Search Results (3,040)

Monopiles are the predominant foundation type for offshore wind turbines (OWTs). Their diameters have increased substantially to accommodate larger structures, while current design approaches primarily rely on the API “p-y” model to simulate soil–pile interaction (SPI), which significantly underestimates the ultimate lateral pile capacity of large-diameter monopiles. Further, the API model accounts only for lateral soil resistance, neglecting mechanisms that substantially influence the lateral response of piles with low length-to-diameter (L/D) ratios, including pile toe shear, toe moment, and axial interfacial shaft friction. To address these problems, this study proposes a complete set of mechanism-aligned, spring-based SPI models capable of accurately simulating lateral pile response in sand across the full L/D spectrum typical of OWTs. The models include: a one-spring “p-y” model for flexible piles, capturing distributed lateral soil resistance; a two-spring “p-y + M_R-θ_R” model for semi-rigid piles, which additionally accounts for pile toe shear and bending moment resistance against rigid-body rotations; and a three-spring “p-y + M_R-θ_R + M_p-θ_p” model for rigid piles, which further includes rotational springs to account for distributed moment resistance due to rotation-induced shaft friction effects in sand. The derived spring parameter formulas have been calibrated using readily available engineering parameters, such as soil modulus, friction angle, and pile geometry. The three mechanism-aligned SPI models were validated against full-scale offshore monopile tests, centrifuge tests, and small-scale laboratory experiments, achieving less than 10% error in predicted pile capacities and less than 15% error in soil–pile coupled stiffness evolution. Full article

The soybean aphid (Aphis glycines) and soybean cyst nematode (Heterodera glycines) are major aboveground and belowground pests of soybean (Glycine max) in the U.S. Midwest, but the molecular basis of their combined effects on soybean defense remains poorly understood. This study examines how soybean genotypes influence demographic and root-transcriptomic responses to single and combined pest infestation. Soybean cyst nematode reproduction increased under combined infestation in the susceptible cultivar but remained unchanged in the resistant cultivar, whereas soybean aphid populations declined when plants were also infested with nematodes. Root RNA-seq revealed strong time-dependent transcriptional responses, with substantially more differentially expressed genes at 30 days post-infestation than at 5 days post-infestation. Co-expression and enrichment analyses showed that early responses were associated with defense signaling, plant–pathogen interaction, and cutin, suberin, and wax biosynthesis, whereas later responses involved redox processes, isoflavonoid biosynthesis, phenylpropanoid metabolism, and one-carbon metabolism. Several differentially expressed soybean genes co-localized with known soybean cyst nematode resistance quantitative trait loci, including genes near the rhg1 region. Together, these results suggest that soybean genotypes strongly influence soybean aphid–soybean cyst nematode interactions and identify candidate genes and pathways that may contribute to durable resistance against interacting aboveground and belowground pests. Full article

Long-span bridges in mountainous areas are usually exposed to nonstationary winds (e.g., thunderstorms), which pose a significant threat to the driving safety of vehicles. However, current analysis on the wind–vehicle–bridge interaction was mainly implemented based on the assumption of stationary wind input, which would lead to the distortion in the assessment of driving safety under nonstationary extreme wind events. In this study, a nonstationary wind–vehicle–bridge coupling analysis framework was found to investigate the dynamic response and driving safety under nonstationary events. Firstly, the Wavelet–Hilbert scheme was introduced to simulate the nonstationary wind velocity, and the two-dimension indicial function was employed to model the transient aerodynamic loads. Then, the nonstationary wind–vehicle–bridge coupling system was developed, and the separate iteration method was employed to obtain the response of the coupling system. Finally, the driving safety is evaluated based on statistical accident risk coefficients, derived from wheel contact forces. The results show that the vertical contact forces transference ratio, lateral contact forces, and vehicle accident risk coefficients under nonstationary winds are higher than those resulting from equivalent stationary winds. In addition, the accident risk coefficients increase with the transient wind velocity, duration, and vehicle velocity. In particular, the risk coefficient increases by approximately 201%, 36%, and 79%, respectively, with the increase in transient wind velocity, duration, and vehicle velocity. Full article

This study evaluates the 20-year operational performance (2006–2025) of a preseason prediction system for Atlantic hurricane activity developed at North Carolina State University (NCSU) and compares it with forecasts from Colorado State University (CSU), Tropical Storm Risk (TSR), and NOAA. Unlike previous studies based primarily on hindcast experiments, this analysis uses real-time forecasts generated under evolving model configurations, providing a realistic assessment of operational forecast skill. Results show that NCSU April forecasts exhibit lower mean absolute error than other April-issued forecasts and achieve performance comparable to later-issued forecasts from NOAA and CSU, indicating that improved model formulation can partially offset the advantage of later initialization. To identify the sources of forecast improvement, regression and ensemble analyses are conducted. Forecast adjustments between early- and late-season forecasts are primarily explained by changes in tropical North Atlantic sea surface temperature (SST), while ENSO contributes secondarily as forecast uncertainty decreases beyond the spring predictability barrier. These results establish a clear hierarchy of predictors, with Atlantic SST providing the dominant source of preseason predictability. Multi-model ensemble experiments further show that simple averaging does not outperform the best individual models; instead, selective combinations yield the highest skill, with optimal configurations differing between named storm and hurricane predictions, demonstrating that forecast improvement depends on combining complementary information rather than increasing ensemble size. Forecast performance is also shown to be predictand-dependent, with named storm counts more sensitive to late-spring environmental evolution and hurricane counts more strongly constrained by basin-scale thermodynamic conditions. Despite these advances, all models exhibit reduced skill during extreme seasons, reflecting the intrinsic limits of seasonal predictability. Overall, these results demonstrate that preseason hurricane forecast skill is governed by the interaction of forecast timing, model capability, and a hierarchical structure of environmental predictors, providing a unified framework for interpreting differences among forecasting systems and guiding future model development. Full article

The interaction between tunnelling and retaining walls represents a complex soil–structure interaction problem that can significantly influence wall deformation and stability. This study investigates and compares the behaviour of cantilever and soil-nailed retaining walls subjected to tunnel excavation beneath the wall in dry Toyoura sand. A series of three-dimensional finite element analyses was performed using an advanced hypoplastic constitutive model to simulate nonlinear sand behaviour and stress-path dependency. Tunnel depth was varied using cover-to-diameter (C/D) ratios of 1.83, 3.33, 4.83, and 6.33. The computed results show that both retaining systems exhibit similar settlement patterns due to tunnelling, with maximum settlement reaching approximately 22.8 mm in the case of C/D = 4.83. However, soil nailing has limited influence on reducing tunnelling-induced settlement. In contrast, the soil-nailed wall develops larger rotation and overturning response due to tensile forces mobilized in the soil nails by tunnelling-induced ground movement. For the shallowest tunnel case (C/D = 1.83), maximum tensile forces reach approximately 72 kN and 60 kN in the top and middle nails, respectively. Tunnelling also causes significant redistribution of contact pressure and shear stress beneath the wall base, including partial loss of contact for shallow tunnels. In addition, lateral earth pressure increases substantially, resulting in total lateral forces up to 3.3 times the pre-tunnelling values. The results demonstrate that tunnel depth governs the wall response, while soil nailing primarily affects rotational behaviour and internal force development rather than settlement mitigation. Full article

Renibacterium salmoninarum, the etiological agent of bacterial kidney disease, is a facultative intracellular pathogen whose interaction with salmonid phagocytic cells remains poorly resolved at the protein level. Here, we aimed to define the temporal protein-abundance architecture of SHK-1 macrophage-like cells after R. salmoninarum inoculation and to test whether this response supports broad canonical cell-death pathway engagement. We used label-free quantitative LC-MS/MS proteomics to profile SHK-1 cells over a 48 h post-inoculation time course. Because the design included a single non-infected T0 baseline, analyses were framed as baseline-referenced post-inoculation comparisons rather than a fully controlled mock time course. Of 6842 proteins retained for statistical modeling, 2254 were strictly differentially abundant in at least one contrast relative to T0 (adjusted p < 0.05 and |log₂FC| ≥ 0.585). Perturbation was strongest at 1–2 h and progressively contracted at later time points. Among 1278 recurrent proteins, k-means clustering resolved four temporal modules capturing coordinated remodeling of lysosomal, immunometabolic, cytoskeletal, stress-response, and antioxidant programs. A curated cell-death panel spanning apoptosis, pyroptosis, necroptosis, ferroptosis, and PANoptosis yielded only three detected markers; CASP3 and MLKL met the strict threshold, whereas ACSL4 remained sub-threshold. Overall, early host-cell remodeling, rather than broad canonical death-program execution, was the predominant proteomic signature of SHK-1 cells during the first 48 h after R. salmoninarum inoculation. Full article

Background: Appetite regulation is governed by a complex neuroendocrine network that integrates peripheral peptide signals with hypothalamic and brainstem circuits to coordinate energy intake and maintain energy homeostasis. Disruption of these pathways contributes to obesity and other disorders characterised by dysregulated feeding behaviour. Objective: To map and synthesise the current evidence on the role of appetite-regulating peptide hormones and central neural pathways in appetite control, obesity pathophysiology, and emerging therapeutic approaches. Methods: A scoping review of the literature was conducted to identify and synthesise evidence relating to the physiological and pathological mechanisms of appetite regulation. The review examined the actions of key peptide hormones, including ghrelin, glucagon-like peptide-1 (GLP-1), peptide YY (PYY), leptin, and insulin, their interactions within the gut–brain axis, and their effects on central appetite-regulating circuits. Results The evidence highlights the central role of the arcuate nucleus in integrating peripheral hormonal signals with neural pathways controlling feeding behaviour. Appetite regulation is mediated by the balance between orexigenic neuropeptide Y/agouti-related peptide (NPY/AgRP) neurons and anorexigenic pro-opiomelanocortin/cocaine- and amphetamine-regulated transcript (POMC/CART) neurons, with further modulation by the paraventricular, lateral, and ventromedial hypothalamic nuclei. The literature identifies hormone resistance, impaired satiety signalling, and altered neuroendocrine feedback as major contributors to obesity. Evidence on therapeutic interventions demonstrates the potential of GLP-1 receptor agonists, including liraglutide and semaglutide, and the dual incretin agonist tirzepatide, while also highlighting challenges related to treatment durability, adverse effects, and weight regain following discontinuation. Conclusions: Current evidence demonstrates that appetite regulation involves highly interconnected peripheral and central signalling pathways. The reviewed literature supports the development of multi-target and precision-based therapeutic strategies for obesity and identifies important areas for future research, including mechanisms of treatment resistance, long-term efficacy, and inter-individual variability in neuroendocrine responses. Full article

The interfacial transition zone (ITZ) in the aggregate periphery is often regarded as the weakest area in concrete. In this study, the results of extensive image analysis provide a new insight. First, fluorescence microscopy (FM) was adopted to obtain the microstructure of “complete ITZ”, which overcomes several limitations of the scanning electron microscope method. Then, an ITZ recognition interactive algorithm was proposed, which quantitatively characterizes the pore distributions in the ITZ and cement paste in both lateral and longitudinal directions. Finally, based on the experimental and statistical results, the pore distributions around aggregates, coarse sand and fine sand were characterized. Along the lateral direction, a high non-uniformity was observed in the porosity between units, taken at the same distance from the aggregate/sand surface. On the contrary, along the longitudinal direction, statistical results show minimal increases in the porosity within the ITZ. This is also applicable even in the innermost ITZs. Full article

Background/Objectives: Postoperative remodeling and positional deviations of the mandibular coronoid process (CP) after orthognathic surgery remain insufficiently characterized, particularly in three-dimensional analyses. The aim of this study was to evaluate qualitative and quantitative CP changes following bimaxillary orthognathic surgery using a deep learning-assisted three-dimensional workflow. Methods: This retrospective study included 75 patients treated with combined orthodontic–surgical therapy, including 25 patients with skeletal Class II malocclusion and 50 patients with skeletal Class III malocclusion. Preoperative and 6-month postoperative computed tomography scans were analyzed. Automatic segmentation and three-dimensional reconstruction were performed using a convolutional neural network based on the nnU-Net architecture. Qualitative assessment included evaluation of CP displacement patterns and visualization of local surface differences using heat maps. Quantitative analysis included volumetric assessment of preoperative and postoperative CP models, calculation of apposition-compatible (Vapo) and resorption-compatible (Vres) volumetric changes, and mixed-effects modeling accounting for within-patient correlations. Results: Medial displacement of the CP predominated in both skeletal classes and was more frequent in Class III patients. Qualitative surface analysis demonstrated a consistent location-dependent remodeling pattern, characterized by predominant apposition-compatible changes on the lateral and medial surfaces and predominant resorption-compatible changes along the anterior border. Quantitative analyses revealed an overall positive remodeling balance, although substantial inter-individual variability was observed. Mixed-effects analyses demonstrated no significant overall effects of side or skeletal class on volumetric remodeling; however, a significant interaction between side and skeletal class was identified for net remodeling balance. A significant random patient effect indicated considerable variability in remodeling response among individuals. Conclusions: AI-assisted three-dimensional analysis enables a reproducible assessment of postoperative CP remodeling following orthognathic surgery. Coronoid process remodeling is characterized by heterogeneous, location-dependent surface changes and substantial inter-individual variability. The observed remodeling patterns are compatible with adaptive responses to altered postoperative biomechanical conditions, although the underlying biological mechanisms remain to be clarified. Full article

Rectangular piles are increasingly utilized in engineering due to their high lateral bearing capacity, which benefits from an adjustable cross-sectional stiffness. However, research on rectangular piles within slope topography remains relatively scarce. Therefore, based on the principle of equal cross-sectional area, this paper establishes four sets of finite element models for rectangular piles with varying aspect ratios to conduct numerical analyses of their bearing characteristics under combined loading at slope angles of 0°, 15°, 20°, and 30°. The results demonstrate that: (1) Under combined loading, the lateral and vertical bearing capacities of rectangular piles interact; as the loading angle increases, the lateral bearing capacity decreases while the vertical bearing capacity increases. (2) Increasing the aspect ratio can significantly enhance the bearing capacity of rectangular piles. Under flat-ground conditions, compared to a pile with an aspect ratio of 1, a rectangular pile with an aspect ratio of 4 exhibits a roughly 75% increase in ultimate lateral bearing capacity and a 15.8% increase in vertical bearing capacity. (3) The critical section of the pile typically occurs within a depth range of 0.28 L to 0.43 L, where its stress mode gradually transitions from predominantly lateral bending and shearing to primarily vertical axial compression. (4) Slopes induce a reduction in the pile’s bearing capacity, but the bearing capacity curve for the pile with an aspect ratio of 4 declines more gently. Thus, rectangular piles with large aspect ratios possess greater engineering applicability in slope topography. This study reveals the bearing mechanism of rectangular piles under the combined influence of the slope weakening effect and the cross-section enhancement effect, providing a methodological reference for the design and application of novel pile foundations in slope terrains. Full article

Lane-changing and overtaking constitute a typical complex driving manoeuvre for intelligent vehicles operating on structured roads; this task demands that the vehicle not only plan a safe and smooth lane-change trajectory but also requires the control system to maintain high tracking accuracy and lateral stability. Addressing the challenges of real-time path planning and stable tracking control inherent in lane-changing and overtaking scenarios, this paper proposes a trajectory planning and control method that integrates an improved artificial potential field (APF) approach with a lateral–longitudinal cooperative controller. Regarding path planning, the proposed method constructs attractive and repulsive fields based on the APF framework, while introducing virtual target points, elliptical obstacle models, and velocity-dependent repulsive fields to mitigate the risk of local minima and enhance dynamic obstacle avoidance capabilities. To ensure trajectory continuity and trackability, a fifth-order polynomial is employed to smooth the planned path. Regarding control, the method utilises a Linear Quadratic Regulator (LQR)—optimised via a genetic algorithm—for lateral control; this is coupled with a dual-PID longitudinal controller that generates throttle and braking commands based on vehicle speed errors, thereby establishing a cooperative lateral–longitudinal tracking control strategy. The proposed method is validated using a CarSim–MATLAB/Simulink co-simulation platform. Simulation results demonstrate that the proposed method significantly improves trajectory-tracking accuracy and vehicle stability during lane-changing and overtaking manoeuvres. In a single lane-change scenario, the maximum lateral error is reduced from approximately 0.62 m to 0.22 m, and the heading angle error decreases from about 0.058 rad to 0.01 rad; in a continuous lane-changing scenario, the maximum lateral error drops from approximately 0.30 m to 0.04 m, while the heading angle error falls from about 0.016 rad to 0.005 rad. Furthermore, the yaw rate, sideslip angle, and lateral acceleration are reduced by 39.1%, 22.2%, and 28.9%, respectively. These results confirm that, under the specified simulation conditions, the proposed method exhibits superior tracking performance and stability. Future research could further explore more complex driving scenarios, such as curved roads, multi-vehicle interactions, sensor uncertainties, actuator delays, and real-vehicle field experiments. Full article

Background/Objectives: The aim of this study was to compare the effectiveness of the Reciproc Blue (RB) and MicroMega Remover (MR) systems in removing root canal filling material and to evaluate the effect of passive ultrasonic irrigation (PUI) on remaining filling material (RFM) using micro-computed tomography (micro-CT)-based three-dimensional (3D) analysis. Methods: Forty single-rooted mandibular premolar teeth were included in the study. The root canals were prepared up to size F2 using the ProTaper Gold rotary file system and obturated with the lateral compaction technique. After the initial micro-CT scan, the teeth were randomly divided into four groups: Group RB, Group MR, Group RB + PUI, and Group MR + PUI (n = 10). Following retreatment, a second micro-CT scan was performed. The percentage of RFM was calculated, and statistical analyses were performed using Kruskal–Wallis and Mann–Whitney U tests with Bonferroni correction. A rank-based factorial analysis was additionally performed (p < 0.05). Results: RFM was observed in all groups. No significant difference was found between the RB (7.37%) and MR (7.31%) systems (p > 0.05). However, the groups treated with PUI (RB + PUI and MR + PUI) showed significantly lower RFM values than the groups without PUI (p = 0.001). Factorial analysis revealed no significant effect of file system or file system × PUI interaction, whereas PUI significantly reduced RFM (p < 0.001). Conclusions: The RB and MR systems demonstrated similar effectiveness in removing root canal filling material. Although complete canal cleanliness could not be achieved, under the in vitro conditions of the present study, PUI significantly reduced the amount of micro-CT-measured RFM. Full article

Reinforced concrete (RC) infilled frames are widely used structural systems; however, seismic design provisions often idealize masonry infill as non-structural, leading to uncertainty in performance assessment. This study experimentally and numerically investigates the role of unreinforced masonry infill in RC frames, focusing on load-transfer mechanisms, strain evolution, and energy redistribution. Two 2/3-scale single-bay, single-storey RC frames (bare and fully infilled) were tested under constant axial load and quasi-static reversed cyclic lateral loading. Reinforcement strain gauges were used to capture local deformation demands, and a nonlinear macro-model was developed and validated against experimental results. Results show that the presence of masonry infill significantly increases ultimate strength, initial stiffness, and energy dissipation capacity, in comparatively more brittle post-peak cyclic behavior and accelerated stiffness degradation that leads to more abrupt post-peak degradation. Strain measurements provide clear evidence of a staged interaction mechanism: at low drift levels, the infill governs lateral resistance through diagonal compression strut action, limiting reinforcement demand in the frame; with increasing drift, progressive cracking and crushing of the infill promote a gradual transfer of forces to the RC frame, reflected by increasing reinforcement strains and stiffness degradation. At higher drift levels, the system transitions to frame-dominated behavior with localized strain concentration and shear failure at column bases or joints. These findings demonstrate that infill significantly modifies structural response and highlight the importance of incorporating strain-based mechanisms in the seismic assessment of infilled RC frames. Full article

This study conducted shaking table tests on silo-bulk systems to enhance the understanding of their seismic performance. A novel experimental setup was designed to measure the horizontal pressure and acceleration of the bulk material against the silo wall, enabling the assessment of interaction and energy dissipation effects within the system. Dynamic characteristics, including accelerations, displacement responses, and lateral pressures of the granular particles, were recorded at various earthquake intensity levels. The influence and energy dissipation effect of the granular particles on the dynamic behavior of the silo-bulk system were analyzed, providing an experimental basis for determining the effective mass coefficient of the granular material. The results indicate that a flat-bottom circular silo-bulk system exhibits favorable seismic performance. The stiffness-to-mass ratio and natural frequency of the system decrease with increasing bulk mass. Under seismic excitation, the bulk material contributes significantly to energy dissipation and damping control within the system. The calculated effective mass coefficient ranges approximately between 0.5–0.65 for the half-full silo and 0.5–0.70 for the full silo. The acceleration amplitude and additional lateral pressure on the silo wall exceed those within the bulk material itself, with the additional lateral pressure increasing progressively along the silo height. The overpressure coefficient can reach 2.0 under high-level seismic excitation corresponding to the intensity VII. The relevant results can provide reference for the seismic design of silos. Full article

This paper presents a flight–attachment–crawling robot (FACR) for close-range inspection of large-scale crane structures, aiming to improve access efficiency and contact-based inspection capability in elevated and discontinuous metallic environments. The proposed robot integrates flight, magnetic attachment and crawling units. To clarify the multimodal operating mechanism, dynamic models are established for the flight, wall-supported locomotion, and wall-attachment modes. Computational fluid dynamics simulations are then conducted to analyze near-wall aerodynamic effects, including the influence of wall proximity and lateral-rotor activation on rotor wake interaction, lift variation, and wall-normal support. A prototype platform is developed, and representative staged experiments are carried out to evaluate multimodal operation. The results show that the proposed FACR can support key multimodal operating stages required for crane-oriented inspection and provides a feasible platform-level solution for combining aerial mobility, wall-surface operation, and fixed-point attachment in complex industrial environments. Full article