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   2137716篇
  免费   154120篇
  国内免费   5460篇
耳鼻咽喉   28586篇
儿科学   63873篇
妇产科学   56268篇
基础医学   309434篇
口腔科学   61345篇
临床医学   199128篇
内科学   413688篇
皮肤病学   43273篇
神经病学   173621篇
特种医学   80279篇
外国民族医学   434篇
外科学   318817篇
综合类   44170篇
现状与发展   2篇
一般理论   737篇
预防医学   166124篇
眼科学   47566篇
药学   160755篇
  9篇
中国医学   5004篇
肿瘤学   124183篇
  2021年   16585篇
  2019年   17166篇
  2018年   24247篇
  2017年   18383篇
  2016年   20184篇
  2015年   23027篇
  2014年   31531篇
  2013年   47646篇
  2012年   65717篇
  2011年   69167篇
  2010年   40468篇
  2009年   37667篇
  2008年   64534篇
  2007年   67849篇
  2006年   68535篇
  2005年   65937篇
  2004年   63202篇
  2003年   60254篇
  2002年   58541篇
  2001年   104832篇
  2000年   108231篇
  1999年   90638篇
  1998年   23788篇
  1997年   21325篇
  1996年   21091篇
  1995年   19853篇
  1994年   18494篇
  1993年   17244篇
  1992年   70742篇
  1991年   68684篇
  1990年   66501篇
  1989年   63926篇
  1988年   58877篇
  1987年   57321篇
  1986年   54134篇
  1985年   51823篇
  1984年   38150篇
  1983年   32408篇
  1982年   18333篇
  1979年   34355篇
  1978年   23790篇
  1977年   19886篇
  1976年   18609篇
  1975年   19604篇
  1974年   23922篇
  1973年   22984篇
  1972年   21525篇
  1971年   20265篇
  1970年   19006篇
  1969年   17571篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
61.
Leocani  L.  Comi  G. 《Neurological sciences》2006,27(1):s27-s29
Neurological Sciences - Brain plasticity, intended as the pattern of functional and structural changes in responses to environmental physiological or pathological events, is underlined by several...  相似文献   
62.
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   
63.
64.
65.
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   
66.
67.
68.
69.
70.
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