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   1787748篇
  免费   123796篇
  国内免费   2609篇
耳鼻咽喉   25467篇
儿科学   54510篇
妇产科学   47095篇
基础医学   256599篇
口腔科学   51754篇
临床医学   159028篇
内科学   339846篇
皮肤病学   39142篇
神经病学   137540篇
特种医学   69769篇
外国民族医学   276篇
外科学   276509篇
综合类   36692篇
现状与发展   2篇
一般理论   479篇
预防医学   125599篇
眼科学   42189篇
药学   141226篇
  10篇
中国医学   4442篇
肿瘤学   105979篇
  2018年   18416篇
  2017年   14401篇
  2016年   16277篇
  2015年   18302篇
  2014年   24852篇
  2013年   36395篇
  2012年   50046篇
  2011年   52722篇
  2010年   31052篇
  2009年   29376篇
  2008年   49736篇
  2007年   52708篇
  2006年   53699篇
  2005年   51350篇
  2004年   49386篇
  2003年   47361篇
  2002年   45853篇
  2001年   97024篇
  2000年   99824篇
  1999年   83012篇
  1998年   20658篇
  1997年   18211篇
  1996年   18229篇
  1995年   17153篇
  1994年   15708篇
  1993年   14720篇
  1992年   62904篇
  1991年   60601篇
  1990年   59105篇
  1989年   56942篇
  1988年   51888篇
  1987年   50491篇
  1986年   47345篇
  1985年   45164篇
  1984年   32716篇
  1983年   27587篇
  1982年   14992篇
  1981年   13117篇
  1979年   29464篇
  1978年   19985篇
  1977年   17487篇
  1976年   15323篇
  1975年   17197篇
  1974年   20309篇
  1973年   19509篇
  1972年   18590篇
  1971年   17464篇
  1970年   16331篇
  1969年   15468篇
  1968年   13995篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
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   
82.
83.
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   
84.
85.
芦荟自古就被用作化妆品和药物添加剂,近来更受喜爱。虽应用广泛,但过敏反应罕有报道。作者用芦荟叶的油性提取物、来自整个植株的芦荟粉及浓缩的芦荟凝胶,对相继就诊的702例患者做斑贴试验。设计专门的问卷调查芦荟的使用、使用原因、使用部位、不良反应、患者职业、个人爱好及是否为遗传性过敏体质。患者均未对任一制剂发生任何反应。需对芦荟所含的两种成分加以鉴别:即芦荟叶皮含有的具有促进肠蠕动、潜在抗菌及抗癌特性的蒽醌类物质。  相似文献   
86.
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   
87.
88.
89.
Published data devoted to making and characterization of the properties of polymeric wound dressings with proteolytic action are reviewed. These data are indicative of individual dependence of the physicochemical properties, activity, and stability of each particular enzyme on the type of polymer matrix and the method of immobilization. In order to obtain wound dressings, which are active in physiological medium and retain their activity upon sterilization, it is necessary to optimize the composition and characteristics of a polymer matrix and the enzyme included into its structure. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 40, No. 8, pp. 24–28, August, 2006.  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