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   32488篇
  免费   2652篇
  国内免费   108篇
耳鼻咽喉   415篇
儿科学   988篇
妇产科学   608篇
基础医学   4208篇
口腔科学   764篇
临床医学   3281篇
内科学   6338篇
皮肤病学   340篇
神经病学   3238篇
特种医学   1353篇
外科学   4690篇
综合类   622篇
一般理论   23篇
预防医学   3198篇
眼科学   1047篇
药学   2129篇
中国医学   43篇
肿瘤学   1963篇
  2021年   323篇
  2020年   245篇
  2019年   343篇
  2018年   397篇
  2017年   320篇
  2016年   364篇
  2015年   492篇
  2014年   766篇
  2013年   1315篇
  2012年   1696篇
  2011年   1918篇
  2010年   1072篇
  2009年   1007篇
  2008年   1791篇
  2007年   2018篇
  2006年   2066篇
  2005年   2122篇
  2004年   1992篇
  2003年   1973篇
  2002年   2001篇
  2001年   355篇
  2000年   279篇
  1999年   412篇
  1998年   471篇
  1997年   392篇
  1996年   371篇
  1995年   338篇
  1994年   333篇
  1993年   317篇
  1992年   280篇
  1991年   258篇
  1990年   248篇
  1989年   276篇
  1988年   266篇
  1987年   262篇
  1986年   265篇
  1985年   278篇
  1984年   360篇
  1983年   346篇
  1982年   472篇
  1981年   444篇
  1980年   434篇
  1979年   254篇
  1978年   270篇
  1977年   270篇
  1976年   208篇
  1975年   206篇
  1974年   231篇
  1973年   218篇
  1972年   183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.
36.
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   
37.
38.
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   
39.
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   
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