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   2686158篇
  免费   191250篇
  国内免费   10714篇
耳鼻咽喉   35590篇
儿科学   87324篇
妇产科学   74630篇
基础医学   377735篇
口腔科学   72628篇
临床医学   243677篇
内科学   531787篇
皮肤病学   64115篇
神经病学   219798篇
特种医学   103271篇
外国民族医学   753篇
外科学   399440篇
综合类   58144篇
现状与发展   13篇
一般理论   1001篇
预防医学   203354篇
眼科学   59217篇
药学   197179篇
  23篇
中国医学   7416篇
肿瘤学   151027篇
  2021年   21893篇
  2019年   22123篇
  2018年   31089篇
  2017年   24084篇
  2016年   27612篇
  2015年   31459篇
  2014年   42984篇
  2013年   63072篇
  2012年   84039篇
  2011年   88560篇
  2010年   53600篇
  2009年   51285篇
  2008年   82306篇
  2007年   87266篇
  2006年   88867篇
  2005年   84917篇
  2004年   81368篇
  2003年   78510篇
  2002年   75557篇
  2001年   132585篇
  2000年   135656篇
  1999年   114422篇
  1998年   32955篇
  1997年   29180篇
  1996年   29080篇
  1995年   28191篇
  1994年   25816篇
  1993年   24029篇
  1992年   87633篇
  1991年   84123篇
  1990年   81177篇
  1989年   78412篇
  1988年   71745篇
  1987年   70193篇
  1986年   65634篇
  1985年   62486篇
  1984年   46361篇
  1983年   39167篇
  1982年   23091篇
  1981年   20538篇
  1979年   40287篇
  1978年   28239篇
  1977年   23913篇
  1976年   22140篇
  1975年   23650篇
  1974年   27775篇
  1973年   26380篇
  1972年   24721篇
  1971年   22886篇
  1970年   21006篇
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
71.
Neu-Laxova syndrome (NLS) is a rare autosomal recessive syndrome, characterized by severe intrauterine growth retardation (IUGR), microcephaly, abnormal brain development, oedema and ichthyosis. It was first reported in 1971 by Neu et al. (Pediatrics 47: 610-612) and since then no more than 60 cases have been reported. A newborn girl delivered from a 29-year-old healthy mother was admitted to hospital with a thick membrane covering her body and dismorphic appearance. The diagnosis of NLS was made according to characteristic features. The syndrome is known to have a poor prognosis and the baby lived for 9 weeks. This case is one of the longest living cases of NLS and the fourth case reported from Turkey.  相似文献   
72.
The clinical outcome and appropriate management for patients showing 'borderline changes' on allograft biopsy after renal transplantation is still controversial. In an attempt to identify predictive factors of clinical outcome of patients with such lesions, we reviewed the clinical course of 91 patients with borderline changes. Multivariate analysis revealed significant and independent effects of histological stage (i + t < or = or > 2) and time to borderline changes (< or = or > 3 months after transplant) on serum creatinine levels at 1 year from borderline changes episodes (respectively, p = 0.04 and p = 0.02) and only a significant effect of time to borderline changes on serum creatinine levels at 2 years (p = 0.005). Renal function at 1 year and 2 years as 5- and 8-year graft survival were not significantly different in the group of patients treated with antirejection therapy (T group, n = 49) compared with the untreated group (UT group, n = 42). This study strongly suggests that borderline changes with histological score (i + t) > 2 and late episodes of borderline changes should be considered to be of poor prognosis.  相似文献   
73.
74.
75.
Primary chemotherapy administered to breast cancer patientsis the best model to identify baseline features able to predictwhich patients may be most likely to benefit or not from a cytotoxicregimen. In the March issue of Annals of Oncology two papersevaluated the predictive role of immunohistochemical p53 expressionon  相似文献   
76.
77.
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   
78.
79.
Bifid mandibular canal.   总被引:1,自引:0,他引:1  
PURPOSE: To determine the incidence and characteristics of bifid mandibular canals. METHODS: A retrospective study was performed using panoramic radiographs of 2012 patients subjected to dental treatment in the Dental Clinic of the Valencia University Dental School (Valencia, Spain) between 1996 and 1999. The goal was to investigate the presence of double mandibular canals. RESULTS: The extraoral panoramic radiographs revealed a total of 7 images suggestive of bifid canals. Mandibular computed tomography revealed the existence of this anatomic variant in 2 of 3 patients. An analysis was performed on the incidence of this type of image in extraoral panoramic radiography, its possible interpretations, and the clinical implications of bifid mandibular canals. CONCLUSIONS: In this study, 0.35% of canals were bifid. All cases were in women.  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