内质网应激在氟暴露致小鼠睾丸损伤中的作用

探讨了内质网应激在亚慢性氟暴露致小鼠睾丸损伤中的作用及分子机制.选用健康初断乳ICR雄性小鼠30只,随机分为对照组（C）、低氟组（LF）和高氟组（HF）,分别饮用自来水、5、30 mg·L^-1氟化钠水溶液90 d.亚慢性氟暴露结束后,以睾丸脏器系数、睾丸组织氧化/抗氧化酶和形态结构、精子质量、睾丸细胞凋亡、葡萄糖调节蛋白78（GRP78）、CCAAT/增强子结合蛋白同源蛋白（CHOP）、半胱氨酸天冬氨酸蛋白酶12（CASPASE-12）、半胱氨酸天冬氨酸蛋白酶3（CASPASE-3）为观测点.结果表明,与对照组比,LF组和HF组LDH、SOD、T-AOC活性下降,MDA含量上升,HF组GSH-PX活性下降,差异有统计学意义（p<0.05或p<0.01）;LF组可见细胞层次减少、间隙变大,成熟精子数量减少,HF组细胞溶解、层次紊乱,空泡化严重,少见成熟精子;LF组和HF组小鼠的精子活力降低,HF组小鼠精子数量下降,畸形率上升,差异有统计学意义（p<0.05或p<0.01）;LF组和HF组睾丸细胞凋亡指数上升,差异有统计学意义（p<0.01）;LF组和HF组Grp78、Caspase-12、Caspase-3基因表达水平上升,差异有统计学意义（p<0.05或p<0.01）.结果提示,除氧化应激以外,Caspase-12和Caspase-3基因表达异常可能是氟暴露致小鼠睾丸细胞凋亡异常的分子机制之一.     

Fas/FasL途径在氟暴露致PC12细胞凋亡中的作用

为了探讨Fas/FasL途径在氟暴露致PC12细胞凋亡中的作用及其机制,采用含20、40、80、160mg/L NaF培养液处理PC12细胞.结果表明,所有剂量NaF处理12、24、36、48h,PC12细胞活性升高;上述不同剂量NaF处理24h后,与对照组比,PC12细胞的活性氧水平、细胞凋亡率、细胞内Fas/FasL信号转导通路Fas和FasL、Caspase8、FADD、Caspase3基因和蛋白表达水平均呈显著上升（P < 0.05）,而Bid基因和蛋白表达水平显著下降（P < 0.05）,且呈氟暴露剂量依赖性.结果提示Fas/FasL途径在氟暴露致PC12细胞凋亡中起重要作用,其中FADD可能是Fas/FasL凋亡途径中的重要靶分子.     

Density functional theory (DFT) studies of vanadium-titanium based selective catalytic reduction (SCR) catalysts

Based on density functional theory (DFT) and basic structure models, the chemical reactions on the surface of vanadium-titanium based selective catalytic reduction (SCR) denitrification catalysts were summarized. Reasonable structural models (non-periodic and periodic structural models) are the basis of density functional calculations. A periodic structure model was more appropriate to represent the catalyst surface, and its theoretical calculation results were more comparable with the experimental results than a non-periodic model. It is generally believed that the SCR mechanism where NH₃ and NO react to produce N₂ and H₂O follows an Eley-Rideal type mechanism. NH₂NO was found to be an important intermediate in the SCR reaction, with multiple production routes. Simultaneously, the effects of H₂O, SO₂ and metal on SCR catalysts were also summarized.     

Ozone pollution characteristics and sensitivity analysis using an observation-based model in Nanjing, Yangtze River Delta Region of China

Ground-level ozone (O₃) has become a critical pollutant impeding air quality improvement in Yangtze River Delta region of China. In this study, we present O₃ pollution characteristics based on one-year online measurements during 2016 at an urban site in Nanjing, Jiangsu Province. Then, the sensitivity of O₃ to its precursors during 2 O₃ pollution episodes in August was analyzed using a box model based on observation (OBM). The relative incremental reactivity (RIR) of hydrocarbons was larger than other precursors, suggesting that hydrocarbons played the dominant role in O₃ formation. The RIR values for NO_X ranged from –0.41%/% to 0.19%/%. The O₃ sensitivity was also analyzed based on relationship of simulated O₃ production rates with reductions of VOC and NO_X derived from scenario analyses. Simulation results illustrate that O₃ formation was between VOCs-limited and transition regime. Xylenes and light alkenes were found to be key species in O₃ formation according to RIR values, and their sources were determined using the Positive Matrix Factorization (PMF) model. Paints and solvent use was the largest contributor to xylenes (54%), while petrochemical industry was the most important source to propene (82%). Discussions on VOCs and NO_X reduction schemes suggest that the 5% O₃ control goal can be achieved by reducing VOCs by 20%. To obtain 10% O₃ control goal, VOCs need to be reduced by 30% with VOCs/NO_X larger than 3:1.     

中国光伏组件报废量的预测

在采用威布尔分布模型分析光伏组件使用寿命分布情况的基础上,使用神经网络模型和市场供给A模型分别对中国光伏装机容量和组件报废量进行预测。将光伏组件按照不同质量分成2阶段,考虑不同退化情景预测组件报废量,并计算组件中有价值材料和金属报废量。预测结果表明:2025年后中国光伏组件报废量爆发,到2050年,中国光伏组件报废量最高可达60.22 GW,累计报废最高可达673 GW。在4种退化情景下,到2050年,典型贵金属方面最高产生3134.5 t的Ag;稀有金属方面最高产生228.1 t的Te;463.4 t的Cd,58.5 t的Ga,29.8 t的In;有毒有害金属方面最高产生263.9 t的Pb;Si最高产生量43735.4 t。到2050年,光伏组件材料累积废弃总量最高可达64623193.6 t。     

亚慢性氟暴露致小鼠海马损伤的影响及分子机制研究

为探明亚慢性氟中毒致小鼠海马损伤及分子机制,选用ICR雄性小鼠140只,随机分为对照(C)、低氟(LF)、高氟(HF)、低氟(LF)+L钙离子通道激动剂(FPL)、低氟(LF)+L钙离子通道抑制剂(NIF)、高氟(HF)+激动剂(FPL)、高氟(HF)+抑制剂(NIF) 7组,分别饮用自来水、5、30 mg·L~(-1)氟化钠水溶液90 d,氟染毒第84 d分别腹腔注射生理盐水、FPL64176、Nifedipine7d.同时,采用开场行为及水迷宫检测学习记忆能力;通过HE切片染色观察海马形态结构;根据试剂盒说明检测脑组织谷胱甘肽过氧化物酶(GSH-PX)、总超氧化物歧化酶(SOD)酶活性及丙二醛(MDA)含量;利用RT-PCR和Western Blot法分别检测海马内凋亡相关分子CaMKⅡ和Bax、Bcl-2基因/蛋白表达.结果发现,HF组、LF+FPL组和HF+FPL组小鼠毛发粗糙,暴躁不安.LF、HF组小鼠自发活动、探究行为及空间学习记忆力显著下降(p0.05),海马细胞损伤,SOD、GSH-PX活性极显著下降(p0.01),CaMKⅡ基因/蛋白表达水平显著(p0.05)或极显著(p0.01)上调,Bax基因/蛋白表达水平显著(p0.05)或极显著(p0.01)上调,Bcl-2基因/蛋白表达水平显著(p0.05)或极显著(p0.01)下调,Bax与Bcl-2基因/蛋白表达水平比值显著(p0.05)或极显著(p0.01)上调;LF+FPL、HF+FPL处理加剧了上述基因/蛋白表达水平,LF+NIF、HF+NIF组可逆转上述基因/蛋白表达水平.结果提示,氟中毒致脑损伤与L型钙离子通道及下游相关分子表达异常密切相关,而L钙离子通道抑制剂(Nifedipine)能改善氟暴露造成的海马损伤.     

大型工业企业污染物防治的会计成本控制策略研究

为了降低大型工业企业污染物防治的成本,提出会计成本控制策略研究。基于自然对数模型,对企业污染物防治的会计成本控制模型进行构建。采用最小二乘回归分析法,分析会计成本控制模型的约束变量,设计能源消费结构,将污染排放水平等参量作为结构的解释变量,对模型的回归系数进行计算,完成会计成本控制模型的构建。引入面板数据随机分析法,分析大型工业企业污染防治的弹性关系,通过会计成本控制模型,实现会计成本的最优控制。     

Reduction of heavy metal content in Hiroshima Bay oysters (Crassostrea gigas) by purification

Cultured oysters from Hiroshima Bay were analysed to determine the content of nine trace elements, cadmium (Cd), lead (Pb), chromium (Cr), arsenic (As), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), and iron (Fe) and compared with oysters treated for 48 h in both artificial sea water and a solution of 0.5% ethylenediaminetetraacetic acid (EDTA) in artificial sea water. It was found that the values of As and Fe in both groups of treated oysters were significantly lower than in the untreated oysters and that the Pb and Mn levels tended to be lower. It was also found that oysters treated in 0.5% EDTA solution in artificial sea water had lower levels of Cd and Cu than the oysters treated only in artificial sea water.     

Development of monitoring technology for airborne particulate matter

Particulate matter suspended in the air has adverse effects onhuman health. Its level of concentration is an important parameter in evaluating the degree of hazard it poses to the atmosphere. Conventional methods used in measuring particulatematter are often filter-based, which indicates some disadvantagesbecause such a base requires labor and time. In this study, to achieve real-time measurements, a new electrical method was developed for measuring PM10 and PM2.5 concentrations. The basicprinciple is to electrically charge particles passing through thePM inlet using a corona charger and measure the currents createdby charged particles to obtain the number concentration of particulate matter. A new type inlet based on the particle cupimpactor configuration was designed and its performance was evaluated. A unipolar diffusion charger was developed and thecharger's efficiency was determined experimentally in terms ofPn, which represents the penetration through the charger,P, times the average charge number acquired by a particle,n, for different particle sizes. The correlation was constructed between the PM10 (or the PM2.5) mass concentrationsand the electrical currents due to particles, which were chargedby the diffusion charger.