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   1560篇
  免费   134篇
  国内免费   1篇
耳鼻咽喉   3篇
儿科学   27篇
妇产科学   46篇
基础医学   266篇
口腔科学   34篇
临床医学   193篇
内科学   257篇
皮肤病学   8篇
神经病学   97篇
特种医学   176篇
外科学   214篇
综合类   6篇
一般理论   1篇
预防医学   150篇
眼科学   13篇
药学   92篇
中国医学   1篇
肿瘤学   111篇
  2023年   11篇
  2022年   12篇
  2021年   24篇
  2020年   27篇
  2019年   33篇
  2018年   34篇
  2017年   42篇
  2016年   43篇
  2015年   52篇
  2014年   54篇
  2013年   74篇
  2012年   128篇
  2011年   107篇
  2010年   80篇
  2009年   74篇
  2008年   101篇
  2007年   95篇
  2006年   98篇
  2005年   87篇
  2004年   96篇
  2003年   76篇
  2002年   71篇
  2001年   25篇
  2000年   20篇
  1999年   19篇
  1998年   14篇
  1997年   15篇
  1996年   12篇
  1995年   5篇
  1994年   10篇
  1993年   10篇
  1992年   6篇
  1991年   17篇
  1990年   16篇
  1989年   9篇
  1988年   4篇
  1987年   8篇
  1986年   4篇
  1985年   6篇
  1984年   5篇
  1983年   4篇
  1982年   8篇
  1981年   6篇
  1979年   5篇
  1974年   3篇
  1973年   5篇
  1972年   3篇
  1933年   7篇
  1932年   5篇
  1931年   3篇
排序方式: 共有1695条查询结果,搜索用时 15 毫秒
21.
22.
23.
24.
Summary The diagnostic value of oesophageal echocardiography is most striking in patients in whom precordial studies are of inadequate quality or fail to establish a definitive diagnosis. Oesophageal studies have excellent image quality, can be completed within 10 minutes without complications and, in most instances, enables the clinical question to be answered. In 50 patients referred for suspected thoracic aorta pathology, oesophageal echocardiography correctly excluded or diagnosed the type of aortic dissection, aortic aneurysm or the site of coarctation. Of 35 patients referred with suspected infective endocarditis, oesophageal echocardiography revealed complications in 18 patients, including vegetation, mycotic aneurysm, abscess or chordal rupture. Oesophageal echocardiography is extremely helpful to visualize intracardiac mass lesions. In 27 patients with a history of systemic or pulmonary embolism, the technique confirmed the presence, size and position of a mass lesion in 11 patients. Oesophageal color Doppler flow imaging further expands the diagnostic capabilities, particularly in patients with mitral valve prosthesis. Our experience indicates that oesophageal echocardiography significantly extends the diagnostic potential of echocardiography. Detailed knowledge of cardiothoracic anatomy and its pathologic sequelae is, however, a prerequisite for the efficient and safe application of this method.  相似文献   
25.

Background

Although, person centred care has for a long time been an important approach to nursing care, it is often not a reality in the clinical environment. The focus of health research has, until recently, been on the physical aspects of a persons’ illness and this has influenced how care is delivered. There is a need to broaden the focus from the illness to the person who is ill. A holistic approach to the persons’ social and cultural experience of their illness will aid health care professions to provide person centred care.This paper will make the argument that narrative inquiry is a well suited to health care research in general and nursing research in particular as it focuses its inquiry on the individual person's experience of their illness – ‘what matters’ from the person's point of view. Narrative inquiry explores the narrative from a temporal, social and spatial view.

Conclusions

There is a need to find what is important from the patients’ ‘point of view’ to optimise care. Narrative Inquiry is a methodology often used in education and sociology. It is a gentle relational methodology that has the capability to uncover what is important to the person in their situation. The research findings are presented narratively, that is, informally and engagingly for the consumer of the research.  相似文献   
26.
OBJECTIVES: The purpose of this work was to study the clonal relationship between the cells that secrete monoclonal proteins in an IgA/ IgE double multiple myeloma patient. Double monoclonal gammopathy is a rare condition in which two types of monoclonal proteins can be found in the serum and/or urine of patients with multiple myeloma or gammopathy of undetermined significance. The study of the relationship between the cells expressing the different monoclonal proteins may provide insight in the pathogenesis of these disorders. METHODS: The clonal relationship of the two tumoral plasma cell populations was examined by immunophenotyping and sequence analysis of the variable regions of the immunoglobulin heavy chain genes. Both immunoglobulin sequences were isolated from the bone marrow using a polymerase chain reaction (PCR)-based cloning strategy. Rare isotype-switch variants were detected by a myeloma-specific PCR in combination with different isotype-specific primers. An in vitro culture system, based on the activation of the CD40 molecule on the B cell, was used in order to isolate and expand myeloma-related B cells from peripheral blood that could possibly be regarded as myeloma precursor cells. RESULTS: The variable parts of the immunoglobulin heavy chains linked to either Calpha or Cepsilon were exactly the same, including the same somatic mutations. From the in vitro CD40 cultures B cells could be isolated that either expressed IgA or IgE with exactly the same variable immunoglobulin part as the myeloma clone. No pre-switched IgM myeloma-related B cells could be found. CONCLUSION: Both cell populations in this IgA/IgE myeloma patient shared a common clonal origin. No evidence for a pre-switched IgM precursor myeloma cell was found in this patient.  相似文献   
27.
28.
29.
30.
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