The Antibacterial Activity Mode of Action of Plantaricin YKX against Staphylococcus aureus

We aimed to evaluate the inhibitory effect and mechanism of plantaricin YKX on S. aureus. The mode of action of plantaricin YKX against the cells of S. aureus indicated that plantaricin YKX was able to cause the leakage of cellular content and damage the structure of the cell membranes. Additionally, plantaricin YKX was also able to inhibit the formation of S. aureus biofilms. As the concentration of plantaricin YKX reached 3/4 MIC, the percentage of biofilm formation inhibition was over 50%. Fluorescent dye labeling combined with fluorescence microscopy confirmed the results. Finally, the effect of plantaricin YKX on the AI-2/LuxS QS system was investigated. Molecular docking predicted that the binding energy of AI-2 and plantaricin YKX was −4.7 kcal/mol and the binding energy of bacteriocin and luxS protein was −183.701 kcal/mol. The expression of the luxS gene increased significantly after being cocultured with plantaricin YKX, suggesting that plantaricin YKX can affect the QS system of S. aureus.     

The RHIM of the Immune Adaptor Protein TRIF Forms Hybrid Amyloids with Other Necroptosis-Associated Proteins

TIR-domain-containing adapter-inducing interferon-β (TRIF) is an innate immune protein that serves as an adaptor for multiple cellular signalling outcomes in the context of infection. TRIF is activated via ligation of Toll-like receptors 3 and 4. One outcome of TRIF-directed signalling is the activation of the programmed cell death pathway necroptosis, which is governed by interactions between proteins that contain a RIP Homotypic Interaction Motif (RHIM). TRIF contains a RHIM sequence and can interact with receptor interacting protein kinases 1 (RIPK1) and 3 (RIPK3) to initiate necroptosis. Here, we demonstrate that the RHIM of TRIF is amyloidogenic and supports the formation of homomeric TRIF-containing fibrils. We show that the core tetrad sequence within the RHIM governs the supramolecular organisation of TRIF amyloid assemblies, although the stable amyloid core of TRIF amyloid fibrils comprises a much larger region than the conserved RHIM only. We provide evidence that RHIMs of TRIF, RIPK1 and RIPK3 interact directly to form heteromeric structures and that these TRIF-containing hetero-assemblies display altered and emergent properties that likely underlie necroptosis signalling in response to Toll-like receptor activation.     

Improved filtered mesoscale interphase heat transfer model

Mesoscale structures that form in gas-solid flows considerably affect interphase heat transfer.A filtered interphase heat transfer model accounts for the effect...     

A Bregman-Split-Based Compressive Sensing Method for Dynamic Harmonic Estimation

In order to overcome the spectral interference of the conventional Fourier transform in the International Electrotechnical Commission framework, this paper introduces a Bregman-split-based compressive sensing (BSCS) method to estimate the Taylor–Fourier coefficients in a multi-frequency dynamic phasor model. Considering the DDC component estimation, this paper transforms the phasor problem into a compressive sensing model based on the regularity and sparsity of the dynamic harmonic signal distribution. It then derives an optimized hybrid regularization algorithm with the Bregman split method to reconstruct the dynamic phasor estimation. The accuracy of the model was verified by using the cross entropy to measure the distribution differences of values. Composite tests derived from the dynamic phasor test conditions were then used to verify the potentialities of the BSCS method. Simulation results show that the algorithm can alleviate the impact of dynamic signals on phasor estimation and significantly improve the estimation accuracy, which provides a theoretical basis for P-class phasor measurement units (PMUs).     

金红石TiO_2中本征缺陷扩散性质的第一性原理计算

基于密度泛函理论的爬坡弹性带方法,对金红石相二氧化钛晶体中钛间隙、钛空位、氧间隙、氧空位4种本征缺陷的扩散特征进行了研究.对比4种本征缺陷在晶格内部沿不同扩散路径的过渡态势垒后发现,缺陷扩散过程呈现出明显的各向异性.其中,钛间隙和氧间隙沿[001]方向具有最小的扩散势垒路径,激活能分别为0.505 eV和0.859 eV;氧空位和钛空位的势垒最小的扩散路径分别沿[110]方向和[111]方向,激活能分别为0.735 eV和2.375 eV.     

基于虚拟仪器的导弹质心定位系统设计与实现

针对传统导弹质心定位设备精度低,操作繁琐等弊端,从弹体质心定位原理出发,合理选取力矩计算参考点,建立质心定位模型;以基于PCI总线的内插式DAQ虚拟仪器测控平台为依托,突出“通用性、精确性、高效性”的设计理念,制定系统总体设计方案,围绕导弹质量测量与质心定位技术展开研究与工程实现;实际应用表明,本系统可拓展应用于多型导弹和大型圆柱形工件的称重与质心定位,满足导弹飞行控制研究和装配工艺要求。     

基于串行最小频移键控的8进制调制的研究

提出了一种新型的基于串行结构的最小频移键控调制技术,产生了相位连续,频谱宽度窄,每码元时间有两次π/2相移,类似于传统最小频移键控调制信号,给出了该调制方案的理论推导,并将其应用于8进制的多维多阶调制系统中。理论和仿真分析了不同的8进制调制方案在频谱特性,残留色散容限,自相位调制容限的不同,还分析了其受到系统滤波带宽的影响。最后仿真实现了通过350km的色散完全补偿的光纤120Gb/s的数据传输。     

Enzymatic Synthesis of a Diastereomer of Neoabyssomicin Derivative Using the Diels-Alderase AbyU

Main observation and conclusion The enzyme AbyU catalyses a Diels-Alder (DA) reaction during abyssomicin C biosynthesis.In this study,AbyU is shown to convert t...     

Synthesis and Characterization of Polymers Derived from the Copolymerization of 1,1′-Dihydroxyethyl-2,2′-Biimidazole and the Diglycidyl Ether of Bisphenol A

Abstract

1,1′-Dihydroxyethyl-2,2′-biimidazole has been used as a copolymerizing monomer with the diglycidyl ether of bisphenol A in the preparation of biimidazole-containing epoxy polymers. Polymerization reactions were studied in bulk, with and without catalyst, and in N,N-dimethylforma-mide and anisole solvents, with and without catalyst. FT-IR and NMR spectra, molecular weight, thermal and solubility characteristics were obtained. Polymers isolated as amorphous light brown solids were found to be only sparingly soluble in THF or in highly polar nitrogen-containing solvents (DMF, NMP, pyridine). These materials exhibited molecular weights up to 37 000 for SnC1₄-catalyzed polymerization carried out in DMF. A glass-transition temperature of 391°C was observed for polymers obtained under uncatalyzed solventless conditions. The glass transition temperature was 373°C for product obtained under SnC1₄-catalyzed, solventless conditions. Thermogravimetric analysis in air of polymers obtained under varying solvent and catalyst conditions showed less than 25% weight loss below 330°C and greater than 75% weight loss above 400°C.