全文获取类型
收费全文 | 1411357篇 |
免费 | 117840篇 |
国内免费 | 6644篇 |
专业分类
耳鼻咽喉 | 17617篇 |
儿科学 | 44992篇 |
妇产科学 | 38172篇 |
基础医学 | 193207篇 |
口腔科学 | 37959篇 |
临床医学 | 128166篇 |
内科学 | 294130篇 |
皮肤病学 | 33350篇 |
神经病学 | 116767篇 |
特种医学 | 57788篇 |
外国民族医学 | 278篇 |
外科学 | 221184篇 |
综合类 | 32578篇 |
现状与发展 | 3篇 |
一般理论 | 518篇 |
预防医学 | 112567篇 |
眼科学 | 30000篇 |
药学 | 98825篇 |
5篇 | |
中国医学 | 2387篇 |
肿瘤学 | 75348篇 |
出版年
2018年 | 15008篇 |
2017年 | 11733篇 |
2016年 | 14099篇 |
2015年 | 15800篇 |
2014年 | 21935篇 |
2013年 | 32978篇 |
2012年 | 40805篇 |
2011年 | 43818篇 |
2010年 | 27060篇 |
2009年 | 26301篇 |
2008年 | 40889篇 |
2007年 | 43541篇 |
2006年 | 44488篇 |
2005年 | 43079篇 |
2004年 | 41046篇 |
2003年 | 39697篇 |
2002年 | 37664篇 |
2001年 | 66996篇 |
2000年 | 68776篇 |
1999年 | 57588篇 |
1998年 | 17472篇 |
1997年 | 15622篇 |
1996年 | 16478篇 |
1995年 | 16696篇 |
1994年 | 15556篇 |
1993年 | 14579篇 |
1992年 | 47685篇 |
1991年 | 46319篇 |
1990年 | 44458篇 |
1989年 | 42309篇 |
1988年 | 39178篇 |
1987年 | 38506篇 |
1986年 | 36273篇 |
1985年 | 35111篇 |
1984年 | 26798篇 |
1983年 | 22526篇 |
1982年 | 14368篇 |
1981年 | 12901篇 |
1980年 | 12181篇 |
1979年 | 23905篇 |
1978年 | 17422篇 |
1977年 | 14709篇 |
1976年 | 13455篇 |
1975年 | 14041篇 |
1974年 | 16391篇 |
1973年 | 15644篇 |
1972年 | 14411篇 |
1971年 | 13203篇 |
1970年 | 12064篇 |
1969年 | 11250篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
Elizabeth D. Krebs Robert B. Hawkins J. Hunter Mehaffey Clifford E. Fonner Alan M. Speir Mohammed A. Quader Jeffrey B. Rich Leora T. Yarboro Nicholas R. Teman Gorav Ailawadi 《The Journal of thoracic and cardiovascular surgery》2019,157(4):1533-1542.e2
Objectives
Expedient extubation after cardiac surgery has been associated with improved outcomes, leading to postoperative extubation frequently during overnight hours. However, recent evidence in a mixed medical-surgical intensive care unit population demonstrated worse outcomes with overnight extubation. This study investigated the impact of overnight extubation in a statewide, multicenter Society of Thoracic Surgeons database.Methods
Records from 39,812 patients undergoing coronary artery bypass grafting or valve operations (2008-2016) and extubated within 24 hours were stratified according to extubation time between 06:00 and 18:00 (day) or between 18:00 and 6:00 (overnight). Outcomes including reintubation, mortality, and composite morbidity-mortality were evaluated using hierarchical regression models adjusted for Society of Thoracic Surgeons predictive risk scores. To further analyze extubation during the night, a subanalysis stratified patients into 3 groups: 06:00 to 18:00, 18:00 to 24:00, and 24:00 to 06:00.Results
A total of 20,758 patients were extubated overnight (52.1%) and were slightly older (median age 66 vs 65 years, P < .001) with a longer duration of ventilation (4 vs 7 hours, P < .001). Day and overnight extubation were associated with equivalent operative mortality (1.7% vs 1.7%, P = .880), reintubation (3.7% vs 3.4%, P = .141), and composite morbidity-mortality (8.2% vs 8.0%, P = .314). After risk adjustment, overnight extubation was not associated with any difference in reintubation, mortality, or composite morbidity-mortality. On subanalysis, those extubated between 24:00 and 06:00 exhibited increased composite morbidity-mortality (odds ratio, 1.18; P = .001) but no difference in reintubation or mortality.Conclusions
Extubation overnight was not associated with increased mortality or reintubation. These results suggest that in the appropriate clinical setting, it is safe to routinely extubate cardiac surgery patients overnight. 相似文献23.
Metabolism describes the series of chemical reactions that are concerned with the provision of energy to biological systems. They may be divided into reactions involved in energy yield (catabolism: demand exceeds supply), and energy storage (anabolism: supply exceeds demand). Regulation of these pathways is critical for homeostasis, and derangements in metabolism are seen in a wide variety of pathological processes. Understanding metabolism is key to the treatment of many diseases, notably diabetes, as well as underpinning clinical nutritional support. 相似文献
24.
25.
Die Anaesthesiologie - 相似文献
26.
Bela Anand-Apte Jennifer R. Chao Ruchira Singh Heidi Stöhr 《Journal of neuroscience research》2019,97(1):88-97
Sorsby fundus dystrophy (SFD), an autosomal dominant, fully penetrant, degenerative disease of the macula, is manifested by symptoms of night blindness or sudden loss of visual acuity, usually in the third to fourth decades of life due to choroidal neovascularization (CNV). SFD is caused by specific mutations in the Tissue Inhibitor of Metalloproteinase-3, (TIMP3) gene. The predominant histo-pathological feature in the eyes of patients with SFD are confluent 20–30 m thick, amorphous deposits found between the basement membrane of the retinal pigment epithelium (RPE) and the inner collagenous layer of Bruch's membrane. SFD is a rare disease but it has generated significant interest because it closely resembles the exudative or “wet” form of the more common age-related macular degeneration (AMD). In addition, in both SFD and AMD donor eyes, sub-retinal deposits have been shown to accumulate TIMP3 protein. Understanding the molecular functions of wild-type and mutant TIMP3 will provide significant insights into the patho-physiology of SFD and perhaps AMD. This review summarizes the current knowledge on TIMP3 and how mutations in TIMP3 cause SFD to provide insights into how we can study this disease going forward. Findings from these studies could have potential therapeutic implications for both SFD and AMD. 相似文献
27.
28.
29.
Christopher D Hue Frances S Cho Siqi Cao Cameron R ”Dale” Bass David F Meaney Barclay Morrison III 《Journal of cerebral blood flow and metabolism》2015,35(7):1191-1198
Owing to the frequent incidence of blast-induced traumatic brain injury (bTBI) in recent military conflicts, there is an urgent need to develop effective therapies for bTBI-related pathologies. Blood-brain barrier (BBB) breakdown has been reported to occur after primary blast exposure, making restoration of BBB function and integrity a promising therapeutic target. We tested the hypothesis that treatment with dexamethasone (DEX) after primary blast injury potentiates recovery of an in vitro BBB model consisting of mouse brain endothelial cells (bEnd.3). DEX treatment resulted in complete recovery of transendothelial electrical resistance and hydraulic conductivity 1 day after injury, compared with 3 days for vehicle-treated injured cultures. Administration of RU486 (mifepristone) inhibited effects of DEX, confirming that barrier restoration was mediated by glucocorticoid receptor signaling. Potentiated recovery with DEX treatment was accompanied by stronger zonula occludens (ZO)-1 tight junction immunostaining and expression, suggesting that increased ZO-1 expression was a structural correlate to BBB recovery after blast. Interestingly, augmented ZO-1 protein expression was associated with specific upregulation of the α+ isoform but not the α− isoform. This is the first study to provide a mechanistic basis for potentiated functional recovery of an in vitro BBB model because of glucocorticoid treatment after primary blast injury. 相似文献
30.
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