收费全文 | 5025篇 |
免费 | 255篇 |
国内免费 | 240篇 |
耳鼻咽喉 | 43篇 |
儿科学 | 123篇 |
妇产科学 | 98篇 |
基础医学 | 331篇 |
口腔科学 | 241篇 |
临床医学 | 439篇 |
内科学 | 749篇 |
皮肤病学 | 147篇 |
神经病学 | 206篇 |
特种医学 | 220篇 |
外科学 | 644篇 |
综合类 | 900篇 |
预防医学 | 508篇 |
眼科学 | 117篇 |
药学 | 318篇 |
中国医学 | 260篇 |
肿瘤学 | 176篇 |
2023年 | 36篇 |
2021年 | 17篇 |
2020年 | 14篇 |
2018年 | 38篇 |
2017年 | 38篇 |
2016年 | 57篇 |
2015年 | 198篇 |
2014年 | 121篇 |
2013年 | 173篇 |
2012年 | 131篇 |
2011年 | 302篇 |
2010年 | 252篇 |
2009年 | 199篇 |
2008年 | 156篇 |
2007年 | 81篇 |
2006年 | 119篇 |
2005年 | 135篇 |
2004年 | 395篇 |
2003年 | 357篇 |
2002年 | 312篇 |
2001年 | 289篇 |
2000年 | 156篇 |
1999年 | 243篇 |
1998年 | 150篇 |
1997年 | 141篇 |
1996年 | 131篇 |
1995年 | 88篇 |
1994年 | 80篇 |
1993年 | 156篇 |
1992年 | 131篇 |
1991年 | 76篇 |
1990年 | 60篇 |
1989年 | 68篇 |
1988年 | 44篇 |
1987年 | 42篇 |
1986年 | 34篇 |
1985年 | 30篇 |
1983年 | 11篇 |
1982年 | 14篇 |
1981年 | 12篇 |
1971年 | 11篇 |
1969年 | 12篇 |
1967年 | 10篇 |
1965年 | 13篇 |
1935年 | 10篇 |
1933年 | 11篇 |
1932年 | 11篇 |
1927年 | 14篇 |
1926年 | 18篇 |
1925年 | 10篇 |
Methods: Sixty-four rabbits were instrumented for measurement of left ventricular pressure, cardiac output, and myocardial infarct size (IS). All rabbits were subjected to 30 min of occlusion of a major coronary artery and 2 h of subsequent reperfusion. Rabbits underwent a treatment period consisting of either no intervention for 35 min (control group, n = 12) or 15 min of 1 minimum alveolar concentration desflurane inhalation followed by a 10-min washout period (desflurane group, n = 12). Four additional groups received the tyrosine kinase inhibitor genistein (5 mg/kg) or lavendustin A (1.3 mg/kg) at the beginning of the treatment period with (desflurane-genistein group, n = 11; desflurane-lavendustin A group, n = 12) or without desflurane inhalation (genistein group, n = 9; lavendustin A group, n = 8).
Results: Hemodynamic values were similar in all groups during baseline (left ventricular pressure, 87 +/- 14 mmHg [mean +/- SD]; cardiac output, 198 +/- 47 ml/min), during coronary artery occlusion (left ventricular pressure, 78 +/- 12 mmHg; cardiac output, 173 +/- 39 ml/min), and after 2 h of reperfusion (left ventricular pressure, 59 +/- 17; cardiac output, 154 +/- 43 ml/min). IS in the control group was 55 +/- 10% of the area at risk. The tyrosine inhibitors had no effect on IS (genistein group, 56 +/- 13%; lavendustin A group, 49 +/- 13%; each P = 1.0 vs. control group). Desflurane preconditioning reduced IS to 40 +/- 15% (P = 0.04 vs. control group). Tyrosine kinase inhibitor administration had no effect on IS reduction (desflurane-genistein group, 44 +/- 13%; desflurane-lavendustin A group, 44 +/- 16%; each P = 1.0 vs. desflurane group). 相似文献
Methods: The authors studied a random selection of 489 adult patients undergoing ambulatory surgery. Smoking status was determined by self-report and confirmed with end-expired carbon monoxide analysis. The risk of respiratory complications (i.e., desaturation, cough, laryngospasm, bronchospasm, breath-holding, or apnea) and wound infection (i.e., wound redness or discharge +/- positive microbial culture, requiring antibiotic therapy) in smokers versus nonsmokers was ascertained. Odds ratios were estimated from multivariable logistic regression and adjusted for age, gender, body mass index, partner's smoking status, domiciliary smoking exposure, and extent and duration of surgery.
Results: Most smokers continued to smoke up until the day of surgery. Smokers had a higher rate of respiratory complications (32.8%vs. 25.9%; adjusted odds ratio, 1.71; 95% confidence interval, 1.03-2.84;P = 0.038) and wound infection (3.6%vs. 0.6%; odds ratio, 16.3; 95% confidence interval, 1.58-175;P = 0.019). Odds ratios comparing current plus ex-smokers with nonsmokers were of similar magnitude for most of these complications. 相似文献