Quantum Chemistry Study on Local Structure and Properties of Amorphous Fe80P20 Alloy

According to the structure features of Fe80P20, A series of clusters Fe4P were designed and focused on studying the stability of local structure, charge distribution and chemical bond, Using the DFT method, energy and structure of Fe4P clusters were optimized and analyzed. The computational results showed that the energy of cluster 1（2） has the lowest energy, and the possibility of its existence in the Fe80P20 is high. Analyzing the transition states among the clusters, it was found that the clusters in the doublet state are more stable than those in the quartet state. The numbers of the Fe-P bond in the clusters play important roles in the cluster stability and electrons transfer properties, The more numbers of Fe-P bonds in the clusters, the higher the cluster stability, and the weaker the ability of P atom to get electron, The number of Fe atoms, which has bonding interactions with the P atom, is direct proportional to the average 3d orbit population of Fe atom. Basing on the orbital population, average magnetic moments of each Fe atom in the Fe4P clusters were calculated, and they are all smaller than that of single metal Fe atom. This suggests that all Fe4P clusters have soft magnetic property and they are expected to be perfect material for preparing soft magnetic apparatus.

MicroRNAs of bone marrow mesenchymal stem cell-derived exosomes regulate acute myeloid leukemia cell proliferation and apoptosis

Background:Acute myeloid leukemia(AML)is a malignant hematological disease,originating from hematopoiesis stem cell differentiation obstruction and clonal proliferation.New reagents or biologicals for the treatment of AML are urgently needed,and exosomes have been identified as candidate biomarkers for disease diagnosis and prognosis.This study aimed to investigate the effects of exosomes from bone marrow mesenchymal stem cells(BMSCs)on AML cells as well as the underlying microRNA(miRNA)-mediated mechanisms.Methods:Exosomes were isolated using a precipitation method,followed by validation using marker protein expression and nanoparticle tracking analysis.Differentially expressed miRNAs were identified by deep RNA sequencing and confirmed by quantitative real-time polymerase chain reaction(qPCR).Cell proliferation was assessed by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt method,and cell cycle progression and apoptosis were detected by flow cytometry.Functional gene expression was analyzed by qPCR and Western blotting(WB).Significant differences were determined using Student’s t test or analysis of variance.Results:BMSCs-derived exosomes effectively suppressed cell proliferation(both P<0.0001 at 10 and 20μg/mL)and cell cycle progression(P<0.01 at G0-G1 stage),and also significantly enhanced cell apoptosis(P<0.001)in KG-1a cells.There were 1167 differentially expressed miRNAs obtained from BMSCs-derived exosomes compared with KG-1a cell-derived exosomes(P<0.05).Knockdown of hsa-miR-124-5p in BMSCs abrogated the effects of BMSCs-derived exosomes in regulating KG-1a such as the change in cell proliferation(both P<0.0001 vs.normal KG-1a cell[NC]at 48 and 72 h).KG-1a cells treated with BMSCs-derived exosomes suppressed expression of structural maintenance of chromosomes 4(P<0.001 vs.NC by qPCR and P<0.0001 vs.NC by WB),which is associated with the progression of various cancers.This BMSCs-derived exosomes effect was significantly reversed with knockdown of hsa-miR-124-5p(P<0.0001 vs.NC by WB).Conclusions:BMSCs-derived exosomes suppress cell proliferation and cycle progression and promote cell apoptosis in KG-1a cells,likely acting through hsa-miR-124-5p.Our study establishes a basis for a BMSCs-derived exosomes-based AML treatment.