Crystal structure,phase transitions,and thermodynamic properties of magnesium metavanadate(MgV_(2)O_(6))

As a promising anode material for magnesium ion rechargeable batteries,magnesium metavanadate(MgV_(2)O_(6))has attracted considerable research interest in recent years.A MgV_(2)O_(6)sample was synthesized via a facile solid-state reaction by multistep-firing stoichiometric mixtures of MgO and V2O5 powder under an air atmosphere.The solid-state phase transition fromα-MgV_(2)O_(6)toβ-MgV_(2)O_(6)occurred at 841 K and the enthalpy change was 4.37±0.04 kJ/mol.The endothermic effect at 1014 K and the enthalpy change was 26.54±0.26 kJ/mol,which is related to the incongruent melting ofβ-MgV_(2)O_(6).In situ XRD was performed to investigate phase transition of the as-prepared MgV_(2)O_(6)at high temperatures.The cell parameters obtained by Rietveld refinement indicated that it crystallizes in a monoclinic system with the C2/m space group,and the lattice parameters of a=9.280 A°,b=3.501 A°,c=6.731 A°,β=111.76°.The solid-state phase transition fromα-MgV_(2)O_(6)toβ-MgV_(2)O_(6)was further studied by thermal kinetics,indicating that this process is controlled first by a fibril-like mechanism and then by a spherulitic-type mechanism with an increasing heating rate.Additionally,the enthalpy change of MgV_(2)O_(6)at high temperatures was measured utilizing the drop calorimetry,heat capacity was calculated and given as:Cp=208.3+0.03583T-4809000T^(−2)(298-923 K)(J mol^(−1)K^(−1)),the high-temperature heat capacity can be used to calculate Gibbs free energy of MgV_(2)O_(6)at high temperatures.

Oxidation behavior of FeV_(2)O_(4)and FeCr_(2)O_(4)particles in the air:Nonisothermal kinetic and reaction mechanism

High-temperature oxidation behavior of ferrovanadium(FeV_(2)O_(4))and ferrochrome(FeCr_(2)O_(4))spinels is crucial for the application of spinel as an energy material,as well as for the clean usage of high-chromium vanadium slag.Herein,the nonisothermal oxidation behavior of FeV_(2)O_(4)and FeCr_(2)O_(4)prepared by high-temperature solid-state reaction was examined by thermogravimetry and X-ray diffraction(XRD)at heating rates of 5,10,and 15 K/min.The apparent activation energy was determined by the Kissinger-Akahira-Sunose(KAS)method,whereas the mechanism function was elucidated by the Malek method.Moreover,in-situ XRD was conducted to deduce the phase transformation of the oxidation mechanism for FeV_(2)O_(4)and FeCr_(2)O_(4).The results reveal a gradual increase in the overall apparent activation energies for FeV_(2)O_(4)and FeCr_(2)O_(4)during oxidation.Four stages of the oxidation process are observed based on the oxidation conversion rate of each compound.The oxidation mechanisms of FeV_(2)O_(4)and FeCr_(2)O_(4)are complex and have distinct mechanisms.In particular,the chemical reaction controls the entire oxidation process for FeV_(2)O_(4),whereas that for FeCr_(2)O_(4)transitions from a three-dimensional diffusion model to a chemical reaction model.According to the in-situ XRD results,numerous intermediate products are observed during the oxidation process of both compounds,eventually resulting in the final products FeVO_(4)and V2O_(5)for FeV_(2)O_(4)and Fe_(2)O_(3)and Cr_(2)O_(3)for FeCr_(2)O_(4),respectively.

Biomarkers for early diagnosis of autism obtained through bioinformatics analysis of human blood sample

Objective:autism spectrum disorder(ASD),a serious disorder that begins early in life,con-tinues throughout the lifespan.Children with ASD who are diagnosed early are more responsive to therapeutic interventions and have less social and language impair-ment than children diagnosed later;however,current di-agnostic measures are mostly applied to children older than one year and lack the appropriate biological markers for early diagnosis of ASD.Using bioinformatic analy-sis,this study explores the molecular information mech-anism of ASD.Method:in this study,we used dataset GSE6575 from Gene Expression Omnibus(GEO)to an-alyze the mRNA expression profile of ASD,including 35 ASD samples and 12 normal control samples looking for different genes and we did enrichment analysis of those genes.We then used the STRING database to construct a protein-protein interaction(PPI)network of differential genes.Finally,Cytoscape plug-in cytoHubba was used to search for hub genes.The diagnostic value of the hub genes was verified by subject operating characteristic curves.Result:we looked for 50 different genes and did an enrichment analysis of those genes.The results of the enrichment analysis showed that these differential genes were mainly concentrated in the response to viruses,the immune regulation of inflammation and energy metabo-lism.Using Cytoscape plug-in cytoHubba,we found ten different genes.We drew ROC curves for all ten genes among which two genes,interleukin 2 receptor subunit beta(IL2Rβ)and perforin 1(PRF1),had good sensitivity and specificity for the early diagnosis of autism.The ar-eas under the ROC curves were 0.855,0.830 for IL2Rβ,PRF1.Conclusion:data analysis using the GEO data-base can provide new insights into the etiology of ASD as well as some possible biomarkers and therapeutic targets for early diagnosis and treatment of ASD.