邻苯二甲酸二丁酯诱导小鼠神经行为学改变及相关生理生化指标分析

探究邻苯二甲酸二丁酯诱导小鼠神经行为学改变及与细胞外调节蛋白激酶(ERK1/2)通路相关蛋白的关联.雄性KM小鼠36只,随机分成4组:生理盐水组、50 mg·kg~(-1)·d~(-1) DBP组、50 mg·kg~(-1)·d~(-1)维生素E(VE)组、DBP+VE组,连续灌胃处理28 d,观察Morris水迷宫结果,检测小鼠脑海马组织的氧化应激(活性氧(ROS)荧光强度、还原型谷胱甘肽(GSH)与丙二醛(MDA)含量)、脑源性神经营养因子(BDNF)、磷酸化cAMP反应元件结合蛋白(p-CREB)、caspase-3水平,Western blot分析ERK1/2及其磷酸化(p-ERK1/2)水平;HE、Nissl染色及Hoechst 33258荧光染色分析脑组织CA1区病理学变化.结果表明,与对照组比较,50 mg·kg~(-1)·d~(-1) DBP组小鼠的学习记忆下降,氧化应激、p-ERK1/2、caspase-3水平上升,BDNF、p-CREB表达下降,差异均有统计学意义(p0.05,p0.01);海马组织CA1病理学损伤及凋亡程度增加.给予抗氧化剂VE处理后,DBP+VE组小鼠的学习记忆上升,氧化应激、p-ERK1/2、caspase-3水平降低,BDNF、p-CREB表达上升,差异均有统计学意义(p0.05);海马组织CA1病理学损伤及凋亡程度降低.由此推测,DBP暴露导致小鼠海马组织CA1病理学损伤、神经元凋亡程度增加、学习记忆下降、其神经行为学改变可以通过添加VE得到缓解,相关生理生化指标测试表明ERK系统应激氧化性损伤机制参与介导了毒理学过程.     

白洋淀喹诺酮类抗生素污染特征及其与环境因子相关性研究

利用超高效液相色谱串联质谱法(HPLC-MS)对白洋淀水体和沉积物中喹诺酮类(Quinolones,QNs)抗生素进行检测,并研究其生态风险空间分异特征,探究其与环境因子的相关性.结果表明:①白洋淀氧氟沙星(Ofloxacin,OFL)和氟甲喹(Flumequine,FLU)的检出率最高(100%),其次为马波沙星(Marbofloxacin,MAR)和氟罗沙星(Fleroxacin,FLE)(≥60%),其余QNs的检出率较低(≤35%);②白洋淀水体和沉积物中QNs抗生素浓度范围分别为153.39～1550.07 ng·L~(-1)和10.22～381.85 ng·g~(-1),水体中QNs在S1处浓度最高,S4处最低,沉积物中QNs在S2处浓度最高;③相关性分析结果表明,水体透明度(Secchi depth,SD)、总氮(Total nitrogen,TN)、总磷(Total phosphorus,TP)、硝氮(Nitrate nitrogen,NO~-_3-N)、沉积物氨氮(Ammonia nitrogen,NH_3-Ns)和沉积物总氮(TNs)与QNs相关性显著,其中,SD、TP和NH_3-Ns与部分QNs(MAR、恩诺沙星(Enrofloxacin,ENR)和FLE)显著相关(p0.01),表明生活污水和养殖废水对QNs的贡献较大;④生态风险评价结果表明,白洋淀QNs总体处于中低风险水平,其中,ENR处于中高风险水平,其余QNs处于低风险水平;就空间分布而言,除S1和S9为高风险区外,其余各点为中低风险区.     

缓释碳源生态基质对低碳氮比河水脱氮效果研究

通过缓释碳源生态基质颗粒脱氮效果实验,比较了缓释碳源生态基质颗粒填料柱与普通砾石填料柱对各种形态氮的去除效果.结果发现,装填生态基质颗粒的实验组出水NO_2~--N、NO_3~--N和TN去除率分别为90.60%、90.32%和63.66%,明显高于对照组-16.39%、-1.51%和25.06%的去除率,说明缓释碳源生态基质可显著增强反硝化作用强度,提高TN去除率.高通量分析结果表明,生态基质组相对丰度超过1%的菌属数量高于对照组,其中,反硝化菌属相对丰度达到30%以上,生态基质释放的纤维素碳源有利于异养反硝化微生物的生长繁殖,使反应器内的微生物群落结构发生显著改变,提高了脱氮效率.     

基于条件高斯模拟的城市灰尘Pb元素的空间分布特征

城市灰尘是分散于城市不同区域的表面固体颗粒物。城市灰尘对城市环境造成的污染越来越多地受到人们的关注,尤其是城市灰尘重金属对城市生存环境造成的危害。本文利用R软件中的Gstat包,对金华市城市地表灰尘中的Pb元素含量进行500次条件高斯模拟,并从中随机抽出3次模拟对其模拟结果进行分析,从模拟结果可以看出研究区Pb元素总体上显示出相似的空间变化趋势,但在细部空间变化上是有差别的。条件高斯模拟法对未知点的模拟值具有不确定性,克服了普通克里格法的平滑效应,能够更好地反映研究区的随机性和结构性。     

均匀流场水平潜流人工湿地对四环素类抗生素的去除效果

利用均匀流场水平潜流人工湿地实验系统处理含四环素类抗生素废水,考察了湿地系统对抗生素的去除率、出水口差向代谢产物的含量以及抗生素在湿地植物中的累积情况。实验结果表明:在水力停留时间为2 d、土霉素、四环素、金霉素和强力霉素进水质量浓度均为200 μg/L时,出水中上述4种抗生素的平均去除率分别为98.62%、93.06%、99.13%和92.25%;出水可检出3种四环素类抗生素代谢产物,分别为差向土霉素、差向金霉素和差向四环素,质量浓度分别为(3.69±0.23) μg/L、(13.81±0.47) μg/L和(19.00±0.63) μg/L;湿地植物美人蕉的根、茎、叶中可以检测到土霉素和四环素,四环素含量的大小顺序为茎>根>叶。     

Entomotoxic effect of silicon dioxide nanoparticles on Plutella xylostella (L.) (Lepidoptera: Plutellidae) under laboratory conditions

The use of higher dosage and repeated applications of conventional pesticides have led to the rapid development of insect resistance to pesticide and adverse effects on human health and environment. Accordingly, researchers are prompted to identify an alternative entomotoxic agent for crop protection. Nanocides are being considered as alternatives to conventional insecticides because they are expected to lessen the application rate and reduce the chances of resistance development in pests. In this study, we evaluated the entomotoxic effects of nanosilica on larvae of Plutella xylostella, in a laboratory by using dust spray, larva dipping, leaf dipping, and solution spray methods. Dust treatment showed a more highly significant effect than the other three treatments. The mortality percentage increased up to 58% and 85% at 24 and 72 h after treatment, respectively, when nanosilica was applied at a rate of 1 mg cm^?2. In all four bioassays, mortality rate increased with both increased time after nanosilica exposure and increased concentration. Light microscopy and scanning electron microscopy images showed that larval death was due to desiccation, body wall abrasion, and spiracle blockage. These results suggested that nanosilica can be an alternative to conventional pesticides if dust formulation would be properly used.     

燃煤发电职业危害暴露健康负担评价方法*

为评估煤电行业从业人员因遭受职业危害暴露引起的健康负担大小,根据工作暴露矩阵法对燃煤发电职业暴露程度进行估算,利用健康效应分析和伤残调整寿命年指标构建燃煤发电职业暴露健康负担评价体系,实现职业暴露健康负担的量化评价。将所构建的评价体系应用于3个燃煤电厂进行对比分析,结果表明:各类危害因素中,粉尘所致健康危害最大,人均健康负担约为8.861 a;各生产环节中,运输煤系统所致健康影响最大,约占整个生产过程的45.53%。     

基于臭氧-麸皮工艺深度处理煤制气废水的研究

以河南省某化工企业生产过程中煤制气废水为研究对象,通过絮凝、臭氧-麸皮协同催化氧化、A/O生化处理的组合工艺改善废水的可生化性,能显著降低煤制气废水中的污染物浓度,COD由2 800 mg/L降至46 mg/L,氨氮质量浓度降至2.1 mg/L,总酚去除率达到99%,整个流程简单易操作,不产生二次污染,且能实现麸皮的高价值利用,达到GB 8978—1996的一级排放标准。     

低温下氨氮对淡水浮游藻生长及群落结构影响的生态模拟研究

为了探讨春季藻类快速生长的机制,研究较低温度下氨氮对淡水浮游藻类生长及群落结构变化的影响,对南开大学新开湖水体藻类进行了室内生态模拟试验研究.在10℃、125μmol·m·s-1光强条件下,培养液中氨氮最终浓度设置为1.0、1.5、2.0、2.5、3.0mg·L-1和对照组(不添加氨氮),每隔1～2天加入氨氮至初始设定值,培养时间为26d.结果表明,浮游藻类在1.0mg·L-1组生长最好,最大生长密度为1.53×105cells·L-1,高于对照组;浮游藻类在高于2.0mg·L-1处理组中生长明显受到抑制,抑制作用随着氨氮浓度的增大而增大,其中3.0mg·L-1处理组的最大生物量仅为5.4×104cells·L-1.随着培养时间的进行硅藻逐渐取代绿藻而成为绝对优势藻,随着藻类的生长,粗刺四刺藻(Treubaria crassispina)在所有处理组中由优势种而逐渐消失,近缘针杆藻(Saffinis affinis)和新月藻(Closterium lunula)在培养后期逐渐成为优势种,但在不同氨氮浓度下表现出不同生长密度.除1.0mg·L-1处理组外,其它处理组中的物种多样性指数差异不显著(p>0.05).氨氮影响浮游藻类的生长,影响优势种的变化,并且对浮游藻类的群落结构变化有一定的影响.     

Effective adsorption of quadrivalent cerium by synthesized laurylsulfonate green rust in a central composite design

The layered laurylsulfonate intercalated green rust (lauryl-S GR) was synthesized to evaluate the influence of synthesis parameters and aqueous conditions on the adsorption of Ce^IV. The maximum adsorption capacity of 305.58 mg/g by lauryl-S GR was predictably obtained. The pseudo-first-order kinetic model was appropriate in fitting the whole uptake process in a weak acid environment. Three isotherm models including Langmuir, Freundlich, and Tempkin were all reliable in depicting the isotherm adsorption process. The maximum monolayer adsorption capacity of lauryl-S GR towards Ce^IV was 315.46 mg/g. Ce species including CeO and Ce₂O₃ besides CeO₂ were matched in the XPS distribution, directly indicating the reduction reaction brought by Fe^II in the GR occurred to hydrated Ce^IV ions during the adsorption. Nano-sized Ce particles attached to the lauryl-S GRs after the adsorption experiments were observed in the morphological characterization. Flocculated materials were formed on the surface of the lauryl-S GR at a pH of 7, which further reduced the active sites and disrupted the continuous uptake of Ce^IV to the lauryl-S GR. This study expands the application of GRs and supplies an ideal iron-based material for the construction of the affiliated recovery pathway to the traditional separation of Ce.