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   16613篇
  免费   2181篇
  国内免费   24篇
耳鼻咽喉   115篇
儿科学   722篇
妇产科学   339篇
基础医学   2468篇
口腔科学   476篇
临床医学   1787篇
内科学   3724篇
皮肤病学   157篇
神经病学   1196篇
特种医学   687篇
外科学   2563篇
综合类   442篇
一般理论   15篇
预防医学   1695篇
眼科学   192篇
药学   1425篇
中国医学   6篇
肿瘤学   809篇
  2021年   207篇
  2020年   150篇
  2019年   203篇
  2018年   239篇
  2017年   190篇
  2016年   165篇
  2015年   222篇
  2014年   352篇
  2013年   466篇
  2012年   681篇
  2011年   688篇
  2010年   383篇
  2009年   353篇
  2008年   667篇
  2007年   740篇
  2006年   690篇
  2005年   703篇
  2004年   678篇
  2003年   685篇
  2002年   682篇
  2001年   608篇
  2000年   640篇
  1999年   557篇
  1998年   253篇
  1997年   216篇
  1996年   231篇
  1995年   202篇
  1994年   225篇
  1993年   198篇
  1992年   454篇
  1991年   426篇
  1990年   425篇
  1989年   374篇
  1988年   357篇
  1987年   322篇
  1986年   323篇
  1985年   347篇
  1984年   272篇
  1983年   209篇
  1982年   166篇
  1981年   174篇
  1980年   137篇
  1979年   235篇
  1978年   176篇
  1977年   192篇
  1976年   149篇
  1975年   164篇
  1974年   202篇
  1973年   204篇
  1972年   135篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
A cohort of 1163 pregnant women in two small towns in South Wales, UK, was identified and followed until the children born to them were five years of age. Growth in these children is described and a number of determinants identified. Social-class differences were very small at birth but differences in height became clear by the age of two years and in head circumference before this. In height the differences were largely accounted for by greater growth in social class I, but there was a gradient in head circumference throughout all the social classes. The social class effects gradually increased as the children became older. Parity of the mothers had a small effect on size at birth but age of the mother had no effect once parity was allowed for. Data on illnesses in the children were collected but no effect on growth could be detected. By far the most important determinant of growth which could be controlled is maternal smoking. About 40% of the women smoked, about 17% heavily (15 or more cigarettes per day) and the prevalence of smoking altered little during pregnancy. There was a graded effect of smoking on growth up to a 9% deficit in birth-weight, a 2% deficit in length at birth and a 1.5% deficit in head circumference in the babies born to the mothers who smoked most heavily (25 or more cigarettes per day) compared with non-smokers. There effects decreased with age but there were still residual effects at age five years.  相似文献   
2.
3.
4.
We thank Coceani and L'Abbate for their comments on our paper.We concur that ‘pathophysiology cannot be inferred fromcoronary lumenography alone’, and this was one of thekey motivations in conducting the present study.  相似文献   
5.
The second documented case of renal aspergilloma due to Aspergillusflavus is presented. The merits of the medical therapy thatfailed are discussed. Pathological examination showed a nidusof aspergillus around suture material persisting from a pyelolithotomyoperation 2 years before in India. We argue that this was thereason for the failure of the medical therapy. This is the firstcase of its kind reported.  相似文献   
6.
BACKGROUND: The demand for renal replacement therapy (RRT) in England has risen steadily, although from a lower base than many other developed countries. Predicting the future demand for RRT and the impact of factors such as the acceptance rate, transplant supply and patient survival, is required in order to inform the planning of such services. METHODS: A discrete event simulation model estimates the future demand for RRT in England in 2010 for a range of scenarios. The model uses current prevalence and current and projected future acceptance rates, survival rates and the transitions between modalities to predict future patient numbers. National population and mortality data, published literature and data from the UK Renal Registry and UK Transplant, are used to estimate unmet need for RRT, the impact of changing demography and incidence of Type 2 diabetes, patient haemodialysis (HD) survival and transplant supply. RESULTS: By 2010 the predicted prevalence will have increased from about 30,000 in 2000 to between 42 and 51,000 (900-1000 p.m.p.), an average annual growth of 4.5-6%. Changing transplant supply has a small effect on overall numbers but changes the proportion of patients with functioning graft by up to 8%. Even with an optimistic increase in transplant supply (11% p.a. for 5 years), numbers on HD will continue to rise substantially, especially in the elderly. The factors most influencing future patient numbers are the acceptance rate and dialysis survival. CONCLUSION: This model predicts a substantial growth in the RRT population to 2010 to a rate approaching 1000 p.m.p., particularly in the elderly and those on HD, with a steady state not being reached for at least 25 years.  相似文献   
7.
    
We present our comments on the above article.  相似文献   
8.
9.
10.
OBJECTIVE--To compare the assessment of severity of coronary artery stenosis by the conventional pathology methods with a method designed to resemble quantitative angiography. DESIGN--31 human hearts harvested at necropsy were fixed by perfusion of the aortic root with 10% formol saline at 120 mm Hg for 24 hours. The right coronary and left anterior descending coronary arteries were transversely sliced every 2 mm and the absolute lumen dimensions plotted against the distance from the coronary ostium. Stenosis figures were calculated by comparing the lumen diameter with the lumen diameters in adjacent normal arterial segments in a manner identical to that used in angiographic measurement. The coronary artery segments were then processed histologically. Stenosis was then remeasured by comparing the lumen diameter with the diameter of the vessel within the internal elastic lamina identified by elastic van Gieson staining. RESULTS--Compared with the method that was analogous to angiography, the pathology method used on histological slides overestimated the degree of stenosis by 25-30%. The lack of concordance between the methods was not a function of the severity of the stenosis. CONCLUSION--When they read necropsy reports in which the severity of coronary artery stenosis is assessed cardiologists should be aware of the discrepancy between clinical and pathological methods.  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