Search Results (269)

This paper focuses on the scoring-wheel cutting process for circular structures of OLED display panels, conducting in-depth research through an experiment–analysis–optimization system. Based on the Taguchi experimental design, a three-factor, five-level experiment is conducted, with the blade wheel angle (A), cutting speed (B), and pressure (C) set as influencing factors, and the scratch depth (h), width (w), median crack depth (l), and transverse crack width (d) set as evaluation indicators. The experiments are carried out using a self-developed dicing-wheel cutting device, and the morphology, roughness, and hardness of the cutting surface and cross-section are characterized by means of ultra-depth-of-field microscopy, laser confocal microscopy, microhardness tester, and other equipment. The research shows that the order of factors affecting the cutting quality is as follows: A > C > B. Through the analysis of morphology and crack characteristics, it is determined that the optimal parameter combination is a dicing wheel angle of 130°, a cutting speed of 20 mm/s, and a pressure of 11 N. The verification results indicate that this combination can reduce surface roughness, stabilize hardness, and realize efficient and precise processing of special-shaped structures in OLED display panels, providing strong theoretical and technical support for industrial process optimization. Full article

This study examines the incorporation of chopped glass fiber and nano-silica into epoxy, focusing on their effects on the tribological and mechanical properties. Three reinforcement ratios (1 wt.%, 3 wt.%, and 5 wt.%) were analyzed by scratch tests and profilometric analysis. The coefficient of friction (COF), scratch depth, and scratch width values of the unreinforced epoxy resin were measured as 0.45, 37.73 µm and 479 µm, respectively. The addition of glass fibers contributed to improved scratch performance by restricting material removal and stabilizing groove morphology, although higher fiber ratios caused an increase in COF. The results indicated that nano-silica increased scratch resistance with a COF of 0.42 at 5 wt.%, giving a scratch depth of 19.92 µm and a scratch width of 166 µm. Glass fiber also improved scratch performance, although there were high COF values for higher ratios, which could be due to the aggregation effect of the fibers. Statistical validation of the results was carried out through the Taguchi method and ANOVA analyses. These analyses showed that reinforcement type and ratio played an important role in scratch behavior. SEM analyses of worn surfaces showed that nano-silica can dissipate stress and minimize plastic deformation to yield improved scratch morphology. Overall, the results emphasize the complementary role of glass fiber and nano-silica reinforcements in improving the scratch resistance of epoxy resin for industrial applications. Full article

This study examines the effects of electrolyte composition, specifically the incorporation of dispersed particles, on the properties and formation kinetics of micro-arc oxidation (MAO) coatings on a bioinert titanium alloy. Coatings with particles of β-tricalcium phosphate (CP), wollastonite (CS), and combined coatings containing both types of particles (SP) were obtained. The MAO process was carried out using a Micro-Arc 3.0 unit in pulsed potentiostatic anode mode, with the process voltage ranging from 350 to 500 volts. The surface morphology and internal structure of the coatings were examined using scanning electron microscopy. The elemental composition of the coatings was determined by the EDX method, while the phase composition and fine structure of the coatings were investigated by XRD and TEM methods, respectively. The adhesion properties of the coatings were determined by means of scratch testing. When the MAO process voltage was increased to 500 V, the thickness of CP, CS, and SP coatings increased to 80, 50, and 50 μm, respectively. Notably, SP coatings demonstrated the highest adhesion strength (critical load L_c = 22 N), indicating their potential for use in load-bearing medical implants, where preventing delamination under mechanical stress is critical. Full article

The anodic oxidation technique was used for surface modification, resulting in the creation of a titanium-based nanotube oxide layer on a coarse-grained and ultrafine-grained Ti-13Nb-13Zr alloy. The modified surface morphology was analyzed using scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD). The electrochemical impedance spectroscopy (EIS) method was employed to evaluate the corrosion stability of the Ti-13Nb-13Zr alloy before and after anodic oxidation. Corrosion stability was determined by exposing the examined alloy to a solution that simulates environment in the human organism (Ringer’s solution). To examine the titanium-based nanotube oxide layer adhesion on the Ti-13Nb-13Zr alloy’s surface, a scratch test was performed. The hydrophilicity of the modified surface was measured using the contact angle between a drop of Ringer’s solution and the modified surface. The anodic oxidation led to the creation of a nanotube oxide layer on the surface of the Ti-13Nb-13Zr (wt.%) alloy. The impact of the ultrafine-grained structure on the homogeneity of the nanotube oxide layer obtained using anodic oxidation was observed. The ultrafine-grained structure contributed to the increased diameter of the nanotubes, while the combined effect of anodic oxidation and high-pressure torsion significantly increased the roughness of the Ti-13Nb-13Zr alloy’s surface, which is expected to enhance biomechanical compatibility by reducing cytotoxicity, providing a more adaptable modulus of elasticity for human body conditions and ensuring adequate corrosion resistance and hydrophilicity. In this study, it was established that the examined alloy had suitable corrosion resistance for utilization in medicine as a metallic implant in the human body. The scratch test showed acceptable adhesion from the titanium-based nanotube oxide layer created using anodic oxidation. Also, the determination of the surface contact angle showed that the surface after anodic oxidation was more hydrophilic than the surface before anodic oxidation. Full article

In this study, the effects of plasma assistance on the electron beam physical vapour deposition (EB-PVD) process were investigated using an industrial coater (Smart Coater ALD Vacuum Technologies GmbH) equipped with a dual hollow cathode system. This configuration enabled the generation of a plasma environment during the deposition of the ceramic top coat onto a metallic substrate. The objective was to assess how plasma assistance influences the microstructure and thickness distribution of 7% wt. yttria-stabilised zirconia (YSZ) thermal barrier coatings (TBCs). Coatings were deposited with and without plasma assistance to enable a direct comparison. The thickness uniformity and columnar morphology of the 7YSZ top coats were evaluated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The mechanical properties of the deposited coatings were verified by the scratch test method. The results demonstrate that, in the presence of plasma, columnar grains become more uniformly spaced and exhibit sharper, well-defined boundaries even at reduced substrate temperatures. XRD analysis confirmed that plasma-assisted EB-PVD processes allow for maintaining the desired tetragonal phase of YSZ without inducing secondary phases or unwanted texture changes. These findings indicate that plasma-assisted EB-PVD can achieve desirable coating characteristics (uniform thickness and optimised columnar structure) more efficiently, offering potential advantages for high-temperature applications in aerospace and power-generation industries. Continued development of the EB-PVD process with the assistance of plasma generation could further improve deposition rates and TBC performance, underscoring the promising future of HC-assisted EB-PVD technology. Full article

Developing high-performance bio-based epoxy resins as sustainable alternatives to petroleum-derived bisphenol A (BPA) epoxies for recyclable carbon fiber-reinforced polymers (CFRPs) is pivotal in materials research. Herein, the bio-based bisphenol monomer BDEF was synthesized from the lignin derivative 4-propylguaiacol. The derived epoxy monomer BDEF-EP was cured with adipic acid to form a bio-based vitrimer. Stress relaxation synergistically accelerates through intrinsic dynamic carboxylic acid ester exchange and enhanced chain mobility from the flexible propyl structure. At 220 °C, this vitrimer shows rapid stress relaxation (τ* < 30 s) and repairs ~90% of surface scratches in 30 min. It exhibits tensile and flexural strengths of 69 MPa and 105 MPa, respectively. BDEF-EP’s low viscosity reduces diluent needs in composite fabrication, lowering costs and improving efficiency. The resulting bio-based CFRP achieves tensile and flexural strengths of 543 MPa and 414 MPa, respectively, which are comparable to commercially available petroleum-derived CFRP. In addition, CFRP containing dynamic crosslinked networks demonstrates degradable recyclability in ethylene glycol solvent, preserving the surface morphology and chemical structure of recovered carbon fibers. The results demonstrate that this bio-based epoxy vitrimer has promising potential for developing sustainable, degradable, and recyclable CFRP composites. Full article

Aero-engines, as complex systems integrating numerous rotating components and accessory equipment, operate under harsh and demanding conditions. Prolonged use often leads to frequent mechanical wear and surface defects on accessory parts, which significantly compromise the engine’s normal and stable performance. Therefore, accurately and rigorously identifying failure modes is of critical importance. In this study, failure modes are categorized into notches, scuffs, and scratches based on original bearing structure images. The YOLOv8 architecture is adopted as the base framework, and a Dilated Reparameterization Block (DRB) is introduced to enhance the Dilation-Wise Residual (DWR) module. This structure uses a large convolutional kernel to capture fragmented and sparse features in wear images, ensuring a wide receptive field. The concept of structural reparameterization is incorporated into DWR to improve its ability to capture detailed target information. Additionally, the standard convolutional layer in the head of the improved DWR-DRB structure is replaced by Spatial-Depth Convolution (SPD-Conv) to reduce the loss of wear morphology and enhance the accuracy of fault feature extraction. Finally, a fusion structure combining Focaler and MPDIoU is integrated into the loss function to leverage their strengths in handling imbalanced classification and bounding box geometric regression. The proposed method achieves effective recognition and diagnosis of mechanical wear fault patterns. The experimental results demonstrate that, compared to the baseline YOLOv8, the proposed method improves the mAP50 for fault diagnosis and recognition from 85.4% to 91%. Full article

Background/Objectives: Pompia is an ancient, endemic citrus ecotype native to Sardinia (Italy), characterized by distinctive morphology and high content of bioactive compounds. Despite increasing interest, several aspects of this fruit, including its histological characteristics, remain poorly understood. This study aims to address this gap by investigating the anatomical features and spatial distribution of secretory cavities involved in essential oil (EO) production and accumulation, while also evaluating the EO’s chemical profile and associated biological activity. Methods: Pompia peel (flavedo and albedo) was subjected to histological analysis through fixation, dehydration, resin inclusion and sectioning. Sections were stained with 0.05% toluidine blue and observed under a light microscope to measure different parameters of secretory cavities. Essential oil (EO) was obtained from Pompia peel by hydrodistillation and characterized by gas chromatography–mass spectrometry (GC–MS) analysis. The biological activity of Pompia EO was assessed in vitro using NIH/3T3 fibroblasts, where wound-healing was evaluated by scratch assay and anti-senescence effects by β-galactosidase and γH2AX activity. Results: Microscopic analysis of the peel revealed pronounced variability in depth and size of the secretory cavities, along with the presence of lenticel-like structures in the epidermis. GC–MS analysis showed that Pompia EO is dominated by limonene (89%), with minor compounds including myrcene, geranial and neral. In vitro biological assays demonstrated that the EO promotes cell migration in a wound-healing model at concentrations ≥ 12.5 µg/mL and reduces markers of cellular senescence, including β-galactosidase activity and γH2AX foci, in etoposide-induced senescent fibroblasts. Conclusions: Overall, this study provides the first histological characterization of Pompia peel and confirms the bioactive potential of its EO. These findings support future applications in skin regeneration and anti-aging strategies and contribute to the valorization of this underexplored Citrus ecotype. Full article

The apoptotic mechanism is complex and involves many pathways. Defects can occur at any time along these pathways, resulting in malignant cell transformation and resistance to anticancer drugs. Collective efforts have made great progress in the implementation of natural products in clinical use and in discovering new therapeutic opportunities. This study aimed to screen volatile compounds of Warburgia salutaris leaf extracts and investigate their pro-apoptotic effects on MCF-7 cells. The approach was mainly based on determining cell viability using MTT and scratch assays, and DNA synthesis and damage using BrdU and comet assays, respectively. DAPI/PI stains were used for morphological analysis and expression was determined by RT-PCR and human apoptotic proteome profiler. Warburgia salutaris extracts exhibited antiproliferative effects on MCF-7 cells in a time- and dose-dependent manner. Acetone and methanol extracts exhibited low IC₅₀ at 24, 48 and 72 h. Furthermore, the scratch test revealed that MCF-7 does not metastasise when treated with IC₅₀. Expression showed upregulation of pro-apoptotic proteins and executioner caspases. Taken together, these findings suggest that leaves can promote apoptosis through the intrinsic apoptotic pathway, as observed by upregulation of the Bax and caspase 3 proteins. This paper provides new insights into the mechanisms of action of W. salutaris leaf extracts in the development of anticancer drugs. Full article

Pressure ulcers (PUs) are localized injuries caused by prolonged mechanical loading and ischemia, often leading to delayed healing and high recurrence rates. Although conventional treatments aim to support tissue repair, their efficacy remains limited, prompting interest in noninvasive therapies such as the pulsed electromagnetic field (PEMF). The PEMF has been reported to enhance cellular proliferation, re-epithelialization, and collagen remodeling, but its effects in pressure ulcer models, particularly concerning genetic background, remain unclear. This study investigated the therapeutic effects of the PEMF in a murine pressure ulcer model established by ischemia and reperfusion injury induced with externally attached magnets in two mouse strains, BALB/c and C57BL/6. The PEMF (10 Hz, 24 h per day) was used to treat PU-induced mice from day 4 to day 15 in BALB/c mice and to day 14 in C57BL/6 mice. Wound healing was assessed by gross morphological observation, histological analysis, and digital quantification of epidermal lesion length and collagen-positive area. In BALB/c mice, PEMF-treated wounds showed a modest trend toward improved re-epithelialization and collagen deposition, although the differences were not statistically significant. In contrast, C57BL/6 mice exhibited a significantly shorter length of epidermal lesion in the PEMF group on day 14, indicating enhanced epidermal regeneration. Collagen analysis showed comparable levels between treated and control groups in both strains, with no significant differences observed. To further assess the cellular response to PEMF, a scratch wound assay was conducted using HaCaT cells. Quantitative analysis demonstrated that PEMF treatment accelerated cell migration and wound closure in vitro. These findings suggest that PEMF enhances epidermal regeneration and keratinocyte mobility, with therapeutic responses potentially influenced by genetic background. This study supports the potential application of PEMF in pressure ulcer treatment and underscores the importance of strain selection in preclinical wound healing research. Full article

Background/Objectives: Cancer is one of the leading causes of death worldwide, and skin cancer is especially prevalent and lethal in Brazil. Despite advancements in treatment, there is still a need for new anticancer agents that are effective, selective, and less toxic. This study aimed to evaluate the cytotoxic and therapeutic potential of the peptide PEPAD. Methods: The cytotoxicity of PEPAD was assessed by MTT assay in murine melanoma (B16F10-Nex2), human melanoma (SK-MEL-28), breast (MCF-7), and cervical (HeLa) cancer cell lines. Selectivity was evaluated in healthy cells (RAW 264.7 and FN1). Morphological changes were analyzed by microscopy. Cell migration was assessed using scratch assays. Apoptotic features were evaluated using MitoTracker Deep Red, NucBlue, CaspACETM labeling, and flow cytometry. Immunogenic cell death was investigated by calreticulin and HMGB1 release. Molecular dynamics simulations explored peptide structure and interaction with lipid membranes. Results: PEPAD showed IC₅₀ values of 7.4 µM and 18 µM in B16F10-Nex2 and SK-MEL-28 cells, respectively, and >60 µM in MCF-7 and HeLa cells. Low toxicity was observed in healthy cells (IC₅₀ > 56 µM), indicating high selectivity. Apoptotic morphology and reduced cell migration were observed. Flow cytometry and fluorescence probes confirmed apoptosis and mitochondrial swelling. Calreticulin and HMGB1 release indicated immunogenic cell death. Simulations showed that PEPAD maintains a stable α-helical conformation and interacts with membranes. Conclusions: These findings highlight PEPAD’s selective cytotoxicity and its potential as an anticancer agent with apoptotic and immunogenic properties, making it a promising candidate for therapeutic development. Full article

Single-crystal 4H silicon carbide (4H-SiC) is a key substrate material for third-generation semiconductor devices, where surface and subsurface integrity critically affect performance and reliability. This study systematically examined the evolution of surface morphology and subsurface damage (SSD) during nanoscratching of 4H-SiC under varying normal loads (0–100 mN) using a nanoindenter equipped with a diamond Berkovich tip. Scratch characteristics were assessed using scanning electron microscopy (SEM), while cross-sectional SSD was characterised via focused ion beam (FIB) slicing and transmission electron microscopy (TEM). The results revealed three distinct material removal regimes: ductile removal below 14.5 mN, a brittle-to-ductile transition between 14.5–59.3 mN, and brittle removal above 59.3 mN. Notably, substantial subsurface damage—including median cracks exceeding 4 μm and dislocation clusters—was observed even within the transition zone where the surface appeared smooth. A thin amorphous layer at the indenter-substrate interface suppressed immediate surface defects but promoted subsurface damage nucleation. Crack propagation followed slip lines or their intersections, demonstrating sensitivity to local stress states. These findings offer important insights into nanoscale damage mechanisms, which are essential for optimizing precision machining processes to minimise SSD in SiC substrates. Full article

Chromium–aluminum nitride (CrAlN) coatings were deposited on polished H13 tool steel substrates using direct current (DC) magnetron sputtering. The Cr/Al composition in the target was varied by inserting either four or eight chromium (Cr) plugs into cavities machined into an aluminum (Al) plate target. Nitrogen was introduced as a reactive gas to facilitate the formation of the nitride phase. Coatings were deposited at substrate bias voltages of −30 V, −50 V, and −60 V to study the combined effects of composition and ion energy on coating properties. Compositional analysis of coatings deposited at a −50 V bias revealed Cr/Al ratios of approximately 0.8 and 1.7 for the 4- and 8-plug configurations, respectively. This increase in the Cr/Al ratio led to a 2.6-fold improvement in coating hardness. Coatings produced using the eight-Cr-plug target exhibited a nearly linear increase in hardness with increasing substrate bias voltage. Cross-sectional scanning electron microscopy revealed a uniform bilayer structure consisting of an approximately 0.5 µm metal interlayer beneath a 2–3 µm CrAlN coating. Surface morphology analysis indicated the presence of coarse microdroplets in coatings with the lower Cr/Al ratio. These microdroplets were significantly suppressed in coatings with higher Cr/Al content, especially at increased bias voltages. This suppression is likely due to enhanced ion bombardment associated with the increased Cr content, attributed to Cr’s relatively higher atomic mass compared to Al. Coatings with lower hardness exhibited greater scratch resistance, likely due to the influence of residual compressive stresses. The findings highlight the critical role of both Cr/Al content and substrate bias in tailoring the tribo-mechanical performance of PVD CrAlN coatings for wear-resistant applications. Full article

Automated surface defect detection in steel manufacturing is pivotal for ensuring product quality, yet it remains an open challenge owing to the extreme heterogeneity of defect morphologies—ranging from hairline cracks and microscopic pores to elongated scratches and shallow dents. Existing approaches, whether classical vision pipelines or recent deep-learning paradigms, struggle to simultaneously satisfy the stringent demands of industrial scenarios: high accuracy on sub-millimeter flaws, insensitivity to texture-rich backgrounds, and real-time throughput on resource-constrained hardware. Although contemporary detectors have narrowed the gap, they still exhibit pronounced sensitivity–robustness trade-offs, particularly in the presence of scale-varying defects and cluttered surfaces. To address these limitations, we introduce MBY (MBDNet-Attention-YOLO), a lightweight yet powerful framework that synergistically couples the MBDNet backbone with the YOLO detection head. Specifically, the backbone embeds three novel components: (1) HGStem, a hierarchical stem block that enriches low-level representations while suppressing redundant activations; (2) Dynamic Align Fusion (DAF), an adaptive cross-scale fusion mechanism that dynamically re-weights feature contributions according to defect saliency; and (3) C2f-DWR, a depth-wise residual variant that progressively expands receptive fields without incurring prohibitive computational costs. Building upon this enriched feature hierarchy, the neck employs our proposed MultiSEAM module—a cascaded squeeze-and-excitation attention mechanism operating at multiple granularities—to harmonize fine-grained and semantic cues, thereby amplifying weak defect signals against complex textures. Finally, we integrate the Inner-SIoU loss, which refines the geometric alignment between predicted and ground-truth boxes by jointly optimizing center distance, aspect ratio consistency, and IoU overlap, leading to faster convergence and tighter localization. Extensive experiments on two publicly available steel-defect benchmarks—NEU-DET and PVEL-AD—demonstrate the superiority of MBY. Without bells and whistles, our model achieves 85.8% mAP@0.5 on NEU-DET and 75.9% mAP@0.5 on PVEL-AD, surpassing the best-reported results by significant margins while maintaining real-time inference on an NVIDIA Jetson Xavier. Ablation studies corroborate the complementary roles of each component, underscoring MBY’s robustness across defect scales and surface conditions. These results suggest that MBY strikes an appealing balance between accuracy, efficiency, and deployability, offering a pragmatic solution for next-generation industrial quality-control systems. Full article

In familial Alzheimer’s disease (FAD), presenilin 1 (PSEN1) E280A cholinergic-like neurons (ChLNs) induce aberrant secretion of extracellular amyloid beta (eAβ). How PSEN1 E280A ChLNs-eAβ affects microglial activity is still unknown. We obtained induced microglia-like cells (iMG) from human peripheral blood cells (hPBCs) in a 15-day differentiation process to investigate the effect of bolus addition of Aβ42, PSEN1 E280A cholinergic-like neuron (ChLN)-derived culture supernatants, and PSEN1 E280A ChLNs on wild type (WT) iMG, PSEN1 E280A iMG, and sporadic Alzheimer’s disease (SAD) iMG. We found that WT iMG cells, when challenged with non-cellular (e.g., lipopolysaccharide, LPS) or cellular (e.g., Aβ42, PSEN1 E280A ChLN-derived culture supernatants) microenvironments, closely resemble primary human microglia in terms of morphology (resembling an “amoeboid-like phenotype”), expression of surface markers (Ionized calcium-binding adapter molecule 1, IBA-1; transmembrane protein 119, TMEM119), phagocytic ability (high pHrodo™ Red E. coli BioParticles™ phagocytic activity), immune metabolism (i.e., high generation of reactive oxygen species, ROS), increase in mitochondrial membrane potential (ΔΨm), response to ATP-induced transient intracellular Ca²⁺ influx, cell polarization (cluster of differentiation 68 (CD68)/CD206 ratio: M1 phenotype), cell migration activity according to the scratch wound assay, and especially in their inflammatory response (secretion of cytokine interleukin-6, IL-6; Tumor necrosis factor alpha, TNF-α). We also found that PSEN1 E280A and SAD iMG are physiologically unresponsive to ATP-induced Ca²⁺ influx, have reduced phagocytic activity, and diminished expression of Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) protein, but when co-cultured with PSEN1 E280A ChLNs, iMG shows an increase in pro-inflammatory phenotype (M1) and secretes high levels of cytokines IL-6 and TNF-α. As a result, PSEN1 E280A and SAD iMG induce apoptosis in PSEN1 E280A ChLNs as evidenced by abnormal phosphorylation of protein TAU at residue T205 and cleaved caspase 3 (CC3). Taken together, these results suggest that PSEN1 E280A ChLNs initiate a vicious cycle between damaged neurons and M1 phenotype microglia, resulting in excessive ChLN death. Our findings provide a suitable platform for the exploration of novel therapeutic approaches for the fight against FAD. Full article