Simulations and software development for the Hard X-ray Imager onboard ASO-S

China’s first solar mission,the Advanced Space-based Solar Observatory(ASO-S),is now changing from Phase B to Phase C.Its main scientific objectives are summarized as’1M2B’,namely magnetic field and two types of bursts(solar flares and coronal mass ejections).Among the three scientific payloads,Hard X-ray Imager(HXI)observes images and spectra of X-ray bursts in solar flares.In this paper,we briefly report on the progresses made by the HXI science team(data and software team)during the design phase(till May 2019).These include simulations of HXI imaging,optimization of HXI grids,development of imaging algorithms,estimation of orbital background,as well as in-orbit calibration plan.These efforts provided guidance for the engineering,improved HXI’s imaging capability and reduced the cost of the instrument.

Acetyl-11-keto-β-boswellic acid extracted from Boswellia serrata promotes Schwann cell proliferation and sciatic nerve function recovery

Frankincense can promote blood circulation. Acetyl-11-keto-β-boswellic acid （AKBA） is a small molecule with anti-inflammatory properties that is derived from Boswellia serrata. Here, we hypothesized that it may promote regeneration of injured sciatic nerve. To address this hypothesis, we established a rat model of sciatic nerve injury using a nerve clamping method. Rats were administered AKBA once every 2 days at doses of 1.5, 3, and 6 mg/kg by intraperitoneal injection for 30 days from the 1st day after injury. Sciatic nerve function was evaluated using the sciatic functional index. Degree of muscle atrophy was measured using the triceps surae muscle Cuadros index.Neuropathological changes were observed by hematoxylin-eosin staining. Western blot analysis was used to detect expression of phospho-extracellular signal-regulated kinase 1 and 2 （p-ERK1/2） in injured nerve. S100 immunoreactivity in injured nerve was detected by immunohistochemistry. In vivo experiments showed that 3 and 6 mg/kg AKBA significantly increased sciatic nerve index, Cuadros index of triceps muscle, p-ERK1/2 expression, and S100 immunoreactivity in injured sciatic nerve of sciatic nerve injury model rats. Furthermore,for in vitro experiments, Schwann cells were treated with AKBA at 0–20 μg/mL. Proliferation of Schwann cells was detected by Cell Counting Kit-8 colorimetry assay. The results showed that 2 μg/mL AKBA is the optimal therapeutic concentration. In addition, ERK phosphorylation levels increased following 2 μg/mL AKBA treatment. In the presence of the ERK1/2 inhibitor, PD98059 （2.5 μL/mL）, the AKBA-induced increase in p-ERK1/2 protein expression was partially abrogated. In conclusion, our study shows that AKBA promotes peripheral nerve regeneration with ERK protein phosphorylation playing a key role in this process.

Acetyl-11-keto-beta-boswellic acid promotes sciatic nerve repair after injury: molecular mechanism

Previous studies showed that acetyl-11-keto-beta-boswellic acid(AKBA),the active ingredient in the natural Chinese medicine Boswellia,can stimulate sciatic nerve injury repair via promoting Schwann cell proliferation.However,the underlying molecular mechanism remains poorly understood.In this study,we performed genomic sequencing in a rat model of sciatic nerve crush injury after gastric AKBA administration for 30 days.We found that the phagosome pathway was related to AKBA treatment,and brain-derived neurotrophic factor expression in the neurotrophic factor signaling pathway was also highly up-regulated.We further investigated gene and protein expression changes in the phagosome pathway and neurotrophic factor signaling pathway.Myeloperoxidase expression in the phagosome pathway was markedly decreased,and brain-derived neurotrophic factor,nerve growth factor,and nerve growth factor receptor expression levels in the neurotrophic factor signaling pathway were greatly increased.Additionally,expression levels of the inflammatory factors CD68,interleukin-1β,pro-interleukin-1β,and tumor necrosis factor-αwere also decreased.Myelin basic protein-andβ3-tubulin-positive expression as well as the axon diameter-to-total nerve diameter ratio in the injured sciatic nerve were also increased.These findings suggest that,at the molecular level,AKBA can increase neurotrophic factor expression through inhibiting myeloperoxidase expression and reducing inflammatory reactions,which could promote myelin sheath and axon regeneration in the injured sciatic nerve.