1, 3 -Dimethyl-4,5-di(ureido)-substituted imidazolidin-2-ones have been synthesised by the nitrosation of 1,3-dimethyl-4,5-di(3-ethylureido)imidazolidin-2-one followed by the reactions of amines with the resulting 1,3-dimethyl-4,5-di(3-nitroso3-ethylureido)imidazolidin-2-one, and the structure of 1,3-dimethyl-4,5-di(3-ethylureido)imidazolidin-2-one has been confirmed by X-ray diffraction analysis.

The first representatives of 3,3′-bi(2,4-dioxa-6,8-diazabicyclo[3.3.0]octan-7-ones) have been synthesized by a reaction of glyoxal as form of 2,2′-bi(4,5-dihydroxy-1,3-dioxalane) with N,N′-dialkylureas. Their structures have been supported by X-ray analysis. 1,3-Dialkylimidazolidine-2,4-diones (hydantoins) have been isolated as by-products and their formation mechanism has been experimentally confirmed.

A diastereo specific method for the synthesis of individual enantiomers of 1S,5R- and 1R,5S-glycoluriles has been developed based on the alpha-ureidoalkylation of (S)/(R)-N-carbarnoyl-alpha-amino acids with 4,5-dihydroxyimidazolidin-2-one.

With the aim of carrying out a long-term medical follow-up with radiation dose reconstruction, a cohort of subjects was selected among inhabitants of the most contaminated area in Russia following the Chernobyl accident (the western districts of Bryansk region). The cohort is comprised of 1065 subjects who were under 10 years old at the time of the accident. Most of them were examined on health status in the Chernobyl Sasakawa Health and Medical Cooperation Project. Since the main findings of studies in the project were thyroid abnormalities, selection of subjects was conducted on the basis of the plausible estimates of radiation dose to the thyroid. To estimate thyroid doses, the data from direct measurements of 131I in the thyroid and questionnaire data on individual dietary habits in May 1986 were used. Reasonable approximations were applied to reconstruct individual doses from available data, including doses for those persons who had not been measured for thyroidal radioiodine. The distribution of internal radiation dose to the thyroid among cohort members was obtained. The individual doses to particular subjects are estimated with inevitably essential degree of uncertainty. However, the distribution of subjects into wide dose intervals, from under 200 mGy to over 2 Gy, seems to be an acceptable approach for cohort study in radiation epidemiology.

The title reaction under conditions of a solvent phase transition was found to afford N-(1,3-diethyl-5-hydroxy-2-oxo-4-imidazoli-dinyl)-N,N'-dimethylsulfamide along with expected 2,4-dimethyl-6,8-diethyl-3-thia-2,4,6,8-tetraazabicyclo[3.3.0]octan-7-one 3,3-dioxide.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Physics (ABSTRACT) An alternative approach to the problem of CP-violation is presented. It is based on the possibility of spontaneous CP-breakdown in models with two Higgs doublets. General features of the phenomenon such as stability of the vacuum and the existence of a light axion are discussed. We investigate the feasibility of spontaneously broken CP in the minimal supersymmetric models-the MSSM and NMSSM. The latter is shown to be experimentally viable. The phenomenological implications of the model such as CP-violating effects in the kaon systems and a nonzero neutron electric dipole moment are studied. Acknowledgements I am deeply indebted to Prof. Lay Nam Chang for sharing his intimate knowledge of physics, his keen insight into fundamental problems and, constant support. I greatly appreciate the help and attention of the Department's secretaries in various matters. I am very grateful to the members of my Ph.D. committee for their supervision and efforts to make this work possible.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.