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731.
LI Yunhui YE Huayue DU Min ZHANG Yanfen YE Boping PU Yuepu WANG Dayong 《环境科学学报(英文版)》2009,21(7):971-979
Apart from the liver disruption, embryotoxicity and genotoxicity, microcystin (MC)-LR also could cause neurotoxicity. Nematode Caenorhabditis elegans was explored as a model to study the neurotoxicity. In the present study, we provided evidence to indicate the neurotoxicity on chemotaxis to NaCl and diacetyl, and thermotaxis from MC-LR exposure to C. elegans. As a result, higher concentrations of MC-LR caused significantly severe defects of chemotaxis to NaC1 and diacetyl, and thermotaxis. The neurotoxicity on chemotaxis to NaCl and diacetyl, and thennotaxis from MC-LR exposure might be largely mediated by the damage on the corresponding sensory neurons (ASE, AWA, and AFD) and interneuron AIY. The expression levels of che-1 and odr-7 were significantly decreased (P<0.01) in animals exposed to MC-LR at concentrations lower than 10 μg/L, whereas the expression levels of ttx-1 and ttx-3 could be significantly (P<0.01) lowered in animals even exposed to 1 μg/L of MC-LR. Moreover, both the chemotaxis to NaCl and diacetyl and the thermotaxis were more significantly reduced m MC-LR exposed mutants of che-1(p674), odr-7(ky4), ttx-1(p767), and ttx-3(ks5) than those in exposed wild-type N2 animals at the same concentrations. 相似文献
732.
Chemotaxis to water-soluble attractants is mainly controlled by ASE sensory neuron whose specification is regulated by che-1 in
Caenorhabditis elegans. Our data suggested that exposure to high concentrations of metals, such as Pb, Cu, Ag, and Cr, would result
in severe defects of chemotaxis to water-soluble attractants of NaCl, cAMP, and biotin. Moreover, the morphology of ASE neuron
structures as observed by relative fluorescent intensities and relative size of fluorescent puncta of cell bodies, relative lengths of sensory
endings in ASE neurons, and the expression patterns of che-1 were obviously altered in metal exposed animals when they meanwhile
exhibited obvious chemotaxis defects to water-soluble attractants. In addition, the dendrite morphology could be noticeably changed
in animals exposed to 150 mol/L of Pb, Cu, and Ag. Furthermore, we observed significant decreases of chemotaxis to water-soluble
attractants in Pb exposed che-1 mutant at concentrations more than 2.5 mol/L, and in Cu, Ag, and Cr exposed che-1 mutant at
concentrations more than 50 mol/L. Therefore, impairment of the ASE neuron structures and functions may largely contribute to the
appearance of chemotaxis defects to water-soluble attractants in metal exposed nematodes. 相似文献
733.
采用重庆同兴垃圾焚烧发电厂产生的焚烧飞灰,在感应炉上进行熔融处理实验研究,探讨了熔融温度、熔融时间、碱度等因素对熔融过程中重金属分离效果的影响.结果表明,重金属的挥发率按其熔沸点高低区分明显,Pb、Zn和Cd的挥发率较高,分别为80%、60%和95%左右;Cr、Mn的挥发率均低于10%.随着熔融时间、熔融温度和碱度的增加,Pb、Zn、Cd、Mn、Cr的挥发率变化趋势不明显;铁浴熔融方式可进一步促进Zn、Pb、Hg的挥发,有利于Cr、Cu从熔渣中分离出来,与生铁形成合金.对熔渣的浸出毒性测试结果表明,重金属元素的浸出毒性均可达标(GB5085.3-1996). 相似文献
734.
Most probable number (MPN) and colony-forming unit (CFU) estimates of fecal indicator bacteria (FIB) concentration are common
measures of water quality in aquatic environments. Thus, FIB intensively monitored in Yeongsan Watershed in an attempt to compare
two di erent methods and to develop a statistical model to convert from CFU to MPN estimates or vice versa. As a result, the significant
di erence was found in the MPN and CFU estimates. The enumerated Escherichia coli concentrations in MPN are greater than those in
CFU, except for the measurement in winter. Especially in fall, E. coli concentrations in MPN are one order of magnitude greater than
that in CFU. Contrarily, enterococci bacteria in MPN are lower than those in CFU. However, in general, a strongly positive relationship
are found between MPN and CFU estimates. Therefore, the statistical models were developed, and showed the reasonable converting
FIB concentrations from CFU estimates to MPN estimates. We expect this study will provide preliminary information towards future
research on whether di erent analysis methods may result in di erent water quality standard violation frequencies for the same water
sample. 相似文献
735.
The method for detecting N-nitrosodimethylamine (NDMA) in drinking water using ultra performance liquid chromatography
(UPLC) coupled with tandem mass spectrometry (MS/MS) was improved by optimizing the clean-up procedure to remove the matrix
interference in pretreatment process, and was then applied to a survey of NDMA in both raw and finished water samples from five
water treatment plants in South China. The NDMA concentrations ranged from 4.7 to 15.1 ng/L in raw water samples, and from 4.68
to 46.9 ng/L in finished water. The NDMA concentration in raw water was found to be related with nitrite concentration, and during
the treatment, the NDMA concentration increased following ozonation but decreased after subsequent activated carbon treatment. 相似文献
736.
垃圾渗滤液对黑麦草和高羊茅种子萌发的影响 总被引:1,自引:1,他引:0
为了解垃圾渗滤液作培养液时草本植物种子萌发的情况。以黑麦草和高羊茅两种草本植物种子为研究材料,分别研究了垃圾填埋场渗滤液处理站的渗滤液原液、渗滤液生物处理出水以及渗滤液最终出水在6个不同配比的稀释溶液(V渗滤液/V蒸馏水=1/0,3/1,1/1,1/2,1/3,1/4)下对这两种种子萌发的影响。结果显示:随着渗滤液稀释强度的降低,种子的发芽势、发芽率、发芽指数和活力指数均增加,V渗滤液/V蒸馏水为1/3时,种子发芽率均为最高,黑麦草种子发芽率达96%,高羊茅种子发芽率达79%。用渗滤液作培养液时,更有利于黑麦草种子的萌发;用最终出水作培养液时,更有利于种子的萌发。这两种不同的渗滤液,在不同配比的稀释浓度下对种子的发芽率、发芽势、发芽指数和活力指数等均具有显著的生理作用。 相似文献
737.
城市合流污水A2/O处理系统中TTC ETS活性监测研究 总被引:2,自引:1,他引:1
研究了温度和F/M的变化对A2/O系统TTCETS活性的影响,分析了TTCETS活性与COD降解的相关关系;通过低C/N冲击下TTCETS活性和理化指标的比较,讨论了以TTCETS活性表征系统运行状况的优劣.结果表明,一定范围内,温度与F/M均与TTCETS活性成正相关,TTCETS活性(TF/TSS·t)变化范围约13.2~48.3 mg/(g·h),最大值约为60 mg/(g·h);TTCETS活性与COD去除率相关性显著,并且TTCETS活性可预警系统的异常状态,当TTCETS活性为41.0 mg/(g·h)时,COD去除效率最高. 相似文献
738.
在热重和红外联用进行等温实验的基础上,探讨了氧体积分数为10%、20%,970-1150℃温度范围内化学链燃烧过程中钙基载氧体再生(cas)的氧化特性-结果显示,CaS氧化的直接产物主要为CaSO4,只有在诱导期生成极少量CaO和SO2;但CaSO4与CaS还可进一步反应,生成更多Can和S02.通过对氧气浓度和温度的实验条件改变,研究了CaS04的转化率、转化速率,并辅以S02析出速率分析,获得了CaSO4相对于CaO的瞬时选择性、Ca.SO4的收率和反应选择率.结果表明,钙基载氧体CaSO.再生过程氧化反应的适宜条件为温度970-1000℃以及较高的氧气气氛.这不仅可以抑制S02的排放量从而得到较高的反应选择率.同时反应过程也具有较高的转化速率. 相似文献
739.
740.