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   3431648篇
  免费   250781篇
  国内免费   9211篇
耳鼻咽喉   46433篇
儿科学   113179篇
妇产科学   95725篇
基础医学   481703篇
口腔科学   94756篇
临床医学   314599篇
内科学   673611篇
皮肤病学   81386篇
神经病学   282352篇
特种医学   130777篇
外国民族医学   1111篇
外科学   512345篇
综合类   74062篇
现状与发展   7篇
一般理论   1334篇
预防医学   267484篇
眼科学   77700篇
药学   248274篇
  8篇
中国医学   7250篇
肿瘤学   187544篇
  2019年   27431篇
  2018年   38478篇
  2017年   29543篇
  2016年   33948篇
  2015年   38233篇
  2014年   53270篇
  2013年   79975篇
  2012年   106713篇
  2011年   113197篇
  2010年   67821篇
  2009年   64739篇
  2008年   105213篇
  2007年   111626篇
  2006年   113478篇
  2005年   109196篇
  2004年   104721篇
  2003年   100983篇
  2002年   97565篇
  2001年   165392篇
  2000年   169447篇
  1999年   142484篇
  1998年   41206篇
  1997年   36692篇
  1996年   36715篇
  1995年   35506篇
  1994年   32418篇
  1993年   30337篇
  1992年   110006篇
  1991年   105600篇
  1990年   102324篇
  1989年   98569篇
  1988年   90419篇
  1987年   88582篇
  1986年   82967篇
  1985年   79400篇
  1984年   59539篇
  1983年   50464篇
  1982年   30173篇
  1981年   26900篇
  1979年   52625篇
  1978年   37246篇
  1977年   31388篇
  1976年   29242篇
  1975年   30829篇
  1974年   36711篇
  1973年   35094篇
  1972年   32984篇
  1971年   30503篇
  1970年   28346篇
  1969年   26991篇
排序方式: 共有10000条查询结果,搜索用时 21 毫秒
91.
92.
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   
93.
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   
94.
95.
BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare malignant tumour of the skin, with an estimated incidence of 0.8 to five cases per 1 million people per year. OBJECTIVE: To study epidemiological, immunohistochemical and clinical features, delay in diagnosis, type of treatment and outcome of DFSP from 1982 to 2002. METHODS: Using data from the population-based cancer registry, 66 patients with pathologically proved DFSP were included (fibrosarcomatous DFSP were excluded). Each patient lived in one of the four departments of Franche-Comté (overall population of 1 million people) at the time of diagnosis. The main data sources came from public and private pathology laboratories and medical records. The rules of the International Agency for Research on Cancer were applied. RESULTS: The estimated incidence of DFSP in Franche-Comté was about three new cases per 1 million people per year. Male patients were affected 1.2 times as often as female patients were. The trunk (45%) followed by the proximal extremities (38%) were the most frequent locations. DFSP occurred mainly in young adults between 20 and 39 years of age. Mean age at diagnosis was 43 years, and the mean delay in diagnosis was 10.08 years. Our 66 patients initially underwent a radical local excision. Among them, 27% experienced one or more local recurrences during 9.6 years of follow-up. There was one regional lymph node recurrence without visceral metastases. These recurrences were significantly related to the initial peripheral resection margins. We observed a local recurrence rate of 47% for margins less than 3 cm, vs. only 7% for margins ranging from 3 to 5 cm [P=0.004; OR=0.229 (95%, CI=0.103-0.510)]. The mean time to a first local recurrence was 2.65 years. Nevertheless, there was no death due to the DFSP course at the end of the follow-up, and the final outcome was favourable. CONCLUSION: Our study emphasizes the importance of wide local excision with margins of at least 3 cm in order to prevent local recurrence. However, the recent development of inhibitors of signal transduction by the PDGFB pathway should soon modify the surgical strategy, which is often too mutilating.  相似文献   
96.
97.
98.
99.
100.
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