Browse Articles

A cross-sectional analysis of the quality and characteristics of sleep apnea hypopnea syndrome videos on YouTube, Bilibili, and TikTok

Magnetic particle optical imaging method based on magnetic linear dichroism effect

Magnetic particle imaging (MPI) has attracted considerable attention in recent years because it can achieve functional imaging of magnetic nanoparticles (MNPs) within biological tissues. Developing efficient MPI techniques while simultaneously enhancing imaging resolution is crucial for advancing their clinical applications. In this Letter, we propose a magnetic particle optical imaging (MPOI) method capable of quantitatively mapping the two-dimensional spatial distribution of (MNPs). This approach leverages optical imaging technology to simplify both the construction of the free-field region and the complex image reconstruction process. By extracting the second harmonic signal through phase-sensitive detection, the signal-to-noise ratio of the magnetic linear dichroism image is improved to 60 dB. The proposed method achieves highly sensitive detection of MNPs at concentrations as low as 0.01 mg/ml, along with 50 µm two-dimensional spatial resolution. These results demonstrate that the MPOI method provides a powerful platform for employing magnetic nanoparticles as magnetic labels in the metabolic imaging of living cells.

Deep learning-based assessment of periapical radiographic image quality

Modulation of interfacial Schottky barrier of In2Se3/Ti3C2X2 (X <b>=</b> Cl; F; O; OH) ferroelectric heterostructure

Reducing the interface barrier between metals and semiconductors is crucial for designing high-performance optoelectronic devices based on van der Waals heterostructures. In this study, the van der Waals design strategy is employed to investigate the interface contact characteristics in In2Se3/Ti3C2X2 (X=Cl; F; O; OH) ferroelectric heterostructure, which show metal–semiconductor contact characteristics. Under different out-of-plane polarization states of In2Se3, the In2Se3/Ti3C2Cl2 and In2Se3/Ti3C2O2 heterostructures can undergo a transition from Schottky to Ohmic contact. In contrast, the In2Se3/Ti3C2F2 heterostructure transforms from an n-type Schottky contact to a p-type Schottky contact. Notably, the In2Se3/Ti3C2(OH)2 heterostructure forms an Ohmic contact regardless of the polarization direction of In2Se3, with a tunneling probability of 80.75% and 47.78% for the down and up polarization configurations. The results demonstrate that the contact characteristics of ferroelectric heterostructures are jointly governed by the polarization of the ferroelectric layer and the work function of the metal layer. Specifically, when the polarization-induced electric field (Epi) and the built-in electric field (Ebi) arising from charge transfer are oriented in the same directions, their interaction is enhanced; in contrast, when the two fields are aligned in opposite directions, this interaction is attenuated. Meanwhile, despite the presence of a strong Fermi level pinning effect, this pinning actually results in the formation of an Ohmic contact. Therefore, the results indicate that the In2Se3/Ti3C2X2 (X=Cl; F; O; OH) ferroelectric heterostructure has excellent properties and can provide theoretical guidance for experiments.

Electrical current injury shows no specific acute histological changes in peripheral nerves and their vascular supply

Single-sided non-collinear shear wave mixing for material characterization

This Letter develops a single-sided non-collinear shear wave mixing technique for material characterization based on the phase-matching interface condition. Analytical modeling reveals that the interference between incident and reflected waves produces standing wave patterns whose interaction significantly enhances the mixed wave energy. Finite element simulations and experimental measurements demonstrate that the generated mixed longitudinal wave reaches its maximum amplitude when the mixing occurs at the traction-free surface. Additional simulations confirm the analytical prediction that the amplitude of the mixed longitudinal wave scales proportionally with the Murnaghan third-order elastic constant m. These findings confirm the feasibility of the proposed approach, highlighting its potential as a single-sided ultrasonic nondestructive evaluation technique to characterize the nonlinear elastic properties of a material.

Breakthrough RP-HPLC strategy for synchronous analysis of pyridine and its degradation products in powder for injection using quality metrics

Room-temperature continuous-wave lasing at 318 nm on a relaxed AlGaN template grown on a sapphire substrate

Continuous-wave (CW) lasing at 318 nm is achieved at 20 °C from an ultraviolet B (UVB) laser diode grown on a relaxed AlGaN template atop a sapphire substrate. The device incorporates a refractive index-guided ridge-waveguide structure, high-reflectivity SiO2/Ta2O5 distributed Bragg reflector mirrors, and junction-down mounting on a polycrystalline AlN submount for enhanced optical confinement and heat dissipation. Under CW operation at 20 °C, the threshold current density and current are 4.3 kA cm−2 and 64 mA, respectively. These results demonstrate stable room-temperature CW lasing in an AlGaN UVB laser diode, likely advancing compact and manufacturable laser sources for medical and industrial applications.

Analysis of refractive index sensing properties of independently and arbitrarily tunable multiplexed compound supercell gratings

Ultrafast atomic dimerization of Peierls distortion in semimetal molybdenum ditelluride

Semimetal molybdenum ditelluride (1T′-MoTe2) possesses diverse phase transitions, enriching its application prospects. The structural response during these transitions is crucial to understanding the underlying mechanisms, but the desired details of pathway and time span are still insufficient. Here, we investigate the lattice evolution in few-layer 1T′-MoTe2 after photoexcitation, using ultrafast electron diffraction and density functional theory (DFT) calculations. The observed complex lattice responses with unintuitively evolving Bragg peak intensity and interplanar spacing are best interpreted as the combination of shear displacement and Mo–Mo bond shortening in a few picoseconds, and a metastable structure in nanoseconds, based on the analyses of structure factor and pair distribution function. The DFT calculations reveal that photodoped electrons induce population change of the antibonding states close to the Fermi level, leading to shear displacement and dimerization of Mo pairs. Our findings present valuable insights for elucidating the picture of Peierls distortion in 1T′-MoTe2.

Hybrid real-synthetic dataset framework for robotic hazard detection in industrial environments

Abstract The increasing complexity of industrial environments requires the development of real-time hazard detection and environmental monitoring using intelligent robotic systems. This paper introduces RoboFusion , an integrated framework that combines Autonomous Mobile Robots (AMRs), fixed sensing nodes, and a novel hybrid dataset generation pipeline for data-driven industrial safety. Deployed in a functioning industrial testbed, RoboFusion collected real-time telemetry over 180 days using four sensor suites: two fixed units and two additional units mounted on Near-Field Communication (NFC) guided AMRs, each equipped with 12 sensors sampling at one-minute intervals. This deployment yielded approximately one million multi-modal sensor records, including temperature, humidity, gas concentrations, air quality, and pressure. Data streams were processed onboard using ESP32 microcontrollers, and they were transmitted via Message Queuing Telemetry Transport (MQTT) to an Internet of Things (IoT) cloud platform. The scarcity and imbalance of hazard events in real collected data create a challenge for effective model training. RoboFusion addresses this issue through a structured synthetic dataset generation framework. This framework augments non-hazardous data using statistical augmentation techniques, and it simulates hazardous data through multi-phase curve fitting, spatial propagation modeling, and location-aware hazard scenarios. The resulting synthetic dataset improves coverage of rare and safety-critical scenarios while maintaining consistency with real-world dynamics. Evaluation across four machine learning models, namely Random Forest (RF), Support Vector Machine (SVM), Extreme Gradient Boosting (XGBoost), and Multi-Layer Perceptron (MLP), demonstrates significant cross-domain gains. As an example, hazard F1 scores improved from 0.47 to 0.85 for the RF model, and from 0.16 to 0.79 for the SVM model when models trained on synthetic data were tested against real hazard events. RoboFusion therefore delivers a reproducible robotic sensing platform and an openly accessible hybrid dataset. It introduces a novel approach to hazard simulation that mimics real-world hazards and supports the development of resilient Artificial Intelligence (AI) systems for industrial hazard detection and autonomous safety intelligence.

Shallow trap dynamics and non-thermal spectral shift in sub-10- <i>μ</i> m InGaN micro-LEDs

Miniaturized InGaN micro-light-emitting diodes suffer reliability drifts that are not fully captured by conventional optical/electrical reporting. This study shows that, after 500-h direct current (DC) operation at 40 A cm−2, sub-10-μm devices exhibit a dominant-wavelength red-shift under fixed current that is non-thermal, as verified by &amp;lt;0.5 °C infrared thermography. A capacitance-decomposition model resolves the measured capacitance–voltage (C–V) dispersion into physically distinct trap ensembles and yields sub-40-ns response times, identifying shallow, sidewall-related traps as primary actors. The extracted trap dynamics quantitatively account for the increased series resistance, efficiency peak suppression, and weakened quantum-confined Stark effect screening responsible for the spectral shift. These results establish a mechanism-driven picture of reliability in miniaturized InGaN emitters and provide a general methodology for trap dynamics quantification in wide-bandgap optoelectronics. A display-driving implication is briefly noted, with details in the supplementary material.

Effects of long term canopy change on regulating ecosystem services in a tropical urban park

Second-harmonic vortex beam generation via parallel continuous-wave all-optical domain structuring

We report the generation of second-harmonic vortex beams using nonlinear pitchfork holograms directly induced via a parallel all-optical domain structuring technique in lithium niobate. The method employs a single-step exposure with amplitude-modulated visible continuous-wave laser light to induce ferroelectric domains through a photovoltaic field-assisted process. Subsequent second-harmonic generation from pulsed infrared excitation reveals well-defined vortex beam profiles with tunable topological charge, verified by far-field diffraction and Fourier analysis of the domain structures. These results demonstrate the scalability and versatility of the approach for the parallel fabrication of nonlinear photonic elements tailored for structured light generation.

Gut dysbiosis in a murine model of cutaneous lupus erythematosus correlates with antigen-specific T cells and antigen-presenting cells in skin

Abstract The commensal organisms constituting the human microbiome are increasingly appreciated to fortify epithelial barriers and modulate host immunity. Dysbiosis of both single strains and communities can contribute to inflammatory conditions. Here, we sought to characterize potential dysbiosis in our inducible mouse model of cutaneous lupus erythematosus (CLE). We hypothesized that gut dysbiosis would occur based on several studies that found lower Firmicutes/Bacteroidetes (F/B) ratios and decreased diversity in systemic lupus erythematosus (SLE) cohorts compared to healthy counterparts, a mouse study that identified Ro60 commensal orthologs that can trigger onset of lupus-like disease, and a study of CLE that identified outgrowth of Staphylococcus aureus in the skin. Using whole genome shotgun sequencing, we identified differences in pre- and post-irradiation cohorts, particularly an increase in Duncaniella , a decrease in Prevotella , and a reduction in alpha diversity following irradiation. Baseline alterations in CLE mice gut bacteria compared to littermate controls were also extant, including trends toward increased Parabacterides distasonis and Bacteroides acidifaciens in CLE mice. Importantly, we noted an increase in Phocaeicola sartorii in CLE mice compared to littermate controls post-disease induction. We examined the mycobiome in our mice and noted a reduction of Colletotrichum tofieldiae specifically in CLE mice post-disease induction, and a trend towards increased Periglandula ipomoeae . Last, we correlated abundance of genera and species with flow cytometry data obtained from the skin, lymph node and spleen, and identified specific strains that correlated with presence of antigen-specific T cells and different antigen presenting cell populations. Thus, our model exhibits similar changes to other models of lupus-like disease, and our data identify potential novel strains/species that could be modified for CLE and/or SLE treatment such as through generation of probiotics or specific antimicrobial agents.

Electric field dependence of nanoscale cathodoluminescence inside Cr doped β-Ga2O3 interfaces

Chromium (Cr) is a common impurity in β-Ga2O3 crystals, where its characteristic R1 and R2 luminescence lines are susceptible to both the host crystal field and externally applied fields. In this work, we demonstrate that the Cr cathodoluminescence (CL) quenches toward the bulk of the crystal but enhances with applied reverse bias, reflecting the effect of free carrier depletion with increasing electric field. Furthermore, we illustrate that the R1/R2 CL intensity ratio, measured as the integrated area ratio of R1 to R2, can be used as a direct probe of the electric field in a Ni-β-Ga2O3:Cr Schottky diode. This optical calibration method provides a complementary approach to conventional C–V and I–V measurements for determining electric field strength in the depletion region of β-Ga2O3-based Schottky diodes and can be extended to other semiconductors and multilayer device structures.

Resourceful utilization of crop residue by smallholder farmers in major grain-producing areas: pathways and countermeasures

Efficient conversion of near-field spherical waves to surface waves for microwave energy harvesting

Efficient near-field microwave power reception is fundamentally challenged by the spherical nature of incident wavefronts. We address this limitation by demonstrating a receiver based on an explicit analytical phase compensation model. This model enables a phase gradient metasurface to correct near-field phase variations, efficiently converting incident electromagnetic waves into guided surface waves. A composite structure is constructed by integrating a surface-wave parabolic reflector with an omnidirectional antenna to facilitate high-efficiency energy capture. At 5.8 GHz, the device achieves a simulated efficiency of 70.44% and a measured peak efficiency of 60.4%, exhibiting robust performance across the 5.6–6.0 GHz range. This work provides a generalizable design framework, analytically linking near-field wavefront correction to surface-wave engineering, for a class of high-efficiency microwave energy receivers.

Cladosporium cladosporioides, endophyte of Strelitzia nicolai, as a new producer of Alternariol monomethyl ether with a potential cytotoxic activity

Abstract The emergence of chemotherapy resistance is one of the challenges in cancer therapy, for the adaptability of cells to shield the normal targets, and expressing of efflux pumps to the normal drugs. Thus, searching for lead compounds of multiple targets activity in tumor cells, from novel endophytic fungi of medicinal plants, could be a distinctive approach for cancer chemotherapy. Cladosporium cladosporioides EFBL-025 , endophyte of Strelitzia nicolai, was recognized for the first time as a potential Alternariol monomethyl ether (AME) producer (700.1 μg/l). This isolate was morphologically, and molecularly identified based on the ITS with accession # PX463714. The chemical identity of AME of C. cladosporioides was committed from the FT-IR, HPLC and LC-MS/MS. The molecular mass of the parent molecule was 274.2 m/z, with the same molecular fragmentation pattern of authentic AME, as revealed from LC-MS/MS. AME has a significant activity against the A549 (IC 50 0.65 μg/ml), HepG-2 (IC 50 1.2 μg/ml), MCF-7 cells (IC 50 2.7 μg/ml), with selectivity index 28.2, 14.5 and 8.1 folds, respectively, compared to the OEC cells (IC 50 18.4 μg/ml). The activity of AME was a slightly higher than Taxol towards the tested cells by 1.8 folds. The purified AME has a higher inhibitory activity for Topoisomerase II (IC 50 value 5.7 μg/ml) and I (IC 50 value 7.25 μg/ml), compared to Etoposide (15.02 μg/ml) and Topotecan (27.27 μg/ml). The maximum arrest of the MCF-7 cells growth was observed at G0-G1 phase by 73.9 %, with a potency to induce the apoptosis by 12 folds compared to the control cells, suggesting the interference with the machinery of cellular growth and protein synthesis prior to DNA replication. Upon treatment of MCF-7 cells with AME, the healing activity was reduced by 12.5 % after 24. From the docking analysis, the binding energy of AME with the αβ -tubulin vinca site was -8.3 kcal/mol, compared to -7.4 kcal/mol for vinblastine. The AME binding affinities with Topoisomerase I, II α and II β were -7.3, -8.0, -8.3 kcal/mol, respectively, revealing the higher affinity for Topoisomerase II, as being consistent from the experimental analysis. Thus, this is the first reports exploring the metabolic potency of C. cladosporioides as AME producer, with the different cytotoxic insights.

Direct observation of the (de)lithiation process on the multi-particle LiFePO4 by <i>in situ</i> TEM

The development of nanostructured LiFePO4 (LFP) electrodes represents a prominent research direction in the Li-ion battery field, owing to its intrinsic advantages such as high theoretical capacity and excellent structural stability. Studying the electrochemical reaction mechanisms at the atomic scale by in situ TEM is essential; however, the mechanisms of ion migration on LFP have not yet been fully elucidated. We report atomic-scale in situ TEM studies of delithiation and lithiation in multi-particle LFP coupled to a Li-rich garnet (LLZNO) solid electrolyte. During delithiation, LFP converts to a metastable L0.5FP via a periodicity-doubling mechanism (every second layer) accompanied by the emergence of a solid-solution zone, and we directly observe interparticle Li+ transport that drives reversible LFP–L0.5FP–LFP cycles. Conversely, under reductive bias, lithiation proceeds by an interface-dominated crystalline–amorphous transformation, identifying amorphization as a primary particle-level failure pathway. Tracking the structural evolution of LiFePO4 at the atomic scale during (de)lithiation provides key insights into its kinetic limitations and phase stability, which is essential for optimizing its electrochemical performance.