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81.
82.
Lesion of the bone matrix in vitamin D-resistant rickets   总被引:2,自引:0,他引:2  
  相似文献   
83.
Zusammenfassung Die Ausscheidung des neuen Neuroleptikums, Chlorprothixen, bei Menschen und Ratten wurde in Urin, Galle und Faeces untersucht und als einziges Abbauprodukt Chlorprothixen-Sulfoxyd gefunden. Ausscheidungsprodukte in % der verabreichten Dosis: Beim Menschen (orale Verabreichung) im Urin: 5–29% Sulfoxyd, Faeces: 0–41% unveränderter Stoff + Sulfoxyd. Bei der Ratte (orale oder parenterale Verabreichung) im Urin: bis zu 5% Sulfoxyd, Faeces: 1–7% Sulfoxyd, keine unveränderte Substanz, Galle: bis zu 24% Sulfoxyd.  相似文献   
84.
The striking number of human and murine immunodeficiency disorders which map to the X chromosome suggests that genes localized on this chromosome must have important roles in lymphocyte development. At least seven distinct disorders in the human and two in the mouse disrupt lymphocyte maturation, particularly that of B cells, at characteristic stages. As functional genes mapping to the X chromosome in one mammal are found on the X chromosome in all other mammals, the same genes regulating lymphocyte development are expected to be found on the X chromosome in mouse and man. Investigations into the possible mechanisms of these X-linked disorders have been hampered by the lack of molecular probes for the genes or gene products affected; because of this, and the possibility of correlating one or more of the several hundred B- or T-cell-specific genes with a specific mutation, we surveyed 15 different B- and T-cell-specific cDNA clones for localization to the X chromosome. We report here the characterization of one of these murine cDNA clones, which hybridizes with a large, X-linked gene family, designated XLR (X-linked, lymphocyte-regulated). We show that the XLR gene family is closely linked to the X-linked immunodeficiency described in the CBA/N mouse strain (xid), by restriction fragment length polymorphism (RFLP) analysis of DNA from mice congeneic for xid. This finding, together with data on the expression of the XLR locus in B cells, indicates that this gene family either includes the locus defined by the xid mutation or is adjacent to it in a gene complex which may be important in lymphocyte differentiation.  相似文献   
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86.
Summary The insecticide 4-methylthio-1,2-dithiolane, named charatoxin, blocks the frog muscular twitches elicited through the neuromuscular junction. The activity level and the course of inhibition is comparable to that of 4-dimethyl-amino-1,2-dithiolane, nereistoxin.The authors are grateful to Dr N. Jacobsen, Cheminova A/S for synthesizing the toxins and the 2 analogues.  相似文献   
87.
Grantham BA  Chan F  Nielsen KJ  Fox DS  Barth JA  Huyer A  Lubchenco J  Menge BA 《Nature》2004,429(6993):749-754
Seasonal development of dissolved-oxygen deficits (hypoxia) represents an acute system-level perturbation to ecological dynamics and fishery sustainability in coastal ecosystems around the globe. Whereas anthropogenic nutrient loading has increased the frequency and severity of hypoxia in estuaries and semi-enclosed seas, the occurrence of hypoxia in open-coast upwelling systems reflects ocean conditions that control the delivery of oxygen-poor and nutrient-rich deep water onto continental shelves. Upwelling systems support a large proportion of the world's fisheries, therefore understanding the links between changes in ocean climate, upwelling-driven hypoxia and ecological perturbations is critical. Here we report on the unprecedented development of severe inner-shelf (<70 m) hypoxia and resultant mass die-offs of fish and invertebrates within the California Current System. In 2002, cross-shelf transects revealed the development of abnormally low dissolved-oxygen levels as a response to anomalously strong flow of subarctic water into the California Current System. Our findings highlight the sensitivity of inner-shelf ecosystems to variation in ocean conditions, and the potential impacts of climate change on marine communities.  相似文献   
88.
Latitudinal clines of malate dehydrogenase-1 (MDH-1) allozymes occur within honey bee populations on three continents: Europe, North America and South America. The North and South American populations are introduced and demonstrate that Mdh allelic clines were established within the last 150 years. The frequency of the medium electrophoretic allele increases in frequency with increasing latitude while the fast allele decreases with latitude on all the three continents. The clines are best explained by the average daily high temperature for July on all continents. These parallel clines provide evidence for selection on Mdh alleles in honey bees.  相似文献   
89.
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