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   997789篇
  免费   75076篇
  国内免费   2616篇
耳鼻咽喉   12962篇
儿科学   34466篇
妇产科学   28462篇
基础医学   145302篇
口腔科学   27714篇
临床医学   90321篇
内科学   193570篇
皮肤病学   22916篇
神经病学   79150篇
特种医学   38389篇
外国民族医学   305篇
外科学   149502篇
综合类   23744篇
一般理论   385篇
预防医学   77839篇
眼科学   22618篇
药学   71872篇
  3篇
中国医学   2030篇
肿瘤学   53931篇
  2018年   10561篇
  2017年   8239篇
  2016年   9376篇
  2015年   10598篇
  2014年   14422篇
  2013年   22009篇
  2012年   28995篇
  2011年   30833篇
  2010年   18492篇
  2009年   17438篇
  2008年   28794篇
  2007年   30469篇
  2006年   30971篇
  2005年   29647篇
  2004年   28934篇
  2003年   27802篇
  2002年   26820篇
  2001年   46928篇
  2000年   48040篇
  1999年   40269篇
  1998年   11177篇
  1997年   10096篇
  1996年   10162篇
  1995年   9775篇
  1994年   9091篇
  1993年   8480篇
  1992年   32249篇
  1991年   31459篇
  1990年   31010篇
  1989年   29879篇
  1988年   27168篇
  1987年   27326篇
  1986年   25442篇
  1985年   24606篇
  1984年   18400篇
  1983年   15521篇
  1982年   9288篇
  1981年   8375篇
  1979年   16863篇
  1978年   12219篇
  1977年   10316篇
  1976年   9754篇
  1975年   10178篇
  1974年   12317篇
  1973年   11847篇
  1972年   10888篇
  1971年   10119篇
  1970年   9379篇
  1969年   8729篇
  1968年   8107篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
24.
25.
26.
We report a case of intestinal obstruction in a 73-year-old woman caused by ileocolic intussusception. The underlying cause was a giant submucosal ulcerating lipoma (6?×?3.3?×?3.8 cm) extending from the superior mucosal lip of Bauhin’s valve. Abdominal ultrasonography showed a pathognomonic target-like mass appearing as multiple concentric rings. CT scan confirmed the diagnosis. Because of apparent obstruction, a laparotomy with right hemicolectomy and ileocolic anastomosis was performed. Lipomas most frequently occur in the cecum and ascending colon where they represent the most common submucosal mesenchymal tumor. They typically occur in elderly women with an incidence that varies from 0.15 to 0.56 %. Pain, rectal bleeding, and obstruction are typical symptoms. When faced with an intussusception in children, reduction with air per rectum can be performed. In adults, however, malignant cell spreading and seeding is of big concern. Since approximately 20–50 % of all underlying causes are malignant, explorative surgery is favored in adults.  相似文献   
27.
28.
29.
30.

Objective

Low psoas muscle area is shown to be an indicator for worse postoperative outcome in patients undergoing vascular surgical. Additionally, it has been associated with longer durations of hospital stay in patients with cancer who undergo surgery and subsequently greater health care costs in Europe and the United States. We sought to evaluate this effect on hospital expenditure for patients undergoing vascular repair in a health care system with universal access.

Methods

Skeletal muscle mass was assessed on preoperative abdominal computed tomography scans of patients undergoing open aortic aneurysm repair in a retrospective fashion. The skeletal muscle index (SMI) was used to define low muscle mass. Health care costs were obtained for all patients and the relationship between a low SMI and higher costs was explored using linear regression and cross-sectional analysis.

Results

We included 156 patients (81.5% male) with a median age of 72 years undergoing elective surgery for infrarenal abdominal aortic aneurysm in this analysis. The median SMI for patients with low skeletal muscle mass was 53.21 cm2/kg and for patients without, 70.07 cm2/kg. Hospital duration of stay was 2 days longer in patients with low skeletal muscle mass as compared with patients with normal (14 days vs 11 days; P = .001), as was duration of intensive care stay (3 days vs 1 day; P = .01). The median overall hospital costs were €10,460 higher for patients with a low SMI as compared with patients with a normal physical constitution (€53,739 [interquartile range, €45,007-€62,471] vs €43,279 [interquartile range, €39,509-€47,049]; P = .001). After confounder adjustment, a low SMI was associated with a 14.68% cost increase in overall hospital costs, for a cost increase of €6521.

Conclusions

Low skeletal muscle mass is independently associated with higher hospital as well as intensive care costs in patients undergoing elective aortic aneurysm repair. Strategies to reduce this risk factor are warranted for these patients.  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