漫反射光谱法测定还原糖

通过测定还原糖与斐林试剂反应生成的Cu2O，建立测定还原糖的漫反射光谱分析方法。该方法具有操作方便，灵敏度高，试剂用量少等优点。还原糖在20～120μg范围内呈良好的线性关系，用于实际样品测定，结果满意。     

Molecular mechanics calculations (MM2 and MM3) on enamines and aniline derivatives

The MM2 and MM3 force fields have been extended to cover this class of compounds. Structures, vibrational spectra, and other data for 13 compounds were examined and can be reproduced satisfactorily by MM3. Except for the spectra, the other data can be reproduced somewhat less well by MM2. © 1994 by John Wiley & Sons, Inc.     

用ICP研究鹿科动物骨质疏松症的微量元素特征

鹿科动物的骨质疏松症是近几年出现的一种疾病，它影响鹿的生长发育和繁殖，病重者死亡。我们采集梅花鹿和白唇鹿的毛，血样，用低温灰化方法和温法消解处理样品，用ＩＣＰ分析了毛，血清中微量元素的含量。病梅花鹿毛样中Ｍｇ，Ａｌ，Ｃａ，Ｔｉ，Ｆｅ，Ｃｕ，Ｚｎ的含量比正常组高，Ｔｉ，Ｃｕ，Ｚｎ的偏差率大于１５％，而Ｓｉ，Ｍｎ，Ｐ，Ｐ，Ａｇ，Ｂａ，Ｌａ，Ｃｅ，Ｐｂ比正常组低，Ｖ，Ａｇ，Ｂａ，Ｌａ，Ｃｅ，Ｐｂ存在...     

芳香叔胺引发丙烯腈光聚合研究

我们发现芳香叔胺是丙烯腈聚合极有效的光引发剂。芳香叔胺苯环上氢被正性基取代时,引发能力增加,被负性基取代时,引发能力下降。下列胺的活性次序是:N,N-二甲基对甲苯胺(DMT)>N,N-二羟乙基对甲苯胺(DHET)>N,N-二甲基苯胺(DMA)>N,N-二甲胺基苯甲醛(DMB)>N,N-二甲基对硝基苯胺(DNA)。芳香叔胺引发丙烯腈光聚合属自由基机构,聚合速度与叔胺浓度的0.66次方成正比。在叔胺浓度为10~(-2)—10~(-4)M范围内,聚合物平均聚合度的倒数与叔胺浓度的0.5次方成正比。初步认为在紫外光激发下,芳香叔胺与丙烯腈分子生成激发态电子转移络合物,再分解产生自由基,引发丙烯腈聚合。     

甲基丙烯酸2-羟乙酯水溶液聚合与硫氰化钠的效应

<正> 甲基丙烯酸2-羟乙酯(HEMA)是一带有羟基的功能性单体,它可以在自由基聚合引发剂如过氧化苯甲酰、偶氮二异丁腈、过氧化二碳酸二异丙酯或氧化还原引发体系过硫酸盐-乙酸二甲胺基乙酯的作用下进行自由基聚合,我们已报道带有羟基的单体如HEMA、甲基丙烯酸羟丙酯(HPMA)及甲基丙烯酯3-甲氧基-2-羟丙酯(MHPMA)可用     

铀-2-(3,5-二溴-2-吡啶偶氮)-5-二乙氨基苯酚-Triton X-100析相体系的研究及应用

本文研究了铀-2-(3,5-二溴-2-吡啶偶氨)-5-二乙氨基苯酚(3,5-diBr-PADAP)-Triton X-100析相光度体系,建立了矿石中微量铀的测定方法,在pH 7.5三乙醇胺-盐酸介质中,将胶束溶液在 95±1℃加热 1h.络合物即被Triton X-100相完全富集.络合物最大吸收峰位于565nm.摩尔吸光系数为1.02×10～5L·mol～(-1)·cm～(-1),铀含量在0～12μg/5mL服从比耳定律.采用TBP萃淋树脂分离干扰离子,测定矿石中微量铀,结果满意.     

亲电性对醌二甲烷与富电子烯烃的电荷转移聚合

概述了亲电性对醌二甲烷与富电子烯烃电荷转移聚合的最新进展，着重介绍聚合的一般特征、引发机理、链增长机理，以及单体结构、溶剂对聚合反应的影响。     

RAMPED-UP NMR: multiplexed NMR-based screening for drug discovery

The crucial step in drug discovery is the identification of a lead compound from a vast chemical library by any number of screening techniques. NMR-based screening has the advantage of directly detecting binding of a compound to the target. The spectra resulting from these screens can also be very complex and difficult to analyze, making this an inefficient process. We present here a method, RAMPED-UP NMR, (Rapid Analysis and Multiplexing of Experimentally Discriminated Uniquely Labeled Proteins using NMR) which generates simple spectra which are easy to interpret and allows several proteins to be screened simultaneously. In this method, the proteins to be screened are uniquely labeled with one amino acid type. There are several benefits derived from this unique labeling strategy: the spectra are greatly simplified, resonances that are most likely to be affected by binding are the only ones observed, and peaks that yield little or no information upon binding are eliminated, allowing the analysis of multiple proteins easily and simultaneously. We demonstrate the ability of three different proteins to be analyzed simultaneously for binding to two different ligands. This method will have significant impact in the use of NMR spectroscopy for both the lead generation and lead optimization phases of drug discovery by its ability to increase screening throughput and the ability to examine selectivity. To the best of our knowledge, this is the first time in any format that multiple proteins can be screened in one tube.     

Aggregate manganese Schiff base moieties by terephthalate or acetate: dinuclear manganese and trinuclear mixed metal Mn2/Na complexes

A reaction system consisting of terephthalic acid, NaOH, inorganic Mn(II) or Mn(III) salt, and salicylidene alkylimine resulted in dinuclear manganese complexes (salpn)(2)Mn(2)(mu-phth)(CH(3)OH)(2) (1, salpn = N,N'-1,3-propylene-bis(salicylideneiminato); phth = terephthalate dianion), (salen)(2)Mn(2)(mu-phth)(CH(3)OH)(2) (2, salen = N,N'-ethylene-bis(salicylideneiminato)), (salen)(2)Mn(2)(mu-phth)(CH(3)OH)(H(2)O) (3), and (salen)(2)Mn(2)(mu-phth) (4), while the absence of NaOH in the reaction led to a mononuclear Mn complex (salph)Mn(CH(3)OH)(NO(3)) (5, salph = N,N'-1,2-phenylene-bis(salicylideneiminato)). In addition, a trinuclear mixed metal complex H[Mn(2)Na(salpn)(2)(mu-OAc)(2)(H(2)O)(2)](OAc)(2) (6) was obtained from the reaction system by using maleic acid instead of terephthalic acid. Five-coordinate Mn ions were found in 4 giving rise to an intermolecular interaction and constructing a one-dimensional linear structure. Antiferromagnetic exchange interactions were observed for 1-3, and a total ferromagnetic exchange of 4 was considered to stem from intermolecular magnetic coupling. (1)H NMR signals of phenolate ring and alkylene (or phenylene) backbone of the diamine are similar to those reported in the literature, and the phth protons are at -2.3 to -10.1 ppm. Studies on structure, bond valence sum analysis, and magnetic properties indicate the oxidation states of the Mn ions in 6 to be +3, which are also indicated by ESR spectra in dual mode. Ferromagnetic exchange interaction between the Mn(III) sites was observed with J = 1.74 cm(-1). A quasireversible redox pair at -0.29V/-0.12V has been assigned to the redox of Mn(2)(III)/Mn(III)Mn(II), implying the intactness of the complex backbone in solution.     

Determination of the residue of quizalofop-p-tefuryl in soybean by HPLC

A HPLC method was developed for the analysis of quizalofop-P-tefurylof in soybean. The samples were extracted with methanol-water (volume ratio), The extracts were cleaned up with a column of silica gel. The final residue was detected by HPLC, using a UV detector. The recoveries from the analytical method for soybean were 84.32%–89.25%. Variable coefficients were 0.49%∼1.51%. This method proved to be simple, reliable and accurate. __________ Translated from Chinese Journal of Chromatography, 2005, 23(2)(in Chinese)