The formation and growth of Li-dendrites caused by inhomogeneous Li deposition severely hinder the commercial applications of Li metal batteries due to the consequence of short-circuiting.Herein,we propose a Janus bil...The formation and growth of Li-dendrites caused by inhomogeneous Li deposition severely hinder the commercial applications of Li metal batteries due to the consequence of short-circuiting.Herein,we propose a Janus bilayer composed of black phosphorus(BP)and graphene oxide(GO)as an artificial interface with chemical/mechanical stability and well-regulated Li-ion flux distribution for Li metal anode protection.Owing to the synergy between the fast Li-ion transport of BP in the inner layer and the high mechanical and chemical stability of GO in the outer layer,the GO/BP with good electrolyte wettability acts as a Li-ion regulator that can induce homogeneous growth of Li to suppress the Li dendrites growth.Accordingly,long-term stability(500 h at 1 mA cm^(-2))with a low overpotential of 30 mV is achieved in the symmetric cell with GO/BP-Li anode.Furthermore,the Li–S cell with GO/BP-Li exhibits enhanced cycling performance with a high capacity retention rate of 76.2%over 500 cycles at 1 C.展开更多
Two-state folding and down-hill folding are two kinds of protein folding dynamics for small single domain proteins.Here we apply molecular dynamics(MD)simulation to the two-state protein GB1 and down-hill folding prot...Two-state folding and down-hill folding are two kinds of protein folding dynamics for small single domain proteins.Here we apply molecular dynamics(MD)simulation to the two-state protein GB1 and down-hill folding protein gpW to reveal the relationship of their free energy landscape and folding/unfolding dynamics.Results from the steered MD simulations show that gpW is much less mechanical resistant than GB1,and the unfolding process of gpW has more variability than that of GB1 according to their force-extension curves.The potential of mean force(PMF)of GB1 and gpW obtained by the umbrella sampling simulations shows apparent difference:PMF of GB1 along the coordinate of extension exhibits a kink transition point where the slope of PMF drops suddenly,while PMF of gpW increases with extension smoothly,which are consistent with two-state folding dynamics of GB1 and downhill folding dynamics of gpW,respectively.Our results provide insight to understand the fundamental mechanism of different folding dynamics of twostate proteins and downhill folding proteins.展开更多
α-catenin is an adhesion protein located at the cadherin-based cell-cell adherens junction.α-catenin cross-linksβ-catenin and actin fiber in the adhesion protein complex,and plays an important role in the formation...α-catenin is an adhesion protein located at the cadherin-based cell-cell adherens junction.α-catenin cross-linksβ-catenin and actin fiber in the adhesion protein complex,and plays an important role in the formation and modulation of cell-cell adhesion.The central modulation domains can be unfolded to expose binding site of vinculin when stretching force is applied.Here,we studied the force-induced unfolding dynamics ofα-catenin modulation domains under different loading rates from which the unfolding distance of M2 and M3 domains is determined to be 5-7 nm,and an unfolding intermediate state is identified.We also found that the folding process of M1-M3 domains goes through different pathways with cooperativity.展开更多
The electrochemical carbon dioxide reduction(eCO_(2)RR)to formate,driven by clean energy,is a promising approach for producing renewable chemicals and high-value fuels.Despite its potential,further development faces c...The electrochemical carbon dioxide reduction(eCO_(2)RR)to formate,driven by clean energy,is a promising approach for producing renewable chemicals and high-value fuels.Despite its potential,further development faces challenges due to limitations in electrocatalytic activity and durability,especially for nonnoble metal-based catalysts.Here,naturally abundant bismuth-based nanosheets that can effectively drive CO_(2)-to-formate electrocatalytic reduction are prepared using the plasma-activated Bi_(2)Se_(3) followed by a reduction process.Thus-obtained plasma-activated Bi nanosheets(P-BiNS)feature ultrathin structures and high surface areas.Such nanostructures ensure the P-BiNS with outstanding eCO_(2)RR catalytic performance,highlighted by the current density of over 80 mA cm^(-2) and a formate Faradic efficiency of>90%.Furthermore,P-BiNS catalysts demonstrate excellent durability and stability without deactivation following over 50h of operation.The selectivity for formate production is also studied by density functional theory(DFT)calculations,validating the importance and efficacy of the stabilization of intermediates(^(*)OCHO)on the P-BiNS surfaces.This study provides a facile plasma-assisted approach for developing high-performance and low-cost electrocatalysts.展开更多
Ever-increasing emissions of anthropogenic carbon dioxide(CO_(2))cause global environmental and climate challenges.Inspired by biological photosynthesis,developing effective strategies NeuNlto up-cycle CO_(2)into high...Ever-increasing emissions of anthropogenic carbon dioxide(CO_(2))cause global environmental and climate challenges.Inspired by biological photosynthesis,developing effective strategies NeuNlto up-cycle CO_(2)into high-value organics is crucial.Electrochemical CO_(2)reduction reaction(CO_(2)RR)is highly promising to convert CO_(2)into economically viable carbon-based chemicals or fuels under mild process conditions.Herein,mesoporous indium supported on multi-walled carbon nanotubes(mp-In@MWCNTs)is synthesized via a facile wet chemical method.The mp-In@MWCNTs electrocatalysts exhibit high CO_(2)RR performance in reducing CO_(2)into formate.An outstanding activity(current density-78.5 mA cm^(-2)),high conversion efficiency(Faradaic efficiency of formate over 90%),and persistent stability(∼30 h)for selective CO_(2)-to-formate conversion are observed.The outstanding CO_(2)RR process performance is attributed to the unique structures with mesoporous surfaces and a conductive network,which promote the adsorption and desorption of reactants and intermediates while improving electron transfer.These findings provide guiding principles for synthesizing conductive metal-based electrocatalysts for high-performance CO_(2)conversion.展开更多
Single-molecule magnetic tweezers(MTs) have revealed multiple transition barriers along the unfolding pathway of several two-state proteins, such as GB1 and Csp. In this study, we utilized MTs to measure the force-dep...Single-molecule magnetic tweezers(MTs) have revealed multiple transition barriers along the unfolding pathway of several two-state proteins, such as GB1 and Csp. In this study, we utilized MTs to measure the force-dependent folding and unfolding rates of both protein L(PLWT) and its Y47W mutant(PLY47W) where the mutation point is not at the force-bearing β-strands. The measurements were conducted within a force range of 3–120 pN. Notably, the unfolding rates of both PLWT and PWY47W exhibit distinct force sensitivities below 50 pN and above 60 pN, implying a two-barrier free energy landscape. Both PLWT and PLY47W share the same force-dependent folding rate and the same transition barriers,but the unfolding rate of PLY47W is faster than that of PLWT. Our finding demonstrates that the residue outside of the force-bearing region will also affect the force-induced unfolding dynamics.展开更多
Metal–organic frameworks(MOFs)have attracted significant research interest in biomimetic catalysis.However,the modulation of the activity of MOFs by precisely tuning the coordination of metal nodes is still a signifi...Metal–organic frameworks(MOFs)have attracted significant research interest in biomimetic catalysis.However,the modulation of the activity of MOFs by precisely tuning the coordination of metal nodes is still a significant challenge.Inspired by metalloenzymes with well-defined coordination structures,a series of MOFs containing halogen-coordinated copper nodes(Cu-X MOFs,X=Cl,Br,I)are employed to elucidate their structure–activity relationship.Intriguingly,experimental and theoretical results strongly support that precisely tuning the coordination of halogen atoms directly regulates the enzyme-like activities of Cu-X MOFs by influencing the spatial configuration and electronic structure of the Cu active center.The optimal Cu–Cl MOF exhibits excellent superoxide dismutase-like activity with a specific activity one order of magnitude higher than the reported Cu-based nanozymes.More importantly,by performing enzyme-mimicking catalysis,the Cu–Cl MOF nanozyme can significantly scavenge reactive oxygen species and alleviate oxidative stress,thus effectively relieving ocular chemical burns.Mechanistically,the antioxidant and antiapoptotic properties of Cu–Cl MOF are achieved by regulating the NRF2 and JNK or P38 MAPK pathways.Our work provides a novel way to refine MOF nanozymes by directly engineering the coordination microenvironment and,more significantly,demonstrating their potential therapeutic effect in ophthalmic disease.展开更多
The generation of green hydrogen(H_2) energy is of great significance to solve worldwide energy and environmental issues. Reduced Ti based photocatalyst has recently attracted intensive attention due to its excellent ...The generation of green hydrogen(H_2) energy is of great significance to solve worldwide energy and environmental issues. Reduced Ti based photocatalyst has recently attracted intensive attention due to its excellent photocatalytic activity, while the synthesis of reduced Ti based photocatalysts with high stability is still a great challenge. Here, we report a facile method for synthesis of reduced Ti metal organic frameworks(small amounts of Pt incorporated) encapsulated BP(BP/R-Ti-MOFs/Pt) hybrid nanomaterial with enhanced photocatalytic activity. The strong interaction between Ti and P reduces the valence state of the binding Ti^(4+)on the BP surface, forming abundant reduced Ti^(4+)within R-Ti-MOFs/BP. Such reduced Ti^(4+)render R-Ti-MOFs/BP efficient charge transfer and excellent light absorption capability, thus promote the photocatalytic H_2 production efficiency. Furthermore, the Ti-P interaction stabilizes both reduced Ti^(4+)and BP during the photocatalytic reaction, which greatly enhanced the stability of the obtained BP/R-TiMOFs/Pt photocatalyst.展开更多
Src SH3 protein domain is a typical two-state protein which has been confirmed by research of denaturant-induced unfolding dynamics.Force spectroscopy experiments by optical tweezers and atomic force microscopy have m...Src SH3 protein domain is a typical two-state protein which has been confirmed by research of denaturant-induced unfolding dynamics.Force spectroscopy experiments by optical tweezers and atomic force microscopy have measured the force-dependent unfolding rates with different kinds of pulling geometry.However,the equilibrium folding and unfolding dynamics at constant forces has not been reported.Here,using stable magnetic tweezers,we performed equilibrium folding and unfolding dynamic measurement and force-jump measurement of src SH3 domain with tethering points at its N-and C-termini.From the obtained force-dependent transition rates,a detailed two-state free energy landscape of src SH3 protein is constructed with quantitative information of folding free energy,transition state barrier height and position,which exemplifies the capability of magnetic tweezers to study protein folding and unfolding dynamics.展开更多
Cell migration plays an essential role in a wide variety of physiological and pathological processes. In this paper we numerically discuss the properties of an anisotropic persistent random walk （APRW） model, in whi...Cell migration plays an essential role in a wide variety of physiological and pathological processes. In this paper we numerically discuss the properties of an anisotropic persistent random walk （APRW） model, in which two different and independent persistent times are assumed for cell migrations in the x-and y-axis directions. An intrinsic orthogonal coordinates with the primary and non-primary directions can be defined for each migration trajectory based on the singular vector decomposition method. Our simulation results show that the decay time of single exponential distribution of velocity auto-correlation function （VACF） in the primary direction is actually the large persistent time of the APRW model, and the small decay time of double exponential VACF in the non-primary direction equals the small persistent time of the APRW model. Thus, we propose that the two persistent times of anisotropic migration of cells can be properly estimated by discussing the VACFs of trajectory projected to the primary and non-primary directions.展开更多
The torsional,bending and tensile mechanical properties of Mo_(6)S_(6)nanowire are examined by molecular dynamics(MD)simulations with a first-principles-based reactive force field(ReaxFF).It is found that Mo_(6)S_(6)n...The torsional,bending and tensile mechanical properties of Mo_(6)S_(6)nanowire are examined by molecular dynamics(MD)simulations with a first-principles-based reactive force field(ReaxFF).It is found that Mo_(6)S_(6)nanowire shows unique mechanical properties such as high torsional and bending flexibility,high Young's modulus and strength,and negative Poisson's ratio.The Mo_(6)S_(6)nanowire can be strengthened or weakened via twisting,depending on the twist angle.The Mo_(6)S_(6)nanowire with a slight twist angle shows brittle failure,whereas it with a large twist angle exhibits ductile failure and necking behavior.Twisted Mo_(6)S_(6)nanowires show a crossover in the negative Poisson's ratio at critical strains,that is,Poisson's ratio first decreases but then increases,with a minimum value down to around-0.8 at the strain of 0.01 as the twist angle is 21.0°/nm.The negative Poisson's ratio and the crossover are explained by the bond transform that makes zero angles to the wire cross-section.展开更多
Understanding the hydrate adhesion is important to tackling hydrate accretion in petro-pipelines.Herein,the relationship between the Tetrahydrofuran(THF)hydrate adhesion strength(AS)and surface stiffness on elastic co...Understanding the hydrate adhesion is important to tackling hydrate accretion in petro-pipelines.Herein,the relationship between the Tetrahydrofuran(THF)hydrate adhesion strength(AS)and surface stiffness on elastic coatings is systemically examined by experimental shear force measurements and theoretical methods.The mechanical factor-elastic modulus of the coatings greatly dictates the hydrate AS,which is explained by the adhesion mechanics theory,beyond the usual factors such as wettability and structural roughness.Moreover,the hydrate AS increases with reducing the thickness of the elastic coatings,resulted from the decrease of the apparent surface elastic modulus.The effect of critical thickness for the elastic materials with variable elastic modulus on the hydrate AS is also revealed.This study provides deep perspectives on the regulation of the hydrate AS by the elastic modulus of elastic materials,which is of significance to design anti-hydrate surfaces for mitigation of hydrate accretion in petro-pipelines.展开更多
The ability of membrane technologies to dynamically tune the transport behavior for gases and liquids is critical for their applications.Although various methods have been developed to improve membrane success,tradeof...The ability of membrane technologies to dynamically tune the transport behavior for gases and liquids is critical for their applications.Although various methods have been developed to improve membrane success,tradeoffs still exist among their properties,such as permeability,selectivity,fouling resistance,and stability,which can greatly affect the performance of membranes.Existing elastomeric membrane designs can provide antifracture properties and flexibility;however,these designs still face certain challenges,such as low tensile strength and reliability.Additionally,researchers have not yet thoroughly developed membranes that can avoid fouling issues while realizing precise dynamic control over the transport substances.In this study,we show a versatile strategy for preparing graphene oxide-reinforced elastomeric liquid gating membranes that can finely modulate and dynamically tune the sorting of a wide range of gases and liquids under constant applied pressures.Moreover,the produced membranes exhibit antifouling properties and are adaptable to different length scales,pressures,and environments.The filling of graphene oxide in the thermoplastic polyurethane matrix enhances the composites through hydrogen bonds.Experiments and theoretical calculations are carried out to demonstrate the stability of our system.Our membrane exhibits good stretchability,recovery,and durability due to the elastic nature of the solid matrix and dynamic nature of the gating liquid.Dynamic control over the transport of gases and liquids is achieved through our optimized interfacial design and controllable pore deformation,which is induced by mechanical stimuli.Our strategy will create new opportunities for many applications,such as gas-involved chemical reactions,multiphase separation,microfluidics,multiphase microreactors,and particulate material synthesis.展开更多
Design and development of iron porphyrin-based artificial enzymes system have been attracting a lot of attention.Herein,without any toxic reductant and harsh processing,we present a facile one-pot method to fabricate ...Design and development of iron porphyrin-based artificial enzymes system have been attracting a lot of attention.Herein,without any toxic reductant and harsh processing,we present a facile one-pot method to fabricate bifunctional catalytic nanocomposites consisting of graphene and hemin by using vitamin C as a mild reduction reagent.The presence of graphene helps the formation of a high degree of highly active and stable hemin on the graphene surface in a monomeric form through theirπ-πstacking interaction.As a result,such nanocomposites possess a superior adsorption capacity and intrinsic peroxidase-like catalytic activity.Moreover,by the combination of their dye adsorption ability,RGOhemin nanocomposites can serve as a suitable candidate for efficient capture and removal of dyes via a synergistic effect.Our findings may pave the way to apply graphene-supported artificial enzymes in a variety of fields,such as environmental chemistry,bionics,medicine,and biotechnology.展开更多
Deoxyribonucleic acid(DNA) carries the genetic information in all living organisms. It consists of two interwound single-stranded(ss) strands, forming a double-stranded(ds) DNA with a right-handed double-helical confo...Deoxyribonucleic acid(DNA) carries the genetic information in all living organisms. It consists of two interwound single-stranded(ss) strands, forming a double-stranded(ds) DNA with a right-handed double-helical conformation. The two strands are held together by highly specific basepairing interactions and are further stabilized by stacking between adjacent basepairs. A transition from a dsDNA to two separated ssDNA is called melting and the reverse transition is called hybridization. Applying a tensile force to a dsDNA can result in a particular type of DNA melting, during which one ssDNA strand is peeled away from the other. In this work, we studied the kinetics of strand-peeling and hybridization of short DNA under tensile forces. Our results show that the force-dependent strand-peeling and hybridization can be described with a simple two-state model. Importantly, detailed analysis of the force-dependent transition rates revealed that the transition state consists of several basepairs dsDNA.展开更多
The human brain performs computations via a highly interconnected network of neurons.Taking inspiration from the information delivery and processing mechanism of the human brain in central nervous systems,bioinspired ...The human brain performs computations via a highly interconnected network of neurons.Taking inspiration from the information delivery and processing mechanism of the human brain in central nervous systems,bioinspired nanofluidic iontronics has been proposed and gradually engineered to overcome the limitations of the conventional electron-based von Neumann architecture,which shows the promising potential to enable efficient brain-like computing.Anomalous and tunable nanofluidic ion transport behaviors and spatial confinement show promising controllability of charge carriers,and a wide range of structural and chemical modification paves new ways for realizing brain-like functions.Herein,a comprehensive framework of mechanisms and design strategy is summarized to enable the rational design of nanofluidic systems and facilitate the further development of bioinspired nanofluidic iontronics.This review provides recent advances and prospects of the bioinspired nanofluidic iontronics,including ion-based brain computing,comprehension of intrinsic mechanisms,design of artificial nanochannels,and the latest artificial neuromorphic functions devices.Furthermore,the challenges and opportunities of bioinspired nanofluidic iontronics in the pioneering and interdisciplinary research fields are proposed,including brain–computer interfaces and artificial neurons.展开更多
To extract the dynamic parameters from single molecule manipulation experiments, usually lots of data at different forces need to be recorded. But the measuring time of a single molecule is limited due to breakage of ...To extract the dynamic parameters from single molecule manipulation experiments, usually lots of data at different forces need to be recorded. But the measuring time of a single molecule is limited due to breakage of the tether or degradation of the molecule. Here we propose a data analysis method based on probability maximizalion of the recorded time trace to extract the dynamic parameters from a single measurement. The feasibility of this method was verified by dealing with the simulation data of a two-state system. We also applied this method to estimate the parameters of DNA hairpin folding and unfolding dynamics measured by a magnetic tweezers experiment.展开更多
Hydrogel is a kind of three-dimensional crosslinked polymer material with high moisture content.However,due to the network defects of polymer gels,traditional hydrogels are usually brittle and fragile,which limits the...Hydrogel is a kind of three-dimensional crosslinked polymer material with high moisture content.However,due to the network defects of polymer gels,traditional hydrogels are usually brittle and fragile,which limits their practical applications.Herein,we present a Hofmeister effect-aided facile strategy to prepare high-performance poly(vinyl alcohol)/montmorillonite nanocomposite hydrogels.Layered montmorillonite nanosheets can not only serve as crosslinking agents to enhance the mechanical properties of the hydrogel but also promote the ion conduction.More importantly,based on the Hofmeister effect,the presence of(NH_(4))_(2)SO_(4)can endow nanocomposite hydrogels with excellent mechanical properties by affecting PVA chains'aggregation state and crystallinity.As a result,the as-prepared nanocomposite hydrogels possess unique physical properties,including robust mechanical and electrical properties.The as-prepared hydrogels can be further assembled into a high-performance flexible sensor,which can sensitively detect large-scale and small-scale human activities.The simple design concept of this work is believed to provide a new prospect for developing robust nanocomposite hydrogels and flexible devices in the future.展开更多
Walled cells,such as in plants and fungi,compose an important part of the model systems in biology.The cell wall primarily prevents the cell from over-expansion when exposed to water,and is a porous material distribut...Walled cells,such as in plants and fungi,compose an important part of the model systems in biology.The cell wall primarily prevents the cell from over-expansion when exposed to water,and is a porous material distributed with nanosized pores on it.In this paper,we study the deformation of a membrane patch by an osmotic pressure through a nanopore on the cell wall.We find that there exists a critical pore size or a critical pressure beyond which the membrane cannot stand against the pressure and would inflate out through the pore and further expand.The critical pore size scales linearly with the membrane tension and quadratically with the spontaneous curvature.The critical pressure is inversely proportional to the pore radius.Our results also show that the fluid membrane expansion by pressure is mechanically different from the solid balloon expansion,and predict that the bending rigidity of the membrane in walled cells should be much larger than that of the mammalian cells so as to prevent membrane inflation through the pores on the cell wall.展开更多
Recently,a new phase C'_(1) H_(2) hydrate was experimentally identified.In this work,the diffusive behaviors of H_(2) in C'_(1)phase clathrate hydrate are explored using classic molecular dynamics(MD)simulatio...Recently,a new phase C'_(1) H_(2) hydrate was experimentally identified.In this work,the diffusive behaviors of H_(2) in C'_(1)phase clathrate hydrate are explored using classic molecular dynamics(MD)simulations.It reveals that the cage occupancy by H_(2) molecule negligibly influences the C'_(1) phase clathrate structure but greatly dictates the diffusion coefficient of H_(2)molecule.Due to the small cage size and small windows connecting the neighboring cages in C'_(1) phase clathrate,nonoccupancy of the neighboring cages is demanded to enable the diffusion of H_(2) molecule that is primarily dominated by hopping mechanism.Moreover,the analysis of diffusive free energy landscape reveals lower energy barrier of H_(2) molecule in C'_(1) phase clathrate hydrate than that of other gases in conventional clathrate hydrates,and that H_(2) molecule travels through the windows between neighboring cages with preferential molecular orientation.This study provides critical physical insights into the diffusion behaviors of H_(2) in the C'_(1) phase clathrate hydrate,and implies that the C'_(1) clathrate hydrate is a promising solid structure for the next-generation H_(2) storage.展开更多
基金financially supported by the National Natural Science Foundation of China(21771154)the Shenzhen Fundamental Research Programs(JCYJ20190809161013453)+1 种基金the Fundamental Research Funds for the Central Universities(20720220031)the 111 Project(B16029)。
文摘The formation and growth of Li-dendrites caused by inhomogeneous Li deposition severely hinder the commercial applications of Li metal batteries due to the consequence of short-circuiting.Herein,we propose a Janus bilayer composed of black phosphorus(BP)and graphene oxide(GO)as an artificial interface with chemical/mechanical stability and well-regulated Li-ion flux distribution for Li metal anode protection.Owing to the synergy between the fast Li-ion transport of BP in the inner layer and the high mechanical and chemical stability of GO in the outer layer,the GO/BP with good electrolyte wettability acts as a Li-ion regulator that can induce homogeneous growth of Li to suppress the Li dendrites growth.Accordingly,long-term stability(500 h at 1 mA cm^(-2))with a low overpotential of 30 mV is achieved in the symmetric cell with GO/BP-Li anode.Furthermore,the Li–S cell with GO/BP-Li exhibits enhanced cycling performance with a high capacity retention rate of 76.2%over 500 cycles at 1 C.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11874309,11474237,and 11574310)the 111 Project,China(Grant No.B16029).
文摘Two-state folding and down-hill folding are two kinds of protein folding dynamics for small single domain proteins.Here we apply molecular dynamics(MD)simulation to the two-state protein GB1 and down-hill folding protein gpW to reveal the relationship of their free energy landscape and folding/unfolding dynamics.Results from the steered MD simulations show that gpW is much less mechanical resistant than GB1,and the unfolding process of gpW has more variability than that of GB1 according to their force-extension curves.The potential of mean force(PMF)of GB1 and gpW obtained by the umbrella sampling simulations shows apparent difference:PMF of GB1 along the coordinate of extension exhibits a kink transition point where the slope of PMF drops suddenly,while PMF of gpW increases with extension smoothly,which are consistent with two-state folding dynamics of GB1 and downhill folding dynamics of gpW,respectively.Our results provide insight to understand the fundamental mechanism of different folding dynamics of twostate proteins and downhill folding proteins.
基金the National Nature Science Foundation of China(Grant Nos.11474237 and 11574310)the 111 Project(Grant No.B16029).
文摘α-catenin is an adhesion protein located at the cadherin-based cell-cell adherens junction.α-catenin cross-linksβ-catenin and actin fiber in the adhesion protein complex,and plays an important role in the formation and modulation of cell-cell adhesion.The central modulation domains can be unfolded to expose binding site of vinculin when stretching force is applied.Here,we studied the force-induced unfolding dynamics ofα-catenin modulation domains under different loading rates from which the unfolding distance of M2 and M3 domains is determined to be 5-7 nm,and an unfolding intermediate state is identified.We also found that the folding process of M1-M3 domains goes through different pathways with cooperativity.
基金partial support from the Jiujiang Research Institute at Xiamen University.
文摘The electrochemical carbon dioxide reduction(eCO_(2)RR)to formate,driven by clean energy,is a promising approach for producing renewable chemicals and high-value fuels.Despite its potential,further development faces challenges due to limitations in electrocatalytic activity and durability,especially for nonnoble metal-based catalysts.Here,naturally abundant bismuth-based nanosheets that can effectively drive CO_(2)-to-formate electrocatalytic reduction are prepared using the plasma-activated Bi_(2)Se_(3) followed by a reduction process.Thus-obtained plasma-activated Bi nanosheets(P-BiNS)feature ultrathin structures and high surface areas.Such nanostructures ensure the P-BiNS with outstanding eCO_(2)RR catalytic performance,highlighted by the current density of over 80 mA cm^(-2) and a formate Faradic efficiency of>90%.Furthermore,P-BiNS catalysts demonstrate excellent durability and stability without deactivation following over 50h of operation.The selectivity for formate production is also studied by density functional theory(DFT)calculations,validating the importance and efficacy of the stabilization of intermediates(^(*)OCHO)on the P-BiNS surfaces.This study provides a facile plasma-assisted approach for developing high-performance and low-cost electrocatalysts.
基金Jiujiang Research Institute in Xiamen University for the partial supportthe support of QUT Faculty Centre Strategic Funding provided by the Faculty of Science and QUT Centre for a Waste-Free World+1 种基金the Australian Research Council(ARC)QUT Centre for Materials Science for partial support
文摘Ever-increasing emissions of anthropogenic carbon dioxide(CO_(2))cause global environmental and climate challenges.Inspired by biological photosynthesis,developing effective strategies NeuNlto up-cycle CO_(2)into high-value organics is crucial.Electrochemical CO_(2)reduction reaction(CO_(2)RR)is highly promising to convert CO_(2)into economically viable carbon-based chemicals or fuels under mild process conditions.Herein,mesoporous indium supported on multi-walled carbon nanotubes(mp-In@MWCNTs)is synthesized via a facile wet chemical method.The mp-In@MWCNTs electrocatalysts exhibit high CO_(2)RR performance in reducing CO_(2)into formate.An outstanding activity(current density-78.5 mA cm^(-2)),high conversion efficiency(Faradaic efficiency of formate over 90%),and persistent stability(∼30 h)for selective CO_(2)-to-formate conversion are observed.The outstanding CO_(2)RR process performance is attributed to the unique structures with mesoporous surfaces and a conductive network,which promote the adsorption and desorption of reactants and intermediates while improving electron transfer.These findings provide guiding principles for synthesizing conductive metal-based electrocatalysts for high-performance CO_(2)conversion.
基金supported by the National Natural Science Foundation of China(Grant Nos.12174322 to HC and 12204124 to ZG)111 Project(Grant No.B16029)+1 种基金the Graduate Scientific Research Foundation of Wenzhou University(Grant No.3162023003034 to JH)research grant from Wenzhou Institute。
文摘Single-molecule magnetic tweezers(MTs) have revealed multiple transition barriers along the unfolding pathway of several two-state proteins, such as GB1 and Csp. In this study, we utilized MTs to measure the force-dependent folding and unfolding rates of both protein L(PLWT) and its Y47W mutant(PLY47W) where the mutation point is not at the force-bearing β-strands. The measurements were conducted within a force range of 3–120 pN. Notably, the unfolding rates of both PLWT and PWY47W exhibit distinct force sensitivities below 50 pN and above 60 pN, implying a two-barrier free energy landscape. Both PLWT and PLY47W share the same force-dependent folding rate and the same transition barriers,but the unfolding rate of PLY47W is faster than that of PLWT. Our finding demonstrates that the residue outside of the force-bearing region will also affect the force-induced unfolding dynamics.
基金the National Key R&D Program of China(Grant No.2020YFA0908100)the National Nature Science Foundation(Grant Nos.12274356,82070931,and 82271045)+1 种基金Fundamental Research Funds for the Central Universities(20720220022)the 111 Project(B16029)。
文摘Metal–organic frameworks(MOFs)have attracted significant research interest in biomimetic catalysis.However,the modulation of the activity of MOFs by precisely tuning the coordination of metal nodes is still a significant challenge.Inspired by metalloenzymes with well-defined coordination structures,a series of MOFs containing halogen-coordinated copper nodes(Cu-X MOFs,X=Cl,Br,I)are employed to elucidate their structure–activity relationship.Intriguingly,experimental and theoretical results strongly support that precisely tuning the coordination of halogen atoms directly regulates the enzyme-like activities of Cu-X MOFs by influencing the spatial configuration and electronic structure of the Cu active center.The optimal Cu–Cl MOF exhibits excellent superoxide dismutase-like activity with a specific activity one order of magnitude higher than the reported Cu-based nanozymes.More importantly,by performing enzyme-mimicking catalysis,the Cu–Cl MOF nanozyme can significantly scavenge reactive oxygen species and alleviate oxidative stress,thus effectively relieving ocular chemical burns.Mechanistically,the antioxidant and antiapoptotic properties of Cu–Cl MOF are achieved by regulating the NRF2 and JNK or P38 MAPK pathways.Our work provides a novel way to refine MOF nanozymes by directly engineering the coordination microenvironment and,more significantly,demonstrating their potential therapeutic effect in ophthalmic disease.
基金financially supported by the National Natural Science Foundation of China (21771154, 31371005)the Shenzhen Fundamental Research Programs (JCYJ20190809161013453)+1 种基金the Natural Science Foundation of Fujian Province of China (Nos. 2018J01019, 2018J05025)the Fundamental Research Funds for the Central Universities (20720180019, 20720180016)。
文摘The generation of green hydrogen(H_2) energy is of great significance to solve worldwide energy and environmental issues. Reduced Ti based photocatalyst has recently attracted intensive attention due to its excellent photocatalytic activity, while the synthesis of reduced Ti based photocatalysts with high stability is still a great challenge. Here, we report a facile method for synthesis of reduced Ti metal organic frameworks(small amounts of Pt incorporated) encapsulated BP(BP/R-Ti-MOFs/Pt) hybrid nanomaterial with enhanced photocatalytic activity. The strong interaction between Ti and P reduces the valence state of the binding Ti^(4+)on the BP surface, forming abundant reduced Ti^(4+)within R-Ti-MOFs/BP. Such reduced Ti^(4+)render R-Ti-MOFs/BP efficient charge transfer and excellent light absorption capability, thus promote the photocatalytic H_2 production efficiency. Furthermore, the Ti-P interaction stabilizes both reduced Ti^(4+)and BP during the photocatalytic reaction, which greatly enhanced the stability of the obtained BP/R-TiMOFs/Pt photocatalyst.
基金the National Natural Science Foundation of China(Grant Nos.11874309 and 11474237)the 111 Project(Grant No.B16029)。
文摘Src SH3 protein domain is a typical two-state protein which has been confirmed by research of denaturant-induced unfolding dynamics.Force spectroscopy experiments by optical tweezers and atomic force microscopy have measured the force-dependent unfolding rates with different kinds of pulling geometry.However,the equilibrium folding and unfolding dynamics at constant forces has not been reported.Here,using stable magnetic tweezers,we performed equilibrium folding and unfolding dynamic measurement and force-jump measurement of src SH3 domain with tethering points at its N-and C-termini.From the obtained force-dependent transition rates,a detailed two-state free energy landscape of src SH3 protein is constructed with quantitative information of folding free energy,transition state barrier height and position,which exemplifies the capability of magnetic tweezers to study protein folding and unfolding dynamics.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.31370830,11675134,11474345,and 11604030)the State Key Development Program for Basic Research of China(Grant No.2013CB837200)+1 种基金the 111 Project,China(Grant No.B16029)the China Postdoctoral Science Foundation(Grant No.2016M602071)
文摘Cell migration plays an essential role in a wide variety of physiological and pathological processes. In this paper we numerically discuss the properties of an anisotropic persistent random walk （APRW） model, in which two different and independent persistent times are assumed for cell migrations in the x-and y-axis directions. An intrinsic orthogonal coordinates with the primary and non-primary directions can be defined for each migration trajectory based on the singular vector decomposition method. Our simulation results show that the decay time of single exponential distribution of velocity auto-correlation function （VACF） in the primary direction is actually the large persistent time of the APRW model, and the small decay time of double exponential VACF in the non-primary direction equals the small persistent time of the APRW model. Thus, we propose that the two persistent times of anisotropic migration of cells can be properly estimated by discussing the VACFs of trajectory projected to the primary and non-primary directions.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12172314,11772278,12002350,and 11904300)the Jiangxi Provincial Outstanding Young Talents Program(Grant No.20192BCBL23029)+1 种基金the Fundamental Research Funds for the Central Universities of Xiamen University(Grant Nos.20720210025 and 20720220023)the“111”Project(Grant No.B16029)。
文摘The torsional,bending and tensile mechanical properties of Mo_(6)S_(6)nanowire are examined by molecular dynamics(MD)simulations with a first-principles-based reactive force field(ReaxFF).It is found that Mo_(6)S_(6)nanowire shows unique mechanical properties such as high torsional and bending flexibility,high Young's modulus and strength,and negative Poisson's ratio.The Mo_(6)S_(6)nanowire can be strengthened or weakened via twisting,depending on the twist angle.The Mo_(6)S_(6)nanowire with a slight twist angle shows brittle failure,whereas it with a large twist angle exhibits ductile failure and necking behavior.Twisted Mo_(6)S_(6)nanowires show a crossover in the negative Poisson's ratio at critical strains,that is,Poisson's ratio first decreases but then increases,with a minimum value down to around-0.8 at the strain of 0.01 as the twist angle is 21.0°/nm.The negative Poisson's ratio and the crossover are explained by the bond transform that makes zero angles to the wire cross-section.
基金This work is financially supported by the Key Laboratory of Icing and Anti/De-icing of CARDC(Grant No.IADL20210402)the National Natural Science Foundation of China(Grant Nos.12002350,12172314,11772278 and 11904300)+1 种基金the Jiangxi Provincial Outstanding Young Talents Program(Grant No.20192BCBL23029)the Fundamental Research Funds for the Central Universities(Xiamen University:Grant No.20720210025).
文摘Understanding the hydrate adhesion is important to tackling hydrate accretion in petro-pipelines.Herein,the relationship between the Tetrahydrofuran(THF)hydrate adhesion strength(AS)and surface stiffness on elastic coatings is systemically examined by experimental shear force measurements and theoretical methods.The mechanical factor-elastic modulus of the coatings greatly dictates the hydrate AS,which is explained by the adhesion mechanics theory,beyond the usual factors such as wettability and structural roughness.Moreover,the hydrate AS increases with reducing the thickness of the elastic coatings,resulted from the decrease of the apparent surface elastic modulus.The effect of critical thickness for the elastic materials with variable elastic modulus on the hydrate AS is also revealed.This study provides deep perspectives on the regulation of the hydrate AS by the elastic modulus of elastic materials,which is of significance to design anti-hydrate surfaces for mitigation of hydrate accretion in petro-pipelines.
基金We gratefully acknowledge the support from the National Natural Science Foundation of China(grant No.21808191,21673197,21975209,and 21621091)the National Key R&D Program of China(grant No.2018YFA0209500)+2 种基金the Fundamental Research Funds for the Central Universities(grant No.20720190037)the Natural Science Foundation of Fujian Province of China(grant No.2018J06003)the Special Project of Strategic Emerging Industries from Fujian Development and Reform Commission.We thank Prof.C.Chen and Dr.Q.Kong for the preparation of GO at the Institute of Coal Chemistry,Chinese Academy of Sciences.
文摘The ability of membrane technologies to dynamically tune the transport behavior for gases and liquids is critical for their applications.Although various methods have been developed to improve membrane success,tradeoffs still exist among their properties,such as permeability,selectivity,fouling resistance,and stability,which can greatly affect the performance of membranes.Existing elastomeric membrane designs can provide antifracture properties and flexibility;however,these designs still face certain challenges,such as low tensile strength and reliability.Additionally,researchers have not yet thoroughly developed membranes that can avoid fouling issues while realizing precise dynamic control over the transport substances.In this study,we show a versatile strategy for preparing graphene oxide-reinforced elastomeric liquid gating membranes that can finely modulate and dynamically tune the sorting of a wide range of gases and liquids under constant applied pressures.Moreover,the produced membranes exhibit antifouling properties and are adaptable to different length scales,pressures,and environments.The filling of graphene oxide in the thermoplastic polyurethane matrix enhances the composites through hydrogen bonds.Experiments and theoretical calculations are carried out to demonstrate the stability of our system.Our membrane exhibits good stretchability,recovery,and durability due to the elastic nature of the solid matrix and dynamic nature of the gating liquid.Dynamic control over the transport of gases and liquids is achieved through our optimized interfacial design and controllable pore deformation,which is induced by mechanical stimuli.Our strategy will create new opportunities for many applications,such as gas-involved chemical reactions,multiphase separation,microfluidics,multiphase microreactors,and particulate material synthesis.
基金supported by the National Nature Science Foundation (Nos.21771150,21401154,U1405226)the Fundamental Research Funds for the Central Universities of China (Nos. 20720170011,20720140528,20720160127)+1 种基金111 Project (No. B16029)Doctoral Fund of the Ministry of Education (No.20130121110018)
文摘Design and development of iron porphyrin-based artificial enzymes system have been attracting a lot of attention.Herein,without any toxic reductant and harsh processing,we present a facile one-pot method to fabricate bifunctional catalytic nanocomposites consisting of graphene and hemin by using vitamin C as a mild reduction reagent.The presence of graphene helps the formation of a high degree of highly active and stable hemin on the graphene surface in a monomeric form through theirπ-πstacking interaction.As a result,such nanocomposites possess a superior adsorption capacity and intrinsic peroxidase-like catalytic activity.Moreover,by the combination of their dye adsorption ability,RGOhemin nanocomposites can serve as a suitable candidate for efficient capture and removal of dyes via a synergistic effect.Our findings may pave the way to apply graphene-supported artificial enzymes in a variety of fields,such as environmental chemistry,bionics,medicine,and biotechnology.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.2013121005)the National Natural Science Foundation of China(Grant Nos.11474237 and 11574310)+1 种基金the 111 Project (Grant No.B16029)the National Research Foundation of Singapore through the NRF Investigatorship and the Mechanobiology Institute
文摘Deoxyribonucleic acid(DNA) carries the genetic information in all living organisms. It consists of two interwound single-stranded(ss) strands, forming a double-stranded(ds) DNA with a right-handed double-helical conformation. The two strands are held together by highly specific basepairing interactions and are further stabilized by stacking between adjacent basepairs. A transition from a dsDNA to two separated ssDNA is called melting and the reverse transition is called hybridization. Applying a tensile force to a dsDNA can result in a particular type of DNA melting, during which one ssDNA strand is peeled away from the other. In this work, we studied the kinetics of strand-peeling and hybridization of short DNA under tensile forces. Our results show that the force-dependent strand-peeling and hybridization can be described with a simple two-state model. Importantly, detailed analysis of the force-dependent transition rates revealed that the transition state consists of several basepairs dsDNA.
基金supported by the National Natural Science Foundation of China(Nos.21975209,52273305,22205185,52025132,T2241022,21621091,22021001,and 22121001)the 111 Project(Nos.B17027 and B16029)+2 种基金the National Science Foundation of Fujian Province of China(No.2022J02059)the Science and Technology Projects of Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(No.RD2022070601)the Tencent Foundation(The XPLORER PRIZE).
文摘The human brain performs computations via a highly interconnected network of neurons.Taking inspiration from the information delivery and processing mechanism of the human brain in central nervous systems,bioinspired nanofluidic iontronics has been proposed and gradually engineered to overcome the limitations of the conventional electron-based von Neumann architecture,which shows the promising potential to enable efficient brain-like computing.Anomalous and tunable nanofluidic ion transport behaviors and spatial confinement show promising controllability of charge carriers,and a wide range of structural and chemical modification paves new ways for realizing brain-like functions.Herein,a comprehensive framework of mechanisms and design strategy is summarized to enable the rational design of nanofluidic systems and facilitate the further development of bioinspired nanofluidic iontronics.This review provides recent advances and prospects of the bioinspired nanofluidic iontronics,including ion-based brain computing,comprehension of intrinsic mechanisms,design of artificial nanochannels,and the latest artificial neuromorphic functions devices.Furthermore,the challenges and opportunities of bioinspired nanofluidic iontronics in the pioneering and interdisciplinary research fields are proposed,including brain–computer interfaces and artificial neurons.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11474237 and 11574310)the 111 Project,China(Grant No.B16029)
文摘To extract the dynamic parameters from single molecule manipulation experiments, usually lots of data at different forces need to be recorded. But the measuring time of a single molecule is limited due to breakage of the tether or degradation of the molecule. Here we propose a data analysis method based on probability maximizalion of the recorded time trace to extract the dynamic parameters from a single measurement. The feasibility of this method was verified by dealing with the simulation data of a two-state system. We also applied this method to estimate the parameters of DNA hairpin folding and unfolding dynamics measured by a magnetic tweezers experiment.
基金Project supported by the National Natural Science Foundation of China(Grant No.12274356)the Fundamental Research Funds for the Central Universities(Grant No.20720220022)the 111 Project(Grant No.B16029)。
文摘Hydrogel is a kind of three-dimensional crosslinked polymer material with high moisture content.However,due to the network defects of polymer gels,traditional hydrogels are usually brittle and fragile,which limits their practical applications.Herein,we present a Hofmeister effect-aided facile strategy to prepare high-performance poly(vinyl alcohol)/montmorillonite nanocomposite hydrogels.Layered montmorillonite nanosheets can not only serve as crosslinking agents to enhance the mechanical properties of the hydrogel but also promote the ion conduction.More importantly,based on the Hofmeister effect,the presence of(NH_(4))_(2)SO_(4)can endow nanocomposite hydrogels with excellent mechanical properties by affecting PVA chains'aggregation state and crystallinity.As a result,the as-prepared nanocomposite hydrogels possess unique physical properties,including robust mechanical and electrical properties.The as-prepared hydrogels can be further assembled into a high-performance flexible sensor,which can sensitively detect large-scale and small-scale human activities.The simple design concept of this work is believed to provide a new prospect for developing robust nanocomposite hydrogels and flexible devices in the future.
基金financial support from the National Natural Science Foundation of China(Grant No.12004317)Fundamental Research Funds for Central Universities of China(Grant No.20720200072)111 Project(Grant No.B16029)。
文摘Walled cells,such as in plants and fungi,compose an important part of the model systems in biology.The cell wall primarily prevents the cell from over-expansion when exposed to water,and is a porous material distributed with nanosized pores on it.In this paper,we study the deformation of a membrane patch by an osmotic pressure through a nanopore on the cell wall.We find that there exists a critical pore size or a critical pressure beyond which the membrane cannot stand against the pressure and would inflate out through the pore and further expand.The critical pore size scales linearly with the membrane tension and quadratically with the spontaneous curvature.The critical pressure is inversely proportional to the pore radius.Our results also show that the fluid membrane expansion by pressure is mechanically different from the solid balloon expansion,and predict that the bending rigidity of the membrane in walled cells should be much larger than that of the mammalian cells so as to prevent membrane inflation through the pores on the cell wall.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12172314,11772278,and 11904300)the Jiangxi Provincial Outstanding Young Talents Program(Grant No.20192BCBL23029)+2 种基金the Fundamental Research Funds for the Central Universities(Xiamen University:Grant Nos.20720210025 and 20720220023)the Research Council of Norway(Grant No.262644)the 111 project(Grant No.B16029)。
文摘Recently,a new phase C'_(1) H_(2) hydrate was experimentally identified.In this work,the diffusive behaviors of H_(2) in C'_(1)phase clathrate hydrate are explored using classic molecular dynamics(MD)simulations.It reveals that the cage occupancy by H_(2) molecule negligibly influences the C'_(1) phase clathrate structure but greatly dictates the diffusion coefficient of H_(2)molecule.Due to the small cage size and small windows connecting the neighboring cages in C'_(1) phase clathrate,nonoccupancy of the neighboring cages is demanded to enable the diffusion of H_(2) molecule that is primarily dominated by hopping mechanism.Moreover,the analysis of diffusive free energy landscape reveals lower energy barrier of H_(2) molecule in C'_(1) phase clathrate hydrate than that of other gases in conventional clathrate hydrates,and that H_(2) molecule travels through the windows between neighboring cages with preferential molecular orientation.This study provides critical physical insights into the diffusion behaviors of H_(2) in the C'_(1) phase clathrate hydrate,and implies that the C'_(1) clathrate hydrate is a promising solid structure for the next-generation H_(2) storage.
