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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. PMID:26886513

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

    PubMed Central

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

    2016-01-01

    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. PMID:26886513

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

    PubMed Central

    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. PMID:24553128

  4. 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

  5. [Construction of recombinant yellow fever virus 17D containing 2A fragment as a vaccine vector].

    PubMed

    Xiaowu, Pang; Fu, Wen-Chuan; Guo, Yin-Han; Zhang, Li-Shu; Xie, Tian-Pei; Xinbin, Gu

    2006-05-01

    The Yellow Fever (YF) vaccine, an attenuated yellow fever 17D (YF-17D) live vaccine, is one of the most effective and safest vaccines in the world and is regarded as one of the best candidates for viral expression vector. We here first reported in China the construction and characterization of the recombinant expression vector of yellow fever 17D which contained the proteinase 2A fragment of foot-and-mouth disease virus (FMDV). Three cDNA fragments representing the full-length YF-17D genome, named 5'-end cDNA (A), 3'-end cDNA (B) and middle cDNA (C), were obtained by reverse transcription polymerase chain reaction (RT-PCR), together with the introduction of SP6 enhancer, necessary restriction sites and overlaps for homologous recombination in yeast. Fragment A and B were then introduced into pRS424 in turn by DNA recombination, followed by transfection of fragment C and the recombinant pRS424 containing A and B (pRS-A-B) into yeast. A recombinant vector containing full length cDNA of YF-17D (pRS-YF) was obtained by screening on medium lack of tryptophan and uracil. A recombinant YF-17D expression vector containing FMDV-2A gene fragment (pRS-YF-2A1) was then constructed by methods of DNA recombination and homologous recombination in yeast described above. In vitro transcription of the recombinant vector pRS-YF-2A1 was then carried out and introduced into BHK-21 cells by electroporation. Results of indirect immunofluorescence assay (IFA) and titer determination showed a stable infectious recombinant virus was gotten, whose features such as growth curve were similar to those of the parental YF-17D. The results suggest that the recombinant vector pRS-YF-2A1, by introduction of heterogenous genes via 2A region, is potential to be an effective live vaccine expression vector. PMID:16755933

  6. 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. PMID:21145373

  7. 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

  8. 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. PMID:25223921

  9. Preclinical and Clinical Development of a YFV 17 D-Based Chimeric Vaccine against West Nile Virus

    PubMed Central

    Dayan, Gustavo H.; Pugachev, Konstantin; Bevilacqua, Joan; Lang, Jean; Monath, Thomas P.

    2013-01-01

    Substantial success has been achieved in the development and implementation of West Nile (WN) vaccines for horses; however, no human WN vaccines are approved. This review focuses on the construction, pre-clinical and clinical characterization of ChimeriVax-WN02 for humans, a live chimeric vaccine composed of a yellow fever (YF) 17D virus in which the prM-E envelope protein genes are replaced with the corresponding genes of the WN NY99 virus. Pre-clinical studies demonstrated that ChimeriVax-WN02 was significantly less neurovirulent than YF 17D in mice and rhesus and cynomolgus monkeys. The vaccine elicited neutralizing antibody titers after inoculation in hamsters and monkeys and protected immunized animals from lethal challenge including intracerebral inoculation of high dose of WN NY99 virus. Safety, viremia and immunogenicity of ChimeriVax-WN02 were assessed in one phase I study and in two phase II clinical trials. No safety signals were detected in the three clinical trials with no remarkable differences in incidence of adverse events (AEs) between vaccine and placebo recipients. Viremia was transient and the mean viremia levels were low. The vaccine elicited strong and durable neutralizing antibody and cytotoxic T cell responses. WN epidemiology impedes a classical licensure pathway; therefore, innovative licensure strategies should be explored. PMID:24351795

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

    PubMed Central

    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.

    2006-01-01

    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. PMID:16412488

  11. 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. PMID:16412488

  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. PMID:26517656

  13. 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

  14. A Single 17D Yellow Fever Vaccination Provides Lifelong Immunity; Characterization of Yellow-Fever-Specific Neutralizing Antibody and T-Cell Responses after Vaccination

    PubMed Central

    van Leeuwen, Ester M. M.; Remmerswaal, Ester B. M.; ten Berge, Ineke J. M.; de Visser, Adriëtte W.; van Genderen, Perry J. J.; Goorhuis, Abraham; Visser, Leo G.; Grobusch, Martin P.; de Bree, Godelieve J.

    2016-01-01

    Introduction Prompted by recent amendments of Yellow Fever (YF) vaccination guidelines from boost to single vaccination strategy and the paucity of clinical data to support this adjustment, we used the profile of the YF-specific CD8+ T-cell subset profiles after primary vaccination and neutralizing antibodies as a proxy for potentially longer lasting immunity. Methods and Findings PBMCs and serum were collected in six individuals on days 0, 3, 5, 12, 28 and 180, and in 99 individuals >10 years after YF-vaccination. Phenotypic characteristics of YF- tetramer+ CD8+ T-cells were determined using class I tetramers. Antibody responses were measured using a standardized plaque reduction neutralization test (PRNT). Also, characteristics of YF-tetramer positive CD8+ T-cells were compared between individuals who had received a primary- and a booster vaccination. YF-tetramer+ CD8+ T-cells were detectable on day 12 (median tetramer+ cells as percentage of CD8+ T-cells 0.2%, range 0.07–3.1%). On day 180, these cells were still present (median 0.06%, range 0.02–0.78%). The phenotype of YF-tetramer positive CD8+ T-cells shifted from acute phase effector cells on day 12, to late differentiated or effector memory phenotype (CD45RA-/+CD27-) on day 28. Two subsets of YF-tetramer positive T-cells (CD45RA+CD27- and CD45RA+CD27+) persisted until day 180. Within all phenotypic subsets, the T-bet: Eomes ratio tended to be high on day 28 after vaccination and shifted towards predominant Eomes expression on day 180 (median 6.0 (day 28) vs. 2.2 (day 180) p = 0.0625), suggestive of imprinting compatible with long-lived memory properties. YF-tetramer positive CD8+ T-cells were detectable up to 18 years post vaccination, YF-specific antibodies were detectable up to 40 years after single vaccination. Booster vaccination did not increase titers of YF-specific antibodies (mean 12.5 vs. 13.1, p = 0.583), nor induce frequencies or alter phenotypes of YF-tetramer+ CD8+ T-cells. Conclusion The

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

    PubMed

    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 M S H; 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 P M; 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

  16. Chimeric Yellow Fever Virus 17D-Japanese Encephalitis Virus Vaccine: Dose-Response Effectiveness and Extended Safety Testing in Rhesus Monkeys

    PubMed Central

    Monath, T. P.; Levenbook, I.; Soike, K.; Zhang, Z.-X.; Ratterree, M.; Draper, K.; Barrett, A. D. T.; Nichols, R.; Weltzin, R.; Arroyo, J.; Guirakhoo, F.

    2000-01-01

    ChimeriVax-JE is a live, attenuated recombinant virus prepared by replacing the genes encoding two structural proteins (prM and E) of yellow fever 17D virus with the corresponding genes of an attenuated strain of Japanese encephalitis virus (JE), SA14-14-2 (T. J. Chambers et al., J. Virol. 73:3095–3101, 1999). Since the prM and E proteins contain antigens conferring protective humoral and cellular immunity, the immune response to vaccination is directed principally at JE. The prM-E genome sequence of the ChimeriVax-JE in diploid fetal rhesus lung cells (FRhL, a substrate acceptable for human vaccines) was identical to that of JE SA14-14-2 vaccine and differed from sequences of virulent wild-type strains (SA14 and Nakayama) at six amino acid residues in the envelope gene (E107, E138, E176, E279, E315, and E439). ChimeriVax-JE was fully attenuated for weaned mice inoculated by the intracerebral (i.c.) route, whereas commercial yellow fever 17D vaccine (YF-Vax) caused lethal encephalitis with a 50% lethal dose of 1.67 log10 PFU. Groups of four rhesus monkeys were inoculated by the subcutaneous route with 2.0, 3.0, 4.0, and 5.0 log10 PFU of ChimeriVax-JE. All 16 monkeys developed low viremias (mean peak viremia, 1.7 to 2.1 log10 PFU/ml; mean duration, 1.8 to 2.3 days). Neutralizing antibodies appeared between days 6 and 10; by day 30, neutralizing antibody responses were similar across dose groups. Neutralizing antibody titers to the homologous (vaccine) strain were higher than to the heterologous wild-type JE strains. All immunized monkeys and sham-immunized controls were challenged i.c. on day 54 with 5.2 log10 PFU of wild-type JE. None of the immunized monkeys developed viremia or illness and had mild residual brain lesions, whereas controls developed viremia, clinical encephalitis, and severe histopathologic lesions. Immunized monkeys developed significant (≥4-fold) increases in serum and cerebrospinal fluid neutralizing antibodies after i.c. challenge. In a

  17. 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

  18. 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. PMID:25516543

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

    PubMed Central

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

    2015-01-01

    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. PMID:25516543

  20. 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

    Watson, Alan M; Lam, L K Metthew; Klimstra, William B; Ryman, Kate D

    2016-07-01

    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

  1. 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

  2. Limitations of the complement-fixation test for distinguishing naturally acquired from vaccine-induced yellow fever infection in flavivirus-hyperendemic areas.

    PubMed

    Monath, T P; Craven, R B; Muth, D J; Trautt, C J; Calisher, C H; Fitzgerald, S A

    1980-07-01

    On the basis of previous studies, it has long been stated that 17D yellow fever (YF) vaccine generally does not induce complement-fixing (CF) antibodies, and that the presence of CF antibodies could be used in epidemiological studies to distinguish individuals infected with wild YF virus from vaccinated persons. In January 1979, seroepidemiological investigations were conducted during a YF epidemic in The Gambia, West Africa. Since a mass vaccination campaign was also in progress, it was important to confirm that the CF test could be used for serodiagnosis and determination of the incidence of natural YF infections. The serological responses of 58 individuals who received 17D YF vaccine were studied. The vaccinees fell into three gorups: 1) those with prevaccination YF neutralizing (N) antibodies; 2) immunological virgins without prevaccination YF-N antibody or hemagglutination-inhibiting (HI) antibodies to heterologous flaviviruses (Zika, West Nile, dengue 1, Uganda S, Spondweni, or Ntaya; and 3) those without prevaccination YF-N antibodies but with heterologous flaviviral HI antibodies. Vaccination of persons without prior flaviviral immunological experience resulted in monotypic YF HI and/or N antibody seroconversions, but no CF antibody response. The presence of prevaccination YF N antibodies blocked serological response to the vaccine in a high proportion of the cases; however, 24% of vaccinees in this group had a marked rise in log2 YF CF antibody titer (mean increase of 3.9). Thirteen (46%) of 28 persons without prevaccination YF N, but with heterologous flaviviral HI antibodies demonstrated YF CF antibody seroconversion or increase in titer following vaccination; in this group the mean increase in log2/ YF CF antibody titer was 2.1. The CF antibody response was generally broadly cross-reactive; but in a few individuals, the YF CF antibody response was homotypic. Nine different patterns of HI and CF homologous and heterologous antibody responses were defined

  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. PMID:24920138

  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. A humanized monoclonal antibody neutralizes yellow fever virus strain 17D-204 in vitro but does not protect a mouse model from disease.

    PubMed

    Calvert, Amanda E; Dixon, Kandice L; Piper, Joseph; Bennett, Susan L; Thibodeaux, Brett A; Barrett, Alan D T; Roehrig, John T; Blair, Carol D

    2016-07-01

    The yellow fever virus (YFV) vaccine 17D-204 is considered safe and effective, yet rare severe adverse events (SAEs), some resulting in death, have been documented following vaccination. Individuals exhibiting post-vaccinal SAEs are ideal candidates for antiviral monoclonal antibody (MAb) therapy; the time until appearance of clinical signs post-exposure is usually short and patients are quickly hospitalized. We previously developed a murine-human chimeric monoclonal antibody (cMAb), 2C9-cIgG, reactive with both virulent YFV and 17D-204, and demonstrated its ability to prevent and treat YF disease in both AG129 mouse and hamster models of infection. To counteract possible selection of 17D-204 variants that escape neutralization by treatment with a single MAb (2C9-cIgG), we developed a second cMAb, 864-cIgG, for use in combination with 2C9-cIgG in post-vaccinal therapy. MAb 864-cIgG recognizes/neutralizes only YFV 17D-204 vaccine substrain and binds to domain III (DIII) of the viral envelope protein, which is different from the YFV type-specific binding site of 2C9-cIgG in DII. Although it neutralized 17D-204 in vitro, administration of 864-cIgG had no protective capacity in the interferon receptor-deficient AG129 mouse model of 17D-204 infection. The data presented here show that although DIII-specific 864-cIgG neutralizes virus infectivity in vitro, it does not have the ability to abrogate disease in vivo. Therefore, combination of 864-cIgG with 2C9-cIgG for treatment of YF vaccination SAEs does not appear to provide an improvement on 2C9-cIgG therapy alone. PMID:27126613

  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. 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. PMID:24757521

  8. 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. PMID:18506257

  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. Systems biology approach predicts immunogenicity of the yellow fever vaccine in humans

    PubMed Central

    Lee, Eva K; Cao, Weiping; Nakaya, Helder I; Teuwen, Dirk; Pirani, Ali; Gernert, Kim; Deng, Jiusheng; Marzolf, Bruz; Kennedy, Kathleen; Wu, Haiyan; Bennouna, Soumaya; Oluoch, Herold; Miller, Joseph; Vencio, Ricardo Z; Mulligan, Mark; Aderem, Alan; Ahmed, Rafi; Pulendran, Bali

    2014-01-01

    A major challenge in vaccinology is to prospectively determine vaccine efficacy. Here we have used a systems biology approach to identify early gene ‘signatures’ that predicted immune responses in humans vaccinated with yellow fever vaccine YF-17D. Vaccination induced genes that regulate virus innate sensing and type I interferon production. Computational analyses identified a gene signature, including complement protein C1qB and eukaryotic translation initiation factor 2 alpha kinase 4—an orchestrator of the integrated stress response—that correlated with and predicted YF-17D CD8+ T cell responses with up to 90% accuracy in an independent, blinded trial. A distinct signature, including B cell growth factor TNFRS17, predicted the neutralizing antibody response with up to 100% accuracy. These data highlight the utility of systems biology approaches in predicting vaccine efficacy. PMID:19029902

  11. ChimeriVax-West Nile Virus Live-Attenuated Vaccine: Preclinical Evaluation of Safety, Immunogenicity, and Efficacy

    PubMed Central

    Arroyo, Juan; Miller, Chuck; Catalan, John; Myers, Gwendolyn A.; Ratterree, Marion S.; Trent, Dennis W.; Monath, Thomas P.

    2004-01-01

    The availability of ChimeriVax vaccine technology for delivery of flavivirus protective antigens at the time West Nile (WN) virus was first detected in North America in 1999 contributed to the rapid development of the vaccine candidate against WN virus described here. ChimeriVax-Japanese encephalitis (JE), the first live- attenuated vaccine developed with this technology has successfully undergone phase I and II clinical trials. The ChimeriVax technology utilizes yellow fever virus (YF) 17D vaccine strain capsid and nonstructural genes to deliver the envelope gene of other flaviviruses as live-attenuated chimeric viruses. Amino acid sequence homology between the envelope protein (E) of JE and WN viruses facilitated targeting attenuating mutation sites to develop the WN vaccine. Here we discuss preclinical studies with the ChimeriVax-WN virus in mice and macaques. ChimeriVax-WN virus vaccine is less neurovirulent than the commercial YF 17D vaccine in mice and nonhuman primates. Attenuation of the virus is determined by the chimeric nature of the construct containing attenuating mutations in the YF 17D virus backbone and three point mutations introduced to alter residues 107, 316, and 440 in the WN virus E protein gene. The safety, immunogenicity, and efficacy of the ChimeriVax-WN02 vaccine in the macaque model indicate the vaccine candidate is expected to be safe and immunogenic for humans. PMID:15507637

  12. 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

  13. 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

  14. Yellow fever vaccine

    PubMed Central

    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. PMID

  15. Genome-wide RNA profiling of long-lasting stem cell-like memory CD8 T cells induced by Yellow Fever vaccination in humans.

    PubMed

    Fuertes Marraco, Silvia A; Soneson, Charlotte; Delorenzi, Mauro; Speiser, Daniel E

    2015-09-01

    The live-attenuated Yellow Fever (YF) vaccine YF-17D induces a broad and polyfunctional CD8 T cell response in humans. Recently, we identified a population of stem cell-like memory CD8 T cells induced by YF-17D that persists at stable frequency for at least 25 years after vaccination. The YF-17D is thus a model system of human CD8 T cell biology that furthermore allows to track and study long-lasting and antigen-specific human memory CD8 T cells. Here, we describe in detail the sample characteristics and preparation of a microarray dataset acquired for genome-wide gene expression profiling of long-lasting YF-specific stem cell-like memory CD8 T cells, compared to the reference CD8 T cell differentiation subsets from total CD8 T cells. We also describe the quality controls, annotations and exploratory analyses of the dataset. The microarray data is available from the Gene Expression Omnibus (GEO) public repository with accession number GSE65804. PMID:26484272

  16. Pressure-inactivated yellow fever 17DD virus: implications for vaccine development.

    PubMed

    Gaspar, Luciane P; Mendes, Ygara S; Yamamura, Anna M Y; Almeida, Luiz F C; Caride, Elena; Gonçalves, Rafael B; Silva, Jerson L; Oliveira, Andréa C; Galler, Ricardo; Freire, Marcos S

    2008-06-01

    The successful Yellow Fever (YF) vaccine consists of the live attenuated 17D-204 or 17DD viruses. Despite its excellent record of efficacy and safety, serious adverse events have been recorded and influenced extensive vaccination in endemic areas. Therefore, alternative strategies should be considered, which may include inactivated whole virus. High hydrostatic pressure has been described as a method for viral inactivation and vaccine development. The present study evaluated whether high hydrostatic pressure would inactivate the YF 17DD virus. YF 17DD virus was grown in Vero cells in roller bottle cultures and subjected to 310MPa for 3h at 4 degrees C. This treatment abolished YF infectivity and eliminated the ability of the virus to cause disease in mice. Pressure-inactivated virus elicited low level of neutralizing antibody titers although exhibited complete protection against an otherwise lethal challenge with 17DD virus in the murine model. The data warrant further development of pressure-inactivated vaccine against YF. PMID:18420285

  17. 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

  18. Vaccine activation of the nutrient sensor GCN2 in dendritic cells enhances antigen presentation.

    PubMed

    Ravindran, Rajesh; Khan, Nooruddin; Nakaya, Helder I; Li, Shuzhao; Loebbermann, Jens; Maddur, Mohan S; Park, Youngja; Jones, Dean P; Chappert, Pascal; Davoust, Jean; Weiss, David S; Virgin, Herbert W; Ron, David; Pulendran, Bali

    2014-01-17

    The yellow fever vaccine YF-17D is one of the most successful vaccines ever developed in humans. Despite its efficacy and widespread use in more than 600 million people, the mechanisms by which it stimulates protective immunity remain poorly understood. Recent studies using systems biology approaches in humans have revealed that YF-17D-induced early expression of general control nonderepressible 2 kinase (GCN2) in the blood strongly correlates with the magnitude of the later CD8(+) T cell response. We demonstrate a key role for virus-induced GCN2 activation in programming dendritic cells to initiate autophagy and enhanced antigen presentation to both CD4(+) and CD8(+) T cells. These results reveal an unappreciated link between virus-induced integrated stress response in dendritic cells and the adaptive immune response. PMID:24310610

  19. 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

  20. 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.

  1. 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

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

    PubMed

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

    2016-04-01

    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

  3. YF-22 in flight (US AF photo)

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The YF-22, prototype aircraft for the Air Force's F-22 fighter, cruises over the desert on a flight for the Air Force. It was never involved in any programs with Dryden. The United States Air Force announced the demonstration/validation phase contractors selection for the Advanced Tactical Fighter (ATF) program October 31, 1986. These contractor programs were the Lockheed YF-22 and the Northrop YF-23; each produced two prototypes and ground-based avionics testbeds. First flights of all four prototypes occured in 1990. The YF-22 was first flown on Sept. 29, 1990. The YF-22 was powered by two General Electric YF120-GE-100 engines. The final design, the F-22, was flown sometime in May 1997. The F-22 is capable of efficient supersonic operation without afterburner use (supercruise). Lockheed teamed with General Dynamics (Fort Worth) and Boeing Military Airplanes to produce two YF-22 prototypes, civil registrations N22YF (with GE YF120) and N22YX (P&W YF119). N22YF rolled out at Palmdale August 29, 1990; first flight/ferry to Edwards AFB September 29, 1990; first air refuelling (11th sortie) October 26, 1990; thrust vectoring in flight November 15, 1990; achieved Mach 1.8 December 26, 1990. Flight test demonstrations included `supercruise' flight in excess of Mach 1.58 without afterburner.

  4. 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.

  5. T-Cell Memory Responses Elicited by Yellow Fever Vaccine are Targeted to Overlapping Epitopes Containing Multiple HLA-I and -II Binding Motifs

    PubMed Central

    de Melo, Andréa Barbosa; Nascimento, Eduardo J. M.; Braga-Neto, Ulisses; Dhalia, Rafael; Silva, Ana Maria; Oelke, Mathias; Schneck, Jonathan P.; Sidney, John; Sette, Alessandro; Montenegro, Silvia M. L.; Marques, Ernesto T. A.

    2013-01-01

    The yellow fever vaccines (YF-17D-204 and 17DD) are considered to be among the safest vaccines and the presence of neutralizing antibodies is correlated with protection, although other immune effector mechanisms are known to be involved. T-cell responses are known to play an important role modulating antibody production and the killing of infected cells. However, little is known about the repertoire of T-cell responses elicited by the YF-17DD vaccine in humans. In this report, a library of 653 partially overlapping 15-mer peptides covering the envelope (Env) and nonstructural (NS) proteins 1 to 5 of the vaccine was utilized to perform a comprehensive analysis of the virus-specific CD4+ and CD8+ T-cell responses. The T-cell responses were screened ex-vivo by IFN-γ ELISPOT assays using blood samples from 220 YF-17DD vaccinees collected two months to four years after immunization. Each peptide was tested in 75 to 208 separate individuals of the cohort. The screening identified sixteen immunodominant antigens that elicited activation of circulating memory T-cells in 10% to 33% of the individuals. Biochemical in-vitro binding assays and immunogenetic and immunogenicity studies indicated that each of the sixteen immunogenic 15-mer peptides contained two or more partially overlapping epitopes that could bind with high affinity to molecules of different HLAs. The prevalence of the immunogenicity of a peptide in the cohort was correlated with the diversity of HLA-II alleles that they could bind. These findings suggest that overlapping of HLA binding motifs within a peptide enhances its T-cell immunogenicity and the prevalence of the response in the population. In summary, the results suggests that in addition to factors of the innate immunity, “promiscuous” T-cell antigens might contribute to the high efficacy of the yellow fever vaccines. PMID:23383350

  6. 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. ...

  7. CLONING AND FUNCTIONAL CHARACTERIZATION OF CHICKEN INTERLEUKIN-17D

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The proinflammatory cytokine IL-17D was cloned from a testis cDNA library prepared from the Korean native chicken. The full-length chicken IL-17D (chIL-17D) cDNA consisted of a 348 nucleotide sequence encoding an open reading frame of 116 amino acids with a predicted molecular mass of 17.0 kDa. Co...

  8. 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

  9. Spectrum of disease outcomes in mice infected with YFV-17D

    PubMed Central

    Erickson, Andrea K.

    2015-01-01

    The host and viral factors that influence disease outcome during flavivirus infections are not fully understood. Using the live attenuated yellow fever virus (YFV) vaccine strain 17D as a model system we evaluated how viral dose, inoculation route and immunopathogenesis contributed to disease outcome in mice deficient in the type I IFN response. We found that YFV-17D infection of IFN-α/β receptor knockout mice resulted in three distinct disease outcomes: no clinical signs of disease, fatal viscerotropic disease or fatal neurotropic disease. Interestingly, viral load at disease onset did not correlate with disease outcome. However, we found increased immune infiltrates in the brain tissues of mice that developed neurotropic disease. Additionally, mice that developed viscerotropic disease, as characterized by liver and spleen pathology and/or intestinal haemorrhage, had significantly elevated levels of alanine aminotransferase, monocyte chemotactic protein and IFN-inducible protein (IP)-10 as compared with mice with no clinical signs of disease or neurotropic disease. Furthermore, mice treated with recombinant IP-10 throughout YFV-17D infection showed increased mortality and an increased percentage of mice with viscerotropic disease. Our results demonstrated that viral load did not correlate with pathogenesis, and the host immune response played a pivotal role in disease outcome and contributed to YFV-17D pathogenesis in mice. PMID:25646269

  10. 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 ...

  11. 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

  12. 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

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

    PubMed

    Beck, Andrew S; Barrett, Alan D T

    2015-11-01

    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. PMID:26366673

  14. [Yellow fever vaccination in non-immunocompetent patients].

    PubMed

    Bruyand, M; Receveur, M C; Pistone, T; Verdière, C H; Thiebaut, R; Malvy, D

    2008-10-01

    Any person travelling in countries where yellow fever (YF) is endemic and without presenting contra-indication for the vaccination against YF may be vaccinated. This vaccination can very rarely induce a potentially lethal neurotropic or viscerotropic disease. In severely immunodeficient patients, the vaccination is contra-indicated because postvaccinal encephalitis may occur after the vaccination, due to vaccine strain pathogenecity. It is important to evaluate the general health status in elderly individuals before vaccinating because of the increased risk of viscerotropic disease in people of 60 years of age and over. Pregnant women should not be vaccinated, except if departure to an endemic zone is unavoidable. YF vaccinatio is contra-indicated for newborns under six months of age. Solid organ grafts, congenital immunodeficiency, leukemia, lymphoma, cancer, and immunosuppressive treatments are contra-indications for this vaccination. Nevertheless, YF immunization is possible after a bone marrow graft and a two-year period without graft-versus-host disease or immunosuppressive treatment. There is no data to support that immunization of the dono prior to the graft could confer protection against yellow fever to the recipient. Low doses, short courses of corticosteroids either as systemic treatment or intra-articular injections are not contra-indications for YF vaccination. Patients infected with HIV with stable clinical status and T CD4-cel count above 200 cells per millimetre cube may be vaccinated. Thymic diseases, including thymoma and thymectomy, are contra-indications for YF vaccination. Finally, a substantial residual level of antibodies beyond 10 years after the latest vaccination could confer protection, thus avoiding a new vaccination when it is an issue. PMID:18715730

  15. 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.

  16. [VACCINES].

    PubMed

    Bellver Capella, Vincente

    2015-10-01

    Vaccines are an extraordinary instrument of immunization of the population against infectious diseases. Around them there are many ethical issues. One of the most debated is what to do with certain groups opposition to vaccination of their children. States have managed in different ways the conflict between the duty of vaccination and the refusal to use vaccines: some impose the vaccination and others simply promote it. In this article we deal with which of these two approaches is the most suitable from an ethical and legal point of view. We stand up for the second option, which is the current one in Spain, and we propose some measures which should be kept in mind to improve immunization programs. PMID:26685562

  17. Efficacy and duration of immunity after yellow fever vaccination: systematic review on the need for a booster every 10 years.

    PubMed

    Gotuzzo, Eduardo; Yactayo, Sergio; Córdova, Erika

    2013-09-01

    Abstract. Current regulations stipulate a yellow fever (YF) booster every 10 years. We conducted a systematic review of the protective efficacy and duration of immunity of YF vaccine in residents of disease-endemic areas and in travelers to assess the need for a booster in these two settings and in selected populations (human immunodeficiency virus-infected persons, infants, children, pregnant women, and severely malnourished persons). Thirty-six studies and 22 reports were included. We identified 12 studies of immunogenicity, 8 of duration of immunity, 8 of vaccine response in infants and children, 7 of human-immunodeficiency virus-infected persons, 2 of pregnant women, and 1 of severely malnourished children. Based on currently available data, a single dose of YF vaccine is highly immunogenic and confers sustained life-long protective immunity against YF. Therefore, a booster dose of YF vaccine is not needed. Special considerations for selected populations are detailed. PMID:24006295

  18. Efficacy and Duration of Immunity after Yellow Fever Vaccination: Systematic Review on the Need for a Booster Every 10 Years

    PubMed Central

    Gotuzzo, Eduardo; Yactayo, Sergio; Córdova, Erika

    2013-01-01

    Current regulations stipulate a yellow fever (YF) booster every 10 years. We conducted a systematic review of the protective efficacy and duration of immunity of YF vaccine in residents of disease-endemic areas and in travelers to assess the need for a booster in these two settings and in selected populations (human immunodeficiency virus–infected persons, infants, children, pregnant women, and severely malnourished persons). Thirty-six studies and 22 reports were included. We identified 12 studies of immunogenicity, 8 of duration of immunity, 8 of vaccine response in infants and children, 7 of human-immunodeficiency virus–infected persons, 2 of pregnant women, and 1 of severely malnourished children. Based on currently available data, a single dose of YF vaccine is highly immunogenic and confers sustained life-long protective immunity against YF. Therefore, a booster dose of YF vaccine is not needed. Special considerations for selected populations are detailed. PMID:24006295

  19. 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

  20. Vaccines

    MedlinePlus Videos and Cool Tools

    ... help the body defend itself against foreign invaders. As the antigens invade the body's tissues, they attract ... the suppressor T cells stop the attack. After a vaccination, the body will have a memory of ...

  1. 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

  2. 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. PMID:23458961

  3. Travel Characteristics and Yellow Fever Vaccine Usage Among US Global TravEpiNet Travelers Visiting Countries with Risk of Yellow Fever Virus Transmission, 2009–2011

    PubMed Central

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

    2013-01-01

    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. PMID:23458961

  4. 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.

  5. 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

  6. Inadvertent yellow fever vaccination of a patient with Crohn's disease treated with infliximab and methotrexate.

    PubMed

    Ekenberg, Christina; Friis-Møller, Nina; Ulstrup, Thomas; Aalykke, Claus

    2016-01-01

    We present a case of a 56-year-old woman with Crohn's disease, treated with methotrexate and infliximab, who inadvertently received yellow fever vaccination (YFV) prior to a journey to Tanzania. She was not previously vaccinated against YF. YFV contains live-attenuated virus, and is contraindicated in patients treated with immunosuppressive drugs. Following vaccination, the patient fell ill with influenza-like illness. Elevated transaminase levels and YF viremia were detected. Despite being immunocompromised, the patient did not develop more severe adverse effects. Neutralising antibodies to YF virus were detected on day 14 following vaccination and remained protective at least 10 months after vaccination. Limited data is available on outcomes of YFV in patients receiving immunosuppressive therapy, including biologics, and we report this case as a reminder of vigilance of vaccine recommendations in this population. PMID:27571912

  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. Single Mutation in the Flavivirus Envelope Protein Hinge Region Increases Neurovirulence for Mice and Monkeys but Decreases Viscerotropism for Monkeys: Relevance to Development and Safety Testing of Live, Attenuated Vaccines

    PubMed Central

    Monath, Thomas P.; Arroyo, Juan; Levenbook, Inessa; Zhang, Zhen-Xi; Catalan, John; Draper, Ken; Guirakhoo, Farshad

    2002-01-01

    A chimeric yellow fever (YF) virus/Japanese encephalitis (JE) virus vaccine (ChimeriVax-JE) was constructed by insertion of the prM-E genes from the attenuated JE virus SA14-14-2 vaccine strain into a full-length cDNA clone of YF 17D virus. Passage in fetal rhesus lung (FRhL) cells led to the emergence of a small-plaque virus containing a single Met→Lys amino acid mutation at E279, reverting this residue from the SA14-14-2 to the wild-type amino acid. A similar virus was also constructed by site-directed mutagenesis (J. Arroyo, F. Guirakhoo, S. Fenner, Z.-X. Zhang, T. P. Monath, and T. J. Chambers, J. Virol. 75:934-942, 2001). The E279 mutation is located in a beta-sheet in the hinge region of the E protein that is responsible for a pH-dependent conformational change during virus penetration from the endosome into the cytoplasm of the infected cell. In independent transfection-passage studies with FRhL or Vero cells, mutations appeared most frequently in hinge 4 (bounded by amino acids E266 to E284), reflecting genomic instability in this functionally important region. The E279 reversion caused a significant increase in neurovirulence as determined by the 50% lethal dose and survival distribution in suckling mice and by histopathology in rhesus monkeys. Based on sensitivity and comparability of results with those for monkeys, the suckling mouse is an appropriate host for safety testing of flavivirus vaccine candidates for neurotropism. After intracerebral inoculation, the E279 Lys virus was restricted with respect to extraneural replication in monkeys, as viremia and antibody levels (markers of viscerotropism) were significantly reduced compared to those for the E279 Met virus. These results are consistent with the observation that empirically derived vaccines developed by mouse brain passage of dengue and YF viruses have increased neurovirulence for mice but reduced viscerotropism for humans. PMID:11799188

  9. 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

  10. YF 102 in-duct combustor noise measurement, volume 1

    NASA Technical Reports Server (NTRS)

    Wilson, C. A.

    1977-01-01

    The combustion chamber from a YF 102 gas turbine engine was instrumented with semi-infinite acoustic wave guide probes and installed in a test rig to complement the combustor noise test. These combustor rig tests are described and the recorded data are listed. Internal dynamic pressure level measurements were made at the same locations and at the same operating conditions of the NASA YF 102 test. In addition, the combustor was operated at various off-designed points where one parameter at a time was varied. Background noise recordings were made to determine the magnitude of facility or test rig noise present.

  11. 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.

  12. Identification and expression analysis of duck interleukin-17D in Riemerella anatipestifer infection.

    PubMed

    Diaz, Joyce Anne R; Kim, Woo H; Fernandez, Cherry P; Jeong, Jipseol; Afrin, Fahmida; Lillehoj, Hyun S; Kim, Suk; Kim, Sungwon; Dalloul, Rami A; Min, Wongi

    2016-08-01

    Interleukin (IL)-17D is a proinflammatory cytokine with currently largely unknown biological functions. Here we provide the description of the sequence, bioactivity, and mRNA expression profile of duck IL-17D homologue. A full-length duck IL-17D (duIL-17D) cDNA with a 624-bp coding region was identified from the large intestine. duIL-17D shares approximately 94.7% identity with its chicken counterpart, which is also identified in this work. duIL-17D exhibits 62.6-68.4% and 52.1-53.1% identity with mammalian and piscine homologues. Recombinant duIL-17D promoted the expression of proinflammatory cytokines such as IL-6, IL-8, and IL-1β in duck embryo fibroblast cells. Very low levels of duIL-17D transcript were observed in healthy lymphoid tissues, including bursa, thymus, and spleen, while duIL-17D expression was relatively high in the heart. The duIL-17D expression profiles were examined in mitogen-stimulated splenic lymphocytes, as well as tissues affected by Riemerella anatipestifer infection. The levels of duIL-17D were mostly upregulated in mitogen-activated splenic lymphocytes but downregulated in the liver and spleen of R. anatipestifer-infected ducks. These results provide new insights into the roles of IL-17D in host protective immune responses to Riemerella infection, which can therefore lead to further studies of its biological functions in different disease models of ducks and other avian species. PMID:27060655

  13. 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

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

    PubMed

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

    2015-12-01

    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 3.5h, 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

  15. Nrf2 Induces IL-17D to Mediate Tumor and Virus Surveillance.

    PubMed

    Saddawi-Konefka, Robert; Seelige, Ruth; Gross, Emilie T E; Levy, Eric; Searles, Stephen C; Washington, Allen; Santosa, Endi K; Liu, Beichen; O'Sullivan, Timothy E; Harismendy, Olivier; Bui, Jack D

    2016-08-30

    Cells undergoing xenobiotic or oxidative stress activate the transcription factor nuclear factor erythroid-derived 2-like 2 (Nrf2), which initiates an intrinsic "stress surveillance" pathway. We recently found that the cytokine IL-17D effects a form of extrinsic stress surveillance by inducing antitumor immunity, but how IL-17D is regulated remains unknown. Here, we show that Nrf2 induced IL-17D in cancer cell lines. Moreover, both Nrf2 and IL-17D were induced in primary tumors as well as during viral infection in vivo. Expression of IL-17D in tumors and virally infected cells is essential for optimal protection of the host as il17d(-/-) mice experienced a higher incidence of tumors and exacerbated viral infections compared to wild-type (WT) animals. Moreover, activating Nrf2 to induce IL-17D in established tumors led to natural killer cell-dependent tumor regression. These data demonstrate that Nrf2 can initiate both intrinsic and extrinsic stress surveillance pathways and highlight the use of Nrf2 agonists as immune therapies for cancer and infection. PMID:27545889

  16. Subdoses of 17DD yellow fever vaccine elicit equivalent virological/immunological kinetics timeline

    PubMed Central

    2014-01-01

    Background The live attenuated 17DD Yellow Fever vaccine is one of the most successful prophylactic interventions for controlling disease expansion ever designed and utilized in larger scale. However, increase on worldwide vaccine demands and manufacturing restrictions urge for more detailed dose sparing studies. The establishment of complementary biomarkers in addition to PRNT and Viremia could support a secure decision-making regarding the use of 17DD YF vaccine subdoses. The present work aimed at comparing the serum chemokine and cytokine kinetics triggered by five subdoses of 17DD YF Vaccine. Methods Neutralizing antibody titers, viremia, cytokines and chemokines were tested on blood samples obtained from eligible primary vaccinees. Results and discussion The results demonstrated that a fifty-fold lower dose of 17DD-YF vaccine (587 IU) is able to trigger similar immunogenicity, as evidenced by significant titers of anti-YF PRNT. However, only subdoses as low as 3,013 IU elicit viremia kinetics with an early peak at five days after primary vaccination equivalent to the current dose (27,476 IU), while other subdoses show a distinct, lower in magnitude and later peak at day 6 post-vaccination. Although the subdose of 587 IU is able to trigger equivalent kinetics of IL-8/CXCL-8 and MCP-1/CCL-2, only the subdose of 3,013 IU is able to trigger similar kinetics of MIG/CXCL-9, pro-inflammatory (TNF, IFN-γ and IL-2) and modulatory cytokines (IL-5 and IL-10). Conclusions The analysis of serum biomarkers IFN-γ and IL-10, in association to PRNT and viremia, support the recommendation of use of a ten-fold lower subdose (3,013 IU) of 17DD-YF vaccine. PMID:25022840

  17. Flight test of the YF-23A Advanced Tactical Fighter

    SciTech Connect

    Metz, P. )

    1992-02-01

    The paper describes the approach used in flight tests of the YF-23A Advanced Tactical Fighter (ATF), the fighter which was conceived as a replacement for the F-1 Eagle and which combines stealth techologies with a supercruise capability while retaining the agility necessary in an air superiority fighter. Special attention is given to the flight test concept, flight test preparations, and test objectives. The test methods, the problems encountered, and the test results are described.

  18. 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

  19. 17 CFR 270.17d-1 - Applications regarding joint enterprises or arrangements and certain profit-sharing plans.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... enterprises or arrangements and certain profit-sharing plans. 270.17d-1 Section 270.17d-1 Commodity and... ACT OF 1940 § 270.17d-1 Applications regarding joint enterprises or arrangements and certain profit... effect any transaction in connection with, any joint enterprise or other joint arrangement or...

  20. 17 CFR 270.17d-1 - Applications regarding joint enterprises or arrangements and certain profit-sharing plans.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... enterprises or arrangements and certain profit-sharing plans. 270.17d-1 Section 270.17d-1 Commodity and... ACT OF 1940 § 270.17d-1 Applications regarding joint enterprises or arrangements and certain profit... effect any transaction in connection with, any joint enterprise or other joint arrangement or...

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

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... enterprises or arrangements and certain profit-sharing plans. 270.17d-1 Section 270.17d-1 Commodity and... ACT OF 1940 § 270.17d-1 Applications regarding joint enterprises or arrangements and certain profit... effect any transaction in connection with, any joint enterprise or other joint arrangement or...

  2. 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

    ... enterprises or arrangements and certain profit-sharing plans. 270.17d-1 Section 270.17d-1 Commodity and... ACT OF 1940 § 270.17d-1 Applications regarding joint enterprises or arrangements and certain profit... effect any transaction in connection with, any joint enterprise or other joint arrangement or...

  3. 17 CFR 270.17d-1 - Applications regarding joint enterprises or arrangements and certain profit-sharing plans.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... enterprises or arrangements and certain profit-sharing plans. 270.17d-1 Section 270.17d-1 Commodity and... ACT OF 1940 § 270.17d-1 Applications regarding joint enterprises or arrangements and certain profit... effect any transaction in connection with, any joint enterprise or other joint arrangement or...

  4. 17 CFR 270.17d-3 - Exemption relating to certain joint enterprises or arrangements concerning payment for...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... CFR 270.17d-1), to the extent necessary to permit any such person or principal underwriter to enter... 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,...

  5. Japanese Encephalitis Vaccines

    PubMed Central

    McArthur, Monica A.; Holbrook, Michael R.

    2012-01-01

    Japanese encephalitis (JE) is a significant human health concern in Asia, Indonesia and parts of Australia with more than 3 billion people potentially at risk of infection with Japanese encephalitis virus (JEV), the causative agent of JE. Given the risk to human health and the theoretical potential for JEV use as a bioweapon, the development of safe and effective vaccines to prevent JEV infection is vital for preserving human health. The development of vaccines for JE began in the 1940s with formalin-inactivated mouse brain-derived vaccines. These vaccines have been shown to induce a protective immune response and to be very effective. Mouse brain-derived vaccines were still in use until May 2011 when the last lots of the BIKEN® JE-VAX® expired. Development of modern JE vaccines utilizes cell culture-derived viruses and improvements in manufacturing processes as well as removal of potential allergens or toxins have significantly improved vaccine safety. China has developed a live-attenuated vaccine that has proven to induce protective immunity following a single inoculation. In addition, a chimeric vaccine virus incorporating the prM and E structural proteins derived from the live-attenuated JE vaccine into the live-attenuated yellow fever 17D vaccine virus backbone is currently in clinical trials. In this article, we provide a summary of JE vaccine development and on-going clinical trials. We also discuss the potential risk of JEV as a bioweapon with a focus on virus sustainability if used as a weapon. PMID:23125946

  6. Environmental fate of the next generation refrigerant 2,3,3,3-tetrafluoropropene (HFO-1234yf).

    PubMed

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

    2014-11-18

    The hydrofluoroolefin 2,3,3,3-tetrafluoropropene (HFO-1234yf) has been introduced to replace 1,1,1,2-tetrafluoroethane (HFC-134a) as refrigerant in mobile, including vehicle, air conditioning systems because of its lower global warming potential. HFO-1234yf is volatile at ambient temperatures; however, high production volumes and widespread handling are expected to release this fluorocarbon into terrestrial and aquatic environments, including groundwater. Laboratory experiments explored HFO-1234yf degradation by (i) microbial processes under oxic and anoxic conditions, (ii) abiotic processes mediated by reactive mineral phases and zerovalent iron (Fe(0), ZVI), and (iii) cobalamin-catalyzed biomimetic transformation. These investigations demonstrated that HFO-1234yf was recalcitrant to microbial (co)metabolism and no transformation was observed in incubations with ZVI, makinawite (FeS), sulfate green rust (GR(SO4)), magnetite (Fe(3)O(4)), and manganese oxide (MnO2). Sequential reductive defluorination of HFO-1234yf to 3,3,3-trifluoropropene and 3,3-dichloropropene with concomitant stoichiometric release of fluoride occurred in incubations with reduced cobalamins (e.g., vitamin B12) indicating that biomolecules can transform HFO-1234yf at circumneutral pH and at ambient temperature. Taken together, these findings suggest that HFO-1234yf recalcitrance in aquifers should be expected; however, HFO-1234yf is not inert and a biomolecule may mediate reductive transformation in low redox environments, albeit at low rates. PMID:25329364

  7. 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

  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 was performed with a YF-12 aircraft at ground static conditions. The objective was to collect acoustic and aerodynamic data that could determine the cause of YF-12 inlet noise suppression observed earlier. The results showed that the far-field noise level was lower with the YF-12 inlet than with a bellmouth inlet at engine speeds above 5500 rpm. The differences were about 5 PNdB to 11 PNdB, depending on YF-12 inlet configuration and on engine speed. Measurements showed that YF-12 inlet noise suppression was not caused by flow choking. The spike support struts were probably responsible, as in that region the spectral peak near the blade passing frequency disappeared between 6000 and 6600 rpm, and multiple pure tones were greatly reduced.

  9. 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.

  10. Strain gage installation on the YF-12 aircraft.

    NASA Technical Reports Server (NTRS)

    Wilson, E. J.

    1973-01-01

    A flight-loads measurement program on the YF-12 aircraft required the mounting of 101 strain-gauge bridges in the fuselage, fuel tanks, control surfaces, and three stations on the left wing. The sensors were to be installed primarily on titanium and were required to operate between -70 and +600 F. Strain gauges with modified Karma filaments and backings of glass-fiber reinforced epoxy resin matrices were selected and were installed with an epoxy adhesive. Attention is given to the calibration, mounting, and performance of the sensors in flight-load measurements.

  11. Transfer of Excitation Energy from Pr3+ to Gd3+ in YF3:Pr3+,Gd3+

    NASA Astrophysics Data System (ADS)

    Hirai, Takeshi; Yoshida, Hisashi; Sakuragi, Shiro; Hashimoto, Satoshi; Ohno, Nobuhito

    2007-02-01

    Luminescence and excitation spectra for YF3:Gd3+, YF3:Pr3+, and YF3:Pr3+,Gd3+ have been studied in the vacuum ultraviolet (VUV) spectral region at room temperature. In YF3:Gd3+, Gd3+ ions absorb VUV light ranging from 150 to 200 nm due to 4 f-4 f transitions, yielding an ultraviolet (UV) luminescence line at 311 nm originating from the 4 f-4 f transition (6P7/2→8S7/2 state). In YF3:Pr3+,Gd3+, Pr3+ ions absorb the VUV light (150-200 nm) due to 4 f-5d transitions, and the absorption gives rise to the UV luminescence of Gd3+ ions that is much stronger than that of YF3:Gd3+. In this paper, we discuss the energy transfer process from Pr3+ to Gd3+ ions in YF3:Pr3+,Gd3+ excited by VUV light.

  12. Lanthanide-doped Sr2YF7 nanoparticles: controlled synthesis, optical spectroscopy and biodetection.

    PubMed

    Yang, Yuhan; Tu, Datao; Zheng, Wei; Liu, Yongsheng; Huang, Ping; Ma, En; Li, Renfu; Chen, Xueyuan

    2014-10-01

    Sr2YF7, as an important matrix for trivalent lanthanide (Ln(3+)) ions to fabricate upconversion (UC) or downshifting (DS) phosphors, has been rarely reported. Herein, monodisperse and size-controllable tetragonal-phase Ln(3+)-doped Sr2YF7 nanoparticles (NPs) were synthesized via a facile thermal decomposition method. Upon excitation at 980 nm, UC luminescence properties of Sr2YF7:Ln(3+)/Yb(3+) (Ln = Tm, Er) NPs were systematically surveyed. Particularly, after coating an inert Sr2YF7 shell, the UC luminescence intensities of Sr2YF7:Tm(3+)/Yb(3+) and Sr2YF7:Er(3+)/Yb(3+) NPs were enhanced by ∼22 and 4 times, respectively. Furthermore, intense multicolor DS luminescence was also achieved in Ce(3+)/Tb(3+) or Eu(3+) doped Sr2YF7 NPs, with absolute quantum yields of 55.1% (Tb(3+)) and 11.2% (Eu(3+)). The luminescence lifetimes of (5)D4 (Tb(3+)) and (5)D0 (Eu(3+)) were determined to be 3.7 and 8.1 ms, respectively. By utilizing the long-lived luminescence of Ln(3+) in these Sr2YF7 NPs, we demonstrated their application as sensitive heterogeneous time-resolved photoluminescence bioprobes to detect the protein of avidin and the tumor marker of the carcinoembryonic antigen (CEA) with their limits of detection down to 40.6 and 94.9 pM, and thus reveal the great potential of these Sr2YF7:Ln(3+) nanoprobes in cancer diagnosis. PMID:24998750

  13. The Attenuated Live Yellow Fever Virus 17D Infects the Thymus and Induces Thymic Transcriptional Modifications of Immunomodulatory Genes in C57BL/6 and BALB/C Mice

    PubMed Central

    Melo-Lima, Breno Luiz; Espósito, Danillo Lucas Alves; da Fonseca, Benedito Antônio Lopes; Figueiredo, Luiz Tadeu Moraes; Moreau, Philippe; Donadi, Eduardo Antonio

    2015-01-01

    Thymus is involved in induction of self-tolerance in T lymphocytes, particularly due to Aire activity. In peripheral tissues, Treg cells and immunomodulatory molecules, like the major histocompatibility complex (MHC) class Ib molecules, are essential for maintenance of autotolerance during immune responses. Viral infections can trigger autoimmunity and modify thymic function, and YFV17D immunization has been associated with the onset of autoimmunity, being contraindicated in patients with thymic disorders. Aiming to study the influence of YFV17D immunization on the transcriptional profiles of immunomodulatory genes in thymus, we evaluated the gene expression of AIRE, FOXP3, H2-Q7 (Qa-2/HLA-G), H2-T23 (Qa-1/HLA-E), H2-Q10, and H2-K1 following immunization with 10,000 LD50 of YFV17D in C57BL/6 and BALB/c mice. The YFV17D virus replicated in thymus and induced the expression of H2-Q7 (Qa-2/HLA-G) and H2-T23 (Qa-1/HLA-E) transcripts and repressed the expression of AIRE and FOXP3. Transcriptional expression varied according to tissue and mouse strain analyzed. Expression of H2-T23 (Qa-1/HLA-E) and FOXP3 was induced in thymus and liver of C57BL/6 mice, which exhibited defective control of viral load, suggesting a higher susceptibility to YFV17D infection. Since the immunization with YFV17D modulated thymus gene expression in genetically predisposed individuals, the vaccine may be related to the onset of autoimmunity disorders. PMID:26457200

  14. 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. PMID:12082985

  15. Lanthanide-doped Sr2YF7 nanoparticles: controlled synthesis, optical spectroscopy and biodetection

    NASA Astrophysics Data System (ADS)

    Yang, Yuhan; Tu, Datao; Zheng, Wei; Liu, Yongsheng; Huang, Ping; Ma, En; Li, Renfu; Chen, Xueyuan

    2014-09-01

    Sr2YF7, as an important matrix for trivalent lanthanide (Ln3+) ions to fabricate upconversion (UC) or downshifting (DS) phosphors, has been rarely reported. Herein, monodisperse and size-controllable tetragonal-phase Ln3+-doped Sr2YF7 nanoparticles (NPs) were synthesized via a facile thermal decomposition method. Upon excitation at 980 nm, UC luminescence properties of Sr2YF7:Ln3+/Yb3+ (Ln = Tm, Er) NPs were systematically surveyed. Particularly, after coating an inert Sr2YF7 shell, the UC luminescence intensities of Sr2YF7:Tm3+/Yb3+ and Sr2YF7:Er3+/Yb3+ NPs were enhanced by ~22 and 4 times, respectively. Furthermore, intense multicolor DS luminescence was also achieved in Ce3+/Tb3+ or Eu3+ doped Sr2YF7 NPs, with absolute quantum yields of 55.1% (Tb3+) and 11.2% (Eu3+). The luminescence lifetimes of 5D4 (Tb3+) and 5D0 (Eu3+) were determined to be 3.7 and 8.1 ms, respectively. By utilizing the long-lived luminescence of Ln3+ in these Sr2YF7 NPs, we demonstrated their application as sensitive heterogeneous time-resolved photoluminescence bioprobes to detect the protein of avidin and the tumor marker of the carcinoembryonic antigen (CEA) with their limits of detection down to 40.6 and 94.9 pM, and thus reveal the great potential of these Sr2YF7:Ln3+ nanoprobes in cancer diagnosis.Sr2YF7, as an important matrix for trivalent lanthanide (Ln3+) ions to fabricate upconversion (UC) or downshifting (DS) phosphors, has been rarely reported. Herein, monodisperse and size-controllable tetragonal-phase Ln3+-doped Sr2YF7 nanoparticles (NPs) were synthesized via a facile thermal decomposition method. Upon excitation at 980 nm, UC luminescence properties of Sr2YF7:Ln3+/Yb3+ (Ln = Tm, Er) NPs were systematically surveyed. Particularly, after coating an inert Sr2YF7 shell, the UC luminescence intensities of Sr2YF7:Tm3+/Yb3+ and Sr2YF7:Er3+/Yb3+ NPs were enhanced by ~22 and 4 times, respectively. Furthermore, intense multicolor DS luminescence was also achieved in Ce3+/Tb3+ or Eu3

  16. 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

  17. 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

  18. 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.

  19. Drosulfakinin activates CCKLR-17D1 and promotes larval locomotion and escape response in Drosophila

    PubMed Central

    Chen, Xu; Peterson, Jonathan; Nachman, Ronald J.; Ganetzky, Barry

    2012-01-01

    Neuropeptides are ubiquitous in both mammals and invertebrates and play essential roles in regulation and modulation of many developmental and physiological processes through activation of G-protein-coupled-receptors (GPCRs). However, the mechanisms by which many of the neuropeptides regulate specific neural function and behaviors remain undefined. Here we investigate the functions of Drosulfakinin (DSK), the Drosophila homolog of vertebrate neuropeptide cholecystokinin (CCK), which is the most abundant neuropeptide in the central nervous system. We provide biochemical evidence that sulfated DSK-1 and DSK-2 activate the CCKLR-17D1 receptor in a cell culture assay. We further examine the role of DSK and CCKLR-17D1 in the regulation of larval locomotion, both in a semi-intact larval preparation and in intact larvae under intense light exposure. Our results suggest that DSK/CCKLR-17D1 signaling promote larval body wall muscle contraction and is necessary for mediating locomotor behavior in stress-induced escape response. PMID:22885328

  20. Safety assessment and probiotic evaluation of Enterococcus faecium YF5 isolated from sourdough.

    PubMed

    Tan, Qianglai; Xu, Hengyi; Aguilar, Zoraida P; Peng, Shanshan; Dong, Suqin; Wang, Baogui; Li, Ping; Chen, Tingtao; Xu, Feng; Wei, Hua

    2013-04-01

    Enterococcus faecium YF5, a strain previously isolated from sourdough, was assessed for safety and probiotic potential. Its virulence and antibiotic resistant phenotypes (cytolysin and gelatinase production, antibiotic susceptibility) and genes (cylA, gelE, ace, agg, esp, and vanA) were surveyed. Results indicated that the tested virulence determinants were nontoxic. In addition, E. faecium YF5 was sensitive to 3 antibiotics such as amoxicillin, vancomycin, and chloramphenicol. Furthermore, results of in vivo animal acute oral toxicity of E. faecium YF5 studies were similar to the control group that indicated no abnormalities. In addition, E. faecium YF5 stably survived in low pH, bile salts, gastric, and intestinal fluids in vitro. Moreover, E. faecium YF5 was found to adhere to human colon cancer cell line HT-29 at 3.39 (±0.67) × 10(5) CFU/mL. When cocultured with pathogenic organisms (Enterobacter sakazakii CMCC45402, Escherichia coli CMCC44102, enterohemorrhage Escherichia coli O157: H7 CMCC44828, Salmonella Typhimurium CMCC50071, Shigella flexneri 301, and Shigella sonnei ATCC 29930) and 2 gram-positive strains (Listeria monocytogenes CMCC54001 and Staphylococcus aureus CMCC 26003), it inhibited these foodborne pathogens with exception of S. aureus. Therefore, E. faecium YF5 can be regarded as a safe strain and it may be used as a probiotic preparation or for microecologics. PMID:23488799

  1. 75 FR 9970 - Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Notice of Filing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-04

    ... COMMISSION Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Notice of Filing and... Responsibilities Among the NYSE Amex LLC, BATS Exchange, Inc., C2 Options Exchange, Incorporated, the Chicago Board... allocating regulatory responsibility (``Plan'') filed pursuant to Rule 17d-2 of the Act,\\2\\ by the NYSE...

  2. 75 FR 49005 - Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Notice of Filing of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-12

    ... an Amended 17d-2 Plan Between the Financial Industry Regulatory Authority, Inc. and the Chicago Stock... Industry Regulatory Authority, Inc. (``FINRA'') and the Chicago Stock Exchange, Inc. (``CHX'') (together... 240.17d-2, respectively. \\8\\ See Securities Exchange Act Release No. 12352 (April 20, 1976), 41...

  3. 75 FR 18915 - Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Notice of Filing of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-13

    .... 12352 (April 20, 1976), 41 FR 18808 (May 7, 1976). To address regulatory duplication in these and other...), 41 FR 49091 (November 8, 1976). II. Proposed 17d-2 Plan The proposed 17d-2 Plan is intended to reduce... calendar quarter. \\13\\ See Securities Exchange Act Release No. 58350 (August 13, 2008), 73 FR 48247...

  4. 75 FR 18920 - Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Notice of Filing of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-13

    .... 12352 (April 20, 1976), 41 FR 18808 (May 7, 1976). To address regulatory duplication in these and other...), 41 FR 49091 (November 8, 1976). II. Proposed 17d-2 Plan The proposed 17d-2 Plan is intended to reduce... calendar quarter. \\13\\ See Securities Exchange Act Release No. 58350 (August 13, 2008), 73 FR 48247...

  5. 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

  6. Vaccine and Wild-Type Strains of Yellow Fever Virus Engage Distinct Entry Mechanisms and Differentially Stimulate Antiviral Immune Responses

    PubMed Central

    Fernandez-Garcia, Maria Dolores; Meertens, Laurent; Chazal, Maxime; Hafirassou, Mohamed Lamine; Dejarnac, Ophélie; Zamborlini, Alessia; Despres, Philippe; Sauvonnet, Nathalie; Arenzana-Seisdedos, Fernando

    2016-01-01

    ABSTRACT The live attenuated yellow fever virus (YFV) vaccine 17D stands as a “gold standard” for a successful vaccine. 17D was developed empirically by passaging the wild-type Asibi strain in mouse and chicken embryo tissues. Despite its immense success, the molecular determinants for virulence attenuation and immunogenicity of the 17D vaccine are poorly understood. 17D evolved several mutations in its genome, most of which lie within the envelope (E) protein. Given the major role played by the YFV E protein during virus entry, it has been hypothesized that the residues that diverge between the Asibi and 17D E proteins may be key determinants of attenuation. In this study, we define the process of YFV entry into target cells and investigate its implication in the activation of the antiviral cytokine response. We found that Asibi infects host cells exclusively via the classical clathrin-mediated endocytosis, while 17D exploits a clathrin-independent pathway for infectious entry. We demonstrate that the mutations in the 17D E protein acquired during the attenuation process are sufficient to explain the differential entry of Asibi versus 17D. Interestingly, we show that 17D binds to and infects host cells more efficiently than Asibi, which culminates in increased delivery of viral RNA into the cytosol and robust activation of the cytokine-mediated antiviral response. Overall, our study reveals that 17D vaccine and Asibi enter target cells through distinct mechanisms and highlights a link between 17D attenuation, virus entry, and immune activation. PMID:26861019

  7. Topotactic Transformation Route to Monodisperse β-NaYF4:Ln(3+) Microcrystals with Luminescence Properties.

    PubMed

    Shao, Baiqi; Feng, Yang; Song, Yan; Jiao, Mengmeng; Lü, Wei; You, Hongpeng

    2016-02-15

    A novel nonorganic wet route for direct synthesis of uniform hexagonal β-NaYF4:Ln(3+) (Ln = Eu, Tb, Ce/Tb, Yb/Er, and Yb/Tm) microcrystals with various morphologies has been developed wherein the intermediate routine cubic-hexagonal (α → β) phase transfer process was avoided. The morphology can be effectively tuned into hexagonal disc, prism, and novel hierarchical architectures by systematically fine manipulating the Na2CO3/F(-) feeding ratio. It has been found that the routine α → β phase transfer for NaYF4 was not detected during the growth, while NaY(CO3)F2 emerged in the initial reaction stage and fast transformed into β-NaYF4 via a novel topotactic transformation behavior. Detailed structural analysis showed that β-NaYF4 preferred the [001] epitaxial growth direction of NaY(CO3)F2 due to the structural matching of [001]NaY(CO3)F2//[0001]β-NaYF4. Besides, the potential application of the as-prepared products as phosphors is emphasized by demonstrating multicolor emissions including downconversion, upconversion, and energy transfer (Ce-Tb) process by lanthanides doping. PMID:26841071

  8. Polio Vaccination

    MedlinePlus

    ... inactive polio vaccine OPV=oral polio vaccine Polio Vaccination Pronounced [PO-lee-oh] Recommend on Facebook Tweet ... handling and storage Related Pages Global Vaccines and Immunization Global Polio Also Known As & Abbreviations Polio=poliomyelitis ...

  9. 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

  10. Controllable Phase Transformation and Mid-infrared Emission from Er(3+)-Doped Hexagonal-/Cubic-NaYF4 Nanocrystals.

    PubMed

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

    2016-01-01

    The morphology of hexagonal phase NaYF4:Er(3+) 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:Er(3+) nanocrystals for the first time. And the MIR emission of NaYF4:Er(3+) nanocrystals enhanced remarkably at higher calcination temperature. To prevent uncontrollable morphology from phase transformation, the cubic phase NaYF4:Er(3+) 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:Er(3+) nanocrystals have realized when calcined at different temperatures. And PL spectra demonstrated a more intense MIR emission in the cubic phase NaYF4:Er(3+) nanocrystals with an increasing temperature. Besides, the MIR emission peak of Er(3+) ions had an obvious splitting in cubic phase NaYF4. Therefore, cubic phase NaYF4:Er(3+) 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

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

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

    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.

  12. 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.

  13. 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.

  14. 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

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

    PubMed

    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

  16. 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

  17. Mechanism of YF3 nanoparticle formation in reverse micelles.

    PubMed

    Lemyre, Jean-Luc; Lamarre, Sébastien; Beaupré, Ariane; Ritcey, Anna M

    2011-10-01

    This article reports an investigation of the mechanism of YF(3) nanoparticle formation in two variants of the reverse microemulsion precipitation method. These two variants involve the addition of F(-), either as a microemulsion or directly as an aqueous solution, to Y(3+) dispersed in nonionic reverse micelles. The two methods yield amorphous and single-crystal nanoparticles, respectively. The kinetics of reagent mixing are studied by (19)F NMR and colorimetric model reactions, and the particle growth is monitored by TEM. Mixing and nucleation are shown to occur within seconds to minutes whereas particle growth continues for 4 to 48 h, depending on the particle type. Moreover, the growth rate remains constant during most of the growth period, indicating that Ostwald ripening is the most probable growth mechanism. The single-emulsion method also produces a minority amorphous population that exhibits significantly different growth kinetics, attributed to a coagulation mechanism. Secondary growth experiments, involving the addition of precursor ions to mature particles, have been conducted to evaluate the relative importance of nucleation and the competitive growth of existing particle populations. The key differences between the two methods reside in the nucleation step. In the case of the classical method, nucleation occurs upon intermicellar collisions and under conditions of comparable concentrations of Y(3+) and F(-). This method generates more numerous stable nuclei and smaller particles. In the single-microemulsion method, nucleation occurs in the presence of excess F(-) through the interaction of Y(3+)-containing micelles with microdroplets of aqueous F(-). These conditions lead to the formation of crystalline particles and a wider size distribution of unstable nuclei. PMID:21842856

  18. Diode pumped Pr3+:LiYF4-BBO ultraviolet laser at 320 nm

    NASA Astrophysics Data System (ADS)

    Li, J. H.; Liu, X. H.; Wu, J. B.; Zhang, X.; Li, Y. L.

    2012-03-01

    A diode pumped Pr3+:LiYF4 laser at 639.5 nm has been demonstrated. With an incident pump power of 920 mW, the maximum red output power was 272 mW. Moreover, intracavity second-harmonic generation (SHG) has also been achieved with a maximum ultraviolet power of 23 mW by using a β-BaB2O4 (BBO) nonlinear crystal. To the best of our knowledge, this is the first report on continuous-wave ultraviolet generation by intracavity frequency doubling Pr3+:LiYF4 laser.

  19. 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.

  20. Synthesis, Structural Characterization, and Emission Properties of NaYF4:Er3+/Yb3+ Upconversion Nanoluminophores

    NASA Astrophysics Data System (ADS)

    Giang, Lam Thi Kieu; Marciniak, Lukasz; Hreniak, Dariusz; Anh, Tran Kim; Minh, Le Quoc

    2016-06-01

    We propose a new method to prepare Er3+/Yb3+-codoped β-NaYF4 upconversion nanoluminophores, allowing creation of single-crystalline-phase β-NaYF4: Er3+/Yb3+ with concentrations up to 20 mol.% through a hydrothermal process. Using hexagonal-phase Y(OH)3 precursors with different nanostructures (nanosheets, nanorods, nanotubes, etc.), one can obtain many types of one-dimensional nano-NaYF4:Er3+/Yb3+ materials and significantly improve the multiphase phenomenon, which is a common challenge facing many research groups that use a hydrothermal process for synthesis of NaYF4 compounds. Upon near-infrared laser excitation at 976 nm, the obtained β-NaYF4:Er3+/Yb3+ nanorods emit in green (2H11/2, 4S3/2 → 4I15/2) and red (4F9/2 → 4I15/2) spectral regions with high intensity. Moreover, it is shown that one can change the luminescence integrated intensity ratio between the red and green emissions by varying the concentration and components of Er3+ and Yb3+ in the NaYF4 host material. Comparative studies on the luminescence kinetics of the NaYF4:Er3+/Yb3+ nanoluminophores were also conducted to explain the influence of Yb3+ ion on the upconversion processes.

  1. Characterization of competing distortions in YF e2O4

    NASA Astrophysics Data System (ADS)

    Blasco, J.; Lafuerza, S.; García, J.; Subías, G.; Cuartero, V.; García-Muñoz, J. L.; Popescu, C.; Peral, I.

    2016-05-01

    We report the structural changes of three YF e2O4 -δ (δ <0.1 ) specimens using high resolution synchrotron x-ray powder diffraction between 80 and 300 K. All samples adopt a rhombohedral cell at room temperature (space group R 3 ¯m ). This cell becomes unstable for the three samples on cooling, and the oxygen-poor specimen (δ ˜0.1 ) shows a single transition at 240 K. The nearly stoichiometric (δ ≤0.03 ) compounds exhibit two structural transitions with decreasing temperature at about 240 and 200 K. Each transition is revealed by an anomaly in the heat capacity measurements and a jump in the electric resistivity. Below 240 K, a strong splitting of some diffraction peaks is accompanied by the occurrence of superstructure peaks that follow the propagation vector k =(1 /7 ,-2 /7 ,9 /7 ) . The cell symmetry is then triclinic, and the structural transition is characterized by an expansion of the c axis coupled to a contraction of the other two lattice parameters. There are 49 nonequivalent sites for Fe atoms with a maximum charge disproportionation of ˜0.5 e- . Upon cooling at 200 K, the previous superstructure peaks begin to vanish, and finally they are replaced by a new set of superstructure peaks following the propagation vector k =(1 /4 ,1 /2 ,1 /4 ) with respect to the rhombohedral cell. The transition is also reflected in sudden changes in the lattice parameters that seem to smooth the changes observed in the previous transition. The new cell is also triclinic, and there are 48 nonequivalent Fe sites with a maximum charge disproportionation of ˜0.7 e- . Both phases coexist in a wide temperature range because this second transition is not completed at 80 K. A symmetry mode analysis indicates a complicated pattern for the charge distribution in the Fe sublattice of both distorted structures but clearly discard any bimodal distribution of only two types of Fe cations. Therefore, the sharp jumps in the electric resistivity at the phase transitions are

  2. Ultrasonic assisted synthesis, characterization and influence factors of monodispersed dumbbell-like YF(3) nanostructures.

    PubMed

    Ni, Yonghong; Li, Guoyan; Hong, Jianming

    2010-03-01

    In the present paper, we reported the successful synthesis of dumbbell-like YF(3) nanostructures with a high yield in a mixed system of water/N,N-dimethylformamide (DMF) under the assistance of ultrasound waves of 40kHz with the ultrasonic power of 100% (200W) at 65 degrees C for 2h, employing Y(2)O(3) (99.99%) and NH(4)F as the starting reactants. The product was characterized by means of powder X-ray diffraction (XRD), energy dispersive spectrometry (EDS), transmission electron microscopy (TEM), selected area electron diffraction (SAED) pattern and field-emission scanning electron microscopy (SEM). Some factors influencing the morphology of YF(3) nanostructures, including the ultrasonic time and power, the amount of NH(4)F, and the ratio of water/DMF, were systematically investigated. Research showed that the morphology of YF(3) could be tuned by the volume ratio of water/DMF. The roles of DMF and the ultrasonic wave in the formation of YF(3) nanostructures were discussed. PMID:19751989

  3. 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.

  4. Vaccine Safety

    MedlinePlus

    ... During Pregnancy Frequently Asked Questions about Vaccine Recalls Historical Vaccine Safety Concerns FAQs about GBS and Menactra ... CISA Resources for Healthcare Professionals Evaluation Current Studies Historical Background 2001-12 Publications Technical Reports Vaccine Safety ...

  5. Smallpox Vaccination

    MedlinePlus

    ... Newsletters Events Also Known As Smallpox = Vaccinia Smallpox Vaccination Recommend on Facebook Tweet Share Compartir The smallpox ... like many other vaccines. For that reason, the vaccination site must be cared for carefully to prevent ...

  6. HPV vaccine

    MedlinePlus

    Vaccine - HPV; Immunization - HPV; Gardasil; Cervarix; HPV2; HPV4; Vaccine to prevent cervical cancer ... and Gynecologists. Committee Opinion No. 588: Human Papillomavirus Vaccination. Obstet Gynecol . 2014;123(3):712-8. PMID: ...

  7. Dengue vaccines: Are they safe for travelers?

    PubMed

    Halstead, Scott B; Aguiar, Maira

    2016-01-01

    The four dengue viruses (DENV) circulate among nearly one-half of the world's population in tropical and semitropical countries imposing a huge morbidity burden on travelers. Sanofipasteur has developed a tetravalent live-attenuated vaccine, Dengvaxia, recently approved by the World Health Organization and licensed in four dengue-endemic countries. An additional two dengue vaccines, developed by the National Institute of Allergy and Infectious Diseases (NIAID), USA and Takeda, are entering phase III testing. Dengvaxia is composed of four yellow fever 17D-DENV chimeras, the NIAID vaccine contains three mutagenized DENV and one DENV2/4 chimera while the Takeda vaccine contains an attenuated DENV 2 and three DENV 2-DENV chimeras. Which of these vaccines might be useful in protecting travelers against dengue infections and disease? Dengvaxia requires three doses administered over the course of one year but in addition has safety signals suggesting that susceptible individuals should not be vaccinated. The NIAID vaccine is promising as a travel vaccine as a single dose fully protected susceptible adults against live dengue 2 virus challenge. The protective efficacy and safety of the Takeda vaccine remain to be demonstrated. PMID:27343438

  8. Footrot vaccines and vaccination.

    PubMed

    Dhungyel, Om; Hunter, James; Whittington, Richard

    2014-05-30

    Research on footrot in small ruminants, which is caused by Dichelobacter nodosus, has led to development of vaccines and their application for control, treatment and eradication of the disease in sheep. Footrot vaccines have evolved over decades to contain monovalent whole cell, multivalent recombinant fimbrial, and finally mono or bivalent recombinant fimbrial antigens. Initially whole cell vaccines made against the few known serogroups of D. nodosus were found to be inefficient in control of the disease in the field, which was attributed to the presence of other unidentified serogroups and also the use of inefficient adjuvants. Fimbriae or pili, which are the basis for antigenic variation, were found to be the major protective and also curative antigens but they are not cross protective between the different serogroups. Multivalent vaccines incorporating all the known serogroups have been proven to be of limited efficacy due to the phenomenon of antigenic competition. Recent studies in Nepal, Bhutan and Australia have shown that outbreak-specific vaccination which involves targeting identified serogroups with mono- or bivalent recombinant fimbrial vaccines, can be very effective in sheep and goats. Where multiple serogroups are present in a flock, antigenic competition can be overcome by sequentially targeting the serogroups with different bivalent vaccines every 3 months. A common antigen which would confer immunity to all serogroups would be the ideal immunogen but the initial studies were not successful in this area. Until universal antigen/s are available, flock specific mono or bivalent fimbrial vaccines are likely to be the most effective tool for control and eradication of footrot in sheep and goats. Future research in footrot vaccines should be focused on improving the duration of prophylaxis by incorporating new and emerging immunomodulators or adjuvants with modified delivery vehicles, discovering a common antigen and understanding the mechanisms of

  9. [Vaccination perspectives].

    PubMed

    Saliou, P; Plotkin, S

    1994-01-01

    The aim of vaccinology is to improve the available vaccines and to develop new ones in the light of progress in immunology, molecular biology and biotechnologies. But it must go beyond this, and aim to protect all populations and control diseases, even eradicate them where possible. New vaccine strategies must be developed taking into account the epidemiology of diseases and the inherent logistic problems of implementing these strategies under local conditions. There are three major thrusts to the progress of the discipline. The improvement of the vaccines available. One of the drives of vaccinology is not only to deliver vaccines of increasing safety (replacement of the current vaccine for whooping cough with an acellular vaccine for example), but also to improve vaccine efficacy and immunogenicity (in particular for flu, tuberculosis, cholera and rabies vaccines). The optimisation of vaccination programmes and strategies for vaccinations. The ideal is to protect against the greatest possible number of diseases with the smallest number of vaccinations. The development of combinations of vaccines is central to this goal. The objective for the year 2000 is a hexavalent vaccine DTPP Hib HB. The development of new vaccines. Classic techniques continue to be successfully used (inactivated hepatitis A vaccine; attenuated live vaccines for chicken pox and dengue fever; conjugated polyosidic bacterial vaccines for meningococci and Streptococcus pneumoniae). However, it will become possible to prepare vaccines against most transmissible diseases using genetic engineering techniques.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7921696

  10. 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. PMID:26541249

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

    SciTech Connect

    Oezen, G.

    1991-07-01

    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.

  12. 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.

  13. 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.

  14. 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

    ... No. 12352 (April 20, 1976), 41 FR 18808 (May 7, 1976). To address regulatory duplication in these and... 28, 1976), 41 FR 49091 (November 8, 1976). II. Proposed Plan The proposed 17d-2 Plan is intended to..., 2008), 73 FR 48247 (August 18, 2008) (File No. 4-566) (notice of filing of proposed plan). See...

  15. 75 FR 9976 - Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Notice of Filing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-04

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Notice of Filing and Order Approving and Declaring Effective an Amendment to the Plan for the Allocation of Regulatory Responsibilities Among the BATS Exchange,...

  16. 78 FR 46644 - Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Notice of Filing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-01

    ..., Financial Industry Regulatory Authority, Inc., NYSE Arca, Inc., The NASDAQ Stock Market LLC, NASDAQ OMX BX... to Rule 17d- 2 of the Act,\\2\\ by Financial Industry Regulatory Authority, Inc. (``FINRA'') and Topaz... Securities Exchange Act Release No. 12352 (April 20, 1976), 41 FR 18808 (May 7, 1976). To address...

  17. 75 FR 76758 - Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Order Approving and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-09

    ... CBOE. \\2\\ See Securities Exchange Act Release No. 63230 (November 2, 2010), 75 FR 68632. I... 240.17d-2, respectively. \\8\\ See Securities Exchange Act Release No. 12352 (April 20, 1976), 41 FR.... \\9\\ See Securities Exchange Act Release No. 12935 (October 28, 1976), 41 FR 49091 (November 8,...

  18. 75 FR 68632 - Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Notice of Filing of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-08

    ... No. 12352 (April 20, 1976), 41 FR 18808 (May 7, 1976). To address regulatory duplication in these and... 28, 1976), 41 FR 49091 (November 8, 1976). II. Proposed Plan The proposed 17d-2 Plan is intended to... (August 13, 2008), 73 FR 48247 (August 18, 2008) (File No. 4-566) (notice of filing of proposed plan)....

  19. 17 CFR 270.17d-3 - Exemption relating to certain joint enterprises or arrangements concerning payment for...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... CFR 270.17d-1), to the extent necessary to permit any such person or principal underwriter to enter... joint enterprises or arrangements concerning payment for distribution of shares of a registered open-end... relating to certain joint enterprises or arrangements concerning payment for distribution of shares of...

  20. 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

    ... CFR 270.17d-1), to the extent necessary to permit any such person or principal underwriter to enter... joint enterprises or arrangements concerning payment for distribution of shares of a registered open-end... relating to certain joint enterprises or arrangements concerning payment for distribution of shares of...

  1. 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

    ... CFR 270.17d-1), to the extent necessary to permit any such person or principal underwriter to enter... joint enterprises or arrangements concerning payment for distribution of shares of a registered open-end... relating to certain joint enterprises or arrangements concerning payment for distribution of shares of...

  2. 17 CFR 270.17d-3 - Exemption relating to certain joint enterprises or arrangements concerning payment for...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... CFR 270.17d-1), to the extent necessary to permit any such person or principal underwriter to enter... joint enterprises or arrangements concerning payment for distribution of shares of a registered open-end... relating to certain joint enterprises or arrangements concerning payment for distribution of shares of...

  3. 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

    ... Securities Exchange Act Release No. 61860 (April 7, 2010), 75 FR 18915. I. Introduction Section 19(g)(1) of... Exchange Act Release No. 12352 (April 20, 1976), 41 FR 18808 (May 7, 1976). To address regulatory.... 12935 (October 28, 1976), 41 FR 49091 (November 8, 1976). II. Proposed Plan The proposed 17d-2 Plan...

  4. 75 FR 64765 - Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Order Approving and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-20

    ... 240.17d-2. \\3\\ See Securities Exchange Act Release No. 62935 (September 17, 2010), 75 FR 57998. I... Exchange Act Release No. 12352 (April 20, 1976), 41 FR 18808 (May 7, 1976). To address regulatory... Release No. 12935 (October 28, 1976), 41 FR 49091 (November 8, 1976). II. Proposed Plan The proposed...

  5. 75 FR 28080 - Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Order Approving and...

    Federal Register 2010, 2011, 2012, 2013, 2014

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    ... Securities Exchange Act Release No. 61861 (April 7, 2010), 75 FR 18920. I. Introduction Section 19(g)(1) of... Exchange Act Release No. 12352 (April 20, 1976), 41 FR 18808 (May 7, 1976). To address regulatory.... 12935 (October 28, 1976), 41 FR 49091 (November 8, 1976). II. Proposed Plan The proposed 17d-2 Plan...

  6. 75 FR 18925 - Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Notice of Filing of...

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    ... Securities Exchange Act Release No. 12352 (April 20, 1976), 41 FR 18808 (May 7, 1976). To address regulatory... 28, 1976), 41 FR 49091 (November 8, 1976) (``Rule 17d-2 Adopting Release''). ] II. Proposed Plan On... Securities Exchange Act Release No. 60598 (September 1, 2009), 74 FR 46280 (September 8, 2009)....

  7. 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

  8. The synthesis and mechanism exploration of europium-doped LiYF4 micro-octahedron phosphors with multilevel interiors.

    PubMed

    Zhang, Xiangyu; Wang, Minqiang; Ding, Jijun; Deng, Jianping; Ran, Chenxin; Yang, Zhi

    2014-04-14

    Multi-layered hollow LiYF4:Eu(3+) micro-octahedrons, with about 400 nm of single-layer thickness and 300 nm of interlayer space, have been synthesized via a facile hydrothermal route in the presence of surfactant ethylenediamine tetraacetic acid (EDTA). The mechanisms of the morphology evolution of the LiYF4:Eu micro-octahedrons are investigated in detail. Time-dependent experiments indicate that the growth of the micro-octahedrons undergoes four different stages including the aggregation growth of the primary YF3 particle, the transformation of the substance from the orthorhombic-phase YF3 to the tetragonal-phase LiYF4 by the Kirkendall effect with the inward diffusion of quasi-steady state LiF species, adsorption and in situ crystallization, and local Ostwald ripening. The Ostwald ripening process is terminated by the organic adsorption of interlaminar leading to a hollow structure with multilevel interiors. The LiYF4:Eu micro-octahedrons are annealed under the designed temperatures, which leads to the collapse of octahedral structures indicating the role of EDTA on building the octahedron. The spectral measurements show that the calcination approach has a stronger effect on the luminescence tuning of the LiYF4:Eu micro-octahedrons due to the modification of the crystal phase, structure and size. The present study is of great importance in the preparation of rare-earth ion doped LiYF4 hollow materials as well as in applications as building blocks for functional devices. PMID:24522524

  9. 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

    2012-02-01

    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

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

    PubMed Central

    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. PMID:25597900

  11. 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

  12. Results of NASTRAN modal analyses and ground vibration tests on the YF-12A airplane

    NASA Technical Reports Server (NTRS)

    Kordes, E. E.; Curtis, A. R.

    1975-01-01

    The YF-12A aircraft, a delta-winged vehicle powered by two jet engines, was utilized in an investigation of the structural dynamic characteristics of a large, flexible, supersonic research vehicle. A large NASA structural analysis (NASTRAN) finite-element model was used to compute the ten lowest frequency symmetric and ten lowest frequency antisymmetric modes for the YF-12A aircraft. The results of the analysis were compared with experimental data obtained in a ground vibration test conducted with the completed aircraft. It was found that the finite-element structural model employed provides an adequate prediction of the dynamic behavior of the aircraft structure in the case of basic wing and body modes.

  13. 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. PMID:25543131

  14. A review of supersonic cruise flight path control experience with the YF-12 aircraft

    NASA Technical Reports Server (NTRS)

    Berry, D. T.; Gilyard, G. B.

    1976-01-01

    Flight research with the YF-12 aircraft indicates that solutions to many handling qualities problems of supersonic cruise are at hand. Airframe/propulsion system interactions in the Dutch roll mode can be alleviated by the use of passive filters or additional feedback loops in the propulsion and flight control systems. Mach and altitude excursions due to atmospheric temperature fluctuations can be minimized by the use of a cruise autothrottle. Autopilot instabilities in the altitude hold mode have been traced to angle of attack-sensitive static ports on the compensated nose boom. For the YF-12, the feedback of high-passed pitch rate to the autopilot resolves this problem. Manual flight path control is significantly improved by the use of an inertial rate of climb display in the cockpit.

  15. 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.

  16. 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

  17. Yellow fever vector live-virus vaccines: West Nile virus vaccine development.

    PubMed

    Arroyo, J; Miller, C A; Catalan, J; Monath, T P

    2001-08-01

    By combining molecular-biological techniques with our increased understanding of the effect of gene sequence modification on viral function, yellow fever 17D, a positive-strand RNA virus vaccine, has been manipulated to induce a protective immune response against viruses of the same family (e.g. Japanese encephalitis and dengue viruses). Triggered by the emergence of West Nile virus infections in the New World afflicting humans, horses and birds, the success of this recombinant technology has prompted the rapid development of a live-virus attenuated candidate vaccine against West Nile virus. PMID:11516995

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

    NASA Astrophysics Data System (ADS)

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

    1981-09-01

    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. 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.

  20. 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.

  1. 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.

  2. Magnetic reversal in Dy-doped DyF e2/YF e2 superlattice films

    NASA Astrophysics Data System (ADS)

    Stenning, G. B. G.; Bowden, G. J.; de Groot, P. A. J.; van der Laan, G.; Figueroa, A. I.; Bencok, P.; Steadman, P.; Hesjedal, T.

    2015-03-01

    Reversible magnetic exchange springs can be formed in the magnetically soft YF e2 layers of epitaxial DyF e2/YF e2 multilayer films. Here we show that the insertion of just two monolayers of DyF e2 , placed directly in the middle of the YF e2 layers, brings about substantial changes. Results are presented for a Dy-doped (110)-oriented [DyFe2(60Å) /YFe2(120 Å ) /DyFe2(8 Å ) /YFe2(120 Å ) ] 15 multilayer film, measured at 100 K in fields of up to ±10 T. Using bulk magnetometry, micromagnetic modeling, and Dy-specific x-ray magnetic circular dichroism, it is shown that Dy doping substantially increases the number of spin states available to the system. Altogether 12 distinct spring states are identified which bring additional complexity to the magnetic reversal process. In particular, the exchange springs are no longer reversible, exhibiting magnetic exchange-spring collapse. Full and partial magnetic loops are presented for fields applied along the in-plane easy [001] axis and the in-plane hard [1 ¯10 ] axis. In particular, it is demonstrated that exchange-spring collapse is sharpest when the field is applied along a hard in-plane [1 ¯10 ] axis.

  3. 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).

  4. 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.

  5. Size-dependent cytotoxicity of europium doped NaYF ₄ nanoparticles in endothelial cells.

    PubMed

    Chen, Shizhu; Zhang, Cuimiao; Jia, Guang; Duan, Jianlei; Wang, Shuxiang; Zhang, Jinchao

    2014-10-01

    Lanthanide-doped sodium yttrium fluoride (NaYF4) nanoparticles exhibit novel optical properties which make them be widely used in various fields. The extensive applications increase the chance of human exposure to these nanoparticles and thus raise deep concerns regarding their riskiness. In the present study, we have synthesized europium doped NaYF4 (NaYF4:Eu(3+)) nanoparticles with three diameters and used endothelial cells (ECs) as a cell model to explore the potential toxic effect. The cell viability, cytomembrane integrity, cellular uptake, intracellular localization, intracellular reactive oxygen species (ROS), mitochondrial membrane potential (MMP), apoptosis detection, caspase-3 activity and expression of inflammatory gene were studied. The results indicated that these nanoparticles could be uptaken into ECs and decrease the cell viability, induce the intracellular lactate dehydrogenase (LDH) release, increase the ROS level, and decrease the cell MMP in a size-dependent manner. Besides that, the cells were suffered to apoptosis with the caspase-3 activation, and the inflammation specific gene expressions (ICAM1 and VCAM1) were also increased. Our results suggest that the damage pathway may be related to the ROS generation and mitochondrial damage. The results provide novel evidence to elucidate their toxicity mechanisms and may be helpful for more rational applications of these compounds in the future. PMID:25175221

  6. Fabrication and upconversion luminescence properties of YF3:Er3+ hollow nanofibers via monoaxial electrospinning combined with fluorination method.

    PubMed

    Li, Dan; Dong, Xiangting; Yu, Wensheng; Wang, Jinxian; Liu, Guixia

    2014-06-01

    YF3:Er3+ hollow nanofibers were successfully fabricated via fluorination of the relevant Y2O3:Er3+ hollow nanofibers which were obtained by calcining the electrospun PVP/[Y(NO3)3 + Er(NO3)3] composite nanofibers. The morphology and properties of the products were investigated in detail by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and fluorescence spectrometer. YF3:Er3+ hollow nanofibers were pure orthorhombic phase with space group Pnma and were hollow-centered structure with the mean diameter of 172 +/- 23 nm, and YF3:Er3+ hollow nanofibers were composed of nanoparticles with the diameter ranging from 30 nm to 50 nm. Upconversion emission spectrum analysis manifested that YF3:Er3+ hollow nanofibers emitted strong green and weak red upconversion emission centering at 524 nm, 543 nm and 653 nm, respectively. The green emissions and the red emission were respectively originated from 2H11/2/4S3/2 --> 4I15/2 and 4F9/2 --> 4I15/2 energy levels transitions of the Er3+ ions. Moreover, the emitting colors of YF3:Er3+ hollow nanofibers were located in the green region in CIE chromaticity coordinates diagram. The luminescent intensity of YF3:Er3+ hollow nanofibers was increased remarkably with the increasing doping concentration of Er3+ ions. The possible formation mechanism of YF3:Er3+ upconversion luminescence hollow nanofibers was also discussed. This preparation technique could be applied to prepare other rare earth fluoride upconversion luminescence hollow nanofibers. PMID:24738372

  7. HPV vaccine

    MedlinePlus

    Vaccine - HPV; Immunization - HPV; Gardasil; Cervarix; HPV2; HPV4; Vaccine to prevent cervical cancer ... HPV is a common virus that is spread through sexual contact. There are several types of HPV. ...

  8. Diphtheria Vaccination

    MedlinePlus

    ... and adults - Tetanus-diphtheria-acellular Pertussis vaccine Diphtheria Vaccination Pronounced (dif-THEER-ee-a) Recommend on Facebook ... Related Pages Pertussis Tetanus Feature Story: Adults Need Immunizations, Too Abbreviations DTaP=Pediatric - Diphtheria-Tetanus-acellular Pertussis ...

  9. Genome shuffling of Lactococcus lactis subspecies lactis YF11 for improving nisin Z production and comparative analysis.

    PubMed

    Zhang, Y F; Liu, S Y; Du, Y H; Feng, W J; Liu, J H; Qiao, J J

    2014-05-01

    Nisin has been widely used in the food industry as a safe and natural preservative to increase the shelf time of many foods. In this study, genome shuffling was applied to improve nisin Z production of Lactococcus lactis ssp. lactis YF11 (YF11) via recursive protoplast fusion. Ultraviolet irradiation and diethyl sulfate mutagenesis were used to generate parental strains for genome shuffling. After 4 rounds of genome shuffling, the best-performing strain F44 was obtained, which showed dramatic improvements in tolerance to both glucose (ranging from 8 to 15% (wt/vol) and nisin (ranging from 5,000 to 14,000 IU/mL). Fed-batch fermentation showed that the nisin titer of F44 was up to 4,023 IU/mL, which was 2.4 times that of the starting strain YF11. Field emission scanning electron microscope micrographs of YF11 and F44 revealed the apparent differences in cell morphology. Whereas YF11 displayed long and thin cell morphology, F44 cells were short and thick and with a raised surface in the middle of the cell. With the increasing glucose and nisin content in the medium, cells of both YF11 and F44 tended to become shrunken; however, alterations in YF11 cells were more pronounced than those of F44 cells, especially when cultured in tolerance medium containing both nisin and glucose. Nuclear magnetic resonance analysis demonstrated that the structure of nisin from YF11 and F44 was the same. Expression profiling of nisin synthesis related genes by real-time quantitative PCR showed that the transcription level of nisin structural gene nisZ and immunity gene nisI of F44 was 48 and 130% higher than that of the starting strain YF11, respectively. These results could provide valuable insights into the molecular basis underlying the nisin overproduction mechanism in L. lactis, thus facilitating the future construction of industrial strains for nisin production. PMID:24612797

  10. Giardia vaccination.

    PubMed

    Olson, M E; Ceri, H; Morck, D W

    2000-05-01

    Recently, a Giardia vaccine has become commercially available in the USA for prevention of clinical signs of giardiasis and reduction of cyst shedding in dogs and cats. The vaccine is based upon the current state of knowledge of Giardia antigenicity and immunology. Here, Merle Olson, Howard Ceri and Douglas Morck describe studies that led to the development of this vaccine and subsequent efficacy studies. Immunoprophylaxis and immunotherapeutic application of the vaccine are discussed. PMID:10782082

  11. The Human NK Cell Response to Yellow Fever Virus 17D Is Primarily Governed by NK Cell Differentiation Independently of NK Cell Education.

    PubMed

    Marquardt, Nicole; Ivarsson, Martin A; Blom, Kim; Gonzalez, Veronica D; Braun, Monika; Falconer, Karolin; Gustafsson, Rasmus; Fogdell-Hahn, Anna; Sandberg, Johan K; Michaëlsson, Jakob

    2015-10-01

    NK cells play an important role in the defense against viral infections. However, little is known about the regulation of NK cell responses during the first days of acute viral infections in humans. In this study, we used the live attenuated yellow fever virus (YFV) vaccine 17D as a human in vivo model to study the temporal dynamics and regulation of NK cell responses in an acute viral infection. YFV induced a robust NK cell response in vivo, with an early activation and peak in NK cell function at day 6, followed by a delayed peak in Ki67 expression, which was indicative of proliferation, at day 10. The in vivo NK cell response correlated positively with plasma type I/III IFN levels at day 6, as well as with the viral load. YFV induced an increased functional responsiveness to IL-12 and IL-18, as well as to K562 cells, indicating that the NK cells were primed in vivo. The NK cell responses were associated primarily with the stage of differentiation, because the magnitude of induced Ki67 and CD69 expression was distinctly higher in CD57(-) NK cells. In contrast, NK cells expressing self- and nonself-HLA class I-binding inhibitory killer cell Ig-like receptors contributed, to a similar degree, to the response. Taken together, our results indicate that NK cells are primed by type I/III IFN in vivo early after YFV infection and that their response is governed primarily by the differentiation stage, independently of killer cell Ig-like receptor/HLA class I-mediated inhibition or education. PMID:26283480

  12. Who Needs Chickenpox Vaccine

    MedlinePlus

    ... Not Get Chickenpox Vaccine Types of Chickenpox Vaccine Child and Adult Immunization Schedules Possible Side Effects of Chickenpox Vaccine Childcare and School Vaccine Requirements Also Known As & Abbreviations ...

  13. 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. PMID:20172531

  14. 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.

  15. Theoretical investigations of the optical and EPR spectra for trivalent cerium and ytterbium ions in orthorhombic YF3 crystal

    NASA Astrophysics Data System (ADS)

    Liu, Hong-Gang; Zheng, Wen-Chen

    2016-09-01

    The optical spectra and electron paramagnetic resonance (EPR) parameters (g factors and hyperfine structure constants A) for trivalent cerium and ytterbium ions in YF3 crystal with orthorhombic structure are investigated together by the complete diagonalization (of energy matrix) method (CDM). The obtained results are in reasonable agreement with the experimental ones. More importantly, two magnetically nonequivalent centers in YF3 crystal observed in EPR experiments are confirmed and ascribed to their specific positions in a unit cell by our calculations based on superposition model (SPM) analysis. Such identification of local sites with different magnetic properties would help us to understand not only the EPR spectra and magnetic susceptibility of other lanthanide ions doped in crystals with the same structure as YF3 but also the energy transfer scheme between two lanthanide ions occupying such two sites. All results are discussed carefully.

  16. Pr3+/Yb3+ co-doped beta-phase NaYF4 microprisms: controlled synthesis and upconversion luminescence.

    PubMed

    Gao, Wei; Zheng, Hairong; Gao, Dangli; He, Enjie; Li, Jiao; Tu, Yinxun

    2014-06-01

    Pr3+/Yb3+ co-doped hexagonal NaYF4(beta-NaYF4) microprisms were synthesized by the hydrothermal method, and ethylenediaminetetraacetic acid (EDTA) was introduced to control the size of the microcrystal samples. Bright upconverted fluorescence emission was observed when the samples were excited with an infrared (IR) laser at 976.4 nm. The emission was found to originate from the transitions of 3P0-3F2, 3P0-3H6 or 1G4-3H4, 3P1-3H6, 3P0-3H5, 3P1-3H5, and 3P0-3H4 of Pr3+ ions. Possible mechanisms for upconversion fluorescence and concentration dependence as well as the crystal structure and its formation of NaYF4:Yb3+/Pr3+ microprisms were explored and discussed based on the experimental observations. PMID:24738388

  17. 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

    2013-12-01

    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.

  18. Synthesis and photolysis of NaYF4@SiO2@TiO2 core-shell nanocomposites

    NASA Astrophysics Data System (ADS)

    Shi, Guoyou; Mao, Yifu; Ren, Guozhong; Gong, Lunjun; Zhi, Zhugong

    2014-12-01

    Monodisperse β-NaYF4 nanocrystals were synthesized with oleic acid as capping ligands by solvothermal method, and then, SiO2 and TiO2 were coated successively. Intense ultraviolet light is emitted from NaYF4:Yb/Tm under the 980 nm laser and the intensity of ultraviolet light reduce dramatically after these nanocrystals were coated with SiO2 and TiO2 shells, which means NaYF4@SiO2@TiO2 core-shell nanocomposites can be used to realize the infared photocatalysis. Photocatalytic activity of these nanocomposites is demonstrated using methyl orange (MO) as a chemical probe under the 980 nm laser excitation.

  19. A force field for 3,3,3-fluoro-1-propenes, including HFO-1234yf.

    PubMed

    Raabe, Gabriele; Maginn, Edward J

    2010-08-12

    The European Union (EU) legislation 2006/40/EC bans from January 2011 the cooperative marketing of new car types that use refrigerants in their heating, ventilation, and air conditioning (HVAC) systems with global warming potentials (GWP) higher than 150. Thus, the phase-out of the presently used tetrafluoroethane refrigerant R134a necessitates the adoption of alternative refrigerants. Fluoropropenes such as 2,3,3,3-tetrafluoro-1-propene (HFO-1234yf) are currently regarded as promising low GWP refrigerants, but the lack of experimental data on their thermophysical properties hampers independent studies on their performance in HVAC systems or in other technical applications. In principle, molecular modeling can be used to predict the relevant properties of refrigerants, but adequate intermolecular potential functions ("force fields") are lacking for fluoropropenes. Thus, we developed a transferable force field for fluoropropenes composed of CF(3)-, -CF=, -CH=, CF(2)=, and CH(2)= groups and applied the force field to study 3,3,3 trifluoro-1-propene (HFO-1243zf), 2,3,3,3-tetrafluoro-1-propene (HFO-1234yf), and hexafluoro-1-propene (HFO-1216). We performed Gibbs ensemble simulations on these three fluoropropenes to compute the vapor pressure, saturated densities, and heats of vaporization. In addition, molecular dynamics simulations were conducted to provide predictions for the density, thermal expansivity, isobaric heat capacity, and transport properties of liquid HFO-1234yf in the temperature range from 263.15 to 310 K and pressures up to 2 MPa. Agreement between simulation results and experimental data and/or correlations (when available) was good, thereby validating the predictive ability of the force field. PMID:20684636

  20. 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

    2012-09-01

    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. PMID:22863660

  1. Measured and predicted noise of the Avco-Lycoming YF-102 turbofan noise

    NASA Technical Reports Server (NTRS)

    Clark, B. J.; Mcardle, J. G.; Homyak, L.

    1979-01-01

    Acoustic testing of the AVCO-Lycoming YF-102 turbofan engine was done on a static test stand in support of the quiet short-haul research aircraft acoustic design. Overall noise levels were dominated by the fan noise emanating from the exhaust duct, except at high power settings when combination tones were generated in the fan inlet. Component noise levels, calculated by noise prediction methods were in reasonable agreement with the measured results. Far-field microphones placed at ground level were found superior to those at engine centerline height, even at high frequencies.

  2. Measured and predicted noise of the AVCO-Lycoming YF-102 turbofan engine

    NASA Technical Reports Server (NTRS)

    Clark, B. J.; Mcardle, J. G.; Homyak, L.

    1979-01-01

    Acoustic testing of the AVCO-Lycoming YF-102 turbofan engine was done on a static test stand at Lewis Research Center in support of the Quiet Short-Haul Research Aircraft (QSRA) acoustic design. Overall noise levels are dominated by the fan noise emanating from the exhaust duct, except at high power settings when combination tones are generated in the fan inlet. Component noise levels, calculated by noise prediction methods developed at Lewis Research Center for the ANOP program, are in reasonable agreement with the measured results. Far-field microphones placed at ground level were found superior to those at engine centerline height, even at high frequencies.

  3. New technique for the direct measurement of core noise from aircraft engines. [YF 102 turbofan engine

    NASA Technical Reports Server (NTRS)

    Krejsa, E. A.

    1981-01-01

    The core noise levels from gas turbine aircraft engines were measured using a technique which requires that fluctuating pressures be measured in the far field and at two locations within the engine core. The cross spectra of these measurements are used to determine the levels of the far-field noise that propagated from the engine vore. The technique makes it possible to measure core noise levels even when other noise sources dominate. The technique was applied to signals measured from an Avco Lycoming YF102 turbofan engine. Core noise levels as a function of frequency and radiation angle were measured and are presented over a range of power settings.

  4. Absolute quantum yield measurements of colloidal NaYF4: Er3+, Yb3+ upconverting nanoparticles.

    PubMed

    Boyer, John-Christopher; van Veggel, Frank C J M

    2010-08-01

    In this communication we describe a technique for measuring the absolute quantum yields (QYs) of upconverting nanomaterials based on the use of a commercially available fluorimeter and an integrating sphere. Using this setup, we have successfully acquired luminescence efficiency data (pump laser, absorbed pump, and visible emitted intensities) for lanthanide-doped upconverting nanoparticles. QYs in the range of 0.005% to 0.3% were measured for several NaYF(4): 2% Er(3+), 20% Yb(3+) nanoparticles with particle sizes ranging from 10 to 100 nm while a QY of 3% was measured for a bulk sample. PMID:20820726

  5. 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.

  6. 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

  7. Hepatitis Vaccines.

    PubMed

    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

  8. Dengue vaccine

    PubMed Central

    Jindal, Harashish; Bhatt, Bhumika; Malik, Jagbir Singh; SK, Shashikantha

    2014-01-01

    Dengue has emerged as one of the major global public health problems. The disease has broken out of its shell and has spread due to increased international travel and climatic changes. Globally, over 2.5 billion people accounting for >40% of the world's population are at risk from dengue. Since the 1940s, dengue vaccines have been under investigation. A live-attenuated tetravalent vaccine based on chimeric yellow fever-dengue virus (CYD-TDV) has progressed to phase III efficacy studies. Dengue vaccine has been found to be a cost-effective intervention to reduce morbidity and mortality. Current dengue vaccine candidates aim to protect against the 4 dengue serotypes, but the recent discovery of a fifth serotype could complicate vaccine development. In recent years, an urgent need has been felt for a vaccine to prevent the morbidity and mortality from this disease in a cost-effective way. PMID:25424928

  9. 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 ...

  10. Synthesis of 10 nm β-NaYF4:Yb,Er/NaYF4 Core/Shell Upconversion Nanocrystals with 5 nm Particle Cores.

    PubMed

    Rinkel, Thorben; Raj, Athira Naduviledathu; Dühnen, Simon; Haase, Markus

    2016-01-18

    A new method is presented for preparing gram amounts of very small core/shell upconversion nanocrystals without additional codoping of the particles. First, ca. 5 nm β-NaYF4:Yb,Er core particles are formed by the reaction of sodium oleate, rare-earth oleate, and ammonium fluoride, thereby making use of the fact that a high ratio of sodium to rare-earth ions promotes the nucleation of a large number of β-phase seeds. Thereafter, a 2 nm thick NaYF4 shell is formed by using 3-4 nm particles of α-NaYF4 as a single-source precursor for the β-phase shell material. In contrast to the core particles, however, these α-phase particles are prepared with a low ratio of sodium to rare-earth ions, which efficiently suppresses an undesired nucleation of β-NaYF4 particles during shell growth. PMID:26633748

  11. 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. PMID:17952663

  12. 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. PMID:25421918

  13. 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.

  14. Effect of Metal Coating on NaYF4:Yb3+,Tm 3+ Upconversion Nanoparticles

    NASA Astrophysics Data System (ADS)

    Alazemi, Abdulrahman

    Upconversion is the process in which two or more low-energy photons are absorbed and emitted as one high-energy photon. This research reports on the effect of layer-by-layer polyelectrolytes and silver coating on hexagonal NaYF4:Yb3+,Tm3+ in an attempt to enhance the upconversion intensity. The synthesized upconversion nanoparticles were separated into two, ˜140 nm and a mixture of two populations, ˜250 nm and ˜25 nm. The former case observed enhancement, when silver coated on the upconversion nanoparticles using hydroquinone as the reducing agent, with no layers and with several layers (three, four and five) of polyelectrolytes. The size (140 nm) and morphology of the hexagonal NaYF4:Yb 3+,Tm3+ were similar. The enhancement was confirmed when sodium cyanide was added to remove the silver coating from the sample resulting in a decrease in the upconversion intensity. Quenching was observed in the latter case, when silver coating was unsuccessful and that there are two populations of upconversion nanoparticles (large ˜250 nm and small ˜25 nm).

  15. Absolute quantum yield measurements of colloidal NaYF4: Er3+, Yb3+ upconverting nanoparticles

    NASA Astrophysics Data System (ADS)

    Boyer, John-Christopher; van Veggel, Frank C. J. M.

    2010-08-01

    In this communication we describe a technique for measuring the absolute quantum yields (QYs) of upconverting nanomaterials based on the use of a commercially available fluorimeter and an integrating sphere. Using this setup, we have successfully acquired luminescence efficiency data (pump laser, absorbed pump, and visible emitted intensities) for lanthanide-doped upconverting nanoparticles. QYs in the range of 0.005% to 0.3% were measured for several NaYF4: 2% Er3+, 20% Yb3+ nanoparticles with particle sizes ranging from 10 to 100 nm while a QY of 3% was measured for a bulk sample.In this communication we describe a technique for measuring the absolute quantum yields (QYs) of upconverting nanomaterials based on the use of a commercially available fluorimeter and an integrating sphere. Using this setup, we have successfully acquired luminescence efficiency data (pump laser, absorbed pump, and visible emitted intensities) for lanthanide-doped upconverting nanoparticles. QYs in the range of 0.005% to 0.3% were measured for several NaYF4: 2% Er3+, 20% Yb3+ nanoparticles with particle sizes ranging from 10 to 100 nm while a QY of 3% was measured for a bulk sample. Electronic supplementary information (ESI) available: Experimental details, powder XRDs and TEM micrographs of the samples. See DOI: 10.1039/c0nr00253d

  16. Negative ion-gas reaction studies using ion guides and accelerator mass spectrometry I: SrF3-, YF3-, ZrF3-, YF4- and ZrF5- in NO2

    NASA Astrophysics Data System (ADS)

    Eliades, J. A.; Zhao, X.-L.; Litherland, A. E.; Kieser, W. E.

    2015-10-01

    Typical accelerator mass spectrometry (AMS) ion sources readily produce useable currents of a wide variety of negative ions, including exotic species, and the sensitivity and dynamic range of AMS can be used for relatively unambiguous ion identification at low count rates. Difficulty producing negative ion currents with high fluxes (ex. when electron binding energies are small) and unambiguous identification of reaction products can be obstacles to negative ion-gas reaction studies. Thus, an AMS setup can be considered to be suitable for certain ion-gas reaction studies. Presented here are preliminary studies on interactions of SrF3-, YF3-, ZrF3-, YF4- and ZrF5- with NO2 gas at <50 eV kinetic energies using a prototype radio-frequency quadrupole (RFQ) instrument installed before the accelerator on the low-energy side of an AMS system. The superhalogen anions SrF3-, YF4- and ZrF5- were found to be highly unreactive with NO2, consistent with expected electron binding energies greater than 3.6 eV. YF3- and ZrF3- were found to have large overall attenuation cross sections in NO2 of 7.6 × 10-15 ± 4.4% cm2 and 1.5 × 10-14 ± 21% cm2 respectively at the ion energies created under the experimental conditions. The major reaction channels were shown to be electron transfer and oxygen capture. A cluster NO2·(YF3-) was also observed.

  17. 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

  18. 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.

  19. 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. PMID:27007737

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

    DOE PAGESBeta

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

    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.

  1. Surfactant effects on efficiency enhancement of infrared-to-visible upconversion emissions of NaYF4:Yb-Er.

    PubMed

    Tan, Mei Chee; Al-Baroudi, Lara; Riman, Richard E

    2011-10-01

    Infrared-to-visible rare earth doped upconversion phosphors that convert multiple photons of lower energy to higher energy photons offer a wide range of technological applications. The brightness (i.e., emission intensities) and energy efficiency of phosphors are important performance characteristics that determine which applications are appropriate. Optical efficiency can be used as a measure of the upconversion emission performance of these rare earth doped phosphors. In this work, hexagonal-phase NaYF(4):Yb-Er was synthesized using the hydrothermal method in the presence of surfactants like trioctylphosphine, polyethylene glycol monooleate, and polyvinylpyrrolidone. The upconversion emission optical efficiencies of NaYF(4):Yb-Er were measured to quantify and evaluate the effects of surface coatings and accurately reflect the brightness and energy efficiency of these phosphors. Polyvinylpyrrolidone-modified NaYF(4):Yb-Er particles were found to be ~5 times more efficient and brighter than the unmodified particles. The difference in efficiency was attributed to reduced reflectance losses at the particle-air interface via refractive index mismatch reduction between the core NaYF(4):Yb-Er particles and air using polyvinylpyrrolidone as a surfactant. PMID:21870851

  2. HPV Vaccine

    MedlinePlus

    ... can cause problems like genital warts and some kinds of cancer, a vaccine is an important step in preventing infection and protecting against the spread of HPV. That's why doctors recommend that all girls and guys get the vaccine at these ages: ...

  3. Rotavirus Vaccine

    MedlinePlus

    Why get vaccinated?Rotavirus is a virus that causes diarrhea, mostly in babies and young children. The diarrhea can be severe, and lead ... and fever are also common in babies with rotavirus.Before rotavirus vaccine, rotavirus disease was a common ...

  4. Anthrax Vaccine

    MedlinePlus

    ... products some military personnel, as determined by the Department of Defense These people should get five doses of vaccine ( ... cdc.gov/agent/anthrax/vaccination/. Contact the U.S Department of Defense (DoD): call 1-877-438-8222 or visit ...

  5. Schistosomiasis vaccines

    PubMed Central

    Siddiqui, Bilal A.; Ganley-Leal, Lisa

    2011-01-01

    Schistosomiasis is a major neglected tropical disease of public health importance to a billion people. An estimated 200 million people are currently infected; an additional 779 million individuals are at risk to acquire the infection in 74 countries. Despite many years of implementation of mass anti-parasitic drug therapy programs and other control measures, this disease has not been contained and continues to spread to new geographic areas.  The discovery of a protective vaccine still remains the most potentially effective means for the control of this disease, especially if the vaccine provides long-term immunity against the infection. A vaccine would contribute to the reduction of schistosomiasis morbidity through induced immune responses leading to decrease in parasite load and reduced egg production. This vaccine could be administered to children between the ages of 3 and 12 years to prevent severe infection in a particularly high risk population. This review summarizes the current status of schistosomiasis vaccine development. PMID:22048120

  6. Typhoid vaccines.

    PubMed

    Aggarwal, A; Dutta, A K

    2001-08-01

    Typhoid fever continues to be a major public health problem in developing countries with about 33 million cases per year. Protective efficacy of traditional acetone/phenol killed vaccines is similar to newer typhoid vaccines (Ty21A and Vi antigen vaccine) but side effects of these newer vaccines are considerably less. Though the mortality is low, typhoid fever causes considerable morbidity and loss of working days. Problems during treatment are increasing due to emergence and spread of multidrug resistant S. typhi. Hence to decrease the incidence of typhoid fever in addition to ensuring safe water supply and excreta disposal a typhoid vaccine needs to be introduced in the National Immunization Schedule. PMID:11563251

  7. 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.

  8. Rotavirus vaccines.

    PubMed

    Barnes, G

    1998-01-01

    Encouraging results have been reported from several large trials of tetravalent rhesus rotavirus vaccine, with efficacy of 70-80% against severe disease. A recent Venezuelan study showed similar results to trials in USA and Europe. The vaccine may soon be licensed in USA. It provides the exciting prospect of a strategy to prevent one of the world's major child killers. Other candidate vaccines are under development including human-bovine reassortants, neonatal strains, non-replicating rotaviruses, vector vaccines and other genetically engineered products. Second and third generation rotavirus vaccines are on the horizon. The need for a rotavirus vaccine is well accepted by paediatricians, but public health authorities need to be lobbied. Other issues which need to be addressed include relative importance of non-group A rotaviruses, possible administration with OPV, the influence of breast feeding, and most importantly, cost. It is essential that rotavirus vaccine is somehow made available to all of the world's children, not just those in developed countries. PMID:9553287

  9. [Rabbies vaccination].

    PubMed

    Jelinek, Tomas

    2016-01-01

    With very few exceptions, rabies is occurring around the globe. The clinical course of this mammal-transmitted infection is almost universally fatal. Thus, the disease is causing more human deaths than any other zoonosis. Due to the lack of effective therapeutic options, pre- or post-exposure vaccination remains the only effective means to avoid development of fatal disease. Save and highly effective cell culture vaccines which have been available for decades provide long-lasting protection. Various vaccination schedules have been tested and are being recommended. PMID:27268449

  10. 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

  11. 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.

  12. Synthesis of NaYF4:Yb3+, Er3+ upconversion nanoparticles in normal microemulsions.

    PubMed

    Shan, Shu-Nan; Wang, Xiu-Ying; Jia, Neng-Qin

    2011-01-01

    An interface-controlled reaction in normal microemulsions (water/ethanol/sodium oleate/oleic acid/n-hexane) was designed to prepare NaYF4:Yb3+, Er3+ upconversion nanoparticles. The phase diagram of the system was first studied to obtain the appropriate oil-in-water microemulsions. Transmission electron microscopy and X-ray powder diffractometer measurements revealed that the as-prepared nanoparticles were spherical, monodisperse with a uniform size of 20 nm, and of cubic phase with good crystallinity. Furthermore, these nanoparticles have good dispersibility in nonpolar organic solvents and exhibit visible upconversion luminescence of orange color under continuous excitation at 980 nm. Then, a thermal treatment for the products was found to enhance the luminescence intensity. In addition, because of its inherent merit in high yielding and being economical, this synthetic method could be utilized for preparation of the UCNPs on a large scale. PMID:21968102

  13. Synthesis of NaYF4:Yb3+, Er3+ upconversion nanoparticles in normal microemulsions

    NASA Astrophysics Data System (ADS)

    Shan, Shu-Nan; Wang, Xiu-Ying; Jia, Neng-Qin

    2011-10-01

    An interface-controlled reaction in normal microemulsions (water/ethanol/sodium oleate/oleic acid/ n-hexane) was designed to prepare NaYF4:Yb3+, Er3+ upconversion nanoparticles. The phase diagram of the system was first studied to obtain the appropriate oil-in-water microemulsions. Transmission electron microscopy and X-ray powder diffractometer measurements revealed that the as-prepared nanoparticles were spherical, monodisperse with a uniform size of 20 nm, and of cubic phase with good crystallinity. Furthermore, these nanoparticles have good dispersibility in nonpolar organic solvents and exhibit visible upconversion luminescence of orange color under continuous excitation at 980 nm. Then, a thermal treatment for the products was found to enhance the luminescence intensity. In addition, because of its inherent merit in high yielding and being economical, this synthetic method could be utilized for preparation of the UCNPs on a large scale.

  14. Tailoring Plasmonic Enhanced Upconversion in Single NaYF4:Yb(3+)/Er(3+) Nanocrystals.

    PubMed

    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:Yb(3+)/Er(3+) 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

  15. 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.

  16. Unusual behavior of Tb3+ in K3YF6 green-emitting phosphor.

    PubMed

    Gusowski, Marek A; Ryba-Romanowski, Witold

    2008-08-15

    We report on photoluminescence studies of Tb3+ in a polycrystalline cryolite type K3YF6 host. The location of the Tb3+ in the center of inversion forbids the electric-dipole transitions of terbium ions in this material. As a consequence almost the entire luminescence intensity is related to the 5D4-(7)F5 magnetic-dipole transition, and it is contained in the extremely narrow spectral bandwidth amounting to 1.7 nm at 8K and to 18 nm at room temperature. The phosphor under study can be efficiently excited making use of intense f-d transitions of Tb3+ in the UV-vacuum-UV region and may be of interest for applications requiring high spectral purity of the emission. PMID:18709087

  17. 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. PMID:22730026

  18. Plasmonic enhanced emissions from cubic NaYF4:Yb: Er/Tm nanophosphors

    PubMed Central

    Sudheendra, L.; Ortalan, Volkan; Dey, Sanchita; Browning, Nigel D.; Kennedy, I.M.

    2011-01-01

    A metal shell was used in this study to provide significant enhancement of the up-converted emission from cubic NaYF4 nanoparticles, creating a valuable composite material for labeling in biology and other applications – use of the cubic form of the material obviates the need to undertake a high temperature transformation to the naturally more efficient hexagonal phase. The NaYF4 matrix contained ytterbium sensitizer and an Erbium (Er) or Thulium (Tm) activator. The particle sizes of the as-synthesized nanoparticles were in the range of 20–40 nm with a gold shell thickness of 4–8 nm. The gold shell was macroscopically amorphous. The synthesis method was based on a citrate chelation. In this approach, we exploited the ability of the citrate ion to act as a reductant and stabilizer. Confining the citrate ion reductant on the nanophosphor surface rather than in the solution was critical to the gold shell formation. The plasmonic shell enhanced the up-conversion emission of Tm from visible and near-infrared regions by up to a factor of 8, in addition to imparting a visible color arising from the plasmon absorption of the gold shell. The up-conversion enhancement observed with Tm and Er were different for similar gold coverages, with local crystal field changes as a possible route to enhance up-conversion emission from high symmetry structural hosts. These novel up-converting nanophosphor particles combine the phosphor and features of a gold shell, providing a unique platform for many biological imaging and labeling applications. PMID:21709812

  19. Arthropod vaccines.

    PubMed

    Lee, R; Opdebeeck, J P

    1999-03-01

    Antigens located in the midgut of the tick are hidden from the host's immune system. Egg production of ticks can be reduced when ticks are fed on animals vaccinated with midgut antigens of the tick, and a subunit vaccine formulated with the recombinant antigen Bm86 is now available that can reduce the number of ticks infesting cattle grazing on pasture. Midgut antigens used in vaccines against insects that transmit pathogenic organisms to humans have not been as effective in reducing insect fecundity and an alternative approach may be necessary. Transmission-blocking vaccines directed at interfering with the vector-pathogen interaction could result in loss of vector competence and block the spread of disease-causing organisms. PMID:10198800

  20. 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 ...

  1. Meningococcal Vaccines

    MedlinePlus

    ... is an infection of the covering of the brain and the spinal cord. Meningococcal disease also causes ... legs, have problems with their nervous systems, become deaf or mentally ... use of meningococcal vaccine is important for people at highest risk.

  2. 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 ...

  3. 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 ...

  4. Live Virus Smallpox Vaccine

    MedlinePlus

    ... Index SMALLPOX FACT SHEET The Live Virus Smallpox Vaccine The vaccinia virus is the "live virus" used ... cannot cause smallpox. What is a "live virus" vaccine? A "live virus" vaccine is a vaccine that ...

  5. Pertussis (Whooping Cough) Vaccination

    MedlinePlus

    ... Tetanus-diphtheria-acellular Pertussis vaccine Pertussis (Whooping Cough) Vaccination Pronounced (per-TUS-iss) Recommend on Facebook Tweet ... The best way to prevent it is through vaccinations. The childhood vaccine is called DTaP. The whooping ...

  6. Promoting Vaccine Confidence.

    PubMed

    Smith, Michael J

    2015-12-01

    Vaccine hesitancy incorporates a wide range of parental attitudes and behaviors surrounding vaccines. Ironically, the very success of the immunization program has fueled vaccine concerns; because vaccine-preventable diseases are no longer prevalent, attention has shifted to the safety and necessity of vaccines themselves. This article reviews some of the underlying themes of vaccine hesitancy as well as specific vaccine safety concerns. Strategies for discussing vaccines with concerned parents are also discussed. PMID:26337737

  7. Microwave-assisted synthesis of hydrophilic BaYF5:Tb/Ce,Tb green fluorescent colloid nanocrystals.

    PubMed

    Lei, Yongqian; Pang, Min; Fan, Weiqiang; Feng, Jing; Song, Shuyan; Dang, Song; Zhang, Hongjie

    2011-01-01

    Hydrophilic Ce, Tb doped BaYF(5) nanocrystals with uniform size were synthesized by a microwave-assisted route. The synthesized nanocrystals can be well dispersed in hydrophilic solutions (DMSO, DMF, EG, H(2)O). This synthesis procedure represents a less time consuming method, with high product yield and without using any assistant or/and template reagents, which may be expected to be a general method for rapid synthesis of other hydrophilic RE doped fluoride fluorescent nanocrystals. The Ce(3+), Tb(3+) codoped BaYF(5) nanocrystals show bright green fluorescence emission. The Ce(3+) acts as an effective energy transfer medium and the emission at the high (5)D(3) energy level of Tb is enhanced in this host material. PMID:21076744

  8. 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.

  9. The effect of chloroquine prophylaxis on yellow fever vaccine antibody response: comparison of plaque reduction neutralization test and enzyme-linked immunosorbent assay.

    PubMed

    Barry, M; Patterson, J E; Tirrell, S; Cullen, M R; Shope, R E

    1991-01-01

    Weekly oral chloroquine prophylaxis for malaria has been associated with impaired antibody response to intradermal rabies vaccination. Experimental data indicate that chloroquine may inhibit yellow fever virus in vitro, yet there has been no clinical evidence to suggest that antibody response to yellow fever vaccine is impaired by concomitant oral administration of chloroquine. A prospective trial was undertaken to evaluate the antibody response to yellow fever 17D vaccine (Connaught Laboratories) of volunteers who were randomized to taking either chloroquine or no drug. Of fifty subjects, 28 were randomized to taking chloroquine, 22 were randomized to taking no drug. Yellow fever 17D vaccine was administered on day 0 and blood sampled on days 0, 14, 35 and 210. Chloroquine was administered weekly for four weeks. There was no significant difference in peak antibody titer by plaque reduction neutralization testing (PRNT) between the group that took chloroquine (mean log peak of reciprocal titer 1.43 +/- SD 0.60) with vaccine subcutaneously compared to vaccine-only group (mean log peak of reciprocal titer = 1.21 +/- 0.55). All fifty subjects seroconverted to yellow fever vaccine by day 210. ELISA testing was also performed on all subjects. The two tests showed good correlation (Spearman r = 0.675), although ELISA readings were positive by day 14 in significantly more subjects (p = .01). We conclude that routine anti-malarial doses of chloroquine do not affect antibody response to yellow fever 17D vaccine. ELISA testing, a less complex and less time-consuming test, correlates well with PRNT and is proposed for additional trials to measure yellow fever 17D vaccine response in flavivirus non-immune subjects. PMID:1996743

  10. The acute, developmental, genetic and inhalation toxicology of 2,3,3,3-tetrafluoropropene (HFO-1234yf).

    PubMed

    Tveit, Ann; Rusch, George M; Muijser, Hans; Tegelenbosch-Schouten, Mariska-M

    2013-10-01

    2,3,3,3-Tetrafluoropropene (HFO-1234yf) is being developed as a refrigerant because it has a very low global warming potential (less than 10), as contrasted to the hydrofluorocarbons, which is intended to replace with values of over 500. Several toxicology studies were conducted to develop a toxicology profile for this material. There was no lethality in mice and rats receiving single 4-hour exposures up to 101,850 or 405,800 ppm, respectively. Additionally, there was no mortality or clinical signs of toxicity when rabbits were exposed to 100,000 ppm for 1 hour. Exposures up to 120,000 ppm did not induce cardiac sensitization to adrenalin in dogs. Rats were exposed to HFO-1234yf at levels of 5000, 20,000 and 50,000 ppm 6 hours/day 5 days/week for 2 weeks and at levels of 5000, 15,000 and 50,000 ppm for 4 weeks and for 90 days. No treatment-related adverse effects were noted in these studies. HFO-1234yf was not genotoxic in a mouse and a rat micronucleus assay, and unscheduled DNA synthesis assay and was not clastogenic in human lymphocytes. HFO-1234yf was mutagenic to Salmonella typhimurium TA 100 and Escherichia coli (WP2 uvrA) at concentrations of 20% and higher in the presence of metabolic activation only. There were no biologically significant effects in a rat developmental toxicity study with exposures up to 50,000 ppm. PMID:23742174

  11. Testing and analysis of dual-mode adaptive landing gear, taxi mode test system for YF-12A

    NASA Technical Reports Server (NTRS)

    Gamon, M. A.

    1979-01-01

    The effectiveness of a dual mode adaptive landing gear system in reducing the dynamic response of an airplane during ground taxiing was studied. The dynamic taxi tests of the YF-12A research airplane are presented. A digital computer program which simulated the test conditions is discussed. The dual mode system as tested provides dynamic taxi response reductions of 25 percent at the cg and 30 to 45 percent at the cockpit.

  12. Cancer vaccines

    PubMed Central

    2015-01-01

    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. PMID:25904595

  13. Upconversion and tribological properties of β-NaYF4:Yb,Er film synthesized on silicon substrate

    NASA Astrophysics Data System (ADS)

    Wang, Chuanying; Cheng, Xianhua

    2016-05-01

    In this work, β-NaYF4:Yb,Er upconversion (UC) film was successfully prepared on silicon (Si) substrate via self-assemble method for the first time. The chemical composition and surface morphology of the UC film were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), water contact angle (WCA), X-ray power diffraction (XRD), and scanning electron microscopy (SEM) measurements. To investigate the effects of KH-560 primer film and chemical reactions on the UC luminescence properties of β-NaYF4:Yb,Er UC film, decay profiles of the 540 nm and 655 nm radiations were measured. Furthermore, tribological test was applied to qualitatively evaluate the adhesion of the UC film. The results indicate that the UC film has been successfully prepared on Si substrate by covalent chemical bonds. This work provides a facile way to synthesize β-NaYF4:Yb,Er UC film with robust adhesion to the substrate, which can be applicable for other UC films.

  14. 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

  15. 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. PMID:25377774

  16. Rabies Vaccine

    MedlinePlus

    ... and booster doses should be given as needed. (Testing or booster doses are not recommended for travelers.) Ask your doctor for details. Vaccination After an Exposure:Anyone who has been bitten by an animal, or who otherwise may have been exposed to ...

  17. 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

  18. 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…

  19. Typhoid Vaccine

    MedlinePlus

    ... it while traveling. Typhoid strikes about 21 million people a year around the world and kills about 200,000. ... booster dose is needed every 2 years for people who remain at risk. Live typhoid vaccine (oral)Four doses: one capsule every other day for a week (day 1, day 3, day ...

  20. Polio Vaccine

    MedlinePlus

    ... of the world. It would only take one person infected with polio virus coming from another country to bring the ... However, any medicine could cause a serious side effect, such as a severe allergic reaction or even death. The risk of polio vaccine causing serious harm is extremely small.

  1. 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. PMID:12287671

  2. 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...

  3. Quenching of the upconversion luminescence of NaYF4:Yb3+,Er3+ and NaYF4:Yb3+,Tm3+ nanophosphors by water: the role of the sensitizer Yb3+ in non-radiative relaxation

    NASA Astrophysics Data System (ADS)

    Arppe, Riikka; Hyppänen, Iko; Perälä, Niina; Peltomaa, Riikka; Kaiser, Martin; Würth, Christian; Christ, Simon; Resch-Genger, Ute; Schäferling, Michael; Soukka, Tero

    2015-07-01

    We have studied the mechanisms of water-based quenching of the upconversion photoluminescence of upconverting nanophosphors (UCNPs) via luminescence decay measurements for a better understanding of the non-radiative deactivation pathways responsible for the relatively low upconversion luminescence efficiency in aqueous solutions. This included both upconversion luminescence measurements and the direct excitation of emissive energy states of Er3+ and Yb3+ dopants in NaYF4:Yb3+,Er3+ UCNPs by measuring the decays at 550 and 655 nm upon 380 nm excitation and at 980 nm upon 930 nm excitation, respectively. The luminescence intensities and decays were measured from both bare and silanized NaYF4:Yb3+,Er3+ and NaYF4:Yb3+,Tm3+ UCNPs in H2O and D2O. The measurements revealed up to 99.9% quenching of the upconversion photoluminescence intensity of both Er3+ and Tm3+ doped bare nanophosphors by water. Instead of the multiphonon relaxation of excited energy levels of the activators, the main mechanism of quenching was found to be the multiphonon deactivation of the Yb3+ sensitizer ion caused by OH-vibrations on the surface of the nanophosphor. Due to the nonlinear nature of upconversion, the quenching of Yb3+ has a higher order effect on the upconversion emission intensity with the efficient Yb-Yb energy migration in the ~35 nm nanocrystals making the whole nanophosphor volume susceptible to surface quenching effects. The study underlines the need of efficient surface passivation for the use of UCNPs as labels in bioanalytical applications performed in aqueous solutions.We have studied the mechanisms of water-based quenching of the upconversion photoluminescence of upconverting nanophosphors (UCNPs) via luminescence decay measurements for a better understanding of the non-radiative deactivation pathways responsible for the relatively low upconversion luminescence efficiency in aqueous solutions. This included both upconversion luminescence measurements and the direct excitation

  4. 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.

  5. Up-conversion luminescence polarization control in Er3+-doped NaYF4 nanocrystals

    NASA Astrophysics Data System (ADS)

    Hui, Zhang; Yun-Hua, Yao; Shi-An, Zhang; Chen-Hui, Lu; Zhen-Rong, Sun

    2016-02-01

    We propose a femtosecond laser polarization modulation scheme to control the up-conversion (UC) luminescence in Er3+-doped NaYF4 nanocrystals dispersed in the silicate glass. We show that the UC luminescence can be suppressed when the laser polarization is changed from linear through elliptical to circular, and the higher repetition rate will yield the lower control efficiency. We theoretically analyze the physical control mechanism of the UC luminescence polarization modulation by considering on- and near-resonant two-photon absorption, energy transfer up-conversion, and excited state absorption, and show that the polarization control mainly comes from the contribution of near-resonant two-photon absorption. Furthermore, we propose a method to improve the polarization control efficiency of UC luminescence in rare-earth ions by applying a two-color femtosecond laser field. Project supported by the Young Scientists Fund of the National Natural Science Foundation of China (Grant No. 11304396), the National Natural Science Foundation of China (Grant Nos. 11474096 and 51132004), and the Shanghai Municipal Science and Technology Commission, China (Grant No. 14JC1401500).

  6. Composition tuning the upconversion emission in NaYF4:Yb/Tm hexaplate nanocrystals.

    PubMed

    Zhang, Hua; Li, Yujing; Lin, Yungchen; Huang, Yu; Duan, Xiangfeng

    2011-03-01

    Single crystal hexagonal NaYF4:Yb/Tm nanocrystals have been synthesized with uniform size, morphology and controlled chemical composition. Spectroscopic studies show that these nanocrystals exhibit strong energy upconversion emission when excited with a 980 nm diode laser, with two primary emission peaks centered around 452 nm and 476 nm. Importantly, the overall and relative emission intensity at these wavelengths can be readily tuned by controlling the concentration of the trivalent rare earth element dopants at the beginning of the synthesis which has been confirmed by EDX for the first time. Through systematic studies, the optimum rare earth ion doping concentration can be determined for the strongest emission intensity at the selected peak(s). Confocal microscopy studies show that the upconversion emission from individual NCs can be readily visualized. These studies demonstrate a rational approach for fine tuning the upconversion properties in rare-earth doped nanostructures and can broadly impact areas ranging from energy harvesting, energy conversion to biomedical imaging and therapeutics. PMID:21264435

  7. Composition Tuning the Upconversion Emission in NaYF4:Yb/Tm Hexaplate Nanocrystals

    PubMed Central

    Zhang, Hua; Li, Yujing; Lin, Yungchen

    2011-01-01

    Single crystal hexagonal NaYF4:Yb/Tm nanocrytstals have been synthesized with uniform size, morphology and controlled chemical composition. Spectroscopic studies show that these nanocrystals exhibit strong energy upconversion emission when excited with a 980 nm diode laser, with two primary emission peaks centered around 452 nm and 476 nm. Importantly, the overall and relative emission intensity at these wavelengths can be readily tuned by controlling the concentration of the trivalent rare earth element dopants at the beginning of the synthesis which has been confirmed by EDX for the first time. Through systematic studies, the optimum rare earth ion doping concentration can be determined for the strongest emission intensity at the selected peak(s). Confocal microscope studies show that the upconversion emission from individual NCs can be readily visualized. These studies demonstrate a rational approach for fine tuning the upconversion properties in rare-earth doped nanostructures, and can broadly impact areas ranging from energy harvesting, energy conversion to biomedical imaging and therapeutics. PMID:21264435

  8. Biofunctionalization, cytotoxicity, and cell uptake of lanthanide doped hydrophobically ligated NaYF4 upconversion nanophosphors

    NASA Astrophysics Data System (ADS)

    Shan, Jingning; Chen, Jianbo; Meng, Juan; Collins, Josh; Soboyejo, Wole; Friedberg, Joseph S.; Ju, Yiguang

    2008-11-01

    Surface biofunctionalization of the hydrophobic lanthanide ion doped hexagonal phase NaYF4:Yb,Er upconversion nanophosphors (UCNPs) was achieved by introducing amino and carboxyl groups, respectively. Amino groups were added by using the 3-aminopropyltrimethoxysilane reaction after a thin layer of SiO2 coating. The carboxyl groups on surface were added directly by coating modified amphiphilic polyacrylic acid polymer. Experimental studies of cytotoxicity and cell uptake of UCNPs were conducted. The cytotoxicity analysis of the functionalized UCNPs was conducted by methylthiazol tetrazolium assays. Cell uptake was accomplished by incubating the UCNPs with human osteosarcoma cells and proved by transmission electron microscopy. The results showed that the functionalized UCNPs had very low toxicity compared with the control group, while UCNPs taken into the cells indicated that they had very high biocompatibility. The imaging of UCNPs, which were incubated with AB12 mouse mesothelioma cells and excited by 1 W 980 nm light, showed individual particles with visible light emission. These results exhibited promising applications of functionalized UCNPs in cell imaging and photodynamic therapy.

  9. PρT Property for HFO-1234yf in the Gaseous Phase

    NASA Astrophysics Data System (ADS)

    Tanaka, Katsuyuki; Higashi, Yukihiro

    Measurement of the PρT property for HFO-1234yf (2,3,3,3-tetrafluoropropene) in the gaseous phase was carried out using metal-bellows volumometer. Two hundreds and three PρT properties were obtained in the range of temperatures from (310 to 360) K, of pressures from (927 to 2895) kPa and of densities from (52 to 239) kg/m3. The experimental uncertainties are estimated to be 10 mK for temperatures, 2 kPa for pressures, and (0.11 to 0.31) kg/m3 for densities. The sample purity was better than 99.85 % in mole fraction. On the basis of the present data, the virial equation of state was correlated and the virial coefficients were obtained. In addition, the saturated vapor densities were determined from present virial equation of state by substituting the available vapor pressure values. Moreover, the present data were compared with values calculated from existing equations of state.

  10. Non-collinear spin DFT for lanthanide ions in doped hexagonal NaYF4

    NASA Astrophysics Data System (ADS)

    Yao, Ge; Huang, Shuping; Berry, Mary T.; May, P. Stanley; Kilin, Dmitri S.

    2014-02-01

    Trivalent lanthanide ions (Ln3+) doped in hexagonal (β)-NaYF4 nanocrystals (Na24Y23Ln1F96, Ln = La, Ce, Pr, Nd, Pm, Sm, Eu, Gd) were systematically studied by density functional theory (DFT) with a perturbative account for spin-orbit coupling. The simulated results, including the optimised molecular structures, electronic and magnetic properties, are compared to previous spin-polarised DFT studies in the same system. The spin-orbit coupling effects become significant with the increase in the number of unpaired 4f electrons in the doped lanthanide ions, particularly for the Sm3+-, Eu3+- and Gd3+-doped nanocrystals. Abnormal behaviour of Eu3+-doped nanocrystals was observed due to the Wybourne-Downer mechanism. A 'sandwich-like' 2p-4f-4d,5d electronic structure for Na24Y23Ln1F96 and the energies of the highest occupied 4f electrons from Ce3+ to Gd3+ are consistent with Dorenbos's relationship. The energy difference between the first and second Russell-Saunders terms (2S+1L) of the lanthanide dopant is consistent with Carnall's experimental results and with earlier spin-polarised DFT calculations.

  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. Near-infrared light triggered superior photocatalytic activity from MoS2-NaYF4:Yb(3+)/Er(3+) nanocomposites.

    PubMed

    Chatti, Manjunath; Adusumalli, Venkata N K B; Ganguli, Sagar; Mahalingam, Venkataramanan

    2016-08-01

    A near infrared (NIR) responsive photocatalyst, composed of a narrow band gap semiconductor (i.e. MoS2) and an optical material possessing upconverting ability (i.e. NaYF4:Yb(3+)/Er(3+)) has been successfully prepared via a simple hydrothermal method. The latter has the ability to convert NIR light into visible light while the MoS2 uses the light to degrade organic pollutants. Upon near infrared (NIR) excitation of the MoS2-NaYF4:Yb(3+)/Er(3+) nanocomposites, the energy of the strong green and the red emissions along with the weak violet emissions from the NaYF4:Yb(3+)/Er(3+) nanocrystals (NCs) is transferred to MoS2. This results in enhanced NIR light triggered photocatalytic performance, as verified by studying the degradation of Rhodamine B (RhB) dye under 980 nm laser excitation. The strong photocatalytic activity of MoS2-NaYF4:Yb(3+)/Er(3+) composites is attributed to the layered nature of the photocatalyst which leads to the efficient separation of photogenerated carriers (electron-hole pairs) and excellent upconversion properties of NaYF4:Yb(3+)/Er(3+) NCs. The study also shows the importance of the composite formation, as the physical mixture leads to only very low photocatalytic activity. Our results can be helpful in the structural design and development of high-performance photocatalysts. PMID:27424735

  13. 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.

  14. Ozone and TFA impacts in North America from degradation of 2,3,3,3-Tetrafluoropropene (HFO-1234yf), a potential greenhouse gas replacement.

    PubMed

    Luecken, Deborah J; L Waterland, Robert; Papasavva, Stella; Taddonio, Kristen N; Hutzell, William T; Rugh, John P; Andersen, Stephen O

    2010-01-01

    We use a regional-scale, three-dimensional atmospheric model to evaluate U.S. air quality effects that would result from replacing HFC-134a in automobile air conditioners in the U.S. with HFO-1234yf. Although HFO-1234yf produces tropospheric ozone, the incremental amount is small, averaging less than 0.01% of total ozone formed during the simulation. We show that this production of ozone could be compensated for by a modest improvement in air conditioner efficiency. Atmospheric decomposition of HFO-1234yf produces trifluoroacetic acid (TFA), which is subject to wet and dry deposition. Deposition and concentrations of TFA are spatially variable due to HFO-1234yf's short atmospheric lifetime, with more localized peaks and less global transport when compared to HFC-134a. Over the 2.5 month simulation, deposition of TFA in the continental U.S. from mobile air conditioners averages 0.24 kg km(-2), substantially higher than previous estimates from all sources of current hydrofluorocarbons. Automobile air conditioning HFO-1234yf emissions are predicted to produce concentrations of TFA in Eastern U.S. rainfall at least double the values currently observed from all sources, natural and man-made. Our model predicts peak concentrations in rainfall of 1264 ng L(-1), a level that is 80x lower than the lowest level considered safe for the most sensitive aquatic organisms. PMID:19994849

  15. Human Vaccines & Immunotherapeutics

    PubMed Central

    Riedmann, Eva M

    2013-01-01

    DNA vaccine for T1D promising in the clinic HPV vaccines halved infections in US teenage girls Modified DC immunotherapy against melanoma New study looks at clinical severity of human H7N9 infections Prevnar vaccines are valuable for healthcare systems GAPVAC: New consortium in the fight of brain cancer Cytomegalovirus vaccine to enter phase 3 Malaria vaccination using chemically attenuated parasites

  16. Fish Vaccines in Aquaculture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccination is a proven, cost-effective method to prevent infectious diseases in animals. Current fish vaccines can be categorized as killed fish vaccines or modified live vaccines. The major advantage of live vaccine is their ability to stimulate both cell-mediated and humoral immune responses for ...

  17. Vaccine-Preventable Disease Photos

    MedlinePlus

    ... 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 Tips for Finding Vaccine Records Trusted Sources of Vaccine ... PRETEENS Vaccines You Need ...

  18. Pneumococcal Polysaccharide Vaccine

    MedlinePlus

    Pneumococcal polysaccharide vaccine (PPSV)Treatment of pneumococcal infections with penicillin and other drugs used to be more effective. But ... the disease, through vaccination, even more important. Pneumococcal polysaccharide vaccine (PPSV) protects against 23 types of pneumococcal ...

  19. 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 ...

  20. 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 ...

  1. Your Baby's First Vaccines

    MedlinePlus

    ... Barcodes Related Link Vaccines & Immunizations 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 ...

  2. Vaccines and Pregnancy

    MedlinePlus

    ... pregnancy, please see the MotherToBaby fact sheet Seasonal Influenza Vaccine (Flu Shot) during Pregnancy ( http: / / mothertobaby. org/ fact- sheets/ seasonal- influenza- vaccine- flu- shot- pregnancy/ pdf/ ). Nasal spray flu vaccines ...

  3. Vaccinations and HIV

    MedlinePlus

    ... Do not measure your viral load within 4 weeks of any vaccination. Flu shots have been studied ... live” vaccination in the past 2 or 3 weeks. Still, the “MMR” vaccine against measles, mumps and ...

  4. Varicella (Chickenpox) Vaccine

    MedlinePlus

    ... vaccine called MMRV, which contains both chickenpox and MMR vaccines, may be given instead of the two individual ... like rash (about 1 person in 20) than MMR and varicella vaccines given separately. Moderate Problems:Seizure (jerking or staring) ...

  5. Vaccines for Pregnant Women

    MedlinePlus

    ... virus (HBV) during pregnancy Vaccination and Pregnancy Resources, journal articles, more sources, etc., from Immunization Action Coalition Video: "Vaccines and Your Baby" (26:41 min) Vaccine Education Center, Children's Hospital of Philadelphia, November 2002 Also ...

  6. Vaccine refrigeration

    PubMed Central

    McColloster, Patrick J; Martin-de-Nicolas, Andres

    2014-01-01

    This commentary reviews recent changes in Centers for Disease Control (CDC) vaccine storage guidelines that were developed in response to an investigative report by the Office of the Inspector General. The use of temperature data loggers with probes residing in glycol vials is advised along with storing vaccines in pharmaceutical refrigerators. These refrigerators provide good thermal distribution but can warm to 8 °C in less than one hour after the power is discontinued. Consequently, electric grid instability influences appropriate refrigerator selection and the need for power back-up. System Average Interruption Duration Index (SAIDI) values quantify this instability and can be used to formulate region-specific guidelines. A novel aftermarket refrigerator regulator with a battery back-up power supply and microprocessor control system is also described. PMID:24442209

  7. 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.

  8. Lanthanide doped Y6O5F8/YF3 microcrystals: phase-tunable synthesis and bright white upconversion photoluminescence properties.

    PubMed

    Wang, Song; Deng, Ruiping; Guo, Hailing; Song, Shuyan; Cao, Feng; Li, Xiyan; Su, Shengqun; Zhang, Hongjie

    2010-10-14

    High-quality Y(6)O(5)F(8)/YF(3) microcrystals have been synthesised by using a hydrothermal and subsequent calcination route. Upon changing the initial solution pH value, the as-prepared microcrystal can be well tuned from YF(3) octahedron microcrystals to YF(3) hollow spheres and finally to Y(6)O(5)F(8) microtubes. The as-obtained microcrystals have been characterised by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and photoluminescence (PL) spectra. When the Y(6)O(5)F(8):Ln(3+) microtubes are excited by a 980 nm continual wave laser diode, bright red, green, and blue room temperature upconversion PL emissions have been observed. A series of white light emissions have been obtained by precisely adjusting dopants concentration in Y(6)O(5)F(8) microtubes. PMID:20714629

  9. Rotavirus Vaccine -- Questions and Answers

    MedlinePlus

    ... to these vaccines. The infant's immune response to influenza vaccine administered at the same time as rotavirus vaccine ... previously that an inactivated vaccine (e.g., inactivated influenza vaccine) may be administered either simultaneously or at any ...

  10. Construction and characterization of recombinant flaviviruses bearing insertions between E and NS1 genes

    PubMed Central

    Bonaldo, Myrna C; Mello, Samanta M; Trindade, Gisela F; Rangel, Aymara A; Duarte, Adriana S; Oliveira, Prisciliana J; Freire, Marcos S; Kubelka, Claire F; Galler, Ricardo

    2007-01-01

    Background The yellow fever virus, a member of the genus Flavivirus, is an arthropod-borne pathogen causing severe disease in humans. The attenuated yellow fever 17D virus strain has been used for human vaccination for 70 years and has several characteristics that are desirable for the development of new, live attenuated vaccines. We described here a methodology to construct a viable, and immunogenic recombinant yellow fever 17D virus expressing a green fluorescent protein variant (EGFP). This approach took into account the presence of functional motifs and amino acid sequence conservation flanking the E and NS1 intergenic region to duplicate and fuse them to the exogenous gene and thereby allow the correct processing of the viral polyprotein precursor. Results YF 17D EGFP recombinant virus was grew in Vero cells and reached a peak titer of approximately 6.45 ± 0.4 log10 PFU/mL at 96 hours post-infection. Immunoprecipitation and confocal laser scanning microscopy demonstrated the expression of the EGFP, which was retained in the endoplasmic reticulum and not secreted from infected cells. The association with the ER compartment did not interfere with YF assembly, since the recombinant virus was fully competent to replicate and exit the cell. This virus was genetically stable up to the tenth serial passage in Vero cells. The recombinant virus was capable to elicit a neutralizing antibody response to YF and antibodies to EGFP as evidenced by an ELISA test. The applicability of this cloning strategy to clone gene foreign sequences in other flavivirus genomes was demonstrated by the construction of a chimeric recombinant YF 17D/DEN4 virus. Conclusion This system is likely to be useful for a broader live attenuated YF 17D virus-based vaccine development for human diseases. Moreover, insertion of foreign genes into the flavivirus genome may also allow in vivo studies on flavivirus cell and tissue tropism as well as cellular processes related to flavivirus infection. PMID

  11. 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

  12. 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

  13. Human Vaccines & Immunotherapeutics

    PubMed Central

    Riedmann, Eva M

    2014-01-01

    Efficacy and safety of first-ever Dengue vaccine candidate in Phase 3 Agenus‘ brain cancer vaccine doubles survival rate in GBM patients New study: Rotavirus vaccines dramatically cut hospitalization rates in US children Therapeutic vaccines – from heart disease to cancer Agenus‘ genital herpes vaccine significantly reduces viral burden in Phase 2 The latest on PaxVax‘ and Gotovax AB’s cholera vaccine candidates ACIP ponders recommendation for Prevnar use in seniors PMID:25424916

  14. Human Vaccines & Immunotherapeutics

    PubMed Central

    Riedmann, Eva M.

    2012-01-01

    Two therapeutic HPV vaccine candidates successful in phase 1 Flu shot may prevent heart attacks and stroke CDX-1401 combined with TLR agonist: Positive phase 1 results Three MRSA vaccines in early clincial trials Ovarian cancer vaccine candidate DPX-Survivac: Positive interim results from phase 1 Chinese biotech partnership brings first hepatitis E vaccine to the market Therapeutic vaccine for treatment of genital herpes enters phase 2 Visionary concept: Printable vaccines PMID:23817319

  15. 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.

  16. Human Vaccines & Immunotherapeutics: News

    PubMed Central

    Riedmann, Eva M.

    2014-01-01

    Oncolytic immunotherapy reduces the size of melanoma tumors in phase 3 trial EV71 vaccine protects children against HFMD Influenza vaccination important for risk groups Bharat‘s rotavirus vaccine is safe and modestly efficacious Successfully avoiding the cold-chain for vaccines FDA approval for Stallergenes’ sublingual grass pollen allergy immunotherapy HPV vaccination campaign could change from three to two doses in the UK Valneva continues phase 2/3 trial of Pseudomonas aeruginosa vaccine PMID:25290656

  17. Influence of Shell Formation on Morphological Structure, Optical and Emission Intensity on Aqueous Dispersible NaYF4:Ce/Tb Nanoparticles.

    PubMed

    Ansari, Anees A; Parchur, A K; Kumar, B; Rai, S B

    2016-07-01

    A highly water-dispersible NaYF4:Ce/Tb (core), NaYF4:Ce/Tb@NaYF4(core/shell) and NaYF4:Ce/Tb@NaYF4@SiO2 (core/shell/SiO2) nanoparticles (NPs) were synthesized via a general synthesis approach. The growth of an inert NaYF4 and silica shell (~14 nm) around the core-NPs resulted in an increase of the average size of the nanopaticles as well as broadening of their size distribution. The optical band-gap energy slightly decreases after shell formation due to the increase the crystalline size. To optimize the influence of shell formation a comparative analysis of photoluminescence properties (excitation, emission, and luminescence decay time) of the core, core/shell, and core/shell/SiO2 NPs were measured. The emission intensity was significantly enhanced after inert shell formation around the surface of the core NPs. The Commission International de l'Eclairage chromaticity coordinates of the emission spectrum of core, core/shell, core/shell/SiO2 NPs lie closest to the standard green color emission at 545 nm. By quantitative spectroscopic measurements of surface-modified core-NPs, it was suggested that encapsulation with inert and silica layers was found to be effective in retaining both luminescence intensity and dispersibility in aqueous environment. Considering the high aqueous dispersion and enhanced luminescence efficiency of the core-NPs make them an ideal luminescent material for luminescence bioimaging and optical biosensors. PMID:27207570

  18. 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.

  19. Vaccines.gov

    MedlinePlus

    ... Getting Vaccinated More Info Glossary Our Partners Related Websites AIDS.gov Biomedical Advanced Research and Development Authority (BARDA) CDC Vaccines Countermeasures Injury Compensation Program ...

  20. Flight study of a vehicle operational status and monitoring system. [applied to systems on YF-12 aircraft

    NASA Technical Reports Server (NTRS)

    Love, J. E.; Fox, W. J.; Wicklund, E. J.

    1964-01-01

    An analog onboard monitoring system was installed on a YF-12 airplane as the first phase of a program to monitor the engine inlet and portions of the airplane's electrical and fuel management subsystems in flight. The system provided data which were considered to form a suitable base for diagnostic test logic and decision criteria for the rest of the program. The data were also adequate for the purpose of maintaining the engine inlet and identifying malfunctions within it. The investigation showed that the requirements of an onboard monitoring system should be considered during the original design of the system to be monitored.

  1. Viscosity Correlation for 2,3,3,3-Tetrafluoropropene (HFO-1234yf) Based on the Extended Corresponding States Model

    NASA Astrophysics Data System (ADS)

    Akasaka, Ryo

    The viscosity of 2,3,3,3-tetrafluoropropene (HFO-1234yf) has been successfully correlated with the extended corresponding states (ECS) model for transport properties. The thermodynamic equation of state developed in our earlier work forms the basis of this work. The viscosity correlation presented here is valid for temperatures from 260 K to 340 K and for pressures up to 20 MPa. The correlation can be applied to both liquid and gas phases in a single procedure. The estimated uncertainties are 2 % for liquid phase and 2.5 % for gas phase, which roughly correspond to experimental uncertainties.

  2. 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.

  3. 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. PMID:26588242

  4. Sequential Infection with Common Pathogens Promotes Human-like Immune Gene Expression and Altered Vaccine Response.

    PubMed

    Reese, Tiffany A; Bi, Kevin; Kambal, Amal; Filali-Mouhim, Ali; Beura, Lalit K; Bürger, Matheus C; Pulendran, Bali; Sekaly, Rafick-Pierre; Jameson, Stephen C; Masopust, David; Haining, W Nicholas; Virgin, Herbert W

    2016-05-11

    Immune responses differ between laboratory mice and humans. Chronic infection with viruses and parasites are common in humans, but are absent in laboratory mice, and thus represent potential contributors to inter-species differences in immunity. To test this, we sequentially infected laboratory mice with herpesviruses, influenza, and an intestinal helminth and compared their blood immune signatures to mock-infected mice before and after vaccination against yellow fever virus (YFV-17D). Sequential infection altered pre- and post-vaccination gene expression, cytokines, and antibodies in blood. Sequential pathogen exposure induced gene signatures that recapitulated those seen in blood from pet store-raised versus laboratory mice, and adult versus cord blood in humans. Therefore, basal and vaccine-induced murine immune responses are altered by infection with agents common outside of barrier facilities. This raises the possibility that we can improve mouse models of vaccination and immunity by selective microbial exposure of laboratory animals to mimic that of humans. PMID:27107939

  5. 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

  6. 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. PMID:26137385

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

    PubMed

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

    2016-08-01

    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. 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

  9. 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...

  10. [Color-tunable nano-material alpha-NaYF4 : Yb, Er, Tm prepared by microemulsion-hydrothermal method].

    PubMed

    Long, Dan-Dan; Zhang, Qing-Xia; Wang, Yu; Zhang, Fan; Wang, Yan-Fei; Zhou, Xin; Qi, Xiao-Hua; Zhang, Heng; Yan, Jing-Hui; Zou, Ming-Qiang

    2013-08-01

    NaYF4 : Yb3+, Er3+, Tm3+ nanoparticles were prepared by microemulsion-hydrothermal method. Crystal phase, morphology and structure of the samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The luminescence properties were studied by up-conversional fluorescence spectroscopy. The XRD patterns of as-prepared samples were in agreement with the PDF # 77-2042 of cubic NaYF4. SEM images of the particles showed that the samples were cotton-like spherical in shape and which were assembled by smaller nano-particles. The average size was 120 nm, while the shape was regular and the particle size was homogeneous. Under the excitation of 980 nm, the as-prepared particles could emit blue (438 and 486 nm), green (523 and 539 nm) and red (650 nm) light simultaneously. It can be seen from the color coordinates figure (CIE) that when doping concentration ratio of Tm3+ and E3+ increased from 0 to 2, the whole emitting light color of samples movedto green region. While the ratio was 1 : 1, pseudo white light was obtained. As the ratio changed from 2 to 7, the luminous color was moved to red region. PMID:24159845

  11. 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.

  12. Transport of NaYF4:Er3+, Yb3+ up-converting nanoparticles into HeLa cells

    NASA Astrophysics Data System (ADS)

    Sikora, Bożena; Fronc, Krzysztof; Kamińska, Izabela; Koper, Kamil; Szewczyk, Sebastian; Paterczyk, Bohdan; Wojciechowski, Tomasz; Sobczak, Kamil; Minikayev, Roman; Paszkowicz, Wojciech; Stępień, Piotr; Elbaum, Danek

    2013-06-01

    An effective, simple and practically useful method to incorporate fluorescent nanoparticles inside live biological cells was developed. The internalization time and concentration dependence of a frequently used liposomal transfection factor (Lipofectamine 2000) was studied. A user friendly, one-step technique to obtain water and organic solvent soluble Er3+ and Yb3+ doped NaYF4 nanoparticles coated with polyvinylpyrrolidone was obtained. Structural analysis of the nanoparticles confirmed the formation of nanocrystals of the desired sizes and spectral properties. The internalization of NaYF4 nanoparticles in HeLa cervical cancer cells was determined at different nanoparticle concentrations and for incubation periods from 3 to 24 h. The images revealed a redistribution of nanoparticles inside the cell, which increases with incubation time and concentration levels, and depends on the presence of the transfection factor. The study identifies, for the first time, factors responsible for an effective endocytosis of the up-converting nanoparticles to HeLa cells. Thus, the method could be applied to investigate a wide range of future ‘smart’ theranostic agents. Nanoparticles incorporated into the liposomes appear to be very promising fluorescent probes for imaging real-time cellular dynamics.

  13. 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.

  14. Optical and structural properties of YF3 thin films prepared by ion-assisted deposition or ion beam sputtering techniques

    NASA Astrophysics Data System (ADS)

    Robic, Jean-Yves; Muffato, Viviane; Chaton, Patrick; Ida, Michel; Berger, M.

    1994-11-01

    The properties of materials in thin films are strongly dependent on the coating techniques and on the technological parameters. We have investigated about some optical and structural properties of YF3 thin films prepared using different energetic techniques: ion assisted deposition (IAD) and ion beam sputtering (IBS). The properties of the thin films obtained by these energetic processes are compared to the properties obtained by classical electron beam evaporation. In classical evaporation, the optical properties in the visible range depend on the temperature of the deposition and on the incidence of the vapor flux. The optical properties are correlated with the density of the films measured by Rutherford backscattering. In the case of IAD, the influence on optical properties, both in the visible and in the infrared range, of some technological parameters (pressure, ion energy and ion density) are illustrated. The refractive index and the extinction coefficient have been obtained by spectrophotometry. Furthermore, we show that IBS may lead to YF3 layers of high density.

  15. 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

  16. Hepatitis B Vaccination Protection

    MedlinePlus

    ... The hepatitis B vaccination is a non-infectious, vaccine prepared from recombinant yeast cultures, rather than human blood or plasma. There is no risk of contamination from other bloodborne pathogens nor is there any ... from the vaccine. The vaccine must be administered according to the ...

  17. 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

  18. 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

    Cui, Xianjin; Mathe, Domokos; Kovács, Noémi; Horváth, Ildikó; Jauregui-Osoro, Maite; Torres Martin de Rosales, Rafael; Mullen, Gregory E D; Wong, Wilson; Yan, Yong; Krüger, Dirk; Khlobystov, Andrei N; Gimenez-Lopez, Maria; Semjeni, Mariann; Szigeti, Krisztián; Veres, Dániel S; Lu, Haizhou; Hernández, Ignacio; Gillin, William P; Protti, Andrea; Petik, Katalin Kis; Green, Mark A; Blower, Philip J

    2016-02-17

    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 [(18)F]-fluoride or radiometal-bisphosphonate conjugates (e.g., (64)Cu and (99m)Tc), 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

  19. Yellow Fever/Japanese Encephalitis Chimeric Viruses: Construction and Biological Properties

    PubMed Central

    Chambers, Thomas J.; Nestorowicz, Ann; Mason, Peter W.; Rice, Charles M.

    1999-01-01

    A system has been developed for generating chimeric yellow fever/Japanese encephalitis (YF/JE) viruses from cDNA templates encoding the structural proteins prM and E of JE virus within the backbone of a molecular clone of the YF17D strain. Chimeric viruses incorporating the proteins of two JE strains, SA14-14-2 (human vaccine strain) and JE Nakayama (JE-N [virulent mouse brain-passaged strain]), were studied in cell culture and laboratory mice. The JE envelope protein (E) retained antigenic and biological properties when expressed with its prM protein together with the YF capsid; however, viable chimeric viruses incorporating the entire JE structural region (C-prM-E) could not be obtained. YF/JE(prM-E) chimeric viruses grew efficiently in cells of vertebrate or mosquito origin compared to the parental viruses. The YF/JE SA14-14-2 virus was unable to kill young adult mice by intracerebral challenge, even at doses of 106 PFU. In contrast, the YF/JE-N virus was neurovirulent, but the phenotype resembled parental YF virus rather than JE-N. Ten predicted amino acid differences distinguish the JE E proteins of the two chimeric viruses, therefore implicating one or more residues as virus-specific determinants of mouse neurovirulence in this chimeric system. This study indicates the feasibility of expressing protective antigens of JE virus in the context of a live, attenuated flavivirus vaccine strain (YF17D) and also establishes a genetic system for investigating the molecular basis for neurovirulence determinants encoded within the JE E protein. PMID:10074160

  20. Vaccines today, vaccines tomorrow: a perspective.

    PubMed

    Loucq, Christian

    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

  1. 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

  2. Human vaccines & immunotherapeutics: news.

    PubMed

    Riedmann, Eva M

    2013-07-01

    Recent advances in the development of immunotherapeutic mAbs for cancer New vaccine reduces malaria infection by 72% Bavarian Nordic's cancer immunotherapy shows promise in colorectal cancer Chinese HFMD vaccine shows high efficacy in Phase 3 Two-dose regimen of Merck's Gardasil looks effective Accelerating influenza vaccine development using synthetic biology A key role for gut microbes in vaccination Understanding of and attitudes towards vaccines: a study in teenagers. PMID:23863285

  3. Existing antiviral vaccines.

    PubMed

    Ravanfar, Parisa; Satyaprakash, Anita; Creed, Rosella; Mendoza, Natalia

    2009-01-01

    The innovation of vaccines has allowed for one of the greatest advancements in the history of public health. The first of the vaccines have been the antiviral vaccines, in particular the smallpox vaccine that was first developed by Edward Jenner in 1796. This article will review vaccination for the following viral diseases: measles, mumps, rubella, polio, hepatitis A, hepatitis B, influenza, rotavirus, rabies, monkeypox, smallpox, Japanese encephalitis, and yellow fever. PMID:19335723

  4. Countering Vaccine Hesitancy.

    PubMed

    Edwards, Kathryn M; Hackell, Jesse M

    2016-09-01

    Immunizations have led to a significant decrease in rates of vaccine-preventable diseases and have made a significant impact on the health of children. However, some parents express concerns about vaccine safety and the necessity of vaccines. The concerns of parents range from hesitancy about some immunizations to refusal of all vaccines. This clinical report provides information about addressing parental concerns about vaccination. PMID:27573088

  5. Enhanced emission at 2.85 μm of Ho3+/Pr3+ co-doped α-NaYF4 single crystal

    NASA Astrophysics Data System (ADS)

    Wang, Cheng; Xia, Hai-ping; Feng, Zhi-gang; Zhang, Zhi-xiong; Jiang, Dong-sheng; Zhang, Jian; Sheng, Qi-guo; Tang, Qing-yang; He, Shi-nan; Jiang, Hao-chuan; Chen, Bao-jiu

    2016-01-01

    The Ho3+/Pr3+ co-doped NaYF4 single crystals with various Pr3+ concentrations and constant Ho3+ molar percentage of ~1% were grown by an improved Bridgman method. Compared with the Ho3+ single-doped NaYF4 crystal, an obviously enhanced emission band at 2.85 μm is observed under 640 nm excitation. The Judd-Ofelt strength parameters ( Ω 2, Ω 4 and Ω 6) are calculated, the radiative transition probabilities ( A), the fluorescence branching ratios ( β) and the radiative lifetime ( τ rad) are obtained in the meantime. The energy transfer from Pr3+ to Ho3+ and the optimum fluorescence emission of Ho3+ ions around 2.85 μm are investigated. Moreover, the maximum emission cross section of above samples at 2.85 μm is calculated to be 0.72×10-20 cm2 for the NaYF4 single crystal with Ho3+ molar percentage of 1% and Pr3+ molar percentage of 0.5% according to the measured absorption spectrum. All results suggest that the Ho3+/Pr3+ co-doped NaYF4 single crystal may have potential applications in mid-infrared lasers.

  6. 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. PMID:25875488

  7. Ultraviolet upconversion enhancement in triply doped NaYF4:Tm3+, Yb3+ particles: The role of Nd3+ or Gd3+ Co-doping

    NASA Astrophysics Data System (ADS)

    Pokhrel, Madhab; Valdes, Carolina; Mao, Yuanbing

    2016-08-01

    Upconversion (UC) particles are currently under intensive investigation, normally for their visible instead of ultraviolet (UV) light luminescence under near-infrared (NIR) irradiation. As a commonly studied host, NaYF4 in particular is known to have low phonon energy and high UC efficiency. Here, we present our work on enhancing UC luminescence in the UV region by adding a third dopant into a binary-doped NaYF4:Yb3+,Tm3+ host. More specifically, neodymium (Nd3+) or gadolinium (Gd3+) ions was co-doped into parent NaYF4:20mol%Yb3+,0.5mol%Tm3+ UC particles to enhance their UV UC luminescence. Experimental results demonstrated that these particles exhibited the highest degree of UV UC enhancements when co-doped with 0.05mol% Nd3+ or 2.0mol% Gd3+, expanding the potential of this type of materials into many possible applications by directly converting NIR irradiation into UV light. Fundamentally, the UV UC emission dependence of these triply doped NaYF4:Yb3+,Tm3+ particles with different Nd3+ and Gd3+ doping concentrations was investigated in terms of ground state absorption, excited state absorption and energy transfer UC mechanisms.

  8. UV, visible and near-infrared lights induced NOx destruction activity of (Yb,Er)-NaYF4/C-TiO2 composite

    PubMed Central

    Wu, Xiaoyong; Yin, Shu; Dong, Qiang; Liu, Bin; Wang, Yuhua; Sekino, Tohru; Lee, Soo Wohn; Sato, Tsugio

    2013-01-01

    Titanium dioxide (TiO2) is a well-known photocatalyst for environmental cleaning and energy conversion. However, it can only be excited by ultraviolet light for photocatalysis due to its wide band gap (3.2 eV). In this paper, we present a novel (Yb,Er)-NaYF4/C-TiO2 composite which can be perfectly induced not only by ultraviolet light but also weak visible and near infrared lights, owing to the increased carbon doping contents and optimal energy transfer between up-conversion phosphor and C doped TiO2 compared with that of solely C-TiO2. Consequently, the (Yb,Er)-NaYF4/C-TiO2 composite can present the outstanding continuous NOx gas destruction ability under the irradiation of ultraviolet, weak visible and infrared lights much superior to pure C-TiO2, P25 titania and even that of (Yb,Er)-NaYF4/N-TiO2 composite, due to the nice synergetic effect of (Yb,Er)-NaYF4 and C-TiO2, indicating a promising potential in the photocatalyst application with high efficiency of ultraviolet, visible and infrared lights induced photocatalysis simultaneously. PMID:24108086

  9. Remarkable enhancement of upconversion fluorescence and confocal imaging of PMMA Opal/NaYF(4):Yb(3+), Tm(3+)/Er(3+) nanocrystals.

    PubMed

    Yin, Ze; Zhu, Yongsheng; Xu, Wen; Wang, Jing; Xu, Sai; Dong, Biao; Xu, Lin; Zhang, Shuang; Song, Hongwei

    2013-05-01

    Novel PMMA opal photonic crystal/NaYF(4):Yb(3+), Tm(3+)/Er(3+) nanocrystal composites were fabricated and tremendous improvement in upconversion luminescence (UCL) was observed under infrared 980 nm excitation. They were also explored to improve brightness of cell images. PMID:23539518

  10. 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. PMID:25902360

  11. 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).

  12. Obesity vaccines

    PubMed Central

    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. PMID:24365968

  13. Rotavirus vaccine: a review.

    PubMed

    Kumar, Goel Manish; Arun, Kumar; Bilas, Jain Ram; Ruchi, Jain; Pardeep, Khanna; Pradeep, Siwach

    2012-12-01

    Worldwide, large proportion i.e., 37% of deaths due to diarrhea in young children is attributed to rotavirus. A monovalent P1A[8] G1 vaccine and a pentavalent bovine-human reassortant vaccine human rotavirus vaccine had shown good clinical efficacy without any increase in intussusception among vaccine recipients. WHO recommends that the first dose of rotavirus vaccine should be administered to infants up to age of 6-15 weeks irrespective of the prior history of rotavirus infection and the maximum age for administering the last dose of the vaccine should be 32 weeks. Booster doses are not recommended. The current update reviews the issues related to rotavirus vaccines and their usages like milestones in the development of rotavirus vaccines, concerns regarding their efficacy and cost-effectiveness, immunity after natural infection, potential for changes in virus strains, current recommendations, post marketing surveillance, and future challenges and scope for further research regarding rotavirus vaccines. PMID:25145068

  14. [Developments in HPV vaccination].

    PubMed

    de Melker, Hester; Kenter, Gemma; van Rossum, Tekla; Conyn-van Spaendonck, Marina

    2012-01-01

    Vaccination against the human papilloma virus (HPV) has been included in the national Vaccination Programme of the Netherlands for 12-year-old girls since 2010. Vaccination coverage for the birth cohort of 1997 was 56.; there is a gradual increase in uptake. Continuous safety monitoring brought no new unknown serious side effects to light; many girls suffered from transient symptoms such as painful arm, fatigue and headache. After the current vaccines that protect against HPV types 2 and 4 types, respectively and induce some cross protection, vaccines are being developed that can induce broader protection. HPV vaccination of 12-year-old girls is cost-effective, even for relatively low vaccination coverage. The potential protection of HPV vaccination extends beyond prevention of cervical cancer by preventing other oncological manifestations of HPV infection in women as well as men and genital warts. The preventive HPV vaccines do not appear to be effective in treating existing abnormalities. PMID:23171565

  15. Current Vaccine Shortages and Delays

    MedlinePlus

    ... Patient Education Programs and Tools VTrckS (Vaccine Tracking System) Immunization Registries (IIS) Vaccines for Children (VFC) Stop Transmission of Polio (STOP) Vaccine Management Business Improvement Project (VMBIP) Global Immunizations & Vaccinations Immunization Program ...

  16. Mumps - Vaccine Q and A

    MedlinePlus

    ... containing vaccine, given as combination measles, mumps, rubella (MMR) vaccine, separated by at least 28 days, are routinely ... been vaccinated should also receive 1 dose of MMR vaccine, but adults who work in healthcare, a school/ ...

  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. Side Effects of Smallpox Vaccination

    MedlinePlus

    ... Index SMALLPOX FACT SHEET Side Effects of Smallpox Vaccination The smallpox vaccine prevents smallpox. For most people, ... go away without treatment: The arm receiving the vaccination may be sore and red where the vaccine ...

  19. Vaccination: An Act of Love

    MedlinePlus

    ... benefits of vaccines. For this reason, we created Vaccination Week in the Americas to get vaccines to ... and no one gets left behind. Help the vaccination teams when they come to your town, your ...

  20. Human Papillomavirus (HPV) Vaccine (Gardasil)

    MedlinePlus

    ... changes or ringing in the ears.Like all vaccines, HPV vaccines will continue to be monitored for unusual ... visit CDC's website at http://www.cdc.gov/vaccines. HPV Vaccine (Gardasil) Information Statement. U.S. Department of Health ...

  1. Human Papillomavirus (HPV) Vaccine (Cervarix)

    MedlinePlus

    ... changes or ringing in the ears. Like all vaccines, HPV vaccines will continue to be monitored for unusual ... gov/std/hpv and http://www.cdc.gov/vaccines HPV Vaccine (Cervarix) Information Statement. U.S. Department of Health ...

  2. 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

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 75 FR 48712 - Proposed Vaccine Information Materials for Influenza Vaccine

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-11

    ... season, 2009 H1N1 influenza vaccine is being incorporated into the seasonal vaccine formulation... vaccine provides some protection. The 2010-2011 vaccine provides protection against H1N1 (pandemic.... People who got the 2009 H1N1 vaccine still need to get vaccinated with the 2010-2011 influenza...

  9. Importance of suppression of Yb(3+) de-excitation to upconversion enhancement in β-NaYF4: Yb(3+)/Er(3+)@β-NaYF4 sandwiched structure nanocrystals.

    PubMed

    Xiang, Guotao; Zhang, Jiahua; Hao, Zhendong; Zhang, Xia; Pan, Guo-Hui; Luo, Yongshi; Lü, Wei; Zhao, Haifeng

    2015-04-20

    Nanosized Yb(3+) and Er(3+) co-doped β-NaYF4 cores coated with multiple β-NaYF4 shell layers were synthesized by a solvothermal process. X-ray diffraction and scanning electron microscopy were used to characterize the crystal structure and morphology of the materials. The visible and near-infrared spectra as well as the decay curves were also measured. A 40-fold intensity increase for the green upconversion and a 34-fold intensity increase for the red upconversion were observed as the cores are coated with three shell layers. The origin of the upconversion enhancement was studied on the basis of photoluminescence spectra and decay times. Our results indicate that the upconversion enhancement in the sandwiched structure mainly originates from the suppression of de-excitation of Yb(3+) ions. We also explored the population of the Er(3+4)F9/2 level. The results reveal that energy transfer from the lower intermediate Er(3+4)I13/2 level is dominant for populating the Er(3+4)F9/2 level when the nanocrystal size is relatively small; however, with increasing nanocrystal size, the contribution of the green emitting Er(3+4)S3/2 level for populating the Er(3+4)F9/2 level, which mainly comes from the cross relaxation energy transfer from Er(3+) ions to Yb(3+) ions followed by energy back transfer within the same Er(3+)-Yb(3+) pair, becomes more and more important. Moreover, this mechanism takes place only in the nearest Er(3+)-Yb(3+) pairs. This population route is in good agreement with that in nanomaterials and bulk materials. PMID:25848860

  10. HIV/AIDS and Vaccines

    MedlinePlus

    ... Prevention Research : Vaccines Subscribe Translate Text Size Print Vaccines What Are Vaccines and What Do They Do? A vaccine—also ... immune response against the disease. Is There a Vaccine for HIV? No. There is currently no vaccine ...

  11. Efficient near-infrared quantum cutting in NaYF4: Ho3+, Yb3+ for solar photovoltaics.

    PubMed

    Deng, Kaimo; Gong, Tao; Hu, Lingxun; Wei, Xiantao; Chen, Yonghu; Yin, Min

    2011-01-31

    Quantum cutting converting a ultraviolet photon into two near-infrared photons has been demonstrated by spectroscopic measurements in NaYF4:Ho3+,Yb3+ synthesized by hydrothermal method. Evidence is provided to confirm the occurrence of quantum cutting. Upon excitation of Ho3+ 5G4 level, near-infrared quantum cutting could occur through a two-step resonance energy transfer from Ho3+ to Yb3+ by cross relaxation, with a maximum quantum efficiency of 155.2%. This result reveals the possibility of violet to near-infrared quantum cutting with a quantum efficiency larger than 100% in Ho3+/Yb3+ codoped fluorides, suggesting the possible application in modifying the solar spectrum to enhance the efficiency of silicon solar cells. PMID:21368989

  12. Mechanism of Biological Compatibility of Water-Soluble Yb3+, Er3+ Codoped NaYF4 Nanoparticles.

    PubMed

    Liu, Chen; Chen, Huan; Li, Shouying; Xu, Hong; Zhao, Dan

    2016-04-01

    Water soluble NaYF4 nanocrystals codoped with 20 mol% Yb3+, 2 mol% Er3+ were prepared by a facile solvothermal approach using polyvinylpyrrolidone (PVP) as a surfactant. As a potential material for luminescent probes, in votroeffects of upconversion nanoparticles (UCNPs) on human aenocarcinoma (SGC-7901) cells with different concentrations were observed. These effects range from cell viability, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) production, AnnexinV-FITC-propidium iodide (PI) apoptosis detection, and cell cycles. Our results demonstrated that the cells treated with UCNPs showed a decrease in cell viability accompanied the decreased MMP and the release of ROS. When treated with 400 µg/mL UCNPs, AnnexinV-FITC-PI apoptosis detection showed the UCNPs induced apoptosis, the cell cycle indicated the UCNPs suppressor cells in the G1 phase obviously, thereby reducing cell activity. PMID:27451683

  13. Computer simulation of aircraft motions and propulsion system dynamics for the YF-12 aircraft at supersonic cruise conditions

    NASA Technical Reports Server (NTRS)

    Brown, S. C.

    1973-01-01

    A computer simulation of the YF-12 aircraft motions and propulsion system dynamics is presented. The propulsion system was represented in sufficient detail so that interactions between aircraft motions and the propulsion system dynamics could be investigated. Six degree-of-freedom aircraft motions together with the three-axis stability augmentation system were represented. The mixed compression inlets and their controls were represented in the started mode for a range of flow conditions up to the inlet unstart boundary. Effects of inlet moving geometry on aircraft forces and movements as well as effects of aircraft motions on the inlet behavior were simulated. The engines, which are straight subjects, were represented in the afterburning mode, with effects of changes in aircraft flight conditions included. The simulation was capable of operating in real time.

  14. A Review of Study on Thermodynamic Properties of Hydrofluoroolefin Refrigerants R 1234yf and R 1234ze(E)

    NASA Astrophysics Data System (ADS)

    Akasaka, Ryo; Kayukawa, Yohei; Tanaka, Katsuyuki; Higashi, Yukihiro

    A comprehensive review is presented for the study on the thermodynamic properties of R 1234yf (2,3,3,3- tetrafluoropropene) and R 1234ze(E) (trans-1,3,3,3-tetrafluoropropene), which are considered as a possible replacement for conventional refrigerants with far from negligible global warming potential. Available experimental data for the critical parameters, vapor pressures, liquid/vapor densities, heat capacities, and speeds of sound are compiled, and reliability of each data is evaluated. A brief summary is also given for equations of state developed for these refrigerants, including comparison of deviations from experimental values and valid ranges of each equation of state. Recommended equations are selected which can be applied to refrigeration system analysis.

  15. A throat-bypass stability system for a YF-12 aircraft research inlet using self-acting mechanical valves

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

    Results of a wind tunnel investigation are presented. The inlet was modified so that airflow can be removed through a porous cowl-bleed region in the vicinity of the throat. Bleed plenum exit flow area is controlled by relief type mechanical valves. Unlike valves in previous systems, these are made for use in a high Mach flight environment and include refinements so that the system could be tested on a NASA YF-12 aircraft. The valves were designed to provide their own reference pressure; hence, do not respond to slowly varying disturbances. However, the results show that the system can absorb internal-airflow-transients that are too fast for a conventional bypass door control system and that the two systems complement each other quite well. Increased tolerance to angle of attack and Mach number changes is indicated. The valves should provide sufficient time for the inlet control system to make geometry changes required to keep the inlet started.

  16. A throat-bypass stability system for a YF-12 aircraft research inlet using self-acting mechanical valves

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

    Results of a wind tunnel investigation are presented. The inlet was modified so that airflow can be removed through a porous cowl-bleed region in the vicinity of the throat. Bleed plenum exit flow area is controlled by relief type mechanical valves. Unlike valves in previous systems, these are made for use in a high Mach flight environment and include refinements so that the system could be tested on a NASA YF-12 aircraft. The valves were designed to provide their own reference pressure. The results show that the system can absorb internal-airflow-transients that are too fast for a conventional bypass door control system and that the two systems complement each other quite well. Increased tolerance to angle of attack and Mach number changes is indicated. The valves should provide sufficient time for the inlet control system to make geometry changes required to keep the inlet started.

  17. Narcolepsy Following Yellow Fever Vaccination: A Case Report.

    PubMed

    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

  18. 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

  19. MMR Vaccine (Measles, Mumps, and Rubella)

    MedlinePlus

    Attenuvax® Measles Vaccine ... R-Vax® II (as a combination product containing Measles Vaccine, Rubella Vaccine) ... M-R® II (as a combination product containing Measles Vaccine, Mumps Vaccine, Rubella Vaccine)

  20. NaYF{sub 4}:Er,Yb/Bi{sub 2}MoO{sub 6} core/shell nanocomposite: A highly efficient visible-light-driven photocatalyst utilizing upconversion

    SciTech Connect

    Sun, Yuanyuan; Wang, Wenzhong Sun, Songmei; Zhang, Ling

    2014-04-01

    Highlights: • Design and synthesis of NaYF{sub 4}:Er,Yb/Bi{sub 2}MoO{sub 6} based on upconversion. • NaYF{sub 4}:Er,Yb/Bi{sub 2}MoO{sub 6} nanocomposite was prepared for the first time. • Core–shell structure benefits the properties. • Upconversion contributed to the enhanced photocatalytic activity. • Helps to understand the functionality of new type photocatalysts. - Abstract: NaYF{sub 4}:Er,Yb/Bi{sub 2}MoO{sub 6} core/shell nanocomposite was designed and prepared for the first time based on upconversion. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution TEM (HRTEM), energy dispersive X-ray spectroscopy (EDS) and diffuse reflectance spectra (DRS). The results revealed that the as-synthesized NaYF{sub 4}:Er,Yb/Bi{sub 2}MoO{sub 6} consisted of spheres with a core diameter of about 26 nm and a shell diameter of around 6 nm. The core was upconversion illuminant NaYF{sub 4}:Er,Yb and the shell was Bi{sub 2}MoO{sub 6} around the core, which was confirmed by EDS. The NaYF{sub 4}:Er,Yb/Bi{sub 2}MoO{sub 6} exhibited higher photocatalytic activity for the photodecomposition of Rhodamine B (RhB) under the irradiation of Xe lamp and green light emitting diode (g-LED). The mechanism of the high photocatalytic activity was discussed by photoluminescence spectra (PL), which is mainly attributed to upconversion of NaYF{sub 4}:Er,Yb in the NaYF{sub 4}:Er,Yb/Bi{sub 2}MoO{sub 6} nanocomposite and the core–shell structure.

  1. 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.

  2. Pneumococcal Vaccines (PCV, PPSV)

    MedlinePlus

    ... Know About Zika & Pregnancy 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, ...

  3. 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 ...

  4. [Biotechnology and vaccinations].

    PubMed

    Peret, R

    1990-12-01

    Current biotechnologies used in the manufacture of new vaccines are of three kinds: Genetic recombinations leading to either vaccinal sub-units or living vaccines represented by recombinant vectors; Chemical synthesis techniques; Use of the spatial configuration of an anti-antibody similar to the initial antigen. These are the anti-idiotype vaccines. Genetic engineering is the basis of a new generation of vaccines, sought with the aim of attempting to eradicate a number of diseases throughout the world. However, there is presently an inadequacy in resources, most often linked to financial considerations, which limits widespread systematic vaccination. In the future, vaccines against dental caries will probably be obtained from purified proteins of hydrolase fractions common to cariogenic bacteria and resulting from genetic recombinations in the form of vaccinal sub-units. PMID:2077866

  5. Smallpox Vaccine Overview

    MedlinePlus

    ... complications from the vaccinia virus can be severe. Benefit of Vaccine Following Exposure Vaccination within 3 days ... Policies About CDC.gov Link to Us All Languages Contact CDC Centers for Disease Control and Prevention ...

  6. Hepatitis B Vaccine

    MedlinePlus

    ... as a combination product containing Hepatitis A Vaccine, Hepatitis B Vaccine) ... What is hepatitis B?Hepatitis B is a serious infection that affects the liver. It is caused by the hepatitis B virus. ...

  7. Tetanus (Lockjaw) Vaccination

    MedlinePlus

    ... adults - Tetanus-diphtheria-acellular Pertussis vaccine Tetanus (Lockjaw) Vaccination Recommend on Facebook Tweet Share Compartir Tetanus (lockjaw) ... Related Pages Diphtheria Pertussis Feature Story: Adults Need Immunizations, Too Also Known As & Abbreviations Tetanus = Lockjaw DTaP = ...

  8. Meningococcal Vaccine (For Parents)

    MedlinePlus

    ... Things to Know About Zika & Pregnancy Your Child's Immunizations: Meningococcal Vaccines KidsHealth > For Parents > Your Child's Immunizations: ... are at increased risk of developing meningococcal disease. Immunization Schedule Vaccination with MCV4 is recommended: when kids ...

  9. Hepatitis A Vaccine

    MedlinePlus

    Twinrix® (as a combination product containing Hepatitis A Vaccine, Hepatitis B Vaccine) ... What is hepatitis A?Hepatitis A is a serious liver disease caused by the hepatitis A virus (HAV). HAV is found in ...

  10. Your child's first vaccines

    MedlinePlus

    ... these vaccines today: [ ] DTaP [ ] Hib [ ] Hepatitis B [ ] Polio [ ] PCV13 (Provider: Check appropriate boxes) 1. Why get vaccinated? ... the 6-month dose is not needed. Pneumococcal (PCV13) 4 2 months, 4 months, 6 months, 12- ...

  11. Vaccines and animal welfare.

    PubMed

    Morton, D B

    2007-04-01

    Vaccination promotes animal welfare by protecting animal health, but it also has other welfare benefits, e.g. recent investigations have looked at the potential of vaccines in immunoneutering such as immunocastration--a humane alternative to the painful traditional methods. Similarly, vaccination can be used during disease outbreaks as a viable alternative to stamping-out, thus avoiding the welfare problems that on-farm mass slaughter can cause. Protecting animal health through vaccination leads to improved animal welfare, and maintaining good welfare ensures that animals can respond successfully to vaccination (as poor welfare can lead to immunosuppression, which can affect the response to vaccination). It is clear that vaccination has tremendous advantages for animal welfare and although the possible side effects of vaccination can have a negative effect on the welfare of some individual animals, the harm caused by these unwanted effects must be weighed against the undoubted benefits for groups of animals. PMID:17633300

  12. 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

  13. Vaccine Reaction Images

    MedlinePlus

    ... Training Materials Q fever Info & Guidance for Clinicians Salmonella Shigella Smallpox Smallpox Basics Vaccine Basics Clinicians Vaccination ... Metals Nerve Agents Pulmonary Agents Riot Control Agents Toxic Alcohols Vesicants Chemical-Specific Fact Sheets Toxicology FAQs ...

  14. 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.

  15. 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.

  16. Vaccines in Dermatology

    PubMed Central

    Shah, Mitali M; Shah, Aishani C; Mahajan, Rashmi S; Bilimoria, Freny E

    2015-01-01

    A vaccine is a biological preparation that improves immunity to a specific disease. More than two centuries have passed since the first successful vaccine for smallpox was developed. We’ve come a long way since. Today's vaccines are among the 21st century's most successful and cost-effective public health tools for preventing diseases. PMID:26120155

  17. 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. PMID:27368091

  18. 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 ...

  19. Vaccines in dermatological diseases.

    PubMed

    Magel, G D; Mendoza, N; Digiorgio, C M; Haitz, K A; Lapolla, W J; Tyring, S K

    2011-06-01

    Vaccines have been a cornerstone in medicine and public health since their inception in the 18th century by Edward Jenner. Today, greater than 20 vaccines are used worldwide for the prevention of both viral and bacterial diseases. This article will review the vaccines used for the following dermatological diseases: smallpox, measles, mumps, rubella, chickenpox, shingles, and human papillomavirus. PMID:21566552

  20. 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. PMID:20638452

  1. Human immunodeficiency virus vaccines.

    PubMed

    Goepfert, Paul; Bansal, Anju

    2014-12-01

    Although some success was achieved in recent years in HIV prevention, an effective vaccine remains the means with the most potential of curtailing HIV-1 infections worldwide. Despite multiple failed attempts, a recent HIV vaccine regimen demonstrated modest protection from infection. Although the protective efficacy in this trial was not sufficient to warrant licensure, it spurred renewed optimism in the field and has provided valuable insights for improving future vaccine designs. This review summarizes the pertinent details of vaccine development and discusses ways the field is moving forward to develop a vaccine to prevent HIV infection and disease progression. PMID:25287587

  2. 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.

  3. Vaccine-Associated Uveitis.

    PubMed

    Benage, Matthew; Fraunfelder, Frederick W

    2016-01-01

    All of the widely administered vaccines have been reported to cause uveitis. The ocular inflammation is usually temporary and resolves with topical ocular steroids. During a 26-year period, a total of 289 cases of vaccine-associated uveitis were reported to three adverse reaction reporting databases. Hepatitis B vaccine, either alone or administered with other vaccines, appears to be the leading offender. Clinicians are encouraged to report cases of vaccine- or drug-associated ocular adverse reactions to www.eyedrugregistry.com. PMID:27039491

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

    PubMed

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

    2016-06-01

    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 Er(3+)-doped upconversion nanoparticles (UCNPs) with double excitation bands for simultaneous deep macroscopic and microscopic imaging. The material structure and the excitation wavelength of Er(3+)-singly doped UCNPs were further optimized to enhance the upconversion emission efficiency. After optimization, we found that NaYF4:30%Er(3+)@NaYF4:2%Er(3+) 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 Er(3+)-doped UCNPs as bioprobe. PMID:27375936

  5. 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

  6. Hexagonal β-NaYF4:Yb(3+), Er(3+) Nanoprism-Incorporated Upconverting Layer in Perovskite Solar Cells for Near-Infrared Sunlight Harvesting.

    PubMed

    Roh, Jongmin; Yu, Haejun; Jang, Jyongsik

    2016-08-10

    Hexagonal β-NaYF4:Yb(3+), Er(3+) nanoprisms, successfully prepared using a hydrothermal method, were incorporated into CH3NH3PbI3 perovskite solar cells (PSCs) as an upconverting mesoporous layer. Due to their near-infrared (NIR) sunlight harvesting, the PSCs based on the upconverting mesoporous layer exhibited a power conversion efficiency of 16.0%, an increase of 13.7% compared with conventional TiO2 nanoparticle-based PSCs (14.1%). This result suggests that the hexagonal β-NaYF4:Yb(3+), Er(3+) nanoprisms expand the absorption range of the PSC via upconversion photoluminescence, leading to an enhancement of the photocurrent. PMID:27472304

  7. Ideal-Gas Heat Capacity for 2,3,3,3-Tetrafluoropropene (HFO-1234yf) Determined from Speed-of-Sound Measurements

    NASA Astrophysics Data System (ADS)

    Kano, Yuya; Kayukawa, Yohei; Fujii, Kenichi; Sato, Haruki

    2010-12-01

    The isobaric ideal-gas heat capacity for HFO-1234yf, which is expected to be one of the best alternative refrigerants for HFC-134a, was determined on the basis of speed-of-sound measurements in the gaseous phase. The speed of sound was measured by means of the acoustic resonance method using a spherical cavity. The resonance frequency in the spherical cavity containing the sample gas was measured to determine the speed of sound. After correcting for some effects such as the thermal boundary layer and deformation of the cavity on the resonance frequency, the speed of sound was obtained with a relative uncertainty of 0.01 %. Using the measured speed-of-sound data, the acoustic-virial equation was formulated and the isobaric ideal-gas heat capacity was determined with a relative uncertainty of 0.1 %. A temperature correlation function of the isobaric ideal-gas heat capacity for HFO-1234yf was also developed.

  8. Vaccinations for Pregnant Women

    PubMed Central

    Swamy, Geeta K.; Heine, R. Phillips

    2014-01-01

    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 infant 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 provider resources. PMID:25560127

  9. 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

  10. 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. PMID:25560127

  11. 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

  12. Vaccines for allergy.

    PubMed

    Linhart, Birgit; Valenta, Rudolf

    2012-06-01

    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

  13. Immunology of vaccination.

    PubMed

    Beverley, P C L

    2002-01-01

    An ideal vaccine is relatively easy to define, but few real vaccines approach the ideal and no vaccines exist for many organisms, for which a vaccine is the only realistic protective strategy in the foreseeable future. Many difficulties account for the failure to produce these vaccines. All micro-organisms deploy evasion mechanisms that interfere with effective immune responses and, for many organisms, it is not clear which immune responses provide effective protection. However, recent advances in methods for studying immune response to pathogens have provided a better understanding of immune mechanisms, including immunological memory, and led to the realisation that the initiation of immune responses is a key event requiring triggering through 'danger' signals. Based on these findings, the development of novel adjuvants, vectors and vaccine formulations allowing stimulation of optimal and prolonged protective immunity should lead to the introduction of vaccines for previously resistant organisms. PMID:12176847

  14. 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

  15. [Vaccinations for the travellers].

    PubMed

    Gendrel, Dominique

    2004-03-15

    Immunisations for the traveller include, before specific vaccine, a correct immunisation schedule according to national recommendations with appropriate boosters and hepatitis B immunisation. The yellow fever vaccine is required to entry in countries of endemic area and quadrivalent ACYW135 meningococcal vaccine for entry in Saudi Arabia. Hepatitis A immunisation could be performed at 1 year of age and is recommended for travellers in tropical areas and children vaccination control the disease both in the patient and in the contacts. Meningococcal A+C vaccines are required for travellers in meningitis-prone areas of tropical Africa during the dry season (December to June), and quadrivalent ACYW135 is useful only in Burkina-Faso and Niger. Typhoid and rabies vaccines are required for ambulatory travellers in endemic areas, as Japanese encephalitis in south-west Asia. In central Europe, tick-borne encephalitis vaccination is recommended for patients travelling in forest areas during spring and summer. PMID:15176511

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

    PubMed Central

    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.

    2015-01-01

    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 × 1010 or 4 × 1011 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. PMID:26390090

  17. 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.

  18. 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. PMID:25996781

  19. New tuberculosis vaccines.

    PubMed

    Martín Montañés, Carlos; Gicquel, Brigitte

    2011-03-01

    The current tuberculosis (TB) vaccine, bacille Calmette-Guerin (BCG), is a live vaccine used worldwide, as it protects against severe forms of the disease, saving thousands of lives every year, but its efficacy against pulmonary forms of TB, responsible for transmission of the diseases, is variable. For more than 80 years now no new TB vaccines have been successfully developed. Over the last decade the effort of the scientific community has resulted in the design and construction of promising vaccine candidates. The goal is to develop a new generation of vaccines effective against respiratory forms of the disease. We will focus this review on new prophylactic vaccine candidates that aim to prevent TB diseases. Two are the main strategies used to improve the immunity conferred by the current BCG vaccine, by boosting it with new subunit vaccines, and a second strategy is focused on the construction of new more effective live vaccines, capable to replace the current BCG and to be used as prime vaccines. After rigorous preclinical studies in different animal models new TB vaccine candidates enter in clinical trials in humans. First, a small Phase I for safety followed by immunological evaluation in Phase II trials and finally evaluated in large population Phase III efficacy trials in endemic countries. At present BCG prime and boost with different subunit vaccine candidates are the more advanced assessed in Phase II. Two prime vaccines (based on recombinant BCG) have been successfully evaluated for safety in Phase I trials. A short number of live attenuated vaccines are in advance preclinical studies and the candidates ready to enter Phase I safety trials are produced under current good manufacturing practices. PMID:21420568

  20. 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. PMID:26496243

  1. Temperature-dependent upconversion luminescence and dynamics of NaYF4:Yb3+/Er3+ nanocrystals: influence of particle size and crystalline phase.

    PubMed

    Yu, Wei; Xu, Wen; Song, Hongwei; Zhang, Shuang

    2014-04-28

    Oleic acid-capped NaYF4:Yb(3+)/Er(3+) upconversion nanocrystals (UCNCs) with different sizes and crystalline phases were prepared, and their temperature-dependent upconversion luminescence (UCL) and dynamics were studied. It is interesting to observe that the temperature-dependent behavior of UCL for the β-phase (25 nm, 45 nm and bulk) and α-phase (<10 nm) UCNCs is quite different. The UCL intensity of Er(3+) ions of the β-phase NaYF4 demonstrates a maximum around 100 K, while the intensity of the α-phase quenches monotonously with elevated temperature (10-400 K). The intensity ratio of (2)H11/2-(4)I15/2 to (4)S3/2-(4)I15/2, RHS, increases solely with temperature for β-phase NaYF4, while for the α-phase sample, it demonstrates a complex and indeterminate variation as a function of temperature. In the β-phase samples, rising processes were observed in the dynamics of Er(3+) ions, while in the α-phase sample, no rising process was observed and the decay processes of Er(3+) ions were bi-exponential. The rationale for these different temperature-dependent UCL properties was explained carefully. PMID:24577323

  2. 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. PMID:24065169

  3. Estimated 2017 refrigerant emissions of 2,3,3,3-tetrafluoropropene (HFC-1234yf) in the United States resulting from automobile air conditioning.

    PubMed

    Papasavva, Stella; Luecken, Deborah J; Waterland, Robert L; Taddonio, Kristen N; Andersen, Stephen O

    2009-12-15

    In response to recent regulations and concern over climate change, the global automotive community is evaluating alternatives to the current refrigerant used in automobile air conditioning units, 1,1,1,2-tetrafluoroethane, HFC-134a. One potential alternative is 2,3,3,3-tetrafluoropropene (HFC-1234yf, also known as HFO-1234yf). We have developed a spatially and temporally resolved inventory of likely future HFC refrigerant emissions from the U.S. vehicle fleet in 2017, considering regular, irregular, servicing, and end-of-life leakages. We estimate the annual leak rate emissions for each leakage category for a projected 2017 U.S. vehicle fleet by state, and spatially apportion these leaks to a 36 km square grid over the continental United States. This projected inventory is a necessary first step in analyzing for potential atmospheric and ecosystem effects, such as ozone and trifluoroacetic acid production, that might result from widespread replacement of HFC-134a with HFC-1234yf. PMID:20000517

  4. Optimizing infrared to near infrared upconversion quantum yield of β-NaYF4:Er3+ in fluoropolymer matrix for photovoltaic devices

    NASA Astrophysics Data System (ADS)

    Ivaturi, Aruna; MacDougall, Sean K. W.; Martín-Rodríguez, Rosa; Quintanilla, Marta; Marques-Hueso, Jose; Krämer, Karl W.; Meijerink, Andries; Richards, Bryce S.

    2013-07-01

    The present study reports for the first time the optimization of the infrared (1523 nm) to near-infrared (980 nm) upconversion quantum yield (UC-QY) of hexagonal trivalent erbium doped sodium yttrium fluoride (β-NaYF4:Er3+) in a perfluorocyclobutane (PFCB) host matrix under monochromatic excitation. Maximum internal and external UC-QYs of 8.4% ± 0.8% and 6.5% ± 0.7%, respectively, have been achieved for 1523 nm excitation of 970 ± 43 Wm-2 for an optimum Er3+ concentration of 25 mol% and a phosphor concentration of 84.9 w/w% in the matrix. These results correspond to normalized internal and external efficiencies of 0.86 ± 0.12 cm2 W-1 and 0.67 ± 0.10 cm2 W-1, respectively. These are the highest values ever reported for β-NaYF4:Er3+ under monochromatic excitation. The special characteristics of both the UC phosphor β-NaYF4:Er3+ and the PFCB matrix give rise to this outstanding property. Detailed power and time dependent luminescence measurements reveal energy transfer upconversion as the dominant UC mechanism.

  5. 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

  6. 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

  7. [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

  8. The Danish vaccination register.

    PubMed

    Grove Krause, T; Jakobsen, S; Haarh, M; Mølbak, K

    2012-01-01

    Immunisation information systems (IIS) are valuable tools for monitoring vaccination coverage and for estimating vaccine effectiveness and safety. Since 2009, an advanced IIS has been developed in Denmark and will be implemented during 2012–14. This IIS is based on a database existing since 2000. The reporting of all administered vaccinations including vaccinations outside the national programme will become mandatory. Citizens will get access to data about their own vaccinations and healthcare personnel will get access to information on the vaccinations of their patients. A national concept of identification, a national solution combining a personal code and a card with codes, ensures easy and secure access to the register. From the outset, the IIS will include data on childhood vaccinations administered from 1996 and onwards. All Danish citizens have a unique identifier, a so called civil registration number, which allows the linking of information on vaccinations coming from different electronic data sources. The main challenge will be to integrate the IIS with the different electronic patient record systems currently existing at general practitioner, vaccination clinic and hospital level thereby avoiding double-entry. A need has been identified for an updated international classification of vaccine products on the market. Such a classification would also be useful for the future exchange of data on immunisations from IIS between countries. PMID:22551494

  9. Nasal vaccine innovation.

    PubMed

    Jabbal-Gill, Inderjit

    2010-12-01

    The current vaccine market is gaining momentum in the development of alternative administration routes namely intranasal, oral, topical, pulmonary, vaginal, and rectal; the nasal route offers the most promising opportunity for vaccine administration. It can enhance convenience, safety, elicit both local and systemic immune responses; thus potentially provide protection from pathogens at the site of entry. Nasal vaccine innovation comes with both opportunities and challenges. The innovative strategies used by industry and researchers to overcome the hurdles are discussed in this article: these include live-attenuated vaccines, adjuvants, mucoadhesives, particulate delivery systems, virus-like particles, vaccine manufacture, challenges of regulatory authorities, and the nasal vaccine impact on market potential. Critical issues for effective nasal vaccination are the antigen-retention period that enables its interaction with the lymphatic system and choice of an adjuvant that is nontoxic and induces the required immune response. Co-adjuvanting by means of a mucoadhesive technology addresses some of these issues. ChiSys(®), a natural bioadhesive with proven intranasal safety profile, has already demonstrated efficacy for several nasally delivered vaccines including norovirus. With the looming threat of a pandemic, alternatives such as intranasal vaccination will ultimately facilitate greater public compliance and rapid mass global vaccination. PMID:21047271

  10. The Meningitis Vaccine Project.

    PubMed

    LaForce, F Marc; Konde, Kader; Viviani, Simonetta; Préziosi, Marie-Pierre

    2007-09-01

    Epidemic meningococcal meningitis is an important public health problem in sub-Saharan Africa. Current control measures rely on reactive immunizations with polysaccharide (PS) vaccines that do not induce herd immunity and are of limited effectiveness in those under 2 years of age. Conversely, polysaccharide conjugate vaccines are effective in infants and have consistently shown an important effect on decreasing carriage, two characteristics that facilitate disease control. In 2001 the Meningitis Vaccine Project (MVP) was created as a partnership between PATH and the World Health Organization (WHO) with the goal of eliminating meningococcal epidemics in Africa through the development, licensure, introduction, and widespread use of conjugate meningococcal vaccines. Since group A Neisseria meningitidis (N. meningitidis) is the dominant pathogen causing epidemic meningitis in Africa MVP is developing an affordable (US$ 0.40 per dose) meningococcal A (Men A) conjugate vaccine through an innovative international partnership that saw transfer of a conjugation and fermentation technology to a developing country vaccine manufacturer. A Phase 1 study of the vaccine in India has shown that the product is safe and immunogenic. Phase 2 studies have begun in Africa, and a large demonstration study of the conjugate vaccine is envisioned for 2008-2009. After extensive consultations with African public health officials a vaccine introduction plan has been developed that includes introduction of the Men A conjugate vaccine into standard Expanded Programme on Immunization (EPI) schedules but also emphasizes mass vaccination of 1-29 years old to induce herd immunity, a strategy that has been shown to be highly effective when the meningococcal C (Men C) conjugate vaccine was introduced in several European countries. The MVP model is a clear example of the usefulness of a "push mechanism" to finance the development of a needed vaccine for the developing world. PMID:17521780

  11. Cutaneous reactions to vaccinations.

    PubMed

    Rosenblatt, Adena E; Stein, Sarah L

    2015-01-01

    Vaccinations are important for infectious disease prevention; however, there are adverse effects of vaccines, many of which are cutaneous. Some of these reactions are due to nonspecific inflammation and irritation at the injection site, whereas other reactions are directly related to the live attenuated virus. Rarely, vaccinations have been associated with generalized hypersensitivity reactions, such as erythema multiforme, Stevens-Johnson syndrome, urticaria, acute generalized exanthematous pustulosis, and drug hypersensitivity syndrome. The onset of certain inflammatory dermatologic conditions, such as lichen planus, granuloma annulare, and pemphigoid, were reported to occur shortly after vaccine administration. Allergic contact dermatitis can develop at the injection site, typically due to adjuvant ingredients in the vaccine, such as thimerosal and aluminum. Vaccinations are important to promote development of both individual and herd immunity. Although most vaccinations are considered relatively safe, there may be adverse effects associated with any vaccine. Cutaneous manifestations make up a large portion of the types of reactions associated with vaccines. There are many different reasons for the development of a cutaneous reaction to a vaccination. Some are directly related to the injection of a live attenuated virus, such as varicella or vaccinia (for immunity to smallpox), whereas others cause more nonspecific erythema and swelling at the injection site, as a result of local inflammation or irritation. Vaccinations have also been associated in rare reports with generalized hypersensitivity reactions, such as erythema multiforme, Stevens-Johnson syndrome, urticaria, acute generalized exanthematous pustulosis, and drug hypersensitivity syndrome. There have been case reports associating the administration of a vaccine with the new onset of a dermatologic condition, such as lichen planus, granuloma annulare, and Sweet syndrome. Finally, allergic contact

  12. 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.

  13. Meningitis C vaccine (North American vaccine).

    PubMed

    Lattanzi, Maria; Del Giudice, Giuseppe

    2002-01-01

    North American Vaccine Inc (NAVI) has launched a conjugate polysaccharide vaccinefor the prevention of meningitis caused by group C meningococcal bacteria [433475]. The vaccine is based upon conjugate technology, incorporating the serogroup C polysaccharide (CPS) of all three major serogroups. Antibody-dependent, complement-mediated activity was demonstrated in mice and non-human primates, with no detectable adverse effects [277193]. Approval was filed for in the UK in January 2000 [353305]. In July 2000, Baxter received approval for NeisVac-C in the UK, and by September 2000 the vaccine was expected to be incorporated into the NHS's immunization campaign against meningitis C [381225]. NeisVac-C will initially appear labeled from NAVI; Baxter completed its acquisition of NAVI in June 2000 [375389]. Baxter estimates the worldwide global market for the vaccine at US $600 million per year [376204]. PMID:12054072

  14. Energy levels and crystal field parameters for Nd3+ ions in BaY2F8, LiKYF5, and K2YF5 single crystals.

    PubMed

    Karbowiak, M; Gnutek, P; Rudowicz, C

    2012-02-15

    The available experimental energy levels of Nd(3+) ions doped into single crystals of BaY(2)F(8), LiKYF(5), and K(2)YF(5), which exhibit low site symmetry, are reanalyzed. A combined approach based on the ascent/descent in symmetry (ADS) method, the superposition model (SPM) analysis, and the pseudosymmetry axes method (PAM) is utilized to extract the crystal field (CF) parameters, B(kq), from experimental spectra. Corresponding sets of the free-ion parameters are also fitted. The crystallographic data are used to establish the axis systems most appropriate for approximation of the actual monoclinic C(2) site symmetry to higher orthorhombic D(2) and tetragonal D(4) symmetry used in CF calculations for BaY(2)F(8). Similarly, for triclinic C(1) site symmetry in LiKYF(5) and K(2)YF(5) approximation to monoclinic C(2) and orthorhombic D(2) symmetry for LiKYF(5), whereas the monoclinic C(s) symmetry for K(2)YF(5), are considered. It is shown that the C(2v) approximation used previously for K(2)YF(5):Nd(3+) is not suitable. SPM enables to calculate for the unapproximated and idealized polyhedrons YF(8) in a given ion-host system of the combined coordination factors Sg(k,q) expressed in the modified crystallographic axis system CAS* and approximated symmetry adapted axis systems, respectively. The quantities Sg(k,q) serve as input for PAM calculations for independent determination of the axis system appropriate for higher symmetry approximations. The pseudosymmetry axes represent the axis system that reflects most closely the approximated higher symmetry of the nearest ligands in a paramagnetic complex embodied in the 4th-rank CF parameters. The combined ADS/SPM/PAM approach provides sets of starting CF parameters (CFPs) in well-defined axis systems. Multiple fittings starting from different points in the CF parameter space yield converging solutions, thus increasing the reliability of the final optimized solutions, which may be then considered as the global minima. The

  15. 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

  16. Recombinant influenza vaccines.

    PubMed

    Sedova, E S; Shcherbinin, D N; Migunov, A I; Smirnov, Iu A; Logunov, D Iu; Shmarov, M M; Tsybalova, L M; Naroditskiĭ, B S; Kiselev, O I; Gintsburg, A L

    2012-10-01

    This review covers the problems encountered in the construction and production of new recombinant influenza vaccines. New approaches to the development of influenza vaccines are investigated; they include reverse genetics methods, production of virus-like particles, and DNA- and viral vector-based vaccines. Such approaches as the delivery of foreign genes by DNA- and viral vector-based vaccines can preserve the native structure of antigens. Adenoviral vectors are a promising gene-delivery platform for a variety of genetic vaccines. Adenoviruses can efficiently penetrate the human organism through mucosal epithelium, thus providing long-term antigen persistence and induction of the innate immune response. This review provides an overview of the practicability of the production of new recombinant influenza cross-protective vaccines on the basis of adenoviral vectors expressing hemagglutinin genes of different influenza strains. PMID:23346377

  17. [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. PMID:26920587

  18. Vaccines against leptospirosis.

    PubMed

    Adler, Ben

    2015-01-01

    Vaccines against leptospirosis followed within a year of the first isolation of Leptospira, with the first use of a killed whole cell bacterin vaccine in guinea pigs published in 1916. Since then, bacterin vaccines have been used in humans, cattle, swine, and dogs and remain the only vaccines licensed at the present time. The immunity elicited is restricted to serovars with related lipopolysaccharide (LPS) antigen. Likewise, vaccines based on LPS antigens have clearly demonstrated protection in animal models, which is also at best serogroup specific. The advent of leptospiral genome sequences has allowed a reverse vaccinology approach for vaccine development. However, the use of inadequate challenge doses and inappropriate statistical analysis invalidates many of the claims of protection with recombinant proteins. PMID:25388138

  19. 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

  20. On the nature of carrier relaxation and ion-ion interactions in ultrasmall β-NaYF4:Eu3+ nanocrystals - effect of the surface

    NASA Astrophysics Data System (ADS)

    Podhorodecki, Artur; Banski, Mateusz; Noculak, Agnieszka; Sojka, Bartlomiej; Pawlik, Grzegorz; Misiewicz, Jan

    2012-12-01

    The purely hexagonal phase of ultrasmall (~10 nm) NaYF4 nanocrystals (NCs), containing different Eu concentrations, has been obtained by a modified co-thermolysis method. Detailed investigations of the excitation and relaxation mechanisms of the Eu ions in such NCs are reported. Based on the photoluminescence excitation, absorbance, photoluminescence and emission decay times measured as a function of the excitation wavelengths, it has been shown that two Eu sites with different excitation and relaxation characteristics are present in the case of ultrasmall NaYF4 NCs. It has been shown that, when the Eu concentration increases, strong ion-ion interactions influence the relaxation phenomena in Eu ions, changing their optical properties. Moreover, these ion-ion interactions enable connections between the surface ions and the internal ones via energy transfer from the surface to the NCs core. Furthermore, it has been proposed that the different kinetic properties of the surface Eu ions are mainly caused by the formation of a charge transfer state between the ions and ligand groups attached to the NCs surface.The purely hexagonal phase of ultrasmall (~10 nm) NaYF4 nanocrystals (NCs), containing different Eu concentrations, has been obtained by a modified co-thermolysis method. Detailed investigations of the excitation and relaxation mechanisms of the Eu ions in such NCs are reported. Based on the photoluminescence excitation, absorbance, photoluminescence and emission decay times measured as a function of the excitation wavelengths, it has been shown that two Eu sites with different excitation and relaxation characteristics are present in the case of ultrasmall NaYF4 NCs. It has been shown that, when the Eu concentration increases, strong ion-ion interactions influence the relaxation phenomena in Eu ions, changing their optical properties. Moreover, these ion-ion interactions enable connections between the surface ions and the internal ones via energy transfer from the

  1. What Vaccinations Do You Need?

    MedlinePlus

    ... Newsroom Contact Us You are here Home » What Vaccinations Do You Need? A Guide for Adults with ... a Kidney Transplant Why do I need a vaccination? Vaccinations, usually given as a shot, protect you ...

  2. Vaccine Treatment for Prostate Cancer

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  3. What Vaccines Do You Need?

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    ... 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 ...

  4. 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 ...

  5. Diphtheria Vaccination: Who Needs It?

    MedlinePlus

    ... and adults - Tetanus-diphtheria-acellular Pertussis vaccine Diphtheria Vaccination: Who Needs It? Recommend on Facebook Tweet Share ... need this vaccine? Yes, the Advisory Committee on Immunization Practices (ACIP) recommends 5 doses of diphtheria and ...

  6. Liver Disease and Adult Vaccination

    MedlinePlus

    ... Resources for Healthcare Professionals Liver 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 ...

  7. HIV Infection and Adult Vaccination

    MedlinePlus

    ... Resources for Healthcare Professionals HIV Infection and Adult Vaccination Recommend on Facebook Tweet Share Compartir Vaccines are ... percentage is less than 15%. Learn about adult vaccination and other health conditions Asplenia Diabetes Type 1 ...

  8. New technologies for influenza vaccines.

    PubMed

    Dormitzer, Philip R; Tsai, Theodore F; Del Giudice, Giuseppe

    2012-01-01

    Influenza vaccine preparations have been administered to humans since the late 1930s, and the diversity of approaches in licensed trivalent seasonal or monovalent pandemic products is unparalleled by vaccines against any other target. These approaches include inactivated whole virus vaccines, detergent or solvent "split" vaccines, subunit vaccines, live attenuated vaccines, adjuvanted vaccines, intramuscular vaccines, intradermal vaccines, intranasal vaccines, egg-produced vaccines and mammalian cell culture-produced vaccines. The challenges of influenza immunization, including multiple co-circulating strains, antigenic change over time, a broad age spectrum of disease, and the threat of pandemics, continue to drive the development of new approaches. This review describes some of the new approaches to influenza immunization that are the subjects of active research and development. PMID:22251994

  9. [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. PMID:16277033

  10. 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

  11. Vaccines for Drug Abuse

    PubMed Central

    Shen, Xiaoyun; Orson, Frank M.; Kosten, Thomas R.

    2012-01-01

    Current medications for drug abuse have had only limited success. Anti-addiction vaccines to elicit antibodies that block the pharmacological effects of drugs have great potential for treating drug abuse. We review the status for two vaccines that are undergoing clinical trials (cocaine and nicotine) and two that are still in pre-clinical development (methamphetamine and heroin). We also outline the challenges and ethical concerns for anti-addiction vaccine development and their use as future therapeutics. PMID:22130115

  12. 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. PMID:24373316

  13. Rabies vaccines and interferon

    PubMed Central

    Turner, G. S.

    1972-01-01

    Samples of Fermi, Semple, modified Semple, Duck embryo and tissue culture rabies vaccine were inoculated by different routes and in different doses into rabbits, mice and hamsters. The vaccines induced neither detectable interferon nor immediate protection against lethal challenge with CVS rabies virus. Under similar conditions, high but transient levels of interferon were induced in control animals of the same species with the polynucleotide complex Poly I.C. Hamsters but not mice were protected by Poly I.C.-induced interferon. No autointerference by vaccine with challenge virus was established. Vaccine-induced protection in mice was directly related to immune response. PMID:4506993

  14. 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

  15. Cochlear-Meningitis Vaccination

    MedlinePlus

    ... and otolaryngologists) and families should review the vaccination records of current and prospective cochlear implant recipients to ensure that all ... of Use Join Donate ENTConnect Contact Us ...

  16. Vaccines: the Fourth Century▿

    PubMed Central

    Plotkin, Stanley A.

    2009-01-01

    Vaccine development, which began with Edward Jenner's observations in the late 18th century, has entered its 4th century. From its beginnings, with the use of whole organisms that had been weakened or inactivated, to the modern-day use of genetic engineering, it has taken advantage of the tools discovered in other branches of microbiology. Numerous successful vaccines are in use, but the list of diseases for which vaccines do not exist is long. However, the multiplicity of strategies now available, discussed in this article, portends even more successful development of vaccines. PMID:19793898

  17. Anthrax vaccination strategies

    PubMed Central

    Cybulski, Robert J.; Sanz, Patrick; O'Brien, Alison D.

    2009-01-01

    The biological attack conducted through the U.S. postal system in 2001 broadened the threat posed by anthrax from one pertinent mainly to soldiers on the battlefield to one understood to exist throughout our society. The expansion of the threatened population placed greater emphasis on the reexamination of how we vaccinate against Bacillus anthracis. The currently-licensed Anthrax Vaccine, Adsorbed (AVA) and Anthrax Vaccine, Precipitated (AVP) are capable of generating a protective immune response but are hampered by shortcomings that make their widespread use undesirable or infeasible. Efforts to gain U.S. Food and Drug Administration (FDA) approval for licensure of a second generation recombinant protective antigen (rPA)-based anthrax vaccine are ongoing. However, this vaccine's reliance on the generation of a humoral immune response against a single virulence factor has led a number of scientists to conclude that the vaccine is likely not the final solution to optimal anthrax vaccine design. Other vaccine approaches, which seek a more comprehensive immune response targeted at multiple components of the B. anthracis organism, are under active investigation. This review seeks to summarize work that has been done to build on the current PA-based vaccine methodology and to evaluate the search for future anthrax prophylaxis strategies. PMID:19729034

  18. Vaccine delivery using nanoparticles

    PubMed Central

    Gregory, Anthony E.; Titball, Richard; Williamson, Diane

    2013-01-01

    Vaccination has had a major impact on the control of infectious diseases. However, there are still many infectious diseases for which the development of an effective vaccine has been elusive. In many cases the failure to devise vaccines is a consequence of the inability of vaccine candidates to evoke appropriate immune responses. This is especially true where cellular immunity is required for protective immunity and this problem is compounded by the move toward devising sub-unit vaccines. Over the past decade nanoscale size (<1000 nm) materials such as virus-like particles, liposomes, ISCOMs, polymeric, and non-degradable nanospheres have received attention as potential delivery vehicles for vaccine antigens which can both stabilize vaccine antigens and act as adjuvants. Importantly, some of these nanoparticles (NPs) are able to enter antigen-presenting cells by different pathways, thereby modulating the immune response to the antigen. This may be critical for the induction of protective Th1-type immune responses to intracellular pathogens. Their properties also make them suitable for the delivery of antigens at mucosal surfaces and for intradermal administration. In this review we compare the utilities of different NP systems for the delivery of sub-unit vaccines and evaluate the potential of these delivery systems for the development of new vaccines against a range of pathogens. PMID:23532930

  19. Vaccines, our shared responsibility.

    PubMed

    Pagliusi, Sonia; Jain, Rishabh; Suri, Rajinder Kumar

    2015-05-01

    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. PMID:25749248

  20. Molecular basis of vaccination.

    PubMed

    Del Giudice, G; Pizza, M; Rappuoli, R

    1998-02-01

    Vaccines represent the most cost-effective means to prevent infectious diseases. Most of the vaccines which are currently available were developed long before the era of molecular biology and biotechnology. They were obtained following empirical approaches leading to the inactivation or to the attenuation of microorganisms, without any knowledge neither of the mechanisms of pathogenesis of the disease they were expected to protect from, nor of the immune responses elicited by the infectious agents or by the vaccine itself. The past two decades have seen an impressive progress in the field of immunology and molecular biology, which have allowed a better understanding of the interactions occurring between microbes and their hosts. This basic knowledge has represented an impetus towards the generation of better vaccines and the development of new vaccines. In this monograph we briefly summarize some of the most important biotechnological approaches that are currently followed in the development of new vaccines, and provide details on an approach to vaccine development: the genetic detoxification of bacterial toxins. Such an approach has been particularly successful in the rational design of a new vaccine against pertussis, which has been shown to be extremely efficacious and safe. It has been applied to the construction of powerful mucosal adjuvants, for administration of vaccines at mucosal surfaces. PMID:9789264

  1. 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.

  2. 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.

  3. Influence of the Synthesis Parameters on the Properties of NaYF4:Yb3+,Tm3+ Nanoparticles.

    PubMed

    Plohl, Olivija; Majaron, Boris; Ponikvar-Svet, Maja; Makovec, Darko; Lisjak, Darja

    2015-01-01

    Fluorescent nanoparticles, especially fluorides, have received a great deal of interest due to their optical properties, making them suitable for applications in bio-imaging. For this reason they need to exhibit a superior chemical stability in aqueous media. We have studied the influence of the synthesis parameters on the chemical stability of NaYF(4) nanoparticles co-doped with Yb(3+) and Tm(3+). These nanoparticles have different crystal structures, and were synthesized hydrothermally or with thermal decomposition. The samples were characterized with X-ray diffraction and transmission electron microscopy. The up-conversion fluorescence of nanoparticles dispersed in water was measured at 400-900 nm. The partial dissolution of the fluorine in water was detected with an ion-selective electrode for all the samples. The dissolution of the other constituent ions was analysed with an optical emission spectrometer using inductively coupled plasma. The nanoparticles with a hexagonal crystal structure and sizes of around 20 nm that were synthesized with thermal decomposition showed a superior chemical stability in water together with a superior up-conversion fluorescence yield. PMID:26680706

  4. Structural investigations of sol-gel-derived LiYF 4 and LiGdF 4 powders

    NASA Astrophysics Data System (ADS)

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

    2007-11-01

    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 19F nuclear magnetic resonance (NMR) studies showed that samples heat treated at 300 °C are already crystallized but for a full crystallization in LiGdF 4 and LiYF 4 a thermal treatment at 550 °C is needed. Temperature dependence of powder morphology was analyzed by scanning electron microscopy (SEM).

  5. 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.

  6. 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.

  7. Estimated photochemical ozone creation potentials (POCPs) of CF 3CF dbnd CH 2 (HFO-1234yf) and related hydrofluoroolefins (HFOs)

    NASA Astrophysics Data System (ADS)

    Wallington, T. J.; Sulbaek Andersen, M. P.; Nielsen, O. J.

    2010-04-01

    The photochemical ozone creation potentials (POCPs) for CF 3CF dbnd CH 2 and other commercially significant hydrofluoroolefins have been estimated for the first time. CF 3CF dbnd CH 2 (HFO-1234yf) has a POCP of 7.0 which is less than that for ethane (12.3) and greater than for methane (0.6). Methane and ethane have sufficiently low POCPs that they are usually considered unreactive with respect to ozone formation in urban areas and accordingly are exempt from volatile organic compound (VOC) emission regulations. Estimated POCPs for other hydrofluoroolefins are: CH 2dbnd CF 2, 18.0; CF 2dbnd CF 2, 12.5; CH 2dbnd CHCF 3, 10.7; CF 2dbnd CFCF 3, 5.4; Z-CHF dbnd CFCF 3, 5.6; E-CHF dbnd CFCF 3, 7.3; CH 2dbnd CHCF 2CF 3, 6.6; and t-CHF dbnd CHCF 3, 6.4.

  8. Upconversion, size analysis, and fiber filling of NaYF4: Ho3+, Yb3+ crystals and nanocolloids

    NASA Astrophysics Data System (ADS)

    Patel, Darayas; Lewis, Ashley; Wright, Donald; Velentine, Maucus; Lewis, Danielle; Valentine, Ruben; Sarkisov, Sergey

    2014-03-01

    Nano-colloids and nano-crystals doped with ions of rare-earth elements have recently attracted a lot of attention in the scientific community. This attention is due to unique physical, chemical and optical properties attributed to nanometer size of the particles. They have great potential of being used in applications spanning from new types of lasers, especially blue and UV ones, phosphorous display monitors, optical communications, and fluorescence imaging. In this paper we investigate the near-infrared upconversion luminescence in bulk crystals and nanocolloid filled photonic crystal fiber with ytterbium and holmium co-doped NaYF4 phosphor. The phosphor is prepared by using simple co-precipitation synthetic method. The initially prepared phosphor has very week upconversion fluorescence. The fluorescence significantly increased after the phosphor was annealed at a temperature of 600 °C. Nanocolloids of this phosphor were obtained using 1-propanol as solvent and they were utilized as laser filling medium in photonic crystal fibers. Under 980 nm diode laser excitation very strong upconversion signals were obtained for ytterbium and holmium co-doped phosphor at 541 nm, 646 nm and 751 nm. Pump power emissions, laser ablation and size analysis of the particles was conducted to understand the upconversion mechanisms. The particle sizes of the nanocolloids were analyzed using Atomic Force Microscope and Malvern Zetasizer instrument. The reported nanocolloids are good candidates for fluorescent biosensing applications and also as a new laser filling medium in fiber laser.

  9. 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

  10. 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.

  11. Tetanus, Diphtheria, Pertussis (Tdap) Vaccine

    MedlinePlus

    Adacel® (as a combination product containing Diphtheria, Tetanus Toxoids, Acellular Pertussis Vaccine) ... Boostrix® (as a combination product containing Diphtheria, Tetanus Toxoids, Acellular Pertussis Vaccine)

  12. Universal influenza vaccines: Shifting to better vaccines.

    PubMed

    Berlanda Scorza, Francesco; Tsvetnitsky, Vadim; Donnelly, John J

    2016-06-01

    Influenza virus causes acute upper and lower respiratory infections and is the most likely, among known pathogens, to cause a large epidemic in humans. Influenza virus mutates rapidly, enabling it to evade natural and vaccine-induced immunity. Furthermore, influenza viruses can cross from animals to humans, generating novel, potentially pandemic strains. Currently available influenza vaccines induce a strain specific response and may be ineffective against new influenza viruses. The difficulty in predicting circulating strains has frequently resulted in mismatch between the annual vaccine and circulating viruses. Low-resource countries remain mostly unprotected against seasonal influenza and are particularly vulnerable to future pandemics, in part, because investments in vaccine manufacturing and stockpiling are concentrated in high-resource countries. Antibodies that target conserved sites in the hemagglutinin stalk have been isolated from humans and shown to confer protection in animal models, suggesting that broadly protective immunity may be possible. Several innovative influenza vaccine candidates are currently in preclinical or early clinical development. New technologies include adjuvants, synthetic peptides, virus-like particles (VLPs), DNA vectors, messenger RNA, viral vectors, and attenuated or inactivated influenza viruses. Other approaches target the conserved exposed epitope of the surface exposed membrane matrix protein M2e. Well-conserved influenza proteins, such as nucleoprotein and matrix protein, are mainly targeted for developing strong cross-protective T cell responses. With multiple vaccine candidates moving along the testing and development pipeline, the field is steadily moving toward a product that is more potent, durable, and broadly protective than previously licensed vaccines. PMID:27038130

  13. Vaccine hesitancy, vaccine refusal and the anti-vaccine movement: influence, impact and implications.

    PubMed

    Dubé, Eve; Vivion, Maryline; MacDonald, Noni E

    2015-01-01

    Despite being recognized as one of the most successful public health measures, vaccination is perceived as unsafe and unnecessary by a growing number of parents. Anti-vaccination movements have been implicated in lowered vaccine acceptance rates and in the increase in vaccine-preventable disease outbreaks and epidemics. In this review, we will look at determinants of parental decision-making about vaccination and provide an overview of the history of anti-vaccination movements and its clinical impact. PMID:25373435

  14. 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

  15. [HPV prophylactic vaccines].

    PubMed

    Konopnicki, D

    2014-09-01

    Since 2007, two prophylactic vaccines against Human Papillomavirus (HPV) infection and HPV. induced lesions (both precancerous dysplasia and cancer) have been registered in Belgium. In multicentre randomized trials including more than 64,000 patients, these vaccines were shown to be highly efficient against the occurrence of condyloma and of dysplastic lesion in the cervix, vagina and vulva in females and in the anus in males. These vaccines display an excellent tolerance and safety profile, the most common adverse event being minor and transient side effects at the injection site. The protection given by these vaccines is more important in subjects that have not been in contact with HPV previously ; moreover the title of neutralizing antibodies against HPV are significantly higher in children vaccinated before 15 years-old age compared to young person vaccinated after this age. For these two reasons, it is recommended to vaccinate before the first sexual relationships. Recently, several studies have demonstrated that vaccination by two doses given at 0 and 6 months in children before 15 years-old was equivalent to the three doses scheme that should be given at 0, 1 or 2 and 6 months in subjects aged 15 years or more. In the countries that have achieved a high vaccine coverage among their young female population, the prevalence of HPV infection and the incidence of high grade cervical dysplasia have significantly decreased while condyloma has almost disappeared four years after the implementation of HPV vaccination. In HIV-positive subjects who are particularly susceptible to infection and lesions induced by HPV, vaccination brings levels of antibody comparable to what is found in the general population with similar safety. PMID:25675641

  16. 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. PMID:24986118

  17. Clinical development of Ebola vaccines.

    PubMed

    Sridhar, Saranya

    2015-09-01

    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

  18. 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

  19. Vaccines for lymphomas: idiotype vaccines and beyond.

    PubMed

    Houot, Roch; Levy, Ronald

    2009-05-01

    Therapeutic vaccines for lymphomas have been developed to induce active and long-lasting immune responses against lymphoma capable of eradicating the tumor. Most of these vaccines use the tumor B cell idiotype (the unique variable region of the surface immunoglobulin) as a tumor-specific antigen. The first human clinical trial for lymphoma vaccine was initiated 20 years ago. Along with several other phase I/II trials, it showed encouraging results which supported the initiation of three phase III trials. The results of these trials have recently been released (although not published yet) which failed to demonstrate a prolongation in progression-free survival following chemotherapy. Despite this disappointing result, a number of observations have accumulated over the years that suggest some clinical efficacy of lymphoma vaccines. Several strategies are being developed to improve these results that include optimization of antigen delivery and presentation as well as enhancement of anti-tumor T cell function. This review describes the clinical development of lymphoma vaccines and delineates advances, problems and prospects towards integration of this strategy in the therapeutic armamentarium for lymphoma. PMID:18951668

  20. Advances in influenza vaccination

    PubMed Central

    Reperant, Leslie A.; Rimmelzwaan, Guus F.

    2014-01-01

    Influenza virus infections yearly cause high morbidity and mortality burdens in humans, and the development of a new influenza pandemic continues to threaten mankind as a Damoclean sword. Influenza vaccines have been produced by using egg-based virus growth and passaging techniques that were developed more than 60 years ago, following the identification of influenza A virus as an etiological agent of seasonal influenza. These vaccines aimed mainly at eliciting neutralizing antibodies targeting antigenically variable regions of the hemagglutinin (HA) protein, which requires regular updates to match circulating seasonal influenza A and B virus strains. Given the relatively limited protection induced by current seasonal influenza vaccines, a more universal influenza vaccine that would protect against more—if not all—influenza viruses is among the largest unmet medical needs of the 21st century. New insights into correlates of protection from influenza and into broad B- and T-cell protective anti-influenza immune responses offer promising avenues for innovative vaccine development as well as manufacturing strategies or platforms, leading to the development of a new generation of vaccines. These aim at the rapid and massive production of influenza vaccines that provide broad protective and long-lasting immunity. Recent advances in influenza vaccine research demonstrate the feasibility of a wide range of approaches and call for the initiation of preclinical proof-of-principle studies followed by clinical trials in humans. PMID:24991424

  1. Influenza Vaccine, Live Intranasal

    MedlinePlus

    ... the next 7 days, who requires a protected environment (for example, following a bone marrow transplant). Sometimes ... The National Vaccine Injury Compensation ProgramThe National Vaccine Injury Compensation Program (VICP) is a federal program that was created to compensate people who may have ...

  2. 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

  3. Vaccination to Prevent Cancer.

    PubMed

    Clements, Dennis

    2016-01-01

    Vaccines stimulate the immune system, mimicking infectious attacks and thereby promoting the development of protective antibodies and/or cellular immunity so that the body is immune to infection when live native infections attack. Some of these infections are associated with cancer-causing changes in the body; thus some vaccines may help prevent cancer. PMID:27621345

  4. Influenza vaccination during pregnancy.

    PubMed

    2016-02-01

    In a randomised, double-blind trial in pregnant women, a seasonal inactivated influenza vaccine without a lipid adjuvant and covering strain A/H1N1v was partially effective: the incidence of influenza in the mothers and their infants was about 1.8% with the vaccine versus 3.6% with placebo. No noteworthy adverse reactions were reported. PMID:27042735

  5. 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

  6. 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. PMID:26458840

  7. 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. PMID:23598487

  8. Comparative Neuropathogenesis and Neurovirulence of Attenuated Flaviviruses in Nonhuman Primates▿ †

    PubMed Central

    Maximova, Olga A.; Ward, Jerrold M.; Asher, David M.; St. Claire, Marisa; Finneyfrock, Brad W.; Speicher, James M.; Murphy, Brian R.; Pletnev, Alexander G.

    2008-01-01

    Based on previous preclinical evaluation in mice and monkeys, the chimeric TBEV/DEN4Δ30 virus, carrying the prM and E protein genes from a highly virulent Far Eastern strain of tick-borne encephalitis virus (TBEV) on the backbone of a nonneuroinvasive dengue type 4 virus (DEN4), has been identified as a promising live attenuated virus vaccine candidate against disease caused by TBEV. However, prior to use of this vaccine candidate in humans, its neurovirulence in nonhuman primates needed to be evaluated. In the present study, we compared the neuropathogeneses of the chimeric TBEV/DEN4Δ30 virus; Langat virus (LGTV), a former live TBEV vaccine; and yellow fever 17D virus vaccine (YF 17D) in rhesus monkeys inoculated intracerebrally. TBEV/DEN4Δ30 and YF 17D demonstrated remarkably similar spatiotemporal profiles of virus replication and virus-associated histopathology in the central nervous system (CNS) that were high in cerebral hemispheres but progressively decreased toward the spinal cord. In contrast, the neurovirulence of LGTV exhibited the reverse profile, progressing from the site of inoculation toward the cerebellum and spinal cord. Analysis of the spatiotemporal distribution of viral antigens in the CNS of monkeys revealed a prominent neurotropism associated with all three attenuated viruses. Nevertheless, TBEV/DEN4Δ30 virus exhibited higher neurovirulence in monkeys than either LGTV or YF 17D, suggesting insufficient attenuation. These results provide insight into the neuropathogenesis associated with attenuated flaviviruses that may guide the design of safe vaccines. PMID:18353947

  9. Vaccines for military use.

    PubMed

    Artenstein, Andrew W

    2009-11-01

    Vaccines have long been used by military forces in order to prevent communicable diseases and thereby preserve the fighting force. A tradition that began with the mass vaccination of the Continental Army against smallpox during the War of the American Revolution in the late 18th century continues today with routine and deployment-based vaccination of military forces against potential pathogens of nature and biological weapon threats. As their role has expanded in recent years to include humanitarian and peacekeeping missions, the military's use of vaccines against infectious diseases has concomitantly broadened to include civilian populations worldwide. The emergence of new threats and the recognition of additional global challenges will continue to compel the development and promotion of vaccines to combat infectious diseases of military significance. PMID:19837279

  10. 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. PMID:20850688

  11. Against vaccine assay secrecy

    PubMed Central

    Herder, Matthew; Hatchette, Todd F; Halperin, Scott A; Langley, Joanne M

    2015-01-01

    Increasing the transparency of the evidence base behind health interventions such as pharmaceuticals, biologics, and medical devices, has become a major point of critique, conflict, and policy focus in recent years. Yet the lack of publicly available information regarding the immunogenicity assays upon which many important, widely used vaccines are based has received no attention to date. In this paper we draw attention to this critical public health problem by reporting on our efforts to secure vaccine assay information in respect of 10 vaccines through Canada's access to information law. We argue, under Canadian law, that the public health interest in having access to the methods for these laboratory procedures should override claims by vaccine manufacturers and regulators that this information is proprietary; and, we call upon several actors to take steps to ensure greater transparency with respect to vaccine assays, including regulators, private firms, researchers, research institutions, research funders, and journal editors. PMID:25826194

  12. Next generation vaccines.

    PubMed

    Riedmann, Eva M

    2011-07-01

    In February this year, about 100 delegates gathered for three days in Vienna (Austria) for the Next Generation Vaccines conference. The meeting held in the Vienna Hilton Hotel from 23rd-25th February 2011 had a strong focus on biotech and industry. The conference organizer Jacob Fleming managed to put together a versatile program ranging from the future generation of vaccines to manufacturing, vaccine distribution and delivery, to regulatory and public health issues. Carefully selected top industry experts presented first-hand experience and shared solutions for overcoming the latest challenges in the field of vaccinology. The program also included several case study presentations on novel vaccine candidates in different stages of development. An interactive pre-conference workshop as well as interactive panel discussions during the meeting allowed all delegates to gain new knowledge and become involved in lively discussions on timely, interesting and sometimes controversial topics related to vaccines. PMID:22002157

  13. Developing new smallpox vaccines.

    PubMed Central

    Rosenthal, S. R.; Merchlinsky, M.; Kleppinger, C.; Goldenthal, K. L.

    2001-01-01

    New stockpiles of smallpox vaccine are required as a contingency for protecting civilian and military personnel against deliberate dissemination of smallpox virus by terrorists or unfriendly governments. The smallpox vaccine in the current stockpile consists of a live animal poxvirus (Vaccinia virus [VACV]) that was grown on the skin of calves. Because of potential issues with controlling this earlier manufacturing process, which included scraping VACV lesions from calfskin, new vaccines are being developed and manufactured by using viral propagation on well-characterized cell substrates. We describe, from a regulatory perspective, the various strains of VACV, the adverse events associated with calf lymph-propagated smallpox vaccine, the issues regarding selection and use of cell substrates for vaccine production, and the issues involved in demonstrating evidence of safety and efficacy. PMID:11747717

  14. [Varicella vaccination: who should be vaccinated these days?].

    PubMed

    Hügle, Boris; Suchowerskyj, Philipp; Schuster, Volker

    2005-02-24

    In July 2004 the STIKO (German National Commission for Vaccinations) recommended routine varicella vaccination (together with the first MMR vaccination) for all healthy infants. The previous recommendations for vaccination of adolescents with no history of varicella and patient groups at risk remain valid. In persons with severely depressed cellular immunity or pregnant women vaccination with live attenuated VZV vaccines is contraindicated. Experience gained in the United States show that widespread introduction of VZV vaccination results in a decrease in both the incidence of varicella and concomitant complications including herpes zoster. PMID:18441563

  15. Vaccination coverage among adults, excluding influenza vaccination - United States, 2013.

    PubMed

    Williams, Walter W; Lu, Peng-Jun; O'Halloran, Alissa; Bridges, Carolyn B; Kim, David K; Pilishvili, Tamara; Hales, Craig M; Markowitz, Lauri E

    2015-02-01

    Vaccinations are recommended throughout life to prevent vaccine-preventable diseases and their sequelae. Adult vaccination coverage, however, remains low for most routinely recommended vaccines and below Healthy People 2020 targets. In October 2014, the Advisory Committee on Immunization Practices (ACIP) approved the adult immunization schedule for 2015. With the exception of influenza vaccination, which is recommended for all adults each year, other adult vaccinations are recommended for specific populations based on a person's age, health conditions, behavioral risk factors (e.g., injection drug use), occupation, travel, and other indications. To assess vaccination coverage among adults aged ≥19 years for selected vaccines, CDC analyzed data from the 2013 National Health Interview Survey (NHIS). This report highlights results of that analysis for pneumococcal, tetanus toxoid-containing (tetanus and diphtheria vaccine [Td] or tetanus and diphtheria with acellular pertussis vaccine [Tdap]), hepatitis A, hepatitis B, herpes zoster (shingles), and human papillomavirus (HPV) vaccines by selected characteristics (age, race/ethnicity,† and vaccination indication). Influenza vaccination coverage estimates for the 2013-14 influenza season have been published separately. Compared with 2012, only modest increases occurred in Tdap vaccination among adults aged ≥19 years (a 2.9 percentage point increase to 17.2%), herpes zoster vaccination among adults aged ≥60 years (a 4.1 percentage point increase to 24.2%), and HPV vaccination among males aged 19-26 years (a 3.6 percentage point increase to 5.9%); coverage among adults in the United States for the other vaccines did not improve. Racial/ethnic disparities in coverage persisted for all six vaccines and widened for Tdap and herpes zoster vaccination. Increases in vaccination coverage are needed to reduce the occurrence of vaccine-preventable diseases among adults. Awareness of the need for vaccines for adults is low

  16. 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

  17. Laser vaccine adjuvants

    PubMed Central

    Kashiwagi, Satoshi; Brauns, Timothy; Gelfand, Jeffrey; Poznansky, Mark C

    2014-01-01

    Immunologic adjuvants are essential for current vaccines to maximize their efficacy. Unfortunately, few have been found to be sufficiently effective and safe for regulatory authorities to permit their use in vaccines for humans and none have been approved for use with intradermal vaccines. The development of new adjuvants with the potential to be both efficacious and safe constitutes a significant need in modern vaccine practice. The use of non-damaging laser light represents a markedly different approach to enhancing immune responses to a vaccine antigen, particularly with intradermal vaccination. This approach, which was initially explored in Russia and further developed in the US, appears to significantly improve responses to both prophylactic and therapeutic vaccines administered to the laser-exposed tissue, particularly the skin. Although different types of lasers have been used for this purpose and the precise molecular mechanism(s) of action remain unknown, several approaches appear to modulate dendritic cell trafficking and/or activation at the irradiation site via the release of specific signaling molecules from epithelial cells. The most recent study, performed by the authors of this review, utilized a continuous wave near-infrared laser that may open the path for the development of a safe, effective, low-cost, simple-to-use laser vaccine adjuvant that could be used in lieu of conventional adjuvants, particularly with intradermal vaccines. In this review, we summarize the initial Russian studies that have given rise to this approach and comment upon recent advances in the use of non-tissue damaging lasers as novel physical adjuvants for vaccines. PMID:25424797

  18. Vaccines against nicotine.

    PubMed

    Cerny, Erich H; Cerny, Thomas

    2009-04-01

    Medications against any dependence-inducing drug face a dilemma: if they are efficient, they will induce withdrawal symptoms and the patient is likely to stop taking his medication. Anti drug vaccines are irreversible, provide protection over years and need booster injections far beyond the critical phase of acute withdrawal symptoms. Interacting rather with the drug in the blood than with a receptor in the brain, the vaccines are, in addition, free of side effects due to central interaction. For drugs like nicotine interacting with different types of receptors in many organs, this is a further advantage. There are three reasons that anti drug vaccines have first been developed against nicotine. Firstly, in most parts of the world 20 to 50% of the adult population smoke and any smoking cessation treatment will have an important impact on public health and be commercially a very attractive product. The second reason are the smokers themselves, who would like to quit in significant numbers and who have shown good compliance for any form of treatment. Thirdly, the quantities of cocaine or heroine taken by dependant persons are higher than the quantity of nicotine per cigarette, which makes an anti nicotine vaccine the easier vaccine project. Three anti nicotine vaccines are today in an advanced stage of clinical evaluation. We report here how those vaccines work, on the progress of the trials and future developments to expect. Results show that the efficiency of the vaccines is directly related to the antibody levels of the probates, a fact which will help to optimize further the vaccine effect. We expect the vaccines to appear on the market during a time window between 2009 and 2011. PMID:19276649

  19. 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. PMID:15056044

  20. The Vaccine Safety Datalink: successes and challenges monitoring vaccine safety.

    PubMed

    McNeil, Michael M; Gee, Julianne; Weintraub, Eric S; Belongia, Edward A; Lee, Grace M; Glanz, Jason M; Nordin, James D; Klein, Nicola P; Baxter, Roger; Naleway, Allison L; Jackson, Lisa A; Omer, Saad B; Jacobsen, Steven J; DeStefano, Frank

    2014-09-22

    The Vaccine Safety Datalink (VSD) is a collaborative project between the Centers for Disease Control and Prevention (CDC) and 9 health care organizations. Established in 1990, VSD is a vital resource informing policy makers and the public about the safety of vaccines used in the United States. Large linked databases are used to identify and evaluate adverse events in over 9 million individuals annually. VSD generates rapid, important safety assessments for both routine vaccinations and emergency vaccination campaigns. VSD monitors safety of seasonal influenza vaccines in near-real time, and provided essential information on the safety of influenza A (H1N1) 2009 monovalent vaccine during the recent pandemic. VSD investigators have published important studies demonstrating that childhood vaccines are not associated with autism or other developmental disabilities. VSD prioritizes evaluation of new vaccines; searches for possible unusual health events after vaccination; monitors vaccine safety in pregnant women; and has pioneered development of biostatistical research methods. PMID:25108215

  1. Use of Coupled Rate Equations to Model NIR-to-Visible Upconversion Kinetics in Er3+, Yb3+: NaYF4 Nanocrystals

    NASA Astrophysics Data System (ADS)

    Yao, Ge

    The Er3+, Yb3+: NaYF4 system is the most efficient upconversion (UC) phosphor known, and yet the kinetic details of the mechanism responsible for upconversion are poorly understood. In this work, the dynamics of the photo-physical processes leading to NIR-to-visible upconversion luminescence in Er3+, Yb3+: NaYF 4 nanocrystals are investigated using a coupled-rate-equation model. The rate equations used in the simulation contain parameters representing the microscopic rate constants for individual mechanistic steps. Following initial population of the excited Yb3+ 2F5/2 state in the NIR, the population density of the excited states of the Er 3+ and Yb3+ ions are propagated as a function of time. Experimental spectroscopic characterization performed in our research group provides the data with which to study the kinetics of the UC process. The data include the time evolution of green, red, 1.0microm, and 1.5microm emission following pulsed excitation (decay curves), and the relative integrated intensity ratios of green, red, 1.0microm, and 1.5microm emission as a function of excitation power. Simulated and experimental decay curves and intensity ratios are compared to determine the optimum set of parameterized kinetic rate constants. The curve fits and integrated-relative-intensity-ratio fits are optimized using a Nelder-Meade simplex search method, in which the parameters are chosen to minimize the chi2 value calculated from the difference of the simulated and measure intensity ratios and the simulated and measured decay curves. The optimized parameter values obtained from the fits are physically reasonable, which suggests that the rate-equation modeling is an appropriate approach to describe the UC process in Er 3+, Yb3+: NaYF4 nanocrystals.

  2. Highly uniform YF{sub 3}:Ln{sup 3+} (Ln = Ce{sup 3+}, Tb{sup 3+}) walnut-like microcrystals: Hydrothermal synthesis and luminescent properties

    SciTech Connect

    Wang, Xiaojie; Sheng, Tianqi; Fu, Zuoling; Li, Wenhao; Jeong, Jung Hyun

    2013-06-01

    Graphical abstract: The emission spectra of Y{sub 0.98−x}F{sub 3}:0.02Ce{sup 3+}, xTb{sup 3+} microcrystals with different Tb{sup 3+} concentrations demonstrated that energy transfer from the Ce{sup 3+} and Tb{sup 3+} ions is highly efficient. The concentration quenching phenomenon occurs when the x = 0.13. We have discussed it in detail based on experiments and quantitative calculations. Highlights: ► YF{sub 3}:Ce{sup 3+}, Tb{sup 3+} walnut-like microcrystals were prepared by a hydrothermal synthesis. ► The optical properties of YF{sub 3}:Ce{sup 3+}, Tb{sup 3+} phosphors have been investigated in detail. ► The energy transfer distance and efficiency from Ce{sup 3+} to Tb{sup 3+} ions were calculated. ► The dipole–dipole interaction should be the dominant mechanism for energy transfer. - Abstract: Uniform and well-crystallized YF{sub 3} walnut-like microcrystals were prepared by a facile one-step hydrothermal synthesis. The crystalline phase, size, morphology, and luminescence properties were characterized using powder X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), photoluminescence (PL) and photoluminescent excitation spectra (PLE). The results revealed that the existence of Ce{sup 3+} (sensitizer) can dramatically enhance green emission centered at 545 nm of Tb{sup 3+} (activator) in codoped samples due to an efficient energy transfer from Ce{sup 3+} to Tb{sup 3+}. The critical energy transfer distance between Ce{sup 3+} and Tb{sup 3+} was also calculated by methods of concentration quenching and spectral overlapping. Experimental analysis and theoretical calculations indicated that the dipole–dipole interaction should be the dominant mechanism for the Ce{sup 3+}–Tb{sup 3+} energy transfer.

  3. Bioinformatics analysis of Brucella vaccines and vaccine targets using VIOLIN

    PubMed Central

    2010-01-01

    Background Brucella spp. are Gram-negative, facultative intracellular bacteria that cause brucellosis, one of the commonest zoonotic diseases found worldwide in humans and a variety of animal species. While several animal vaccines are available, there is no effective and safe vaccine for prevention of brucellosis in humans. VIOLIN (http://www.violinet.org) is a web-based vaccine database and analysis system that curates, stores, and analyzes published data of commercialized vaccines, and vaccines in clinical trials or in research. VIOLIN contains information for 454 vaccines or vaccine candidates for 73 pathogens. VIOLIN also contains many bioinformatics tools for vaccine data analysis, data integration, and vaccine target prediction. To demonstrate the applicability of VIOLIN for vaccine research, VIOLIN was used for bioinformatics analysis of existing Brucella vaccines and prediction of new Brucella vaccine targets. Results VIOLIN contains many literature mining programs (e.g., Vaxmesh) that provide in-depth analysis of Brucella vaccine literature. As a result of manual literature curation, VIOLIN contains information for 38 Brucella vaccines or vaccine candidates, 14 protective Brucella antigens, and 68 host response studies to Brucella vaccines from 97 peer-reviewed articles. These Brucella vaccines are classified in the Vaccine Ontology (VO) system and used for different ontological applications. The web-based VIOLIN vaccine target prediction program Vaxign was used to predict new Brucella vaccine targets. Vaxign identified 14 outer membrane proteins that are conserved in six virulent strains from B. abortus, B. melitensis, and B. suis that are pathogenic in humans. Of the 14 membrane proteins, two proteins (Omp2b and Omp31-1) are not present in B. ovis, a Brucella species that is not pathogenic in humans. Brucella vaccine data stored in VIOLIN were compared and analyzed using the VIOLIN query system. Conclusions Bioinformatics curation and ontological

  4. [Current events in vaccination].

    PubMed

    Aubert, M; Aumaître, H; Beytout, J; Bloch, K; Bouhour, D; Callamand, P; Chave, C; Cheymol, J; Combadière, B; Dahlab, A; Denis, F; De Pontual, L; Dodet, B; Dommergues, M-A; Dufour, V; Gagneur, A; Gaillat, J; Gaudelus, J; Gavazzi, G; Gillet, Y; Gras-le-Guen, C; Haas, H; Hanslik, T; Hau-Rainsard, I; Larnaudie, S; Launay, O; Lorrot, M; Loulergue, P; Malvy, D; Marchand, S; Picherot, G; Pinquier, D; Pulcini, C; Rabaud, C; Regnier, F; Reinert, P; Sana, C; Savagner, C; Soubeyrand, B; Stephan, J-L; Strady, C

    2011-11-01

    The annual meeting of the Infectious Disease Society of America (IDSA) ; which brought together nearly 5000 participants from over 80 countries in Vancouver, Canada, October 21 to 24, 2010 ; provided a review of the influenza (H1N1) 2009 pandemic, evaluated vaccination programmes and presented new vaccines under development. With 12,500 deaths in the United States in 2009-2010, the influenza (H1N1) 2009 pandemic was actually less deadly than the seasonal flu. But it essentially hit the young, and the toll calculated in years of life lost is high. The monovalent vaccines, whether live attenuated or inactivated with or without adjuvants, were well tolerated in toddlers, children, adults and pregnant women. In order to protect infants against pertussis, family members are urged to get their booster shots. The introduction of the 13-valent Pneumococcal conjugated vaccine in the beginning of 2010 may solve - but for how long ? - the problem of serotype replacement, responsible for the re-increasing incidence of invasive Pneumococcal infections observed in countries that had introduced the 7-valent vaccine. The efficacy of a rotavirus vaccine has been confirmed, with a reduction in hospitalization in the United States and a reduction in gastroenteritis-related deaths in Mexico. In the United States, vaccination of pre-adolescents against human papillomavirus (HPV) has not resulted in any specific undesirable effects. Routine vaccination against chicken pox, recommended since 1995, has not had an impact on the evolution of the incidence of shingles. Vaccination against shingles, recommended in the United States for subjects 60 years and over, shows an effectiveness of 55 %, according to a cohort study (Kaiser Permanente, Southern California). Although some propose the development of personalized vaccines according to individual genetic characteristics, the priority remains with increasing vaccine coverage, not only in infants but also in adults and the elderly. Vaccine

  5. [Current events in vaccination].

    PubMed

    Aubert, M; Aumaître, H; Beytout, J; Bloch, K; Bouhour, D; Callamand, P; Chave, C; Cheymol, J; Combadière, B; Dahlab, A; Denis, F; De Pontual, L; Dodet, B; Dommergues, M A; Dufour, V; Gagneur, A; Gaillat, J; Gaudelus, J; Gavazzi, G; Gillet, Y; Gras-le-Guen, C; Haas, H; Hanslik, T; Hau-Rainsard, I; Larnaudie, S; Launay, O; Lorrot, M; Loulergue, P; Malvy, D; Marchand, S; Picherot, G; Pinquier, D; Pulcini, C; Rabaud, C; Regnier, F; Reinert, P; Sana, C; Savagner, C; Soubeyrand, B; Stephan, J L; Strady, C

    2011-05-01

    The annual meeting of the Infectious Disease Society of America (IDSA); which brought together nearly 5000 participants from over 80 countries in Vancouver, Canada, October 21 to 24, 2010; provided a review of the influenza (H1N1) 2009 pandemic, evaluated vaccination programmes and presented new vaccines under development. With 12,500 deaths in the United States in 2009-2010, the influenza (H1N1) 2009 pandemic was actually less deadly than the seasonal flu. But it essentially hit the young, and the toll calculated in years of life lost is high. The monovalent vaccines, whether live attenuated or inactivated with or without adjuvants, were well tolerated in toddlers, children, adults and pregnant women. In order to protect infants against pertussis, family members are urged to get their booster shots. The introduction of the 13-valent Pneumococcal conjugated vaccine in the beginning of 2010 may solve--but for how long?--the problem of serotype replacement, responsible for the re-increasing incidence of invasive Pneumococcal infections observed in countries that had introduced the 7-valent vaccine. The efficacy of a rotavirus vaccine has been confirmed, with a reduction in hospitalization in the United States and a reduction in gastroenteritis-related deaths in Mexico. In the United States, vaccination of pre-adolescents against human papillomavirus (HPV) has not resulted in any specific undesirable effects. Routine vaccination against chicken pox, recommended since 1995, has not had an impact on the evolution of the incidence of shingles. Vaccination against shingles, recommended in the United States for subjects 60 years and over, shows an effectiveness of 55%, according to a cohort study (Kaiser Permanente, Southern California). Although some propose the development of personalized vaccines according to individual genetic characteristics, the priority remains with increasing vaccine coverage, not only in infants but also in adults and the elderly. Vaccine

  6. Vaccinations for the Older Adult.

    PubMed

    Gnanasekaran, Gowrishankar; Biedenbender, Rex; Davidson, Harley Edward; Gravenstein, Stefan

    2016-08-01

    Vaccine response declines with age, but currently recommended vaccines are safe and effective in reducing, if not preventing, disease altogether. Over the last decade, advancements in vaccine immunogenicity, either by increasing dose or conjugating vaccines to protein, have resulted in more immunogenic vaccines that also seem more effective in reducing clinical disease both for influenza and pneumococcus. Meanwhile, there is a resurgence in incident pertussis, exceeding prevalence from five decades ago, adding older adults to a recommended target vaccination group. This article discusses currently available vaccines, in the context of current epidemiology and recommendations, for older adults. PMID:27394026

  7. Giant enhancement of upconversion in ultra-small Er3+/Yb3+:NaYF4 nanoparticles via laser annealing

    NASA Astrophysics Data System (ADS)

    Bednarkiewicz, A.; Wawrzynczyk, D.; Gagor, A.; Kepinski, L.; Kurnatowska, M.; Krajczyk, L.; Nyk, M.; Samoc, M.; Strek, W.

    2012-04-01

    Most of the synthesis routes of lanthanide-doped phosphors involve thermal processing which results in nanocrystallite growth, stabilization of the crystal structure and augmentation of luminescence intensity. It is of great interest to be able to transform the sample in a spatially localized manner, which may lead to many applications like 2D and 3D data storage, anti-counterfeiting protection, novel design bio-sensors and, potentially, to fabrication of metamaterials, 3D photonic crystals or plasmonic devices. Here we demonstrate irreversible spatially confined infrared-laser-induced annealing (LIA) achieved in a thin layer of dried colloidal solution of ultra-small ˜8 nm NaYF4 nanocrystals (NCs) co-doped with 2% Er3+ and 20% Yb3+ ions under a localized tightly focused beam from a continuous wave 976 nm medium power laser diode excitation. The LIA results from self-heating due to non-radiative relaxation accompanying the NIR laser energy upconversion in lanthanide ions. We notice that localized LIA appears at optical power densities as low as 15.5 kW cm-2 (˜354 ± 29 mW) threshold in spots of 54 ± 3 µm diameter obtained with a 10 × microscope objective. In the course of detailed studies, a complete recrystallization to different phases and giant 2-3 order enhancement in luminescence yield is found. Our results are highly encouraging and let us conclude that the upconverting ultra-small lanthanide-doped nanophosphors are particularly promising for direct laser writing applications.

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

    PubMed

    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 1h. For metabolite identification by (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. PMID:22664346

  9. Experimental evaluation of a spinning-mode acoustic-treatment design concept for aircraft inlets. [suppression of YF-102 engine fan noise

    NASA Technical Reports Server (NTRS)

    Heidelberg, L. J.; Rice, E. J.; Homyak, L.

    1980-01-01

    An aircraft-inlet noise suppressor method based on mode cutoff ratio was qualitatively checked by testing a series of liners on a YF-102 turbofan engine. Far-field directivity of the blade passing frequency was used extensively to evaluate the results. The trends and observations of the test data lend much qualitative support to the design method. The best of the BPF liners attained a suppression at design frequency of 19 dB per unit length-diameter ratio. The best multiple-pure-tone linear attained a remarkable suppression of 65.6 bB per unit length-diameter ratio.

  10. 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

  11. Depositing CdS nanoclusters on carbon-modified NaYF4:Yb,Tm upconversion nanocrystals for NIR-light enhanced photocatalysis

    NASA Astrophysics Data System (ADS)

    Tou, Meijie; Mei, Yuanyuan; Bai, Song; Luo, Zhenguo; Zhang, Yong; Li, Zhengquan

    2015-12-01

    High-quality hexagonal NaYF4:Yb,Tm upconversion nanocrystals (UCNs) prepared in organic solutions display uniform sizes and strong UC emissions, but they possess a hydrophobic surface which hinders combining them with various semiconductor nanocrystals (NCs) to form a hybrid NIR-activated photocatalyst. Herein we present a facile approach to modify hydrophobic UCNs with a uniform carbon layer and enable them with hydrophilicity and surface functionalization. The carbon shell provides a good substrate for enriching with metal ions and in situ generation of CdS nanoclusters on the particle surface which can utilize both the upconverted UV and visible emissions. The developed NaYF4:Yb,Tm@C@CdS nanoparticles are characterized with TEM, SEM, XRD, PL and UV-Vis spectra and their formation mechanism is elucidated. The products display good photocatalytic activity under visible light and obviously enhanced performance under Vis-NIR light, due to the efficient utilization of UC emissions and the strong adsorption capacity of the carbon shell. The working mechanism of the hybrid photocatalysts is also proposed.High-quality hexagonal NaYF4:Yb,Tm upconversion nanocrystals (UCNs) prepared in organic solutions display uniform sizes and strong UC emissions, but they possess a hydrophobic surface which hinders combining them with various semiconductor nanocrystals (NCs) to form a hybrid NIR-activated photocatalyst. Herein we present a facile approach to modify hydrophobic UCNs with a uniform carbon layer and enable them with hydrophilicity and surface functionalization. The carbon shell provides a good substrate for enriching with metal ions and in situ generation of CdS nanoclusters on the particle surface which can utilize both the upconverted UV and visible emissions. The developed NaYF4:Yb,Tm@C@CdS nanoparticles are characterized with TEM, SEM, XRD, PL and UV-Vis spectra and their formation mechanism is elucidated. The products display good photocatalytic activity under

  12. 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

  13. LASERS AND PHYSICAL PROCESSES IN THEM: Lithium yttrium fluoride (LiYF4:Nd3+)—promising laser material for picosecond spectroscopy

    NASA Astrophysics Data System (ADS)

    Kaminskiĭ, A. A.; Demchuk, M. I.; Zhavoronkov, N. I.; Mikhaĭlov, V. P.

    1989-01-01

    An investigation was made of passive mode locking in lasers with active media in the form of anisotropic fluorides LiYF4 and LiLuF4 activated with Nd3+ ions. Selection of the optical dynamics of laser pulses (due to the 4F3/2→4I11/2 transition) and use of Soviet dyes characterized by different bleaching intensities and different relaxation times ensured a minimum duration of ~ 6 ps with an energy of 10 mJ per pulse.

  14. Reliability analysis of forty-five strain-gage systems mounted on the first fan stage of a YF-100 engine

    NASA Technical Reports Server (NTRS)

    Holanda, R.; Frause, L. M.

    1977-01-01

    The reliability of 45 state-of-the-art strain gage systems under full scale engine testing was investigated. The flame spray process was used to install 23 systems on the first fan rotor of a YF-100 engine; the others were epoxy cemented. A total of 56 percent of the systems failed in 11 hours of engine operation. Flame spray system failures were primarily due to high gage resistance, probably caused by high stress levels. Epoxy system failures were principally erosion failures, but only on the concave side of the blade. Lead-wire failures between the blade-to-disk jump and the control room could not be analyzed.

  15. Tuberculosis vaccines in clinical trials

    PubMed Central

    Rowland, Rosalind; McShane, Helen

    2011-01-01

    Effective prophylactic and/or therapeutic vaccination is a key strategy for controlling the global TB epidemic. The partial effectiveness of the existing TB vaccine, bacille Calmette–Guérin (BCG), suggests effective vaccination is possible and highlights the need for an improved vaccination strategy. Clinical trials are evaluating both modifications to the existing BCG immunization methods and also novel TB vaccines, designed to replace or boost BCG. Candidate vaccines in clinical development include live mycobacterial vaccines designed to replace BCG, subunit vaccines designed to boost BCG and therapeutic vaccines designed as an adjunct to chemotherapy. There is a great need for validated animal models, identification of immunological biomarkers of protection and field sites with the capacity for large-scale efficacy testing in order to develop and license a novel TB vaccine or regimen. PMID:21604985

  16. Novel Vaccination Strategies against Tuberculosis

    PubMed Central

    Andersen, Peter; Kaufmann, Stefan H.E.

    2014-01-01

    The tuberculosis (TB) pandemic continues to rampage despite widespread use of the BCG (Bacillus Calmette–Guérin) vaccine. Novel vaccination strategies are urgently needed to arrest global transmission and prevent the uncontrolled development of multidrug-resistant forms of Mycobacterium tuberculosis. Over the last two decades, considerable progress has been made in the field of vaccine development with numerous innovative preclinical candidates and more than a dozen vaccines in clinical trials. These vaccines are developed either as boosters of the current BCG vaccine or as novel prime vaccines to replace BCG. Given the enormous prevalence of latent TB infection, vaccines that are protective on top of an already established infection remain a high priority and a significant scientific challenge. Here we discuss the current state of TB vaccine research and development, our understanding of the underlying immunology, and the requirements for an efficient TB vaccine. PMID:24890836

  17. [Vaccines for the future].

    PubMed

    Girard, M P

    2009-05-01

    The field of vaccines and vaccinology has seen remarkable progress during the past 20 years. Many vaccines, however, still need to be improved, either because the protection they provide is relatively short-lived and would greatly benefit from the development of booster formulations (as is the case for tuberculosis), or because they only cover part of the many serotypes of the pathogen that causes the disease (rotaviruses, papillomaviruses, or Streptococcus pneumoniae). In addition, still many diseases lack a proper preventive vaccine, such as AIDS, hepatitis C, malaria, viral pneumonias, croup and bronchiolitis, dengue fever, leishmaniasis, Staphylococcus aureus, groups A and B Streptococcus, Shigellas and enterotoxigenic Escherichia coli, to only name a few. These are the current targets of vaccines under development, a great many of which will hopefully reach the market within the coming 10 years. The development of preventive vaccines against chronic diseases such as AIDS and hepatitis C will probably require more time, due to basic science complexities to be overcome first. It is likely that the future will also see an emphasis on therapeutic vaccines targeted against noninfectious diseases such as cancers (lung, skin, prostate, etc) and metabolic or neurologic diseases (atherosclerosis, Alzheimer's disease). This review will focus on examples of preventive vaccines under development that target infectious diseases with a heavy global burden on public health. PMID:19446671

  18. 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

  19. 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. PMID:12530114

  20. [Vaccinations in respiratory medicine].

    PubMed

    Lode, H M; Stahlmann, R

    2015-09-01

    Vaccinations are the most successful and cost-effective measures for prevention of infections. Important pathogens of respiratory tract infections (e.g. influenza viruses and pneumococci) can be effectively treated by vaccinations. The seasonal trivalent and recently now quadrivalent influenza vaccines include antigens from influenza A and B type viruses, which have to be modified annually oriented to the circulating strains. The effective protection by influenza vaccination varies considerably (too short protection time, mismatch); therefore, administration late in the year is the best approach (November/December). Two pneumococcal vaccines are recommended for adults: the over 30-year-old 23-valent polysaccharide vaccine (PPV23) and the 4-year-old 13-valent conjugate vaccine (PCV13). The immunological and clinical efficacy of PPV23 is controversially discussed; however, a moderate reduction of invasive pneumococcal infections is widely accepted. The PCV13 stimulates a T-cell response and has currently demonstrated its clinical efficacy in an impressive study (CAPiTA). The problem of PCV13 is the relatively limited coverage of only 47% of the currently circulating invasive pneumococcal serotypes. PMID:26330051

  1. 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.

  2. Anti-addiction vaccines

    PubMed Central

    Shen, Xiaoyun; Orson, Frank M.

    2011-01-01

    Despite intensive efforts to eradicate it, addiction to both legal and illicit drugs continues to be a major worldwide medical and social problem. Anti-addiction vaccines can produce the antibodies to block the effects of these drugs on the brain, and have great potential to ameliorate the morbidity and mortality associated with illicit drug intoxications. This review provides a current overview of anti-addiction vaccines that are under clinical trial and pre-clinical research evaluation. It also outlines the development challenges, ethical concerns, and likely future intervention for anti-addiction vaccines. PMID:22003367

  3. Hepatitis B vaccination.

    PubMed

    Romanò, Luisa; Paladini, Sara; Galli, Cristina; Raimondo, Giovanni; Pollicino, Teresa; Zanetti, Alessandro R

    2015-01-01

    Hepatitis B virus is a worldwide leading cause of acute and chronic liver disease including cirrhosis and hepatocellular carcinoma. Effective vaccines have been available since the early '80s and vaccination has proved highly successful in reducing the disease burden, the development of the carrier state and the HB-related morbidity and mortality in the countries where vaccination has been implemented.   Neutralizing (protective) antibodies (anti-HBs) induced by vaccination are targeted largely towards the amino acid hydrophilic region, referred to as the common a determinant which is present on the outer protein coat or surface antigen (HBsAg), spanning amino acids 124-149. This provides protection against all HBV genotypes (from A to H) and is responsible for the broad immunity afforded by hepatitis B vaccination. Thus, alterations of residues within this region of the surface antigen may determine conformational changes that can allow replication of the mutated HBV in vaccinated people. An important mutation in the surface antigen region was identified in Italy some 25 years ago in infants born to HBsAg carrier mothers who developed breakthrough infections despite having received HBIG and vaccine at birth. This virus had a point mutation from guanosine to adenosine at nucleotide position 587, resulting in aa substitution from glycine (G) to arginine (R) at position 145 in the a determinant. Since the G145R substitution alters the projecting loop (aa 139-147) of the a determinant, the neutralizing antibodies induced by vaccination are no longer able to recognize the mutated epitope. Beside G145R, other S-gene mutations potentially able to evade neutralizing anti-HBs and infect vaccinated people have been described worldwide. In addition, the emergence of Pol mutants associated with resistance to treatment with nucleos(t)ide analogues can select viruses with crucial changes in the overlapping S-gene, potentially able to alter the S protein immunoreactivity. Thus

  4. Developing vaccines against pandemic influenza.

    PubMed Central

    Wood, J M

    2001-01-01

    Pandemic influenza presents special problems for vaccine development. There must be a balance between rapid availability of vaccine and the safeguards to ensure safety, quality and efficacy of vaccine. Vaccine was developed for the pandemics of 1957, 1968, 1977 and for the pandemic alert of 1976. This experience is compared with that gained in developing vaccines for a possible H5N1 pandemic in 1997-1998. Our ability to mass produce influenza vaccines against a pandemic threat was well illustrated by the production of over 150 million doses of 'swine flu' vaccine in the USA within a 3 month period in 1976. However, there is cause for concern that the lead time to begin vaccine production is likely to be about 7-8 months. Attempts to reduce this time should receive urgent attention. Immunogenicity of vaccines in pandemic situations is compared over the period 1968-1998. A consistent feature of the vaccine trials is the demonstration that one conventional 15 microg haemagglutinin dose of vaccine is not sufficiently immunogenic in naive individuals. Much larger doses or two lower doses are needed to induce satisfactory immunity. There is some evidence that whole-virus vaccines are more immunogenic than split or subunit vaccines, but this needs substantiating by further studies. H5 vaccines appeared to be particularly poor immunogens and there is evidence that an adjuvant may be needed. Prospects for improving the development of pandemic vaccines are discussed. PMID:11779397

  5. A low-toxic site-directed mutant of Clostridium perfringens ε-toxin as a potential candidate vaccine against enterotoxemia.

    PubMed

    Li, Qing; Xin, Wenwen; Gao, Shan; Kang, Lin; Wang, Jinglin

    2013-11-01

    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 (mETX (H106P) , mETX (S111H) , mETX (S111Y) , mETX (F199H) , mETX (F199E) , mETX (S111YF199E) ) were generated and then expressed in Escherichia coli. Both mETX (F199E) and mETX (H106P) 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. mETX (F199E) induces the same protection as mETX (H106P) , 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 mETX (F199E) is another promising candidate vaccine against enterotoxemia and other diseases caused by ETX. PMID:23835363

  6. 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

  7. 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 ...

  8. 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

  9. 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.

  10. Recombinant vaccines against leptospirosis.

    PubMed

    Dellagostin, Odir A; Grassmann, André A; Hartwig, Daiane D; Félix, Samuel R; da Silva, Éverton F; McBride, Alan J A

    2011-11-01

    Leptospirosis is an important neglected infectious disease that occurs in urban environments, as well as in rural regions worldwide. Rodents, the principal reservoir hosts of pathogenic Leptospira spp., and other infected animals shed the bacteria in their urine. During occupational or even recreational activities, humans that come into direct contact with infected animals or with a contaminated environment, particularly water, are at risk of infection. Prevention of urban leptospirosis is largely dependent on sanitation measures that are often difficult to implement, especially in developing countries. Vaccination with inactivated whole-cell preparations (bacterins) has limited efficacy due to the wide antigenic variation of the pathogen. Intensive efforts towards developing improved recombinant vaccines are ongoing. During the last decade, many reports on the evaluation of recombinant vaccines have been published. Partial success has been obtained with some surface-exposed protein antigens. The combination of protective antigens and new adjuvants or delivery systems may result in the much-needed effective vaccine. PMID:22048111

  11. Ingredients of Vaccines

    MedlinePlus

    ... more effective. Common substances found in vaccines include: Aluminum gels or salts of aluminum which are added as adjuvants to help the ... December 2003, pp. 1394-1397 ...quantities of mercury, aluminum, formaldehyde, human serum albumin, antibiotics, and yeast proteins ...

  12. Your child's first vaccines

    MedlinePlus

    ... or more of these vaccines today: [ ] DTaP [ ] Hib [ ] Hepatitis B [ ] Polio [ ] PCV13 (Provider: Check appropriate boxes) 1. Why ... are at greatest risk for Hib disease. 5. Hepatitis B Signs and symptoms include tiredness, diarrhea and vomiting, ...

  13. Tetanus, Diphtheria (Td) Vaccine

    MedlinePlus

    Tenivac® (as a combination product containing Diphtheria, Tetanus Toxoids) ... Why get vaccinated?Tetanus and diphtheria are very serious diseases. They are rare in the United States today, but people who do become ...

  14. Vaccines (immunizations) - overview

    MedlinePlus

    ... has NOT shown any link between thimerosal and autism or other medical problems. Allergic reactions are rare ... in vaccines is not associated with risk of autism. J Pediatr. 2013;164:561-567. PMID: 23545349 ...

  15. Substance Abuse Vaccines

    PubMed Central

    Orson, Frank M.; Kinsey, Berma M.; Singh, Rana A. K.; Wu, Yan; Gardner, Tracie; Kosten, Thomas R.

    2008-01-01

    Conventional substance abuse treatments have only had limited success for drugs such as cocaine, nicotine, methamphetamine, and phencyclidine. New approaches, including vaccination to block the effects of these drugs on the brain, are in advanced stages of development. Although several potential mechanisms for the effects of anti-drug vaccines have been suggested, the most straightforward and intuitive mechanism involves binding of the drug by antibodies in the bloodstream, thereby blocking entry and/or reducing the rate of entry of the drug into the central nervous system. The benefits of such antibodies on drug pharmacodynamics will be influenced by both the quantitative and the qualitative properties of the antibodies. The sum of these effects will determine the success of the clinical applications of anti-drug vaccines in addiction medicine. This review will discuss these issues and present the current status of vaccine development for nicotine, cocaine, methamphetamine, phencyclidine, and morphine. PMID:18991962

  16. National Vaccine Program Office

    MedlinePlus

    ... collaboration and coordination among federal agencies and other stakeholders whose mandate is to help reduce the burden ... how NVPO works with federal and non-federal stakeholders to continually assess and strengthen vaccine safety efforts. ...

  17. [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. PMID:26341041

  18. HPV Vaccine and Pregnancy

    MedlinePlus

    ... 16/18 vaccine: a combined analysis of five randomized controlled trials. Obstet Gynecol 114(6):1179-1188. ... types 16 and 18: pooled analysis of two randomized clinical trials. BMJ 340:C712. Winckworth LC and ...

  19. Vaccines and Thimerosal

    MedlinePlus

    ... cause any harm. Thimerosal prevents the growth of bacteria in vaccines. Thimerosal is added to vials of ... dose vials) to prevent growth of germs, like bacteria and fungi. Introduction of bacteria and fungi has ...

  20. Tetanus, Diphtheria (Td) Vaccine

    MedlinePlus

    Tenivac® (as a combination product containing Diphtheria, Tetanus Toxoids) ... Why get vaccinated?Tetanus and diphtheria are very serious diseases. They are rare in the United States today, but people who do become infected often have severe ...