Numerical simulation study of ionization characteristics of argon dielectric barrier discharge

In order to better analyze the characteristics of particle distribution and its influencing factors in the ionized space during the process of coaxial dielectric barrier discharge,a self-designed two-dimensional axisymmetric structure exciter was used to carry out optical diagnosis,with the electron temperature calculated through Gaussian fitting.A plasma model was applied to conduct research on the discharge process through numerical simulation,with the changes in electron density and electron temperature were analyzed by using different discharge parameters.The research results show that with an increase in discharge voltage,pressure inside the reactor and relative permittivity,the discharge process is promoted.In addition,a rise in current density leads to an increase in the number of charged particles on the surface of the medium during the discharge process,while a rise in discharge intensity causes an increase in the electron density.Electron temperature decreases due to the increased loss of collision energy between particles.These results were confirmed by comparing experimental data with simulation results.

Exosomes loaded a smart bilayer-hydrogel scaffold with ROS-scavenging and macrophage-reprogramming properties for repairing cartilage defect

Enhancing the regeneration of cartilage defects remains challenging owing to limited innate self-healing as well as acute inflammation arising from the overexpression of reactive oxygen species(ROS)in post-traumatic microenvironments.Recently,stem cell-derived exosomes(Exos)have been developed as potential cell-free therapy for cartilage regeneration.Although this approach promotes chondrogenesis,it neglects the emerging inflammatory microenvironment.In this study,a smart bilayer-hydrogel dual-loaded with sodium diclofenac(DC),an anti-inflammatory drug,and Exos from bone marrow-derived mesenchymal stem cells was developed to mitigate initial-stage inflammation and promote late-stage stem-cell recruitment and chondrogenic differentiation.First,the upper-hydrogel composed of phenylboronic-acid-crosslinked polyvinyl alcohol degrades in response to elevated levels of ROS to release DC,which mitigates oxidative stress,thus reprogramming macrophages to the pro-healing state.Subsequently,Exos are slowly released from the lower-hydrogel composed of hyaluronic acid into an optimal microenvironment for the stimulation of chondrogenesis.Both in vitro and in vivo assays confirmed that the dual-loaded bilayer-hydrogel reduced post-traumatic inflammation and enhanced cartilage regeneration by effectively scavenging ROS and reprogramming macrophages.The proposed platform provides multi-staged therapy,which allows for the optimal harnessing of Exos as a therapeutic for cartilage regeneration.

High glucose promotes macrophage M1 polarization through miR-32/Mef2d/cAMP signaling pathway

Chronic inflammation is a crucial inducerof diabetesvascular complications.Onereason is that high glucose easily induces macrophage activation.1 Macrophages are the principal participants in innate immunity and exist in all human tissues.In pathological vascular,infiltrated macrophages secrete inflammatory factors leading to an increase in plaque stability.?In macrophage polarization,autophagy plays an important role.Enhancement of macrophage autophagy could induce macrophage polarization from the M1 phenotype to M2 phenotype and inhibit inflammatory reactions.3 Our previous research found that high glucose condition promotes miR-32 expression and macrophage M1 polarization,4 but the mechanism of miR-32 promoting macrophage M1 polarization is unclear.In this study,we found that,under a high-glucose condition,miR-32/Mef2d/cAMP signaling promoted M1 macrophage polarization via inhibited autophagy.These results provide a theoretical and experimental basis for the prevention and treatment of T2D vascular inflammation.

Robust Joule-heating ceramic reactors for catalytic CO oxidation

Joule-heating reactors have the higher energy efficiency and product selectivity compared with the reactors based on radiative heating.Current Joule-heating reactors are constructed with electrically-conductive metals or carbon materials,and therefore suffer from stability issue due to the presence of corrosive or oxidizing gases during high-temperature reactions.In this study,chemicallystable and electrically-conductive(La_(0.80)Sr_(0.20))_(0.95)FeO_(3)(LSF)/Gd_(0.1)Ce_(0.9)O_(2)(GDC)ceramics have been used to construct Joule-heating reactors for the first time.Taking the advantage of the resistance decrease of the ceramic reactors with temperature increase,the ceramic reactors heated under current control mode achieved the automatic adjustment of heating to stabilize reactor temperatures.In addition,the electrical resistance of LSF/GDC reactors can be tuned by the content of the highconductive LSF in composite ceramics and ceramic density via sintering temperature,which offers flexibility to control reactor temperatures.The ceramic reactors with dendritic channels(less than 100μm in diameter)showed the catalytic activity for CO oxidation,which was further improved by coating efficient MnO_(2)nanocatalyst on reactor channel wall.The Joule-heating ceramic reactors achieved complete CO oxidation at a low temperature of 165℃.Therefore,robust ceramic reactors have successfully demonstrated effective Joule heating for CO oxidation,which are potentially applied in other high-temperature catalytic reactions.