不同构象铂(Ⅱ)配合物与G-肌动蛋白作用的光谱研究

The cyclohexamethylene-diamine squaric acid platinum(Ⅱ) complexs(R,R, S,S) binding to G-actin and the consquence conformation change were studied by N-(1-pyrenyl) maleimide(NPM) labeled fluorescence and intrinsic fluorescence. The binding and chemical kinetics were determined by fluorometry. The results showed that when R (Pt/actin molar ratio) was lower than 30, the Pt binded to G-actin strong binding sites(-SH), when R was larger than 30, the Pt binded to G-actin weaker binding sites. The consquence conformation changes were determined by CD. The CD results showed that R was smaller than 60, G-actin α-helix contents decreased slowly, R was larger than 60, G-actin conformation changed obviously. The reaction of R,R complex of platinum(Ⅱ) S,S complex of platinum(Ⅱ) with G-actin was similar to that of with S,S complex of platinum(Ⅱ).     

新型树状大分子核醚-四硅烷的合成

以季戊四醇为原料合成了一种新型树状大分子核--醚-四硅烷,可用于树状大分子构筑.通过季戊四醇(1)与溴丙烯的醚化反应得到四烯丙基醚2,然后在Pt催化作用下,2与硅氯仿通过硅氢化反应生成醚-四(三氯硅烷) 3(可直接与多种官能团反应生成树状大分子),3经过LiAlH4还原后得到目标产物醚-四硅烷4.通过IR, 1H NMR, 13C NMR对中间体和目标产物的结构进行了表征,并对产物的结构进行了讨论和确认.     

Formation and photoluminescence of silver nanoparticles stabilized by a two-armed polymer with a crown ether core

Silver nanoparticles were synthesized by the use of a two-armed polymer with a crown ether core [poly(styrene)]-dibenzo-18-crown-6-[poly(styrene)] based on the flexibility of the polymer chains and the complex effect of crown ether with Ag(+) and Ag. The size of silver nanoparticles could be tailored by controlling the initial concentrations of the polymer and Ag(+), and the molecular weight of the polymer. The emission of silver nanoparticles was blue-shifted, and the intensity of the photoluminescence of silver nanoparticles stabilized by the polymer was significantly increased due to the complex effect between the crown ether embedded in the polymer and the silver nanoparticles.     

分散法制备的CuCl/MCM-41上C3H6选择催化还原NO反应的研究

研究了由分散法制备的两种CuCl/MCM-41催化剂上丙烯在过量氧存在下选择催化还原NO反应, 发现所制备的CuCl/AlMCM-41催化剂的反应活性明显高于CuCl/SiMCM-41. XRD, IR, TPR及ESR的研究结果表明, CuCl/AlMCM-41催化剂上的主要活性中心是与骨架铝配位的铜离子(Cu2+/Cu+).     

pH值和钙离子对尖吻蝮蛇抗血小板凝集素二级结构的影响

尖吻蝮蛇毒中抗血小板凝集素是凝血因子IX/凝血因子X结合蛋白，它具有抗凝血和抑制血小板凝集双重活性。用红外光谱、拉曼光谱和CD谱研究了抗血小板凝集素的二级结构以及pH值和钙离子对其二级结构的影响。用CD谱测得，在水溶液中，抗血小板凝集素的主要骨架构象为β-折叠(26.3%)和α-螺旋(19.6%)结构。拉曼光谱显示，在粉末状态，其α-螺旋含量显著降低。CD谱还表明，抗血小板凝集素在pH值3.0～11.0范围内保持稳定的天然结构，钙离子诱导的抗血小板凝集素结构变化是可逆的，钙离子在稳定抗血小板凝集素的天然结构中起重要作用。     

魔角旋转核磁共振代谢组学方法对镧、铈急性生物效应的比较研究

利用高分辨魔角旋转核磁共振(MAS 1H NMR)技术对腹腔注射不同剂量[2, 10, 50 mg/kg(体重)]的硝酸镧[La(NO3)3]和硝酸铈[Ce(NO3)3] 的雄性Wistar大鼠肝、肾组织的MAS 1H NMR谱进行比较分析, 研究了La(NO3)3和Ce(NO3)3的急性生物效应, 并结合模式识别技术对不同剂量La(NO3)3和Ce(NO3)3的急性生物效应进行了分类. 研究结果表明, La(NO3)3对大鼠的急性毒性主要表现为肝毒, Ce(NO3)3对大鼠肝、肾同时造成损伤. 该方法可用于其它稀土及金属化合物的毒性预测和毒理学研究.     

偏氟乙烯／三氟乙烯共聚物介电松弛的结晶度效应

用改进的介电松弛谱仪（精度２‰）测定了ＶＤＦ／ＴｒＦＥ（７／２７、６５／３５、５２／４８ｍｏｌ％）共聚物溶液成膜、液氮淬火、熔融慢冷和热处理试样在－１２０—１３０℃、１０－２一１０４Ｈｚ范围的复数介电常数．介电松弛研究结果显示低结晶度的淬火试样较高结晶度的熔融慢冷和热处理试样的Ｔｃ高．结晶度上升，居里点处的介电常数增大．室温以下的介电频率谱分别由代表非晶区分子运动的β松弛（低频部）和局域运动的γ松弛（高频部）叠合而成．随结晶度提高，β松弛峰减小，γ松弛峰增大；非晶松弛强度减弱．晶区松弛强度增强．     

SYNTHESIS AND MESOMORPHIC PROPERTIES OF FISHBONE-LIKE LIQUID CRYSTALLINE POLYSILSESQUIOXANES——Ⅰ. FISHBONE-LIKE, β-DIKETONE-BASED LIQUID CRYSTALLINE POLYSILSESQUIOXANES AND THEIR COPPER COMPLEXES*

Two kinds of fishbone-like, β-diketone-based liquid crystalline polysilsesquioxanes(FBDKLCP'S), homopolymeric (H-FBDKLCP) and copolymeric (C-FBDKaLCP) have been first synthesized via the hydrosilylation reaction of a vinyl-terminated β-diketone with the homopolymeric ladderlike polyhydrosilsesquioxane (LPHSQ) and random copolymethylhydrosilsesquioxane (LRPMHSQ) respectively. These new kinds of FBDKLCP with M of 10~4 is thermotroic liquid crystalline polymer and its clearing temperatures T_i's and mesophase range △T's are much higher than those of the corresponding comb-like β-diketone liquid crystalline polysiloxane (DKLCP) by about 200℃. Similar results have been observed with the comparison of the two different structure Cu-coordinating compounds The significant increases in T_((?))'s and △T's of the FBDKLCP and Cu-FBDKLCP are mainly attributed to the great rigidity of the ladderlike polysilsesquioxane backbone.     

稀溶液中环型聚苯乙烯的激基缔合物荧光效应

采用乙酸乙酯为环型和线型聚苯乙烯的非良溶剂, 确定了Mark-Houwink方程分别为[η]_r=1.91×10~(-2)·M~(0.607)和[η]_l=4.06×10~(-2)·M~(0.572)。研究了环型和线型聚苯乙烯的激基缔合物的荧光效应。通过稀溶液中环型和线型高分子线团在柔顺性上存在着差异, 解释了二者之间在荧光效应方面的差异, 并根据实验结果,确定了(I_E/I_M)c→0～M关系式分别为(I_E/I_M)r,c→0=1.91+3.40×10~(-6)M和(I_E/I_M)l,c→0=2.15+3.05×10~(-6)M。