Cu2ZnSn(S,Se)4 thin-films prepared from selenized nanocrystals ink.

For the first time, CZTS ink was formulated using low-temperature heating up synthesis of NCs. Besides, the influence of powder concentration on the properties of the films was examined. Subsequently, the CZTS films were annealed under a selenium (Se)/argon (Ar) atmosphere at different temperatures to enhance their properties. The influence of selenization temperature on the properties of CZTS films was examined in detail. Structural analysis showed a peak shift towards lower 2θ values for CZTSSe films because of Se incorporation, resulting in larger lattice parameters for CZTSSe than CZTS. As the selenization temperature increases, an increment in the grain size was observed and the band gap was decreased from 1.52 to 1.05 eV. Hall Effect studies revealed a significant improvement in the mobility and carrier concentration with respect to selenization temperatures. Moreover, film selenized at 550 °C exhibited higher photoconductivity as compared to other films, indicating their potential application in the field of low-cost thin-film solar cells.

Análisis retrospectivo de las historias clínicas de una clínica veterinaria en Bogotá / Retrospective analysis of clinical histories from a veterinary clinic of Bogotá

Se presenta un análisis de la base de datos de historias médicas de una clínica veterinaria ubicada en la ciudad de Bogotá, Colombia, con el propósito de establecer el orden de importancia de las distintas patologías diagnosticadas en los perros desde la perspectiva de su frecuencia, edad de presentación, razas afectadas y género. El estudio abarca 72.248 registros, realizados entre los años 1994 y 2004. Los procesos que afectan piel y tegumentos representaron el 24,5/100 de la casuística estudiada, las patologías gastroentéricas el 13,2/100, las infestaciones por distintos tipos de parásitos el 7,9/100 y los diagnósticos odontológicos el 7,1/100. Las dos razas más prevalentes son el Labrador retriever con un 23,2/100 y el French poodle con un 18/100, lo cual significa que entre ellas constituyen el 41,2/100 de las razas atendidas en consulta. Aún cuando el presente trabajo, dadas las características de la metodología utilizada y sobre todo del tipo de muestra, no constituye necesariamente un reflejo exacto de lo que acontece en la ciudad en términos de patologías que afectan a los perros, si es un primer referente y la muestra estudiada es amplia en número de casos y tiempo de observación.

Adjuvant effects of dimethyl dioctadecyl ammonium bromide, complete Freund's adjuvant and aluminium hydroxide on neutralizing antibody, antibody-isotype and delayed-type hypersensitivity responses to Semliki Forest virus in mice.

Outbred mice were inoculated subcutaneously with inactivated Semliki Forest virus (SFV) in saline and combinations of the virus with complete Freund's adjuvant (CFA) aluminium hydroxide (Al) and dimethyl dioctadecyl ammonium bromide (DDA). The immune response was evaluated for delayed-type hypersensitivity, for total ELISA antibodies and antibody-isotypes and for neutralizing antibodies. DDA was the most efficient adjuvant in inducing DTH, CFA the second and Al induced a DTH response that was only slightly higher (statistically not significant) than that induced by the inactivated virus without adjuvants. All adjuvants enhanced the production of ELISA antibodies to similar levels. However, the levels of neutralizing antibodies induced were low in mice which were inoculated with the inactivated SFV alone or mixtures of the virus with Al. DDA induced high levels of neutralizing antibodies and CFA induced intermediate levels. The pattern of antibody-isotypes induced by DDA and CFA was different from the pattern induced by the inactivated virus or by the virus mixed with Al: DDA and CFA induced low amounts of IgG1 antibodies and relatively higher amounts of IgG2a and IgG2b antibodies while the inactivated virus and the mixture of the virus with Al induced higher proportions of IgG1 antibodies. In sera from convalescent mice the majority of antibody activity resided in the IgG2a and IgG2b immunoglobulin subclasses, while IgG1 antibodies were undetectable.