拟合粘度曲线法研究高聚物的长链支化

本文介绍了用计算机试误法拟合粘度曲线,讨论支化参数的方法,本法可以同时确定支化临界分子量和支化程度,在此基础上可以同时得到支化参数及平均分子量、分子量分布.以聚乙烯标准参考物:SRM 1475(线型)、1476(支化物)及镍催化顺式聚丁二烯为对象介绍了上述方法.     

PURIFICATION AND PARTIAL CHARACTERIZATION OF POLYSACCHARIDES FROM THE POLLEN OF TYPHA ANGUSTIFILIA L

Three polysaccharides TAA, TAB and TAC were purified from the pollen of Typha An-gustifilia L..TAA is mainly composed of α-L-arabinofuranose, β-D-galactose and α-D-galac-turonic acid.TAB and TAC contain the backbone mainly composed of (1→5)-linked-L-arabi-nosyl residue.     

辅酶Q10的合成

以2,3,4,5-四甲氧基甲苯为原料, 经溴化、生成格氏试剂后在碘化亚铜存在下与(E)-4-氯-2-甲基-1-苯磺酰基-2-丁烯缩合得到合成辅酶Q10的关键中间体6-(E-3'-甲基-4'-苯磺酰基-2'-丁烯基)-2,3,4,5-四甲氧基甲苯. 此中间体与茄尼基溴缩合、脱砜基化反应和氧化三步反应, 最终制得标题化合物辅酶Q10, 以2,3,4,5-四甲氧基甲苯计总收率达31.3%.     

聚邻苯二胺修饰电极抗坏血酸氧化酶生物传感器的研究

本文报道了聚邻苯二胺／抗坏血酸氧化酶生物传感器，用这种传感器测定人体血清中的抗坏血酸，线性范围在１．０×１０＾－４～２．５×１０＾－７ｍｏｌ／Ｌ之间，响应时间为７ｓ，检测限为１．０×１０＾－８ｍｏｌ／Ｌ。该传感器具有选择性好、灵敏度高和响应时间短等特点。     

THE STRUCTURAL BASIS OF THE POOR FIBRIN SPECIFICITY OF UROKINASE(Ⅰ)——KNOWLEDGE-BASED PREDICTION OF KRINGLE STRUCTURES OF UROKINASE AND ITS RELATED PROTEINS

The Kringle-1 structure of plasminogen (PGK-1), the Kringle-2 structure of tissue plasminogen activator (PAK-2) and the Kringle structure of prourokinase (UKK) has been modeled on the basis of the three-dimensional structure of Kringle-1 of prothrombin (PTK-1) at 2.8 resolution. The predicted three-dimensional structure of these Kringles shows that the binding site of PGK-1 is characterized by an apparent dipolar site, the polar parts of which are separated by a hydrophobic region. PAK-2 possesses the anionic center but has not a cationic binding center which might be provided by a guanidinium group from Arg-69 located adjacent to the Arg-71 position. UKK possesses neither the anionic binding center nor the cationic center which are probably the main reason for the poor fibrin specificity of urokinase.     

HIGH PRECISION AUTOMATIC CAPILLARY VISCOMETER

An automatic capillary viscometer with optical fibres as cold light source and a thermostat in which the temperature can be regulated within ±5×10~(-4)℃have been developed for the determination of flow time with an accuracy of ±4×10~(-3) sec. The basic principle, construction, specifications as well as the main features of this instrument are described.     

聚苯基不对称三嗪的热分解

用高分辨裂解气相色谱－质谱（ＨＲＰｙＧＣ－ＭＳ）考察了由对苯二眯腙和四种不同芳香族四酮合成的聚苯基不对称三嗪的热分解行为，鉴定了相应裂解产物的组成、分布及其与高分子结构的关系，并用热重法（ＴＧ）测定了它们的热分解反应动力学参数，提出了其热分解反应机理．     

Synthesis and Expression in Escherichia coli of a Human Neutrophil Activating Protein-1/Interleukin-8 Gene

The complete gene coding for human neutrophilactivating protein-1/interleukin-8 was synthesized using a semi-chemical semi-enzymatic method. The synthetic gene was then overexpressed in Escherichia coli under the temperature-regulated control of the P_RP_L tandem promoters. As determined by SDS-PAGE and densitometry, the overexpressed protein comprised up to 18.5% and 10.9% of the total soluble protein in E. coli cells grown in shake flasks and in batch fermentation, respectively. The recombinant NAP-1/IL-8 was then purified to>95% homogeneity by gel filtration and cation exchange chromatography. The purified protein appeared as a single band on the SDS-PAGE gel and possessed potent chemotactic activity in the concentration of <10 ng/ml, as assayed by the agarose plate method. An early skin reactivity was also observed when the pure NAP-1/IL-8 was injected subcutaneously into the rabbits. The N-terminal 36 amino acid sequence of the recombinant NAP1/IL-8 was determined using the Edman method and was sho     

囊泡表面分子间通讯交流体系的构建: 利用受体的分子识别行为调控酶的活性

在人工双层膜囊泡表面, 构建了一个通过人工受体的分子识别行为控制酶反应活性的超分子体系. 体系以生物体细胞信号转导系统为模拟原型, 由作为受体的烷基胺、被受体识别的信号分子吡哆醛衍生物、乳酸脱氢酶、受体和酶之间的媒介物Cu^2＋以及作为体系载体的合成肽脂囊泡五个成分构成．通过UV-vis光谱法及动态光散射测定对体系进行了评价, 结果表明: 随着受体疏水参数增大, 其对信号分子的识别能力增强, 二者呈良好的线性关系; 通过信号分子与囊泡表面静电相互作用的研究表明信号分子具有选择性; 媒介物与信号分子–受体可形成化学计量比为1∶2的配合物, 其形成能力比媒介物与酶的结合能力更强．作为结论, 体系中烷基胺受体对磷酸吡哆醛信号分子的识别有效控制了处于囊泡表面的乳酸脱氢酶的活性．     

SYNTHESIS AND-CHARACTERIZATION OF THE SOLUBLE, HIGH MOLECULAR WEIGHT AND LADDERLIKE POLYHYDROSILSESQUIOXANE AND ITS COPOLYMERS

The high molecular ladderlike polyhydrosilsesquioxane (LPHSQ) and its copolymer, ladderlike random copolymethylhydrosilsesquioxane (LR-PMHSQ) and ladderlike block copolymethylsilsesqui-oxane(LB-PMHSQ) have been synthesized by a preaminolysis reaction of the corresponding trichlorosilane with 1 ,4-phenylene diamine(PDA) then by hydrolysis and polycondensation reactions The thermographs of these polymers measured by DSC method indicate that these macromolecular backbones are very rigid as seen from the DSC curves which are almost horizontal from room temperature until 350 ~C without noticeable glass transition. The content of Si—H group in the polymers can be regulated by changing the composition of the two copolymerized monomers. So the ladderlike polymers including its copolymers can be the useful precursors for the functional polymers, especially such as fishbone-like liquid crystalline polymers.