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   1715569篇
  免费   139032篇
  国内免费   2951篇
耳鼻咽喉   22944篇
儿科学   55878篇
妇产科学   48486篇
基础医学   241972篇
口腔科学   49514篇
临床医学   153676篇
内科学   336860篇
皮肤病学   35540篇
神经病学   142022篇
特种医学   69222篇
外国民族医学   481篇
外科学   261082篇
综合类   41150篇
现状与发展   3篇
一般理论   697篇
预防医学   133144篇
眼科学   39037篇
药学   128491篇
  5篇
中国医学   3098篇
肿瘤学   94250篇
  2018年   17349篇
  2016年   14953篇
  2015年   17355篇
  2014年   24060篇
  2013年   36329篇
  2012年   50135篇
  2011年   52773篇
  2010年   30995篇
  2009年   29506篇
  2008年   50129篇
  2007年   52894篇
  2006年   53354篇
  2005年   51687篇
  2004年   50985篇
  2003年   48430篇
  2002年   47249篇
  2001年   77285篇
  2000年   79660篇
  1999年   67915篇
  1998年   19094篇
  1997年   17427篇
  1996年   17220篇
  1995年   16887篇
  1994年   15822篇
  1993年   14921篇
  1992年   56426篇
  1991年   54711篇
  1990年   53408篇
  1989年   51673篇
  1988年   47946篇
  1987年   47377篇
  1986年   44998篇
  1985年   43615篇
  1984年   32735篇
  1983年   28148篇
  1982年   16682篇
  1981年   14898篇
  1980年   13982篇
  1979年   30967篇
  1978年   21485篇
  1977年   18142篇
  1976年   17062篇
  1975年   17877篇
  1974年   21853篇
  1973年   21008篇
  1972年   19145篇
  1971年   18030篇
  1970年   16508篇
  1969年   15508篇
  1968年   14166篇
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
91.
92.
In einer clusteranalytischen Untersuchung mit 137 Patienten, die einen Parasuizid verübt hatten, wurden 6 Subgruppen unter Berücksichtigung der Klassifikationsvariable “suicide intent” isoliert. Es wurde die Hypothese geprüft, dass sich sowohl die Motivstrukturen als auch die Raten an wiederholten Parasuiziden in Abh?ngigkeit der Clusterl?sung bedeutsam voneinander unterscheiden. Die Ergebnisse unterstützen die Annahme einer zunehmenden Ausdifferenzierung der interpersonell orientierten Motivstrukturen mit sinkendem bzw. einer Einengung der Motivstruktur auf den Todeswunsch mit steigendem “suicide intent”. Es wurden folgende Subgruppen differenziert: eine Suizid-Hochrisikogruppe mit ausschlie?licher Todesintention und -motivation, 2 moderate Suizid-Risikogruppen mit hoher Todesintention und leichten Tendenzen zu interpersoneller Motivation, eine Subgruppe, gekennzeichnet durch eine manipulativ/strategisch orientierte Motivstruktur und auff?llig h?ufigen Parasuizidwiederholungen, eine Subgruppe mit vorrangig appellativ orientierten Motiven, Kontrollverlust und vergleichsweise seltenen Parasuizidwiederholungen und eine Subgruppe mit ambivalenter Motivstruktur (interpersonell und todesorientiert).  相似文献   
93.
Cytokines play a part in the control of cellular growth, differentiation and development. Given such pleiotropic activities, it is not unexpected that the expression of the cytokines is tightly regulated. When cytokine-mediated processes are altered by mutation and/or overexpression of some cytokine or cytokine receptor genes, oncogenic transformation can occur. Oncogenes which derive their transforming potential through this mechanism include sis, which represents the activated form of the platelet-derived growth factor B chain, hst1/K-fgflint-2, which share appreciable homology with the gene family of fibroblast growth factors, fms, which is related to the cell surface receptor for macrophage-colony stimulating factor, and erbB-1, which encodes a truncated form of the epidermal growth factor receptor. Cytokine treatment has resulted in modulation of aberrant oncogene activity in some model systems.  相似文献   
94.
95.
The prevalence of heavy alcohol consumption is a major problem of increasing proportions throughout the world. Although alcohol sensitizing drugs and more recently serotonin uptake inhibitors are drug interventions with some following, their long term beneficial consequences have yet to be demonstrated. In recent years, we have demonstrated that manipulating activity in the renin-angiotensin system will dramatically alter voluntary alcohol consumption in rats. Based on these findings, the present study evaluated the ability of a class of drugs known as the angiotensin converting enzyme inhibitors to reduce voluntary alcohol drinking in laboratory animals. These drugs prevent the conversion of angiotensin I to angiotensin II. They have been licensed for use in Europe and North America and are indicated in the treatment of hypertension. Our experiments showed that both captopril (Capoten, Squibb) and enalapril (Vasotec, Merck Sharpe & Dohme) can reduce alcohol drinking in both normotensive and hypertensive animals regardless of whether the pattern of intake is in a bout or of a less exaggerated nature. Furthermore, this change in alcohol intake can occur without concomitant changes in blood pressure, plasma renin activity, overall fluid balance, or the distribution and metabolism of alcohol. Taken together these findings suggest that the angiotensin converting enzyme inhibitors should be evaluated in a clinical setting for they may prove to be a useful new treatment or treatment adjunct for alcohol abuse in humans.  相似文献   
96.
It has long been noted that tetanus is rare in leprosy patients. Five cases of tetanus are reported in leprosy patients in Addis Ababa, Ethiopia. Although natural immunity to tetanus occurs and this appears to be higher in leprosy patients than in the general population, it is not completely protective. Further research on the relationship between tetanus and leprosy is indicated. Although firm epidemiologic data are lacking, it is prudent to give leprosy patients at least one dose of tetanus toxoid.  相似文献   
97.
98.
The use of additional epidural sympathetic block during and after microvascular surgery in the lower extremities to prevent vasospasm is generally agreed on. However, a significant fall in the perfusion rate of the transplants was seen after application of bupivacaine (Marcain) via the epidural catheter. This effect has, to our knowledge, not been described before and is probably caused by the sympathectomy effect of this type of analgesia.  相似文献   
99.
100.
Neglected tears of the patellar tendon due to loss of active extension remain a difficult therapeutic endeavor. The goals in the approach to this diagnosis include restoration of both structural and functional integrity of the extensor mechanism. A procedure has been developed utilizing Z-shortening of the patellar tendon, Z-lengthening of the quadriceps tendon, and the semitendinosis gracilis as a biologic splint. This technique allows establishment of preoperative goals, including restoration of the muscle-tendon complex in its anatomic position, restoration of quadriceps function, preservation of vascularity of the reconstructed tendon, and splinting of the patellar tendon. This reconstruction allows early mobilization and rehabilitation.  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