Myasthenia gravis (MG) is a neuromuscular autoimmune disorder resulting from autoantibodies attacking components of the neuromuscular junction. Recent studies have implicated the aberrant expression ...of microRNAs (miRNAs) in the pathogenesis of MG; however, the underlying mechanisms remain largely unknown. This study aimed to identify key genes regulated by miRNAs in MG. Six dysregulated pathways were identified through differentially expressed miRNAs and mRNAs in MG, and significant crosstalk was detected between five of these. Notably, crosstalk between the “synaptic long-term potentiation” pathway and four others was mediated by five genes involved in the MAPK signaling pathway. Furthermore, 14 key genes regulated by miRNAs were detected, of which six—MAPK1, RAF1, PGF, PDGFRA, EP300, and PPP1CC—mediated interactions between the dysregulated pathways. MAPK1 and RAF1 were responsible for most of this crosstalk (80%), likely reflecting their central roles in MG pathogenesis. In addition, most key genes were enriched in immune-related local areas that were strongly disordered in MG. These results provide new insight into the pathogenesis of MG and offer new potential targets for therapeutic intervention.
High performance liquid chromatography coupled with quadruple-time-of-flight mass spectrometry（HPLC-Q-TOF-MS）method was developed for analyzing the hydrolytic mixtures of ginsenoside R_（g1） in acidic ...conditions（pH 3）. Three catalysts, a heteropolyacid（H_4SiW_（12）O_（40）, SiW_（12） for short）, its complex with γ-CD（SiW_（12）/γ-CD for short） and formic acid, were used for comparison. The chemical transformation products were identified based on the accurate mass measurement and the fragment ions obtained from tandem mass spectrometry. It was concluded that the catalytic efficiency of SiW_（12）（≈SiW_（12）/γ-CD） is ca. 410 times higher than that of formic acid, thus becoming the most efficient catalyst for chemical transformations of ginsenosides.
We report the observation of anomalous magnetic anisotropy driven by nonmagnetic ZrO2 nanoparticles in epitaxial La2/3Sr1/3MnO (LSMO) films grown on LaAlO3 (LAO) substrates. The compressive epitaxial ...strain imposed by the lattice mismatch of substrate and film is tuned by the density of ZrO2 nanoparticles embedded in the film matrix and affects the magnetic anisotropy as well as the magnetotransport properties. Epitaxial 54 nm thick LSMO thin films with different concentrations of ZrO2 nanoparticles demonstrate anisotropic hysteresis loops concomitant with anisotropic magnetotresistance behavior. The biaxial epitaxial strain, induced by the substrate/film lattice parameter mismatch is partially relaxed by increasing the density of precipitates and they serve as a tuning parameter for the strain state. We interpret our results by a strain-induced interplay of impurity scattering, weak localization and magnetic domain structure.
Abstract
Tungsten-based monolayer transition metal dichalcogenides host a long-lived “dark” exciton, an electron-hole pair in a spin-triplet configuration. The long lifetime and unique spin ...properties of the dark exciton provide exciting opportunities to explore light-matter interactions beyond electric dipole transitions. Here we demonstrate that the coupling of the dark exciton and an optically silent chiral phonon enables the intrinsic photoluminescence of the dark-exciton replica in monolayer WSe
2
. Gate and magnetic-field dependent PL measurements unveil a circularly-polarized replica peak located below the dark exciton by 21.6 meV, equal to E″ phonon energy from Se vibrations. First-principles calculations show that the exciton-phonon interaction selectively couples the spin-forbidden dark exciton to the intravalley spin-allowed bright exciton, permitting the simultaneous emission of a chiral phonon and a circularly-polarized photon. Our discovery and understanding of the phonon replica reveals a chirality dictated emission channel of the phonons and photons, unveiling a new route of manipulating valley-spin.
Inversion symmetry breaking and 3-fold rotation symmetry grant the valley degree of freedom to the robust exciton in monolayer transition-metal dichalcogenides, which can be exploited for ...valleytronics applications. However, the short lifetime of the exciton significantly constrains the possible applications. In contrast, the dark exciton could be long-lived but does not necessarily possess the valley degree of freedom. In this work, we report the identification of the momentum-dark, intervalley exciton in monolayer WSe2 through low-temperature magneto-photoluminescence spectra. Interestingly, the intervalley exciton is brightened through the emission of a chiral phonon at the corners of the Brillouin zone (K point), and the pseudoangular momentum of the phonon is transferred to the emitted photon to preserve the valley information. The chiral phonon energy is determined to be ∼23 meV, based on the experimentally extracted exchange interaction (∼7 meV), in excellent agreement with the theoretical expectation of 24.6 meV. The long-lived intervalley exciton with valley degree of freedom adds an exciting quasiparticle for valleytronics, and the coupling between the chiral phonon and intervalley exciton furnishes a venue for valley spin manipulation.
•The flow field is found to vary greatly downstream of the perforated plate.•The conjugate heat transfer affects NO formation by relocating the flame.•The preferential diffusion is intensified due to ...the two-dimensionality flow.•The coupling effect of these factors above determines the NO generation rate.
The present work examines the NOx emission characteristics of a premixed micro-combustion system with a perforated plate implemented. For this, a three-dimensional (3D) computational model involving a detailed chemical-kinetic mechanism for ammonia-oxygen combustion in the micro-combustor is developed. The model is first validated with the experimental measurements available in the literature before conducting comprehensive analyses. It is found that implementing a perforated plate in the micro-combustion system creates a flow recirculation zone downstream characterized by a low flame temperature and combustion speed. Meanwhile, the conjugate heat transfer between the combustion products and the inner combustor walls is shown to play a key role in the NO generation by relocating the flame in the axial direction and thus changing the chemical reaction rate. Furthermore, the preferential diffusion caused by the variation in the mass diffusivity of different species and the two-dimensionality flow is identified to vary significantly in comparison with the case in the absence of the perforated plate, especially in the vicinity of the recirculation zone. This diffusion effect results in the considerable drop in the N/O atomic ratio, primarily due to the reduction and increase of O2 and H2O, together with less available N2, and consequently affecting the NO generation rate. This work confirms that the flow field, the conjugate heat transfer as well as the preferential diffusion effect could be regarded as the potential mechanisms leading to the NOx emission variation in the recirculation zones.
Aiming at the problem that the change of motor parameters in actual operation will significantly reduce the control accuracy of the motor, this paper proposes a sensorless control method of permanent ...magnet synchronous motor based on an adaptive back-EMF observer. Firstly, in the sensorless vector control algorithm, the mathematical model of the permanent magnet synchronous motor based on the coordinate axis transformation is established, online identification of permanent magnet synchronous motor flux linkage, and the adaptive back EMF observer is constructed. The parameters update the motor model to achieve accurate control of the rotor position and speed of the permanent magnet synchronous motor. Then the back-EMF observer and the adaptive back-EMF observer are verified in the simulation environment. Then the simulation model of the back-EMF observer and the adaptive back-EMF observer is carried out, and the comparison analysis is made. Finally, a permanent magnet synchronous motor control platform is built in the laboratory, and the method proposed in this paper is verified. The results show that, under the condition that the permanent magnet synchronous motor parameters change, the online identification of the parameters and the accurate speed of the permanent magnet synchronous motor can be realized control.
The presented paper proposes a photovoltaic module hot spot detection algorithm based on YOLOv8‐BCB. The algorithm addresses issues such as component efficiency degradation and poor contact in ...long‐term operation of PV systems, with a focus on the hot spot effect’. To achieve rapid detection and localization of small targets in complex scenes, the algorithm incorporates the Weighted Bi‐directional Feature Pyramid Network (BiFPN) into YOLOv8. Additionally, a lightweight upsampling operator called Content‐Aware ReAssembly of FEatures (CARAFE) is used to reduce the detection load on the unmanned aerial vehicle (UAV) detection system. The BiFormer attention mechanism is also integrated into the C2f module to better capture dependencies between sequences and reduce background interference. To highlight the superiority of the authors’ algorithm compared to other high‐quality algorithms, the authors conducted comparative experiments on the same dataset. The YOLOv8‐BCB algorithm surpasses the SSD, faster‐cnn, and RetinaNet algorithms in both accuracy and detection speed. It achieves a precision of 97.1% and a recall rate of 94.9%, with an FPS of 110. The result is a target detection algorithm that is both fast and accurate.
1. A detection model of hot spot for photovoltaic (PV) panel based on YOLOv8‐BCB is established;
2. A small target detection algorithm for unmanned aerial vehicle is proposed;
3. A thermal spot detection test of PV power station was carried out.
Aflatoxins (AFs) including AFB1, AFB2, AFG1 and AFG2 are widely found in agriculture products, and AFB1 is considered one of the most toxic and harmful mycotoxins. Herein, a highly sensitive (at the ...pg mL−1 level) and group-specific enzyme-linked immunosorbent assay (ELISA) for the detection of AFB1 in agricultural and aquiculture products was developed. The AFB1 derivative containing a carboxylic group was synthesized and covalently linked to bovine serum albumin (BSA). The AFB1-BSA conjugate was used as an immunogen to immunize mice. A high-quality monoclonal antibody (mAb) against AFB1 was produced by hybridoma technology, and the mAb-based ELISA for AFB1 was established. IC50 and limit of detection (LOD) of the ELISA for AFB1 were 90 pg mL−1 and 18 pg mL−1, respectively. The cross-reactivities (CRs) of the assay with AFB2, AFG1, and AFG2 were 23.6%, 42.5%, and 1.9%, respectively, revealing some degree of group specificity. Corn flour, wheat flour, and crab roe samples spiked with different contents of AFB1 were subjected to ELISA procedures. The recoveries and relative standard deviation (RSD) of the ELISA for AFB1 in spiked samples were 78.3–116.6% and 1.49–13.21% (n = 3), respectively. Wheat flour samples spiked with the mixed AF (AFB1, AFB2, AFG1, AFG2) standard solution were measured by ELISA and LC-MS/MS simultaneously. It was demonstrated that the proposed ELISA can be used as a screening method for evaluation of AFs (AFB1, AFB2, AFG1, AFG2) in wheat flour samples.
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