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排序方式: 共有1325条查询结果,搜索用时 171 毫秒
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This study evaluates relationships between vegetation and stableisotope distribution within a large, northern peat-accumulatingwetland. Concentration and 相似文献
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The scapula responds to the compressive states of its surrounding matrix produced by muscle functioning and weight bearing in the upper extremity with discernible structural correlates. These structural correlates can be utilized to infer locomotor behavior. After dissection and drying, the weights of several muscles of the shoulder region of 11 adult female baboons (Papio cynocephalus) were statistically compared to various dimensions of the bony scapula. A significant correlation was obtained between the weights of the individual compressive muscles, the combined weights of the compressive muscles and a scapular dimension of width. A nonsignificant correlation between these muscles and a sscapular dimension of length was also found. The results of this study were compared to those of a previous study of the scapular musculature in Macaca and opposing conclusions were obtained. The advisability of lumping macaques and baboons into a single gross locomotor category is rejected. 相似文献
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Xia Li Yunrui Du Steven Siegel Susan Ferro-Novick Peter Novick 《Molecular biology of the cell》2010,21(10):1772-1782
Inheritance of the endoplasmic reticulum (ER) requires Ptc1p, a type 2C protein phosphatase of Saccharomyces cerevisiae. Genetic analysis indicates that Ptc1p is needed to inactivate the cell wall integrity (CWI) MAP kinase, Slt2p. Here we show that under normal growth conditions, Ptc1p inactivates Slt2p just as ER tubules begin to spread from the bud tip along the cortex. In ptc1Δ cells, the propagation of cortical ER from the bud tip to the periphery of the bud is delayed by hyperactivation of Slt2p. The pool of Slt2p that controls ER inheritance requires the CWI pathway scaffold, Spa2p, for its retention at the bud tip, and a mutation within Slt2p that prevents its association with the bud tip blocks its role in ER inheritance. These results imply that Slt2p inhibits a late step in ER inheritance by phosphorylating a target at the tip of daughter cells. The PI4P5-kinase, Mss4p, is an upstream activator of this pool of Slt2p. Ptc1p-dependant inactivation of Slt2p is also needed for mitochondrial inheritance; however, in this case, the relevant pool of Slt2p is not at the bud tip. 相似文献
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R C Siegel C M Black A J Bailey 《Biochemical and biophysical research communications》1979,88(1):281-287
The activity and antigenicity of the collagen crosslinking enzyme, lysyl oxidase, and the proportions of reducible crosslink in skin biopsies from Ehlers-Danlos Type V subjects were equivalent to those of control skin. These results reveal that both the potential for crosslinking, and the ability to form reducible crosslinks is present in Ehlers-Danlos syndrome Type V subjects, clearly demonstrating that the defect in this disorder is not due to a defective crosslinking mechanism. 相似文献
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L J Rever P N Manson M A Randolph M J Yaremchuk A Weiland J H Siegel 《Plastic and reconstructive surgery》1991,87(3):451-458
The mechanism of healing of facial bone fractures was investigated in a rabbit model. Twelve New Zealand white rabbits underwent surgically induced fractures of the right infraorbital rim and fracture ostectomies (4 to 5 mm) of the left infraorbital rim. Animals were sacrificed 2, 4, and 8 weeks postfracture. Bone, including periosteum, obtained from each fracture or fracture osteoctomy site was divided longitudinally for hematoxylin and eosin staining, fluorescent microscopy, microangiography, and microradiography. Sequential fluorochrome labels of oxytetracycline (30 mg/kg), alizarin complexone (30 mg/kg), DCAF (20 mg/kg), and xylenol orange (90 mg/kg) were administered 24 hours preoperatively and at 1, 2, 4, and 8 weeks postfracture. All fracture and fracture ostectomy sites demonstrated vascular ingrowth, mineralization, and woven bone formation by 2 to 4 weeks postoperatively, beginning with a cartilage precursor. Subsequently, the woven bone was replaced with remodeled lamellar bone, resulting in complete bony healing by 8 weeks postoperatively. These steps were substantiated by microscopic, microradiographic, and radiologic examination of the specimens. This study demonstrates that fractures of the facial bones in a rabbit model heal by a process of new bone formation that resembles secondary union in endochondral bones. 相似文献
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Molecular mapping of the mouse ob mutation. 总被引:8,自引:0,他引:8
The mouse ob mutation has been mapped relative to a series of RFLPs among the progeny of three separate mouse crosses: an intraspecific backcross, an intraspecific intercross, and an interspecific intercross. Genotypic assignment at the ob locus was made by making use of measurements of body mass index and the plasma concentrations of glucose and insulin. These data have suggested that the development of diabetes in these animals is a consequence of unlinked polygenes. There was also evidence that unlinked Mus spretus alleles can diminish the obesity of ob/ob mice. From these data we have mapped several markers on chromosome 6 with the following order: cen-Cola-2-Met-ob-Cpa-Tcrb. The homologs of markers that flank ob map to human chromosome 7q, suggesting that if there is a human homologue of ob, it maps to 7q31. 相似文献
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