Plasmon-induced hot-electron transfer from metal nanostructures is being intensely pursed in current photocatalytic research,however it remains elusive whether molecular-like metal clusters with excitonic behavior can...Plasmon-induced hot-electron transfer from metal nanostructures is being intensely pursed in current photocatalytic research,however it remains elusive whether molecular-like metal clusters with excitonic behavior can be used as light-harvesting materials in solar energy utilization such as photocatalytic methanol steam reforming.In this work,we report an atomically precise Cu_(13)cluster protected by dual ligands of thiolate and phosphine that can be viewed as the assembly of one top Cu atom and three Cu_(4)tetrahedra.The Cu_(13)H_(10)(SR)_(3)(PR’_(3))_(7)(SR=2,4-dichlorobenzenethiol,PR’_(3)=P(4-FC_(6)H_(4))_(3))cluster can give rise to highly efficient light-driven activity for methanol steam reforming toward H_(2)production.展开更多
It remains elusive to realize the distinct catalysis of isomeric catalysts because it becomes challenging to identify structural isomers in the polydisperse nanoparticles.Herein we investigate catalysis of two geometr...It remains elusive to realize the distinct catalysis of isomeric catalysts because it becomes challenging to identify structural isomers in the polydisperse nanoparticles.Herein we investigate catalysis of two geometric isomers for 36-gold-atom nanoclusters with different Au cores arrangements but the same thiolate ligands,thereby providing access to isomer catalysts readily participate in a desired reaction.Compared to the Au_(36)(SR)_(24)with a one-dimensional(1D)layout of Au4 tetrahedral units,the Au_(36)(SR)_(24)with a two-dimensional(2D)layout of Au4 tetrahedral units is more effective for the intramolecular hydroamination of alkyne.Our study suggests that the exposed Au sties of the two Au_(36)(SR)_(24)catalysts favor different reaction intermediates and pathways.The intramolecular H transfer leads to intermediates with the C-N and with C=N for the 1D and 2D Au_(36)(SR)_(24)respectively,and hence the different on-site and off-site pathways for the successive reaction steps account for the different performances of the two Au_(36)(SR)_(24)catalysts.展开更多
With advances in cluster chemistry,atomically precise gold nanoclusters(NCs)with well-defined composition and tunable structure provide an exciting opportunity to uncover the specific roles of the geometrical and elec...With advances in cluster chemistry,atomically precise gold nanoclusters(NCs)with well-defined composition and tunable structure provide an exciting opportunity to uncover the specific roles of the geometrical and electronic structures as well as the capped ligands in overall catalytic performances.The Au NCs possess quantum energy levels and unique optical properties,which have exhibited unexpected photocatalytic and electrocatalytic activities.In this review,we first highlight the electrocatalytic applications of Au NCs,including hydrogen evolution reaction,oxygen reduction reaction,CO_2 reduction and catalytic oxidation reactions,and then present Au NCs-driven photocatalytic applications such as selective organic reactions,decomposition of pollutants and energy conversion reactions.Finally,we conclude this review with a brief perspective on the catalytic field of Au NCs.展开更多
Background:Diabetes significantly delays wound healing through oxidative stress,inflammation and impaired re-epithelialization that lead to defective regulation of the healing process,although the related mechanism re...Background:Diabetes significantly delays wound healing through oxidative stress,inflammation and impaired re-epithelialization that lead to defective regulation of the healing process,although the related mechanism remains unclear.Here,we aim to investigate the potential role and mechanism for the beneficial effect of betulinic acid(BA)on diabetic wound healing.Methods:The molecular effect of BA on hyperglycemia-mediated gene expression,oxidative stress,inflammation and glucose uptake was evaluated in endothelial,fibroblast and muscle cells.Burn injury was introduced to streptozotocin-induced diabetic rats and BA administration through either an intraperitoneal(IP)or topical(TOP)technique was used for wound treatment.Glucose tolerance was evaluated in both muscle tissue and fibroblasts,while oxidative stress and inflammation were determined in both the circulatory system and in wound tissues.The effect of BA on the wound healing process was also evaluated.Results:BA treatment reversed hyperglycemia-induced glucose transporter type 4(GLUT4)sup-pression in both muscle and fibroblast cells.This treatment also partly reversed hyperglycemia-mediated suppression of endothelial nitric oxide synthase(eNOS),nuclear factor erythroid 2-related factor 2(Nrf2)signaling and nuclear factor NFκB p65 subunit(NFκB p65)activation in endothelial cells.An in vivo rat study showed that BA administration ameliorated diabetes-mediated glucose intolerance and partly attenuated diabetes-mediated oxidative stress and inflam-mation in both the circulatory system and wound tissues.BA administration by both IP and TOP techniques significantly accelerated diabetic wound healing,while BA administration by either IP or TOP methods alone had a significantly lower effect.Conclusions:BA treatment ameliorates hyperglycemia-mediated glucose intolerance,endothelial dysfunction,oxidative stress and inflammation.Administration of BA by both IP and TOP tech-niques was found to significantly accelerate diabetic wound healing,indicating that BA could be a potential therapeutic candidate for diabetic wound healing.展开更多
Background:Delayed wound healing is one of the major complications of diabetes mellitus and is characterized by prolonged inflammation,delayed re-epithelialization and consistent oxidative stress,although the detailed...Background:Delayed wound healing is one of the major complications of diabetes mellitus and is characterized by prolonged inflammation,delayed re-epithelialization and consistent oxidative stress,although the detailed mechanism remains unknown.In this study,we aimed to investigate the potential role and effect of pterostilbene(PTE)and hematopoietic stem cells(HSCs)on diabetic wound healing.Methods:Diabetic rats were used to measure the epigenetic changes in both HSCs and peripheral blood mononuclear cells(PBMCs).A cutaneous burn injury was induced in the rats and PTE-treated diabetic HSCs were transplanted for evaluation of wound healing.In addition,several biomedical parameters,including gene expression,oxidative stress,mitochondrial function and inflammation in macrophages,were also measured.Results:Our data showed that PTE had a much stronger effect than resveratrol on accelerating diabetic wound healing,likely because PTE can ameliorate diabetes-induced epigenetic changes to estrogen receptorβpromoter in HSCs,while resveratrol cannot.Further investigation showed that bone marrow transplantation of PTE-treated diabetic HSCs restores diabetes-induced suppression of estrogen receptorβand its target genes,including nuclear respiratory factor-1 and superoxide dismutase 2,and protects against diabetes-induced oxidative stress,mitochondrial dysfunction and elevated pro-inflammatory cytokines in both PBMCs and macrophages,subsequently accelerating cutaneous wound healing.Conclusions:HSC may play an important role in wound healing through transferring epigenetic modifications to subsequent PBMCs and macrophages by differentiation,while PTE accelerates diabetic wound healing by modulating diabetes-induced epigenetic changes in HSCs.Thus,PTE may be a novel therapeutic strategy for diabetic wound healing.展开更多
Metal nanoclusters with accurate compositions and precise crystalline structures hold remarkable attention in serving as a unique model catalyst for well-defined correlations between structure and catalytic activity.M...Metal nanoclusters with accurate compositions and precise crystalline structures hold remarkable attention in serving as a unique model catalyst for well-defined correlations between structure and catalytic activity.More importantly,these metal nanoclusters exhibit strong quantum confinement effects,which differ from their larger nanoparticles in a number of catalytic reactions.This review focuses on recent advances of atomically precise metal nanoclusters for C_(1) compound conversion(C_(O),CO_(2),CH_(4),and HCOOH),including thermally-driven catalysis,photocatalysis,and electrocatalysis.The reaction mechanisms are discussed at an atomic-or even electron-level.It is anticipated that the progress in this research area could be extended to catalytic applications of metal nanoclusters in C_(1) chemistry.展开更多
The structure-dependent catalytic behavior is one of the most important issues in catalysis science.However,it has not been fully understood how different types of atom-packing structures of heterogeneous catalysts pr...The structure-dependent catalytic behavior is one of the most important issues in catalysis science.However,it has not been fully understood how different types of atom-packing structures of heterogeneous catalysts precisely impact the reaction sites and pathways.Here we investigate a periodic series of Au_(8n+4)(TBBT)_(4n+8 )nanoclusters with layer-by-layer structural pattern to catalyze CO_(2) hydrogenation(where n=3–6 is the number of(001)layers;TBBT=4-tert-butyl-benzenethiolate).An encouraging evolution of CO_(2) conversion can be identified:The product selectivity from methanol,formic acid to ethanol can be switched by the structure-dependent deformation from the flattened,perfect,to elongated cuboids in Au_(8n+4)(TBBT)_(4n+8).Through a combined study of experiment and theory,we demonstrate that the variation in structural patterns of catalysts can exclusively tune their adsorption strength with reaction intermediates and further control the CO_(2) conversion toward the different products.展开更多
It remains an extreme challenge to activate thermodynamically unfavorable,chemically inert methane molecules under mild conditions.Herein,we report a molecular-like nickel-thiolate hexameric cluster[Ni_(6)(PET)_(12);P...It remains an extreme challenge to activate thermodynamically unfavorable,chemically inert methane molecules under mild conditions.Herein,we report a molecular-like nickel-thiolate hexameric cluster[Ni_(6)(PET)_(12);PET=SC_(2)H_(4)Ph]catalyst that resembles a double crown,comprising of a hexagonal Ni6 kernel encapsulated by an exterior shell of 12 thiolates capable of efficient conversion of methane plus O_(2) to methanol and formic acid under visible light irradiation.展开更多
基金financial support from National Natural Science Foundation of China(22125202,21932004,22101128)Natural Science Foundation of Jiangsu Province(BK20220033)。
文摘Plasmon-induced hot-electron transfer from metal nanostructures is being intensely pursed in current photocatalytic research,however it remains elusive whether molecular-like metal clusters with excitonic behavior can be used as light-harvesting materials in solar energy utilization such as photocatalytic methanol steam reforming.In this work,we report an atomically precise Cu_(13)cluster protected by dual ligands of thiolate and phosphine that can be viewed as the assembly of one top Cu atom and three Cu_(4)tetrahedra.The Cu_(13)H_(10)(SR)_(3)(PR’_(3))_(7)(SR=2,4-dichlorobenzenethiol,PR’_(3)=P(4-FC_(6)H_(4))_(3))cluster can give rise to highly efficient light-driven activity for methanol steam reforming toward H_(2)production.
基金supports from Fundamental Research Funds for the Central Universities,Programs for high-level entrepreneurial and innovative talents introduction of Jiangsu Province,and Scientific and Technological Innovation Foundation of Shunde Graduate School of USTB(No.BK19BE024).
文摘It remains elusive to realize the distinct catalysis of isomeric catalysts because it becomes challenging to identify structural isomers in the polydisperse nanoparticles.Herein we investigate catalysis of two geometric isomers for 36-gold-atom nanoclusters with different Au cores arrangements but the same thiolate ligands,thereby providing access to isomer catalysts readily participate in a desired reaction.Compared to the Au_(36)(SR)_(24)with a one-dimensional(1D)layout of Au4 tetrahedral units,the Au_(36)(SR)_(24)with a two-dimensional(2D)layout of Au4 tetrahedral units is more effective for the intramolecular hydroamination of alkyne.Our study suggests that the exposed Au sties of the two Au_(36)(SR)_(24)catalysts favor different reaction intermediates and pathways.The intramolecular H transfer leads to intermediates with the C-N and with C=N for the 1D and 2D Au_(36)(SR)_(24)respectively,and hence the different on-site and off-site pathways for the successive reaction steps account for the different performances of the two Au_(36)(SR)_(24)catalysts.
基金supported by the National Natural Science Foundation of China(21773109,91845104)。
文摘With advances in cluster chemistry,atomically precise gold nanoclusters(NCs)with well-defined composition and tunable structure provide an exciting opportunity to uncover the specific roles of the geometrical and electronic structures as well as the capped ligands in overall catalytic performances.The Au NCs possess quantum energy levels and unique optical properties,which have exhibited unexpected photocatalytic and electrocatalytic activities.In this review,we first highlight the electrocatalytic applications of Au NCs,including hydrogen evolution reaction,oxygen reduction reaction,CO_2 reduction and catalytic oxidation reactions,and then present Au NCs-driven photocatalytic applications such as selective organic reactions,decomposition of pollutants and energy conversion reactions.Finally,we conclude this review with a brief perspective on the catalytic field of Au NCs.
基金supported by The National Natural Science Foundation of China,Project#:81772097Revival Program of Growth Factors,Project#:SZYZ-TR-10.
文摘Background:Diabetes significantly delays wound healing through oxidative stress,inflammation and impaired re-epithelialization that lead to defective regulation of the healing process,although the related mechanism remains unclear.Here,we aim to investigate the potential role and mechanism for the beneficial effect of betulinic acid(BA)on diabetic wound healing.Methods:The molecular effect of BA on hyperglycemia-mediated gene expression,oxidative stress,inflammation and glucose uptake was evaluated in endothelial,fibroblast and muscle cells.Burn injury was introduced to streptozotocin-induced diabetic rats and BA administration through either an intraperitoneal(IP)or topical(TOP)technique was used for wound treatment.Glucose tolerance was evaluated in both muscle tissue and fibroblasts,while oxidative stress and inflammation were determined in both the circulatory system and in wound tissues.The effect of BA on the wound healing process was also evaluated.Results:BA treatment reversed hyperglycemia-induced glucose transporter type 4(GLUT4)sup-pression in both muscle and fibroblast cells.This treatment also partly reversed hyperglycemia-mediated suppression of endothelial nitric oxide synthase(eNOS),nuclear factor erythroid 2-related factor 2(Nrf2)signaling and nuclear factor NFκB p65 subunit(NFκB p65)activation in endothelial cells.An in vivo rat study showed that BA administration ameliorated diabetes-mediated glucose intolerance and partly attenuated diabetes-mediated oxidative stress and inflam-mation in both the circulatory system and wound tissues.BA administration by both IP and TOP techniques significantly accelerated diabetic wound healing,while BA administration by either IP or TOP methods alone had a significantly lower effect.Conclusions:BA treatment ameliorates hyperglycemia-mediated glucose intolerance,endothelial dysfunction,oxidative stress and inflammation.Administration of BA by both IP and TOP tech-niques was found to significantly accelerate diabetic wound healing,indicating that BA could be a potential therapeutic candidate for diabetic wound healing.
基金supported by the National Natural Science Foundation of China Project(81772097)the National Key Disease Preventive Project for Wound Healing(2018-ZX-01S-001).
文摘Background:Delayed wound healing is one of the major complications of diabetes mellitus and is characterized by prolonged inflammation,delayed re-epithelialization and consistent oxidative stress,although the detailed mechanism remains unknown.In this study,we aimed to investigate the potential role and effect of pterostilbene(PTE)and hematopoietic stem cells(HSCs)on diabetic wound healing.Methods:Diabetic rats were used to measure the epigenetic changes in both HSCs and peripheral blood mononuclear cells(PBMCs).A cutaneous burn injury was induced in the rats and PTE-treated diabetic HSCs were transplanted for evaluation of wound healing.In addition,several biomedical parameters,including gene expression,oxidative stress,mitochondrial function and inflammation in macrophages,were also measured.Results:Our data showed that PTE had a much stronger effect than resveratrol on accelerating diabetic wound healing,likely because PTE can ameliorate diabetes-induced epigenetic changes to estrogen receptorβpromoter in HSCs,while resveratrol cannot.Further investigation showed that bone marrow transplantation of PTE-treated diabetic HSCs restores diabetes-induced suppression of estrogen receptorβand its target genes,including nuclear respiratory factor-1 and superoxide dismutase 2,and protects against diabetes-induced oxidative stress,mitochondrial dysfunction and elevated pro-inflammatory cytokines in both PBMCs and macrophages,subsequently accelerating cutaneous wound healing.Conclusions:HSC may play an important role in wound healing through transferring epigenetic modifications to subsequent PBMCs and macrophages by differentiation,while PTE accelerates diabetic wound healing by modulating diabetes-induced epigenetic changes in HSCs.Thus,PTE may be a novel therapeutic strategy for diabetic wound healing.
基金The authors acknowledge financial supports from the National Key R&D Program of China(no.2018YFE0122600)the National Natural Science Foundation of China(no.21802070).
文摘Metal nanoclusters with accurate compositions and precise crystalline structures hold remarkable attention in serving as a unique model catalyst for well-defined correlations between structure and catalytic activity.More importantly,these metal nanoclusters exhibit strong quantum confinement effects,which differ from their larger nanoparticles in a number of catalytic reactions.This review focuses on recent advances of atomically precise metal nanoclusters for C_(1) compound conversion(C_(O),CO_(2),CH_(4),and HCOOH),including thermally-driven catalysis,photocatalysis,and electrocatalysis.The reaction mechanisms are discussed at an atomic-or even electron-level.It is anticipated that the progress in this research area could be extended to catalytic applications of metal nanoclusters in C_(1) chemistry.
基金We acknowledged financial support from the National Natural Science Foundation of China(No.91961204)the Fundamental Research Funds for the Central Universities,and China Postdoctoral Science Foundation(No.2019M650106).
文摘The structure-dependent catalytic behavior is one of the most important issues in catalysis science.However,it has not been fully understood how different types of atom-packing structures of heterogeneous catalysts precisely impact the reaction sites and pathways.Here we investigate a periodic series of Au_(8n+4)(TBBT)_(4n+8 )nanoclusters with layer-by-layer structural pattern to catalyze CO_(2) hydrogenation(where n=3–6 is the number of(001)layers;TBBT=4-tert-butyl-benzenethiolate).An encouraging evolution of CO_(2) conversion can be identified:The product selectivity from methanol,formic acid to ethanol can be switched by the structure-dependent deformation from the flattened,perfect,to elongated cuboids in Au_(8n+4)(TBBT)_(4n+8).Through a combined study of experiment and theory,we demonstrate that the variation in structural patterns of catalysts can exclusively tune their adsorption strength with reaction intermediates and further control the CO_(2) conversion toward the different products.
基金supported by the National Natural Science Foundation of China(grant nos.21773109 and 91845104)the Scientific and Technological Innovation Foundation of Shunde Graduate School,University of Science and Technology Beijing(USTB)(grant no.BK19BE024).
文摘It remains an extreme challenge to activate thermodynamically unfavorable,chemically inert methane molecules under mild conditions.Herein,we report a molecular-like nickel-thiolate hexameric cluster[Ni_(6)(PET)_(12);PET=SC_(2)H_(4)Ph]catalyst that resembles a double crown,comprising of a hexagonal Ni6 kernel encapsulated by an exterior shell of 12 thiolates capable of efficient conversion of methane plus O_(2) to methanol and formic acid under visible light irradiation.
