Search Results (32,868)

Eddy-current inspection of anisotropic composites, such as aeronautical CFRP, demands models that ensure mathematical rigor, tensorial consistency, and clear energetic interpretation. This work presents a novel unified variational framework with a multiplicative tensor perturbation for the time-harmonic eddy-current problem in anisotropic media with defective regions. The formulation is posed in the natural spaces $H(\mathrm{curl};\Omega )\times H^1\left({\Omega }_c\right)$, and the well-posedness is established via the Lax–Milgram theorem under physically consistent assumptions on permeability and conductivity. The sesquilinear form admits a Hermitian decomposition that separates dissipative and reactive contributions, revealing the energetic structure of the weak formulation. Defects are modeled through multiplicative modifications of the baseline anisotropic conductivity tensor. This congruence-based approach preserves symmetry and positive definiteness, ensuring non-negative Joule losses and structural stability, allowing a modular representation of subsurface delamination, fiber breakage, conductive inclusions, and distributed porosity within a single tensorial framework. A central result of the present formulation is the reconstruction of the complex power functional from the evaluation of the weak form at the solution, showing that the active dissipated power and the magnetic reactive power arise directly from the same integral terms. Through the complex Poynting theorem, the quadratic form is linked to the internal complex power, establishing a direct connection between the variational formulation and measurable quantities such as probe impedance variations. Simulations of realistic layered CFRP configurations, including single- and multi-defect scenarios, confirm that, compared with additive perturbations, the multiplicative model provides enhanced energetic contrast, particularly in strongly anisotropic and interacting defect conditions. Agreement with experimental measurements, supported by a quantitative comparison of dissipated power variations obtained from controlled EC experiments, corroborates the physical relevance and robustness of the proposed complex power functional. Full article

Background/Objectives: Excessive smartphone use has emerged as an important behavioral health concern during adolescence, a developmental period characterized by heightened psychosocial vulnerability. This study aimed to identify psychosocial and behavioral factors associated with excessive smartphone use among Korean adolescents using nationally representative data. Methods: Data were obtained from the 2024 Korean Youth Risk Behavior Web-based Survey (KYRBS), including 54,653 adolescents. Excessive smartphone use was operationally defined as average daily smartphone use of ≥300 min. Multivariable logistic regression was conducted to examine associated factors. An exploratory machine learning analysis using a Light Gradient Boosting Machine included 52,450 participants with complete predictor data. Results: Female sex, higher grade level, lower perceived socioeconomic status, higher perceived daily stress, higher anxiety symptoms, poorer sleep-related recovery, suicidal ideation, and more frequent vigorous physical activity were associated with higher odds of excessive smartphone use. The supplementary modeling approach showed patterns consistent with the regression findings, with grade level, socioeconomic status, and sex contributing prominently. Vigorous physical activity demonstrated a nonlinear association with predicted risk. Conclusions: Excessive smartphone use among adolescents appears to be shaped by developmental stage, socioeconomic context, and psychological vulnerability. These findings support prevention strategies that address emotional well-being and sleep health alongside broader structural and school-based approaches. Full article

Paralympic athletes are challenged by unique systemic strain due to impairment-related physiological and psychological stressors. This study aims to synthesize the current evidence regarding post-exercise recovery modalities in Paralympic athletes, providing an overview of their physiological considerations and practical applications. A narrative review was conducted across PubMed/MEDLINE, Scopus, and Web of Science (inception to December 2025). Inclusion criteria prioritized original research on competitive para-athletes evaluated through physiological or performance-based markers. Evidence identifies four critical domains: (1) Thermoregulation: In spinal cord injury (SCI), upper-body cooling is significantly more effective than lower-body strategies for core temperature reduction; objective monitoring of playing time is essential, as subjective perception is unreliable. (2) Systemic recovery: Sleep quality is compromised by secondary complications (e.g., nocturia and spasticity), and heart rate variability (HRV) serves as a sensitive autonomic marker to validate readiness. (3) Neuromuscular restoration: The early-phase rate of force development (RFD ≤ 50 ms) is more sensitive than the peak strength for detecting neural fatigue, particularly in SCI. (4) Contextual modulators: Infrastructure accessibility and psychological resilience are primary determinants of intervention efficacy. Effective recovery in para-sports requires a shift toward “active-assisted” impairment-specific interventions. Future research must validate specialized monitoring tools and longitudinal impacts on long-term health. Full article

Background: The pain experienced by people with fibromyalgia (FM) is thought to be the result of altered nociceptive processing, impaired descending inhibition and reduced tolerance to physical load. However, the relationship between the amount of exercise and pain reduction remains unclear. Methods: This study synthesized randomized controlled trials of exercise interventions for FM to quantify the combined analgesic effects of different types of exercise. A secondary aim was to standardize exposure using metabolic equivalent of task (MET)-based metrics and examine the association between cumulative intervention dose (MET·h) and analgesic response (Hedges’ g) across intervention arms. Following the PRISMA guidelines, a search was conducted in PubMed for randomized controlled trials published up to 31 December 2025. After screening and a full-text assessment, 15 trials were included. The protocols were converted into MET-defined intensity and weekly MET·min exposure, and the cumulative dose was calculated as the total MET·h accrued over the intervention period. Random-effects models were used to estimate the pooled effects within modality subgroups. Results: Across modalities, exercise was associated with reductions in pain, with effects typically falling within the small-to-moderate range. Larger improvements were observed in structured or supervised programs. The dose-response scatter plot showed wide variability across the dose range, with overlapping confidence intervals. An exploratory fourth-degree polynomial fit explained limited variance (R² = 0.1615) and did not indicate a monotonic dose-response pattern. This suggests that cumulative workload alone is a weak proxy for therapeutic response. Conclusions: Based on these findings, a pain-responsive algorithm combining weekly Visual Analogue Scale (VAS), ΔVAS and Talk Test thresholds was implemented as a preliminary online calculator to support the prescription of exercise tailored to symptoms. Full article

Background/Objectives: Depression is a common and consequential comorbidity among adults with diagnosed diabetes. Prior research has largely emphasized individual health behaviors, with less attention to emotional burden, social context, or theory-driven interpretation. The Multi-Theory Model (MTM) of Health Behavior Change offers an integrative framework for examining behavioral, emotional, and environmental correlates of health outcomes. This study applied MTM to examine correlates of lifetime diagnosed depression among U.S. adults with diagnosed diabetes. Methods: This cross-sectional study analyzed 2023 Behavioral Risk Factor Surveillance System (BRFSS) data from 19,967 adults with diagnosed diabetes, representing approximately 30 million U.S. adults after survey weighting. Lifetime diagnosed depression was assessed based on respondents reporting that a health professional had told them they had a depressive disorder, representing a lifetime history of depression rather than current depressive symptoms. Independent variables were organized into behavioral, emotional, and environmental domains consistent with MTM. Survey-weighted descriptive analyses, Rao–Scott χ² tests, and nested survey-weighted logistic regression models were conducted. Results: The weighted prevalence of lifetime diagnosed depression among adults with diagnosed diabetes was 24.3%. In the fully adjusted MTM-guided model, emotional and environmental domains showed the strongest associations with lifetime diagnosed depression. Frequent mental distress was associated with substantially higher odds of depression (adjusted odds ratio ≈ 10.4, p < 0.001). High social or economic stress and fair or poor self-rated health remained independently associated (p < 0.001). Behavioral factors, including physical activity, smoking, and body mass index, were attenuated after adjustment. Conclusions: Lifetime diagnosed depression among adults with diagnosed diabetes was more strongly associated with emotional burden and adverse social conditions than with health behavior alone, supporting the integration of distress screening and context-responsive interventions into diabetes care. Full article

Aging is associated with disturbances in brain energy metabolism, mitochondrial dysfunction, and increased oxidative stress, all of which increase neuronal vulnerability and contribute to the development of neurodegenerative disorders. Growing evidence indicates that physical exercise exerts neuroprotective effects through the release of exerkines–exercise-induced signaling molecules that mediate communication between peripheral tissues and the brain. Among them, irisin, a proteolytic cleavage product of the membrane protein FNDC5, has emerged as an important mediator of the muscle–brain axis. This review summarizes current knowledge on the molecular mechanisms underlying irisin activity in the central nervous system, with particular emphasis on the AMPK–PGC-1α–FNDC5/BDNF signaling axis, rapid receptor-mediated pathways involving the cAMP/PKA/CREB and ERK/CREB cascades, and the regulation of mitochondrial homeostasis, including biogenesis, dynamics, autophagy, and mitophagy. Experimental studies suggest that irisin may improve neuroplasticity, neuronal survival, mitochondrial function, and reduce oxidative stress, thereby alleviating cognitive deficits in models of aging and neurodegeneration. Although the precise receptor mechanisms and intracellular signaling events remain incompletely understood, accumulating evidence identifies irisin as a promising therapeutic target linking metabolic adaptation with neuroprotection. Further investigation of irisin-dependent pathways may facilitate the development of novel strategies aimed at preserving brain function and delaying the progression of age-related neurodegenerative diseases. Full article

Postural balance is a foundational component of human motor behavior, yet it remains conceptually ambiguous and methodologically heterogeneous across the clinical, educational, and sport sciences. This narrative review aims to provide an integrative framework that clarifies key concepts (postural control vs. postural balance), synthesizes the main sensorimotor and biomechanical mechanisms underpinning balance, and organizes current assessment approaches and functional implications across populations. Narrative literature synthesis was conducted to integrate evidence covering multisensory integration and sensory reweighting, central neural control (spinal, brainstem, cerebellar, and cortical contributions), neuromuscular and biomechanical strategies (e.g., ankle/hip/stepping), and cognitive influences (e.g., dual-task effects). We further summarize commonly used instrumental outcomes derived from force-platform center-of-pressure metrics and widely adopted clinical and functional balance tests, highlighting their typical applications and limitations across the lifespan including pediatric, general adults, older adults, and athletic populations. This review proposes a closed-loop, systems-based model in which postural balance is conceptualized as an emergent functional outcome arising from distributed postural control processes shaped by task, environmental, and individual constraints. In conclusion, integrating mechanistic understanding with population-specific assessment enhances interpretability and supports more precise, context-sensitive balance evaluation and intervention in both health and performance settings. Full article

After neurological injury, individuals often undergo physical therapy to regain motor function, which can be supplemented with use of virtual reality (VR). Rehabilitation commonly employs methods that encourage movement variability to promote functional gains, such as perturbations. Rehabilitation also commonly integrates additional sensory modalities for guidance and cognitive engagement to the protocol. In this exploratory, proof-of-concept study, neurotypical participants were trained on a custom tracing task with targeted dynamic shifting to induce movement variability, under both expected (proactive) and unexpected (reactive) conditions, with and without added auditory feedback. Participants significantly (p < 0.05) improved performance (tracing accuracy) after training with audio feedback. Participants trained without audio feedback showed decreased electrodermal activity (EDA), a measure of physiological engagement. Audio feedback during reach training with complex objectives (e.g., dynamic shifting) can promote performance improvements and cognitive engagement. Full article

Super-resolution microscopy has transformed biological imaging by enabling nanoscale visualization of cellular structures beyond the diffraction limit. However, its effective application in highly dense molecular environments still poses challenges. This is the case for 3D PhotoActivated Localization Microscopy (PALM) achieved through astigmatism in bacterial cells. The limited volume of a single bacterium highly increases the probability of the intensity profiles emitted by single chromophores to overlap, thus strongly decreasing the number of localizations, leading to dramatic undersampling. Dual-color 3D super-resolution in Escherichia coli is achieved through a combination of PALM with Expansion Microscopy (Ex-PALM). PALM provides high specificity through photoactivable (PA) fusion proteins and high localization precision, while ExM physically expands the specimen and separate densely packed molecules. This hybrid approach enables dual-color 3D single-molecule localization with about 3 nm spatial resolution, thus allowing one to measure distances down to the molecular scale. This is achieved by optimizing ExM protocols in bacteria to achieve a 4-fold isotropic expansion, by minimizing both chromatic aberrations and signal crosstalk, and by improving single-molecule sensitivity through highly selective inclined illumination. The method is applied to measure the spatial distribution of HisF and HisH proteins, involved in E. coli histidine biosynthesis. By tagging each protein with a photoactivable fluorescent protein, Ex-PALM reveals that after being synthetized, they co-localize in the bacterial volume with an average 3D distance of 19 nm. By combining labeling specificity with Ex-PALM, an effective method is developed for studying molecular organization in prokaryotes and in high-density samples in general, such as cell organelles or molecular condensates, with broad applications in microbiology, synthetic biology, and cellular biophysics. Full article

Background: Since sedentary habits have become a growing global public health concern, the promotion of physical activity (PA) from early childhood could help children live healthy lifestyles. The aim of this systematic review was to analyze the level of compliance with PA in preschoolers in relation to the reference guidelines. Method: A systematic review of relevant articles was carried out using four databases (PubMed, ProQuest, SCOPUS, and FECYT (Web of Sciences, CCC, CIDW, KJD, MEDLINE, RSCI, and SCIELO)) until 14 May 2025. The methodological assessment process was performed by using an adapted version of the MINORS assessment criteria. Results: A total of 623 studies were initially found and 23 were included in the qualitative synthesis. Conclusions: The results revealed that the average in most contexts usually ranges between 30% and 65% of the child population. Due to different operational criteria, compliance was generally higher when PA was assessed separately using single-behavior guidelines as opposed to when integrated 24 h movement frameworks were used. However, these results should be considered with caution because establishing the level of adherence to PA guidelines is difficult due to the different outcomes and guidelines used to compare the level of children’s PA. In future research, it is important to establish common baseline criteria (specifying more specific ages, common questionnaires, and criteria for calculating PA quantity and intensity) to facilitate more objective and reliable comparisons between studies. This systematic review is important because it highlights the need for healthy educational habits from the first years of a person’s life. Full article

Equine Gastric Ulcer Syndrome is a highly prevalent condition, yet its clinical diagnosis remains challenging due to the nonspecific nature of many associated signs. The relationship between the anatomical location of gastric ulcers and clinical presentation is still poorly defined. This retrospective study aimed to evaluate the association between gastric ulcer location and the clinical signs observed in horses. Medical records of 52 horses diagnosed with gastric ulcers by gastroscopy were retrospectively reviewed. Clinical signs were classified as physical, behavioral, or mixed, and ulcer localization was categorized as Equine Squamous Gastric Disease (ESGD), Equine Glandular Gastric Disease (EGGD), or mixed. Associations between variables were analyzed using chi-square or Fisher’s exact tests, with p < 0.05 considered significant. A significant association was identified between the type of clinical signs and ulcer location (p < 0.001). Physical clinical signs were predominantly associated with ESGD, whereas behavioral and mixed signs were more frequently observed in horses with EGGD or mixed ulceration. Furthermore, both the type of clinical signs and ulcer location were associated with the horse’s sport activity. No association was found between ulcer severity and clinical signs nor between ulcer location and sex. These findings suggest that gastric ulcer location influences clinical presentation, indicating that ESGD and EGGD may be associated with different clinical sign patterns. Full article

Background/Objectives: Salidroside, a bioactive phenylethanol glycoside primarily derived from Rhodiola rosea, and its major in vivo metabolite tyrosol exhibit diverse pharmacological activities. However, their direct molecular targets remain poorly defined. Methods: In the present study, an integrated strategy combining transcriptomic profiling, Connectivity Map (CMap) analysis, and multi-level experimental validation was employed. Transcriptomic signatures derived from A549 cells treated with salidroside or tyrosol were queried against the CMap database. Molecular docking, surface plasmon resonance (SPR), and cellular thermal shift assays (CETSA) were performed to predict and validate binding interactions. Functional validation was performed in SH-SY5Y cells. The phosphorylation level of extracellular signal-regulated kinase (ERK), a downstream signaling event of dopamine D2 receptor (DRD2), was detected after salidroside and tyrosol treatment. DRD2 antagonist sulpiride pre-intervention and small interfering RNA (siRNA)-mediated DRD2 knockdown were conducted to verify the receptor dependence of the compounds’ effects. Results: CMap analysis revealed that the transcriptomic signatures of salidroside and tyrosol showed significant similarity to known DRD2 modulators. Molecular docking predicted potential binding interactions between the two compounds and DRD2, which was confirmed by SPR and CETSA to be direct physical binding. Functional studies showed that both compounds rapidly induced DRD2 downstream ERK phosphorylation in SH-SY5Y cells; this effect was abrogated by sulpiride or DRD2 knockdown, indicating DRD2-dependent signaling activation. Conclusions: These findings identify DRD2 as a direct molecular target of salidroside and tyrosol and provide mechanistic insight into their dopaminergic regulatory effects. This study highlights the utility of CMap-guided target discovery combined with rigorous experimental validation for elucidating the molecular mechanisms of natural products. Full article

This review examines the current state of development and application of artificial intelligence (AI) tools for monitoring nutrition and physical activity in individuals with obesity, with a focus on the physiological complexity of energy balance and the role of chrono-nutrition. Energy intake and expenditure are dynamically coupled and circadian-regulated: meal timing and movement patterns influence insulin sensitivity, thermogenesis, and Non-Exercise Activity Thermogenesis within the same day. Traditional monitoring methods suffer from recall bias and low granularity, while isolated sensors operate in data silos, limiting accuracy. Effective solutions require multimodal, continuous, and temporally aligned data streams. Current AI models exhibit critical limitations in obesity-specific contexts: inaccurate gait and energy expenditure estimates due to biomechanical differences, dietary models underestimating glycemic variability, poor performance on mixed dishes, sauces, and culturally diverse foods, and a lack of validation against gold standards such as doubly labelled water (DLW) and weighed food records. This review proposes a paradigm shift toward obesity-specific AI design, including enriched datasets and multimodal integration. Physical activity monitoring faces similar challenges: systematic measurement bias in wearables, sensor placement issues, and algorithms trained on normal-weight cohorts. In the GLP-1/GIP era, if transparency, ethical safeguards, and equitable access are ensured, AI will act as a catalyst for personalized care, remote monitoring, trial optimization, and next-generation drug discovery. In conclusion, the integration of AI with rigorous validation procedures and inclusive sampling strategies is essential to achieve reliable, fair, and clinically relevant monitoring approaches for obesity management. Full article

Agricultural waste management is a strategic priority for reducing greenhouse gas emissions and transitioning to a circular bioeconomy. The thermochemical conversion of residual biomass into biochar offers a dual solution: waste recovery and the production of high-value functional materials. This narrative review summarizes the relationships among the composition of agricultural biomass, the conversion process parameters, and the structural properties of biochar, highlighting advanced modification strategies: controlled pyrolysis, physical and chemical activation, surface functionalization, and hybrid composite formation. Fundamental adsorption mechanisms, redox processes, and photocatalytic behavior are discussed, with a focus on applications in water treatment (heavy metals, dyes, emerging contaminants). The article proposes an integrative structure–property–performance framework and explores emerging concepts such as sequential use and post-use valorization of saturated biochar. Challenges related to reproducibility, industrial scaling, life cycle assessment, and carbon accounting are analyzed. Finally, a SWOT analysis is presented that highlights the potential of modified biochar as a strategic material in the circular economy. Full article

Autophagy-mitophagy pathways are essential for regulating immune homeostasis. However, their contribution to population-level chronic low-grade systemic inflammation (SI) remains unclear. The objective was to investigate the association between variation in the genes related to the autophagy-mitophagy pathways and SI, and to examine whether lifestyle factors modify this relationship. We conducted genome-wide association studies and gene-set enrichment analyses using data from the Korean Genome and Epidemiology Study (KoGES, n = 28,102) and UK Biobank (UKBB, n = 343,892). SI was defined as an elevated white blood cell count or high-sensitivity C-reactive protein. Using Core Longevity State Vectors (CLSVs)—gene sets representing immune-longevity pathways derived from comparative transcriptomic analysis—we tested six pathways and constructed a weighted genetic risk score (GRS) from significant variants. Gene–lifestyle interactions were examined with respect to major dietary and lifestyle factors. Among six CLSVs, only CLSV-2 (mitophagy and autophagy) showed a significant association with SI (β = 0.425, p = 0.008). Six single nucleotide polymorphisms (SNPs) in autophagy-mitophagy genes (INPP5D, ATG16L1, ATG7, AP3S1, OPTN, and VPS33A) were associated with SI in KoGES (p < 5 × 10⁻⁵), and ten SNPs (genes selected in KoGES plus RAB7A, ATG12, VPS33A, BECN1) reached genome-wide significance in UKBB (p < 5 × 10⁻⁸). A higher GRS was associated with increased SI in both cohorts and was strongly associated with metabolic syndrome (MetS, OR = 1.91 in KoGES; OR = 1.62 in UKBB). SI was characterized by neutrophilia with relative lymphopenia. In UKBB, significant gene–lifestyle interactions were observed for diet, physical activity, smoking, and alcohol (p < 0.01). Favorable lifestyle factors reduced SI most effectively in individuals with protective genotypes. Among individuals with a high vegetable/fruit intake, SI prevalence was 35%, 36%, and 38% in the negative-, zero-, and positive-GRS groups, respectively, compared with 36%, 45%, and 48% in the low-intake groups. In conclusion, genetic variations in autophagy-mitophagy pathways specifically influence SI. Genetic predisposition substantially modifies the benefits of lifestyle, underscoring the importance of integrating genetic and lifestyle factors in understanding SI susceptibility. Full article