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   145098篇
  免费   8608篇
  国内免费   1660篇
耳鼻咽喉   1755篇
儿科学   3841篇
妇产科学   4726篇
基础医学   22278篇
口腔科学   4060篇
临床医学   13048篇
内科学   26335篇
皮肤病学   2881篇
神经病学   10763篇
特种医学   4640篇
外国民族医学   3篇
外科学   18881篇
综合类   5403篇
一般理论   60篇
预防医学   11721篇
眼科学   3264篇
药学   12100篇
  1篇
中国医学   874篇
肿瘤学   8732篇
  2021年   1698篇
  2020年   1054篇
  2019年   1686篇
  2018年   2384篇
  2017年   1723篇
  2016年   1810篇
  2015年   2238篇
  2014年   2795篇
  2013年   3905篇
  2012年   5565篇
  2011年   5976篇
  2010年   3417篇
  2009年   3110篇
  2008年   5146篇
  2007年   5461篇
  2006年   5392篇
  2005年   4844篇
  2004年   4553篇
  2003年   4228篇
  2002年   3912篇
  2001年   6913篇
  2000年   7072篇
  1999年   5885篇
  1998年   2053篇
  1997年   1550篇
  1996年   1098篇
  1995年   982篇
  1992年   3811篇
  1991年   3898篇
  1990年   3640篇
  1989年   3638篇
  1988年   3484篇
  1987年   3328篇
  1986年   3147篇
  1985年   3023篇
  1984年   2124篇
  1983年   1870篇
  1982年   1060篇
  1979年   1956篇
  1978年   1213篇
  1977年   1013篇
  1976年   948篇
  1975年   1219篇
  1974年   1388篇
  1973年   1433篇
  1972年   1376篇
  1971年   1268篇
  1970年   1146篇
  1969年   1124篇
  1968年   1027篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
为探讨钙调素在慢性缺氧性肺动脉高压发病中的作用,将40只Wistar大鼠随机分为四组,I组为正常对照组,不接受任何处理。Ⅱ、Ⅲ、Ⅳ组为实验组,分别间断缺氧1、2、3周,而后采用火焰原子吸收分光光度法及磷酸二酯酶法测定四组大鼠肺组织Ca^2+含量及CaM活性。  相似文献   
42.
Eighty-nine cases of chronic bronchitis were matched against167 asymptomatic controls from the glass bangle industry ofFirozabad. Factors of age, social status, smoking habit andduration of exposure were studied. Duration of exposure wasfound to be a factor contributing significantly to the causationof disease. Requests for reprints should be addressed to: Dr B. N. Gupta, Division of Epidemilogy, Industrial Toxicology Research Centre, Mahatma Gandhi Marg, Lucknow P.O. Box 80, 226001, India  相似文献   
43.
44.
Physical therapy without anesthesia or plaster casts was used to treat 338 cases of clubfoot (CF). Our technique is based on progressive sequential manipulations at birth. We first reduce the varus and later the equinus component of the CF. The gentle stretches used in this technique are complemented by active physiotherapy stimulating the muscles, and then a simple splint is suited to the foot to fix its degree of realignment. When used alone, this technique achieves 77% good and fair results. In resistant cases, complementary surgery was used. We obtained 96% good and fair results.  相似文献   
45.
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   
46.
M Y Fan  Z P Lum  X W Fu  L Levesque  I T Tai  A M Sun 《Diabetes》1990,39(4):519-522
Prolonged survival of pancreatic islet allografts implanted in diabetic BB rats was achieved by encapsulation of individual islets in a protective biocompatible alginate-polylysine-alginate membrane without immunosuppression. Intraperitoneal transplantation of the encapsulated islets reversed the diabetic state of the recipients within 3 days and maintained normoglycemia for 190 days. Normal body weight and urine volume were maintained during this period, and no cataracts were detected in the transplant recipients. In contrast, control rats receiving transplants of unencapsulated islets experienced normoglycemia for less than 2 wk. These results demonstrated that microencapsulation can protect allografted islets from both graft rejection and autoimmune destruction without immunosuppression in an animal model that mimics human insulin-dependent diabetes.  相似文献   
47.
48.
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   
49.
50.
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   
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