铅暴露U251细胞差异表达基因及相关通路(The Interrelated Pathways in Brain Human U251 Glioma Cells by Lead Exposure)

为探讨铅对体外培养的人神经胶质瘤U251细胞(human U251glioma cells,U251)暴露后基因表达的变化以及相关基因通路,选用乙酸铅暴露U251细胞.细胞在乙酸铅中暴露8h和24h后提取RNA,使用cDNA芯片分析基因表达情况,芯片扫描结果经归一化处理,设定Ratio值<0.5或≥2.0为表达有差异基因.结果表明,铅暴露U251细胞导致2840条基因差异表达,使用KEGG和BioCarta数据库分析代表性基因网络.结果发现,铅暴露U251细胞导致大量基因差异表达,涉及多个代谢及信号通路,与神经组织相关的主要信号通路有Ca2+信号通路、Jak-STAT信号通路、MAPK信号通路、Wnt信号通路等,还涉及配体-受体、细胞因子相互作用等.这些通路相互联结,构成复杂的网络系统,调控细胞的生物学功能.     

Competitive adsorption and desorption of copper and lead in some soil of North China

The competitive adsorption and desorption of Pb(II) and Cu(II) ions in the soil of three sites in North China were investigated using single and binary metal solutions with 0.01 mol·L^-1 CaCl₂ as background electrolyte. The desorption isotherms of Pb(II) and Cu(II) were similar to the adsorption isotherms, which can be fitted well by Freundlich equation (R₂>0.96). The soil in the three sites had greater sorption capacities for Pb(II) than Cu(II), which was affected strongly by the soil characteristics. In the binary metal solution containing 1∶1 molar ratio of Pb(II) and Cu(II), the total amount of Pb(II) and Cu(II) adsorption was affected by the simultaneous presence of the two metal ions, indicating the existence of adsorption competition between the two metal ions. Fourier transform infrared (FT-IR) spectroscopy was used to investigate the interaction between soil and metal ions, and the results revealed that the carboxyl and hydroxyl groups in the soil were the main binding sites of metal ions.     

改性柚子皮吸附剂对模拟废水中Pb^2＋的吸附性能

以废柚子皮为原料,经ZnCl2浸泡一加热的化学改性手段制备改性柚子皮生物吸附剂,并通过模拟试验研究该吸附剂对废水中Pb^2＋的去除。考察了模拟废水的pH、吸附时间、吸附剂用量和Pb^2＋初始浓度、温度等因素对柚子皮吸附剂去除Pb^2＋的影响,并研究柚子皮吸附剂对Pb^2＋的吸附动力学及吸附特征。结果表明,模拟废水的pH、吸附时间、吸附剂用量和Pb^2＋初始浓度、温度等因素对柚子皮吸附剂吸附废水中Pb^2＋均有显著影响。适宜的吸附条件为pH5．3-6．5,吸附时间1．5h,吸附剂用量10g·L^-1,Pb^2＋初始质量浓度100mg·L^-1,温度30℃。在该条件下,废水中Pb^2＋去除率在90％以上。柚子皮吸附剂对废水中Pb^2＋的吸附符合动力学二级反应方程,等温吸附规律可用Langmuir、Freundlich和Temkin模型进行较好的描述。     

原子吸收法测定土壤中铅的方法

通过湿法消解土壤样品,利用石墨炉原子吸收分光光度法(GAAS)和火焰原子吸收分光光度法(FAAS)测定不同土壤样品中铅的含量,以验证2种方法的有效性并加以对比。实验结果表明:2种方法均满足土壤中铅含量的测定要求,测定的标准土样含量均在标准值的不确定度范围内,GAAS方法测定结果更接近保证值。二者的相对标准偏差(RSD)值均低于1.5%,FAAS方法的精密度更高,且具有快速简单等优势。     

锌精炼铅塔燃烧系统烟气温度模糊控制研究

针对锌精馏铅塔动态过程中的非线性、非最小相位特征、不稳定性、时滞和负荷干扰,基于模糊控制策略下给出了锌精馏铅塔燃烧系统新的控制方法.运用模糊控制系统对锌精馏铅塔的烟气温度进行仿真研究和实时控制结果表明,该研究所设计的模糊控制器能够克服许多干扰因素,产生了良好的控制效果.     

Arbuscular mycorrhiza confers lead tolerance and uptake in Miscanthus sacchariflorus

The effects of an arbuscular mycorrhizal fungi (AMF) association on the growth, survival capabilities, nutrients and lead (Pb) uptake of Miscanthus sacchariflorus under different Pb concentrations were studied in the form of pot cultures. The treatments comprised inoculation or non-inoculation of the AMF, Gigaspora margarita, and the addition of three Pb concentrations to the soil (0, 100 and 1000?mg?kg^?1). The addition of Pb significantly decreased mycorrhizal colonisation. The inoculation of AMF with Pb increased chlorophyll content, Fv/Fm, total dry mass, indole-3-acetic acid (IAA), total nitrogen, and total phosphorus, whereas H₂O₂ level, indole-3-acetic acid oxidase (IAAO) activity, and peroxidase (POD) activity were low compared to those in the non-inoculated treatments. Moreover, the application of AMF together with Pb doses induces concentrations of Pb in the plant, where the higher dose of Pb (1000?mg?kg^?1) induces a lower content of Pb in the aerial part of the plant but a higher content in the root. G. margarita enhanced the tolerance of M. sacchariflorus against Pb toxicity, and facilitated the accumulation of Pb in the plant roots, whereas translocation to the shoots was inhibited at the highest dose Pb (1000?mg?kg^?1). However, in contaminated soil, the Pb removal capability of M. sacchariflorus with AMF was remarkable.     

石灰对重金属铅影响玉米生长的抑制效应研究

采用盆栽试验,研究了在施用石灰改良的条件下,土壤重金属铅污染对玉米生长的影响。结果表明:土壤重金属铅污染质量分数越高,玉米吸收重金属铅越多,对玉米的生长影响越大。石灰对重金属铅影响玉米生长的抑制效应表现在株高、叶面积、根容积等,改良处理与单一铅污染的处理差异显著。玉米的不同部位对重金属铅吸收由多到少的顺序为根→茎、叶→籽实。     

铅（Pb^2＋）致高血压大鼠胸主动脉病变的相关基因及信号转导途径

采用表达芯片研究铅(Pb2+)致高血压大鼠模型病变主动脉的基因表达谱,以及可能涉及的信号转导途径.结果表明,Pb2+致高血压大鼠和对照组相比,在3463个已知基因和表达序列标签(EST)中,有24个基因和1个EST表达上调幅度≥2倍;有2个基因和1个EST表达下调幅度≥2倍.在差异表达≥2倍的26个基因中,有13个上调的基因与细胞凋亡、局部粘附、细胞生长、增殖、细胞迁移、平滑肌兴奋、胶原重构等生物学过程相关;2个下调基因与能量代谢有关.表达差异基因相对集中的信号途径是与细胞运动、增殖和存活关系密切的局部粘附信号途径.     

城市街道空气中铅污染及其对机体无机盐影响的研究

本文对兰州市不同交通路口铅污染现场监测及交警人群健康体检,结果表明各路口受汽车尾气污染严重,铅浓度在１．１６～２．６４μｇ／ｍ３之间。将１２０名交警分外勤警７０人作为污染组,内勤警及户藉警５０人作为对照组,调查结果尿中δ－氨基乙酰丙酸两组比较没有统计学差异（Ｐ＞０．０５）;污染组发铅、尿铅浓度均显著高于对照组,发锌、铜、钙及血中ＩｇＡ、ＩｇＧ、ＩｇＭ均低于对照组,并具有统计学差异（Ｐ＜０．０５,Ｐ＜０．０１）。提示街道空气铅污染对交警体内无机盐水平及机体免疫能力具有一定的影响。     

Cadmium and Lead Levels in Fish (Tilapia Nilotica) Tissues as Biological Indicator for Lake Water Pollution

Cadmium and lead were determined in different tissues (muscle,gill, stomach, intestine, liver, vertebral column and scales) of Tilapia nilotica from the High Dam Lake, Aswan (Egypt) to assess the lake water pollution with those toxic metals. Fish samples were chosen from different ages and weights to be analyzed along with samples of the aquatic plant(Najas armeta), sediment and lake water.The results showed that cadmium and lead concentrations were higher in fish scales and vertebral column than in the other parts of the fish. Cadmium and lead levels in High Dam lake water and fish (Tilapia nilotica) were a result of the pollution which uptakes from aquatic plants, sediments andgasoline containing lead that leaks from fishery boats. Tilapia nilotica fish was used as a good bio-assay indicator for the lake pollution with cadmium and lead. The fish musclesin this study were in the safety baseline levels for man consumption.