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   2328730篇
  免费   172307篇
  国内免费   5623篇
耳鼻咽喉   30422篇
儿科学   75804篇
妇产科学   64674篇
基础医学   344348篇
口腔科学   64939篇
临床医学   223243篇
内科学   448162篇
皮肤病学   48352篇
神经病学   191425篇
特种医学   84925篇
外国民族医学   603篇
外科学   325379篇
综合类   50441篇
现状与发展   4篇
一般理论   978篇
预防医学   197979篇
眼科学   52111篇
药学   171481篇
  13篇
中国医学   4785篇
肿瘤学   126592篇
  2019年   19164篇
  2018年   26287篇
  2017年   20030篇
  2016年   21752篇
  2015年   24953篇
  2014年   34637篇
  2013年   53509篇
  2012年   73081篇
  2011年   77795篇
  2010年   45204篇
  2009年   42509篇
  2008年   72051篇
  2007年   76729篇
  2006年   76455篇
  2005年   74358篇
  2004年   71202篇
  2003年   67960篇
  2002年   65777篇
  2001年   101828篇
  2000年   104433篇
  1999年   87988篇
  1998年   25224篇
  1997年   22932篇
  1996年   22983篇
  1995年   21808篇
  1994年   20366篇
  1993年   19088篇
  1992年   70289篇
  1991年   69220篇
  1990年   67134篇
  1989年   64244篇
  1988年   59549篇
  1987年   58395篇
  1986年   55699篇
  1985年   53106篇
  1984年   40135篇
  1983年   34783篇
  1982年   20863篇
  1979年   37553篇
  1978年   27224篇
  1977年   22465篇
  1976年   21546篇
  1975年   22591篇
  1974年   27611篇
  1973年   27200篇
  1972年   25370篇
  1971年   23729篇
  1970年   22208篇
  1969年   20614篇
  1968年   19441篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
62.
Primary chemotherapy administered to breast cancer patientsis the best model to identify baseline features able to predictwhich patients may be most likely to benefit or not from a cytotoxicregimen. In the March issue of Annals of Oncology two papersevaluated the predictive role of immunohistochemical p53 expressionon  相似文献   
63.
64.
65.
Cutaneous plasmacytosis is a rare disorder characterized by a benign proliferation of mature plasma cells that appears as multiple dark-brown to purplish skin lesions, often associated with polyclonal hypergammaglobulinaemia. We present the case of a 55-year-old Caucasian man who suffered from a cutaneous plasmacytosis associated with two different carcinomas. Cutaneous plasmacytosis seems to be a reactive process because most cases reported are not associated with any apparent underlying disease. Nevertheless, because few reported cases were associated with malignancies, screening of additional neoplasms would be justified.  相似文献   
66.
Cell physiology and molecular biology typically follow a reductionistic approach in science. In the last decade, molecular principles and pathogenetic factors involved in the development of many diseases have been successfully discovered. Therefore, early biological concepts based on systemic and cybernetic thoughts have been largely overshadowed by these more recent molecular and pathogenetic factors. This review highlights discoveries on bone development and hypothalamic controlled feeding and eating behavior with a cybernetic and systemic perspective. Interestingly, ancient ideas on bone development and hypothalamic function are still reasonable considerations to embed new molecular discoveries into a systemic concept of principles organizing nature.  相似文献   
67.
68.
Patients with multiple system atrophy (MSA) present large changes in blood pressure (BP) due to autonomic disturbances. We analyzed how this change may influence dynamic cerebral autoregulation (DCA). Simultaneous recordings of arterial BP (Finapres) and middle cerebral artery (MCA) blood flow velocity (BFV) (transcranial Doppler) were performed in 10 patients with MSA (61 +/- 12 yr of age) and 12 healthy volunteers (61 +/- 11 yr of age): cerebral BFV response to oscillations in mean BP was studied in the supine position by cross-spectral analysis of mean BP and mean MCA BFV. The DCA was also studied during the decrease in BP the first seconds when standing up from a sitting position by the assessment of the cerebrovascular resistance index (CR; mean BP/mean MCA BFV ratio). The MCA BFV/BP cross-spectral analysis showed a phase for the mid-frequency band (0.07-0.2 Hz) significantly larger in MSA, suggesting more active autoregulation in response to larger changes in BP. Changes in CR reflecting the rate of autoregulation, when standing did not differ between the two groups. These data suggest that dynamic cerebral autoregulation is preserved in MSA.  相似文献   
69.
Contour defects resulting in deformity caused by lack of tissue can be improved by conventional surgery using autologous tissue, but there is always a donor site morbidity. Integra has been available since the early 1980's for use in acute burns and more recently in reconstruction. It has been shown histologically to act as a tissue regeneration template. The regenerated dermis is buried under an autologous thin split-skin graft. In this study, the principle of burying Integra (without the silicone layer) has been applied to deep tissue defects in 12 reconstructive cases. Such regenerated tissues survive at least 3 years after burying. Modification to the technique to avoid visible edges are being developed.  相似文献   
70.
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