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   5590389篇
  免费   394570篇
  国内免费   12686篇
耳鼻咽喉   79641篇
儿科学   185352篇
妇产科学   155545篇
基础医学   784152篇
口腔科学   167669篇
临床医学   523908篇
内科学   1048499篇
皮肤病学   126908篇
神经病学   452121篇
特种医学   209761篇
外国民族医学   2062篇
外科学   827068篇
综合类   135028篇
现状与发展   11篇
一般理论   2589篇
预防医学   456298篇
眼科学   135991篇
药学   410424篇
  18篇
中国医学   11242篇
肿瘤学   283358篇
  2018年   59557篇
  2017年   45616篇
  2016年   51588篇
  2015年   58536篇
  2014年   82196篇
  2013年   126131篇
  2012年   168840篇
  2011年   180522篇
  2010年   108322篇
  2009年   101678篇
  2008年   168347篇
  2007年   179246篇
  2006年   180375篇
  2005年   175440篇
  2004年   169299篇
  2003年   162530篇
  2002年   157656篇
  2001年   239880篇
  2000年   246656篇
  1999年   209506篇
  1998年   64527篇
  1997年   56630篇
  1996年   55888篇
  1995年   53525篇
  1994年   49498篇
  1993年   46777篇
  1992年   167205篇
  1991年   163073篇
  1990年   159147篇
  1989年   154367篇
  1988年   143129篇
  1987年   140632篇
  1986年   133934篇
  1985年   128888篇
  1984年   97773篇
  1983年   84145篇
  1982年   50742篇
  1981年   45699篇
  1979年   91986篇
  1978年   65403篇
  1977年   55949篇
  1976年   52613篇
  1975年   56207篇
  1974年   68198篇
  1973年   66132篇
  1972年   62297篇
  1971年   58217篇
  1970年   54705篇
  1969年   52117篇
  1968年   48528篇
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
71.
Summary: A female patient with isovaleric acidaemia had a successful outcome from pregnancy.  相似文献   
72.
73.
    
Ohne Zusammenfassung  相似文献   
74.
75.
76.
77.
78.
Vitiligo and psoriasis are both common skin disorders. However, psoriasis strictly confined to pre-existing vitiligo areas is rare and suggests a causal relationship. We report here on two patients with a strict anatomical colocalization of vitiligo and psoriasis. The histopathological examinations showed typical changes for both diseases together with a dense infiltrate of CD4+ and CD8+ T cells. By immunohistochemistry, intracytoplasmatic granzyme B and tumour necrosis factor alpha (TNF-alpha) were detected within the T-cell population, suggesting the functional activity of these cells and the creation of a local T helper 1 (Th1)-cytokine milieu. Additionally, in one patient we could identify anti-melanocytic T cells by tetramer staining and enzyme-linked immunospot (ELISPOT) analysis. These skin-infiltrating lymphocytes might trigger, by the local production of Th-1 cytokines such as TNF-alpha and interferon-gamma (IFN-gamma), the eruption of psoriatic plaques in patients with a genetic predisposition for psoriasis.  相似文献   
79.
AIM: The innovations for disease management need to be thoroughly evaluated so that their benefits and potential downsides can be compared with the already existing approaches. Endovascular laser (EVL) treatment for varicose veins offers today several advantages over surgical standard stripping. The Italian Endovenous-laser Working Group (IEWG) is a homogeneous group of surgeons and phlebologists who have been using EVL since 1999 and has undertaken to examine EVL in a multicenter study starting from a well defined rationale, with the benefit of a single protocol to use. METHODS: In a cooperative, multicenter, clinical study, 1076 limbs in 1050 patients, mean age of 54.5 years, 241 males and 809 females affected by chronic venous insufficiency (CVI) were considered eligible for surgery and stratified by CEAP classification in a four-year period (January 1999 December 2003). Inclusion criteria were insufficiency of the great and/or small saphenous vein at various levels, beyond those accessory saphenous trunks with incompetence in the saphenofemoral junction. In all cases truncular reflux apparead up on duplex scan examination, with or without associated varicosities. All the patients underwent a surgery on the basis of the clinical assessment. All the centres involved performed treatment in conformity with the Food and Drug Administration (FDA) validated procedure, using an endo-laser venous system kit with a 810-980 nm diode. Duplex scan was performed in all patients after 36 months with very few lost to follow-up cases. RESULTS: In the immediate postoperative period the results have been impressive, with a very effective closure of incompetent great saphenous vein and the other treated varicose veins (the early occlusion rate has been 99%). Major complications have not been detected: in particular, no deep venous thrombosis (DVT) evaluated duplex ultrasound. The patients' acceptability and satisfaction regarding the procedure, have been measured by means of a questionnaire on the quality of life, and the result was 96.7%. After 36 months, the total occusion rate of saphenous trunks has been 97%. CONCLUSIONS: The first important Italian experience with EVL based on preoperative, perioperative and postoperative duplex control and which is also based on the patients' satisfaction at mid/long-term has indicated some advantages over the standard treatment with the stripping method. In terms of reduced postoperative pain, shorter sick leave, a faster resumption of the normal activities, and, in particular, the total absence of DVT, we can conclude that EVL is a good solution for all patients with anatomic and hemodinamic patterns for saphenous vein surgery.  相似文献   
80.
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