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   1305399篇
  免费   97772篇
  国内免费   1763篇
耳鼻咽喉   16835篇
儿科学   41847篇
妇产科学   35813篇
基础医学   195145篇
口腔科学   35634篇
临床医学   121866篇
内科学   256438篇
皮肤病学   28284篇
神经病学   105824篇
特种医学   48464篇
外国民族医学   267篇
外科学   186040篇
综合类   26159篇
现状与发展   3篇
一般理论   641篇
预防医学   106977篇
眼科学   28871篇
药学   95073篇
  7篇
中国医学   2093篇
肿瘤学   72653篇
  2021年   10914篇
  2019年   11168篇
  2018年   14870篇
  2017年   11293篇
  2016年   12381篇
  2015年   14300篇
  2014年   19639篇
  2013年   29384篇
  2012年   40667篇
  2011年   43040篇
  2010年   24783篇
  2009年   23772篇
  2008年   40180篇
  2007年   42835篇
  2006年   42263篇
  2005年   41229篇
  2004年   39515篇
  2003年   37784篇
  2002年   36541篇
  2001年   56451篇
  2000年   57437篇
  1999年   48520篇
  1998年   13777篇
  1997年   12517篇
  1996年   12857篇
  1995年   12121篇
  1994年   11276篇
  1992年   38490篇
  1991年   37924篇
  1990年   36679篇
  1989年   35467篇
  1988年   32894篇
  1987年   32208篇
  1986年   30710篇
  1985年   28989篇
  1984年   22112篇
  1983年   19362篇
  1982年   11504篇
  1979年   21082篇
  1978年   15516篇
  1977年   12907篇
  1976年   11964篇
  1975年   12910篇
  1974年   15706篇
  1973年   15454篇
  1972年   14616篇
  1971年   13653篇
  1970年   12871篇
  1969年   12138篇
  1968年   11306篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
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   
53.
In rare cases the usage of the internal thoracic vessels as recipient vessels in reconstructive surgery of the head and neck region with free tissue transfer is a challenging but valid alternative if local recipient vessels are unusable.  相似文献   
54.
55.
56.
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   
57.
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   
58.
59.
60.
The absence of the temporary incisors could be to a genetic illness or to some multiple premature extractions. These extractions are the aftermaths of the carious lesions or some traumatisms underwent by the temporary incisors. Beyond measure the loss of the space, the premature loss some temporary incisors very often assign the relational development of the child and disturb its psychological development and the aesthetic function. Across some cases clinics, the authors show that the replacement of the temporary incisors is the therapeutic ideal solution. Indeed, the child prosthesis, replacing the temporary absent incisors, solves the psychological, aesthetic and relational problems of the child.  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