Search Results (1,626)

Natural polysaccharides are used for very different applications and are particularly exploited for preparing hydrogel materials. For instance, gels based on different carbohydrate polymers have been applied to remove unwanted materials from the surface of cultural heritages items. This study was focused on the preparation of novel physical hydrogels suitable for the cleaning of sensitive materials like wood and paper, i.e., to remove the soil from their surface. For this purpose, alginate biopolymer was used and ionically crosslinked with six different amines, in the presence of N-hydroxysuccinimide as a co-gelling agent. All the synthetized gel materials were characterized by a multianalytical approach, using different techniques such as FT-IR, thermal analysis, SEM-EDS, mechanical tests, and evaluation of moisture properties. All the results showed that the introduction of the investigated amines improved the original properties of alginate and provided good cleaning properties when applied to sensitive surfaces. Full article

Burnout among physical education (PE) teachers has become an urgent issue due to the profession’s distinctive physical, emotional, and social demands. This cross-sectional study examined the relationships between the Big Five personality traits and occupational burnout among secondary PE teachers in South Korea (N = 240). Burnout was measured using the Maslach Burnout Inventory–Human Services Survey, and personality traits were assessed with the Big Five Inventory. Correlation and hierarchical multiple regression analyses were conducted to explore the associations between personality traits and the three burnout dimensions: emotional exhaustion, depersonalization, and personal accomplishment. Neuroticism was positively associated with emotional exhaustion and depersonalization, whereas extraversion, agreeableness, and conscientiousness were negatively related to these dimensions. Personal accomplishment was positively linked to extraversion, agreeableness, conscientiousness, and openness, and negatively linked to neuroticism. Regression analyses confirmed that neuroticism was the strongest predictor of emotional exhaustion, while extraversion and agreeableness buffered depersonalization. Openness showed a positive association with depersonalization, suggesting a possible person–environment misfit in structured PE contexts. These findings indicate that personality profiles provide valuable insight into burnout vulnerability among secondary PE teachers and underscore the importance of personality-informed strategies to promote emotional well-being and sustainable professional growth. Full article

Table tennis (TT) is recognized for its accessibility, adaptability, and health benefits, making it suitable for physical education (PE). This study aimed to investigate the prevalence of TT implementation in primary school PE classes and explored associations with teacher characteristics and perceptions regarding injury risk, safety, inclusivity for students with disabilities or special educational needs, student engagement, and the educational value in PE curricula. A cross-sectional survey was conducted among 393 Spanish primary school PE teachers who completed the validated Racket Sports Attitude Scale (RSAS). Associations between teacher characteristics and TT use were tested using Pearson’s Chi-square, with effect sizes reported as Cramer’s V, Phi, and Somers’ D for ordinal variables. Additional analyses examined links between TT adoption and perceptions of injury risk, inclusivity, safety for pupils, ability to enhance engagement, and its educational value in PE. Only 11.7% of teachers reported using TT in PE classes. Implementation rates were not significantly different by sex but were associated with age (χ² = 27.2, p < 0.001, Somers’ D = 0.071) and teaching experience (χ² = 30.0, p < 0.001, Somers’ D = 0.099). TT use showed strong associations with perceptions of lower injury risk (Cramer’s V = 0.707), suitability for students with disabilities (0.712), special educational needs (0.715), safety (0.707), engagement (0.712), and educational value (0.716) (p < 0.001). Despite positive perceptions, TT is underutilized in PE curricula. Full article

Background: Insulin resistance (IR) is a key pathophysiological mechanism linking obesity, type 2 diabetes, and cardiovascular disease. Office workers, due to prolonged sedentary behavior and suboptimal lifestyle patterns, may be particularly susceptible to IR. However, large-scale studies in this occupational group remain scarce. Objective: To evaluate the prevalence of elevated IR risk using non–insulin-based indices—TyG, METS-IR, and SPISE—and their associations with sociodemographic and lifestyle factors in a large sample of Spanish office workers. Methods: This cross-sectional study included 82,020 office workers from Spain (2021–2022). IR risk was assessed using the TyG index, METS-IR, and SPISE, all derived from fasting biochemical and anthropometric data. Sociodemographic and lifestyle variables were self-reported using validated questionnaires. Sex-stratified analyses and multivariate logistic regression models were performed. Results: Men showed significantly higher odds of elevated IR risk compared to women across all indices: TyG (OR = 2.48, 95% CI: 2.37–2.60), METS-IR (OR = 1.47, 95% CI: 1.38–1.57), and SPISE (OR = 1.88, 95% CI: 1.78–1.99). Smoking, physical inactivity, and low adherence to the Mediterranean diet were independently associated with elevated IR scores, regardless of sex or age. Conclusions: A substantial proportion of office workers exhibit elevated insulin resistance risk, particularly among men and those with unhealthy lifestyles. TyG, METS-IR, and SPISE are valuable, low-cost tools for early IR detection in occupational health settings. These findings support the implementation of preventive strategies targeting modifiable behaviors in sedentary working populations. Full article

The understanding of coastal ecosystems regarding variability and resilience under climatic and anthropogenic forcing is reliant upon long-term ecological records. We examined the Helgoland Roads time series (1968–2017), which includes temperature, salinity, nutrients (nitrate, phosphate), and biological parameters (diatoms and Acartia spp.). We applied autocorrelation, multi-taper spectral analysis, and wavelet and cross-wavelet transforms to identify dominant temporal patterns and scale-dependent interactions. Sea surface temperature shows consistent long-term warming, and subdecadal (2–3-year) and decadal (7–8-year) oscillations reflect coherent patterns with the North Atlantic Oscillation and Arctic Oscillation. Salinity varied in anti-phase to Elbe River discharge at 6–7-year scales, reflecting control of seasonal, riverine freshwater, and salinity scenarios. Nutrients, as declining long-term trends (particularly phosphate), are associated with seasonal to multi-year variability linked to episodic discharge events. Biological parameters had strong annual periodicities reflective of bloom cycles but also variability above the annual limit. Diatoms responded to climatic, nutrient, and biological responses at the 3–5-year scale associated with this ecological context, particularly nitrate and phosphate; Acartia (spp.) respond to temperature, salinity, and resource availability (diatoms), reflecting climate/nutrient/trophic linkages. This study indicates that Helgoland Roads is represented as a multi-scale, non-stationary system, in which climate variability, riverine input, and ecological linkages are cascaded down to physical and chemical processes that structure biological communities. Spectral methods reveal scale-dependent synchrony and highlight the risks of trophic mismatch under climate change, emphasizing the importance of sustained high-frequency monitoring. Full article

This paper assesses the correlates of perceived well-being among young women aged 18 to 30 in five Balkan cities: Athens, Greece; Plovdiv, Bulgaria; Bucharest, Romania; Nis, Serbia; and Shtip, North Macedonia, by integrating urban, travel behavioural, and socio-economic features. A cross-sectional survey was employed using standard questionnaires including the Warwick–Edinburgh Mental Well-being Scale (WEMWBS), the short version of the International Physical Activity Questionnaire (IPAQ), and the adapted ALPHA environmental questionnaire. To answer research questions, linear regression models were developed to analyse predictors of well-being at both regional and national levels. Results show that neighbourhood and mobility features play a significant role in shaping mental well-being. Access to walkable sidewalks, green spaces, mixed land-use structure, and attractive local facilities (e.g., shops, recreational centres in the neighbourhood) were consistently associated with higher levels of well-being. Conversely, perceived insecurity, especially at night or regarding bicycle theft, significantly reduced well-being. Physical activity levels, particularly days of walking and vigorous activity, showed strong positive associations, underscoring the role of active lifestyles in promoting mental health. Socio-economic variables, including financial status, relationship status, and work status, were also found to be linked to perceived well-being. Cycling-related variables may affect Greek well-being up to 16.5 times. Perception of crime during the night may negatively affect both Bulgarian and Serbian well-being (up to 10 times), while Romanian well-being is mostly affected by the existence of shopping facilities. Finally, the most impactful factors for well-being in North Macedonia refer to cycling safety and scooter accessibility. Full article

Understanding causal structures in data center cooling systems is essential for energy optimization and fault detection. Conventional methods based on physical connectivity ensure interpretability but often miss latent interactions, while Granger causality captures predictive dependencies yet suffers from sensitivity to data quality and ambiguous directionality. To overcome these limitations, we propose a hybrid causal discovery framework that integrates physics-informed priors with Granger-inspired predictive modeling. A key innovation is the use of a relative increment formulation, which focuses on the proportional change in observables immediately after control actions. This design filters out long-term seasonal trends and emphasizes short-term, actionable effects. Applied to a large-scale dataset from a real data center, the framework successfully recovers known control–feedback links, identifies consistent control–temperature relationships, and reveals cross-unit influences overlooked by traditional approaches. By combining physical priors for directionality with predictive causality for flexibility, the method yields a causal network that is both interpretable and robust, offering a principled basis for decision-making in energy-critical infrastructures. Full article

Hydrogels are three-dimensional polymeric networks capable of retaining large amounts of water. Polyvinyl alcohol (PVA)-based hydrogels exhibit autonomous self-healing through reversible physical interactions within the hydrogel matrix, including hydrogen bonding, crystallite formation, and dynamic crosslinking. However, their long self-healing times and low strength limit practical application. Herein, we propose an effective strategy to simultaneously achieve excellent self-repairing and high mechanical strength. The tensile strength of uncut PVA hydrogel was 1.21 MPa; after cutting and rejoining for 12 h at room temperature (RT), it recovered 94% of the original uncut strength. To accelerate self-healing, hydrogels were treated at 40, 50, and 60 °C for 20, 40, and 60 min. Under optimal conditions (60 °C for 60 min), 96% recovery was achieved. Mechanical properties were further improved by silica (Si) nanoparticles of various sizes (~12, ~85, and ~200 nm). Si-loaded hydrogels, particularly ~12 nm, demonstrated increased mechanical properties, reaching a tensile strength of 1.45 MPa and a self-healing recovery of 95% of the uncut hydrogel strength. Ultra-small (~12 nm) Si nanoparticles enhanced the overall mechanical properties by acting as an efficient nucleating agent and did not hinder the existing self-healing mechanism. The developed strategy will pave the way for novel techniques in hydrogel research and will advance applications such as soft robotics and wound dressing. Full article

Objectives: The present study aimed to examine the relationships between screen time (ST), sleep time (SLT), physical activity engagement (PA), Mediterranean diet (MD) adherence, body mass index (BMI), self-esteem (SE) and academic performance (AP) in high-socioeconomic-status (SES) school-aged youth in southern Spain. Methods: A descriptive, comparative, non-experimental and cross-sectional research study was conducted with a total sample of 217 Spanish students (13.88 ± 1.32). Structural equation modelling (SEM) was employed to analyse relationships between study variables as a function of sex. Results: SLT was positively associated with MD adherence and negatively related with BMI. Both PA and MD adherence were positively linked to SE, whilst MD adherence and SE were also positively related to AP. Regarding sex differences, ST was a stronger determinant among girls, showing negative associations with PA (β = −0.378; p < 0.001) and MD adherence (β = −0.315; p < 0.001), with this pattern not being observed in boys. PA was positively associated with SE in both sexes, but more strongly in boys (β = 0.332; p < 0.001) than in girls (β = 0.190; p = 0.034). In girls, both MD adherence (β = 0.295; p < 0.001) and SE (β = 0.224; p = 0.008) were positively associated with AP, with these associations not being found in boys. Conclusions: The findings underscore the complex interplay between lifestyle behaviours, psychosocial factors, and AP in school-aged youth. Regardless of SES, interventions should focus on reducing ST, promoting PA and MD adherence, and enhancing SE whilst considering sex-specific patterns. Full article

Background/Objective: In the context of global aging, maintaining daily habits such as adequate nutrition and regular exercise are essential to achieve healthy aging. Therefore, the preservation of swallowing and physical functions is fundamental. Jaw-opening force, an important swallowing function, is linked to physical function. Daily health behaviors are shaped by decision-making biases, which influence decision-making. Individuals with high procrastination tendencies may be less likely to engage in health-promoting behaviors, potentially leading to functional decline. While such tendencies are associated with general health behaviors, little is known about their associations with swallowing and physical functions among older adults. The objective of this study was to examine the associations between decision-making biases and swallowing and physical functions in community-dwelling older adults. Methods: A questionnaire survey was conducted to collect basic information and assess decision-making biases. The jaw-opening force (swallowing function) and grip strength (physical function) were measured. Associations of decision-making biases with jaw-opening force and grip strength were examined using multivariable linear regression analysis. We further conducted sex-stratified sensitivity analyses. Results: This cross-sectional study targeted 107 community-dwelling older adults. There was a significant negative association between procrastination tendency and jaw-opening force (B = −0.715, p = 0.005), and grip strength (B = −1.552, p = 0.003), indicating that individuals with a propensity for procrastination had lower jaw-opening force and grip strength. Conclusions: Procrastination tendency may be used as an indicator to detect swallowing and physical functions. Moreover, incorporating this modifiable factor to promote behavior change may prevent functional decline. The study results highlight the significance of considering individuals’ decision-making biases—particularly procrastination tendency—in clinical settings. Full article

This cross-sectional study examined whether physical activity (PA) in nature and overall PA mediate the relationship between nature exposure and quality of life (QoL) across four domains: physical, psychological, social, and environmental, while controlling for perceived financial security. A cross-sectional online survey was conducted, involving 924 adults aged 18 to 79 years (m = 40.0, SD = 12.4); 73.6% were women. Nature exposure, PA in nature, overall PA, and financial security were assessed using nationally language-validated self-report scales and questionnaires. QoL was measured using the WHOQOL-BREF, covering four domains. Mediation models were tested using the regression-based PROCESS macro with 5000 bootstrapped samples. Nature exposure was positively associated with both types of PA and all QoL domains, while financial security was positively linked to PA in nature. PA in nature significantly mediated the relationship between nature exposure and psychological QoL, but not the other domains. In contrast, overall PA was a significant mediator across all QoL domains. In all models, nature exposure and financial security remained significant direct predictors of QoL. Bootstrapped confidence intervals confirmed the significance of indirect effects through overall PA for physical, psychological, social, and environmental QoL. While nature exposure was independently associated with better QoL, this relationship was partly explained by PA. These findings highlight the broader role of PA in linking nature exposure to QoL and underscore the importance of supporting active lifestyles in nature to enhance QoL. To achieve a higher QoL, policies that increase access to and opportunities for nature-based physical activity should be implemented. Full article

Extracellular particles (EPs), an umbrella term encompassing membrane-enclosed extracellular vesicles (EVs) and non-vesicular extracellular particles ([NVEPs], previously described as extracellular condensates [ECs]) contain a complex cargo of biomolecules, including DNA, RNA, proteins, and lipids, reflecting the physiological state of their cell of origin. Identifying proteins associated with EPs that regulate host responses to physiological and pathophysiological processes is of critical importance. Here, we report the findings of our study to gain insight into the proteins associated with NVEPs. We used samples from human semen, the rat brain, and the rhesus macaque (RM) brain and blood to assess the physical properties and proteome profiles of NVEPs from these specimens. The results show significant differences in the zeta potential, concentration, and size of NVEPs across different species. We identified 938, 51, and 509 total proteins from NVEPs isolated from rat brain tissues, RM blood, and human seminal plasma, respectively. The species-specific protein networks show distinct biological themes, while the species-conserved protein interactome was identified with six proteins (ALB, CST3, FIBA/FGA, GSTP1, PLMN/PLG, PPIA) associated with NVEPs in all samples. The six NVEP-associated proteins are prone to aggregation and formation of wide, insoluble, unbranched filaments with a cross-beta sheet quaternary structure, such as amyloid fibrils. Protein-to-function analysis indicates that the six identified proteins are linked to the release of dopamine, immune-mediated inflammatory disease, replication of RNA viruses, HIV-HCV co-infection, and inflammation. These interesting findings have created an opportunity to evaluate NVEPs for their potential use as biomarkers of health and disease. Additional in-depth studies are needed to clarify when and how these proteins sustain their physiological role or transition to pathogenic roles. Full article

Background: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system, which can lead to physical and cognitive disability, fatigue, depression, and sleep disturbance, all of which may impair quality of life (QoL). While the physical disability is widely known to influence the QoL, the relative contributions of cognitive impairment, fatigue, and sleep quality remain incompletely defined. Objectives: To evaluate the relationship between QoL, physical and cognitive disability, sleep quality, fatigue, and depression in people with MS (PwMS), and to explore phenotype-specific differences between relapsing and progressive forms. Methods: In this monocentric cross-sectional study, 112 PwMS underwent physical assessment (EDSS, MSFC), cognitive testing (SDMT, PASAT, MoCA, MMSE), and QoL evaluation (MSIS-29, EQ-5D, EQ-VAS, MSNQ). A subgroup of 29 patients also completed the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Modified Fatigue Impact Scale (MFIS), and Beck Depression Inventory (BDI). Correlation and group analyses were performed. Results: Progressive MS patients showed greater physical disability (mean EDSS 5.8 vs. 2.6, p < 0.001), poorer cognitive performance, and lower QoL. Across the cohort, QoL strongly correlated with physical disability (EDSS) and cognitive performance (SDMT), with physical measures showing stronger associations. In relapsing MS, physical and cognitive impairment were linked to reduced QoL, whereas in progressive MS, physical disability predominated. In the sleep subgroup, poorer PSQI scores, longer sleep latency, and daytime sleepiness correlated with higher fatigue (MFIS), depressive symptoms (BDI), and reduced QoL (MSIS-29, EQ-5D). Conclusions: QoL in MS reflects the combined burden of physical disability, cognitive impairment, fatigue, depression, and poor sleep quality, with phenotype-specific patterns. While physical disability is the main QoL determinant in progressive MS, cognitive deficits with slowed processing speed play an important role in relapsing MS. Comprehensive, multidimensional assessment, including sleep and mood screening, may support individualized management strategies in MS. Full article

Background/Objectives: Self-perceptions in childhood shape motivation, behavior, and well-being; however, their relationship to motor competence and physical fitness remains unclear. We tested whether physical fitness mediates the association between motor competence and domain-specific self-perceptions in middle childhood. Methods: In a school-based sample of 100 ten-year-olds (59 girls, 41 boys; 3 exclusions ≤ 5th MABC-2 percentile), children completed MABC-2 (motor competence), EUROFIT (physical fitness), and SPPC (self-perceptions). Principal component analysis of the nine EUROFIT tests yielded two factors: Motor Fitness (agility/endurance/flexibility/muscular endurance) and Strength/Size (handgrip and BMI). Parallel mediation models (MABC-2 → [Motor Fitness, Strength/Size] → SPPC) were estimated with maximum likelihood and 5000 bias-corrected bootstrap resamples. Benjamini–Hochberg FDR (q = 0.05) was applied within each path family across the six SPPC domains. Results: In baseline models (no covariates), Motor Fitness → Athletic Competence was significant after FDR (β = 0.263, p = 0.003, FDR p = 0.018). Associations with Scholastic (β = 0.217, p = 0.039, FDR p = 0.090) and Social (β = 0.212, p = 0.046, FDR p = 0.090) were positive but did not meet the FDR threshold. Strength/Size showed no associations with any SPPC domain. Direct effects from MABC-2 to SPPC were non-significant. Indirect effects via Motor Fitness were minor and not supported after FDR (e.g., Athletic: β = 0.067, p = 0.106, 95% CI [0.007, 0.174], FDR p = 0.251). In BMIz-adjusted sensitivity models, Motor Fitness remained significantly related to Athletic (β = 0.285, p = 0.008, FDR p = 0.035), Scholastic (β = 0.252, p = 0.018, FDR p = 0.035), and Social (β = 0.257, p = 0.015, FDR p = 0.035); MABC-2 → Motor Fitness was β = 0.235, p = 0.020. Some paths reached unadjusted significance but were not significant after FDR correction (all FDR p-values = 0.120 for indirect effects). Conclusions: Functional Motor Fitness, but not Strength/Size, showed small-to-moderate, domain-specific links with children’s Athletic (and, when adjusting for adiposity, Scholastic/Social) self-perceptions; mediated effects were small and not FDR-supported. Findings highlight the salience of visible, functional performances (e.g., agility/endurance tasks) for children’s self-views and support PE approaches that foster diverse motor skills and motor fitness. Because the study is cross-sectional and BMI-adjusted analyses are presented as robustness checks, caution should be exercised when interpreting the results causally. Full article

The article presents the results of a study of the possibility of using heat-treated ethylene-vinyl acetate copolymer (EVA) as a thermoplastic modifier in a photosensitive composition based on tert-butyl acrylate (tBA). The use of such a modifier in 3D printing compositions is important for improving their physical and mechanical properties at low temperatures. An attempt was also made to use EVA as a polymer chain brancher. The molecular structure of the components and their compositions, rheology, curing kinetics, and phase organization of photocured systems were studied using FTIR and NMR spectroscopy, spectrophotometry, rheometry, Photo-DSC, and scanning electron microscopy. It was found that heat treatment of EVA allows the formation of single C=C bonds in macromolecules, which are necessary for a potential crosslinking agent with tBA. It was shown that EVA effectively functions as a thickener and modifier: with an increase in the modifier concentration, the nature of the composition flow changes from Newtonian to pseudoplastic, the rate of the photochemical polymerization reaction decreases, and the degree of conversion of the system decreases. However, the formation of a heterogeneous phase structure and the absence of a continuous spatial network of chemical bonds prevent the use of EVA simultaneously as a functional additive and crosslinking agent. Full article