Silica-based materials are usually used as delivery systems for antibacterial applications.In rare cases,bactericidal cationic surfactant templated silica composites have been reported as antimicrobial agents.However,...Silica-based materials are usually used as delivery systems for antibacterial applications.In rare cases,bactericidal cationic surfactant templated silica composites have been reported as antimicrobial agents.However,their antibacterial efficacy is limited due to limited control in content and structure.Herein,we report a“dual active templating”strategy in the design of nanostructured silica composites with intrinsic antibacterial performance.This strategy uses cationic and anionic structural directing agents as dual templates,both with active antibacterial property.The cationic-anionic dual active templating strategy further contributes to antibacterial nanocomposites with a spiky surface.With controllable release of dual active antibacterial agents,the spiky nanocomposite displays enhanced anti-microbial and anti-biofilm properties toward Staphylococcus epidermidis.These findings pave a new avenue toward the designed synthesis of novel antibacterial nanocomposites with improved performance for diverse antibacterial applications.展开更多
In the smart logistics industry,unmanned forklifts that intelligently identify logistics pallets can improve work efficiency in warehousing and transportation and are better than traditional manual forklifts driven by...In the smart logistics industry,unmanned forklifts that intelligently identify logistics pallets can improve work efficiency in warehousing and transportation and are better than traditional manual forklifts driven by humans.Therefore,they play a critical role in smart warehousing,and semantics segmentation is an effective method to realize the intelligent identification of logistics pallets.However,most current recognition algorithms are ineffective due to the diverse types of pallets,their complex shapes,frequent blockades in production environments,and changing lighting conditions.This paper proposes a novel multi-feature fusion-guided multiscale bidirectional attention(MFMBA)neural network for logistics pallet segmentation.To better predict the foreground category(the pallet)and the background category(the cargo)of a pallet image,our approach extracts three types of features(grayscale,texture,and Hue,Saturation,Value features)and fuses them.The multiscale architecture deals with the problem that the size and shape of the pallet may appear different in the image in the actual,complex environment,which usually makes feature extraction difficult.Our study proposes a multiscale architecture that can extract additional semantic features.Also,since a traditional attention mechanism only assigns attention rights from a single direction,we designed a bidirectional attention mechanism that assigns cross-attention weights to each feature from two directions,horizontally and vertically,significantly improving segmentation.Finally,comparative experimental results show that the precision of the proposed algorithm is 0.53%–8.77%better than that of other methods we compared.展开更多
Bacterial infection is a major threat to public health.Nanotechnology offers a solu-tion by combining nanomaterials with antibacterial agents.The development of an effective nanocomposite against drug-resistant bacter...Bacterial infection is a major threat to public health.Nanotechnology offers a solu-tion by combining nanomaterials with antibacterial agents.The development of an effective nanocomposite against drug-resistant bacteria such as methicillin-resistant Staphylococcus aureus(MRSA)is highly important yet challenging.Here,an anti-MRSA core–shell structure is designed,containing antibacterial zeolitic imidazolate framework-8(ZIF-8)as the core and bactericidal benzalkonium chloride(BAC)templated rough-surface mesostructured silica nanocomposite(RMSN)as the shell.The resultant ZIF-8@RMSN nanocomposite exhibits sustained release of BAC and zinc ions,effective disruption of the bacterial membrane,generation of oxidative damage of bacterial DNA,leakage of intracellular components,andfinally bacte-rial death.Furthermore,the synergistic antibacterial mechanisms lead to enhanced biofilm elimination performance.In addition,the ZIF-8@RMSN-modified band-aid effectively combats MRSA infection in vivo.This work has provided a promising nanocomposite against MRSA-related infections.展开更多
Designing and synthesizing high-efficiency non-precious metal-based catalysts having uniform active sites increases the reactivity and selectivity of materials and provides a platform for an in-depth understanding of ...Designing and synthesizing high-efficiency non-precious metal-based catalysts having uniform active sites increases the reactivity and selectivity of materials and provides a platform for an in-depth understanding of their catalytic reaction mechanism.In this study,we provided an approach for fabricating isolated nickel single-atom sites(Ni SAs)with high loading(4.9 wt.%)stabilized on nitrogen-doped hollow carbon spheres(NHCS)using a core–shell structured Zn/Ni bimetallic zeolitic imidazolate framework(ZIF)composite as the sacrificial template.The as-fabricated Ni SAs/NHCS catalyst shows superior activity,selectivity,and recycling durability for the catalytic transfer hydrogenation of nitrobenzene to aniline,thus achieving 100%yield of aniline with a turn-over frequency(TOF)value as high as 29.9 h^(−1) under mild conditions.This TOF value is considerably superior to the supported Ni nanoparticle catalysts.The experiments designed show that the hollow structure feature of NHCS facilitates accessible active sites and mass transfer,which thus contributes to the enhancement of the catalytic performance of Ni SAs/NHCS.Density functional theory calculations show the high chemo-selectivity and activity of the Ni SAs catalyst,arising from the unique role of the single Ni-N3 site on simultaneously activating the H donor(N_(2)H_(4))and substrate,as well as the hydrogenation of the–NOH group as the rate-determining step.展开更多
基金Open access funding provided by Shanghai Jiao Tong University
文摘Silica-based materials are usually used as delivery systems for antibacterial applications.In rare cases,bactericidal cationic surfactant templated silica composites have been reported as antimicrobial agents.However,their antibacterial efficacy is limited due to limited control in content and structure.Herein,we report a“dual active templating”strategy in the design of nanostructured silica composites with intrinsic antibacterial performance.This strategy uses cationic and anionic structural directing agents as dual templates,both with active antibacterial property.The cationic-anionic dual active templating strategy further contributes to antibacterial nanocomposites with a spiky surface.With controllable release of dual active antibacterial agents,the spiky nanocomposite displays enhanced anti-microbial and anti-biofilm properties toward Staphylococcus epidermidis.These findings pave a new avenue toward the designed synthesis of novel antibacterial nanocomposites with improved performance for diverse antibacterial applications.
基金supported by the Postgraduate Scientific Research Innovation Project of Hunan Province under Grant QL20210212the Scientific Innovation Fund for Postgraduates of Central South University of Forestry and Technology under Grant CX202102043.
文摘In the smart logistics industry,unmanned forklifts that intelligently identify logistics pallets can improve work efficiency in warehousing and transportation and are better than traditional manual forklifts driven by humans.Therefore,they play a critical role in smart warehousing,and semantics segmentation is an effective method to realize the intelligent identification of logistics pallets.However,most current recognition algorithms are ineffective due to the diverse types of pallets,their complex shapes,frequent blockades in production environments,and changing lighting conditions.This paper proposes a novel multi-feature fusion-guided multiscale bidirectional attention(MFMBA)neural network for logistics pallet segmentation.To better predict the foreground category(the pallet)and the background category(the cargo)of a pallet image,our approach extracts three types of features(grayscale,texture,and Hue,Saturation,Value features)and fuses them.The multiscale architecture deals with the problem that the size and shape of the pallet may appear different in the image in the actual,complex environment,which usually makes feature extraction difficult.Our study proposes a multiscale architecture that can extract additional semantic features.Also,since a traditional attention mechanism only assigns attention rights from a single direction,we designed a bidirectional attention mechanism that assigns cross-attention weights to each feature from two directions,horizontally and vertically,significantly improving segmentation.Finally,comparative experimental results show that the precision of the proposed algorithm is 0.53%–8.77%better than that of other methods we compared.
基金National Natural Science Foundation of China,Grant/Award Number:32171414Natural Science Foundation of Shanghai,Grant/Award Number:23ZR1419500Nature Science Foundation of Chongqing,Grant/Award Number:CSTB2022NSCQ-MSX0461。
文摘Bacterial infection is a major threat to public health.Nanotechnology offers a solu-tion by combining nanomaterials with antibacterial agents.The development of an effective nanocomposite against drug-resistant bacteria such as methicillin-resistant Staphylococcus aureus(MRSA)is highly important yet challenging.Here,an anti-MRSA core–shell structure is designed,containing antibacterial zeolitic imidazolate framework-8(ZIF-8)as the core and bactericidal benzalkonium chloride(BAC)templated rough-surface mesostructured silica nanocomposite(RMSN)as the shell.The resultant ZIF-8@RMSN nanocomposite exhibits sustained release of BAC and zinc ions,effective disruption of the bacterial membrane,generation of oxidative damage of bacterial DNA,leakage of intracellular components,andfinally bacte-rial death.Furthermore,the synergistic antibacterial mechanisms lead to enhanced biofilm elimination performance.In addition,the ZIF-8@RMSN-modified band-aid effectively combats MRSA infection in vivo.This work has provided a promising nanocomposite against MRSA-related infections.
基金the National Natural Science Foundation of China(Nos.21576243 and 21701168)Natural Science Foundation of Zhejiang Province(Nos.LY18B060006,LY17B060001,and LY21B030003)+2 种基金the National Key R&D Program of China(No.2020YFA0406101)Dalian high level talent innovation project(No.2019RQ063)Open project Foundation of State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences(No.20200021).
文摘Designing and synthesizing high-efficiency non-precious metal-based catalysts having uniform active sites increases the reactivity and selectivity of materials and provides a platform for an in-depth understanding of their catalytic reaction mechanism.In this study,we provided an approach for fabricating isolated nickel single-atom sites(Ni SAs)with high loading(4.9 wt.%)stabilized on nitrogen-doped hollow carbon spheres(NHCS)using a core–shell structured Zn/Ni bimetallic zeolitic imidazolate framework(ZIF)composite as the sacrificial template.The as-fabricated Ni SAs/NHCS catalyst shows superior activity,selectivity,and recycling durability for the catalytic transfer hydrogenation of nitrobenzene to aniline,thus achieving 100%yield of aniline with a turn-over frequency(TOF)value as high as 29.9 h^(−1) under mild conditions.This TOF value is considerably superior to the supported Ni nanoparticle catalysts.The experiments designed show that the hollow structure feature of NHCS facilitates accessible active sites and mass transfer,which thus contributes to the enhancement of the catalytic performance of Ni SAs/NHCS.Density functional theory calculations show the high chemo-selectivity and activity of the Ni SAs catalyst,arising from the unique role of the single Ni-N3 site on simultaneously activating the H donor(N_(2)H_(4))and substrate,as well as the hydrogenation of the–NOH group as the rate-determining step.
