A Novel Obstacle Avoidance Consensus Control for Multi-AUV Formation System

In this paper, the fixed-time event-triggered obstacle avoidance consensus control for a multi-AUV time-varying formation system in a 3D environment is presented by using an improved artificial potential field and leader-follower strategy(IAPF-LF). Firstly, the proposed fixed-time control can achieve the desired multi-AUV formation within a fixed settling time in any initial system state. Secondly, an event-triggered communication strategy is developed to govern the communication among AUVs, and the communication energy consumption can be decremented. The time-varying formation obstacle avoidance control algorithm based on IAPF-LF is designed to avoid static and dynamic obstacles, the desired formation is maintained in the presence of external disturbances, and there is no Zeno behavior under the fixed-time event-triggered consensus control strategy.The stability of the system is proved by the Lyapunov function and inequality scaling. Finally, simulation examples and water pool experiments are reported to verify the performance of the proposed theoretical algorithms.

Light amplified oxidative stress in tumor microenvironment by carbonized hemin nanoparticles for boosting photodynamic anticancer therapy

Photodynamic therapy(PDT),which utilizes light excite photosensitizers(PSs)to generate reactive oxygen species(ROS)and consequently ablate cancer cells or diseased tissue,has attracted a great deal of attention in the last decades due to its unique advantages.However,the advancement of PDT is restricted by the inherent characteristics of PS and tumor microenvironment(TME).It is urgent to explore high-performance PSs with TME regulation capability and subsequently improve the therapeutic outcomes.Herein,we reported a newly engineered PS of polymer encapsulated carbonized hemin nanoparticles(P-CHNPs)via a facile synthesis procedure for boosting photodynamic anticancer therapy.Solvothermal treatment of hemin enabled the synthesized P-CHNPs to enhance oxidative stress in TME,which could be further amplified under light irradiation.Excellent in vitro and in vivo PDT effects were achieved due to the improved ROS(hydroxyl radicals and singlet oxygen)generation efficiency,hypoxia relief,and glutathione depletion.Moreover,the superior in vitro and in vivo biocompatibility and boosted PDT effect make the P-CHNPs a potential therapeutic agent for future translational research.