1d3v PIC/MCC simulation of dielectric barrier discharge dynamics in hydrogen sulfide

In this study,we computationally examined the dynamics of dielectric barrier discharge in hydrogen sulfide.The simulations were performed with a 1 d3 v particle-in-cell/Monte Carlo collision model in which a parallel-plate electrode geometry with dielectrics was used.Particle recombination process is represented in the model.The discharge mode was found to be initially Townsend discharge developing from the cathode to the anode,and at the peak of the current,a more stable glow discharge develops from the anode to the cathode.A higher applied voltage results in sufficient secondary electrons to trigger a second current peak,and then the current amplitude increases.As the frequency is increased,it leads to the advance of the phase and an increase in the amplitude of the current peak.A higher dielectric permittivity also makes the discharge occur earlier and more violently in the gap.

Egg cell-secreted aspartic proteases ECS1/2 promote gamete attachment to prioritize the fertilization of egg cells over central cells in Arabidopsis

Double fertilization is an innovative phenomenon in angiosperms,in which one sperm cell first fuses with the egg cell to produce the embryo,and then the other sperm fuses with the central cell to produce the endosperm.However,the molecular mechanism of the preferential fertilization of egg cells is poorly understood.In this study,we report that two egg cell-secreted aspartic proteases,ECS1 and ECS2,play an important role in promoting preferential fertilization of egg cells in Arabidopsis.We show that simultaneous loss of ECS1 and ECS2 function resulted in an approximately 20%reduction in fertility,which can be complemented by the full-length ECS1/2 but not by corresponding active site mutants or by secretion-defective versions of ECS1/2.Detailed phenotypic analysis revealed that the egg cellsperm cell attachment was compromised in ecs1 ecs2 siliques.Limited pollination assays with cyclin-dependent kinase a1(cdka;1)pollen showed that preferential egg cell fertilization was impaired in the ecs1 ecs2 mutant.Taken together,these results demonstrate that egg cells secret two aspartic proteases,ECS1 and ECS2,to facilitate the attachment of sperm cells to egg cells so that preferential fertilization of egg cells is achieved.This study reveals the molecular mechanism of preferential fertilization in Arabidopsis thaliana.