Background:Mastitis seriously affects the mammary health of humans and animals.Studies have found that inflammation and oxidative stress play key roles in the occur-rence and development of mastitis.Therefore,in-depth...Background:Mastitis seriously affects the mammary health of humans and animals.Studies have found that inflammation and oxidative stress play key roles in the occur-rence and development of mastitis.Therefore,in-depth research on related molecular mechanisms is of great significance.Methods:Postpartum mice were anesthetized with pentobarbital and administered lipopolysaccharide to develop the mouse mastitis model.Proteomic analysis was per-formed to compare protein expression in mitochondria-associated endoplasmic retic-ulum membranes(MAM)from two mouse mammary gland groups.Western blot was used to detect the expression of MAM-related proteins in mitochondria.AlphaFold3 was used to predict the molecular structures of phosphofurin acidic cluster sorting protein 2(PACS2)and mitofusin 2(MFN2)and their interaction levels.The MFN2-PACS2 interaction was investigated using co-immunoprecipitation and small interfer-ing RNA.Results:The results showed that the inflammation level in the mammary gland tissue of mice with mastitis significantly increased,the total antioxidant capacity decreased,and the expression of MAM-related proteins MFN2 and PACS2 was significantly downregulated.In cell experiments,overexpression of MFN2 can inhibit inflamma-tion and oxidative stress responses,and promote the interaction between MFN2 and PACS2 to affect the formation of MAMs.Conclusion:In summary,this study suggests that mastitis can alter the expression of MAM-related proteins in mouse breast tissue.The interaction between MFN2 and PACS2 regulates the formation of MAMs.Overexpression of MFN2 can promote the formation of MAMs and inhibit inflammation and oxidative stress response in mam-mary epithelial cells.Our results provided a new theoretical basis and potential thera-peutic targets for the prevention and treatment of mastitis.展开更多
Objective This study aimed to identify high-risk areas for type 2 diabetes mellitus(T2DM)mortality to provide relevant evidence for interventions in emerging economies.Methods Empirical Bayesian Kriging and a discrete...Objective This study aimed to identify high-risk areas for type 2 diabetes mellitus(T2DM)mortality to provide relevant evidence for interventions in emerging economies.Methods Empirical Bayesian Kriging and a discrete Poisson space-time scan statistic were applied to identify the spatiotemporal clusters of T2DM mortality.The relationships between economic factors,air pollutants,and the mortality risk of T2DM were assessed using regression analysis and the Poisson Log-linear Model.Results A coastal district in East Guangdong,China,had the highest risk(Relative Risk[RR]=4.58,P<0.01),followed by the 10 coastal districts/counties in West Guangdong,China(RR=2.88,P<0.01).The coastal county in the Pearl River Delta,China(RR=2.24,P<0.01),had the third-highest risk.The remaining risk areas were two coastal counties in East Guangdong,16 districts/counties in the Pearl River Delta,and two counties in North Guangdong,China.Mortality due to T2DM was associated with gross domestic product per capita(GDP per capita).In pilot assessments,T2DM mortality was significantly associated with carbon monoxide.Conclusion High mortality from T2DM occurred in the coastal areas of East and West Guangdong,especially where the economy was progressing towards the upper middle-income level.展开更多
The atomic-level exploration of structure-property correlations poses significant challenges in establishing precise design principles for electrocatalysts targeting efficient CO_(2)conversion.This study demonstrates ...The atomic-level exploration of structure-property correlations poses significant challenges in establishing precise design principles for electrocatalysts targeting efficient CO_(2)conversion.This study demonstrates how controlled exposure of metal sites governs CO_(2)electroreduction performance through two octanuclear bismuth-oxo clusters with distinct architectures.The Bi_(8)-DMF cluster,constructed using tert–butylthiacalix[4]arene(TC4A)as the sole ligand,features two surface-exposed Bi active sites,while the dual-ligand Bi_(8)-Fc(with TC4A/ferrocene carboxylate)forms a fully encapsulated structure.Electrocatalytic tests reveal Bi_(8)-DMF achieves exceptional formate selectivity(>90%Faradaic efficiency)across a broad potential window(-0.9 V to-1.6 V vs.RHE)with 20 h stability,outperforming Bi_(8)-Fc(60%efficiency at-1.5 V).Theoretical calculations attribute Bi_(8)-DMF's superiority to exposed Bi sites that stabilize the critical*OCHO intermediate via optimized orbital interactions.This work provides crucial guidance for polynuclear catalyst design:moderate exposure of metal active sites significantly enhances CO_(2)reduction performance.展开更多
CO_(2) conversion to CO via the reverse water-gas shift(RWGS)reaction is limited by a low CO_(2) conversion rate and CO selectivity.Herein,an efficient RWGS catalyst is constructed through Enteromorpha prolifera–deri...CO_(2) conversion to CO via the reverse water-gas shift(RWGS)reaction is limited by a low CO_(2) conversion rate and CO selectivity.Herein,an efficient RWGS catalyst is constructed through Enteromorpha prolifera–derived N-rich mesoporous biochar(EPBC)supported atomic-level Cu-Mo_(2)C clusters(Cu-Mo_(2)C/EPBC).Unlike traditional acti-vated carbon(AC)supported Cu-Mo_(2)C particles(Cu-Mo_(2)C/AC),the Cu-Mo_(2)C/EPBC not only presents the better graphitization degree and larger specific surface area,but also uniformly andfirmly anchors atomic-level Cu-Mo_(2)C clusters due to the existence of pyridine nitrogen.Furthermore,the pyridine N of Cu-Mo_(2)C/EPBC strengthens an unblocked electron transfer between Mo_(2)C and Cu clusters,as verified by X-ray absorption spectroscopy.As a result,the synergistic effect between pyridinic N anchoring and the clusters interaction in Cu-Mo_(2)C/EPBC facilitates an improved CO selectivity of 99.95%at 500℃ compared with traditional Cu-Mo_(2)C/AC(99.60%),as well as about 3-fold CO_(2) conversion rate.Density functional theory calculations confirm that pyr-idine N-modified carbon activates the local electronic redistribution at Cu-Mo_(2)C clusters,which contributes to the decreased energy barrier of the transition state of CO^(*)+O^(*)+2H^(*),thereby triggering the transformation of rate-limited step during the redox pathway.This biomass-derived strategy opens perspective on producing sustain-able fuels and building blocks through the RWGS reaction.展开更多
The development of efficient low-load platinum catalysts for CO oxidation is critical for large-scale industrial applications and environmental protection.In this study,a strategy of N_(2)treatment triggered the self-...The development of efficient low-load platinum catalysts for CO oxidation is critical for large-scale industrial applications and environmental protection.In this study,a strategy of N_(2)treatment triggered the self-reforming into fully exposed Pt cluster catalysts was proposed.By adjusting the coordination environment of Pt species on the defect support through N_(2)treatment,the CO catalytic activity was significantly enhanced,achieving complete CO oxidation at 130℃with a Pt loading of only 0.1 wt.%.The turnover frequency of N_(2)-treated Pt_(FEC)/Ti-D at 160℃was 18.3 times that of untreated Pt_(SA)/Ti-D.Comprehensive characterization results indicated that the N_(2)treatment of the Pt single-atom defect catalyst facilitated the reconfiguration and evolution of the defect structure,leading to the aggregation of Pt single atoms into fully exposed Pt clusters.Notably,these fully exposed Pt clusters exhibited a reduced coordination of Pt–O in the first coordination shell compared to single atoms,which resulted in the formation of Pt–Pt metal coordination.This unique coordination structure enhanced the adsorption and activation of CO and O_(2)on the catalyst,thereby resulting in exceptionally low-temperature CO oxidation activity.This work demonstrates a promising strategy for the design,synthesis,and industrial application of efficient low-platinum load catalysts.展开更多
There has been a continuous effort to improve the thermal stability of subnanometric platinum(Pt)cluster(<2 nm) catalyst because Pt cluster on CeO_(2) support can be mobile and aggregated into nanoparticle on heati...There has been a continuous effort to improve the thermal stability of subnanometric platinum(Pt)cluster(<2 nm) catalyst because Pt cluster on CeO_(2) support can be mobile and aggregated into nanoparticle on heating at elevated temperatures,yet this great challenge remains.In this study,a strategy is reported to improve the thermal stability of subnanometric Pt cluster by hydrothermal deposition method.Based on this method,zirconium(Zr) was precisely doped on surface of Ce_(0.95)Zr_(0.05)O_(2) by accurately controlling Pt subnanometric cluster size.The surface doping of Zr is favorable for forming the Zr-O-Ce site and activating surface lattice oxygen atoms,which results in strong electronic interactions to stabilize the Pt subnanometric cluster.After high-temperature aging treatment at 1000℃/4 h,the single atom Pt supported on CeO_(2) is aggregated into larger sized(>3 nm) nanoparticle.In contrast,the single atom Pt supported on Ce_(0.95)Zr_(0.0)5O_(2) displays less agglomeration into subnanometric cluster with size of(1.4±0.3) nm.Moreover,the CO oxide catalytic performance of Ce_(0.95)Zr_(0.0)5O_(2)-Pt is 26% and 31%higher than that of CeO_(2)-Pt and commercial Al_(2)O_(3)-Pt catalysts,respectively.The experimental and density functional theory(DFT) calculations indicate that the Zr-O-Ce site and Pt subnanometric cluster interface have more defect sites and active oxygen species than CeO_(2)-Pt interface,which activate the Mars van Krevelen(MvK) mechanism,facilitating the catalytic performance.展开更多
The robust Mg-H bonds present in magnesium hydride(MgH_(2))hinder the dissociation of hydrogen molecules on MgH_(2),leading to suboptimal thermo dynamic and kinetic properties.Transition metals such as nickel(Ni)and N...The robust Mg-H bonds present in magnesium hydride(MgH_(2))hinder the dissociation of hydrogen molecules on MgH_(2),leading to suboptimal thermo dynamic and kinetic properties.Transition metals such as nickel(Ni)and Nb exhibit superior hydrogen absorption energies as compared to Mg.By integrating two-dimensional Nb_(n)C_(n-1)T_(x)-MXene(with a large specific surface area and strong hydrogen absorption capacity provided by Nb)with Ni clusters,we developed an effective catalyst for hydrogen adsorption in MgH_(2).This study focused on the synthesis of an efficient MXene-Nb_(2)CT_(x)composite containing nano Ni cluster to enhance the hydrogenation and dehydrogenation processes of the Mg/MgH_(2)system.The Txend groups(-F,-O)were found to interact with Ni to create Ni-F or Ni-O bonds,which subsequently engage with adjacent Ni atoms to form Ni-Ni bonds.This interaction facilitates the loading of Ni clusters onto Nb_(2)CT_(x)and mitigates the inhibitory effects of-F or-O on hydrogen adsorption and desorption in the Mg-based system.Consequently,Nb_(2)C and Ni operate synergistic ally to enhance hydrogen dissociation and weaken Mg-H bonds.Theoretical simulations revealed that the inclusion of the Nb_(2)C/Ni catalyst in an elongation of Mg-H bonds enhancehydrogen dissociation and weaken Mg-H bonds.Theoretical simulations revealed that the inclusion of the Nb_(2)C/Ni catalyst in an elongation of Mg-H bonds facilitate hydrogen molecule dissociation on the Nb_(2)C/Ni composite.Hydrogen storage performance assesments demonstrated that the Nb_(2)C/Ni catalyst efficiently catalyzed hydrogen absorption and desorption;specifically,the hydrogenation/dehydrogenation capacity of Nb_(2)C/Ni@MgH_(2)reachedca.5.0 wt%at 100℃,while at 200℃,the capacities for hydrogenation and dehydrogenation reached 7.0 wt%and6.0 wt%,respectively,within 6 min.展开更多
Objective Sepsis patients exhibit diverse immune states,making it crucial to identify subtypes with distinct inflammatory profiles through Th1/Th2 cytokine data for personalized treatment and improved prognosis.Method...Objective Sepsis patients exhibit diverse immune states,making it crucial to identify subtypes with distinct inflammatory profiles through Th1/Th2 cytokine data for personalized treatment and improved prognosis.Methods We retrieved data from sepsis patients who underwent Th1/Th2 cytokine testing in Nanfang Hospital,Southern Medical University from June 1,2020,to February 1,2022.An unsupervised K-means clustering method classified participants based on Th1/Th2 cytokine levels,with the primary outcome being the 7-day mortality rate post-ICU admission.Cox proportional hazards and Restricted Mean Survival Time(RMST)analyses were utilized to explore survival outcomes.Results A total of 321 sepsis patients were included.IL-6(HR 1.69,95%CI:1.22,2.34)and IL-10(HR 1.81,95%CI:1.37,2.40)emerged as independent predictors of 7-day mortality.Unsupervised K-means clustering revealed 3 inflammatory/immune subgroups:Cluster 1(n=166,low inflammatory response),Cluster 2(n=99,moderate inflammatory response with immune suppression),and Cluster 3(n=56,strong inflammatory and immune suppression).Compared to Cluster 1,Clusters 2 and 3 had higher 7-day mortality risks(14.4%vs 23.2%,HR=4.30,95%CI:1.51-12.26;14.4%vs 35.7%,HR=7.32,95%CI:2.57-20.79).Conclusion Septic patients in a protective immune response state(Cluster 1)exhibit better short-term prognoses,suggesting the importance of understanding inflammatory/immune states for precise treatment and improved outcomes.展开更多
To convert carbon dioxide into high-value-added liquid products such as formate with renewable electricity(CO_(2)RR)is a promising strategy of CO_(2) resource utilization.The key is to find a highly efficient and sele...To convert carbon dioxide into high-value-added liquid products such as formate with renewable electricity(CO_(2)RR)is a promising strategy of CO_(2) resource utilization.The key is to find a highly efficient and selective electrocatalyst for CO_(2)RR.Herein,clustered Bi_(28)O_(32)(SO_(4))_(10) was found to show a high formate Faradaic efficiency(FE_(formate))of 96.2%at–1.1 V_(RHE) and FE_(formate) above 90%in a wide potential range from–0.9 to–1.3 V_(RHE) in H-type cell,surpassing the corresponding layered Bi_(2)O_(2)SO_(4)(85.6%FE_(formate) at–1.1 V_(RHE)).The advantageous CO_(2)RR performance of Bi_(28)O_(32)(SO_(4))_(10) over Bi_(2)O_(2)SO_(4) was ascribed to a special two-step in-situ reconstruction process,consisting of Bi_(28)O_(32)(SO_(4))_(10)→Bi_(-2.1)/Bi_(2)O_(2)CO_(3)→Bi_(-2.1)/Bi_(-0.6) during CO_(2)RR.It gave metallic Bi_(-2.1) with lattice distortion of–2.1%at the first step and metallic Bi_(-0.6) with lattice distortion of–0.6%at the second step.In contrast,the usual layered Bi_(2)O_(2)SO_(4) only formed metallic Bi_(-0.6) with weaker lattice strain.The metallic Bi_(-2.1) revealed higher efficiency in stabilizing*CO_(2) intermediate and reducing the energy barrier of CO_(2)RR,while suppressing hydrogen evolution reaction and CO formation.This work delivers a high-performance cluster-type Bi_(28)O_(32)(SO_(4))_(10) electrocatalyst for CO_(2)RR,and elucidates the origin of superior performance of clustered Bi_(28)O_(32)(SO_(4))_(10) electrocatalysts compared with layered Bi_(2)O_(2)SO_(4).展开更多
The growth and thermal stability of Au clusters on a partially-reduced rutile TiO2 （110）-1 × 1 surface were investigated by high-resolution photoelectron spectroscopy using synchrotron- radiation-light. The val...The growth and thermal stability of Au clusters on a partially-reduced rutile TiO2 （110）-1 × 1 surface were investigated by high-resolution photoelectron spectroscopy using synchrotron- radiation-light. The valence-band photoelectron spectroscopy results demonstrate that the Ti^3＋3d feature attenuates quickly with the initial deposition of Au clusters, implying that Au clusters nucleate at the oxygen vacancy sites. The Au4f core-level photoelectron spectroscopy results directly prove the existence of charge transfer from oxygen vacancies to Au clusters. The thermal stability of Au clusters on the partially-reduced and stoichiometric TiO2（110） surfaces was also comparatively investigated by the annealing experiments. With the same film thickness, Au clusters are more thermally stable on the partially-reduced TiO2（110） surface than on the stoichiometric TiO2（110） surface. Meanwhile, large Au nanoparticles are more thermally stable than fine Au nanoparticles.展开更多
基金National Natural Science Foundation of China,Grant/Award Number:32302826 and 32372961Jilin Provincial Special Project for Health Research Talents,Grant/Award Number:2020SCZ40China Postdoctoral Science Foundation,Grant/Award Number:2023M740623。
文摘Background:Mastitis seriously affects the mammary health of humans and animals.Studies have found that inflammation and oxidative stress play key roles in the occur-rence and development of mastitis.Therefore,in-depth research on related molecular mechanisms is of great significance.Methods:Postpartum mice were anesthetized with pentobarbital and administered lipopolysaccharide to develop the mouse mastitis model.Proteomic analysis was per-formed to compare protein expression in mitochondria-associated endoplasmic retic-ulum membranes(MAM)from two mouse mammary gland groups.Western blot was used to detect the expression of MAM-related proteins in mitochondria.AlphaFold3 was used to predict the molecular structures of phosphofurin acidic cluster sorting protein 2(PACS2)and mitofusin 2(MFN2)and their interaction levels.The MFN2-PACS2 interaction was investigated using co-immunoprecipitation and small interfer-ing RNA.Results:The results showed that the inflammation level in the mammary gland tissue of mice with mastitis significantly increased,the total antioxidant capacity decreased,and the expression of MAM-related proteins MFN2 and PACS2 was significantly downregulated.In cell experiments,overexpression of MFN2 can inhibit inflamma-tion and oxidative stress responses,and promote the interaction between MFN2 and PACS2 to affect the formation of MAMs.Conclusion:In summary,this study suggests that mastitis can alter the expression of MAM-related proteins in mouse breast tissue.The interaction between MFN2 and PACS2 regulates the formation of MAMs.Overexpression of MFN2 can promote the formation of MAMs and inhibit inflammation and oxidative stress response in mam-mary epithelial cells.Our results provided a new theoretical basis and potential thera-peutic targets for the prevention and treatment of mastitis.
基金Medical Research Ethics Review Committee of the Guangdong Provincial Center for Disease Control and Prevention,China(No.W96-027E-202307).
文摘Objective This study aimed to identify high-risk areas for type 2 diabetes mellitus(T2DM)mortality to provide relevant evidence for interventions in emerging economies.Methods Empirical Bayesian Kriging and a discrete Poisson space-time scan statistic were applied to identify the spatiotemporal clusters of T2DM mortality.The relationships between economic factors,air pollutants,and the mortality risk of T2DM were assessed using regression analysis and the Poisson Log-linear Model.Results A coastal district in East Guangdong,China,had the highest risk(Relative Risk[RR]=4.58,P<0.01),followed by the 10 coastal districts/counties in West Guangdong,China(RR=2.88,P<0.01).The coastal county in the Pearl River Delta,China(RR=2.24,P<0.01),had the third-highest risk.The remaining risk areas were two coastal counties in East Guangdong,16 districts/counties in the Pearl River Delta,and two counties in North Guangdong,China.Mortality due to T2DM was associated with gross domestic product per capita(GDP per capita).In pilot assessments,T2DM mortality was significantly associated with carbon monoxide.Conclusion High mortality from T2DM occurred in the coastal areas of East and West Guangdong,especially where the economy was progressing towards the upper middle-income level.
基金supported by the Natural Science Foundation of Hunan Province(No.2023JJ30650)the Central South University Innovation-Driven Research Programme(No.2023CXQD061)。
文摘The atomic-level exploration of structure-property correlations poses significant challenges in establishing precise design principles for electrocatalysts targeting efficient CO_(2)conversion.This study demonstrates how controlled exposure of metal sites governs CO_(2)electroreduction performance through two octanuclear bismuth-oxo clusters with distinct architectures.The Bi_(8)-DMF cluster,constructed using tert–butylthiacalix[4]arene(TC4A)as the sole ligand,features two surface-exposed Bi active sites,while the dual-ligand Bi_(8)-Fc(with TC4A/ferrocene carboxylate)forms a fully encapsulated structure.Electrocatalytic tests reveal Bi_(8)-DMF achieves exceptional formate selectivity(>90%Faradaic efficiency)across a broad potential window(-0.9 V to-1.6 V vs.RHE)with 20 h stability,outperforming Bi_(8)-Fc(60%efficiency at-1.5 V).Theoretical calculations attribute Bi_(8)-DMF's superiority to exposed Bi sites that stabilize the critical*OCHO intermediate via optimized orbital interactions.This work provides crucial guidance for polynuclear catalyst design:moderate exposure of metal active sites significantly enhances CO_(2)reduction performance.
基金support from National Natural Science Foundation of China(32101474 and 42377249)National Key Research and Development Program of China(2023YFD2201605).
文摘CO_(2) conversion to CO via the reverse water-gas shift(RWGS)reaction is limited by a low CO_(2) conversion rate and CO selectivity.Herein,an efficient RWGS catalyst is constructed through Enteromorpha prolifera–derived N-rich mesoporous biochar(EPBC)supported atomic-level Cu-Mo_(2)C clusters(Cu-Mo_(2)C/EPBC).Unlike traditional acti-vated carbon(AC)supported Cu-Mo_(2)C particles(Cu-Mo_(2)C/AC),the Cu-Mo_(2)C/EPBC not only presents the better graphitization degree and larger specific surface area,but also uniformly andfirmly anchors atomic-level Cu-Mo_(2)C clusters due to the existence of pyridine nitrogen.Furthermore,the pyridine N of Cu-Mo_(2)C/EPBC strengthens an unblocked electron transfer between Mo_(2)C and Cu clusters,as verified by X-ray absorption spectroscopy.As a result,the synergistic effect between pyridinic N anchoring and the clusters interaction in Cu-Mo_(2)C/EPBC facilitates an improved CO selectivity of 99.95%at 500℃ compared with traditional Cu-Mo_(2)C/AC(99.60%),as well as about 3-fold CO_(2) conversion rate.Density functional theory calculations confirm that pyr-idine N-modified carbon activates the local electronic redistribution at Cu-Mo_(2)C clusters,which contributes to the decreased energy barrier of the transition state of CO^(*)+O^(*)+2H^(*),thereby triggering the transformation of rate-limited step during the redox pathway.This biomass-derived strategy opens perspective on producing sustain-able fuels and building blocks through the RWGS reaction.
基金supported by the National Natural Science Foundation of China(52170118,52322004,52230002)the China Postdoctoral Science Foundation(2024M763296).
文摘The development of efficient low-load platinum catalysts for CO oxidation is critical for large-scale industrial applications and environmental protection.In this study,a strategy of N_(2)treatment triggered the self-reforming into fully exposed Pt cluster catalysts was proposed.By adjusting the coordination environment of Pt species on the defect support through N_(2)treatment,the CO catalytic activity was significantly enhanced,achieving complete CO oxidation at 130℃with a Pt loading of only 0.1 wt.%.The turnover frequency of N_(2)-treated Pt_(FEC)/Ti-D at 160℃was 18.3 times that of untreated Pt_(SA)/Ti-D.Comprehensive characterization results indicated that the N_(2)treatment of the Pt single-atom defect catalyst facilitated the reconfiguration and evolution of the defect structure,leading to the aggregation of Pt single atoms into fully exposed Pt clusters.Notably,these fully exposed Pt clusters exhibited a reduced coordination of Pt–O in the first coordination shell compared to single atoms,which resulted in the formation of Pt–Pt metal coordination.This unique coordination structure enhanced the adsorption and activation of CO and O_(2)on the catalyst,thereby resulting in exceptionally low-temperature CO oxidation activity.This work demonstrates a promising strategy for the design,synthesis,and industrial application of efficient low-platinum load catalysts.
基金supported by National Natural Science Foundation of China (52204376)Youth Foundation of Hebei Province (E2022103007)+1 种基金Open Project of Yunnan Precious Metals Laboratory Co.(YPML-20240502059)Young Elite Scientists Sponsorship Program by CAST (2021QNRC001)。
文摘There has been a continuous effort to improve the thermal stability of subnanometric platinum(Pt)cluster(<2 nm) catalyst because Pt cluster on CeO_(2) support can be mobile and aggregated into nanoparticle on heating at elevated temperatures,yet this great challenge remains.In this study,a strategy is reported to improve the thermal stability of subnanometric Pt cluster by hydrothermal deposition method.Based on this method,zirconium(Zr) was precisely doped on surface of Ce_(0.95)Zr_(0.05)O_(2) by accurately controlling Pt subnanometric cluster size.The surface doping of Zr is favorable for forming the Zr-O-Ce site and activating surface lattice oxygen atoms,which results in strong electronic interactions to stabilize the Pt subnanometric cluster.After high-temperature aging treatment at 1000℃/4 h,the single atom Pt supported on CeO_(2) is aggregated into larger sized(>3 nm) nanoparticle.In contrast,the single atom Pt supported on Ce_(0.95)Zr_(0.0)5O_(2) displays less agglomeration into subnanometric cluster with size of(1.4±0.3) nm.Moreover,the CO oxide catalytic performance of Ce_(0.95)Zr_(0.0)5O_(2)-Pt is 26% and 31%higher than that of CeO_(2)-Pt and commercial Al_(2)O_(3)-Pt catalysts,respectively.The experimental and density functional theory(DFT) calculations indicate that the Zr-O-Ce site and Pt subnanometric cluster interface have more defect sites and active oxygen species than CeO_(2)-Pt interface,which activate the Mars van Krevelen(MvK) mechanism,facilitating the catalytic performance.
基金financially supported by the Natural Science Foundation of Jiangsu Province of China(No.BK20210079)Xuzhou Science and Technology Project(No.KC23011)
文摘The robust Mg-H bonds present in magnesium hydride(MgH_(2))hinder the dissociation of hydrogen molecules on MgH_(2),leading to suboptimal thermo dynamic and kinetic properties.Transition metals such as nickel(Ni)and Nb exhibit superior hydrogen absorption energies as compared to Mg.By integrating two-dimensional Nb_(n)C_(n-1)T_(x)-MXene(with a large specific surface area and strong hydrogen absorption capacity provided by Nb)with Ni clusters,we developed an effective catalyst for hydrogen adsorption in MgH_(2).This study focused on the synthesis of an efficient MXene-Nb_(2)CT_(x)composite containing nano Ni cluster to enhance the hydrogenation and dehydrogenation processes of the Mg/MgH_(2)system.The Txend groups(-F,-O)were found to interact with Ni to create Ni-F or Ni-O bonds,which subsequently engage with adjacent Ni atoms to form Ni-Ni bonds.This interaction facilitates the loading of Ni clusters onto Nb_(2)CT_(x)and mitigates the inhibitory effects of-F or-O on hydrogen adsorption and desorption in the Mg-based system.Consequently,Nb_(2)C and Ni operate synergistic ally to enhance hydrogen dissociation and weaken Mg-H bonds.Theoretical simulations revealed that the inclusion of the Nb_(2)C/Ni catalyst in an elongation of Mg-H bonds enhancehydrogen dissociation and weaken Mg-H bonds.Theoretical simulations revealed that the inclusion of the Nb_(2)C/Ni catalyst in an elongation of Mg-H bonds facilitate hydrogen molecule dissociation on the Nb_(2)C/Ni composite.Hydrogen storage performance assesments demonstrated that the Nb_(2)C/Ni catalyst efficiently catalyzed hydrogen absorption and desorption;specifically,the hydrogenation/dehydrogenation capacity of Nb_(2)C/Ni@MgH_(2)reachedca.5.0 wt%at 100℃,while at 200℃,the capacities for hydrogenation and dehydrogenation reached 7.0 wt%and6.0 wt%,respectively,within 6 min.
文摘Objective Sepsis patients exhibit diverse immune states,making it crucial to identify subtypes with distinct inflammatory profiles through Th1/Th2 cytokine data for personalized treatment and improved prognosis.Methods We retrieved data from sepsis patients who underwent Th1/Th2 cytokine testing in Nanfang Hospital,Southern Medical University from June 1,2020,to February 1,2022.An unsupervised K-means clustering method classified participants based on Th1/Th2 cytokine levels,with the primary outcome being the 7-day mortality rate post-ICU admission.Cox proportional hazards and Restricted Mean Survival Time(RMST)analyses were utilized to explore survival outcomes.Results A total of 321 sepsis patients were included.IL-6(HR 1.69,95%CI:1.22,2.34)and IL-10(HR 1.81,95%CI:1.37,2.40)emerged as independent predictors of 7-day mortality.Unsupervised K-means clustering revealed 3 inflammatory/immune subgroups:Cluster 1(n=166,low inflammatory response),Cluster 2(n=99,moderate inflammatory response with immune suppression),and Cluster 3(n=56,strong inflammatory and immune suppression).Compared to Cluster 1,Clusters 2 and 3 had higher 7-day mortality risks(14.4%vs 23.2%,HR=4.30,95%CI:1.51-12.26;14.4%vs 35.7%,HR=7.32,95%CI:2.57-20.79).Conclusion Septic patients in a protective immune response state(Cluster 1)exhibit better short-term prognoses,suggesting the importance of understanding inflammatory/immune states for precise treatment and improved outcomes.
文摘To convert carbon dioxide into high-value-added liquid products such as formate with renewable electricity(CO_(2)RR)is a promising strategy of CO_(2) resource utilization.The key is to find a highly efficient and selective electrocatalyst for CO_(2)RR.Herein,clustered Bi_(28)O_(32)(SO_(4))_(10) was found to show a high formate Faradaic efficiency(FE_(formate))of 96.2%at–1.1 V_(RHE) and FE_(formate) above 90%in a wide potential range from–0.9 to–1.3 V_(RHE) in H-type cell,surpassing the corresponding layered Bi_(2)O_(2)SO_(4)(85.6%FE_(formate) at–1.1 V_(RHE)).The advantageous CO_(2)RR performance of Bi_(28)O_(32)(SO_(4))_(10) over Bi_(2)O_(2)SO_(4) was ascribed to a special two-step in-situ reconstruction process,consisting of Bi_(28)O_(32)(SO_(4))_(10)→Bi_(-2.1)/Bi_(2)O_(2)CO_(3)→Bi_(-2.1)/Bi_(-0.6) during CO_(2)RR.It gave metallic Bi_(-2.1) with lattice distortion of–2.1%at the first step and metallic Bi_(-0.6) with lattice distortion of–0.6%at the second step.In contrast,the usual layered Bi_(2)O_(2)SO_(4) only formed metallic Bi_(-0.6) with weaker lattice strain.The metallic Bi_(-2.1) revealed higher efficiency in stabilizing*CO_(2) intermediate and reducing the energy barrier of CO_(2)RR,while suppressing hydrogen evolution reaction and CO formation.This work delivers a high-performance cluster-type Bi_(28)O_(32)(SO_(4))_(10) electrocatalyst for CO_(2)RR,and elucidates the origin of superior performance of clustered Bi_(28)O_(32)(SO_(4))_(10) electrocatalysts compared with layered Bi_(2)O_(2)SO_(4).
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.20773113 and No.20803072）, the Hundred Talent Program of Chinese Academy of Sciences, the MOE Program for Changjiang Scholars and Innovative Research Team （No.IRT0756）, and the MPG-CAS Partner-group Program.
文摘The growth and thermal stability of Au clusters on a partially-reduced rutile TiO2 （110）-1 × 1 surface were investigated by high-resolution photoelectron spectroscopy using synchrotron- radiation-light. The valence-band photoelectron spectroscopy results demonstrate that the Ti^3＋3d feature attenuates quickly with the initial deposition of Au clusters, implying that Au clusters nucleate at the oxygen vacancy sites. The Au4f core-level photoelectron spectroscopy results directly prove the existence of charge transfer from oxygen vacancies to Au clusters. The thermal stability of Au clusters on the partially-reduced and stoichiometric TiO2（110） surfaces was also comparatively investigated by the annealing experiments. With the same film thickness, Au clusters are more thermally stable on the partially-reduced TiO2（110） surface than on the stoichiometric TiO2（110） surface. Meanwhile, large Au nanoparticles are more thermally stable than fine Au nanoparticles.
