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

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.

Loop Closure Detection Based on Image Covariance Matrix Matching for Visual SLAM

Tao Ying,Huaicheng Yan,Zhichen Li,Kaibo Shi,Xiangsai Feng 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.11

Loop closure detection is an indispensable part of visual simultaneous location and mapping (SLAM). Correct detection of loop closure can help mobile robot to reduce the problem of cumulative pose drift. At present, the main method for detecting visual SLAM loop closure is the bag of words (BoW) model, but it lacks the spatial distribution information of local features of the image, and the scale will become larger and larger with the increase of data, resulting in the slow operation speed. In order to solve these problems, the image histogram and the key region covariance matrix matching method are used to visually detect the loop closure combined with the global and local image features. In this paper, three different place recognition techniques are studied: histogram only, image covariance matrix matching (ICMM) and cluster loop. Experiments on real datasets show that the proposed method of detecting the loop closure is better than the traditional methods in detecting accuracy and recalling rate, which also improves the operation effect of the SLAM algorithm.

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.

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.

Performance Analysis of Information Time-delay Systems with Bandwidth Constraints and Channel Noise

Xiangchen Du,Xisheng Zhan,Qingsheng Yang,Huaicheng Yan 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.12

In this paper, the performance limitation of information time-delay systems under bandwidth and channel noise constraints are investigated. The channel noise is assumed to be Gaussian white noise and obtain the expression of the performance limitation is obtained using spectrum decomposition and partial factorization techniques. The result shows that the performance limitation depends on the given system’s unstable zeros, time delay and non-minimum phase zero. Moreover, other communication constraints such as the bandwidth and Gaussian white noise also impact performance. Finally, the theoretical result is verified through a simulation.

Quantized Output Feedback Control for Stochastic Semi-Markov Jump Systems With Unreliable Links

Shen, Hao,Dai, Mingcheng,Yan, Huaicheng,Park, Ju H. IEEE 2018 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS PART 2 E Vol.65 No.12

<P>This brief is concerned with the problem of quantized output feedback (OF) control for semi-Markov jump systems subject to unreliable links. The jump among the operation modes is subject to the semi-Markov process, where the transition probabilities depend not only on the next system mode but the sojourn time at current mode as well. The communication link is considered to be unreliable, in which the packet dropouts described by a stochastic Bernoulli parameter and signal quantization are taken into account simultaneously. The purpose is to synthesize an OF controller, which ensures that the closed-loop system is mean-square <TEX>$\sigma $</TEX>-error stable. Some sojourn time-dependent criteria are established for the realizability of admissible OF controller. With the help of those criteria, the controller gains could be obtained by finding a solution to a convex optimization problem. Finally, both a numerical example and a PWM-driven boost converter are presented to confirm the availability and feasibility of the proposed approach.</P>

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.

Finite-time and Fixed-time Bipartite Consensus Tracking for Second-order Multi-agent Systems via an Integral Sliding-mode Approach

Xiao-Feng Zhao,Tao Han,Bo Xiao,Xi-Sheng Zhan,Huaicheng Yan 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.12

This paper investigates the finite-time and fixed-time bipartite consensus tracking (Fin- and Fix-TBCT) problems for second-order multi-agent systems (MASs) under a signed directed communication network, in which both cooperative and competition exist. To achieve bipartite consensus tracking (BCT) within finite time and fixed time, two novel distributed control protocols utilizing integral sliding-mode control concept are presented and discussed, respectively. By virtue of Lyapunov stability and homogeneity with dilation, several sufficient conditions for achieving Fin- and Fix-TBCT for second-order MASs are obtained. Eventually, numerical simulation results are provided to verify the validity of the obtained theoretical results.

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.