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In order to ensure the shielding performance of the shielding cavity of the 5G equipment in the converter station, and to clarify the rule of the influence of the number and size of the cavity aperture on its shielding effectiveness, this study constructs the electromagnetic shielding effectiveness analysis model of the shielding cavity under the HFSS simulation environment, and analyzes the spatial distribution characteristics of the electromagnetic radiation of the 5G microstrip patch antenna. Then, the influence of the slot height of the cavity on the shielding effectiveness is analyzed. It is found that the shielding effectiveness under different slot diameters increases with the increase of the slot height, and the electromagnetic radiation intensity decreases from 24.81 dB at 0.5 mm height to 16.29 dB at 2.0 mm height. At the same time, the analysis shows that the shielding effectiveness decreases with the increase of the slot diameter, and the maximum radiation intensity increases from -15.13 dB at 1.0 mm diameter to 49.87 dB at 7.0 mm diameter. Finally, with a certain proportion of the aperture area, it is found that the shielding effectiveness of the shielding cavity is continuously improved with the increase of the aperture number and the decrease of the aperture diameter.

Red root rot disease is a devastating fungal disease of rubber trees caused by Ganoderma pseudoferreum (Wakef). Biocontrols using beneficial microorganisms are safe and sustainable. We isolated a DHR18 endophytic bacterium from a healthy rubber tree to obtain a new efficient antagonistic bacterium for red root rot disease affecting rubber trees and evaluated the mechanism of action involved using a double culture assay, genome annotation analysis, and the ethyl acetate extraction method. The results revealed that the DHR18 strain inhibits G. pseudoferreum growth and has broad-spectrum antifungal activity by secreting cell wall hydrolases (proteases and chitinases), indole-3-acetic acid, and siderophores. Furthermore, it fixes nitrogen and is involved in biofilm formation and phosphate solubilisation, improving disease resistance and tree growth. The results showed that the antifungal substances secreted by DHR18 are mainly lipopeptides. Simultaneously, DHR18 enhanced the rubber tree resistance to G. pseudoferreum by increasing the activities of defence enzymes superoxide dismutase, phenylalanine ammonia lyase, peroxidase, catalase, and polyphenol oxidase. The results indicate that B. arboris DHR18 has biocontrol potential and could be used as a candidate strain for the control of red root rot disease in rubber trees. [ABSTRACT FROM AUTHOR]

Objective To explore the cardioprotective effectiveness of Guanxin Salvia miltiorrhiza (GXDS) Preparation (a prescribed Chinese herbal formula) and its relationship with inhibition of mast cell degranulation, and investigate the underlying mechanism. Methods Cardiomyocytes H9C2 (2-1) cocultured with mast RBL-2H3 cells cells were transfected with miR-330-3p mimics or ALDH2 Vector, or treated with GXDS or Compound 48/80, a mast cell degranulator. The expression of miR-330-3p and ALDH2 was detected by PCR and Western blotting, and cell proliferation and apoptosis were detected by MTT assay and flow cytometry. Mast cell degranulation and trypsin release were detected by ELISA, and the targeted binding of mast cell degranulation and trypsin release was detected by double luciferase reporter gene. Then, a rat model of myocardial ischemia/reperfusion injury was established by ligating the left anterior descending coronary artery for 30 min followed by reperfusion for 120 min. Then Compound 48/80 or GXDS was used to treat the rats with myocardial injury or sham operation. The myocardial injury was detected by immunohistochemistry in different treatment groups. Results Compound 48/80 inhibited the viability and promoted the apoptosis of H9C2 (2-1) and RBL-2H3 cells, and increased the releases of cTnI and trypsin (P < 0.05). GXDS treatment could promote the viability and inhibit the apoptosis of cardiomyocytes through miR-330-3p/ALDH2 (P < 0.05), and inhibit mast cell degranulation (P < 0.05). Compared with the sham operation rats, the hemodynamic abnormalities, arrhythmia, cardiac edema, infarct size, histopathological damages and levels of cTnI and miR-330-3p were significantly increased and the expression of ALDH2 was down-regulated in the rats of the model group (P < 0.05). GXDS pretreatment protected myocardium by inhibiting mast cell degranulation and trypsin release. Conclusion GXDS inhibits the degranulation of rat cardiac mast cells through miR-330-3p/ALDH2, and thus improves the myocardial ischemia/reperfusion injury.

Acoustic graphene plasmons (GPs) exhibit an exceptional density of electromagnetic states within the mid-infrared (MIR) and terahertz frequency ranges, leading to a pronounced near-field amplification and localization at the nanometer scale. This characteristic renders them highly promising for the development of ultra-sensitive plasmon-enhanced MIR sensing and spectroscopic applications. However, the tight spatial confinement inherent to acoustic GPs results in a significant momentum mismatch, which in turn leads to poor coupling efficiency with light in free space. To overcome this limitation, we leverage numerical simulations to show that GPs can act as an intermediary to facilitate efficient excitation of acoustic GPs by incident MIR radiation, achieving an extinction spectrum peak value of approximately 0.9. The proposed gas sensor based on the acoustic GP resonator is composed of pristine, large-area graphene, an array of periodic metal nanocubes, and a slender polyethylenimine (PEI) layer that adsorbs CO2, situated between the nanocubes and the graphene sheet. The sensing performance of the proposed sensor is numerically investigated. It is demonstrated that by incorporating a CO2-absorbing material into the acoustic GPs, we can perform highly sensitive assessments of the absorption bands within the PEI layer upon CO2 adsorption. The observed behavior of the acoustic GPs indicates a weakening and broadening with increasing CO2 concentrations, a phenomenon attributed to the alteration in the permittivity of the PEI in the interstitial layer due to CO2 adsorption. Numerical simulation results indicate that the sensitivity of the proposed hybrid gas sensor can reach up to 0.0183% ppm−1, which offers a remarkable 95-fold enhancement over the gas sensor based on graphene nanoribbons. Our findings underscore the potential of acoustic GP nanoresonators as a transformative platform for ultrasensitive plasmon-enhanced sensing applications, particularly when integrated with various gas adsorption layers or molecular agents. [ABSTRACT FROM AUTHOR]

The current research mainly focuses on the influence of different voltage forms on partial discharge for the interturn insulation of a transformer, and the discharge characteristics and its mechanism of interturn insulation under the action of preload are unclear. Therefore, a partial discharge test platform under the synergistic action of preloading force and electrical stress is constructed based on the actual operation conditions of the interturn insulation of a 750 kV transformer. Then, the partial discharge characteristics and its mechanism is explored by using (OM, SEM, FTIR, XRD, EDS, FEA). It is found that the statistical parameters and damage degree of interturn insulation decrease first and then increase with the increase in preload. Moreover, there is an inflection point at 1000 N. The reason is that the preload causes the deformation of the holes and air gaps between the layers of insulating paper and in the insulating paper. As a result, the contact area and volume of partial discharge are changed, which further changes the characteristics of partial discharge for interturn insulation. This study can provide a reference for the maintenance and structural optimization of 750 kV transformers. [ABSTRACT FROM AUTHOR]