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   4440篇
  免费   459篇
  国内免费   49篇
耳鼻咽喉   33篇
儿科学   144篇
妇产科学   137篇
基础医学   537篇
口腔科学   143篇
临床医学   468篇
内科学   735篇
皮肤病学   205篇
神经病学   410篇
特种医学   335篇
外国民族医学   1篇
外科学   544篇
综合类   161篇
一般理论   21篇
预防医学   346篇
眼科学   130篇
药学   394篇
  1篇
中国医学   13篇
肿瘤学   190篇
  2021年   53篇
  2020年   51篇
  2019年   74篇
  2018年   74篇
  2017年   54篇
  2016年   68篇
  2015年   76篇
  2014年   114篇
  2013年   131篇
  2012年   182篇
  2011年   168篇
  2010年   114篇
  2009年   118篇
  2008年   156篇
  2007年   200篇
  2006年   185篇
  2005年   160篇
  2004年   171篇
  2003年   149篇
  2002年   134篇
  2001年   124篇
  2000年   133篇
  1999年   117篇
  1998年   78篇
  1997年   78篇
  1996年   94篇
  1995年   87篇
  1994年   60篇
  1993年   69篇
  1992年   95篇
  1991年   105篇
  1990年   108篇
  1989年   97篇
  1988年   95篇
  1987年   96篇
  1986年   98篇
  1985年   96篇
  1984年   73篇
  1983年   70篇
  1982年   55篇
  1981年   43篇
  1980年   49篇
  1979年   45篇
  1978年   47篇
  1977年   50篇
  1973年   34篇
  1971年   40篇
  1970年   33篇
  1969年   39篇
  1967年   31篇
排序方式: 共有4948条查询结果,搜索用时 15 毫秒
1.
2.
3.
Reluctance to use kidneys from older donors (>50 years of age) is based on reports of inferior results. We reviewed our experience with 45 kidneys transplanted from older donors. Primary nonfunction, immediate graft function, and 1-, 2- and 3-year graft survival rates were similar to those obtained with kidneys transplanted from donors aged between 20 and 40 years. Renal function at 1 year (as measured by serum creatinine) was poorer in kidneys from older donors. No beneficial effect with respect to graft survival was noted with cyclosporin therapy compared to conventional immunosuppression; however, the numbers are small. We conclude that kidneys from older donors are a valuable source for transplantation.  相似文献   
4.
5.
6.

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   
7.
Suckling rat pups were given intraperitoneal fluoride injections at selected ages so that we could study fluoride uptake in the enamel of the maxillary first molar at various stages of enamel development. Plasma fluoride levels in six-day-old and 11-day-old pups were monitored following the intraperitoneal injection of fluoride. The findings indicate that: (1) fluoride was more easily taken up and retained during the early stages of enamel formation, but fluoride uptake can occur during all stages of enamel formation; (2) when injections were started early in enamel formation, more fluoride was contained in the enamel of the maxillary first molar at 13 days of age; and (3) the same dose of fluoride per gram body weight resulted in greater exposure to elevated plasma fluoride levels in six-day-old pups than in 11-day-old pups.  相似文献   
8.
Irradiation and choroidal melanoma.   总被引:2,自引:2,他引:0       下载免费PDF全文
  相似文献   
9.
Retinoblastoma. The relationship of proliferating cells to blood vessels   总被引:1,自引:0,他引:1  
In 150 retinoblastomas the authors found a uniform thickness of the cuff of viable retinoblastoma cells that surrounds blood vessels. The mean thickness was 98.7 microns with a standard deviation of 11.9 microns. The cross-sectional area of the cuff was negatively correlated with the mitotic activity in the cuff and positively correlated with the diameter of the central vessel. The mitotic activity in the cuff of cells was inversely related to the distance from the central blood vessel. When the cuff was divided into three concentric rings, the inner ring contained a mean of 6.2 mitotic figures, the middle ring contained a mean of 2.9 mitotic figures, and the outer ring contained a mean of 0.6 mitotic figures. This pattern of growth is similar to that observed in other rapidly growing neoplasms in humans and experimental animals. In these tumors this pattern results from reduction in oxygen tension with increased distance from the central blood vessel.  相似文献   
10.
The problem of protein calorie malnutrition following major gastrointestinal surgery can be treated with central venous or enteric alimentation, with the latter being preferred. The authors describe a simple technique for the conversion of biliary stents placed after pancreaticoduodenal surgery into jejunal feeding tubes when the stenting function is no longer needed. Three illustrative cases are presented. In each case, the procedure took less than 30 min and had no associated morbidity. This technique allows early conversion from central venous to enteric alimentation without the need to create a second surgical enterostomy.  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