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排序方式: 共有846条查询结果,搜索用时 15 毫秒
121.
122.
M Gaunt A Lloyd A Ross Naylor ND London PR Bell 《Canadian Metallurgical Quarterly》1998,16(6):543-545
Melorheostosis is a very rare bone disease of unknown etiology characterised by linear hyperostosis and associated with fibrosis of soft tissues and the skin. This uncommon sclerosing bone dysplasia was first described by Leri and Joanny in 1922, and since then, until 1993, approximately 300 cases were reported in the literature. Linear scleroderma is a localised proliferation of connective tissue and has rarely been associated with melorheostosis. In this paper, we present a new case of melorheostosis with linear scleroderma which, to the best of our knowledge, is the first case reported in Turkey. 相似文献
123.
ND Oakes GJ Cooney S Camilleri DJ Chisholm EW Kraegen 《Canadian Metallurgical Quarterly》1997,46(11):1768-1774
To elucidate cellular mechanisms of insulin resistance induced by excess dietary fat, we studied conscious chronically high-fat-fed (HFF) and control chow diet-fed rats during euglycemic-hyperinsulinemic (560 pmol/l plasma insulin) clamps. Compared with chow diet feeding, fat feeding significantly impaired insulin action (reduced whole body glucose disposal rate, reduced skeletal muscle glucose metabolism, and decreased insulin suppressibility of hepatic glucose production [HGP]). In HFF rats, hyperinsulinemia significantly suppressed circulating free fatty acids but not the intracellular availability of fatty acid in skeletal muscle (long chain fatty acyl-CoA esters remained at 230% above control levels). In HFF animals, acute blockade of beta-oxidation using etomoxir increased insulin-stimulated muscle glucose uptake, via a selective increase in the component directed to glycolysis, but did not reverse the defect in net glycogen synthesis or glycogen synthase. In clamp HFF animals, etomoxir did not significantly alter the reduced ability of insulin to suppress HGP, but induced substantial depletion of hepatic glycogen content. This implied that gluconeogenesis was reduced by inhibition of hepatic fatty acid oxidation and that an alternative mechanism was involved in the elevated HGP in HFF rats. Evidence was then obtained suggesting that this involves a reduction in hepatic glucokinase (GK) activity and an inability of insulin to acutely lower glucose-6-phosphatase (G-6-Pase) activity. Overall, a 76% increase in the activity ratio G-6-Pase/GK was observed, which would favor net hepatic glucose release and elevated HGP in HFF rats. Thus in the insulin-resistant HFF rat 1) acute hyperinsulinemia fails to quench elevated muscle and liver lipid availability, 2) elevated lipid oxidation opposes insulin stimulation of muscle glucose oxidation (perhaps via the glucose-fatty acid cycle) and suppression of hepatic gluconeogenesis, and 3) mechanisms of impaired insulin-stimulated glucose storage and HGP suppressibility are not dependent on concomitant lipid oxidation; in the case of HGP we provide evidence for pivotal involvement of G-6-Pase and GK in the regulation of HGP by insulin, independent of the glucose source. 相似文献
124.
Optical and scanning electron microscopy have been used to study the growth and redistribution of Cd and Cd(OH)2 in sintered plate electrodes as a function of charge rate and cycle number. As expected, the growth of both components was found to increase with increasing cycle number and decreasing charge rate. Because the deposits, particularly after extended cycling, always contained appreciable quantities of Cd metal in both the charged and discharged state, the sizes of Cd(OH)2 crystallites were difficult to quantify. High charge and discharge rates promoted greater aggregation and redistribution of active material towards the electrode edge. This resulted in a considerable decrease in the available pore volume per unit mass of active material and in extreme cases to localized pore blockage. The trapping of Cd metal by highly crystalline, unchargeable hexagonal platelets of (-Cd(OH)2 resulted in about 50% of the active material becoming obsolete after 100 cycles at high charge and discharge rates. At this stage only the finely divided Cd metal in the electrode interior continued to function. Low charge rates gave deposits of more uniform size and distribution but these contained a high percentage of large Cd particles which discharged less efficiently than those produced at the high charge rate. 相似文献
125.
126.
To help evaluate J. Piaget's and L. Kohlberg's differing theories about the motivational sources of moral realism, 48 5-yr-olds were orally presented stories in which obedient conduct was followed by punishment and disobedient conduct was followed by reward. Stories varied according to whether the character's conduct was given first, followed by the outcome, or vice versa, and according to whether the agent of outcome was a respected adult or chance. Ss' use of the character's conduct, rather than the outcomes, as their basis for moral judgments was measured. Both story order and agent of outcome affected the choice of dimension used. Earlier data reported by Kohlberg and others, in which response outcomes determined many moral judgments, would seem to be artifacts of the story design. Children in this study regularly showed attention to adults and to their rules, as Piaget's theory postulates. (French summary) (8 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
127.
A technique for studying the catalytic activity of enzymes spread as a film at an air-water interface, by exchanging the subphase under the film to remove unspread enzyme molecules, was developed, and its effectiveness was studied using surface-spread mitochondrial malate dehydrogenase. Mitochondrial malate dehydrogenase formed stable films which gave reproducible pi-A curves. The enzyme activity was measured by the oxidation rate of reduced nicotinamide adenine dinucleotide (NADH) in the presence of the substrate oxalacetic acid. Oxalacetic acid and NADH were injected into the subphase. The catalytic activity of the enzyme was dependent on the surface pressure of the film. The maximum catalytic activity was observed at a surface pressure of 4.4 dynes/cm. The activity was higher at intermediate surface pressures than at very low or very high surface pressures. A high bulk catalytic activity was observed in the unstable region, i.e., at a high degree of compression, of the film. The catalytic activity of the surface-spread enzyme was only a fraction of an equivalent amount of enzyme in solution. 相似文献
128.
Probabilistic inventory models assume that demand follows a stable distribution with known parameters. This assumption is reasonable where substantial demand history is available under stable conditions. However, for slow-moving items, such as maintenance items, usually little history is available. In such cases, the assumption of known parameters seems unnecessarily arbitrary. We present here a model that takes into account the uncertainty of the unknown parameters, determines the optimal inventory decision, updates the original distribution assumptions as the passage of time increases our information concerning the parameters, and determines optimal policy. 相似文献
129.
ND Harvey 《Canadian Metallurgical Quarterly》1976,20(1):5-7
The families of 26 patients with Ebstein's anomaly were examined. There were 120 first-degree relatives, 100 of whom were living, and 93 of these were examined. Information was available on 14 of the 20 who had died. No case of Ebstein's anomaly was found among the first-degree relatives, but 2 had ventricular septal defects and another, who died at 7 months, was said to have had congenital heart disease. In more distant relatives there were 6 with congenital heart disease, including 2 with ventricular septal defects and 2 with Fallot's tetralogy. 相似文献
130.