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Aeromonas salmonicida is the pathogen of furunculosis, causing a septicaemic infection that influences both salmonid and non-salmonid fish. Early diagnosis of these contagions is essential for disease surveillance and prevention, so that the rapid and sensitive approach is required. Herein, recombinase polymerase amplification (RPA) assay and RPA with a lateral flow dipstick (RPA-LFD) were produced for testing A. salmonicida. The RPA and RPA-LFD primer sets were devised based on the conserved fragment sequence of vapA gene. Then, RPA and RPA-LFD reaction systems were established, and the reaction temperature and time were optimized. After optimization, the RPA method was capable to test A. salmonicida within 10 min and the RPA-LFD method can detect A. salmonicida in only 5 min. The RPA and RPA-LFD methods exhibited high specificity with no cross-reaction with others strains. To assess sensitivity, a partial vapA gene was cloned, and serial plasmid dilutions were created ranging from 1×106 to 1×10− 1 copies/µL. The detection limit of RPA was 1×102 copies/µL and the detection limit of RPA-LFD was 1 copies/µL. For spiked turbot tissue samples, the sensitivity detecting of A. salmonicida was 1.2×101 CFU/mL and 1.2 CFU/mL by RPA and RPA-LFD, respectively. Therefore, our RPA and RPA-LFD assays exhibited excellent specificity and sensitivity, which provided two simple, fast and dependable methods to conduct large-scale field investigations of A. salmonicida in resource-limited settings.

In this research, Vibrio vulnificus formalin-killed (FKCs) vaccine and ghost (VVGs) vaccine were successfully developed, and shown to prevent vibriosis of Scophthalmus maximus resulting from V. vulnificus. The antibody titre of FKCs and VVGs vaccine was 1: 2

Aeromonas salmonicida is the pathogen underlying furunculosis, causing a septicemic infection that influences both salmonid and non-salmonid fish. Early diagnosis of these contagions is essential for disease surveillance and prevention, so a rapid and sensitive approach is needed. Herein, a recombinase polymerase amplification EXO (RPA-EXO) assay and RPA with a lateral flow dipstick (RPA-LFD) were produced for testing A. salmonicida. The RPA-EXO and RPA-LFD primer sets were devised based on the conserved fragment sequence of the vapA gene. Then, RPA-EXO and RPA-LFD reaction systems were established, and the reaction temperature and time were optimized. After optimization, the RPA-EXO method was capable of testing A. salmonicida within 10 min, and the RPA-LFD method could detect A. salmonicida in only 5 min. The RPA-EXO and RPA-LFD methods exhibited high specificity with no cross-reaction with other strains. To assess sensitivity, a partial vapA gene was cloned, and serial plasmid dilutions were created ranging from 1 × 10

Single-shot ultrafast multi-frame imaging technology plays a crucial role in the observation of laser-induced plasma. However, there are many challenges in the application of laser processing, such as technology fusion and imaging stability. To provide a stable and reliable observation method, we propose an ultrafast single-shot multi-frame imaging technology based on wavelength polarization multiplexing. Through the frequency doubling and birefringence effects of the BBO and the quartz crystal, the 800 nm femtosecond laser pulse was frequency doubled to 400 nm, and a sequence of probe sub-pulses with dual-wavelength and different polarization was generated. The coaxial propagation and framing imaging of multi-frequency pulses provided stable imaging quality and clarity, as well as high temporal/spatial resolution (200 fs and 228 lp/mm). In the experiments involving femtosecond laser-induced plasma propagation, the probe sub-pulses measured their time intervals by capturing the same results. Specifically, the measured time intervals were 200 fs between the same color pulses and 1 ps between the adjacent different. Finally, based on the obtained system time resolution, we observed and revealed the evolution mechanism of femtosecond laser-induced air plasma filaments, the multifilament propagation of femtosecond laser in fused silica, and the influence mechanism of air ionization on laser-induced shock waves.

The femtosecond laser ablation of metals is a complex and violent nonequilibrium process, and numerous studies have sought to reveal the evolution of a single physical phenomenon, such as laser-induced periodic surface micro-nanostructures or plasma eruptions. By considering the multiphysics scenarios of energy and heat transfer, structural mechanics, hydrodynamics, and nucleation dynamics, a femto-nanosecond and nano-micrometer multiscale framework combining electron–phonon-coupled heat transfer, lattice deformation, phase transition, and plasma eruption was constructed to describe the heat and mass transfer mechanism of femtosecond laser–copper interaction. A multiphysics model was proposed in this study to simulate the ablation process with different laser fluences. Ablation occurs at low near-threshold fluences primarily via a combination of the thermal phase transition process of melting and thermoplastic deformation coupled with the nonthermal phase transition process of hot electron explosion. Marangoni convection and non-uniform nucleation at the solid–liquid interface create micro-nano structures on the surface of the ablation crater. At a high laser fluence, plasma plumes are emitted via gasification and eruption, and as the material is heated to decrease its density, the surface is broken into a micro-column structure, and then the micro-columns fracture and erupt to form micro-nano structures and plasma plumes. Numerical results offer a better understanding of surface topography modifications and plasma plume evolution and promote the application of femtosecond laser precision fabrication in the fields of aviation, mechanics, electronics, and materials engineering.