Accumulating evidence suggests that the nucleus accumbens, which is involved in mechanisms of reward and addiction, plays a role in the pathogenesis of depression and in the action of anti-depressants. In the current ...Accumulating evidence suggests that the nucleus accumbens, which is involved in mechanisms of reward and addiction, plays a role in the pathogenesis of depression and in the action of anti-depressants. In the current study, intraperitoneal injection of nomifensine, a dopamine reuptake inhibitor, decreased depression-like behaviors in the Wistar Kyoto rat model of depression in the sucrose-preference and forced swim tests. Nomifensine also reduced membrane excitability in medium spiny neurons in the core of the nucleus accumbens in the childhood Wistar Kyoto rats as evaluated by electrophysiological recording. In addition, the expression of dopamine D2-like receptor mRNA was downregulated in the nucleus accumbens, striatum and hippocampus of nomifensine-treated childhood Wistar Kyoto rats. These experimental ifndings indicate that impaired inhibition of medium spiny neurons, mediated by dopamine D2-like receptors, may be involved in the formation of depression-like behavior in childhood Wistar Kyoto rats, and that nomifensine can alleviate depressive behaviors by reducing medium spiny neuron membrane excitability.展开更多
During effector-triggered immunity(ETI)against the devastating rice blast pathogen Magnaporthe oryzae,Pi9 functions as an intracellular resistance protein sensing the pathogen-secreted effector AvrPi9 in rice.Importan...During effector-triggered immunity(ETI)against the devastating rice blast pathogen Magnaporthe oryzae,Pi9 functions as an intracellular resistance protein sensing the pathogen-secreted effector AvrPi9 in rice.Importantly,the underlying recognition mechanism(s)between Pi9 and AvrPi9 remains elusive.In this study,We identified a rice ubiquitin-like domain-containing protein(UDP),AVRPI9-INTERACTING PROTEIN 1(ANP1),which is directly targeted by AvrPi9 and also binds to Pi9 in plants.Phenotypic analysis of anip1 mu-tants and plants overexpressing ANIP1 revealed that ANIP1 negatively modulates rice basal defense against M.oryzae.ANiP1 undergoes 26S proteasome-mediated degradation,which can be blocked by both AvrPi9 and Pi9.Moreover,ANIP1 physically associates with the rice WRKY transcription factor OsWRKY62,which also interacts with AvrPi9 and Pi9 in plants.In the absence of Pi9,ANIP1 negatively regulates OsWRKY62 abundance,which can be promoted by AvrPi9.Accordingly,knocking out of OsWRKY62 in a non-Pi9 back-ground decreased immunity against M.oryzae.However,we also observed that OsWRKY62 plays negative roles in defense against a compatible M.oryzae strain in Pi9-harboring rice.Pi9 binds to ANiP1 and OsWRKY62 to form a complex,which may help to keep Pi9 in an inactive state and weaken rice immunity.Furthermore,using competitive binding assays,we showed that AvrPi9 promotes Pi9 dissociation from ANiP1,which could be an important step toward ETI activation.Taken together,our results reveal an immune strategy whereby a UDP-WRKY module,targeted by a fungal effector,modulates rice immunity in distinct ways in the presence or absence of the corresponding resistance protein.展开更多
Electroactive biofilm plays a crucial rule in the electron transfer efficiency of microbial electrochemical systems(MES).However,the low ability to form biofilm and the low conductivity of the formed biofilm substanti...Electroactive biofilm plays a crucial rule in the electron transfer efficiency of microbial electrochemical systems(MES).However,the low ability to form biofilm and the low conductivity of the formed biofilm substantially limit the extracellular electron transfer rate of microbial cells to the electrode surfaces in MES.展开更多
The activation of NLRC4 is a major host response against intracellular bacteria infection.However,NLRC4 activation after a host senses diverse stimuli is difficult to understand.Here,we found that the IncRNA LNCGM1082...The activation of NLRC4 is a major host response against intracellular bacteria infection.However,NLRC4 activation after a host senses diverse stimuli is difficult to understand.Here,we found that the IncRNA LNCGM1082 plays a critical role in the activation of NLRC4.LNCGM1082 in macrophages affects the maturation of interleukin(IL)-1βand pyroptotic cell death only after exposure to an NLRC4 ligand.Similar to NLRC4-/-mice,LNCGM1082-/-mice were highly sensitive to Salmonella Typhimurium(S.T)infection.LNCGM1082 deficiency in mouse or human macrophages inhibited IL-1βmaturation and pyroptosis.Mechanistically,LNCGM1082 induced the binding of PKCS with NLRC4 in both mice and humans.In contrast,NLRC4 did not bind PKCo in LNCGM1082-/-macrophages.The activity of the IncRNA LNCGM1082 induced by S.T may be mediated through TLR5 in the macrophages of both mice and humans.In summary,our data indicate that TLR5-mediated LNCGM1082 activity can promote the binding of PKC with NLRC4 to activate NLRC4 and induce resistance to bacterial infection.展开更多
Electroactive microorganisms(EAMs)could utilize extracellular electron transfer(EET)pathways to exchange electrons and energy with their external surroundings.Conductive cytochrome proteins and nanowires play crucial ...Electroactive microorganisms(EAMs)could utilize extracellular electron transfer(EET)pathways to exchange electrons and energy with their external surroundings.Conductive cytochrome proteins and nanowires play crucial roles in controlling electron transfer rate from cytosol to extracellular electrode.Many previous studies elucidated how the c-type cytochrome proteins and conductive nanowires are synthesized,assembled,and engineered to manipulate the EET rate,and quantified the kinetic processes of electron generation and EET.Here,we firstly overview the electron transfer pathways of EAMs and quantify the kinetic parameters that dictating intracellular electron production and EET.Secondly,we systematically review the structure,conductivity mechanisms,and engineering strategies to manipulate conductive cytochromes and nanowire in EAMs.Lastly,we outlook potential directions for future research in cytochromes and conductive nanowires for enhanced electron transfer.This article reviews the quantitative kinetics of intracellular electron production and EET,and the contribution of engineered c-type cytochromes and conductive nanowire in enhancing the EET rate,which lay the foundation for enhancing electron transfer capacity of EAMs.展开更多
产电微生物是微生物燃料电池、电解池和电合成等微生物电化学技术(Microbial electrochemical technologies,METs)的研究基础。产电微生物与电极界面间的胞外电子传递(Extracellular electron transfer,EET)效率低以及生物被膜形成能力...产电微生物是微生物燃料电池、电解池和电合成等微生物电化学技术(Microbial electrochemical technologies,METs)的研究基础。产电微生物与电极界面间的胞外电子传递(Extracellular electron transfer,EET)效率低以及生物被膜形成能力弱限制了METs在有机物降解、电能生产、海水淡化、生物修复和生物传感等方面的应用。因此,强化产电微生物与电极界面间的相互作用是过去几年的主要研究热点。针对近年的研究,本文系统概述了通过改造产电微生物来增强微生物-电极间相互作用的各种策略,重点分析了这些策略的适用性和局限性,并展望了强化产电微生物-电极界面作用在微生物电化学技术利用方面的研究前景。展开更多
In the previous construction of attributed-based encryption for circuits on lattices, the secret key size was exponential to the number of AND gates of the circuit. Therefore, it was suitable for the shallow circuits ...In the previous construction of attributed-based encryption for circuits on lattices, the secret key size was exponential to the number of AND gates of the circuit. Therefore, it was suitable for the shallow circuits whose depth is bounded. For decreasing the key size of previous scheme, combining the techniques of Two-to-One Recoding (TOR), and sampling on lattices, we propose a new Key-Policy Attribute-Based Encryption (KP-ABE) scheme for circuits of any arbitrary polynomial on lattices, and prove that the scheme is secure against chosen plaintext attack in the selective model under the Learning With Errors (LWE) assumptions. In our scheme, the key size is proportional to the number of gates or wires in the circuits.展开更多
Electroactive bacteria could perform bi-directional extracellular electron transfer(EET)to exchange electrons and energy with extracellular environments,thus playing a central role in microbial electro-fermentation(EF...Electroactive bacteria could perform bi-directional extracellular electron transfer(EET)to exchange electrons and energy with extracellular environments,thus playing a central role in microbial electro-fermentation(EF)process.Unbalanced fermentation and microbial electrosynthesis are the main pathways to produce value-added chemicals and biofuels.However,the low efficiency of the bi-directional EET is a dominating bottleneck in these processes.In this review,we firstly demonstrate the main bi-directional EET mechanisms during EF,including the direct EET and the shuttle-mediated EET.Then,we review representative milestones and progresses in unbalanced fermentation via anode outward EET and microbial electrosynthesis via inward EET based on these two EET mechanisms in detail.Furthermore,we summarize the main synthetic biology strategies in improving the bi-directional EET and target products synthesis,thus to enhance the efficiencies in unbalanced fermentation and microbial electrosynthesis.Lastly,a perspective on the applications of microbial electro-fermentation is provided.展开更多
A new kind of open cellular foam material with three dimensionally interconnected TiC/Ti struts was prepared by a two-step sponge-coating and high frequency induction heating process. The microstructure, composition a...A new kind of open cellular foam material with three dimensionally interconnected TiC/Ti struts was prepared by a two-step sponge-coating and high frequency induction heating process. The microstructure, composition and compression strength of the prepared TiC/Ti foam materials were characterized. It was confirmed that the incorporation of Ti into TiC resulted in an inter-bonded Ti-TiC-Ti layered structure in the struts, which enhanced the plasticity of the composite foam materials.展开更多
We investigated the macro-and micro-mechanical properties of rigid-grain and soft-chip mixtures(GCMs)through numerical simulations using the discrete element method.We present a novel framework for the discrete modeli...We investigated the macro-and micro-mechanical properties of rigid-grain and soft-chip mixtures(GCMs)through numerical simulations using the discrete element method.We present a novel framework for the discrete modeling of soft chips and rigid grains in conjunction with calibration processes.Several numerical triaxial tests were also performed on GCMs with 0%,10%,20%,and 30%volumetric chip contents,P.The simulation results demonstrate that increasing P leads to higher GCM toughness,higher deviatoric peak stress,and higher corresponding shear strain.Higher P also contributes to more volume contraction and less dilation.The friction angles at both the peak and residual state significantly increase with increasing P.In view of the micro-mechanical features,strong contact force chains develop along the loading direction,which results in considerable anisotropy in the peak and residual states.Both the formation of strong force chains and rotation of grains decrease with increasing P,whereas the grain sliding percentage increases.The tensile force is mobilized with shearing and higher P leads to less mobilization of the tensile force.These findings are useful for better understanding the internal structure of GCMs with different soft-chip contents,especially in granular mixture mechanics and geomechanics.展开更多
Electroactive microorganisms(EAMs)play important roles in biogeochemical redox processes and have been of great interest in the fields of energy recovery,waste treatment,and environmental remediation.However,the curre...Electroactive microorganisms(EAMs)play important roles in biogeochemical redox processes and have been of great interest in the fields of energy recovery,waste treatment,and environmental remediation.However,the currently identified EAMs are difficult to be widely used in complex and diverse environments,due to the existence of poor electron transfer capability,weak environmental adaptability,and difficulty with engineering modifications,etc.Therefore,rapid and efficient screening of high performance EAMs from environments is an effective strategy to facilitate applications of microbial fuel cells(MFCs).In this study,to achieve efficient degradation of methyl orange(MO)by MFC and electricity harvest,a more efficient exoelectrogen Shewanella carassii-D5 that belongs to Shewanella spp.was first isolated from activated sludge by WO_(3) nanocluster probe technique.Physiological properties experiments confirmed that S.carassii-D5 is a Gram-negative strain with rounded colonies and smooth,slightly reddish surface,which could survive in media containing lactate at 30℃.Moreover,we found that S.carassii-D5 exhibited remarkable MO degradation ability,which could degrade 66%of MO within 72 h,1.7 times higher than that of Shewanella oneidensis MR-1.Electrochemical measurements showed that MFCs inoculated with S.carassii-D5 could generate a maximum power density of 704.6 mW/m^(2),which was 5.6 times higher than that of S.oneidensis MR-1.Further investigation of the extracellular electron transfer(EET)mechanism found that S.carassii-D5 strain had high level of c-type cytochromes and strong biofilm formation ability compared with S.oneidensis MR-1,thus facilitating direct EET.Therefore,to enhance indirect electron transfer and MO degradation capacity,a synthetic gene cluster ribADEHC encoding riboflavin synthesis pathway from Bacillus subtilis was heterologously expressed in S.carassii-D5,increasing riboflavin yield from 1.9 to 9.0 mg/g DCW with 1286.3 mW/m^(2) power density output in lactate fed-MFCs.Furthermore,results showed that the high EET rate endowed a faster degradation efficient of MO from 66%to 86%with a maximum power density of 192.3 mW/m^(2),which was 1.3 and 1.6 times higher than that of S.carassii-D5,respectively.Our research suggests that screening and engineering high-efficient EAMs from sludge is a feasible strategy in treating organic pollutants.展开更多
An increasing number of web services are being invoked by users to create user applications(e.g.,mashups). However, over time, a few good services in service systems have become deprecated, i.e., the service is init...An increasing number of web services are being invoked by users to create user applications(e.g.,mashups). However, over time, a few good services in service systems have become deprecated, i.e., the service is initially available and is invoked by service users, but later becomes unavailable. Therefore, the prediction of service deprecation has become a key issue in creating reliable long-term user applications. Most existing research has overlooked service deprecation in service systems and has failed to consider long-term service reliability when making service recommendations. In this paper, we propose a method for predicting service deprecation, which comprises two components: Service Comprehensive Feature Modeling(SCFM) for extracting service features relevant to service deprecation and Deprecated Service Prediction(DSP) for building a service deprecation prediction model. Our experimental results on a real-world dataset demonstrate that our method yields an improved Area-Under-the-Curve(AUC) value over existing methods and thus has better accuracy in service deprecation prediction.展开更多
基金supported by the National Natural Science Foundation of China,No.31271198 and 81121001grants from the Shanghai Committee of Science and Technology,No.11ZR1415900the State Key Laboratory of Medical Neurobiology,Fudan University,No.10-12
文摘Accumulating evidence suggests that the nucleus accumbens, which is involved in mechanisms of reward and addiction, plays a role in the pathogenesis of depression and in the action of anti-depressants. In the current study, intraperitoneal injection of nomifensine, a dopamine reuptake inhibitor, decreased depression-like behaviors in the Wistar Kyoto rat model of depression in the sucrose-preference and forced swim tests. Nomifensine also reduced membrane excitability in medium spiny neurons in the core of the nucleus accumbens in the childhood Wistar Kyoto rats as evaluated by electrophysiological recording. In addition, the expression of dopamine D2-like receptor mRNA was downregulated in the nucleus accumbens, striatum and hippocampus of nomifensine-treated childhood Wistar Kyoto rats. These experimental ifndings indicate that impaired inhibition of medium spiny neurons, mediated by dopamine D2-like receptors, may be involved in the formation of depression-like behavior in childhood Wistar Kyoto rats, and that nomifensine can alleviate depressive behaviors by reducing medium spiny neuron membrane excitability.
基金supported by grants from the National Natural Science Foundation of China(31972229)the Agricultural Science and Technology Innovation Program(ASTIP)+1 种基金the Pests and Diseases Green Prevention and Control Major Special Project([110202101045([LS-05)]China Postdoctoral Science Foundation awards 2019M660893 and 2020T130710.
文摘During effector-triggered immunity(ETI)against the devastating rice blast pathogen Magnaporthe oryzae,Pi9 functions as an intracellular resistance protein sensing the pathogen-secreted effector AvrPi9 in rice.Importantly,the underlying recognition mechanism(s)between Pi9 and AvrPi9 remains elusive.In this study,We identified a rice ubiquitin-like domain-containing protein(UDP),AVRPI9-INTERACTING PROTEIN 1(ANP1),which is directly targeted by AvrPi9 and also binds to Pi9 in plants.Phenotypic analysis of anip1 mu-tants and plants overexpressing ANIP1 revealed that ANIP1 negatively modulates rice basal defense against M.oryzae.ANiP1 undergoes 26S proteasome-mediated degradation,which can be blocked by both AvrPi9 and Pi9.Moreover,ANIP1 physically associates with the rice WRKY transcription factor OsWRKY62,which also interacts with AvrPi9 and Pi9 in plants.In the absence of Pi9,ANIP1 negatively regulates OsWRKY62 abundance,which can be promoted by AvrPi9.Accordingly,knocking out of OsWRKY62 in a non-Pi9 back-ground decreased immunity against M.oryzae.However,we also observed that OsWRKY62 plays negative roles in defense against a compatible M.oryzae strain in Pi9-harboring rice.Pi9 binds to ANiP1 and OsWRKY62 to form a complex,which may help to keep Pi9 in an inactive state and weaken rice immunity.Furthermore,using competitive binding assays,we showed that AvrPi9 promotes Pi9 dissociation from ANiP1,which could be an important step toward ETI activation.Taken together,our results reveal an immune strategy whereby a UDP-WRKY module,targeted by a fungal effector,modulates rice immunity in distinct ways in the presence or absence of the corresponding resistance protein.
基金This research was supported by the National Key Research and Development Program of China(2018YFA0901300)the National Natural Science Foundation of China(NSFC 32071411,32001034,and 21621004)the Tianjin Science and Technology Plan Project(20JCQNJC00830).
文摘Electroactive biofilm plays a crucial rule in the electron transfer efficiency of microbial electrochemical systems(MES).However,the low ability to form biofilm and the low conductivity of the formed biofilm substantially limit the extracellular electron transfer rate of microbial cells to the electrode surfaces in MES.
基金NSFC grants(grant numbers 81901677,82271779,91842302,81970457,and 91629102)The Tianjin Science and Technology Commission(grant number,18JCZDJC35300)+1 种基金A Ministry of Science and Technology(grant number,2016YFC1303604)The State Key Laboratory of Medicinal Chemical Biology and the Fundamental Research Funds for the Central University,Nankai university(63191724).
文摘The activation of NLRC4 is a major host response against intracellular bacteria infection.However,NLRC4 activation after a host senses diverse stimuli is difficult to understand.Here,we found that the IncRNA LNCGM1082 plays a critical role in the activation of NLRC4.LNCGM1082 in macrophages affects the maturation of interleukin(IL)-1βand pyroptotic cell death only after exposure to an NLRC4 ligand.Similar to NLRC4-/-mice,LNCGM1082-/-mice were highly sensitive to Salmonella Typhimurium(S.T)infection.LNCGM1082 deficiency in mouse or human macrophages inhibited IL-1βmaturation and pyroptosis.Mechanistically,LNCGM1082 induced the binding of PKCS with NLRC4 in both mice and humans.In contrast,NLRC4 did not bind PKCo in LNCGM1082-/-macrophages.The activity of the IncRNA LNCGM1082 induced by S.T may be mediated through TLR5 in the macrophages of both mice and humans.In summary,our data indicate that TLR5-mediated LNCGM1082 activity can promote the binding of PKC with NLRC4 to activate NLRC4 and induce resistance to bacterial infection.
基金National Key Research and Development Program of China,Grant/Award Number:2018YFA0901300National Natural Science Foundation of China,Grant/Award Numbers:22378305,32071411,32001034,21621004Tianjin Science and Technology Plan Project,Grant/Award Number:20JCQNJC00830。
文摘Electroactive microorganisms(EAMs)could utilize extracellular electron transfer(EET)pathways to exchange electrons and energy with their external surroundings.Conductive cytochrome proteins and nanowires play crucial roles in controlling electron transfer rate from cytosol to extracellular electrode.Many previous studies elucidated how the c-type cytochrome proteins and conductive nanowires are synthesized,assembled,and engineered to manipulate the EET rate,and quantified the kinetic processes of electron generation and EET.Here,we firstly overview the electron transfer pathways of EAMs and quantify the kinetic parameters that dictating intracellular electron production and EET.Secondly,we systematically review the structure,conductivity mechanisms,and engineering strategies to manipulate conductive cytochromes and nanowire in EAMs.Lastly,we outlook potential directions for future research in cytochromes and conductive nanowires for enhanced electron transfer.This article reviews the quantitative kinetics of intracellular electron production and EET,and the contribution of engineered c-type cytochromes and conductive nanowire in enhancing the EET rate,which lay the foundation for enhancing electron transfer capacity of EAMs.
文摘产电微生物是微生物燃料电池、电解池和电合成等微生物电化学技术(Microbial electrochemical technologies,METs)的研究基础。产电微生物与电极界面间的胞外电子传递(Extracellular electron transfer,EET)效率低以及生物被膜形成能力弱限制了METs在有机物降解、电能生产、海水淡化、生物修复和生物传感等方面的应用。因此,强化产电微生物与电极界面间的相互作用是过去几年的主要研究热点。针对近年的研究,本文系统概述了通过改造产电微生物来增强微生物-电极间相互作用的各种策略,重点分析了这些策略的适用性和局限性,并展望了强化产电微生物-电极界面作用在微生物电化学技术利用方面的研究前景。
文摘In the previous construction of attributed-based encryption for circuits on lattices, the secret key size was exponential to the number of AND gates of the circuit. Therefore, it was suitable for the shallow circuits whose depth is bounded. For decreasing the key size of previous scheme, combining the techniques of Two-to-One Recoding (TOR), and sampling on lattices, we propose a new Key-Policy Attribute-Based Encryption (KP-ABE) scheme for circuits of any arbitrary polynomial on lattices, and prove that the scheme is secure against chosen plaintext attack in the selective model under the Learning With Errors (LWE) assumptions. In our scheme, the key size is proportional to the number of gates or wires in the circuits.
基金This research was supported by the National Key Research and Development Program of China(No.2018YFA0901300)Independent Innovation Fund of Tianjin University(0903065070,0903065083,0903065084).
文摘Electroactive bacteria could perform bi-directional extracellular electron transfer(EET)to exchange electrons and energy with extracellular environments,thus playing a central role in microbial electro-fermentation(EF)process.Unbalanced fermentation and microbial electrosynthesis are the main pathways to produce value-added chemicals and biofuels.However,the low efficiency of the bi-directional EET is a dominating bottleneck in these processes.In this review,we firstly demonstrate the main bi-directional EET mechanisms during EF,including the direct EET and the shuttle-mediated EET.Then,we review representative milestones and progresses in unbalanced fermentation via anode outward EET and microbial electrosynthesis via inward EET based on these two EET mechanisms in detail.Furthermore,we summarize the main synthetic biology strategies in improving the bi-directional EET and target products synthesis,thus to enhance the efficiencies in unbalanced fermentation and microbial electrosynthesis.Lastly,a perspective on the applications of microbial electro-fermentation is provided.
文摘A new kind of open cellular foam material with three dimensionally interconnected TiC/Ti struts was prepared by a two-step sponge-coating and high frequency induction heating process. The microstructure, composition and compression strength of the prepared TiC/Ti foam materials were characterized. It was confirmed that the incorporation of Ti into TiC resulted in an inter-bonded Ti-TiC-Ti layered structure in the struts, which enhanced the plasticity of the composite foam materials.
基金This work was supported by National Natural Science Foundation of China(81472226,81971921 and 31670166)National Key Project for Infectious Diseases of China(2017ZX10202202 and 2018ZX10301208)+1 种基金Chinese Academy of Medical Sciences(2018PT31044)Shanghai Municipal Education Commission(2017-01-07-00-07-E00057).
基金This research was supported by the Doctoral Fund of Central South University(grant number 1053320170862)National Nat-ural Science Foundation of China(grant number 51678575)+1 种基金the Science Foundation of CARS(grant number 2019YJ026)The authors express their appreciation for the financial assistance.
文摘We investigated the macro-and micro-mechanical properties of rigid-grain and soft-chip mixtures(GCMs)through numerical simulations using the discrete element method.We present a novel framework for the discrete modeling of soft chips and rigid grains in conjunction with calibration processes.Several numerical triaxial tests were also performed on GCMs with 0%,10%,20%,and 30%volumetric chip contents,P.The simulation results demonstrate that increasing P leads to higher GCM toughness,higher deviatoric peak stress,and higher corresponding shear strain.Higher P also contributes to more volume contraction and less dilation.The friction angles at both the peak and residual state significantly increase with increasing P.In view of the micro-mechanical features,strong contact force chains develop along the loading direction,which results in considerable anisotropy in the peak and residual states.Both the formation of strong force chains and rotation of grains decrease with increasing P,whereas the grain sliding percentage increases.The tensile force is mobilized with shearing and higher P leads to less mobilization of the tensile force.These findings are useful for better understanding the internal structure of GCMs with different soft-chip contents,especially in granular mixture mechanics and geomechanics.
基金supported by the National Key Research and Development Program of China(2018YFA0901300)the National Natural Science Foundation of China(NSFC 32071411,32001034,and 21621004)+1 种基金Tianjin Science and Technology Plan Project(20JCQNJC00830)Tianjin Research Innovation Project for Postgraduate Students(2020YJSB045).
文摘Electroactive microorganisms(EAMs)play important roles in biogeochemical redox processes and have been of great interest in the fields of energy recovery,waste treatment,and environmental remediation.However,the currently identified EAMs are difficult to be widely used in complex and diverse environments,due to the existence of poor electron transfer capability,weak environmental adaptability,and difficulty with engineering modifications,etc.Therefore,rapid and efficient screening of high performance EAMs from environments is an effective strategy to facilitate applications of microbial fuel cells(MFCs).In this study,to achieve efficient degradation of methyl orange(MO)by MFC and electricity harvest,a more efficient exoelectrogen Shewanella carassii-D5 that belongs to Shewanella spp.was first isolated from activated sludge by WO_(3) nanocluster probe technique.Physiological properties experiments confirmed that S.carassii-D5 is a Gram-negative strain with rounded colonies and smooth,slightly reddish surface,which could survive in media containing lactate at 30℃.Moreover,we found that S.carassii-D5 exhibited remarkable MO degradation ability,which could degrade 66%of MO within 72 h,1.7 times higher than that of Shewanella oneidensis MR-1.Electrochemical measurements showed that MFCs inoculated with S.carassii-D5 could generate a maximum power density of 704.6 mW/m^(2),which was 5.6 times higher than that of S.oneidensis MR-1.Further investigation of the extracellular electron transfer(EET)mechanism found that S.carassii-D5 strain had high level of c-type cytochromes and strong biofilm formation ability compared with S.oneidensis MR-1,thus facilitating direct EET.Therefore,to enhance indirect electron transfer and MO degradation capacity,a synthetic gene cluster ribADEHC encoding riboflavin synthesis pathway from Bacillus subtilis was heterologously expressed in S.carassii-D5,increasing riboflavin yield from 1.9 to 9.0 mg/g DCW with 1286.3 mW/m^(2) power density output in lactate fed-MFCs.Furthermore,results showed that the high EET rate endowed a faster degradation efficient of MO from 66%to 86%with a maximum power density of 192.3 mW/m^(2),which was 1.3 and 1.6 times higher than that of S.carassii-D5,respectively.Our research suggests that screening and engineering high-efficient EAMs from sludge is a feasible strategy in treating organic pollutants.
文摘An increasing number of web services are being invoked by users to create user applications(e.g.,mashups). However, over time, a few good services in service systems have become deprecated, i.e., the service is initially available and is invoked by service users, but later becomes unavailable. Therefore, the prediction of service deprecation has become a key issue in creating reliable long-term user applications. Most existing research has overlooked service deprecation in service systems and has failed to consider long-term service reliability when making service recommendations. In this paper, we propose a method for predicting service deprecation, which comprises two components: Service Comprehensive Feature Modeling(SCFM) for extracting service features relevant to service deprecation and Deprecated Service Prediction(DSP) for building a service deprecation prediction model. Our experimental results on a real-world dataset demonstrate that our method yields an improved Area-Under-the-Curve(AUC) value over existing methods and thus has better accuracy in service deprecation prediction.