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   1518686篇
  免费   118005篇
  国内免费   3605篇
耳鼻咽喉   19939篇
儿科学   49759篇
妇产科学   43548篇
基础医学   215216篇
口腔科学   41469篇
临床医学   132826篇
内科学   310888篇
皮肤病学   36861篇
神经病学   125420篇
特种医学   56231篇
外国民族医学   464篇
外科学   223677篇
综合类   33352篇
现状与发展   3篇
一般理论   519篇
预防医学   120796篇
眼科学   33875篇
药学   105976篇
  1篇
中国医学   3895篇
肿瘤学   85581篇
  2021年   13327篇
  2019年   14359篇
  2018年   20879篇
  2017年   15173篇
  2016年   16526篇
  2015年   18542篇
  2014年   25603篇
  2013年   37979篇
  2012年   53286篇
  2011年   56344篇
  2010年   32480篇
  2009年   30167篇
  2008年   51035篇
  2007年   53963篇
  2006年   53911篇
  2005年   52293篇
  2004年   49504篇
  2003年   47039篇
  2002年   45251篇
  2001年   75589篇
  2000年   77600篇
  1999年   63831篇
  1998年   17433篇
  1997年   15733篇
  1996年   15853篇
  1995年   15010篇
  1994年   13569篇
  1993年   12726篇
  1992年   46721篇
  1991年   44220篇
  1990年   42224篇
  1989年   40136篇
  1988年   36673篇
  1987年   35840篇
  1986年   33375篇
  1985年   31694篇
  1984年   24134篇
  1983年   20268篇
  1982年   12333篇
  1981年   10895篇
  1979年   20993篇
  1978年   14757篇
  1977年   12263篇
  1976年   11545篇
  1975年   11857篇
  1974年   14259篇
  1973年   13843篇
  1972年   12897篇
  1971年   11750篇
  1970年   11175篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
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   
62.
63.
A 65-year-old man developed acute limb ischemia, severe abdominal wall and lower limb livedo reticularis following a coronary angiogram. The differential diagnoses of acute limb ischemia and multiple cholesterol emboli syndrome (MCES) are discussed. This work was performed at Long Island Jewish Medical Center, 270-05, 76th Avenue, New Hyde Park, NY 11040.  相似文献   
64.
65.
66.
67.
68.
69.
70.
Cutaneous plasmacytosis is a rare disorder characterized by a benign proliferation of mature plasma cells that appears as multiple dark-brown to purplish skin lesions, often associated with polyclonal hypergammaglobulinaemia. We present the case of a 55-year-old Caucasian man who suffered from a cutaneous plasmacytosis associated with two different carcinomas. Cutaneous plasmacytosis seems to be a reactive process because most cases reported are not associated with any apparent underlying disease. Nevertheless, because few reported cases were associated with malignancies, screening of additional neoplasms would be justified.  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