Ca2＋ has been established as an important second messenger regulating pollen germination and tube growth. However, to date, only a few signaling components have been identified to decode and relay Ca2＋ signals in gr...Ca2＋ has been established as an important second messenger regulating pollen germination and tube growth. However, to date, only a few signaling components have been identified to decode and relay Ca2＋ signals in growing pollen tubes. Here, we report a function for the calcineurin B-like （CBL） Ca2＋ sensor proteins CBL1 and CBL9 from Arabidopsis in pollen germination and tube growth. Both proteins are expressed in mature pollen and pollen tubes and impair pollen tube growth and morphology if transiently overexpressed in tobacco pollen. The induction of these phenotypes requires efficient plasma membrane targeting of CBL1 and is independent of Ca2＋ binding to the fourth EF-hand of CBL1. Overexpression of CBL1 or its closest homolog CBL9 in Arabidopsis renders pollen germination and tube growth hypersensitive towards high external K＋ concentrations while disruption of CBL1 and CBL9 reduces pollen tube growth under low K~ conditions. Together, our data identify a crucial function for CBL1 and CBL9 in pollen germination and tube growth and suggest a model in which both proteins act at the plasma membrane through regulation of K＋ homeostasis.展开更多
The effects of fertilization on activity and composition of soil microbial community depend on nutrient and water availability;however,the combination of these factors on the response of microorganisms was seldom stud...The effects of fertilization on activity and composition of soil microbial community depend on nutrient and water availability;however,the combination of these factors on the response of microorganisms was seldom studied.This study investigated the responses of soil microbial community and enzyme activities to changes in moisture along a gradient of soil fertility formed within a long-term(24 years)field experiment.Soils(0–20 cm)were sampled from the plots under four fertilizer treatments:i)unfertilized control(CK),ii)organic manure(M),iii)nitrogen,phosphorus,and potassium fertilizers(NPK),and iv)NPK plus M(NPK+M).The soils were incubated at three moisture levels:constant submergence,five submerging-draining cycles(S-D cycles),and constant moisture content at 40%water-holding capacity(low moisture).Compared with CK,fertilization increased soil organic carbon(SOC) by 30.1%–36.3%,total N by 27.3%–38.4%,available N by 35.9%–56.4%,available P by 61.4%–440.9%,and total P by 28.6%–102.9%.Soil fertility buffered the negative effects of moisture on enzyme activities and microbial community composition.Enzyme activities decreased in response to submergence and S-D cycles versus low moisture.Compared with low moisture,S-D cycles increased total phospholipid fatty acids(PLFAs)and actinomycete,fungal,and bacterial PLFAs.The increased level of PLFAs in the unfertilized soil after five S-D cycles was greater than that in the fertilized soil.Variations in soil microbial properties responding to moisture separated CK from the long-term fertilization treatments.The coefficients of variation of microbial properties were negatively correlated with SOC,total P,and available N.Soils with higher fertility maintained the original microbial properties more stable in response to changes in moisture compared to low-fertility soil.展开更多
In assessing an insect-resistant genetically engineered （IRGE） crop before its commercialization, researchers normally use so-called ＂Tier-1 assays＂ as the initial step to determine the effects of the crop on non-...In assessing an insect-resistant genetically engineered （IRGE） crop before its commercialization, researchers normally use so-called ＂Tier-1 assays＂ as the initial step to determine the effects of the crop on non-target organisms. In these tests, the insecticidal proteins （IPs） produced by the IRGEs are added to the diets of test organisms in the laboratory. Test organisms in such assays can be directly exposed to much higher concentrations of the test IPs than they would encounter in the field. The results of Tier-1 assays are thus more conservative than those generated in studies in which the organisms are exposed to the IPs by feeding on IRGE plant tissue or in the case of predators or parasites, by feeding on invertebrate prey or hosts that have fed on IRGE plant tissue. In this report, we consider three important factors that must be considered in Tier-1 assays： （i） methods for delivery of the IP to the test organisms; （ii） the need for and selection of compounds used as positive controls; and （iii） methods for monitoring the concentration, stability and bioactivity of the IP during the assay. We also analyze the existing data from Tier-1 assays regarding the toxicity of Bt Cry proteins to non-target arthropod species. The data indicate that the widely used Bt proteins have no direct toxicity to non-target organisms展开更多
In recent years,femtosecond(fs)-lasers have evolved into a versatile tool for high precision micromachining of transparent materials because nonlinear absorption in the focus can result in refractive index modificatio...In recent years,femtosecond(fs)-lasers have evolved into a versatile tool for high precision micromachining of transparent materials because nonlinear absorption in the focus can result in refractive index modifications or material disruptions.However,when high pulse energies or low numerical apertures are required,nonlinear side effects such as self-focusing,filamentation or white light generation can decrease the modification quality.In this paper,we apply simultaneous spatial and temporal focusing(SSTF)to overcome these limitations.The main advantage of SSTF is that the ultrashort pulse is only formed at the focal plane,thereby confining the intensity distribution strongly to the focal volume and suppressing detrimental nonlinear side effects.Thus,we investigate the optical breakdown within a water cell by pump-probe shadowgraphy,comparing conventional focusing and SSTF under equivalent focusing conditions.The plasma formation is well confined for low pulse energies,2 mJ,but higher pulse energies lead to the filamentation and break-up of the disruptions for conventional focusing,thereby decreasing the modification quality.In contrast,plasma induced by SSTF stays well confined to the focal plane,even for high pulse energies up to 8 mJ,preventing extended filaments,side branches or break-up of the disruptions.Furthermore,while conventional focusing leads to broadband supercontinuum generation,only marginal spectral broadening is observed using SSTF.These experimental findings are in excellent agreement with numerical simulations of the nonlinear pulse propagation and interaction processes.Therefore,SSTF appears to be a powerful tool to control the processing of transparent materials,e.g.,for precise ophthalmic fs-surgery.展开更多
Complex protein interaction networks constitute plant metabolic and signaling systems. Bimolecular fluorescence complementation （BiFC） is a suitable technique to investigate the formation of protein complexes and th...Complex protein interaction networks constitute plant metabolic and signaling systems. Bimolecular fluorescence complementation （BiFC） is a suitable technique to investigate the formation of protein complexes and the localization of protein-protein interactions in planta. However, the generation of large plasmid collections to facilitate the exploration of complex interaction networks is often limited by the need for conventional cloning techniques. Here, we report the implementation of a GATEWAY vector system enabling large-scale combination and investigation of candidate proteins in BiFC studies. We describe a set of 12 GATEWAY-compatible BiFC vectors that efficiently permit the combination of candidate protein pairs with every possible N-or C-terminal sub-fragment of S（CFP）3A or Venus, respectively, and enable the performance of multicolor BiFC （mcBiFC）. We used proteins of the plant molybdenum metabolism, in that more than 20 potentially interacting proteins are assumed to form the cellular molybdenum network, as a case study to establish the functionality of the new vectors. Using these vectors, we report the formation of the molybdopterin synthase complex by interaction of Arabidopsis proteins Cnx6 and Cnx7 detected by BiFC as well as the simultaneous formation of Cnx6/Cnx6 and Cnx6/Cnx7 complexes revealed by mcBiFC. Consequently, these GATEWAY-based BiFC vector systems should significantly facilitate the large-scale investigation of complex regulatory networks in plant cells.展开更多
Objectives:Timing of drain removal and its effects on complications after major pancreatectomy remain controversial.We designed this study to assess whether early drain removal after major pancreatectomy influences th...Objectives:Timing of drain removal and its effects on complications after major pancreatectomy remain controversial.We designed this study to assess whether early drain removal after major pancreatectomy influences the incidence of complications in the patients with low risk of postoperative pancreatic fistula(POPF).Methods:This is a single-center randomized controlled trial(RCT).A total of 144 patients undergoing pancreaticoduodenectomy(PD)and distal pancreatectomy(DP)who met the criteria,including drain amylase on postoperative day(POD)1 and 3 less than 5000 U/L and drain output within POD 3 less than 300 mL/d,were randomly assigned to early drain removal(POD 3)or standard drain removal(≥POD 5).The primary outcome was major complications(Clavien-Dindo grades 2-4),and the secondary outcome was POPF,reintervention treatment,readmission,and total medical expense within 3 months after surgery.Results:A total of 5 patients in early drain removal group had at least 1 major complications(grades 2-4),compared to 15 patients in standard drain removal group(P=.028).The incidence of grade B/C pancreatic fistula was not significantly different(2.8%vs 0%).Multivariate analysis demonstrated that early drain removal was an independent factor associated with a reduced risk of major complications(P=.039,odds ratio=0.314).Majority of major complications occurred in PD patients,and only very few cases occurred in DP patients.Stratified analysis showed that early drain removal significantly reduced the major complications only in the patients undergoing PD.Conclusion:This single-center RCT shows early drain removal on POD 3 is safe for both DP and PD patients,under our criteria.Early drain removal could reduce the incidence of major complications in patients undergoing PD.展开更多
Dear Editor, Phytohormones are essential regulators of plant develop- ment, but their role in the signaling processes between plants and fungi during arbuscular mycorrhizal （AM） establishment is far from being unde...Dear Editor, Phytohormones are essential regulators of plant develop- ment, but their role in the signaling processes between plants and fungi during arbuscular mycorrhizal （AM） establishment is far from being understood （Ludwig-M011er, 2010）. AM coloni- zation leads to extensive effects on host metabolism, as revealed by transcriptome studies of AM plants （Hogekamp et al., 2011）. Some genes have been specified as an AM core set, since they are mycorrhizal-responsive, irrespective of the identity of the plant,展开更多
Genome-wide association studies(GWASs)have identified hundreds of loci across the human genome conferring susceptibility to autoimmune diseases(AIDs),some of which are shared between more than two diseases.However,thi...Genome-wide association studies(GWASs)have identified hundreds of loci across the human genome conferring susceptibility to autoimmune diseases(AIDs),some of which are shared between more than two diseases.However,this univariate approach has limitations in detecting complex genotype-phenotype correlations.展开更多
Let M be a 3×3 integer matrix which is expanding in the sense that each of its eigenvalues is greater than 1 in modulus and let D?Z^(3)be a digit set containing|det M|elements.Then the unique nonempty compact set...Let M be a 3×3 integer matrix which is expanding in the sense that each of its eigenvalues is greater than 1 in modulus and let D?Z^(3)be a digit set containing|det M|elements.Then the unique nonempty compact set T=T(M,D)defined by the set equation MT=T+D is called an integral self-affine tile if its interior is nonempty.If D is of the form D={0,v,...,(|det M|-1)v},we say that T has a collinear digit set.The present paper is devoted to the topology of integral self-affine tiles with collinear digit sets.In particular,we prove that a large class of these tiles is homeomorphic to a closed 3-dimensional ball.Moreover,we show that in this case,T carries a natural CW complex structure that is defined in terms of the intersections of T with its neighbors in the lattice tiling{T+z:z∈Z^(3)}induced by T.This CW complex structure is isomorphic to the CW complex defined by the truncated octahedron.展开更多
In the last years, increasing smartphones’ capabilities have caused a paradigm shift in the way of users’ view and using mobile devices. Although researchers have started to focus on behavioral models to explain and...In the last years, increasing smartphones’ capabilities have caused a paradigm shift in the way of users’ view and using mobile devices. Although researchers have started to focus on behavioral models to explain and predict human behavior, there is limited empirical research about the influence of smartphone users’ individual differences on the usage of security measures. The aim of this study is to examine the influence of individual differences on cognitive determinants of behavioral intention to use security measures. Individual differences are measured by the Five-Factor Model;cognitive determinants of behavioral intention are adapted from the validated behavioral models theory of planned behavior and technology acceptance model. An explorative, quantitative survey of 435 smartphone users is served as data basis. The results suggest that multiple facets of smartphone user’s personalities significantly affect the cognitive determinants, which indicate the behavioral intention to use security measures. From these findings, practical and theoretical implications for companies, organizations, and researchers are derived and discussed.展开更多
Herein,a one-step co-pyrolysis protocol was adopted for the first time to prepare a novel pyrogenic carbon-Cu^(0)/Fe_(3)O_(4)heteroatoms (FCBC) in CO_(2)ambiance to discern the roles of each component in PDS activatio...Herein,a one-step co-pyrolysis protocol was adopted for the first time to prepare a novel pyrogenic carbon-Cu^(0)/Fe_(3)O_(4)heteroatoms (FCBC) in CO_(2)ambiance to discern the roles of each component in PDS activation.During co-pyrolysis,CO_(2)catalyzed formation of reducing gases by biomass which facilitated reductive transformation of Fe^(3+)and Cu^(2+)to Cu^(0)and Fe_(3)O_(4),respectively.According to the analysis,the resulting metal (oxide) catalyzed graphitization of biocharand decomposition of volatile substances resulting in an unprecedented surface area (1240 m^(2)/g).The resulting FCBC showed greater structural defects and less electrical impedance.Batch experiments indicated that Rhodamine B (RhB) degradation by FCBC (100%) was superior to Fe_(3)O_(4)(50%) and Cu^(0)/Fe_(3)O_(4)(76.4%) in persulfate (PDS) system,which maintained reasonable efficiency (75.6%-63.6%) within three cycles.The reactive oxygen species (ROS) associated with RhB degradation was identified by an electron paramagnetic resonance and confirmed by scavenging experiments.RhB degradation invoked both(sulfate and dominantly hydroxyl) radical and non-radical (singlet oxygen,^(1)O_(2)) pathways.Regarding FCBC,Cu^(0)can continuously react with Fe^(3+)in Fe_(3)O_(4)to generate larger quantities of Fe^(2+),and both Cu^(0)and Fe^(2+)activated PDS to yield sulfate radicals which was quickly converted to hydroxyl radical.Besides,Cu^(0)/Cu^(2+)could complex with PDS to form a metastable complex,which particularly contributed to1O_(2)generation.These cascade reactions by FCBC were reinforced by carbonyl group of biochar and favorable electron transfer ability.This work highlighted a new approach to prepare a magnetic and environment-benign heterogonous catalyst to remove organic pollutants in water.展开更多
Lithium's(Li)ubiquitous distribution in the environment is a rising concern due to its rapid proliferation in the modern electronic industry.Li enigmatic entry into the terrestrial food chain raises many questions...Lithium's(Li)ubiquitous distribution in the environment is a rising concern due to its rapid proliferation in the modern electronic industry.Li enigmatic entry into the terrestrial food chain raises many questions and uncertainties that may pose a grave threat to living biota.We examined the leverage existing published articles regarding advances in global Li resources,interplay with plants,and possible involvement with living organisms,especially humans and animals.Globally,Li concentration(<10 e300 mg kg1)is detected in agricultural soil,and their pollutant levels vary with space and time.High mobility of Li results in higher accumulation in plants,but the clear mechanisms and specific functions remain unknown.Our assessment reveals the causal relationship between Li level and biota health.For example,lower Li intake(<0.6 mM in serum)leads to mental disorders,while higher intake(>1.5 mM in serum)induces thyroid,stomach,kidney,and reproductive system dysfunctions in humans and animals.However,there is a serious knowledge gap regarding Li regulatory standards in environmental compartments,and mechanistic approaches to unveil its consequences are needed.Furthermore,aggressive efforts are required to define optimum levels of Li for the normal functioning of animals,plants,and humans.This review is designed to revitalize the current status of Li research and identify the key knowledge gaps to fight back against the mountainous challenges of Li during the recent digital revolution.Additionally,we propose pathways to overcome Li problems and develop a strategy for effective,safe,and acceptable applications.展开更多
基金This work was supported by the British Heart Foundation, Heart Research UK, Biotechnology and Biological Sciences Research Council, Medical Research Council, Wellcome Trust, KC Wong/China Scholarship Council, and EU COST ACTION B35.
文摘Ca2＋ has been established as an important second messenger regulating pollen germination and tube growth. However, to date, only a few signaling components have been identified to decode and relay Ca2＋ signals in growing pollen tubes. Here, we report a function for the calcineurin B-like （CBL） Ca2＋ sensor proteins CBL1 and CBL9 from Arabidopsis in pollen germination and tube growth. Both proteins are expressed in mature pollen and pollen tubes and impair pollen tube growth and morphology if transiently overexpressed in tobacco pollen. The induction of these phenotypes requires efficient plasma membrane targeting of CBL1 and is independent of Ca2＋ binding to the fourth EF-hand of CBL1. Overexpression of CBL1 or its closest homolog CBL9 in Arabidopsis renders pollen germination and tube growth hypersensitive towards high external K＋ concentrations while disruption of CBL1 and CBL9 reduces pollen tube growth under low K~ conditions. Together, our data identify a crucial function for CBL1 and CBL9 in pollen germination and tube growth and suggest a model in which both proteins act at the plasma membrane through regulation of K＋ homeostasis.
文摘The effects of fertilization on activity and composition of soil microbial community depend on nutrient and water availability;however,the combination of these factors on the response of microorganisms was seldom studied.This study investigated the responses of soil microbial community and enzyme activities to changes in moisture along a gradient of soil fertility formed within a long-term(24 years)field experiment.Soils(0–20 cm)were sampled from the plots under four fertilizer treatments:i)unfertilized control(CK),ii)organic manure(M),iii)nitrogen,phosphorus,and potassium fertilizers(NPK),and iv)NPK plus M(NPK+M).The soils were incubated at three moisture levels:constant submergence,five submerging-draining cycles(S-D cycles),and constant moisture content at 40%water-holding capacity(low moisture).Compared with CK,fertilization increased soil organic carbon(SOC) by 30.1%–36.3%,total N by 27.3%–38.4%,available N by 35.9%–56.4%,available P by 61.4%–440.9%,and total P by 28.6%–102.9%.Soil fertility buffered the negative effects of moisture on enzyme activities and microbial community composition.Enzyme activities decreased in response to submergence and S-D cycles versus low moisture.Compared with low moisture,S-D cycles increased total phospholipid fatty acids(PLFAs)and actinomycete,fungal,and bacterial PLFAs.The increased level of PLFAs in the unfertilized soil after five S-D cycles was greater than that in the fertilized soil.Variations in soil microbial properties responding to moisture separated CK from the long-term fertilization treatments.The coefficients of variation of microbial properties were negatively correlated with SOC,total P,and available N.Soils with higher fertility maintained the original microbial properties more stable in response to changes in moisture compared to low-fertility soil.
文摘In assessing an insect-resistant genetically engineered （IRGE） crop before its commercialization, researchers normally use so-called ＂Tier-1 assays＂ as the initial step to determine the effects of the crop on non-target organisms. In these tests, the insecticidal proteins （IPs） produced by the IRGEs are added to the diets of test organisms in the laboratory. Test organisms in such assays can be directly exposed to much higher concentrations of the test IPs than they would encounter in the field. The results of Tier-1 assays are thus more conservative than those generated in studies in which the organisms are exposed to the IPs by feeding on IRGE plant tissue or in the case of predators or parasites, by feeding on invertebrate prey or hosts that have fed on IRGE plant tissue. In this report, we consider three important factors that must be considered in Tier-1 assays： （i） methods for delivery of the IP to the test organisms; （ii） the need for and selection of compounds used as positive controls; and （iii） methods for monitoring the concentration, stability and bioactivity of the IP during the assay. We also analyze the existing data from Tier-1 assays regarding the toxicity of Bt Cry proteins to non-target arthropod species. The data indicate that the widely used Bt proteins have no direct toxicity to non-target organisms
基金This study was supported by the Thuringian Ministry of Education,Science and Culture(OptiMi 2020-Graduate Research School‘Green Photonics’,B514-10061)the German Research Foundation(Leibniz program)the Carl Zeiss Foundation.
文摘In recent years,femtosecond(fs)-lasers have evolved into a versatile tool for high precision micromachining of transparent materials because nonlinear absorption in the focus can result in refractive index modifications or material disruptions.However,when high pulse energies or low numerical apertures are required,nonlinear side effects such as self-focusing,filamentation or white light generation can decrease the modification quality.In this paper,we apply simultaneous spatial and temporal focusing(SSTF)to overcome these limitations.The main advantage of SSTF is that the ultrashort pulse is only formed at the focal plane,thereby confining the intensity distribution strongly to the focal volume and suppressing detrimental nonlinear side effects.Thus,we investigate the optical breakdown within a water cell by pump-probe shadowgraphy,comparing conventional focusing and SSTF under equivalent focusing conditions.The plasma formation is well confined for low pulse energies,2 mJ,but higher pulse energies lead to the filamentation and break-up of the disruptions for conventional focusing,thereby decreasing the modification quality.In contrast,plasma induced by SSTF stays well confined to the focal plane,even for high pulse energies up to 8 mJ,preventing extended filaments,side branches or break-up of the disruptions.Furthermore,while conventional focusing leads to broadband supercontinuum generation,only marginal spectral broadening is observed using SSTF.These experimental findings are in excellent agreement with numerical simulations of the nonlinear pulse propagation and interaction processes.Therefore,SSTF appears to be a powerful tool to control the processing of transparent materials,e.g.,for precise ophthalmic fs-surgery.
文摘Complex protein interaction networks constitute plant metabolic and signaling systems. Bimolecular fluorescence complementation （BiFC） is a suitable technique to investigate the formation of protein complexes and the localization of protein-protein interactions in planta. However, the generation of large plasmid collections to facilitate the exploration of complex interaction networks is often limited by the need for conventional cloning techniques. Here, we report the implementation of a GATEWAY vector system enabling large-scale combination and investigation of candidate proteins in BiFC studies. We describe a set of 12 GATEWAY-compatible BiFC vectors that efficiently permit the combination of candidate protein pairs with every possible N-or C-terminal sub-fragment of S（CFP）3A or Venus, respectively, and enable the performance of multicolor BiFC （mcBiFC）. We used proteins of the plant molybdenum metabolism, in that more than 20 potentially interacting proteins are assumed to form the cellular molybdenum network, as a case study to establish the functionality of the new vectors. Using these vectors, we report the formation of the molybdopterin synthase complex by interaction of Arabidopsis proteins Cnx6 and Cnx7 detected by BiFC as well as the simultaneous formation of Cnx6/Cnx6 and Cnx6/Cnx7 complexes revealed by mcBiFC. Consequently, these GATEWAY-based BiFC vector systems should significantly facilitate the large-scale investigation of complex regulatory networks in plant cells.
基金This study was supported by the project of application and promotion of capital special clinical research from Beijing Municipal Science&Technology Commission(Z171100001017017018).
文摘Objectives:Timing of drain removal and its effects on complications after major pancreatectomy remain controversial.We designed this study to assess whether early drain removal after major pancreatectomy influences the incidence of complications in the patients with low risk of postoperative pancreatic fistula(POPF).Methods:This is a single-center randomized controlled trial(RCT).A total of 144 patients undergoing pancreaticoduodenectomy(PD)and distal pancreatectomy(DP)who met the criteria,including drain amylase on postoperative day(POD)1 and 3 less than 5000 U/L and drain output within POD 3 less than 300 mL/d,were randomly assigned to early drain removal(POD 3)or standard drain removal(≥POD 5).The primary outcome was major complications(Clavien-Dindo grades 2-4),and the secondary outcome was POPF,reintervention treatment,readmission,and total medical expense within 3 months after surgery.Results:A total of 5 patients in early drain removal group had at least 1 major complications(grades 2-4),compared to 15 patients in standard drain removal group(P=.028).The incidence of grade B/C pancreatic fistula was not significantly different(2.8%vs 0%).Multivariate analysis demonstrated that early drain removal was an independent factor associated with a reduced risk of major complications(P=.039,odds ratio=0.314).Majority of major complications occurred in PD patients,and only very few cases occurred in DP patients.Stratified analysis showed that early drain removal significantly reduced the major complications only in the patients undergoing PD.Conclusion:This single-center RCT shows early drain removal on POD 3 is safe for both DP and PD patients,under our criteria.Early drain removal could reduce the incidence of major complications in patients undergoing PD.
文摘Dear Editor, Phytohormones are essential regulators of plant develop- ment, but their role in the signaling processes between plants and fungi during arbuscular mycorrhizal （AM） establishment is far from being understood （Ludwig-M011er, 2010）. AM coloni- zation leads to extensive effects on host metabolism, as revealed by transcriptome studies of AM plants （Hogekamp et al., 2011）. Some genes have been specified as an AM core set, since they are mycorrhizal-responsive, irrespective of the identity of the plant,
基金financed by Minciencias title proyect"Variantes geneticas y mutaciones genomicas identificadas por secuenciacion de ultima generacion(NGS)en familias colombianas:en busca de marcadores comunes de tautologia autoinmune-No.121577758377"was partially supported from Universidad del Norte,Barranquilla,Colombia.
文摘Genome-wide association studies(GWASs)have identified hundreds of loci across the human genome conferring susceptibility to autoimmune diseases(AIDs),some of which are shared between more than two diseases.However,this univariate approach has limitations in detecting complex genotype-phenotype correlations.
基金supported by a grant funded by the Austrian Science Fund and the Russian Science Foundation(Grant No.I 5554)supported by National Natural Science Foundation of China(Grant No.12101566)。
文摘Let M be a 3×3 integer matrix which is expanding in the sense that each of its eigenvalues is greater than 1 in modulus and let D?Z^(3)be a digit set containing|det M|elements.Then the unique nonempty compact set T=T(M,D)defined by the set equation MT=T+D is called an integral self-affine tile if its interior is nonempty.If D is of the form D={0,v,...,(|det M|-1)v},we say that T has a collinear digit set.The present paper is devoted to the topology of integral self-affine tiles with collinear digit sets.In particular,we prove that a large class of these tiles is homeomorphic to a closed 3-dimensional ball.Moreover,we show that in this case,T carries a natural CW complex structure that is defined in terms of the intersections of T with its neighbors in the lattice tiling{T+z:z∈Z^(3)}induced by T.This CW complex structure is isomorphic to the CW complex defined by the truncated octahedron.
文摘In the last years, increasing smartphones’ capabilities have caused a paradigm shift in the way of users’ view and using mobile devices. Although researchers have started to focus on behavioral models to explain and predict human behavior, there is limited empirical research about the influence of smartphone users’ individual differences on the usage of security measures. The aim of this study is to examine the influence of individual differences on cognitive determinants of behavioral intention to use security measures. Individual differences are measured by the Five-Factor Model;cognitive determinants of behavioral intention are adapted from the validated behavioral models theory of planned behavior and technology acceptance model. An explorative, quantitative survey of 435 smartphone users is served as data basis. The results suggest that multiple facets of smartphone user’s personalities significantly affect the cognitive determinants, which indicate the behavioral intention to use security measures. From these findings, practical and theoretical implications for companies, organizations, and researchers are derived and discussed.
基金supported by the National Natural Science Foundation of China (Nos. 41771349, 41977117, 41977085)Qing-Lan Project of Yangzhou University (2020)+2 种基金High-level Talent Support Plan of Yangzhou University (2019)the Key Research and Development Program of Zhejiang Province (No. 2019C02053)Foreign Expert Recruitment Program of Jiangsu Province (No. BX2020050)。
文摘Herein,a one-step co-pyrolysis protocol was adopted for the first time to prepare a novel pyrogenic carbon-Cu^(0)/Fe_(3)O_(4)heteroatoms (FCBC) in CO_(2)ambiance to discern the roles of each component in PDS activation.During co-pyrolysis,CO_(2)catalyzed formation of reducing gases by biomass which facilitated reductive transformation of Fe^(3+)and Cu^(2+)to Cu^(0)and Fe_(3)O_(4),respectively.According to the analysis,the resulting metal (oxide) catalyzed graphitization of biocharand decomposition of volatile substances resulting in an unprecedented surface area (1240 m^(2)/g).The resulting FCBC showed greater structural defects and less electrical impedance.Batch experiments indicated that Rhodamine B (RhB) degradation by FCBC (100%) was superior to Fe_(3)O_(4)(50%) and Cu^(0)/Fe_(3)O_(4)(76.4%) in persulfate (PDS) system,which maintained reasonable efficiency (75.6%-63.6%) within three cycles.The reactive oxygen species (ROS) associated with RhB degradation was identified by an electron paramagnetic resonance and confirmed by scavenging experiments.RhB degradation invoked both(sulfate and dominantly hydroxyl) radical and non-radical (singlet oxygen,^(1)O_(2)) pathways.Regarding FCBC,Cu^(0)can continuously react with Fe^(3+)in Fe_(3)O_(4)to generate larger quantities of Fe^(2+),and both Cu^(0)and Fe^(2+)activated PDS to yield sulfate radicals which was quickly converted to hydroxyl radical.Besides,Cu^(0)/Cu^(2+)could complex with PDS to form a metastable complex,which particularly contributed to1O_(2)generation.These cascade reactions by FCBC were reinforced by carbonyl group of biochar and favorable electron transfer ability.This work highlighted a new approach to prepare a magnetic and environment-benign heterogonous catalyst to remove organic pollutants in water.
基金funded by the The 111 project of the Education Ministry of China(B18053)The National Natural Science Foundation(32130081).
文摘Lithium's(Li)ubiquitous distribution in the environment is a rising concern due to its rapid proliferation in the modern electronic industry.Li enigmatic entry into the terrestrial food chain raises many questions and uncertainties that may pose a grave threat to living biota.We examined the leverage existing published articles regarding advances in global Li resources,interplay with plants,and possible involvement with living organisms,especially humans and animals.Globally,Li concentration(<10 e300 mg kg1)is detected in agricultural soil,and their pollutant levels vary with space and time.High mobility of Li results in higher accumulation in plants,but the clear mechanisms and specific functions remain unknown.Our assessment reveals the causal relationship between Li level and biota health.For example,lower Li intake(<0.6 mM in serum)leads to mental disorders,while higher intake(>1.5 mM in serum)induces thyroid,stomach,kidney,and reproductive system dysfunctions in humans and animals.However,there is a serious knowledge gap regarding Li regulatory standards in environmental compartments,and mechanistic approaches to unveil its consequences are needed.Furthermore,aggressive efforts are required to define optimum levels of Li for the normal functioning of animals,plants,and humans.This review is designed to revitalize the current status of Li research and identify the key knowledge gaps to fight back against the mountainous challenges of Li during the recent digital revolution.Additionally,we propose pathways to overcome Li problems and develop a strategy for effective,safe,and acceptable applications.
