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   2345689篇
  免费   175826篇
  国内免费   5867篇
耳鼻咽喉   32303篇
儿科学   79204篇
妇产科学   64277篇
基础医学   339611篇
口腔科学   63739篇
临床医学   218373篇
内科学   456817篇
皮肤病学   48986篇
神经病学   190325篇
特种医学   88860篇
外国民族医学   915篇
外科学   341171篇
综合类   51692篇
现状与发展   2篇
一般理论   801篇
预防医学   191310篇
眼科学   52104篇
药学   173886篇
  7篇
中国医学   5068篇
肿瘤学   127931篇
  2019年   18605篇
  2018年   26189篇
  2017年   19728篇
  2016年   21559篇
  2015年   24631篇
  2014年   34087篇
  2013年   52602篇
  2012年   72159篇
  2011年   76605篇
  2010年   45106篇
  2009年   42229篇
  2008年   71355篇
  2007年   75971篇
  2006年   76244篇
  2005年   73926篇
  2004年   71296篇
  2003年   68543篇
  2002年   66680篇
  2001年   108057篇
  2000年   111794篇
  1999年   94455篇
  1998年   26680篇
  1997年   24109篇
  1996年   24197篇
  1995年   23019篇
  1994年   21717篇
  1993年   20268篇
  1992年   75635篇
  1991年   74117篇
  1990年   71886篇
  1989年   68502篇
  1988年   63350篇
  1987年   62195篇
  1986年   58634篇
  1985年   56084篇
  1984年   42329篇
  1983年   35826篇
  1982年   21180篇
  1981年   19127篇
  1979年   38153篇
  1978年   26936篇
  1977年   22447篇
  1976年   21507篇
  1975年   22664篇
  1974年   27084篇
  1973年   26344篇
  1972年   24277篇
  1971年   22324篇
  1970年   20970篇
  1969年   19012篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
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   
72.
73.
AIM: The intention was to investigate cerebrospinal fluid pressure (CSFP) and volume of cerebrospinal fluid (CSF) drained during and after thoracic- and thoracoabdominal aneurysm repair. The findings were related to the occurrence of postoperative neurologic deficits. METHODS: Twenty-nine patients (12 with thoracic and 17 with thoracoabdominal aortic aneurysm) were operated without shunting or extracorporeal circulation. For monitoring of CSFP an intrathecal catheter was placed in all patients. The volume of CSF withdrawn intraoperatively, on the day of operation as well as on the 1st and 2nd postoperative day was recorded. RESULTS: Twenty-six patients had no postoperative neurologic sequelae. One patient had postoperative paraplegia while 2 had paraparesis. The three patients with neurologic sequelae had higher CSFP intraoperatively than those without neurologic symptoms (P=0.04). Median CSFP during aortic cross-clamping was 19 mmHg and 10 mmHg and the median volumes of CSF drained on the day of operation 210 and 85 mL in the two groups, respectively. There was a significant positive correlation between CSFP and central venous pressure. CONCLUSIONS: A higher intraoperative CSFP was observed in patients with neurologic sequelae following thoracic- and thoracoabdominal aneurysm repair. Further, there was a tendency of higher volumes of CSF drained in this group of patients. Although, the series is too small to allow firm conclusions, it supports the view that CSFP monitoring and drainage is beneficial during thoracic- and thoracoabdominal aneurysm repair.  相似文献   
74.
75.
76.
77.
Primary chemotherapy administered to breast cancer patientsis the best model to identify baseline features able to predictwhich patients may be most likely to benefit or not from a cytotoxicregimen. In the March issue of Annals of Oncology two papersevaluated the predictive role of immunohistochemical p53 expressionon  相似文献   
78.
79.
80.
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