首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   481篇
  免费   15篇
  国内免费   9篇
耳鼻咽喉   1篇
儿科学   1篇
妇产科学   1篇
基础医学   14篇
口腔科学   18篇
临床医学   27篇
内科学   180篇
神经病学   35篇
特种医学   22篇
外科学   143篇
综合类   36篇
预防医学   5篇
药学   17篇
中国医学   2篇
肿瘤学   3篇
  2024年   2篇
  2023年   8篇
  2022年   16篇
  2021年   21篇
  2020年   20篇
  2019年   20篇
  2018年   19篇
  2017年   14篇
  2016年   19篇
  2015年   29篇
  2014年   45篇
  2013年   41篇
  2012年   16篇
  2011年   27篇
  2010年   22篇
  2009年   24篇
  2008年   22篇
  2007年   31篇
  2006年   23篇
  2005年   12篇
  2004年   9篇
  2003年   12篇
  2002年   4篇
  2001年   6篇
  2000年   4篇
  1999年   7篇
  1998年   3篇
  1997年   4篇
  1996年   2篇
  1995年   3篇
  1994年   2篇
  1993年   1篇
  1991年   1篇
  1990年   4篇
  1989年   4篇
  1987年   4篇
  1986年   2篇
  1985年   1篇
  1984年   1篇
排序方式: 共有505条查询结果,搜索用时 0 毫秒
1.
血管移植搭桥治疗巨大动脉瘤   总被引:1,自引:0,他引:1  
目的探讨中、高流量血管搭桥方法对颅内巨大颅内动脉瘤的治疗。方法8例巨大和颅底复杂动脉瘤患者,主要表现头痛发病者5例,视力减退者2例,面部麻木者1例。未破裂动脉瘤6例,2例患者发生动脉瘤破裂,Hunt-Hess分级分别为Ⅰ级和Ⅱ级。血管造影证实:动脉瘤体位于颈内动脉海绵窦段(C4段)4例、床突上段(C1段)2例、大脑中动脉M2~M1段者2例动脉瘤大小为2.5~6.0cm,平均直径3.7cm。其中6例动脉瘤为梭形,2例为宽颈动脉瘤。8例患者均采用额颞开颅,骨瓣要尽可能低到颅底,以缩短搭桥移植血管在颅外走行长度。通常用7-0显微缝线吻合移植血管与颈外动脉,用8-0缝线吻合移植血管与颅内段颈内动脉和大脑中动脉。4例患者利用大隐静脉移植搭桥,4例患者利用桡动脉移植搭桥。颅内、外搭桥完毕后将动脉瘤近心端和远端的供血动脉结扎和夹闭,阻断动脉瘤的全部血供。对3例有压迫脑神经或颅内占位引起颅压高的患者,将动脉瘤切除。结果5例术后头痛消失,1例视力减退者明显改善,1例动眼神经麻痹恢复。5例术后行脑血管造影检查,3例行CT血管造影检查,7例搭桥吻合血管全部畅通,动脉瘤消失。2例术后出现暂时性一侧肢体力弱,肌力在Ⅱ~Ⅲ级之间,术后1个月完全恢复。结论中、高流量颅内外血管搭桥可作为治疗颅内巨大动脉瘤的有效方法。  相似文献   
2.
Background Contemporary diagnosis of ACS and risk stratification are essential for appropriate management and reduction of mortality and recurrent ischemic events, in the acute phase of disease and after hospitalization. The Universal Definition of Myocardial Infarction recommends the detection of troponin levels above the 99th percentile.Objectives To evaluate the occurrence of early death and acute myocardial infarction (AMI) in patients without elevation of troponin (<0.034 ng/mL), patients with mild elevation (above the 99th percentile [>0.034 ng/mL and <0.12 ng/mL)], and patients with significant elevation of troponin (above the diagnostic cutoff for AMI defined by the troponin kit (≥0.12 ng/mL)]; and to analyze the impact of troponin on the indication for invasive strategy and myocardial revascularization.Methods Cross-sectional cohort study of patients with ACS with assessment of peak troponin I, risk score, prospective analysis of 30-day clinical outcomes and two-sided statistical tests, with statistical significance set at p<0.05.Results A total of 494 patients with ACS were evaluated. Troponin > 99th percentile and below the cutoff point, as well as values above the cutoff, were associated with higher incidence of composite endpoint (p<0.01) and higher rates of percutaneous or surgical revascularization procedures (p<0.01), without significative difference in 30-day mortality.Conclusions Troponin levels above the 99th percentile defined by the universal definition of AMI play a prognostic role and add useful information to the clinical diagnosis and risk scores by identifying those patients who would most benefit from invasive risk stratification and coronary revascularization procedures.  相似文献   
3.
目的;研究两种激光在心肌血管重建术(TMR)中的组织学效应。方法:实验犬随机分为2组:连续波CO2激光组(n=20)及调制Nd:YAG激光组(n=10),2组均经心外膜法行激光打孔,观察激光孔道的组织学改变。结果:CO2激光孔道周围出现明显的碳化带、凝固性坏死层及心肌变性层,经8周的修复,出现不同程度的微循环改建,尤以碳化程度轻的部位为著;而Nd:YAG激光孔道未见碳化物形成,凝固性坏死及心肌变性范围明显减小,术中并发症的发生均较CO2激光减轻。结论:Nd:YAG激光孔道的热损伤程度轻,有利于心肌内微循环改建,以改善心肌供血,且具有术中并发症少等优点。  相似文献   
4.
BackgroundCoronary artery bypass grafting (CABG) improves survival in patients with heart failure and severely reduced left ventricular systolic function (LVEF). Limited data exist regarding adverse cardiovascular event rates after CABG in patients with heart failure with midrange ejection fraction (HFmrEF; LVEF > 40% and < 55%).MethodsWe analyzed data on isolated CABG patients from the Veterans Affairs national database (2010-2019). We stratified patients into control (normal LVEF and no heart failure), HFmrEF, and heart failure with reduced LVEF (HFrEF) groups. We compared all-cause mortality and heart failure hospitalization rates between groups with a Cox model and recurrent events analysis, respectively.ResultsIn 6533 veterans, HFmrEF and HFrEF was present in 1715 (26.3%) and 566 (8.6%) respectively; the control group had 4252 (65.1%) patients. HFrEF patients were more likely to have diabetes mellitus (59%), insulin therapy (36%), and previous myocardial infarction (31%). Anemia was more prevalent in patients with HFrEF (49%) as was a lower serum albumin (mean, 3.6 mg/dL). Compared with the control group, a higher risk of death was observed in the HFmrEF (hazard ratio [HR], 1.3 [1.2-1.5)] and HFrEF (HR, 1.5 [1.2-1.7]) groups. HFmrEF patients had the higher risk of myocardial infarction (subdistribution HR, 1.2 [1-1.6]; P = .04). Risk of heart failure hospitalization was higher in patients with HFmrEF (HR, 4.1 [3.5-4.7]) and patients with HFrEF (HR, 7.2 [6.2-8.5]).ConclusionsHeart failure with midrange ejection fraction negatively affects survival after CABG. These patients also experience higher rates myocardial infarction and heart failure hospitalization.  相似文献   
5.
Background Revascularization of a fracture depends on fracture stability and fracture gap conditions. The aim of the study was to determine quantitatively the revascularization and tissue differentiation in an animal model with different fracture gaps and controlled biomechanical conditions.Materials and method The study was performed on ten sheep with an osteotomy on the right metatarsal. The fracture was stabilized by an external fixator that allowed adjustable axial interfragmentary movement. Two groups of five sheep each were adjusted to a medium sized gap (M, 2.1 mm) and a large gap (L, 5.7 mm) under comparable interfragmentary strain (30–32%). The animals were killed after 9 weeks, and the metatarsals were prepared for undecalcified histology and analysis of tissue differentiation and vessel distribution.Results Group M showed significantly more revascularization (M=1.62, L=0.85 vessels/mm2), more bone formation (M=37.2%, L=13.9%) and less fibrocartilage tissue (M=18.1%, L=39.1%) than group L. Larger vessels (>40 m) were found mainly in the medullary channel, and smaller vessels (<20 m) mainly in the peripheral callus. Histologically, group M showed partial bony bridging of the osteotomy gap, and the group L had delayed healing.Conclusion A good reduction of a fracture with small interfragmentary gaps is important for its revascularization and healing.  相似文献   
6.
股深动脉血流重建治疗下肢动脉硬化闭塞症   总被引:12,自引:1,他引:12  
目的总结股深动脉血流重建治疗下肢动脉硬化闭塞症的经验。方法选择FontaineⅢ、Ⅳ期下肢动脉硬化闭塞症共23例。入选标准:膝上无理想的用于旁路术的流出道,股深动脉主干长度达到或超过股骨干中点且与胭动脉间有侧支血管,近端动脉病变导致股深动脉内无正常动脉血流。采用旁路术、取栓术及股深动脉成形术重建股深动脉血流。结果全部FontaineⅢ期病例于术后肢体静息痛消失;9例FontaineⅣ期病例中术后肢体静息痛消失7例,6例于术后10d行截足(趾)术,1例于术后1周行膝上截肢术。手术后踝/肱血压指数显著增加(P〈0.01)。术后22例随访2个月至6年,移植血管3年通畅率为82%。结论股深动脉血流重建治疗严重肢体缺血简单、安全、有效。  相似文献   
7.
大网膜包裹人工神经移植体再血管化及神经再生的研究   总被引:1,自引:0,他引:1  
目的 探讨大网膜包裹人工神经移植体的早期再血管化,以及增强移植体血供对神经再生的影响。方法 75只大耳白兔制作成左前肢正中神经2.0cm缺损,随机分成3组:A组,带蒂大网膜包裹人工神经移植体移植;B组,人工神经移植体桥接神经缺损;C组,自体神经桥接神经缺损,作为对照组。术后3、7和14d应用伊凡思蓝(evans blue bound to albumin,EBA)毛细血管造影,检测各组移植体的再血管化;术后12周通过电生理、光镜、透射电镜等检测评估神经再生的效果。结果 A、C组术后3d移植神经出现再血管化,7d和14d再血管化程度逐渐增强;B组7d出现再血管化,与A、C组比较,再血管化延迟。术后12周,A组和C组运动神经传导速度、有髓神经纤维密度、神经内纤维组织面积及面积比、髓鞘厚度、髓鞘直径等差异无统计学意义(P〉0.05),但均优于B组,差异有统计学意义(P〈0.05)。结论 大网膜包裹人工神经移植体可促进移植体早期再血管化,增强移植体血供,促进神经再生。  相似文献   
8.
《Brain & development》2021,43(10):1051-1056
BackgroundPost varicella angiopathy (PVA) is an underdiagnosed but potentially severe disease in both pediatric and adult settings. No guidelines are available for the medical and neurosurgical management of this condition. We report the first pediatric case with headache and PVA who was treated with surgical revascularization before the onset of ischemic events.MethodsThis case report was conducted via retrospective chart review. A literature review was also completed, in order to identify previously described PVA undergone to revascularization.ResultsWe report on a 9-year-old boy presenting with a long history of headache and PVA involving the distal left middle cerebral artery. The arterial lesion rapidly worsened over a 10 months’ period with formation of focal moyamoya-like collaterals, despite an adequate intravenous antiviral treatment. The pattern of headaches significantly changed with a clear left-side lateralization and a “re-build-up” phenomenon on EEG. The patient was treated with left superficial temporal artery - middle cerebral artery (STA-MCA) bypass and encephalo-duro-arterio-myo-pericranial-synangiosis. This combined treatment resulted in an immediate and persistent improvement of brain perfusion, accompanied by prompt resolution of neurological symptoms.Two cases who presented with Suzuki stage III (unilateral or bilateral) moyamoya PVA and recurrent strokes or transient ischemic attacks despite adequate pharmacological prophylaxis have been surgically treated using both indirect and direct revascularization technique. The outcome was good in both cases.ConclusionSurgical revascularization may have a role in the treatment of PVA and may prevent stroke. Given the lack of standardized treatment algorithms, individualized regimens should be formulated on a case-specific basis.  相似文献   
9.
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号