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   1682944篇
  免费   118820篇
  国内免费   2536篇
耳鼻咽喉   23978篇
儿科学   55773篇
妇产科学   48704篇
基础医学   252383篇
口腔科学   47670篇
临床医学   143249篇
内科学   324212篇
皮肤病学   36428篇
神经病学   128356篇
特种医学   64653篇
外国民族医学   426篇
外科学   258322篇
综合类   33671篇
现状与发展   1篇
一般理论   407篇
预防医学   124048篇
眼科学   39141篇
药学   129289篇
  1篇
中国医学   3238篇
肿瘤学   90350篇
  2018年   15634篇
  2015年   15134篇
  2014年   20877篇
  2013年   31991篇
  2012年   43750篇
  2011年   47211篇
  2010年   27806篇
  2009年   26233篇
  2008年   45667篇
  2007年   49437篇
  2006年   50233篇
  2005年   49061篇
  2004年   47364篇
  2003年   45846篇
  2002年   45269篇
  2001年   76462篇
  2000年   78789篇
  1999年   66474篇
  1998年   18509篇
  1997年   16464篇
  1996年   16948篇
  1995年   15929篇
  1994年   15054篇
  1993年   14072篇
  1992年   53059篇
  1991年   52926篇
  1990年   52581篇
  1989年   50959篇
  1988年   47470篇
  1987年   46576篇
  1986年   44308篇
  1985年   42362篇
  1984年   31462篇
  1983年   27306篇
  1982年   15948篇
  1981年   14280篇
  1979年   30147篇
  1978年   21383篇
  1977年   18372篇
  1976年   17466篇
  1975年   19343篇
  1974年   22878篇
  1973年   21920篇
  1972年   20956篇
  1971年   19646篇
  1970年   18325篇
  1969年   17675篇
  1968年   16612篇
  1967年   14702篇
  1966年   13449篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.
The prevalence of heavy alcohol consumption is a major problem of increasing proportions throughout the world. Although alcohol sensitizing drugs and more recently serotonin uptake inhibitors are drug interventions with some following, their long term beneficial consequences have yet to be demonstrated. In recent years, we have demonstrated that manipulating activity in the renin-angiotensin system will dramatically alter voluntary alcohol consumption in rats. Based on these findings, the present study evaluated the ability of a class of drugs known as the angiotensin converting enzyme inhibitors to reduce voluntary alcohol drinking in laboratory animals. These drugs prevent the conversion of angiotensin I to angiotensin II. They have been licensed for use in Europe and North America and are indicated in the treatment of hypertension. Our experiments showed that both captopril (Capoten, Squibb) and enalapril (Vasotec, Merck Sharpe & Dohme) can reduce alcohol drinking in both normotensive and hypertensive animals regardless of whether the pattern of intake is in a bout or of a less exaggerated nature. Furthermore, this change in alcohol intake can occur without concomitant changes in blood pressure, plasma renin activity, overall fluid balance, or the distribution and metabolism of alcohol. Taken together these findings suggest that the angiotensin converting enzyme inhibitors should be evaluated in a clinical setting for they may prove to be a useful new treatment or treatment adjunct for alcohol abuse in humans.  相似文献   
104.
105.
Pulmonary valve insertion during reoperation for tetralogy of Fallot   总被引:1,自引:0,他引:1  
Our experience with pulmonary valve insertion during reoperation for residual lesions after initial open repair of tetralogy of Fallot in 15 patients is reported. Preoperatively, 14 patients were in moderate to severe congestive heart failure, and all 15 had decreased right ventricular (RV) function at cardiac catheterization. All 15 patients had pulmonary insufficiency but not as an isolated finding. The most common residual lesions encountered were ventricular septal defect in 9, tricuspid insufficiency in 11, and peripheral pulmonary arterial stenosis in 6. Tissue valves were inserted in all patients. Mean peak RV-left ventricular pressure ratio measured in the operating room decreased from 0.61 +/- 0.10 (+/- the standard deviation) to 0.47 +/- 0.17 (p less than 0.05). There were no operative deaths. At follow-up (mean, 33 months), all but 1 patient were in New York Heart Association Class I or II. Pulmonary valve insertion should be considered during reoperation for tetralogy of Fallot when pulmonary insufficiency and RV failure are present.  相似文献   
106.
107.
108.
Median cervical cysts are congenital anomalies arising from remaining thyroglossal duct epithelium. A major problem in the surgical treatment of these cysts is the high frequency of recurrence. Embryonic considerations indicate an important causal role for the hyoid bone in these recurrences. We studied the relationship between operative techniques and the number of recurrences in 36 patients treated in our hospital. Fourteen patients sent from other hospitals had a recurrent fistula; in thirteen cases the hyoid bone was still in place. All patients who had the central part of the hyoid bone excised were cured. In 14 patients without adequate excisions of the hyoid bone we found four recurrences. To prevent recurrence a total excision of thyroglossal duct epithelium is necessary.  相似文献   
109.
Eighty-eight patients with blunt renal trauma were examined sonographically. Rupture of the kidney was diagnosed in 41 patients and contusion of the kidney in 45. The correlation between operative findings, sonography and urography showed positive sonographic findings to be correct in all patients with rupture of the kidney. In 4 patients with normal sonograms, the diagnosis of a contusion was based on the urographic results. Three patients underwent angiography. An intimal lesion was seen in 2 and a tear of the renal artery in 1. The results of our investigation suggest that sonography should be applied in the first place in the evaluation of blunt renal trauma. It is the investigation of choice during follow-up after surgical as well as conservative therapy.  相似文献   
110.
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