Search Results (3,031)

Objectives: This study aimed to examine the structure of anthropometric characteristics, motor skills and specific motor skills in young football players. Methods: Study participants (427 male football players) were divided into pre-pioneers (11–13 y), n = 133; pioneers (13–15 y), n = 160; and cadets (15–17 y), n = 134. The entire sample of subjects was evaluated using 13 anthropometric and seven motor variables. The factor structure for each chronological age group was determined using Hotelling’s method. Results: Anthropometric characteristics showed three extracted factors in the pre-pioneers group, four factors in the pioneer group and two factors in the cadet group. Motor skills displayed three factors for the youngest group, two factors for the pioneers and three factors for the cadet group. Four factors were determined for specific motor skills in pre-pioneers, four in pioneers and three in cadet age. Conclusions: This study revealed structural variability and non-uniformity in the latent dimensions across age groups, with the total number of factors fluctuating between two and four. This study revealed two consistent latent dimensions in anthropometric data across all age groups: general morphological parameters and subcutaneous fat tissue. In motor skills, an initial universal factor is separated into central and energetic regulation of movements. Finally, specific motor skills demonstrated a transition from a highly differentiated four-factor structure in younger players toward a more integrated functional system in the oldest cohort, comprising intermuscular coordination, running speed with and without a ball; segmental speed of the lower extremities with a ball; and explosive force in hitting a ball with the foot and head. Full article

Objectives: This study aimed to evaluate the masking ability of different thicknesses of advanced lithium disilicate (ALDS) ceramic used for implant-supported crowns compared to conventional lithium disilicate (LDS) and to assess the influence of their combination with various implant abutment materials. Methods: Two types of high-translucency computer-aided design/computer-aided manufacturing (CAD/CAM) glass–ceramics in shade A2 were tested: IPS e.max CAD (LDS) and CEREC Tessera (ALDS). Each material was sectioned into four thicknesses (n = 8 per group). Four implant abutments were evaluated: titanium (Ti), yellow-anodized titanium (TiY), pink-anodized titanium (TiP), and white zirconia (Zir). The translucency parameter (TP₀₀) and color difference (∆E₀₀) between the glass–ceramic and abutment were calculated using the CIEDE2000 formula. Results: Significant differences were observed between 1.0 mm and 2.5 mm thicknesses in all groups except for ALDS on TiY. Both glass–ceramics on TiY and TiP showed lower ∆E00 values than those on Ti, except for 2.0 mm and 2.5 mm ALDS. Additionally, their ∆E00 values were lower than those on Zir. Clinically acceptable ∆E₀₀ values occurred for 2.5 mm LDS on TiP, 2.0 mm ALDS on TiY and TiP, and 2.5 mm ALDS on TiY and TiP. ALDS demonstrated lower TP₀₀ values than LDS at corresponding thicknesses. Conclusions: Greater restoration thickness and titanium anodization improved color masking. Anodized titanium enhanced the glass–ceramic masking ability. ALDS at 2.0–2.5 mm on TiY or TiP and 2.5 mm LDS on TiP achieved clinically acceptable masking, with ALDS showing lower translucency than LDS. Full article

This study examined relationships between electrical parameters, namely impedance (Z), admittance (Y), parallel capacitance (Cp), and series capacitance (Cs), and beef tenderness in the semimembranosus muscle during ageing for 3, 7, 14, and 28 days at 4 ± 1 °C. It also assessed selected compositional traits after 14 days. The effects of electrode configuration and signal frequency on measurement sensitivity were evaluated. Beef from Holstein–Friesian bulls (n = 8) representing two feeding treatments was used. Electrical measurements were performed with an in-house sensor and an LCR-based system. Two electrode configurations were applied: T, across the muscle fibres, and L, along the fibres. pH, Warner–Bratzler shear force (WBSF), and cooking loss were determined during ageing. Chemical composition and fatty acid profile were analysed after 14 days. WBSF decreased during ageing, whereas cooking loss showed a non-linear pattern, increasing up to day 14 and decreasing after 28 days. Electrical parameters were strongly affected by frequency and electrode configuration. After 14 days of ageing, the strongest relationship with tenderness was found for Z in the T configuration at 1 kHz (r = −0.834). The T configuration better reflected moisture content and fatty acid groups, whereas the L configuration was more informative for ash. Cs provided additional information related to protein. These findings indicate the potential usefulness of this approach for rapid beef quality screening under strictly standardised measurement conditions, although the observed relationships require confirmation in a larger sample set. Full article

According to the most recent data published by the World Health Organization (WHO), it is estimated that approximately 332 million persons worldwide suffer from depression. The relationship between depression and alcohol consumption is complex and bidirectional. This study aimed to investigate the effects of cannabidiol (CBD) on behavior and malondialdehyde (MDA) imbalance in female Wistar rats exposed to chronic stress and alcohol. Sixteen intact cycle female 5-month-old Wistar rats were randomly assigned to two groups: the Control group (n = 8), and the CBD group (n = 8), which received CBD at a dose of 10 mg/kg. Following chronic stress induction, during the three-week treatment period, the animals were exposed to alcohol on three separate occasions. CBD-treated females showed increased freezing time in the Open Field test with no clear anxiolytic effect. In the Y maze and Morris Water Maze, they exhibited improved memory-related performance. Brain MDA levels were reduced, while plasma MDA was unchanged. Cortisol tended to be higher in the CBD group. CBD administration showed potential cognitive and central antioxidant effects, but no clear anxiolytic effect. Full article

Relaxor ferroelectric single crystals, such as Pb(In₁/₂Nb₂/₃)O₃–Pb(Mg₁/₂Nb₂/₃)O₃–PbTiO₃, possess extraordinary electro-optic (EO) coefficients, offering immense potential for next-generation integrated modulators. However, the application of PIN-PMN-PT in fiber-optic gyroscopes (FOGs) is hindered by the challenge of fabricating high-quality optical waveguides with strict mode selectivity, as conventional diffusion typically excites multi-mode propagation. Here, the fabrication of high-quality, mode-selective waveguides is achieved in rhombohedral PIN-PMN-PT via a nickel in-diffusion technique. The resulting graded-index structures exhibit a Gaussian profile with a maximum refractive index change (∆n) of 1.53% while preserving the single crystal structure. Under specific processing conditions, we achieve precise mode selectivity, enabling exclusive transverse electric (TE) mode transmission. This mode selectivity fulfills the requirements for single-mode Y-branch geometries, establishing a robust platform for ultra-compact, low driving voltage modulators and advancing the miniaturization of inertial navigation and integrated photonic systems. Full article

Natural gas reservoirs characterized by high heterogeneity and containing bottom-bound water often face the problem of water intrusion, making it difficult to recover the recoverable gas. This paper addresses the issue of enhanced gas recovery in water-flooded reservoirs and, through high-temperature, high-pressure long-core displacement experiments, investigates the displacement effects of different reservoir properties and injection media (dry gas, N₂, CO₂) under simulated water-flooding conditions. The experiment utilized two sets of sandstone cores—one with moderate permeability (304.8 mD) and one with high permeability (1004.6 mD). Three cores from each set were spliced together to form a 0.9 m long core, simulating the gas injection and displacement process following water infiltration. The results indicate that while water intrusion occurs more rapidly in high-permeability reservoirs, gas injection yields better recovery results than in medium-permeability reservoirs. Among the three injection media, dry gas demonstrated the best displacement efficiency, followed by N₂, with CO₂ performing the worst. CO₂ tends to react with highly mineralized formation water under high-temperature and high-pressure conditions, forming precipitates and causing energy to be absorbed by the water, which reduces displacement efficiency. It is recommended that dry gas injection be used for enhanced recovery in the moderate-permeability reservoirs of the Y gas field, while N₂ injection may be considered for the high-permeability reservoirs to balance effectiveness and cost. The research results provide experimental support for subsequent gas injection to enhance gas recovery in this gas field. Full article

Genetic diversity and antifungal susceptibility profiles of Aspergillus fumigatus are critical for understanding the evolution of resistance in clinical and environmental settings. We performed comprehensive genomic characterization of A. fumigatus isolates using whole-genome sequencing combined with phenotypic susceptibility assays. SnpEff-based variant annotation identified 76,079 single-nucleotide polymorphisms, revealing a high proportion of mutations (78.8%) in upstream and downstream regulatory regions, whereas high-impact coding variants remained rare (0.083%). Several key mutations were identified, including the well-established cyp51A M220V and HMG1 S212P/Y564H mutations. Moreover, a diverse array of peripheral cyp51A polymorphisms (M39I, E402D, N248K, and K372N) was detected, although these variants did not correlate with the resistant phenotypes. Our comparative genomic analysis identified a novel A586T substitution in the FKS1 gene in an isolate with an elevated minimum effective concentration of caspofungin, suggesting its possible association with reduced susceptibility, although functional validation is required. In isolates lacking canonical target-site mutations, the high frequency of regulatory-region variants indicated the involvement of non–target-site mechanisms. This study provides a detailed map of the genomic landscape of A. fumigatus and identifies candidate loci for future functional validation. Our results demonstrate the utility of high-throughput genomic surveillance for monitoring emerging resistance trends and characterizing the genetic background of clinical fungal pathogens. Full article

We study functions satisfying the composition law $F\left(xy\right)+F(x/y)=P\left(F\right(x),F(y\left)\right)$ with a symmetric polynomial combiner P. We prove that symmetry together with a quadratic degree bound on P forces a composition law of d’Alembert type. We establish a degree mismatch exclusion criterion showing that symmetric polynomial combiners with $degP(u,v)\ge 3$ do not admit nonconstant continuous solutions, provided the leading term does not cancel (Theorem 1). For continuous nonconstant functions $F:{\mathbb{R}}_{>0}\to \mathbb{R}$ with $F\left(1\right)=0$ satisfying the composition law with a symmetric polynomial P of degree at most two, the combiner is necessarily of the form $P(u,v)=2u+2v+cuv$, $c\in \mathbb{R}$ (Theorem 3). The equation reduces in logarithmic coordinates to the classical d’Alembert functional equation. For $c\ne 0$, one obtains hyperbolic or trigonometric branches, while $c=0$ yields the squared-logarithm family. Under the cost-function assumptions $F\ge 0$ and convexity, only the hyperbolic branch with $c>0$ remains. A unit log-curvature calibration selects the canonical value $c=2$, which yields the canonical reciprocal cost $F\left(x\right)=\frac{1}{2}(x+x^{-1})-1$. For $c\ne 0$, the result extends to ${\mathbb{R}}_{>0}^n$: every solution depends only on a single linear combination of coordinate logarithms; for $c=0$, the solution is a general quadratic form ${\sum }_{i,j}{a}_{ij}ln{x}_{i}ln{x}_j$. In either case, nontrivial coordinate-wise separable costs are excluded. Full article

Background/Objectives: Cholinergic dysfunction plays a central role in memory impairment, yet trihexyphenidyl (THP)-based paradigms remain less explored than scopolamine-based models. This study aimed to characterize a THP-induced cholinergic challenge in a two-trial Y-maze with a 24 h interval and to compare the effects of donepezil and tacrine on recall-phase exploratory allocation. Methods: Male Wistar rats (n = 9/group) were studied in a validation phase including saline, THP 5 mg/kg, and THP 10 mg/kg groups, followed by an intervention phase including control, THP 10 mg/kg, donepezil 1 and 3 mg/kg + THP, and tacrine 3 and 5 mg/kg + THP groups. All treatments were administered intraperitoneally (i.p.). Acquisition- and recall-phase behavior was analyzed. Recall outcomes included arm times, arm entries, the novel-to-familiar arm time ratio (U/K time ratio), the novel-to-familiar arm entry ratio (U/K entry ratio), discrimination indices and time-per-entry indices. Data were analyzed by one-way ANOVA; Tukey’s post hoc test was used in the validation experiment, whereas Dunnett’s test was used in the intervention experiment for comparisons against THP 10. Results: THP at 10 mg/kg produced a robust recall-phase phenotype, with increased familiar-arm exploration, reduced novel-arm exploration and lower normalized indices. Under THP challenge, donepezil was associated with clearer effects at 3 mg/kg, whereas tacrine displayed a broader dose-dependent profile, with the strongest shift in recall-phase exploratory allocation toward the novel arm observed at 5 mg/kg. Conclusions: THP 10 mg/kg produced a robust recall-phase exploratory phenotype in a 24 h two-trial Y-maze paradigm. Under THP challenge, donepezil and tacrine were associated with shifts in recall-phase exploratory allocation. These findings support the potential utility of THP-based paradigms for studying cholinergic disruption in Y-maze settings, while direct comparison with scopolamine-based models remains to be established. Full article

Quercetin, a naturally occurring flavonoid, exhibits antiproliferative and pro-apoptotic effects across various cancer models. Topotecan, a topoisomerase I inhibitor, is used in the treatment of retinoblastoma; however, its clinical utility is limited by dose-dependent toxicity. This study aimed to investigate whether quercetin is associated with enhanced topotecan-induced cytotoxicity in retinoblastoma and to explore the underlying mechanisms under both two-dimensional (2D) and three-dimensional (3D) conditions. Cell viability was assessed using the MTT assay, and drug interactions were evaluated using the combination index (CI) based on the Chou–Talalay method. Apoptosis was analyzed by Annexin V-FITC/PI staining and flow cytometry. Reactive oxygen species (ROS) levels and mitochondrial membrane potential were evaluated using fluorometric methods, and N-acetyl-L-cysteine (NAC) was used for functional modulation of oxidative stress. Three-dimensional tumor spheroid models were used to assess treatment effects under conditions that partially recapitulate tumor architecture. Gene expression levels of apoptosis-related markers and PI3K/Akt/mTOR pathway components were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). The combination of quercetin and topotecan was associated with synergistic cytotoxic effects in Y79 cells (CI < 1), accompanied by increased ROS levels, mitochondrial membrane depolarization, and elevated apoptotic cell death. NAC co-treatment partially attenuated ROS levels and restored cell viability. In 3D spheroid models, combination treatment induced structural disruption, reduced viability, and increased cell death, effects that were partially reversed by NAC. Gene expression analysis revealed upregulation of pro-apoptotic genes and downregulation of survival-related genes, along with increased PTEN expression. Quercetin is associated with enhanced topotecan-induced cytotoxicity in retinoblastoma cells under both 2D and 3D conditions. These effects were associated with ROS-associated cellular stress, mitochondrial dysfunction, and modulation of apoptotic and survival-related pathways. The partial rescue by NAC supports a contributory, but not exclusive, role of oxidative stress. These findings should be interpreted within a preclinical context and suggest that quercetin may represent a potential adjunct strategy warranting further validation in translational and in vivo models. Full article

Background/Objectives: The uprighting of mesially tipped mandibular second molars following first molar loss is a complex surgical and orthodontic challenge. Conventional methods often result in reciprocal anchorage loss. Mini-implants (MIs) have emerged as essential temporary anchorage devices (TADs) that provide absolute anchorage and enable more predictable tooth movements. Methods: Numerical simulations were performed to evaluate the forces required for mandibular second molar uprighting under two conditions: first, only with the second molar present, and second, with both the second and the third molars present. Although the periodontal ligament exhibits nonlinear and viscoelastic behavior in vivo, a linear elastic approximation was adopted to allow for a reliable evaluation of comparative stress distribution and initial displacement patterns within the scope of this exploratory biomechanical study. Stress distribution in the roots, periodontal ligament, and alveolar bone was assessed for each scenario. Two three-dimensional (3D) models of the left mandibular segment were created from scans of a human mandible and its teeth. The first model included the canine, the first and second premolars, and the second molar. A second model additionally incorporated the third molar. A retromolar MI was placed in both models. Molar uprighting was simulated using a spring connecting the implant to a button bonded on the mesial surface of the second molar. A force of 200 g was applied because in clinical orthodontic practice, forces that exceed approximately 2 N may cause pain or undesirable tooth mobility. Displacements along the X, Y, and Z axes, as well as regions of peak stress, were analyzed. Results: Model 1 showed maximum displacements at the furcation/mid-root, distal root apex, and distal crown, with von Mises stresses of 0.470 to 0.371 MPa. In Model 2, peak displacements occurred at the mesial root and crown, with stresses of 0.185 and 0.149 MPa, respectively. The magnitude of displacements was in the order of 10⁻⁵ mm. Such values represent initial mechanical responses rather than clinically observable tooth movements. However, the differences between models (e.g., the stress reduction) are expected to be clinically meaningful. Conclusions: Since clinical measurements regarding the stress distribution on teeth and surrounding tissues during orthodontic molar uprighting movements are impossible to perform, the finite element method (FEM) can offer insight into these aspects. The presence of the third molar significantly modulates the biomechanics of second molar uprighting via retromolar MIs. When the third molar is present, the second molar exhibits a reduced tendency for deformation during distalization, although this leads to a slower displacement. This FEM provides biomechanical insights but does not support direct clinical decision-making. The present findings should be viewed as theoretical biomechanical tendencies that require confirmation through clinical, experimental, and longitudinal studies before translation into clinical practice. Full article

Let R be a commutative ring, and let $S=R[Y_1,\dots ,Y_n]$ denote the polynomial ring in n variables $Y_1,\dots ,Y_n$. We introduce an admissible term order on the monomials in these variables and extend the classical definition of circuits to the case where coefficients lie in a commutative ring R. We investigate the conditions under which an ideal of $R[Y_1,\dots ,Y_n]$, generated by linear forms, can be generated by R-circuits. Specific results are obtained when $R=K[x_1,\dots ,x_m]$, which is the polynomial ring over a field K. Full article

Background/Objectives: Non-sedate magnetic resonance imaging (MRI) can be challenging for young children with neuromotor disabilities, often resulting in motion-degraded images that complicate interpretation in the context of underlying neuropathology. This study aimed to characterize tolerance factors and barriers related to awake MRI of the pediatric brain and to examine additional considerations in analyzing structural scans affected by motion and pathology. Methods: 10 children (mean age 5y9m; 5 girls; GMFCS level IV) with cerebral palsy (CP) underwent non-sedate 3T MRI of the brain. Tolerance factors and challenges were documented. MRI quality and automated structural preprocessing with Freesurfer (FS) v.8.0 were reviewed by a pediatric neuroradiologist and neurologist. To assess the impact of motion, automated basal ganglia segmentation was compared with manual segmentation. Segmentation accuracy was characterized using Dice Coefficient (D). Results: Five participants (50%) tolerated non-sedate structural MRI, although two of them were unable to remain still. Factors affecting MRI tolerance included sensitivity to scanner noise (n = 4), hyperkinetic movement (n = 2), difficulty with positioning/padding (n = 4), fear of clinical environment (n = 2) or confined scanner interior (n = 2), and earbud discomfort (n = 3). Automated structural preprocessing with FS yielded discrepancies in gray-white matter boundaries in motion-degraded scans, necessitating manual correction. Automated segmentation of motion-compromised scans closely agreed with manual delineation of the caudate (D ≥ 0.85) and putamen (D ≥ 0.78), while the pallidum was least reproducible (D = 0.58). Conclusions: Tailored acquisition and processing strategies are necessary to support non-sedate MRI in children with CP, preserve downstream neuroimaging analyses, and promote inclusion of underrepresented populations in research. Full article

To address the challenges of constrained grid-like compartments, a motion framework integrating adaptive obstacle avoidance planning and active disturbance rejection control is proposed. First, an Adaptive Rapidly exploring Random Tree Star (Adaptive RRT*) algorithm based on multi-source state feedback is developed. Scaled-down model simulations show that, compared to conventional algorithms, its path length (374.28 mm), planning time (0.30 s), and node count (50.83) are reduced by at least 29.5%, 64.7%, and 28.6%, respectively, achieving a 100% planning success rate. Next, a control scheme based on Extended State Observer–Model Predictive Control (ESO-MPC) is designed. Simulations indicate that under nominal conditions, tracking errors are reduced by 5.78–84.35% compared to traditional MPC. Under a 20% link mass perturbation, the scheme effectively eliminates phase lag. Under complex scenarios involving parameter perturbation and a 0.6 N·m step torque disturbance, the tracking error reduction ranges from 25.27% to 87.59%, exhibiting excellent disturbance rejection robustness. Physical experiments conducted on a scaled-down experimental platform further verify that the maximum tracking errors of the manipulator end-effector along the x, y, and z axes under ESO-MPC are 0.88 mm, 0.85 mm, and 0.89 mm, respectively, significantly outperforming the 2.41 mm, 2.39 mm, and 2.47 mm observed with MPC. Finally, obstacle avoidance and trajectory-tracking simulations of an industrial manipulator in a full-scale ship compartment environment validate the engineering feasibility of the proposed framework. Full article

The paper utilizes the synergy of vibration and hot air flow to form a composite force field, and low-quality fine coal with viscous moisture is subjected to ash removal. The vibration signals of the bed surface at different positions are collected online using an accelerometer, and the dominant force affecting the vibration behavior of the bed is analyzed using signal time-domain analysis. By examining the impact of the synergy between vibration and airflow on the ash removal effect of low-quality, viscous moisture coal, the response of the drying and sorting behavior of low-quality fine coal to this synergy is elucidated. Based on the study of the experimental results of dehydration and ash removal of −6 + 1 mm fine coal, under the synergy of temperature and load force field, when the air flow temperature is 90 °C, v = 0.65 m/s, and f = 20 Hz, the collision force range between particles is 120 nN–370 N, which is different from that between particles. The liquid bridge force is large, which can achieve the fracture of liquid bridges between particles and strengthen the loose fluidization of particles. In addition, based on the study of the vibration characteristics of the bed surface at different positions, the vibration along the y-axis direction plays a dominant role in the density segregation behavior of the bed particles. With the increase in gas velocity and vibration frequency, the ash content of the selected clean coal exhibits a trend of first decreasing and then increasing. At the same time, the ash segregation degree initially increases and then decreases. Moreover, under the conditions of v = 0.65 m/s and f = 20 Hz, the separation effect of fine coal is the best. The separation accuracy E values of 1–6 mm without fine particles are 0.06 g/cm³, and the ash content of the clean coal is 12.55%. Full article