Effect of nonylphenol on steroidogenesis of rat Leydig cells

Nonylphenol is the primary final biodegradation product of nonylphenol polyethoxylate (NPE), a non-ionic surfactant that is frequently incorporated into pesticide and detergent formulation. Recent researchers have hypothesized that environmental/ occupational exposure to nonylphenol poses adverse effects on reproductive system of humans and wildlife species. During our study, in vivo and in vitro experiments were performed to examine the effect of nonylphenol on testosterone biosynthesis of rat Leydig cells. In experiment in vivo, serum testosterone (T) as well as luteinizing hormone (LH) levels were detected after animals had been treated with different doses (0 mg/kg/day, 125 mg/kg/day, and 250 mg/kg/day) of nonylphenol for 50 days by gavage, and the final result revealed that testosterone level dramatically declined at the dose of 250 mg/kg/day, while LH level ascended at the dose of 125 mg/kg/day and 250 mg/kg/day. In experiment in vitro, primary cultured Leydig cells were exposed to nonylphenol for 48 h, including low concentrations (0 mg/L, 0.0011 mg/L, 0.0033 mg/L, 0.0055 mg/L, 0.011 mg/L, 0.022 mg/L) and higher concentrations (0.11 mg/L, 0.55 mg/L, 1.1 mg/L, 1.65 mg/L, 2.2 mg/L, 2.75 mg/L, 3.3 mg/L, 5.5 mg/L). Increase of testosterone levels was observed at low concentrations of nonylphenol while reduction was detected at higher concentrations.     

纳米Al_2O_3和Cd联合暴露对铜锈环棱螺体内Cd的生物积累和抗氧化酶活性的影响

金属氧化物纳米颗粒的广泛应用导致它们大量地释放到水环境中,其独特的理化性质有可能改变水环境中其他共存污染物(如重金属)的生态毒性。为评价沉积物中纳米氧化铝(Al2O3-NPs)对重金属Cd生态毒性的影响,采用底栖生物慢性暴露研究了Al2O3-NPs存在条件下Cd在底栖动物铜锈环棱螺体内生物积累的变化和Cd对肝胰脏抗氧化防御系统关键成分超氧化物歧化酶(SOD)与脂质过氧化指标丙二醛(MDA)以及Ⅱ相反应的关键酶谷胱甘肽-S-转移酶(GST)的影响。结果表明,低Cd浓度(5μg·g-1)时,Al2O3-NPs对Cd生物积累没有影响;中、高Cd浓度(25、100μg·g-1)时,Al2O3-NPs显著促进Cd的生物积累,Al2O3-NPs对Cd的生物转运具有明显的携带效应。低Cd浓度时,无Al2O3-NPs处理组和Al2O3-NPs处理组的SOD活性与对照组相比均没有显著差异;中Cd浓度时,SOD活性显著升高,而高Cd浓度时,SOD活性显著下降,而且Al2O3-NPs处理组的SOD活性显著低于无Al2O3-NPs处理组,Al2O3-NPs的存在加重了Cd对肝胰脏细胞的氧化胁迫或损伤。高Cd浓度时,无Al2O3-NPs处理组和Al2O3-NPs处理组的MDA水平均显著升高,但Al2O3-NPs处理组的MDA水平显著低于无Al2O3-NPs处理组,进一步证明Al2O3-NPs对Cd氧化损伤的增强作用。中、高Cd浓度时,无Al2O3-NPs处理组和Al2O3-NPs处理组的GST活性均显著下降,但Al2O3-NPs处理组的GST活性均显著低于无Al2O3-NPs处理组,同样说明了Al2O3-NPs对Cd毒性的增强作用。本研究提供了在沉积物-底栖动物体系中Al2O3-NPs促进重金属生物积累的证据,而且Cd毒性的变化与肝胰脏中Cd的生物积累水平的变化基本一致,在中、高Cd浓度下,由于Al2O3-NPs的存在显著促进了Cd的生物积累,因而增强了Cd对铜锈环棱螺的生态毒性。     

管道截面对氢气/空气预混爆炸影响的实验研究

为研究管道截面对氢气/空气预混火焰形状与传播速度的影响,选用三个长度都为1m而截面尺寸不同的方形管道进行实验。实验结果表明,在截面为80mm×80mm的管道中,四种氢气浓度下预混火焰都发展形成了郁金香火焰。火焰传播速度呈现上升,下降,再上升的波动。在截面为100mm×100mm和150mm×150mm的管道中,只有在氢气浓度20%下形成郁金香火焰,并且传播速度也出现上述的波动。而在氢气浓度25%,30%,40%下,预混火焰都呈指尖形传至管口,未出现郁金香火焰,传播速度都是不断上升。三个管道对比中,截面为100mm×100mm的管道内火焰平均传播速度最快,且压力波第一峰值最大。     

浅谈青岛市雨水径流污染与控制措施

随着城市化的发展,水资源的污染和匮乏已经成为人们普遍关注的问题,而由此引出的对雨水径流污染的研究和控制也已不是新鲜话题。尤其对于将要承办2008年奥运会水上项目的青岛来说雨水的意义尤为重要。在对青岛市雨水水质实地调查后,结合国内外雨水研究的先进经验,对青岛市今后的雨水污染控制和利用提出了一些建议和意见。     

A moderated mediation test of personality,coping, and health among deployed soldiers

Our study examines how personality and coping influence soldiers' psychological health among 648 US Army personnel who were at that time deployed in Iraq at the height of an insurgency. Conscientiousness, neuroticism, and extraversion were associated with different coping behaviors, and these were in turn related to psychological distress. Conscientiousness was positively associated with problem‐focused coping and negatively with avoidance coping, whereas neuroticism was most positively associated with avoidance coping. Extraversion was positively related to both seeking social support and avoidance coping. As expected, avoidance coping was positively associated with psychological distress. Coping style explained more variance in the relationship between personality and distress among soldiers who perceived higher levels of threat, thus supporting a moderated mediation hypothesis. We discuss implications for facilitating the stress coping of workers who face acute and potentially traumatic stress exposures. Copyright © 2011 John Wiley & Sons, Ltd.     

Prediction of minimum ignition energy of aerosols using flame kernel modeling combined with flame front propagation theory

Flammable aerosols have created many fire and explosion hazards in the process industry, but the flammability of aerosols has not been fully understood. The minimum ignition energy has been widely used as an indicator for flammability of combustible mixtures, but the amount of experimental data on the minimum ignition energy of aerosols is very limited. In this work, the minimum ignition energy of tetralin aerosols is predicted using an integrated model. The model applies the flame front propagation theory in aerosol systems to the growth of the flame kernel, which was created during the spark discharge in the ignition process. The aerosol minimum ignition energy was defined as the minimum level of energy in the initial flame kernel to maintain the kernel temperature above the minimum ignition temperature of 1073 K specific for tetralin aerosols during the kernel growth. The minimum ignition energy obtained in the model is influenced by the fuel-air equivalence ratio and the size of the aerosol droplets. For tetralin aerosols of 40 μm diameter, E_min decreases significantly from 0.32 mJ to 4.3 × 10 e⁻³ mJ when the equivalence ratio rises from 0.57 to 1.0. For tetralin aerosols of 0.57 equivalence ratio, E_min increases from as 0.09 mJ to 0.32 mJ when the droplet diameter rises from 10 μm to 60 μm. The trends are in agreement with previous experimental observations. The method used in current work has the potential to prediction of the minimum ignition energy of aerosol.     

基于ARCGIS的水泥行业碳排放点源分布与变化分析

首先对水泥行业产能与产量数据进行调研,对不同的工艺采用不同的CO2排放因子系统地计算了2000—2009年各点源企业水泥生产的CO2排放量,在点源企业排放量数据的基础上分析计算了各省份及全国总排放量的年度增长趋势。其次利用ARCGIS绘制了全国水泥行业排放点源年度分布图并分析了其空间分布特征,调查分析了我国水泥企业CO2排放源点源分布与变化规律,对水泥工业节能减排、发展低碳经济的工作具有重要的意义。     

废催化剂中金属组分回收利用概述

废催化剂中金属组分的回收利用具有经济性和环保性,从工程项目开发的角度,对废催化剂中金属组分回收利用技术与经济等方面的问题进行了概述,主要包括废催化剂原料的收集与分类、回收技术方案选择、经济评价及关键理论,同时也指出了相关问题及发展前景。     

应用瞬变电磁法防治煤矿顶板砂岩水的实践

研究了华北型煤田顶板砂岩的赋水规律,总结出顶板砂岩水的综合防治方法。应用瞬变电磁法探测某煤矿顶板岩层发育的含(导)水构造,为安全生产工作提供了技术指导。