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   1466075篇
  免费   107491篇
  国内免费   2439篇
耳鼻咽喉   18491篇
儿科学   46128篇
妇产科学   38875篇
基础医学   214495篇
口腔科学   38639篇
临床医学   138660篇
内科学   289739篇
皮肤病学   30204篇
神经病学   122170篇
特种医学   55702篇
外国民族医学   278篇
外科学   210273篇
综合类   27967篇
现状与发展   4篇
一般理论   734篇
预防医学   119023篇
眼科学   32886篇
药学   105985篇
  8篇
中国医学   2308篇
肿瘤学   83436篇
  2021年   13900篇
  2019年   14296篇
  2018年   18713篇
  2017年   14201篇
  2016年   15515篇
  2015年   17939篇
  2014年   25066篇
  2013年   37206篇
  2012年   52295篇
  2011年   55297篇
  2010年   31817篇
  2009年   30320篇
  2008年   51384篇
  2007年   54653篇
  2006年   53921篇
  2005年   52856篇
  2004年   50560篇
  2003年   47839篇
  2002年   46240篇
  2001年   57722篇
  2000年   58325篇
  1999年   49871篇
  1998年   15800篇
  1997年   14136篇
  1996年   14328篇
  1995年   13433篇
  1994年   12422篇
  1993年   11698篇
  1992年   39069篇
  1991年   38469篇
  1990年   37127篇
  1989年   35910篇
  1988年   33297篇
  1987年   32575篇
  1986年   31084篇
  1985年   29378篇
  1984年   22742篇
  1983年   19888篇
  1982年   12249篇
  1979年   21353篇
  1978年   15835篇
  1977年   13182篇
  1976年   12204篇
  1975年   13096篇
  1974年   15868篇
  1973年   15605篇
  1972年   14677篇
  1971年   13692篇
  1970年   12883篇
  1969年   12141篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
32.
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   
33.
34.
35.
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   
36.
Cell physiology and molecular biology typically follow a reductionistic approach in science. In the last decade, molecular principles and pathogenetic factors involved in the development of many diseases have been successfully discovered. Therefore, early biological concepts based on systemic and cybernetic thoughts have been largely overshadowed by these more recent molecular and pathogenetic factors. This review highlights discoveries on bone development and hypothalamic controlled feeding and eating behavior with a cybernetic and systemic perspective. Interestingly, ancient ideas on bone development and hypothalamic function are still reasonable considerations to embed new molecular discoveries into a systemic concept of principles organizing nature.  相似文献   
37.
38.
Contour defects resulting in deformity caused by lack of tissue can be improved by conventional surgery using autologous tissue, but there is always a donor site morbidity. Integra has been available since the early 1980's for use in acute burns and more recently in reconstruction. It has been shown histologically to act as a tissue regeneration template. The regenerated dermis is buried under an autologous thin split-skin graft. In this study, the principle of burying Integra (without the silicone layer) has been applied to deep tissue defects in 12 reconstructive cases. Such regenerated tissues survive at least 3 years after burying. Modification to the technique to avoid visible edges are being developed.  相似文献   
39.
40.
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