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   30463篇
  免费   2452篇
  国内免费   106篇
耳鼻咽喉   411篇
儿科学   847篇
妇产科学   538篇
基础医学   3915篇
口腔科学   738篇
临床医学   3073篇
内科学   6070篇
皮肤病学   321篇
神经病学   3085篇
特种医学   1316篇
外科学   4473篇
综合类   578篇
一般理论   20篇
预防医学   3042篇
眼科学   1010篇
药学   1954篇
中国医学   43篇
肿瘤学   1587篇
  2021年   301篇
  2020年   230篇
  2019年   325篇
  2018年   358篇
  2017年   290篇
  2016年   339篇
  2015年   458篇
  2014年   718篇
  2013年   1257篇
  2012年   1613篇
  2011年   1841篇
  2010年   1015篇
  2009年   971篇
  2008年   1720篇
  2007年   1957篇
  2006年   1980篇
  2005年   2017篇
  2004年   1898篇
  2003年   1883篇
  2002年   1944篇
  2001年   284篇
  2000年   213篇
  1999年   347篇
  1998年   446篇
  1997年   366篇
  1996年   347篇
  1995年   324篇
  1994年   315篇
  1993年   298篇
  1992年   235篇
  1991年   212篇
  1990年   190篇
  1989年   216篇
  1988年   220篇
  1987年   218篇
  1986年   218篇
  1985年   242篇
  1984年   318篇
  1983年   315篇
  1982年   453篇
  1981年   423篇
  1980年   422篇
  1979年   237篇
  1978年   240篇
  1977年   259篇
  1976年   190篇
  1975年   195篇
  1974年   207篇
  1973年   201篇
  1972年   172篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
32.
A 7-cm anterior mediastinal tumor in an 80-year-old woman was found by light and electron microscopy to be a neuroblastoma. Immunoreactivity for neuron-specific enolase, synaptophysin, and chromogranin supported the diagnosis. Neuroblastoma is an uncommon tumor in adults and we are not aware of a previous report of such a tumor in a patient of this age.  相似文献   
33.
34.
Gene amplification allows transformed cells to overexpress specific genes and gain a survival advantage. For this reason, cloning and characterization of amplified genes can improve our understanding of the biology of transformed cells. The techniques of in-gel renaturation and chromosome microdissection can enrich for amplified DNA sequences, but both are labor intensive and have other drawbacks. We have developed an alternative strategy of enriching for amplified DNA sequences that involves two-directional agarose gel electrophoresis of extrachromosomal circular DNA. Extrachromosomal circles can be detected with repetitive DNA probes and can be used to produce DNA probes suitable for fluorescence in situ hybridization for location of genomic origin. The ability to enrich for amplified DNA without specialized equipment or transformed cell metaphases should prove useful in the search for new genes which are important in tumor cell progression.  相似文献   
35.
The prevention of the spread of disease by drinking water relies on a tripartate arrangement among the supplier, the regulator and their medical advisers. This paper describes the role of Public Health Medicine in Scotland in preventing a ‘significant risk to health’ from potable water. The legislative framework is highlighted. The rationale of water monitoring is examined and the role of Consultant in Public Health Medicine. The concept of Significant Medical Risk Values is introduced and their derivation, uses, and levels presented.  相似文献   
36.
The purpose of this paper is to detail the contraindications for surgery, with curative intent for those patients who suffer from a head and neck malignancy that invades the intracranial space. This is based on a 30-year experience of over 250 patients. The most important contraindications are anatomical. Surgery is not done if the following structures are invaded: brain stem, eloquent portions of the cerebrum, superior sagittal sinus, both internal carotid arteries, both cavernous sinuses and certain vital bridging veins. Certain tumor factors are absolute but are occasionally relative contraindications: such as distant metastatic disease especially if multiple and at multiple anatomic sites. Some tumors that behave in a particularly virulent fashion that defy complete resection but are often difficult to predict preoperatively. Lack of patient medical fitness or absence of patient commitment to the operative procedure is make-up two serious contraindications to surgery. Presented at the 77th Annual Meeting of the German Society for Oto-Rhino-Laryngology, Head and Neck Surgery, 24–28 May 2006, Mannheim, Germany.  相似文献   
37.
The authors review the relationship that has evolved over the years between the Department of Psychiatry at Oregon Health Sciences University and Oregon's community and state mental health programs. They describe the compatibility that exists between the basic requirements of academic psychiatry departments and public mental health programs and demonstrate how these organizations have been able to fulfill one another's needs in Oregon. Specific examples of successful collaborations in the areas of education, administration, research, and service are presented to illustrate how relationships that have been designed to meet specific requirements of one organization can fulfill many requirements of both. Suggestions are provided for those organizations contemplating similar collaborative endeavors.  相似文献   
38.
39.
40.
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