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.     

基于AIS轨迹修复的船舶排放空间表征改进方法与应用

基于船舶自动识别系统（Automatic Identification System,AIS）数据表征船舶排放是目前船舶排放空间表征的主流方法,但AIS船舶轨迹点缺失会造成船舶排放量低估和船舶空间分布表征错误,进而影响船舶排放控制区的划分.为改进船舶排放空间表征,本研究以2013年广东省AIS船舶数据为例,采用基于时间和经纬度的三次样条方法对AIS船舶轨迹进行修复,结合动力法计算船舶排放,分析对比AIS轨迹修复前后船舶排放表征的差异,并利用空气质量模型和卫星观测评估AIS轨迹修复对船舶排放表征和广东沿海空气质量模拟的改进效果.结果表明：轨迹修复后广东省海域船舶轨迹点总数由4685773个增至5746664个,船舶NO_x排放量增加了0.6%.对于轨迹点与排放缺失集中的粤东海域,轨迹修复后船舶轨迹点数增加了88%,NO_x排放量在广东省船舶排放量的占比提升至22%,特别是在粤东重点修复海域NO_x排放量增加了2.7倍.原始轨迹在广东省海域较为稀疏,在粤东海域有明显轨迹缺失;轨迹修复后广东省海域船舶轨迹更为密集,粤东海域船舶轨迹得以补充,船舶排放空间分布更连贯.对比模拟结果与卫星观测结果,轨迹修复后粤东重点修复海域船舶模拟浓度与观测浓度的偏差由51%减至6%,总体上船舶排放模拟结果更接近卫星观测结果.     

金属改性对SAPO-34低温还原NO性能的影响

采用浸渍法制备金属改性SAPO-34分子筛催化剂,分析比较了不同单金属（Cu或Co）及不同比例双金属（Cu：Co=1：1、3：1、5：1,质量比）改性催化剂对NO的催化还原性能,评价了不同催化剂的N₂选择性,并采用扫描电子显微镜（SEM）、比表面积测试、X射线衍射分析（XRD）、NH₃-程序升温脱附（NH₃-TPD）等表征手段对催化剂的物化性能进行了分析.结果表明,单金属Cu改性催化剂具有较宽的温度区间,在250~450℃范围内NO的转化率始终保持在100%;双金属改性使NO转化率保持为100%的最低温度下降了25~50℃,显著拓宽了低温段窗口,其中,Cu₃Co₁/SAPO-34催化剂的低温催化还原性能最好,200℃即可实现100%的NO转化率,175℃下的转化率也高达80%以上.Cu-Co双金属改性SAPO-34分子筛催化剂具有优异的低温催化还原NO性能,具有在机动车尾气、工业废气的低温脱硝治理领域应用的潜力.     

核壳结构KNbO3@Co(OH)2的制备及其活化过一硫酸盐降解帕珠沙星的研究

制备了以KNbO₃为载体材料的Co（OH）₂复合材料并对其进行了详细的表征,分析了材料的组成成分、组成形态进而确定了其为核壳结构形貌的KNbO₃@Co（OH）₂.利用合成的样品作为催化剂活化过一硫酸盐（peroxymonosulfate,PMS）来降解帕珠沙星（pazufloxacin,PZF）,结果表明制备的催化剂对PZF的去除效率显著增加.讨论了不同初始PMS剂量对降解效率的影响,发现随着PMS增加可活化生成更多的硫酸根自由基（sulfate radicals,SO₄^·-）和羟基自由基（hydroxyl radicals,HO^·）来降解PZF,但继续增大PMS用量降解效率未见明显提升.酸性和中性pH值条件下利于反应活化PMS降解PZF,而碱性体系减缓反应,甚至强碱体系更易形成Co（OH）₂沉淀不利于反应体系中活性组分CoOH⁺的形成,大大抑制了催化性能.此外,在体系中加入淬灭剂叔丁醇（tert-Butanol,TBA）或者乙醇（ethanol,ETOH）进行自由基的淬灭实验,结果表明SO₄^·-自由基为体系降解PZF过程中主要贡献的自由基,而HO^·自由基的贡献较少.催化剂具有较好的稳定性5次循环之后仍能在10 min之内完全去除PZF.本研究提出了新的思路为制备其他载体的Co（OH）₂核壳结构提供参考依据,同时将该催化剂结合高级氧化技术应用到水体新兴有机污染物净化领域具有很好的应用前景.     

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.     

粗放型绿色屋顶基质层对降雨出流水质影响

为研究粗放型绿色屋顶基质层对雨水出流N、P、COD和SS淋失的影响,根据华中地区降雨强度和水质实际情况,构建了3种不同基材配方的绿色屋顶基质层,在9场模拟暴雨下进行绿色屋顶的基质出流水质监测。结果表明:本试验各绿色屋顶设施对TN、NH₄+-N、NO₃--N和SS都有较好的削减作用,但对TP和PO₄3--P淋失现象明显,绿色屋顶的出流中以颗粒态P和溶解态N为主;去除出流中SS,对净化COD效果显著;生物炭的添加对出流污染物有明显的控制作用,能有效缓解降雨初期污染物浓度高的问题,同时能显著增加植物地上部生物量;厚度为5 cm的绿色屋顶出流水中N和COD较10 cm厚度低,但其SS出流平均浓度偏高,且植物后期不能维持良好的长势。粗放型绿色屋顶设施运行稳定后截污效应良好,具有较高的可行性和广阔的应用前景。     

Aerosol optical properties under different pollution levels in the Pearl River Delta (PRD) region of China

To clarify the aerosol hygroscopic growth and optical properties of the Pearl River Delta(PRD)region,integrated observations were conducted in Heshan City of Guangdong Province from October 19 to November 17,2014.The concentrations and chemical compositions of PM_(2.5),aerosol optical properties and meteorological parameters were measured.The mean value of PM_(2.5) increased from less than 35(excellent) to 35-75 μg/m~3(good) and then to greater than 75 μg/m~3(pollution),corresponding to mean PM_(2.5) values of 24.9,51.2,and 93.3 μg/m~3,respectively.The aerosol scattering hygroscopic growth factor(f(RH = 80%)) values were 2.0,2.12,and 2.18 for the excellent,good,and pollution levels,respectively.The atmospheric extinction coefficient(σext)and the absorption coefficient of aerosols(σ_(ap)) increased,and the single scattering albedo(SSA)decreased from the excellent to the pollution levels.For different air mass sources,under excellent and good levels,the land air mass from northern Heshan had lower f(RH) and σ_(sp) values.In addition,the mixed aerosol from the sea and coastal cities had lower f(RH) and showed that the local sources of coastal cities have higher scattering characteristics in pollution periods.     

Phosphate recovery with granular acid-activated neutralized red mud: Fixed-bed column performance and breakthrough curve modelling

Granular acid-activated neutralized red mud (AaN-RM) has been successfully prepared with good chemical stability and physical strength. However, its potential for industrial application remains unknown. Therefore, the performance of granular AaN-RM for phosphate recovery in a fixed-bed column was investigated. The results demonstrated that the phosphate adsorption performance of granular AaN-RM in a fixed-bed column was affected by various operational parameters, such as the bed depth, flow rate, initial solution pH and initial phosphate concentration. With the optimal empty-bed contact time (EBCT) of 24.27 min, the number of processed bed volumes and the phosphate adsorption capacity reached 496.95 and 84.80 mg/g, respectively. Then, the saturated fixed-bed column could be effectively regenerated with a 0.5 mol/L HCl solution. The desorption efficiency remained as high as 83.45% with a low weight loss of 3.57% in the fifth regeneration cycle. In addition, breakthrough curve modelling showed that a 5-9-1 feed-forward artificial neural network (ANN) could be effectively applied for the optimization of the fixed-bed adsorption system; the coefficient of determination (R²) and the root mean square error (RMSE) evaluated on the validation-testing data were 0.9987 and 0.0183, respectively. Therefore, granular AaN-RM fixed-bed adsorption exhibits promising potential for phosphate removal and recovery from polluted water.     

Performance of different macrophytes in the decontamination of and electricity generation from swine wastewater via an integrated constructed wetland-microbial fuel cell process

Plants constitute a major element of constructed wetlands(CWs).In this study,a coupled system comprising an integrated vertical flow CW(IVCW) and a microbial fuel cell(MFC) for swine wastewater tre atment was developed to research the effects of macrophytes commonly employed in CWs,Canna indica,Acorus calamus,and Ipomoea aquatica,on decontamination and electricity production in the system.Because of the different root types and amounts of oxygen released by the roots,the rates of chemical oxygen demand(COD) and ammonium nitrogen(NH_4~+-N) removal from the swine wastewater differed as well.In the unplanted,Canna indica,Acorus calamus,and Ipomoea aquatica systems,the COD removal rates were 80.20%,88.07%,84.70%,and 82.20%,respectively,and the NH_4~+-N removal rates were 49.96%,75.02%,70.25%,and 68.47%,respectively.The decontamination capability of the Canna indica system was better than those of the other systems.The average output voltages were 520±42,715±20,660±27,and 752±26 mV for the unplanted,Canna indica,Acorus calamus,and Ipomoea aquatica systems,respectively,and the maximum power densities were 0.2230,0.4136,0.3614,and0.4964 W/m~3,respectively.Ipomoea aquatica had the largest effect on bioelectricity generation promotion.In addition,electrochemically active bacteria,Geobacter and Desulfuromonas,were detected in the anodic biofilm by high-throughput sequencing analysis,and Comamonas(Proteobacteria),which is widely found in MFCs,was also detected in the anodic biofilm.These results confirmed the important role of plants in IVCW-MFCs.     

An investigation of changes in water quality throughout the drinking water production/distribution chain using toxicological and fluorescence analyses

Changes in water quality from source water to finished water and tap water at two conventional drinking water treatment plants(DWTPs) were monitored.Beside the routine water quality testing,Caenorhabditis elegans-based toxicity assays and the fluorescence excitation–emission matrices technique were also applied.Both DWTPs supplied drinking water that met government standards.Under current test conditions,both the investigated finished water and tap water samples exhibited stronger lethal,genotoxic and reprotoxic potential than the relative source water sample,and the tap water sample was more lethal but tended to be less genotoxic than the corresponding finished water sample.Meanwhile,the nearly complete removal of tryptophan-like substances and newly generated tyrosine-like substances were observed after the treatment of drinking water,and humic-like substances were identified in the tap water.Based on these findings,toxic pollutants,including genotoxic/reproductive toxicants,are produced in the drinking water treatment and/or distribution processes.Moreover,further studies are needed to clarify the potentially important roles of tyrosine-like and humic-like substances in mediating drinking water toxicity and to identify the potential sources of these contaminants.Additionally,tryptophan-like fluorescence may be adopted as a useful parameter to monitor the treatment performance of DWTPs.Our observations provided insights into the importance of utilizing biotoxicity assays and fluorescence spectroscopy as tools to complement the routine evaluation of drinking water.