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。     

Performance of the Rapidec®Carba NP assay for the detection of different carbapenemases in Klebsiella pneumoniae and Escherichia coli strains

PurposeThe spread of infections caused by Enterobacterales strains resistant to carbapenems is a global public health problem, and early detection of carbapenemases is very important to prevent their spread. The rapid detection of carbapenemase production with the new commercial assay Rapidec® Carba NP test is based on the biochemical detection of imipenem hydrolysis. Our study aims to evaluate the performance of the Rapidec® Carba NP test in OXA-48 positive isolates highly prevalent in our country and also in isolates with more than one carbapenemase gene that have an increased prevalence and to examine whether it can be used for confirmation of carbapenemase positivity in the routine laboratory.MethodsA total of 97 strains of 94 carbapenem-resistant Klebsiella pneumoniae and three carbapenem-resistant Escherichia coli isolated from various clinical specimens were included in the study. The results of the Rapidec® Carba NP assay were compared with those obtained by the multiplex PCR test.ResultsThe sensitivity of the Rapidec® Carba NP test was 97.8% for all carbapenemase-positive isolates. Of 90 PCR positive isolates, one OXA-48 and one OXA-48 ?+ ?NDM positive isolates were negative with Rapidec® Carba NP test.ConclusionsThe positive results detected by the Rapidec® Carba NP test make an important contribution to the early detection of carbapenemase production and infection control practices. Since two carbapenemase positive isolates were found to be negative with the Rapidec® Carba NP test in our study, it was concluded that negative results of carbapenem-resistant isolates obtained with this assay should be confirmed with an additional carbapenemase detection method to exclude false-negative results.     

Analysis of AcrB in Klebsiella pneumoniae reveals natural variants promoting enhanced multidrug resistance

Infections caused by Klebsiella pneumoniae are often difficult to manage due to the high frequency of multidrug resistance, often conferred by efflux pumps. In this study, we analyzed sequence variations of the major RND family multidrug efflux pump AcrB from 387 assembled K. pneumoniae genomes. We confirm that AcrB is a highly-conserved efflux pump in K. pneumoniae, and identified several variants that were prevalent in clinical isolates. Molecular dynamics analyses on two of these variants (L118M and S966A) suggested conformational changes that may correlate with increased drug efflux capabilities. The L118M change resulted in enhanced protein rigidity while the flexibility of drug binding pockets was stable or increased, and the interactions between the proximal pockets and water molecules were stronger. For S966A, the significantly enlarged proximal pocket suggested higher drug accommodation ability. Consistent with these predictions, the L118M and S966A variants conferred a slightly increased ability to grow in the presence of tetracycline and to survive cefoxitin exposure when overexpressed. In summary, our results suggest that the emergence of enhanced-function AcrB variants may be a potential risk for increased antibiotic resistance in clinical K. pneumoniae isolates.     

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.     

早孕期监测子宫动脉多普勒参数在预测低危人群不良妊娠结局的价值

目的 建立妊娠11~13+6周子宫动脉多普勒参数在低危人群中的正常参考值，同时评估其对不良妊娠结局的预测价值。方法 收集2019年6月至2021年6月于我院行产前超声检查的妊娠11~13+6周孕妇，根据妊娠结局分组。收集两侧子宫动脉多普勒指标，包括搏动指数（PI）、阻力指数（RI）、舒张早期是否有切迹，以及孕妇基本临床资料和胎儿出生信息，将以上相关参数进行统计学分析。结果 最终纳入800例孕妇，包括正常妊娠结局组740例和不良妊娠结局组60例。两组孕妇体质量指数（BMI）、分娩孕周和胎儿出生体质量比较，差异均有统计学意义（均P＜0.05）。随着孕周的增加，子宫动脉两侧平均搏动指数（mPI）、平均阻力指数（mRI）和两侧舒张早期切迹检出率均呈逐渐下降的趋势。ROC曲线分析显示，mPI、mRI及两侧舒张早期切迹预测妊娠结局的曲线下面积（AUC）分别为0.542、0.574、0.521，三者联合预测妊娠结局的AUC为0.648；孕妇BMI、年龄mPI、mRI及两侧舒张早期切迹预测妊娠结局的AUC为0.751。结论 建立了低危人群在妊娠11~13+6周子宫动脉多普勒参数的正常参考值范围。在妊娠11~13+6周单纯应用子宫动脉多普勒参数预测妊娠结局的价值有限，将子宫动脉参数与临床相关指标结合可提高对不良妊娠结局的预测价值。     

Communicating regulatory high-throughput sequencing data using BioCompute Objects

This project demonstrates the use of the IEEE 2791–2020 Standard (BioCompute Objects [BCO]) to enable the complete and concise communication of results from next generation sequencing (NGS) analysis. One arm of a clinical trial was replicated using synthetically generated data made to resemble real biological data and then two independent analyses were performed. The first simulated a pharmaceutical regulatory submission to the US Food and Drug Administration (FDA) including analysis of results and a BCO. The second simulated an FDA review that included an independent analysis of the submitted data. Of the 118 simulated patient samples generated, 117 (99.15%) were in agreement in the two analyses. This process exemplifies how a template BCO (tBCO), including a verification kit, facilitates transparency and reproducibility, thereby reinforcing confidence in the regulatory submission process.     

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.     

Induction of tumor cell autosis by myxoma virus-infected CAR-T and TCR-T cells to overcome primary and acquired resistance

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