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排序方式: 共有523条查询结果,搜索用时 312 毫秒
1.
This research aimed to evaluate the alga Scenedesmus obliquus toxicity induced by textiledyeing effluents(TDE).The toxicity indicator of TDE in alga at the physiological(algal growyth),biochemical(chlorophyll-a(Chl-a) synthesis and superoxide dismutase(SOD) activity) and structural(cell membrane integrity) level were investigated.Then we further study the relationship among toxicity indicators at physiological and biochemical level,and supplemented by research on algal biomacromolecules.According to the analysis of various endpoints of the alga,the general sensitivity sequence of toxicity endpoints of Scenedesmus obliquus was:SOD activity Chl-a synthesis algal growth.The stimulation rate of SOD activity increased from day 3(57.25%~83.02%) to day 6(57.25%~103.81%),and then decreased on day 15(-4.23%~-32.96%),which indicated that the antioxidant balance system of the algal cells was destroyed.The rate of Chl-a synthesis inhibition increased gradually,reaching19.70%~79.39% on day 15,while the rate of growth inhibition increased from day 3(-12.90%~10.16%) to day 15(-21.27%~72.46%).Moreover,the algal growth inhibition rate was positively correlated with the inhibition rate of SOD activity or Chl-a synthesis,with the correlation coefficients were 0.6713 and 0.5217,respectively.Algal cells would be stimulating to produce excessive reactive oxygen species,which would cause peroxidation in the cells,thereby destroying chloroplasts,inhibiting chlorophyll synthesis and reducing photosynthesis.With increasing exposure time,irreversible damage to algae can lead to death.This study is expected to enhance our understanding of the ecological risks through algal tests caused by TDE. 相似文献
2.
Arsenobetaine, two arsenosugars, dimethylarsinate and several unidentified arsenic species were detected in extracts of the haemolymph of the Dungeness crab, Cancer magister, by using HPLC-ICP-MS. This is the first report of the presence of arsenosugars in the haemolymph/blood of marine animals. Total, extractable and residual arsenic concentrations were determined by ICP-MS. The concentration of total arsenic was in the range of 1.4-3.8 [micro sign]g ml(-1). Nearly all (98%) the arsenic was found to be extractable, and accounted for primarily by arsenobetaine, two arsenosugars and dimethylarsinate. The results demonstrate that arsenic compounds present in the diet of crabs are not fully metabolized in the gut. They are, at least partly, taken up into the haemolymph. The concurrence of arsenobetaine and arsenosugars suggests that the use of repeated haemolymph sampling in crustaceans could facilitate investigations into the kinetics of the biotransformation pathways of arsenic compounds. Finally, the present study clearly demonstrates the unique capabilities of HPLC-ICP-MS for the detection and identification of minor arsenic components amongst the predominant arsenobetaine. 相似文献
3.
赖智华 《防灾科技学院学报》2007,9(1):69-72
震相识别与分析是地震预报与速报的基础.为识别赣南地区的震相,用震例统计和实例说明了不同距离,不同方位,不同类型的地震震相特征、地震震相与爆破波形的区别,并阐述了如何快速、准确地对有感地震进行速报. 相似文献
4.
推行清洁生产实现可持续发展 总被引:1,自引:1,他引:1
赖周平 《石油化工环境保护》1999,(4):15-19
对集团公司全面开展清洁生产的情况做了综述和总结,几年来的清洁生产实践表明,清洁生产促进了石化企业的发展,同时降低了废物排放,取得了明显的成果。清洁生产是保护环境的有力手段,也是实施可持续发展战略的重要措施 相似文献
5.
Lee P. Shulman MD Patricia L. Gordon Donald S. Emerson R. Sidney Wilroy Sherman Elias 《黑龙江环境通报》1993,13(5):403-409
We describe the prenatal diagnosis of isolated bilateral fetal microphthalmia in a woman at increased risk of having a fetus with microphthalmia. Ultrasound examinations at 161 and 19-5 weeks' gestation demonstrated bilateral fetal microphthalmia with no other associated structural defects. The patient elected to terminate her pregnancy at 19.5 weeks. Pathological evaluation of the products of conception obtained by dilation and evacuation confirmed the prenatal diagnosis of isolated bilateral fetal microphthalmia. 相似文献
6.
Farideh Z. Bischoff PhD Dorothy E. Lewis Joe Leigh Simpson Dianne D. Nguyen Jeffrey Scott Wendy Schober Sarah Murrell Sherman Elias 《黑龙江环境通报》1995,15(12):1182-1184
Recovering and analysing fetal erythrocytes from maternal blood is being pursued for non-invasive prenatal genetic diagnosis. We report the observation of 46, XY/47, XXY mosaicism in fetal cells from a woman whose first-trimester chorionic villus sampling (CVS) initially showed only 46, XY. Only after exhaustive (500 cells) analysis were four XXY cells found in cultured villi. 相似文献
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9.
Thomas J. Myers Sherman Swanson 《Journal of the American Water Resources Association》1996,32(2):253-265
ABSTRACT: Detailed studies of long-term management impacts on rangeland streams are few because of the cost of obtaining detailed data replicated in time. This study uses government agency aquatic habitat, stream morphologic, and ocular stability data to assess land management impacts over four years on three stream reaches of an important rangeland watershed in northwestern Nevada. Aquatic habitat improved as riparian vegetation reestablished itself with decreased and better controlled livestock grazing. However, sediment from livestock disturbances and road crossings and very low stream flows limited the rate of change. Stream type limited the change of pool variables and width/depth ratio, which are linked to gradient and entrenchment. Coarse woody debris removal due to previous management limited pool recovery. Various critical-element ocular stability estimates represented changes with time and differences among reaches very well. Ocular stability variables tracked the quantitative habitat and morphologic variables well enough to recommend that ocular surveys be used to monitor changes with time between more intensive aquatic surveys. 相似文献
10.
Lai Li-Wei Cheng Wan-Li 《Environmental science and pollution research international》2017,24(17):14924-14933
Environmental Science and Pollution Research - Daily time air quality indices, which can reflect air quality in 1 day, are suitable for identifying daily exposure during conditions of poor... 相似文献