Reaction characteristics of andrographolide and its analogue AL-1 with GSH, as a simple chemical simulation of NF-κB inhibition

14-α-Lipoic acid-3,19-dihydroxyandrographolide (AL-1, 2) is an analogue of andrographolide (Andro, 1) coupled to α-lipoic acid (LA, 4). AL-1 was at least 10-fold more potent than the natural parent compound Andro in inhibiting nuclear factor (NF)-κB activation in RIN-m cells. In the present study, glutathione (GSH, 3) was used as a simple chemical model molecule of NF-κB with cysteine 62. The characteristics of the reaction between AL-1 or Andro and GSH were investigated to trace some possible elucidation for the inhibitive mechanism and stronger inhibition of AL-1 to NF-κB activation. The results showed that the main reaction products of AL-1 and Andro were identical, sulfhydryl adduct and amino adduct. AL-1 reacted much faster than Andro with GSH. The product yield of AL-1 was much higher than that of Andro. It was speculated that AL-1 might inhibit NF-κB by the same mechanism as Andro. And the faster reaction rate and higher yield may account for the stronger NF-κB inhibition of AL-1 when compared with Andro.     

One-pot, solvothermal synthesis of TiO(2)-graphene composite nanosheets

In this article, we propose a facile one-pot solvothermal route for synthesizing TiO(2)-graphene composite nanosheets (TGCN). In the system, ethylene glycol not only as a reducing agent can convert graphene oxide to reduced graphene oxide nanosheets, but also is employed to control the hydrolysis and condensation rates of tetrabutoxytitanium. The obtained TGCN hybrid materials are characterized by atomic force microscopy, transmission electron microscopy, UV-vis spectroscopy, Raman spectroscopy, X-ray photo-electron spectroscopy, X-ray diffraction, and thermal gravimetric analysis. It is found that the quantity of H(2)O used in the reaction is the key to obtain high-quality product. The photocatalytic activities of the products are evaluated using the photocatalytic degradation of methylene blue (MB) as a probe reaction. The results showed that the obtained TGCN have an enhanced adsorption capacity and remarkable improvements in the photodegradation rate of MB under visible light compared to P25.     

图的预解Estrada指标的界的估计（英文）

n阶图G的子图中心度,即后来著名的Estrada指标定义为EE（G）=∑_（i=1）~N e~（λ2）.其中λ_1,λ_2……λ_n为图G的特征值.作为复杂网络的一种中心性测度和一种分子结构描述符,Estrada指标在许多研究领域有着广泛的应用.最近,Estrada和High-ama引进了一种新的复杂网络中心度,即∑_（i=1）~n n-1n-1λ_i：他们称之为预解中心度,后来又被称为预解Estrada指标.本文主要利用图G的顶点数和边数给出了图G的预解Estrada指标的若干界.     

Stochastic damage model for concrete based on energy equivalent strain

Starting with the framework of conventional elastoplastic damage mechanics, a class of stochastic damage constitutive model is derived based on the concept of energy equivalent strain. The stochastic damage model derived from the parallel element model is adopted to develop the uniaxial damage evolution function. Based on the expressions of damage energy release rates (DERRs) conjugated to the damage variables thermodynamically, the concept and its tensor formulations of energy equivalent strain is proposed to bridge the gap between the uniaxial and the multiaxial constitutive models. Furthermore, a simplified coupling model is proposed to consider the evolution of plastic strain. And the analytical expressions of the constitutive model in 2-D are established from the abstract tensor expression. Several numerical simulations are presented against the biaxial loading test results of concrete, demonstrating that the proposed models can reflect the salient features for concrete under uniaxial and biaxial loading conditions.     

混凝土静力与动力损伤本构模型研究进展述评

对混凝土材料在静力和动力载荷作用下的损伤本构关系模型进行了评述.梳理了混凝土本构关系研究的历史脉络和逻辑脉络;归纳总结了在混凝土本构关系研究发展过程中具有代表性意义、并且对重大工程建设具有参考意义的若干混凝土静力和动力损伤本构模型.基于对混凝土材料非线性及随机性的理解和诠释,阐述了混凝土静力和动力本构关系研究的发展趋势.      

变形双重介质分形油藏非达西流动分析

考虑与实际生产相符的介质的双重特性和分形特征,并考虑介质的变形,引入双重分形介质渗透率模数,建立应力敏感地层双重分形介质系统的流动方程.采用Douglas-Jones预估-校正法获得无限大地层定产量生产时变形双重分形介质模型的数值解和无限大地层定压生产时分形介质双孔模型的数值解,作出了典型的压力曲线图版.     

铬、钕双掺钆镓石榴石(Cr4+,Nd3+):Gd3 Ga5 O12激光晶体光学性能的研究

用提拉法生长了掺铬、钕的钆镓石榴石(Cr^4 ,Nd^3 ：GGG)自调Q激光品体。报道了室温下的吸收光谱和荧光光谱特性。分析了Cr离子浓度对光谱性质的影响。比较了Cr^4 ：GGG,Nd^3 ：GGG和(Cr^4 ,Nd^3 )：GGG晶体吸收光谱的关系。测量了(Cr^4 ,Nd^3 )：GGG晶体和Nd^3 ：GGG晶体的荧光寿命,它们分别是33μs和250μs。实验表明,(Cr^4 ,Nd^3 )：GGG晶体是一种非常有潜力的自调Q激光晶体,可以实现大功率激光器的小型化和全固态化。     

空间-时间分数阶对流扩散方程的数值解法

本文考虑一个空间-时间分数阶对流扩散方程.这个方程是将一般的对流扩散方程中的时间一阶导数用α(0＜α＜1)阶导数代替,空间二阶导数用β(1＜β＜2)阶导数代替.本文提出了一个隐式差分格式,验证了这个格式是无条件稳定的,并证明了它的收敛性,其收敛阶为O(ι h).最后给出了数值例子.     

一维硅纳米材料的可控制备和机理

一维硅纳米材料具有不同于体硅材料的特殊光电性能,在光电子领域具有潜在的应用价值.通过"剪裁"一维硅纳米材料的尺寸、形貌和化学组分等,可以调控其物理化学性质.因此,探索并实现一维硅纳米材料的可控制备对于其实际应用至关重要.本文综述了一维硅纳米材料可控制备的最新进展,介绍了几种重要的制备方法及其生长机理,比较了不同方法在可控制备一维硅纳米材料中的优缺点,并展望了其未来发展方向.     

Design of porous Co3O4 nanosheets via one-step synthesis as high-performance anode materials for lithium-ion batteries

Journal of Solid State Electrochemistry - The morphology of Co-based zeolitic imidazolate framework is affected by the molar ratio of 2-methylimidazole and Co2+ used during the synthesis. In this...