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141.
SPARC (osteonectin, BM-40) is a matricellular glycoprotein that is expressed in many embryogenic and adult tissues undergoing remodeling or repair. SPARC modulates cellular interaction with the extracellular matrix (ECM), inhibits cell adhesion and proliferation, and regulates growth factor activity. To explore further the function and activity of this protein in tissue homeostasis, we have developed several monoclonal antibodies (MAbs) that recognize distinct epitopes on SPARC. The MAbs bind to SPARC with high affinity and identify SPARC by ELISA, Western blotting, immunoprecipitation, immunocytochemistry, and/or immunohistochemistry. The MAbs were also characterized in functional assays for potential alteration of SPARC activity. SPARC binds to collagen I and laminin-1 through an epitope defined by MAb 293; this epitope is not involved in the binding of SPARC to collagen III. The other MAbs did not interfere with the binding of SPARC to collagen I or III or laminin-1. Inhibition of the anti-adhesive effect of SPARC on endothelial cells by MAb 236 was also observed. Functional analysis of SPARC in the presence of these novel MAbs now confirms that the activities ascribed to this matricellular protein can be assigned to discrete subdomains.  相似文献   
142.
We have constructed a partial linkage map in tetraploid potato which integrates simplex, duplex and double-simplex AFLP markers. The map consists of 231 maternal and 106 paternal markers with total map lengths of 990.9 cM and 484.6 cM. The longer of the two cumulative map lengths represents approximately 25% coverage of the genome. In tetraploids, much of the polymorphism between parental clones is masked by `dosage' which significantly reduces the number of individual markers that can be scored in a population. Consequently, the major advantage of using AFLPs – their high multiplex ratio – is reduced to the point where the use of alternative multi-allelic marker types would be significantly more efficient. The segregation data and map information have been used in a QTL analysis of late blight resistance, and a multi-allelic locus at the proximal end of chromosome VIII has been identified which contributes significantly to the expression of resistance. No late blight resistance genes or QTLs have previously been mapped to this location. Received: 1 October 1997 / Accepted: 18 March 1998  相似文献   
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Nerve growth factor   总被引:2,自引:0,他引:2  
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147.
Summary A racemic mixture of the molecularly dissymmetric compound 1,1-binaphthyl will spontaneously develop optical activity when melted, cooled, and allowed to crystallize. The distribution of optical rotations in individual samples shows that the resolutions occur in a truly spontaneous manner (i.e., without the influence of any external chiral agent). However, addition of small amounts of certain chiral compounds promotes the generation of one enantiomeric form of binaphthyl. The results are often not completely consistent and this suggests that the nucleation of binaphthyl is sensitive to very low concentrations of unknown chiral agents.Presented at the International Symposium on Generation and Amplification of Asymmetry in Chemical Systems, Jülich, September 24–26, 1973.  相似文献   
148.
Reviews in Fish Biology and Fisheries -  相似文献   
149.
Three spoils from Bold Moss Tip, St. Helens, and one from Neston, England were collected for experiment to find the problems and solutions to reclaim the coal-mine lands of Bold Moss Tip, from seeds and tillers of Agrostis stolonifera, A. capillaris and Hocus lanatus. Low pH (3.0 to 6.8), deficient in nutrient, especially N (0. 24 to 0. 28 ppm), P(0. 016 to 6.1 ppm). and excess of Mg(>1000ppm), Na(84 to 325ppm), and Fe (>20 000ppm)were found in the spoils of Bold Moss Tip, which was supposed to be the most difficult problems of restoration. Tillers of A. stolonifera and A. capillaris could not be planted directly to the bare spoils of Bold Moss Tip, but those of vegetated spoils (Site 2 and Site 3) could support the growth of tillers. The pH value was found to be the key factor to control seed germinations of the three species, below pH 3, there were no germination. A. stolonifera and A. capillaris germinated with the highest rates (97% and 96%) at pH 5 and pH7(p<0. 01)respectively. The application of lime stone could increase spoil pH significantly (p<0. 001), from 2.2 to 7. 3, when 40 t·ha-1 lime stone was added. Lime stone had the best effect to the four spoils. Lime stone +NP significantly increased the yield of dry matters of Site 2 (p<0. 001); The highest yield, 735.6 g · m-1, was gained from the treatment of spoils of Neston with lime stone + N; Lime could also increase the yield of Site 1 from 0 to 125. l g·m-1(p<0. 05). Gypsum had some effect to spoils of Site 2 and Neston, compared with the bland treatment, but did no influence to the spoils of Site 1. Washing had minimum effect toward the spoils of Site 2, and showed no effect to Site 1 and Neston; Throughout the 8-weed% experiment there was little change in the pH of Site 1, even though the spoils were washed everyday. Fertilisers alone had no effect to the bare spoils of Bold Moss Tip, and Neston, but they could enhance the growth of seedling of Site 2, however together with lime stone, the role of fertilisers were significant (p<0. 001). Both nitrogen and phosphorus were essential to the spoils of Bold Moss Tip . Without top-soils, the bare of Bold Moss Tip can be revegetated only by application of lime stone, but better effect coult be obtained by addition of nitrogen and phosphorus. The rates of 20 to 60 t·ha-1, 75 kg N ha-1 and 50 kg P ha-1 of lime stone, nitrogen, phosphorus respectively, are suggested for application.  相似文献   
150.
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