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   1264127篇
  免费   94847篇
  国内免费   1587篇
耳鼻咽喉   16313篇
儿科学   41003篇
妇产科学   34947篇
基础医学   189433篇
口腔科学   34734篇
临床医学   117775篇
内科学   247977篇
皮肤病学   27279篇
神经病学   101860篇
特种医学   46764篇
外国民族医学   265篇
外科学   178600篇
综合类   25749篇
现状与发展   3篇
一般理论   568篇
预防医学   104662篇
眼科学   28045篇
药学   92595篇
  7篇
中国医学   2022篇
肿瘤学   69960篇
  2018年   13539篇
  2017年   10397篇
  2016年   11331篇
  2015年   13083篇
  2014年   18011篇
  2013年   27500篇
  2012年   37587篇
  2011年   39981篇
  2010年   23059篇
  2009年   22259篇
  2008年   37765篇
  2007年   40393篇
  2006年   39978篇
  2005年   39109篇
  2004年   37552篇
  2003年   35967篇
  2002年   34872篇
  2001年   56038篇
  2000年   57067篇
  1999年   48107篇
  1998年   13401篇
  1997年   12225篇
  1996年   12651篇
  1995年   11924篇
  1994年   11113篇
  1993年   10403篇
  1992年   38202篇
  1991年   37679篇
  1990年   36462篇
  1989年   35269篇
  1988年   32698篇
  1987年   32032篇
  1986年   30524篇
  1985年   28786篇
  1984年   21941篇
  1983年   19194篇
  1982年   11365篇
  1981年   10321篇
  1979年   20944篇
  1978年   15393篇
  1977年   12790篇
  1976年   11845篇
  1975年   12811篇
  1974年   15588篇
  1973年   15362篇
  1972年   14512篇
  1971年   13552篇
  1970年   12786篇
  1969年   12065篇
  1968年   11229篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
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   
64.
65.
APACHE II score and abdominal sepsis. A prospective study   总被引:7,自引:0,他引:7  
Therapeutic trials for intra-abdominal sepsis require pretreatment stratification; physiologic scoring has been recently proposed for this purpose. We have prospectively tested the validity of one such scoring system, namely, the Acute Physiology and Chronic Health Evaluation (APACHE II). As part of a larger database, we correlated APACHE II scores with mortality in 100 patients hospitalized for generalized peritonitis or abdominal abscess. Use of steroids was recorded because of our suspicion that steroids increase mortality but blunt the physiologic response to sepsis. Thirty-one patients died, including 12 of 19 patients receiving steroids. Stepwise discriminant analysis revealed that the APACHE II score and steroid use were each independently associated with the rate of mortality. We report a prospective validation of pretreatment APACHE II scoring in abdominal sepsis. Steroid use is an independent risk factor.  相似文献   
66.
The present study demonstrates that alcohol-induced memory impairment can be attenuated by pretreatment with an oral tryptophan supplementation. These results provide support for the role of a brain serotonin deficit in this impairment and highlight the impact a dietary manipulation can have on a complex behavioral process.  相似文献   
67.
68.
The Dundee Memory Clinic was established in 1991. This paper reviews the diagnosis of the first 150 attenders and compares the findings with those of other memory clinics.  相似文献   
69.
This study examines the relationships between patient characteristics and surrogate decision maker characteristics on surrogates' preferences for life-sustaining treatments. Caucasian and African-American caregivers and noncaregivers (n=110) responded to a vignette involving a medical crisis in a hospitalized older man who suffered cardiac arrest, one of the most common causes of death among older Americans. This man was described as either a cognitively intact or moderately demented family member. Participants made decisions regarding cardiopulmonary resuscitation (CPR), CPR and ventilation, and CPR and tube feeding. Analyses followed a 2 (cognitive status) 2 (caregiving status) 2 (racial background) analysis of covariance design, with education and income used as covariates. In general, participants were less likely to initiate life-sustaining treatments in demented patients. Caucasian caregivers were less likely to initiate CPR and ventilation and CPR and tube feeding. Results indicate that characteristics of the patient and the interplay between cultural issues and experience with caregiving affect surrogate judgements regarding life-sustaining treatments.  相似文献   
70.
Choristomas, masses of normal tissues in aberrant locations, contain smooth muscle fibers and fibrous tissues. We describe the MR imaging features of two choristomas located in the internal auditory canals and arising from the facial and vestibulocochlear nerves. Both lesions enhanced with contrast material. In one case, enhancement was seen in the geniculate ganglion and greater superficial petrosal nerve. In the other, a medial component enhanced less than the lateral component did.  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