收费全文 | 8050篇 |
免费 | 695篇 |
国内免费 | 247篇 |
耳鼻咽喉 | 138篇 |
儿科学 | 155篇 |
妇产科学 | 135篇 |
基础医学 | 982篇 |
口腔科学 | 161篇 |
临床医学 | 949篇 |
内科学 | 1469篇 |
皮肤病学 | 79篇 |
神经病学 | 628篇 |
特种医学 | 265篇 |
外国民族医学 | 1篇 |
外科学 | 1257篇 |
综合类 | 505篇 |
一般理论 | 6篇 |
预防医学 | 724篇 |
眼科学 | 163篇 |
药学 | 631篇 |
5篇 | |
中国医学 | 120篇 |
肿瘤学 | 619篇 |
2024年 | 22篇 |
2023年 | 119篇 |
2022年 | 226篇 |
2021年 | 384篇 |
2020年 | 228篇 |
2019年 | 297篇 |
2018年 | 327篇 |
2017年 | 236篇 |
2016年 | 259篇 |
2015年 | 334篇 |
2014年 | 369篇 |
2013年 | 397篇 |
2012年 | 595篇 |
2011年 | 647篇 |
2010年 | 363篇 |
2009年 | 283篇 |
2008年 | 412篇 |
2007年 | 449篇 |
2006年 | 425篇 |
2005年 | 399篇 |
2004年 | 318篇 |
2003年 | 282篇 |
2002年 | 238篇 |
2001年 | 129篇 |
2000年 | 114篇 |
1999年 | 144篇 |
1998年 | 76篇 |
1997年 | 66篇 |
1996年 | 73篇 |
1995年 | 50篇 |
1994年 | 36篇 |
1993年 | 39篇 |
1992年 | 76篇 |
1991年 | 75篇 |
1990年 | 62篇 |
1989年 | 35篇 |
1988年 | 37篇 |
1987年 | 49篇 |
1986年 | 31篇 |
1985年 | 20篇 |
1984年 | 21篇 |
1983年 | 31篇 |
1982年 | 14篇 |
1981年 | 13篇 |
1979年 | 22篇 |
1978年 | 16篇 |
1976年 | 12篇 |
1974年 | 14篇 |
1973年 | 21篇 |
1968年 | 13篇 |
Background
Patients undergoing cardiac surgery are at significant risk of developing postoperative acute kidney injury (AKI). Neutrophil–lymphocyte ratio (NLR) is a widely available inflammatory biomarker which may be of prognostic value in this setting.Methods
We conducted a systematic review and meta-analysis of studies reporting associations between perioperative NLR with postoperative AKI. We searched Medline, Embase and the Cochrane Library, without language restriction, from inception to May 2022 for relevant studies. We meta-analysed the reported odds ratios (ORs) with 95% confidence intervals (CIs) for both elevated preoperative and postoperative NLR with risk of postoperative AKI and need for renal replacement therapy (RRT). We conducted a meta-regression to explore inter-study statistical heterogeneity.Results
Twelve studies involving 10,724 participants undergoing cardiac surgery were included, with eight studies being deemed at high risk of bias using PROBAST modelling. We found statistically significant associations between elevated preoperative NLR and postoperative AKI (OR 1.45, 95% CI 1.18–1.77), as well as postoperative need for RRT (OR 2.37, 95% CI 1.50–3.72). Postoperative NLR measurements were not of prognostic significance.Conclusions
Elevated preoperative NLR is a reliable inflammatory biomarker for predicting AKI following cardiac surgery. 相似文献Methods: Wild-type [alpha]1, [beta]2, [gamma]2s GABAA receptor subunit complementary DNAs were transfected into human embryonic kidney cells grown on glass coverslips using a calcium phosphate transfection method. After transfection (36-72 h), cells were whole cell patch clamped and exposed to combinations of the following: 0.3-1,000 [mu]m [gamma]-aminobutyric acid (GABA), 0-10 [mu]m propofol, and 0-1,650 [mu]m sevoflurane. Chemicals were delivered to the cells using two 10-channel infusion pumps and a rapid solution exchanger.
Results: Both propofol and sevoflurane alone enhanced the amplitude of GABAA receptor responses to submaximal concentrations of GABA in a dose-dependent manner. The enhancement was underpinned by an increase in the apparent affinity of the receptor for GABA. Coapplication of both anesthetics further enhanced the apparent affinity of the receptor for GABA. 相似文献