Localization of Na+-K+ ATPases in Quasi-Native Cell Membranes

Na+-K+ ATPases have been observed and located by in situ AFM and single molecule recognition technique, topography and recognition imaging (TREC) that is a unique technique to specifically identify single protein in complex during AFM imaging. Na+-K+ ATPases were well distributed in the inner leaflet of cell membranes with about 10% aggregations in total recognized proteins. The height of Na+-K+ ATPases measured by AFM is in the range of 12-14 nm, which is very consistent with the cryoelectron microscopy result. The unbinding force between Na+-K+ ATPases in the membrane and anti-ATPases on the AFM tip is about 80 pN with the apparent loading rate at 40 nN/s.

The synthesis and properties of meso-tetra(4-alkylamidophenyl)porphyrin liquid crystals and their Zn complexes

A series of novel, long-chain-substituted, porphyrin derivatives, meso-tetra (4-alkylamidophenyl) porphyrin ligands and their Zn complexes (alkyl = 8,10,12,14,16,18) were prepared by acylation of the amino groups of 5,10,15,20-tetra(4-aminophenyl)porphyrin by alkyl chloride. Mesomorphism was investigated by DSC, polarized optical microscopy (POM) and X-ray diffraction (XRD). Only ligands containing chains > 12 carbon atoms displayed liquid crystalline behaviour, which exhibited a high phase transition temperature and a broad mesophase temperature span, Zn complexes showed no liquid crystalline behaviour. Cyclic voltammetry, luminescence spectra and surface photovoltage spectroscopy revealed that covalent linking of an alkylamido group to the tetraphenylporphyrin molecule influences, significantly, the properties of the porphyrin macrocycle.

Study on stimulated emission of Eu2+ in crystal KMgF3 : Eu2+

The line emission peak of Eu2+ ion in crystal KMgF3 is at 360 nm. The probability of stimulated emission on 4f(7) (P-6(7/2))-> 4f(7)(S-8(7/2)) transition was predicted with a four-level decay model of Eu2+6P7/2 excited states proposed by the authors. Optic gain and net gain coefficient (g = 11.4 +/- 3.2)cm(-1) of 360 nm emission in crystal KMgF3 : Eu2+ were measured by ASE method, and the predication was proved by experiment. The net gain coefficient can be increased by annealing or doping crystal KMgF3 : Eu2+ with Gd3+ or Ce3+.

The study of synthesis of poly(ethylene oxide)-b-poly(N,N-dimethylacrylamide) by atom transfer radical polymerization and self-assembly in selective solvents

Poly( ethylene oxide)-b-poly(N, N-dimethylacrylamide) (PEO-b-PDMA) was synthesized by successive atom transfer radical polymerization (ATRP) of N, N-dimethylacrylamide (DMA) monomer using PEO-Br macro initiators as initiator, CuBr and 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazamacrocyclotetra decane (Me-6[14] aneN(4)) as catalyst and ligand. PEO-Br macroinitiator was synthesized by esterification of PEO with 2-bromoisobutyryl bromide. GPC and H-1 NMR studies show that the plot of ln([DMA](0)/[ DMA]) against the reaction time is linear, and the molecular weight of the resulting PDMA increased linearly with the conversion. Within 3 h, the polymerization can reach almost 60% of conversion. PEO-b-PDMA copolymer with low polydispersity index (M-w/M-n approximate to 1.1) is obtained. Self-assembly of PEO-b-PDMA in selective solvents is also studied. It could self-assemble into micelles in methanol/acetone (1/10, v/v) solution. TEM analyses of the PEO-b-PDMA micelles with narrow size distribution revealed that their size and shape depend much on the copolymer composition.

Phase transition and conformational variation of N-alkylated branched poly(ethyleneimine) comblike polymer

A series of branched poly(ethyleneimine) (PEI) derived polymers with different lengths of n-alkyl side chains, denoted as PEI(n)Cs (n = 12, 14, 16, 18, 20, number of carbon atoms in alkyl side group), have been prepared by a N-alkylation method, and systematically characterized by differential scanning calorimertry (DSC) and wide-angle X-ray diffraction (WARD) as well as Fourier transform infrared spectroscopy (FTIR). The side chains grafted on these comblike polymers are long enough to form crystalline phase composed of paraffin-like crystallites. The crystallization of the side chains forces the branched poly(ethyleneimine) molecules to pack into layered structure, between which the crystallites are located. The melting temperatures of the side chain crystallites increase from -12.36 to +51.49 degreesC with increasing the length of the side chains from n. = 12 to n = 20, which are a little bit lower than the corresponding pristine n-alkanes. PEI18C was taken as an example in this work for the investigation of phase transition and conformational variation of the side chains with temperature changing.

聚电解质溶液浓度区域的划分

按照DeGennes[1] 提出的标度概念 ,柔性高分子溶液可以划分为稀溶液 ,亚浓溶液和浓溶液 3个区域 ,它们之间分别以接触浓度c 和交叠浓度c 为分界线 .钱人元等[2 ] 根据聚苯乙烯溶液激基荧光强度浓度依赖性的实验结果 ,提出稀溶液区还应细分为极稀溶液和稀溶液两个区域 ,它的分界浓度称为动态接触浓度cs.中性高分子溶液存在这一分界浓度 ,已经得到体积排除色谱[3 ] 、高分子溶液的物理凝胶化[4] 、以及动态光散射[5] 等研究结果的证实 .本文作者之一 (程 )从中性高分子在溶液中由于范德华分子间吸引力的存在容易自缔合而形成团族的概念出发 ,导出了溶液粘度与cs 之间的理论关系[6,7] .聚电解质由于在溶液中可以离解为聚离子和对离子的特性 ,关于它的溶液浓度区域的划分问题 ,已经引发了一些理论的[8～ 11] 和许多实验的研究 ,其中包括光散射[12～ 14 ] 、小角X射线散射[15] 、小角中子散射[16] 、准弹性中子散射[17] 、溶液电导[18] 和溶液粘度[19]等 .这些研究中的绝大多数 ,仍然将溶液划分为稀溶液 ,亚浓溶液和浓溶液 3个区域.

A new series of Ru(II)polypyridine surfactants: Synthesis, 2D NMR, fluorescence, electrochemistry and electrochemiluminescence

A new series of Ru(II) polypyridine surfactants, Ru(bpy)(2)[phenNH CO(CH2)(n)CH3](PF6)(2), where n is 10, 12, 14 or 16, has been prepared and characterized. The H-1-NMR spectra of these new Ru(II) complexes were attributed and discussed by the H-1-H-1 COSY method. The comparative analysis of IR spectra of these complexes and their responding free ligands has shown that there are intensive d --> pi* feedback interactions between central Ru(II) and their ligands. Their fluorescent, electrochemical and electrochemiluminescent behaviours are also reported.

非均匀化处理稀土铝合金的组织结构

通过在6063变形铝合金中添加适量的稀土元素，免去了在挤压前的高温均匀化处理。试验结果表明，合金的结构和性能得到了改善，可应用于型材的生产。

PPA在LLDPE/LDPE农膜加工中的应用

本工作以LLDPE／LDPE为基料，添加氟弹性体加工改性剂DynamarPPA，采用LDPE挤出机加工农膜。结果表明，挤出机加工LLDPE的能力大幅度地提高，使共混物中LLDPE含量从原来的40％增加到80％，薄膜的物理机械性质亦有明显改善，而主机电流和挤出量未见变化。在添加无滴剂母料条件下，可加工LLDPE总含量达95％的无滴膜，且该膜的力学性质和光学性质均住。

地奥心血康对犬心肌缺血再灌注的血液过氧化脂质、氧自由基及红细胞超氧化物歧化酶活力的影响

目的：观察地奥心血康（ＤＡＸＸＫ）对犬心肌缺血再灌注的血液ＬＰＯ，氧自由基及红细胞ＳＯＤ的影响。方法：１８只成年杂种犬复制心肌缺血再灌注模型，分为ＤＡＸＸＫ治疗组和０．９％氯化钠注射液对照组。以荧光法测定血液ＬＰＯ；电子自旋共振（ＥＳＲ）行全血氧自由基捕捉；ＮＢＴ比色法测定红细胞及心肌中ＳＯＤ活力。结果：ＤＡＸＸＫ组血中ＬＰＯ含量低于对照组（Ｐ＜０．０５）；红细胞及心肌ＳＯＤ活力高于对照组（Ｐ＜０．０５，Ｐ＜０．０１）；对照组冠脉血中有强的氧自由基信号出现，而ＤＡＸＸＫ组的ＥＳＲ谱中氧自由基信号消失。结论

一种新型的铅钙板栅合金——Pb-Ca-Sn-Al-Na

钠加到Pb—Ca—Sn—Al合金中,可以改善它的延伸率和浇铸性能。对于Pb—Ca—Sn—Al合金来说,钠是有效的变晶剂,它的最佳含量是0.01～0.077％。

时间分辨荧光法定量测定卟琳混合物

采用时间分辨荧光法定量分析了四苯基卟吩/四-邻氯苯基卟吩和四苯基卟吩/锌-四苯基卟吩两双组分体系,还测定了光敏治癌药物HPD制剂中以聚集体和单体形式存在的血卟啉衍生物的相对含量,结果表明,本法对于结构相似而荧光光谱严重重叠的双组分混合物,可不经预分离而直接定量测定。

三出口萃取工艺极值公式

为了缩短工艺流程,提高分离效率,许多单位都相继进行了三出口萃取分离工艺的研究。研究结果表明,三出口工艺不仅可应用于稀土元素的分离,而且还可应用于非稀土元素的分离。若采用三出口工艺分离Sm、Eu、Gd或Gd、Tb、Dy,可一次得到三个产品,即纯Sm、Gd及富Eu、或纯Gd、Dy和富Tb。由于缩短了工艺流程,从而提高了贵重稀土元素Eu和Tb的收率。三出口工艺应用于Cu、Co、Ni的分离时,可同时得到较纯的Cu、Ni及含量高于90％的Co产品,缩短了工艺流程,降低了消耗。