Search Results (23,015)

:Piezoelectric actuators are core components in precision motion control due to their unique electromechanical coupling properties. This paper establishes a dynamic model for a partially laminated piezoelectric–metal–piezoelectric beam actuator based on the Euler–Bernoulli beam theory. The model comprises symmetrically bonded piezoelectric layers on both sides of a central metal substrate, with the piezoelectric material partially distributed along the beam length. The structure is analyzed segment-wise along the beam’s longitudinal length direction. By applying continuity conditions at the interfaces of varying cross-sections and leveraging the structural symmetry, analytical solutions for both the natural frequency and output displacement are derived. The analytical predictions are validated against finite-element results, and experiments also verify the accuracy of the analytical solution of the analytical voltage–displacement response. In addition, the effects of key geometric parameters on the dynamic performance are systematically investigated. The proposed model provides theoretical guidance for tuning the resonance characteristics and drive displacement design of the PMP actuators. Full article

To address the issues of easy leakage and low sand-flushing efficiency of coiled tubing working fluid in shale gas horizontal wells, this study investigates the flow behavior of foam fluid in both the coiled tubing and the annulus during foam sand-flushing operations, and optimizes operational parameters to enhance sand-flushing efficiency. Considering the dynamic variations in foam fluid properties with temperature and pressure, secondary flow effects in the spiral section, annular eccentricity, wellbore trajectory, and the solid phase in sand-carrying fluid, a one-dimensional steady-state hydraulic model incorporating flow and heat transfer is developed for the entire wellbore. This model covers the spiral, straight, jet, and annular sections of coiled tubing. Using field data from an example well, simulations yield the pressure distribution along the foam circulation path, the total circulation time, and key operational parameters. The feasibility of coiled tubing foam sand-flushing in shale gas horizontal wells is demonstrated, and the optimization of operational parameters to improve sand-flushing efficiency is analyzed. The findings provide important guidance for parameter design and equipment selection for safe and efficient sand-flushing operations in shale gas horizontal wells. Full article

Diet quality, nutrition knowledge, and psychosomatic literacy—defined as the understanding of the interactions between diet, gut microbiota, and mental well-being—may shape weight-related behaviours in youth. This study used a cross-sectional design to integrate these domains with digital information pathways in Central–Eastern Europe. This study assessed diet quality, nutrition, and psychosomatic knowledge, supplement use, and health-information sources among Polish adolescents and young adults, with emphasis on age-related differences and the role of social media. A cross-sectional, anonymous online survey (October 2025–January 2026) was conducted in Poland (final analytical sample: n = 478; adolescents 15–19 years vs. young adults 20–30 years). Of 591 individuals who accessed the survey, 478 were included in the final analytical sample. Diet quality was estimated from FFQ data using KomPAN-derived indices (pHDI-10, nHDI-14, DQI). Nutrition knowledge (0–25 points), psychosomatic/gut–brain indicators, supplementation, and information sources were analysed using χ²/Fisher tests and Mann–Whitney U tests with effect sizes. The primary outcomes measured were dietary supplement use and excess body weight (BMI ≥ 25 kg/m²). Multivariable logistic regression examined predictors of supplement use and BMI ≥ 25 kg/m². Overall diet quality was low to moderate, with limited intake of whole grains, legumes, and fish, and common nutrition misconceptions. Social media was the most frequently indicated source of diet/supplement information and was independently associated with more frequent supplement use (OR = 2.29; 95% CI: 1.43–3.64). Adolescents reported lower whole-grain intake and more misconceptions than young adults. Predictors of BMI ≥ 25 kg/m² included male sex (OR = 2.46; 95% CI: 1.46–4.15), lower education, and lower nutrition knowledge, while age showed a non-linear positive association with excess body weight. Polish adolescents and young adults show gaps between declared pro-health attitudes and actual diet quality/competencies. Social media reliance appears particularly linked to product-oriented behaviours (supplementation). Prevention should strengthen nutrition and food safety education, digital health literacy, and professional guidance on supplementation, especially in adolescents. Our findings suggest that social media is a primary driver for dietary supplementation among Polish youth, more so than objective nutrition knowledge. While diet quality is linked to weight status, the relationship is complex. These results may inform future public health interventions targeting digital health literacy to promote balanced nutrition and safe supplementation practices. Full article

Impact-damaged reinforced concrete (RC) columns often experience significant reductions in load-carrying capacity and ductility when subjected to subsequent axial loading. Carbon fiber-reinforced polymer (CFRP) sheets have been widely used to strengthen such damaged columns; however, the underlying strengthening mechanism remains insufficiently understood, largely due to the difficulty of experimentally capturing the evolution of internal damage. To address this issue, a three-dimensional (3D) meso-scale finite element (FE) model has been developed to investigate the mechanical behavior of CFRP-strengthened impact-damaged RC columns. The proposed model captures the evolution of micro-damage within concrete and provides a more realistic representation of impact-induced damage compared with conventional homogeneous models. The model was first validated against available experimental results, showing good agreement in both failure modes and responses. Based on the validated model, three typical strengthening schemes, including the longitudinally applied CFRP, U-shaped CFRP, and fully wrapped CFRP, are systematically examined in terms of failure patterns, load-carrying capacity, stiffness, ductility, and energy dissipation. The results indicate that the fully wrapped CFRP configuration most effectively mitigated damage in the impact-affected zone and increased the load-carrying capacity by up to 86%. Furthermore, a quantitative evaluation framework based on strengthening indices for axial capacity and energy dissipation is proposed, indicating that strengthening with two CFRP layers can lead to a desirable ductile failure mode within the scope of this numerical investigation. These findings provide useful mechanistic insights into the strengthening process and offer preliminary guidance for the rehabilitation of impact-damaged RC columns, though further validation is required before practical implementation. Full article

Culturally unsafe mental health services contribute to persistent inequities for Aboriginal and Torres Strait Islander peoples, yet existing cultural safety frameworks lack clear, prioritised, community-endorsed implementation guidance. This study aimed to establish Aboriginal consensus on cultural safety principles, implementation priorities and practical actions for culturally safe mental health services. A three-round modified Delphi study was conducted with 37 Aboriginal participants from Western Australia with expertise in mental health, social and emotional wellbeing and lived experience. In Round 1, participants completed an online survey rating the importance of cultural safety principles and identifying those requiring urgent action. In Rounds 2 and 3, facilitated yarning sessions reviewed findings, refined principles, grouped them into implementation domains, and identified priority actions. Aboriginal Participatory Action Research ensured Aboriginal leadership and governance throughout. All principles achieved strong consensus for importance. The most urgent priorities were trustworthiness, Aboriginal governance, trauma-informed care, addressing racism and strengthening the Aboriginal workforce. Participants organised the refined principles into six implementation domains, with Leadership and Governance identified as foundational to reform. Trustworthiness was reframed as an aspirational outcome requiring structural change. This study provides a community-endorsed, prioritised framework for translating cultural safety principles into mental health service practice and policy. Full article

Peripheral nerve injuries involving critical-sized gaps remain a major clinical challenge. Although autologous nerve grafting is considered the gold standard for peripheral nerve repair, its clinical application is limited by the availability of donor nerve tissue and the risk of donor-site morbidity, including sensory deficits and functional impairment. Therefore, nerve guidance conduits (NGCs) have emerged as a promising alternative when combined with bioactive modulation strategies. In this study, we evaluated bisvinyl sulfonemethyl (BVSM)-crosslinked gelatin conduits integrated with electrical stimulation (ES) at different frequencies (0, 2, 20, and 200 Hz) in a rat sciatic nerve defect model over a 4-week recovery period (n = 10 per group). Structural regeneration was assessed by morphometric analysis, electrophysiology, macrophage infiltration, CGRP immunoreactivity, retrograde Fluorogold tracing, quantitative PCR of growth factors and inflammatory cytokines, and behavioral testing. Among all stimulation paradigms, low-frequency ES at 2 Hz produced the most pronounced regenerative effects. The 2 Hz group demonstrated significantly greater axon number, axonal density, and regenerated nerve area compared with control and high-frequency groups (p < 0.05). Electrophysiological assessments revealed improved nerve conduction velocity, higher MAP amplitudes, and shorter latencies. Enhanced macrophage recruitment and elevated CGRP expression were observed, suggesting coordinated neuroimmune and neurochemical activation. Gene expression analysis indicated upregulation of neurotrophic factors and balanced inflammatory cytokine responses under low-frequency stimulation. In contrast, high-frequency stimulation (200 Hz) failed to enhance overall regeneration and showed reduced axonal metrics, suggesting possible overstimulation-associated suppression. Collectively, these findings demonstrate that BVSM-crosslinked conduits provide a stable and biocompatible regenerative scaffold, and that appropriately tuned low-frequency electrical stimulation (2 Hz) optimally enhances structural, molecular, and functional recovery. The integration of material engineering with bioelectrical modulation represents a promising strategy for next-generation bioelectronic interfaces in peripheral nerve repair. Full article

As natural nanoscale intercellular messengers, exosomes exhibit considerable potential in modulating inflammation, angiogenesis, immunoregulation, and tissue remodeling, making them attractive candidates for regenerative medicine. However, their clinical translation remains limited by rapid systemic clearance, nonspecific biodistribution, insufficient lesion retention, and functional attenuation in hostile pathological microenvironments. In this review, we propose that biomaterial engineering should evolve from providing passive exosome carriers to constructing active regulatory platforms capable of precise spatiotemporal control. We summarize engineering strategies along two complementary dimensions. In the temporal dimension, biomaterials can enable sustained, sequential, or microenvironment-responsive release to match the dynamic phases of tissue repair. In the spatial dimension, biomaterials can improve local retention, tissue anchoring, structural guidance, endogenous cell recruitment, and lesion-specific delivery. Using cutaneous wound healing, osteochondral regeneration, myocardial repair, and neural regeneration as representative examples, we further analyze these strategies through a “clinical challenge–engineering strategy–biological mechanism” framework, with particular attention to how engineered systems influence key signaling pathways such as PI3K/Akt, Wnt/β-catenin, NF-κB, and PTEN/PI3K/Akt/mTOR. We also discuss translational barriers, including exosome heterogeneity, safety concerns inherited from parental cells, large-scale GMP-compliant manufacturing, product standardization, storage stability, and regulatory classification of exosome–biomaterial hybrids. Finally, we highlight emerging directions, including multi-mechanism combinational systems, closed-loop responsive platforms, and artificial intelligence-assisted design for personalized exosome therapeutics. This review provides a design-oriented framework to accelerate the bench-to-bedside development of biomaterial-enabled precision exosome therapy. Full article

Triplophysa yarkandensis (Cypriniformes: Nemacheilidae), a rare endemic fish in the Tarim River Basin, Xinjiang, China, plays a pivotal role in maintaining the stability of plateau saline–alkaline aquatic ecosystems, yet its survival is increasingly threatened by habitat salinization. However, the multi-dimensional synergistic adaptation mechanisms linking its phenotypic variation, intestinal structure, and associated microbial communities to extreme saline–alkaline stress remain poorly understood. In this study, we innovatively integrated morphological/intestinal histological characterization, 16S rRNA gene sequencing, and microbial ecological analyses (co-occurrence networks and assembly processes) to systematically decode its adaptive strategies. Results revealed that T. yarkandensis exhibits a streamlined body shape, morphological variability, and elongated intestinal villi that may support locomotion and nutrient/ion uptake under osmotic stress. Its gut exerts a stringent selective filter, driving distinct differentiation between water and gut microbial communities—with gut-enriched core taxa (Aurantimicrobium and Aestuariivirga) and functional pathways (unsaturated fatty acid biosynthesis and ABC transporters) specialized for osmoregulation. Notably, the water microbial assembly is dominated by stochastic processes, while the gut assembly relies on host-driven deterministic selection, forming a habitat-specific adaptive pattern. These findings uncover the synergistic adaptation system of host phenotype and gut microbiota for survival in extreme saline–alkaline habitats, advancing our understanding of fish–microbe co-evolution in extreme ecosystems and providing critical theoretical support for the conservation of rare plateau fish, as well as guidance for the utilization of saline–alkaline water resources in aquaculture. Full article

Access to autism intervention services is shaped by persistent structural constraints, including limited availability, cost, and service continuity, which often require caregivers to assume expanded roles in supporting their children’s development. This study examines how such constraints contribute to the emergence and persistence of caregivers as proxy interventionists and how technology-mediated systems support or partially support these roles from a human factors perspective. A sequential mixed-methods design was employed across two phases. The first phase integrated quantitative caregiver and service provider surveys with qualitative interviews to examine service access, early technology adoption, and satisfaction patterns during periods of disrupted service delivery. The second phase examined post-adoption contexts through caregiver and service provider qualitative interviews to understand sustained caregiver-mediated practices, technology use, and associated cognitive, emotional, and coordination demands. An empirically grounded conceptual framework was derived to organize relationships among structural access constraints, role redistribution, technology-mediated interaction mechanisms, and human factors demands. The findings highlight the need for human-centered digital systems that provide structured guidance, coordination support, and accessible intervention resources. This work contributes to the design of scalable, technology-mediated support systems for autism care and offers practical implications for user-centered digital health interventions. Full article

Tool-using AI agents couple a language model with controller logic, memory, and external tools such as browsers, email, calendars, file systems, and transaction APIs. This architecture expands capability, but it also enlarges the security boundary: agents routinely ingest untrusted content while holding privileges that can reveal private data and trigger external side effects. The resulting failures are not limited to poor text generation; they include prompt injection, indirect injection through tool outputs, confused-deputy behavior, unauthorized actions, and misleading claims about the tool state. Because large-scale testing on deployed products is difficult, vendor-specific, and ethically sensitive, we present a transparent, theoretical simulation-based framework for evaluating user-facing risk in tool-using agents. The methodological contribution is a formal threat model that separates compromise, harm, and severity, and a Monte Carlo evaluation pipeline that maps architectural choices (permissions, retrieval, memory exposure, and approvals) and defensive controls to comparable outcome metrics. We instantiate the framework for six representative threat scenarios and nine defense configurations, reporting attack success rate (ASR), benign task success, latency overhead, and severity-weighted harm. Across scenarios, the least-privilege tool design is the strongest single broad control, human-in-the-loop approvals sharply reduce high-impact actions and exports but degrade under user error and habituation, retrieval allowlisting nearly eliminates indirect injection while leaving other channels largely unaffected, and rate limiting reduces tail severity more than ASR. These results position agent safety as an architectural and operational problem and because they arise from an assumption-explicit simulator rather than field measurements, should be read as comparative design guidance rather than incident-rate estimates for any deployed product. Full article

Conductive polymer microcellular foamed materials are a type of functional composite that combines lightweight cell structures with controllable conductivity. Their core feature lies in regulating the cell structure of the material through microcellular foaming technology, along with the introduction of conductive fillers or the intrinsic conductivity of the polymer, to achieve enhanced electrical performance. This paper systematically reviews conductive polymers and their microcellular foamed materials, highlighting research progress in foaming mechanisms, preparation processes, and functional applications. It first analyzes the key mechanisms of bubble nucleation, growth, and stabilization during the microcellular foaming of conductive polymers. Then, it elaborates on the research status and functional mechanisms of these materials in three typical application scenarios: electromagnetic shielding, flexible sensors, and thermal management. Finally, it outlines the future development directions of conductive polymer microcellular foamed materials in multifunctional integration, green fabrication, and intelligent applications, aiming to provide theoretical guidance and technical pathways for future research. Full article

Providing reliable sensory feedback is one of the most challenging aspects of transfemoral prosthetics, motivating the development of intuitive vibrotactile interfaces capable of conveying information about limb position in real-time. The aim of this study was to develop a vibrotactile feedback prototype and examine which interstimulus intervals (ISIs) and vibration waveforms might best enhance recognition of sequential tactile patterns. The results will be used to inform the development of a prototype to be tested on participants with transfemoral amputation where prosthetic feedback is provided. A forearm-mounted six-actuator feedback system, encoding eight lower-limb configurations, was used in two experiments with healthy adults. Experiment 1 assessed recognition accuracy across ISIs from 10 to 110 ms, while Experiment 2 compared sinusoidal and square waveforms under matched conditions. Recognition accuracy was high across all tested conditions, with no significant effects of ISI (p = 0.79) or waveform type (p = 0.17). These results indicate that participants were able to interpret spatially distributed vibrotactile patterns even under rapid temporal sequencing and with differing signal shapes. The system therefore offers design flexibility for real-time prosthetic feedback, suggesting that fast update rates may be achievable without a statistically detectable reduction in perceptual clarity within the tested conditions. These findings provide practical guidance for developing robust, user-friendly sensory substitution systems intended to increase proprioceptive awareness in transfemoral prosthesis users. Full article

Mosquito-borne infectious diseases remain a major challenge to public health, highlighting the need for efficient and accessible gene editing approaches. Receptor-mediated ovary transduction of cargo (ReMOT) offers an alternative to embryonic microinjection, in which P2C, an ovary-targeting peptide, enables ovarian delivery of the editing components. However, key design parameters and operational boundaries of the P2C-based ReMOT system have not been clearly defined. Here, we performed a methodological evaluation of the P2C-mediated ReMOT CRISPR/Cas9 system in Aedes aegypti. Cas9-P2C fusion proteins with different configurations were constructed and assessed through ovarian targeting assays, in vitro cleavage analyses, and in vivo gene editing experiments. Our results show that full-length Cas9-P2C fusion proteins exhibit nuclease activity and enable effective ovarian delivery. In contrast, linear truncation of the P2C peptide markedly reduced ovarian targeting, indicating a dependence on structural integrity. Using this delivery strategy, we generated kynurenine monooxygenase (KMO) edited mosquitoes, demonstrating feasibility under the conditions tested. In addition, protein injection was also associated with reduced reproductive performance, providing physiological reference for ReMOT applications. Overall, this study defines the key design parameters and operational boundaries of the P2C-based ReMOT system, providing methodological guidance for its application and optimization in future mosquito genetic studies. Full article

To address severe strata pressure induced by large end-area hanging spans and poor caving of thick, hard roofs in western coal mines, this study takes the 1302 working face of Zhujiamao Coal Mine as a case study. A multiscale mechanical model is developed to describe the progressive evolution of a stratified hard roof from a continuous beam to a cantilever beam and finally to an arched triangular hanging roof. Limit criteria for the maximum hanging length under bending and shear failure are derived, indicating that bending governs end-area roof instability. The theoretical results show good agreement with field observations and numerical simulations, providing guidance for liquid nitrogen fracturing target selection. Coupled FLAC3D-3DEC simulations reveal the staged deformation of overlying strata and clarify the spatial correspondence between the “O-X” fracture pattern and the arched triangular hanging roof. Based on these findings, a collaborative weakening strategy integrating directional drilling, hydraulic pre-cracking, and deep liquid nitrogen fracturing is proposed. Field observations and comparative tests confirm that this method effectively forms a three-dimensional fracture network, reduces roof stiffness and strength, shortens the caving interval, lowers peak shield resistance, and promotes stable caving of the end-area hanging roof. Full article

Accurate crop classification in complex and heterogeneous agricultural landscapes is often challenged by mixed-pixel effects and spatial autocorrelation. This study proposes a prior-guided crop classification framework that integrates accessible Moderate Resolution Imaging Spectroradiometer (MODIS) optical and Sentinel-1 synthetic aperture radar (SAR) time-series data with explicit phenological and structural priors. By embedding physically meaningful constraints into temporal feature learning, the model shifts from purely data-driven learning toward biophysically interpretable discrimination between crop types and background classes. Performance was rigorously evaluated using spatial cross-validation (SCV) to ensure geographic independence. Results demonstrate that the prior-guided CNN achieves an overall accuracy (OA) of 98.66% and a Kappa of 0.9832, outperforming unguided deep learning and conventional machine learning models. Notably, the framework exhibits high spatial robustness, with a minimal performance gap between random and spatial validation (ΔOA = 0.0049). In addition to improving classification accuracy, integrating phenological features with SAR-based prior information enhances the stability of non-crop categories in fragmented scenarios, while leveraging readily available medium-resolution data to support large-scale applications. These findings demonstrate that embedding physically meaningful prior knowledge into multi-source time-series learning improves classification accuracy while enhancing spatial generalizability and interpretability. More broadly, the proposed framework offers a transferable paradigm for integrating domain knowledge with deep learning, providing a practical and scalable solution for crop mapping in heterogeneous agricultural landscapes using widely accessible medium-resolution data. Full article