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   1801471篇
  免费   124667篇
  国内免费   2633篇
耳鼻咽喉   25674篇
儿科学   54994篇
妇产科学   47240篇
基础医学   258165篇
口腔科学   52160篇
临床医学   160670篇
内科学   342123篇
皮肤病学   39362篇
神经病学   138899篇
特种医学   70216篇
外国民族医学   276篇
外科学   278765篇
综合类   36878篇
现状与发展   2篇
一般理论   494篇
预防医学   126983篇
眼科学   42446篇
药学   142374篇
  10篇
中国医学   4435篇
肿瘤学   106605篇
  2018年   18704篇
  2017年   14591篇
  2016年   16478篇
  2015年   18530篇
  2014年   25260篇
  2013年   36995篇
  2012年   51044篇
  2011年   53707篇
  2010年   31597篇
  2009年   29895篇
  2008年   50689篇
  2007年   53675篇
  2006年   54705篇
  2005年   52378篇
  2004年   50357篇
  2003年   48161篇
  2002年   46612篇
  2001年   97133篇
  2000年   99943篇
  1999年   83141篇
  1998年   20838篇
  1997年   18352篇
  1996年   18342篇
  1995年   17256篇
  1994年   15814篇
  1993年   14805篇
  1992年   62957篇
  1991年   60662篇
  1990年   59159篇
  1989年   57007篇
  1988年   51966篇
  1987年   50537篇
  1986年   47405篇
  1985年   45214篇
  1984年   32785篇
  1983年   27657篇
  1982年   15056篇
  1981年   13187篇
  1979年   29516篇
  1978年   20034篇
  1977年   17523篇
  1976年   15347篇
  1975年   17241篇
  1974年   20334篇
  1973年   19551篇
  1972年   18631篇
  1971年   17502篇
  1970年   16364篇
  1969年   15492篇
  1968年   14021篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
53.
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   
54.
55.
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   
56.
57.
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   
58.
59.
In chronic myeloid leukaemia, CD34(+) stem/progenitor cells appear resistant to imatinib mesylate (IM) in vitro and in vivo. To investigate the underlying mechanism(s) of IM resistance, it is essential to quantify Bcr-Abl kinase status at the stem cell level. We developed a flow cytometry method to measure CrkL phosphorylation (P-CrkL) in samples with <10(4) cells. The method was first validated in wild-type (K562) and mutant (BAF3) BCR-ABL(+) as well as BCR-ABL(-) (HL60) cell lines. In response to increasing IM concentration, there was a linear reduction in P-CrkL, which was Bcr-Abl specific and correlated with known resistance. The results were comparable to those from Western blotting. The method also proved to be reproducible with small samples of normal and Ph(+) CD34(+) cells and was able to discriminate between Ph(-), sensitive and resistant Ph(+) cells. This assay should now enable investigators to unravel the mechanism(s) of IM resistance in stem cells.  相似文献   
60.
Using complete denture treatment as an introduction to clinical patient care for dental students, the purposes of the Complete Denture Prosthodontics Transition Clinic at the University of Colorado School of Dentistry are to reduce the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience, and to encourage development of student self-confidence and skills. In the 2002 spring semester, faculty at the University of Colorado School of Dentistry initiated the Complete Denture Prosthodontics Transition Clinic for DS-II (second-year) dental students, as an introduction to clinical patient care. Each patient was assigned to a team of two dental students. Three Division of Prosthodontics faculty members staffed each clinic session, providing a student-to-faculty ratio of approximately 6.6:1 and a patient-to-faculty ratio of approximately 3.3:1. All DS-II students in the Class of 2004 delivered their first complete dentures no later than 8 months (average, 184 days) after the last day of the preclinical complete denture prosthodontics course. The time from the diagnostic appointment through the denture placement appointment averaged 39 days for patients treated in this program, compared with an average of 98 days or more for previous classes. The program was successful in achieving the goal of reducing the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience.  相似文献   
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