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   2286999篇
  免费   167470篇
  国内免费   4443篇
耳鼻咽喉   31225篇
儿科学   74726篇
妇产科学   64511篇
基础医学   324012篇
口腔科学   63019篇
临床医学   204551篇
内科学   446315篇
皮肤病学   52932篇
神经病学   182541篇
特种医学   88612篇
外国民族医学   665篇
外科学   343281篇
综合类   49857篇
现状与发展   3篇
一般理论   715篇
预防医学   171860篇
眼科学   52069篇
药学   170093篇
  8篇
中国医学   5509篇
肿瘤学   132408篇
  2019年   17718篇
  2018年   25263篇
  2017年   19517篇
  2016年   22041篇
  2015年   24699篇
  2014年   34522篇
  2013年   51121篇
  2012年   69499篇
  2011年   73569篇
  2010年   43382篇
  2009年   41193篇
  2008年   68105篇
  2007年   72250篇
  2006年   73337篇
  2005年   70516篇
  2004年   67360篇
  2003年   64591篇
  2002年   62328篇
  2001年   118039篇
  2000年   121155篇
  1999年   100939篇
  1998年   26962篇
  1997年   24115篇
  1996年   24199篇
  1995年   22840篇
  1994年   20828篇
  1993年   19591篇
  1992年   76037篇
  1991年   72867篇
  1990年   70718篇
  1989年   67664篇
  1988年   61801篇
  1987年   60140篇
  1986年   56518篇
  1985年   53489篇
  1984年   39903篇
  1983年   33635篇
  1982年   19595篇
  1981年   17161篇
  1979年   35287篇
  1978年   24376篇
  1977年   20972篇
  1976年   19039篇
  1975年   20486篇
  1974年   24285篇
  1973年   23410篇
  1972年   22200篇
  1971年   20460篇
  1970年   19179篇
  1969年   18130篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
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   
52.
53.
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   
54.
55.
56.
57.
58.
59.
60.
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