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   1696036篇
  免费   123729篇
  国内免费   3783篇
耳鼻咽喉   21775篇
儿科学   55669篇
妇产科学   46168篇
基础医学   241327篇
口腔科学   48764篇
临床医学   151347篇
内科学   333617篇
皮肤病学   38672篇
神经病学   131162篇
特种医学   63888篇
外国民族医学   242篇
外科学   257297篇
综合类   38979篇
现状与发展   4篇
一般理论   531篇
预防医学   124252篇
眼科学   40307篇
药学   123689篇
  7篇
中国医学   4484篇
肿瘤学   101367篇
  2021年   12825篇
  2019年   13539篇
  2018年   19979篇
  2017年   15235篇
  2016年   16650篇
  2015年   18989篇
  2014年   26256篇
  2013年   37980篇
  2012年   52785篇
  2011年   55467篇
  2010年   32805篇
  2009年   30724篇
  2008年   51572篇
  2007年   54845篇
  2006年   55294篇
  2005年   52568篇
  2004年   50763篇
  2003年   48179篇
  2002年   46383篇
  2001年   91793篇
  2000年   93608篇
  1999年   76974篇
  1998年   19721篇
  1997年   17272篇
  1996年   17392篇
  1995年   16742篇
  1994年   15294篇
  1993年   14073篇
  1992年   57387篇
  1991年   55271篇
  1990年   52972篇
  1989年   50750篇
  1988年   46135篇
  1987年   44939篇
  1986年   42227篇
  1985年   39989篇
  1984年   29354篇
  1983年   24910篇
  1982年   13899篇
  1979年   25531篇
  1978年   17574篇
  1977年   14909篇
  1976年   13879篇
  1975年   14566篇
  1974年   17636篇
  1973年   16946篇
  1972年   15677篇
  1971年   14453篇
  1970年   13434篇
  1969年   12519篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Individuals with sudden unilateral deafness offer a unique opportunity to study plasticity of the binaural auditory system in adult humans. Stimulation of the intact ear results in increased activity in the auditory cortex. However, there are no reports of changes at sub-cortical levels in humans. Therefore, the aim of the present study was to investigate changes in sub-cortical activity immediately before and after the onset of surgically induced unilateral deafness in adult humans. Click-evoked auditory brainstem responses (ABRs) to stimulation of the healthy ear were recorded from ten adults during the course of translabyrinthine surgery for the removal of a unilateral acoustic neuroma. This surgical technique always results in abrupt deafferentation of the affected ear. The results revealed a rapid (within minutes) reduction in latency of wave V (mean pre = 6.55 ms; mean post = 6.15 ms; p < 0.001). A latency reduction was also observed for wave III (mean pre = 4.40 ms; mean post = 4.13 ms; p < 0.001). These reductions in response latency are consistent with functional changes including disinhibition or/and more rapid intra-cellular signalling affecting binaurally sensitive neurons in the central auditory system. The results are highly relevant for improved understanding of putative physiological mechanisms underlying perceptual disorders such as tinnitus and hyperacusis.  相似文献   
3.
4.
5.
6.
There is a large and growing population of long-term cancer survivors. Primary care physicians (PCPs) are playing an increasingly greater role in the care of these patients across the continuum of cancer survivorship. In this role, PCPs are faced with the responsibility of managing a range of medical and psychosocial late effects of cancer treatment. In particular, the sexual side effects of treatment which are common and have significant impact on quality of life for the cancer survivor, often go unaddressed. This is an area of clinical care and research that has received increasing attention, highlighted by the presentation of this special issue on Cancer and Sexual Health. The aims of this review are 3-fold. First, we seek to overview common presentations of sexual dysfunction related to major cancer diagnoses in order to give the PCP a sense of the medical issues that the survivor may present with. Barriers to communication about sexual health issues between patient/PCPs in order are also described in order to emphasize the importance of PCPs initiating this important conversation. Next, we provide strategies and resources to help guide the PCP in the management of sexual dysfunction in cancer survivors. Finally, we discuss case examples of survivorship sexual health issues and highlight the role that a PCP can play in each of these case examples.  相似文献   
7.
8.

Background

Since recent reports have shown that (-)-Epigallocatechin-3-gallate (EGCG) could be used for treating proliferative and inflammatory disorders, we explored its use for the management of corneal chemical burns.

Materials and methods

Initially, EGCG was assayed on the rabbit corneal epithelial cell line RCE1(5T5) to establish the best testing conditions, and to avoid unwanted outcomes in the experimental animals. Then, we studied its effects on cell proliferation, cell cycle progression and cell differentiation. Afterwards, we instilled EGCG in experimental grade II corneal alkali burns in mice, three times a day up to 21 days, and evaluated by slit lamp examination and histological sections of corneal epithelial, corneal endothelial and stromal edema, as well as the presence of inflammatory cells and neovascularization.

Results

EGCG reduced cell growth and led to a decline in the proportion of proliferative cells in a concentration dependent manner. At 10 μM, EGCG promoted cell differentiation, an effect not related with apoptosis or cytotoxicity. When 10 μM EGCG was instilled in corneal alkali burns in mice three times a day up to 21 days, EGCG significantly reduced corneal opacity and neovascularization. The improved clinical appearance of the cornea was associated to a controlled epithelial growth; epithelial morphology was similar to that observed in normal epithelium and contrasted with the hyperproliferative, desquamating epithelium observed in control burn wounds. EGCG reduced corneal, stromal and endothelial edema, and wound inflammation.

Conclusion

This work constitutes the first evidence for the use of EGCG in the acute phase of a corneal alkali burn, representing a possible novel alternative to improve patient outcomes as an add-on therapy.  相似文献   
9.
The aim of this study is to review the literature to find out the exact etiology of anastomotic cancers of colon post resection and differentiate them between a recurrence, second primary, and metastatic disease (local manifestation of systemic disease). Web-based literature search was done, and datas collected. We searched PubMed for papers using the keywords colon cancer recurrence, anastomotic recurrence, and recurrent colon carcinoma. We also searched for systematic review in the same topic. In addition, we used our personal referrence archive. Anastomotic recurrences of colon are postulated to arise due to inadequate margins, tumor implantation by exfoliated cells, altered biological properties of bowel anastomosis, and missed synchronous lesions. Some tumors are unique with repeated recurrence after repeated resection. Duration after primary surgery plays a major role in differentiating recurrent and second primary lesions. Repeated recurrences after repeated resections have to be considered a manifestation of systemic disease or metastatic disease due to the virulence of the disease. A detailed analysis and study of patients with colonic anastomotic lesion are required to differentiate it between a recurrent, a second primary lesion, and a metastatic disease (local manifestation of a systemic disease). The nomenclature is significant to study the survival of these patients, as a second primary lesion will have different survival compared to that of recurrent lesions.  相似文献   
10.
ObjectivesTo fill an empirical gap in the literature by examining changes in quality of care measures occurring when multispecialty clinic systems were acquired by hospital-owned, vertically integrated health care delivery systems in the Twin Cities area.ConclusionsMoving a clinic system into a vertically integrated delivery system resulted in limited increases in quality of care indicators. Caution is warranted when the acquisition causes disruption in referral patterns.  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