Search Results (4,589)

Background: In children with cerebral palsy, bony acetabular deficiencies are common and may be associated with progressive hip subluxation, abnormal joint loading, and ultimately hip dislocation. Hip reconstruction surgery is typically performed to prevent dislocation, and this includes acetabular reshaping using acetabuloplasty. The location of acetabular deficiency may vary among individuals; however, only radiographs are used for planning and intraoperative correction in many centers. Precise reconstruction and preop planning are necessary for the accurate correction of acetabular coverage. This study compares conventional hip reconstruction with a 3D-guided technique using individual preop 3D planning and 3D-printed guides during surgery to determine which method allows for a more accurate correction. We hypothesize that the patient-specific 3D planning leads to more precise anatomical correction of acetabular coverage compared to conventional freehand osteotomy. Methods: This study was registered in the German Clinical Trial Register (DRKS-ID: DRKS00031356) on 14 July 2023. In a randomized controlled trial, various imaging-based parameters were used to assess the bony anatomy preoperatively and postoperatively. Preoperative and 6-week postoperative computed tomography (CT) scans are part of routine clinical care. Additionally, an immediate postoperative CT scan was performed. One hip was operated on using individualized 3D preoperative planning, while the other hip was corrected using a conventional surgical approach. A standardized subtrochanteric osteotomy was performed for the varisation, derotation, and shortening of the proximal femur. This osteotomy was followed by acetabuloplasty under fluoroscopic control. For the 3D-planned operation, patient-specific cutting and repositioning guides were produced based on preoperative CT imaging. Patients with bilateral cerebral palsy (GMFCS levels I–V), aged 4–18 years, with an open triradiate growth plate and a migration index ≥ 40% in at least one hip were included. In a preliminary retrospective part, this project reproduces the existing three-dimensional acetabular index (3-DAI) and compares it with established radiographic methods to determine the utility and reliability of a reconstructed 3D CT measurement technique. A further component of the retrospective part is the creation of an age-adjusted database of typically developed hips and the development of a 3D head coverage index (3D-HCI) as a new 3D parameter to express acetabular coverage; therefore, it will be used as a secondary parameter and correlated to the 3DAI in the prospective part. Conclusions: Improved precision may have meaningful clinical implications for long-term joint congruency, load distribution, pain, and mobility outcomes. Full article

With the increasing use of reinforced concrete segments in large-scale tunnels, engineering projects have placed higher mechanical demands on concrete, and the choice of concrete materials significantly influences these mechanical properties. This study is based on the preliminary mix design for the concrete used in the Second Undersea Tunnel Project, with the mass content of nano-SiO₂ (NS) (1–3%), the volume content of steel fibers (SF) (0.5–1.5%) and the volume content of polypropylene fibers (PPF) (0.05–0.25%) as independent variables and using compressive strength (Y₁), splitting tensile strength (Y₂), and toughness index (Y₃) as response variables. Using the Box–Behnken response surface design method, response surface models for each parameter were established and analyzed. The effects of NS, SF, and PPF on the mechanical properties of the concrete were investigated. Combining the MOPSO algorithm and the entropy-weighted TOPSIS method, a multi-objective cooperative optimization study was conducted. Finally, a microstructural analysis of the optimal NSDHFRC was performed. The results indicate that Y₁, Y₂, and Y₃ all initially increase and then decrease with increasing NS content; Y₁ and Y₃ increase with increasing SF content. However, when the SF content exceeds a certain level, the fiber spacing becomes too dense, weakening the effective bridging effect between fibers, resulting in a decrease in Y₂ at excessively high SF contents; PPF can suppress crack formation within a certain content range, but its effect on Y₁ is relatively weak. Due to agglomeration and water absorption, both Y₂ and Y₃ decrease when the PPF content is too high. It was determined that the optimal solution occurs when the mass fraction of NS is 2.15%, and the volume fractions of SF and PPF are 1.37% and 0.063%, respectively, with Y₁, Y₂, and Y₃ being 69.94 MPa, 5.49 MPa, and 1.99, respectively. Experimental verification confirmed that the relative error is within 5%. A microscopic analysis of the optimal solution revealed that an appropriate amount of NS refines the concrete structure through physical and chemical reactions, improves the interface transition zone, and enhances the bond strength between the fibers and the matrix. Meanwhile, PPF and SF distribute stress, respectively delaying the propagation of microcracks and macrocracks during different loading stages. These findings provide a reference for practical engineering applications. Full article

In this study, NH₂-MgO was employed as a crosslinking agent to covalently link boron nitride (BN) and silicon carbide whiskers (SiC_w) via an amidation reaction, yielding the BN-MgO-SiC_w hybrid filler. The BN-MgO-SiC_w/PBz composites were fabricated using a ball-milling-assisted solution mixing method combined with hot-press molding, and their comprehensive properties were systematically evaluated. The results demonstrate that the BN-MgO-SiC_w/PBz composite exhibits excellent thermal conductivity, favorable dielectric properties, superior thermal stability, and outstanding mechanical performance. At a filler loading of 50 wt%, the composite achieved a thermal conductivity of 1.41 W/mK, which is substantially higher than that of the KH560-BN/PBz composite (0.91 W/mK) and approximately 5.2 times that of the neat PBz matrix. The dielectric constant (ε) and dielectric loss (tan δ) of the BN-MgO-SiC_w/PBz composite were 6.81 and 0.013, respectively, remaining at relatively low levels. The thermal degradation temperature at 30% weight loss (T₃₀) and the heat resistance index temperature (T_HRI) reached 572 °C and 244 °C, respectively, both higher than those of the KH560-BN/PBz composite at the same filler loading (511 °C and 224 °C). The tensile strength and flexural strength of the BN-MgO-SiC_w/PBz composite were 50.0 MPa and 72.3 MPa, respectively, exceeding those of the KH560-BN/PBz composite (39.4 MPa and 56.2 MPa) while remaining slightly below those of the neat PBz matrix. Collectively, these findings indicate that the BN-MgO-SiC_w/PBz composite holds great promise as a novel material with well-balanced comprehensive properties, making it a strong candidate for applications in fields such as electronic packaging. Full article

With increasing traffic loads and increasingly complex climate conditions, accurate prediction of the International Roughness Index (IRI) of asphalt pavements is crucial for developing effective maintenance plans. However, traditional regression models have limitations in capturing the coupled effects of traffic, structure, and environmental factors. To overcome this limitation, this study constructed a dataset containing 10,836 samples based on the Long-Term Pavement Performance (LTPP) database, integrating traffic load, pavement structure parameters, and climate variables. The variance inflation factor (VIF) and correlation analysis were used to validate the effectiveness of feature selection. We trained nine machine learning models and optimized the hyperparameters using a Bayesian optimization method with five-fold cross-validation to ensure good generalization ability. Results show that the TabPFN model, based on prior information, achieved the best overall performance with a coefficient of determination $R^2$ = 0.9474 and a low prediction error (RMSE = 0.138) on the test set. Paired t-tests based on cross-validation further confirmed that TabPFN’s predictive performance is statistically superior to the baseline model. SHAP and generalized additive model (GAM) analyses indicate that traffic load is the main driver of IRI growth, while structural layer thickness, within a certain range, can mitigate pavement roughness. Climatic factors have indirect long-term effects through cumulative environmental exposure. Although the main drivers differ slightly among different pavement structures, traffic load consistently plays a dominant role. To enhance the model’s practical applicability, we also developed a user-friendly graphical interface (GUI) for fast and accurate IRI prediction. Full article

Background/Objective: Buccal delivery offers a potential route to circumvent gastrointestinal degradation and hepatic first-pass metabolism, but hydrophilic peptides typically exhibit limited mucosal permeation. Nanostructured lipid carriers (NLCs) have been proposed as delivery platforms capable of modulating interfacial interactions and improving mucosal transport. This study aimed to quantitatively evaluate the ex vivo buccal permeation of angiotensin II (Ang II), used as a hydrophilic peptide model, when associated with NLCs compared with free peptide under matched Franz diffusion cell conditions. Methods: Ang II-associated NLCs were prepared by melt emulsification combined with a low-energy injection technique. Particle size, polydispersity index, and zeta potential were determined by dynamic light scattering and laser Doppler electrophoresis. Association efficiency and drug loading were quantified by indirect spectrofluorometric analysis. Ex vivo permeation studies were conducted using porcine buccal mucosa mounted in Franz diffusion cells, and cumulative permeation, steady-state flux, and apparent permeability coefficients were calculated. Results: The NLCs exhibited nanometric size, moderate polydispersity, and association efficiency above 80%, and remained colloidally stable at 4 °C for 28 days. In ex vivo experiments, Ang II-associated NLCs showed measurable cumulative permeation, reaching approximately 9% after 2 h, whereas free Ang II was not detected in the receptor compartment under the tested conditions. Conclusions: This work provides a quantitative ex vivo buccal transport comparison of a hydrophilic peptide model delivered as NLC-associated versus free peptide under matched Franz cell conditions. The findings support further investigation of NLC-based approaches for buccal delivery of vasoactive peptides and provide a rational basis for future in vivo evaluation of mucosal delivery performance and systemic exposure. Full article

Background and Objectives: Despite critically low levels of chronic kidney disease (CKD) awareness worldwide, there is no psychometrically validated instrument to comprehensively assess CKD awareness across socioecological levels. This study aimed to develop, psychometrically evaluate and validate a multidimensional awareness scale grounded in socioecological theory for patients with stage 3–4 CKD. Materials and Methods: This methodological study enrolled 908 stage 3–4 CKD patients. Scale development proceeded through systematic stages: comprehensive literature review, qualitative interviews (n = 15), expert panel evaluation (n = 25), and pilot testing. The initial 72-item pool was refined to 41 items (Content Validity Index = 0.912). The sample was randomly split for exploratory factor analysis (EFA; n = 454) and confirmatory factor analysis (CFA; n = 454). Psychometric evaluation encompassed internal consistency (Cronbach’s α, McDonald’s ω), test–retest reliability (n = 30; 4-week interval), convergent validity (average variance extracted [AVE], composite reliability [CR]), discriminant validity (Fornell–Larcker criterion), and criterion validity (correlation with Turkish Health Literacy Scale-32 [TSOY-32]). Results: EFA revealed a seven-factor structure with an acceptable explained variance of 43.8%. Following iterative item elimination based on communalities (h² < 0.20) and factor loadings (λ < 0.30), CFA confirmed the final 34-item model with good fit (CFI = 0.972; RMSEA = 0.070 [90% CI: 0.067–0.074]). The factor structure captured awareness across core socioecological levels (Individual, Interpersonal/Institutional, Community, and Systemic), complemented by Treatment Adherence and Social Impact dimensions. Internal consistency coefficients were α = 0.884 and ω = 0.889 for the total scale. Test–retest reliability yielded an ICC of 0.954 (95% CI: 0.907–0.978). Convergent and discriminant validity were confirmed via composite reliability (CR: 0.740–0.953) and the Fornell–Larcker criterion. Criterion validity analysis revealed a significant correlation with TSOY-32 (r = 0.810, p < 0.001). Conclusions: The CKD Awareness Scale (CKD-AS-34) represents a novel, psychometrically validated, multidimensional awareness instrument for CKD. This scale enables clinicians to identify awareness deficits spanning individual to systemic levels, facilitating personalised patient education and targeted public health interventions. Full article

Background: The optimal frequency of EEG biofeedback sessions for elite athletes remains unclear, despite growing adoption of neurofeedback in high-performance sport. Methods: This randomized, controlled study compared three EEG biofeedback protocols (daily, every-other-day, every-third-day) in 24 national-level male judo athletes stratified into three phenotypic groups. Each protocol comprised 15 standardized sessions. Pre- and post-intervention assessments included functional indices (strength, power) and neurophysiological measures (Frontal Alpha Index, EMG amplitude/RMS, corrected strength sum). Biosensor performance was validated via signal quality metrics. Results: Daily EEG biofeedback produced superior improvements in strength, FAI, and fatigue resistance. Although LRG showed the largest pre–post RMS increase (+17.44 μV vs. +16.54 μV in HRG), HRG maintained the highest post-intervention RMS values and best fatigue resistance (MF_drop = −2.15 Hz). Significant group × time interactions were observed for FAI (p = 0.027) and RMS (p = 0.019). Every-other-day protocols yielded moderate gains, while every-third-day protocols produced minimal or maladaptive EMG–load dynamics. A robust dose–response relationship was evident. Conclusions: Session frequency is critical for optimizing neurofeedback interventions in elite athletes. Daily EEG biofeedback confers superior adaptation compared to less frequent dosing. Full article

Ripple currents on the direct current (DC) bus in variable frequency drive (VFD) systems originate from motor load current fluctuations and the high-frequency switching of power devices. The resulting Joule heating within the DC-link capacitors is a primary driver of lifespan degradation. To address the lack of systematic models for multi-phase H-bridge inverters and the over-design caused by empirical methods, this paper proposes a novel analytical method that incorporates the 2kπ/N phase difference of parallel units for precise ripple current quantification. First, a dynamic DC-link capacitor model is established based on a single-phase H-bridge inverter, and the expressions for the instantaneous, average, and root mean square (RMS) input currents are derived. Furthermore, by introducing the 2kπ/N phase difference (where k = 0, 1, …, N − 1) among N parallel H-bridge units, a universal analytical expression for the RMS input current and its harmonic spectrum in a multi-phase system is obtained. The analysis reveals that ripple current harmonics concentrate at 2m × f_sw (where m is a positive integer and f_sw is switching frequency) and their sidebands (2m × f_sw ± f_o, f_o is output fundamental frequency), and the coupling influence of modulation index and power factor angle on ripple amplitude is quantitatively characterized. A 12 × 160 kW twelve-phase H-bridge inverter is taken as a case study, and MATLAB (v2023b) simulations and hardware experiments demonstrate that the theoretical calculations are in close agreement with the simulated and measured results, with the errors of input current harmonic amplitudes all below 5%. Compared with traditional empirical design, the proposed method reduces the capacitor volume and cost by approximately 15–20% while ensuring system reliability. This method is directly extensible to other multi-phase inverter topologies, providing a theoretical foundation for the accurate selection of DC-link capacitors. Full article

Light availability is a key environmental factor influencing plant functional traits and ecological strategies. To investigate how natural populations of Iris pumila respond to contrasting irradiance, we conducted an in situ reciprocal transplant experiment using clonal genotypes from two natural populations, each originating from an open dune and a shaded forest habitat. Leaves collected from each of the replanted and transplanted genotypes were analyzed for structural (specific leaf area—SLA, leaf dry matter content—LDMC), physiological (specific leaf water content—SLWC, photosynthetic pigments) and biochemical (peroxidase—POD, glutathione reductase—GR, phenolics and anthocyanins) traits. Shade-grown individuals developed thinner leaves with higher SLA and chlorophyll content, enhancing light-harvesting efficiency, whereas sun-exposed plants exhibited greater LDMC, increased POD and GR activities and higher anthocyanin levels—traits consistent with enhanced photoprotection under high irradiance. All genotypes exhibited pronounced plasticity to light intensity, with habitat exerting a stronger influence on trait expression than population origin. To evaluate oxidative balance, we proposed the ODAC index (Oxidative Damage to Antioxidant Capacity), which integrates lipid peroxidation with antioxidant capacity. ODAC values revealed consistent population-level differences, with higher values in Dune genotypes across habitats, indicating a constitutively elevated oxidative load relative to antioxidant protection and suggesting differentiation in redox regulation between populations. Overall, leaf trait variation in I. pumila appears to be primarily driven by plastic responses to light conditions, while differentiation in oxidative physiology contributes to functional divergence between populations. Full article

Nanoemulsions are widely recognized as versatile delivery platforms capable of stably loading lipophilic active ingredients. Although low-energy phase inversion methods enable nanoemulsion formation under ambient and low-shear conditions, their scalability and applicability in practical formulation environments remain insufficiently validated. Here, we develop oil-in-water (O/W) nanoemulsions via a low-energy phase inversion process and systematically investigate their composition-dependent formation, scalability, and formulation stability. By precisely tuning the composition of a mixed nonionic surfactant system, monodisperse nanoemulsions with an average droplet size of ~110 nm and a polydispersity index (PDI ≤ 0.20) are reproducibly obtained under ambient, low-shear conditions. The optimized nanoemulsions maintain their nanoscale dispersion characteristics over 30 days of storage and exhibit consistent droplet size and distribution upon scale-up to 1 L. Furthermore, the nanoemulsions retain structural stability when incorporated into polymer-based formulations under various temperature conditions and repeated thermal cycling. These results demonstrate that low-energy phase inversion enables a scalable and formulation-compatible nanoemulsion platform, providing practical guidelines for industrial formulation and manufacturing of delivery systems for lipophilic active ingredients. Full article

Vertical axis wind turbines (VAWTs) suffer from dynamic stall (DS) at low tip-speed ratios (λ), where cyclic variations in angle of attack (α) dominate the blade aerodynamics, severely undermining aerodynamic performance and power extraction. The coupled influence of airfoil parameters on DS remains unexplored. To address this gap, a fully coupled parametric study using 126 incompressible URANS simulations is conducted, examining three geometric parameters of symmetric airfoils: maximum thickness (t/c), chordwise position of maximum thickness (x_t/c), and leading-edge (LE) radius index (I). The results show that coupled geometric modification fundamentally alters the stall mechanism, shifting it from abrupt, LE-driven separation toward a gradual, trailing-edge (TE)-controlled process as airfoils transition from thin, forward-x_t/c profiles to thicker configurations with aft x_t/c and reduced I. This transition enhances boundary-layer (BL) stability, delays DS onset, weakens dynamic stall vortex (DSV) formation, and mitigates unsteady aerodynamic loading. Within the investigated design space, the best-performing configuration (NACA0024–4.5/3.5) achieves a 73% increase in turbine power coefficient (C_P) relative to the baseline airfoil (NACA0018–6.0/3.0), mainly through passive control of BL separation and vortex development. These findings highlight the limitations of single-parameter optimization and establish a physics-based, coupled-design framework for mitigating DS-induced performance losses in VAWTs. Full article

The strategic choice of training system is essential for adapting viticulture to current climate change, ensuring a balance of physiological efficiency and the sustainability of productivity and oenological quality. This study evaluated the effects of vertical shoot positioning and foldable lyre systems (set at angles of 20°, 30° and 40°) on the physiological performance and yield of ‘Merlot’ grapevines. The experiment was conducted in a humid temperate region in Brazil over two consecutive seasons. The experiment followed a randomized block design. The variables evaluated included: the number of clusters per shoot, cluster weight, pruning weight, Ravaz Index, leaf area and yield; gas exchange parameters such as net CO₂ assimilation rate, stomatal conductance, transpiration rate, rubisco carboxylation efficiency, intercellular CO₂ concentration and photosynthetic photon flux density; and chemical composition of berries such as pH, Total Soluble Solids and Titratable Acidity. The data were subjected to an analysis of variance, and the means were compared using Tukey’s test at a 5% probability level. The results indicated that canopy architecture significantly influenced solar radiation interception, with the 30° and 40° foldable lyre systems achieving the highest mean daily radiation levels, exceeding the vertical positioning system by 73.7% and 76.6%, respectively. Although gas exchange at the leaf level remained comparable across all systems, agronomic performance varied considerably. The 40° foldable lyre system achieved the highest yield (22.99 t ha⁻¹), representing a 63.1% increase over the vertical positioning system (14.10 t ha⁻¹). The number of buds in the foldable lyre systems increased by around 70%, which is closely in line with the observed increase in yield. In addition, the foldable lyre systems provided about 40% more leaf area than the vertical positioning system. These findings suggest that divided canopy systems, such as foldable lyre systems, particularly at 30° and 40°, optimize bud load, fruitfulness per shoot, light interception and significantly increase yield without compromising individual physiological efficiency and berry chemical composition, with a balance between vegetation and fruit load preserved and with positive effects on the ripeness and quality of the grapes. Full article

Power system blackouts remain a major concern for modern electricity networks, as they often result from cascading failures that lead to substantial load shedding and widespread service disruptions. This paper presents a dynamic resilience assessment of hybrid AC/DC power systems and investigates the effectiveness of voltage-source-converter-based high-voltage direct current (VSC-HVDC) technology in enhancing system resilience under outage contingencies. The study contributes by integrating protection devices and their settings into the analysis and by providing a quantitative evaluation of the system response to N-2 and N-3 contingencies using PSS^®E simulations. The demand not served index is used as a measure of resilience, and its cumulative distribution functions are computed to compare the performance of AC and DC interconnections. The results underscore the importance of VSC-HVDC links in mitigating cascading failures, highlighting their potential as a resilience-enhancing component in modern power grids. Full article

Background: Informal sewing workers are widely exposed to ergonomic and workload-related risks but remain largely excluded from formal occupational health protection, particularly in low- and middle-income countries. This study evaluated integrated physical and mental workload risks associated with WMSDs among informal sewing workers to develop contextually feasible preventive guidelines based on the Hierarchy of Ergonomic Control. Methods: A mixed-methods study was conducted among 150 informal sewing workers in Ubon Ratchathani Province, Thailand. Quantitative data were collected using a structured questionnaire, the Rapid Upper Limb Assessment (RULA), the Nordic Musculoskeletal Questionnaire (NMQ), and the NASA Task Load Index (NASA-TLX). Associations between sociodemographic characteristics, ergonomic risks, and WMSDs were analyzed using chi-square tests and correlation analysis. Qualitative data were obtained through a focus group discussion with key stakeholders to develop ergonomic control strategies guided by the HEC framework. Results: The majority of participants were female and middle-aged, with widespread exposure to high-risk ergonomic conditions, including prolonged sitting, repetitive tasks, and awkward postures. A high prevalence of WMSDs was observed, particularly in the neck, shoulders, and back. Younger workers and those with lower educational attainment experienced significantly higher ergonomic risk exposure and WMSD prevalence. NASA-TLX results indicated that physical demand and performance pressure were the main contributors to overall workload. Application of the HEC framework showed that elimination and substitution controls were the most effective strategies for reducing ergonomic risks, followed by engineering controls, while administrative measures and personal protective equipment were less effective. Conclusions: Informal sewing workers face substantial ergonomic and mental workload risks that contribute to a high burden of WMSDs. Prioritizing higher-order ergonomic controls, integrating workload management, and implementing community-based ergonomic interventions are essential to improving occupational health and reducing inequities among informal workers. Full article

Simple shear testing is a widely used method in geotechnical engineering for evaluating soil liquefaction susceptibility, deformation characteristics, and shear strength under controlled loading conditions. This study presents a bibliometric analysis of research trends in simple shear testing based on 367 publications indexed in the Scopus database between 2000 and 2024, analyzed using VOS-viewer. It appears that the current research output on this topic has greatly increased lately. The number of research articles reached a peak in 2024 with a total of 42 research articles. The most frequently cited journals on this topic are Soil Dynamics and Earthquake Engineering, with a total of 48 research articles (1173 citations); the Journal of Geotechnical and Geo-environmental Engineering, with a total of 34 research articles (772 citations); and the Canadian Geotechnical Journal, with a total of 10 research articles (250 citations). This indicates substantial research interest in earthquake engineering and soil mechanics. The output shows that there is a major emphasis on research done in the USA, with a total of 104 research articles (1215 citations). The highest average citations per document belong interestingly to the research done by Taiwanese, with a total of 36.73 citations. Similarly, it appears that there is a good impact on soil liquefaction studies. The research findings show that confining pressure, strain rates, and volume ratio affect the shear strength of the soil. Advances in boundary control and shear testing techniques have improved the reliability of experimental results. The study underscores the growing need for more sophisticated numerical modeling techniques and field verification to bridge the gap between laboratory findings and real geotechnical applications. These findings contribute to improving soil characterization methods, which enable safer and more efficient geotechnical designs for infrastructure development. Full article