Dear Editor,This letter investigates predefined-time optimization problems(OPs) of multi-agent systems(MASs), where the agent of MASs is subject to inequality constraints, and the team objective function accounts for ...Dear Editor,This letter investigates predefined-time optimization problems(OPs) of multi-agent systems(MASs), where the agent of MASs is subject to inequality constraints, and the team objective function accounts for impulse effects. Firstly, to address the inequality constraints,the penalty method is introduced. Then, a novel optimization strategy is developed, which only requires that the team objective function be strongly convex.展开更多
Dear Editor,This letter is concerned with the problem of time-varying formation tracking for heterogeneous multi-agent systems(MASs) under directed switching networks. For this purpose, our first step is to present so...Dear Editor,This letter is concerned with the problem of time-varying formation tracking for heterogeneous multi-agent systems(MASs) under directed switching networks. For this purpose, our first step is to present some sufficient conditions for the exponential stability of a particular category of switched systems.展开更多
Dear Editor,This letter studies the bipartite consensus tracking problem for heterogeneous multi-agent systems with actuator faults and a leader's unknown time-varying control input. To handle such a problem, the ...Dear Editor,This letter studies the bipartite consensus tracking problem for heterogeneous multi-agent systems with actuator faults and a leader's unknown time-varying control input. To handle such a problem, the continuous fault-tolerant control protocol via observer design is developed. In addition, it is strictly proved that the multi-agent system driven by the designed controllers can still achieve bipartite consensus tracking after faults occur.展开更多
All maritime industries are plagued by marine biofouling pollution,which causes large economic and environmental costs.Therefore,there is an urgent need for ecofriendly alternatives that can effectively reduce the neg...All maritime industries are plagued by marine biofouling pollution,which causes large economic and environmental costs.Therefore,there is an urgent need for ecofriendly alternatives that can effectively reduce the negative consequences of biofouling pollution.This study aimed to produce novel capsaicin-inspired amide derivatives(CIADs)with multifunctional antifouling features by introducing amide compounds to aromatic compounds via a Friedel-Crafts alkylation reaction.The structure of the CIADs was characterized using FTIR,1H NMR,13C NMR,and HRMS,and the comprehensive antifouling capacity was determined by thermal stability,anti-ultraviolet,antibacterial,anti-algal,and marine field experiments.CIADs showed good thermal stability and did not show obvious weight loss before 226°C.2,4-dihydroxy-3,5-diphenylimidemet-hylbenzophenone(DDB)had an excellent ultraviolet absorption effect,which was even better than that of 2-hydroxy-4-(octyloxy)benzophenone.The antibacterial and anti-algal rates of N-(2,4-dimethyl-3-chloro-5-benzamide-methyl-6-hydroxybenzyl)benzamide(NDCBHB)were more than 99.5%and 64.0%,respectively,and the surface of antifouling coating with NDCBHB(NDCBHB-AC)was covered with only a small amount of sludge and biofilm,its antifouling effect was better than that of chlorothalonil.The above work provides a reference for preparing green and multifunctional antifouling agents.展开更多
Multi-agent systems often require good interoperability in the process of completing their assigned tasks.This paper first models the static structure and dynamic behavior of multiagent systems based on layered weight...Multi-agent systems often require good interoperability in the process of completing their assigned tasks.This paper first models the static structure and dynamic behavior of multiagent systems based on layered weighted scale-free community network and susceptible-infected-recovered(SIR)model.To solve the problem of difficulty in describing the changes in the structure and collaboration mode of the system under external factors,a two-dimensional Monte Carlo method and an improved dynamic Bayesian network are used to simulate the impact of external environmental factors on multi-agent systems.A collaborative information flow path optimization algorithm for agents under environmental factors is designed based on the Dijkstra algorithm.A method for evaluating system interoperability is designed based on simulation experiments,providing reference for the construction planning and optimization of organizational application of the system.Finally,the feasibility of the method is verified through case studies.展开更多
Plants have long served as a cornerstone for drug discovery,offering a vast repertoire of bioactive compounds with proven efficacy in combating oxidative stress,a pivotal driver of chronic diseases such as cancer,diab...Plants have long served as a cornerstone for drug discovery,offering a vast repertoire of bioactive compounds with proven efficacy in combating oxidative stress,a pivotal driver of chronic diseases such as cancer,diabetes,cardiovascular disorders,and neurodegenerative conditions.This review synthesizes current knowledge on plant-derived antioxidants,emphasizing their mechanisms,therapeutic potential,and quantitative efficacy validated through standardized assays.Key phytochemicals,including polyphenols,carotenoids,flavonoids,and terpenoids,neutralize reactive oxygen species(ROS)through radical scavenging,enzyme modulation,and gene regulation.For instance,lutein,a carotenoid found in leafy greens,demonstrates potent antioxidant activity with IC50 values of 1.75μg/mL against hydroxyl radicals and 2.2μg/mL in lipid peroxidation inhibition,underscoring its role in mitigating cardiovascular and ocular diseases.Similarly,quercetin,a ubiquitous flavonoid in onions and berries,exhibits remarkable ROS-scavenging capacity,with IC50 values of 0.55μg/mL,2,2-Diphenyl-1-picrylhydrazyl(DPPH)and 1.17μg/mL,2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS),supporting its use in reducing inflammation and neurodegeneration.The therapeutic promise of these compounds extends to disease-specific applications.Limonoids from citrus fruits,such as limonin(IC_(50)15-31μg/mL),enhance Phase II detoxification enzymes,offering protection against chemical carcinogens.Sulforaphane,a glucosinolate derived from cruciferous vegetables,shows potent anticancer activity with an IC50 of 85.66 mg in DPPH radical scavenging,whileβ-sitosterol(IC_(50)1.43-2.42 mM)inhibits tumor proliferation and cholesterol synthesis.Synergistic interactions further amplify their efficacy:phytoestrogens like genistein(IC_(50)13.00 ppm)and terpenoids such asα-pinene(IC_(50)12.57 mg/mL)collectively enhance antiinflammatory and antimicrobial responses,illustrating the multi-targeted nature of plant-based therapies.Beyond disease prevention,these compounds address age-related decline.Ascorbic acid(vitamin C),with an IC50 of 11.81μg/mL for antioxidant activity,mitigates skin aging and accelerates wound healing,while seleniumnanoparticles(IC_(50)0.437μg/mL)bolster immune function and reduce chemotherapy-induced toxicity.Dietary fibers,exemplified by sugar beet fibers(IC_(50)52.32μg/mL for DPPH scavenging),further contribute to cardiovascular health by lowering Low-Density Lipoprotein(LDL)cholesterol.This review not only catalogs the antioxidant prowess of phytochemicals but also highlights their translational potential.Advances in nanotechnology,such as nano-formulated curcumin,have overcome bioavailability challenges,enhancing clinical applicability.By integrating quantitative metrics(e.g.,IC50,radical scavenging rates)with mechanistic insights,this work bridges the gap between traditional knowledge and modern pharmacology.展开更多
Dear Editor,An adaptive consensus control algorithm for uncertain multi-agent systems(MAS),capable of guaranteeing unified prescribed performance,is presented in this letter.Unlike many existing prescribed performance...Dear Editor,An adaptive consensus control algorithm for uncertain multi-agent systems(MAS),capable of guaranteeing unified prescribed performance,is presented in this letter.Unlike many existing prescribed performance related works,the developed control exhibits some features.Firstly,a distributed prescribed time observer is introduced so that not only each follower is able to estimate the leader’s signal within a predetermined time,but also the control design for each agent is independent with its neighbors.展开更多
Multi‐agent reinforcement learning relies on reward signals to guide the policy networks of individual agents.However,in high‐dimensional continuous spaces,the non‐stationary environment can provide outdated experi...Multi‐agent reinforcement learning relies on reward signals to guide the policy networks of individual agents.However,in high‐dimensional continuous spaces,the non‐stationary environment can provide outdated experiences that hinder convergence,resulting in ineffective training performance for multi‐agent systems.To tackle this issue,a novel reinforcement learning scheme,Mutual Information Oriented Deep Skill Chaining(MioDSC),is proposed that generates an optimised cooperative policy by incorporating intrinsic rewards based on mutual information to improve exploration efficiency.These rewards encourage agents to diversify their learning process by engaging in actions that increase the mutual information between their actions and the environment state.In addition,MioDSC can generate cooperative policies using the options framework,allowing agents to learn and reuse complex action sequences and accelerating the convergence speed of multi‐agent learning.MioDSC was evaluated in the multi‐agent particle environment and the StarCraft multi‐agent challenge at varying difficulty levels.The experimental results demonstrate that MioDSC outperforms state‐of‐the‐art methods and is robust across various multi‐agent system tasks with high stability.展开更多
Melatonin(N-acetyl-5-methoxytryptamine)is known as the hormone of darkness because it is synthesized at night and involved in regulating the circadian clock.The hormone is primarily synthesized by the vertebrate pinea...Melatonin(N-acetyl-5-methoxytryptamine)is known as the hormone of darkness because it is synthesized at night and involved in regulating the circadian clock.The hormone is primarily synthesized by the vertebrate pineal gland,but is ubiquitous among invertebrates,unicellular organisms,plants,and even cyanobacteria(Hattori and Suzuki,2024).Melatonin is well-conserved evolutionarily and possesses several physiological functions,such as immune response,bone and glucose metabolism,and memory formation besides regulating the circadian rhythm.展开更多
基金supported in part by the National Natural Science Foundation of China(62276119)the Natural Science Foundation of Jiangsu Province(BK20241764)the Postgraduate Research & Practice Innovation Program of Jiangsu Province(KYCX22_2860)
文摘Dear Editor,This letter investigates predefined-time optimization problems(OPs) of multi-agent systems(MASs), where the agent of MASs is subject to inequality constraints, and the team objective function accounts for impulse effects. Firstly, to address the inequality constraints,the penalty method is introduced. Then, a novel optimization strategy is developed, which only requires that the team objective function be strongly convex.
基金supported in part by the National Natural Science Foundation of China(62273255,62350003,62088101)the Shanghai Science and Technology Cooperation Project(22510712000,21550760900)+1 种基金the Shanghai Municipal Science and Technology Major Project(2021SHZDZX0100)the Fundamental Research Funds for the Central Universities
文摘Dear Editor,This letter is concerned with the problem of time-varying formation tracking for heterogeneous multi-agent systems(MASs) under directed switching networks. For this purpose, our first step is to present some sufficient conditions for the exponential stability of a particular category of switched systems.
基金supported by the National Natural Science Foundation of China(62325304,U22B2046,62073079,62376029)the Jiangsu Provincial Scientific Research Center of Applied Mathematics(BK20233002)the China Postdoctoral Science Foundation(2023M730255,2024T171123)
文摘Dear Editor,This letter studies the bipartite consensus tracking problem for heterogeneous multi-agent systems with actuator faults and a leader's unknown time-varying control input. To handle such a problem, the continuous fault-tolerant control protocol via observer design is developed. In addition, it is strictly proved that the multi-agent system driven by the designed controllers can still achieve bipartite consensus tracking after faults occur.
基金supported by the Scientific Research Project funded by the Qingdao Postdoctoral Science Foundation(No.QDBSH20230102075)the China Postdoctoral Science Foundation(No.2023M733337)the National Natural Science Foundation of China(No.U2141251).
文摘All maritime industries are plagued by marine biofouling pollution,which causes large economic and environmental costs.Therefore,there is an urgent need for ecofriendly alternatives that can effectively reduce the negative consequences of biofouling pollution.This study aimed to produce novel capsaicin-inspired amide derivatives(CIADs)with multifunctional antifouling features by introducing amide compounds to aromatic compounds via a Friedel-Crafts alkylation reaction.The structure of the CIADs was characterized using FTIR,1H NMR,13C NMR,and HRMS,and the comprehensive antifouling capacity was determined by thermal stability,anti-ultraviolet,antibacterial,anti-algal,and marine field experiments.CIADs showed good thermal stability and did not show obvious weight loss before 226°C.2,4-dihydroxy-3,5-diphenylimidemet-hylbenzophenone(DDB)had an excellent ultraviolet absorption effect,which was even better than that of 2-hydroxy-4-(octyloxy)benzophenone.The antibacterial and anti-algal rates of N-(2,4-dimethyl-3-chloro-5-benzamide-methyl-6-hydroxybenzyl)benzamide(NDCBHB)were more than 99.5%and 64.0%,respectively,and the surface of antifouling coating with NDCBHB(NDCBHB-AC)was covered with only a small amount of sludge and biofilm,its antifouling effect was better than that of chlorothalonil.The above work provides a reference for preparing green and multifunctional antifouling agents.
基金supported by the Key R&D Projects in Jiangsu Province(BE2021729)the Key Primary Research Project of Primary Strengthening Program(KYZYJKKCJC23001).
文摘Multi-agent systems often require good interoperability in the process of completing their assigned tasks.This paper first models the static structure and dynamic behavior of multiagent systems based on layered weighted scale-free community network and susceptible-infected-recovered(SIR)model.To solve the problem of difficulty in describing the changes in the structure and collaboration mode of the system under external factors,a two-dimensional Monte Carlo method and an improved dynamic Bayesian network are used to simulate the impact of external environmental factors on multi-agent systems.A collaborative information flow path optimization algorithm for agents under environmental factors is designed based on the Dijkstra algorithm.A method for evaluating system interoperability is designed based on simulation experiments,providing reference for the construction planning and optimization of organizational application of the system.Finally,the feasibility of the method is verified through case studies.
基金funded by the project of Scientific Research Start-up Funds for Doctoral Talents of Zhaotong University-Mingzheng Duan,Grant number:202406Young Talent Project of Talent Support Program for the Development of Yunnan,Grant number:210604199008271015.
文摘Plants have long served as a cornerstone for drug discovery,offering a vast repertoire of bioactive compounds with proven efficacy in combating oxidative stress,a pivotal driver of chronic diseases such as cancer,diabetes,cardiovascular disorders,and neurodegenerative conditions.This review synthesizes current knowledge on plant-derived antioxidants,emphasizing their mechanisms,therapeutic potential,and quantitative efficacy validated through standardized assays.Key phytochemicals,including polyphenols,carotenoids,flavonoids,and terpenoids,neutralize reactive oxygen species(ROS)through radical scavenging,enzyme modulation,and gene regulation.For instance,lutein,a carotenoid found in leafy greens,demonstrates potent antioxidant activity with IC50 values of 1.75μg/mL against hydroxyl radicals and 2.2μg/mL in lipid peroxidation inhibition,underscoring its role in mitigating cardiovascular and ocular diseases.Similarly,quercetin,a ubiquitous flavonoid in onions and berries,exhibits remarkable ROS-scavenging capacity,with IC50 values of 0.55μg/mL,2,2-Diphenyl-1-picrylhydrazyl(DPPH)and 1.17μg/mL,2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS),supporting its use in reducing inflammation and neurodegeneration.The therapeutic promise of these compounds extends to disease-specific applications.Limonoids from citrus fruits,such as limonin(IC_(50)15-31μg/mL),enhance Phase II detoxification enzymes,offering protection against chemical carcinogens.Sulforaphane,a glucosinolate derived from cruciferous vegetables,shows potent anticancer activity with an IC50 of 85.66 mg in DPPH radical scavenging,whileβ-sitosterol(IC_(50)1.43-2.42 mM)inhibits tumor proliferation and cholesterol synthesis.Synergistic interactions further amplify their efficacy:phytoestrogens like genistein(IC_(50)13.00 ppm)and terpenoids such asα-pinene(IC_(50)12.57 mg/mL)collectively enhance antiinflammatory and antimicrobial responses,illustrating the multi-targeted nature of plant-based therapies.Beyond disease prevention,these compounds address age-related decline.Ascorbic acid(vitamin C),with an IC50 of 11.81μg/mL for antioxidant activity,mitigates skin aging and accelerates wound healing,while seleniumnanoparticles(IC_(50)0.437μg/mL)bolster immune function and reduce chemotherapy-induced toxicity.Dietary fibers,exemplified by sugar beet fibers(IC_(50)52.32μg/mL for DPPH scavenging),further contribute to cardiovascular health by lowering Low-Density Lipoprotein(LDL)cholesterol.This review not only catalogs the antioxidant prowess of phytochemicals but also highlights their translational potential.Advances in nanotechnology,such as nano-formulated curcumin,have overcome bioavailability challenges,enhancing clinical applicability.By integrating quantitative metrics(e.g.,IC50,radical scavenging rates)with mechanistic insights,this work bridges the gap between traditional knowledge and modern pharmacology.
基金supported in part by the National Key Research and Development Program of China(2022YFB4701400/4701401)the National Natural Science Foundation of China(61991400,61991403,62250710167,61860206008,61933012,62273064)+1 种基金the Chongqing Outstanding Young Talents Support Program(cstc2024ycjh-bgzxm0085)CAAI-Huawei MindSpore Open Fund。
文摘Dear Editor,An adaptive consensus control algorithm for uncertain multi-agent systems(MAS),capable of guaranteeing unified prescribed performance,is presented in this letter.Unlike many existing prescribed performance related works,the developed control exhibits some features.Firstly,a distributed prescribed time observer is introduced so that not only each follower is able to estimate the leader’s signal within a predetermined time,but also the control design for each agent is independent with its neighbors.
基金National Natural Science Foundation of China,Grant/Award Number:61872171The Belt and Road Special Foundation of the State Key Laboratory of Hydrology‐Water Resources and Hydraulic Engineering,Grant/Award Number:2021490811。
文摘Multi‐agent reinforcement learning relies on reward signals to guide the policy networks of individual agents.However,in high‐dimensional continuous spaces,the non‐stationary environment can provide outdated experiences that hinder convergence,resulting in ineffective training performance for multi‐agent systems.To tackle this issue,a novel reinforcement learning scheme,Mutual Information Oriented Deep Skill Chaining(MioDSC),is proposed that generates an optimised cooperative policy by incorporating intrinsic rewards based on mutual information to improve exploration efficiency.These rewards encourage agents to diversify their learning process by engaging in actions that increase the mutual information between their actions and the environment state.In addition,MioDSC can generate cooperative policies using the options framework,allowing agents to learn and reuse complex action sequences and accelerating the convergence speed of multi‐agent learning.MioDSC was evaluated in the multi‐agent particle environment and the StarCraft multi‐agent challenge at varying difficulty levels.The experimental results demonstrate that MioDSC outperforms state‐of‐the‐art methods and is robust across various multi‐agent system tasks with high stability.
基金supported by JSPS KAKENHI Grant Number JP22K11823 to AH and JP22J01508 to KW。
文摘Melatonin(N-acetyl-5-methoxytryptamine)is known as the hormone of darkness because it is synthesized at night and involved in regulating the circadian clock.The hormone is primarily synthesized by the vertebrate pineal gland,but is ubiquitous among invertebrates,unicellular organisms,plants,and even cyanobacteria(Hattori and Suzuki,2024).Melatonin is well-conserved evolutionarily and possesses several physiological functions,such as immune response,bone and glucose metabolism,and memory formation besides regulating the circadian rhythm.
