A High Order Bound Preserving Finite Difference Linear Scheme for Incompressible Flows

We propose a high order finite difference linear scheme combined with a high order bound preserving maximum-principle-preserving (MPP) flux limiter to solve the incompressible flow system. For such problem with highly oscillatory structure but not strong shocks, our approach seems to be less dissipative and much less costly than a WENO type scheme, and has high resolution due to a Hermite reconstruction. Spurious numerical oscillations can be controlled by the weak MPP flux limiter. Numerical tests are performed for the Vlasov-Poisson system, the 2D guiding-center model and the incompressible Euler system. The comparison between the linear and WENO type schemes, with and without the MPP flux limiter, will demonstrate the good performance of our proposed approach.     

A Priori Subcell Limiting Approach for the FR/CPR Method on Unstructured Meshes

A priori subcell limiting approach is developed for high-order flux reconstruction/correction procedure via reconstruction (FR/CPR) methods on two-dimensional unstructured quadrilateral meshes. Firstly, a modified indicator based on modal energy coefficients is proposed to detect troubled cells, where discontinuities exist. Then, troubled cells are decomposed into nonuniform subcells and each subcell has one solution point. A second-order finite difference shock-capturing scheme based on nonuniform nonlinear weighted (NNW) interpolation is constructed to perform the calculation on troubled cells while smooth cells are calculated by the CPR method. Numerical investigations show that the proposed subcell limiting strategy on unstructured quadrilateral meshes is robust in shock-capturing.     

A meta-analysis on salvage surgery as a potentially curative procedure in patients with isolated local recurrent or persistent esophageal cancer after chemoradiotherapy

BackgroundIsolated local recurrent or persistent esophageal cancer (EC) after curative intended definitive (dCRT) or neoadjuvant chemoradiotherapy (nCRT) with initially omitted surgery, is a potential indication for salvage surgery. We aimed to evaluate safety and efficacy of salvage surgery in these patients.Material and methodsA systematic literature search following PRISMA guidelines was performed using databases of PubMed/Medline. All included studies were performed in patients with persistent or recurrent EC after initial treatment with dCRT or nCRT, between 2007 and 2017. Survival analysis was performed with an inverse-variance weighting method.ResultsOf the 278 identified studies, 28 were eligible, including a total of 1076 patients. Postoperative complications after salvage esophagectomy were significantly more common among patients with isolated persistent than in those with locoregional recurrent EC, including respiratory (36.6% versus 22.7%; difference in proportion 10.9 with 95% confidence interval (CI) [3.1; 18.7]) and cardiovascular complications (10.4% versus 4.5%; difference in proportion 5.9 with 95% CI [1.5; 10.2]). The pooled estimated 30- and 90-day mortality was 2.6% [1.6; 3.6] and 8.0% [6.3; 9.8], respectively. The pooled estimated 3-year and 5-year overall survival (OS) were 39.0% (95% CI: [35.8; 42.2]) and 19.4% [95% CI:16.5; 22.4], respectively. Patients with isolated persistent or recurrent EC after initial CRT had similar 5-year OS (14.0% versus 19.7%, difference in proportion −5.7, 95% CI [-13.7; 2.3]).ConclusionsSalvage surgery is a potentially curative procedure in patients with locally recurrent or persistent esophageal cancer and can be performed safely after definitive or neoadjuvant chemoradiotherapy when surgery was initially omitted.     

食管癌高、低发区食管鳞癌患者生存及其影响因素分析

目的 探讨食管癌高、低发区食管鳞癌患者的生存状况及其影响因素。方法 收集38 741例经病理学证实为食管鳞癌患者的资料，其中，高发区患者23 273例（60.1%），低发区15 468例（39.9%）。所有患者均行食管癌根治术。运用卡方检验分析不同临床病理特征患者的组间差异，Kaplan-Meier法绘制不同临床病理特征患者的生存曲线并用Log rank进行检验。多因素Cox比例风险回归模型法分析影响生存的主要因素。结果 低发区男性患者所占比例高于高发区（P<0.001），低发区诊断年龄≥50岁食管癌患者所占比例高于高发区（P<0.001）。高发区食管鳞癌患者的整体生存优于低发区患者（P<0.001）。Cox比例风险回归模型综合分析结果表明：高低发区、性别、确诊年龄、肿瘤部位、分化程度、TNM分期和肿瘤家族史均是影响食管鳞癌患者生存的独立因素。结论 高发区食管鳞癌患者整体生存优于低发区；低发区是食管鳞癌患者预后差的独立危险因素。     

2013-2017年我国四种恶性肿瘤住院费用水平及结构变动度分析

背景　恶性肿瘤给家庭、社会带来了沉重的医疗、经济负担，极易导致部分家庭“因病致贫”或放弃治疗，目前相关研究多集中于单一病种、分散地域的研究，仍缺乏对于全国范围与多病种恶性肿瘤住院费用变化及结构构成的考量。目的　分析2013-2017年我国4种恶性肿瘤住院费用水平以及影响住院费用的主要项目和结构变动情况，为控制医疗费用上涨、深化新医改提供参考依据。方法　本研究数据来源于《2014中国卫生和计划生育统计年鉴》《2015中国卫生和计划生育统计年鉴》《2016中国卫生和计划生育统计年鉴》《2017中国卫生和计划生育统计年鉴》以及《2018中国卫生健康统计年鉴》，样本跨度为2013-2017年。统计“30种疾病人均住院费用”中的胃恶性肿瘤、肺恶性肿瘤、食管恶性肿瘤以及膀胱恶性肿瘤的数据，4种恶性肿瘤的人均住院费用包括药费、检查费、治疗费、手术费和手术材料费。2019年4-8月，采用结构变动度法分析我国2013-2017年4种恶性肿瘤的住院费用的结构变动情况〔结构变动值（VSV）、结构变动度（DSV）、结构变动贡献率〕。结果　2013-2017年，4种恶性肿瘤的人均住院费用逐年上升，其中胃恶性肿瘤的人均住院费用始终最高，且肺恶性肿瘤的人均住院费用上升幅度最大。2013-2017年，在4种恶性肿瘤住院各项费用的占比中，药费占比最高且总体逐年下降。从4种恶性肿瘤住院各项费用的实际变化来看，药费在2013-2014年有所上升，2014-2017年逐年下降；检查费在2013-2014年下降，2014-2017年缓慢上升；手术费与手术材料费在2013-2017年逐年上升。2013-2017年，在4种恶性肿瘤住院各项费用中均是药费的VSV最大；4种恶性肿瘤药费、检查费的VSV均呈负向变化，手术费和手术材料费的VSV均呈正向变化，治疗费的VSV增减均不明显。2013-2017年，4种恶性肿瘤住院费用的DSV从大到小依次为肺恶性肿瘤、胃恶性肿瘤、食管恶性肿瘤、膀胱恶性肿瘤。2013-2017年，4种恶性肿瘤住院各项费用中均是药费的结构变动贡献率最大，治疗费的结构变动贡献率最小；除药费外，胃恶性肿瘤、肺恶性肿瘤住院各项费用中均是手术材料费和手术费的结构变动贡献率次之，食管恶性肿瘤住院各项费用中手术费、检查费的结构变动贡献率次之，膀胱恶性肿瘤住院各项费用中检查费、手术材料费的结构变动贡献率次之。结论　2013-2017年我国4种恶性肿瘤手术费的结构变动贡献率虽然较为理想，但药费、治疗费仍是住院费用结构的重点调整对象；同时为有效降低恶性肿瘤的人均住院费用，应当加强控制手术材料费与检查费；而胃恶性肿瘤与肺恶性肿瘤患者的疾病经济负担严重，若要缓解应加强疾病的早期预防与住院费用管控。     

肿瘤性复杂性胸壁缺损的修复策略及对肿瘤治疗的积极影响

复杂性胸壁缺损的修复一直是一项极具挑战性的工作。肿瘤性复杂性胸壁缺损的修复决策及其执行困难是限制胸壁肿瘤治疗方法选择及影响预后的重要因素之一。皮瓣解剖学研究的深入、胸壁支持结构重建技术的进步、显微外科技术的发展、麻醉护理的发展、对综合治疗的重视和治疗手段的进步等,使传统认为不可切除的胸壁肿瘤得以彻底地切除和安全有效地修复,从而使与缺损修复相关的肿瘤切除及辅助治疗的禁忌证缩减到最小程度,有效地提高了胸壁肿瘤患者的生存质量,并很大程度上延长了生存率。作者以湖南省肿瘤医院整形外科15年565例胸壁肿瘤切除后修复重建的临床资料为依据,充实了胸壁肿瘤切除及修复的策略:(1)可靠的胸壁骨性支架重建;(2)有效的软组织修复;(3)麻醉及护理与手术团队的合作;(4)系统有序的综合治疗。并进一步明确了复杂胸壁肿瘤切除及重建的细节理念,包括胸部肿瘤治疗中加强多学科合作的密切性和科学性,整形外科医生参与肿瘤治疗整体规划的主动性和时机前移等。