Metal components analysis of metallothionein-III in the brain sections of metallothionein-I and metallothionein-II null mice exposed to mercury vapor with HPLC/ICP-MS

Mercury vapor is effectively absorbed via inhalation and easily passes through the blood–brain barrier; therefore, mercury poisoning with primarily central nervous system symptoms occurs. Metallothionein (MT) is a cysteine-rich metal-binding protein and plays a protective role in heavy-metal poisoning and it is associated with the metabolism of trace elements. Two MT isoforms, MT-I and MT-II, are expressed coordinately in all mammalian tissues, whereas MT-III is a brain-specific member of the MT family. MT-III binds zinc and copper physiologically and is seemed to have important neurophysiological and neuromodulatory functions. The MT functions and metal components of MTs in the brain after mercury vapor exposure are of much interest; however, until now they have not been fully examined. In this study, the influences of the lack of MT-I and MT-II on mercury accumulation in the brain and the changes of zinc and copper concentrations and metal components of MTs were examined after mercury vapor exposure by using MT-I, II null mice and 129/Sv (wild-type) mice as experimental animals. MT-I, II null mice and wild-type mice were exposed to mercury vapor or an air stream for 2 h and were killed 24 h later. The brain was dissected into the cerebral cortex, the cerebellum, and the hippocampus. The concentrations of mercury in each brain section were determined by cold vapor atomic absorption spectrometry. The concentrations of mercury, copper, and zinc in each brain section were determined by inductively coupled plasma mass spectrometry (ICP-MS). The mercury accumulated in brains after mercury vapor exposure for MT-I, II null mice and wild-type mice. The mercury levels of MT-I, II null mice in each brain section were significantly higher than those of wild-type mice after mercury vapor exposure. A significant change of zinc concentrations with the following mercury vapor exposure for MT-I, II null mice was observed only in the cerebellum analyzed by two-way analysis of variance. As for zinc, the copper concentrations only changed significantly in the cerebellum. Metal components of metal-binding proteins of soluble fractions in the brain sections were analyzed by size-exclusion high-performance liquid chromatography (HPLC) connected with ICP-MS. From the results of HPLC/ICP-MS analyses, it was concluded that the mercury components of MT-III and high molecular weight metal-binding proteins in the cerebellum of MT-I, II null mice were much higher than those of wild-type mice. It was suggested that MT-III is associated with the storage of mercury in conditions lacking MT-I, and MT-II. It was also suggested that the physiological role of MT-III and some kind of high molecular weight proteins might be impaired by exposure to mercury vapor and lack of MT-I and MT-II.     

Cu(phen)22+与6-巯基嘌呤及DNA间的相互作用

在Tris-NaCl（pH=7.2）缓冲溶液中,应用伏安法、电子吸收光谱分析、溴化乙锭荧光分析、粘度测量和琼脂糖凝胶电泳等技术研究了Cu（phen）2^2＋（phen=1,10-邻菲咯啉）与6-巯基嘌呤（6-MP）及DNA间的相互作用。结果表明,Cu（phen）2^2＋与6-MP发生了明显的相互作用,其作用产物不仅与小牛胸腺DNA具有更强的相互作用,并且在H2O2和抗坏血酸存在下对质粒pBR322 DNA具有更强的断裂能力,与DNA的作用模式可能为部分插入模式。     

Studies on Solid State Reactions of Coordination Compounds（LXXI）──Solid State Reactions of o－Aminobenzoic Acid with Copper（Ⅱ） Acetate and Formate at Room Temperature

ＳｔｕｄｉｅｓｏｎＳｏｌｉｄＳｔａｔｅＲｅａｃｔｉｏｎｓｏｆＣｏｏｒｄｉｎａｔｉｏｎＣｏｍｐｏｕｎｄｓ（ＬＸＸＩ）──ＳｏｌｉｄＳｔａｔｅＲｅａｃｔｉｏｎｓｏｆｏ－ＡｍｉｎｏｂｅｎｚｏｉｃＡｃｉｄｗｉｔｈＣｏｐｐｅｒ（Ⅱ）ＡｃｅｔａｔｅａｎｄＦｏｒｍ...     

催化荧光法测定痕量铜的研究

本文拟定了一个催化荧光法测定痕量铜的新方法,确定了该催化反应的速度方程式和反应级数。方法检测限达0.1ng Cu/ml,相对标准偏差为3.7％,具有较好的选择性,可不经分离直接用于头发样品中铜的测定,回收及对照实验结果令人满意。     

Dicopper(I) oxalate complexes as molecular precursors for the deposition of copper compounds

The synthesis, characterization, and thermal decomposition behavior of dicopper(I) oxalato complexes L₄Cu₂(C₂O₄) (L = CNtBu (2a), CNCMe₂CH₂tBu (2b), CNC₆H₃Me₂-2,6 (2c)) is reported. 2c can be prepared in a straightforward manner by the reaction of stoichiometric amounts of Cu₂O and oxalic acid with four equivalents of CNC₆H₃Me₂-2,6, while those complexes with aliphatic isocyanides are better prepared from a copper(I) oxalato complex with alkine capping ligands (Me₃SiCCSiMe₃)₂Cu₂(C₂O₄) (1) via ligand exchange. Crystallographic and spectroscopic evidence for 2a-c confirms the anticipated dinuclear structure with the oxalate in a μ-1,2,3,4 bridging mode and an essentially σ-character of the terminal isocyanides. In solid form the complexes are stable at room temperature and can be handled in air for some time. Their decomposition was studied by thermal gravimetric analysis coupled with mass spectrometry, and the degradation pathway was shown to depend on the type of isocyanide capping ligand. Decomposition of 2a,b takes place between 150 and 200 °C to give CuCN in a clean process that involves isobutene elimination from the terminal ligands, with elimination of (CN)₂ and conversion to elemental copper at higher temperatures. Heating of 2c leads to CuO (and then to Cu₂O) via release of the intact isocyanide, CO₂, and CO in a well-behaved thermal process around 200-280 °C.     

石墨炉原子吸收光谱法直接测定血样中硒

用石墨炉原子吸收光谱法，以硝酸铜和硝酸铵为基体改进剂，塞曼效应扣背景，采用标准加入法可直接测定血样中硒，回收率为95％～105％，相对标准偏差为5．8％，检出限为96pg，测定结果准确可靠。     

方波伏安法测定镍铜合金中的镍含量

在0.01mol·L-1的氨水-氯化铵缓冲溶液(pH 9.3)中,镍(Ⅱ)于-1.25V(vs.SCE)出现一灵敏的方波伏安峰。镍(Ⅱ)浓度在1.5×10-6～1.0×10-4mol·L-1与伏安峰高呈线性关系,线性方程为ip(μA)=2.1870+0.6328c(μmol·L-1),相关系数为0.9991。方法的标准偏差为0.7％。该法应用于镍铜合金样品中镍的测定,结果满意。     

铜表面腐蚀的激光扫描微区光电压图象的研究

铜表面腐蚀的激光扫描微区光电压图象的研究杨迈之，张雯，蔡生民，任聚杰（北京大学化学系，北京，１０００７１）（河北医学院化学系，石家庄）潘传智，杨勇（浙江工业大学化工系，杭州）（厦门大学化学系，厦门）关键词铜，缓蚀剂，微区光电压图铜的腐蚀与防腐早已引起...     

石英晶体微天平技术研究纳米TiO_2表面Cu(Ⅱ)吸附与光化学还原过程

环境中排放的重金属离子Cu!对水生和陆生生物有强的毒害性。饮用水中Cu!的浓度高于1.0mg·L-1时,将会导致人畜得血色沉着病和胃肠粘膜病[1]。Cu!无法进行生物降解,除去废水中Cu!的常见方法有离子交换、置换、化学沉淀等[2],然而这些方法需要消耗大量的化学试剂,成本高。近来,研     

Synthesis, spectroscopic and thermal studies of the copper(II) aspartame chloride complex

Aspartame adduct of copper(II) chloride Cu(Asp)₂Cl₂·2H₂O (Asp=aspartame) is synthesized and characterized by elemental analysis, FT IR, UV/vis, ESR spectroscopies, TG, DTG, DTA measurements and molecular mechanics calculations. Aqueous solution of the green solid absorbs strongly at 774 and 367 nm. According to the FT IR spectra, the aspartame moiety coordinates to the copper(II) ion via its carboxylate ends, whereas the ammonium terminal groups give rise to hydrogen bonding network with the water, the chloride ions or neighboring carboxylate groups. The results suggest tetragonally distorted octahedral environment of the copper ions.