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Tangential ultrasonic vibration and vertical ultrasonic vibration are applied in the surface burnishing process (SBP) to study the improvement mechanism of both on the machining performance. The force in the machining process is collected by a Kistler force sensor. The surface roughness (Sa, Sq, Ssk, and Sku) and cross-section hardness of the machined samples are characterized. A molecular dynamic model is established to discuss the acoustic softening effect. Experimental results show that the vertical ultrasonic can reduce the normal force (Fz) value in the machining process. Meanwhile, the tangential ultrasonic vibration can suppress the volatility of the X-axis direction force (Fx) and Y-axis direction force (Fy) while reducing the tangential force (Ft) value. Compared with SBP treated samples, the two-dimensional ultrasonic vibration-assisted surface burnishing process (2D-USBP) can better improve the surface properties of the sample, such as improving the surface roughness, the surface hardness, and the thickness of the strengthening layer. Molecular dynamic results show the introduction of ultrasonic vibration to change the microstructure in the sample. Under the excitation of ultrasonic vibration, the dislocation density and potential energy are increased, and the plastic deformation force is decreased.

BACKGROUND: Leucine (Leu) is an essential amino acid that facilitates skeletal muscle satellite cell differentiation, yet its mechanism remains underexplored. Sestrin2 (SESN2) serves as a Leu sensor, binding directly to Leu, while ribophorin II (RPN2) acts as a signaling factor in multiple pathways. This study aimed to elucidate Leu's impact on mouse C2C12 cell differentiation and skeletal muscle injury repair by modulating RPN2 expression through SESN2, offering a theoretical foundation for clinical skeletal muscle injury prevention and treatment. RESULTS: Leu addition promoted C2C12 cell differentiation compared to the control, enhancing early differentiation via myogenic determinant (MYOD) up‐regulation. Sequencing revealed SESN2 binding to and interacting with RPN2. RPN2 overexpression up‐regulated MYOD, myogenin and myosin heavy chain 2, concurrently decreased p‐GSK3β and increased nuclear β‐catenin. Conversely, RPN2 knockdown yielded opposite results. Combining RPN2 knockdown with Leu rescued increased p‐GSK3β and decreased nuclear β‐catenin compared to Leu absence. Hematoxylin and eosin staining results showed that Leu addition accelerated mouse muscle damage repair, up‐regulating Pax7, MYOD and RPN2 in the cytoplasm, and nuclear β‐catenin, confirming that the role of Leu in muscle injury repair was consistent with the results for C2C12 cells. CONCLUSION: Leu, bound with SESN2, up‐regulated RPN2 expression, activated the GSK3β/β‐catenin pathway, enhanced C2C12 differentiation and expedited skeletal muscle damage repair. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

We construct a sequence of explicit blow-ups and blow-downs on an irreducible compact Hermitian symmetric spaces |$X$| which transforms it into a projective space of the same dimension. Moreover, this resolves a birational map given by Landsberg and Manivel. Centers of the blow-ups for |$X$| are constructed by loci of chains of minimal rational curves and centers of the blow-ups for the projective space are constructed from the variety of minimal rational tangents of |$X$| and its higher secant varieties. The result was known in the special case where |$X$| is of rank 2 and could be found in Zak's monograph "Tangents and secants of algebraic varieties." [ABSTRACT FROM AUTHOR]

To investigate the desorption behavior of O2 through CO2/N2 injection in the gob of a gassing mine, we focused on the adsorption configuration of coal containing O2–CH4. The mechanism underlying the enhancement of O2 desorption in coal due to CO2/N2 injection was elucidated using the Grand Canonical Ensemble Monte Carlo (GCMC) and Molecular Dynamics (MD) methods. Furthermore, the impact of CH4 on O2 desorption was unveiled by detailed calculations and studies of energy variation, concentration distribution, and diffusion coefficients of oxygen.Our findings indicate the following: (1) CO2 and N2 facilitate the displacement of oxygen primarily by occupying adsorption sites. The CO2–O2 model exhibits a significantly higher concentration of free O2 molecules compared to the N2–O2 model, and the CO2–O2–CH4 model surpasses the N2–O2–CH4 model in free O2 molecules. (2) The total energy of the CO2–O2 model is lower than that of the N2–O2 model, indicating greater stability in the former. Similarly, the total energy of the CO2–O2–CH4 model is lower than that of the N2–O2–CH4 model, highlighting its superior stability. It is concluded that CO2 injection is more effective in promoting oxygen desorption than N2, regardless of the presence of methane. (3) Under equivalent injection pressure, the root mean square displacement of O2 in the CO2–O2 system surpasses that in the N2–O2 system. Furthermore, compared to the N2–O2–CH4 system, the CO2–O2–CH4 system exhibits a larger root mean square displacement of O2, signifying higher O2 molecule activity. The diffusion coefficient of O2 in the CO2–O2 system is higher, underscoring the superior effectiveness of CO2 in promoting O2 desorption.In summary, our research outcomes offer valuable theoretical insights for fire prevention technology in goaf. [ABSTRACT FROM AUTHOR]

Modified micromechanical bridging model is established with consideration of the fiber rupture effect at debonding and slipping stages. The bridging model includes the debonding and slipping rupture of fibers and establishes the fiber/matrix interfacial parameters (friction τ0, chemical bonding force Gd, slip-hardening coefficient β). A different interfacial bonding can cause fiber rupture. The influence of the interfacial conditions on the fiber rupture risk was investigated. In the modified bridging model, the effective bridging stress, the debonding rupture stress, and the slipping rupture stress were clearly identified. Finally, single-fiber pullout tests with different embedded lengths were carried out to validate the bridging model. The relationship between the fiber bridging stress and the crack opening predicted by the bridging model was consistent with the experimental results. This modified micromechanical bridging model can be used to quantitatively calculate the actual fiber bridging capacity and to predict the ductility of the high ductility cementitious composites reinforced by different types of fibers.

With the acceleration of urbanisation, urban areas are subject to the combined effects of the accumulation of various natural factors, such as changes in temperature leading to the thermal expansion or contraction of surface materials (rock, soil, etc.) and changes in precipitation and humidity leading to an increase in the self-weight of soil due to the infiltration of water along the cracks or pores in the ground. Therefore, the subsidence of urban areas has now become a serious geological disaster phenomenon. However, the use of traditional neural network prediction models has limitations when examining the causal relationships between time series surface deformation data and multiple influencing factors and when applying multiple influencing factors for predictive analyses. To this end, Sentinel-1A data from March 2017 to February 2023 were used as the data source in this paper, based on time series deformation data acquired using the small baseline subset interferometric synthetic aperture radar (SBAS-InSAR) technique. A sparrow search algorithm–convolutional neural network–long short-term memory (SSA-CNN-LSTM) neural network prediction model was built. The six factors of temperature, humidity, precipitation, and ground temperature at three different depths below the surface (5 cm, 10 cm, and 15 cm) were taken as the input of the model, and the surface deformation data were taken as the output of the neural network model. The correlation between the spatial and temporal evolution characteristics of the ground subsidence in urban areas and various influencing factors was analysed using grey correlation analysis, which proved that these six factors contribute to some extent to the deformation of the urban surface. The main urban area of Hohhot City, Inner Mongolia Autonomous Region, was used as the study area. In order to verify the efficacy of this neural network prediction model, the prediction effects of the multilayer perceptron (MLP), backpropagation (BP), and SSA-CNN-LSTM models were compared and analysed, with the values of the correlation coefficients of the feature points of A1, B1, and C1 being in the range of 0.92, 0.83, and 0.93, respectively. The results show that compared with the traditional MLP and BP neural network models, the SSA-CNN-LSTM model achieves a higher performance in predicting time series surface deformation data in urban areas, which provides new ideas and methods for this area of research. [ABSTRACT FROM AUTHOR]

Aiming at the problems of small chaotic space and weak chaotic ability of existing chaotic mapping models, a new three-dimensional chaotic mapping model is designed by coupling two-dimensional Henon chaotic mapping model and Sine chaotic mapping model. Aiming at the problem that the security of encryption system will be reduced if the key is reused, this paper designs a new key generation method using Chebyshev mapping and plaintext image. Using the 3D chaotic mapping and key generation method designed in this paper, a color image encryption method is proposed. The results show that the method can encrypt images safely and effectively and protect the security of image information. [ABSTRACT FROM AUTHOR]

Background and Aim: Hepatotoxicity is a well‐defined reaction to methotrexate (MTX), a drug commonly used for the treatment of rheumatoid arthritis and various tumours. We sought to elucidate the mechanism underlying MTX‐induced hepatotoxicity and establish a potentially effective intervention strategy. Methods: We administered MTX to liver cells and mice and assessed hepatotoxicity by cell viability assay and hepatic pathological changes. We determined ferroptosis and ferritinophagy by detecting ferroptosis‐related markers and autophagic degradation of ferritin heavy chain 1 (FTH1). Results: We have shown that hepatocytes treated with MTX undergo ferroptosis, and this process can be attenuated by ferroptosis inhibitors. Interestingly, NCOA4‐mediated ferritinophagy was found to be involved in MTX‐induced ferroptosis, which was demonstrated by the relief of ferroptosis through the inhibition of autophagy or knockdown of Ncoa4. Furthermore, MTX treatment resulted in the elevation of high‐mobility group box 1 (HMGB1) expression. The depletion of Hmgb1 in hepatocytes considerably alleviated MTX‐induced hepatotoxicity by limiting autophagy and the subsequent autophagy‐dependent ferroptosis. It is noteworthy that glycyrrhizic acid (GA), a precise inhibitor of HMGB1, effectively suppressed autophagy, ferroptosis and hepatotoxicity caused by MTX. Conclusion: Our study shows the significant roles of autophagy‐dependent ferroptosis and HMGB1 in MTX‐induced hepatotoxicity. It emphasizes that the inhibition of ferritinophagy and HMGB1 may have potential as a therapeutic approach for preventing and treating MTX‐induced liver injury. [ABSTRACT FROM AUTHOR]

The fiber length has a significant impact on the fiber bridging capacity and the mechanical properties of high ductility cementitious composites (HDCCs), which is related to fiber/matrix interfacial bonding. However, this fundamental knowledge of HDCCs design has rarely been investigated systematically. To this end, this study deeply investigates the effect of the fiber length on the bridging stress and the complementary energy with various fiber/matrix interfacial bonds in theory. Then, the mechanical performances of HDCCs with various fiber lengths and compressive strengths were evaluated experimentally. In micromechanical design, longer fibers can achieve stronger bridging stress and more sufficient complementary energy regardless of the fiber/matrix interfacial bonding properties. However, it should be noted that the increase in bridging capacity was quite slow for the overlong fibers and excessive interfacial bonding. The experiments indicated that overlong fibers (18 mm and 24 mm) easily twined on the mixer blade and were hard to disperse evenly. The HDCCs with shorter fibers displayed better workability. The compressive strength was less affected by the fiber length, and most striking differences were less than 5.0%, while the flexural properties and the tensile properties first increased and then decreased when the fiber length ranged from 6 mm to 24 mm. Consequently, the fibers with lengths of 9 mm and the fibers with lengths of 12 mm were better candidates for the HDCCs with compressive strengths of 30 MPa to 80 MPa, and fibers with lengths of 9 mm caused the HDCCs to exhibit higher ductility properties in general.