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   1721909篇
  免费   133807篇
  国内免费   4102篇
耳鼻咽喉   24263篇
儿科学   55029篇
妇产科学   49653篇
基础医学   249756篇
口腔科学   49825篇
临床医学   154235篇
内科学   328685篇
皮肤病学   37219篇
神经病学   138133篇
特种医学   67678篇
外国民族医学   462篇
外科学   262790篇
综合类   44870篇
现状与发展   2篇
一般理论   629篇
预防医学   135683篇
眼科学   40794篇
药学   126581篇
  3篇
中国医学   3361篇
肿瘤学   90167篇
  2018年   16646篇
  2016年   14865篇
  2015年   17045篇
  2014年   23708篇
  2013年   36343篇
  2012年   48249篇
  2011年   51064篇
  2010年   30291篇
  2009年   28535篇
  2008年   47925篇
  2007年   51481篇
  2006年   51734篇
  2005年   50198篇
  2004年   49015篇
  2003年   47091篇
  2002年   45584篇
  2001年   75029篇
  2000年   76685篇
  1999年   64676篇
  1998年   18930篇
  1997年   17287篇
  1996年   17140篇
  1995年   16311篇
  1994年   15477篇
  1993年   14504篇
  1992年   53571篇
  1991年   52514篇
  1990年   51605篇
  1989年   49873篇
  1988年   45987篇
  1987年   45916篇
  1986年   43148篇
  1985年   41925篇
  1984年   31935篇
  1983年   27332篇
  1982年   16755篇
  1981年   15310篇
  1979年   31056篇
  1978年   22442篇
  1977年   18937篇
  1976年   17746篇
  1975年   18886篇
  1974年   23201篇
  1973年   22352篇
  1972年   20864篇
  1971年   19401篇
  1970年   18332篇
  1969年   17465篇
  1968年   15935篇
  1967年   14489篇
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
71.
72.
73.
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   
74.
It has long been noted that tetanus is rare in leprosy patients. Five cases of tetanus are reported in leprosy patients in Addis Ababa, Ethiopia. Although natural immunity to tetanus occurs and this appears to be higher in leprosy patients than in the general population, it is not completely protective. Further research on the relationship between tetanus and leprosy is indicated. Although firm epidemiologic data are lacking, it is prudent to give leprosy patients at least one dose of tetanus toxoid.  相似文献   
75.
The use of additional epidural sympathetic block during and after microvascular surgery in the lower extremities to prevent vasospasm is generally agreed on. However, a significant fall in the perfusion rate of the transplants was seen after application of bupivacaine (Marcain) via the epidural catheter. This effect has, to our knowledge, not been described before and is probably caused by the sympathectomy effect of this type of analgesia.  相似文献   
76.
Neglected tears of the patellar tendon due to loss of active extension remain a difficult therapeutic endeavor. The goals in the approach to this diagnosis include restoration of both structural and functional integrity of the extensor mechanism. A procedure has been developed utilizing Z-shortening of the patellar tendon, Z-lengthening of the quadriceps tendon, and the semitendinosis gracilis as a biologic splint. This technique allows establishment of preoperative goals, including restoration of the muscle-tendon complex in its anatomic position, restoration of quadriceps function, preservation of vascularity of the reconstructed tendon, and splinting of the patellar tendon. This reconstruction allows early mobilization and rehabilitation.  相似文献   
77.
Computed tomography (CT) is currently the imaging modality of choice for assessing the morphology of the adrenal glands in adult patients. Much useful information can be gained using CT in disease processes which primarily involve one or both of the adrenal glands, such as adenomas, as well as in entities which secondarily affect the adrenals, such as pituitary or metastatic disease. The size and configuration of the glands can be readily determined, and masses may be detected. We discuss CT of normal and abnormal adrenal glands with sonographic (US) and pathological correlation, when available. Entities which may mimic adrenal abnormalities are emphasized. Relative advantages of US over CT in the pediatric patient are discussed.  相似文献   
78.
Membrane-bound CD14 acts as a receptor for lipopolysaccharide (LPS) on monocytes/macrophages and neutrophils. Studies have suggested that the activation of monocytes/macrophages by the binding of LPS to membrane-bound CD14 may require the association of a signal-transducing molecule with membrane-bound CD14. The observation that non-CD14 expressing cells, such as endothelial cells, can nevertheless be activated by a complex of LPS and a soluble form of CD14 (sCD14) suggests that the receptor for this complex may be identical to the signal transducing molecule associated with membrane-bound CD14. The studies described show that two CD14-specific MoAb are able to block the LPS-induced activation of endothelial cells but do not affect the response of monocytes to LPS. This suggests that the interaction of the sCD14:LPS complex with endothelial cells is distinct from the interaction of membrane-bound CD14 with its putative signal-transducing molecule.  相似文献   
79.
Most prosthetic joint infections (PJI) are due to wound contamination at the time of surgery. Some infections occur due to the hematogenous spread of bacteria from distant sites of infection. A review of the literature fails to associate PJI with transient bacteremias from invasive dental procedures. Several authors have described conditions which, they believe, render patients with prosthetic joints more at risk for infection. Prosthetic joint patients with these "high risk" conditions have the same types of infecting organisms as other patients with PJI. This indicates that the infecting bacteria are from wound contamination or distant sites of infection and not related to dental procedure bacteremias. Based on this review, antibiotic prophylaxis is not indicated for patients with prosthetic joints when receiving invasive dental procedures, since there is no proven benefit and there are known risks involved with the use of antibiotics. However, the American Dental Association (ADA) and the American Academy of Orthopaedic Surgeons (AAOS), in an advisory statement, suggest prophylaxis for "high risk" patients. The ADA and AAOS recommend a single dose of amoxicillin, cephradine, or clindamycin when prophylaxis is selected. The dentist is ultimately responsible for making treatment recommendations for his or her patients.  相似文献   
80.
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