全文获取类型
收费全文 | 13285篇 |
免费 | 920篇 |
国内免费 | 248篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 334篇 |
妇产科学 | 64篇 |
基础医学 | 945篇 |
口腔科学 | 82篇 |
临床医学 | 1844篇 |
内科学 | 4185篇 |
皮肤病学 | 28篇 |
神经病学 | 834篇 |
特种医学 | 557篇 |
外国民族医学 | 2篇 |
外科学 | 2422篇 |
综合类 | 1568篇 |
现状与发展 | 1篇 |
一般理论 | 2篇 |
预防医学 | 494篇 |
眼科学 | 45篇 |
药学 | 635篇 |
6篇 | |
中国医学 | 185篇 |
肿瘤学 | 188篇 |
出版年
2024年 | 14篇 |
2023年 | 261篇 |
2022年 | 314篇 |
2021年 | 597篇 |
2020年 | 568篇 |
2019年 | 612篇 |
2018年 | 564篇 |
2017年 | 448篇 |
2016年 | 376篇 |
2015年 | 431篇 |
2014年 | 887篇 |
2013年 | 760篇 |
2012年 | 595篇 |
2011年 | 728篇 |
2010年 | 583篇 |
2009年 | 609篇 |
2008年 | 664篇 |
2007年 | 664篇 |
2006年 | 566篇 |
2005年 | 532篇 |
2004年 | 407篇 |
2003年 | 385篇 |
2002年 | 283篇 |
2001年 | 267篇 |
2000年 | 192篇 |
1999年 | 205篇 |
1998年 | 194篇 |
1997年 | 203篇 |
1996年 | 133篇 |
1995年 | 151篇 |
1994年 | 109篇 |
1993年 | 114篇 |
1992年 | 120篇 |
1991年 | 120篇 |
1990年 | 96篇 |
1989年 | 79篇 |
1988年 | 73篇 |
1987年 | 72篇 |
1986年 | 69篇 |
1985年 | 62篇 |
1984年 | 62篇 |
1983年 | 39篇 |
1982年 | 42篇 |
1981年 | 45篇 |
1980年 | 28篇 |
1979年 | 32篇 |
1978年 | 23篇 |
1977年 | 22篇 |
1976年 | 24篇 |
1973年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 328 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.
《Diagnostic and interventional imaging》2020,101(6):335-345
This article was designed to provide a pediatric cardiac computed tomography angiography (CCTA) expert panel consensus based on opinions of experts of the Société Française d’Imagerie Cardiaque et Vasculaire diagnostique et interventionnelle (SFICV) and of the Filiale de Cardiologie Pédiatrique Congénitale (FCPC). This expert panel consensus includes recommendations for indications, patient preparation, CTA radiation dose reduction techniques, and post-processing techniques. The consensus was based on data from available literature (original papers, reviews and guidelines) and on opinions of a group of specialists with extensive experience in the use of CT imaging in congenital heart disease. In order to reach high potential and avoid pitfalls, CCTA in children with congenital heart disease requires training and experience. Moreover, pediatric cardiac CCTA protocols should be standardized to acquire optimal images in this population with the lowest radiation dose possible to prevent unnecessary radiation exposure. We also provided a suggested structured report and a list of acquisition protocols and technical parameters in relation to specific vendors. 相似文献
4.
Feasibility and Diagnostic Potential of Pulmonary Transit Time Measurement by Contrast Echocardiography: A Pilot Study 下载免费PDF全文
5.
6.
《The Journal of thoracic and cardiovascular surgery》2023,165(2):449-459.e4
ObjectiveThe objective of this study was to investigate the association between morphological variation and postsurgical pulmonary vein (PV) stenosis (PPVS) in patients with cardiac total anomalous pulmonary venous connection (TAPVC).MethodsThis single-center, retrospective study included 168 pediatric patients who underwent surgical repair of cardiac TAPVC from 2013 to 2019 (connection to the coronary sinus [CS], n = 136; connection directly to the right atrium [RA], n = 32). Three-dimensional computed tomography modeling and geometric analysis were performed to investigate the morphological features; their relevance to the PPVS was examined.ResultsThe connection type had no association with PPVS (CS type: 18% vs right atrial type: 19%; P = .89) but there was a higher incidence of PPVS in patients with a single PV orifice than > 1 orifice (P < .001). Confluence-to-total PV area ratio (hazard ratio, 4.78, 95% CI, 1.86-12.32; P = .001) and length of drainage route (hazard ratio, 1.22; 95% CI, 1.14-1.31; P < .001) had a 4- and 1-fold increase in the risk for PPVS in the CS type after adjustment for age and preoperative pulmonary venous obstruction. In the right atrial type, those with anomalous PV return to the RA roof were more likely to develop PPVS than to the posterior wall of the RA (P < .001).ConclusionsThe number of inter-junction PV orifice correlated with PPVS development in cardiac TAPVC. The confluence-to-total PV ratio, length of drainage route, and anomalous PV return to the RA roof are important predictors for PPVS. Morphological subcategorization in this clinical setting can potentially assist in surgical decision-making. 相似文献
7.
《Journal of pediatric surgery》2023,58(6):1090-1094
BackgroundThe purpose of this study was to assess diagnostic accuracy and neonatal outcomes in fetuses with a suspected proximal gastrointestinal obstruction (GIO).MethodsAfter IRB approval, a retrospective chart review was conducted on prenatally suspected and/or postnatally confirmed cases of proximal GIO at a tertiary care facility (2012–2022). Maternal-fetal records were queried for presence of a double bubble ± polyhydramnios, and neonatal outcomes were assessed to calculate the diagnostic accuracy of fetal sonography.ResultsAmong 56 confirmed cases, the median birthweight and gestational age at birth were 2550 g [interquartile range (IQR) 2028–3012] and 37 weeks (IQR 34–38), respectively. There was one (2%) false-positive and three (6%) false-negatives by ultrasound. Double bubble had a sensitivity, specificity, positive predictive value, and negative predictive value for proximal GIO of 85%, 98%, 98%, and 83%, respectively. Pathologies included 49 (88%) with duodenal obstruction/annular pancreas, three (5%) with malrotation, and three (5%) with jejunal atresia. The median postoperative length of stay was 27 days (IQR 19–42). Cardiac anomalies were associated with significantly higher complications (45% vs 17%, p = 0.030).ConclusionsIn this contemporary series, fetal sonography has high diagnostic accuracy for detecting proximal gastrointestinal obstruction. These data are informative for pediatric surgeons in prenatal counseling and preoperative discussions with families.Level of EvidenceDiagnostic Study, Level III. 相似文献
8.
9.
10.
Viviana Maestrini Lucia I. Birtolo Sara Cimino Paolo Severino Massimo Mancone Marco Francone Sanjay M. Banypersad Flavia Ventriglia Luigi Tritapepe Fabio Miraldi Francesco Fedele 《Echocardiography (Mount Kisco, N.Y.)》2019,36(5):992-995
A 20‐year‐old Congolese woman presented with presyncope, dyspnea, and anasarca. Past medical history was unremarkable. Echocardiography revealed a rare combination of giant right atrium (RA), a dilated and hypertrophied right ventricle, subvalvular pulmonary stenosis (subPS), severe tricuspid regurgitation (TR), pericardial effusion and what appeared to be a spontaneously closed ventricular septal defect (VSD). Cardiac Magnetic Resonance and Cardiac Computed Tomography confirmed the findings excluding the presence of intra‐cardiac and extra‐cardiac shunt and other associated congenital anomalies. The patient underwent subPS resection, right atrioplasty, and tricuspid annuloplasty. Multimodality approach facilitated the detection of the abnormalities and provided clarity when determining the optimal surgical strategy. 相似文献