全文获取类型
收费全文 | 109676篇 |
免费 | 6223篇 |
国内免费 | 3048篇 |
专业分类
耳鼻咽喉 | 359篇 |
儿科学 | 1686篇 |
妇产科学 | 531篇 |
基础医学 | 5536篇 |
口腔科学 | 439篇 |
临床医学 | 15514篇 |
内科学 | 24851篇 |
皮肤病学 | 461篇 |
神经病学 | 5885篇 |
特种医学 | 3984篇 |
外国民族医学 | 291篇 |
外科学 | 6578篇 |
综合类 | 24303篇 |
现状与发展 | 1篇 |
预防医学 | 6043篇 |
眼科学 | 341篇 |
药学 | 12858篇 |
98篇 | |
中国医学 | 6674篇 |
肿瘤学 | 2514篇 |
出版年
2024年 | 79篇 |
2023年 | 1045篇 |
2022年 | 2104篇 |
2021年 | 3341篇 |
2020年 | 3190篇 |
2019年 | 2541篇 |
2018年 | 2711篇 |
2017年 | 2736篇 |
2016年 | 3229篇 |
2015年 | 3057篇 |
2014年 | 10705篇 |
2013年 | 9111篇 |
2012年 | 8125篇 |
2011年 | 8088篇 |
2010年 | 8335篇 |
2009年 | 7561篇 |
2008年 | 5775篇 |
2007年 | 4962篇 |
2006年 | 4668篇 |
2005年 | 3919篇 |
2004年 | 3108篇 |
2003年 | 2705篇 |
2002年 | 2229篇 |
2001年 | 2150篇 |
2000年 | 1844篇 |
1999年 | 1541篇 |
1998年 | 1255篇 |
1997年 | 1195篇 |
1996年 | 918篇 |
1995年 | 842篇 |
1994年 | 808篇 |
1993年 | 633篇 |
1992年 | 537篇 |
1991年 | 504篇 |
1990年 | 446篇 |
1989年 | 375篇 |
1988年 | 361篇 |
1987年 | 305篇 |
1986年 | 268篇 |
1985年 | 328篇 |
1984年 | 271篇 |
1983年 | 151篇 |
1982年 | 191篇 |
1981年 | 164篇 |
1980年 | 133篇 |
1979年 | 102篇 |
1978年 | 84篇 |
1977年 | 68篇 |
1976年 | 39篇 |
1975年 | 28篇 |
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
71.
《The Journal of thoracic and cardiovascular surgery》2023,165(1):149-158.e4
BackgroundCoronary artery bypass grafting (CABG) improves survival in patients with heart failure and severely reduced left ventricular systolic function (LVEF). Limited data exist regarding adverse cardiovascular event rates after CABG in patients with heart failure with midrange ejection fraction (HFmrEF; LVEF > 40% and < 55%).MethodsWe analyzed data on isolated CABG patients from the Veterans Affairs national database (2010-2019). We stratified patients into control (normal LVEF and no heart failure), HFmrEF, and heart failure with reduced LVEF (HFrEF) groups. We compared all-cause mortality and heart failure hospitalization rates between groups with a Cox model and recurrent events analysis, respectively.ResultsIn 6533 veterans, HFmrEF and HFrEF was present in 1715 (26.3%) and 566 (8.6%) respectively; the control group had 4252 (65.1%) patients. HFrEF patients were more likely to have diabetes mellitus (59%), insulin therapy (36%), and previous myocardial infarction (31%). Anemia was more prevalent in patients with HFrEF (49%) as was a lower serum albumin (mean, 3.6 mg/dL). Compared with the control group, a higher risk of death was observed in the HFmrEF (hazard ratio [HR], 1.3 [1.2-1.5)] and HFrEF (HR, 1.5 [1.2-1.7]) groups. HFmrEF patients had the higher risk of myocardial infarction (subdistribution HR, 1.2 [1-1.6]; P = .04). Risk of heart failure hospitalization was higher in patients with HFmrEF (HR, 4.1 [3.5-4.7]) and patients with HFrEF (HR, 7.2 [6.2-8.5]).ConclusionsHeart failure with midrange ejection fraction negatively affects survival after CABG. These patients also experience higher rates myocardial infarction and heart failure hospitalization. 相似文献
72.
Joseph Wheatley Zhengyang Liu Joel Loth Mark P. Plummer Jahan C. Penny-Dimri Reny Segal Julian Smith Luke A. Perry 《Acta anaesthesiologica Scandinavica》2023,67(2):131-141
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73.
74.
Farrukh Ahmad 《World Journal of Critical Care Medicine》2022,11(4):228-235
The cholinergic anti-inflammatory pathway (CAP) refers to the anti-inflammatory effects mediated by the parasympathetic nervous system. Existence of this path way was first demonstrated when acetylcholinesterase inhibitors showed benefits in animal models of sepsis. CAP functions via the vagus nerve. The systemic anti-inflammatory effects of CAP converges on the α7 nicotinic acetylcholine receptor on splenic macrophages, leading to suppression of pro-inflammatory cytokines and simultaneous stimulation of anti-inflammatory cytokines, including interleukin 10. CAP offers a novel mechanism to mitigate inflammation. Electrical vagal nerve stimulation has shown benefits in patients suffering from rheumatoid arthritis. Direct agonists like nicotine and GTS-1 have also demonstrated anti-inflammatory properties in models of sepsis and acute respiratory distress syndrome, as have acetylcholinesterase inhibitors like Galantamine and Physostigmine. Experience with coronavirus disease 2019 (COVID-19) induced acute respiratory distress syndrome indicates that immunomodulators have a protective role in patient outcomes. Dexamethasone is the only medication currently in use that has shown to improve clinical outcomes. This is likely due to the suppression of what is referred to as a cytokine storm, which is implicated in the lethality of viral pneumonia. Nicotine transdermal patch activates CAP and harvests its anti-inflammatory potential by means of an easily administered depot delivery mechanism. It could prove to be a promising, safe and inexpensive additional tool in the currently limited armamentarium at our disposal for management of COVID-19 induced acute hypoxic respiratory failure. 相似文献
75.
J. M. Nolde M. P. Schlaich D. I. Sessler A. Mian T. B. Corcoran C. K. Chow M. T. V. Chan F. K. Borges M. H. McGillion P. S. Myles N. L. Mills P. J. Devereaux G. S. Hillis 《Anaesthesia》2023,78(7):853-860
Myocardial injury due to ischaemia within 30 days of non-cardiac surgery is prognostically relevant. We aimed to determine the discrimination, calibration, accuracy, sensitivity and specificity of single-layer and multiple-layer neural networks for myocardial injury and death within 30 postoperative days. We analysed data from 24,589 participants in the Vascular Events in Non-cardiac Surgery Patients Cohort Evaluation study. Validation was performed on a randomly selected subset of the study population. Discrimination for myocardial injury by single-layer vs. multiple-layer models generated areas (95%CI) under the receiver operating characteristic curve of: 0.70 (0.69–0.72) vs. 0.71 (0.70–0.73) with variables available before surgical referral, p < 0.001; 0.73 (0.72–0.75) vs. 0.75 (0.74–0.76) with additional variables available on admission, but before surgery, p < 0.001; and 0.76 (0.75–0.77) vs. 0.77 (0.76–0.78) with the addition of subsequent variables, p < 0.001. Discrimination for death by single-layer vs. multiple-layer models generated areas (95%CI) under the receiver operating characteristic curve of: 0.71 (0.66–0.76) vs. 0.74 (0.71–0.77) with variables available before surgical referral, p = 0.04; 0.78 (0.73–0.82) vs. 0.83 (0.79–0.86) with additional variables available on admission but before surgery, p = 0.01; and 0.87 (0.83–0.89) vs. 0.87 (0.85–0.90) with the addition of subsequent variables, p = 0.52. The accuracy of the multiple-layer model for myocardial injury and death with all variables was 70% and 89%, respectively. 相似文献
76.
目的探讨认知重构干预对急性心肌梗死(AMI)介入手术患者不良情绪及疾病感知的影响。方法72例AMI介入手术患者随机分为两组各36例,对照组给予常规护理干预,研究组在对照组基础上给予认知重构干预,比较两组的不良情绪、疾病感知以及治疗依从性。结果干预后,研究组的HAMA、HAMD评分均低于对照组,疾病感知各项评分均高于对照组(P<0.05)。研究组的治疗依从性为94.44%,高于对照组的75.00%(P<0.05)。结论认知重构干预对急性心肌梗死介入手术患者的不良情绪及疾病感知均有积极的影响,可提升患者的治疗依从性。 相似文献
77.
《The Journal for Nurse Practitioners》2019,15(3):e65-e68
A 76-year-old female patient presented to the emergency department with substernal chest pain and dyspnea symptoms. She reported that the symptoms started 2 days earlier. These symptoms can arise from both cardiac and noncardiac conditions. It is difficult to ascribe chest pain and dyspnea symptoms to a single cause. Recognizing these symptoms is critical for inpatient cardiac and primary care nurse practitioners to choose the correct diagnosis and facilitate more effective treatment planning. 相似文献
78.
周天保 《中华移植杂志(电子版)》2019,13(3):252-254
目前,国内外肝移植学界对肝移植术后急性排斥反应(AR)的机制阐释为T细胞介导的细胞免疫应答,但为获得长期生存仍需长期乃至终身服用免疫抑制剂。即使如此,临床上AR仍时有发生,并导致相当一部分受者移植肝功能丧失,更重要的是受者术后还受到感染、肿瘤和其他一系列不良反应及沉重经济负担的影响。因此,为肝移植AR机制提出新的理论解释,更全面深入阐明肝移植免疫排斥反应的内在机制,进而依据新的机制研制出新型免疫抑制剂已势在必行。本文就B细胞介导的体液免疫应答在肝移植AR中的作用作一综述。 相似文献
79.