http://dspace.utalca.cl/handle/1950/1512 Search the Channel search http://dspace.utalca.cl/simple-search http://dspace.utalca.cl/handle/1950/9081 Title: Varietal discrimination of Chilean wines by direct injection mass spectrometry analysis combined with multivariate statistics<br/><br/>Authors: Villagra, E.; Santos, L.S.; Vaz, B.G.; Eberlin, M.N.; Laurie, V.F.<br/><br/>Abstract: A simple, direct injection, electrospray ionization Fourier transform mass spectrometry (ESI FT-MS) method, in combination with multivariate statistics, was used for the characterization and sorting of Chilean wines. 47 commercial red wines labelled as Cabernet Sauvignon, Carmenere, Syrah, and Pinot noir, and 25 white wines of the varieties Chardonnay and Sauvignon blanc were diluted, directly infused into the mass spectrometer, and analyzed in negative ion mode. The signature ions used for statistical analyses were manually filtered out from the signals with m/z ratios over 10%. The results of principal component analysis allowed a good sorting of white wines, but not so in the case of reds. The main three principal components explained 96.82% and 85.65% of the variance for white and red wines, respectively. Instead, linear discriminant analysis, allowed the correct discrimination of 100.00% of white and 95.74% of red samples. The validation of these results using the leave-one-out cross-validation method gave lower percentages of correct classification (76.00% and 61.70% of white and red samples respectively), suggesting that some of the wine samples analyzed might have been blends of more than one variety. Consequently, ESI FT-MS direct injection analysis of wines can be used for sample discrimination, but requires a stronger mathematical model built with spectral information of pure and blended samples before improving the percentages of classification. (C) 2011 Elsevier Ltd. All rights reserved.<br/><br/>Description: Reprint Address: Laurie, VF (reprint author), Univ Talca, Sch Agr Sci, 2 Norte 685, Talca, Chile. Wed, 28 Nov 2012 19:09:07 GMT http://dspace.utalca.cl/handle/1950/8826 Title: rypanosoma cruzi induces apoptosis in ex vivo infected human chorionic villi<br/><br/>Authors: Duaso, J.; Rojo, G.; Jana, E.; Galanti, N.; Cabrera, G.; Bosco, C.; Lopez-Munoz, R.; Maya, J.D.; Ferreira, J.; Kemmerling, U.<br/><br/>Abstract: Chagas' disease, produced by the haemoflagellated protozoan Trypanosoma cruzi (T. cruzi), is one of the most frequent endemic diseases in Latin America. In spite that in the past few years T. cruzi congenital transmission has become of epidemiological importance, studies about this mechanism of infection are scarce. The placental tissue undergoes apoptosis throughout gestation, as part of its normal turnover. On the other hand, it is known that T cruzi induces, delays or inhibits apoptosis in other mammalian tissues. In order to determine the effect of parasite invasion on normal apoptosis in the placenta, explants of human chorionic villi were incubated with 105 trypomastigotes for 24 h. Effective infection was tested by visualizing T cruzi antigens in histological preparations and by PCR. Upon infection, apoptotic cell death was determined by light and transmission electron microscopy, TUNEL analysis, measurement of caspase-3 like activity and immunohistochemical detection of caspase 3 cleaved cytokeratin 18. Our results clearly show that T cruzi induces apoptosis in the chorionic villi and suggest that this is one of mechanisms used by the parasite to insure infection and invasion of human placenta and fetus. (C) 2011 Elsevier Ltd. All rights reserved<br/><br/>Description: Kemmerling, U (Kemmerling, U.). Univ Talca, Fac Ciencias Salud, Dept Estomatol, Talca, Chile Tue, 11 Sep 2012 20:34:11 GMT http://dspace.utalca.cl/handle/1950/1514 Title: El sistema privado de salud desde la perspectiva del analisis economico<br/><br/>Authors: Barcia Lehmann, Rodrigo<br/><br/>Abstract: This article analyzes the legal regulation of ISAPREs from the vantage point of law and economics and makes a case for passing some amendments to this private health system based on market failures. The private health system ofISAPREs has not been able to satisfy the expectations of third age people whoare discriminated against by an adverse selection. This article explains how thisadverse selection works and accounts for the inability of ISAPREs to efectivelycompete in that market segment. In addition, it puts forward a solution to this problem consisting in a new market of indefinite health contracts which creates a new value and gives confidence to risk adverse individuals. This new market shall also create incentives for ISAPREs to compete in the segment of third agepeople and obtain important scale economies in their costs, besides giving them leverage to negotiate under equal conditions on behalf of their affiliates in the market of catastrophic diseases, in which there is a truly monopoly at the hand of the medical profession.<br/><br/>Description: 22 p. Fri, 30 Sep 2005 22:24:46 GMT http://dspace.utalca.cl/handle/1950/1513 Title: The Chilean AFP Retiring System<br/><br/>Authors: Barcia Lehmann, Rodrigo<br/><br/>Abstract: El presente trabajo se dividira en tres partes. En la primera se analizaran lasreformas del sistema previsional chileno, en la segunda los principales problemas que ha presentado y presenta este sistema. En la ultima parte se abordarann los resguardos que se deben tomar al elaborar un sistema de pension de capitalizacion individual y se hara una breve evaluacion de la conveniencia de adoptar el sistema.<br/><br/>Description: 25 p. Fri, 30 Sep 2005 22:10:26 GMT