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.     

荔枝草治疗急性咽炎有效部位筛选＊

目的 筛选荔枝草治疗急性咽炎的有效部位，研究治疗急性咽炎的作用机制，为荔枝草资源的药食两用开发提供理论依据。方法 通过二甲苯致小鼠耳肿胀试验筛选荔枝草抗炎有效部位，采用氨水刺激喉部法建立大鼠急性咽炎模型，通过行为学观察、ELISA双抗夹心检测、病理形态学观察和咽部组织蛋白表达研究乙酸乙酯部位对大鼠急性咽炎的治疗效果。结果 荔枝草乙酸乙酯提取物对二甲苯致小鼠耳肿胀有明显的抑制作用，氨水刺激建立的急性咽炎模型符合急性咽炎动物模型特征，乙酸乙酯部位提取物可显著改善急性咽炎大鼠的咽部病理形态学表现。不同剂量治疗组大鼠血清及咽部组织中IL-1β、IL-6及TNF-α炎性因子数量均下降，高剂量组下降最为明显。荔枝草乙酸乙酯提取物可明显增加大鼠咽部组织IκBα蛋白表达，降低NF-κBp65蛋白表达。结论 荔枝草乙酸乙酯部位提取物对急性咽炎具有治疗作用，可能与抑制咽部炎症病理改变的发生，能调节血液中炎症因子、抑制NF-κB表达和IκBα解离有关。     

Curcumin Encapsulated into Biocompatible Co-Polymer PLGA Nanoparticle Enhanced Anti-Gastric Cancer and Anti-Helicobacter Pylori Effect

Background: The current disadvantages (high cost, toxicity, resistance) of chemotherapy for gastric cancer opted people for alternative therapy from natural source. Curcumin (natural product) possess multiple biological activities but low bio-availability limits their uses as therapeutic. The Nano-formulation of curcumin increased the bioavailability and productivity of anti-cancer and anti-bacterial properties. The present study was initiated to determine the anti-cancer and anti-bacterial effect of Nano curcumin against gastric cancer and H. pylori. Methods: Curcumin loaded PLGA nanoparticles (CUR-NPs) was prepared by single emulsion solvent evaporation method. The MIC were determined using agar dilution method to find the anti-H. Pylori activity of Nano curcumin. The cytotoxicity of Nano curcumin was evaluated by MTT assay and the apoptotic effect (cell cycle arrest and morphology change) was shown by PI staining and microscopy. Results: The MIC of nanocurcumin and curcumin for all four H. pylori strains were 8 µg/ml and 16 µg/ml respectively. The inhibition rate of gastric cancer cells after treatment with curcumin was increased from 6% to 67% for 24h, from 8% to 75% for 48h, from 10% to 83% for 72h. In case of nanocurcumin, the inhibition rate increased from 7% to 69% for 24h, 11% to 87% for 48h and 16% to 97% for 72h. The IC50 of curcumin and Nano-curcumin were 24.20 µM and 18.78 µM respectively for 72 h. The population of cells in sub-G0 population increased from 4.1% in the control group to 24.5% and 57.8% when treated with curcumin and nanocurcumin respectively. After 72h of treatment with nanocurcumin, the apoptotic cells population increased as compared to native curcumin treated cells. Conclusion: The Nano curcumin might be used as a potential therapeutics against gastric cancer and H. Pylori. There is need of further in vivo study in order to validate CUR-NPs activity.     

Eulerian Algorithms for Computing the Forward Finite Time Lyapunov Exponent Without Finite Difference upon the Flow Map

In this paper, effective Eulerian algorithms are introduced for the computation of the forward finite time Lyapunov exponent (FTLE) of smooth flow fields. The advantages of the proposed algorithms mainly manifest in two aspects. First, previous Eulerian approaches for computing the FTLE field are improved so that the Jacobian of the flow map can be obtained by directly solving a corresponding system of partial differential equations, rather than by implementing certain finite difference upon the flow map, which can significantly improve the accuracy of the numerical solution especially near the FTLE ridges. Second, in the proposed algorithms, all computations are done on the fly, that is, all required partial differential equations are solved forward in time, which is practically more natural. The new algorithms still maintain the optimal computational complexity as well as the second order accuracy. Numerical examples demonstrate the effectiveness of the proposed algorithms.     

High Order Finite Difference Hermite WENO Fixed-Point Fast Sweeping Method for Static Hamilton-Jacobi Equations

In this paper, we combine the nonlinear HWENO reconstruction in [43] and the fixed-point iteration with Gauss-Seidel fast sweeping strategy, to solve the static Hamilton-Jacobi equations in a novel HWENO framework recently developed in [22]. The proposed HWENO frameworks enjoys several advantages. First, compared with the traditional HWENO framework, the proposed methods do not need to introduce additional auxiliary equations to update the derivatives of the unknown function $\phi$. They are now computed from the current value of $\phi$ and the previous spatial derivatives of $\phi$. This approach saves the computational storage and CPU time, which greatly improves the computational efficiency of the traditional HWENO scheme. In addition, compared with the traditional WENO method, reconstruction stencil of the HWENO methods becomes more compact, their boundary treatment is simpler, and the numerical errors are smaller on the same mesh. Second, the fixed-point fast sweeping method is used to update the numerical approximation. It is an explicit method and does not involve the inverse operation of nonlinear Hamiltonian, therefore any Hamilton-Jacobi equations with complex Hamiltonian can be solved easily. It also resolves some known issues, including that the iterative number is very sensitive to the parameter $ε$ used in the nonlinear weights, as observed in previous studies. Finally, to further reduce the computational cost, a hybrid strategy is also presented. Extensive numerical experiments are performed on two-dimensional problems, which demonstrate the good performance of the proposed fixed-point fast sweeping HWENO methods.     

浅谈脑梗死的中医病因病机与中医药治疗近况

脑梗死是缺血性卒中之一,随着人口老龄化发展趋势,目前已越居我国居民致残和死亡的首要病因。中医药治疗脑梗死有着重要特色和优势,目前在医学领域中仍占着不可动摇的地位,现就针对古代医家及近现代医家对中风病中医病因病机认识,以及中医药治疗方面针对经典方、经验方、中成药、中医外治等方面进行总结综述。     

红外光谱数据融合对栽培滇重楼产地鉴别*

目的 多样的环境因素使得不同产地栽培滇重楼的化学成分也丰富多样，不同居群栽培滇重楼的甾体皂苷类成分具有很大的差异，多源数据融合分析能更全面的表征药材化学信息，建立一个高效而准确的产地鉴别模型，为其资源合理开发利用提供依据。方法 以来自云南和四川的8个产地（保山、楚雄、大理、红河、丽江、成都、文山、玉溪）共366份栽培滇重楼根茎为实验材料，采集其傅里叶变换近红外光谱（FT-NIR）和衰减全反射-傅里叶变换中红外光谱（ATR-FTMIR）数据。采用Kennard-Stone算法将不同产地的样品分为2/3的训练集和1/3的预测集，基于4种特征变量提取方法（CARS、VIP、SPA、SO-Covsel）结合2种数据融合策略（低级数据融合和中级数据融合），建立偏最小二乘产地判别分析模型。根据模型参数交叉验证均方根误差（RMSECV）和预测均方根误差（RMSEP）评估模型的稳定性，模型训练集和预测集准确率（ACC）评估模型分类性能。结果 近红外光谱和中红外光谱均能反应不同产地栽培滇重楼的化学成分差异，在中级数据融合中，基于VIP和SPA提取的特征变量建立的模型正确率均大于94%。相较于中级数据融合，低级数据融合模型得到了最为满意的结果，其预测集分类正确率达到100%。结论 根据近红外和中红外数据建立的低级数据融合PLS-DA模型，能够用于栽培滇重楼的产地鉴别分析。     

七叶一枝花甾体皂苷种类及含量差异研究进展＊

重楼是我国传统的名贵中药，七叶一枝花为历版《中国药典》收载的重楼药材两个基原植物之一，具有清热解毒、消肿止痛、活血化瘀等功效，其主要活性成分为甾体皂苷类物质。由于重楼市场需求量剧增和七叶一枝花成药时间较长，导致大量依靠人工种植。然而，人工种植过程中产地、采收年限和采收月份都会影响七叶一枝花的甾体皂苷含量。本文系统地总结了七叶一枝花中主要活性成分甾体皂苷的种类，以及不同产地、不同生长年限及不同采收月份的七叶一枝花根茎中甾体皂苷含量差异的研究现状，以期为进一步研究七叶一枝花品质差异、野生资源驯化及规范化种植提供参考。     

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.