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.     

胎儿小脑蚓部不同超声纹理特征与胎儿畸形关系的初探郭永华 肖宝军

目的：总结后颅窝正常和异常的胎儿小脑及小脑蚓部的矢状面的声像学特征,了解小脑细微结构的改变与胎儿畸形的关系。     

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。     

Clinical Study on CT-guided Modified Akupotomye in the Treatment of Lumbar Nerve Posterior Branch Compression

Objective: To observe the clinical effect of modified akupotomye closed lysis under CT guidance on compression of posterior lumbar nerve branch.Methods: Patients were diagnosed by HRCT 3-D reconstruction combined with clinical symptoms and signs.After HRCT three-dimensional reconstruction combined with clinical symptoms and signs, the patients were confirmed as posterior lumbar nerve compression.After CT accurate surface positioning, CT-guided modified akupotomye was used for closed lysis of the posterior lumbar nerve branch.Oswestry Dysfunction Index Questionnaire(ODI) was used for quantitative scoring, 7 days before and after treatment and 6 months after treatment.Results: In 62 cases, 20 cases were cured, with 25 cases markedly effective, 11 cases effective, and 36 cases ineffective.The total effective rate was 90.3%.ODI score: Self-paired t test 7 days before after treatment, P < 0.01;Before treatment and 6 months after treatment, self-paired t test(P < 0.01);Self-paired t-test was performed 7 days after treatment and 6 months after treatment(P > 0.05).Conclusion: With CT precise positioning, the modified akupotomye can be used to do closed lysis, to relieve the adhesion and compression, so that the low back pain can be relieved, with good clinical.The akupotomye closed lysis, combined with modern imaging technology has not only achieved good clinical effect, but also can improve the accuracy, safety and scientificity of akupotomye treatment.