全文获取类型
收费全文 | 10466篇 |
免费 | 531篇 |
国内免费 | 151篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 267篇 |
妇产科学 | 33篇 |
基础医学 | 498篇 |
口腔科学 | 9篇 |
临床医学 | 2278篇 |
内科学 | 3954篇 |
皮肤病学 | 12篇 |
神经病学 | 130篇 |
特种医学 | 461篇 |
外国民族医学 | 1篇 |
外科学 | 1047篇 |
综合类 | 1380篇 |
预防医学 | 193篇 |
眼科学 | 12篇 |
药学 | 662篇 |
4篇 | |
中国医学 | 131篇 |
肿瘤学 | 65篇 |
出版年
2023年 | 205篇 |
2022年 | 362篇 |
2021年 | 410篇 |
2020年 | 400篇 |
2019年 | 401篇 |
2018年 | 446篇 |
2017年 | 251篇 |
2016年 | 243篇 |
2015年 | 284篇 |
2014年 | 813篇 |
2013年 | 620篇 |
2012年 | 478篇 |
2011年 | 571篇 |
2010年 | 477篇 |
2009年 | 479篇 |
2008年 | 555篇 |
2007年 | 524篇 |
2006年 | 472篇 |
2005年 | 408篇 |
2004年 | 368篇 |
2003年 | 302篇 |
2002年 | 238篇 |
2001年 | 237篇 |
2000年 | 200篇 |
1999年 | 183篇 |
1998年 | 142篇 |
1997年 | 146篇 |
1996年 | 127篇 |
1995年 | 95篇 |
1994年 | 81篇 |
1993年 | 77篇 |
1992年 | 63篇 |
1991年 | 53篇 |
1990年 | 56篇 |
1989年 | 31篇 |
1988年 | 42篇 |
1987年 | 58篇 |
1986年 | 39篇 |
1985年 | 27篇 |
1984年 | 26篇 |
1983年 | 18篇 |
1982年 | 21篇 |
1981年 | 16篇 |
1980年 | 16篇 |
1979年 | 14篇 |
1978年 | 15篇 |
1977年 | 14篇 |
1976年 | 11篇 |
1975年 | 9篇 |
1973年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
1.
2.
3.
4.
《Journal of Cardiovascular Computed Tomography》2020,14(4):363-369
BackgroundData on left ventricular (LV) deformation imaging using CT angiography (CTA) are scarce and the feasibility of atrial deformation analysis by CT has not been addressed. We aimed to compare 2D echocardiographic and CT derived LV and left atrial (LA) global longitudinal strain (GLS) obtained by using a novel feature tracking algorithm in patients following transcatheter aortic valve implantation.MethodsTwenty-eight patients were included who underwent retrospectively-gated 256-slice CTA and speckle-tracking echocardiography (STE) on the same day. CT datasets in 10% increments were reconstructed throughout the cardiac cycle. LV GLS and LA global peak reservoir strain (LA GS) was measured.ResultsMedian absolute values for LV GLS were 19.9 [14.8–22.4] vs. 19.9 [16.8–24.7], as measured by CT vs STE, respectively (p = 0.017). We found good inter-modality correlation for LV GLS (ρ = 0.78, p < 0.05) with a mean bias of −1.6. Regarding atrial measurements, the median LA GS was 19.0 [13.5–27.3] for CT vs. 28.0 [17.5–32.6] for STE (p < 0.001) with a mean bias of −5.6 between CT and STE and a correlation coefficient of ρ = 0.87, p < 0.001. CT measurements were highly reproducible: intra-observer intra-class correlation coefficient was 0.96 for LV GLS and 0.95 for LA GS.ConclusionWe detected good correlation between CTA and echocardiography-based LV and LA longitudinal strain parameters. CTA provides accurate strain measurements with high reproducibility. Feature tracking-based deformation analysis could provide a clinically important addition to CT examinations by complementing anatomical information with functional data. 相似文献
5.
《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
6.
7.
《Saudi Pharmaceutical Journal》2022,30(6):669-678
BackgroundIschemia reperfusion (I/R) play an imperative role in the expansion of cardiovascular disease. Sinomenine (SM) has been exhibited to possess antioxidant, anticancer, anti-inflammatory, antiviral and anticarcinogenic properties. The aim of the study was scrutinized the cardioprotective effect of SM against I/R injury in rat.MethodsRat were randomly divided into normal control (NC), I/R control and I/R + SM (5, 10 and 20 mg/kg), respectively. Ventricular arrhythmias, body weight and heart weight were estimated. Antioxidant, inflammatory cytokines, inflammatory mediators and plasmin system indicator were accessed.ResultsPre-treated SM group rats exhibited the reduction in the duration and incidence of ventricular fibrillation, ventricular ectopic beat (VEB) and ventricular tachycardia along with suppression of arrhythmia score during the ischemia (30 and 120 min). SM treated rats significantly (P < 0.001) altered the level of antioxidant parameters. SM treatment significantly (P < 0.001) repressed the level of creatine kinase MB (CK-MB), creatine kinase (CK) and troponin I (Tnl). SM treated rats significantly (P < 0.001) repressed the tissue factor (TF), thromboxane B2 (TXB2), plasminogen activator inhibitor 1 (PAI-1) and plasma fibrinogen (Fbg) and inflammatory cytokines and inflammatory mediators.ConclusionOur result clearly indicated that SM plays anti-arrhythmia effect in I/R injury in the rats via alteration of oxidative stress and inflammatory reaction. 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