Zeroing neural network (ZNN) has been applied to various time-varying problems solving, and numerous ZNN models have been developed in recent years, such as power-type varying-parameter ZNN (PT-VR-ZNN) for solving time-varying quadratic minimization problems, adaptive fuzzy-type ZNN (AFT-ZNN) for solving time-variant matrix inversion and fuzzy power ZNN (FPZNN) for solving time-varying quadratic programming problems. As a time-varying problem and imperative research hot spot in science and engineering, the synchronization of chaotic systems has developed for decades. However, the research on chaos synchronization using ZNN method is rarely reported. Therefore, this paper proposes a time-varying fuzzy parameter ZNN (TVFP-ZNN) model to realize chaotic systems synchronization against the external noises. The most prominent feature of the TVFP- ZNN model is that the time-varying fuzzy parameter generated by the fuzzy logic system is applied in this model. Moreover, the above mentioned three models are also applied to realize the same chaotic systems synchronization for comparison. Compared with above three models, the proposed TVFP-ZNN model not only possesses the fastest convergence speed, but also maintains strongest robustness to noises. Besides, the excellent performances of the TVFP-ZNN model are verified by rigorous mathematical validation. Furthermore, the effectiveness and robustness of the proposed TVFP-ZNN model for chaotic systems synchronization are verified by comparative numerical simulation results. Finally, the process of the proposed TVFP-ZNN model for chaotic system synchronization is displayed on the oscilloscope based on the field programmable gate array (FPGA) to further illustrate its practical application ability.

The zeroing neural network (ZNN) model, a powerful approach for addressing time-varying problems, has been extensively applied in the calculation and optimization fields. In this article, a new pattern activation function, the power piecewise activation function (PPAF), is proposed to establish a predefined fixed-time convergent ZNN (PFTZNN) for finding solutions to the time-varying quadratic programming problem. In comparison with the traditional activation functions, multisegmentation is a remarkable feature of the PPAF; consequently, the advantage of PPAF is that its parameters can be flexibly adjusted according to actual needs. Specifically, because of the multisegment characteristics of the PPAF, the convergence speed of the PPAF-activated PFTZNN model can be flexibly adjusted based on distinct requirements. The fixed-time convergence property of the PPAF-activated PFTZNN model is validated by detailed mathematical theoretical analysis, and its upper bound convergence time is directly calculated. Then, the comparative simulation results of the PPAF-activated PFTZNN model with other existing ZNN models for time-varying quadratic programming are provided for the further verification of its superior convergence speed and robustness. In addition, the proposed PFTZNN model is applied for dual-arm manipulator cooperative trajectory tracking, and its practical application ability is demonstrated by united simulation experiments of MATLAB and Robot studio. Finally, the PFTZNN model is also applied to control a real dual-arm manipulator to complete the trajectory tracking task, which further validates its superior performance together and widespread applicability.

The formation of neutrophil extracellular trap (NET) is a critical host defense when neutrophils migrate to infection sites. Pyroptosis is a newly identified programmed cell death, which is tightly regulated by inflammasome activation. However, the mechanism of pyroptotic signaling participating in NET production remains to be elucidated. In this study, the zebrafish larvae otic vesicle microinjection model was used to infect larvae with hemolysin-overexpressing Edwardsiella piscicida (EthA⁺), and a rapid migration of neutrophils to infection sites was observed. Intriguingly, EthA⁺ infection effectively induced significant neutrophil membrane rupture in vivo, which was dependent on caspase-B (caspy2) and gasdermin Eb (GSDMEb) but not caspase-A or gasdermin Ea. Specifically, the EthA⁺E. piscicida infection induced pyroptosis along with NETosis in vitro, and depletion of either caspy2 or GSDMEb impaired NET formation in vivo. Consequently, inhibition of the caspy2–GSDMEb axis-gated NETosis impaired bacterial clearance in vivo. Altogether, these data provide evidence that teleost fish innate immune cells, including neutrophils, express features of pyroptosis that are critical for NETosis in teleost innate immunity. Key Points Zebrafish caspy2–GSDMEb axis contributes to neutrophil pyroptosis in vivo. Depletion of caspy2 or GSDMEb impairs the process of NETosis. Pyroptosis-gated NETosis plays a critical role in teleost innate immunity.

Trained immunity defines long-term memory of innate immunity based on transcriptional, epigenetic, and metabolic modifications of myeloid cells, which are characterized by elevated proinflammatory responses toward homologous or heterologous secondary stimuli in mammals. However, the evidence of trained immunity-associated immune cells and its molecular mechanism in teleost fish remains largely unknown. In this study, we established a trained immunity activation model in turbot (Scophthalmus maximus) and found that administration with β-glucan induces protection against a bacterial infection. Through single-cell RNA sequencing to annotate 14 clusters of innate and adaptive immune cells, as well as two clusters of blood cells, from head kidney and spleen, respectively, we characterized that neutrophil displays cardinal features of trained immunity by analyzing the expression abundance of trained immunity database–related genes at the single-cell level. Subsequently, through establishing an in vivo training and in vitro neutrophil challenge model, we found that the trained neutrophils exhibit a significant elevation of the IL-1R signaling pathway after Edwardsiella piscicida infection. Furthermore, inhibition of neutrophil’s IL-1R signaling pathway through anakinra treatment impaired the heightened production of reactive oxygen, nitrogen species, lactate, as well as the neutrophil extracellular traps formation and bacterial killing ability. Taken together, these findings characterized neutrophil as the orchestrator to express features of trained immunity, and revealed that the IL-1R signaling pathway plays a critical role in induction of trained immunity for bacterial clearance in teleost fish.