity were separately maximized. Analytical methods such as XRD, SEM, and FTIR could be used to study crystal structure, morphology, and fluorescent spectroscopy in order to obtain luminescence properties. From the photo-luminescence spectra, emissions centered at 347, 364, 452, 478, 648 and 803 nm were observed. Some results show that increasing each DOE factor up to an optimum value resulted in an increase in emission intensity, followed by reduction. To optimize UV emission, as a final result to the UV emission optimization, each design had a suggestion.

  19. Tularemia vaccines - an overview.

    PubMed

    McMurry, Julie A; Moise, Leonard; Gregory, Stephen H; De Groot, Anne S

    2007-10-01

    F tularensis is among of the most virulent pathogens known, yet it remains poorly understood. Correlates of protection involve robust CD4+ and CD8+ T cell responses, and the production of IFN-gamma, TNF-alpha, and IL-12. Novel approaches may be required to develop a safe vaccine that achieves these correlates. In contrast to other types of vaccines, epitope-based vaccines combine targeted biologic activity with the practical advantages of platform independence, scalable synthesis and manufacturing. These advantages, coupled with the proof of principle achieved with an epitope-based tularemia vaccine, suggest that this approach might be applied more widely to develop vaccines against other pathogens, intracellular bacteria most notably.

  20. Vaccines for Canine Leishmaniasis

    PubMed Central

    Palatnik-de-Sousa, Clarisa B.

    2012-01-01

    Leishmaniasis is the third most important vector-borne disease worldwide. Visceral leishmaniasis (VL) is a severe and frequently lethal protozoan disease of increasing incidence and severity due to infected human and dog migration, new geographical distribution of the insect due to global warming, coinfection with immunosuppressive diseases, and poverty. The disease is an anthroponosis in India and Central Africa and a canid zoonosis (ZVL) in the Americas, the Middle East, Central Asia, China, and the Mediterranean. The ZVL epidemic has been controlled by one or more measures including the culling of infected dogs, treatment of human cases, and insecticidal treatment of homes and dogs. However, the use of vaccines is considered the most cost–effective control tool for human and canine disease. Since the severity of the disease is related to the generation of T-cell immunosuppression, effective vaccines should be capable of sustaining or enhancing the T-cell immunity. In this review we summarize the clinical and parasitological characteristics of ZVL with special focus on the cellular and humoral canine immune response and review state-of-the-art vaccine development against human and canine VL. Experimental vaccination against leishmaniasis has evolved from the practice of leishmanization with living parasites to vaccination with crude lysates, native parasite extracts to recombinant and DNA vaccination. Although more than 30 defined vaccines have been studied in laboratory models no human formulation has been licensed so far; however three second-generation canine vaccines have already been registered. As expected for a zoonotic disease, the recent preventive vaccination of dogs in Brazil has led to a reduction in the incidence of canine and human disease. The recent identification of several Leishmania proteins with T-cell epitopes anticipates development of a multiprotein vaccine that will be capable of protecting both humans and dogs against VL. PMID:22566950

  1. Lassa fever vaccine.

    PubMed

    Fisher-Hoch, Susan P; McCormick, Joseph B

    2004-04-01

    Lassa fever remains a serious challenge to public health in West Africa threatening both local residents in rural areas and those who serve them, particularly medical care providers. Given the ecology of the rodent host and conditions in the endemic area, a vaccine is mandatory for control. The challenge is to overcome the scientific, political and economic obstacles to producing a human use vaccine candidate. There are some scientific issues to resolve. It is known that the G-protein confers protection but we do not know its duration. If the N-protein is also included there may be a better duration of protection but it is unclear whether the N-protein as a vaccine may possibly enhance the infection. The original vaccinia vector must be replaced by new vectors, chimeras or by delivering DNA in some format. A live vaccine is attractive because it can confer protection in a single shot. A killed vaccine is more stable, particularly for distribution in the tropics but usually requires repeated shots. For practical reasons a live vaccine format should probably be pursued, which could then be combined with a yellow fever vaccine, using the same cold chains, since this disease occupies the same endemic areas in West Africa. Lassa vaccine initiatives have suffered from a lack of funding in the past but bioterrorism has brought new resources to Lassa virus science. Adequate funding and applications of new vaccine technologies give hope that we may soon see a vaccine in clinical trials. However, the difficulty of conducting trials in endemic areas and lack of political stability remain serious problems.

  2. First observations of the fourth generation synthetic halocarbons HFC-1234yf, HFC-1234ze(E), and HCFC-1233zd(E) in the atmosphere.

    PubMed

    Vollmer, Martin K; Reimann, Stefan; Hill, Matthias; Brunner, Dominik

    2015-03-03

    Halogenated alkenes are a class of anthropogenic substances, which replace ozone-depleting substances and long-lived greenhouse gases in the foam-blowing, refrigeration, and solvent sectors. We report the first multiyear atmospheric measurements of the hydrofluorocarbons HFC-1234yf (2,3,3,3-tetrafluoroprop-1-ene, CF3CF═CH2), and HFC-1234ze(E) (E-1,3,3,3-tetrafluoroprop-1-ene trans-CF3CH═CHF), and the hydrochlorofluorocarbon HCFC-1233zd(E) (E-1-chloro-3,3,3-trifluoroprop-1-ene trans-CF3CH═CHCl) from the high altitude observatory at Jungfraujoch and from urban Dubendorf (Switzerland). When observations started in 2011 HFC-1234yf was undetectable at Jungfraujoch (mole fractions <0.003 ppt, parts-per-trillion, 10(-12)) but since then the percentage of measurements with detectable mole fractions has steadily increased to 4.5% in 2014. By contrast, in 2014 HFC-1234ze(E) was detectable in half of our samples at Jungfraujoch and in all samples at Dubendorf demonstrating the wide use of this compound within the air mass footprints of the stations. Our back trajectory analysis for the Jungfraujoch observations suggests high emission strength of HFC-1234ze(E) in the Belgium/Netherlands region. HCFC-1233zd(E) is present at very low mole fractions (typically <0.03 ppt) at both stations, and features pronounced seasonality and a general absence of pollution events during our 2013-2014 measurements. This is indicative of the presence of significant emissions from source locations outside the footprints of the two stations. Based on a simple one-box model calculation we estimate globally increasing HCFC-1233zd(E) emissions from 0.2 Gg yr(-1) in 2013 to 0.5 Gg yr(-1) for 2014.

  3. Real-time, non-invasive monitoring of hydrogel degradation using LiYF4:Yb(3+)/Tm(3+) NIR-to-NIR upconverting nanoparticles.

    PubMed

    Jalani, Ghulam; Naccache, Rafik; Rosenzweig, Derek H; Lerouge, Sophie; Haglund, Lisbet; Vetrone, Fiorenzo; Cerruti, Marta

    2015-07-14

    To design a biodegradable hydrogel as cell support, one should know its in vivo degradation rate. A technique commonly used to track gel degradation is fluorescence spectroscopy. However, the fluorescence from conventional fluorophores quickly decays, and the fluorophores are often moderately cytotoxic. Most importantly, they require ultraviolet or visible (UV-Vis) light as the excitation source, which cannot penetrate deeply through biological tissues. Lanthanide-doped upconverting nanoparticles (UCNPs) are exciting alternatives to conventional fluorophores because they can convert near-infrared (NIR) to UV-Vis-NIR light via a sequential multiphoton absorption process referred to as upconversion. NIR light can penetrate up to few cm inside tissues, thus making these UCNPs much better probes than conventional fluorophores for in vivo monitoring. Also, UCNPs have narrow emission bands, high photoluminescence (PL) signal-to-noise ratio, low cytotoxicity and good physical and chemical stability. Here, we show a nanocomposite system consisting of a biodegradable, in situ thermogelling injectable hydrogel made of chitosan and hyaluronic acid encapsulating silica-coated LiYF4:Yb(3+)/Tm(3+) UCNPs. We use these UCNPs as photoluminescent tags to monitor the gel degradation inside live, cultured intervertebral discs (IVDs) over a period of 3 weeks. PL spectroscopy and NIR imaging show that NIR-to-NIR upconversion of LiYF4:Yb(3+)/Tm(3+)@SiO2 UCNPs allows for tracking of the gel degradation in living tissues. Both in vitro and ex vivo release of UCNPs follow a similar trend during the first 5 days; after this time, ex vivo release becomes faster than in vitro, indicating a faster gel degradation ex vivo. Also, the amount of released UCNPs in vitro increases continuously up to 3 weeks, while it plateaus after 15 days inside the IVDs showing a homogenous distribution of UCNPs throughout the IVD tissue. This non-invasive optical method for real time, live tissue imaging holds

  4. A low-toxic site-directed mutant of Clostridium perfringens ε-toxin as a potential candidate vaccine against enterotoxemia

    PubMed Central

    Li, Qing; Xin, Wenwen; Gao, Shan; Kang, Lin; Wang, Jinglin

    2013-01-01

    Clostridium perfringens epsilon toxin (ETX), one of the most potent toxins known, is a potential biological weapon; therefore, the development of an effective vaccine is important for preventing intoxication or disease by ETX. In this study, genetically detoxified epsilon toxin mutants were developed as candidate vaccines. We used site-directed mutagenesis to mutate the essential amino acid residues (His106, Ser111 and Phe199). Six site-directed mutants of ETX (mETXH106P, mETXS111H, mETXS111Y, mETXF199H, mETXF199E, mETXS111YF199E) were generated and then expressed in Escherichia coli. Both mETXF199E and mETXH106P with low or non-cytotoxicity that retained their immunogenicity were selected to immunize mice 3 times, and the mouse survival data were recorded after challenging with recombinant wild-type ETX. mETXF199E induces the same protection as mETXH106P, which was reported previously as a promising toxin mutant for vaccine, and both of them could protect immunized mice against a 100× LD50 dose of active wild-type recombinant ETX. This work showed that mETXF199E is another promising candidate vaccine against enterotoxemia and other diseases caused by ETX. PMID:23835363

  5. DNA vaccines: a review.

    PubMed

    Lewis, P J; Babiuk, L A

    1999-01-01

    Therapeutic and prophylactic DNA vaccine clinical trials for a variety of pathogens and cancers are underway (Chattergoon et al., 1997; Taubes, 1997). The speed with which initiation of these trials occurred is no less than astounding; clinical trials for a human immunodeficiency virus (HIV) gp160 DNA-based vaccine were underway within 36 months of the first description of "genetic immunization" (Tang et al., 1992) and within 24 months of publication of the first article describing intramuscular delivery of a DNA vaccine (Ulmer et al., 1993). Despite the relative fervor with which clinical trials have progressed, it can be safely stated that DNA-based vaccines will not be an immunological "silver bullet." In this regard, it was satisfying to see a publication entitled "DNA Vaccines--A Modern Gimmick or a Boon to Vaccinology?" (Manickan et al., 1997b). There is no doubt that this technology is well beyond the phenomenology phase of study. Research niches and models have been established and will allow the truly difficult questions of mechanism and application to target species to be studied. These two aspects of future studies are intricately interwoven and will ultimately determine the necessity for mechanistic understanding and the evolution of target species studies. The basic science of DNA vaccines has yet to be clearly defined and will ultimately determine the success or failure of this technology to find a place in the immunological arsenal against disease. In a commentary on a published study describing DNA vaccine-mediated protection against heterologous challenge with HIV-1 in chimpanzees, Ronald Kennedy (1997) states, "As someone who has been in the trenches of AIDS vaccine research for over a decade and who, together with collaborators, has attempted a number of different vaccine approaches that have not panned out, I have a relatively pessimistic view of new AIDS vaccine approaches." Kennedy then goes on to summarize a DNA-based multigene vaccine

  6. Nanoparticles for transcutaneous vaccination

    PubMed Central

    Hansen, Steffi; Lehr, Claus‐Michael

    2012-01-01

    Summary The living epidermis and dermis are rich in antigen presenting cells (APCs). Their activation can elicit a strong humoral and cellular immune response as well as mucosal immunity. Therefore, the skin is a very attractive site for vaccination, and an intradermal application of antigen may be much more effective than a subcutaneous or intramuscular injection. However, the stratum corneum (SC) is a most effective barrier against the invasion of topically applied vaccines. Products which have reached the stage of clinical testing, avoid this problem by injecting the nano‐vaccine intradermally or by employing a barrier disrupting method and applying the vaccine to a relatively large skin area. Needle‐free vaccination is desirable from a number of aspects: ease of application, improved patient acceptance and less risk of infection among them. Nanocarriers can be designed in a way that they can overcome the SC. Also incorporation into nanocarriers protects instable antigen from degradation, improves uptake and processing by APCs, and facilitates endosomal escape and nuclear delivery of DNA vaccines. In addition, sustained release systems may build a depot in the tissue gradually releasing antigen which may avoid booster doses. Therefore, nanoformulations of vaccines for transcutaneous immunization are currently a very dynamic field of research. Among the huge variety of nanocarrier systems that are investigated hopes lie on ultra‐flexible liposomes, superfine rigid nanoparticles and nanocarriers, which are taken up by hair follicles. The potential and pitfalls associated with these three classes of carriers will be discussed. PMID:21854553

  7. Vaccines, viruses, and voodoo.

    PubMed

    Borchers, Andrea T; Keen, Carl L; Shoenfeld, Yehuda; Silva, Joseph; Gershwin, M Eric

    2002-01-01

    Vaccinations are invaluable in protection from a wide variety of diseases that can cause substantial morbidity and mortality. Although a rare complication of vaccination, autoimmune disorders represent one of these morbidities. Recently, widespread public concern has arisen from case reports suggesting that--similar to what has been observed after natural viral infections--there might be an association between specific immunizations and autoimmune diseases. Herein we address the biological plausibility of such a connection, focusing particularly on the examples of hepatitis B, rubella, and measles-mumps-rubella (MMR) vaccinations, and the autoimmune diseases they are potentially associated with. Our review of the available data suggests that, for the general population, the risk: benefit ratio is overwhelmingly in favor of vaccinations. However, the possibility cannot be ruled out that, in genetically susceptible individuals, vaccination can result in the unmasking of an autoimmune disease triggered by the immunization. We also critically examine the existing data suggesting a link between immunization against MMR and autism, and briefly discuss the controversial evidence pointing to a possible relationship between mercury exposure from vaccines and autistic disorders. There is a continued urgent need for rigorously designed and executed studies addressing these potential associations, although the use of vaccinations remains a critical public health tool for protection against infectious disease.

  8. Zika Vaccine Development: Flavivirus Foils

    DTIC Science & Technology

    2016-09-01

    Martins, Bavari, Zika Vaccine Development 1 Zika Vaccine Development: Flavivirus Foils Martins KAO, Bavari S. The current Zika virus...contrast, work had been underway for decades on the development of an Ebola virus vaccine , laying the groundwork for a rapid response in 2014. The...broader community’s extensive experience with Dengue virus vaccine development and with the pros and cons of different vaccine platforms has led to

  9. [Pharmacovigilance of vaccines].

    PubMed

    Autret-Leca, E; Bensouda-Grimaldi, L; Jonville-Béra, A P; Beau-Salinas, F

    2006-02-01

    Safety of vaccines must be excellent to make vaccine's strategy acceptable, since it usually has a deferred individual benefit but immediate adverse drug reactions (ADRs). Pharmacovigilance of vaccines after their marketing is crucial because, prior to its availability on the market, the size of clinical trials is insufficient to identify rare or deferred adverse effects. The Pharmacovigilance is based on "spontaneous reporting" of ADRs to the Pharmacovigilance Regional Centre (PVRC) which establishes a relationship between each drug taken by the patient and the ADRs occurrence (imputability). This method is crucial to generate alerts, but under-estimates the real frequency of ADRs (1 to 10% of severe ADRs are reported). Thus pharmacoepidemiology studies are necessary to confirm the alerts identified by spontaneous reporting. ADRs can be specific, related to the antigen of an attenuated alive virus vaccine (lymphocyte meningitis after anti-mumps vaccine) or non-specific, related to a component different from the antigen (aluminium hydroxide involved in the "macrophagic myofasciitis", allergic reactions to neomycin, latex, egg or gelatine). Importance of Pharmacovigilance of vaccines is illustrated. Data, especially case-control studies, about the relationship between multiple sclerosis and hepatitis B vaccine are summarised. Data about the relationship between Crohn's disease or autism and MMR vaccine are analysed. As vaccines are used in healthy people, their safety must be excellent to be accepted. To monitor them after their marketing is the unique way to detect rare ADRs. This surveillance is made through reporting of ADRs to the PVRC. However, an active and intensive surveillance of ADRs as the one set up from the marketing of Prevenar should be systematic.

  10. Drug and vaccine allergy.

    PubMed

    Kelso, John M

    2015-02-01

    Most children with a history of penicillin allergy are labeled allergic and denied treatment with penicillin and sometimes other beta-lactam antibiotics. Most of these children never were or are no longer allergic to penicillin. Penicillin skin testing and oral challenge can identify patients who are not currently allergic, allowing them to be treated with penicillin. Children with egg allergy are often denied influenza vaccination, because the vaccine contains a small amount of egg protein. However, recent studies have demonstrated that children with even severe egg allergy can safely receive the vaccine, reducing their risk of the morbidity and mortality associated with influenza.

  11. Research toward Malaria Vaccines

    NASA Astrophysics Data System (ADS)

    Miller, Louis H.; Howard, Russell J.; Carter, Richard; Good, Michael F.; Nussenzweig, Victor; Nussenzweig, Ruth S.

    1986-12-01

    Malaria exacts a toll of disease to people in the Tropics that seems incomprehensible to those only familiar with medicine and human health in the developed world. The methods of molecular biology, immunology, and cell biology are now being used to develop an antimalarial vaccine. The Plasmodium parasites that cause malaria have many stages in their life cycle. Each stage is antigenically distinct and potentially could be interrupted by different vaccines. However, achieving complete protection by vaccination may require a better understanding of the complexities of B- and T-cell priming in natural infections and the development of an appropriate adjuvant for use in humans.

  12. Alphavirus-Based Vaccines.

    PubMed

    Lundstrom, Kenneth

    2016-01-01

    Alphavirus vectors based on Semliki Forest virus, Sindbis virus, and Venezuelan equine encephalitis virus have been widely applied for vaccine development. Naked RNA replicons, recombinant viral particles, and layered DNA vectors have been subjected to immunization in preclinical animal models with antigens for viral targets and tumor antigens. Moreover, a limited number of clinical trials have been conducted in humans. Vaccination with alphavirus vectors has demonstrated efficient immune responses and has showed protection against challenges with lethal doses of virus and tumor cells, respectively. Moreover, vaccines have been developed against alphaviruses causing epidemics such as Chikungunya virus.

  13. Vaccines against drug abuse.

    PubMed

    Shen, X Y; Orson, F M; Kosten, T R

    2012-01-01

    The currently available medications for the treatment of drug abuse have had only limited success. Anti-addiction vaccines, aimed at eliciting antibodies that block the pharmacological effects of drugs, have great potential for treating drug abuse. We review the status of two vaccines that are undergoing clinical trials (for cocaine and nicotine addiction) and two that are still in preclinical development (for methamphetamine and heroin addiction). We also outline the challenges and ethical concerns associated with the development of anti-addiction vaccines and their use as future therapeutics.

  14. The HPV vaccine mandate controversy.

    PubMed

    Haber, Gillian; Malow, Robert M; Zimet, Gregory D

    2007-12-01

    In this editorial we address the controversies surrounding human papillomavirus (HPV) vaccine school-entry mandate legislation, but differentiate between the mandate debate and issues specific to the vaccine itself. Our goal is not to take a stand in favor of or opposed to mandates, but rather to critically examine the issues. We discuss the following arguments against HPV vaccine school-entry requirements: 1. The public health benefit of mandated HPV vaccination is not sufficient to warrant the intrusion on parental autonomy; 2. A vaccine that prevents a non-casually transmitted infection should not be mandated; 3. Opt-out provisions are inherently unfair to parents who oppose HPV vaccination; 4. Limited health care dollars should not be directed toward cervical cancer prevention; and 5. The vaccine is expensive and potential problems with supply suggest that mandates should not be implemented until insurance coverage and supply issues are resolved. Next, we critically evaluate the following critiques of HPV vaccination itself: 1. Giving girls HPV vaccine implies tacit consent to engage in sexual activity; 2. Giving girls this vaccine will confer a false sense of protection from sexually transmitted infections and will lead to sexual disinhibition; 3. Children already have too many vaccinations on the immunization schedule; 4. Long-term side effects of HPV vaccine are unknown; 5. The vaccine's enduring effectiveness is unknown and booster shots may be required; and 6. It is wrong to only target girls with HPV vaccine; boys should be vaccinated as well.

  15. Vaccine safety controversies and the future of vaccination programs.

    PubMed

    François, Guido; Duclos, Philippe; Margolis, Harold; Lavanchy, Daniel; Siegrist, Claire-Anne; Meheus, André; Lambert, Paul-Henri; Emiroğlu, Nedret; Badur, Selim; Van Damme, Pierre

    2005-11-01

    In the years following the hepatitis B vaccination/multiple sclerosis controversy, a number of new issues regarding vaccine safety have been raised, in some cases leading to more debate and confusion. Against this background, an international group of experts was convened to review the current points of view concerning the use of thimerosal as a preservative and its potential risks; the suggested link between thimerosal-containing vaccines and acute lymphoblastic leukemia; the alleged association between aluminum-containing vaccines/macrophagic myofasciitis and general systemic complaints; a possible link between vaccination and autoimmune pathology; and a hypothetical link between measles-mumps-rubella vaccination and autism. At present, there are no data to conclude that childhood vaccines, and in particular hepatitis B vaccine, pose a serious health risk or justify a change in current immunization practice. However, vaccine "scares" continue to have an international impact on immunization coverage. Creating a positive environment for immunization can be achieved by repositioning the value of vaccines and vaccination, supported by evidence-based information. The role of international organizations, the media, and the industry in the implementation of communication strategies was discussed and the impact of litigation issues on vaccination was evaluated. The Viral Hepatitis Prevention Board confirms its commitment to current recommendations for universal and risk group hepatitis B vaccination and further encourages the conduct of vaccine safety studies and the dissemination of their results.

  16. Parental knowledge of paediatric vaccination

    PubMed Central

    Borràs, Eva; Domínguez, Àngela; Fuentes, Miriam; Batalla, Joan; Cardeñosa, Neus; Plasencia, Antoni

    2009-01-01

    Background Although routine vaccination is a major tool in the primary prevention of some infectious diseases, there is some reluctance in a proportion of the population. Negative parental perceptions of vaccination are an important barrier to paediatric vaccination. The aim of this study was to investigate parental knowledge of paediatric vaccines and vaccination in Catalonia. Methods A retrospective, cross-sectional study was carried out in children aged < 3 years recruited by random sampling from municipal districts of all health regions of Catalonia. The total sample was 630 children. Parents completed a standard questionnaire for each child, which included vaccination coverage and knowledge about vaccination. The level of knowledge of vaccination was scored according to parental answers. Results An association was observed between greater vaccination coverage of the 4:4:4:3:1 schedule (defined as: 4 DTPa/w doses, 4 Hib doses, 4 OPV doses, 3 MenC doses and 1 MMR dose) and maternal age >30 years (OR: 2.30; 95% CI: 1.20–4.43) and with a knowledge of vaccination score greater than the mean (OR: 0.45; 95% CI: 0.28–0.72). The score increased with maternal educational level and in parents of vaccinated children. A total of 20.47% of parents stated that vaccines could have undesirable consequences for their children. Of these, 23.26% had no specific information and 17.83% stated that vaccines can cause adverse reactions and the same percentage stated that vaccines cause allergies and asthma. Conclusion Higher vaccination coverage is associated with older maternal age and greater knowledge of vaccination. Vaccination coverage could be raised by improving information on vaccines and vaccination. PMID:19473498

  17. Vaccines against typhoid fever.

    PubMed

    Guzman, Carlos A; Borsutzky, Stefan; Griot-Wenk, Monika; Metcalfe, Ian C; Pearman, Jon; Collioud, Andre; Favre, Didier; Dietrich, Guido

    2006-05-01

    Because of high infectivity and significant disease burden, typhoid fever constitutes a major global health problem. Implementation of adequate food handling practices and establishment of safe water supplies are the cornerstone for the development of an effective prevention program. However, vaccination against typhoid fever remains an essential tool for the effective management of this disease. Currently, there are two well tolerated and effective licensed vaccines. One is based on defined subunit virulence (Vi) polysaccharide antigen and can be administered either intramuscularly or subcutaneously and the other is based on the use of live attenuated bacteria for oral administration. The advantages and disadvantages of the various approaches taken in the development of a vaccine against typhoid fever are discussed, along with the potential for future vaccine candidates.

  18. Antibacterials: A sweet vaccine

    NASA Astrophysics Data System (ADS)

    Bundle, David

    2016-03-01

    Vaccination with a synthetic glycoconjugate, in combination with the administration of an inhibitor that blocks capsular polysaccharide synthesis in bacteria, could offer an alternative route to combat bacterial infections.

  19. Smallpox vaccine revisited.

    PubMed

    Capriotti, Teri

    2002-12-01

    Smallpox is a serious contagious disease which is back in the public eye. Yet, most health care providers are unprepared for its return. Nurses will be key health care professionals in a smallpox outbreak or vaccination program.

  20. Your child's first vaccines

    MedlinePlus

    ... of these vaccines today: [ ] DTaP [ ] Hib [ ] Hepatitis B [ ] Polio [ ] PCV13 (Provider: Check appropriate boxes) 1. Why get ... out of 4 who are chronically infected. 6. Polio Signs and symptoms can include flu-like illness, ...

  1. Future of Polio Vaccines

    PubMed Central

    2009-01-01

    Summary Over the past half-century, global use of highly effective vaccines against poliomyelitis brought this disease to the brink of elimination. Mounting evidence argues that a high level of population immunity must be maintained to preserve a polio-free status of the entire world after wild poliovirus circulation is stopped. Shifting factors in the risk-benefit-cost equation favor the creation of new poliovirus vaccines to be used in the foreseeable future. Genetically stable attenuated virus strains could be developed for an improved oral poliovirus vaccine, but proving their safety and efficacy would be impractical because of the enormous size of the clinical trials required. New versions of inactivated poliovirus vaccine (IPV) that could be used globally should be developed. An improved IPV must be efficacious, inexpensive, safe to manufacture, and easy to administer. Combination products containing IPV along with other protective antigens should become part of routine childhood immunizations around the world. PMID:19545205

  2. Pneumococcal Vaccines (PCV, PPSV)

    MedlinePlus

    ... Your 1- to 2-Year-Old Your Child's Immunizations: Pneumococcal Vaccines (PCV, PPSV) KidsHealth > For Parents > Your ... but also help stop the infections from spreading. Immunization Schedule PCV13 immunizations are given to all infants ...

  3. Promoting HPV Vaccination Online.

    PubMed

    Lee, Moon J; Cho, Jieun

    2017-01-01

    We investigated the effects of message framing and online media channel on young adults' perceived severity of human papillomavirus (HPV), perceived barriers and benefits of getting HPV vaccination, and behavioral intention to get vaccinated. An experiment was conducted with 142 college students. We found an interaction effect: The loss-framed message posted on Facebook was more effective in increasing the number of people who expressed their willingness to get HPV vaccination than the gain-framed message presented on Facebook. However, this framing effect was not found when the identical message was presented on an online newspaper. People's perceptions of severity of HPV and barriers of getting HPV vaccination were also influenced, depending on which media channel the information was circulated.

  4. Ingredients of Vaccines

    MedlinePlus

    ... quantities of mercury, aluminum, formaldehyde, human serum albumin, antibiotics, and yeast proteins in vaccines have not been found to be harmful in humans or experimental animals... Top of Page Related Pages Common Questions about ...

  5. Polymer hydrogels: Chaperoning vaccines

    NASA Astrophysics Data System (ADS)

    Staats, Herman F.; Leong, Kam W.

    2010-07-01

    A cationic nanosized hydrogel (nanogel) shows controlled antigen delivery in vivo following intranasal administration and hence holds promise for a clinically effective adjuvant-free and needle-free vaccine system.

  6. Pneumococcal vaccine (image)

    MedlinePlus

    Pneumococcal vaccine is an immunization against Streptococcus pneumoniae , a bacterium that frequently causes meningitis and pneumonia in the elderly, and people with chronic illnesses. Pneumococcal pneumonia accounts for 10 to ...

  7. Vaccine delivery management.

    PubMed

    Cheyne, J

    1989-01-01

    During the typical 12- to 18-month voyage of a vaccine from manufacturer to immunization site, many situations arise in which the cold chain may be interrupted. Extensive efforts have been made in the 1980s to ensure an uninterrupted cold chain through the use of improved equipment and better training of personnel. One important advance is the vaccine cold-chain monitor, which identifies weak spots in the cold chain and prevents the use of heat-damaged vaccine. Further improvements will require efforts by the recipient countries (e.g., better use of the private sector for transport and equipment management), by donor agencies (e.g., greater consideration of the operational and maintenance costs of the equipment selected and resolution of fuel shortages), and by industry (e.g., more appropriate packaging and pricing of vaccine, extension of the expiration period, and increased heat stability.

  8. Veterinary vaccines against toxoplasmosis.

    PubMed

    Hiszczyńska-Sawicka, Elżbieta; Gatkowska, Justyna M; Grzybowski, Marcin M; Długońska, Henryka

    2014-09-01

    Toxoplasma gondii is a cosmopolitan protozoan parasite that infects a wide range of mammal and bird species. Common infection leads to high economic (e.g., abortions in sheep) and human (e.g., congenital toxoplasmosis or neurotoxoplasmosis in humans) losses. With one exception (Toxovax for sheep), there are no vaccines to prevent human or animal toxoplasmosis. The paper presents the current state and challenges in the development of a vaccine against toxoplasmosis, designed for farm animals either bred for consumption or commonly kept on farms and involved in parasite transmission. So far, the trials have mostly revolved around conventional vaccines and, compared with the research using laboratory animals (mainly mice), they have not been very numerous. However, the results obtained are promising and could be a good starting point for developing an effective vaccine to prevent toxoplasmosis.

  9. [Development of new vaccines].

    PubMed

    González-Romo, Fernando; Picazo, Juan J

    2015-10-01

    Recent and important advances in the fields of immunology, genomics, functional genomics, immunogenetics, immunogenomics, bioinformatics, microbiology, genetic engineering, systems biology, synthetic biochemistry, proteomics, metabolomics and nanotechnology, among others, have led to new approaches in the development of vaccines. The better identification of ideal epitopes, the strengthening of the immune response due to new adjuvants, and the search of new routes of vaccine administration, are good examples of advances that are already a reality and that will favour the development of more vaccines, their use in indicated population groups, or its production at a lower cost. There are currently more than 130 vaccines are under development against the more wished (malaria or HIV), difficult to get (CMV or RSV), severe re-emerging (Dengue or Ebola), increasing importance (Chagas disease or Leishmania), and nosocomial emerging (Clostridium difficile or Staphylococcus aureus) infectious diseases.

  10. Sequential coating upconversion NaYF4:Yb,Tm nanocrystals with SiO2 and ZnO layers for NIR-driven photocatalytic and antibacterial applications.

    PubMed

    Tou, Meijie; Luo, Zhenguo; Bai, Song; Liu, Fangying; Chai, Qunxia; Li, Sheng; Li, Zhengquan

    2017-01-01

    ZnO is one of the most promising materials for both photocatalytic and antibacterial applications, but its wide bandgap requires the excitation of UV light which limits their applications under visible and NIR bands. Herein, we demonstrate a facile approach to synthesize core-shell-shell hybrid nanoparticles consisting of hexagonal NaYF4:Yb,Tm, amorphous SiO2 and wurtzite ZnO. The upconversion nanocrystals are used as the core seeds and sequentially coated with an insulting shell and a semiconductor layer. Such hybrid nanoparticles can efficiently utilize the NIR light through the upconverting process, and display notable photocatalytic performance and antibacterial activity under NIR irradiation. The developed NaYF4:Yb,Tm@SiO2@ZnO nanoparticles are characterized with TEM, XRD, EDS, XPS and PL spectra, and their working mechanism is also elucidated.

  11. Governments, off-patent vaccines, smallpox and universal childhood vaccination.

    PubMed

    Music, Stanley

    2010-01-22

    WHO is now celebrating more than 30 years of freedom from smallpox. What was originally seen as a victory over an ancient scourge can now be viewed as an epidemiologically driven programme to overcome governmental inertia and under-achievement in delivering an off-patent vaccine. Though efforts are accelerating global vaccine use, a plea is made to push the world's governments to commit to universal childhood vaccination via a proposed new programme. The latter should begin by exploiting a long list of ever more affordable off-patent vaccines, vaccines that can virtually eliminate the bulk of the world's current vaccine-preventable disease burden.

  12. Tuberculosis vaccine development: recent progress.

    PubMed

    Orme, I M; McMurray, D N; Belisle, J T

    2001-03-01

    Recent years have seen a renewed effort to develop new vaccines against tuberculosis. As a result, several promising avenues of research have developed, including the production of recombinant vaccines, auxotrophic vaccines, DNA vaccines and subunit vaccines. In this article we briefly review this work, as well as consider the pros and cons of the animal models needed to test these new vaccines. Screening to date has been carried out in mouse and guinea pig models, which have been used to obtain basic information such as the effect of the vaccine on bacterial load, and whether the vaccine can prevent or reduce lung pathology. The results to date lead us to be optimistic that new candidate vaccines could soon be considered for evaluation in clinical trials.

  13. DNA vaccines: roles against diseases

    PubMed Central

    Khan, Kishwar Hayat

    2013-01-01

    Vaccination is the most successful application of immunological principles to human health. Vaccine efficacy needs to be reviewed from time to time and its safety is an overriding consideration. DNA vaccines offer simple yet effective means of inducing broad-based immunity. These vaccines work by allowing the expression of the microbial antigen inside host cells that take up the plasmid. These vaccines function by generating the desired antigen inside the cells, with the advantage that this may facilitate presentation through the major histocompatibility complex. This review article is based on a literature survey and it describes the working and designing strategies of DNA vaccines. Advantages and disadvantages for this type of vaccines have also been explained, together with applications of DNA vaccines. DNA vaccines against cancer, tuberculosis, Edwardsiella tarda, HIV, anthrax, influenza, malaria, dengue, typhoid and other diseases were explored. PMID:24432284

  14. HPV vaccines: a controversial issue?

    PubMed Central

    Nicol, A.F.; Andrade, C.V.; Russomano, F.B.; Rodrigues, L.L.S.; Oliveira, N.S.; Provance, D.W.

    2016-01-01

    Controversy still exists over whether the benefits of the available HPV vaccines outweigh the risks and this has suppressed uptake of the HPV vaccines in comparison to other vaccines. Concerns about HPV vaccine safety have led some physicians, healthcare officials and parents to withhold the recommended vaccination from the target population. The most common reason for not administering the prophylactic HPV vaccines are concerns over adverse effects. The aim of this review is the assessment of peer-reviewed scientific data related to measurable outcomes from the use of HPV vaccines throughout the world with focused attention on the potential adverse effects. We found that the majority of studies continue to suggest a positive risk-benefit from vaccination against HPV, with minimal documented adverse effects, which is consistent with other vaccines. However, much of the published scientific data regarding the safety of HPV vaccines appears to originate from within the financially competitive HPV vaccine market. We advocate a more independent monitoring system for vaccine immunogenicity and adverse effects to address potential conflicts of interest with regular systematic literature reviews by qualified individuals to vigilantly assess and communicate adverse effects associated with HPV vaccination. Finally, our evaluation suggests that an expanded use of HPV vaccine into more diverse populations, particularly those living in low-resource settings, would provide numerous health and social benefits. PMID:27074168

  15. Epilepsy and vaccinations: Italian guidelines.

    PubMed

    Pruna, Dario; Balestri, Paolo; Zamponi, Nelia; Grosso, Salvatore; Gobbi, Giuseppe; Romeo, Antonino; Franzoni, Emilio; Osti, Maria; Capovilla, Giuseppe; Longhi, Riccardo; Verrotti, Alberto

    2013-10-01

    Reports of childhood epilepsies in temporal association with vaccination have had a great impact on the acceptance of vaccination programs by health care providers, but little is known about this possible temporal association and about the types of seizures following vaccinations. For these reasons the Italian League Against Epilepsy (LICE), in collaboration with other Italian scientific societies, has decided to generate Guidelines on Vaccinations and Epilepsy. The aim of Guidelines on Vaccinations and Epilepsy is to present recent unequivocal evidence from published reports on the possible relationship between vaccines and epilepsy in order to provide information about contraindications and risks of vaccinations in patients with epilepsy. The following main issues have been addressed: (1) whether contraindications to vaccinations exist in patients with febrile convulsions, epilepsy, and/or epileptic encephalopathies; and (2) whether any vaccinations can cause febrile seizures, epilepsy, and/or epileptic encephalopathies. Diphtheria-tetanus-pertussis (DTP) vaccination and measles, mumps, and rubella vaccination (MMR) increase significantly the risk of febrile seizures. Recent observations and data about the relationships between vaccination and epileptic encephalopathy show that some cases of apparent vaccine-induced encephalopathy could in fact be caused by an inherent genetic defect with no causal relationship with vaccination.

  16. Vaccination strategies against influenza.

    PubMed

    Hanon, E

    2009-01-01

    Every year, Influenza virus infection is at the origin of substantial excess in morbidity and mortality in developed as well as developing countries. Influenza viruses undergo antigenic drift which cause annual replacement of strain included in classical trivalent vaccines. Less frequently, this virus can also undergo antigenic shift, which corresponds to a major antigenic change and can lead to an extra medical burden. Several vaccines have been made available to immunize individuals against seasonal as well as pandemic influenza viruses. For seasonal Influenza vaccines, live attenuated and classical inactivated trivalent vaccines have been licensed and are widely used. Additionally, several strategies are under investigations to improve further the efficacy of existing seasonal vaccines in children and elderly. These include the use of adjuvant, increase in antigen content, or alternative route of delivery. Similarly, several approaches have been licensed to address additional challenge posed by pandemic viruses. The different vaccination strategies used to maximise protection against seasonal as well as pandemic influenza will be reviewed and discussed in the perspective the current threat posed by the H1N1v pandemic Influenza.

  17. Rationalizing vaccine injury compensation.

    PubMed

    Mello, Michelle M

    2008-01-01

    Legislation recently adopted by the United States Congress provides producers of pandemic vaccines with near-total immunity from civil lawsuits without making individuals injured by those vaccines eligible for compensation through the Vaccine Injury Compensation Program. The unusual decision not to provide an alternative mechanism for compensation is indicative of a broader problem of inconsistency in the American approach to vaccine-injury compensation policy. Compensation policies have tended to reflect political pressures and economic considerations more than any cognizable set of principles. This article identifies a set of ethical principles bearing on the circumstances in which vaccine injuries should be compensated, both inside and outside public health emergencies. A series of possible bases for compensation rules, some grounded in utilitarianism and some nonconsequentialist, are discussed and evaluated. Principles of fairness and reasonableness are found to constitute the strongest bases. An ethically defensible compensation policy grounded in these principles would make a compensation fund available to all individuals with severe injuries and to individuals with less-severe injuries whenever the vaccination was required by law or professional duty.

  18. Recombinant baculovirus displayed vaccine

    PubMed Central

    Prabakaran, Mookkan; Kwang, Jimmy

    2014-01-01

    The rapid evolution of new sublineages of H5N1 influenza in Asia poses the greatest challenge in vaccine development for pre-pandemic preparedness. To overcome the antigenic diversity of H5N1 strains, multiple vaccine strains can be designed based on the distribution of neutralizing epitopes in the globular head of H5 hemagglutinin (HA). Recently, we selected two different HAs of H5N1 strains based on the neutralizing epitopes and reactivity with different neutralizing antibodies. The HAs of selected vaccine strains were individually expressed on the baculovirus envelope (bivalent-BacHA) with its native antigenic configuration. Further, oral delivery of live bivalent-BacHA elicited broadly reactive humoral, mucosal and cell-mediated immune responses and showed complete protection against antigenically distinct H5N1 strains in mice. The strategy for the vaccine strain selection, vaccine design and route of administration will provide an idea for development of a widely protective vaccine against highly pathogenic H5N1 for pre-pandemic preparedness. PMID:23941989

  19. Simultaneous synthesis and amine-functionalization of single-phase BaYF5:Yb/Er nanoprobe for dual-modal in vivo upconversion fluorescence and long-lasting X-ray computed tomography imaging

    NASA Astrophysics Data System (ADS)

    Liu, Hongrong; Lu, Wei; Wang, Haibo; Rao, Ling; Yi, Zhigao; Zeng, Songjun; Hao, Jianhua

    2013-06-01

    In this work, we developed a novel and biocompatible dual-modal nanoprobe based on single-phase amine-functionalized BaYF5:Yb/Er nanoparticles (NPs) for upconversion (UC) fluorescence and in vivo computed X-ray tomography (CT) bioimaging for the first time. High-quality water-soluble amine-functionalized BaYF5:Yb/Er NPs with an average size of 24 nm were synthesized by a facile environmentally friendly hydrothermal method for simultaneous synthesis and surface functionalization. Structure investigation based on the Rietveld refinement method revealed that the as-synthesized BaYF5:Yb/Er NPs present a cubic phase structure, which differs from the previously reported tetragonal structure. Under 980 nm excitation, high-contrast green and red UC emissions were observed from HeLa cells incubated with these amine-functionalized NPs. The UC spectra measured from the NPs incubated with HeLa cells presented only green and red UC emissions without any autofluorescence, further revealing that these NPs are ideal candidates for fluorescent bioimaging. In addition, the cell cytotoxicity test showed low cell toxicity of these NPs. These amine-functionalized NPs were also successfully used as CT agents for in vivo CT imaging because of the efficient X-ray absorption efficiency of Ba and doped Yb ions. A prolonged (2 h) signal enhancement of the spleen in a mouse was observed in CT imaging, which can improve the detection of splenic diseases. More importantly, the simultaneous X-ray and UC in vivo bioimaging was demonstrated in a nude mouse for the first time, indicating the as-prepared UCNPs can be successfully used as dual-modal bioprobes. These results demonstrate that BaYF5:Yb/Er NPs are ideal nanoprobes for dual-modal fluorescent/CT bioimaging with low cytotoxicity, non-autofluorescence, and enhanced detection of the spleen.

  20. What is a Therapeutic HIV Vaccine?

    MedlinePlus

    ... Services HIV Overview What is a Therapeutic HIV Vaccine? (Last updated 10/17/2016; last reviewed 10/ ... from the body. What is a therapeutic HIV vaccine? A therapeutic HIV vaccine is a vaccine that’s ...

  1. What is a Preventive HIV Vaccine?

    MedlinePlus

    ... Services HIV Overview What is a Preventive HIV Vaccine? (Last updated 2/20/2017; last reviewed 2/ ... preventive HIV vaccine. What is a preventive HIV vaccine? A preventive HIV vaccine is given to people ...

  2. Vaccinations for Adults with Hepatitis C Infection

    MedlinePlus

    Vaccinations for Adults with Hepatitis C Infection This table shows which vaccinations you should have to protect your health if ... sure you and your healthcare provider keep your vaccinations up to date. Vaccine Do you need it? ...

  3. Vaccinations for Adults with HIV Infection

    MedlinePlus

    Vaccinations for Adults with HIV Infection The table below shows which vaccinations you should have to protect your health if ... sure you and your healthcare provider keep your vaccinations up to date. Vaccine Do you need it? ...

  4. Vaccine discovery and translation of new vaccine technology.

    PubMed

    Rappuoli, Rino; Black, Steven; Lambert, Paul Henri

    2011-07-23

    An unprecedented increase in new vaccine development has occurred over the past three decades. This activity has resulted in vaccines that protect against an increased range of vaccine-preventable diseases, vaccines that reduce the number of required injections, and vaccines with improved safety and purity. New methods of discovery, such as reverse vaccinology, structural biology, and systems biology, promise new vaccines for different diseases and efficient development pathways for these vaccines. We expect development of vaccines not only for infectious diseases in children but also for healthy adults, pregnant women, and elderly people, and for new indications such as autoimmune disease and cancer. We have witnessed a concomitant development of new technology for assessment of vaccine safety to rapidly identify potential safety issues. Success of these new approaches will depend on effective implementation of vaccination programmes, creative thinking on the part of manufacturers and regulators as to how best to ensure that safe and effective vaccines are available in a timely manner, and improvement of public awareness about the benefits and risks of new vaccines in a way that encourages confidence in vaccines.

  5. Measuring government commitment to vaccination.

    PubMed

    Glassman, Amanda; Zoloa, Juan Ignacio; Duran, Denizhan

    2013-04-18

    Vaccination is among the most cost-effective health interventions and has attracted ever greater levels of funding from public and private donors. However, some countries, mainly populous lower-middle income countries, are lagging behind on vaccination financing and performance. In this paper, we discuss the rationale for investing in vaccination and construct a metric to measure government commitment to vaccination that could promote accountability and better tracking of performance. While noting the limitations of available data, we find that populous middle-income countries, which stand to gain tremendously from increased vaccination uptake, perform poorly in terms of their vaccination outcomes.

  6. Identifying and Addressing Vaccine Hesitancy

    PubMed Central

    Kestenbaum, Lori A.; Feemster, Kristen A.

    2015-01-01

    In the 20th century, the introduction of multiple vaccines significantly reduced childhood morbidity, mortality, and disease outbreaks. Despite, and perhaps because of, their public health impact, an increasing number of parents and patients are choosing to delay or refuse vaccines. These individuals are described as vaccine hesitant. This phenomenon has developed due to the confluence of multiple social, cultural, political and personal factors. As immunization programs continue to expand, understanding and addressing vaccine hesitancy will be crucial to their successful implementation. This review explores the history of vaccine hesitancy, its causes, and suggested approaches for reducing hesitancy and strengthening vaccine acceptance. PMID:25875982

  7. Identifying and addressing vaccine hesitancy.

    PubMed

    Kestenbaum, Lori A; Feemster, Kristen A

    2015-04-01

    In the 20th century, the introduction of multiple vaccines significantly reduced childhood morbidity, mortality, and disease outbreaks. Despite, and perhaps because of, their public health impact, an increasing number of parents and patients are choosing to delay or refuse vaccines. These individuals are described as "vaccine hesitant." This phenomenon has developed due to the confluence of multiple social, cultural, political, and personal factors. As immunization programs continue to expand, understanding and addressing vaccine hesitancy will be crucial to their successful implementation. This review explores the history of vaccine hesitancy, its causes, and suggested approaches for reducing hesitancy and strengthening vaccine acceptance.

  8. Glycoconjugate Vaccines: The Regulatory Framework.

    PubMed

    Jones, Christopher

    2015-01-01

    Most vaccines, including the currently available glycoconjugate vaccines, are administered to healthy infants, to prevent future disease. The safety of a prospective vaccine is a key prerequisite for approval. Undesired side effects would not only have the potential to damage the individual infant but also lead to a loss of confidence in the respective vaccine-or vaccines in general-on a population level. Thus, regulatory requirements, particularly with regard to safety, are extremely rigorous. This chapter highlights regulatory aspects on carbohydrate-based vaccines with an emphasis on analytical approaches to ensure the consistent quality of successive manufacturing lots.

  9. [Pneumococcal vaccines. New conjugate vaccines for adults].

    PubMed

    Campins Martí, Magda

    2015-11-01

    Pneumococcal infections are a significant cause of morbidity and mortality, and are one of the 10 leading causes of death worldwide. Children under 2 years have a higher incidence rate, followed by adults over 64 years. The main risk group are individuals with immunodeficiency, and those with anatomical or functional asplenia, but can also affect immunocompetent persons with certain chronic diseases. Significant progress has been made in the last 10 years in the prevention of these infections. Until a few years ago, only the 23-valent non-conjugate pneumococcal vaccine was available. Its results were controversial in terms of efficacy and effectiveness, and with serious limitations on the type of immune response induced. The current possibility of using the 13-valent conjugate vaccine in adults has led to greater expectations in improving the prevention of pneumococcal disease in these age groups.

  10. [Pertussis vaccine. Reemergence of the disease and new vaccination strategies].

    PubMed

    Moraga-Llop, Fernando A; Campins-Martí, Magda

    2015-03-01

    Pertussis continues to be a public health problem despite the significant decrease in its incidence due to routine vaccination. Resurgence of the disease in countries that have maintained high vaccination coverage has been observed in recent years. Although vaccination is the most effective preventive control measure, both natural and artificial immunity wane over time, and thus the protection offered by current vaccines is not long-lasting. Furthermore, acellular vaccines are less effective. The implementation of new vaccine strategies is required. Vaccination of pregnant women is the most effective strategy for preventing pertussis in young infants, who are the most vulnerable, and should be recommended together with cocooning, ie vaccination of future household and extra-domiciliary contacts who are the main transmitters of the disease.

  11. Rhodococcus equi (Prescottella equi) vaccines; the future of vaccine development.

    PubMed

    Giles, C; Vanniasinkam, T; Ndi, S; Barton, M D

    2015-09-01

    For decades researchers have been targeting prevention of Rhodococcus equi (Rhodococcus hoagui/Prescottella equi) by vaccination and the horse breeding industry has supported the ongoing efforts by researchers to develop a safe and cost effective vaccine to prevent disease in foals. Traditional vaccines including live, killed and attenuated (physical and chemical) vaccines have proved to be ineffective and more modern molecular-based vaccines including the DNA plasmid, genetically attenuated and subunit vaccines have provided inadequate protection of foals. Newer, bacterial vector vaccines have recently shown promise for R. equi in the mouse model. This article describes the findings of key research in R. equi vaccine development and looks at alternative methods that may potentially be utilised.

  12. 9 CFR 113.318 - Pseudorabies Vaccine.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Pseudorabies Vaccine. 113.318 Section... Virus Vaccines § 113.318 Pseudorabies Vaccine. Pseudorabies Vaccine shall be prepared from virus-bearing... be used for preparing seeds for vaccine production. All serials of vaccine shall be prepared from...

  13. 9 CFR 113.303 - Bluetongue Vaccine.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Bluetongue Vaccine. 113.303 Section... Virus Vaccines § 113.303 Bluetongue Vaccine. Bluetongue Vaccine shall be prepared from virus-bearing... be used for preparing the seeds for vaccine production. All serials of vaccine shall be prepared...

  14. 9 CFR 113.318 - Pseudorabies Vaccine.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Pseudorabies Vaccine. 113.318 Section... Virus Vaccines § 113.318 Pseudorabies Vaccine. Pseudorabies Vaccine shall be prepared from virus-bearing... be used for preparing seeds for vaccine production. All serials of vaccine shall be prepared from...

  15. 9 CFR 113.318 - Pseudorabies Vaccine.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Pseudorabies Vaccine. 113.318 Section... Virus Vaccines § 113.318 Pseudorabies Vaccine. Pseudorabies Vaccine shall be prepared from virus-bearing... be used for preparing seeds for vaccine production. All serials of vaccine shall be prepared from...

  16. 9 CFR 113.313 - Measles Vaccine.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Measles Vaccine. 113.313 Section 113... Vaccines § 113.313 Measles Vaccine. Measles Vaccine shall be prepared from virus-bearing cell culture... for preparing the production seed virus for vaccine production. All serials of vaccine shall...

  17. 9 CFR 113.318 - Pseudorabies Vaccine.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Pseudorabies Vaccine. 113.318 Section... Virus Vaccines § 113.318 Pseudorabies Vaccine. Pseudorabies Vaccine shall be prepared from virus-bearing... be used for preparing seeds for vaccine production. All serials of vaccine shall be prepared from...

  18. 9 CFR 113.303 - Bluetongue Vaccine.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Bluetongue Vaccine. 113.303 Section... Virus Vaccines § 113.303 Bluetongue Vaccine. Bluetongue Vaccine shall be prepared from virus-bearing... be used for preparing the seeds for vaccine production. All serials of vaccine shall be prepared...

  19. 9 CFR 113.313 - Measles Vaccine.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Measles Vaccine. 113.313 Section 113... Vaccines § 113.313 Measles Vaccine. Measles Vaccine shall be prepared from virus-bearing cell culture... for preparing the production seed virus for vaccine production. All serials of vaccine shall...

  20. 9 CFR 113.303 - Bluetongue Vaccine.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Bluetongue Vaccine. 113.303 Section... Virus Vaccines § 113.303 Bluetongue Vaccine. Bluetongue Vaccine shall be prepared from virus-bearing... be used for preparing the seeds for vaccine production. All serials of vaccine shall be prepared...