Plasmonic metal nanomaterials with intrinsic surface–enhanced Raman scattering(SERS)and photothermal properties,especially AuAg nanoalloys with both the outstanding merits of Au and Ag nanocrystals,show huge applicat...Plasmonic metal nanomaterials with intrinsic surface–enhanced Raman scattering(SERS)and photothermal properties,especially AuAg nanoalloys with both the outstanding merits of Au and Ag nanocrystals,show huge application prospects in bacterial theranostics.However,the direct exposure of AuAg nanoalloys in external conditions probably cause undesirable reactions and poisonous metal ion leakage during SERS detection and photothermal antibacterial therapy process,which severely hinder bacterial theranostics applications.Herein,we report an ultrastable graphene–isolated AuAg nanoalloy(GAA)with AuAg core confined in few–layer graphitic shell as a versatile platform for bacterial detection and therapy.The encapsulation of graphene ensures the good stability of AuAg core,that its superior SERS and photothermal properties are therefore further guaranteed.GAA is used for SERS detection of two vital bacterial biomarkers(including corrosive cyanide and pyocyanin),exhibiting good SERS quantitative and multiplexing ability.GAA is further used for photothermal antibacterial therapy application,and ultrahigh antibacterial efficacies for both Gram–negative Escherichia coli and Gram–positive Staphylococcus aureus are achieved under 808 nm laser irradiation.This work proposes a valuable method to develop robust bacterial theranostic platform.展开更多
Aims Radial growth in response to climate has been reported in many trees,but the sex-specific responses of tree-ring growth associated with altitude in dioecious trees are still poorly known.This study aims to examin...Aims Radial growth in response to climate has been reported in many trees,but the sex-specific responses of tree-ring growth associated with altitude in dioecious trees are still poorly known.This study aims to examine whether(i)there are sex-related responses of tree-ring growth to climate in dioecious trees;(ii)these responses could be changed with altitude elevation.Methods The tree-ring width and basal area increment(BAI)were measured over the past 30 years(1982-2011),and the sexual differences in relationship between BAI and time span and correlations between ring width and climatic factors were investigated in Populus cathayana trees at two altitude sites(1,450 m and 1,750 m a.s.l.)in Xiaowutai Mountain,Hebei,north China.Important Findings The BAI was increased over the past 30 years.Trees at high-altitude sites had significantly lower mean ring width and mean BAI than those trees at low-altitude sites(P<0.001).In addition,sexual dif-ferences in tree-ring growth and its response to climate were more pronounced by altitude elevation.Male trees had a significantly larger mean ring width and mean BAI than did females at high-alti-tude sites,whereas no significant sexual differences in these traits were detected at low-altitude sites.Female trees were sensitive to previous October-November temperatures at high altitude but to current February and April precipitation at low altitude(P<0.05),whereas male trees were sensitive to current June temperature at high altitude but to January precipitation at low altitude(P<0.05).Our results indicated that the responses of tree-ring growth to cli-mate are sex dependent and can be changed with altitude elevation.展开更多
基金funding support from the National Key Research and Development Program of China(Nos.2022YFC2403501,2020YFA0210800)National Natural Science Foundation of China(No.22225401)+1 种基金Science and Technology Innovation Program of Hunan Province(No.2020RC4017)China Postdoctoral Science Foundation(No.2021M701145)。
文摘Plasmonic metal nanomaterials with intrinsic surface–enhanced Raman scattering(SERS)and photothermal properties,especially AuAg nanoalloys with both the outstanding merits of Au and Ag nanocrystals,show huge application prospects in bacterial theranostics.However,the direct exposure of AuAg nanoalloys in external conditions probably cause undesirable reactions and poisonous metal ion leakage during SERS detection and photothermal antibacterial therapy process,which severely hinder bacterial theranostics applications.Herein,we report an ultrastable graphene–isolated AuAg nanoalloy(GAA)with AuAg core confined in few–layer graphitic shell as a versatile platform for bacterial detection and therapy.The encapsulation of graphene ensures the good stability of AuAg core,that its superior SERS and photothermal properties are therefore further guaranteed.GAA is used for SERS detection of two vital bacterial biomarkers(including corrosive cyanide and pyocyanin),exhibiting good SERS quantitative and multiplexing ability.GAA is further used for photothermal antibacterial therapy application,and ultrahigh antibacterial efficacies for both Gram–negative Escherichia coli and Gram–positive Staphylococcus aureus are achieved under 808 nm laser irradiation.This work proposes a valuable method to develop robust bacterial theranostic platform.
基金This research was supported by the National Natural Science Foundation of China(31170389 and 31370596)the Innovative Team Foundation of the Sichuan Provincial Department of Education(14TD0015).
文摘Aims Radial growth in response to climate has been reported in many trees,but the sex-specific responses of tree-ring growth associated with altitude in dioecious trees are still poorly known.This study aims to examine whether(i)there are sex-related responses of tree-ring growth to climate in dioecious trees;(ii)these responses could be changed with altitude elevation.Methods The tree-ring width and basal area increment(BAI)were measured over the past 30 years(1982-2011),and the sexual differences in relationship between BAI and time span and correlations between ring width and climatic factors were investigated in Populus cathayana trees at two altitude sites(1,450 m and 1,750 m a.s.l.)in Xiaowutai Mountain,Hebei,north China.Important Findings The BAI was increased over the past 30 years.Trees at high-altitude sites had significantly lower mean ring width and mean BAI than those trees at low-altitude sites(P<0.001).In addition,sexual dif-ferences in tree-ring growth and its response to climate were more pronounced by altitude elevation.Male trees had a significantly larger mean ring width and mean BAI than did females at high-alti-tude sites,whereas no significant sexual differences in these traits were detected at low-altitude sites.Female trees were sensitive to previous October-November temperatures at high altitude but to current February and April precipitation at low altitude(P<0.05),whereas male trees were sensitive to current June temperature at high altitude but to January precipitation at low altitude(P<0.05).Our results indicated that the responses of tree-ring growth to cli-mate are sex dependent and can be changed with altitude elevation.
