Search Results (10,679)

Background: The keratorefractive lenticule extraction (KLEx) procedure has gained popularity because of its safety and effectiveness; however, its predictability remains variable, as it may be over- or under-corrected. This study aimed to evaluate visual and refractive outcomes following the utilisation of VISULYZE-generated nomograms (Carl Zeiss Meditec AG, Jena, Germany) and OcuLign cyclotorsion alignment tools (Carl Zeiss Meditec AG, Jena, Germany). Methods: This retrospective consecutive cohort study included patients undergoing KLEx, grouped into four sequential treatment phases: PRE-NOMOGRAM, NOMOGRAM, OCULIGN & NOMOGRAM, and OCULIGN. Results: A total of 688 patients (1264 eyes) were included. The OCULIGN group showed numerically higher efficacy, with 83.0% achieving post-operative (PO) uncorrected distance visual acuity (UDVA) 20/20 or better, with no loss of corrected distance visual acuity (CDVA) lines, and 67.0% gaining one line. Predictability and accuracy were high across groups, with the OCULIGN group demonstrating a strong correlation between attempted and achieved spherical equivalent (R² = 0.9908), and 95.5% of eyes within ±0.50 D. Early PO outcomes suggested minimal refractive shift at one month. The NOMOGRAM group demonstrated numerically improved astigmatism correction (100.0% within ≤0.50 D), while the OCULIGN & NOMOGRAM group showed high precision in axis alignment. However, baseline imbalances were present, and between-group differences were relatively small. Conclusions: The use of OcuLign cyclotorsion alignment and VISULYZE-generated nomograms was associated with favourable visual and refractive outcomes following KLEx. However, given the retrospective, sequential design, imbalanced baseline, and limited follow-up duration, these findings should be interpreted cautiously. Further prospective, randomised studies with longer follow-up are required to confirm these observations. Full article

The rapid and reliable detection of dopamine (DA) is crucial for clinical diagnostics and neurochemical research. Here, we present an advanced electrochemical sensor fabricated by integrating 3D printing technology with bimetallic nanomaterials to achieve high sensitivity, selectivity, and reproducibility. A conductive polylactic acid (PLA) electrode was 3D-printed and subsequently activated to expose electroactive carbon domains. The surface was then modified with AgPt bimetallic nanoparticles (NPs), synthesized via a one-step solvothermal method, and coated with Nafion^TM 117 to form the AgPt@A-3DPE sensor platform. Morphological and structural characterization confirmed the formation of uniform, quasi-spherical AgPt nanoparticles with excellent dispersion. The sensor exhibited outstanding electrochemical performance, including a wide linear detection range for DA (0.5–100 µM), a low limit of detection (LOD) of 0.037 µM, and a significantly enhanced electroactive surface area (1.04 cm²). Furthermore, it demonstrates high selectivity in complex matrices, with minimal interference from common biomolecules such as ascorbic acid, uric acid, and glucose. Moreover, the practical applicability of the AgPt@A-3DPE sensor was successfully validated through the analysis of real human urine samples. This work demonstrates a low-cost, scalable, and highly efficient sensing approach, opening new avenues for personalized diagnostics and real-time monitoring of neurotransmitters in biomedical applications. Full article

Background/Objectives: The oral administration of donepezil has been shown to have common side effects due to systemic drug delivery, with fluctuations in blood and brain donepezil concentrations. Therefore, we obtained nanostructured lipid carriers loaded with donepezil (donepezil–NLC) for nose-to-brain targeting. Methods: The obtained NLCs were characterized by measurements of particle size, the polydispersity index, zeta potential, encapsulation efficiency, atomic force microscopy, Differential Scanning Calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, and in vitro release studies. Plasma and brain pharmacokinetic studies in Wistar rats were carried out to determine brain targeting. Results: Donepezil–NLC showed low polydispersity and nanometric size, high zeta potential, and high drug entrapment efficiency. Microscopy images showed spherical particles with regular surfaces. Thermal analysis, X-ray diffraction, and FTIR-ATR suggested the formation of an amorphous lipid matrix and the incorporation of donepezil molecularly dispersed within the lipid matrix. In vitro drug release studies demonstrated a biphasic drug release pattern with an initial burst followed by sustained release, with results better fitted to the Korsmeyer–Peppas model (n-value > 0.5). Following the nasal administration of donepezil–NLC, brain pharmacokinetic studies in Wistar rats demonstrated a significant improvement in bioavailability. Compared to the intravenous injection of donepezil, the AUC^0–ꝏ value was 10.5-fold higher. Drug targeting efficiency and direct transport percentage showed extremely higher values, suggesting nose-to-brain targeting after donepezil–NLC intranasal administration. Conclusions: Donepezil–NLC has proven to be an efficient drug delivery system for the nose to the brain, which may reduce systemic toxicity and improve Alzheimer’s therapy with low doses of donepezil and fewer adverse effects. Full article

In this study, N-doped carbon dots (CDs) functionalized with L-carnitine-loaded β-cyclodextrin were synthesized with a hydrothermal method using two different Rhododendron spp. (R. luteum and R. ponticum) as carbon sources. The synthesized carbon dots (LC/β-CD@Rh.l/N-CD (CD₁) and LC/β-CD@Rh.p/N-CD (CD₂)) showed monodisperse distributions, with a size of 3–5 nm and a spherical structure. The stability of these biogenic CDs in water and their effects on marine ecosystems were investigated using A. salina larvae (nauplii). Biogenic CDs were exposed to varying concentrations of 5–100 μL for 24, 48, 72, and 96 h, and the LC₅₀ values were calculated as 12.858 µg/L for CD₁ and 21.058 µg/L for CD₂. Bactericidal and fungicidal activities of CDs at sublethal concentrations were observed to have similar effects. Likewise, antioxidant activities (SOD, CAT), oxidative stress markers (ROS, MDA), and DPPH radical scavenging activities were investigated; SOD, CAT, and MDA activities varied depending on the exposure time of the larvae. Additionally, CDs induced high ROS generation and DPPH radical scavenging activity in nauplii. In fluorescence microscopy and TEM micrographs, different structural abnormalities were detected in larvae depending on the concentration of CDs, such as various degrees of abdominal fractures and fragmentation, and limb loss. Full article

Background: Apremilast (APM) is a selective phosphodiestrase-4 (PDE-4) inhibitor currently administered orally for the treatment of psoriasis. However, gastrointestinal irritation, frequent dosage regimens, and patient noncompliance limit its oral administration. Additionally, the poor permeability and solubility of APM make dermal administration challenging. Objective: The current study aims to formulate an optimized APM-loaded nanoemulsion formulation (APM-NE) to enhance drug delivery to deep psoriatic skin layers, thereby increasing dermal drug concentration for the effective treatment of psoriasis. Method: Using the phase titration method, the nanoemulsion (NE) was made with Capryol 90, Tween 20, and Labrasol as oil, surfactant, and co-surfactant, respectively. Results: The optimized formulation (F5) exhibited favorable physicochemical properties: mean droplet size of 147.4 ± 2.4 nm, and an entrapment efficiency (EE) reaching 86.30 ± 2.54%. TEM confirmed spherical, uniformly distributed droplets. In vitro release (86.1 ± 0.24%) followed zero-order kinetics. To enhance skin retention, F5 was incorporated into 2% Carbopol 980 gel, yielding F5G with pseudoplastic flow. Ex vivo permeation showed significantly higher drug delivery for F5 (1266.50 ± 5.6 µg/cm²) and F5G (1057.7 ± 6.76 µg/cm²) compared to crude APM gel (CR-APMG). In vivo, the inhibition of edema in rat paws was highest with F5G (66.83 ± 0.23%). RAW 264.7 cell studies showed 92.37% nitric oxide inhibition, and histopathology confirmed reduced inflammation. Conclusions: These results support APM-NE gel as a promising topical strategy for psoriasis therapy. Full article

Purpose: To evaluate the impact of a myopia control (MC) spectacle lens incorporating peripheral defocus on functional visual parameters compared to conventional single vision (SV) lenses. Methods: Thirty-nine young adults (age 21.1 ± 1.3 years; spherical equivalent −2.85 ± 2.8 D) participated in this single-session, within-subject crossover design. Distance and near LogMAR VA were assessed centrally and at 22° nasal and temporal off-axis. Distance contrast sensitivity (CS) was measured across five spatial frequencies (1.5–18 cpd) and the Area Under the Log CS Function (AULCSF) calculated. Retinal sensitivity was evaluated using automated static perimetry. Dynamic visual performance was assessed using a standardized video game platform. Outcomes were compared using repeated measures ANOVA or Wilcoxon signed-rank tests. Results: Central VA was comparable between lens types. MC lenses significantly reduced off-axis distance VA (nasal: 0.35 ± 0.15 LogMAR; temporal: 0.20 ± 0.14 LogMAR; both p < 0.001) and near VA (nasal: 0.72 ± 0.25 LogMAR; temporal: 0.34 ± 0.2 LogMAR; both p < 0.001). Off-axis AULCSF was significantly reduced with MC lenses (nasal: 12.07 ± 5.06 vs. 26.37 ± 5.00 units; temporal: 13.00 ± 6.93 vs. 27.14 ± 4.64 units; both p < 0.001), while central AULCSF remained similar between lens types (SV: 27.87 ± 5.04 vs. MC: 27.15 ± 5.02 units; p = 0.277). No significant differences were found for visual field indices (all p > 0.05). Video game accuracy was comparable between lenses, but task completion time was slower with MC lenses (20.71 ± 10.08 vs. 18.39 ± 6.65 s; p = 0.012). Conclusions: MC spectacle lenses preserve central VA, CS, and visual field sensitivity but induce significant off-axis VA and off-axis CS reductions. Dynamic visuomotor accuracy is maintained, though task completion speed is modestly reduced. These functional trade-offs should be considered when prescribing MC lenses. Full article

To improve the adaptability and adhesion of wall-climbing robots on complex curved surfaces, a self-adaptive spherical magnetic wheel robot is proposed for inspecting three-dimensional variable-curvature structures. The robot employs a bilateral wheeled design with passive magnetic modules that automatically adjust to contact conditions, ensuring efficient adhesion without active control. A Halbach-array magnetic circuit further enhances adhesion without increasing size or weight. Simulations analyze the effect of swing angle on adhesion and determine the minimum adaptable curvature radius. Experiments show stable climbing on surfaces with radii of 100–350 mm, obstacle-crossing up to 7 mm, and a payload capacity of 16.63 kg. Compared with existing designs, the robot offers improved curvature adaptability and load capacity under similar size and weight constraints. Full article

A microsporidian species, Glugea sp., was identified infecting the visceral cavity of commercial sardines (Sardina pilchardus) from an Atlantic fishery. Macroscopic examination revealed a white, friable mass that readily disintegrates, releasing spherical to ovoid microsporidian spores. Ultrastructural analysis shows an isofilar polar tube with 10–15 coils arranged in one to three rows. The study combined macrophotography, light microscopy, histological staining, transmission electron microscopy (TEM), and molecular analyses. Morphologically, Glugea sp. shares some features with Glugea vincentiae; however, molecular data do not support a close phylogenetic relationship between these two species. Phylogenetic analysis based on 18S rRNA sequences places the organism within a clade comprising G. plecoglossi, G. thunni, G. atherinae, G. gasterostei, G. hertwigi and G. anomala. Despite the high sequence similarity observed within this group, morphological and ultrastructural characteristics allowed differentiation of the present species, highlighting the limitations of relying solely on conserved molecular markers for species delimitation. A comprehensive morphological and molecular description of Glugea sp. is provided. Given the ecological and economic relevance of microsporidia, as well as their recognized role in animal and human disease, this new host–parasite association may have implications for fisheries and food safety, particularly considering the widespread consumption of sardines. Full article

Background/Objectives: Toric intraocular lens (IOL) implantation is the standard approach for correcting corneal astigmatism during cataract surgery and refractive lens exchange (RLE). Evidence on outcomes in eyes with high corneal astigmatism (≥2.00 diopters, D), particularly in heterogeneous real-world settings, remains limited. This study evaluated visual, refractive, and astigmatic vector outcomes of toric IOL implantation in a consecutive high-astigmatism cohort and investigated predictors of residual astigmatic error. Methods: This single-center, single-surgeon retrospective analysis of prospectively collected data included 161 eyes (118 patients) with preoperative corneal astigmatism ≥ 2.00 D undergoing cataract surgery or RLE with toric IOL implantation (June 2023–December 2025). Primary outcomes at one month included visual acuity, manifest refraction, and Alpins vector analysis at the corneal plane. Secondary analyses comprised refractive stability assessment (n = 75 eyes, median seven months), comparison of astigmatic outcomes between emmetropia-targeted and intentional myopia-targeted eyes, and multivariate regression of predictors of residual astigmatic error. Results: Mean postoperative UDVA and CDVA were 0.19 ± 0.24 and 0.09 ± 0.15 logMAR, respectively. Spherical equivalent prediction error was −0.19 ± 0.42 D (69.6% within ±0.50 D of target). Mean residual cylinder was 0.52 ± 0.49 D; 62% and 88.8% of eyes achieved ≤0.50 D and ≤1.00 D, respectively. Vector analysis demonstrated a mean difference vector of 0.53 ± 0.44 D, a correction index of 1.04 ± 0.20, and near-zero centroid deviation (0.03 D @ 43°), indicating the absence of systematic directional prediction error. Refractive outcomes were stable at medium-term follow-up. Astigmatic correction accuracy was equivalent between emmetropia-targeted and intentional myopia-targeted eyes (p > 0.05 for all primary metrics). Multivariate regression identified IOL cylinder power (β = 0.051, p = 0.031) and oblique astigmatism orientation (β = 0.299 vs. WTR, p = 0.032) as independent predictors of greater residual astigmatic error. No sight-threatening complications occurred. Conclusions: Toric IOL implantation provides safe, predictable, and stable correction of high corneal astigmatism in a real-world mixed cohort. Astigmatic accuracy is maintained regardless of intended spherical refractive strategy, supporting the use of toric IOLs in highly myopic patients targeted for residual myopia. Oblique astigmatism orientation is an independent predictor of reduced correction accuracy, consistent with known limitations of current toric calculators for this meridian. Full article

The current paper studies the global shell layer of the Finite Ring Continuum framework in the symmetry-complete regime realized here by framed finite fields, ${\mathbb{F}}_{\mathsf{p}}(\mathsf{t};0,1,e_{\mathsf{t}})$, with $\mathsf{p}=4\mathsf{t}+1$. We show that a single symmetry-complete shell carries a unified finite Euclidean datum for which its continuum comparison interpretation reproduces the familiar structural roles of e, $\pi$, and i of a one-phase step with an exponential kernel, a half-period, and a quarter-turn, respectively. In the same shell, the orbital geometry is generated by additive meridian action and multiplicative phase action from that same frame datum. The resulting orbital shell has a canonical spherical completion, combinatorially equivalent to the two-sphere, with labels depending on the chosen frame, but the shell type fixed up to isomorphism. Arbitrary finite-precision approximation on this external spherical comparison object is then obtained within every fixed symmetry-complete shell by the scale-periodic framed-rational refinement generated by the same frame datum. The Fourier formalism is developed strictly as a discrete Fourier transform over the shell ring, with conventional continuum Fourier language becoming a continuum large-$\mathsf{p}$ comparison case of that shell formalism. Full article

The nonlinear dynamic response of aerospace thin-walled structures in a post-buckling state under thermo-acoustic loads is critical for their design. This study investigates this phenomenon through integrated experimental and numerical approaches. Acoustic tests on thermally stressed flat plates yielded results in close agreement with finite element and reduced-order modal (FEM/ROM) simulations, with first-order frequency deviations within ±2 Hz and strain values of the same order of magnitude (10.7 µε vs. 9.5 µε at 50 °C). A key observation is the non-monotonic variation in the thermal modal frequency, which initially decreases then increases with the buckling coefficient, while dynamic strain data further validate the computational model. Comparative analysis of three Haynes 188 alloy geometries—flat plates, cylindrical shells, and spherical shells—reveals distinct behaviors rooted in their critical buckling temperatures (68.46 °C, 151.20 °C, and 698.28 °C, respectively): flat plates exhibit softening–hardening transitions with a frequency range of 491–624 Hz; cylindrical shells show irregular responses with a dramatic frequency drop from 1120 Hz to 360 Hz; and spherical shells maintain the highest stability and frequency range (1913–2109 Hz), governed by the buckling coefficient’s linear effect. Time-domain and probability density function (PDF) analyses elucidate the snap-through phenomena and the modulating roles of the buckling coefficient and sound pressure level (SPL). These findings underscore that geometric configuration and inherent stiffness are critical to post-buckling performance, providing a theoretical basis for designing aerospace components in extreme environments. Full article

Room acoustics computer models based on geometrical acoustics usually handle the sound reflections by the assumption of plane waves. However, if the sound source is a point source, which is usually the case, the spherical wave reflection would be more correct. An approximate model for the spherical wave reflection is presented, starting with the assumption of an infinite plane. It was found that the errors caused due to the simplified plane wave assumption can be significant, especially for hard surfaces and near grazing incidence. As something new, the gradual transition from a spherical wave to a plane wave approximation was addressed. For sound propagation exceeding 50 times the wavelength, the plane wave approximation was found to be fully justified, but for shorter distances the spherical wave reflection model should be applied. In contrast to previous work on spherical wave reflection, the reflection from a finite-sized surface was studied. For the first time, the spherical wave reflection model was combined with the complex radiation impedance of a finite-sized surface. One interesting application example of the spherical reflection model is the attenuation of sound propagation above the audience area in a performance space. Finally, the extension of the spherical wave reflection model to higher order reflections was addressed. Full article

The exploration of lunar caves is a critical aspect of the space exploration program of the European Space Agency (ESA). To facilitate this mission, the DAEDALUS study investigated a novel spherical robot design in 2021. The proposed robot uses a unique telescopic linear rod mechanism to generate rotation and hence locomotion. This drive mechanism requires a dedicated control scheme to ensure both locomotion and simultaneously stabilization of the robot. The overall task of following a curved trajectory is also a problem that cannot be solved by simple algorithms. In this work, we introduce, calculate, and simulate a solution for these tasks, the Virtual Pose Instruction Plane (VPIP). The VPIP breaks the problem of multiple independent controllable rods down to two controllable parameters (roll and pitch of the plane), which control the linear motion velocity, balance and ultimately curvature motion of the robot. Initial simulations show that both speed and cornering can be controlled by the VPIP. Full article

Background/Objectives: The clinical decision between preserving periodontally compromised teeth and replacing them with dental implants represents a complex clinical dilemma influenced by biological, prosthetic, economic, and professional factors. The aim of this pilot study was to develop and preliminarily validate a questionnaire designed to assess dentists’ attitudes and therapeutic preferences regarding the use of periodontally compromised teeth as prosthetic abutments versus extraction and implant-supported rehabilitation. Methods: An observational cross-sectional study was conducted, among Romanian dentists, using a structured self-administered questionnaire consisting of 43 items organized into seven sections addressing clinical attitudes, decision-making factors, professional competence, prosthetic treatment preferences, and implant-related clinical practices. A total of 111 Romanian dentists completed the questionnaire. Responses were recorded using a five-point Likert scale. Statistical analysis was performed using IBM SPSS Statistics software. Internal consistency was evaluated using Cronbach’s alpha coefficient and intraclass correlation coefficient (ICC). Construct validity was assessed using exploratory factor analysis based on Principal Component Analysis with Varimax rotation. Results: The questionnaire demonstrated good internal consistency across most sections, with Cronbach’s alpha values ranging between 0.795 and 0.859 after scale optimization. Item–total correlations indicated adequate contribution of individual items to overall scale reliability. Intraclass correlation coefficients confirmed moderate reliability for individual items and good reliability for average section scores. Exploratory factor analysis showed satisfactory sampling adequacy (KMO = 0.709) and statistically significant Bartlett’s test of sphericity (p < 0.001), supporting the suitability of the data for factor analysis. The sample population was predominantly composed of early-career dentists with limited clinical experience, which should be considered when interpreting the findings. Conclusions: The developed questionnaire demonstrated satisfactory psychometric properties, including good internal consistency and acceptable construct validity, supporting its use as a research instrument for assessing Romanian dentists’ self-reported attitudes, therapeutic preferences, and perception-based decision patterns regarding the preservation of periodontally compromised teeth and implant-supported prosthetic rehabilitation. Full article

To investigate the distribution pattern and magnitude of residual stress at the weld toe of pipe-sphere connections in welded hollow sphere joints, the blind-hole method was employed to measure welding residual stress at both the spherical weld toe and pipe weld toe, yielding the magnitude and distribution characteristics of the residual stress. Additionally, the VISUAL-Environment finite element simulation software was utilized to obtain the temperature field, residual stress field, and residual stress distribution curves at the weld seam. The results indicate that welding residual stress in the entire welded hollow sphere joint exhibits both periodic and stochastic characteristics, with these two patterns showing good consistency. Meanwhile, finite element analysis results reveal the presence of both residual tensile and compressive stresses on the spherical surface and the connected pipe, with the welding residual stress maintaining a self-equilibrated state across the entire specimen. This study provides a foundational basis for subsequent research on the fatigue performance of grid structures with welded hollow sphere joints. Full article