二氧化硫衍生物对小鼠心、肝、肺蛋白质的氧化损伤作用

研究了二氧化硫(SO2)衍生物--亚硫酸钠和亚硫酸氢钠混合物(分子比为3:1),对小鼠心、肝、肺中蛋白质的氧化损伤作用,探讨其分子作用机制.连续5 d对动物腹腔注射SO2衍生物,每天注射剂量为0、0.025、0.100、0.400 g·kg-1.用2,4-二硝基苯肼比色法测定不同器官组织中蛋白质羰基含量.结果表明,SO2衍生物染毒剂量为0.025、0.100 和0.400 g·kg-1时,小鼠心、肝、肺蛋白质羰基含量染毒组与对照组相比均呈现不同程度的增加,不同器官羰基含量增量大小的次序为:肝＞肺＞心;其染毒剂量与心、肝、肺蛋白质羰基含量之间存在明显的剂量效应关系(p＜0.05),线性拟合确定系数分别为0.894、0.893和0.903.由此认为,SO2衍生物可引起小鼠心、肝、肺组织蛋白质的氧化损伤,以及不同组织器官的蛋白质氧化损伤程度不同.     

气溶胶水溶性无机物及有机物的离子色谱测定

利用离子色谱技术同时测定大气气溶胶中的水溶性有机物 (WSOC)与各种无机成分 ,检测出 1 2种无机离子 (F- ,Cl- ,NO-2 ,NO-3 ,SO2 -3 ,SO2 -4 ,PO3-4 ,Na ,NH 4,K ,Mg2 ,Ca2 )及 7种WSOC (甲酸、乙酸、甲磺酸、乙二酸、丙二酸、丁二酸、戊二酸 ) .该方法对无机离子的线性范围为 0 0 1— 1 0 0 0 μg·m- 3,有机物的线性范围为 0 0 0 5—1 0 μg·m- 3,相关系数除NH 4以外均高于 99 9% ,最低检测限为 0 0 0 0 1— 0 0 0 0 5 μg·m- 3,相对标准偏差为 0 43— 1 32 % .利用该技术 ,对北京市 2 0 0 1— 2 0 0 2年度大气PM2 5中水溶性物种的浓度水平进行了测定 .结果表明 ,北京市PM2 5中主要的水溶性组分为SO2 -4 ,NO-3 和NH 4,其浓度水平分别为 1 1 1 ,7 8和 6 2 μg·m- 3,各占PM2 5 质量的 1 0 6% ,7 4%及5 7% ,而WSOC的浓度水平为 0 0 1 1— 0 1 1 8μg·m- 3,占PM2 5质量浓度的 0 0 1— 0 1 % ,其中 ,乙二酸的浓度最高 ,其次为乙酸、丁二酸 ,丙二酸等 .     

长江口水体中重金属形态交换过程的研究

研究了重金属在水体中溶解态和颗粒态的含量分布,并以一个代表性水平剖面和垂直剖面分析了金属形态交换过程。其动态交换是,重金属由颗粒态沿水平方向交换时向溶解态转化,形态转化强度为Ｎｉ〉Ｆｅ〉Ｃｏ〉Ｃｕ〉Ｍｎ〉Ｐｂ;重金属的垂向交换过程,都是被铁锰（水合）氧化物及有机质吸附,向金属铁锰氧化物态转化,形态转化强度为Ｐｂ〉Ｃｕ〉Ｍｎ〉Ｆｅ〉Ｎｉ〉Ｃｏ,最后得出长江口海域金属污染程度及环境现状。     

大庆石化空气污染区树木叶片内蛋白质、核酸、游离氨基酸及过氧化物酶同工酶含量的变化

石化空气污染区树木叶片内的蛋白质、核酸、游离氨基酸及过氧化物酶同工酶含量较对照区有明显的变化,变化 幅度小的树木的抗污染能力强,变化幅度大的抗污能力弱。其中蛋白质、核酸含量表现出降低,游离氨基酸和过氧化物酶同工酶含量升高。供试的几种绿化树木抗污能力由强至弱依次为云杉、旱垂柳、中东杨、白榆、丁香、白蜡槭。     

A numerical model for transient-hysteretic flow and solute transport in unsaturated porous media

A two-dimensional flow and transport model was developed for simulating transient water flow and nonreactive solute transport in heterogeneous, unsaturated porous media containing air and water. The model is composed of a unique combination of robust and accurate numerical algorithms for solving the Richards', Darcy flux, and advection-dispersion equations. The mixed form of Richards' equation is solved using a finite-element formulation and a modified Picard iteration scheme. Mass lumping is employed to improve solution convergence and stability behavior. The flow algorithm accounts for hysteresis in the pressure head-water content relationship. Darcy fluxes are approximated with a Galerkin and Petrov-Galerkin finite-element method developed for random heterogeneous porous media. The transport equation is solved using an Eulerian-Lagrangian method. A multi-step, fourth-order Runge-Kutta, reverse particle tracking technique and a quadratic-linear interpolation scheme are shown to be superior for determining the advective concentration. A Galerkin finite-element method is used for approximating the dispersive flux. The unsaturated flow and transport model was applied to a variety of rigorous problems and was found to produce accurate, mass-conserving solutions when compared to analytical solutions and published numerical results.     

小麦籽实中蛋白质-Cd,Pb结合形态及其稳定性

在体外消化酶模拟条件下,对小麦籽实中Ｃｄ,Ｐｂ蛋白质结合体的稳定性进行了研究．结果表明:小麦籽实中存在的表观分子量为５４．５×１０３和５．５×１０３的蛋白质－Ｃｄ,Ｐｂ结合体,在体外胃蛋白酶和胰蛋白酶消化后,蛋白质结构发生变化．特别是分子量为５４．５×１０３的Ｃｄ,Ｐｂ－蛋白质结合体不稳定,容易被胰蛋白酶分解,变成分子量为５．５×１０３的稳定的Ｃｄ,Ｐｂ－蛋白质结合体或更小的多肽．     

低浓度有机磷萃取剂P204促进普通小球藻(Chlore11a vulgaris)生长的研究

本文以普通小球藻为实验对象,研究了有机磷萃取剂P204在低浓度（相似文献   

粉末凹凸棒石对水溶性阳离子染料废水的脱色研究

本文研究了凹凸棒石粘土处理阳离子染料废水的吸附脱色规律。结果表明,粉末凹凸棒石对水溶性阳离子染料具有优良的脱色效果。例如,染料初始浓度１００ｍｇ·ｌ＾－１（色度相当于２２００￣４０００倍）,粘土投加量０．５％,七种被研究的阳离子染料废水平均脱色率近９９％,吸附机理主要是离子交换。     

赤泥对电解锰渣中可溶性锰离子固化效果研究

为了探讨赤泥固化电解锰渣中可溶性锰离子的固化效果和可行性,本文采用X射线衍射(XRD)、电子扫描显微镜(SEM)和X射线荧光光谱(XRF)等分析手段,对比评估了新鲜赤泥、陈旧赤泥(堆放1年以上)、生石灰以及陈旧赤泥复合生石灰等固化剂在不同添加剂量下对电解锰渣中可溶性锰离子的固化效果,并初步阐释了赤泥固化电解锰渣中可溶性...     

Selective cellular and molecular effects of beryllium on lymphocytes†

An involvement of the immune system has been implicated in many of the whole animal effects of beryllium (Be) and its compounds and thus lymphocytes are a relevant cell model to study some of the cellular and molecular actions of the metal. Recent results indicate micromolar concentrations of Be salts are weakly mitogenic to lymphocytes in vitro probably as a result of direct interactions with the cell membranes. Furthermore evidence has been obtained that high affinity lymphocyte Be‐binding may be predictive of the potential to express delayed Be hypersensitivity in vivo. Although sub mitogenic concentrations of Be salts may actually activate accessory (macrophage type) cells, concentrations normally mitogenic to lymphocytes were found to inhibit their proliferative response to accessory cell dependent mitogens as a result of a Be²⁺ concentration dependent destruction of the adherent cell population. Higher concentrations of Be salts proved cytostatic to lymphocytes possibly by the established property of intracellularly accumulated Be²⁺ to inhibit cell division. Lymphocyte proliferation can be related to increases in protein phosphoryl‐ation capacity which in vitro can be inhibited by Be²⁺ and preliminary evidence indicates that tyrosine phosphorylation may be particularly sensitive.