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
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,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
Temporary plugging and diversion fracturing(TPDF)is widely used to promote the uniform and complex distribution of multi-clustered hydraulic fractures(HFs)in a horizontal well of the unconventional formations.However,...Temporary plugging and diversion fracturing(TPDF)is widely used to promote the uniform and complex distribution of multi-clustered hydraulic fractures(HFs)in a horizontal well of the unconventional formations.However,the migration behavior of temporary plugging agent(TPA),as a function of the concentration and particle size of TPA and cluster-perforation numbers,etc.,determining the effectiveness of this technique,remains unclear.Therefore,this study conducted innovatively a series of TPDF simulation experiments on transparent polymethyl methacrylate(PMMA)specimens(cubic block of 30 cm×30 cm×30 cm)to explore visually the migration behavior of TPA in multi-clustered HFs in a horizontal well.A laboratory hydraulic sandblasting perforation completion technique was implemented to simulate the multi-cluster perforations.All the distributions of wellbore,perforations,HFs,and TPA can be seen clearly inside the PMMA specimen post the experiment.The results show that there are four characteristic plugging positions for the TPA:mouth of HF,middle of HF,tip of HF,and the intersection of HFs.Small particle size TPA tends to migrate to the fracture tip for plugging,while large particle size TPA tends to plug at the fracture mouth.The migration of the TPA is influenced obviously by the morphology of the fracture wall.A smooth fracture wall is conducive to the migration of the TPA to the far end of HFs,but not conducive to generating the plugging zone and HF diversion.In contrast,a"leaf vein"fracture of rough wall is conducive to generating the plugging layer and the diversion of HFs,but not conducive to the migration of the TPA to the far end of HFs.The migration ability of TPA in a"shell"pattern is intermediate between the two above cases.Increasing TPA concentration can encourage TPA to migrate more quickly to the characteristic plugging position,and thereby to promote the creation of effective plugging and subsequently the multi-stage diversion of the HFs.Nevertheless,excessive concentration may cause the TPA to settle prematurely,affecting the propagation of the HFs to the far end.Increasing the number of clusters to a certain extent can encourage TPA to migrate into the HFs and form plugging,and promote the diversion.An evaluation system for the migration ability of granular TPA has been established,and it was calculated that when there is no plugging expectation target,the comprehensive migration ability of small particle size TPA is stronger than that of large particle size TPA.This research provides theoretical foundation for the optimization of temporary plugging parameters.展开更多
With the aid of multi-agent based modeling approach to complex systems, the hierarchy simulation models of carrier-based aircraft catapult launch are developed. Ocean, carrier, aircraft, and atmosphere are treated as ...With the aid of multi-agent based modeling approach to complex systems, the hierarchy simulation models of carrier-based aircraft catapult launch are developed. Ocean, carrier, aircraft, and atmosphere are treated as aggregation agents, the detailed components like catapult, landing gears, and disturbances are considered as meta-agents, which belong to their aggregation agent. Thus, the model with two layers is formed i.e. the aggregation agent layer and the meta-agent layer. The information communication among all agents is described. The meta-agents within one aggregation agent communicate with each other directly by information sharing, but the meta-agents, which belong to different aggregation agents exchange their information through the aggregation layer first, and then perceive it from the sharing environment, that is the aggregation agent. Thus, not only the hierarchy model is built, but also the environment perceived by each agent is specified. Meanwhile, the problem of balancing the independency of agent and the resource consumption brought by real-time communication within multi-agent system （MAS） is resolved. Each agent involved in carrier-based aircraft catapult launch is depicted, with considering the interaction within disturbed atmospheric environment and multiple motion bodies including carrier, aircraft, and landing gears. The models of reactive agents among them are derived based on tensors, and the perceived messages and inner frameworks of each agent are characterized. Finally, some results of a simulation instance are given. The simulation and modeling of dynamic system based on multi-agent system is of benefit to express physical concepts and logical hierarchy clearly and precisely. The system model can easily draw in kinds of other agents to achieve a precise simulation of more complex system. This modeling technique makes the complex integral dynamic equations of multibodies decompose into parallel operations of single agent, and it is convenient to expand, maintain, and reuse the program codes.展开更多
BACKGROUND Ulcerative colitis(UC)is a chronic and debilitating inflammatory bowel disease.Cumulative evidence indicates that excess hydrogen peroxide,a potent neutrophilic chemotactic agent,produced by colonic epithel...BACKGROUND Ulcerative colitis(UC)is a chronic and debilitating inflammatory bowel disease.Cumulative evidence indicates that excess hydrogen peroxide,a potent neutrophilic chemotactic agent,produced by colonic epithelial cells has a causal role leading to infiltration of neutrophils into the colonic mucosa and subsequent development of UC.This evidence-based mechanism identifies hydrogen peroxide as a therapeutic target for reducing agents in the treatment of UC.CASE SUMMARY Presented is a 41-year-old female with a 26-year history of refractory UC.Having developed steroid dependence and never achieving complete remission on treatment by conventional and advanced therapies,she began treatment with oral R-dihydrolipoic acid(RDLA),a lipid-soluble reducing agent with intracellular site of action.Within a week,rectal bleeding ceased.She was asymptomatic for three years until a highly stressful experience,when she noticed blood in her stool.RDLA was discontinued,and she began treatment with oral sodium thiosulfate pentahydrate(STS),a reducing agent with extracellular site of action.After a week,rectal bleeding ceased,and she resumed oral RDLA and discontinued STS.To date,she remains asymptomatic with normal stool calprotectin while on RDLA.CONCLUSION STS and RDLA are reducing agents that serve as highly effective and safe therapy for the induction and maintenance of remission in UC,even in patients refractory or poorly controlled by conventional and advanced therapies.Should preliminary findings be validated by subsequent clinical trials,the use of reducing agents could potentially prevent thousands of colectomies and represent a paradigm shift in the treatment of UC.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 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 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 National Natural Science Foundation of China Joint Fund for Enterprise Innovation and Development,Enrichment Mechanism and Stereoscopic Development of Shale Oil in Continental Rift Basins(No.U24B6002).
文摘Temporary plugging and diversion fracturing(TPDF)is widely used to promote the uniform and complex distribution of multi-clustered hydraulic fractures(HFs)in a horizontal well of the unconventional formations.However,the migration behavior of temporary plugging agent(TPA),as a function of the concentration and particle size of TPA and cluster-perforation numbers,etc.,determining the effectiveness of this technique,remains unclear.Therefore,this study conducted innovatively a series of TPDF simulation experiments on transparent polymethyl methacrylate(PMMA)specimens(cubic block of 30 cm×30 cm×30 cm)to explore visually the migration behavior of TPA in multi-clustered HFs in a horizontal well.A laboratory hydraulic sandblasting perforation completion technique was implemented to simulate the multi-cluster perforations.All the distributions of wellbore,perforations,HFs,and TPA can be seen clearly inside the PMMA specimen post the experiment.The results show that there are four characteristic plugging positions for the TPA:mouth of HF,middle of HF,tip of HF,and the intersection of HFs.Small particle size TPA tends to migrate to the fracture tip for plugging,while large particle size TPA tends to plug at the fracture mouth.The migration of the TPA is influenced obviously by the morphology of the fracture wall.A smooth fracture wall is conducive to the migration of the TPA to the far end of HFs,but not conducive to generating the plugging zone and HF diversion.In contrast,a"leaf vein"fracture of rough wall is conducive to generating the plugging layer and the diversion of HFs,but not conducive to the migration of the TPA to the far end of HFs.The migration ability of TPA in a"shell"pattern is intermediate between the two above cases.Increasing TPA concentration can encourage TPA to migrate more quickly to the characteristic plugging position,and thereby to promote the creation of effective plugging and subsequently the multi-stage diversion of the HFs.Nevertheless,excessive concentration may cause the TPA to settle prematurely,affecting the propagation of the HFs to the far end.Increasing the number of clusters to a certain extent can encourage TPA to migrate into the HFs and form plugging,and promote the diversion.An evaluation system for the migration ability of granular TPA has been established,and it was calculated that when there is no plugging expectation target,the comprehensive migration ability of small particle size TPA is stronger than that of large particle size TPA.This research provides theoretical foundation for the optimization of temporary plugging parameters.
基金Aeronautical Science Foundation of China (2006ZA51004)
文摘With the aid of multi-agent based modeling approach to complex systems, the hierarchy simulation models of carrier-based aircraft catapult launch are developed. Ocean, carrier, aircraft, and atmosphere are treated as aggregation agents, the detailed components like catapult, landing gears, and disturbances are considered as meta-agents, which belong to their aggregation agent. Thus, the model with two layers is formed i.e. the aggregation agent layer and the meta-agent layer. The information communication among all agents is described. The meta-agents within one aggregation agent communicate with each other directly by information sharing, but the meta-agents, which belong to different aggregation agents exchange their information through the aggregation layer first, and then perceive it from the sharing environment, that is the aggregation agent. Thus, not only the hierarchy model is built, but also the environment perceived by each agent is specified. Meanwhile, the problem of balancing the independency of agent and the resource consumption brought by real-time communication within multi-agent system （MAS） is resolved. Each agent involved in carrier-based aircraft catapult launch is depicted, with considering the interaction within disturbed atmospheric environment and multiple motion bodies including carrier, aircraft, and landing gears. The models of reactive agents among them are derived based on tensors, and the perceived messages and inner frameworks of each agent are characterized. Finally, some results of a simulation instance are given. The simulation and modeling of dynamic system based on multi-agent system is of benefit to express physical concepts and logical hierarchy clearly and precisely. The system model can easily draw in kinds of other agents to achieve a precise simulation of more complex system. This modeling technique makes the complex integral dynamic equations of multibodies decompose into parallel operations of single agent, and it is convenient to expand, maintain, and reuse the program codes.
文摘BACKGROUND Ulcerative colitis(UC)is a chronic and debilitating inflammatory bowel disease.Cumulative evidence indicates that excess hydrogen peroxide,a potent neutrophilic chemotactic agent,produced by colonic epithelial cells has a causal role leading to infiltration of neutrophils into the colonic mucosa and subsequent development of UC.This evidence-based mechanism identifies hydrogen peroxide as a therapeutic target for reducing agents in the treatment of UC.CASE SUMMARY Presented is a 41-year-old female with a 26-year history of refractory UC.Having developed steroid dependence and never achieving complete remission on treatment by conventional and advanced therapies,she began treatment with oral R-dihydrolipoic acid(RDLA),a lipid-soluble reducing agent with intracellular site of action.Within a week,rectal bleeding ceased.She was asymptomatic for three years until a highly stressful experience,when she noticed blood in her stool.RDLA was discontinued,and she began treatment with oral sodium thiosulfate pentahydrate(STS),a reducing agent with extracellular site of action.After a week,rectal bleeding ceased,and she resumed oral RDLA and discontinued STS.To date,she remains asymptomatic with normal stool calprotectin while on RDLA.CONCLUSION STS and RDLA are reducing agents that serve as highly effective and safe therapy for the induction and maintenance of remission in UC,even in patients refractory or poorly controlled by conventional and advanced therapies.Should preliminary findings be validated by subsequent clinical trials,the use of reducing agents could potentially prevent thousands of colectomies and represent a paradigm shift in the treatment of UC.
