全文获取类型
收费全文 | 40388篇 |
免费 | 3511篇 |
国内免费 | 922篇 |
专业分类
耳鼻咽喉 | 123篇 |
儿科学 | 817篇 |
妇产科学 | 323篇 |
基础医学 | 2340篇 |
口腔科学 | 219篇 |
临床医学 | 7627篇 |
内科学 | 16157篇 |
皮肤病学 | 93篇 |
神经病学 | 1439篇 |
特种医学 | 1917篇 |
外国民族医学 | 1篇 |
外科学 | 3983篇 |
综合类 | 4577篇 |
现状与发展 | 1篇 |
预防医学 | 858篇 |
眼科学 | 154篇 |
药学 | 2488篇 |
20篇 | |
中国医学 | 609篇 |
肿瘤学 | 1075篇 |
出版年
2024年 | 31篇 |
2023年 | 825篇 |
2022年 | 873篇 |
2021年 | 1980篇 |
2020年 | 2006篇 |
2019年 | 2003篇 |
2018年 | 1780篇 |
2017年 | 1401篇 |
2016年 | 1260篇 |
2015年 | 1351篇 |
2014年 | 2633篇 |
2013年 | 2592篇 |
2012年 | 1921篇 |
2011年 | 2156篇 |
2010年 | 1706篇 |
2009年 | 1803篇 |
2008年 | 1837篇 |
2007年 | 1904篇 |
2006年 | 1560篇 |
2005年 | 1480篇 |
2004年 | 1180篇 |
2003年 | 1157篇 |
2002年 | 884篇 |
2001年 | 890篇 |
2000年 | 746篇 |
1999年 | 691篇 |
1998年 | 656篇 |
1997年 | 591篇 |
1996年 | 451篇 |
1995年 | 463篇 |
1994年 | 408篇 |
1993年 | 390篇 |
1992年 | 366篇 |
1991年 | 321篇 |
1990年 | 332篇 |
1989年 | 258篇 |
1988年 | 253篇 |
1987年 | 187篇 |
1986年 | 190篇 |
1985年 | 190篇 |
1984年 | 189篇 |
1983年 | 159篇 |
1982年 | 167篇 |
1981年 | 104篇 |
1980年 | 95篇 |
1979年 | 82篇 |
1978年 | 88篇 |
1977年 | 62篇 |
1976年 | 51篇 |
1975年 | 26篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
采用Mimics对心脏进行三维重构,用3-matic进行模型优化以及模型误差分析,对左心室室壁运动做速度分布假设,基于UDF宏文件对左心室室壁运动编写程序,将血液视为非牛顿流体,采用动网格技术研究不同血压对左心室血液流动的影响。模拟发现当左心室收缩时,压力梯度明显,内部压力减小。当左心室舒张时,内部压力逐渐增高。二尖瓣口处的速率先增大后减小。血压升高,左心室内剪切应力持续增大,极易破坏红细胞结构,产生溶血现象,导致心脏功能紊乱。 相似文献
2.
3.
《The Journal of thoracic and cardiovascular surgery》2023,165(1):94-103.e24
ObjectiveNew-onset postoperative atrial fibrillation (POAF) after cardiac surgery is common, with rates up to 60%. POAF has been associated with early and late stroke, but its association with other cardiovascular outcomes is less known. The objective was to perform a meta-analysis of the studies reporting the association of POAF with perioperative and long-term outcomes in patients with cardiac surgery.MethodsWe performed a systematic review and a meta-analysis of studies that presented outcomes for cardiac surgery on the basis of the presence or absence of POAF. MEDLINE, EMBASE, and the Cochrane Library were assessed; 57 studies (246,340 patients) were selected. Perioperative mortality was the primary outcome. Inverse variance method and random model were performed. Leave-one-out analysis, subgroup analyses, and metaregression were conducted.ResultsPOAF was associated with perioperative mortality (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.58-2.33), perioperative stroke (OR, 2.17; 95% CI, 1.90-2.49), perioperative myocardial infarction (OR, 1.28; 95% CI, 1.06-1.54), perioperative acute renal failure (OR, 2.74; 95% CI, 2.42-3.11), hospital (standardized mean difference, 0.80; 95% CI, 0.53-1.07) and intensive care unit stay (standardized mean difference, 0.55; 95% CI, 0.24-0.86), long-term mortality (incidence rate ratio [IRR], 1.54; 95% CI, 1.40-1.69), long-term stroke (IRR, 1.33; 95% CI, 1.21-1.46), and longstanding persistent atrial fibrillation (IRR, 4.73; 95% CI, 3.36-6.66).ConclusionsThe results suggest that POAF after cardiac surgery is associated with an increased occurrence of most short- and long-term cardiovascular adverse events. However, the causality of this association remains to be established. 相似文献
4.
《The British journal of oral & maxillofacial surgery》2022,60(4):499-506
The aim of this study was to carry out a retrospective multicentre study comparing the morphological outcome of 8 techniques used for the management of sagittal synostosis versus a large cohort of control patients. Computed tomographic (CT) images were obtained from children CT-scanned for non-craniosynostosis related events (n = 241) and SS patients at preoperative and postoperative follow-up stages (n = 101). No significant difference in morphological outcomes was observed between the techniques considered in this study. However, the majority of techniques showed a tendency for relapse. Further, the more invasive procedures at older ages seem to lead to larger intracranial volume compared to less invasive techniques at younger ages. This study can be a first step towards future multicentre studies, comparing surgical results and offering a possibility for objective benchmarking of outcomes between methods and centres. 相似文献
5.
Jeffrey J. Silbiger 《Echocardiography (Mount Kisco, N.Y.)》2019,36(5):954-957
Secondary tricuspid regurgitation (TR) caused by right ventricular enlargement in the setting of left heart disease/pulmonary hypertension has been well described. In contrast, that associated with right atrial enlargement—atrial functional TR (AF‐TR)—remains largely underappreciated. AF‐TR most often occurs in the setting of lone atrial fibrillation, although it is also seen in its absence (idiopathic AF‐TR). Several recent studies have found that the prevalence, hemodynamic significance, and prognosis of AF‐TR are not inconsequential, suggesting increased physician awareness of this novel clinical entity is warranted. This article discusses the pathogenesis, echocardiographic findings, and treatment of this underappreciated cause of secondary TR. 相似文献
6.
7.
8.
目的:探讨3D-CRT 低剂量区 V5体积的大小对非小细胞肺癌患者肺功能的影响。方法:收集我院肿瘤科2014年4月~2015年10月收治的46例首次行三维适形放射治疗且顺利完成治疗的非小细胞肺癌患者,对每例患者分别在治疗前以及治疗后的1、3个月进行肺功能检测,分析3D-CRT 低剂量区 V5体积的大小与肺功能变化之间的关系。结果:放疗后1个月的 FEV1%、FVC%值明显高于放疗前且差异均具有显著性。放疗后1个月、3个月的 DLCO%值明显低于放疗前,且放疗前的与放疗后3个月的差异具有显著性;V5≦45%、45%55%三组放疗前后的 FEV1%值和 FVC%值比较差异均不具有显著性。V5≦45%、45%55%三组放疗前后的 DLCO%值均呈逐渐下降趋势,且 V5>55%组的放疗前后 DLCO%值比较差异具有显著性。而 V5≦45%组和45%55%时,DLCO%值降低的趋势更加显著。 相似文献
9.
10.