收费全文 | 15382篇 |
免费 | 837篇 |
国内免费 | 101篇 |
耳鼻咽喉 | 155篇 |
儿科学 | 292篇 |
妇产科学 | 162篇 |
基础医学 | 2148篇 |
口腔科学 | 218篇 |
临床医学 | 1550篇 |
内科学 | 3780篇 |
皮肤病学 | 404篇 |
神经病学 | 1815篇 |
特种医学 | 1070篇 |
外科学 | 2304篇 |
综合类 | 75篇 |
一般理论 | 7篇 |
预防医学 | 622篇 |
眼科学 | 225篇 |
药学 | 754篇 |
中国医学 | 7篇 |
肿瘤学 | 732篇 |
2023年 | 140篇 |
2022年 | 178篇 |
2021年 | 404篇 |
2020年 | 243篇 |
2019年 | 326篇 |
2018年 | 374篇 |
2017年 | 267篇 |
2016年 | 387篇 |
2015年 | 385篇 |
2014年 | 554篇 |
2013年 | 760篇 |
2012年 | 1202篇 |
2011年 | 1187篇 |
2010年 | 740篇 |
2009年 | 691篇 |
2008年 | 1081篇 |
2007年 | 1073篇 |
2006年 | 1034篇 |
2005年 | 1014篇 |
2004年 | 905篇 |
2003年 | 803篇 |
2002年 | 748篇 |
2001年 | 177篇 |
2000年 | 135篇 |
1999年 | 163篇 |
1998年 | 159篇 |
1997年 | 138篇 |
1996年 | 85篇 |
1995年 | 83篇 |
1994年 | 60篇 |
1993年 | 48篇 |
1992年 | 57篇 |
1991年 | 41篇 |
1990年 | 56篇 |
1989年 | 40篇 |
1988年 | 28篇 |
1987年 | 29篇 |
1986年 | 27篇 |
1985年 | 24篇 |
1984年 | 28篇 |
1983年 | 30篇 |
1982年 | 24篇 |
1980年 | 15篇 |
1979年 | 19篇 |
1978年 | 15篇 |
1977年 | 22篇 |
1975年 | 18篇 |
1974年 | 21篇 |
1973年 | 15篇 |
1930年 | 16篇 |
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Methods: The authors performed a double-blinded, placebo-controlled, multicenter trial to compare the effect of bisoprolol with that of placebo on 1-yr composite outcome including cardiovascular mortality, nonfatal myocardial infarction, unstable angina, congestive heart failure, and cerebrovascular insult. Bisoprolol was given orally before and after surgery for a maximum of 10 days. Adrenergic receptor polymorphisms and safety outcome measures of bisoprolol therapy were also determined.
Results: A total of 224 patients were enrolled. Spinal block could not be established in 5 patients. One hundred ten patients were assigned to the bisoprolol group, and 109 patients were assigned to the placebo group. The mean duration of treatment was 4.9 days in the bisoprolol group and 5.1 days in the placebo group. Bisoprolol therapy reduced mean heart rate by 10 beats/min. The primary outcome was identical between treatment groups and occurred in 25 patients (22.7%) in the bisoprolol group and 24 patients (22.0%) in the placebo group during the 1-yr follow-up (hazard ratio, 0.97; 95% confidence interval, 0.55-1.69; P = 0.90). However, carriers of at least one Gly allele of the [beta]1-adrenergic receptor polymorphism Arg389Gly showed a higher number of adverse events than Arg homozygous (32.4% vs. 18.7%; hazard ratio, 1.87; 95% confidence interval, 1.04-3.35; P = 0.04). 相似文献