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   297305篇
  免费   17303篇
  国内免费   417篇
耳鼻咽喉   4209篇
儿科学   10310篇
妇产科学   10257篇
基础医学   45135篇
口腔科学   7498篇
临床医学   24247篇
内科学   55981篇
皮肤病学   6369篇
神经病学   21090篇
特种医学   11650篇
外国民族医学   43篇
外科学   46939篇
综合类   7772篇
现状与发展   1篇
一般理论   160篇
预防医学   19952篇
眼科学   6969篇
药学   20980篇
中国医学   787篇
肿瘤学   14676篇
  2018年   3625篇
  2017年   2663篇
  2016年   3081篇
  2015年   3503篇
  2014年   4600篇
  2013年   7251篇
  2012年   9102篇
  2011年   9484篇
  2010年   6149篇
  2009年   5573篇
  2008年   8715篇
  2007年   9539篇
  2006年   9396篇
  2005年   9008篇
  2004年   8695篇
  2003年   8193篇
  2002年   7797篇
  2001年   13372篇
  2000年   13696篇
  1999年   11465篇
  1998年   3043篇
  1997年   2806篇
  1996年   2647篇
  1995年   2559篇
  1994年   2354篇
  1992年   8338篇
  1991年   8487篇
  1990年   8286篇
  1989年   8107篇
  1988年   7351篇
  1987年   7106篇
  1986年   6750篇
  1985年   6542篇
  1984年   4786篇
  1983年   4138篇
  1982年   2480篇
  1979年   4439篇
  1978年   3232篇
  1977年   2737篇
  1976年   2510篇
  1975年   2838篇
  1974年   3359篇
  1973年   3366篇
  1972年   3122篇
  1971年   2955篇
  1970年   2844篇
  1969年   2584篇
  1968年   2540篇
  1967年   2375篇
  1966年   2264篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 23, No. 5, pp. 540–549, May, 1989.  相似文献   
102.
alpha 1-Antiproteinase is the major inhibitor of proteolytic enzymes, such as elastase, in human plasma. Its elastase-inhibitory capacity can be inactivated by exposure to hydroxyl radicals (.OH) generated either by pulse radiolysis or by an Fe3+-EDTA/H2O2/ascorbic acid system. Inactivation of alpha 1-antiproteinase by radiolytically-generated .OH under anoxic conditions was decreased by adding a range of anti-inflammatory drugs to the reaction mixtures, including the thiol compound penicillamine. However, under conditions favouring formation of oxysulphur radicals, protection by thiols such as penicillamine was much decreased. It is proposed that sulphur-containing radicals resulting from attack of biologically-produced oxidants upon penicillamine in the presence of O2 can themselves inactivate alpha 1-antiproteinase, and that such radicals might contribute to the side-effects produced by penicillamine or gold thiol therapy in rheumatoid arthritis.  相似文献   
103.
A lawsuit directed by parents at a day care program following an outbreak of infectious disease would most likely be based on the legal theory of negligence--the failure to exercise due care as required by circumstances. In the determination of liability for infectious diseases in child day care, the element of causation is most critical. Did the day care facility's actions or failure to act cause the harm? Another important question is whether an infectious disease can be occupational and under what circumstances. Although worker's compensation laws initially had no provisions for occupational disease, now all states recognize responsibility for them. Awareness of potential problems with legal liability and establishment of procedures to minimize risk are important for day care providers, public health officials, clinicians, and parents.  相似文献   
104.
Synovectomy of the knee in patients with hemophilia presenting in countries with demographic characteristics that make central referral difficult is the subject of this article. Ten patients, six surgeons, and two countries contributed to this study, which demonstrated that approximately 40% of these patients had no further hemarthroses into the affected joint and the remainder had reduced frequency and severity of bleeding. Continuous passive motion has an important place in postoperative management, and manipulation with the patient under anesthesia is of doubtful value. The possible relationship between diminished range of movement and a successful outcome in terms of abolition of hemorrhage is explored. One patient underwent synovectomy of the knee without complication; the other nine suffered significant complications.  相似文献   
105.
Four psychiatric syndromes related to reproductive function in women have been identified: postpartum depression, premenstrual syndrome (PMS), post-hysterectomy depression, and involutional melancholia. The authors review what is known about these syndromes and conclude, first, that postpartum depression comprises three separate syndromes, the most severe of which is most likely a variant of primary affective disorder. Second, research into the syndromal nature, biology, and treatment of PMS is still in its infancy due to a variety of methodological difficulties. Third, the rate of depression among women during the involutional period or following hysterectomy for benign pathology is not higher than it is at other times.  相似文献   
106.
107.
Enoximone is a positive inotropic agent belonging to the group of phosphodiesterase F-III inhibitors. The drug was tested in 34 patients uncontrolled by sympathomimetic drugs and referred to our department for urgent heart transplantation or circulatory assistance. After insertion of a Swan-Ganzgatheter and a radial artery catheter for haemodynamic monitoring, enoximone was administered as a 15-minute intravenous bolus injection of 1 to 2.5 mg/kf every 8 hours, in addition to sympathomimetic agents. Clinical and haemodynamic improvement was observed after thirty minutes in 30 patients. The cardiac index rose from 1.82 to 2.67 l/min/m2 and the pulmonary wedge pressure fell from 30.8 to 18.9 mmHg. Systemic arterial resistance decreased from 2170 to 1520 dyn. s. cm-5, and pulmonary resistance from 5.5 to 4.6 Wood units (p less than 0.01 for all values). Four patients had no haemodynamic improvement and were put on circulatory assistance, using a Jarvik 7 total artificial heart in 3 of them and heterotopic circulatory assistance in one. After clinical investigation for contra-indication to heart transplantation, and as their improved haemodynamic status permitted, 12 of the 30 patients were considered suitable (group B) for heart transplantation. Transplantation was performed within a week of admission in 11 patients without any need for mechanical assistance. One of the group B patients who required implantation of a Jarvik 7 artificial heart died after 12 hours of assistance. Eighteen patients were considered unsuitable for transplantation (group A) and treated medically.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
108.
109.
Diesters based on isosteviol and dicarboxylic acids were synthesized and tested for antituberculous activity. Isosteviol and some of its derivatives exhibit appreciable tuberculostatic properties in vitro, the activity being dependent on the length of the polymethylene spacer connecting two ent-beyeran fragments. The mechanism of the antituberculous action of isosteviol derivatives are discussed. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 9, pp. 12–13, September, 2006.  相似文献   
110.
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