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   2319564篇
  免费   161828篇
  国内免费   5540篇
耳鼻咽喉   30833篇
儿科学   74943篇
妇产科学   62229篇
基础医学   336420篇
口腔科学   64262篇
临床医学   215812篇
内科学   441606篇
皮肤病学   48738篇
神经病学   187484篇
特种医学   88055篇
外国民族医学   572篇
外科学   332738篇
综合类   47510篇
现状与发展   3篇
一般理论   787篇
预防医学   186739篇
眼科学   51739篇
药学   176102篇
  12篇
中国医学   5679篇
肿瘤学   134669篇
  2021年   18320篇
  2019年   19100篇
  2018年   26911篇
  2017年   20797篇
  2016年   22947篇
  2015年   25921篇
  2014年   35732篇
  2013年   53499篇
  2012年   74012篇
  2011年   78302篇
  2010年   45576篇
  2009年   42540篇
  2008年   71901篇
  2007年   76469篇
  2006年   76755篇
  2005年   73528篇
  2004年   69838篇
  2003年   66815篇
  2002年   64465篇
  2001年   111570篇
  2000年   114489篇
  1999年   96157篇
  1998年   26285篇
  1997年   23344篇
  1996年   23131篇
  1995年   21773篇
  1994年   20097篇
  1993年   18877篇
  1992年   74298篇
  1991年   72064篇
  1990年   70372篇
  1989年   67137篇
  1988年   61568篇
  1987年   60139篇
  1986年   56959篇
  1985年   54017篇
  1984年   39917篇
  1983年   33900篇
  1982年   19549篇
  1979年   36055篇
  1978年   24951篇
  1977年   21251篇
  1976年   19727篇
  1975年   21146篇
  1974年   25309篇
  1973年   24698篇
  1972年   23086篇
  1971年   21598篇
  1970年   19929篇
  1969年   18643篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
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   
62.
Leocani  L.  Comi  G. 《Neurological sciences》2006,27(1):s27-s29
Neurological Sciences - Brain plasticity, intended as the pattern of functional and structural changes in responses to environmental physiological or pathological events, is underlined by several...  相似文献   
63.
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   
64.
65.
66.
67.
68.
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   
69.
70.
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