Quantum dots enhance Cu2+-induced hepatic L02 cells toxicity

As a new class of xenogenous nanoparticle,quantum dots (QDs) possess the potential to co-exist with Cu2+ in human liver.The combined toxicity is thus concerned.Considering QDs and Cu2+ are known ROS (reactive oxygen species) inducer,we investigated the combined oxidative stress and corresponding protective strategy using human hepatic L02 cells.The results demonstrated that the presence of a small amount of MPA-CdTe QDs (2 μg/mL) in a Cu2+ solution (2.5-20 μg/mL) resulted in a higher toxicity with up to 8-fold cell viability decrease,which was accompanied by cell morphology changes.The combined toxicity was then confirmed as ROS associated oxidative stress with up to 300% and 35% increase of the intracellular ROS level and glutathione S-transferase (GST) activity,respectively.N-acetylcysteine (NAC) can also provide almost complete protection against the induced toxicity.Therefore,the ROS associated oxidant injury might be responsible for the QDs-Cu2+/Cu2+ induced toxicity and could be balanced through cytoprotective antioxidant enzyme GST.     

A possible in situ 3H and 3He source in Earth’s interior: an alternative explanation of origin of 3He in deep Earth

Origin of ³He in the Earth is a mystery. Lacking a production mechanism, scientists assume ³He was trapped in the Earth, when the Earth was formed. In contrast to this assumption, we have found ³He and ³H concentrations in excess of the atmospheric values in the deep waters of the volcanic Lakes Pavin (France), Laacher (Germany) and Nemrut (Turkey). This paper reports the result of finding ³H in these three volcanic lakes that appear to originate from the mantle. Because ³H has a half-life of 12.3 years, this ³H and the resulting ³He must have formed recently in the mantle and not be part of a primordial reservoir. The nuclear reactions that generate tritium might be a source of “missing” energy in the interior of the Earth.     

沈阳市区臭氧污染状况调查与分析

对沈阳市区环境空气中的臭氧污染现状进行了调查与分析,利用沈阳市大气自动监测系统的数据,分别分析了沈阳城市中心区和城市边缘区臭氧的污染情况以及臭氧与其他污染物之间的相关性,并总结了臭氧与其他污染物的季节性变化趋势。     

Kinetic-spectrophotometric determination of free cyanide by stopped-flow reversed flow injection analysis

A stopped-flow reversed flow injection method for the determination of free cyanide is proposed. Pyridine-barbituric acid mixture is injected in the flow system as reagent to form the colour species with cyanide. The flow is stopped when the reagent zone comes in the flow cell, where absorbance-time data are collected at 580nm wavelength. The linear range of the determination is 0.1 -10μg/ml CN-. The sampling rate is 60h-1 and the relative standard deviation is 1.6% (n=16) at 5.0 μg/ml CN-1 level. With satisfactory results, the proposed method was applied to the determination of free cyanide in wastewater without sample pretreatment.     

饮用水中硝酸盐去除方法比较

本文综述了饮用水中硝酸盐的各种去除方法及其优缺点.通过分析比较,认为离子交换法和生物反硝化法都可用于大规模生产饮用水,但最有发展前途目前研究最多的是生物反硝化法.该法将硝酸盐转化为氮气,无废液产生,处理费用低.但异氧反硝化法需进行复杂的后处理除去过量的有机物,自养反硝化法会造成出水硫酸盐含量增高.     

毛细管柱气相色谱质谱法分析优先监测物的质量控制研究——Ⅰ.半挥发性有机物

报道了毛细管柱气相色谱质谱联用(GC-MS)方法分析半挥发性有机物的质量控制研究结果.对分析的全过程提出了质量控制标准.应用同位素标记内标物(IS),替代掺样物(SS)和基质掺样/重复基质掺样(MS/MSD)的回收率来判断样品处理与分析结果的可靠性.根据77种目标化合物,特别是标定检验化合物(CCC)和系统检验化合物(SPCC)的响应系数范围,确定GC-MS系统的工作状态和最终结果的正确性.给出了满足质量控制标准的12个土壤样品的结果.     

污染环境的刑事责任问题探讨

根据一些发达国家的法律实践和我国环境保护工作的实际需要,探讨了对环境造成严重恶果的行为,应设立“污染环境罪”来调整人们行为的最后法律手段的必要性,并就污染环境罪的基本特征及与其它法律责任的区别作了分析和阐述,提出在我国刑法中应专条补充设立“污染环境罪”规定的建议。     

我国淡水水域光合产物的气候生产力探讨

根据太阳辐射在水体中的有效分布、生长季水温和浮游植物光合生态特性等因子,模拟计算了我国大陆东部淡水水域的光合生产力、气候生产力及其季节变化的地理规律。从中得知,这些水域初级产物的年气候生产力主要呈纬向分布,由南向北递减,各地范围在 1.6-24.4gC/m²·a之间,长江以南是>15.0gC/m²·a的高值区,长城以北和四川盆地为<10.0gC/m²·a的低值区,因此,在气候生产力高值区有可能充分利用气候资源优势,开发低成本的自然淡水水域渔业;而在低生产力区,受自然资源的局限其自然捕鱼量需适量控制,因地制宜。