The light absorption properties of semiconductor-based photocatalysts to a large extent determine the relevant catalytic performance.Traditional strategies in broadening the light absorption range are usually accompan...The light absorption properties of semiconductor-based photocatalysts to a large extent determine the relevant catalytic performance.Traditional strategies in broadening the light absorption range are usually accompanied with unfavorable changes in redox ability and dynamics of photoinduced species that would confuse the comprehensive optimization.In this work,we propose a nontrivial excitonic transition regulation strategy for gaining sub-bandgap light absorption in low-dimensional semiconductor-based photocatalysts.Using bismuth oxybromide(BiOBr)as a model system,we highlight that the light absorption cut-off edge could be effectively extended up to 500 nm by introducing Bi vacancies.On the basis of theoretical simulations and spectroscopic analyses,we attributed the broadening of light absorption to the promotion of excitonic transition that is generally forbidden in pristine BiOBr system,associated with Bi-vacancy-induced excited-state symmetry breaking.In addition,Bi vacancy was demonstrated to implement negligible effects on other photoexcitation properties like excited-state energy-level profiles and kinetics.Benefiting from these features,the defective sample exhibits a notable advantage in gaining visible-light-driven photocatalytic reactions.展开更多
Although food availability and the abundance of seed predators have been postulated to affect seed dispersal,it is not clear how seed-eating animals modify their scatter-hoarding strategies in response to different le...Although food availability and the abundance of seed predators have been postulated to affect seed dispersal,it is not clear how seed-eating animals modify their scatter-hoarding strategies in response to different levels of interspecific competition.We placed paired germinated and ungerminated acorns of Quercus mongolica on 30-cm high platforms to exclude potential interspecific competition of the predominant larder hoarders Apodemus peninsulae and Myodes rufocanus,to investigate seed dispersal by a predominant scatter-hoarder,Tamias sibiricus,in the field in north-eastern China.Our results showed that T.sibiricus ate more acorns in situ in the absence of interspecific competition.In the presence of interspecific competition of A.peninsulae and C.rufocanus,however,more acorns were scatter-hoarded by T.sibiricus.Regardless of interspecific competition,germination of acorns showed no significant effects on seed dispersal patterns,inconsistent with the“seed perishability hypothesis”that animals avoid hoarding seeds with high perishability.Exclusion of interspecific competition,though relatively increasing the per capita seed abundance,appears to reduce seed dispersal,scatter-hoarding and seedling establishment.Therefore,we propose that moderate interspecific competition rather than competition exclusion may benefit seed scatter-hoarding and seedling establishment.展开更多
Ebola virus(EBOV) causes severe hemorrhagic fever in humans and non-human primates with high rates of fatality. Glycoprotein(GP) is the only envelope protein of EBOV, which may play a critical role in virus attachment...Ebola virus(EBOV) causes severe hemorrhagic fever in humans and non-human primates with high rates of fatality. Glycoprotein(GP) is the only envelope protein of EBOV, which may play a critical role in virus attachment and entry as well as stimulating host protective immune responses.However, the lack of expression of full-length GP in Escherichia coli hinders the further study of its function in viral pathogenesis. In this study, the vp40 gene was fused to the full-length gp gene and cloned into a prokaryotic expression vector. We showed that the VP40-GP and GP-VP40 fusion proteins could be expressed in E.coli at 16 ℃. In addition, it was shown that the position of vp40 in the fusion proteins affected the yields of the fusion proteins, with a higher level of production of the fusion protein when vp40 was upstream of gp compared to when it was downstream. The results provide a strategy for the expression of a large quantity of EBOV full-length GP, which is of importance for further analyzing the relationship between the structure and function of GP and developing an antibody for the treatment of EBOV infection.展开更多
基金supported by the National Key Research and Development Program of China(Nos.2022YFA1502903 and 2021YFA1501502)the Strategic Priority Research Program of Chinese Academy of Sciences(Nos.XDB36000000 and XDB0450102)+3 种基金the National Natural Science Foundation of China(22275179)the Anhui Provincial Key Research and Development Program(No.2022a05020054)the Youth Innovation Promotion Association of CAS(No.Y2021123)the Fundamental Research Funds for the Central Universities(No.WK2060000039)。
文摘The light absorption properties of semiconductor-based photocatalysts to a large extent determine the relevant catalytic performance.Traditional strategies in broadening the light absorption range are usually accompanied with unfavorable changes in redox ability and dynamics of photoinduced species that would confuse the comprehensive optimization.In this work,we propose a nontrivial excitonic transition regulation strategy for gaining sub-bandgap light absorption in low-dimensional semiconductor-based photocatalysts.Using bismuth oxybromide(BiOBr)as a model system,we highlight that the light absorption cut-off edge could be effectively extended up to 500 nm by introducing Bi vacancies.On the basis of theoretical simulations and spectroscopic analyses,we attributed the broadening of light absorption to the promotion of excitonic transition that is generally forbidden in pristine BiOBr system,associated with Bi-vacancy-induced excited-state symmetry breaking.In addition,Bi vacancy was demonstrated to implement negligible effects on other photoexcitation properties like excited-state energy-level profiles and kinetics.Benefiting from these features,the defective sample exhibits a notable advantage in gaining visible-light-driven photocatalytic reactions.
基金the National Natural Science Foundation of China(31760156)the Young Talents Invitation Program of Shandong Provincial Colleges and Universities.
文摘Although food availability and the abundance of seed predators have been postulated to affect seed dispersal,it is not clear how seed-eating animals modify their scatter-hoarding strategies in response to different levels of interspecific competition.We placed paired germinated and ungerminated acorns of Quercus mongolica on 30-cm high platforms to exclude potential interspecific competition of the predominant larder hoarders Apodemus peninsulae and Myodes rufocanus,to investigate seed dispersal by a predominant scatter-hoarder,Tamias sibiricus,in the field in north-eastern China.Our results showed that T.sibiricus ate more acorns in situ in the absence of interspecific competition.In the presence of interspecific competition of A.peninsulae and C.rufocanus,however,more acorns were scatter-hoarded by T.sibiricus.Regardless of interspecific competition,germination of acorns showed no significant effects on seed dispersal patterns,inconsistent with the“seed perishability hypothesis”that animals avoid hoarding seeds with high perishability.Exclusion of interspecific competition,though relatively increasing the per capita seed abundance,appears to reduce seed dispersal,scatter-hoarding and seedling establishment.Therefore,we propose that moderate interspecific competition rather than competition exclusion may benefit seed scatter-hoarding and seedling establishment.
基金jointly supported by the National Science and Technology Major Project (2012ZX10004219 and 2012ZX10004403)the Presidential Fund of the Chinese Academy of Sciences and the Wuhan Key Laboratory on Emerging Infectious Diseases and Biosafety
文摘Ebola virus(EBOV) causes severe hemorrhagic fever in humans and non-human primates with high rates of fatality. Glycoprotein(GP) is the only envelope protein of EBOV, which may play a critical role in virus attachment and entry as well as stimulating host protective immune responses.However, the lack of expression of full-length GP in Escherichia coli hinders the further study of its function in viral pathogenesis. In this study, the vp40 gene was fused to the full-length gp gene and cloned into a prokaryotic expression vector. We showed that the VP40-GP and GP-VP40 fusion proteins could be expressed in E.coli at 16 ℃. In addition, it was shown that the position of vp40 in the fusion proteins affected the yields of the fusion proteins, with a higher level of production of the fusion protein when vp40 was upstream of gp compared to when it was downstream. The results provide a strategy for the expression of a large quantity of EBOV full-length GP, which is of importance for further analyzing the relationship between the structure and function of GP and developing an antibody for the treatment of EBOV infection.
