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   121542篇
  免费   7045篇
  国内免费   1591篇
耳鼻咽喉   1646篇
儿科学   3110篇
妇产科学   4315篇
基础医学   18461篇
口腔科学   3778篇
临床医学   9468篇
内科学   22218篇
皮肤病学   2461篇
神经病学   8153篇
特种医学   4101篇
外国民族医学   3篇
外科学   17456篇
综合类   5245篇
一般理论   34篇
预防医学   8724篇
眼科学   2847篇
药学   10313篇
中国医学   824篇
肿瘤学   7021篇
  2021年   1064篇
  2019年   1098篇
  2018年   1686篇
  2017年   1224篇
  2016年   1297篇
  2015年   1542篇
  2014年   1993篇
  2013年   2564篇
  2012年   3724篇
  2011年   3989篇
  2010年   2407篇
  2009年   2139篇
  2008年   3606篇
  2007年   3844篇
  2006年   3787篇
  2005年   3378篇
  2004年   3157篇
  2003年   2933篇
  2002年   2756篇
  2001年   6750篇
  2000年   6937篇
  1999年   5710篇
  1998年   1846篇
  1997年   1388篇
  1996年   945篇
  1995年   862篇
  1992年   3731篇
  1991年   3807篇
  1990年   3551篇
  1989年   3554篇
  1988年   3429篇
  1987年   3277篇
  1986年   3091篇
  1985年   2968篇
  1984年   2048篇
  1983年   1792篇
  1982年   985篇
  1979年   1909篇
  1978年   1184篇
  1977年   986篇
  1976年   918篇
  1975年   1191篇
  1974年   1358篇
  1973年   1414篇
  1972年   1357篇
  1971年   1247篇
  1970年   1137篇
  1969年   1121篇
  1968年   1024篇
  1967年   897篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Effects of the MAO-A-inhibitor brofaromine (BRO), 10 mg/kg po after repeated (twice daily for 14 days) administration on the spontaneous behavior (exploratory and basal locomotor activities) and the exploratory activity modified by methoxamine, clonidine and d-amphetamine in male Wistar rats were studied in both light and dark phases of a diurnal cycle (L: 0700-1900 h). After single administration BRO in the light phase had no effects. In the dark phase BRO decreased the exploration (62% of control, p less than 0.01), increased the clonidine-evoked hypoactivity and amphetamine-evoked hyperactivity. The L-D differences occurred also after repeated administration. BRO in the light phase did not influence the exploration, decreased basal locomotor activity, did not change methoxamine and clonidine action and potentiated the action of amphetamine. In the dark phase, however, it did not influence the exploration and basal locomotor activity, intensified the methoxamine effect, and did not change the clonidine and amphetamine actions. The results demonstrate that the effects of BRO on behavior in rats: 1) differ from the effects caused by other antidepressants which are not MAO inhibitors; 2) are phase-dependent after both single and repeated administration.  相似文献   
12.
The present authors investigated the excretion, distribution and pharmacokinetics of the novel potential antirheumatic agent flobufen and its active metabolite after p.o. and i.v. doses of 2, 10 and 50 mg/kg administered to rats. The drug is resorbed well from the digestive tract and mostly it is metabolized to the principal metabolite M, which is only slowly excreted from the organism mainly by renal clearance. Within the whole dose range the kinetics of the drug is linear. Binding of flobufen and M to proteins is high (95-99%). The highest concentrations of radioactive metabolites (mostly M) were found in the plasma, liver, lungs, kidneys, connective tissue and inflammatory foci. The penetration of metabolites through the placenta and excretion in human milk are relatively important.  相似文献   
13.
14.
The clinical, radiologic, and histopathologic findings of a case of bilateral dacryops is reported in a 49-year-old man. The patient presented with cystic masses located in superior lateral orbits and underwent bilateral excisions of these without any postoperative complications.  相似文献   
15.
A patient with Graves' disease had a symptomatic thrombocytopathy during periods of remission. When euthyroid, she noticed bruising, petechiae, and epistaxis. Hemostatic abnormalities included prolongation of the bleeding time by aspirin, reduced platelet retention (a second-phase defect), and abnormal thrombin-induced aggregation and serotonin release. When hyperthyroid, bleeding symptoms resolved, and platelet function returned to normal. These observations suggest that mild bleeding disorders may be influenced either directly or indirectly by thyroid hormone levels.  相似文献   
16.
Measurements of the fetal eyeball and its pattern of growth   总被引:1,自引:0,他引:1  
  相似文献   
17.
18.
19.
Computed tomography of the brain in the Smith-Lemli-Opitz syndrome   总被引:1,自引:0,他引:1  
Computed tomographic (CT) scans of the brain in a child with Smith-Lemli-Opitz syndrome revealed enlargement of the ventricular system, hypoplasia of the cerebellum, and abnormal thickening of the gray matter, consistent with pachygyria. These findings have been previously noted in autopsies performed on patients with this disorder. We conclude that CT scanning is a valuable tool in the evaluation of children suspected of having the Smith-Lemli-Opitz syndrome.  相似文献   
20.
Normal seminal vesicles were studied histologically in 80, and by Feulgen’s cytophotometric method in 10 autopsied cases (males, 44–82 years of age). In every case large, hyperchromatic nuclei were found. By cytophotometry euploid polyploid atypia was also shown in every case, which is characteristic of benign hormonal dysplasia.  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