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   1341546篇
  免费   112777篇
  国内免费   6372篇
耳鼻咽喉   16725篇
儿科学   43092篇
妇产科学   36613篇
基础医学   183944篇
口腔科学   36304篇
临床医学   121097篇
内科学   279093篇
皮肤病学   31964篇
神经病学   110782篇
特种医学   55656篇
外国民族医学   274篇
外科学   210603篇
综合类   31606篇
现状与发展   2篇
一般理论   419篇
预防医学   107131篇
眼科学   28112篇
药学   94041篇
  5篇
中国医学   2230篇
肿瘤学   71002篇
  2018年   13446篇
  2017年   10687篇
  2016年   12841篇
  2015年   14353篇
  2014年   20049篇
  2013年   29856篇
  2012年   36422篇
  2011年   39086篇
  2010年   24485篇
  2009年   23999篇
  2008年   36542篇
  2007年   38964篇
  2006年   40095篇
  2005年   38699篇
  2004年   36908篇
  2003年   35977篇
  2002年   33973篇
  2001年   66141篇
  2000年   67984篇
  1999年   56646篇
  1998年   16747篇
  1997年   15032篇
  1996年   16028篇
  1995年   16255篇
  1994年   15112篇
  1993年   14176篇
  1992年   47126篇
  1991年   45775篇
  1990年   43988篇
  1989年   41839篇
  1988年   38773篇
  1987年   38100篇
  1986年   35883篇
  1985年   34651篇
  1984年   26376篇
  1983年   22128篇
  1982年   13853篇
  1981年   12457篇
  1980年   11729篇
  1979年   23565篇
  1978年   17078篇
  1977年   14395篇
  1976年   13195篇
  1975年   13732篇
  1974年   16105篇
  1973年   15425篇
  1972年   14194篇
  1971年   13058篇
  1970年   11897篇
  1969年   11119篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
122.
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   
123.
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   
124.
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   
125.
Case report 506   总被引:1,自引:0,他引:1  
  相似文献   
126.
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   
127.
128.
129.
The number and complexity of available tests and therapies is expanding and financial resources are shrinking. Clinicians must now consider how to give the best care while limiting health expenses. Decision analysis is a tool used to guide clinicians in the practice of medicine, and to supplement and enhance intuitive decision making based on clinical experience.  相似文献   
130.
The role of caffeine or coffee in causing or promoting the incidence of serious disease is equivocal. Two design factors may account for the discrepancies in reported findings on the effects of coffee drinking: (a) imprecision of measurement and (b) confounding variables. A study of 2,714 white U.S. adults disclosed that, of 32 risk factors analyzed by linear and logistic regression, only sex and cigarette smoking were found to be important potential confounders of caffeine and coffee intake. Partial R2 values of the other 30 risk factors were relatively small and were inconsistent for each sex. It is unlikely that any of these factors could explain any of the reported associations between caffeine or coffee consumption and certain diseases. However, certain weak associations with caffeine or coffee intake should be included in the study design when they are known to be risk factors of a disease under investigation. These factors for men are dietary fat intake, vitamin C intake, and body mass index; and for women are vitamin use, alcohol intake, stress, and perceived health status.  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