首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7922篇
  免费   337篇
  国内免费   83篇
耳鼻咽喉   3篇
儿科学   333篇
妇产科学   65篇
基础医学   145篇
临床医学   3998篇
内科学   1995篇
皮肤病学   9篇
神经病学   20篇
特种医学   372篇
外科学   280篇
综合类   750篇
预防医学   128篇
药学   207篇
  2篇
中国医学   18篇
肿瘤学   17篇
  2023年   95篇
  2022年   181篇
  2021年   218篇
  2020年   218篇
  2019年   181篇
  2018年   247篇
  2017年   169篇
  2016年   168篇
  2015年   239篇
  2014年   519篇
  2013年   463篇
  2012年   428篇
  2011年   512篇
  2010年   425篇
  2009年   485篇
  2008年   515篇
  2007年   512篇
  2006年   457篇
  2005年   419篇
  2004年   326篇
  2003年   232篇
  2002年   170篇
  2001年   201篇
  2000年   172篇
  1999年   119篇
  1998年   71篇
  1997年   75篇
  1996年   75篇
  1995年   56篇
  1994年   45篇
  1993年   24篇
  1992年   38篇
  1991年   25篇
  1990年   18篇
  1989年   22篇
  1988年   21篇
  1987年   21篇
  1986年   23篇
  1985年   11篇
  1984年   28篇
  1983年   14篇
  1982年   24篇
  1981年   13篇
  1980年   13篇
  1979年   8篇
  1978年   9篇
  1977年   6篇
  1976年   14篇
  1975年   5篇
  1974年   5篇
排序方式: 共有8342条查询结果,搜索用时 31 毫秒
1.
2.
3.

Background and objectives

A prompt and effective management of trauma patient is necessary. The aim of this case report is to highlight the importance of intraoperative echocardiography as a useful tool in patients suffering from refractory hemodynamic instability no otherwise explained.

Case report

A 41 year‐old woman suffered a car accident. At the emergency department, no abnormalities were found in ECG or chest X‐ray. Abdominal ultrasound revealed the presence of abdominal free liquid and the patient was submitted to urgent exploratory laparotomy. Nevertheless, she persisted suffering arterial hypotension and metabolic acidosis. Looking for the reason of her hemodynamic instability, intraoperative transthoracic echocardiography was performed, finding out the presence of pericardial effusion. Once the cardiac surgeon extracted pericardial clots, patient's situation improved clinically and analytically.

Conclusion

Every anesthesiologist should be able to use the intraoperative echocardiography as an effective tool in order to establish the appropriate measures to promote the survival of patients suffering severe trauma.  相似文献   
4.
5.
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   
6.
7.
8.
9.
Abstract Guillain-Barré syndrome (GBS) is a disease of the peripheral nervous system, which is caused by aberrant immune responses directed against some components of peripheral nerves. GBS is rarely accompanied by cardiovascular involvement. We describe a case of acute neuropathy complicated by sudden heart failure and left ventricular dysfunction which had a presumably neurogenic origin. Pathogenesis of acute heart failure is probably due to transitorial stunned myocardium and neurogenic cardiac injury. We show a rare case of transitorial and acute cardiac dysfunction by echocardiography and laboratory markers of heart failure.  相似文献   
10.
实时三维超声对室间隔缺损的直视效果及影响因素分析   总被引:2,自引:0,他引:2  
目的探讨实时三维超声(RT3DE)对室间隔缺损(VSD)全貌的直视效果及其影响因素。 方法应用RT3DE对238例VSD患者进行检查,其中包括法洛四联症(TOF)36例、完全型心内膜垫缺损(TECD)2例和十字交叉心2例。获取并切割“全容积三维”图像,寻找最佳视角显示病变结构全貌。 结果RT3DE对中型和大型VSD(直径≥5mm)的直视效果优于小型VSD(〈5mm)。可显示缺损的形状、部位及毗邻结构。胸骨旁四腔位和心底短轴位RT3DE图像效果最佳,胸骨旁长轴位及心尖五腔位次之。 结论VSD的大小、部位及三维图像质量是决定RT3DE观察效果的主要因素。RT3DE可清晰直视中型及大型VSD的全貌。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号