Adaptive scale model reconstruction for radio synthesis imaging

A sky model from CLEAN deconvolution is a particularly effective high dynamic range reconstruction in radio astronomy,which can effectively model the sky and remove the sidelobes of the point spread function(PSF)caused by incomplete sampling in the spatial frequency domain.Compared to scale-free and multi-scale sky models,adaptive-scale sky modeling,which can model both compact and diffuse features,has been proven to have better sky modeling capabilities in narrowband simulated data,especially for large-scale features in high-sensitivity observations which are exactly one of the challenges of data processing for the Square Kilometre Array(SKA).However,adaptive scale CLEAN algorithms have not been verified by real observation data and allow negative components in the model.In this paper,we propose an adaptive scale model algorithm with non-negative constraint and wideband imaging capacities,and it is applied to simulated SKA data and real observation data from the Karl G.Jansky Very Large Array(JVLA),an SKA precursor.Experiments show that the new algorithm can reconstruct more physical models with rich details.This work is a step forward for future SKA image reconstruction and developing SKA imaging pipelines.

Epigallocatechin-3-gallate Alleviates Cognitive Deficits in APP/PS1 Mice

Alzheimer's disease(AD)shows cognitive impairments in clinic,which is multifactorial with different etiopathogenic mechanisms such as A|3 deposition,neuroinflammation and neuronal dystrophy involved.Therefore,multi-targets drugs with neuroprotective,anti-amyloidogenic and anti-inflammatory properties will be effective in AD treatment.Epigallocatechin-3-gallate(EGCG)possesses a broad spectrum of pharmacological activities in the prevention and treatment of multiple neurodegenerative diseases.In the present study,we showed that oral administration of EGCG(50 mg/kg)for 4 months significantly attenuated the cognitive deficits in APP/PS1 transgenic mice,which served as AD model.Moreover,EGCG induced an improvement in dendritic integrity and expression levels of synaptic proteins in the brain of APP/PS 1 mice.And EGCG exerted obvious anti-inflammatory effects,which was manifested by alleviating microglia activation,decreasing pro-inflammatory cytokine(IL-β)and increasing anti-inflammatory cytokines(IL-10,IL-β).Furthermore,p-amyloid(AP)plaques were markedly reduced in the hippocampus of 6-month old APP/PS 1 mice after EGCG treatment.In conclusion,these findings indicate that EGCG improves AD-like cognitive impairments through neuroprotective,anti-amyloidogenic and anti-inflammatory effects,thus is a promising therapeutic can didate for AD.

Band Alignment at the Al2O3/β-Ga2O3 Interface with CHF3 Treatment

The energy band alignment at the atomic layer deposited Al2O3/β-Ga2O3 interface with CHF3 treatment was characterized by x-ray photoelectron spectroscopy and secondary ion mass spectrometry(SIMS).With additional CHF3 plasma treatment,the conduction band offset increases from 1.95±0.1 eV to 2.32±0.1 eV;and the valence band offset decreases from 0.21±0.1 eV to-0.16±0.1 eV.As a result,the energy band alignment changes from type I to type II.This energy band alignment transition could be attributed to the downshift of the core-level of Ga 3d,resulting from the Ga–F bond formation in the F-rich interfacial layer,which is confirmed by the SIMS results.