排序方式: 共有26条查询结果,搜索用时 15 毫秒
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模糊形态学的理论概念 总被引:1,自引:0,他引:1
本文将经典集上的形态运算扩展到模糊集,并且以模糊集理论和模糊形态学的观点,建立了完备格。运用模糊集上的截集概念本文将经典集上的形态运算扩展到模糊集,并且以模糊集理论和模糊形态学的观点,建立了完备格。 相似文献
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We have determined that the porcine thyroidal TSH receptor is a glycoprotein heterotetramer composed of two Mr approximately 35,000 (epsilon) covalently linked subunits which interact noncovalently with two copies of delta (Mr 66,000) chains. 相似文献
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S Islam 《Experientia》1979,35(9):1206-1207
Conditioned taste aversion (CTA) established in rats by associating saccharin drinking with subsequent poisoning by Russell's viper venom. Retention test revealed 76 and 56% reduction of saccharin intake in venom and antivenom-venom groups. No CTA was observed in antivenom and control groups. 相似文献
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Highly efficient cell-mediated gene transfer using non-viral vectors and FuGene6: in vitro and in vivo studies 总被引:1,自引:0,他引:1
Hellgren I Drvota V Pieper R Enoksson S Blomberg P Islam KB Sylvén C 《Cellular and molecular life sciences : CMLS》2000,57(8-9):1326-1333
The present study was undertaken to develop an efficient non-viral gene delivery system for cardiovascular gene therapy. We investigated transfection efficiency and toxic properties of the new transfection reagent, FuGene6, and compared it with two other transfection reagents, Tfx-50 and LipoTaxi. For in vivo experiments, the plasmid was delivered intramuscularly via transplantation of fibroblasts transfected with plasmid and FuGene6. Conditions for efficient gene delivery were initially studied in vitro. Human and rabbit fibroblasts were isolated from skin, cultured and transfected with phVEGF165 or pCMVbeta gal plasmids, coding for vascular endothelial growth factor (VEGF) or beta-galactosidase, respectively. The effect of the DNA amount and the DNA:transfection reagent ratio on plasmid uptake were studied. Of the transfection reagents tested, only FuGene6 provided high-efficiency and dose-dependent plasmid transfer both for cell-localised (beta-galactosidase) and secreted (VEGF) gene products. When analysed with an MTT assay, FuGene6 showed no toxicity at low doses. Optimised conditions were applied for in vivo reporter gene delivery. Rabbits were injected intramuscularly with ex vivo-transfected fibroblasts. As in in vitro studies, ex vivo-transfected fibroblasts showed highly efficient gene expression in vivo. Tissue sections were analysed with macrophage-specific immunostaining. No signs of inflammation were seen in the region of fibroblast injection. This study demonstrates that FuGene6 is a highly efficient transfection reagent that may be useful for in vitro non-viral transfection of primary human and rabbit fibroblasts and for in vivo therapeutic non-viral gene delivery. 相似文献
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Islam FS Gault AG Boothman C Polya DA Charnock JM Chatterjee D Lloyd JR 《Nature》2004,430(6995):68-71
The contamination of ground waters, abstracted for drinking and irrigation, by sediment-derived arsenic threatens the health of tens of millions of people worldwide, most notably in Bangladesh and West Bengal. Despite the calamitous effects on human health arising from the extensive use of arsenic-enriched ground waters in these regions, the mechanisms of arsenic release from sediments remain poorly characterized and are topics of intense international debate. We use a microscosm-based approach to investigate these mechanisms: techniques of microbiology and molecular ecology are used in combination with aqueous and solid phase speciation analysis of arsenic. Here we show that anaerobic metal-reducing bacteria can play a key role in the mobilization of arsenic in sediments collected from a contaminated aquifer in West Bengal. We also show that, for the sediments in this study, arsenic release took place after Fe(III) reduction, rather than occurring simultaneously. Identification of the critical factors controlling the biogeochemical cycling of arsenic is one important contribution to fully informing the development of effective strategies to manage these and other similar arsenic-rich ground waters worldwide. 相似文献