无胶筛分芯片电泳研究贝类毒素-软骨藻酸与寡聚DNA的相互作用

近年来,我国日趋严重的赤潮已给海洋渔业带来了极大的损失,也对人类的健康构成威胁．赤潮毒素可对海洋养殖产生严重的污染,食用贝类所富集的贝类毒素严重损害食用者身体健康．根据其中毒症状,贝类毒素被分为4大类：引起腹泻性中毒(Diarrhetic Shellfish Poisoning,DSP)的贝类毒素;引起麻痹性中毒(Paralytic Shellfish Poisoning,PSP)的贝类毒素;     

Multiple 3D flaws in coupled electro-magneto-thermo-elastic multiphase composites by extended hypersingular integral equation method

This work presents extended hypersingular integral equation (E-HIE) method to analyze the multiple 3D mixed-mode flaws problem in fully coupled electro-magneto-thermo-elastic multiphase composites under extended electro-magneto-thermo-elastic coupled loads through intricate theoretical analysis and numerical simulations. First, the problem is reduced to solving a set of E-HIEs. Analytical solutions for the extended singular stresses, the extended stress intensity factors (E-SIFs), the extended energy release rate and the extended strain energy density factors (E-SEDFs) near the flaws front are obtained. Then, the numerical method for the E-HIEs for two 3D flaws subjected to extended coupled loads is proposed. Finally, numerical solutions of E-SIFs and E-SEDFs of some examples are given, and the effect of flaws orientation, interaction and shielding is discussed.     

Dual Catalysis of Gold Nanoclusters: Photocatalytic Cross-Dehydrogenative Coupling by Cooperation of Superatomic Core and Molecularly Modified Staples**

Thiolate-protected gold nanoclusters (AuNCs) have attracted significant attention as nano-catalysts, revealing a superatomic core and gold-thiolate staples as distinct structural units. Here, we demonstrate the unprecedented dual catalytic activity of thiolate-protected [Au₂₅(SR)₁₈]⁻ nanoclusters, involving both photosensitized ¹O₂ generation by the Au₁₃ superatomic core and catalytic carbon-carbon bond formation facilitated by Au₂(SR)₃ staples. This synergistic combination of two different catalytic units enables efficient cross-dehydrogenative coupling of terminal alkynes and tertiary aliphatic amines to afford propargylamines in high yields of up to 93 %. Mixed-ligand AuNCs bearing both thiolate and alkynyl ligands revealed the intermediacy of the alkynyl-exchanged AuNCs toward both photosensitization and C−C bond-forming catalytic cycles. Density functional theory calculations also supported the intermediacy of the alkynyl-exchanged AuNCs. Thus, the use of ligand-protected metal nanoclusters has enabled the development of an exceptional multifunctional catalyst, wherein distinct nanocluster components facilitate cooperative photo- and chemo-catalysis.     

水溶性阳离子卟啉与ctDNA的相互作用及其聚集行为研究

水溶性阳离子卟啉作为多功能DNA结合试剂在光动力学疗法、抗病毒药物等方面得到了越来越多的应用,因此研究阳离子卟啉与DNA的相互作用引起人们极大的兴趣。文章采用吸收光谱、荧光光谱和共振光散射技术研究了meso-四(4-三甲铵基苯基)卟啉(TMAP)和5-苯基-10,15,20-三(N-甲基-4-吡啶基)卟啉(TriMPyP)两种水溶性阳离子卟啉在水溶液中的聚集状态及与小牛胸腺DNA(ctDNA)的相互作用。在R>1时(R=c_TMAP/c_DNA),TMAP在DNA分子表面发生聚集,吸收光谱有明显的减色效应,卟啉的荧光被猝灭。在R<1时,TMAP与DNA以外部结合方式结合,荧光得到增强,共振光信号减弱。DNA的加入,使TriMPyP的聚集程度进一步增加。考察了离子强度对卟啉与DNA相互作用的影响,离子强度增大,卟啉的荧光得到增强,卟啉与DNA的结合方式发生改变。     

Interaction between two circular cylinders in slow flow of Bingham viscoplastic fluid

The interaction between two circular cylinders was studied in the slow flow of a Bingham viscoplastic fluid in an infinite medium without any inertia effects. The configuration studied is that in which the flow direction is parallel to the centre line of the cylinders. Finite-element numerical simulations were used with an approximation by Papanastasiou's regularisation method. The case of high yield stress effect was particularly examined. The convergence of the solutions was examined in detail. Changes in the rigid zones, kinematics and stresses were determined in relation to the degree of interaction, which is a function of the distance between the cylinders and the effect of yield stress. The results compared with the case of a single cylinder show that yield stress reduces interaction effects. The transition between configurations with interacting cylinders and configuration with isolated cylinders was examined as a function of the effect of yield stress. Correlations were proposed for the drag coefficient and the stability criterion when the cylinders are interacting.     

Interaction between two spheres placed in tandem arrangement in steady and pulsating flow

The interaction among two spheres in tandem formation are studied for a Reynolds number of 300 using both steady and pulsating inflow conditions. The purpose is to further investigate the force characteristics as well as the shedding patterns of the two spheres as the separation distance is changed from 1.5 to 12 sphere diameters. The method used for the simulations is the volume of solid (VOS) method, an approach based on the volume of fluid (VOF) method. Comparisons with other computational methods have shown VOS to accurately resolve the flow field around solid spheres. The results show that the separation distance plays a significant role in changing the flow patterns and shedding frequencies at moderate separation distances, whereas effect on drag is observed even at a separation distance of 12 diameters.     

Conjugate heat transfer with Large Eddy Simulation for gas turbine components

CHT (Conjugate Heat Transfer) is a main design constraint for GT (gas turbines). Most existing CHT tools are developed for chained, steady phenomena. A fully parallel environment for CHT has been developed and applied to two configurations of interest for the design of GT. A reactive Large Eddy Simulations code and a solid conduction solver exchange data via a supervisor. A flame/wall interaction is used to assess the precision and the order of the coupled solutions. A film-cooled turbine vane is then studied. Thermal conduction in the blade implies lower wall temperature than adiabatic results and CHT reproduces the experimental cooling efficiency. To cite this article: F. Duchaine et al., C. R. Mecanique 337 (2009).     

羟基磷灰石与牛血清白蛋白相互作用的原位红外光谱研究

应用原位(in situ)全反射红外光谱研究牛血清白蛋白在电化学法制备的羟基磷灰石表面的吸附和成键行为, 探索电化学法制备的HA生物材料/生物环境界面过程和生物相容性的微观本质.     

马兜铃酸与人血清白蛋白相互作用的荧光光谱研究

采用荧光光谱技术研究了模拟生理条件下马兜铃酸与人血清白蛋白(HSA)的相互作用.结果显示:马兜铃酸与人血清白蛋白有强的结合,结合位置与色氨酸残基间的距离r为2.5nm,二者间的结合是疏水和静电力共同作用的结果.