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   1808522篇
  免费   133845篇
  国内免费   2640篇
耳鼻咽喉   23243篇
儿科学   60100篇
妇产科学   49988篇
基础医学   250658篇
口腔科学   49124篇
临床医学   155908篇
内科学   351350篇
皮肤病学   35174篇
神经病学   148599篇
特种医学   74799篇
外国民族医学   474篇
外科学   278815篇
综合类   42548篇
现状与发展   3篇
一般理论   579篇
预防医学   142676篇
眼科学   39760篇
药学   132688篇
  3篇
中国医学   3617篇
肿瘤学   104901篇
  2018年   37680篇
  2017年   29958篇
  2016年   34150篇
  2015年   16688篇
  2014年   22445篇
  2013年   33269篇
  2012年   51126篇
  2011年   67762篇
  2010年   45959篇
  2009年   37970篇
  2008年   64966篇
  2007年   70412篇
  2006年   47783篇
  2005年   48590篇
  2004年   49296篇
  2003年   48812篇
  2002年   45607篇
  2001年   76236篇
  2000年   79114篇
  1999年   66744篇
  1998年   18118篇
  1997年   16748篇
  1996年   16530篇
  1995年   16216篇
  1994年   15302篇
  1993年   14401篇
  1992年   55590篇
  1991年   53965篇
  1990年   52758篇
  1989年   50995篇
  1988年   47358篇
  1987年   46704篇
  1986年   44408篇
  1985年   42958篇
  1984年   32124篇
  1983年   27659篇
  1982年   16267篇
  1981年   14469篇
  1979年   30590篇
  1978年   21144篇
  1977年   17786篇
  1976年   16774篇
  1975年   17593篇
  1974年   21537篇
  1973年   20692篇
  1972年   18865篇
  1971年   17783篇
  1970年   16333篇
  1969年   15316篇
  1968年   13982篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
72.
73.
74.
PURPOSE: In children with locally advanced or recurrent malignant tumours, prognosis can be improved by regional deep hyperthermia (RHT) in combination with platin-based chemotherapy. However, because of the increasing number of patients that achieve long-time remission with this therapy, it is necessary to evaluate long-term sequelae of thermochemotherapy. During the years 1993-2004 one has observed avascular osteonecrosis (AON) of the femoral head after RHT in seven children with pelvic germ cell tumours or rhabdomyosarcomas. METHODS: Although AON may develop in patients with malignancies treated with chemo- or radiotherapy alone, RHT might nevertheless contribute to the occurrence of AON. In order to determine potential risk factors for AON after RHT, this study analysed the relationship of AON to the patient's age, medical history and treatment parameters such as thermal dose equivalent and power output. RESULTS AND CONCLUSIONS: In the present study AON was associated with young age as well as intensity of hyperthermia indicated by high power levels that exceed 20 W per kg body weight and/or application of eight or more heat sessions as well as additional radiotherapy. Based on this observation, it was assumed that an optimized three dimensional thermal field modelling may be helpful to avoid hazardous temperatures in the femoral heads during RHT treatment and to reduce AON of the femoral heads.  相似文献   
75.
76.
Carbon monoxide (CO), a byproduct of heme catalysis, was shown to have potent cytoprotective and anti-inflammatory effects. In vivo recipient CO inhalation at low concentrations prevented ischemia/reperfusion (I/R) injury associated with small intestinal transplantation (SITx). This study examined whether ex vivo delivery of CO in University of Wisconsin (UW) solution could ameliorate intestinal I/R injury. Orthotopic syngenic SITx was performed in Lewis rats after 6 h cold preservation in control UW or UW that was bubbled with CO gas (0.1-5%) (CO-UW). Recipient survival with intestinal grafts preserved in 5%, but not 0.1%, CO-UW improved to 86.7% (13/15) from 53% (9/17) with control UW. At 3 h after SITx, grafts stored in 5% CO-UW showed improved intestinal barrier function, less mucosal denudation and reduced inflammatory mediator upregulation compared to those in control UW. Preservation in CO-UW associated with reduced vascular resistance (end preservation), increased graft cyclic guanosine monophosphate levels (1 h), and improved graft blood flow (1 h). Protective effects of CO-UW were reversed by ODQ, an inhibitor of soluble guanylyl cyclase. In vitro culture experiment also showed better preservation of vascular endothelial cells with CO-UW. The study suggests that ex vivo CO delivery into UW solution would be a simple and innovative therapeutic strategy to prevent transplant-induced I/R injury.  相似文献   
77.
The absence of the temporary incisors could be to a genetic illness or to some multiple premature extractions. These extractions are the aftermaths of the carious lesions or some traumatisms underwent by the temporary incisors. Beyond measure the loss of the space, the premature loss some temporary incisors very often assign the relational development of the child and disturb its psychological development and the aesthetic function. Across some cases clinics, the authors show that the replacement of the temporary incisors is the therapeutic ideal solution. Indeed, the child prosthesis, replacing the temporary absent incisors, solves the psychological, aesthetic and relational problems of the child.  相似文献   
78.
79.
背景:针对糖尿病患者Lp(a)水平和冠状动脉疾病(CAD)严重程度之间关系的研究较少并且结论有争议。另外,目前尚无关于apo(a)多态性与上述疾病关系的研究。本研究旨在探讨大样本2型糖尿病患者中冠状动脉粥样硬化的程度与Lp(a)水平及apo(a)多态性的相关性。方法:连续选取227例2型糖  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