首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   230篇
  免费   7篇
  2021年   2篇
  2016年   3篇
  2015年   8篇
  2014年   4篇
  2013年   7篇
  2012年   11篇
  2011年   11篇
  2010年   3篇
  2009年   7篇
  2008年   5篇
  2007年   14篇
  2006年   7篇
  2005年   12篇
  2004年   11篇
  2003年   14篇
  2002年   13篇
  2001年   2篇
  2000年   4篇
  1999年   8篇
  1998年   4篇
  1997年   3篇
  1996年   2篇
  1994年   2篇
  1993年   2篇
  1991年   3篇
  1990年   4篇
  1989年   2篇
  1988年   1篇
  1987年   2篇
  1986年   1篇
  1985年   1篇
  1984年   8篇
  1983年   3篇
  1982年   1篇
  1981年   1篇
  1980年   2篇
  1978年   3篇
  1975年   5篇
  1974年   4篇
  1973年   3篇
  1972年   4篇
  1971年   2篇
  1970年   6篇
  1969年   7篇
  1968年   1篇
  1967年   2篇
  1966年   1篇
  1965年   2篇
  1963年   2篇
  1938年   1篇
排序方式: 共有237条查询结果,搜索用时 31 毫秒
1.
2.
The hypothesis that male diabetes mutant mice (C57Bl/KsJ-db/db) are suffering from impairment of testicular steroidogenic function and pituitary LH release was tested. A smaller postpubertal increase of testicular weight and a reduction of plasma testosterone and androstenedione levels by 65% at 17 weeks of age were most obvious from the comparison to homozygous lean controls. The ability of constant amounts of Leydig cells, either in crude interstitial cell or in purified Leydig cell suspensions, to respond to maximal doses of hCG or cyclic AMP-was reduced by at least 40% in adult diabetes mice. This defect could be attributed to a 40% decrease of steroid-17 alpha-monooxygenase activity as compared to lean mice. No differences occurred, however, if Leydig cells were submaximally stimulated. GnRH-stimulated pituitary LH release was not significantly changed. The impairment of testicular steroidogenic function in diabetes mutant mice may represent a further aspect of infertility of these animals and of diabetes mellitus.  相似文献   
3.
Estimation of pyruvate decarboxylation in perfused rat skeletal muscle   总被引:12,自引:0,他引:12  
A total of 46 E. coli strains showing mannose-resistant, P-blood-group independent hemagglutination of human erythrocytes were tested for binding to neuraminic acid. Nine of the strains completely lost their hemagglutination activity after the erythrocytes were treated with neuraminidase. To characterize the receptor structure, different neuraminic acid containing glycoproteins, their desialylated derivatives and neuraminyl oligosaccharides were tested for hemagglutination inhibition. These studies showed that the nine strains had binding specificity for alpha 2-3 linked neuraminic acid.  相似文献   
4.
The garnet-type phase Li7La3Zr2O12 (LLZO) attracts significant attention as an oxide solid electrolyte to enable safe and robust solid-state batteries (SSBs) with potentially high energy density. However, while significant progress has been made in demonstrating compatibility with Li metal, integrating LLZO into composite cathodes remains a challenge. The current perspective focuses on the critical issues that need to be addressed to achieve the ultimate goal of an all-solid-state LLZO-based battery that delivers safety, durability, and pack-level performance characteristics that are unobtainable with state-of-the-art Li-ion batteries. This perspective complements existing reviews of solid/solid interfaces with more emphasis on understanding numerous homo- and heteroionic interfaces in a pure oxide-based SSB and the various phenomena that accompany the evolution of the chemical, electrochemical, structural, morphological, and mechanical properties of those interfaces during processing and operation. Finally, the insights gained from a comprehensive literature survey of LLZO–cathode interfaces are used to guide efforts for the development of LLZO-based SSBs.  相似文献   
5.
Abstract: Labeled palmitic acid ([16-14C]palmitate) (0).5 μCi) was injected into rat sciatic nerves in vivo to characterize thc incorporation of this fatty acid into complex peripheral nerve lipids after time lapses of 1 min to 2 weeks. For the first 30 min after intraneural injection, the label was concentrated in nerve diglycerides. Thereafter, the relative diglyccride label declined rapidly, and phospholipid radioactivity rose steadily. After 120 min, phospholipids contained over 70% of the total lipid radioactivity. Among the phospholipids, phosphatidylcholine had the largest percentage of total phospholipid label, and acylation of lysophosphatidylcholine accounted for approximately 75% of this label. With time, there was conversion of [16-14C]palmitate to other long-chain fatty acids by elongation and desaturation. Phosphatidic acid was labeled also, suggesting the operation of the de novo biosynthetic mechanism. However, the specific radioactivity of 1,2-diacylglycerol was much higher than that of phosphatidic acid, suggesting phosphorylation of diglycerides by diglyceride kinase. After nerve section and survival of 2 h to 50 days, the injection of [16-14C]palmitate into the degenerating distal segment revealed an overall decline of phospholipid labeling and a commensurate increase of triglyceride radioactivity. Phosphatidylcholine in degenerating nerve contained a larger percentage of the fatty acid label than that in normal nerve. Almost all of the labeling was due to acylation of lysophosphatidylcholine, implying a much smaller contribution of the de novo pathway. Phosphatidylethanolamine and phosphatidylserine showed a relative loss of radioactivity. The changes were apparent at 1 day, but not at 2 h, suggesting loss of homeostatic control, presumably by interruption of axonal flow. An incidental observation was the stimulation of phosphatidylcholine biosynthesis by acylation of lysophosphatidylcholine in the contralateral unoperated sciatic nerve.  相似文献   
6.
The release of amino acids by skeletal muscle was studied in the isolated perfused rat hindquarter. Adrenalectomy depressed the formation of glutamine and alanine as well as the efflux of all other amino acids measured. Betamethasone--a synthetic glucocorticoid--caused a significant increase in the efflux of nearly all amino acids up to the level of normal controls. The release of amino acids was also increased in perfused hindquarters of diabetic rats. On the other hand, insulin exhibited a depressing effect on the release of amino acids by hindquarters of normal rats. The metabolic integrity of the muscle tissue was proved by measuring creatine phosphate, ATP, ADP and water content as well as by the significant insulin effect on glucose uptake and on [14C]leucine incorporation into muscle proteins.  相似文献   
7.
8.
9.
Objective: Severe obesity is a clear indication for appropriate, effective weight loss therapy. One option is operative intervention, e.g., gastric banding. Risks of the operation and therapeutic alternatives need to be comprehensibly presented to the patient. The literature has shown that better informed consent is obtained using information presented in a multimedia/video‐based format. The current study developed and evaluated a multimedia program aimed at obtaining informed consent from obese patients before gastric banding. Research Methods and Procedure: An interactive multimedia program was developed with information about preoperative examinations, the operation itself, hospital stay, operative risks, alternative therapies, and the pathophysiology and health risks of obesity. Two groups (Group 1, n = 20, mean age 38 years, informed consent attained with conventional document information; Group 2, n = 20, mean age 37 years, informed consent attained with additional multimedia information) were interviewed regarding comprehensibility of the information presented, personal satisfaction, and anxiety levels during the informed consent process. Results: Group 2 showed significantly better (p < 0.05) understanding of the presented information and higher levels of satisfaction with the informed consent process. Anxiety levels did not significantly differ between the two groups. Discussion: Because patient satisfaction with the informed consent process and understanding of the presented information significantly improved, the multimedia program clearly benefits both surgeons and patients. Personal contact from the surgeon remains essential. High volumes of information presented in multimedia format do not alleviate patient anxiety, and personal contact may be beneficial.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号