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   737篇
  免费   48篇
  国内免费   46篇
耳鼻咽喉   2篇
儿科学   48篇
妇产科学   24篇
基础医学   78篇
口腔科学   38篇
临床医学   96篇
内科学   188篇
皮肤病学   13篇
神经病学   24篇
特种医学   116篇
外科学   35篇
综合类   10篇
一般理论   1篇
预防医学   54篇
眼科学   3篇
药学   59篇
  1篇
肿瘤学   41篇
  2023年   6篇
  2022年   8篇
  2021年   8篇
  2020年   2篇
  2019年   5篇
  2018年   12篇
  2017年   10篇
  2016年   16篇
  2015年   19篇
  2014年   21篇
  2013年   32篇
  2012年   15篇
  2011年   16篇
  2010年   20篇
  2009年   24篇
  2008年   15篇
  2007年   46篇
  2006年   22篇
  2005年   17篇
  2004年   5篇
  2003年   10篇
  2002年   14篇
  2001年   11篇
  2000年   9篇
  1999年   15篇
  1998年   47篇
  1997年   53篇
  1996年   54篇
  1995年   44篇
  1994年   31篇
  1993年   30篇
  1992年   7篇
  1991年   13篇
  1990年   9篇
  1989年   15篇
  1988年   27篇
  1987年   21篇
  1986年   16篇
  1985年   16篇
  1984年   8篇
  1983年   10篇
  1982年   9篇
  1981年   8篇
  1980年   11篇
  1978年   5篇
  1977年   8篇
  1976年   2篇
  1975年   4篇
  1965年   1篇
  1960年   1篇
排序方式: 共有831条查询结果,搜索用时 15 毫秒
1.
2.
Summary Dock workers (n = 218) occupationally exposed to green coffee beans (GCB) were studied, using a specific questionnaire for allergic symptoms and skin tests for common and occupational allergens. Thirty-one workers (14.3%) complained of allergic symptoms of the eye, nose and bronchial system at the workplace. The prick tests, using both commercial allergens and specific extracts prepared from the most common types of coffee and their corresponding sacks, confirmed a sensitization in 21 workers (9.6%). A positive skin reaction to castor beans (CB) was found in nearly all these cases; in ten workers there was also a positive reaction to GCB allergens and in 14 cases prick tests were positive to extracts of sacks. There was a good concordance between prick tests and specific IgE for CB (95.0%) and also, but to a lesser extent, for GCB. The authors concluded that there is a significant risk of sensitization to CB and GCB allergens in dock workers occupied in handling green coffee bean, despite the fact that the exposure is not continuous. CB emerged as a common contaminant of GCB from various countries. For effective prevention, a modification of the methods of transport is required to avoid CB contamination to other products. Eliminating environmental dust during shipping operations is the most important preventive measure and it can be achieved by the use of containers, as some exporting countries are already doing.  相似文献   
3.
4.

Background  

Shoulder disorders are a common health problem in western societies. Several treatment protocols have been developed for the clinical management of persons with shoulder pain. However available evidence does not support any protocol as being superior over others. Systematic reviews provide some evidence that certain physical therapy interventions (i.e. supervised exercises and mobilisation) are effective in particular shoulder disorders (i.e. rotator cuff disorders, mixed shoulder disorders and adhesive capsulitis), but there is an ongoing need for high quality trials of physical therapy interventions. Usually, physical therapy consists of active exercises intended to strengthen the shoulder muscles as stabilizers of the glenohumeral joint or perform mobilisations to improve restricted mobility of the glenohumeral or adjacent joints (shoulder girdle). It is generally accepted that a-traumatic shoulder problems are the result of impingement of the subacromial structures, such as the bursa or rotator cuff tendons. Myofascial trigger points (MTrPs) in shoulder muscles may also lead to a complex of symptoms that are often seen in patients diagnosed with subacromial impingement or rotator cuff tendinopathy. Little is known about the treatment of MTrPs in patients with shoulder disorders.  相似文献   
5.
6.
7.
8.
BACKGROUND: Cyclosporin has been shown to facilitate renal vasoconstriction and to have an antinatriuretic effect. The existence of an interference of cyclosporin with the vasodilating properties of endothelium mediated by nitric oxide production could mediate these effects. On the other hand, the infusion of the nitric oxide precursor L-arginine has been shown to induce renal vasodilatation and to facilitate natriuresis in normal volunteers. We have investigated the renal effects of the administration of an infusion of L-arginine in renal transplant patients chronically treated with cyclosporin. To facilitate the analysis of the data the effects of the administration of a similar dose of cyclosporin on renal function during the infusion of a vehicle were also investigated during the administration of a vehicle of L-arginine. DESIGN: Ten male renal transplant patients, chronically treated with cyclosporin and with a stable renal function were studied during 2 consecutive days after the administration of the usual morning dose of cyclosporin. The first day they received an intravenous infusion of vehicle and the second the infusion of graded doses of L-arginine (50, 100, 150 mg/kg/h) during 3 consecutive h. RESULTS: The first day, after cyclosporin administration a significant fall (P < 0.01) was observed in natriuresis and kaliuresis in the absence of changes in renal plasma flow and glomerular filtration rate. After the administration of L-arginine significant (P < 0.01) increases of renal plasma flow, glomerular filtration rate, and natriuresis were seen. The increase in blood levels of cyclosporin after its administration did not differ between days 1 and 2. CONCLUSION: These results indicate that L-arginine facilitates renal vasodilatation and natriuresis in renal transplant patients. Furthermore, the observed increase in sodium excretion could indicate that L-arginine counteracts the antinatriuretic effect of cyclosporin.   相似文献   
9.
Does altered biomechanics cause marrow edema?   总被引:21,自引:0,他引:21  
Schweitzer  ME; White  LM 《Radiology》1996,198(3):851
  相似文献   
10.
The gene for retinitis pigmentosa 3 (RP3), the most frequent form of X- linked RP (XLRP), has been mapped previously to a chromosome interval of less than 1000 kbp between the DXS1110 marker and the OTC locus at Xp21.1-p11.4. Employing a novel technique, YAC Representation Hybridization (YRH)', we have recently identified a small XLRP associated microdeletion in this interval, as well as several putative exons including the 3' end of a gene that was truncated by the deletion. cDNA library screening and sequencing of a cosmid centromeric to the deletion has now enabled us to identify numerous additional exons and to detect several point mutations in patients with XLRP. The predicted gene product shows homology to RCC1, the guanine-nucleotide- exchange factor (GEF) of the Ras-like GTPase Ran. Our findings suggest that we have cloned the long-sought RP3 gene, and that it may encode the GEF of a retina-specific GTP-binding protein.   相似文献   
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