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Interaction of Caffeine with Bovine Serum Albumin： Determination of Binding Constants and the Binding Site by Spectroscopic Methods

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Chinese Journal of Chemistry 2011年第3期29卷 433-440页

作者： Wu, Qiong jiang, fenglei Li, Chaohong Hu, Yanjun Liu, Yi Key Laboratory for the Synthesis and Application of Organic Functional Molecules (Ministry of Education) College of Chemistry and Chemical Engineering Hubei University Wuhan Hubei 430062 China State Key Laboratory of Virology Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education) College of Chemistry and Molecular Sciences Wuhan University Wuhan Hubei 430072 China Key Laboratory for Oral Biomedical Engineering (Ministry of Education) School and Hospital of Stomatology Wuhan University Wuhan Hubei 430072 China

The interaction of caffeine with bovine serum albumin （BSA） under physiological condition was investigated by fluorescence, UV-vis absorption and circular dichroism （CD） spectroscopy. Fluorescence data revealed that the fluorescence quenching of BSA by caffeine was a result of the formation of BSA-caffeine complex. The binding constants Ka at different temperatures and corresponding thermodynamic parameters △H, △G and △S were calculated. The spectroscopic measurements and the thermodynamic parameters suggested that van der Waals interaction and hydrogen bonds were the predominant intermolecular forces to stabilize the complex. The conformational change of BSA induced by caffeine has been analyzed by means of CD and synchronous fluorescence spectroscopy. Furthermore, it is observed from the probe of competitive experiments that the binding location of caffeine with BSA could be the same as warfarin binding site I of BSA, which was also revealed by fluorescence anisotropy.

关键词： caffeine bovine serum albumin fluorescence spectroscopy UV-vis spectroscopy site competitivebinding

Highly efficient and multidimensional extraction of targets from complex matrices using aptamer-driven recognition

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Nano Research 2017年第1期10卷 145-156页

作者： Jie Wang Haijing Shen Chi Huang Qinqin Ma Yaning Tan fenglei jiang Chao Ma Quan Yuan Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education) College of Chemistry and Molecular Sciences Wuhan University Wuhan 430072 China Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China Hefei 230026 China

Adsorbents are widely employed in both fundamental and applied research areas such as separation technology, biotechnology, and environmental science. Selectivity and reusability are two most important requirements for adsorbents. Aptamers exhibit perfect selectivity and easy regeneration, which make them uniquely effective adsorption materials. Herein, we have rationally designed novel aptamer-based adsorbents and investigated their performance in extraction/ separation of targets from an aqueous solution. These adsorbents can selectively extract targets from complicated sample matrices containing background compounds. Moreover, they can also be easily recycled without a significant loss of adsorption capacity. Notably, the adsorbents did not affect the activity of isolated biological samples, revealing their potential for the purification/separation of biomolecules. Composite adsorbents were constructed using aptamer-based adsorbents and a porous polymer, displaying highly efficient target separation from aqueous solution. Finally, separation columns were constructed, and targets in the aqueous solution were efficiently separated by these columns. The aptamerbased adsorbents described here exhibit great promise for potential applications in separation technology, biotechnology, and environment-related areas.

关键词： aptamer adsorbent selectivity separation extraction

Biophysical studies of the interaction between a triazole derivative and bovine serum albumin by multi-spectroscopic and molecular modeling methods

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Science China Chemistry 2011年第5期54卷 788-796页

作者： FU JiaXin WANG KaiWei GE YuShu jiang fenglei SUN XiaoHong LIU Yang LIU Yi Department of Chemical Engineering College of Chemistry and Environmental EngineeringYangtze UniversityJingzhou 434023China College of Chemistry and Molecular Sciences Wuhan UniversityWuhan 430072China College of Chemical Engineering Northwest UniversityXi'an 710069China

The interaction between 3-thiol-4-(2,4-dichlorobenzylideneamino)-5-methyl-4H-1,2,4-triazole (CBTZ) and bovine serum albumin (BSA) under physiological conditions was investigated by fluorescence,UV-vis absorption and circular dichroism (CD) spectroscopy as well as molecular modeling methods. The result of fluorescence experiment indicates the static quenching as a result of the formation of the CBTZ-BSA complex. The binding constants (Ka) at different temperatures were calculated according to the modified Stern-Volmer equation. The enthalpy change (-H) and entropy change (-S) were determined based on the van′t Hoff equation. Both negative-H and-S indicated that van der Waals and hydrogen-bonding forces were the dominant intermolecular forces to stabilize the CBTZ-BSA complex. Site marker competitive replacement experiments demonstrated that binding of CBTZ to BSA primarily took place in sub-domain IIA (Sudlow's site I). The binding distance (r = 7.2 nm) between CBTZ and the tryptophan residue of BSA was estimated according to the theory of fluorescence resonance energy transfer (FRET). The conformational studies by circular dichroism (CD) and three-dimensional fluorescence spectroscopy showed that the presence of CBTZ induced minor changes of the secondary structure of BSA. Molecular modeling study further confirmed the binding mode obtained experimentally.

关键词： triazole bovine serum albumin fluorescence quenching binding site molecular modeling

Research on mass loss and nose shape evolution of kinetic energy projectiles penetrating concrete at high velocity

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Acta Mechanica Sinica 2024年第7期40卷 92-108页

作者： Zhiyan Yao fenglei Huang Jinzhu Li State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

The high-speed penetration of concrete targets by kinetic energy projectiles results in apparent mass loss,which blunts the nose of the projectile and decrease its penetration *** friction work between the projectile and the concrete target,the plastic deformation of the projectile,and the cutting of aggregates to the projectile significantly affect the mass loss of the *** address these effects,a discrete iterative model is developed for the mass loss and nose shape evolution of the projectile by coupling three mechanisms based on the effect of temperature on *** the model,both friction work and plastic work increase the temperature of the projectile's surface layer,thereby weakening the strength of this part and rendering it easier for mass loss to occur due to aggregate *** model discretizes the projectile and penetration process with respect to the space and time dimensions,*** mass loss and nose shape evolution of the projectile are obtained by iteratively calculating a point-by-point *** predicted depth of penetration(DOP),mass loss,and residual projectile profile are compared with experimental data to validate the *** comparison shows satisfactory agreement between the calculated results and experimental ***,the deceleration,velocity,DOP,and mass loss during penetration are analyzed with respect to ***,based on the model,the effects of projectile strength,caliber-radius-head(CRH),and concrete target strength on penetration are discussed.

关键词： Kinetic energy projectile High-velocity penetration Coupled model Mass loss Nose shape evolution

Shock-induced energy localization and reaction growth considering chemical-inclusions effects for crystalline explosives

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Defence Technology（防务技术） 2024年第3期33卷 278-294页

作者： Ruqin Liu Yanqing Wu Xinjie Wang fenglei Huang Xiaona Huang Yushi Wen State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China School of Power and Mechanical Engineering Wuhan UniversityWuhan430072HubeiChina Institute of Chemical Materials China Academy of Engineering Physics(CAEP)Mianyang621999SichuanChina

Chemical inclusions significantly alter shock responses of crystalline explosives in macroscale gap experiments but their microscale dynamics origin remains *** shock-induced energy localization,overall physical responses,and reactions in a-1,3,5-trinitro-1,3,5-triazinane(a-RDX)crystal entrained various chemical inclusions were investigated by the multi-scale shock technique implemented in the reactive molecular dynamics *** indicated that energy localization and shock reaction were affected by the intrinsic factors within chemical inclusions,i.e.,phase states,chemical compositions,and *** atomic origin of chemical-inclusions effects on energy localization is dependent on the dynamics mechanism of interfacial molecules with free space volume,which includes homogeneous intermolecular compression,interfacial impact and shear,and void collapse and *** introducing various chemical inclusions,the initiation of those dynamics mechanisms triggers diverse decay rates of bulk RDX molecules and hereby impacts on growth speeds of final *** chemical inclusions can reduce the effectiveness of the void during the shock *** the shockwave velocity of 9 km/s,the parent RDX decay rate in RDX entrained amorphous carbon decreases the most and is about one fourth of that in RDX with a vacuum void,and solid HMX and TATB inclusions are more reactive than amorphous carbon but less reactive than dry air or acetone *** lessdense shocking system denotes the greater increases in local temperature and stress,the faster energy liberation,and the earlier final reaction into equilibrium,revealing more pronounced responses to the present intense *** quantitative models associated with the relative system density(RD_(sys))were proposed for indicating energy-localization mechanisms and evaluating initiation safety in the shocked crystalline ***_(sys)is defined by the density ratio of defective RDX to perfec

关键词： Shock responses Energy localization Crystalline explosives Chemical inclusions Reactive molecular dynamics

Experimental and numerical analyses of the effect of fibre content on the close-in blast performance of a UHPFRC beam

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Defence Technology（防务技术） 2024年第1期31卷 242-261页

作者： Junbo Yan Qiyue Zhang Yan Liu Yingliang Xu Zhenqing Shi Fan Bai fenglei Huang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

Limited research has been conducted on the influences of fiber content on close-in blasting characteristics for ultrahigh-performance fiber-reinforced concrete(UHPFRC)*** paper aims to address this knowledge gap through experimental and mesoscale numerical *** were conducted on ten UHPFRC beams built with varying steel fiber volumetric fractions subjected to close-in explosive ***,this study considered other parameters,such as the longitudinal reinforcement type and *** the case of UHPFRC beams featuring normal-strength longitudinal reinforcement of diametersΦ12,Φ16,andΦ20,a reduction in maximum displacement by magnitudes of19.6%,19.5%,and 17.4%was observed,respectively,as the volumetric fractions of fiber increased from1.0%to 2.5%.In addition,increasing the longitudinal reinforcement ratio and using high-strength steel longitudinal reinforcement both significantly reduced the deformation characteristics and increase the blasting resistances of UHPFRC ***,the effects on the local crushing and spalling damage were not significant.A mesoscale finite element model,which considers the impacts of fiber parameters on UHPFRC beam behaviors,was also established and well correlated with the test ***,parametric analyses were further conducted to examine the impacts of the steel fiber content and length and the hybrid effects of various types of microfibers and steel fibers on the blasting performance of UHPFRC beams.

关键词： Blast performance Close-in blast Fiber content Mesoscale approach UHPFRC beams

High-speed penetration of ogive-nose projectiles into thick concrete targets:Tests and a projectile nose evolution model

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Defence Technology（防务技术） 2024年第2期32卷 553-571页

作者： Xu Li Yan Liu Junbo Yan Zhenqing Shi Hongfu Wang Yingliang Xu fenglei Huang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing401120China China Research and Development Academy of Machinery Equipment Beijing100089China

The majority of the projectiles used in the hypersonic penetration study are solid flat-nosed cylindrical projectiles with a diameter of less than 20 *** study aims to fill the gap in the experimental and analytical study of the evolution of the nose shape of larger hollow projectiles under hypersonic *** the hypersonic penetration test,eight ogive-nose AerMet100 steel projectiles with a diameter of 40 mm were launched to hit concrete targets with impact velocities that ranged from 1351 to 1877 m/*** erosion of the projectiles was observed during high-speed penetration of heterogeneous targets,and apparent localized mushrooming occurred in the front nose of recovered *** examining the damage to projectiles,a linear relationship was found between the relative length reduction rate and the initial kinetic energy of projectiles in different penetration ***,microscopic analysis revealed the forming mechanism of the localized mushrooming phenomenon for eroding penetration,i.e.,material spall erosion abrasion mechanism,material flow and redistribution abrasion mechanism and localized radial upsetting deformation ***,a model of highspeed penetration that included erosion was established on the basis of a model of the evolution of the projectile nose that considers radial upsetting;the model was validated by test data from the literature and the present *** upon the impact velocity,v0,the projectile nose may behave as undistorted,radially distorted or *** to the effects of abrasion of the projectile and enhancement of radial upsetting on the duration and amplitude of the secondary rising segment in the pulse shape of projectile deceleration,the predicted DOP had an upper limit.

关键词： High-speed penetration Concrete target Erosion Projectile nose evolution model

Enhanced Photocatalytic Behaviors of TiO2 Nanocomposites Doped with CdSe Quantum Dots

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Enhanced Photocatalytic Behaviors of TiO2 Nanocomposites Dop...

Research on the quasi-isentropic driving model of aluminized explosives in the detonation wave propagation direction

科技引领产业、支撑跨越发展——第六届湖北科技论坛

作者： Yuesheng Li Meifang Zhang Kan Li Aiqing Zhang fenglei jiang Department of Chemistry and Life Sciences Xianning University State Key Laboratory of Virology & Key Laboratory of Analytical Chemistry for Biology and Medicine(MOE) College of Chemistry and Molecular SciencesWuhan University Key Laboratory of Catalysis and Materials Science of Hubei Province South-Central Nationalities University

CdSe quantum dots（QDs）-doped TiO photocatalysts were synthesized by a facile sol-gel method at room temperature and characterized by fluorescence spectroscopy,UV-vis diffuse reflectance spectroscopy, Hadamard transform imaging microscopy,FT-IR,XRD,FE-SEM,HRTEM,XPS and nitrogen sorption spectroscopy. The photocatalytic activities were investigated by degrading malachite green（MG） in aqueous solution under visible light *** results revealed that the catalysts doped with CdSe QDs exhibited much higher photocatalytic activities than both controlled TiO（without doped QDs） and P25（TiO,Degussa）.According to the structural and surface analyses,the enhanced photocatalytic activities could be attributed to its strong absorption and low recombination rate of the electron-hole pairs because of the heterojunction formed by CdSe QDs and *** the adsorption isotherms demonstrated the Langmuir type *** study presented new types of photocatalysts for environmental applications.

关键词： CdSe quantum dots doped TiO2 photocatalysts

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Defence Technology（防务技术） 2024年第2期32卷 596-618页

作者： Hongfu Wang Yan Liu Fan Bai Chao He Yingliang Xu Qiang Zhou Chuan Xiao fenglei Huang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China China Research and Development Academy of Machinery Equipment Beijing100089China Beijing Institute of Technology Chongqing Innovation Center Chongqing401120China

Taking CL-20(Hexanitrohexaazaisowurtzitane)-based aluminized explosives with high gurney energy as the research object, this research experimentally investigates the work capability of different aluminized explosive formulations when driving metal flyer plates in the denotation wave propagation *** research results showed that the formulations with 43 μm aluminum(Al) powder particles(The particle sizes of Al powder were in the range of 2~43 μm) exhibited the optimal performance in driving flyer plates along the denotation wave propagation direction. Compared to the formulations with Al powder 13 μm, the formulations with Al powder 2 μm delivered better performance in accelerating metal flyer plates in the early stage, which, however, turned to be poor in the later stage. The CL-20-based explosives containing 25% Al far under-performed those containing 15% Al. Based on the proposed quasi-isentropic hypothesis, relevant isentropy theories, and the functional relationship between detonation parameters and entropy as well as Al reaction degree, the characteristic lines of aluminized explosives in accelerating flyer plates were theoretically studied, a quasi-isentropic theoretical model for the aluminized explosive driving the flyer plate was built and the calculation methods for the variations of flyer plate velocity, Al reaction degree, and detonation product parameters with time and axial positions were developed. The theoretical model built is verified by the experimental results of the CL-20-based aluminized explosive driving flyer plate. It was found that the model built could accurately calculate the variations of flyer plate velocity and Al reaction degree over time. In addition, how physical parameters including detonation product pressure and temperature varied with time and axial positions was identified. The action time of the positive pressure after the detonation of aluminized explosives was found prolonged and the downtrend of the temperature was

关键词： Aluminized explosive Flyer plate experiment Quasi-isentropic theoretical model Al reaction Driving characteristics