Biomedical subjects

S H Rubin

Publications and source records attributed to S H Rubin.

13 recordsLinked to original sources

PubMed1976

Improvement of faculty teaching performance in a department of obstetrics and gynecology by student evaluation.

The primary purpose of a faculty evaluation program is to upgrade the over-all quality of teaching and to identify the strengths and weaknesses of the individual teacher. Effective medical educators can thereby be suitably identified by objective and subjective criteria. Improvement of faculty teaching performance enhances student learning and can improve recruitment into our discipline.

Education, Medical↗

PubMed1976

Spectrophotometric determination of sodium nitroprusside and its photodegradation products.

A specific spectrophotometric method of analysis for sodium nitroprusside was developed utilizing the molar absorptivity values at the maxima appearing in the electronic spectrum at 394 and 498 nm that may be attributed to metal d leading to pi* NO transitions. These measurements appear to be indicative of the unaltered nitroferricyanide complex. A reaction sequence is postulated for aqueous solutions of nitroprusside exposed to normal artificial light. Evidence suggests that one species in the sequence is nitroferricyanide in a higher energy state but with the nitrosyl moiety still present in the coordination sphere, which exhibits an increased molar absorptivity at 394 nm. The molar absorptivity at the 498-nm maximum remains unchanged. Corroborating polarographic data are presented.

Chemical Phenomena↗

PubMed1976

Stability of vitamin C (ascorbic acid) in tablets.

Stability of ascorbic acid (vitamin C) in various tablet formulations and the nature and extent of formation of decomposition products (dehydroascorbic acid, diketogulonic acid, and oxalic acid) were determined under normal conditions of storage and in simulated use tests. IR spectrophotometric, colorimetric, fluorometric, titrimetric, polarographic, and chromatographic methods were applied. Recent implications concerning the instability of ascorbic acid in tablets and the potentially harmful nature of the breakdown products are shown to be unfounded. Under normal storage conditions, commerical-type ascorbic acid tablets are stable for over 5 years (greater than 95% potency retention). The amounts of all three breakdown products formed under the various storage conditions constitute a small percentage of the ascorbic acid content and pose no dietary hazard. IR spectroscopy was inadequate as a quantitative method for evaluating ascorbic acid potency in tablet formulations. The official titration methods and TLC, colorimetric, and polarographic determinations correlate well and define accurately the stability of ascorbic acid in these dosage forms.

Ascorbic Acid↗

PubMed1975

Effect of feeding polyunsaturated fatty acids with a low vitamin E diet on blood levels of tocopherol in men performing hard physical labor.

A diet made low in vitamin E by elimination of foods considered good sources of the vitamin was fed for 13 months to two groups of men engaged in strenuous labor. With a daily average dietary intake of about 9.4 mg of total tocopherols, a progressive decline in blood levels of tocopherol from 1.42 to 0.81 mg/100 ml was observed in the five control subjects. The test group of 30 men received a daily supplement of tocopherol-stripped safflower oil containing 88 g of polyunsaturated fatty acids and 2.3 mg of tocopherols. Average blood plasma levels of tocopherol in this group dropped rapidly from an initial value of 1.01 to about 0.5 mg/100 ml within 5 months and remained relatively stable thereafter. No muscular weakness or other physical symptoms were reported.

Adult↗

PubMed1974