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911.
The output-beam scanning and switching characteristics of lasers with separately controlled twin-stripe electrodes are reported. The spacing between the stripes is small (5m from centre to centre) and the spacing region is either etched or ion-implanted for better current isolation. The implanted laser oscillates in the fundamental mode. The output beam of this laser can be scanned over a radiation angle range of 7° almost linearly with injection currents. The etched laser oscillates in the first-order mode. The output beam of this laser can be switched with a deflection angle as large as ±8°.  相似文献   
912.
Grignard reagents react with formic acid in tetrahydrofuran to produce aldehydes in relatively good yields Various aldehydes such as alkyl, aryl, allyl, benzyl and vinyl aldehydes were prepared from the corresponding Grignard reagents. The reaction with vinyl Grignard reagents proceeded with retention of configuration.  相似文献   
913.
22-Oxacalcitriol 3-hemiglutarate, a haptenic derivative of 22-oxacalcitriol, was synthesized to obtain a specific antibody for use in radioimmunoassay. Three antisera were elicited in rabbits against the hapten conjugated with bovine serum albumin, and their specificity was examined by cross-reaction study. One of the antisera was found to be satisfactorily specific, and expected to provide a radioimmunoassay useful for the pharmacokinetic study of 22-oxacalcitriol.  相似文献   
914.
915.
Synthesis of P1, P2-disubstituted methylenebis(phosphonate)s as inhibitors of inosine monophosphate dehydrogenase is presented.  相似文献   
916.
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919.
Abstract

Chemical synthesis of inositol phosphates which are involved in a newly discovered intracellular transduction system is required. For this purpose, phosphorylation is a crucial step. However, phosphorylation of inositol derivatives which involve vicinally situated hydroxyl functions is quite difficult because of steric crowdness and easy formation of cyclic phosphate. This problem was solved by the following two methods. One method consists of the reaction of an inositol derivative with butyllithium and tetrabenzyl pyrophosphate. By this reaction, various inositol polyphosphates were obtained in good yields. The other involves a new phosphitylating agent, 2-diethylamino-1,3,2-benzodioxaphosphepine. Thus, inositols were first treated with the phosphoramidite in the presence of tetrazole and the resulting phosphites were oxidized by mCPBA to give the corresponding phosphates in excellent yields.  相似文献   
920.
Reaction of N-heterocyclic carbene (NHC)-stabilized PGeP-type germylene Ge{o-(PiPr2)C6H4}2MeIiPr ( 1 ) (MeIiPr=1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) with Ni(cod)2 gave pincer germylene complex Ni[Ge{o-(PiPr2)C6H4}2](MeIiPr) ( 2 ), in which the Ge center of 2 is significantly pyramidalized. Theoretical calculation on 2 predicted the ambiphilicity of the germanium center, which was confirmed by reactivity studies. Thus, complex 2 reacted with both Lewis base MeIMe (MeIMe=1,3,4,5-tetramethylimidazol-2-ylidene) and Lewis acid BH3⋅SMe2 at the germanium center to afford the adducts Ni[Ge{o-(PiPr2)C6H4}2MeIMe](MeIiPr) ( 3 ) and Ni[Ge{o-(PiPr2)C6H4}2⋅BH3](MeIiPr) ( 4 ), respectively. Furthermore, the former was slowly converted to dinuclear complex Ni2[Ge{o-(PiPr2)C6H4}2]2(MeIMe)2 ( 5 ) at room temperature. Complex 5 can be regarded as a dimer of the MeIMe analog of 2 with a Ni-Ge-Ge-Ni linkage.  相似文献   
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