Effects of Lead on Temporal Response Properties of Retinal Ganglion Cells in Developing Rats

Neonatal rats have taken in lead, during the period from their parturition to their weaning, from the milk of dams fed with water containing 0.2% lead acetate solutions. The alterations in the temporal response properties of retinal ganglion cells in adult rats (90 days) following the lead exposure at their developing stage have been studied. The results of this investigation demonstrate that the lead exposure in neonatal rats causes decreases in the optimal temporal frequency, bandwidth at half amplitude, temporal resolution and response phase of the retinal ganglion cells in adult rats. Compared with the sustained cells, the transient cells have a much greater alteration in temporal response properties.     

Rapid Synthesis of Lead Oxide Nanorods by One-step Solid-state Chemical Reaction at Room Temperature

A simple and facile method was reported to synthesize lead oxide nanorods. Nanorods of lead oxide were obtained directly from grinding solid metal salt and sodium hydroxide in agate mortar with the assistance of a suitable nonionic surfactant in only one step, which is different from the result of hydroxide in solution. The product has been characterized by XRD, TEM and SEM. The formation mechanism of rod-like morphology is discussed and the surfactant plays an important soft-template role in modifying the interface of solid-state reaction and according process of rod-formation.     

Crown-containing butadienyl dyes 8. Structures and complexation of chromogenic dithia-15(18)-crown-5(6) ethers

The structures of new butadienyl dyes of the benzothiazole series containing the dithia-15-crown-5 (2a) or dithia-18-crown-6 (2b) fragments were established by X-ray diffraction. Complexation of dyes 2a,b with Hg²⁺, Pb²⁺, Cd²⁺, Ag⁺, Zn²⁺, and alkaline-earth cations in aqueous-acetonitrile solutions was studied by spectrophotometry. At a high percentage of water in solutions (P _w ≈ 50%), these dyes have a very low ability to bind Pb²⁺ cations (logK < 2) and virtually do not bind Cd²⁺, Zn²⁺, and alkaline-earth cations. At the same time, these dyes form stable 1: 1 complexes with Hg²⁺ and Ag⁺ cations at all P _w. The stability constants of complexes with the Ag⁺ cation increase with increasing P _w because the free energy of hydration of this cation is much lower than the free energy of solvation in acetonitrile. In the P _w range from 0 to 75%, the stability constants of the complexes of dyes 2a,b with the Hg²⁺ cation are larger than those of the corresponding complexes with the Ag⁺ cation by more than four orders of magnitude. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 90–96, January, 2006.     

一种新颖有机-无机杂化配位聚合物[(C10H16N)2（Pb2I6）·2DMF·H2O]n的自组装合成和晶体结构(英)

A novel coordination polymer [(C₁₀H₁₆N)₂（Pb₂I₆）·2DMF·H₂O]_n (C₁₀H₁₆N=N-butyl-2-Methy-Pyridinium) was synthesized by the reaction of Pb(NO₃)₂ with C₆H₁₀NI at room temperature in DMF solvent and structurally characterized by means of X-ray single diffraction. The title compound crystallizes in triclinic system, space group P1 with a=1.1237(2) nm, b=1.25330(16) nm, c=0.808 00(12) nm, α=102.523(4)°, β=92.475(5)°, γ=95.712(10)°, V=1.102 9(3) nm³, Z=1, D_c=2.470 Mg·m^-3, F(000)=738, chemical formula C₂₆H₄₈N₄O₃Pb₂I₆ and M_r=1 640.46, μ（MoKα）=11.849 mm^-1, the final R=0.057 8 and wR=0.166 5 for 3716 observed reflections with I > 2σ(I). The title compound consists of cations ([(C₁₀H₁₆N)⁺] and anion chain(PbI₃^-),they are combined by static attracting forces in the crystal. DMF and H₂O locate between the organic and inorganic moiety. CCDC: 210812.     

1570例学龄前儿童血铅水平调查

为了解顺德伦教学龄前儿童血铅水平及铅中毒发病情况 ,以便及时采取有效措施 ,根据整群分层随机抽样 ,检测了本区学龄前儿童血铅水平 ,并进行了流行病学分析。结果表明 ,本次调查学龄前儿童 1 5 70例 ,血铅水平为 (1 0 8 6± 79 8) μg/L ,儿童铅中毒患病率为 5 0 76% ;男童血铅水平及铅中毒患病率都高于女童 ,但无明显统计学差异 (P >0 0 5 ) ;年龄越大血铅水平相对越高 ,铅中毒患病率也越高 ,并存在明显差异 (P <0 0 1 )。提示顺德伦教学龄前儿童血铅水平及铅中毒患病率维持在较高水平 ,应及时采取有效措施 ,防治儿童铅中毒。     

Inhibition of Pb-Leaching from Lead Crystal Glass by Coating with Films Prepared by the Sol-Gel Method

The chemical durability of lead glass tumblers (24% PbO) in a 4% (v/v) acetic acid solution before and after coating with sol-gel derived SiO2 films was assessed to determine the extent of reduction in Pb-leaching that can be achieved. It was found that by coating the internal surface of the glass tumblers with 1 ml of 10% TEOS solutions at 100°C and densifying the coating formed at 500°C for 1 h, it was possible to reduce Pb-leaching to about one quarter of that of the uncoated glass.     

Synthesis of calix[4]arene library substituted with peptides at the upper rim

A fluorescence-labeled calix[4]arene library substituted with peptides at the upper rim was synthesized. Screening of the library for binding a dye-labeled oligopeptide indicated that some peptidocalix[4]arenes selectively bind the oligopeptide. The chemosensitivity of the library members for a target peptide was also investigated.     

Two Novel Antifungal Saponins from Tibetan Herbal Medicine Clematis tangutica

Antifungal assay-guided isolation of the ethanol extract of the aerial parts of Clematis tangutica yielded two novel triterpene saponins. Their structures were determined to be 3-O-α-L-arabinopyranosyl hederagenin 28-O-α-L-rhamnopyranosyl ester (1) and 3-O-β-D-glucopyranosyl-(1→4)-α-L-arabinopyranosyl hederagenin 28-O-α-L-rhamnopyranosyl ester (2) on the basis of spectral data and chemical reactions.     

两种含锌化合物对慢性染铅大鼠海马NADPH-d阳性神经元影响的比较

为探讨硫酸锌(ZnSO4)和牛磺酸锌(TZC)拮抗铅对学习记忆的损害的不同，采用NADPH-黄递酶(NADPH-d)组化，观察了饮用含0.2g／L醋酸铅(PbAc)饮水和含不同剂量(5．0，15．0g／kg)ZnSO4、(5．9、17．7g／kg)TZC饲料喂养的大鼠海马一氧化氮合酶(NOS)活性的变化。结果表明，各补锌组均不同程度地缓解铅致NOS活力减低，铅 低TZC组、铅 高ZnSO4组和铅 低ZnSO4组大鼠海马神经元的NOS活性明显高于染铅组，其中铅 低TZC组的保护作用最显著，而铅 高TZC组的NOS活性明显低于对照组，而接近染铅组水平。结论是锌对抗铅的毒性作用与锌的化学结合形式、锌的剂量密切相关。     

Bioanalytical methods applied to endocrine disrupting polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans. A review

The usual methods for determining polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF) and polychlorinated biphenyls (PCB) are generally expensive and time consuming. This fact has favored the development of faster and cheaper techniques, based on immunoassays and bioassays. This paper reviews these bioanalytical methods and their analytical importance at the present moment.