Preparação e caracterização de blendas de quitosana/poli(álcool vinílico) reticuladas quimicamente com glutaraldeído para aplicação em engenharia de tecido

In this study, novel Chitosan/PVA based films were chemically crosslinked by glutaraldehyde, under pH=(4,00 ±0,05), in order to achieve structures tailored for wound tissue engineering applications. Both precursors and developed films were characterized by FTIR, SEM and XRD in order to determine the presence of chemicals groups and nanostructural order, respectively. The results have shown that the glutaraldehyde crosslinking have altered the crystallinity of pure chitosan and the increase on the C=N bands and simultaneous decrease on NH2 bands suggested that Chitosan/GA crosslinking has preference to occur in carbon-2 of the saccharide ring by the Schiff's base reaction. Also, FTIR spectroscopy clearly showed that crosslinking has also taken place with blends of PVA and chitosan. The mechanical properties presented high degree dependence with on the increase of the content of chitosan and glutaraldehyde. The results have indicated that, by controlling the ratio [PVA]/[chitosan] in the blends and the extent of chemical crosslinking, it was possible to tailor the hybrid network produced aiming to obtain properties of interest for the specific application.

Avaliação de uma proposta contextualizada sobre o ensino de polarimetria nos cursos de farmácia e engenharia de alimentos, na Universidade Federal do Ceará

This work deals with an evaluation of an experimental application about polarimetry for pharmacy and food engineering courses. Foods obtained from the undergraduate students were used for demonstrating multidisciplinary concepts and these concepts were associated to the teaching of polarimetry. According to the results, the benefits of the contextualization are beyond the class and the undergraduating students became interested in control of quality of foods. From these results, it can be concluded that the experimental emphasis given is valid and creates motivation and interest for learning physico-chemistry, in comparison with the traditional methodology applied to teach polarimetry.

Epístolas Sacrílegas. Las declaraciones públicas de líderes evangélicos chilenos ante el gobierno militar de Pinochet (1974 y 1986)

Resumen La relación establecida entre el mundo evangélico y la dictadura militar chilena es uno de los episodios más significativos de la historia política y religiosa reciente en Chile. Si bien este fenómeno ha sido investigado tanto por las ciencias sociales como por la teología, sus posturas han tendido a desarrollarse de manera desvinculada, ofreciendo una imagen parcelada de la problemática. El presente artículo intenta ser un aporte en este ámbito específico, para lo cual se ha fijado un objetivo concreto: analizar los elementos ideológicos y políticos distintivos de las declaraciones públicas realizadas por el mundo evangélico ante el gobierno militar, vinculándolas con los contextos ideológicos en los cuales se emitieron estas declaraciones. Para ello, metodológicamente se han analizado dos declaraciones fundamentales realizadas por los líderes y pastores evangélicos ante el régimen militar chileno (fuentes primarias), lo cual permitirá complejizar la imagen que se posee sobre la relación entre el mundo evangélico y la dictadura militar chilena.