Microwave modeling and validation in food thawing applications.

Developing temperature fields in frozen cheese sauce undergoing microwave heating were simulated and measured. Two scenarios were investigated: a centric and offset placement on the rotating turntable. Numerical modeling was performed using a dedicated electromagnetic Finite Difference Time Domain (FDTD) module that was two-way coupled to the PHYSICA multiphysics package.

Bile acids and bile alcohols in a child with hepatic 3 beta-hydroxy-delta 5-C27-steroid dehydrogenase deficiency: effects of chenodeoxycholic acid treatment.

Duodenal bile, urine, plasma, and feces from a child with hepatic 3 beta-hydroxy-delta 5-C27-steroid dehydrogenase deficiency were analyzed by fast atom bombardment mass spectrometry and gas chromatography-mass spectrometry to investigate the formation and excretion of abnormal bile acids and bile alcohols. The biliary bile salts consisted of glycocholic acid (25%) and of sulfated and glycine conjugated di- and trihydroxycholenoic acids (55%), two C27 bile acids, and eleven sulfated bile alcohols (mainly tetrols, 20%), all having 3 beta,7 alpha-dihydroxy-delta 5 or 3 beta,7 alpha,12 alpha-trihydroxy-delta 5 ring structures. In plasma, sulfated cholenoic acids constituted 65% and unconjugated 3 beta,7 alpha-dihydroxy-5-cholestenoic acid 25% of the total level, 71 micrograms/ml.

Some aspects of bilirubin determination in the newborn using dimethyl sulfoxide.

Although serum bilirubin determination is a common procedure in most clinical laboratories, the test seems to be of particular importance in the screening of neonates, especially the premature or the erythroblastotic infant. However, bilirubin determination is subject to interferences, particularly in the presence of hemolysis and lipemia, which may seriously affect the results. It is, therefore, of paramount importance to the pediatrician to be aware of these potential shortcomings of the test.

Associated problems of protein electrophoresis, staining and densitometry.

The process of electrophoresis, a separation phenomenon, is mistakenly understood to include the sequential processes ancillary to analyte resolution, that is, staining and quantification, where the latter could be elution followed by photometry or integrating-calculating-densitometry. The theories involved in electrophoresis itself are well worked out and equally well understood but the problems which are associated with separation, chemical reaction to generate a chromogen and quantification, perhaps partly forgotten and perhaps partly ignored, are taken up and described here. They include albumin trail, resolution, unequivalent staining, prestaining and the densitometry problems associated with band widths, opacity effects and polychromaticities.