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   1449538篇
  免费   117838篇
  国内免费   6251篇
耳鼻咽喉   18719篇
儿科学   47252篇
妇产科学   41475篇
基础医学   204482篇
口腔科学   38565篇
临床医学   131278篇
内科学   289169篇
皮肤病学   33720篇
神经病学   118311篇
特种医学   55158篇
外国民族医学   474篇
外科学   213643篇
综合类   41271篇
现状与发展   14篇
一般理论   488篇
预防医学   113676篇
眼科学   32560篇
药学   103088篇
  58篇
中国医学   6201篇
肿瘤学   84025篇
  2021年   13292篇
  2019年   13025篇
  2018年   17983篇
  2017年   14086篇
  2016年   15535篇
  2015年   18048篇
  2014年   24960篇
  2013年   35767篇
  2012年   48722篇
  2011年   51337篇
  2010年   30587篇
  2009年   29014篇
  2008年   46412篇
  2007年   48879篇
  2006年   49312篇
  2005年   47611篇
  2004年   44842篇
  2003年   42685篇
  2002年   40937篇
  2001年   73624篇
  2000年   75130篇
  1999年   62198篇
  1998年   17367篇
  1997年   15826篇
  1996年   15866篇
  1995年   15088篇
  1994年   13620篇
  1993年   12720篇
  1992年   45979篇
  1991年   43632篇
  1990年   41616篇
  1989年   39658篇
  1988年   36257篇
  1987年   35423篇
  1986年   32925篇
  1985年   31316篇
  1984年   23850篇
  1983年   20038篇
  1982年   12223篇
  1981年   10788篇
  1979年   20712篇
  1978年   14577篇
  1977年   12084篇
  1976年   11364篇
  1975年   11619篇
  1974年   13988篇
  1973年   13533篇
  1972年   12633篇
  1971年   11469篇
  1970年   10910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