首页 | 官方网站   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   2006039篇
  免费   155235篇
  国内免费   3036篇
医药卫生   2164310篇
  2018年   18453篇
  2015年   18420篇
  2014年   25364篇
  2013年   38828篇
  2012年   52452篇
  2011年   56040篇
  2010年   32938篇
  2009年   31398篇
  2008年   53690篇
  2007年   56815篇
  2006年   57805篇
  2005年   55862篇
  2004年   55152篇
  2003年   52647篇
  2002年   51713篇
  2001年   93202篇
  2000年   96587篇
  1999年   81485篇
  1998年   21926篇
  1997年   19865篇
  1996年   20061篇
  1995年   19427篇
  1994年   18264篇
  1993年   17298篇
  1992年   66967篇
  1991年   66223篇
  1990年   65155篇
  1989年   62978篇
  1988年   58504篇
  1987年   57686篇
  1986年   54774篇
  1985年   52993篇
  1984年   39494篇
  1983年   33946篇
  1982年   19620篇
  1981年   17731篇
  1980年   16649篇
  1979年   37899篇
  1978年   26550篇
  1977年   22409篇
  1976年   21260篇
  1975年   22889篇
  1974年   27819篇
  1973年   26594篇
  1972年   24726篇
  1971年   23387篇
  1970年   21538篇
  1969年   20308篇
  1968年   18709篇
  1967年   16955篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
82.
83.
84.
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   
85.
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   
86.
87.
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   
88.
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   
89.
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   
90.
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-23

京公网安备 11010802026262号