全文获取类型
收费全文 | 197篇 |
免费 | 18篇 |
国内免费 | 8篇 |
专业分类
妇产科学 | 4篇 |
基础医学 | 31篇 |
口腔科学 | 6篇 |
临床医学 | 17篇 |
内科学 | 71篇 |
皮肤病学 | 1篇 |
神经病学 | 5篇 |
特种医学 | 11篇 |
外科学 | 1篇 |
综合类 | 27篇 |
预防医学 | 6篇 |
眼科学 | 2篇 |
药学 | 21篇 |
中国医学 | 13篇 |
肿瘤学 | 7篇 |
出版年
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 3篇 |
2020年 | 4篇 |
2019年 | 21篇 |
2018年 | 25篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 12篇 |
2013年 | 9篇 |
2012年 | 5篇 |
2011年 | 15篇 |
2010年 | 8篇 |
2009年 | 9篇 |
2008年 | 18篇 |
2007年 | 9篇 |
2006年 | 15篇 |
2005年 | 22篇 |
2004年 | 10篇 |
2003年 | 13篇 |
2002年 | 3篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1998年 | 1篇 |
1994年 | 4篇 |
1993年 | 1篇 |
1986年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有223条查询结果,搜索用时 15 毫秒
1.
目的观察抑制人脐静脉内皮细胞系ECV304细胞内内皮高表达脂多糖相关因子1(endothe-lial-overexpressed lipopolysaccharide-associated factor 1,EOLA1)基因表达后细胞生长的变化。方法构建EGFP-EOLA1融合蛋白表达载体pEGFP-N2/EOLA1,转染ECV304细胞,G418压力筛选获得稳定表达株;设计靶点特异性的寡核苷酸,连接到经BamHⅠ和HindⅢ酶切线性化的pSlincer3.1/H1质粒上。转染重组质粒到稳定表达EGFP-EOLA1融合蛋白的ECV304细胞,检测靶基因的抑制情况,观察EOLA1表达被抑制后细胞生长的改变。结果抑制EOLA1表达后ECV304细胞生长明显减慢。结论EOLA1基因在细胞内参与了细胞生长的调控。 相似文献
2.
目的:探讨血小板对妊高征患者血清刺激下的ECV304细胞(ECV304)表达人血小板/T细胞活化抗原1(PTA1)和释放血小板衍生生长因子(PDGF)的影响。方法①用间接免疫荧光染色结合流式细胞仪分析观察血小板与妊高征患者血清刺激的ECV304细胞孵育前后PTA1的表达②用ELISA方法检测血小板与妊高征患者血清刺激的ECV304细胞孵育前后PDGF的量。结果:①血小板与妊高征患者血清刺激(24h、48h)的ECV304细胞孵育后PTA1表达的百分率(6.32%、4.13%)明显低于对照组(15.51%、5.64%)(P<0.05)。②妊高征患者血清刺激ECV304细胞8h、24h、48h释放PDGF的量(1593、2625、2175ng/L)明显高于正常孕妇组(235、405、133.5ng/L)差异显著(P<0.01)。③血小板与妊高征患者血清刺激的ECV304细胞孵育后,24h、48h细胞培养上清液中PDGF-B的量又进一步增加(3266、2360ng/L),与对照组比差异显著(P<0.05)。结论:ECV304细胞与血小板之间的黏附可能是通过PTA1分子发挥作用的,同时导致了PDGF的进一步释放。 相似文献
3.
目的 研究钙离子进入ECV30 4内皮细胞株的途径和血管紧张素Ⅱ (AⅡ )对钙内流的影响。方法 用膜片钳的细胞贴附式和全细胞方式记录ECV30 4内皮细胞的通道活动。结果 (1 )在记录单通道电流时电极液含 1 2 0mmol·L- 1 CaCl2 ,细胞浴液不含K+ 、Na+ 时 ,Ca2 + 经非选择性阳离子通道 (CAN)内流的电导为γ0 =(1 2 90± 2 1 1 ) pS(n =4)。1× 1 0 - 7mol·L- 1 AⅡ可显著增强通道电流幅度和延长通道开放时 ,其电导增大为γ1 =(2 2 1 8± 2 2 9)pS(n =4)。全细胞记录得到的结果与单通道的一致。 (2 )用全细胞方式记录到ECV30 4内皮细胞的电压依赖性钙通道电流 ,记录到该峰值电流为 (2 9 32± 3 56)pA(n =4) ,2 0 μmol·L- 1 nifedepine能抑制这个峰值电流 ,被抑制后的电流峰值为 (6 0 0± 3 94)pA(n =4)。 2 μmol·L- 1 BayK8644能显著激活通道活动。结论 Ca2 + 经CAN进入ECV30 4细胞 ,AⅡ可显著增强CAN的钙流 相似文献
4.
营养素防护同型半胱氨酸致ECV304细胞损伤和凋亡 总被引:1,自引:0,他引:1
目的: 探讨叶酸、维生素E(VE)和硒(Se)对同型半胱氨酸(homocysteine, Hcy)诱导ECV304细胞损伤和凋亡的防护作用及其机制。方法: 采用倒置显微镜观察和MTT实验检测各种营养素对Hcy细胞损伤作用的防护,采用琼脂糖凝胶DNA电泳和流式细胞仪检测各种营养素对Hcy诱导细胞凋亡作用的防护。并通过测定细胞内脂质过氧化水平、细胞内抗氧化酶活力及对细胞内活性氧产生的改变研究其保护机制。结果: 叶酸、VE和Se都可防护Hcy的细胞增殖抑制和诱导细胞凋亡作用,并都可明显减少细胞内MDA含量。叶酸可以明显增加细胞内SOD活力,叶酸和Se可以明显增加细胞内GSH-Px活力。VE对Hcy诱导的细胞内活性氧产生具有明显抑制作用,而Se和叶酸抑制作用不明显。结论: 叶酸、VE和Se都可以防护Hcy导致的细胞增殖抑制,并可以抑制Hcy诱导的细胞凋亡,但其作用机制不同。 相似文献
5.
External electrical cardioversion in patients with cardiac implantable electronic devices: Is it safe and is immediate device interrogation necessary?
下载免费PDF全文
![点击此处可从《Pacing and clinical electrophysiology : PACE》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Nikki AHA Pluymaekers MD Elton AMP Dudink MD MSc Lucas Boersma MD PhD Ömer Erküner MD Marloes Gelissen MSc Vincent van Dijk MD Maurits Wijffels MD PhD Trang Dinh MD Kevin Vernooy MD PhD Harry JGM Crijns MD PhD Jippe Balt MD PhD Justin GLM Luermans MD PhD 《Pacing and clinical electrophysiology : PACE》2018,41(10):1336-1340
6.
7.
Julia Anna Lurz Christian Luecke David Lang Christian Besler Karl-Philipp Rommel Karin Klingel Reinhard Kandolf Volker Adams Katharina Schöne Gerhard Hindricks Gerhard Schuler Axel Linke Holger Thiele Matthias Gutberlet Philipp Lurz 《JACC: Cardiovascular Imaging》2018,11(1):38-45
Objectives
The aim of the present study was to evaluate whether extracellular volume fraction (ECV) can reliably inform on the extent of diffuse fibrosis in the simultaneous presence of myocardial inflammation, which has not been verified to date.Background
Diffuse myocardial fibrosis is associated with unfavorable outcome in patients with cardiomyopathy, and is of prognostic relevance. Assessment of ECV bears promise for being a noninvasive surrogate parameter, but it may be altered by other pathologies.Methods
In this prospective study, 107 consecutive patients with clinical suspicion of inflammatory cardiomyopathy were included. All patients underwent left ventricular (LV) endomyocardial biopsy (EMB) and cardiac magnetic resonance imaging on a 1.5-T scanner. T1 mapping was obtained with the modified Look-Locker inversion recovery sequence, and ECV was calculated.Results
Myocardial inflammation was present in 66 patients. Patients with and without inflammation were of similar age and had comparable LV ejection fraction (37 ± 17% vs. 36 ± 18%; p = 0.9) and symptom duration (median 14 days [interquartile range: 5 to 36 days] vs. median 14 days [interquartile range: 7 to 30 days]; p = 0.73). Although LV collagen volume percentage was comparable between groups (inflammation 12.3 ± 17.8% vs. noninflammation 11.4 ± 7.9%; p = 0.577), ECV was significantly higher in patients with inflammation (0.37 ± 0.06%) than in those without inflammation (0.33 ± 0.08%; p = 0.02). Importantly, ECV adequately estimated the degree of LV fibrosis percentage only in patients without inflammation (r = 0.72; p < 0.0001) and not in those with inflammation (r = 0.24; p = 0.06).Conclusions
These findings prove the theoretical concept of ECV as an estimate for diffuse myocardial fibrosis, but only in the absence of significant myocardial inflammation. Assuming that various degrees of myocardial inflammation and fibrosis coexist in such a scenario, the measured ECV will reflect a sum of these different pathologies but will not inform solely on the extent of diffuse fibrosis. 相似文献8.
《JACC: Cardiovascular Imaging》2014,7(7):667-675
ObjectivesThis study evaluated the accuracy of T2, T1, and extracellular volume (ECV) quantification as novel quantitative tissue markers in comparison with standard “Lake-Louise” cardiac magnetic resonance (CMR) criteria to diagnose myocarditis.BackgroundNovel approaches using T2 and T1 mapping may overcome the limitations of signal intensity-based parameters, which would potentially result in a better diagnostic accuracy compared with standard CMR techniques in suspected myocarditis.MethodsCMR was performed in 104 patients with myocarditis and 21 control subjects at 1.5-T. Patients with myocarditis underwent CMR 2 weeks (interquartile range: 1 to 7 weeks) after presentation with new-onset heart failure (n = 66) or acute chest pain (n = 38). T2 and T1 mapping were implemented into a standard protocol including T2-weighted (T2w), early gadolinium enhancement (EGE) CMR, and late gadolinium enhancement (LGE) CMR. T2 quantification was performed using a free-breathing, navigator-gated multiecho sequence. T1 quantification was performed using the modified Look-Locker inversion recovery sequence before and after administration of 0.075 mmol/kg gadobenate dimeglumine. T2, T1, and ECV maps were generated using a plug-in for the OsiriX software (Pixmeo, Bernex, Switzerland) to calculate mean global myocardial T2, T1, and ECV values.ResultsThe diagnostic accuracies of conventional CMR were 70% (95% confidence interval [CI]: 61% to 77%) for T2w CMR, 59% (95% CI: 56% to 73%) for EGE, and 67% (95% CI: 59% to 75%) for LGE. The diagnostic accuracies of mapping techniques were 63% (95% CI: 53% to 73%) for myocardial T2, 69% (95% CI: 60% to 76%) for native myocardial T1, and 76% (95% CI: 68% to 82%) for global myocardial ECV. The diagnostic accuracy of CMR was significantly improved to 90% (95% CI: 84% to 95%) by a stepwise approach, using the presence of LGE and myocardial ECV ≥27% as diagnostic criteria, compared with 79% (95% CI: 71% to 85%; p = 0.0043) for the Lake-Louise criteria.ConclusionsIn patients with clinical evidence for subacute, severe myocarditis, ECV quantification with LGE imaging significantly improved the diagnostic accuracy of CMR compared with standard Lake-Louise criteria. 相似文献
9.
10.
Enrique Galve Eduardo Alegría Alberto Cordero Lorenzo Fácila Jaime Fernández de Bobadilla Carla Lluís-Ganella Pilar Mazón Carmen de Pablo Zarzosa José Ramón González-Juanatey 《Revista espa?ola de cardiología》2014
Cardiovascular disease develops in a slow and subclinical manner over decades, only to manifest suddenly and unexpectedly. The role of prevention is crucial, both before and after clinical appearance, and there is ample evidence of the effectiveness and usefulness of the early detection of at-risk individuals and lifestyle modifications or pharmacological approaches. However, these approaches require time, perseverance, and continuous development. The present article reviews the developments in 2013 in epidemiological aspects related to prevention, includes relevant contributions in areas such as diet, weight control methods (obesity is now considered a disease), and physical activity recommendations (with warnings about the risk of strenuous exercise), deals with habit-related psychosocial factors such as smoking, provides an update on emerging issues such as genetics, addresses the links between cardiovascular disease and other pathologies such as kidney disease, summarizes the contributions of new, updated guidelines (3 of which have recently been released on topics of considerable clinical importance: hypertension, diabetes mellitus, and chronic kidney disease), analyzes the pharmacological advances (largely mediocre except for promising lipid-related results), and finishes by outlining developments in the oft-neglected field of cardiac rehabilitation. This article provides a briefing on controversial issues, presents interesting and somewhat surprising developments, updates established knowledge with undoubted application in clinical practice, and sheds light on potential future contributions. 相似文献