全文获取类型
收费全文 | 1411333篇 |
免费 | 113476篇 |
国内免费 | 3339篇 |
专业分类
耳鼻咽喉 | 18360篇 |
儿科学 | 46607篇 |
妇产科学 | 41051篇 |
基础医学 | 200809篇 |
口腔科学 | 37698篇 |
临床医学 | 126080篇 |
内科学 | 284486篇 |
皮肤病学 | 33368篇 |
神经病学 | 116916篇 |
特种医学 | 53838篇 |
外国民族医学 | 464篇 |
外科学 | 210558篇 |
综合类 | 32755篇 |
现状与发展 | 3篇 |
一般理论 | 487篇 |
预防医学 | 110038篇 |
眼科学 | 31517篇 |
药学 | 98537篇 |
1篇 | |
中国医学 | 3349篇 |
肿瘤学 | 81226篇 |
出版年
2021年 | 10863篇 |
2019年 | 11673篇 |
2018年 | 16586篇 |
2017年 | 12675篇 |
2016年 | 14265篇 |
2015年 | 16012篇 |
2014年 | 22572篇 |
2013年 | 33417篇 |
2012年 | 45409篇 |
2011年 | 47961篇 |
2010年 | 28176篇 |
2009年 | 27072篇 |
2008年 | 44337篇 |
2007年 | 46856篇 |
2006年 | 47412篇 |
2005年 | 45882篇 |
2004年 | 43767篇 |
2003年 | 41709篇 |
2002年 | 40201篇 |
2001年 | 73015篇 |
2000年 | 74538篇 |
1999年 | 61582篇 |
1998年 | 16995篇 |
1997年 | 15434篇 |
1996年 | 15587篇 |
1995年 | 14795篇 |
1994年 | 13398篇 |
1993年 | 12583篇 |
1992年 | 45845篇 |
1991年 | 43489篇 |
1990年 | 41506篇 |
1989年 | 39562篇 |
1988年 | 36196篇 |
1987年 | 35361篇 |
1986年 | 32868篇 |
1985年 | 31294篇 |
1984年 | 23834篇 |
1983年 | 20031篇 |
1982年 | 12210篇 |
1981年 | 10781篇 |
1979年 | 20707篇 |
1978年 | 14582篇 |
1977年 | 12091篇 |
1976年 | 11365篇 |
1975年 | 11623篇 |
1974年 | 13989篇 |
1973年 | 13534篇 |
1972年 | 12635篇 |
1971年 | 11471篇 |
1970年 | 10913篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Nancy C. Lee 《Public health reports (Washington, D.C. : 1974)》2015,130(2):121-Apr;130(2):121
3.
Wojciech Szychta M.D. Ph.D. Gheorghe Cerin M.D. Ph.D. F.E.S.C. Bogdan Adrian Popa M.D. Armienti Felice M.D. Guido Lanzillo M.D. Ph.D. Marco Diena M.D. Grzegorz Opolski M.D. Ph.D. F.E.S.C. 《Echocardiography (Mount Kisco, N.Y.)》2015,32(6):1040-1043
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning. 相似文献
4.
5.
Improvement in Tricuspid Annular Plane Systolic Excursion with Pulmonary Hypertension Therapy in Pediatric Patients 下载免费PDF全文
6.
7.
8.
9.
10.
Krishna Pillai Javid Akhter Terence C. Chua Mena Shehata Nayef Alzahrani Issan Al-Alem David L. Morris 《Medicine》2015,94(9)
Thermal ablation of liver tumors near large blood vessels is affected by the cooling effect of blood flow, leading to incomplete ablation. Hence, we conducted a comparative investigation of heat sink effect in monopolar (MP) and bipolar (BP) radiofrequency ablation (RFA), and microwave (MW) ablation devices.With a perfused calf liver, the ablative performances (volume, mass, density, dimensions), with and without heat sink, were measured. Heat sink was present when the ablative tip of the probes were 8.0 mm close to a major hepatic vein and absent when >30 mm away. Temperatures (T1 and T2) on either side of the hepatic vein near the tip of the probes, heating probe temperature (T3), outlet perfusate temperature (T4), and ablation time were monitored.With or without heat sink, BP radiofrequency ablated a larger volume and mass, compared with MP RFA or MW ablation, with latter device producing the highest density of tissue ablated. MW ablation produced an ellipsoidal shape while radiofrequency devices produced spheres.Percentage heat sink effect in Bipolar radiofrequency : Mono-polar radiofrequency : Microwave was (Volume) 33:41:22; (mass) 23:56:34; (density) 9.0:26:18; and (relative elipscity) 5.8:12.9:1.3, indicating that BP and MW devices were less affected.Percentage heat sink effect on time (minutes) to reach maximum temperature (W) = 13.28:9.2:29.8; time at maximum temperature (X) is 87:66:16.66; temperature difference (Y) between the thermal probes (T3) and the temperature (T1 + T2)/2 on either side of the hepatic vessel was 100:87:20; and temperature difference between the (T1 + T2)/2 and temperature of outlet circulating solution (T4), Z was 20.33:30.23:37.5.MW and BP radiofrequencies were less affected by heat sink while MP RFA was the most affected. With a single ablation, BP radiofrequency ablated a larger volume and mass regardless of heat sink. 相似文献