Showing papers by "Universidad del Norte, Colombia published in 1991"
TL;DR: In this paper, the effect of metal particle size, metal precursor, support and presence of adsorbates on the formation of the hydride phase on supported Pd catalysts was investigated using temperature programmed techniques, Co and/or H 2 chemissorption and FTIR of co-adsorbed CO and H 2.
Abstract: Summary The effect of metal particle size, metal precursor, support and the presence of adsorbates on the formation of the hydride phase on supported Pd catalysts was investigated using temperature programmed techniques, Co and/or H 2 chemissorption and FTIR of co-adsorbed CO and H 2 . Cyclopropane hydrogenolysis was used as the probe reaction. It was found that the hydride could represent analternative hydrogenation route. It is not responsible for the initial deactivation observed and its formation is not prevented by O 2 or CO preadsorbed on thesurface of Pd Exposure of the ctalyst to hydrogen at high temperature has no influence on the hydride formation.
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TL;DR: In this paper, the authors present results of studies realized on hepatitis B cell mediated inunology as well as on the immune response to Hepatitis B vaccine, which seems to be dueto a failure in antigen presentation.
Abstract: The purpose of this review is to present results of studies realized on Hepatitis B cell mediated inununology as well as on the immune response to Hepatitis B vaccine. Since 1980, several studies on this subjet has heen published, some of them dealt with antibody production, ceii pmliferation under antigen and mitogens stimulation, defects on T cell, B-T ceiis and macmphages; some of these studies, are contradictories. Using mouoclonal antibodies against CD8, binded to polystirene plate we were able to separate CD4 sub-populations and perform experiments trying to explain the mon-response to specif antigen, which seems to be dueto a failure in antigen presentation.