Trichloroethylene （TCE） is a major pollutant that affects both occupational and general environments. The liver is an important target organ of TCEE. Substantial efforts and remarkable progress into understanding TC...Trichloroethylene （TCE） is a major pollutant that affects both occupational and general environments. The liver is an important target organ of TCEE. Substantial efforts and remarkable progress into understanding TCE cytotoxicity have been made in cultured liver cells. However, the molecular mechanisms by which TCE induces hepatotoxicity are not well understood. SET （also known as protein phosphatase 2A inhibitor, 12PP2A, or template-activating factor-I, TAF-D is a nuclear protein that regulates histone modification, gene transcription, DNA replication, nucleosome assembly,展开更多
Ray tracing method is used to study the propagation of collimated beams in a liquid-core cylindrical lens(LCL),which has dual functions of diffusion cell and image formation.The diffusion images on the focal plane of ...Ray tracing method is used to study the propagation of collimated beams in a liquid-core cylindrical lens(LCL),which has dual functions of diffusion cell and image formation.The diffusion images on the focal plane of the used LCL are simulated by establishing and solving both linear and nonlinear ray equations,the calculated results indicate that the complex imaging results of LCL in inhomogeneous media can be treated by the law of ray propagation in homogeneous media under the condition of small refractive index gradient of diffusion solution.Guided by the calculation conditions,the diffusion process of triethylene glycol aqueous solution is experimentally studied at room temperature by using the LCL in this paper.The spatial and temporal concentration profile Ce(z,t)of diffusion solution is obtained by analyzing diffusion image appearing on the focal plane of the LCL;Then,the concentration-dependent diffusion coefficient is assumed to be a polynomial D(C)=D0×(1+α1C+α2C2+α3C3+…).The finite difference method is used to solve the Fick diffusion equation for calculating numerically the concentration profiles Cn(z,t).The D(C)of triethylene glycol aqueous solution is obtained by comparing the Cn(z,t)with Ce(z,t).Finally,the obtained polynomial D(C)is used to calculate the refractive index profiles nn(z,t)s of diffusion solution in the used LCL.Based on the ray propagation law in inhomogeneous media and the calculated n(z,t),the ray tracing method is used again to simulate the dynamic images of the whole experimental diffusion process to varify the correctness of the calculated D(C).The method presented in this work opens up a new way for both measuring and verifying the concentration-dependent liquid diffusion coefficients.展开更多
By incorporating the contribution of solute atoms to the Helmholtz free energy of solid solution,a linear relation is derived between Young's modulus and the concentration of solute atoms.The solute atoms can eith...By incorporating the contribution of solute atoms to the Helmholtz free energy of solid solution,a linear relation is derived between Young's modulus and the concentration of solute atoms.The solute atoms can either increase or decrease Young's modulus of solid solution,depending on the first-order derivative of the Helmholtz free energy with respect to the concentration of solute atoms.Using this relation,a closed-form solution of the chemical stress in an elastic plate is obtained when the diffusion behavior in the plate can be described by the classical Fick's second law with convection boundary condition on one surface and zero flux on the other surface.The plate experiences tensile stress after short diffusion time due to asymmetrical diffusion,which will likely cause surface microcracking.The results show that the effect of the concentration dependence of Young's modulus on the evolution of chemical stress in elastic plates is negligible if the change of Young's modulus due to the diffusive motion of solute atomsis is not compatible in magnitude with Young's modulus of the pure material.Also,a new diffusion equation is developed for strictly regular binary solid solution.The effective diffusivity is a nonlinear function of the concentration of solute atoms.展开更多
Large Seebeck coefficients induced by high degeneracy of conduction band minimum,and low intrinsic lattice thermal conductivity originated from large lattice vibrational anharmonicity render Mg_(3)Sb_(2)as a promising...Large Seebeck coefficients induced by high degeneracy of conduction band minimum,and low intrinsic lattice thermal conductivity originated from large lattice vibrational anharmonicity render Mg_(3)Sb_(2)as a promising n-type thermoelectric material.Herein,we demonstrated unique concentration-dependent occupation behaviors of Cu in Mg_(3.4)Sb_(1.5)Bi_(0.49)Te_(0.01)matrix,evidenced by structural characterization and transport property measurements.It is found that Cu atoms prefer to enter the interstitial lattice sites in Mg_(3)Sb_(2)host with low doping level(Mg_(3.4)Sb_(1.5)Bi_(0.49)Te_(0.01)+x%Cu,x<0.3%),acting as donors for providing additional electrons without deteriorating the carrier mobility.When x is larger than 0.3%,the excessive Cu atoms are inclined to substitute Mg atoms,yielding acceptors to decrease the electron concentration.As a result,the electrical conductivity of the Mg_(3.4)Sb_(1.5)Bi_(0.49)Te_(0.01)+0.3%Cu sample reaches 2.3×10^(4)S/m at 300 K,increasing by 300%compared with that of the pristine sample.The figure of merit zT values in the whole measured temperature range are significantly improved by the synergetic improvement of power factor and reduction of thermal conductivity.An average zT∼1.07 from 323 K to 773 K has been achieved for the Mg_(3.4)Sb_(1.5)Bi_(0.49)Te_(0.01)+0.3%Cu sample,which is about 30%higher than that of the Mg_(3.4)Sb_(1.5)Bi_(0.49)Te_(0.01) sample.展开更多
The impact of reductive pulmonary inhalants on ultrafine particles(UFPs)-induced pulmonary oxidative stress remains a crucial consideration,yet the concentration-dependent effects of these inhalants have remained unex...The impact of reductive pulmonary inhalants on ultrafine particles(UFPs)-induced pulmonary oxidative stress remains a crucial consideration,yet the concentration-dependent effects of these inhalants have remained unexplored.Here we synthesized composite UFPs simulating atmospheric UFPs,primarily composed of metals and quinones.We subjected these UFPs to varying concentrations(0e7000 mM)of two reductive pulmonary inhalants,N-acetylcysteine and salbutamol,to assess their influence on oxidative potential,measured through the dithiothreitol assay(OP^(DTT)).Simultaneously,we analysed the soluble metal content of UFPs to uncover potential relationships between oxidative potential and metal solubility.Our results unveil a dual role played by these inhalants in shaping the OPDTT of composite UFPs.Specifically,OP^(DTT) generally increased as inhalant concentrations rose from 0 to 300 mM.However,an intriguing reversal occurred when concentrations exceeded 500 mM,resulting in a decline in OPDTT.Relative to untreated UFPs,these inhalants induced promotion and inhibition effects within concentration ranges of 100e500 and>1000 mM,respectively.While no significant correlation emerged between OP^(DTT) and soluble metal content as inhalant concentrations ranged from 0 to 7000 mM,noteworthy positive correlations emerged at lower inhalant concentrations(e.g.,N-acetylcysteine at 0 e300 mM).These findings provide insights into the potential influence of reductive pulmonary inhalants on health risks associated with UFP exposure,further underscoring the need for continued research in this critical area.展开更多
Prelithiation has been intensively investigated in high-capacity lithiumion batteries(LIBs).However,the optimization of prelithiation degrees for long service life of LIBs still remains a challenge.The positive effect...Prelithiation has been intensively investigated in high-capacity lithiumion batteries(LIBs).However,the optimization of prelithiation degrees for long service life of LIBs still remains a challenge.The positive effect of prelithiation on suppressing degradation of LIBs,besides directly pursuing the high first Coulomb efficiency which has been widely reported in the literature,is revealed and discussed based on an analytical model focusing on the interfacial delamination in electrodes.For full charge-discharge cycling,well-designed prelithiation can effectively suppress the delamination and reduce the debonding size by approximately 25%,compared with the case without prelithiation.For the strategy combining partial charge-discharge cycling and prelithiation,the largest reversible capacity without debonding can be significantly improved by approximately100%with well-designed prelithiation.This work is expected to provide a prelithiation design principle and further improve the mechanical stability of LIB electrodes.展开更多
We present a comprehensive numerical framework for the electrical and optical modeling and simulation of hybrid quantum dot light-emitting diodes(QD-LEDs).We propose a model known as hopping mobility to calculate the ...We present a comprehensive numerical framework for the electrical and optical modeling and simulation of hybrid quantum dot light-emitting diodes(QD-LEDs).We propose a model known as hopping mobility to calculate the carrier mobility in the emissive organic layer doped with quantum dots(QDs).To evaluate the ability of this model to describe the electrical characteristics of QD-LEDs,the measured data of a fabricated QD-LED with different concentrations of QDs in the emissive layer were taken,and the corresponding calculations were performed based on the proposed model.The simulation results indicate that the hopping mobility model can describe the concentration dependence of the electrical behavior of the device.Then,based on the continuity equation for singlet and triplet excitons,the exciton density profiles of the devices with different QD concentrations were extracted.Subsequently,the corresponding luminance characteristics of the devices were calculated,where the results are in good agreement with the experimental data.展开更多
The most widely used method of identification of microbial morphology and structure is microscopy,but it can be difficult to distinguish between pathogens with a similar appearance.Existing fluorescent staining method...The most widely used method of identification of microbial morphology and structure is microscopy,but it can be difficult to distinguish between pathogens with a similar appearance.Existing fluorescent staining methods require a combination of a variety of fluorescent materials to meet this demand.In this study,unique concentration-dependent fluorescent carbon dots(CDs)were synthesized for the identification and quantification of pathogens.The emission wavelength of the CDs could be tuned spanning the full visible region by virtue of aggregation-induced narrowing of bandgaps.This tunable emission wavelength of the specific concentration response to diverse microbes can be used to distinguish microorganisms with a similar appearance,even in a same genus.A hyperspectral microscopy system was demonstrated to distinguish Aspergillus flavus and A.fumigatus based on the results above.The identification accuracy of the two similar-looking pathogens can be close to 100%,and the relative proportions and spatial distributions can also be profiled from the mixture of the pathogens.This technique can provide a solution to the fast detection of microorganisms and is potentially applicable to a wide range of problems in areas such as healthcare,food preparation,biotechnology,and health emergency.展开更多
The on-surface self-assembly of inorganic atomic clusters and organic molecules offers significant opportunities to design novel hybrid materials with tailored functionalities.By adopting the advantages from both inor...The on-surface self-assembly of inorganic atomic clusters and organic molecules offers significant opportunities to design novel hybrid materials with tailored functionalities.By adopting the advantages from both inorganic and organic components,the hybrid self-assembly molecules have shown great potential in future optoelectrical devices.Herein,we report the co-deposition of 4,8-diethynylbenzo[1,2-d-4,5-d0]bisoxazole(DEBBA)and Se atoms to produce a motif-adjustable organic–inorganic hybrid self-assembly system via the non-covalent interactions.By controlling the coverage of Se atoms,various chiral molecular networks containing Se,Se_(6),Se_(8),and terminal alkynes evolved on the Ag(111)surface.In particular,with the highest coverage of Se atoms,phase segregation into alternating one-dimensional chains of non-covalently bonded Se_(8) clusters and organic ligands has been noticed.The atom-coverage dependent evolution of self-assembly structures reflects the remarkable structural adaptability of Se clusters as building blocks based on the spontaneous resize to reach the maximum non-covalent interactions.This work has significantly extended the possibilities of flexible control in self-assembly nanostructures to enable more potential functions for broad applications.展开更多
The rebinding kinetics of an amino acid ligand to ferrous microperoxidase-11 (MP11) after photolysis of aggregated ferrous MP11 was measured in aqueous solution with femtosecond transient visible absorption spectrosco...The rebinding kinetics of an amino acid ligand to ferrous microperoxidase-11 (MP11) after photolysis of aggregated ferrous MP11 was measured in aqueous solution with femtosecond transient visible absorption spectroscopy. The kinetics of CO rebinding to ferrous MP11 after photolysis of MP11CO was also measured in aqueous solution with femtosecond transient visible absorption spectroscopy. From these measurements, we found that either Val-11 or Lys-13 rebinds to ferrous MP11 exponentially with an 8 picosecond time constant in aggregated ferrous MP11 solution and that CO rebinds to ferrous MP11 nonexponentially with subnanosecond time scale in MP11CO solution. The kinetics of both the amino acid and CO rebinding to ferrous MP11 in MP11 system mimics that in carbon monoxide oxidation activator protein (CooA) or carboxymethyl cytochrome c (CmCytC) system. We also measured the kinetics of CO rebinding to ferrous MP11 in aqueous solution at different MP11CO concentrations and found that MP11CO concentration has an obvious effect on the kinetics of CO rebinding to ferrous MP11, where both the germinate yield and rate of CO rebinding to ferrous MP11 increase with the increase of MP11CO concentration. These findings suggested that the picosecond amino acid ligand rebinding process could disturb the proximal heme-ligand structure that possibly leads to the subnanosecond CO rebinding kinetics in MP11CO, CooACO and CmCytCCO systems.展开更多
Chirality and luminescence are important for both chemistry and biology,which are highly influenced by aggregation.In this work,a pair of metalated tetraphenylethylene(TPE)-based organic cage enantiomers are reported,w...Chirality and luminescence are important for both chemistry and biology,which are highly influenced by aggregation.In this work,a pair of metalated tetraphenylethylene(TPE)-based organic cage enantiomers are reported,which fea-ture a quadrangular prismatic cage structure.These homochiral cages exhibit concentration-dependent chiral behaviors alongside a propensity for thermodynamic aggregation.Aggregation caused quench effect is found for these cages accom-panying the increasing of the concentrations.When a poor solvent is added to produce a kinetical aggregation,the aggregation-annihilation circular dichroism and aggregation-induced emission behaviors are observed for these enantiomeric cages.By comparing these observations with the photophysical behaviors of a pair of structurally similar organic molecular enantiomers,the unique photophysical proper-ties observed are intricately linked to the metal-integrated TPE-functionalized cage structures.展开更多
基金supported by NSFC (the National Natural Science Foundation of China) [81273126, 30972454]the Key Project of Guangdong Natural Science Foundation [S2012020010903]+2 种基金the Project of Shenzhen Basic Research Plan [JCYJ20120616 154222545]the Upgrade Scheme of Shenzhen Municipal Key Laboratory [CXB201005260068A]Medical Scientific Research Foundation of Guangdong Province (A2012577)
文摘Trichloroethylene （TCE） is a major pollutant that affects both occupational and general environments. The liver is an important target organ of TCEE. Substantial efforts and remarkable progress into understanding TCE cytotoxicity have been made in cultured liver cells. However, the molecular mechanisms by which TCE induces hepatotoxicity are not well understood. SET （also known as protein phosphatase 2A inhibitor, 12PP2A, or template-activating factor-I, TAF-D is a nuclear protein that regulates histone modification, gene transcription, DNA replication, nucleosome assembly,
基金the National Natural Science Foundation of China(Grant No.11804296)the Joint Key Project of Yunnan Province,China(Grant Nos.2018FY001-020 and 2018ZI002)the Fund from the Educational Department of Yunnan Province,China(Grant No.2016CYH05).
文摘Ray tracing method is used to study the propagation of collimated beams in a liquid-core cylindrical lens(LCL),which has dual functions of diffusion cell and image formation.The diffusion images on the focal plane of the used LCL are simulated by establishing and solving both linear and nonlinear ray equations,the calculated results indicate that the complex imaging results of LCL in inhomogeneous media can be treated by the law of ray propagation in homogeneous media under the condition of small refractive index gradient of diffusion solution.Guided by the calculation conditions,the diffusion process of triethylene glycol aqueous solution is experimentally studied at room temperature by using the LCL in this paper.The spatial and temporal concentration profile Ce(z,t)of diffusion solution is obtained by analyzing diffusion image appearing on the focal plane of the LCL;Then,the concentration-dependent diffusion coefficient is assumed to be a polynomial D(C)=D0×(1+α1C+α2C2+α3C3+…).The finite difference method is used to solve the Fick diffusion equation for calculating numerically the concentration profiles Cn(z,t).The D(C)of triethylene glycol aqueous solution is obtained by comparing the Cn(z,t)with Ce(z,t).Finally,the obtained polynomial D(C)is used to calculate the refractive index profiles nn(z,t)s of diffusion solution in the used LCL.Based on the ray propagation law in inhomogeneous media and the calculated n(z,t),the ray tracing method is used again to simulate the dynamic images of the whole experimental diffusion process to varify the correctness of the calculated D(C).The method presented in this work opens up a new way for both measuring and verifying the concentration-dependent liquid diffusion coefficients.
文摘By incorporating the contribution of solute atoms to the Helmholtz free energy of solid solution,a linear relation is derived between Young's modulus and the concentration of solute atoms.The solute atoms can either increase or decrease Young's modulus of solid solution,depending on the first-order derivative of the Helmholtz free energy with respect to the concentration of solute atoms.Using this relation,a closed-form solution of the chemical stress in an elastic plate is obtained when the diffusion behavior in the plate can be described by the classical Fick's second law with convection boundary condition on one surface and zero flux on the other surface.The plate experiences tensile stress after short diffusion time due to asymmetrical diffusion,which will likely cause surface microcracking.The results show that the effect of the concentration dependence of Young's modulus on the evolution of chemical stress in elastic plates is negligible if the change of Young's modulus due to the diffusive motion of solute atomsis is not compatible in magnitude with Young's modulus of the pure material.Also,a new diffusion equation is developed for strictly regular binary solid solution.The effective diffusivity is a nonlinear function of the concentration of solute atoms.
基金supported by the National Key Research and Development Program of China(Nos.2018YFA0702100 and 2019YFA0210001)National Natural Science Foundation of China(No.U21A2054 and 52072234)K.Guo acknowledges the support from Key Discipline of Materials Science and Engineering,Bureau of Education of Guangzhou(No.202255464)。
文摘Large Seebeck coefficients induced by high degeneracy of conduction band minimum,and low intrinsic lattice thermal conductivity originated from large lattice vibrational anharmonicity render Mg_(3)Sb_(2)as a promising n-type thermoelectric material.Herein,we demonstrated unique concentration-dependent occupation behaviors of Cu in Mg_(3.4)Sb_(1.5)Bi_(0.49)Te_(0.01)matrix,evidenced by structural characterization and transport property measurements.It is found that Cu atoms prefer to enter the interstitial lattice sites in Mg_(3)Sb_(2)host with low doping level(Mg_(3.4)Sb_(1.5)Bi_(0.49)Te_(0.01)+x%Cu,x<0.3%),acting as donors for providing additional electrons without deteriorating the carrier mobility.When x is larger than 0.3%,the excessive Cu atoms are inclined to substitute Mg atoms,yielding acceptors to decrease the electron concentration.As a result,the electrical conductivity of the Mg_(3.4)Sb_(1.5)Bi_(0.49)Te_(0.01)+0.3%Cu sample reaches 2.3×10^(4)S/m at 300 K,increasing by 300%compared with that of the pristine sample.The figure of merit zT values in the whole measured temperature range are significantly improved by the synergetic improvement of power factor and reduction of thermal conductivity.An average zT∼1.07 from 323 K to 773 K has been achieved for the Mg_(3.4)Sb_(1.5)Bi_(0.49)Te_(0.01)+0.3%Cu sample,which is about 30%higher than that of the Mg_(3.4)Sb_(1.5)Bi_(0.49)Te_(0.01) sample.
基金supported by the National Natural Science Foundation of China(grant numbers 91844000 and 41421064)the China Postdoctoral Science Foundation(grant number 2022M720232).
文摘The impact of reductive pulmonary inhalants on ultrafine particles(UFPs)-induced pulmonary oxidative stress remains a crucial consideration,yet the concentration-dependent effects of these inhalants have remained unexplored.Here we synthesized composite UFPs simulating atmospheric UFPs,primarily composed of metals and quinones.We subjected these UFPs to varying concentrations(0e7000 mM)of two reductive pulmonary inhalants,N-acetylcysteine and salbutamol,to assess their influence on oxidative potential,measured through the dithiothreitol assay(OP^(DTT)).Simultaneously,we analysed the soluble metal content of UFPs to uncover potential relationships between oxidative potential and metal solubility.Our results unveil a dual role played by these inhalants in shaping the OPDTT of composite UFPs.Specifically,OP^(DTT) generally increased as inhalant concentrations rose from 0 to 300 mM.However,an intriguing reversal occurred when concentrations exceeded 500 mM,resulting in a decline in OPDTT.Relative to untreated UFPs,these inhalants induced promotion and inhibition effects within concentration ranges of 100e500 and>1000 mM,respectively.While no significant correlation emerged between OP^(DTT) and soluble metal content as inhalant concentrations ranged from 0 to 7000 mM,noteworthy positive correlations emerged at lower inhalant concentrations(e.g.,N-acetylcysteine at 0 e300 mM).These findings provide insights into the potential influence of reductive pulmonary inhalants on health risks associated with UFP exposure,further underscoring the need for continued research in this critical area.
基金the National Natural Science Foundation of China(Nos.12072183,11872236 and 12172205)。
文摘Prelithiation has been intensively investigated in high-capacity lithiumion batteries(LIBs).However,the optimization of prelithiation degrees for long service life of LIBs still remains a challenge.The positive effect of prelithiation on suppressing degradation of LIBs,besides directly pursuing the high first Coulomb efficiency which has been widely reported in the literature,is revealed and discussed based on an analytical model focusing on the interfacial delamination in electrodes.For full charge-discharge cycling,well-designed prelithiation can effectively suppress the delamination and reduce the debonding size by approximately 25%,compared with the case without prelithiation.For the strategy combining partial charge-discharge cycling and prelithiation,the largest reversible capacity without debonding can be significantly improved by approximately100%with well-designed prelithiation.This work is expected to provide a prelithiation design principle and further improve the mechanical stability of LIB electrodes.
文摘We present a comprehensive numerical framework for the electrical and optical modeling and simulation of hybrid quantum dot light-emitting diodes(QD-LEDs).We propose a model known as hopping mobility to calculate the carrier mobility in the emissive organic layer doped with quantum dots(QDs).To evaluate the ability of this model to describe the electrical characteristics of QD-LEDs,the measured data of a fabricated QD-LED with different concentrations of QDs in the emissive layer were taken,and the corresponding calculations were performed based on the proposed model.The simulation results indicate that the hopping mobility model can describe the concentration dependence of the electrical behavior of the device.Then,based on the continuity equation for singlet and triplet excitons,the exciton density profiles of the devices with different QD concentrations were extracted.Subsequently,the corresponding luminance characteristics of the devices were calculated,where the results are in good agreement with the experimental data.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.61935010,61975069,21905253,and 51973200)the China Postdoctoral Science Foundation(Nos.2018M640681 and 2019T120632)+5 种基金the Natural Science Foundation of Henan(No.202300410372)Key-Area Research and Development Program of Guangdong Province(No.2020B090922006)Guangdong Project of Science and Technology Grants(No.2018B030323017)Guangzhou science and technology project(Nos.201903010042 and 201904010294)Youth project of science and technology research program of Chongqing Education Commission of China(No.KJQN202001322)the Science and Technology Development Fund from Macao SAR(File Nos.0125/2018/A3 and 0071/2019/AMJ).
文摘The most widely used method of identification of microbial morphology and structure is microscopy,but it can be difficult to distinguish between pathogens with a similar appearance.Existing fluorescent staining methods require a combination of a variety of fluorescent materials to meet this demand.In this study,unique concentration-dependent fluorescent carbon dots(CDs)were synthesized for the identification and quantification of pathogens.The emission wavelength of the CDs could be tuned spanning the full visible region by virtue of aggregation-induced narrowing of bandgaps.This tunable emission wavelength of the specific concentration response to diverse microbes can be used to distinguish microorganisms with a similar appearance,even in a same genus.A hyperspectral microscopy system was demonstrated to distinguish Aspergillus flavus and A.fumigatus based on the results above.The identification accuracy of the two similar-looking pathogens can be close to 100%,and the relative proportions and spatial distributions can also be profiled from the mixture of the pathogens.This technique can provide a solution to the fast detection of microorganisms and is potentially applicable to a wide range of problems in areas such as healthcare,food preparation,biotechnology,and health emergency.
基金the Guangdong Basic and Applied Basic Research Foundation(Nos.2019A1515110819 and 2020A1515010767)NRF-CRP grant“Two Dimensional Covalent Organic Framework:Synthesis and Applications”(No.NRF-CRP16-2015-02,funded by National Research Foundation,Prime Minister’s Office,Singapore)+1 种基金the Shenzhen Peacock Plan(No.KQTD2016053112042971)the National Natural Science Foundation of China(Nos.21802067 and 21771156).
文摘The on-surface self-assembly of inorganic atomic clusters and organic molecules offers significant opportunities to design novel hybrid materials with tailored functionalities.By adopting the advantages from both inorganic and organic components,the hybrid self-assembly molecules have shown great potential in future optoelectrical devices.Herein,we report the co-deposition of 4,8-diethynylbenzo[1,2-d-4,5-d0]bisoxazole(DEBBA)and Se atoms to produce a motif-adjustable organic–inorganic hybrid self-assembly system via the non-covalent interactions.By controlling the coverage of Se atoms,various chiral molecular networks containing Se,Se_(6),Se_(8),and terminal alkynes evolved on the Ag(111)surface.In particular,with the highest coverage of Se atoms,phase segregation into alternating one-dimensional chains of non-covalently bonded Se_(8) clusters and organic ligands has been noticed.The atom-coverage dependent evolution of self-assembly structures reflects the remarkable structural adaptability of Se clusters as building blocks based on the spontaneous resize to reach the maximum non-covalent interactions.This work has significantly extended the possibilities of flexible control in self-assembly nanostructures to enable more potential functions for broad applications.
基金financially supported by the National Natural Science Foundation of China (20603047, 20733001)the Fundamental Research Funds for the Central Universitiesthe Research Funds of Renmin University of China (10XNJ047)
文摘The rebinding kinetics of an amino acid ligand to ferrous microperoxidase-11 (MP11) after photolysis of aggregated ferrous MP11 was measured in aqueous solution with femtosecond transient visible absorption spectroscopy. The kinetics of CO rebinding to ferrous MP11 after photolysis of MP11CO was also measured in aqueous solution with femtosecond transient visible absorption spectroscopy. From these measurements, we found that either Val-11 or Lys-13 rebinds to ferrous MP11 exponentially with an 8 picosecond time constant in aggregated ferrous MP11 solution and that CO rebinds to ferrous MP11 nonexponentially with subnanosecond time scale in MP11CO solution. The kinetics of both the amino acid and CO rebinding to ferrous MP11 in MP11 system mimics that in carbon monoxide oxidation activator protein (CooA) or carboxymethyl cytochrome c (CmCytC) system. We also measured the kinetics of CO rebinding to ferrous MP11 in aqueous solution at different MP11CO concentrations and found that MP11CO concentration has an obvious effect on the kinetics of CO rebinding to ferrous MP11, where both the germinate yield and rate of CO rebinding to ferrous MP11 increase with the increase of MP11CO concentration. These findings suggested that the picosecond amino acid ligand rebinding process could disturb the proximal heme-ligand structure that possibly leads to the subnanosecond CO rebinding kinetics in MP11CO, CooACO and CmCytCCO systems.
基金National Natural Science Foundation of China,Grant/Award Numbers:22375075,22171106,21731002,21975104,22301103,22201101Guangdong Major Project of Basic and Applied Research,Grant/Award Number:2019B030302009+4 种基金Natural Science Foundation of Guangdong Province,Grant/Award Number:2022A1515011937Fundamental Research Funds for the Central Universities,Grant/Award Number:21622103China Postdoctoral Science Foundation,Grant/Award Numbers:2022M711327,2023T160269Guangdong Provincial Key Laboratory of Speed Capability Research,Grant/Award Number:2023B1212010009Jinan University。
文摘Chirality and luminescence are important for both chemistry and biology,which are highly influenced by aggregation.In this work,a pair of metalated tetraphenylethylene(TPE)-based organic cage enantiomers are reported,which fea-ture a quadrangular prismatic cage structure.These homochiral cages exhibit concentration-dependent chiral behaviors alongside a propensity for thermodynamic aggregation.Aggregation caused quench effect is found for these cages accom-panying the increasing of the concentrations.When a poor solvent is added to produce a kinetical aggregation,the aggregation-annihilation circular dichroism and aggregation-induced emission behaviors are observed for these enantiomeric cages.By comparing these observations with the photophysical behaviors of a pair of structurally similar organic molecular enantiomers,the unique photophysical proper-ties observed are intricately linked to the metal-integrated TPE-functionalized cage structures.
