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   170759篇
  免费   6378篇
  国内免费   322篇
耳鼻咽喉   3037篇
儿科学   6367篇
妇产科学   4353篇
基础医学   24028篇
口腔科学   4773篇
临床医学   12669篇
内科学   30998篇
皮肤病学   4655篇
神经病学   15751篇
特种医学   8933篇
外国民族医学   24篇
外科学   28238篇
综合类   1087篇
一般理论   39篇
预防医学   8003篇
眼科学   4591篇
药学   11765篇
中国医学   347篇
肿瘤学   7801篇
  2023年   763篇
  2021年   1264篇
  2020年   1129篇
  2019年   1299篇
  2018年   2844篇
  2017年   2356篇
  2016年   3305篇
  2015年   3680篇
  2014年   3844篇
  2013年   5400篇
  2012年   8351篇
  2011年   7759篇
  2010年   4611篇
  2009年   3697篇
  2008年   7681篇
  2007年   8525篇
  2006年   8552篇
  2005年   8962篇
  2004年   8516篇
  2003年   8420篇
  2002年   8314篇
  2001年   6176篇
  2000年   6238篇
  1999年   5397篇
  1998年   1570篇
  1997年   1295篇
  1996年   988篇
  1995年   799篇
  1992年   2385篇
  1991年   2313篇
  1990年   2273篇
  1989年   2118篇
  1988年   1852篇
  1987年   1842篇
  1986年   1703篇
  1985年   1638篇
  1984年   1279篇
  1983年   1021篇
  1979年   1376篇
  1978年   1009篇
  1977年   850篇
  1975年   1078篇
  1974年   1112篇
  1973年   1015篇
  1972年   1023篇
  1971年   994篇
  1970年   883篇
  1969年   825篇
  1968年   796篇
  1967年   743篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Intratumor heterogeneity is a main cause of the dismal prognosis of glioblastoma (GBM). Yet, there remains a lack of a uniform assessment of the degree of heterogeneity. With a multiscale approach, we addressed the hypothesis that intratumor heterogeneity exists on different levels comprising traditional regional analyses, but also innovative methods including computer-assisted analysis of tumor morphology combined with epigenomic data. With this aim, 157 biopsies of 37 patients with therapy-naive IDH-wildtype GBM were analyzed regarding the intratumor variance of protein expression of glial marker GFAP, microglia marker Iba1 and proliferation marker Mib1. Hematoxylin and eosin stained slides were evaluated for tumor vascularization. For the estimation of pixel intensity and nuclear profiling, automated analysis was used. Additionally, DNA methylation profiling was conducted separately for the single biopsies. Scoring systems were established to integrate several parameters into one score for the four examined modalities of heterogeneity (regional, cellular, pixel-level and epigenomic). As a result, we could show that heterogeneity was detected in all four modalities. Furthermore, for the regional, cellular and epigenomic level, we confirmed the results of earlier studies stating that a higher degree of heterogeneity is associated with poorer overall survival. To integrate all modalities into one score, we designed a predictor of longer survival, which showed a highly significant separation regarding the OS. In conclusion, multiscale intratumor heterogeneity exists in glioblastoma and its degree has an impact on overall survival. In future studies, the implementation of a broadly feasible heterogeneity index should be considered.  相似文献   
2.
3.
4.
5.
6.
7.
8.
9.
10.

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