MD2 blockade prevents modified LDL-induced retinal injury in diabetes by suppressing NADPH oxidase-4 interaction with Toll-like receptor-4

Chen Huaicheng,Yan Tao,Song Zongming,Ying Shilong,Wu Beibei,Ju Xin,Yang Xi,Qu Jia,Wu Wencan,Zhang Zongduan,Wang Yi 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

Modified LDL-induced inflammation and oxidative stress are involved in the pathogenesis of diabetic retinopathy. Recent studies have also shown that modified LDL activates Toll-like receptor 4 (TLR4) to mediate retinal injury. However, the mechanism by which modified LDL activates TLR4 and the potential role of the TLR4 coreceptor myeloid differentiation protein 2 (MD2) are not known. In this study, we inhibited MD2 with the chalcone derivatives L2H17 and L6H21 and showed that MD2 blockade protected retinal Müller cells against highly oxidized glycated-LDL (HOG-LDL)-induced oxidative stress, inflammation, and apoptosis. MD2 inhibition reduced oxidative stress by suppressing NADPH oxidase-4 (NOX4). Importantly, HOG-LDL activated TLR4 and increased the interaction between NOX4 and TLR4. MD2 was required for the activation of these pathways, as inhibiting MD2 prevented the association of NOX4 with TLR4 and reduced NOX4-mediated reactive oxygen species production and TLR4-mediated inflammatory factor production. Furthermore, treatment of diabetic mice with L2H17 significantly reduced LDL extravasation in the retina and prevented retinal dysfunction and apoptosis by suppressing the TLR4/MD2 pathway. Our findings provide evidence that MD2 plays a critical role in mediating modified LDL-induced cell injury in the retina and suggest that targeting MD2 may be a potential therapeutic strategy.

Subsidence estimation of breakwater built on loosely deposited sandy seabed foundation: Elastic model or elasto-plastic model

Shen, Jianhua,Wu, Huaicheng,Zhang, Yuting The Society of Naval Architects of Korea 2017 International Journal of Naval Architecture and Oc Vol.9 No.4

In offshore area, newly deposited Quaternary loose seabed soils are widely distributed. There are a great number of offshore structures has been built on them in the past, or will be built on them in the future due to the fact that there would be no very dense seabed soil foundation could be chosen at planed sites sometimes. However, loosely deposited seabed foundation would bring great risk to the service ability of offshore structures after construction. Currently, the understanding on wave-induced liquefaction mechanism in loose seabed foundation has been greatly improved; however, the recognition on the consolidation characteristics and settlement estimation of loose seabed foundation under offshore structures is still limited. In this study, taking a semi-coupled numerical model FSSI-CAS 2D as the tool, the consolidation and settlement of loosely deposited sandy seabed foundation under an offshore breakwater is investigated. The advanced soil constitutive model Pastor-Zienkiewics Mark III (PZIII) is used to describe the quasi-static behavior of loose sandy seabed soil. The computational results show that PZIII model is capable of being used for settlement estimation problem of loosely deposited sandy seabed foundation. For loose sandy seabed foundation, elastic deformation is the dominant component in consolidation process. It is suggested that general elastic model is acceptable for subsidence estimation of offshore structures on loose seabed foundation; however, Young's modulus E must be dependent on the confining effective stress, rather than a constant in computation.

Subsidence estimation of breakwater built on loosely deposited sandy seabed foundation: Elastic model or elasto-plastic model

Jianhua Shen,Huaicheng Wu,Yuting Zhang 대한조선학회 2017 International Journal of Naval Architecture and Oc Vol.9 No.4

In offshore area, newly deposited Quaternary loose seabed soils are widely distributed. There are a great number of offshore structures has been built on them in the past, or will be built on them in the future due to the fact that there would be no very dense seabed soil foundation could be chosen at planed sites sometimes. However, loosely deposited seabed foundation would bring great risk to the service ability of offshore structures after construction. Currently, the understanding on wave-induced liquefaction mechanism in loose seabed foundation has been greatly improved; however, the recognition on the consolidation characteristics and settlement estimation of loose seabed foundation under offshore structures is still limited. In this study, taking a semi-coupled numerical model FSSI-CAS 2D as the tool, the consolidation and settlement of loosely deposited sandy seabed foundation under an offshore breakwater is investigated. The advanced soil constitutive model Pastor- Zienkiewics Mark III (PZIII) is used to describe the quasi-static behavior of loose sandy seabed soil. The computational results show that PZIII model is capable of being used for settlement estimation problem of loosely deposited sandy seabed foundation. For loose sandy seabed foundation, elastic deformation is the dominant component in consolidation process. It is suggested that general elastic model is acceptable for subsidence estimation of offshore structures on loose seabed foundation; however, Young's modulus E must be dependent on the confining effective stress, rather than a constant in computation.

Observer-based Adaptive Bipartite Time-varying Formation Tracking of Multi-agent System with Bounded Unknown Input

Xiaoyi Zhang,Jie Wu,Xisheng Zhan,Tao Han,Huaicheng Yan 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.12

In this paper, the bipartite time-varying formation tracking (BTVFT) problem is studied for multi-agent system (MAS) with the state of agents is unpredictable and a tracking leader of unknown bounded control input. Based on available states and unavailable states, a innovative kind of adaptive BTVFT protocols for MAS is respectively proposed in this article. Then by using Lyapunov stability theory, the result implies that under the appropriate assumptions, one group of followers will trace the leader agent and achieve given formation, while another group of followers will accomplish a given formation at the opposite to the origin. Furthermore, simulation example is represented to validate the performance and effectiveness of the design techniques.

Leader-following Adaptive Guaranteed-performance Consensus Control for Multi-agent Systems With Exogenous Disturbance

Na Zhao,Jie Wu,Xisheng Zhan,Tao Han,Huaicheng Yan 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.3

In this paper, the problem of leader-following distributed guaranteed-performance consensus for multiagent systems (MASs) subject to exogenous disturbances is investigated. First, a disturbance observer is designedfor each follower, which can be used to efficiently estimate the external disturbances. Next, an adaptive distributedstate feedback consensus protocol with guaranteed performance constraints is proposed based on the above proposed observer. Most of the existing literature on guaranteed performance does not consider unknown disturbances. Unlike existing schemes, consensus control with fully distributed guaranteed-performance is accomplished usingthis protocol, which solves the consensus control problem of exogenous disturbances. The consensus criterion ofadaptive guaranteed-performance is given by using Riccati inequality, and the adjustment method of consensuscontrol gain is given by using linear matrix inequality for leader-following situation. At last, the derived analyticalresults are validated by presenting a simulation example.

Distributed Finite-time Adaptive Containment and Bipartite Containment Control for Nonlinear Multi-agent System

Zijing Li,Jie Wu,Xisheng Zhan,Tao Han,Huaicheng Yan 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.5

Distributed second-order finite-time adaptive containment and bipartite containment control are investigated for multi-agent system with disturbance and nonlinear function under undirected graph in this paper. Firstly, two controllers are designed to achieve finite-time adaptive containment and bipartite containment control, which both based on terminal sliding mode. Then, desired finite-time containment and bipartite containment protocols are proposed and settling time can be estimated. It is proved that settling time of finite-time containment is associated to initial state. Feasibility of theory is proved by simulation experiments.

Adaptive Bipartite Output Containment Control of Heterogeneous Multi-agent Systems Based on Output Regulation Approach

Jie Cheng,Xisheng Zhan,Jie Wu,Huaicheng Yan 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.1

In this paper, the adaptive bipartite output containment problem is investigated, for a signed graph of heterogeneous multi-agent systems (HMASs). An adaptive state feedback algorithm and an output feedback algorithm are designed to ensure that cooperative and antagonistic agents enter different convex hull. A novel protocol is proposed for heterogeneous systems to deal with the bipartite output containment problem, where only the leader’s neighbours can learn the leader’s system matrix without all followers. Then, based on output regulation approach, Lyapunov stability analysis and some other methods guarantee that the bipartite output containment control problem is implemented. Finally, the validity of our analytical results is verified by the numerical simulations provided.

Optimal Tracking Performance of Communication Constrained Systems with Quantization and Packet Dropouts

Mengxi Jiang,Xisheng Zhan,Jie Wu,Tao Han,Huaicheng Yan 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.6

In this paper, the optimal tracking performance of communication constrained systems by considering quantization, packet dropouts, noise and control input power constraints is studied. The frequency domain method is utilized to analyze the optimal tracking performance of the communication constrained systems. The explicit expression of the optimal tracking performance is deduced by partial fraction decomposition method and innerouter factorization method. The results indicate that the optimal tracking performance for a controlled object is only affected by the plant’s inherent characteristics (non-minimum phase zeros and unstable poles) and network factors (quantization, packet dropouts and noise). Eventually, a simulation is offered to validate the theory.

An Approach for the Stability of Communication Constrained Networked Time-delay Control Systems

Siwei Qiao,Qingsheng Yang,Jie Wu,Xisheng Zhan,Huaicheng Yan 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.4

This paper aims to solve the stability problem of networked time-delay systems by frequency-domain analysis. The communication network quality is affected by bandwidth, noise, and packet dropouts. The main techniques are spectral decomposition and frequency-domain analysis. By means of utilizing those techniques, the expression of minimum signal-to-noise ratio which stabilizes the networked time-delay systems is obtained. Further, it is shown that the minimum value of system stability depends on the certain constraints (bandwidth and packet dropout probability) of communication channel, the position of unstable poles and the non-minimum phase zeros of given model. Moreover, an acquired result clearly brings out the contact among the status of the researched system, communication channel parameters, and the structural property of the considered model. Some simulation examples are given to provide validation of the final result.

Distributed Adaptive Bipartite Containment Control of Linear Multi-agent Systems with Structurally Balanced Graph

Zihan Liu,Xisheng Zhan,Jie Wu,Tao Han,Huaicheng Yan 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.11

This study researches the bipartite containment control problem of heterogeneous linear multi-agent systems under a signed digraph. The bipartite containment problem can be viewed as the output regulation problem by devising a compensator. By distributing a coupling weight which is time-varying to each follower, the adaptive protocols are proposed. Thus, we propose the distributed dynamic state feedback and output feedback protocols in conjunction with adaptive control, by which followers will converge to the convex hull crossed by leaders. Additionally, based on the utilization of the Lyapunov function approach, some extensive criteria are deduced to guarantee the bipartite containment of heterogeneous multi-agent system. The final simulations demonstrate the viability of the theoretical results.