Antagonism of phenanthrene cytotoxicity for human embryo lung fibroblast cell line HFL-I by green tea polyphenols

Polycyclic aromatic hydrocarbons (PAHs) have been detected in some commercial teas around the world and pose a threat to tea consumers. However, green tea polyphenols (GTP) possess remarkable antioxidant and anticancer effects. In this study, the potential of GTP to block the toxicity of the model PAH phenanthrene was examined in human embryo lung fibroblast cell line HFL-I. Both GTP and phenanthrene treatment individually caused dose-dependent inhibition of cell growth. A full factorial design experiment demonstrated that the interaction of phenanthrene and GTP significantly reduced growth inhibition. Using the median effect method showed that phenanthrene and GTP were antagonistic when the inhibitory levels were less than about 50%. Apoptosis and cell cycle detection suggested that only phenanthrene affected cell cycle significantly and caused cell death; GTP lowered the mortality of HFL-I cells exposed to phenanthrene; However, GTP did not affect modulation of the cell cycle by phenanthrene.     

Polycyclic aromatic hydrocarbons (PAHs) in surface sediments of Liaodong Bay,Bohai Sea,China

Materials and methods  

The levels and possible sources of 16 polycyclic aromatic hydrocarbons (PAHs) were investigated in the surface sediments of Liaodong Bay, Bohai Sea, China.     

复合混凝法处理高浓度聚丙烯酰胺生产废水

采用聚合氯化铝(PAC)混凝和活性炭吸附的复合混凝法处理高浓度聚丙烯酰胺(PAM)生产废水.实验结果表明,最佳处理条件为:废水 pH 6.5,废水温度 35℃,先加入 PAC 混凝后再加入活性炭,PAC 加入量250 mg/L,活性炭加入量 200 mg/L.在此最佳条件下,废水 COD 去除率达 52.0%.该复合混...     

印制电路板酸性蚀刻废液的膜电解再生

高度精细化线路和高层数印制电路板产量的增加,导致酸性蚀刻废液的排放量越来越大,对环境的负荷也随之增大.介绍了酸性蚀刻废液膜电解再生的基本原理,进行了中试规模的应用研究,并与其他电解再生方法进行技术与经济比较分析.结果表明,在槽电压为5V、电解时间为2h的条件下,酸性蚀刻废液的氧化还原电位由480 mV升至540mV,所...     

Direct evidence for interaction between lead ions and kidney DNA from silver crucian carp

A direct interaction of lead (Pb) with kidney DNA from silver crucian carp (Carassius auratus gibelio) has been systematically studied in vitro using multi-techniques, including UV-vis absorption, extended X-ray absorption fine structure, vacuum ultraviolet circular dichroism spectral methods and gel electrophoresis. We find that Pb is bound with four oxygen or nitrogen atoms of DNA in its fresh shell at the distances of 2.64 A. Additionally, Pb may bind to the oxygen atom of nucleic acid or nitrogen atom of base pairs of DNA in that obvious changes in the secondary structure of DNA are found after Pb treatment. However, this direct interaction of Pb with DNA do not cause DNA cleavage in vitro.     

Heat stress increases the efficiency of EDTA in phytoextraction of heavy metals

Solution culture and pot experiments were carried out to investigate the effects of root damage on phytoextraction of heavy metals. In hydroponics, roots of corn (Zea mays L.) seedlings were pretreated with heating stress, and then were exposed to 250 microM Pb+250 microM EDTA solutions for 7d. The results showed that the preheating treatment significantly increased Pb transportation from roots to shoots. In pot experiments, the effect of hot EDTA solution (95 degrees C) on the accumulation of heavy metal in the shoot of corn and pea (Pisum sativum L.) was also examined. Compared to normal EDTA (25 degrees C) treatment, application of hot EDTA solution to the soil surface increased the total removal of Pb in shoots of corn and pea by about 8- and 12-fold, respectively, in an artificially multimetal-contaminated soil. In addition, hot EDTA solution increased the shoot Cu removal by about 6-fold for corn and 9-fold for pea, respectively, in a naturally Cu-contaminated soil. These results suggested that exposure of roots to high temperature could increase the efficiency of EDTA on the accumulation of heavy metals in shoots. This new approach can help to minimize the amount of chelate applied in the field and reduce the potential risk of heavy metals' leaching.     

激励生态农业发展的环境经济政策分析

本文着重探讨了激励生态农业发展的环境经济政策分析过程。该方法体系从农业环境经济系统的起始元——农户入手 ,建立了农户环境经济行为模式 ,进而通过指向农户的环境经济政策激励机制模型分析 ,寻找促进生态农业发展的环境经济政策包。     

典型脆弱生态区的稳定性与可持续农业发展

本文利用分形理论对脆弱生态区的稳定性进行了定量分析 ,并据此指出了脆弱生态区农业可持续发展的限制性因素。最后以内蒙古翁牛特旗为例 ,提出了其农业可持续发展的合理化建议。     

复杂地质条件下光面爆破间断不耦合装药结构的试验研究

以现场试验研究为基础,提出了利用间断不耦合装药结构,改善含软夹层岩体光爆效果的技术措施,并给出了在含夹层石灰岩和页岩中,其夹层厚度与最佳间断距离之间的关系曲线。采用该项技术不仅能保证施工安全,而且能保证边坡无浮石危险,对于确保边坡长久安全有着非常重要的意义     

疏水滤料过滤性能研究

对普通７２９ 滤料和疏水７２９ 滤料的透气性、阻力特性、静态集尘特性以及在加湿和不加湿两种条件下的动态集尘清灰特性进行了全面的试验研究,通过对两种滤料各项性能的试验结果加以分析、比较,从而为疏水滤料处理含湿烟气的实际应用提供指导和依据