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   2549962篇
  免费   200019篇
  国内免费   3969篇
耳鼻咽喉   36304篇
儿科学   86562篇
妇产科学   72125篇
基础医学   362875篇
口腔科学   72867篇
临床医学   225825篇
内科学   498948篇
皮肤病学   54853篇
神经病学   204537篇
特种医学   101746篇
外国民族医学   1064篇
外科学   387878篇
综合类   59951篇
现状与发展   4篇
一般理论   867篇
预防医学   197094篇
眼科学   58669篇
药学   191457篇
  5篇
中国医学   4747篇
肿瘤学   135572篇
  2018年   24844篇
  2016年   21163篇
  2015年   24234篇
  2014年   33662篇
  2013年   51627篇
  2012年   70161篇
  2011年   74321篇
  2010年   44222篇
  2009年   42092篇
  2008年   71134篇
  2007年   75506篇
  2006年   76396篇
  2005年   74377篇
  2004年   72867篇
  2003年   70037篇
  2002年   68605篇
  2001年   119689篇
  2000年   124180篇
  1999年   105432篇
  1998年   29014篇
  1997年   26279篇
  1996年   26570篇
  1995年   25645篇
  1994年   24194篇
  1993年   22633篇
  1992年   86050篇
  1991年   83920篇
  1990年   82138篇
  1989年   78795篇
  1988年   73085篇
  1987年   71987篇
  1986年   67942篇
  1985年   65491篇
  1984年   49083篇
  1983年   42061篇
  1982年   24680篇
  1981年   22207篇
  1980年   20512篇
  1979年   46005篇
  1978年   32107篇
  1977年   27065篇
  1976年   25476篇
  1975年   27186篇
  1974年   32735篇
  1973年   31536篇
  1972年   29019篇
  1971年   26892篇
  1970年   24992篇
  1969年   23209篇
  1968年   21200篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
Granuloma annulare possibly triggered by antitetanus vaccination   总被引:4,自引:0,他引:4  
We report the case of a 6-year-old girl with granuloma annulare (GA) possibly related to antitetanus vaccinations. The first episode occurred 2 months after the girl had been vaccinated but the lesions were not located at the vaccination site. After 1 year of being free of lesions, she had a second episode unrelated to vaccination. After another 6-month lesion-free period, the girl was administered another antitetanus vaccination and a solitary lesion developed at the vaccination site within 3 days. A few lesions developed on her legs in the 2 months following the appearance of the initial plaque. The literature includes two reports of cases with papular lesions limited to the hepatitis B vaccination site, both histopathologically consistent with necrobiotic granuloma, but clinically not suggestive of GA. To the best of our knowledge, GA following antitetanus vaccination and occurring at the vaccination site has not been reported before. Either the trauma alone from the injection or a vaccine-induced immunological reaction might have triggered the necrobiosis of collagen through some unexplained mechanisms.  相似文献   
993.
994.
Poncet病(病例报告及文献复习)   总被引:4,自引:0,他引:4  
目的 探讨Poncet病的诊断与治疗。方法 通过病例报告及献复习,综述了Poncet病的发病机理、临床表现。结果 提高对Poncet病的认识。结论 临床上对风湿性或类风湿性关节炎病人均应与本病鉴别。  相似文献   
995.
996.
结果 髌股关节的压力与应力随膝关节屈曲角度的增加而升高,随膝关节屈曲角度的减小而降低(图3~8).不同膝关节屈曲角度下弓步变化和跨步变化的髌股关节压力见表1.  相似文献   
997.
998.
BACKGROUND: The recent amalgamation of data by users of the Perinatal Problem Identification Programme (PPIP) throughout South Africa has culminated in the publication of the Saving Babies report. OBJECTIVES: To determine the absolute rate of death from intrapartum-related birth asphyxia, and the contribution of intrapartum-related asphyxia to total perinatal mortality in South African hospitals, and to identify the primary obstetric causes and avoidable factors for these deaths. METHODS: The amalgamated PPIP data for the year 2000 were obtained from 27 state hospitals (6 metropolitan, 12 town and 9 rural) in South Africa. In PPIP-based audit, all perinatal deaths are assigned primary obstetric causes and avoidable factors, and these elements were obtained for all deaths resulting from intrapartum-related birth asphyxia. RESULTS: There were 123,508 births in the hospitals surveyed, with 4,142 perinatal deaths among infants > or = 1,000 g, giving a perinatal mortality rate of 33.5/1,000 births. The perinatal mortality rate from intrapartum-related birth asphyxia was 4.8/1,000 births. The most frequent avoidable factors were delay by mothers in seeking attention during labour (36.6%), signs of fetal distress interpreted incorrectly (24.9%), inadequate fetal monitoring (18.0%) and no response to poor progress in labour (7.0%). The perinatal mortality rates for metropolitan, town, and rural areas were 30.0, 39.4 and 30.9/1,000 births respectively. The contribution of intrapartum-related birth asphyxia to perinatal mortality in these areas was 10.8%, 16.7% and 26.4% respectively. CONCLUSION: The high rates of perinatal death from intrapartum-related birth asphyxia in South Africa are typical of those in underdeveloped countries, with the most serious deficiencies in rural areas. Most of these deaths are avoidable and the reduction of these rates presents an important challenge to providers of perinatal care in this country. Areas worthy of research and action include provision of mothers' waiting facilities in rural regions, improvements in fetal monitoring, partogram-based labour management, and the establishment of midwifery staffing norms for South African labour units.  相似文献   
999.
Oxidative stress is an important factor in many pathological conditions such as inflammation, cancer, ageing and organ response to ischemia-reperfusion. Humans have developed a complex antioxidant system to eliminate or attenuate oxidative stress. Liver ischemia-reperfusion injury occurs in a number of clinical settings, including liver surgery, transplantation, and hemorrhagic shock with subsequent fluid resuscitation, leading to significant morbidity and mortality. It is characterized by significant oxidative stress but accompanied with depletion of endogenous antioxidants. This review has 2 aims: firstly, to highlight the clinical significance of liver ischemia-reperfusion injury, the underlying mechanisms and the main pathways by which the antioxidants function, and secondly, to describe the new developments that are ongoing in antioxidant therapy and to present the experimental and clinical evidence about the role of antioxidants in modulating hepatic ischemia-reperfusion injury.  相似文献   
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