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   1706011篇
  免费   124788篇
  国内免费   4246篇
耳鼻咽喉   21825篇
儿科学   55784篇
妇产科学   46245篇
基础医学   243399篇
口腔科学   48930篇
临床医学   152413篇
内科学   334727篇
皮肤病学   38751篇
神经病学   131577篇
特种医学   64150篇
外国民族医学   243篇
外科学   257965篇
综合类   40851篇
现状与发展   6篇
一般理论   531篇
预防医学   125182篇
眼科学   40456篇
药学   125020篇
  18篇
中国医学   5145篇
肿瘤学   101827篇
  2021年   13228篇
  2019年   13866篇
  2018年   20305篇
  2017年   15560篇
  2016年   16929篇
  2015年   19356篇
  2014年   26697篇
  2013年   38527篇
  2012年   53380篇
  2011年   56131篇
  2010年   33277篇
  2009年   31104篇
  2008年   51999篇
  2007年   55296篇
  2006年   55715篇
  2005年   52901篇
  2004年   51201篇
  2003年   48716篇
  2002年   46866篇
  2001年   92160篇
  2000年   93822篇
  1999年   77099篇
  1998年   19815篇
  1997年   17336篇
  1996年   17448篇
  1995年   16803篇
  1994年   15344篇
  1993年   14120篇
  1992年   57438篇
  1991年   55324篇
  1990年   53032篇
  1989年   50799篇
  1988年   46180篇
  1987年   44978篇
  1986年   42282篇
  1985年   40023篇
  1984年   29403篇
  1983年   24948篇
  1982年   13953篇
  1979年   25587篇
  1978年   17629篇
  1977年   14987篇
  1976年   13932篇
  1975年   14601篇
  1974年   17671篇
  1973年   16981篇
  1972年   15716篇
  1971年   14492篇
  1970年   13480篇
  1969年   12554篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Two patients with angiolymphoid hyperplasia with eosinophilia isolated to the orbit had eyelid swelling, a superior orbital mass, and histories of intermittent obstructive airway disease. One patient later developed a transient peripheral blood eosinophilia as high as 36%. One lesion recurred 38 months postoperatively and responded to systemic corticosteroid therapy.  相似文献   
992.
alpha 1- and beta-adrenoceptors were studied ex vivo in the brains of rats receiving repeated daily treatment with the standard antidepressant imipramine or the atypical antidepressant S-adenosyl-L-methionine (SAM), which has minimal effects on monoamine reuptake or turnover. Consistent with past studies, a decrease in the density of beta receptors at three weeks and an increase in the affinity of alpha 1 receptors for the agonist phenylephrine at one week of treatment was observed with imipramine. By comparison, an increase in the density of beta receptors and a decrease in the affinity of alpha 1 receptors for phenylephrine was observed at one week of treatment with SAM. These changes were no longer apparent at three weeks of treatment. The results suggest that treatment with SAM does lead to changes in adrenergic neurotransmission, but that down regulation of beta receptors or increased agonist affinity of alpha 1 receptors may not be necessary for the production of antidepressant effects.  相似文献   
993.
Several substances can interfere with microtubular function eg. colchicine. Melatonin, a hormone secreted by the pineal gland has similar effects as colchicine on microtubules. In this study melatonin levels were determined in both plasma and seminal plasma of patients with good or impaired motility and forward progression. There was no statistically significant difference between the mean plasma and seminal plasma values of patients with good or impaired motility and forward progression. There was no correlation between seminal plasma melatonin and impaired motility or any other semen parameter. There was also no correlation between plasma and seminal plasma concentrations of melatonin. High seminal plasma melatonin concentrations were not necessarily associated with impaired sperm motility. From these it is concluded that seminal plasma melatonin plays no important role in sperm motility.  相似文献   
994.
Repeated administration of the antimanic drug lithium (4 mEq/kg/day for 2, 4 or 6 days, i.p.) to rats produced a progressive decline and eventual depletion of dynorphin-A (1-8) (DYN) concentration whereas Met5-enkephalin (ENK) was only marginally decreased in the neurointermediate lobe of the pituitary (NIL). Administration of a neuroleptic haloperidol neither affected ENK and DYN levels nor influenced lithium-induced changes. The study reveals that lithium produces a preferential perturbation in the dynorphin system relative to the enkephalin system. These results taken together with other evidence, indicate that dynorphin is possibly coreleased with vasopressin following lithium administration and provide a pharmacological support to the previously described colocalization and corelease of these endogenous peptides in the NIL.  相似文献   
995.
996.
997.
The physically disabled physician   总被引:1,自引:0,他引:1  
S F Wainapel 《JAMA》1987,257(21):2935-2938
This article reviews the available literature on physically disabled physicians and discusses the attitudinal, environmental, and political barriers they may encounter. Information on 215 physicians and 92 medical students with a wide range of disabilities was analyzed. Currently available personal and technological resources are outlined and special issues pertaining to medical education are highlighted. Greater awareness and acceptance by medical peers are essential for professional success.  相似文献   
998.
Fifty-four patients with 65 superficial malignant lesions were treated by local hyperthermia combined with radiation therapy at the National Cancer Center Hospital, Tokyo. Hyperthermia was delivered with an Aloka Model HMS-020 (2450 MHz) or with a horn-type applicator of BSD-1000 (80-90 MHz). Relatively small tumours, those less than 4 cm in thickness, were treated by using 2450 MHz while 80-90 MHz delivered through the horn-type applicator was used for tumours exceeding 5 cm in thickness. The radiation dose was 4 Gy twice a week or 2 Gy five times a week, the total dose being 40-60 Gy. A total of six to 10 hyperthermia treatments ranging from 40 to 60 min each, with the tumour heated to more than 42.5 degrees C, were given twice a week within 1 h following radiation therapy. Complete response was achieved in 16 of the 30 patients (55 per cent) treated with the 2450 MHz microwave, and partial response in seven others (23 per cent). Tumours treated with the BSD-1000 achieved complete response in 10 out of 33 patients (30 per cent) and partial response in nine others (27 per cent). In five out of nine patients classified as partial responders, however, complete disappearance of tumour cells was noted by post-treatment histological examination. Complete plus partial response rates were thus essentially the same with the Aloka HMS-020 and the BSD-1000, though the rate of complete response was apparently higher with the Aloka unit, probably because it was used on smaller tumours.  相似文献   
999.
The 5q- abnormality   总被引:5,自引:0,他引:5  
S D Nimer  D W Golde 《Blood》1987,70(6):1705-1712
  相似文献   
1000.
The paper is concerned with the results of a study of the circadian rhythm of cortisol secretion and sensitivity of the hypothalamohypophyseal system to small doses of dexamethasone administered in different time of a day to patients with obesity. Disturbance of the circadian rhythm of cortisol secretion resulting in change of the nature of cortisol discharge in the second half of a day, was revealed. Three groups of patients were defined with relation to the type of response of the hypothalamohypophyseal system to dexamethasone administration: with normal, paradoxical and hypersensitive reactions. The results of the study of the circadian rhythm and response of the hypothalamohypophyseal system to dexamethasone were indicative of hypothalamic disturbances in obesity. The authors emphasized the relationship between the nature of sensitivity of the hypothalamohypophyseal system to dexamethasone and age at which the disease developed.  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