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   10869篇
  免费   352篇
  国内免费   27篇
耳鼻咽喉   156篇
儿科学   161篇
妇产科学   290篇
基础医学   2149篇
口腔科学   211篇
临床医学   554篇
内科学   1020篇
皮肤病学   412篇
神经病学   852篇
特种医学   1556篇
外科学   1472篇
综合类   47篇
预防医学   771篇
眼科学   98篇
药学   1085篇
中国医学   92篇
肿瘤学   322篇
  2023年   38篇
  2022年   32篇
  2021年   58篇
  2020年   52篇
  2019年   75篇
  2018年   203篇
  2017年   137篇
  2016年   186篇
  2015年   124篇
  2014年   230篇
  2013年   383篇
  2012年   708篇
  2011年   1054篇
  2010年   478篇
  2009年   166篇
  2008年   773篇
  2007年   936篇
  2006年   901篇
  2005年   737篇
  2004年   657篇
  2003年   656篇
  2002年   564篇
  2001年   371篇
  2000年   478篇
  1999年   262篇
  1998年   77篇
  1997年   53篇
  1996年   38篇
  1995年   47篇
  1994年   24篇
  1993年   19篇
  1992年   24篇
  1991年   27篇
  1990年   31篇
  1989年   24篇
  1988年   26篇
  1986年   20篇
  1985年   32篇
  1984年   23篇
  1983年   21篇
  1982年   30篇
  1981年   30篇
  1980年   29篇
  1979年   28篇
  1978年   29篇
  1976年   19篇
  1975年   26篇
  1974年   18篇
  1973年   19篇
  1963年   19篇
排序方式: 共有10000条查询结果,搜索用时 23 毫秒
1.
2.
There is a sharp difference in how one views TCR structure–function–behaviour dependent on whether its recognition of major histocompatibility complex‐encoded restriction elements (R) is germline selected or somatically generated. The generally accepted or Standard model is built on the assumption that recognition of R is by the V regions of the αβ TCR, which is not driven by allele specificity, whereas the competing model posits that recognition of R is allele‐specific. The establishing of allele‐specific recognition of R by the TCR would rule out the Standard model and clear the road to a consideration of a competing construct, the Tritope model. Here, the case for allele‐specific recognition (germline selected) is detailed making it obvious that the Standard model is untenable.  相似文献   
3.
4.
5.
Computerized information systems, especially decision support systems, have become an increasingly important role in medical applications, particularly in those where important decision must be made effectively and reliably. But the possibility of using computers in medical decision making is limited by many difficulties, including the complexity of conventional computer languages, methodologies and tools. Thus a conceptual simple decision making model with the possibility of automating learning should be used. In this paper we introduce a cardiological knowledge-based system based on the decision tree approach supporting the mitral valve prolapse determination. Prolapse is defined as the displacement of a bodily part from its normal position. The term mitral valve prolaps (PMV), therefore, implies that the mitral leaflets are displaced relative to some structure, generally taken to be the mitral annulus. The implications of the PMV are the following: disturbed normal laminar blood flow, turbulence of the blood flow, injury of the chordae tendinae, the possibility of thrombus's composition, bacterial endocarditis, and finally hemodynamic changes defined as mitral insufficiency and mitral regurgitation. Uncertainty persists about how it should be diagnosed and about its clinical importance. It is our deep belief that the echocardiography enables properly trained experts armed with proper criteria to evaluate PMV almost 100%. But unfortunately, there are some problems concerned with the use of echocardiography. In that manner we have decided to start a research project aimed at finding new criteria and enabling the general practitioner to evaluate PMV using conventional methods and to select potential patients from the general population. To empower one to perform needed activities we have developed a computer tool called ROSE (computeRised prOlaps Syndrom dEtermination) based on algorithms of automatic learning. This tool supports the definition of new criteria and the selection of potential PMV-patients.  相似文献   
6.
Detectable TNF levels in sera 33% of patients with sepsis following pancreatitis have been found. No correlation was observed between serum TNF concentration and the severity of illness. However, monocytes and granulocytes of septic patients exerted higher TNF-mediated cytotoxicity than leukocytes of normal blood donors. The in vitro TNF-producing capacity was also higher in the patients in the study group, and it decreased only before fatal outcoming of sepsis. Our results suggest that determination of the TNF-producing capacity of leukocytes might be more informative than measurement of the serum TNF level in the evaluation of the severity or prognosis of sepsis.  相似文献   
7.
8.
9.
10.
In the neurosurgical approach to intracranial aneurysms which are often accompanied by arterial spasm and cortical ischaemia, monitoring procedures aim to obtain useful information on cerebral function. SEPs evoked by stimulation of the median nerve at the wrist and of the tibial nerve at the medial malleolus were registered in 45 patients with intracranial aneurysms during neurosurgical procedures. Our results show SEP abnormalities during different stages of neurosurgical procedures in 36 patients out of the monitored 45. Significant abnormalities of SEPs with respect to the control group were decrease of the amplitude of N 20-P 25 complex, lengthening of the absolute latency of the waves N 20- and P 25 and lengthening of the central conduction time (CCT) (N 13-N 20). The greatest SEP abnormalities were registered during the neurosurgical approach to aneurysm and during the clipping procedure. However, the changes were reversible in the majority of the patients. The aim of this paper was to focus on early detection of some cerebral function disturbances during the neurosurgical procedure as well as the prevention of possible brain damage.  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