Studies of microbial sulfate reduction have suggested that the magnitude of sulfur isotope fractionation varies with sulfate concentration. Small apparent sulfur isotope fractionations preserved in Archean rocks have been interpreted as suggesting Archean sulfate concentrations of <200 μm, while larger fractionations thereafter have been interpreted to require higher concentrations. In this wor...

normal 0 false false false en-us x-none ar-sa since its first discovery in an iranian male in 1961, zinc(zn) deficiency in humans is now known to be an important malnutrition problem world-wide. it is more prevalent in areas of high cereal and low animal food consumption. the diet may not necessarily be low in zinc, but its bio-availability plays a major role in its absorption. phytic acid is t...

The mechanism of CD40/CD154-induced chemokine production and its potential role in renal inflammatory disease were explored. Human proximal tubule cells maintained in primary culture were used as the experimental model. With the use of immunocytochemistry, confocal microscopy, and a cell fractionation assay, the CD40 receptor was found to be expressed in the cell membrane of the epithelial cell...

Chick interferon has been purified to varying extents by several groups of investigators. Burke's (1961) starting material was interferon produced in chorioallantoic membranes; this was purified about 2o-fold mainly by chromatography on DEAE and SM celluloses. Zemla & Vilcek (196I) precipitated interferon, produced in chick embryo fibroblasts, with acetone or ethanol at I O ° to 1 5 ° and claim...