Aggregation-induced thermally activated delayed fluorescence(TADF)phenomena have attracted extensive attention recently.In this paper,several theoretical models including monomer,dimer,and complex are used for the exp...Aggregation-induced thermally activated delayed fluorescence(TADF)phenomena have attracted extensive attention recently.In this paper,several theoretical models including monomer,dimer,and complex are used for the explanation of the luminescent properties of(R)-5-(9H-carbazol-9-yl)-2-(1,2,3,4-tetrahydronaphthalen-1-yl)isoindoline-1,3-dione((R)-ImNCz),which was recently reported[Chemical Engineering Journal 418129167(2021)].The polarizable continuum model(PCM)and the combined quantum mechanics and molecular mechanics(QM/MM)method are adopted in simulation of the property of the molecule in the gas phase,solvated in acetonitrile and in aggregation states.It is found that large spin–orbit coupling(SOC)constants and a smaller energy gap between the first singlet excited state and the first triplet excited state(△E_(st))in prism-like single crystals(SC_(p)-form)are responsible for the TADF of(R)-lmNCz,while no TADF is found in block-like single crystals(SC_(b)-form)with a larger △E_(st).The multiple ultralong phosphorescence(UOP)peaks in the spectrum are of complex origins,and they are related not only to ImNCz but also to a minor amount of impurities(ImNBd)in the crystal prepared in the laboratory.The dimer has similar phosphorescence emission wavelengths to the(R)-lmNCz-SC_(p) monomers.The complex composed of(R)-lmNCz and(R)-lmNBd contributes to the phosphorescent emission peak at about 600 nm,and the phosphorescent emission peak at about 650 nm is generated by(R)-lmNBd.This indicates that the impurity could also contribute to emission in molecular crystals.The present calculations clarify the relationship between the molecular aggregation and the light-emitting properties of the TADF emitters and will therefore be helpful for the design of potentially more useful TADF emitters.展开更多
We propose a catalytically activated duplication model to mimic the coagulation and duplication of the DNA polymer system under the catalysis of the primer RNA. In the model, two aggregates of the same species can coa...We propose a catalytically activated duplication model to mimic the coagulation and duplication of the DNA polymer system under the catalysis of the primer RNA. In the model, two aggregates of the same species can coagulate themselves and a DNA aggregate of any size can yield a new monomer or double itself with the help of RNA aggregates. By employing the mean-field rate equation approach we analytically investigate the evolution behaviour of the system. For the system with catalysis-driven monomer duplications, the aggregate size distribution of DNA polymers αk（t） always follows a power law in size in the long-time limit, and it decreases with time or approaches a time-independent steady-state form in the case of the duplication rate independent of the size of the mother aggregates, while it increases with time increasing in the case of the duplication rate proportional to the size of the mother aggregates. For the system with complete catalysis-driven duplications, the aggregate size distribution αk（t） approaches a generalized or modified scaling form.展开更多
We propose a catalytically activated aggregation-fragmentation model of three species, in which two clusters of species A can coagulate into a larger one under the catalysis of B clusters; otherwise, one cluster of sp...We propose a catalytically activated aggregation-fragmentation model of three species, in which two clusters of species A can coagulate into a larger one under the catalysis of B clusters; otherwise, one cluster of species A will fragment into two smaller clusters under the catalysis of C clusters. By means of mean-field rate equations, we derive the asymptotic solutions of the cluster-mass distributions ak（t） of species A, which is found to depend strongly on the competition between the catalyzed aggregation process and the catalyzed fragmentation process. When the catalyzed aggregation process dominates the system, the cluster-mass distribution ak（t） satisfies the conventional scaling form. When the catalyzed fragmentation process dominates the system, the scaling description of ak （t） breaks down completely and the monodisperse initial condition of species A would not be changed in the long-time limit. In the marginal case when the effects of catalyzed aggregation and catalyzed fragmentation counteract each other, ak（t） takes the modified scaling form and the system can eventually evolve to a steady state.展开更多
Two series of novel derivatives of4,5,6,7-tetrahydrothieno [3,2-c]pyridine were synthesized and structurally characterized by 1^H NMR and MS. Their in vivo antiplatelet aggregation activities were evaluated.
Antimicrobial peptides(AMPs)are potentially powerful alternatives to conven-tional antibiotics in combating multidrug resistance,given their broad spectrum of activity.They mainly interact with cell membranes through ...Antimicrobial peptides(AMPs)are potentially powerful alternatives to conven-tional antibiotics in combating multidrug resistance,given their broad spectrum of activity.They mainly interact with cell membranes through surface electrostatic potentials and the formation of secondary structures,resulting in permeability and destruction of target microorganism membranes.Our earlier work showed that two leading AMPs,MSI-78(4–20)and pardaxin(1–22),had potent antimicrobial activ-ity against a range of bacteria.It is known that the attachment of moderate-length lipid carbon chains to cationic peptides can further improve the functionality of these peptides through enhanced interactions with the membrane lipid bilayer,inducing membrane curvature,destabilization,and potential leakage.Thus,in this work,we aimed to investigate the antimicrobial activity,oligomerization propensity,and lipid-membrane binding interactions of a range of N-terminal lipidated analogs of MSI-78(4–20)and pardaxin(1–22).Molecular modeling results suggest that aggregation of the N-lipidated AMPs may impart greater structural stability to the peptides in solu-tion and a greater depth of lipid bilayer insertion for the N-lipidated AMPs over the parental peptide.Our experimental and computationalfindings provide insights into how N-terminal lipidation of AMPs may alter their conformations,with subsequent effects on their functional properties in regard to their self-aggregation behavior,membrane interactions,and antimicrobial activity.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11974216,11874242,21933002 and 11904210)Shandong Provincial Natural Science Foundation,China(Grant No.ZR2019MA056)+1 种基金the support of the Taishan Scholar Project of Shandong Provincethe project funded by China Postdoctoral Science Foundation(Grant No.2018M642689)。
文摘Aggregation-induced thermally activated delayed fluorescence(TADF)phenomena have attracted extensive attention recently.In this paper,several theoretical models including monomer,dimer,and complex are used for the explanation of the luminescent properties of(R)-5-(9H-carbazol-9-yl)-2-(1,2,3,4-tetrahydronaphthalen-1-yl)isoindoline-1,3-dione((R)-ImNCz),which was recently reported[Chemical Engineering Journal 418129167(2021)].The polarizable continuum model(PCM)and the combined quantum mechanics and molecular mechanics(QM/MM)method are adopted in simulation of the property of the molecule in the gas phase,solvated in acetonitrile and in aggregation states.It is found that large spin–orbit coupling(SOC)constants and a smaller energy gap between the first singlet excited state and the first triplet excited state(△E_(st))in prism-like single crystals(SC_(p)-form)are responsible for the TADF of(R)-lmNCz,while no TADF is found in block-like single crystals(SC_(b)-form)with a larger △E_(st).The multiple ultralong phosphorescence(UOP)peaks in the spectrum are of complex origins,and they are related not only to ImNCz but also to a minor amount of impurities(ImNBd)in the crystal prepared in the laboratory.The dimer has similar phosphorescence emission wavelengths to the(R)-lmNCz-SC_(p) monomers.The complex composed of(R)-lmNCz and(R)-lmNBd contributes to the phosphorescent emission peak at about 600 nm,and the phosphorescent emission peak at about 650 nm is generated by(R)-lmNBd.This indicates that the impurity could also contribute to emission in molecular crystals.The present calculations clarify the relationship between the molecular aggregation and the light-emitting properties of the TADF emitters and will therefore be helpful for the design of potentially more useful TADF emitters.
基金supported by the National Natural Science Foundation of China (Grant Nos 10275048,10305009 and 10875086)by the Zhejiang Provincial Natural Science Foundation of China (Grant No 102067)
文摘We propose a catalytically activated duplication model to mimic the coagulation and duplication of the DNA polymer system under the catalysis of the primer RNA. In the model, two aggregates of the same species can coagulate themselves and a DNA aggregate of any size can yield a new monomer or double itself with the help of RNA aggregates. By employing the mean-field rate equation approach we analytically investigate the evolution behaviour of the system. For the system with catalysis-driven monomer duplications, the aggregate size distribution of DNA polymers αk（t） always follows a power law in size in the long-time limit, and it decreases with time or approaches a time-independent steady-state form in the case of the duplication rate independent of the size of the mother aggregates, while it increases with time increasing in the case of the duplication rate proportional to the size of the mother aggregates. For the system with complete catalysis-driven duplications, the aggregate size distribution αk（t） approaches a generalized or modified scaling form.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.10275048 and 10875086)by the Science Foundation of Shihezi University (Grant No.RCZX200745)
文摘We propose a catalytically activated aggregation-fragmentation model of three species, in which two clusters of species A can coagulate into a larger one under the catalysis of B clusters; otherwise, one cluster of species A will fragment into two smaller clusters under the catalysis of C clusters. By means of mean-field rate equations, we derive the asymptotic solutions of the cluster-mass distributions ak（t） of species A, which is found to depend strongly on the competition between the catalyzed aggregation process and the catalyzed fragmentation process. When the catalyzed aggregation process dominates the system, the cluster-mass distribution ak（t） satisfies the conventional scaling form. When the catalyzed fragmentation process dominates the system, the scaling description of ak （t） breaks down completely and the monodisperse initial condition of species A would not be changed in the long-time limit. In the marginal case when the effects of catalyzed aggregation and catalyzed fragmentation counteract each other, ak（t） takes the modified scaling form and the system can eventually evolve to a steady state.
文摘Two series of novel derivatives of4,5,6,7-tetrahydrothieno [3,2-c]pyridine were synthesized and structurally characterized by 1^H NMR and MS. Their in vivo antiplatelet aggregation activities were evaluated.
基金The National Health and Medical Research Council,Grant/Award Numbers:APP2018256,APP1142472,APP1158841,APP1185426Australian Research Council,Grant/Award Numbers:FT210100271,DP210102781,DP160101312,LE200100163+5 种基金Cancer Council Victoria funding,Grant/Award Number:APP1163284Australia-China Science and Research Fund-Joint Research Centre on Personal Health Technologies,Grant/Award Number:ACSRF65777Australian Dental Research Foundation GrantPawsey Supercomputing CentreNational Computational InfrastructureAustralian National Fabrication Facility,Grant/Award Number:VictorianNode。
文摘Antimicrobial peptides(AMPs)are potentially powerful alternatives to conven-tional antibiotics in combating multidrug resistance,given their broad spectrum of activity.They mainly interact with cell membranes through surface electrostatic potentials and the formation of secondary structures,resulting in permeability and destruction of target microorganism membranes.Our earlier work showed that two leading AMPs,MSI-78(4–20)and pardaxin(1–22),had potent antimicrobial activ-ity against a range of bacteria.It is known that the attachment of moderate-length lipid carbon chains to cationic peptides can further improve the functionality of these peptides through enhanced interactions with the membrane lipid bilayer,inducing membrane curvature,destabilization,and potential leakage.Thus,in this work,we aimed to investigate the antimicrobial activity,oligomerization propensity,and lipid-membrane binding interactions of a range of N-terminal lipidated analogs of MSI-78(4–20)and pardaxin(1–22).Molecular modeling results suggest that aggregation of the N-lipidated AMPs may impart greater structural stability to the peptides in solu-tion and a greater depth of lipid bilayer insertion for the N-lipidated AMPs over the parental peptide.Our experimental and computationalfindings provide insights into how N-terminal lipidation of AMPs may alter their conformations,with subsequent effects on their functional properties in regard to their self-aggregation behavior,membrane interactions,and antimicrobial activity.
