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   566879篇
  免费   29576篇
  国内免费   638篇
耳鼻咽喉   7163篇
儿科学   19269篇
妇产科学   13184篇
基础医学   97009篇
口腔科学   13337篇
临床医学   51208篇
内科学   102138篇
皮肤病学   12852篇
神经病学   36204篇
特种医学   20880篇
外国民族医学   53篇
外科学   83727篇
综合类   8769篇
现状与发展   2篇
一般理论   122篇
预防医学   40361篇
眼科学   13289篇
药学   45030篇
  2篇
中国医学   1421篇
肿瘤学   31073篇
  2021年   5470篇
  2019年   4838篇
  2018年   7076篇
  2017年   5114篇
  2016年   6150篇
  2015年   6636篇
  2014年   8996篇
  2013年   12629篇
  2012年   18534篇
  2011年   20306篇
  2010年   11705篇
  2009年   10186篇
  2008年   17585篇
  2007年   19348篇
  2006年   18694篇
  2005年   17832篇
  2004年   17339篇
  2003年   16493篇
  2002年   15802篇
  2001年   23061篇
  2000年   23526篇
  1999年   19400篇
  1998年   5462篇
  1997年   4558篇
  1996年   4589篇
  1995年   4286篇
  1992年   14689篇
  1991年   16077篇
  1990年   16234篇
  1989年   15853篇
  1988年   14529篇
  1987年   14382篇
  1986年   13344篇
  1985年   12868篇
  1984年   9530篇
  1983年   8093篇
  1982年   4240篇
  1979年   9028篇
  1978年   6442篇
  1977年   5219篇
  1976年   5551篇
  1975年   6657篇
  1974年   7462篇
  1973年   7203篇
  1972年   6631篇
  1971年   6360篇
  1970年   5935篇
  1969年   5483篇
  1968年   5201篇
  1967年   4636篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Sudden cardiac death (SCD) due to ventricular arrhythmias hasa high morbidity and mortality. It is no wonder that cardiologists,rather than patching up survivors, are dedicated to findingpredictors of cardiac electrical instability to prevent SCD.The implantable cardiac defibrillator (ICD) has evolved as theultimate strategy for sudden arrhythmic death. In secondaryprevention, individuals are recognized by an aborted arrhythmicevent. By stratifying according to left ventricular ejectionfraction (LVEF) below 35%, SCD may also be prevented by an ICDin individuals without any prior arrhythmic event.1 However,the relative SCD risk based  相似文献   
992.
The paper presents the results of experimental and clinical testing of 3-hydroxypyridine derivatives (emoxipin, mexidol and new compounds) various extreme conditions (hypoxia, hyper- and hypothermia, vibration, hypokinesia, ionizing and nonionizing radiation and others). Analysis of the results led to the conclusion that 3-hydroxipiridine derivatives are a group of compounds worthy of further in-depth investigations in a broad range of extreme conditions in order to assess their potential use in development of new medical protectors of humans and animals facing extreme factors of various nature.  相似文献   
993.
994.
995.
996.
The aim of the study was to assess both p27 and p53 expression in the stromal and epithelial component of carcinosarcoma and to assess if their expression in the latter is different than in endometrial carcinoma. Immunohistochemical staining for p27 and p53 was performed on paraffin-embedded tissue blocks of 18 uterine specimens with carcinosarcoma and their expression assessed. Their expression in the epithelial element was also compared to that in 35 paraffin-embedded tissue blocks of endometrial endometrioid carcinoma. Reduced p27 expression was observed in a similarly high proportion of the stromal (77.8%) as well as of the epithelial component (66.7%) of carcinosarcoma. Although statistically not significant, the proportion of reduced p27 expression in endometrial carcinoma (85.7%) was higher than in the epithelial element of carcinosarcoma. The percentage of p53 overexpression in both elements of carcinosarcomas and in endometrial carcinomas was low and also similar (27.8 and 20.0%, respectively). Our results indicate that reduced p27 expression is common and p53 overexpression is infrequent in carcinosarcoma. Their similar rates of expression in the stromal and epithelial elements of the tumor support the contention of a monoclonal origin of carcinosarcoma. Unexpectedly, reduced p27 expression is more common in endometrial carcinoma than in the epithelial element of carcinosarcoma, in spite of the less favorable prognosticators and outcome in the latter. Further studies of p27 expression in carcinosarcoma are indicated to establish its clinical value in this aggressive malignancy.  相似文献   
997.
998.
The worldwide shortage of organs for transplantation makes it important to understand why some oppose donation. Attitudes vary with religion and ethnicity. Accordingly, we undertook a qualitative study of the attitudes of 141 U.K. Muslim Indo-Asians to organ donation. Participants were observed, focus group discussions held and in-depth individual interviews conducted. We identified a high level of alienation from the health care system in general. With respect to organ donation in particular, its importance was generally discounted, often in deference to authority figures within the community who appeared negatively disposed. The culture-specific issues arguing against donation included a sense of the sacredness of the body, a fatalistic approach to illness, a belief that organs took on an independent role as 'witnesses' to an individual's life on Judgement Day and an anxiety that the donor would have no control of the probity of the recipient of an organ. We believe these data suggest a need to improve in a culturally sensitive fashion the provision of health information provided to this community.  相似文献   
999.
1000.
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