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During the exploitation of deep coal resources, the gas hazard becomes increasingly significant, severely threatening the high-quality development of the coal industry and the occupational safety and health of miners. Coal seam water injection is underground coal mines' most commonly used dust control measure. Additionally, it is an effective method for preventing localized coal and gas outburst hazards. After injecting water into the coal seam, spontaneous imbibition causes the retained water in the fractures to migrate under capillary action and widely distribute the water within the coal seam, which enhances the wetting degree of the coal by water and the effectiveness of gas prevention. To reveal the migration characteristics of water in the coal during spontaneous imbibition and its impact on gas control, a self-developed gas-bearing coal spontaneous imbibition system was used to conduct isobaric water injection imbibition and gas desorption experiments on gas-bearing coal samples. The results showed that after the water was injected into the coal sample, it migrated from bottom to top under capillary action, resulting in three stages of abrupt, rapid, and gradual changes in the electrical resistivity of different layers of the coal sample over time. The migration distance of water increased with the imbibition time, but the rate of increase gradually decreased. The compaction load increase reduced the coal sample's average pore size, resulting in faster water migration speed. After imbibition, the water content decreased gradually from bottom to top along the axial direction and showed a non-uniform distribution in the radial direction. During imbibition, the water displaced gas within the coal sample, and the amount of gas displaced increased with the imbibition time. Increasing the amount of water injected and the coal sample compacted load can promote water migration within the coal, expanding the wetted area and displacing more gas. After imbibition, due to the displaced gas being released and the water-lock effect, the atmospheric gas desorption amount of the coal sample decreased with an increase in the amount of water injected, following a modified power function relationship. When the amount of water injected into the coal sample was low, increasing the water-injected amount could significantly reduce the gas desorption expansion energy of the coal sample. However, this trend became less apparent as the amount of water injected continued to increase. To improve the effectiveness of coal seam water injection in preventing gas outburst hazards, it is recommended to carry out water injection operations as early as possible to expand the wetted area of the coal seam and to add gas drainage holes to prevent increased coal body outburst tendencies due to local gas pressure rise in the coal seam. [ABSTRACT FROM AUTHOR]

This paper studies the vibrational behaviors of a distributive mass-loaded microscale circular diaphragm submerged in a fluid. The vibration of the diaphragm involving loadings simultaneously induced by an acoustic field and the adhesion of distributive mass has been investigated. Two different types of adsorbates, namely, in the form of discrete particles (mass only) and a uniform layer (mass and rigidity), are considered and compared. Moreover, the pre-existing stress in the diaphragm has also been taken into consideration. Based on Lamb's hypotheses of the fluid-loaded structure in conjunction with the Rayleigh–Ritz theorem, an analytical solution for the dynamic characteristics of the coupling system, including the resonant frequency, mode shape, and the quality factor, is developed. The results have been compared with those of the finite element simulations, and a good agreement has been obtained. The results reveal that the adsorbate properties contribute differently to the dynamic response of the micro-diaphragm in the fluid, and the contribution may be intervened by tuning the pre-stress. The theoretical model and novel analytical solution are of interest in the design of micro-diaphragm-based biosensing devices. [ABSTRACT FROM AUTHOR]

L. monocytogenes is a widely used infection model for the research on pathogenesis and host defense against gram-positive intracellular bacteria. Emerging evidence indicates that posttranslational modifications play a critical role in the regulation of macroautophagy/autophagy. However, little is known about the posttranslational modifications of ATG7, the essential protein in the autophagy process. In this study, we demonstrated that the RING-type E3 ligase TRIM7/RNF90 positively regulated autophagosome accumulation by promoting the ubiquitination of ATG7 at K413, thereby affecting L. monocytogenes infection. TRIM7 expression was induced by a variety range of conditions, including starvation, rapamycin stimulation, and L. monocytogenes infection. TRIM7 deficiency in mice or cells resulted in elevated innate immune responses and increased L. monocytogenes infection. ATG7 was associated with TRIM7 and the positive regulatory role of TRIM7 in L. monocytogenes infection-, starvation- or rapamycin-induced autophagosome accumulation was suggested by TRIM7 deficiency, TRIM7 overexpression, and TRIM7 knockdown. Further mechanistic investigation indicated that TRIM7 promoted the K63-linked ubiquitination of ATG7 at K413 and ubiquitination at this site was required for the function of ATG7 in autophagy and L. monocytogenes infection. Thus, our findings suggested a new regulator in intracellular bacterial infection and autophagy, with a novel posttranslational modification targeting ATG7. This research may expand our understanding of host anti-bacterial defense and the role of autophagy in intracellular bacterial infection. Abbreviations: ATG3: autophagy related 3; ATG5: autophagy related 5; ATG7: autophagy related 7; ATG10: autophagy related 10; ATG12: autophagy related 12; ATG16L1: autophagy related 16 like 1; Baf A1: bafilomycin A1; CQ: chloroquine; BMDC: bone marrow-derived dendritic cell; BMDM: bone marrow-derived macrophage; CFUs: colony-forming units; CXCL10/IP-10: C-X-C motif chemokine ligand 10; EBSS: Earle's balanced salt solution; ELISA: enzyme-linked immunosorbent assay; IFIT1/ISG56: interferon induced protein with tetratricopeptide repeats 1; IFNB/IFN-β: interferon beta; IL6: interleukin 6; IRF3, interferon regulatory factor 3; Lm: L. monocytogenes; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MEF: mouse embryonic fibroblast; MOI: multiplicity of infection; PLA: proximity ligation assay; PMA: phorbol myristate acetate; PMA-THP1, PMA-differentiated THP1; PMs: peritoneal macrophages; PTMs: posttranslational modifications; STING1, stimulator of interferon response cGAMP interactor 1; TBK1, TANK binding kinase 1; TNF/TNF-α: tumor necrosis factor; TRIM7/RNF90: tripartite motif containing; Hainan Provincial Natural Science Foundation of China. [ABSTRACT FROM AUTHOR]

This paper presents a theoretical model, based on the Rayleigh-Ritz method, to analyze the dynamic response of circular micro-diaphragms in contact with a fluid. The fluid is assumed to be incompressible, inviscid, and irrotational. In the model, a linear combination of polynomials is utilized to construct the mode shapes, and the Rayleigh quotient for fluid-structure coupling system is implemented to obtain the dynamic characteristics of pre-stressed diaphragms. Theoretical calculations are well validated by a finite element model. The relationships of the natural frequencies and quality factors to the mode shape are systematically investigated. The investigation proves that it is necessary to adopt exact mode shapes, instead of approximate mode shapes, to ensure the accuracy in the theoretical evaluation of the vibration of the diaphragm in the fluid. Furthermore, the quality factor associated with acoustic radiation losses is mode dependent, and its dependency on the mode number shows plate, membrane, and plate-membrane transition behaviors as pre-stress varies. These findings can be useful in the applications of diaphragm-based resonators. [ABSTRACT FROM AUTHOR]

The free vibration of circular diaphragms subjected to in-plane tensile biaxial stress while in contact with a fluid is analyzed using the Rayleigh-Ritz method, in which the linear superposition of a number of polynomial functions is used to describe the displacement of the diaphragm. The diaphragm is placed into a hole in an infinite rigid wall, and the fluid is assumed to be incompressible and inviscid. Analytical expressions for the nondimensional added virtual mass incremental factor and the quality factor are easily derived using the proposed method. Our numerical results are validated by comparisons with published theoretical results and a finite element model. This work demonstrates the thermal stress contribution to the nondimensional added virtual mass incremental factor and the quality factor, which is important in the design of circular-diaphragm-based sensors. [ABSTRACT FROM AUTHOR]

The accurate determination of coalbed methane (CBM) content is of great significance for its development and utilization as well as for the prevention and control of coal mine gas disaster. In the process of determining CBM content, the coal–gas adsorption system existing in the natural environment is affected by variable temperature–pressure interactions. In this study, methane (CH4) adsorption tests were carried out on coals at different initial equilibrium pressures (IEPs) and in different cooling processes (CPs). The test results indicate that dominant and retrograde adsorption processes existed in the cooling and adsorption processes of the coal sample reaction chamber. During the adsorption process, the temperature variation broke the original adsorption equilibrium, which in turn induced the pressure change in the coal sample reaction chamber, thus resulting in the retrograde adsorption. The intensity of the dominant adsorption increased and then decreased, causing an increase and then a decrease in the retrograde adsorption rate. The commonly used adsorption kinetic models were modified, including the modified pseudo-first-order kinetic model, modified pseudo-second-order kinetic model, modified Bangham kinetic model (MBKM), modified intra-particle diffusion model and modified double exponential model (MDEM). These modified models were used to describe the kinetic characteristics of the dominant process of CH4 adsorption on coals in a variable temperature and pressure environment. The results show that among the modified kinetic models, the MDEM can describe better the kinetic process of the dominant adsorption, followed by the MBKM. The IEP showed positive correlation with the dominant adsorption rate at the initial stage of cooling. For the two CPs (i.e., 293.15–283.15 K and 273.15–263.15 K), the initial adsorption rates at the IEP of 3.83 MPa were, respectively, about 4 and 3 times higher than those at the IEP of 0.72 MPa. The retrograde adsorption process can be described better by a linear model. A peak retrograde adsorption rate existed throughout the adsorption process and increased with increasing IEP. The study of the kinetic process of CH4 adsorption on the coal matrix under the effect of low temperatures and variable pressures will improve understanding of the CH4 adsorption mechanism in a low temperature and variable pressure environment, and provide theoretical support for the development and application of new techniques for CBM content determination. [ABSTRACT FROM AUTHOR]