全文获取类型
收费全文 | 4343943篇 |
免费 | 349418篇 |
国内免费 | 14147篇 |
专业分类
耳鼻咽喉 | 61202篇 |
儿科学 | 139860篇 |
妇产科学 | 115042篇 |
基础医学 | 665970篇 |
口腔科学 | 118466篇 |
临床医学 | 392814篇 |
内科学 | 786705篇 |
皮肤病学 | 110680篇 |
神经病学 | 361510篇 |
特种医学 | 168133篇 |
外国民族医学 | 616篇 |
外科学 | 666471篇 |
综合类 | 119804篇 |
现状与发展 | 23篇 |
一般理论 | 2619篇 |
预防医学 | 364494篇 |
眼科学 | 101901篇 |
药学 | 306440篇 |
21篇 | |
中国医学 | 11522篇 |
肿瘤学 | 213215篇 |
出版年
2021年 | 52898篇 |
2020年 | 37233篇 |
2019年 | 61693篇 |
2018年 | 78815篇 |
2017年 | 59365篇 |
2016年 | 65413篇 |
2015年 | 78499篇 |
2014年 | 113592篇 |
2013年 | 180617篇 |
2012年 | 135242篇 |
2011年 | 141676篇 |
2010年 | 131449篇 |
2009年 | 131335篇 |
2008年 | 125510篇 |
2007年 | 133976篇 |
2006年 | 141460篇 |
2005年 | 136359篇 |
2004年 | 135550篇 |
2003年 | 124885篇 |
2002年 | 113544篇 |
2001年 | 152864篇 |
2000年 | 147341篇 |
1999年 | 135322篇 |
1998年 | 64869篇 |
1997年 | 60789篇 |
1996年 | 58876篇 |
1995年 | 59490篇 |
1994年 | 53655篇 |
1993年 | 49866篇 |
1992年 | 97637篇 |
1991年 | 94423篇 |
1990年 | 90693篇 |
1989年 | 88263篇 |
1988年 | 81360篇 |
1987年 | 79855篇 |
1986年 | 75143篇 |
1985年 | 74085篇 |
1984年 | 62246篇 |
1983年 | 55785篇 |
1982年 | 45935篇 |
1981年 | 42966篇 |
1980年 | 40331篇 |
1979年 | 53629篇 |
1978年 | 44278篇 |
1977年 | 39003篇 |
1976年 | 36370篇 |
1975年 | 36565篇 |
1974年 | 39956篇 |
1973年 | 38227篇 |
1972年 | 35937篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Chrystalle Katte Carreon Annachiara Benini Christopher Baird David Hoganson Michele Borisuk Sitaram Emani Sophie Hofferberth Robert F. Padera Stephen P. Sanders 《The Journal of thoracic and cardiovascular surgery》2019,157(1):342-350.e3
Objectives
Although valved venous homografts (VVHs) are used for establishing right ventricle-to-pulmonary artery continuity in some complex heart defects, the tissue changes that occur in situ have not been described. We review the gross and microscopic changes observed in explanted VVH conduits and their effects on functionality.Methods
In total, 20 explanted VVH conduits were evaluated for valve integrity, presence of thrombus, and stenosis. Hematoxylin and eosin– and trichrome-stained sections were reviewed for neointima formation, wall remodeling, inflammation, and calcification. Regurgitation and narrowing were assessed on pre-explant echocardiogram, and angiographic video clips were correlated with tissue findings. The source of the proliferating cells within the conduits was investigated by fluorescent in situ hybridization.Results
Thirteen male and 7 female infants underwent VVH implantation either as part of a composite Sano shunt (65%) or to establish right ventricle-to-pulmonary artery continuity in biventricular hearts (35%). The median duration of conduits in situ was 140 days (range: 98-340 days). Conduits were predominantly explanted for staged conversion to bidirectional Glenn (60%) and conduit upsizing (20%). The valves remained intact and functional in 75% of cases. Occlusive thrombosis was absent in all. Wall thickening due to neointima formation and wall remodeling was uniformly present and appeared to be driven by smooth muscle actin–expressing cells, which by fluorescent in situ hybridization are predominantly of recipient origin. Minimal calcification and mild adventitial chronic inflammation were present.Conclusions
Vein wall thickening is a uniform finding and can cause stenosis. The valves remain functional in most, and vein walls undergo remodeling with only minimal inflammation and calcification. 相似文献992.
Introduction
Vestibular neurotomy is a functional surgery for Meniere's disease in the event of medical treatment failure. The aim of the study was to assess the efficacy and complications of vestibular neurotomy, and to address the question of postoperative compensation.Material and method
All patients included in this retrospective study underwent a vestibular neurotomy at our center between 2009 and 2016. A preoperative evaluation was performed including MRI, audiometry, and videonystagmography. The functional level of disability was evaluated by the Dizziness Handicap Inventory (DHI) score. In all patients suboccipital retrosigmoid approach was performed. All patients underwent early postoperative vestibular rehabilitation. One month and two years after surgery, we assessed the effectiveness of treatment on dizziness, disability and imbalance. At the time of this study (2 to 8 years), DHI and patients’ satisfaction by patient's global impression of change (PGIC) scale were evaluated.Results
Fifteen patients aged between 42 and 74 years of age were included in our study. Postoperative complications occurred in two patients (meningitis and a wound infection). At one month, all patients had a dramatic clinical improvement with decreased vertigo. Two years after surgery, 85% of the patients were cured and had no dizziness or balance disorder. Only one patient experienced bilateralization and only one had a persistent poor compensation.Conclusion
Vestibular neurotomy is a very effective treatment in the case of Meniere's disease resistant to medical treatment, with very good functional results and an extremely low failure rate. 相似文献993.
994.
995.
Stephan Koter Tina U. Cohnert Korbinian B. Hindermayr Jörg Lindenmann Maximilian Brückner Wolfgang K. Oswald Georg Werkgartner Doris Wagner 《Journal of vascular surgery》2019,69(4):1227-1232
Objective
Low psoas muscle area is shown to be an indicator for worse postoperative outcome in patients undergoing vascular surgical. Additionally, it has been associated with longer durations of hospital stay in patients with cancer who undergo surgery and subsequently greater health care costs in Europe and the United States. We sought to evaluate this effect on hospital expenditure for patients undergoing vascular repair in a health care system with universal access.Methods
Skeletal muscle mass was assessed on preoperative abdominal computed tomography scans of patients undergoing open aortic aneurysm repair in a retrospective fashion. The skeletal muscle index (SMI) was used to define low muscle mass. Health care costs were obtained for all patients and the relationship between a low SMI and higher costs was explored using linear regression and cross-sectional analysis.Results
We included 156 patients (81.5% male) with a median age of 72 years undergoing elective surgery for infrarenal abdominal aortic aneurysm in this analysis. The median SMI for patients with low skeletal muscle mass was 53.21 cm2/kg and for patients without, 70.07 cm2/kg. Hospital duration of stay was 2 days longer in patients with low skeletal muscle mass as compared with patients with normal (14 days vs 11 days; P = .001), as was duration of intensive care stay (3 days vs 1 day; P = .01). The median overall hospital costs were €10,460 higher for patients with a low SMI as compared with patients with a normal physical constitution (€53,739 [interquartile range, €45,007-€62,471] vs €43,279 [interquartile range, €39,509-€47,049]; P = .001). After confounder adjustment, a low SMI was associated with a 14.68% cost increase in overall hospital costs, for a cost increase of €6521.Conclusions
Low skeletal muscle mass is independently associated with higher hospital as well as intensive care costs in patients undergoing elective aortic aneurysm repair. Strategies to reduce this risk factor are warranted for these patients. 相似文献996.
997.
998.
Richard B. Gunderman 《Academic radiology》2019,26(6):860-861
999.
1000.