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   2792篇
  免费   178篇
  国内免费   19篇
耳鼻咽喉   11篇
儿科学   56篇
妇产科学   68篇
基础医学   298篇
口腔科学   54篇
临床医学   192篇
内科学   567篇
皮肤病学   43篇
神经病学   77篇
特种医学   309篇
外科学   330篇
综合类   215篇
一般理论   3篇
预防医学   175篇
眼科学   306篇
药学   112篇
中国医学   1篇
肿瘤学   172篇
  2023年   26篇
  2022年   47篇
  2021年   99篇
  2020年   42篇
  2019年   61篇
  2018年   70篇
  2017年   43篇
  2016年   64篇
  2015年   47篇
  2014年   80篇
  2013年   112篇
  2012年   129篇
  2011年   139篇
  2010年   69篇
  2009年   70篇
  2008年   143篇
  2007年   130篇
  2006年   119篇
  2005年   135篇
  2004年   125篇
  2003年   114篇
  2002年   106篇
  2001年   117篇
  2000年   94篇
  1999年   84篇
  1998年   33篇
  1997年   34篇
  1996年   32篇
  1995年   33篇
  1994年   29篇
  1993年   21篇
  1992年   35篇
  1991年   35篇
  1990年   39篇
  1989年   34篇
  1988年   48篇
  1987年   42篇
  1986年   39篇
  1985年   45篇
  1984年   17篇
  1983年   29篇
  1982年   21篇
  1981年   11篇
  1980年   11篇
  1979年   12篇
  1978年   18篇
  1977年   15篇
  1976年   19篇
  1972年   11篇
  1970年   10篇
排序方式: 共有2989条查询结果,搜索用时 46 毫秒
991.
992.
993.
Sphenoidal sinus mucoceles are indolent lesions that, when sufficiently large, can compress on the optic canal or superior orbital fissure, rapidly causing loss of vision, optic neuropathy, ptosis, pain, ophthalmoplegia, and diplopia. We herein report a 72-year-old gentleman who presented acutely with Cranial Nerve II, III, and IV palsies secondary to a sphenoidal sinus mucocele that was confirmed on magnetic resonance imaging and successfully treated with endoscopic drainage. This cause of orbital apex syndrome is important for clinicians to know as early diagnosis and treatment is critical in recovering visual potential.  相似文献   
994.
Chew  S. K.  Maizura  M.  Hazwani  A. Y.  Tan  T. C. 《Sport Sciences for Health》2020,16(3):523-530
Sport Sciences for Health - The research aims to examine the effects of fructooligosaccharide (FOS) concentrations on the physicochemical properties of formulated sports drinks (FSDs) and the...  相似文献   
995.
The chronic and systemic administration of rapamycin extends life span in mammals. Rapamycin is a pharmacological inhibitor of mTOR. Metformin also inhibits mTOR signaling but by activating the upstream kinase AMPK. Here we report the effects of chronic and systemic administration of the two mTOR inhibitors, rapamycin and metformin, on adult neural stem cells of the subventricular region and the dendate gyrus of the mouse hippocampus. While rapamycin decreased the number of neural progenitors, metformin-mediated inhibition of mTOR had no such effect. Adult-born neurons are considered important for cognitive and behavioral health, and may contribute to improved health span. Our results demonstrate that distinct approaches of inhibiting mTOR signaling can have significantly different effects on organ function. These results underscore the importance of screening individual mTOR inhibitors on different organs and physiological processes for potential adverse effects that may compromise health span.  相似文献   
996.
997.
998.
OBJECTIVE: The purpose of this article is to discuss MRI of the pediatric knee and familiarize the reader with conditions encountered in the pediatric population. Clinical scenarios are included to convey important concepts and to orient the learner to normal variants and abnormalities of the pediatric knee. The conditions discussed include, but are not limited to, distal femoral metaphysial irregularity, isolated popliteus tendon avulsion, juvenile idiopathic arthritis, and discoid meniscus. CONCLUSION: The knee is the joint that is most commonly imaged by MRI in children. Injury patterns and signs of other pathologic processes seen in skeletally immature patients are different from those seen in adults. Interpreting pediatric knee MRI studies may be a challenge for those unfamiliar with the evolving patterns of normal development and of the signs of conditions that are more prevalent in children. Through case scenarios, this article describes and provides images that depict conditions commonly encountered in the pediatric knee. Most of the described normal findings and abnormalities are more prevalent in the pediatric population than in adults, and a few of the conditions are, in fact, unique to pediatric patients.  相似文献   
999.
OBJECTIVE: This article reviews the imaging features of revisions and complications of hip replacement arthroplasty and relates these features to the current understanding about how and why these failures occur. CONCLUSION: Short-term failures of hip replacements are most commonly the result of instability and dislocation. Complications ranging from osteolysis caused by granulomatous reaction to particulate wear debris lead to many long-term failures. Attempts to reduce wear debris through changes in design and materials have reduced the rate of some complications but have resulted in new ones. Infection remains a devastating complication that is difficult to resolve.  相似文献   
1000.
Normal squamous epithelial cells readily undergo terminal differentiation in culture and are commonly used in differentiation studies. Several intracellular markers of squamous differentiation such as keratin, involucrin, transglutaminase and cholesterol sulfate have been well-studied and described by other workers. We have recently reported a surface membrane antigen in squamous carcinoma of the head and neck antigen in squamous carcinoma of the head and neck which is recognized by a murine monoclonal antibody SQMI. In this paper, we present our studies on the ultrastructural localization of SQMI antigen in cultured squamous epithelial cells using gold-labelled antibody. The cells studied included both normal and cancer cells at different degrees of differentiation. Under both transmission and scanning electron microscopy examination, the SQMI antigen was localized at the membrane surface of cultured cells, particularly at sites of cell-cell interdigitation. No association with desmosomal structure was observed in any of the specimens examined. There was however an association of SQMI antigen with microvilli of cell membrane. No non-specific cytoplasmic localization of SQMI antigen was observed. The intensity of SQM1 antigen revealed by gold-labelling appeared to have a positive correlation with the degree of differentiation of the cells in culture.  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