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61.
Environmental Science and Pollution Research - Glucose -mediated one-pot hydrothermal method has been utilized to synthesize hollow spherical MgO-ZnO (xMgO-(1-x)ZnO, x?=?0, 0.2, 0.4,...  相似文献   
62.
Alarming environmental pollution from petroleum based non-biodegradable disposable packaging films has generated concern for development of alternatives from natural polymers such as starch. In the present work, the biodegradability of a self-supporting film made from starch and polyvinyl alcohol (PVA) (starch:PVA?=?9:1 as the polymer) together with glutaraldehyde as crosslinker and sodium propionate (SP) as antimicrobial was investigated by soil burial method. The changes in soil composition namely pH, organic carbon, available and total nitrogen, and water holding capacity as a result of biodegradation were also estimated. The film underwent ≈?90% biodegradation within a period of 28 days, with simultaneous increase in soil nutrients. Moreover, the pH remained in the accepted limit for plant growth. Thus, antimicrobial in the film did not hamper its biodegradation, rather disposal of the film in soil might facilitate plant growth.  相似文献   
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Tea, Camellia sinensis (L.) O. Kuntze, is grown conventionally (application of chemical fertilizer and pesticides) as well as organically in Darjeeling hills and adjoining plains. Studies on parasitic Hymenoptera gain relevance due to their effective role as biocontrol agents for maintenance of ecological balance and as biological indicators of health of tea agro-ecosystem. Diversity of the hymenopterans was studied using Shannon-Weaver index (1963) both at morphospecies and family levels. The analysis reflected the changing diversity of this group with season, pesticide application and the condition of the tea crop. It further indicated that mainly four parasitoid groups such as braconids, ichneumonids, eulophids and scelionids, showed greater diversity in organic plantation as compared to conventional. Since species (= RTU: recognizable taxonomic unit) diversity and family diversity indices agreed with one another a surrogacy based system (family for RTU) could be adopted for diversity analysis.  相似文献   
66.
Studies on cadmium toxicity in plants: a review   总被引:58,自引:0,他引:58  
This review emphasises cadmium toxicity on plants with regards to ecological, physiological and biochemical aspects. Cadmium toxicity in plants and problems concerning tolerance and ecological performance are discussed briefly. Efforts have been made to compare the relative sensitivity of various plant groups including micro-and macro-flora. This review may help in interdisciplinary studies to assess the ecological significance of metal stress.  相似文献   
67.
Exposure to environmental pollutants is known to be harmful to health, in general, and to lungs in particular. In this respect, traffic police are at particular risk due to the nature of their job, since they are exposed to emissions from the vehicles. Here, we show that in the traffic police of Hyderabad city, India, the plasma levels of lipid peroxides are high, whereas the concentrations of the nitric oxide are low. In addition, the levels of various antioxidants in the RBC lysate such as catalase, superoxide dismutase and glutathione peroxidase were found to be low with no significant alteration in plasma ceruloplasmin levels. These results suggest that exposure to air pollutants, a major portion of which is due to emissions from the vehicles, can increase oxidant stress, decrease the levels of antioxidants and nitric oxide. This imbalance in the oxidant/antioxidant system may lead to lung damage and is likely to cause respiratory problems in individuals exposed to air pollution.  相似文献   
68.
Twenty-one wild brown rats (Rattus norvegicus) were collected from four areas of Milan (Italy). Main organs were harvested from each rat, fixed in 10% neutral buffer formalin, and embedded in paraffin. Organ sections were stained with hematoxylin and eosin, kidney sections were also stained with the Ziehl-Neelsen method. Graphite furnace atomic absorption spectrophotometry was performed on all kidney samples. The presence of inclusion bodies and karyocytomegaly was scored. Six adult rats out of 21 (28.6%) showed kariocytomegaly and intranuclear inclusion bodies of the renal proximal tubules, characteristic of lead toxicity. The nuclear inclusion bodies were always Ziehl-Neelsen positive. The six rats which showed the characteristic histological alterations ascribed to lead, had lead concentrations statistically higher than the three control rats (4 microg/g wet wt. versus 0.09 microg/g wet wt., P<0.001) and than the captured wild rats. Intranuclear inclusion bodies were found in rats with kidney lead concentrations greater than 0.6 microg/g wet weight. There were significant differences between the four areas of capture. The incidence of intranuclear inclusion bodies and karyocytomegaly in proximal tubular cells was higher in rats with high lead levels detected by spectrophotometry. The present results indicate a renal lead concentration of 0.6 microg/g wet weight as a threshold to detect histologic kidney changes due to lead absorption. Results demonstrate that the examination of adult free-living rats may be considered an appropriate method to obtain a rapid, sensitive, easy, cost effective estimate of lead contamination in urban areas. Animal models allow us to evaluate potential human health risk associated with environmental contamination.  相似文献   
69.
Plankton is a kaleidoscopic spectrum of organisms with repre-sentatives from almost all phyla of animals and thousands of non-flowering plants. Unicellular protozoans, invertebrates and bacteriato diatoms all drift around as the plankton community. The produc-tion rate of plankton is determined by a host of environmental pa-rameters like physico-chemical properties of water and soil, mete-orological characteristics of the region, and morphometric and hy-drographic features of the water body[3]…  相似文献   
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