Chemical looping oxidative propane dehydrogenation controlled by oxygen bulk diffusion over FeVO_(4)oxygen carrier pellets

The oxygen distribution and evolution within the oxygen carrier exert significant influence on chemical looping processes.This paper describes the influence of oxygen bulk diffusion within FeVO4 oxygen carrier pellets on the chemical looping oxidative propane dehydrogenation(CL-ODH).During CL-ODH,the oxygen concentration at the pellet surface initially decreased and then maintained stable before the final decrease.At the stage with the stable surface oxygen concentration,the reaction showed a stable C3H6 formation rate and high C3H6 selectivity.Therefore,based on Fick’s second law,the oxygen distribution and evolution in the oxygen carrier at this stage were further analyzed.It was found that main reactions of selective oxidation and over-oxidation were controlled by the oxygen bulk diffusion.C3H8 conversion rate kept decreasing during this stage due to the decrease of the oxygen flux caused by the decline of oxygen gradient within the oxygen carrier,while C3H6 selectivity increased due to the decrease of overoxidation.In addition,reaction rates could increase with the propane partial pressure due to the increase of the oxygen gradient within the oxygen carrier until the bulk transfer reached its limit at higher propane partial pressure.This study provides fundamental insights for the diffusion-controlled chemical looping reactions.

Beneficial effects of AOS-iron supplementation on intestinal structure and microbiota in IDA rats

The objective of this study was to investigate the effects of agar oligosaccharide-iron(AOS-iron)on intestinal tissue pathology and microbiota in IDA rats induced by a low-iron diet,further to find the relationship between intestinal microbiota and iron metabolic disorders.After 4 weeks of AOS-iron supplementation,the fecal iron content of IDA rats markedly increased in a dose-dependent manner,only the damaged cecum and colon tissues in medium-dose(MD)and high-dose(HD)groups were repaired to the baseline,while the diversity of gut microbiota was improved even at low dose(LD).Furthermore,the supplementation of AOS-iron altered the composition of gut microbiota.At the genus level,the beneficial microbiota was enriched in AOS-iron groups,but the relative abundance of potential opportunistic pathogens obviously reduced compared to that in the anemia model(AM)group.Spearman’s correlation analysis revealed that biochemical parameters,including blood metabolic parameters,iron contents,body weight,GSH-PX and T-AOC activity,were positively correlated with SMB53,Anaerotruncus,Anaerostipes and Coprobacillus but negatively correlated with Morganella,Fusobacterium and Serratia.These findings indicated that AOS-iron effectively repaired the damaged intestinal tissue and ameliorated iron metabolic disorders by regulating gut microbiota desirably,which could provide references for the treatment of IDA.

Transcriptome-based insights into the calcium transport mechanism of chick chorioallantoic membrane

Chorioallantoic membrane(CAM)is responsible for respiratory gas exchange,eggshell calcium transport,embryonic acid-base equilibrium,allantoic ion,and water reabsorption during avian embryonic development.To further understand the timing of CAM gene expression during chick embryonic development,especially the calcium absorption mechanism,transcriptome quantitative comparative analysis was conducted on chick CAM during the embryonic period(E)of 9,13,17,and 20 days.A total of 6378 differentially expressed genes(DEGs)were identified.Functional enrichment analysis of DEGs showed that CAM DEGs were mainly involved in biological processes such as"ion transport regulation","immune response"and"cell cycle".Time series analysis of the differential genes showed that the functional cells of CAM began to proliferate and differentiate at E9 and the calcium content of egg embryo increased significantly at E13.Simultaneously,the observation of the ultrastructure of the eggshell showed that the interstice of the fiber layer was enlarged at E13,and the mastoid layer was partly exposed.Therefore,it is preliminarily inferred that CAM calcium transport starts at E13,and genes such as TRPV6,S100 A10,and RANKL cooperate to regulate calcium release and transport.

Malondialdehyde treatment reduced immunoreactivity of amandin and delayed its digestion

Objectives:The secondary products of lipid oxidation are one of the main factors inducing protein oxidation.The effects of oxidation treatment with malondialdehyde(MDA)on the immunoreactivity of amandin and its digestion were studied.Materials and Methods:The rabbit IgG binding ability of amandin was analyzed by western blotting,and the changes in amandin oxidation and immunoreactivity during digestion of amandin with different degrees of oxidation were investigated in combination with an almond allergen enzyme-linked immunosorbent assay kit.Alteration of linear epitopes of amandin by oxidation was investigated by liquid chromatography-tandemmass spectrometry(LC-MS/MS).Results:The results showed that the immunoreactivity of amandin was significantly reduced after 1 mmol/L MDA and 100 mmol/L MDA treat-ment.However,the 1 mmol/L MDA treatment was owing to cleavage of linear epitope peptide in amandin and oxidation of the active amino acid.The 100 mmol/L MDA treatment was due to aggregation of amandin and significant decrease in its solubility.Oxidation also reduced di-gestibility of amandin and significantly affected immunoreactivity during digestion.LC-MS/MS also identified four oxidation-prone methionine sites(aa 264-274,298-308,220-240,and 275-297)in gamma conglutinin 1.Conclusions:MDA treatment reduced the immunoreactivity of amandin.MDA treatment also led to protein aggregation,which slowed down the digestion of amandin and altered the immunoreactivity of amandin during digestion.