This paper reviews the possible generation mechanism of the circadian time signal in the suprachiasmatic nucleus in mammals, based on our findings that continuous infusion of insulin into rat brain caused complete losses of various circadian rhythms. This also describes the role of the suprachiasmatic nucleus as the central site of regulation of energy supply to the brain. From these two aspects, dependency of our lives on the circadian clock and contribution of such researches to medical biology are discussed.
Black diffraction lines and black-and-white lines were observed across the 220 thermal diffuse spot on X-ray film photographs of perfect germanium crystals using monochromatized synchrotron radiations. The diffraction line profiles were observed by means of two-crystal and triple-crystal diffractometries. A good agreement between the experimental diffraction line profile and the theoretical calculation based on the dynamical diffraction theory obtained leads to the conclusion that the cause of the line can be attributed to the anomalous transmission of the thermally scattered X-rays in the absorbing perfect crystal.
The structural studies of molecular liquids, plastic crystals and solutions were carried out by X-ray diffraction methods. Wide-angle X-ray scattering experiments were applid to molecular lipuids and to plastic crystals to obtain the diffraction patterns, i. e., diffuse patterns. In these experiments, the energy- dispersive diffractometry was useful. For the study of solutions, the mixing state was discussed from the concentration fluctuation, the Kirkwood- Buff parameters and the correlation length obtained from the small-angle X-ray scattering. The results of liquid CCl4, phasela of CCl4 and tert-butyl alcohol-water mixtures are reported as the examples of a molecular liquid, a plastic crystal and a solution, respectively.