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   1645721篇
  免费   134569篇
  国内免费   2784篇
耳鼻咽喉   22205篇
儿科学   53840篇
妇产科学   47168篇
基础医学   233852篇
口腔科学   48237篇
临床医学   145281篇
内科学   323772篇
皮肤病学   35230篇
神经病学   134249篇
特种医学   66469篇
外国民族医学   476篇
外科学   251595篇
综合类   40185篇
现状与发展   3篇
一般理论   617篇
预防医学   125345篇
眼科学   37220篇
药学   124079篇
  3篇
中国医学   3078篇
肿瘤学   90170篇
  2018年   16256篇
  2016年   14101篇
  2015年   16378篇
  2014年   22488篇
  2013年   33550篇
  2012年   45920篇
  2011年   48120篇
  2010年   28232篇
  2009年   26973篇
  2008年   45559篇
  2007年   47849篇
  2006年   48440篇
  2005年   46842篇
  2004年   46131篇
  2003年   44055篇
  2002年   42984篇
  2001年   76083篇
  2000年   78707篇
  1999年   66807篇
  1998年   18111篇
  1997年   16638篇
  1996年   16545篇
  1995年   16229篇
  1994年   15247篇
  1993年   14398篇
  1992年   55657篇
  1991年   53983篇
  1990年   52760篇
  1989年   51015篇
  1988年   47405篇
  1987年   46722篇
  1986年   44459篇
  1985年   43024篇
  1984年   32175篇
  1983年   27714篇
  1982年   16287篇
  1981年   14573篇
  1980年   13706篇
  1979年   30589篇
  1978年   21180篇
  1977年   17870篇
  1976年   16816篇
  1975年   17670篇
  1974年   21599篇
  1973年   20775篇
  1972年   18946篇
  1971年   17858篇
  1970年   16365篇
  1969年   15333篇
  1968年   14006篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
OBJECTIVES: To identify and describe current women's thoughts about the menopause, hormone treatment (HT) and perceptions about breast cancer. METHODS: Between December 2004 and January 2005, 4201 postmenopausal women in seven European countries were interviewed via a standardized computer-aided telephone interview protocol. RESULTS: Almost all women reported to have experienced climacteric symptoms, and 63% of the women rated them as being severe. Only 52% of women were aware of the benefits of HT for relief of climacteric symptoms. Although 84% felt that severe symptoms should be treated, only 40% had used HT at some point in time. Thirty-four percent of the women preferring treatment with natural products did so because of the risk of breast cancer associated with HT. HT was recognized by 59% of the women as one of the most important contributors to an increased breast cancer risk. Most women received their information about HT and breast cancer risk from the media. CONCLUSIONS: This European survey reveals that the majority of women experience climacteric symptoms but that their decision whether or not to use HT is highly dependent on their concern about breast cancer risk. An increase in knowledge of the benefits and risks of HT is required for women to make appropriate decisions about hormone use.  相似文献   
92.
Bleeding disorders encountered during administration of hormone replacement therapy (HRT) are reviewed. The incidence of bleeding disorders is dependent on the phase of HRT and the age of the patient. In the diagnosis of these bleedings transvaginal sonography and minihysteroscopy are very important methods. Endometrial thickness can be monitored exactly by transvaginal sonography. Outpatient minihysteroscopy without anesthesia results in higher compliance to HRT after the procedure. In hormonal treatment of bleeding disorders during HRT, the sonographically supported progestogen test is very useful and can reduce endometrium thickness. Operative treatments include myoma and polyp resection as well as endometrial ablation. By these methods a high rate of bleeding-free HRT can be reached. The problem of endometrial cancer during HRT is discussed on the basis of new literature and critical statements. The review shows the importance of individual diagnostic and treatment schedules for bleeding disorders during HRT.  相似文献   
93.
94.
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   
95.
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   
96.
97.
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   
98.
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   
99.
100.
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   
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