Compaction of sandy founda tion for the Kanev hydroelectric station by the C-629 hydrovibrator

Abstract

Research in the field of adrenal cortical function has been limited by the inability of existing techniques to measure precisely the kind and amounts of steroids elaborated by the gland. Particularly in man, the indicators have been indirect and inadequate. These have consisted principally of the alterations in certain non-steroid constituents of the blood, changes in the total number of circulating lymphocytes and eosinophils, and variations in end products of steroid metabolism found in the urine. Biological assays (1, 2) of the blood level of adrenal cortical hormones were developed with the hope that they would provide greater specific-ity, but have proved to be neither sufficiently sensitive nor precise. Chemical methods (3, 4, 5) for the determination of blood steroids have been proposed. The first satisfactory direct quantitative measurement of 17-hydroxycorticosteroids in the blood of human subjects was reported by Nelson and Samuels (6).