Search Results (6,252)

Multiphase swirling flows in confined spaces induce highly destructive, nonlinear fluid–structure interaction (FSI) vibrations. Understanding the underlying physical mechanisms is critical for ensuring the safety of industrial operations. This study proposes a mesoscopic multiscale framework coupling the Multi-Relaxation Time Lattice Boltzmann Method with Large Eddy Simulation (MRT-LBM-LES) and the Flügge thin-walled cylindrical shell equations to analyze two-way FSI responses. Variational Mode Decomposition (VMD) and the Hilbert–Huang Transform (HHT) are employed to decouple non-stationary broadband excitation signals. The macroscopic topological evolution of the swirling air core—from initial depression to critical breakthrough—is accurately captured. Dynamic mapping reveals a strict time-domain phase-locking mechanism between macroscopic flow instability and microscopic high-frequency structural excitation caused by cavitation bubble collapse. Furthermore, a dimensionless cross-scale energy cascade index is defined to quantify energy transfer. Results indicate that while higher discharge flow rates delay the critical breakthrough, they trigger a delayed, high-amplitude step mutation in the energy cascade, amplifying the global cumulative excitation energy by nearly 75%. Notably, the dominant high-frequency excitation consistently converges within a narrow band of 760 Hz to 790 Hz, independent of flow rate variations. These findings provide a theoretical foundation for unsteady excitation source localization and targeted vibration reduction in complex industrial pipeline networks. Full article

Background/Objectives: Food allergy prevention is no longer understood as the simple avoidance of allergenic foods. The first 1000 days (from conception to, approximately, 24 months of age) include prenatal, perinatal and postnatal windows in which diet, epithelial barrier integrity, microbial ecology, immune maturation and family-level implementation interact. This narrative review was developed as a Commission-proposed SIAIP-oriented clinical framework, rather than a formal guideline or consensus statement. Evidence from guidelines, systematic reviews, randomised trials, birth cohorts and mechanistic studies was organised by developmental window and interpreted according to endpoint validity, confounding, feasibility and clinical readiness. Prenatal factors include maternal allergen non-avoidance, whole-diet quality, micronutrient and fatty acid status, antibiotic exposure, environmental context and maternal microbiome. Perinatal factors include mode of delivery, intrapartum and neonatal antibiotics, gestational maturity, early colonisation, breastfeeding initiation and routine vaccination. Postnatal factors include eczema, skin barrier inflammation, the timing and regularity of allergen introduction, breastfeeding management, infant diet diversity, siblings, daycare, pets, smoke and pollution, physical activity and equitable implementation. The strongest actionable evidence remains eczema-linked risk recognition and timely, sustained oral exposure to peanut and well-cooked egg. Maternal and environmental factors are clinically important, but many are contextual rather than prescriptive; they should guide non-restrictive, non-blaming counselling rather than deterministic risk labelling. Full article

The aim of this study was to investigate the effects of surface treatments and thermocycling on the shear bond strength of a 3D-printed permanent crown resin. A total of 120 disc-shaped specimens (10 × 3 mm) were fabricated using a 3D printer and randomly assigned to four groups according to surface repair protocols: airborne-particle abrasion with Al₂O₃, bur roughening, 37% orthophosphoric acid etching, and a control group with no surface treatment. All specimens received a silane coupling agent followed by an adhesive resin application, and repair was performed using a highly filled flowable composite. Each group was divided into three subgroups and subjected to 1000, 5000, or 15,000 thermal cycles. Shear bond strength was measured, failure modes were analyzed, and data were evaluated using two-way ANOVA and Tukey’s post hoc test (p < 0.05). The sandblasting group exhibited the highest bond strength (18.7 ± 5.0 MPa), which was significantly higher than the control (12.6 ± 3.7 MPa) and acid-etching (14.2 ± 3.8 MPa) groups (p < 0.05). Aging periods had no significant effect on bond strength (p > 0.05). Additionally, the interaction between surface treatment and thermocycling had no significant effect (p = 0.823). Under the tested conditions, airborne-particle abrasion resulted in the highest shear bond strength of 3D-printed permanent crown resin. Full article

The rapid advancement of autonomous driving technologies makes the effective coordination of vehicle groups a critical requirement for ensuring both safety and efficiency in smart urban environments. Although individual autonomous vehicles may operate correctly in isolation, their collective behavior can still lead to emergent issues such as deadlocks or collisions arising from complex inter-vehicle interactions. To address this challenge, we propose a hybrid automaton-based control framework for autonomous vehicle groups that integrates both normal and emergency operational modes to jointly guarantee safety and performance. In this paper, we present the formal specification and verification of the proposed system using rewriting logic and the Maude tool. Our main contributions are threefold: (1) the construction of detailed hybrid automata models that capture vehicle dynamics and decision-making; (2) the development of formal specifications in Maude from these models; and (3) the systematic verification of key system properties, including core safety invariants, such as collision avoidance, obstacle stopping, and velocity bounds. The verification results demonstrate that the proposed model consistently upholds safety conditions, ensures that vehicles come to a safe stop before encountering obstacles, and effectively prevents collisions within the group. Full article

Background: Paclitaxel is a cornerstone chemotherapeutic agent widely used in breast cancer treatment, primarily through the stabilization of microtubule dynamics. Beyond its canonical tubulin-targeting activity, increasing evidence suggests that paclitaxel may engage additional molecular targets, contributing to its complex pharmacological profile. In this study, an integrated computational workflow was applied to evaluate the structural compatibility between paclitaxel and the neurokinin-2 receptor (NK2R), a G protein-coupled receptor involved in tumor-associated inflammatory and proliferative signaling pathways. Physicochemical profiling and target prediction were performed using SwissADME and SwissTargetPrediction, followed by molecular docking and molecular dynamics simulations using AutoDock Vina and GROMACS 2024.1. Paclitaxel exhibited physicochemical properties consistent with transient interactions in hydrophobic transmembrane environments. Docking analysis identified a plausible binding mode within the NK2R transmembrane cavity, primarily stabilized by hydrophobic contacts. Molecular dynamics simulations over 100 ns revealed stable ligand occupancy and overall complex stability, while MM-PBSA calculations indicated a favorable transient association. The predicted interaction is consistent with secondary or non-canonical receptor engagement. While NK2R is not established as a pharmacological target of paclitaxel, the results support the structural feasibility of a previously uncharacterized receptor interaction and provide a reproducible computational framework for exploring GPCR-associated effects of cytotoxic agents. Full article

Plantations dominated by different tree species can differ in soil nutrient cycling and microbial community assembly, but corresponding bacterial and fungal patterns have not been characterized for mature plantation stands and a natural secondary forest in the Longmen Mountains of southwestern China. This study compared a natural secondary forest (SF) with four plantations, Magnolia officinalis (MO), Juglans regia (JR), Larix gmelinii (LG), and Cryptomeria japonica (CJ), in the Longmen Mountains of southwestern China, and investigated soil physicochemical properties, enzyme activities, bacterial and fungal community composition, co-occurrence networks, and predicted functional profiles in the 0–20 and 20–40 cm soil layers. The results showed that stand type was associated with total nitrogen (TN; p = 0.012), dissolved organic carbon (DOC; p < 0.001), dissolved organic nitrogen (DON; p < 0.001), and urease activity (p = 0.018), whereas pH differed between soil layers (p = 0.024) but not among stand types (p = 0.270). Relative to SF topsoil, DOC was 29.2% higher in JR and 36.1% higher in LG, while DON was 42.0% higher in JR and 51.4% higher in LG. TN and DON also showed stand type × soil layer interactions. None of the bacterial or fungal Chao1, Shannon, or Simpson indices showed significant stand type, soil layer, or interaction effects. In contrast, PERMANOVA indicated that bacterial and fungal community composition differed among the sampled stand types (p < 0.05), and fungal community composition also differed between the two soil layers (p < 0.05), whereas bacterial community composition did not. Paired partial dbRDA indicated that the integrated soil environmental gradients represented by the first three PCA axes were associated with bacterial community composition (R² = 0.083, p = 0.012), whereas the corresponding association was not significant for fungi (R² = 0.080, p = 0.371). Within the retained co-occurrence network analysis, MO had the most complex bacterial network, and JR had the most complex fungal network. PICRUSt2-predicted profiles were dominated by metabolism (38.6%–39.3%), but no bacterial KEGG Level 1 category or FUNGuild trophic-mode category showed a stand type, soil layer, or interaction effect after correction for multiple testing. These findings indicate that differences among the sampled stands were expressed more clearly in active carbon and nitrogen pools and microbial community composition than in alpha diversity or broad predicted functional profiles. Full article

Ring-stiffened cylindrical shells are widely used as load-bearing components in submarine pressure-hull sections. Existing underwater explosion studies have mainly emphasized incident-face denting or global failure, leaving unresolved how circumferential shock-wave diffraction and internal structural load transfer produce different response sequences and plastic-strain accumulation at the incident, side, and rear faces. A mechanism-oriented underwater explosion model test was conducted using a 44 g TNT charge at a stand-off distance of 0.50 m, and a fluid–structure interaction model was established in MSC.Dytran using the general coupling method. The model incorporated the Cowper–Symonds strain-rate effect of 16MnR steel and was validated against the Cole empirical peak pressure and measured incident-face residual deformations. The calculated free-field peak pressure was 35.50 MPa, with an error of 0.65%, while the mean relative error of the six residual-deformation measurements was 13.50%. The shell plating between adjacent ring stiffeners exhibited higher velocity and acceleration peaks than the stiffeners, indicating the local constraint imposed by the ring stiffeners. The side-face nodes showed symmetric transverse expansion, and the corresponding elements exhibited no discernible equivalent plastic strain. The rear-face center displayed a delayed axial response, and its representative element reached a final equivalent plastic strain of approximately $1.32\times {10}^{-3}$, compared with $0.40\times {10}^{-3}$ for the incident-face element. These results identify distinct circumferential response modes and show that macroscopic motion amplitude is not simply correlated with local plastic deformation. Full article

Quantum tunneling is conventionally described by the Schrödinger wave equation with a prescribed static potential barrier, providing accurate transmission probabilities but offering limited insight into the microscopic dynamics of particle–barrier interactions. In this work, we develop a dynamical second-quantization framework in which the barrier is modeled as an ensemble of quantized internal modes rather than as an externally imposed classical potential. The tunneling particle interacts directly with these microscopic barrier excitations through a coupled particle–barrier Hamiltonian, from which the Heisenberg equations of motion are derived. Collective coherent excitations of the barrier modes give rise to an emergent effective barrier that naturally recovers the conventional rectangular barrier and the WKB transmission limit under appropriate conditions. Unlike standard treatments, the present formulation explicitly incorporates microscopic barrier dynamics and provides a unified description of particle–barrier coupling within a second-quantized formalism. The framework further suggests that repeated tunneling events may experience different microscopic interaction histories, motivating a statistical interpretation of tunneling times. Because both the particle and barrier are treated within the same operator formalism, the theory provides a natural foundation for extension to relativistic quantum transport, photonic barriers, cavity quantum electrodynamics, and other structured quantum media. Full article

Calcium silicate-based cements are hydraulic biomaterials that form a calcium silicate hydrate (C-S-H) gel during hydration, a process fundamental to their setting and progressive physicochemical development. Although these materials are widely used in vital pulp therapy, evidence regarding the effects of adhesive strategy and restoration timing on bonding performance, particularly for newer premixed formulations, remains limited. This study evaluated the effects of cement type, adhesive strategy, and restoration timing on the shear bond strength (SBS) of resin composite bonded to MTA Angelus and Well-Root PT. A total of 270 specimens were distributed across two cement types, three adhesive strategies, and three restoration intervals (45 min, 24 h, and 7 days). After thermocycling, SBS and failure modes were assessed. SBS data were analyzed using three-way ANOVA, whereas failure-mode distributions were evaluated using chi-square or Fisher’s exact tests (α = 0.05). Cement type, adhesive strategy, restoration timing, and their interactions significantly influenced SBS (p < 0.001). Well-Root PT exhibited higher early bond strength than MTA Angelus. The two-step etch-and-rinse adhesive produced the highest SBS values, whereas the universal adhesive produced the lowest. Restoration after 24 h significantly increased SBS compared with restoration after 45 min, with no additional improvement observed at 7 days. Within the limitations of this in vitro study, bonding performance was influenced by cement type, adhesive strategy, and restoration timing. The time-dependent increase in SBS is consistent with continued hydration and development of the C-S-H gel-based cement matrix, although the specific microstructural changes underlying this behavior were not directly characterized. Full article

With the rapid development of E-commerce platforms (EPs) and the accumulation of consumer data, demand information sharing has become increasingly important in green supply chains. However, the interaction between selling mode selection and information-sharing strategies remains insufficiently explored. This study develops a game-theoretic model for a green supply chain consisting of a manufacturer and an EP to examine selling modes and information-sharing decisions under reselling and agency modes. The results indicate that information sharing is highly dependent on information accuracy. Specifically, when information accuracy exceeds a threshold, the manufacturer no longer purchases demand information because the marginal benefit cannot compensate for the acquisition cost. Under the reselling mode, the EP shares information only when information accuracy falls within an intermediate range, whereas under the agency mode, it always chooses to share information due to additional information-sharing revenue. Moreover, the manufacturer prefers the agency mode when the service cost performance factor is below the critical threshold and switches to the reselling mode otherwise. Information sharing consistently improves environmental performance, while the preferred selling mode depends on the service cost performance factor. The extension further shows that introducing an information collection cost narrows the information-sharing region and weakens the EP’s incentive to share information. Full article

Compared with single-swirl configurations, linearly arranged multi-swirl burners introduce complex inter-jet interactions that significantly alter flame dynamics; however, the underlying mechanisms remain poorly understood. In this study, direct numerical simulation (DNS) is employed to investigate a lean-hydrogen multi-swirl flame, aiming to elucidate its flame structure and dynamic evolution. The flame development region is divided into upstream (Region 1) and downstream (Region 2) regions, based on the critical location where the flame stretch transitions from positive to negative. The flow field, flame morphology, thickness, stretch, curvature, and their joint statistical relationships are systematically compared between the two regions. The results show that in Region 1, the flame stretch is dominated by positive strain rate, and the flame maintains a continuous structure and a small thickness. In Region 2, the curvature stretch becomes dominant, leading to severe flame wrinkling, local extinction and breakup, with the mean flame thickness increasing to about 1.5 times that of the laminar flame. Joint PDF analyses reveal that negative flame stretch is correlated with a large negative curvature in Region 2, whereas in Region 1, it is not affected by the curvature sign. The downstream flame also exhibits higher displacement speeds, indicating intensified turbulence–flame interaction. This study reveals the streamwise transition mechanism of the multi-swirl flame from strain-dominated to curvature-dominated dynamics, clarifies the distinct coupling modes of upstream stabilization and downstream fragmentation, and provides new theoretical guidance for stable combustion and wide-operability design of lean-hydrogen swirl combustors. Full article

Background/Objectives: Transthoracic lateral shoulder radiography serves as an important method for traumatic shoulder injuries and dislocations, but tissue overlap and breathing motion often compromise image quality and are particularly prominent in obese patients. This study aims to compare the image quality differences between the deep-inspiration breath-hold (DIBH) strategy and the routine free-breathing (FB) method in transthoracic lateral shoulder radiography for patients with different body mass indices (BMI), and to clarify the clinical application value of the breath-holding strategy. Methods: A total of 128 patients with traumatic shoulder injuries, glenohumeral dislocation, postoperative follow-up, and symptomatic degenerative shoulder osseous lesions were prospectively enrolled to undergo radiography. Anteroposterior (AP) projection and transthoracic lateral views applying both FB and DIBH methods were performed. They were stratified into three groups (BMI < 24 kg/m², 24–28 kg/m², and ≥28 kg/m²). Two experienced radiologists independently evaluated the subjective image quality regarding anatomical depiction and abnormality visualization between the two methods, which were compared using a four-point scale (1, poor; 4, excellent), with inter-observer consistency analyzed. The edge sharpness (ES) was also calculated and compared quantitatively. The interaction effect of BMI grouping and respiratory mode regarding ES measurement was evaluated; cumulative-link mixed-effects models with subject-level random intercepts were also fitted to test whether the benefit of DIBH varied with BMI grouping for the subjective scores. Results: The DIBH method presented superior anatomical depiction scores relative to the FB method (p < 0.001). For reader 1, median scores were 3.0 (interquartile range, IQR, 3.0–3.0) for FB radiographs and 3.5 (IQR, 3.0–4.0) for the DIBH method (z = −8.014, p < 0.001). Consistently higher median scores were also documented by reader 2 for the DIBH method: 3.0 (IQR, 3.0–3.0) for the FB method versus 3.0 (IQR, 3.0–4.0) for the DIBH method (z = −7.616, p < 0.001). For lesion depiction, the scores of the DIBH images were better than those of the FB images with p < 0.05 for reader 1 (p = 0.005) and reader 2 (p = 0.046). Moderate-to-excellent inter-reader consistency was observed. The mean ES of the DIBH method was significantly higher than that of the FB method (2.27 ± 0.73 vs. 2.02 ± 0.70; paired t = 4.80, df = 127, p < 0.001). No significant differences in ES values or subjective scores for DIBH images existed among three BMI subgroups (p > 0.05); FB anatomical scores differed significantly for both readers (reader 1: p = 0.041; reader 2: p = 0.026). There was no significant interaction between the BMI grouping and the respiratory mode regarding ES measurement (F = 0.061, df = 2, 125, p = 0.941). Conclusions: The deep-inspiration breath-hold strategy significantly improves image quality and lesion conspicuity for depicting shoulder abnormalities compared with the routine free-breathing method in transthoracic lateral shoulder radiography, without requiring additional equipment or changes to the radiographic system, when interpreted in conjunction with the corresponding AP radiograph in clinical practice for cooperative patients. Full article

Land transport infrastructure (LTI) is a core component of sustainable transport systems, shaping mobility, efficiency, and the spatial distribution of development gains. Existing studies of urban–rural income inequality mainly focus on individual transport modes or aggregate infrastructure scale, with limited attention to transport-system composition and its contextual dependence. This study addresses this gap by conceptualizing LTI as a layered system and examining how its internal composition is associated with urban–rural income inequality across different levels of urbanization and economic development. Using a balanced panel of 286 prefecture-level cities from 2013 to 2023, the study constructs ratio-based indicators of compositional shifts within road systems, within rail systems, and between rail and road infrastructure. Two-way fixed-effects models incorporate interactions with urbanization and economic development. Conditional marginal-effect maps are then used to identify how these associations change across development contexts. The results reveal a clear stage-dependent pattern. Urbanization generally attenuates the inequality-widening association of mobility-oriented upgrading, whereas economic development influences whether such upgrading reinforces spatial polarization or supports wider diffusion. When urbanization and development are both sufficiently advanced, the marginal association may shift toward inequality reduction. At earlier stages, accessibility-oriented roads and conventional rail tend to show stronger equalizing associations. Mobility-oriented roads and high-speed rail are more likely to be associated with narrower inequality in more advanced settings. Mechanism-oriented analyses yield evidence consistent with two potential channels: the agricultural–non-agricultural labor-productivity gap and the non-agricultural employment share. The extended analyses and robustness checks broadly support the main findings. These findings indicate that transport infrastructure upgrading should be evaluated not only in terms of efficiency, but also according to whether the resulting infrastructure mix broadens access to opportunities, improves resource allocation, and supports inclusive regional development. Full article

Accurately assessing the fatigue levels of air traffic controllers is crucial for reducing human errors in ATC and ensuring the safe and orderly operation of the civil aviation transportation system. In remote tower scenarios, air traffic controllers’ work environments and task interaction modes differ significantly from those in traditional towers, and traditional fatigue detection approaches relying on physiological monitoring can cause intrusive disruptions to ATC operations. To overcome these limitations, this study proposes a scenario-based, non-invasive assessment framework for accurate and low-interference fatigue recognition. Taking three key scenario elements (traffic load, main operation screen brightness, and core work area illuminance) as the basis for measuring fatigue, the framework bridges the mapping from scenario elements to fatigue status, thereby enabling the transition of assessment inputs from physiological metrics to scenario features. In this mapping, fatigue labels are determined using a fusion strategy. Specifically, objective fatigue labels are derived from optimal wave features extracted from electroencephalogram data using one-way analysis of variance (OW-ANOVA), which are then fused with subjective labels based on the Karolinska Sleepiness Scale (KSS) self-reports through fuzzy C-means (FCM) clustering. Ultimately, a hybrid intelligent classification model integrating the Gannet optimization algorithm (GOA) and random forest (RF) is constructed to perform the primary assessment task. The experimental results indicate that the proposed framework achieves a recognition accuracy of 95.00%, outperforming six other commonly used classification or combination models. Ablation experiments and robustness tests validate the effectiveness of the fused labeling strategy and GOA modules, as well as the method’s excellent stability in resisting data noise. Furthermore, feature interpretability analysis reveals the quantitative influence of the three core fatigue drivers used. The research findings confirm the feasibility of non-invasive fatigue assessment for remote tower controllers leveraging scenario-based elements, which can offer intelligent decision support for controller shift scheduling, visual environment optimization, and targeted safety interventions. Full article

We review a theoretical and experimental programme with the aim of understanding two intimately related fundamental phenomena in biophysics: (i) the classical analogue of Fröhlich phonon condensation in macromolecules driven out of thermal equilibrium and (ii) the consequent activation of long-range resonant electrodynamic intermolecular forces. Both phenomena are underpinned by explicit Hamiltonian models. The first is derived by applying the time-dependent variational principle (TDVP) to the quantum Wu–Austin model, producing a fully classical Hamiltonian in action-angle variables whose nonlinear rate equations exhibit a nonequilibrium phase transition: the channelling of supplied energy into the lowest-frequency collective mode. The second is grounded in a classical electrodynamic Hamiltonian for two coupled oscillating dipoles whose normal-mode structure predicts long-range (∼$1/r^3$) resonant interactions, absent at thermal equilibrium but activated by out-of-equilibrium collective oscillations. We also discuss a complementary Hamiltonian approach that connects Fröhlich’s rate equations directly to Hamilton’s equations of motion, clarifying the role of bath-mediated nonlinear coupling and the conditions for strong condensation at room temperature. In addition, the TDVP is applied to a Davydov–Holstein–Fröhlich Hamiltonian describing electron–phonon motion along the backbone of a specific DNA sequence and its cognate restriction enzyme, EcoRI: the time-domain Fourier cross-spectrum of the resulting electron currents exhibits a sharp co-resonance peak for the canonical recognition sequence that disappears upon randomisation, providing a sequence-specific electrodynamic signature of DNA–protein recognition. Experimental evidence from THz near-field spectroscopy, fluorescence correlation spectroscopy, and direct observation of protein clustering is reviewed in relation to these theoretical predictions. The results establish a coherent physical picture suggesting that metabolic energy supply can play a role in driving macromolecules into coherently oscillating states that activate selective, distance-reaching electrodynamic forces capable of contributing to the organisation of biochemical reactions in living matter. Full article