Sanford K Figdor

The synthesis of corticosteroids methylated at C21

Die Darstellung der beiden epimeren C21-Methylderivate des 9α-Fluorprednisolons wird beschrieben. 9α-Fluor-21-methyl-1, 4-pregnadien-11β, 17α, 21B-triol-3, 20-dion-21-azetat ist ein hochwirksames entzündungshemmendes Steroid, vollkommen frei von Nebenwirkungen der Natrium- und Wasserretention des C21-unsubstituierten 9α-Fluorprednisolons.

Automated calculation of carbon-14 and sulfur-35 radioactivity in biological samples by external standardization and a computer program

Abstract Recent technical advances in liquid scintillation spectrometers have resulted in the development of an automatic external standardization procedure to estimate quench and to simplify the process of converting observed radioactivity into corrected true radioactivity. In practice a radioactive sample is counted in the normal fashion and then briefly recounted in the presence of a fixed source of gamma radiation such as barium-133 or radium-226. The resultant Compton electrons are counted in two separate channels and the ratio of these counts plotted against quench (or efficiency) results in a general calibration curve suitable for converting observed counts for the nuclide under study into corrected true radioactivity. An example with carbon-14 is described in detail. This simplified counting method is ideally suited for direct automatic data processing with subsequent computer treatment of the data and a system is described by which this objective is achieved.