19 research outputs found

    Sistema de grupos sanguíneos AB em felídeos neotropicais e compatibilidade com gatos domésticos

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    RESUMO O principal sistema de grupos sanguíneos reconhecido para gatos é o AB. Os felinos apresentam anticorpos naturais contra o antígeno do tipo sanguíneo a que não pertencem, o que torna os testes de compatibilidade e as tipagens sanguíneas importantes na prevenção de reações transfusionais. O objetivo deste estudo foi realizar a tipagem sanguínea de oito gatos-mouriscos (Puma yagouaroundi), oito jaguatiricas (Leopardus pardalis), sete gatos-palheiros (Leopardus colocolo), sete gatos domésticos (Felis catus) da raça Persa e oito gatos domésticos sem raça definida (SRD), bem como realizar testes de compatibilidade entre os tipos sanguíneos iguais das diferentes espécies, para avaliar a possibilidade de transfusões interespecíficas. A técnica empregada para a tipagem foi a hemaglutinação em tubos de ensaio. A ocorrência do tipo sanguíneo tipo A foi de 100% entre as jaguatiricas, os gatos-palheiros e os gatos Persas e de 85,72% entre os gatos SRD. A ocorrência do tipo B foi de 100% nos gatos-mouriscos e de 14,28% nos gatos SRD. Considerando os testes de compatibilidade sanguínea, 87,5% (n=4) das jaguatiricas foram incompatíveis com os gatos domésticos, 100% (n= 6) dos gatos-palheiros foram compatíveis com os gatos domésticos e 100% (n= 4) dos gatos-mouriscos foram incompatíveis com os gatos domésticos do tipo B

    Straining and relaxation properties of wet paper during heating

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    The influence of increasing temperature on the strength and relaxation of wet press-dry paper was studied using a tensile tester equipped with a special heating chamber. The heating chamber made fast heating possible without detectable moisture loss. The results showed that temperature had a significant influence on the straining, relaxation and re-straining behavior of wet paper. The majority of observed changes due to increased temperature seem to originate from the softening of wet fibers. The observed short time scale phenomena in wet paper have practical significance for fiber webs dried under tension in paper machines. Straining–relaxation–de-straining cycles were used to analyze the effect of heating on the work of straining and apparent plastic and elastic work. Heating affected the amount of mechanical energy absorbed by the sample and the amount of elastic energy recoverable in a straining–relaxation–de-straining cycle. Increased temperature reduced the work of straining and both elastically and plastically absorbed energy. The hysteresis work of the examined wet papers was estimated to correspond to a 1–22 mK temperature change. This suggests that temperature changes in wet paper induced by straining play no role in practice. After mechanical conditioning, tensile stiffness in the re-straining of wet paper depended only marginally on temperature, whereas in initial straining the effect of temperature was clearly stronger. The linear thermal expansion coefficient of wet paper in the machine direction was estimated and the influence of moisture content on the linear thermal expansion coefficient of paper was found to be relatively small
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