全文获取类型
收费全文 | 5507篇 |
免费 | 621篇 |
国内免费 | 169篇 |
专业分类
耳鼻咽喉 | 56篇 |
儿科学 | 219篇 |
妇产科学 | 175篇 |
基础医学 | 111篇 |
口腔科学 | 78篇 |
临床医学 | 1239篇 |
内科学 | 1257篇 |
皮肤病学 | 113篇 |
神经病学 | 300篇 |
特种医学 | 181篇 |
外科学 | 1622篇 |
综合类 | 18篇 |
预防医学 | 336篇 |
眼科学 | 325篇 |
药学 | 36篇 |
肿瘤学 | 231篇 |
出版年
2023年 | 106篇 |
2021年 | 61篇 |
2020年 | 96篇 |
2019年 | 41篇 |
2018年 | 126篇 |
2017年 | 173篇 |
2016年 | 182篇 |
2015年 | 140篇 |
2014年 | 226篇 |
2013年 | 297篇 |
2012年 | 88篇 |
2011年 | 117篇 |
2010年 | 224篇 |
2009年 | 335篇 |
2008年 | 117篇 |
2007年 | 66篇 |
2006年 | 103篇 |
2005年 | 79篇 |
2003年 | 56篇 |
2002年 | 44篇 |
2001年 | 108篇 |
2000年 | 71篇 |
1999年 | 132篇 |
1998年 | 175篇 |
1997年 | 200篇 |
1996年 | 302篇 |
1995年 | 255篇 |
1994年 | 196篇 |
1993年 | 119篇 |
1992年 | 127篇 |
1991年 | 139篇 |
1990年 | 69篇 |
1989年 | 133篇 |
1988年 | 105篇 |
1987年 | 79篇 |
1986年 | 108篇 |
1985年 | 86篇 |
1984年 | 92篇 |
1983年 | 75篇 |
1982年 | 67篇 |
1981年 | 64篇 |
1980年 | 80篇 |
1979年 | 43篇 |
1978年 | 61篇 |
1977年 | 46篇 |
1976年 | 45篇 |
1975年 | 46篇 |
1972年 | 38篇 |
1964年 | 49篇 |
1963年 | 47篇 |
排序方式: 共有6297条查询结果,搜索用时 0 毫秒
81.
Impact of severe tricuspid regurgitation on accuracy of systolic pulmonary arterial pressure measured by Doppler echocardiography: Analysis in an unselected patient population 下载免费PDF全文
Beini Fei MB Ting Fan MB Ling Zhao MB Xiaoli Pei MD Xianhong Shu PhD MD Xiaoyan Fang MD Leilei Cheng PhD MD 《Echocardiography (Mount Kisco, N.Y.)》2017,34(7):1082-1088
Pulmonary arterial pressure is an important index in cardiovascular disorders, especially for pulmonary hypertension (PH). Doppler echocardiography (DE) is widely used as a noninvasive method to assess pulmonary arterial pressure. However, recent studies have found several hemodynamic factors that affect its accuracy in estimating systolic pulmonary arterial pressure (sPAP). But the effect of tricuspid regurgitation (TR) has not been investigated. Therefore, our study is aimed to determine whether the severity of TR will affect the accuracy of sPAP measured by DE in an unselected patient population. We retrospectively studied 177 patients who underwent DE and right heart catheterization (RHC) examinations. Patients were categorized into 3 groups according to the severity of TR (mild, moderate, and severe). The discrepancy in sPAP measured by DE and RHC was calculated and compared in each group. Determinants of discordant results between two methods were also evaluated. Age, gender, interval between DE and RHC, sequence of DE and RHC were similar among groups (all P>.05). Differences in sPAP, RAP, and tricuspid regurgitation pressure gradient (TR‐PG) were similar in group 1 and 2 (all P>.05), while all significantly higher in group 3 (all P<.05). The difference in sPAP between DE and RHC was affected independently by severe TR and severe PH (both P<.05). Severe TR and severe PH affect the accuracy of sPAP measured by DE. Modification of echocardiographic sPAP measurements by taking into consideration of these factors may lead to reduced systemic errors. 相似文献
82.
Reji Pappy MD Thomas A. Hennebry MB BCH BAO FACC FSCAI Mazen S. Abu‐Fadel MD FACC FSCAI 《Catheterization and cardiovascular interventions》2011,78(4):625-631
Subintimal recanalization is beneficial in selected patients with peripheral chronic total occlusions (CTO). However, in complex cases, re‐entry into the true arterial lumen may prove to be unsuccessful with a conventional guidewire or a re‐entry catheter when using standard femoral artery access. Our case series describes these technical dilemmas along with strategies that can be utilized to overcome these challenges. © 2011 Wiley‐Liss, Inc. 相似文献
83.
Peter A. Sims MSc MB MFCM MRCGP 《Medicine, conflict, and survival》2013,29(3):199-200
Community physicians have recently, albeit often reluctantly, been involved in preparations for nuclear war. This paper suggests an alternative: that they should use their skills in epidemiology and in preventive and social medicine in the prevention of nuclear war. 相似文献
84.
Francisco Leyva MD Abbasin Zegard MB ChB Kiran Patel PhD Jonathan Panting MB ChB Howard Marshall MD Tian Qiu PhD 《Pacing and clinical electrophysiology : PACE》2018,41(3):290-298
1 Background and aims
Right ventricular pacing may lead to heart failure (HF). Upgrades from pacemakers to cardiac resynchronization therapy (CRT) were excluded from most randomized, controlled trials. We sought to determine the long‐term outcomes of upgrading from pacemakers to CRT with (CRT‐D) or without (CRT‐P) defibrillation in patients with no history of sustained ventricular arrhythmias.2 Methods and results
In this observational study, clinical events were quantified in relation to the type of implant (de novo or upgrade) and device type at upgrade (CRT‐P or CRT‐D). Patients underwent CRT implantation (n = 1,545; 1,314 [85%] de novo implants and 231 [15%] upgrades) over a median of 4.6 years [interquartile range: 2.4–7.0]. In analyses of crude event rates, upgrades had a higher total mortality (adjusted hazard ratio [aHR]: 1.33; 95% confidence interval [CI] 0.10–1.61), a higher total mortality or HF hospitalization (aHR: 1.26; 95% CI 1.05–1.51), but similar mortality or hospitalization for major adverse cardiac events (MACEs, aHR: 1.15; 95% CI 0.96–1.38). No group differences emerged in any of these endpoints after propensity score matching. After inverse probability weighting in upgrades, total mortality (HR: 0.55; 95% CI 0.36–0.73), total mortality or HF hospitalization (HR: 0.56; 95% CI 0.34–0.79), and total mortality or hospitalization for MACEs (HR: 0.61; 95% CI 0.40–0.82) were lower after CRT‐D than after CRT‐P.3 Conclusion
Upgrading from pacemakers to CRT was associated with a similar long‐term risk of mortality and morbidity to de novo CRT. After upgrade, CRT‐D was associated with a lower mortality than CRT‐P. 相似文献85.
86.
Ralph H. Arnold MB ChB 《Medicine, conflict, and survival》2013,29(4):259-261
This article examines the risk of proliferation of nuclear weapons to several Third World countries, exemplified by recent events in Iraq, and the possibility of rapid acquisition of a nuclear weapons capability in developed countries. It considers the role of the International Atomic Energy Agency and the United Nations in preventing proliferation and calls for wider powers for the latter. The role of the civil nuclear power industry and of reprocessing of nuclear fuel to produce plutonium is stressed, with emphasis on the part played by nuclear power in Japan and the THORP reprocessing plant at Sellafield. 相似文献
87.
Case report and review of nonischemic spontaneous papillary muscle rupture reports between 2000 and 2015 下载免费PDF全文
Pishoy Gouda MB BCh BAO Lisa Weilovitch MD Ronak Kanani MD Bryan Har MD 《Echocardiography (Mount Kisco, N.Y.)》2017,34(5):786-790
Spontaneous papillary muscle rupture (PMR) is a rare cardiovascular emergency. We present a 63‐year‐old male who presents with acute dyspnea who was found to have an anterior PMR, with no evidence of coronary artery disease, infection, or trauma. A review of cases of nonischemic spontaneous PMR published in 2000–2015 identified 11 additional cases of spontaneous PMR. Posterior and anterior papillary muscles involvement was identified in 54.5% and 45.5% of cases, respectively. Rapid identification due to advances in imaging modalities and improved surgical management has led to optimal outcomes in patients with spontaneous PMR. 相似文献
88.
89.
ECG‐gated pulmonary artery CTA for evaluation of right ventricular function in patients with acute pulmonary embolism 下载免费PDF全文
90.