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   2101076篇
  免费   151567篇
  国内免费   5351篇
耳鼻咽喉   28108篇
儿科学   63073篇
妇产科学   55478篇
基础医学   304395篇
口腔科学   60470篇
临床医学   195506篇
内科学   405891篇
皮肤病学   42335篇
神经病学   170071篇
特种医学   78805篇
外国民族医学   432篇
外科学   312053篇
综合类   44092篇
现状与发展   2篇
一般理论   668篇
预防医学   164171篇
眼科学   46866篇
药学   158698篇
  10篇
中国医学   4992篇
肿瘤学   121878篇
  2019年   16131篇
  2018年   23041篇
  2017年   17568篇
  2016年   19238篇
  2015年   21964篇
  2014年   30087篇
  2013年   45917篇
  2012年   62920篇
  2011年   66432篇
  2010年   38920篇
  2009年   36282篇
  2008年   62371篇
  2007年   65652篇
  2006年   66484篇
  2005年   64052篇
  2004年   61486篇
  2003年   58734篇
  2002年   57183篇
  2001年   104590篇
  2000年   107961篇
  1999年   90302篇
  1998年   23449篇
  1997年   21052篇
  1996年   20888篇
  1995年   19680篇
  1994年   18336篇
  1993年   17072篇
  1992年   70503篇
  1991年   68448篇
  1990年   66294篇
  1989年   63744篇
  1988年   58703篇
  1987年   57170篇
  1986年   54006篇
  1985年   51664篇
  1984年   38002篇
  1983年   32264篇
  1982年   18208篇
  1979年   34236篇
  1978年   23685篇
  1977年   19788篇
  1976年   18505篇
  1975年   19526篇
  1974年   23824篇
  1973年   22891篇
  1972年   21435篇
  1971年   20186篇
  1970年   18926篇
  1969年   17493篇
  1968年   16358篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
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   
52.
53.
54.
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   
55.
56.
57.
58.
59.
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   
60.
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