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   4057篇
  免费   232篇
  国内免费   16篇
耳鼻咽喉   19篇
儿科学   76篇
妇产科学   48篇
基础医学   498篇
口腔科学   146篇
临床医学   345篇
内科学   945篇
皮肤病学   40篇
神经病学   566篇
特种医学   170篇
外科学   586篇
综合类   20篇
一般理论   2篇
预防医学   197篇
眼科学   65篇
药学   202篇
中国医学   7篇
肿瘤学   373篇
  2023年   40篇
  2022年   64篇
  2021年   108篇
  2020年   89篇
  2019年   99篇
  2018年   116篇
  2017年   77篇
  2016年   118篇
  2015年   136篇
  2014年   168篇
  2013年   245篇
  2012年   294篇
  2011年   294篇
  2010年   154篇
  2009年   151篇
  2008年   209篇
  2007年   261篇
  2006年   212篇
  2005年   211篇
  2004年   167篇
  2003年   163篇
  2002年   145篇
  2001年   30篇
  2000年   17篇
  1999年   24篇
  1998年   56篇
  1997年   29篇
  1996年   41篇
  1995年   25篇
  1994年   37篇
  1993年   43篇
  1992年   16篇
  1991年   19篇
  1990年   17篇
  1989年   14篇
  1988年   22篇
  1987年   19篇
  1986年   19篇
  1985年   19篇
  1984年   19篇
  1983年   17篇
  1982年   30篇
  1981年   23篇
  1980年   16篇
  1979年   16篇
  1978年   13篇
  1977年   18篇
  1976年   19篇
  1974年   15篇
  1970年   12篇
排序方式: 共有4305条查询结果,搜索用时 0 毫秒
1.
This article focuses on in vivo data from tests performed in normal subjects and in patients who had abnormal growth hormone (GH) status. Experimental data in human subjects demonstrate that GH acutely inhibits glucose disposal in skeletal muscle. At the same time GH stimulates the turnover and oxidation of free fatty acid (FFA), and experimental evidence suggests a causal link between elevated FFA levels and insulin resistance in skeletal muscle. Observational data in GH-deficient adults do not indicate that GH replacement is associated with significant impairment of glucose tolerance, but it is recommended that overdosing be avoided and glycemic control be monitored.  相似文献   
2.
A cDNA encoding a transmembrane 140 kDa isoform of the neural cell adhesion molecule, NCAM, was transfected into the rat glioma cell line BT4Cn. Transfectants with a homogeneously high expression of NCAM-B showed a decreased capacity for penetration of an artificial basement membrane when compared to cells transfected with expression-vector alone or untransfected cells. However, when injected subcutaneously into nude mice, both NCAM expressing cells and control cells produced invasive tumors. Nude mice injected with NCAM positive cells developed tumors with slower growth rates as compared to those induced by NCAM negative cells. This implies that NCAM may not only be involved in adhesive and motile behaviour of glioma cells, but also in their growth regulation.  相似文献   
3.
International Journal of Public Health - Die Übertragungswege des HIV, welche in der Bevölkerung eine Rolle spielen, sind heute bekannt. Neben der sexuellen Übertragung, der...  相似文献   
4.
The wear was examined in 39 Christiansen total hip prostheses, which were removed because of mechanical loosening after being used 5 (3-11) years. In the polyacetal acetabular cups, the head had made an eccentric defect, the mean volume of which was 680 (180-3310) mm3. The mean penetration of the head into the wall of the cup was 0.8 (0.1-3.2) mm. In two additional cups the head had penetrated right through the wall of the cup. In three prostheses the polyacetal sleeve of the trunnion was so worn that the head bore directly on the stem. There was a positive correlation between wear and the time the prostheses had been used before symptoms of loosening presented.  相似文献   
5.
6.
7.

Background  

Despite considerable knowledge about musculoskeletal disorders (MSD) and physical, psychosocial and individual risk factors there is limited knowledge about physical activity as a factor in preventing MSD. In addition, studies of physical activity are often limited to either leisure activity or physical activity at work. Studies among military personnel on the association between physical activity at work and at leisure and MSD are lacking. This study was conducted to find the prevalence of MSD among personnel in the Royal Norwegian Navy and to assess the association between physical activity at work and at leisure and MSD.  相似文献   
8.
9.
Background: Central neuraxial blockades find widespread applications. Severe complications are believed to be extremely rare, but the incidence is probably underestimated.

Methods: A retrospective study of severe neurologic complications after central neuraxial blockades in Sweden 1990-1999 was performed. Information was obtained from a postal survey and administrative files in the health care system. During the study period approximately 1,260,000 spinal blockades and 450,000 epidural blockades were administered, including 200,000 epidural blockades for pain relief in labor.

Results: The 127 complications found included spinal hematoma (33), cauda equina syndrome (32), meningitis (29), epidural abscess (13), and miscellaneous (20). Permanent neurologic damage was observed in 85 patients. Incidence of complications after spinal blockade was within 1:20-30,000 in all patient groups. Incidence after obstetric epidural blockade was 1:25,000; in the remaining patients it was 1:3600 (P < 0.0001). Spinal hematoma after obstetric epidural blockade carried the incidence 1:200,000, significantly lower than the incidence 1:3,600 females subject to knee arthroplasty (P < 0.0001).  相似文献   

10.
The aim of the study was to compare salivary variables in a group of vegetarians with a group of omnivores. Twenty-nine vegetarians, 19 women and 10 men, mean age 35 yr, and 28 omnivores, 20 women and 8 men, mean age 35 yr, were compared in terms of salivary secretion rate, pH, buffer capacity, mutans streptococci and lactobacilli. The vegetarians had a significantly higher secretion rate, but there were no other significant differences regarding the salivary variables. The difference in secretion rate may have been caused by some lifestyle factor(s) differing between vegetarians and omnivores which probably mainly include nutrient(s), texture and roughness of the food.  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