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Ore is a crucial component in the process of industrialization, and its crushing is a practice that is inextricably linked to our society. This study aims to simulate the crushing process of minerals in a comminution device using the Discrete Element Method (DEM) by characterizing the bonding parameters of mineral particles. Utilizing the EDEM software (2018) for discrete element simulations, the study investigated the influence of bonding parameters on the compressive strength and other performance indicators of the particle bonding model. The study was executed through the application of a Box–Behnken Design (BBD) and Response Surface Methodology (RSM), which facilitated the construction of a second-order response surface regression model. The optimal values for normal stiffness per unit area, shear stiffness per unit area, critical normal stress, and critical shear stress were meticulously determined. The subsequent simulation experiments strongly verify the feasibility of the proposed characterization method for key parameters. [ABSTRACT FROM AUTHOR]

In this study, N-doped straw biochar(N-BC) was prepared using urea for the removal of Pb2+, Cu2+, and Cr6+ from water. SEM, FT-IR, XRD, and XPS characterization analyses demonstrated the successful loading of N onto the biochar. The adsorption performance of the N-doped biochar was evaluated by orthogonal and single-factor experiments. The results showed that the magnitude of the effect on the adsorption of the three heavy metals was consistent with initial pH > dosing > pyrolysis temperature. In addition, the optimum initial pH for the adsorption of Pb2+, Cu2+, and Cr6+ was 5, 6, and 2, respectively. Compared to the single biochar, the adsorption of Pb2+, Cu2+, and Cr6+ by N-doped biochar increased from 6.33, 4.25, and 3.78 mg/g to 30.2, 16.28, and 14.53 mg/g. The adsorption of Pb2+, Cu2+, and Cr6+ followed quasi-secondary kinetics and the Langmuir model. Mechanistic studies showed that the adsorption mechanism of N-doped biochar for Cu2+ and Pb2+ involved surface adsorption, cation-π bonding, and complexation, while that for Cr6+ included electrostatic attraction and reduction. The reusability and excellent adsorption properties of the surface N-doped biochar from cycling experiments indicate that biochar is a good material for the removal of heavy metals from water. [ABSTRACT FROM AUTHOR]

Rapid identification of pathogens is critical for early and appropriate treatment of bloodstream infections. The various culture‐independent assays that have been developed often have long turnaround times, low sensitivity and narrow pathogen coverage. Here, we propose a new multiplex PCR assay, MeltArray, which uses intact microbial cells as the source of genomic DNA (gDNA). The successive steps of the MeltArray assay, including selective lysis of human cells, microbial cell sedimentation, microbial cellular DNA extraction, target‐specific pre‐amplification and multiplex PCR detection, allowed the detection of 35 major bloodstream infectious pathogens in whole blood within 5.5 h. The limits of detection varied depending on the pathogen and ranged from 1 to 5 CFU/mL. Of 443 blood culture samples, including 373 positive blood culture samples and 70 negative blood culture samples, the MeltArray assay showed a sensitivity of 93.8% (350/373, 95% confidence interval [CI] = 90.7%–96.0%), specificity of 98.6% (69/70, 95% CI = 91.2%–99.9%), positive predictive value of 99.7% (95% CI = 98.1%–99.9%), and negative predictive value of 75.0% (95% CI = 64.7%–83.2%). The MeltArray detection results of 16 samples differed from MALDI–TOF and were confirmed by Sanger sequencing. Further testing of 110 whole blood samples from patients with suspected bloodstream infections using blood culture results revealed that the MeltArray assay had a clinical sensitivity of 100% (9/9, 95% CI = 62.8%–100.0%), clinical specificity of 74.5% (70/94, 95% CI = 64.2%–82.7%), positive predictive value of 27.3% (95% CI = 13.9%–45.8%), and negative predictive value of 100.0% (95% CI = 93.5%–100.0%). Compared with metagenomic next‐generation sequencing, the MeltArray assay displayed a positive agreement of 85.7% (6/7, 95% CI = 42.0%–99.2%) and negative agreement of 100.0% (4/4, 95% CI = 39.6%–100.0%). We conclude that the MeltArray assay can be used as a rapid and reliable tool for direct identification of pathogens in bloodstream infections. [ABSTRACT FROM AUTHOR]

To clarify microorganisms resulted mildew on Hainan cigar tobacco leaves and screen their antagonistic strains to prevent tobacco leaves from mildew, mildew and antagonistic microorganisms were isolated from the surface of Hainan moldy cigar tobacco and purified. Morphological and molecular methods were combined to identify microbial species. The identification and screening results showed that the main microorganisms resulted mildew on Hainan cigar tobacco were Talaromyces funiculosus, Scopulariopsis brevicaulis and Aspergillus occultus. Two antagonistic strains with good antagonistic effects were screened out, namely Bacillus subtilis and Bacillus halotolerans. The main microorganisms resulted mildew on Hainan cigar tobacco were mainly Talaromycetes, Scopularia and Aspergillus strains. The screened two strains of Bacillus had good antagonism to mold, which provided a reference for the prevention and control of mildew on cigar tobacco. [ABSTRACT FROM AUTHOR]

In order to quantitatively detect Honghuadajinyuan in mixed tobacco leaves, cultivar-specific primers and TaqMan MGB probes were designed. The specificity and sensitivity of the primers and the probes were detected, and the reaction conditions of the fluorescent quantitative PCR were determined. On this basis, a regression equation was established to quantitatively detect the single cultivar of Honghuadajinyuan in mixed tobacco leaves. The results showed that the combination of the primers and the probes H1-R/F/T had satisfactory specificity. The regression equation was established and the determination coefficient R² was 0.997. When the template DNA (55 ng·µL-1) was 2 µL, the detection limit of Honghuadajinyuan was 0.11 ng. The error range of the content of Honghuadajinyuan in mixed tobacco leaves detected by this method was between 2.5% and 3.5%, suggesting that this method could be applied to the quantitative detection of Honghuadajinyuan in specific mixed tobacco leaves. [ABSTRACT FROM AUTHOR]

In this research, hierarchical CuO microspheres have been successfully synthesised by a facile reflux method. Scanning electron microscopy results clearly revealed that the hierarchical CuO microspheres were composed of two-dimensional nanosheets. The morphology of the prepared products could be tailored by changing the precursor concentration. The CuO-2 sample shows a higher NOx gas sensing performance with a low detection limit of 0.97 ppm, high gas response of 64.93 %, and short response time of 5.33 s to 97.0 ppm NOx at room temperature. The CuO-2 sensor also presents good selectivity and stability. The significantly improved gas response was concluded to be related to the well aligned microstructures and the improved conductivity of the CuO-2 sample. The unique hierarchical structure allows effective and rapid gas diffusion towards the sensing surfaces. In addition, the sensing mechanism based on the hierarchical CuO microspheres is discussed. [ABSTRACT FROM AUTHOR]

In this paper, the In(OH)3/Co(OH)2/rGO (ICG) nanohybrids have been synthesized via a simple reflux method. It was found that the nanostructures were actually composed of thin nanosheets or nanowires. The addition of indium in Co(OH)2 on rGO results in increase in the specific area of nanohybrids (105.7m2g-1). That enhanced the gas sensing responses to NOx compared with Co(OH)2/rGO significantly. The ICG nanohybrids with the mass ratio of 5:1 (ICG-5) exhibited excellent gas-sensing properties with low detection limit of 0.97ppm and high sensitivity of 75.32% to 97ppm NOx at room temperature (RT). The gas sensor also showed excellent selectivity to NOx when other common gases such as NH3, CO, C2H2 and H2 were present. The sensing mechanism could be attributed to the charge carrier concentration of Co(OH)2 greatly increased by indium doping, which at last encourages the electron transfer during the interaction with gases. [ABSTRACT FROM AUTHOR]