铟掺杂一维半导体氧化锌纳米螺旋制备及表征

利用化学气相沉积的方法,在硅衬底上生长了铟掺杂的氧化锌纳米螺旋结构.通过X-射线衍射仪、扫描电子显微镜、透射电子显微镜、选区电子衍射等手段对样品的形貌和结构进行了表征.结果表明,合成的纳米螺旋由纳米带旋转而成,曲率半径为几个微米.纳米带宽约200 nm,厚约几十纳米,铟杂质的引入使其生长方向沿(1010)方向.     

Copper and zinc dismetabolism in the mouse brain upon chronic cuprizone treatment

Recent reports describe successful treatment using copper chelation therapy in neurodegenerative animal models. However, the success claimed for chelation therapy in neurodegenerative diseases is still rather controversial. To acquire new information on copper metabolism/homeostasis, we utilized cuprizone, a very sensitive and selective copper-chelating agent with well-known neurotoxic properties, as a relevant chemical model in mice. Upon cuprizone treatment, mice developed a pronounced astrocytosis, with brain oedema and spongiosis characterised by vacuolisations of the neuropil predominantly in the white matter. In addition, cuprizone treatment severely altered copper and zinc homeostasis in the central nervous system (CNS) as well as in all other tissues examined, with increasing metal ion concentrations particularly in the CNS. Concomitant with this increase in the Cu and Zn concentration in the brain, metallothionein-I and -II were also highly immunoreactive in astrocyte, consistent with the astrocytosis and demyelination observed in our and other laboratories.Received 23 February 2005; received after revision 3 May 2005; accepted 13 May 2005     

Increased mitochondrial palmitoylcarnitine/carnitine countertransport by flavone causes oxidative stress and apoptosis in colon cancer cells

Cancer cell metabolism is characterized by limited oxidative phosphorylation in order to minimize oxidative stress. We have previously shown that the flavonoid flavone in HT-29 colon cancer cells increases the uptake of pyruvate or lactate into mitochondria, which is followed by an increase in O₂^−.. production that finally leads to apoptosis. Similarly, a supply of palmitoylcarnitine in combination with carnitine induces apoptosis in HT-29 cells by increasing the mitochondrial respiration rate. Here we show that flavone-induced apoptosis is increased more than twofold in the presence of palmitoylcarnitine due to increased mitochondrial fatty acid transport and the subsequent metabolic generation of O₂^−. in mitochondria is the initiating factor for the execution of apoptosis. Received 12 August 2005; received after revision 12 October 2005; accepted 14 October 2005     

铅锌矿采矿废物污染对土壤原生动物的影响

对甘肃省成县王家山严家沟铅锌矿采矿废物污染土壤及对照土壤中的原生动物进行了研究。结果表明，铅锌矿采矿废物污染对原生动物群落有很大影响，主要体现在物种多样性十分显著地下降，群落组成和结构发生巨大变化，污染土壤和土壤群落的优势类群和优势种不同。根据研究结果，腐生波豆虫（Bodo putrinus)和梅氏扁豆虫（Phacodinium metchnico ffi)可作为铅锌类污染土壤环境的指示种类。     

一个人类锌指蛋白家族新基因ZFP28的克隆及表达

Krupple型锌指蛋白是一类具有重要功能的转录调节因子，初步克隆了一个新的人类krupple型锌指蛋白基因，经国际基因命我委员会批准命名为ZFP28。此基因长4076个碱基，含8个外显子，在基因组DNA上长18kb。它编码的蛋白质全长868个氨基酸，含1个信号肽，2个KRAB框和14个C2H2型的锌指。Northem Bolt分析表明该基因在人类早期胚胎的各个组织中普遍表达，在肺和肝中的表达水平最强，其结构和表达特征预示着它编码的是一个具DNA结合功能的转录调控因子。     

一种测定微量铜的高灵敏度动力学方法

根据铜对磷钼酸氧化碘化钾反应的催化效应,提出了有效测定痕量铜的动力学方法.并建立了测定条件,铜的浓度在0～0.64μg/mL范围内标准曲线是直线,检测限量为1ng/mL.该方法用于La_2O_3中铜的测定,重现率为95.6％.Rs_o为2.2％.     

Extraordinary levels of cadmium and zinc in a marine sponge,Tedania charcoti Topsent: inorganic chemical defense agents

The Antarctic marine spongeTedania charcoti has been shown to contain extraordinarily high natural concentrations of cadmium and zinc, which have in turn been correlated to the ability of the crude ethanol extract to modulate protein phosphorylation in chicken forebrain and to inhibit the growth of several test bacteria.     

Alopecia induced in young mice by exposure to excess dietary zinc

Summary Second generation mice were exposed to normal (50 ppm, Group I) or excess (2000 ppm, Group II) zinc in the maternal diet during gestation and lactation, then weaned and continued on the mother's diet until sacrifice at 8 weeks. Tibia zinc reflected dietary intake. Group II had reduced plasma copper, body weight, and hematocrit; the second coat of hair appeared late and was lighter in color than Group I, possibly as an effect of copper and pigmentation development and hair growth.     

Superoxide dismutase activity during the plasmodial life cycle ofPhysarum polycephalum

Summary Superoxide dismutase activity was slow throughout the cell cycle of surface cultures ofPhysarum polycephalum. This activity increased markedly when the organism was induced to spherulate. Glutathione (GSH) and hydrogen peroxide (H₂O₂) concentrations changed very little during the cell cycle. During spherulation GSH decreased; H₂O₂ and the cyanide-resistant respiration of plasmodial homogenates increased.     

阻燃剂硼酸锌的合成

硼酸锌是一种性能优良的无机添加型阻燃剂。组成为 2ZnO·3B2 O3·3.5H2 O的低水合硼酸锌应用得最为广泛。采用硼砂法合成了低水合硼酸锌 ,用正交法确定的最佳工艺条件是 :反应温度为 338K ,硫酸锌和硼砂的配料比为 1 .0 5∶1 ,液固比为 3.5∶1 ,反应时间为6h .