Search Results (615)

Ready-to-eat (RTE) foods can carry antimicrobial-resistant pathogens; however, few studies link real-world surveillance to practical interventions. This study addressed this gap by estimating the prevalence of Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA) in ready-to-eat foods from Al-Qassim and evaluating a rapid, orthogonal confirmation workflow (culture → MALDI-TOF MS → Vitek 2 → mecA/mecC PCR). The in vitro activity of citrate-stabilized silver nanoparticles (AgNPs) against food-derived MRSA was quantified, and synergy with oxacillin (primary) and ciprofloxacin (secondary) was examined. Silver-susceptibility stability was assessed over 20 days of sub-MIC serial passage, with attention to whether β-lactam co-exposure constrained drift. We surveyed 149 RTE products and paired the confirmation workflow with mechanistic tests of AgNPs as antibiotic adjuvants. S. aureus was recovered from 24.2% of products and MRSA from 6.7%, with higher recovery from animal-source matrices and street-vendor outlets. MALDI-TOF MS provided rapid species confirmation and revealed two reproducible low-mass peaks (m/z 3990 and 4125) associated with MRSA, supporting spectral triage pending molecular confirmation. Antimicrobial susceptibility testing showed the expected β-lactam split (MRSA oxacillin/cefoxitin non-susceptible; MSSA oxacillin-susceptible but largely penicillin-resistant), with last-line agents retained. Citrate-stabilized AgNPs displayed consistent potency against food-derived MRSA (MIC 8–32 µg/mL; MIC₅₀ 16; MIC₉₀ 32) and were predominantly bactericidal (MBC/MIC ≤ 4 in 90%). Checkerboards demonstrated frequent AgNP–oxacillin synergy (median fractional inhibitory concentration index [FICI] 0.37; 4–16-fold oxacillin MIC reductions) and additive-to-synergistic effects with ciprofloxacin (median FICI 0.63), translating time–kill assays into rapid, sustained bactericidal activity without antagonism. During sub-MIC evolution, silver MICs rose modestly (median two-fold) and often regressed off drug; oxacillin co-exposure limited drift. RTE foods therefore represent credible MRSA exposure routes. Integrating MALDI-assisted triage with automated AST enables scalable surveillance, and standardized AgNP formulations emerge as promising β-lactam adjuvants—pending in situ efficacy, safety, and residue evaluation. Full article

Understanding the combined effects of water and dynamic disturbance on rock behavior is essential for deep underground engineering, where groundwater and blasting often coexist. Existing studies have mainly emphasized static weakening by water or the strength characteristics under impact, while the energy evolution process remains insufficiently addressed. To fill this gap, uniaxial impact compression tests were conducted on dry and water-saturated skarn specimens using a separated Split Hopkinson Pressure Bar system. The relationship between peak stress and impact pressure was analyzed, and the total input energy, releasable elastic strain energy, and dissipated energy were quantified to examine their evolution with strain. The results indicate that water saturation significantly reduces dynamic strength and modifies the damage process. During the compaction and elastic stages, dissipated energy is low but slightly higher in water-saturated specimens due to microcrack initiation. In the plastic stage, dry specimens exhibit faster energy dissipation, while water-saturated specimens show reduced capacity for crack propagation dissipation. Damage–strain curves follow an S-shaped pattern, with water-saturated specimens presenting higher damage growth rates in the plastic stage. These findings clarify the energy-based damage mechanisms of skarn under impact loading and provide theoretical support for evaluating stability in water-rich underground environments. Full article

Aim: This study analyzed the concurrent validity of the Optojump infrared photocell system for estimating lower limb peak power by comparing it with the 15 s Wingate anaerobic test (WAnT) and examining relationships with sprint performance indicators. Methods: Twelve physically active university students (ten males, two females; age: 23.39 ± 1.47 years; body mass: 73.08 ± 9.19 kg; height: 173.67 ± 6.97 cm; BMI: 24.17 ± 1.48 kg·m⁻²) completed a cross-sectional validation protocol. Participants performed WAnT on a calibrated Monark ergometer (7.5% body weight for males, 5.5% for females), 30 s continuous jump tests using the Optojump system (Microgate, Italy), and 30 m sprint assessments with 10 m and 20 m split times. Peak power was expressed in absolute (W), relative (W·kg⁻¹), and allometric (W·kg^−0.67) terms. Results: Thirty-second continuous jump testing produced systematically higher peak power values across all metrics (p < 0.001). Mean differences indicated large effect sizes: relative power (Cohen’s d = 0.99; 18.263 ± 4.243 vs. 10.99 ± 1.58 W·kg⁻¹), absolute power (d = 0.86; 1381.71 ± 393.44 vs. 807.28 ± 175.45 W), and allometric power (d = 0.79). Strong correlations emerged between protocols, with absolute power showing the strongest association (r = 0.842, p < 0.001). Linear regression analysis revealed that 30 s continuous jump-derived measurements explained 71% of the variance in Wingate outcomes (R² = 0.710, p < 0.001). Sprint performance showed equivalent predictive capacity for both tests (Wingate: R² = 0.66; 30 s continuous jump: R² = 0.67). Conclusions: The Optojump infrared photocell system provides a valid and practical alternative to laboratory-based ergometry for assessing lower limb anaerobic power. While it systematically overestimates absolute values compared with the Wingate anaerobic test, its strong concurrent validity (r > 0.80), large effect sizes, and equivalent predictive ability for sprint performance (R² = 0.66–0.71) confirm its reliability as a field-based assessment tool. These findings underscore the importance of sport-specific, weight-bearing assessment technologies in modern sports biomechanics, providing coaches, practitioners, and clinicians with a feasible method for monitoring performance, talent identification, and training optimization. The results further suggest that Optojump-based protocols can bridge the gap between laboratory precision and ecological validity, supporting both athletic performance enhancement and injury prevention strategies. Full article

Currently, the customs inspection of wood-boring pests in timber still primarily relies on manual visual inspection, which involves observing insect holes on the timber surface and splitting the timber for confirmation. However, this method has significant drawbacks such as long detection time, high labor cost, and accuracy relying on human experience, making it difficult to meet the practical needs of efficient and intelligent customs quarantine. To address this issue, this paper develops a rapid identification system based on the peristaltic signals of wood-boring pests through the PyQt framework. The system employs a deep learning model with multi-attention mechanisms, namely the Residual Denoising Vision Network (RDVNet). Firstly, a LabVIEW-based hardware–software system is used to collect pest peristaltic signals in an environment free of vibration interference. Subsequently, the original signals are clipped, converted to audio format, and mixed with external noise. Then signal features are extracted through three cepstral feature extraction methods Mel-Frequency Cepstral Coefficients (MFCC), Power-Normalized Cepstral Coefficients (PNCC), and RelAtive SpecTrAl-Perceptual Linear Prediction (RASTA-PLP) and input into the model. In the experimental stage, this paper compares the denoising module of RDVNet (de-RDVNet) with four classic denoising models under five noise intensity conditions. Finally, it evaluates the performance of RDVNet and four other noise reduction classification models in classification tasks. The results show that PNCC has the most comprehensive feature extraction capability. When PNCC is used as the model input, de-RDVNet achieves an average peak signal-to-noise ratio (PSNR) of 29.8 and a Structural Similarity Index Measure (SSIM) of 0.820 in denoising experiments, both being the best among the comparative models. In classification experiments, RDVNet has an average F1 score of 0.878 and an accuracy of 92.8%, demonstrating the most excellent performance. Overall, the application of this system in customs timber quarantine can effectively improve detection efficiency and reduce labor costs and has significant practical value and promotion prospects. Full article

Understanding how solvents influence the luminescence behavior of Cu(I) complexes is crucial for designing advanced optical sensors. This study reports the synthesis, structures and photophysical investigation of an 8-hydroxyquinoline-functionalized 1H-imidazo[4,5-f][1,10]phenanthroline ligand, ipqH₂, and its four Cu(I) complexes with diphosphine co-ligands. Photoluminescence studies demonstrated distinct solvent-dependent excited-state mechanisms. In DMSO/alcohol mixtures, free ipqH₂ exhibited excited-state proton transfer (ESPT) and enol-keto tautomerization, producing dual emission at about 447 and 560 nm, while the complexes resisted ESPT due to hydrogen bond blocking by PF₆⁻ anions and Cu(I) coordination. In DMSO/H₂O, aggregation-caused quenching (ACQ) and high-energy O–H vibrational quenching dominated, but complexes 1 and 2 showed a significant red-shifted emission (569–574 nm) with high water content due to solvent-stabilized intra-ligand charge transfer and metal-to-ligand charge transfer ((IL+ML)CT) states. In DMSO/DMF, hydrogen bond competition and solvation-shell reorganization led to distinct responses: complexes 1 and 3, with flexible bis[(2-diphenylphosphino)phenyl]ether (POP) ligands, displayed peak splitting and (IL + ML)CT redshift emission (501 ⟶ 530 nm), whereas complexes 2 and 4, with rigid 9,9-dimethyl-4,5-bis(diphenylphosphino)-9H-xanthene (xantphos), showed weaker responses. The flexibility of the diphosphine ligand dictated DMF sensitivity, while the coordination, the hydrogen bonds between PF₆⁻ anions and ipqH₂, and water solubility governed the alcohol/water responses. This work elucidates the multifaceted solvent-responsive mechanisms in Cu(I) complexes, facilitating the design of solvent-discriminative luminescent sensors. Full article

Water electrolysis represents a viable and scalable green hydrogen production technology, which mitigates carbon emissions and contributes to environmental sustainability. Transition metal-based layered double hydroxides (LDHs) exhibit excellent oxygen evolution reaction (OER) efficiency, attributed to their adjustable interlayer spacing combined with abundant active sites. Here, we report a uniform multimetallic catalyst, demonstrating robust and efficient OER performance for high-performance water splitting. SEM and TEM confirmed its ultrathin hierarchical nanosheet structure. The characteristic peaks of LDH in XRD and Raman spectra further verified the successful synthesis of the LDH material. Fe-CoZn LDH delivers exceptional OER performance in 1 M KOH, requiring overpotentials of just 209, 238, and 267 mV to reach 10, 100, and 400 mA cm⁻², respectively. The catalyst also demonstrates exceptional hydrogen evolution reaction (HER) performance, achieving 10 mA cm⁻² at 119 mV. It also has excellent stability, with stable operation for up to 100 h under 100 mA cm⁻² in 1 M KOH electrolyte solution. Full article

Argillaceous slate (AS) is a typical metamorphic rock with well-developed bedding, widely distributed globally. Its bedding structure significantly impacts slope stability assessment, and the challenges associated with slope anchoring and support arising from bedding characteristics have become a focal point in the engineering field. In this study, with bedding dip angle as the key variable, mechanical tests such as uniaxial compression, triaxial compression, direct shear, and Brazilian splitting tests were conducted on AS. Additionally, field anchoring grouting diffusion tests on AS slopes were carried out. The aim is to investigate the basic mechanical properties of AS and the grout diffusion law under different bedding dip angles. The research results indicate that the bedding dip angle has a remarkable influence on the failure mode, stress–strain curve, and mechanical indices such as compressive strength and elastic modulus of AS specimens. The stress–strain curves in uniaxial and triaxial tests, as well as the stress-displacement curve in the Brazilian splitting test, all undergo four stages: crack closure, elastic deformation, crack propagation, and post-peak failure. As the bedding dip angle increases, the uniaxial and triaxial compressive strengths and elastic modulus first decrease and then increase, while the splitting tensile strength continuously decreases. The consistency of the bedding in AS causes the grout to diffuse in a near-circular pattern on the bedding plane centered around the borehole. Among the factors affecting the diffusion range of the grout, the bedding dip angle and grouting angle have a relatively minor impact, while the grouting pressure has a significant impact. A correct understanding and grasp of the anisotropic characteristics of AS and the anchoring grouting diffusion law are of great significance for slope stability assessment and anchoring design in AS areas. Full article

Background/Objectives: Acute myocardial infarction (MI) is a major cause of death worldwide, and it imposes a heavy burden on health care systems. Although diagnostic methods have improved, detecting the disease early and accurately is still difficult. Recently, AI has demonstrated increasing capability in improving ECG-based MI detection. From this perspective, this scoping review aimed to systematically map and evaluate AI applications for detecting MI through ECG data. Methods: A systematic search was performed in Ovid MEDLINE, Ovid Embase, Web of Science Core Collection, and Cochrane Central. The search covered publications from 2015 to 9 October 2024; non-English articles were included if a reliable translation was available. Studies that used AI to diagnose MI via ECG were eligible, and studies that used other diagnostic modalities were excluded. The review was performed per the PRISMA extension for scoping reviews (PRISMA-ScR) to ensure transparent and methodological reporting. Of a total of 7189 articles, 220 were selected for inclusion. Data extraction included parameters such as first author, year, country, AI model type, algorithm, ECG data type, accuracy, and AUC to ensure all relevant information was captured. Results: Publications began in 2015 with a peak in 2022. Most studies used 12-lead ECGs; the Physikalisch-Technische Bundesanstalt database and other public and single-center datasets were the most common sources. Convolutional neural networks and support vector machines predominated. While many reports described high apparent performance, these estimates frequently came from relatively small, single-source datasets and validation strategies prone to optimism. Cross-validation was reported in 57% of studies, whereas 36% did not specify their split method, and several noted that accuracy declined under inter-patient or external validation, indicating limited generalizability. Accordingly, headline figures (sometimes ≥99% for accuracy, sensitivity, or specificity) should be interpreted in light of dataset size, case mix, and validation design, with risks of spectrum/selection bias, overfitting, and potential data leakage when patient-level independence is not enforced. Conclusions: AI-based approaches for MI detection using ECGs have grown quickly. Diagnostic performance is limited by dataset and validation issues. Variability in reporting, datasets, and validation strategies have been noted, and standardization is needed. Future work should address clinical integration, explainability, and algorithmic fairness for safe and equitable deployment. Full article

This study evaluates the mechanical performance and sustainability potential of fiber-reinforced concrete incorporating mine tailings as the fine aggregate and waste tire wire as the reinforcing fiber. The concrete mixtures contained 0.2%, 0.4%, and 0.6% waste tire wire with the natural fine aggregate replaced entirely with Pb-Zn-Cu tailings. The mixtures were tested for porosity, water absorption, compressive strength, splitting tensile strength, flexural strength, toughness, fracture energy, and ductility to assess their mechanical performance and durability. The mine tailings improved the microstructure and reduced water absorption, particularly with tire wire. Using waste tire wire improved the compressive, tensile, and flexural performance; in particular, W-6 showed a 18.2% rise in compressive strength and a more than twofold increase in flexural strength relative to the control mix. The flexural toughness and fracture energy rose by up to 161%, while the ductility peaked at a fiber content of 0.2%. These gains were attributed to fiber crack-bridging and post-cracking energy absorption. The dual-waste system also reduced porosity, improved durability, and demonstrated strong potential for rigid pavement applications such as highways, industrial yards, and airport runways that require high fatigue resistance and a long service life. Beyond technical performance, this approach offers a sustainable solution that lowers maintenance, reduces life-cycle costs, and aligns with circular economy principles. Full article

To investigate the regulatory mechanism of polyoxymethylene (POM) fiber on the workability and mechanical properties of C30-grade coral aggregate concrete (CAC), this study designed six groups of CAC specimens with varying POM fiber volume fractions (0%, 0.2%, 0.4%, 0.6%, 0.8%, and 1.0%). Cube compressive test, axial compressive test, split tensile test, and flexural tests of CAC specimens after 28 days of curing were conducted, while observing their failure modes under ultimate load and stress–strain curves. The experimental results indicate that POM fiber incorporation significantly reduced the slump and slump flow of the CAC mixtures. The cube compressive strength, axial compressive strength, split tensile strength, and flexural strength of CAC initially increased and then decreased with increasing POM fiber volume fraction, peaking at 0.6% fiber content. Compared to the fiber-free group, these properties improved by 14.78%, 15.50%, 17.01%, 46.13%, and 3.69%, respectively. Analysis of failure modes under ultimate load revealed that POM fibers effectively reduced crack quantity and main crack width, producing a favorable bridging effect that promoted a transition from brittle fracture to ductile failure. However, when fiber volume fraction exceeded 0.8%, fiber agglomeration led to diminished mechanical performance. Based on experimental data, the constitutive relationship established using the Carreira and Chu model achieved a goodness-of-fit exceeding 0.99 for CAC stress–strain curves, effectively predicting mechanical behavior and providing theoretical support for marine engineering applications of coral aggregate concrete. This study provides a theoretical basis for exploiting coral aggregates as low-carbon resources, promoting CAC application in marine engineering, and leveraging POM fibers’ reinforcement of CAC to reduce reliance on high-carbon cement. Combined with coral aggregates’ local availability (cutting transportation emissions), it offers a technical pathway for marine engineering material preparation. Full article

Dynamic fatigue of rocks under repeated cyclic impact is a nonconservative property, as surrounding rocks in real environments subjects them to variable impact disturbances, and the degree of damage varies under different energy level loads. To evaluate the dynamic response and fatigue damage characteristics of rocks under multi-level cyclic impacts, uniaxial cyclic impact tests were carried out on granite with various stress paths and energy levels using a modified split Hopkinson pressure bar. Dynamic deformation characteristics of specimens under different loading modes were investigated by introducing the deformation modulus of the loading stage. Evolution of macroscopic cracks during the impact process was investigated based on high-speed camera images, and the microscopic structure of damaged specimens was examined using SEM. In addition, cumulative energy dissipation was used to assess the damage of rocks. Results show that the deformation modulus of the loading stage, dynamic peak stress and strain of specimens increase with the impact energy, and the deformation modulus of the loading stage decreases as the damage level increases. Propagation rate of tensile cracks in rock was correlated with participation time of the higher energy level, which observed the following sequence: linearly decreasing > same > linearly increasing energy level, and cyclic loading of nonlinear energy level produced more tensile cracks and rock spalling than the same energy level. Compared with cyclic impacts of the same energy level, multi-level impacts form more microcracks and fatigue striations. The cumulative rate of specimen damage under the same energy change rate is as follows: linear decreasing > same > linear increasing loading. This provides a new case study for evaluating the dynamic damage, crushing efficiency and load-bearing capacity of rocks in real engineering environments. Full article

Stimulated Brillouin scattering (SBS) in microresonators offers a unique way to develop narrow-linewidth chip-scale lasers. Yet their coherence performance is hindered by the cascaded SBS process, which clamps the output power and broadens the fundamental linewidth of the first-order Stokes wave. Resonance splitting proves to be an effective approach to suppress intracavity SBS cascading. However, precisely aligning and controlling the resonance splitting behavior remains challenging. We address these issues by proposing a piezoelectrically actuated grating-embedded tantalum pentoxide (Ta₂O₅) microring resonator. This microresonator comprises a Bragg grating segment that induces a counter-propagating wave and a ring segment that is integrated with a lead zirconate titanate (PZT) actuator. The half-circumference Bragg grating has a peak reflectivity of 31% at 1549.8 nm and a bandwidth of 88.89 pm, which is narrow enough to ignite resonance splitting in only one azimuthal mode. The PZT actuator empowers the resonator with a frequency tuning rate of 0.1726 GHz/V, particularly useful for post-fabrication compensation and splitting control. The proposed architecture offers a promising solution to breaking the intracavity cascaded SBS chain with frequency tuning capability, paving the way towards highly coherent chip-scale laser sources. Full article

As mining operations extend deeper underground, support structures are increasingly subjected to severe impact loads. The dynamic mechanical performance of column-type support systems has, therefore, become a pressing concern. In the present research, a Split Hopkinson Pressure Bar (SHPB) apparatus, combined with Scanning Electron Microscopy (SEM), is used to systematically examine how the water-to-cement ratio, number of carbon-fiber reinforced polymer (CFRP) layers, and strain rate influence the dynamic compressive behavior and microstructural evolution of CFRP-confined high-water material. The results indicate that unconfined specimens are strongly strain rate-dependent, with peak strength following a rise–fall trend. A lower water–cement ratio results in a denser internal structure and improved strength. Additionally, CFRP confinement markedly enhances peak strength and impact resistance, refines failure modes, and promotes the formation of denser hydration products by limiting lateral deformation. This confinement effect effectively mitigates microstructural damage under high strain rates. These findings clarify the reinforcement mechanism of CFRP from both macroscopic and microscopic perspectives, offering theoretical insights and engineering references for the design of impact-resistant support systems in deep mining applications. Full article

Dry topsoil restricts root growth and nutrient uptake in arid regions, thereby significantly reducing crop yield. Hydraulic lift occurs due to the dry topsoil and wet deep soil. This study investigates the effects of topsoil drought intensity (three field capacities in topsoil: 60–70% (W1), 50–60% (W2), and 40–50% (W3)) and nitrogen application rate (N1: 120, N2: 240, and N3: 360 kg ha⁻¹) on cotton quality and the distribution of nitrogen in soil and plant under hydraulic lift using a root-splitting device. The upper pot of the root-splitting device was 22 cm high, with a 26 cm top diameter and a 23 cm bottom diameter; the lower pot of the root-splitting device was 45 cm high, with a 48 cm top diameter and a 36 cm bottom diameter. Topsoil moisture was maintained at W1 without nitrogen application under the control treatment (CK). The W2 and W3 treatments (representing different topsoil drought intensities) were designed to compare the interactive effects of water and nitrogen fertiliser on nitrogen distribution and cotton quality with the CK treatment. Results indicate that the concentrations of nitrate nitrogen (NO₃⁻-N) in the 10–20 cm soil were generally higher than those in the 0–10 cm soil. The topsoil drought intensity and nitrogen application rate had significant impacts on nitrogen concentrations in cotton organs. The W2 treatment produced the maximum nitrogen concentration, except for the root nitrogen concentration in 2021. The nitrogen concentration in the roots and stems peaked at 240 kg ha⁻¹ of nitrogen application rate. The topsoil drought intensity and nitrogen application rate had considerable influences on the cotton dry matter. The nitrogen application rate had a significant impact on the following indexes: internal nitrogen-fertiliser use efficiency (INUE), physiological nitrogen-fertiliser use efficiency (PNUE), and nitrogen-fertiliser recovery efficiency (NRE), except for PNUE in 2020. The INUE of other treatments decreased by 13.82–43.44% compared with CK treatment. In 2021, fibre length and elongation were significantly impacted by the topsoil drought intensity, nitrogen application rates, and their interactions. The nitrogen application rate’s effects on the uniformity index were significant in 2020 and 2021. The hydraulic lift magnitude, NRE, and NO₃⁻-N in the 0–10 cm soil were significantly correlated with each other. There were correlations among cotton quality indexes: fibre length and strength, uniformity index and micronaire, and micronaire and elongation. These findings provide a reference for future research on the mechanism by which hydraulic lift participates in nitrogen distribution in soil and crops and also offer a new direction to utilize deep water to improve the utilization rate of water resources. Full article

High strength and high ductility concrete (HSHDC) exhibit exceptional compressive strength (up to 90 MPa) and remarkable tensile ductility (ultimate tensile strain reaching 6%), making them highly resilient under impact loading. To elucidate the influence of strain rate and wet–dry cycling of salt spray on the dynamic compressive response of HSHDC, a series of tests was conducted using a 75 mm split Hopkinson pressure bar (SHPB) system on specimens exposed to cyclic corrosion for periods ranging from 0 to 180 days. The alternating seasonal corrosion environment was reproduced by using a programmable walk-in environmental chamber. Subsequently, both uniaxial compression and SHPB tests were employed to evaluate the post-corrosion dynamic compressive properties of HSHDC. Experimental findings reveal that corrosive exposure significantly alters both the static and dynamic compressive mechanical behavior and constitutive characteristics of HSHDC, warranting careful consideration in long-term structural integrity assessments. As corrosion duration increases, the quasi-static and dynamic compressive strengths of HSHDC exhibit an initial enhancement followed by a gradual decline, with stress reaching its peak at 120 days of corrosion under all strain rates. All specimens demonstrated pronounced strain-rate sensitivity, with the dynamic increase factor (DIF) being minimally influenced by the extent of corrosion under dynamic strain rates (112.6–272.0 s⁻¹). Furthermore, the peak energy-consumption capacity of HSHDC was modulated by both the duration of corrosion and the applied strain rate. Full article