不同介质凝胶体系中草酸钙结晶的研究

研究了五种不同介质（水、氯化钠、合成尿、正常人尿液和尿石患者尿液）的凝胶体系中草酸钙（CaC2O4）晶体的生长,及各种体系中防石药物柠檬酸钾（K3cit）对CaC2O4生长的影响.没有加K3cit时,CaC2O4晶体以一水草酸钙（calcium oxalate monohydrate, COM）为主要物相,但在氯化钠和合成尿的凝胶体系中同时出现了二水草酸钙（calcium oxalate dihydrate, COD）和三水草酸钙（calcium oxalate trihydrate, COT）,肾结石患者尿液中出现COD,而正常人尿液中没有COD和COT生成.加入K3cit后,水、氯化钠和合成尿介质的凝胶体系中,COT的含量显著增加,患者尿液中产生大量COD,而正常人尿液中出现了少量的COD和极个别的COT.COT的增加与低温、体系中高的离子强度及金属离子等因素有关.K3cit具有诱导COD和COT的生成、减小COM晶体比表面积的作用,从而有利于防治草酸钙结石的形成.     

Enthalpies of dilution of electrolyte solutions by flow microcalorimetry

The enthalpies of dilution of NaCl, Me₄NBr, andn-Bu₄NBr were measured in water at 25°C with a new flow microcalorimeter. The data were analyzed with a polynomial equation, and the derived relative apparent molal enthalpies _L are in good agreement with literature values. Provided care is taken that mixing is complete, flow calorimeters are as reliable and much less time-consuming than cell-type instruments for enthalpies of dilution measurements.     

Microcalorimetric studies on the non-competitive inhibition of bovine liver arginase

Two methods, e.g. initial rate method and thermokinetic reduced extent method were presented for studies on non-competitive inhibition. Arginase-catalyzed the hydrolysis of L-arginine toL-ornithine and urea and the inhibition of this reaction by sodium fluoride were studied in the absence and presence of exogenous of Mn²⁺at 37°C in 40 mM sodium barbiturate-hydrochloric acid buffer solution (pH 7.4). Both methods were successively used to determine the values of K₁. The advances and disadvantages of each method were compared in this paper. Exogenous Mn²⁺ could result in more sensitivity of arginase to F^-1. Since the inhibition of arginase by F^-1 depends on the pH values of the reaction system and behave as a non-competitive inhibition, it probably due to its small volume and high electronic density allow it access to the activity site of the enzyme and replaces of μ-OH₂ (or μ-OH) as the bridge ligand with Mn(II, II) cluster. However, further studies are necessary to determine the modes of interaction of F^-1 with bovine liver arginase. This revised version was published online in August 2006 with corrections to the Cover Date.     

水合硫酸氢钠催化合成2-乙氧基萘

以-水合硫酸氢钠为催化剂，β-萘酚和无水乙醇为原料合成了2-乙氧基萘。优化反应条件为：β-萘酚150mmol，无水乙醇900mmol，催化剂2．0g，回流反应时间5h，产率85．5％。     

恒电流库仑法测定基准试剂三氧化二砷的含量

用恒电流库仑法测定基准试剂三氧化二砷的含量，以恒电流通过含有碘化钾，基准试剂三氧化二砷试样的弱碱性水溶液，利用工作电极铂阳极上电生滴定剂I2与亚砷酸盐定量反应，以死停终点法确定滴定终点，测量出电解电流和电解时间，根据法拉第电解定律并利用EXCEL计算出基准试剂三氧化二砷的含量。方法的回收率为100％。     

Easy saponification by metal silanolates: application in SPPS and in (S)-5-hydroxynorvaline preparation

Alkali metal trimethylsilanolates, TMSO⁻, M⁺, has been used for efficient conversion of methyl esters into their corresponding anhydrous acid salts under mild non-aqueous conditions. This strategy has been applied to SPPS for the preparation of neurotoxin cyclic analogues and in (S)-5-hydroxynorvaline synthesis.     

Solvent extraction of sodium picrate with 15-crown-5 into carbon tetrachloride. The determination of the dimer-formation constant of a crown ether-univalent metal salt 1∶1∶1 complex

The theory is derived to determine the dimer-formation constant,K ₂, of a crown ethermetal salt 111 complex in organic solvents of low dielectric constant by solvent extraction. The theoretical predictions are verified experimentally by extraction of sodium picrate (NaA) with 15-crown-5 (15C5) into carbon tetrachloride. All the experiments were conducted at 25°C. The logK ₂ value of the Na(15C5)A complex in carbon tetrachloride has been determined to be 4.05±0.11. Moreover, the partition constant of the complex is calculated.     

Hydration of complexes of 18-crown-6 with potassium nitrate or potassium picrate in the polymer phase

Adsorption of water vapor by granular polymer based on dibenzo-18-crown-6 and containing potassium nitrate or potassium picrate in the polymer phase was studied by the isopiestic method at 298 K. The adsorption of water vapor is described by isotherms corresponding (according to BDDT classification) to polymolecular absorption with a high adsorptive potential. In terms of the Aranovich model of polymolecular absorption, the monolayer capacity and differential heat of adsorption were calculated, and the stoichiometry of hydration of the potassium nitrate and potassium picrate complexes with immobilized crown ether was estimated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1940–1942, October, 1998.     

Conductance studies in amide-water mixtures. II. Sodium salts inN,N-dimethylformamide-water mixtures at 35°C

Conductance data for sodium nitrite, chloride, and acetate in water andN,N-dimethylformamide (DMF)-water mixtures (74.82D42.48) for the concentration range 0.001–0.04N, as well as the densities, viscosities, and dielectric constants of the solvent mixtures at 35°C, are reported. The data have been analyzed by the Fuoss (1975) equation. The existence of a maximum in the viscosity at a 13 mole ratio of DMF and water is indicated. The Walden products for all the three salts pass through a maximum while the equivalent conductances show a minimum with increasing DMF content. The maxima in the Walden product are attributed to the dehydration of ions by the cosolvent (DMF).Part I:Indian J. Chem. 14A, 1015 (1976).Deceased.     

十二烷基硫酸钠毛细管电泳法分析非还原单克隆抗体药物纯度的前处理条件优化

十二烷基硫酸钠毛细管电泳法因具有快速、分辨率高的优势，已成为单克隆抗体纯度分析的主流方法。在非还原单克隆抗体纯度检测中，其样品前处理过程对于结果有显著影响。为优化样品前处理，考察了以碘乙酰胺和N-乙基马来酰亚胺为巯基封闭剂，在pH 6.0~9.0的样品缓冲液条件下，不同种类和批次的单抗的纯度。发现在两种巯基封闭剂中，高pH的样品缓冲液会影响巯基封闭的效果，产生较多的抗体片段；而在低pH条件下，抗体片段较少，单抗的纯度更高。因此在进行非还原单抗的纯度检测中，pH 6.0的样品缓冲液为最佳的前处理条件。