101 research outputs found
The effect of some processing conditions on the characteristics of biodegradable microspheres obtained by an emulsion solvent evaporation process
Unloaded microspheres were prepared from polyhydroxybutyrate (PHB) and polyhydroxybutyrate-co-valerate (PHB-HV) polymers using an oil-in-water emulsion solvent evaporation method. The study was conducted to evaluate how the polymer and some process parameters affect properties of the final microspheres such as particle size, superficial area, zeta potential, surface morphology and microsphere degradation. The variables included surfactant concentration in the emulsion water phase and solvent composition. From the results, it was found that the parameters affecting microsphere size the most were surfactant concentration in the emulsion water phase and solvent composition. Properties such as zeta potential, surface area and surface morphology remained pratically unchanged over the range of the processing conditions studied here.011
Propuesta de reacondicionamiento termo-energĂ©tico en tipologĂa escolar localizada en el área metropolitana de San Juan
Posteriormente al terremoto de 1944 acaecido en San Juan, fueron construidas bajo normativas del “Consejo de ReconstrucciĂłn” una serie de escuelas, entre las cuales se destaca la tipologĂa en peine doble materializada por el Arq. Ramos Correa. Estos establecimientos deben remodelarse para adecuarlos a requerimientos fĂsicos y funcionales de la actualidad, siendo el momento oportuno para dar tambiĂ©n soluciones tecnolĂłgicas a componentes de la envolvente, que mejoren su comportamiento termo-energĂ©tico. A tal fin, se desarrolla un procedimiento utilizando modelos de simulaciĂłn que evalĂşan el desempeño del edificio antes y despuĂ©s de cambios propuestos, verificando el cumplimiento de los valores admisibles de las Normas IRAM. Con las mejoras planteadas la energĂa necesaria para calefacciĂłn disminuye entre 28% y 50%, cumpliendo los valores admisibles de la Transmitancia TĂ©rmica en calidad edilicia “B”. Las contribuciones se centran en lo metodolĂłgico-instrumental, y en lo tecnolĂłgico termo-energĂ©tico para su transferencia inmediata a los organismos pertinentes.After the 1944 occurred earthquake in San Juan, a number of schools were built under regulations of the "Reconstruction Council", among them the “double comb” typology materialized by Arch. Ramos Correa stands out. These establishments should be refurbished to suit today´s physical and functional requirements, being the right time to also give technological solutions to envelope components, which improve their thermal-energy performance. Aimed to this, a method is developed using simulation models to evaluate the building performance before and after the proposed changes, to verify compliance with the permissible values of the IRAM Standards. With the proposed constructive improvements, the required energy for heating is reduced between 28% and 50% fulfilling the allowable values of the Thermal Transmittance at “B” building quality. The contributions are focused on instrumental-methodological aspects, and on those technological referred to thermalenergy efficiency, for its immediate transfer to the relevant agencies.Tema 5: Arquitectura ambientalmente consciente.Facultad de Arquitectura y Urbanism
Propuesta de reacondicionamiento termo-energĂ©tico en tipologĂa escolar localizada en el área metropolitana de San Juan
Posteriormente al terremoto de 1944 acaecido en San Juan, fueron construidas bajo normativas del “Consejo de ReconstrucciĂłn” una serie de escuelas, entre las cuales se destaca la tipologĂa en peine doble materializada por el Arq. Ramos Correa. Estos establecimientos deben remodelarse para adecuarlos a requerimientos fĂsicos y funcionales de la actualidad, siendo el momento oportuno para dar tambiĂ©n soluciones tecnolĂłgicas a componentes de la envolvente, que mejoren su comportamiento termo-energĂ©tico. A tal fin, se desarrolla un procedimiento utilizando modelos de simulaciĂłn que evalĂşan el desempeño del edificio antes y despuĂ©s de cambios propuestos, verificando el cumplimiento de los valores admisibles de las Normas IRAM. Con las mejoras planteadas la energĂa necesaria para calefacciĂłn disminuye entre 28% y 50%, cumpliendo los valores admisibles de la Transmitancia TĂ©rmica en calidad edilicia “B”. Las contribuciones se centran en lo metodolĂłgico-instrumental, y en lo tecnolĂłgico termo-energĂ©tico para su transferencia inmediata a los organismos pertinentes.After the 1944 occurred earthquake in San Juan, a number of schools were built under regulations of the "Reconstruction Council", among them the “double comb” typology materialized by Arch. Ramos Correa stands out. These establishments should be refurbished to suit today´s physical and functional requirements, being the right time to also give technological solutions to envelope components, which improve their thermal-energy performance. Aimed to this, a method is developed using simulation models to evaluate the building performance before and after the proposed changes, to verify compliance with the permissible values of the IRAM Standards. With the proposed constructive improvements, the required energy for heating is reduced between 28% and 50% fulfilling the allowable values of the Thermal Transmittance at “B” building quality. The contributions are focused on instrumental-methodological aspects, and on those technological referred to thermalenergy efficiency, for its immediate transfer to the relevant agencies.Tema 5: Arquitectura ambientalmente consciente.Facultad de Arquitectura y Urbanism
Detecção de isolados do Grapevine fanleaf virus em videiras por meio de testes sorológico e molecular.
A degenerescĂŞncia da videira, causada pelo Grapevine fanleaf virus (GFLV), ocorre na maioria dos paĂses vitĂcolas, causando relevantes danos
Relationship between symptom expression and viral infection in grapevines cv. Cabernet sauvignon.
Cultivars of Vitis vinifera (wine grape) are usually more sensitive to viruses compared to cvs. of V. labrusca (common grape) and hybrids that are tolerant to viruses.Evento online
Prevalence and trends of markers of hepatitis B virus, hepatitis C virus and human Immunodeficiency virus in Argentine blood donors
BACKGROUND: Transfusion-transmitted infections are a major problem associated with blood transfusion. The aim of this study was to determine prevalence and trends of HBV, HCV and HIV in blood donors in Argentina. METHODS: A retrospective study was carried out in blood donors of 27 transfusion centers covering the whole country over a period of eight years (2004-2011). Serologic screening assays for HBsAg, anti-HBc, anti-HCV, and anti-HIV were performed in all centers and nucleic acid amplification testing (NAT) was performed in 2 out of the 27 centers. RESULTS: The 2,595,852 samples tested nationwide from 2004 to 2011 showed that the prevalence of HBsAg decreased from 0.336% to 0.198% (p < 0.0001), that of anti-HBc from 2.391% to 2.007% (p < 0.0001), that of anti-HCV from 0.721% to 0.460%, (p < 0.0001) and that of anti-HIV from 0.208% to 0.200 (p = 0.075). The prevalence of HBV, HCV and HIV was unevenly distributed among the different regions of the country. Two out of 74,838 screening- negative samples were positive in NAT assays (1 HIV-RNA and 1 HCV-RNA); moreover, HBV-DNA, HCV-RNA and HIV-RNA were detected in 60.29, 24.54 and 66.67% of screening-positive samples of the corresponding assays. As regards donors age, positive HBV-DNA and HCV-RNA donors were significantly older than healthy donors (46.6, 50.5 and 39.5 y respectively, p < 0.001). CONCLUSIONS: Argentina has a low prevalence of HBsAg, anti-HCV and anti-HIV in blood donors, with a decreasing trend for HBsAg, anti-HBc and anti-HCV but not for anti-HIV over the last 8 years. The uneven distribution of transfusion-transmitted infections prevalence among the different regions of the country highlights the need to implement regional awareness campaigns and prevention. The discrepancy between samples testing positive for screening assays and negative for NAT assays highlights the problem of blood donors who test repeatedly reactive in screening assays but are not confirmed as positive upon further testing. The uneven distribution of age between healthy donors and NAT-positive donors could be related to changes in risks of these pathogens in the general population and might be attributed to a longer exposure to transmission risk factors in elderly people.Fil: Flichman, Diego Martin. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de MicrobiologĂa, InmunologĂa y BiotecnologĂa. Cátedra de VirologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Blejer, Jorgelina L.. FundaciĂłn Hemocentro; ArgentinaFil: Livellara, Beatriz I.. Hospital Italiano; ArgentinaFil: RĂ©, Viviana Elizabeth. Universidad Nacional de Cordoba. Facultad de Medicina. Instituto de VirologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Bartoli, Sonia. Centro regional de Hemoterapia Jujuy; ArgentinaFil: Bustos, Juan A.. Banco de sangre San Jorge; ArgentinaFil: Ansola, Claudia P.. Provincia de Mendoza. Servicio de Hemoterapia; ArgentinaFil: Hidalgo, Susana. Hospital Dr. Enrique Vera Barros; ArgentinaFil: Cerda, MartĂn E.. Hospital Dr. Lucio Molas; ArgentinaFil: Levin, Alicia E.. Provincia de Mendoza. Servicio de Hemoterapia; ArgentinaFil: Huenul, Adriana. Hospital ArtĂ©mides Zatti; ArgentinaFil: Riboldi, Victoria. Hospital Regional RĂo Gallegos; ArgentinaFil: Treviño, Elena M. C.. Universidad Nacional de CĂłrdoba; ArgentinaFil: Salamone, Horacio J.. FundaciĂłn Favaloro; ArgentinaFil: Nuñez, Felix A.. Hospital Italiano; ArgentinaFil: Fernández, Robert J.. FundaciĂłn Hemocentro; ArgentinaFil: Reybaud, Juan F.. FundaciĂłn Favaloro; ArgentinaFil: Campos, Rodolfo Hector. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de MicrobiologĂa, InmunologĂa y BiotecnologĂa. Cátedra de VirologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentin
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