Evidence is presented that after injection of radioactive vitamin B(12) in man, there is a close correlation between the amount of radioactivity excreted and the amount of assayable vitamin B(12) excreted, and thus that the amount of radioactivity excreted is a true measure of the vitamin B(12) excreted. The possible reasons for this occurrence are discussed and it is suggested that in the body...

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A self-complementary, artificial vitamin B12 derivative dimerises in an unprecedented "intra base off/inter base on" coordination mode.

Atomic fountain clocks are showing great promise as primary frequency standards (1). In light of this, we have started a program to develop atomic fountain clocks at the U. S. Naval Observatory. The mission of the observatory, however, dictates different design goals than that of a standards institution. In this paper we will discuss the goals of our atomic fountain project, a scheme for reduci...