Search Results (866)

To satisfy the demands of 5G communication and reliable data connectivity for unmanned aerial vehicles (UAVs), a novel two-element dual-band MIMO antenna with an inherent self-decoupling property based on orthogonal linear polarization diversity is proposed. Distinct from conventional designs relying on extra decoupling components, the antenna realizes isolation enhancement via coupled currents between annular strips and S-shaped strips without additional decoupling structures, representing the core design novelty. Fabricated on a low-cost 1.6 mm thick FR4 substrate, the antenna features compact overall dimensions of 60 mm × 30 mm × 1.6 mm, covering the 2.40–2.73 GHz ISM band and 3.38–3.63 GHz 5G Sub-6 GHz band. Measured results demonstrate that the reflection coefficient remains below −10 dB across the entire operating bands, with port isolation exceeding 27 dB for the 2.4 GHz band and 20 dB for the 3.5 GHz 5G band. The measured realized gain is 0.7–1.5 dB in the lower band and 2.3–2.9 dB in the upper band. The radiation efficiency, which is obtained exclusively from ANSYS HFSS 2025 R1 simulation, is higher than 90% for the lower band and over 80% for the upper band. The calculated envelope correlation coefficient (ECC) is less than 0.15 throughout the working bandwidth, which effectively suppresses inter-channel electromagnetic interference and mitigates channel fading caused by varying UAV attitudes to improve system channel capacity. Further verifications via epoxy encapsulation and co-simulation on an eight-rotor UAV platform prove slight frequency drift after packaging and installation, whereas its bandwidth and isolation still meet practical engineering requirements. Benefiting from a compact layout and omnidirectional radiation performance, the proposed low-cost MIMO antenna is convenient for conformal integration into a UAV fuselage, improving the practicability of UAV-aided emergency communication, equipment inspection and 5G network coverage. Full article

Background and Objectives: Routine laboratory markers may support diagnostic risk stratification for osteoporosis, but their incremental value beyond the Osteoporosis Self-Assessment Tool for Asians (OSTA) remains uncertain in referral-based practice. We evaluated whether serum uric acid, albumin, alkaline phosphatase (ALP), and systemic inflammatory indices improve prediction of DXA-defined osteoporosis beyond OSTA in postmenopausal women. Materials and Methods: This retrospective cross-sectional study included 3504 postmenopausal women referred for DXA between January 2021 and May 2025. Osteoporosis was defined as the lowest T-score ≤ −2.5 at the lumbar spine, total hip, or femoral neck. Sequential exclusions removed patients with chronic hepatobiliary disease, chronic systemic inflammatory disease, bone-active medication exposure, systemic glucocorticoid use, abnormal liver biochemistry, or missing required variables. Multivariable logistic regression assessed associations, and OSTA-based prediction models were internally validated using stratified 10-fold cross-validation. Results: Osteoporosis was present in 1660 women (47.4%). Higher BMI, uric acid, and albumin were independently associated with lower odds of osteoporosis, whereas ALP and calcium were associated with higher odds. OSTA alone achieved an AUC of 0.679. Adding uric acid, albumin, and ALP increased AUC to 0.695 and slightly improved the Brier score, with good calibration. Adding the systemic immune-inflammation index did not materially improve performance. Conclusions: Routine laboratory variables provided only modest incremental value beyond OSTA. The model should be interpreted as an exploratory referral-pathway prioritization approach, not as a standalone population-screening tool. It should not be used as a diagnostic surrogate for DXA or as a fracture-risk model. Full article

Background: Breastfeeding enhances infant and maternal health, but global breastfeeding rates remain suboptimal. Virtual reality (VR) emerges as a promising tool for breastfeeding education. The objective of this review was to assess the effectiveness of VR-based interventions on breastfeeding outcomes in pregnant and postpartum women. Methods: PubMed, Embase, Web of Science, Scopus, and CENTRAL were searched until 10 January 2026, for randomized controlled trials (RCTs) and quasi-experimental studies comparing VR-based interventions (immersive simulations, 360° videos, or head-mounted displays) with standard care or non-VR comparators in pregnant or postpartum women. Primary outcomes included breastfeeding self-efficacy, motivation, and breastfeeding technique (LATCH score). Secondary outcomes included exclusive breastfeeding rates, milk production, and maternal anxiety. Risk of bias was assessed using the RoB 2.0 and ROBINS-I tools for RCTs and non-RCTs, respectively. A random-effects meta-analysis was conducted, with results reported as mean differences (MD) or risk ratios (RR), along with 95% confidence intervals (CIs). Certainty of the evidence was assessed using the GRADE approach. Results: Five studies (4 RCTs and 1 quasi-experimental; n = 344) were included. VR improved prenatal breastfeeding self-efficacy (2 studies, MD: 13.93; 95% CI: 10.96–16.90), motivation (1 study, MD: 2.88; 95% CI: 1.66–4.10), and LATCH score (1 study, MD: 1.72; 95% CI: 1.37–2.07), and reduced time to breastfeeding initiation (1 study, MD: −22.4 min; 95% CI: −29 to −15.9), the certainty of evidence was low to very low for these outcomes. No significant effects were observed for postnatal self-efficacy, exclusive breastfeeding, or maternal anxiety. Formal assessment of publication bias could not be done. The small sample sizes for most outcomes, heterogeneity, the open-label nature of the trials, and the subjective nature of the outcomes should be considered when interpreting these results. Conclusions: VR-based interventions may improve process outcomes, such as prenatal breastfeeding self-efficacy, motivation, breastfeeding technique, and early breastfeeding initiation; the certainty of evidence is low to very low. Evidence for clinically important outcomes, including exclusive breastfeeding and maternal anxiety, remains inconsistent. Larger, well-designed RCTs are warranted before these interventions can be considered in routine practice. Full article

Lithium niobate on insulator (LNOI) has emerged as a promising platform for compact, low-loss phase modulators. The extant LNOI studies evaluate device performance almost exclusively through the Pockels effect, treating piezoelectric–photoelastic strain and thermo-optic drift as decoupled channels. Crucially, both mechanisms directly perturb the phase bias of a fiber-optic gyroscope (FOG), rendering them indispensable in sensing-oriented design. This work establishes a unified multiphysics model of an X-cut TFLN ridge phase modulator that self-consistently couples the electro-optic, piezoelectric–photoelastic, thermo-optic, and pyroelectric channels. The contributions of the four mechanisms are quantitatively decomposed under realistic FOG operating conditions, and the slab thickness, ridge-top width, and electrode gap are systematically optimized to balance modulation efficiency against environmental robustness. The co-optimization of the ridge geometry and electrode gap design maintains the EO overlap factor near 0.55, while reducing the half-wave voltage requirement. This results in a half-wave voltage length of V_πL = 1.65 V·cm at a 4.4 μm electrode gap. The optimized geometry and electrode gap (4.4 μm) are essentially temperature-independent: extracted from the Pockels modulation slope, V_πL remains stable at ≈1.65 V·cm (push–pull single-pass; within ~0.3%) across 25~85 °C. Furthermore, an externally imposed substrate temperature rise of 60 K (the upper end of the 25~85 °C FOG operating range) induces a mode-field-weighted thermal residual corresponding to approximately 27% of the Pockels modulation depth at an applied voltage of 5 V. The present study demonstrates that the DC-coupled operation of TFLN sensor-grade modulators is viable across the full FOG temperature range, without dedicated active temperature stabilization, and the residual thermal-bias offset is absorbed by the FOG’s standard closed-loop servo electronics. The results of the study provide quantitative design guidelines for high-performance, environmentally stable TFLN phase modulators in compact FOG systems. Full article

Mesenchymal stem cells (MSCs) are capable of self-renewal and differentiation into different cellular lineages, including adipocytes, chondrocytes, and osteocytes. This makes them strong candidates for repairing degenerative joint conditions such as osteoarthritis, in which native cartilage lacks repair capacity. The synovium is an attractive MSC source, with synovial MSCs demonstrating superior chondrogenic and proliferative potential compared to those from bone marrow or adipose tissue. The synovial joint is a heterogeneous environment, and MSCs can be isolated from the membrane, fluid, different histological subtypes of fibrous and adipose synovium, and different anatomical regions of synovium. This systematic review assesses whether MSCs from different synovial sources possess distinct properties. 2312 papers were identified, of which 10 met the inclusion and exclusion criteria and were included in the final review. Significant differences were identified in proliferation characteristics, immunophenotype and differentiation potential. Proximity to vasculature appeared to correlate with proliferation and differentiation potential, and MSCs from the synovial membrane may have superior proliferative characteristics compared to those from synovial fluid. More work is required to fully characterise these differences and understand their underlying molecular bases, but these findings may help inform the choice of MSC source for regenerative therapies. Full article

This study examines the schooling experiences of transgender students in Malta within the broader historical and sociocultural influence of the Catholic religion, focusing on how religious discourse shapes processes of inclusion and exclusion. Drawing on semi-structured interviews with transgender students, parents, educators, and school administrators, the findings reveal that Catholic doctrine and its presence within school contexts contribute to the erasure of transgender identities from early childhood onward. In contrast to ecclesiastical narratives that frame transgender identity as a form of “gender ideology,” participants’ accounts demonstrate that social and medical transitions function as critical strategies for survival, well-being, and self-recognition. Methodologically, the study employs qualitative thematic analysis informed by a critical anticolonial framework, enabling an interrogation of how religious authority intersects with colonial legacies to regulate gender and embodiment. The analysis further highlights tensions between the Catholic religion and contemporary human rights and ethical frameworks, particularly in relation to inclusion. The study concludes that if the Catholic religion is to retain relevance within school contexts, it must undergo a substantive ethical reorientation toward inclusivity, recognizing transgender embodiment and agency. In line with emancipatory pedagogical traditions, this entails reimagining the role of the Catholic religion as one that actively supports social justice, critical consciousness, and transformative practices of inclusion. Full article

Obesity poses a significant challenge to societies and healthcare systems worldwide. Metabolic bariatric surgery (MBS) has emerged as a proven primary intervention for severe obesity. This cross-sectional study investigated the interplay between sociodemographic and psychological factors and their influence on attitudes toward eating and body mass index (BMI) among candidates undergoing MBS. Recruitment took place over a period of more than five years. Sociodemographic and BMI data were collected, and psychological evaluations were conducted using standardized self-report questionnaires and clinical interviews. Data were analysed using Pearson and Spearman correlations, multiple linear regression, and bootstrapped mediation analysis. After exclusion of those who did not meet surgical suitability criteria, declined participation, or had incomplete data, the study included 515 participants. Significant associations were found between lower educational attainment, unmarried status, and higher BMI. High neuroticism was linked to increased BMI, depression, and anxiety. Resilience was moderately negatively correlated with anxiety and depressive symptoms and showed a small but statistically significant indirect (partial mediating) effect on the relationship between neuroticism and anxiety or depressive symptoms, although its small magnitude and the cross-sectional design preclude causal interpretation. The findings demonstrate that several variables play substantial roles in eating attitudes and influence BMI in this population. Notably, resilience emerges as a significant psychological factor. However, further research is warranted to fully elucidate its role and impact. These insights provide valuable guidance for refining preoperative assessments. Full article

Strategic Autobiographical Narrative is a pedagogical concept designating the deliberate and structured use of self-narration as a tool for learning, identity reconstruction and community engagement in contexts of social exclusion. Its strategic dimension lies in the conscious articulation of memory, language and transformative action: converting lived experience into pedagogical material capable of resignifying biographical trajectories, sustaining the openness of identity to new readings, and projecting possible futures from a critical and communal perspective. The concept operates through three synchronic registers: as temporal mediation, reopening biographical time where institutions tend to freeze it; as identity mediation, sustaining the mobility of the self against classificatory fixation; and as relational mediation, creating the conditions for the intersubjective event of recognition within a space of non-judgmental listening. Against the disciplinary institution’s tendency to fix identity under a single classificatory reading, the concept recovers the subject’s capacity to reinscribe their past within an open narrative and project a future not prefigured by their carceral present. Its operational methodology is structured around the ELCEN method—listen, read, converse, write and narrate—and deploys diverse autobiographical pathways oriented toward both the reconstruction of the subject’s identity and the community’s sensibilisation in the process of social reintegration. At its core lies a conviction safeguarded by oral tradition for millennia before anyone theorised it: to narrate is to coexist. Full article

Background: Digital exclusion remains a key barrier to equitable access to digital health services, particularly among individuals with visual impairment. Limited access to devices and digital literacy restricts participation in increasingly digital-first healthcare systems. This study aimed to evaluate the feasibility and exploratory service impact of a device recycling and digital inclusion pilot at a tertiary ophthalmic hospital. Materials and Methods: The six-month pilot at Moorfields Eye Hospital involved the refurbishment and distribution of donated electronic devices (laptops and mobile phones) alongside personalised digital literacy training delivered by trained volunteers. Twenty-two patients with visual impairment were enrolled; 18 completed the programme. Pre- and post-intervention questionnaires assessed digital engagement and confidence across key domains. Paired data were analysed using the Wilcoxon signed-rank test. Results: Across 216 item-level engagement responses, the number of responses indicating daily engagement increased from 31 to 49. Mean self-reported confidence scores improved from 3.1 to 5.1 out of 10 (Wilcoxon signed-rank test, V = 148, p = 0.0008; r = 0.81). Patients reported increased use of email, messaging, online forms, and General Practice (GP) appointment systems. Using secondary lifecycle data and modelled estimates, the reuse of refurbished laptops was associated with an indicative saving of approximately 5.3 tonnes of CO₂-equivalent emissions. Conclusions: This service evaluation suggests that a multi-component intervention combining device provision with tailored support may improve digital engagement and confidence among patients with visual impairment. These findings support the feasibility of integrating digital inclusion initiatives within ophthalmology services, with potential co-benefits for environmental sustainability. Full article

Background and Objectives: Professional ballet dancers endure high occlusal loads, increasing cervical defect prevalence. Conventional composites fail frequently under such conditions. This randomized clinical trial (RCT) compared 24-month performance of a polymer-infiltrated ceramic network (PICN, VITA Enamic) versus a self-curing bioactive composite (Stela) for cervical restorations. Materials and Methods: Twenty professional ballet dancers (40 cervical defects: 21 carious, 19 abfraction) were enrolled in a paired split-mouth RCT. Each received one PICN inlay and one self-curing composite restoration on two non-adjacent defects. Restorations were assessed at 6, 12, and 24 months using United States Public Health Service (USPHS) criteria (primary: marginal integrity) and a dye penetration test. Secondary outcomes included secondary caries, hypersensitivity, and Oral Health Impact Profile-14 (OHIP-14). Statistical tests: McNemar, Fisher’s exact, Kaplan–Meier, log-rank (α = 0.05). Results: At 24 months, marginal integrity (USPHS Alpha) was maintained in 91% of PICN restorations for carious defects and 89% for abfraction defects, compared to 70% and 50% for self-curing composite, respectively. No PICN restoration failed (0%). Self-curing composite failures were 20% (carious) and 30% (abfraction) (exploratory uncorrected p = 0.031; non-significant after correction). Dye penetration was lower for PICN in abfraction defects (11% vs. 60%, adjusted p = 0.048) but not in carious defects (9% vs. 30%, adjusted p = 0.317). Kaplan–Meier survival favoured PICN (log-rank p = 0.001); 24-month survival probability: PICN 100% (95% CI: 83–100%), self-curing composite 75% (95% CI: 55–95%). No secondary caries or serious adverse events occurred. Conclusions: PICN hybrid ceramic provided superior marginal integrity and zero failures over 24 months in cervical restorations of professional ballet dancers, outperforming the self curing composite. Within this high-risk population, PICN inlays are recommended for abfraction defects. However, because the study was conducted exclusively in professional ballet dancers, direct extrapolation to the general population should be made with caution. The self-curing composite may be considered for carious defects when light curing is problematic, but patients should be informed of higher failure risk. Longer studies are needed. Full article

Flowering plants have evolved a wide range of strategies to avoid self-fertilization. Although allogamy is common among members of the genus Vanilla, V. lindmaniana is widely known for its ability to self-fertilize, resulting in fruit-set rates of 83–100% following self-pollination. During studies of Vanilla species in the Brazilian Cerrado, populations of V. lindmaniana exhibiting low fruit set under natural conditions were identified. Here, the factors associated with low fruit set in these Cerrado populations were investigated through analyses of floral traits, field observations of pollinators, and experimental treatments designed to assess the breeding system. The flowers of V. lindmaniana are adapted for bird pollination. Although the species commonly produces fruits through facultative autogamy, flowers from the Cerrado populations exhibited a stigma that was separated from the anther by a large rostellum, preventing self-pollination. While autogamy is common in V. lindmaniana, completely allogamous populations may also occur. Such a mixed breeding system may provide advantages over reproductive systems based exclusively on autogamy. Furthermore, it may promote reproductive assurance in the event of pollinator decline or in environments where biotic pollination is irregular or absent. Full article

Cooperative localization for multi-Unmanned Aerial Vehicle (UAV) systems in GPS-degraded environments is often compromised by ideal-communication or uniform-quality assumptions. This paper proposes Quality-Aware Distributed State Estimation (QA-DSE), which combines three operational quality factors—freshness (Age of Information), accuracy (covariance trace), and link reliability (packet loss and channel noise)—into a single multiplicative score $q_{ij}$, modulated by a bounded history-consistency factor based on velocity-propagated self-trajectory continuity. A dual-constraint AND-gate on AoI and covariance trace excludes jointly degraded neighbors, while admitted neighbors are fused through a quality-squared information-matrix update under a stated bounded residual cross-correlation assumption, with an adaptive Covariance-Intersection fallback when the assumption is stressed. Under explicit observability, bounded-noise, bounded-quality, joint-connectivity, and bounded residual cross-correlation assumptions, we establish mean-square bounded error, exponential convergence at a rate inherited from the Kalman update operator, $O\left(n^3+nm\right)$ per-step complexity, Bounded-Input Bounded-Output (BIBO) stability, soft attenuation of single-axis faults (Theorem 4), and hard exclusion under joint AoI–covariance violation (Theorem 5). Under a Ultra-Wideband (UWB)-style cooperative-observation model, Monte Carlo experiments across five scenarios show 74.08–74.24% position- Root Mean Square Error (RMSE) reductions over Covariance Intersection, with the relative advantage held within 73.04–74.24% as the fleet scales from 3 to 50 UAVs; QA-DSE remains within 8.1% of an idealized no-cooperation single-vehicle Kalman filter, demonstrating graceful degradation rather than improvement above that floor. Per-step Central Processing Unit (CPU) time scales from 0.09 ms (5 UAVs) to 0.31 ms (50 UAVs); embedded validation is left to future work. Full article

Inaccurate prediction of shrinkage in self-compacting concrete (SCC) may result in underestimated cracking risk, increased permeability, serviceability deterioration, and reduced long-term durability of concrete structures. Although conventional empirical shrinkage models are widely used in engineering practice, their accuracy is often limited when applied to SCC mixtures with high paste volume, mineral admixtures, manufactured sand, and high-range water-reducing admixtures. Recent machine-learning-based models provide an alternative approach, but single learning algorithms may show limited robustness for small and heterogeneous datasets. In addition, random sample-level data splitting may introduce information leakage when shrinkage measurements obtained at different curing ages from the same mixture are assigned to both training and testing sets. To address these issues, this study develops a stacking-based ensemble learning framework for SCC shrinkage prediction using mixture proportions and curing age as input variables. A multi-source database containing 61 mixture designs and 448 data samples was established from published experimental studies. To obtain a more realistic assessment of model generalization, a mixture-level validation strategy was adopted, in which all age-dependent samples from the same mixture were assigned exclusively to either the training set or the testing set. Under this strategy, 358 data samples were used for model training and 90 data samples were used for independent testing. Four base learners, including multilayer perceptron (MLP), support vector regression (SVR), decision tree (DT), and gradient boosting decision tree (GBDT), were constructed and integrated through different ensemble configurations. The Stacking-SVR model achieved the best overall performance on the independent testing set, with a mean absolute error (MAE) of 13.6 με and a mean absolute percentage error (MAPE) of 7.5%. Compared with GBDT, Stacking-GBDT, and DT models, the proposed Stacking-SVR model reduced the MAPE by approximately 10.7%, 11.8%, and 35.3%, respectively. Stability and applicability analyses further indicate that the proposed framework can provide reliable shrinkage predictions within the investigated mixture and curing-age ranges. However, because the model was developed from a compiled database and does not explicitly include environmental variables such as relative humidity and temperature, its use should be limited to parameter ranges represented in the database. Overall, the results demonstrate that stacking ensemble learning combined with mixture-level validation offers a leakage-controlled and engineering-oriented approach for SCC shrinkage prediction. Full article

This study explores how altruistic tendencies translate into altruistic behavior during evacuation and investigates the dynamic roles of altruistic intent and competitive orientations. A total of 127 adults in a lifelong education program participated in a routine fire-drill evacuation conducted in a naturalistic setting, of whom 124 were retained for the final analyses after data screening and exclusion procedures. Situational altruistic behavior was assessed through a post-drill questionnaire, and the findings should therefore be interpreted as self-reported responses within an exercise-based evacuation context. In stepwise regression analysis, altruistic intent emerged as the strongest predictor of self-reported situational altruistic behavior. While altruistic tendency and desirable competition showed positive associations, excessive competition showed a negative association. Mediation and moderation analyses revealed that altruistic intent mediates the relationship between altruistic tendency and altruistic behavior but does not function as a moderator. In contrast, desirable competition operates as a negative moderator, weakening the influence of altruistic tendency on behavior despite its positive association in the regression analysis, while excessive competition exerts a direct negative effect on altruistic behavior. Although altruistic intent plays a key role in translating altruistic dispositions into helping behavior during evacuation, competitive pressures—whether excessive or efficiency-oriented—can constrain the expression of altruistic responses. More broadly, competition does not simply oppose altruism in evacuation contexts but reshapes how altruistic tendencies are expressed during emergency movement, highlighting the importance of managing competitive dynamics to support cooperative and life-saving behaviors. Full article

Background: Celiac disease (CeD) requires lifelong adherence to a strict gluten-free (GF) diet. During the COVID-19 pandemic, the prevailing clinical assumption was that food supply disruptions and dietary management difficulties would be the primary sources of patient distress. This exploratory cross-sectional study directly tested this assumption in an Italian CeD cohort. Methods: COVIMPACT is an exploratory observational, web-based study conducted in Italy (data collected: July–September 2024; participants retrospectively reported their experiences during the COVID-19 pandemic period 2020–2022). Participants with a confirmed CeD diagnosis were recruited through patient associations and online networks. A structured 26-item questionnaire addressed socio-demographic, nutritional, psychological, and healthcare-access domains. Descriptive statistics, chi-square bivariate analyses (Cramér’s V as effect size), and binary logistic regression were performed using R (v4.1) and Python. Results: Among 118 participants (78% female; median age 36 years; IQR 12–42), 27% reported self-perceived psychological distress. Against expectation, difficulties in accessing GF products and changes in gluten consumption showed no clear associations with distress. Instead, social exclusion showed the strongest association (Firth OR = 5.55, 95% CI: 1.80–17.09, p = 0.003), while reduced physical activity (Firth OR = 5.28, 95% CI: 1.86–14.99, p = 0.002, full model; Firth OR = 5.54, p = 0.001, reduced model) and negative economic impact (Firth OR = 3.77, 95% CI: 0.89–15.97, p = 0.071, trend) were additional associated factors. Female sex showed a non-significant trend (Firth OR = 4.21, p = 0.082). All estimates carry wide confidence intervals (EPV = 4.1) and should be treated as hypothesis-generating. Conclusions: These preliminary findings suggest that social exclusion and physical inactivity may be more strongly associated with self-perceived distress than dietary challenges in contexts where GF food access is structurally protected. Results are exploratory, hypothesis-generating, and should not be generalised beyond this selected Italian cohort. Full article