Objective
There is no objective method to diagnose major depressive disorder (MDD). This study explored the neuroimaging biomarkers using the support vector machine (SVM) method for the diagnosis of ...MDD.
Methods
52 MDD patients and 45 healthy controls (HCs) were involved in resting-state functional magnetic resonance imaging (rs-fMRI) scanning. Imaging data were analyzed with the regional homogeneity (ReHo) and SVM methods.
Results
Compared with HCs, MDD patients showed increased ReHo in the left anterior cingulum cortex (ACC) and decreased ReHo in the left precentral gyrus (PG). No correlations were detected between the ReHo values and the Hamilton Rating Scale for Depression (HRSD) scores. The SVM results showed a diagnostic accuracy of 98.96% (96/97). Increased ReHo in the left ACC, and decreased ReHo in the left PG were illustrated, along with a sensitivity of 98.07%(51/52) and a specificity of100% (45/45).
Conclusion
Our results suggest that abnormal regional neural activity in the left ACC and PG may play a key role in the pathophysiological process of first-episode MDD. Moreover, the combination of ReHo values in the left ACC and precentral gyrusmay serve as a neuroimaging biomarker for first-episode MDD.
The one-step oxidative esterification of methanol and methacrolein to yield methyl methacrylate (MMA) at elevated temperatures and pressures is a crucial chemical procedure for producing MMA. ...However, the conditions under which fire and explosions may occur during this procedure must be determined. This study models gas mixing to predict concentration distribution. Simulation results indicate stability with increasing pressure but wider gradients with higher temperature. Experimental studies on the flammable limits of methanol and methanol/methacrolein vapor mixtures under high temperatures and pressures show that the initial pressure has a significant impact on expanding the explosive limit of flammable vapor, whereas temperature has a relatively minor effect. The combustible limit of the mixed vapor is predicted using the heat balance approach, and a comparison with experimental data shows that the anticipated and real values coincide well.
•The mixing uniformity numerical calculation of methanol and methylacrolein vapor was applied.•The flammability limit of mixed vapor under high temperature and high pressure was determined.•The combustible limit of mixed vapor is predicted by TBM method.
•Fe3+ can reduce the thermal stability of hydroxylamine sulfate.•The 8-step reaction mechanism can explain the decomposition of hydroxylamine sulfate.•The decomposition of hydroxylamine sulfate is a ...self-accelerating reaction.
To study the stability of hydroxylamine sulfate (HAS) when mixed with metal ions (especially Fe3+), the effect of Fe3+ doping on the thermal decomposition of HAS was studied by differential scanning calorimeter. The results indicate that HAS decomposes at 365–376 K and average thermal effect of P1 and P2 are approximately 632.6 J/g and 66.9 J/g, respectively. Fe3+ increases thermal effect of P1 and P2, but it decreases the initial decomposition temperature (To) of P1, and delays the To of P2. The density functional theory calculations results reveal a detailed 8-step reaction model of HAS decomposition with the formation of NH3OH+ as the key step. Notably, Fe3+ affects the thermal decomposition process of HAS by forming a coordination compound Fe(NH2OH)63+ with NH2OH. In addition, model-free method prediction shows that Fe3+ reduces the kinetic parameters and the thermal hazard parameters.
Porous materials have received extensive attention due to their superior adsorption properties, but there are few studies on oil adsorption. In this paper, a new self-design high-temperature reactor ...carried out MCC adsorption experiments, and a complete test system was used to study the adsorption characteristics, pyrolysis kinetics and pyrolysis products. The results of SEM and XRD showed that G3H gradually wetted the surface of MCC and the crystallinity increased. In addition, the pyrolysis parameters of MCC-adsorption-G3H (MAG) were measured by DSC and STA. The results showed that MCC was pyrolyzed in one step while MAG was in two. Meanwhile, thermodynamic model fitting indicated that the first stage was Fn and the second was Cnm autocatalytic. Notably, the variation of pyrolysis activation energy in the first stage was similar to that of adsorption capacity. Pyrolysis products of G3H were measured by Py-GC-MS, and pyrolysis residues of MAG were tested by FTIR. Combined with the volatiles determined by TG-IR, the influence of G3H on the pyrolysis characteristics was obtained, and the pyrolysis path of MAG was summarized. The results showed that porous materials can recycle oil and provided a guideline for industrial production.
Display omitted
•G3H increases pyrolysis rate to 97.13%.•MAG’s main pyrolysis kinetic model is Cnm.•G3H advance synthesis of pyrolysis products.
•Combined with traditional accident investigation and numerical simulation, the process of accident occurrence and development is reconstructed.•The corrosion forms and causes of the failed pipelines ...were determined by means of macro analysis, micro analysis and chemical composition analysis.•The corrosion rate of pipeline is estimated and the mechanism of pipeline corrosion is presented.
A fire accident caused by corrosion leakage of fatty acid pipeline is being investigated. The occurrence and development of leakage and fire are reconstructed through numerical simulation. The total heat release rate of the fire is estimated to be 81.411 MW through leakage amount and on-site fire damage, and the fire scale is determined to be intermediate. In addition, the corrosion site is determined to be the weld junction between the original pipe and the replacement pipe using macroscopic analysis, scanning electron microscopy and energy spectrum analysis, metallographic analysis, and chemical composition analysis. The main reasons for the corrosion are the uniform corrosion and pitting corrosion perforation of the weld caused by the different materials of the new pipe and the original pipe. The internal and external pressure difference of the pipe in service directly leads to the damage and failure of the weak weld.
The interaction of airflow and sea waves seriously affects the flight stability and cruising safety of ground effect vehicles. The influence of different sea states and different angles of attack ...were analyzed numerically on the aerodynamic characteristics of the airfoil under ground effect of wavy wall. The influence of the constant blowing and periodic blowing methods was further studied on the aerodynamic force of the airfoil under ground effect. The simulation results show that the lift coefficient of the airfoil changes periodically with the wave under the wavy ground wall. The amplitude of the lift coefficient fluctuation is larger with the increasing of wave height and angle of attack, or the decreasing of wavelength. Applying the circulation control method for periodic blowing in the same period as the relative motion of the waves can effectively weaken the fluctuation of the airfoil lift coefficient under wavy sea conditions and improve the flight stability and safety of ground effect vehicles.
Lithium-sulfur batteries have attracted attention due to their six-fold specific energy compared with conventional lithium-ion batteries. Dissolution of lithium polysulfides, volume expansion of ...sulfur and uncontrollable deposition of lithium sulfide are three of the main challenges for this technology. State-of-the-art sulfur cathodes based on metal-oxide nanostructures can suppress the shuttle-effect and enable controlled lithium sulfide deposition. However, a clear mechanistic understanding and corresponding selection criteria for the oxides are still lacking. Herein, various nonconductive metal-oxide nanoparticle-decorated carbon flakes are synthesized via a facile biotemplating method. The cathodes based on magnesium oxide, cerium oxide and lanthanum oxide show enhanced cycling performance. Adsorption experiments and theoretical calculations reveal that polysulfide capture by the oxides is via monolayered chemisorption. Moreover, we show that better surface diffusion leads to higher deposition efficiency of sulfide species on electrodes. Hence, oxide selection is proposed to balance optimization between sulfide-adsorption and diffusion on the oxides.
SiC-nanowire-reinforced SiCf/SiC composites were successfully fabricated through an in situ growth of SiC nanowires on SiC fibres via chemical vapour infiltration. The dielectric and microwave ...absorption properties of the composites were investigated within the frequency range of 8.2–12.4 GHz at 25–600 °C. The electric conductivity and complex permittivity of the composites displayed evident temperature-dependent behaviour and were enhanced with increasing temperature. The composites exhibited superior microwave absorption abilities with a minimum reflection loss value of −47.5 dB at 11.4 GHz and an effective bandwidth of 2.8 GHz at 600 °C. Apart from the contribution of the interconnected SiC nanowire network and multiple reflections, the excellent microwave absorption performance was attributed to dielectric loss that originated from SiC nanowires with abundant stacking faults and heterostructure interfaces. Results suggested that the composites are promising candidates for high-temperature microwave absorbing materials.
The efficient and safe capture of radioactive iodine (129I or 131I) is of great significance in nuclear waste disposal. Here, we report millimeter-scale poly(ether sulfone) composite beads loaded ...with porous Cu-BTC Cu3(BTC)2, BTC = 1,3,5-benzenetricarboxylate (Cu-BTC@PES), prepared by a phase inversion method for the removal of volatile iodine. Three kinds of Cu-BTC@PES composite beads were obtained with different Cu-BTC contents of 48.6, 60.2, and 71.9%, respectively. While maintaining crystallinity, the composite beads exhibited higher I2 vapor adsorption capacity (639 mg/g) in the form of iodine molecules. The iodine absorption up to 260 mg/g and the adsorption was followed Langmuir isotherm and pseudo-second-order kinetic model. Furthermore, the composite beads can still absorb more than 85% of iodine after 3 cycles of regeneration with excellent recyclability. The resulting Cu-BTC@PES composite beads show great potential for the sustainable removal of radioactive iodine.
Prostate cancer (PCa) is a leading cause of death among men. The dysregulation of metabolism and autophagy contributes to the progression of PCa. The transcription factor specificity protein 1 (Sp1) ...is implicated in the regulation of metabolism and autophagy. We confirmed that Sp1 is overexpressed in castration-resistant prostate cancer (CRPC) cells. However, the roles of Sp1 in PCa metabolism and autophagy remain unclear. Thus, in the present study, we retrieved the GSE35988 dataset from Gene Expression Omnibus (GEO) database to reinvestigate Sp1 expression and its role in PCa. We found that in PCa, Sp1 knockdown significantly inhibited cell growth, aerobic glycolysis, and hypoxia-induced autophagy, which were accompanied by an increased G1 cell cycle arrest. Pearson correlation indicated that pyruvate kinase isoenzyme type M2 (PKM2) is positively correlated with Sp1 expression. Western blot analysis demonstrated that Sp1 directly regulates PKM2; therefore, Sp1 modulates metabolism and autophagy in CRPC. Western blot analysis and luciferase reporter assay also indicated that the tumor suppressor miR-361-5p inversely regulates Sp1 by directly targeting the binding site in the 3′UTR of Sp1. miR-361-5p overexpression presented effects that are similar to Sp1 depletion in PCa. In summary, this study is the first to demonstrate that miR-361-5p suppresses the Sp1/PKM2 axis, consequently affecting the progression of PCa and the metabolism and autophagy of PCa cells. Therefore, targeting the miR-361-5p/Sp1/PKM2 pathway has considerable clinical significance in preventing the malignant progression of PCa.
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