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   1516244篇
  免费   125863篇
  国内免费   6813篇
耳鼻咽喉   18766篇
儿科学   47763篇
妇产科学   40277篇
基础医学   207235篇
口腔科学   40144篇
临床医学   138353篇
内科学   314989篇
皮肤病学   34190篇
神经病学   128094篇
特种医学   61092篇
外国民族医学   287篇
外科学   236977篇
综合类   34503篇
现状与发展   4篇
一般理论   667篇
预防医学   123553篇
眼科学   31897篇
药学   106297篇
  6篇
中国医学   2543篇
肿瘤学   81283篇
  2019年   11837篇
  2018年   16757篇
  2017年   13352篇
  2016年   15672篇
  2015年   17718篇
  2014年   25017篇
  2013年   37207篇
  2012年   47325篇
  2011年   50931篇
  2010年   31264篇
  2009年   30071篇
  2008年   47933篇
  2007年   51126篇
  2006年   51736篇
  2005年   50703篇
  2004年   48524篇
  2003年   46778篇
  2002年   44358篇
  2001年   67654篇
  2000年   69182篇
  1999年   58361篇
  1998年   19028篇
  1997年   17025篇
  1996年   17857篇
  1995年   17798篇
  1994年   16524篇
  1993年   15484篇
  1992年   48148篇
  1991年   46716篇
  1990年   44852篇
  1989年   42634篇
  1988年   39616篇
  1987年   38927篇
  1986年   36723篇
  1985年   35523篇
  1984年   27602篇
  1983年   23345篇
  1982年   15379篇
  1981年   13838篇
  1980年   13046篇
  1979年   24221篇
  1978年   17878篇
  1977年   15162篇
  1976年   13879篇
  1975年   14298篇
  1974年   16657篇
  1973年   15904篇
  1972年   14550篇
  1971年   13342篇
  1970年   12163篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
The medical world would seem to be one of increasing technology and shrinking financial resources. New tests and therapies constantly appear on the market. Most have been examined for efficacy and side effects. The real question is: where does the new test or therapy fit in with all previous products? Decision analysis is a mathematical tool adapted to assess the relative cost-effectiveness of complex diagnostic and therapeutic strategies.  相似文献   
132.
Herpes zoster probably occurs more often than generally thought. Since it produces a radicular distribution of pain, it should be included in the differential diagnosis of radiculopathy. A case is presented in which evaluating the radicular low back pain before the characteristic rash appears was misleading. Careful history-taking concerning the exact nature of the pain and sensory changes is needed to differentiate between zoster and radiculopathy, if no rash is evident.  相似文献   
133.
134.
Eledoisin has been tried as a possible treatment for dry eye based on the hypothesis that it pharmacologically stimulates tear secretion when topically applied to the eye. To determine if topically applied eledoisin pharmacologically stimulates orbital lacrimal secretion, the orbital lacrimal gland excretory duct of normal rabbits was cannulated, and eledoisin was applied topically with and without prior administration of proparacaine. To determine if topically applied eledoisin stimulated accessory lacrimal gland secretion, isotonic buffer with and without eledoisin was tested in a rabbit model with only accessory lacrimal tissue remaining after the administration of proparacaine. Topically applied eledoisin did not pharmacologically stimulate lacrimal secretion but rather increased lacrimal gland secretion only in non-anesthetized eyes through a sensory reflex mechanism that is blocked by proparacaine.  相似文献   
135.
Chorioretinal folds have been reported as a result of many intraocular and extraocular inflammatory processes or tumors. Visual loss is usually secondary to a combination of the underlying process and chorioretinal folds involving the macula. We report a patient who developed decreased vision, metamorphopsia, chorioretinal folds, and a lamellar macular hole secondary to global compression by a bone fragment. The chorioretinal folds regressed and his vision stabilized following surgical decompression. Chorioretinal folds and lamellar macular hold formation are previously unrecognized complications of reconstructive craniofacial surgery.  相似文献   
136.
Omeprazole is a member of a new class of substituted benzimidazoles. These agents inhibit the proton pump in the gastric parietal cell, blocking the final step in the gastric acid secretory pathway. Omeprazole has been investigated for the treatment of gastric ulcer, duodenal ulcer, gastroesophageal reflux, and various hypersecretory states. The prolonged inhibition of gastric acid secretion allows for once-daily dosing in patients with peptic ulcer disease and gastroesophageal reflux, and once- or twice-daily dosing in patients with Zollinger-Ellison syndrome. Compared with currently available therapies, omeprazole is well tolerated and demonstrates a more rapid ulcer healing rate. It is superior to conventional therapies in the treatment of Zollinger-Ellison syndrome. Side effects are infrequent when the drug is used for the short-term management of ulcers.  相似文献   
137.
Case report 506   总被引:1,自引:0,他引:1  
  相似文献   
138.
We compared the effects of alpha 2- and beta-adrenoreceptor blockade on the central actions of catecholamines and metabolites of alpha-methyldihydroxyphenylalanine, epinephrine, alpha-methylnorepinephrine, and alpha-methylepinephrine were studied. I.c.v. and nucleus tractus solitarii (NTS) injections were carried out under anesthesia. Following i.c.v. injection, both epinephrine and methylepinephrine rapidly reduced blood pressure and heart rate, but the effects of methylnorepinephrine occurred somewhat later. Following microinjection into the nucleus of the solitary tract, epinephrine, methylepinephrine, and methylnorepinephrine all caused hypotension and bradycardia. The hypotensive effects of all 3 amines in the NTS were attenuated in additive fashion by yohimbine, an alpha 2 adrenoreceptor antagonist, and timolol, a beta-adrenoreceptor antagonist, whereas only yohimbine attenuated the bradycardia. The combination of yohimbine and timolol abolished the effects of the amines. These data suggest that in the NTS both alpha 2 and beta adrenoreceptor stimulation contribute to the hypotensive effects of these amines, but that only alpha 2 adrenoreceptors are principally involved in the heart rate response.  相似文献   
139.
140.
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