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   205683篇
  免费   4824篇
  国内免费   457篇
耳鼻咽喉   2807篇
儿科学   7919篇
妇产科学   6311篇
基础医学   26466篇
口腔科学   5859篇
临床医学   17145篇
内科学   36660篇
皮肤病学   4642篇
神经病学   12664篇
特种医学   10798篇
外国民族医学   97篇
外科学   29967篇
综合类   1369篇
一般理论   26篇
预防医学   18351篇
眼科学   4444篇
药学   14246篇
  3篇
中国医学   161篇
肿瘤学   11029篇
  2021年   448篇
  2018年   3901篇
  2017年   4102篇
  2016年   3470篇
  2015年   5160篇
  2014年   4702篇
  2013年   3967篇
  2012年   10771篇
  2011年   5662篇
  2010年   2622篇
  2009年   4237篇
  2008年   2803篇
  2007年   3581篇
  2006年   3785篇
  2005年   11837篇
  2004年   13307篇
  2003年   8825篇
  2002年   3978篇
  2001年   4427篇
  2000年   1728篇
  1999年   5911篇
  1998年   618篇
  1992年   6910篇
  1991年   7126篇
  1990年   7360篇
  1989年   6957篇
  1988年   6485篇
  1987年   6259篇
  1986年   5979篇
  1985年   5253篇
  1984年   3595篇
  1983年   2927篇
  1982年   1018篇
  1981年   792篇
  1980年   843篇
  1979年   3842篇
  1978年   2367篇
  1977年   1783篇
  1976年   1560篇
  1975年   2479篇
  1974年   3111篇
  1973年   2746篇
  1972年   2760篇
  1971年   2747篇
  1970年   2558篇
  1969年   2470篇
  1968年   2242篇
  1967年   2167篇
  1966年   1900篇
  1965年   1131篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
In Part 1 of this study, the mathematical relations between micro and macro measures of effect were derived. The formulas thus obtained can be used for cross level comparisons of findings concerning the effect of some specific risk factor on, eg, mortality. The approach is illustrated by means of an empirical example relating to the association between unemployment and suicide. This relationship is estimated on micro data as well as on aggregate time series data. The findings from the two levels are fairly consistent.  相似文献   
992.
993.
Issuing from the international level of the psychosomatic medicine a critical estimation of the achievements in the GDR is done. The chances for a higher degree of cooperation resulting from the organisational structure of our public health service are illustrated and with the attempt of a preliminary definition for the psychosomatic medicine at the same time a graduated way of education is indicated. The cogent reasons for the acquisition of knowledge and qualification for results and trends of psychosocial medicine derive themselves from the changed development of morbidity in the developed industrial country GDR and immediately need aimed integration.  相似文献   
994.
Ectopic bone formation after total hip arthroplasty   总被引:2,自引:0,他引:2  
Ectopic bone formation (EBF) is a well-known complication of total hip arthroplasty (THA). The etiology and pathogenesis are still obscure. An analysis of 119 consecutive patients with 129 primary THAs was performed to identify factors predisposing to ectopic bone formation, its frequency, and its effect on the results. Gender (male) and the duration of the operative procedure were statistically significant factors in the development of ectopic bone, which occurred in 63% of hips. The effect of grade III EBF on THA was a limited range of movement. Both local and systemic factors seem to play a role in the development of ectopic bone. Gentle handling of tissues may be important if the rate of ectopic bone is to be reduced.  相似文献   
995.
The influence on macrocirculatory parameters by ultraviolet irradiation of autologous venous blood was controlled in 5 patients. The ultraviolet irradiation did not show any positive effect on different sizes of blood supply. Therefore, as a conclusion the recommendation is given in every case at first to attempt the possibilities of a reconstruction of the arterial vascular system before the use of this therapy.  相似文献   
996.
We made a retrospective analysis with regard to the bacteriology and to the therapy of all patients with pleural empyema who were treated in the district lung hospital from 1. 1. 1982-31. 12. 1986. 92 patients had a non-specific empyema, only 3 patients had a specific empyema. All patients were aspirated repeatedly with physiological saline solution instillation and antimicrobic drug instillation in the pleural cavity. This daily aspiration and lavage was successfully in 65 patients. This method was ineffective in 30 patients. We treated 7 patients of this group by the closed drainage (rubber-tube drain), in 4 patients successfully. 3 patients had to be treated by a surgical operation. An insufficient obliteration of the cavity of empyema occurred also in 23 patients of this group. A systematic daily aspiration for a longer time led to regression of the cavity in 4 cases, whereas a surgical operation was necessary in 19 patients. We consider the daily aspiration and lavage as an effective method in patients in early acute stages of empyema.  相似文献   
997.
Disturbances in the metabolism of purines and pyrimidines in neurologically affected patients can be reflected by aberrant concentrations of nucleosides and nucleobases in cerebrospinal fluid (CSF). However, normal values, especially for children at different ages, are lacking. We collected 1000 specimens of CSF from subjects ranging in age from newborn to 18 years, who were undergoing a diagnostic lumbar puncture for several clinical indications. Of these, 78 samples could be used retrospectively as a reference according to our criteria. The analyses were performed with a modified HPLC procedure. None of the substances shows age-dependency except uridine and uric acid. Uridine increases with age, and uric acid increases with age in boys older than 12 years.  相似文献   
998.
Faecal lipids in familial adenomatosis coli   总被引:1,自引:0,他引:1  
Faecal sterols and bile acids from six patients with familial adenomatosis coli (FPC) and 61 healthy men were analysed preoperatively. Faecal concentrations and secretion of neutral sterols, plant sterols, and degradation products of cholesterol were identical in the two groups. No increase was found in the faecal bile acid excretion, and the distribution of individual bile acids was normal in FPC. The results suggest that the development of adenomas in FPC is not associated with abnormal cholesterol and bile acid excretion.  相似文献   
999.
There are no systematic and complex investigations regarding the hemorheologic action of the betablockers propranolol and talinolol. The results on the other ones are contradictory. On the basis of a critical survey of the literature, in-vitro-experiments and studies in animals (rats) and humans may conclude that there are no remarkable deteriorations of rheological parameters in the therapeutic dose range. This is valid for diseases only where the haemodynamic regulation doesn't prevail.  相似文献   
1000.
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