Search Results (542)

This study conducted a 1:3 scale model test to investigate the improvement mechanism of damaged steel–concrete transition segments strengthened by UHPC. Meanwhile, a void region was introduced at the bottom of the transition segment to simulate the grouting defect in practical engineering. Then, static and fatigue tests on these transition segments were carried out on different parameters, including non-strengthening, UHPC strengthening and UHPC strengthening combined with void repair. Digital image correlation (DIC) was employed to characterize the global strain field of the transition segment. The experimental results show that UHPC strengthening reduced the relative displacement by 0.06 mm (46.2%), while UHPC strengthening combined with void repair achieved a reduction of 0.13 mm (96%). The average strain at critical points of the transition segment decreased by 76.2% after UHPC strengthening, while a greater reduction of 86.5% was achieved when UHPC strengthening was combined with void repair. In addition, crack propagation was effectively inhibited following UHPC strengthening. The refined finite element analysis results indicated that the predicted damage state at 1.0 P was in good agreement with the experimental observations, and under the 1.3 P overload condition, the difference between calculated and measured loads at the same displacement level was only 2.5%, and most of the stresses remained below the tensile and compressive strengths of UHPC. Finally, the proposed predictive method for the circumferential tensile stress of the transition segment exhibited a prediction error of 5%, indicating satisfactory accuracy. Full article

Intercellular mitochondrial trafficking has emerged as an important mechanism influencing tumor progression, metabolic adaptability, and cancer cell plasticity. Beyond their classical bioenergetic functions, mitochondria act as central regulators of redox homeostasis, signaling pathways, and epigenetic remodeling. Increasing evidence suggests that mitochondria can be transferred between tumor, stromal, and immune cells through tunneling nanotubes (TNTs), extracellular vesicles (EVs), gap junctions, and cell fusion within the tumor microenvironment. This dynamic excshange enables metabolically compromised cancer cells to restore oxidative phosphorylation, optimize energy production, and survive under hypoxia and therapeutic stress. Mitochondrial transfer has been increasingly associated with enhanced cellular plasticity and adaptive phenotypic transitions, including the acquisition of stem-like features that contribute to tumor heterogeneity, metastasis, and treatment resistance. In addition to bioenergetic restoration, transferred mitochondrial DNA and metabolites participate in retrograde signaling, linking metabolic state to epigenetic regulation and transcriptional reprogramming. This metabolic epigenetic interplay supports tumor cell adaptation to environmental stress and therapeutic pressure. Although significant progress has been made, the precise mechanisms governing mitochondrial integration and their long-term impact on cellular phenotypes remain incompletely understood. A deeper understanding of these processes may reveal novel therapeutic strategies to disrupt tumor adaptability and progression. Specifically, targeting intercellular mitochondrial trafficking and its associated metabolic and epigenetic effects could help limit tumor plasticity, overcome treatment resistance, reduce disease recurrence, and improve overall clinical outcomes in cancer patients. Full article

Lipid oxidation affects the quality and functionality of vegetable oils, and its progression depends largely on fatty acid composition and antioxidant content. Oxidation kinetics provide essential information about oxidative resistance in oils. The determination of activation parameters allows for the evaluation of oxidation susceptibility under thermal stress. Oxidative stability and oxidation kinetics at different temperatures of rosehip, sunflower, olive and jojoba oils were studied using both Rancimat and BQC-Redox System methods, enabling the calculation of kinetic constants and thermodynamic activation parameters for the process. BRS measurements showed an increase in total antioxidant capacity (TAC) with temperature in all samples, with olive oil presenting the highest TAC and jojoba the lowest at 298 K, while rosehip oil showed the lowest TAC at 373 K. Kinetic analysis revealed negative ΔS^# values, indicating the formation of ordered transition states, and similar activation energies (ΔG^# ≈ 56–58 kJ/mol), although jojoba displayed the highest ΔH^# and ΔG^#. Rancimat analysis at 373 K showed clear differences in oxidative stability: jojoba oil had the longest induction period, followed by olive, sunflower, and rosehip. These results correlated with PUFA levels. Principal component analysis (PCA) confirmed strong associations between induction period, fatty-acid composition, and kinetic parameters, demonstrating good agreement between the two analytical methods. Full article

As a complex structural form capable of simultaneously bearing upper-deck highway traffic, lower-deck highway traffic, and rail transit, the curved chord stiffened double-deck continuous steel truss bridge is distinct from traditional single-deck bridges. The spatial superposition of multiple traffic types within this structure may result in multiple components approaching their critical states concurrently. Despite prior research efforts on this structural type, the failure evolution process from local yielding to global collapse under mixed traffic loads remains ambiguous. This study addresses these questions through systematic numerical investigation of a nine-span bridge with a 300 m main span. A two-stage analytical approach is employed: a Midas/Civil analysis first identifies critically stressed regions, then ABAQUS multi-scale modeling enables refined analysis of critical components while maintaining computational efficiency. Twenty-nine combined traffic loading cases encompassing dual- and triple-category configurations are systematically analyzed. The results show that the ultimate load-carrying capacity coefficients range from approximately 7 to 18, with a minimum of 7.137, and the dual-level highway combinations exert greater influence than road–rail combinations. More importantly, three failure path convergence characteristics were discovered. First, the initial failure position under each working condition tends to be consistent, initiating at the lower chord near the top of the mid-span pier, which confirms that inherent structural defects exist at this location. Second, the gusset plate at the top of pier W6 appears as the second failure location in 48% of cases and ranks within the first four locations across all cases. Third, path similarity progressively increases with traffic diversity. Additionally, Q370qE steel exhibits 5–22% stress exceedance with variable critical locations depending on traffic conditions. Based on these convergence characteristics, a safety monitoring scheme is proposed: monitoring points need to be arranged symmetrically on both sides of the bridge on the top chords, bottom chords, web members, and wedge plates near the tops of the piers. Full article

Against the backdrop of increasing penetration of renewable energy sources such as wind and solar power, coupled with intermittent regional power restrictions, ensuring the quality of power transmission has become increasingly critical. The volatility and uncertainty of wind and photovoltaic output exacerbate dynamic fluctuations in net load on the grid side, necessitating hydroelectric units to undertake more frequent Automatic Generation Control (AGC) regulation tasks in complementary hydro–wind–solar operations. However, frequent regulation processes significantly intensify the operational stress on actuating mechanisms within the governor system, thereby accelerating wear and degradation of equipment such as hydraulic turbine servomotors. This study employs modeling and simulation to investigate the influence and mechanistic role of key control parameters in the AGC process on the wear of hydraulic turbine servomotors. Utilizing pulse count and pulse width metrics, a reasonable quantification of this impact is established. A multi-objective optimization framework for AGC parameters is constructed, and frontier solutions are selected based on quantified equipment wear values. Simulation results indicate that the optimized parameters achieve a balanced performance in terms of settling time, steady-state performance, and comprehensive dynamic metrics during power closed-loop transition processes. This approach effectively mitigates the actuation intensity of servomotors while satisfying regulation quality requirements, thereby enhancing the overall performance of the power closed-loop adjustment process. Full article

This paper investigates the mechanical characteristics of rockbolt under combined tensile–shear loading conditions. By studying the stress and deformation throughout the elastic and plastic stages of rockbolt, a failure model for rockbolt under different tensile–shear combination loadings was established. Key parameters, including the maximum bending moment M_A and total plastic deformation λ, were identified and quantified as they evolve with changes in the displacement angle (combined tensile–shear state). The main novelty lies in formulating the key control parameters governing the elastic–plastic transition and failure process of rockbolts under combined tensile–shear loading and further incorporating them into FLAC^2D to improve the simulation of tensile–shear failure of rockbolts. Numerical simulations of rockbolts under combined tensile–shear loading were performed using FLAC^2D. The influence of a rock mass’ Young’s modulus and uniaxial compressive strength on the mechanical response of the rockbolt was investigated. The results indicate that the ultimate load-carrying capacity of the rockbolt remains essentially constant as the displacement angle increases, while the axial tensile force gradually decreases and the shear force gradually increases. The influence of a rock mass’ Young’s modulus on the stress–strain characteristics of the anchor exhibits a nonlinear positive correlation. When the uniaxial compressive strength of the rock mass is low, the rockbolt is prone to slippage during loading. Full article

Decidualization in the human endometrium is not merely a hormone-dependent differentiation process; rather, it represents a multilayered adaptive program characterized by the tight integration of immune regulation, metabolic reprogramming, and cellular stress responses. In this review, endoplasmic reticulum (ER) stress and the associated unfolded protein response (UPR) are proposed as central regulatory mechanisms governing this process. Triggered by increased protein synthesis and secretory demand, UPR activation under physiological conditions preserves proteostasis and supports the secretory capacity of stromal cells. In contrast, chronic or dysregulated activation leads to a maladaptive response characterized by apoptosis, inflammation, and metabolic dysfunction. UPR signaling pathways shape immune tolerance through their effects on macrophage polarization, uterine natural killer (uNK) cell function, and T cell balance. At the metabolic level, adenosine monophosphate-activated protein kinase (AMPK) regulates cellular adaptation through bidirectional interactions with mitochondrial function and redox homeostasis. Within this framework, the ER stress–immune–metabolic axis operates not as a linear pathway but as a dynamic network incorporating multiple feedback loops, thereby constituting a critical threshold mechanism that determines the success of decidualization. Disruption of this axis provides a shared mechanistic basis for pathologies such as recurrent implantation failure, pregnancy loss, and preeclampsia. From a therapeutic perspective, agents including chemical chaperones, UPR modulators, AMPK activators, and anti-inflammatory compounds hold translational potential by targeting these pathological feedback circuits. However, key knowledge gaps remain, particularly regarding the cell type-specific and temporal regulation of ER stress, the molecular boundaries defining the transition from adaptive to pathological states, and interspecies differences. Future studies employing single-cell omics approaches and functional in vivo models will be essential to elucidate the dynamic organization of this axis and to enable the development of targeted and personalized therapeutic strategies. Full article

The phenotypic plasticity of epithelial cells along the epithelial–mesenchymal (E-M) axis, or epithelial–mesenchymal transition (EMT), is a critical aspect of tumour progression and therapeutic resistance. During EMT, epithelial cells gradually acquire mesenchymal traits, facilitating vital functions in embryogenesis, wound healing, fibrosis, and tumour metastasis. This review article investigates the potential interplay between hyperglycaemia-induced metabolic stress and EMT in the context of therapeutic resistance. The study examines a complex, multifaceted network of molecular mechanisms regulating EMT, including specialised transcription factors and signalling pathways as well as growth factors, integrins, and matrix metalloproteinases in various epithelial carcinomas. Emerging findings have demonstrated the existence of EMT hybrid states along the continuum, possessing heightened metastatic potential and distinctive metabolic signatures that play critical roles in the development of therapeutic resistance in cancer cells. Hyperglycaemia has been particularly highlighted for its potential to promote EMT-driven therapeutic resistance through various interconnected mechanisms. Elevated glucose levels induce the increased production of reactive oxygen species (ROS), activation of EMT-promoting transcription factors, and a metabolic shift towards glycolysis. This hyperglycaemic stress involves upregulation of glucose transporters and glycolytic enzymes, creating feed-forward loops that support drug efflux mechanisms and help maintain the mesenchymal phenotype. Clinical data also indicate that hyperglycaemia in OSCC patients is associated with more advanced tumour stages, more extended hospital stays, less effective treatments, and higher rates of local recurrence and distant metastasis. Overall, these insights reveal a deleterious feed-forward loop in which hyperglycaemia promotes EMT-driven therapeutic resistance, with the strongest clinical evidence in oral squamous cell carcinoma (OSCC) and supportive data from pancreatic and breast cancers. Although glycaemic control represents a promising low-risk adjunctive approach, its clinical benefit remains to be validated in prospective interventional studies. Full article

This investigation elucidates the elevated-temperature (650 °C) monotonic mechanical response and very-high-cycle fatigue (VHCF) characteristics of Inconel 718 superalloys additively manufactured via selective laser melting (SLM), with a comparative assessment between the as-built and post-process heat-treated states. The results indicate that mechanical performance improves after heat treatment, primarily due to the formation of γ′ and γ″ precipitates, which interact with dislocations to strengthen the alloy. Relative to the as-built specimens, the fatigue strength of the specimen after heat treatment has increased by more than twice. For the as-built specimen, fatigue cracks nucleate at the specimen surface. However, in the high stress range, crack initiation in the heat-treated specimens consistently occurs at the free surface, whereas under low stress conditions, the crack initiation site transitions to the subsurface region encompassing internal defects. Post heat treatment, the fatigue crack trajectory adopts a markedly ductile and tortuous morphology, engendered by the concerted influence of grain-boundary (Laves/δ) precipitates that enforce repeated crack deflection, matrix-strengthening phases that homogenize plastic strain and the attendant reduction in local strain accumulation under the effect of cyclic load. Full article

Background: Tumor-associated macrophages (TAMs) are key components of the hepatocellular carcinoma (HCC) microenvironment, but their spatial heterogeneity remains incompletely characterized. We aimed to assess the biological and prognostic relevance of a BAG3-associated TAM program in HCC. Methods: Public single-cell RNA sequencing (scRNA-seq) datasets were analyzed to characterize TAM heterogeneity, and an integrated validation scRNA-seq dataset was used to assess reproducibility. Spatial transcriptomics was used to provide spatial context in a small treatment-exposed cohort. Pseudotime, regulatory network, and cell–cell communication analyses were performed to characterize state transitions and microenvironmental interactions. Survival modeling evaluated the prognostic relevance of the BAG3-associated program. Results: Five TAM subsets were identified, including MARCO⁺, MT⁺ RTM−, MMP9⁺, UBE2C⁺, and BAG3⁺ TAMs. Among them, BAG3⁺ TAMs, a less well-characterized subset, exhibited coordinated stress-adaptive, proteostasis-related, and matrix-remodeling programs that were reproduced in the validation dataset. Pseudotime analysis suggested a continuum of TAM states, with BAG3⁺ TAM stress-remodeling features enriched toward late pseudotime. Communication analysis centered on BAG3⁺ TAMs suggested crosstalk between inflammatory stress cues and angiogenic, stromal-remodeling, and immunomodulatory programs; this pattern was primarily supported by HBV-derived samples and recurrently involved the MIF–CD74 axis. Spatial mapping further supported BAG3⁺ TAM-enriched niches with elevated AP-1, EGR1, and NFKB1 activity. A BAG3-associated risk score derived from a 10-gene signature remained an independent prognostic factor for overall survival after clinical adjustment. Conclusions: These findings characterize a BAG3-associated TAM program with spatial, immunoregulatory, and prognostic relevance in HCC, and support its further evaluation in biomarker and mechanistic studies. Full article

High-performance athletes are increasingly exposed to frequent trans-meridian travel, leading to profound circadian desynchronization and gastrointestinal distress. This review examines the complex interplay between the host’s central circadian system and the gut microbiota (GM), both of which exhibit synchronised daily oscillations essential for homeostasis. Rapid time-zone transitions, such as those anticipated for the 2026 FIFA World Cup, induce a state of “gut jet lag,” characterised by the loss of rhythmic microbial functions and impaired intestinal barrier integrity. Circadian misalignment is associated with increased systemic inflammation and disrupted metabolic regulation, which may contribute to impairments in cognitive performance, sleep quality, and muscle recovery. Critically, travel-induced dysbiosis may reduce the production of microbial metabolites, specifically short-chain fatty acids (SCFAs) like acetate, propionate, and butyrate. These SCFAs serve as energy substrates that may enhance glucose uptake, lipid oxidation, and glycogen storage in skeletal muscle. Evidence suggests that travel-related stressors—including dehydration, psychological stress, and shifts toward highly processed diets—further exacerbate the loss of beneficial taxa. To mitigate these effects, this article proposes evidence-informed strategies: timed light exposure to reset the master clock, chronobiotic meal timing to entrain peripheral tissues, and targeted symbiotic supplementation to restore SCFA-producing populations. Integrating these personalised, evidence-informed protocols may support the optimisation of physiological resilience and performance. Full article

Smooth window functions that restrict field actions to finite spacetime domains appear throughout quantum field theory, quantum optics, and open quantum systems, wherever interactions are switched on and off, detectors couple for finite durations, or systems decohere within bounded regions. When such a window function $◊\left(x\right)$ is introduced into the matter action of a covariant field theory, two structural consequences are unavoidable: the windowed Ward identities acquire boundary layer corrections confined to the window transition region, and the contracted Bianchi identity requires a compensating stress-energy contribution at the window boundary. Both consequences follow from the product rule of covariant differentiation and are independent of any specific physical motivation for the window. The present paper develops these consequences systematically for each sector of the Standard Model in curved spacetime. The windowed action prescription is applied to Dirac fermions, complex scalar fields, Maxwell theory, and the complete $SU{\left(3\right)}_c\times SU{\left(2\right)}_L\times U{\left(1\right)}_Y$ gauge Lagrangian. Each sector is shown to recover standard curved spacetime quantum field theory exactly within the localization window, with all deviations confined to a boundary layer whose thickness is set by the applicable operational localization scale—including decoherence, detector resolution, generalized uncertainty, or clock-precision bounds as appropriate. A Noether analysis yields windowed Ward identities of the form ${\nabla }_{\mu }(◊J^{\mu })=0$: gauge invariance and Lorentz symmetry are preserved exactly within the window, and apparent non-conservation is a kinematic boundary effect structurally identical to the open-system flux terms that arise when tracing over environmental degrees of freedom. The non-local boundary term $T_{\mu \nu }^{\mathrm{nl}}$ required by the Bianchi identity decomposes as $T_{\mu \nu }^{\mathrm{nl}}=T_{\mu \nu }^{\mathrm{comp}}+T_{\mu \nu }^{\mathrm{Rem}}$, where $T_{\mu \nu }^{\mathrm{comp}}$ is the boundary layer compensator and $T_{\mu \nu }^{\mathrm{Rem}}$ is its macroscopic coarse-grained remnant in the high-localization-density regime. A formal lemma establishes that, under stated regularity, phase-incoherence, finite-correlation-length, and variance-control assumptions, $T_{\mu \nu }^{\mathrm{comp}}$ vanishes upon coarse-graining for ordinary quantum fields, so standard field evolution leaves no macroscopic stress-energy remnant. The sharp-window limit recovers the Israel junction conditions exactly, and the smooth-window generalization is structurally identical to the Ashtekar–Krishnan dynamical horizon flux balance laws. The generalized uncertainty principle (GUP), extended uncertainty principle (EUP), relativistic GUP (RGUP), and Salecker–Wigner clock bounds constrain only the admissible operational thickness of the window boundary layer, $ϵ$, and do not alter the product rule origin of the windowed Ward identities or the Bianchi-required compensator. Full article

To address the frequency stability challenges arising from the high penetration of renewable energy, this study proposes a coordinated frequency regulation strategy for wind-power–hydrogen coupled systems, considering the Equivalent State of Charge (ESOC). While wind-power–hydrogen integration offers significant regulation potential, frequent ESOC excursions toward operational limits may lead to power interruptions and increased durability-related stress on hydrogen units. To resolve this, a refined mathematical model comprising wind turbines, electrolyzers, and fuel cells is first established to characterize system dynamics. The proposed method adopts an ESOC-based partitioning control logic: within normal ESOC ranges, the hydrogen storage system provides rapid frequency support via virtual inertia control; when ESOC reaches operational thresholds, the hydrogen unit seamlessly transitions out of service to prolong its lifespan, while the wind turbine dynamically compensates for the power deficit through adaptive droop control. Compared with other methods, the strategy proposed in this paper, implemented via DIgSILENT/PowerFactory simulations, improves the frequency nadir by 0.02 Hz during load increases and reduces the frequency peak by 0.04 Hz during load shedding. Under stochastic disturbances, the absolute steady-state frequency error is maintained below 0.02 Hz, while frequency deviations are strictly confined within ±0.5 Hz. These improvements significantly enhance both grid resilience and the operational safety of hydrogen units. Full article

Strong magnetic fields and anisotropic stresses can substantially modify the structure and observable properties of compact stars. In this review, we present a unified treatment of magnetically induced anisotropy across neutron stars, hybrid stars, and white dwarfs, connecting the microphysical equation of state effects to macroscopic structure and multimessenger observables. We demonstrate that magnetic-field geometry plays a decisive role: toroidally oriented (transverse) fields enhance the maximum mass by providing additional perpendicular pressure support, whereas radially oriented fields primarily increase central compression with comparatively small mass gain. In neutron stars, anisotropy and magnetic stresses can shift phase-transition thresholds in hybrid models and enable configurations in the lower mass gap with significantly smaller magnetic energy compared to the gravitational binding energy. We further show that continuous gravitational wave emission from magnetically deformed neutron stars provides a complementary probe of internal field geometry through ellipticity-driven strain evolution. In magnetized white dwarfs, super-Chandrasekhar masses arise from the spatial redistribution of magnetic stresses rather than from globally strong magnetic energy. Taken together, these results highlight that magnetic-field geometry and matter anisotropy are as important as field strength in determining mass–radius relations, tidal deformability, gravitational wave detectability, and the emergence of extreme compact-star configurations. Full article

The sustainable utilization of multiple reclaimed pavement materials is a critical pathway toward green highway construction. This study investigates the performance and synergistic mechanisms of cold-recycled mixtures incorporating both Reclaimed Asphalt Pavement (RAP) and Reclaimed Cement-Stabilized Base (RCSB), using emulsified asphalt as the primary binder. A comprehensive experimental program was conducted to evaluate the effects of reclaimed material proportions, mixing sequences, and curing ages on the mechanical strength, moisture susceptibility, and high-temperature stability of the mixtures. Microscopic characterization via Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS) were employed to elucidate the Interfacial Transition Zone (ITZ) evolution. Results indicate that an optimal RCSB incorporation range of 20–40% establishes a robust “stone-to-stone” rigid skeleton, significantly enhancing the splitting strength (up to 0.87 MPa) and durability (Splitting Strength Ratio, TSR > 91%). SEM observations confirm the formation of a dense interpenetrating network structure within this range, where cement hydration products and asphalt films achieve optimal chemo-physical bonding. Exceeding 40% RCSB leads to a moisture-starved state and a sharp decline in dynamic stability due to insufficient binder coating. Micro-morphological characterization reveals that the transition from macro-interfacial debonding to a robust cohesive failure mode is the fundamental driver for the performance peak at 20–40% RCSB. SEM observations confirm the formation of a dense interpenetrating network structure, where cement hydration products successfully anchor into the asphalt film. This optimized ITZ effectively eliminates the stress concentration and aggregate crushing seen in high-RAP mixtures, thereby ensuring superior mechanical integrity. Furthermore, a pre-wetting mixing sequence ensures a high-energy mineral surface that promotes the heterogeneous nucleation of cement. SEM results show that this prevents the competitive adsorption between cement and asphalt, transforming the ITZ from a friable, loose state into a densified crystalline adhesive matrix. Full article