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The kinetics of (S)-Ala racemization on heterogeneous catalysts based on eight strongly basic anion exchangers modified with 4-hydroxy-3-formylbenzenesulfonic acid (5-sulfosalicylaldehyde) (SSA) in the presence of Cu(II) ions at 25 °C was studied. The “internal capacity” value f = mp/(V0Vp) was introduced to characterize the polymers, (mp : number of quaternary ammonium groups of the polymer sample, V0 : total volume of the swollen polymer, Vp : volume of the inert polymeric matrix). The correlation of the observed first-order rate constants of (S)-Ala racemization with the f values of the anion exchangers was established. According to this correlation the selected anion exchangers could be divided into two types with respect to the chemical nature of the groups attached to the quaternary nitrogen atom. The chemical nature, physical structure and the degree of cross-linking of the polymeric matrix do not affect the correlation. Anion exchangers of the first type have at least one ß-hydroxyalkyl substituent at the Anion exchangers of the second type have (CH3)3 cationic groups. Catalysts prepared with the first type anion exchangers have greater activity as compared with catalysts based on the second type anion exchangers with the same f values. The increase in activity of heterogeneous catalysts can be partially attributed to the 10 to 68 fold increase in OH? concentration in the internal phase of the catalysts as compared to the model homogeneous system, which contains the same amounts of the components as the heterogeneous one. Moreover, an additional acceleration is observed in the heterogeneous racemization as compared to the homogeneous one, ca. 5 fold for the second type anion exchangers and ca. 14 fold for the first type anion exchangers.  相似文献   
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Twenty-five patients (males--11, females--14; aged 18 to 45) with chronic herpes virus infection relapsing at the time of clinical tests were examined, including investigations of the surface architectonics, the ability to blast-transformation and the metabolic status of peripheral-blood lymphocytes. Chronic herpes virus infection was found to be concurrent with changes of the percentage ratio of lymphocytes with the surface micro-patterns of different types, with a more intense activity of the immunity T-chain and with a changed nature of the intracellular metabolism of lymphocyte cells.  相似文献   
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Based on intrafamilial correlations, a component genetic analysis was used to evaluate the contribution made by genetic and environmental factors to variance in body weight and skin fold thickness in children who had various blood pressure. In children with initially elevated and normal blood pressures, the phenotypic variation in the body weight and adipopexia is largely determined by genetic factors, whereas in those with initially lower blood pressure, the phenotypic variation in the above parameters is greatly affected by environmental factors, mainly by those of occasional nature. The findings provide evidence for a differential approach to the primary prevention of hyper- and hypotension in children and adolescents.  相似文献   
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