全文获取类型
收费全文 | 9523篇 |
免费 | 723篇 |
国内免费 | 168篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 261篇 |
妇产科学 | 39篇 |
基础医学 | 622篇 |
口腔科学 | 5篇 |
临床医学 | 1518篇 |
内科学 | 3652篇 |
皮肤病学 | 7篇 |
神经病学 | 635篇 |
特种医学 | 402篇 |
外国民族医学 | 2篇 |
外科学 | 1317篇 |
综合类 | 1081篇 |
现状与发展 | 1篇 |
一般理论 | 2篇 |
预防医学 | 290篇 |
眼科学 | 12篇 |
药学 | 345篇 |
2篇 | |
中国医学 | 118篇 |
肿瘤学 | 90篇 |
出版年
2023年 | 193篇 |
2022年 | 225篇 |
2021年 | 427篇 |
2020年 | 461篇 |
2019年 | 516篇 |
2018年 | 453篇 |
2017年 | 327篇 |
2016年 | 259篇 |
2015年 | 298篇 |
2014年 | 621篇 |
2013年 | 532篇 |
2012年 | 389篇 |
2011年 | 494篇 |
2010年 | 378篇 |
2009年 | 416篇 |
2008年 | 470篇 |
2007年 | 467篇 |
2006年 | 405篇 |
2005年 | 385篇 |
2004年 | 300篇 |
2003年 | 279篇 |
2002年 | 195篇 |
2001年 | 187篇 |
2000年 | 121篇 |
1999年 | 139篇 |
1998年 | 116篇 |
1997年 | 143篇 |
1996年 | 106篇 |
1995年 | 111篇 |
1994年 | 84篇 |
1993年 | 87篇 |
1992年 | 88篇 |
1991年 | 93篇 |
1990年 | 77篇 |
1989年 | 60篇 |
1988年 | 55篇 |
1987年 | 57篇 |
1986年 | 58篇 |
1985年 | 52篇 |
1984年 | 53篇 |
1983年 | 32篇 |
1982年 | 37篇 |
1981年 | 36篇 |
1980年 | 20篇 |
1979年 | 26篇 |
1978年 | 20篇 |
1977年 | 19篇 |
1976年 | 20篇 |
1974年 | 7篇 |
1973年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Journal of Cardiovascular Computed Tomography》2022,16(6):483-490
BackgroundInflammation surrounding the coronary arteries can be non-invasively assessed using pericoronary adipose tissue attenuation (PCAT). While PCAT holds promise for further risk stratification of patients with low coronary artery disease (CAD) prevalence, its value in higher risk populations remains unknown.MethodsCORE320 enrolled patients referred for invasive coronary angiography with known or suspected CAD. Coronary computed tomography angiography (CCTA) images were collected for 381 patients for whom clinical outcomes were assessed 5 years after enrollment. Using semi-automated image analysis software, PCAT was obtained and normalized for the right coronary (RCA), left anterior descending (LAD), and left circumflex arteries (LCx). The association between PCAT and major adverse cardiovascular events (MACE) during follow up was assessed using Cox regression models.ResultsThirty-seven patients were excluded due to technical failure. For the remaining 344 patients, median age was 62 (interquartile range, 55–68) with 59% having ≥1 coronary artery stenosis of ≥50% by quantitative coronary angiography. Mean attenuation values for PCAT in RCA, LAD, and LCx were ?74.9, ?74.2, and ?71.2, respectively. Hazard ratios and 95% confidence intervals (CI) for normalized PCAT in the RCA, LAD, and LCx for MACE were 0.96 (CI: 0.75–1.22, p ?= ?0.71), 1.31 (95% CI: 0.96–1.78, p ?= ?0.09), and 0.98 (95% CI: 0.78–1.22, p ?= ?0.84), respectively. For death, stroke, or myocardial infarction only, hazard ratios were 0.68 (0.44–1.07), 0.85 (0.56–1.29), and 0.57 (0.41–0.80), respectively.ConclusionsIn patients referred for invasive coronary angiography with suspected CAD, PCAT did not predict MACE during long term follow up. Further studies are needed to understand the relationship of PCAT with CAD risk. 相似文献
2.
3.
【摘要】目的 探讨二维斑点追踪显像技术(2D-STI)评估新生儿窒息合并心肌损害后左心室整体及局部心肌的纵向收缩功能在早期诊断窒息新生儿心肌损害中的临床价值。方法 选择2019年07月至2020年12月期间在右江民族医学院附属医院新生儿科住院的足月窒息新生儿61例,经临床确诊合并心肌损害,根据Apgar评分分为轻度组31例和重度组30例,选择同期住院出生的正常足月新生儿30例作为对照组。检测受检者的血清肌酸激酶同工酶(CK-MB)、肌钙蛋白(cTnT)、左室舒张期前后径(LVDId)、左室射血分数(LVEF)、左室短轴缩短率(LVFS)、辛普森法左室射血分数(Simpson EF)、左室三腔心整体应变(GLS-LAX)、左室四腔心整体应变(GLS-A4C)、左室两腔心整体应变(GLS-A2C)、左室整体应变(GLS-AVG),分析GLS-AVG和CK-MB、cTnT三者的相关性。结果 三组间CK-MB和cTnT比较差异有统计学意义(P<0.05)。三组间性别、体重、胎龄均无统计学差异(P>0.05)。三组间LVDId、LVEF、LVFS、Simpson EF比较差异无统计学意义(P>0.05)。GLS-AVG与CK-MB呈负性相关(r=-0.515,P=0.000),GLS-AVG与cTnT呈负性相关(r=-0.912,P=0.000)。结论 GLS-AVG与CK-MB、cTnT具有相关性,GLS-AVG可作为窒息新生儿心肌损害早期诊断指标。 相似文献
4.
《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
5.
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
6.
《中国现代医生》2020,58(13):39-42
目的观察卡托普利对左向右分流先天性心脏病肺动脉高压患者的血液动力学影响。方法随机选取2018年5月~2019年5月我院左向右分流先天性心脏病患者30例,给予所有患者卡托普利治疗,治疗前、治疗后3~5 d分别采用彩色多普勒超声诊断仪(麦瑞Resona 75型)对患者的血液动力学指标进行检测,然后统计分析30例患者治疗前后的血液动力学。结果 30例患者治疗后的PAMP、AMP、TSR均显著低于治疗前(P0.05)。30例患者中治疗后19例TPR/TSR上升,11例TPR/TSR下降。TPR/TSR上升患者治疗后的AMP、TSR、Qp/Qs均显著低于治疗前(P0.05),TPR/TSR、Qs均显著高于治疗前(P0.05);TPR/TSR下降患者治疗后的PAMP、AMP、PAMP/AMP、TPR、TPR/TSR均显著低于治疗前(P0.05),Qp/Qs显著高于治疗前(P0.05)。治疗前TPR/TSR上升患者的TPR/TSR显著低于TPR/TSR下降患者(P0.05),但二者的PAMP、AMP、PAMP/AMP、TPR、TSR、Qp、Qs、Qp/Qs之间的差异均不显著(P0.05)。结论卡托普利能够有效降低左向右分流先天性心脏病患者的肺动脉高压,但会提升患者的Qp/Qs。 相似文献
7.
8.
BackgroundLaparoscopic central bisectionectomy (Couinaud's segment IV, V, and VIII) needs exposure of the RHV and MHV on the surface of the remnant and the resecting side, respectively. Avoiding venous injury is mandatory and laparoscopy-specific cranio-caudal approach to hepatic veins might be helpful [1]. We present this procedure in performing laparoscopic central bisectionectomy.PatientA 45-year-old female was admitted to our hospital with a 6 cm HCC in the segment VIII and IV. Her comorbid disease was non-cirrhotic HBV hepatitis (Child-Pugh grade A) and diabetes (untreated).MethodAfter cholecystectomy, G4 branches were dissected and cut by extra- or intra-hepatic approach. Hilar plate was dissected and the Gant was encircled and occluded by a vascular clip. Afterwards, exposure of the MHV was started at its root on IVC [2,3] and extended in cranio-caudal direction [1]. After sufficient space was obtained around the Gant, the Gant and the MHV were cut. Parenchymal transection between right anterior and right posterior sections was also started form the root of the RHV to its cranio-caudal direction. Liver resection was finished with full exposure of the RHV.ResultsThe operating time was 380 minutes, and the blood loss volume was 30 ml. Postoperative CT image showed exposure of the RHV and umbilical portion of Glissonean branch, and no fluid retention.ConclusionLaparoscopy-specific cranio-caudal approach to hepatic veins may be useful to avoid split injury of venous branches [4], especially if the hepatectomy requires complete exposure of hepatic vein, such as central bisectionectomy. 相似文献
9.