Search Results (3,918)

Interactions between the chemical compounds contained in mouthwashes and the components of dental composites may significantly influence their functional properties. The study investigated the effect of mouthwashes on the mechanical properties and color stability of a restorative nanocomposite. Twelve mouthwashes characterized by different chemical compositions were selected and distilled water was used as a control. Composite specimens were conditioned for 24 h, 48 h, and 72 h. Changes in microhardness (HV), compressive strength (CS) and diametral tensile strength (DTS) were evaluated. In addition, color changes were analyzed using spectrophotometric measurements. The results demonstrated a significant decrease in both HV and CS after exposure to mouthwashes, depending on their composition and immersion time. DTS values remained stable. Color changes were statistically significant; however, the values observed remained within clinically acceptable limits from an esthetic standpoint. The loss of mechanical properties was generally most pronounced during the initial period of contact between the mouthwashes and the tested material, which should be considered as unfavorable. The influence of ethanol molecules on mechanical properties was not stronger than that of many ethanol-free solutions. The frequently suggested correlation between changes in composite material hardness and the pH values of mouthwashes was not confirmed. Full article

This study developed an active packaging material by incorporating tea tree oil (TTO)-loaded lotus stalk biochar (BC@TTO) into a chitosan (CS) matrix. Biochar was prepared from lotus stalks via pyrolysis at 600 °C and characterized, revealing a mesoporous structure with a specific surface area of 35.9 m²/g. Adsorption studies demonstrated that BC exhibited high affinity for TTO, following pseudo-first-order kinetics and the Langmuir isotherm model, with a maximum adsorption capacity of 295.6 mg/g. Chitosan-based composite membranes with varying BC@TTO contents (1–7 wt%) were fabricated by solution casting. The incorporation of BC@TTO significantly enhanced the tensile strength, elongation at break, barrier properties (water vapor and oxygen), and antioxidant/antibacterial activities of the membranes, with optimal performance observed at 3 wt% loading. However, higher loadings led to filler aggregation, reduced transparency, and compromised mechanical properties. In vitro release studies indicated that TTO release followed the Avrami model, suggesting a diffusion-controlled mechanism. Preservation tests on blueberries showed that the CS-3BC@TTO membrane effectively reduced weight loss and maintained fruit quality during storage. This work presents a promising strategy for designing bioactive packaging materials with sustained release functionality for food preservation applications. Full article

Background/Objectives: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Long COVID (LC) are complex multisystem conditions with significant functional disability. Many patients experience symptoms of orthostatic intolerance, which can be captured in some cases as Orthostatic Hypotension (OH) or Postural orthostatic Tachycardia Syndrome (PoTS) on objective testing. Conservative treatments are recommended for first-line symptom management, but there is a lack of efficacy evidence. This study aims to assess the feasibility of an 8-week clinically supervised, personalised Dysautonomia Management Protocol (DMP) in a cohort of ME/CFS and LC patients with subjective and objective evidence of orthostatic intolerance (dysautonomia). Methods: ME/CFS and LC patients with objective dysautonomia on the 10 min active Lean Test (LT) were recruited to an 8-week DMP, with interventions introduced cumulatively every two weeks. Interventions included increasing daily fluid intake to 3 litres and salt intake to 10 g, pacing to avoid crashes and calf activation. Baseline and weekly data collection included the LT, Composite Autonomic Symptom Score questionnaire (COMPASS-31) and Yorkshire Rehabilitation Scale (YRS). Results: Sixteen participants completed the 8-week program, five discontinued during the program, and one was withdrawn following a severe crash. The COMPASS-31 improved by 7.7 points from week 1 to week 8 (p = 0.045), with a medium Cohen’s d effect size of 0.55. For the same period, there was a non-significant (p = 0.16) improvement in the YRS symptom severity score by 2 points. Comparing the final two weeks of the program with the first two weeks, mean heart rate during the LT decreased by 4.8 beats per minute (p = 0.032), with a medium Cohen’s d effect size of 0.44. Adherence to the interventions was highly variable, with none of the patients able to fully employ all four recommendations. Conclusions: The results suggest that targeted conservative interventions could influence autonomic function and symptom reduction. However, the magnitude of change was limited, and statistical significance might not necessarily relate to a clinically significant improvement in symptoms. Full article

The growing demand for lightweight and cost-effective vehicular armor systems has driven the development of hybrid multilayer architectures capable of improving ballistic resistance while reducing structural mass. This study evaluates the ballistic performance of a functionally graded aluminum–Kevlar–cabuya fiber composite system designed for vehicle door protection. A combined experimental–numerical framework was implemented, integrating ballistic testing according to NIJ 0108.01 and STANAG 4569 Level 1 standards with explicit dynamic finite element modeling based on the Johnson–Cook constitutive formulation for AA5083-H32. The multilayer configuration (25 mm aluminum/15 mm Kevlar 29/15 mm treated cabuya composite) successfully resisted 9 × 19 mm and 5.56 × 45 mm FMJ threats without complete perforation. Numerical simulations predicted a maximum back-face deformation of 52.75 mm under 9 mm impact, showing strong agreement with the experimental measurements (mean ± SD, n = 3). Post-impact microstructural analysis revealed a sequential energy dissipation mechanism governed by plastic deformation of the aluminum layer, Kevlar fibrillation and fragment retention, and controlled micro-cracking within the treated cabuya backing layer. With an areal density of 140.87 kg/m², the system achieved a 19% weight reduction compared with conventional steel-based solutions. These results demonstrate the structural-scale feasibility of integrating treated cabuya fiber composites as active energy redistribution layers in certified hybrid vehicular armor systems. Full article

Fused deposition modeling (FDM) of carbon fiber-reinforced polycarbonate (PC-CF) is increasingly used in medical applications due to its excellent strength-to-weight ratio and adaptability for custom geometries. However, sterilization is a critical step that may compromise the structural integrity of polymer composites. This study investigates the effects of two low-temperature sterilization methods—ethylene oxide (EO) and hydrogen peroxide vapor (HP)—on the mechanical, thermal, and viscoelastic properties of FDM-printed PC-CF parts. Characterization included tensile, impact, and hardness tests; thermomechanical analysis (TMA); and dynamic mechanical analysis (DMA). EO sterilization resulted in approximately 20% reduced elongation at break and lower glass transition temperature, indicating a loss of ductility and thermal stability. HP-treated samples showed reduced stiffness (16% in Young modulus) but increased Tg and reduced thermal expansion, suggesting improved dimensional stability. DMA results confirmed distinct viscoelastic behavior between treatment types. These findings provide evidence for selecting appropriate sterilization protocols for FDM-manufactured PC-CF components used in functional medical devices. Full article

Small fiber neuropathy (SFN) is an early and common manifestation of diabetic polyneuropathy in type 2 diabetes mellitus (T2DM), often presenting with pain, dysesthesia, and autonomic dysfunction. Conventional diagnostic methods primarily assess large nerve fibers and may miss early small fiber damage, while skin biopsy, though considered the reference standard, is invasive. Corneal confocal microscopy (CCM) offers a rapid, noninvasive alternative for visualizing and quantifying small nerve fiber pathology in vivo. This was a monocentric observational study including 80 adults with T2DM (18–75 years), conducted at Alexandrovska Hospital, Sofia. Peripheral neuropathy was evaluated using a modified Neuropathy Disability Score and CCM-derived corneal nerve fiber density (CNFD), length (CNFL), and branching density (CNBD). Autonomic and sudomotor function were assessed by cardiovascular reflex tests and Sudoscan. Additional measures included vibration perception threshold, carotid intima–media thickness, body composition analysis, and laboratory parameters. Autonomic neuropathy was present in 66.7% and peripheral neuropathy in 57.5% of participants. Affected patients were older and had higher BMI and longer diabetes duration; peripheral neuropathy was additionally associated with higher HbA1c. Corneal nerve parameters negatively correlated with diabetes duration, HbA1c, intima–media thickness, and vibration threshold. Patients with diabetic retinopathy showed significantly reduced CNFD and CNFL. ROC analysis demonstrated significant discriminative ability of the HRV index for identifying peripheral neuropathy and of CNFD for detecting sudomotor dysfunction. These findings support CCM as a valuable, noninvasive marker of small fiber damage, closely linked to metabolic control, vascular impairment, and both sensory and autonomic dysfunction in T2DM. Full article

This study maps European countries’ resilience to cognitive warfare by developing a cross-national composite measure. The framework integrates three pillars: information ecology, institutional-digital capacity, and socioeconomic context—drawing on a systemic perspective linking social structures to societal functions. Publicly available secondary indicators are compiled from online sources for EU (European Union) and EEA (European Economics Area) states. The dataset is examined through descriptive analysis, association testing, multivariate modelling, dimensionality reduction to derive a composite resilience score, and unsupervised clustering to produce a country typology. Indicators capture governance effectiveness, e-government maturity, public-sector AI (Artificial Intelligence) readiness, digital connectivity and infrastructure, media freedom and broader media-ecosystem quality, academic freedom, and socioeconomic vulnerabilities such as youth labour market exclusion. Results show that resilience aligns most strongly with institutional capacity and governance performance; a healthy ecology acts as a reinforcing layer. Digital infrastructure appears necessary but insufficient without capable, credible institutions and coherent public policy. Socioeconomic vulnerabilities tend to erode resilience and heighten susceptibility to hostile cognitive influence. The study concludes that policy efforts should prioritise governance integrity and effectiveness, end-to-end digital government, responsible public-sector AI capability, and safeguards for media and academic autonomy, alongside measures that improve youth inclusion. Full article

With the expansion of global oil and gas resource exploration and development into deep and ultra deep layers, the efficient development of deep carbonate rock fracture cave reservoirs has become the key to ensuring energy security. However, this type of reservoir commonly faces high temperatures, high salinity, and extremely strong heterogeneity, leading to increasingly severe water content spikes caused by dominant water flow channels. Although the existing traditional inorganic plugging agent has good temperature resistance, it has the defects of great brittleness and easy cracking, while the organic polymer gel is prone to degradation failure under high temperature and high salt environments. In order to solve the above problems, a new biochar-enhanced inorganic composite gel system was constructed by using biochar prepared from agricultural and forestry waste pyrolysis as a functional enhancement component. Through rheological testing, high-temperature and high-pressure mechanical experiments, long-term thermal stability evaluation, and dynamic sealing experiments of fractured rock cores, the reinforcement and toughening laws and rheological control mechanisms of biochar on inorganic matrices were systematically studied. Research has found that a biochar content of 0.5 wt% can significantly improve the micro pore structure of the matrix. By utilizing its micro aggregate filling effect and interfacial chemical bonding, the compressive strength of the solidified body can be increased to over 2 MPa, and there is no significant decline in strength after aging at 130 °C for 30 days. More importantly, the unique “adsorption slow-release” mechanism of biochar effectively stabilizes the hydration reaction kinetics at high temperatures, extending the solidification time of the system to 15 h and solving the problem of flash condensation in deep well pumping. This system exhibits excellent shear thinning characteristics and crack sealing ability, and presents a unique “yield reconstruction” toughness sealing feature. This study elucidates the multidimensional strengthening mechanism of biochar in inorganic cementitious materials, providing technical reference for stable oil and water control in deep fractured reservoirs. Full article

Wheeled multifunctional motorized crossing frames represent a new type of crossing equipment for high-voltage transmission line construction. The initial design is too conservative, having a large safety margin and high material redundancy. Therefore, it is necessary to study a lightweight design version. However, as the structure constitutes an assembly consisting of multiple components, it also exhibits relatively high complexity. In a lightweight design, optimizing multi-component and multi-size parameters can lead to structural interference and separation, seriously affecting the smooth progress of design optimization. Therefore, an optimization design method of a multi-parameter complex assembly structure is proposed to solve this problem. Firstly, the typical stress conditions of the wheeled multifunctional motorized crossing frame were analyzed using its structural model. Then, a finite element model of the beam was established in ANSYS 2021 R1 Workbench, and the mechanical characteristics were analyzed. The results show that the arm support is the key load-bearing component and has significant optimization potential. Subsequently, functional mapping relationships were established among the 14 dimension parameters of the arm support, reducing the number of design variables to six and successfully avoiding component separation or interference during optimization. Through global sensitivity analysis, the height, thickness, and length of the arm body were screened out as the core optimization parameters from six initial design variables. Then, 29 groups of sample points were generated via central composite design (CCD), and a response surface model reflecting the relationships among the arm body’s dimensional parameters, total mass, maximum stress, and maximum deformation was established using the Kriging method. Leave-one-out cross-validation (LOOCV) was performed, and the coefficients of determination (R²) for model fitting were all higher than 0.995, indicating extremely high prediction accuracy. Taking mass and deformation minimization as the optimization objectives, the MOGA algorithm was adopted to perform multi-objective optimization and determine the optimal engineering parameters. Simulation verification was conducted on the optimized arm support, and an eigenvalue buckling analysis was performed simultaneously to verify structural stability. Finally, the proposed optimization method was experimentally verified through mechanical performance tests of the full-scale prototype under symmetric and eccentric loads. The results show that the mass of the optimized arm support is reduced from 217.73 kg to 189.8 kg, with a weight reduction rate of 12.8%. Under an eccentric load of 70,000 N, the maximum deformation of the arm support is 8.9763 mm, the maximum equivalent stress is 314.86 MPa, and the buckling load factor is 6.08, all of which meet the requirements for structural stiffness, strength, and buckling stability. The maximum error between the experimental and finite element results is only 4.64%, verifying the accuracy and reliability of the proposed method. The proposed optimization methodology, validated on a wheeled multifunctional motorized crossing frame, serves as a transferable paradigm for the lightweight design of complex assemblies with coupled dimensional constraints, thereby offering a general reference for the structural optimization of multi-component transmission line equipment, construction machinery, and other multi-component engineering systems. Full article

Endurance performance is influenced by age- and sex-specific physiological determinants, while emerging evidence indicates an increasing prevalence of Relative Energy Deficiency in Sport (REDs) among both young and master endurance runners. Despite its clinical relevance, limited data exist on how long-term endurance training modulates REDs risk, skeletal muscle characteristics, and physiological ageing in comparison with inactive individuals. Methods: This cross-sectional study protocol will examine 112 participants stratified by sex, age (20–35 vs. 65–80 years), and training status (endurance runners vs. inactive controls). Cardiorespiratory fitness (VO₂max) is defined as the primary outcome. Secondary outcomes include body composition, musculoskeletal function, biochemical and hormonal markers, and REDs-related screening variables. Assessments will comprise cardiorespiratory testing, DXA-based bone and body composition analysis, isometric knee dynamometry, mobility testing, validated REDs screening tools (LEAF-Q, LEAM-Q, and IOC REDs CAT2), seven-day dietary and training monitoring, venous blood sampling, and skeletal muscle biopsies from the vastus lateralis. Results: This study is designed to generate an integrated overview of physiological, nutritional, metabolic, and muscle-cell characteristics across sex-, age-, and training-specific subgroups. Conclusions: This protocol provides comprehensive insight into how ageing and sex influence endurance physiology and REDs susceptibility and whether long-term endurance training preserves functional capacity across the lifespan. The findings aim to support evidence-based screening, prevention, and targeted interventions for REDs in endurance athletes. Full article

The transition toward sustainable aviation fuels requires dedicated experimental platforms capable of evaluating alternative fuels under realistic propulsion conditions. This study presents the development and laboratory experimental validation of a modular testing installation designed for sustainable fuels derived from plastic waste pyrolysis, intended for aerospace engine applications. The proposed system is conceived as an integrated small-scale gas turbine assembly that reproduces the functional characteristics of a jet engine and enables controlled laboratory investigations of dynamic behavior, combustion stability, and performance. The installation comprises a compressor, annular combustion chamber, and turbine mounted on a common shaft, along with a fully autonomous fuel supply system equipped with electronically controlled pumping, safety devices, and thermal conditioning of the fuel mixture via an attached Stirling engine. Combustion processes are continuously evaluated using an exhaust gas analysis system to assess fuel composition and combustion quality, while a high-speed camera operating at 50,000 fps enables detailed visualization of flame stability. Operating parameters, including temperatures, pressures, rotational speed, mass flow rates, and thrust, are monitored and recorded through an integrated control and data acquisition system with real-time analysis capabilities. Experimental results demonstrate stable operation and reliable ignition using alternative fuel mixtures, confirming the suitability of the modular installation as a versatile research platform for the assessment and comparative analysis of sustainable aerospace fuels. Full article

To further improve the seismic behavior of high-strength foam concrete filled cold-formed checkered steel composite wall structures, it is crucial to investigate the bond–slip behavior between the cold-formed checkered steel (CFCS) and foam concrete (FC) within the wall. Hence, six CFCSFC specimens were designed and subjected to monotonic and cyclic loading tests to study the influence of anchorage lengths on failure modes, bond strength-slip displacement curves, and characteristic bond strength. Results indicated that with the anchorage length increases, the ultimate bond strength of the specimens continuously decreases, and the specimens exhibit more severe failure under cyclic loading than monotonic loading. Compared to the specimens with a 400 mm anchorage length, the ultimate bond strength decreased by 4.8–9.6% for those with a 500 mm length, and by 10.7–16.0% for those with a 600 mm length. Strain along the inner flange of the steel section generally decreased with increasing anchorage length, with loading end strain significantly exceeding free-end strain. Finite element simulations revealed that specimen failure primarily manifested as steel section yielding when anchorage lengths ranged from 1400 mm to 1800 mm. Furthermore, a calculation formula for characteristic bond strength as a function of anchorage length was proposed. Full article

Background: The control of fleas and ticks in companion animals is a persistent challenge with animal welfare and public health implications. The increasing resistance to antiparasitic treatments, coupled with concerns over the environmental impact and non-target effects of synthetic acaricides, has driven interest in sustainable alternatives. Essential oils (EOs) have emerged as potential candidates due to their complex chemistry and modes of action. Methods: This review critically analyzes the scientific literature on essential oils for ectoparasite control in companion animals. Specifically, it examines their chemical composition, multi-target mechanisms of action, laboratory and field efficacy, role in resistance mitigation, and integration into IPM strategies. Results: Several EOs, particularly those rich in phenolic compounds (thymol, carvacrol, eugenol, and cinnamaldehyde), demonstrate promising in vitro insecticidal and acaricidal activity. Their multi-target mechanisms, affecting neuronal, respiratory, and cuticular functions, not only provide efficacy but also represent a significant barrier to rapid resistance development. However, their translation to reliable field performance is hampered by high volatility, formulation instability, and innate variability. Conclusions: EOs represent a valuable source of bioactive compounds for reducing reliance on conventional acaricides and can play a key role within IPM strategies. To realize their full potential in mitigating resistance, focused advancements are needed in standardized testing, formulation science to enhance stability and residual activity, and rigorous field studies to confirm safety and efficacy. Full article

Background: Changes in body composition, such as decreased muscle mass and increased adipose tissue, are significant in older adults, impacting health, functional capacity, and increasing the risk of metabolic diseases, functional decline, and frailty. Bioelectrical Impedance Analysis (BIA) is a non-invasive tool for assessing body composition, including fat-free mass (FFM), skeletal muscle mass (SMM), and fluid distribution (e.g., ECW/TBW ratio). Complementing BIA, the Mini Nutritional Assessment (MNA) serves as a validated tool for identifying malnutrition risk in the elderly. This study aimed to understand the correlation between BIA-derived parameters, MNA scores and clinical outcomes. Methods: This cross-sectional study involved 195 older adults (mean age 72.8 ± 5.4 years), divided into two groups based on body composition profiles determined by cluster analysis. Data collected included demographics, comprehensive BIA parameters (BMI, fat mass, FFM, SMM, ECW/TBW, phase angle), MNA scores, self-assessed health, chronic disease prevalence, frailty index (TFI), and functional limitations (EQ-5D). Statistical analyses included descriptive statistics, t-tests/ANOVA, chi-square tests, Pearson’s/Spearman’s correlations, point-biserial correlations, regression analyses, and ROC curve analysis to compare groups, explore variable relationships, and assess predictive abilities for malnutrition risk. Results: The first group had significantly higher BMI, AFM (AFM), FFM, and SMM, but a lower ECW/TBW ratio compared to Group 2 (N = 115), which was predominantly female and had higher frailty scores. MNA scores showed significant positive correlations with FFM (rho = 0.165, p = 0.021) and SMM (rho = 0.182, p = 0.011), and a negative correlation with ECW/TBW (rho = −0.188, p = 0.008). Higher adiposity (BMI, fat mass) correlated positively with arterial hypertension and obesity. Lower FFM and SMM were negatively correlated with gastroesophageal reflux disease. Skeletal muscle mass (AUC = 0.634, cut-off ≤ 17.3 kg) and ECW/TBW ratio (AUC = 0.626, cut-off ≥ 49.7%) showed modest discriminatory capacity to identify malnutrition risk. Individuals at risk of malnutrition reported greater functional limitations and lower self-assessed health. Numerous BIA parameters, including segmental muscle mass, total body water, phase angle, and impedance values, significantly correlated with MNA scores. Conclusions: The study highlights the importance of body composition analysis, particularly BIA, in correlation with MNA, for assessing nutritional status, functional limitations, and chronic disease associations in older adults. Integrating BIA and MNA into geriatric assessments provides a complementary profile of nutritional and functional vulnerability. Full article

Squeezed branch piles, originally developed for building and bridge foundations, have been downsized and deployed at larger pile spacing for reinforcing embankments over soft soils. However, the working mechanism of squeezed branch pile-supported embankments remains unclear. In this study, a three-dimensional numerical model of this embankment was established based on field tests. The analyses consider different pile types (squeezed branch piles and straight piles) and pile-head structures (beam-type cap and plate-type cap). These concrete components were modeled utilizing an advanced concrete model, which captures the strain-softening/hardening and yielding behavior. Simulation results show that squeezed branch piles provide better settlement control in the subsoil beneath the embankment than straight piles for the studied cases. The beam-type cap with squeezed branch piles behaves as a pile-beam foundation that reduces maximum settlement by around 38% compared to that of the plate-type cap, while the plate-type cap system functions as a composite foundation that enhances surcharge capacity by about 35–40%. The instability of the embankment is driven by tensile failure in concrete: The beam-type cap leads to a localized failure along the ground beam, and the plate-type cap system induces a progressive failure centered on the squeezed branch piles. Within the plate-type cap, the dimensions of the pile-head plate significantly influence settlement control and the stability of the embankment in soft soil. Full article