Search Results (3,767)

Metal substrates were preprocessed via picosecond laser surface texturing (PLST, 532 nm) to fabricate interfacial microgrooves for tribological performance optimization prior to deposition of a magnesium silicate hydroxide (MSH)/graphite/MoS₂–PI solid lubricant coating. By tuning the PLST parameters (average laser power: 0.2–0.5 W, scan passes: 3–5, hatch spacing: 0.005–0.1 mm), three representative texture geometries (linear, circular, and square) were produced, and the resulting coating performance was compared with conventional mechanical polishing and sandblasting pretreatments. Among the three laser textures, the linear texture exhibited the most excellent tribological performance and interfacial adhesion, outperforming the circular and square counterparts. Ball-on-disk tests in a kerosene-contaminated environment (10 N, 800 rpm) showed that the linear-textured sample reached the lowest steady-state friction coefficient (0.038), lower than polished (0.048) and sandblasted (0.052) controls, together with reduced wear scar dimensions. Progressive-load scratch tests indicated a pronounced adhesion enhancement, with the critical failure load increasing from 7.05 N (polished) to 26.05 N for the linear-textured interface, which is higher than 21.21 N (circular) and 23.78 N (square) textures. Cross-sectional microscopy and EDS mapping reveal that the laser-defined microgrooves (~15 μm depth, ~120 μm width, ~500 μm spacing) act as a parameter-controlled interfacial architecture that promotes mechanical interlocking and provides lubricant-rich reservoirs. This laser-enabled interfacial design suppresses delamination, supports transfer film stability, and ultimately enhances the coating’s tribological performance by reducing friction and wear. Full article

In a previous study, we demonstrated that a novel surface treatment applied to laser-melted Ti6Al4V substrates supports osteoblast-like cell adhesion, proliferation, and the activation of early osteogenic pathways. Building on these preliminary findings, the present work aimed to further investigate the ability of the same surface to promote extracellular matrix (ECM) deposition, organization, and osteogenic maturation, which are critical events for the establishment of a stable bone–implant interface in subperiosteal dental implants. Human osteoblast-like MG-63 cells were cultured on Ti6Al4V discs subjected to different surface treatments, including a proprietary surface modification (ATcs) specifically designed for subperiosteal applications. ECM formation and maturation were evaluated through scanning electron microscopy coupled with energy-dispersive spectroscopy, immunofluorescence, and semiquantitative analyses of osteogenic markers type I collagen (COL1A1), secreted protein acidic and rich in cysteine (SPARC), and dentin matrix protein 1 (DMP1) through Western blotting. The results showed that, while all tested surfaces supported cell adhesion, the ATcs surface promoted a distinct osteogenic profile characterized by enhanced DMP1 expression, organized collagen deposition, and the formation of calcium–phosphate–rich mineralized structures. Compared to surfaces that primarily stimulated cell proliferation or early matrix production, ATcs appeared to favour progression toward late-stage osteogenic maturation and matrix mineralization. Taken together, these findings extend our previous observations and indicate that this novel surface treatment not only supports osteoblast viability and early differentiation but also promotes extracellular matrix maturation, a key prerequisite for effective osseointegration. Although further in vivo studies are required, the present data provide additional biological rationale for the use of ATcs-treated Ti6Al4V surfaces in next-generation custom-made subperiosteal implant designs. Full article

Streptococcus mutans (S. mutans), one of the main etiological pathogens of dental caries, forms dental plaque biofilms that drive tooth decay. Although bacterial membrane vesicles (MVs) are increasingly recognized as modulators of biofilm biology, little is known about MVs generated by S. mutans. The objective of this study is to investigate the role of S. mutans-derived MVs in the development of S. mutans biofilms formed under static conditions in plates or confocal dishes. Transmission electron microscopy and nanoparticle tracking analysis revealed that the MVs were cup-shaped with bilayered membranes and averaged 80.49 $\pm$ 32.24 nm in diameter. The addition of ≥5 µg/mL MVs enhanced biofilm formation during the initial adhesion stage (0 to 6 h), as demonstrated by crystal violet staining and XTT assays. Confocal laser scanning microscopy and scanning electron microscopy confirmed the incorporation of PKH26-labeled MVs into S. mutans biofilms and showed that supplemental MVs increased bacterial viability and extracellular polysaccharide biomass. Furthermore, RT-qPCR analysis revealed upregulated expression of genes related to adhesion and quorum-sensing systems in MV-treated biofilms. In conclusion, these findings indicate that S. muants MVs are integral biofilm components that promote biofilm establishment at the early stage of biofilm formation. Full article

Background/Objectives: Photobiomodulation Therapy (PBMT) is widely used in musculoskeletal rehabilitation. Although its clinical use continues to expand, the dose-dependent metabolic responses on specific musculoskeletal cell populations remain undefined. This study assessed the effects of 1064 nm PBMT on primary human tenocytes and bursa-derived cells across varying fluence and irradiance. Methods: Primary tenocytes and bursa-derived cells were cultured in 24-well plates and exposed to Hiro TT 1064 nm laser at fluences ranging from 1.5 to 6.0 J/cm² and irradiance levels of 90 or 125 mW/cm². Treatments were administered once daily for three consecutive days. Cellular activity was assessed using an XTT assay and bright field microscopy was performed to assess cell morphology and confluency. Statistical analysis was compared to evaluate dose-dependent effects. Results: PBMT demonstrated tissue-dependent effects on cellular metabolic activity and proliferation. In tenocytes, moderate fluence (4.5–6.0 J/cm²) significantly increased metabolic activity compared with control. In contrast, bursa-derived cells exhibited smaller magnitude changes, with most treatment groups demonstrating neutral or modest deviations from control. Conclusions: PBMT of 1064 nm wavelenght produced distinct dose-dependent responses in musculoskeletal cell types, with tenocytes demonstrating a threshold-dependent response and bursa-derived cells showing attenuated effects. These findings support the need for tissue-specific parameters when applying PBMT in clinical tendon-related applications. Full article

Glioblastoma (GBM) remains the most aggressive primary malignant brain tumor in adults, with poor survival largely driven by diffuse cellular infiltration, profound heterogeneity, and near-universal recurrence following standard therapy. Although maximizing the extent of resection is a key determinant of patient outcome, current clinical imaging modalities lack the spatial resolution necessary to detect microscopic tumor invasion and therapy-resistant cell populations. Emerging in vivo imaging technologies capable of cellular and near-single-cell resolution have therefore become a major focus in preclinical neuro-oncology research, with growing relevance for surgical guidance, treatment adaptation, and translational discovery. This review evaluates multiple optical imaging modalities, including multi-photon microscopy, near-infrared II fluorescence imaging, bioluminescence imaging, photoacoustic imaging, optical coherence tomography, confocal laser endomicroscopy, Raman spectroscopy, autofluorescence microscopy, and fluorescence macroscopy with a focus on their ability to detect residual GBM cells. Despite significant advances, these approaches remain constrained by limitations in molecular target availability, probe delivery across the blood–brain barrier, and signal variability within heterogeneous tumor regions. The biological complexity of GBM further challenges detection, as residual tumor cells are spatially dispersed and phenotypically diverse, limiting the effectiveness of single-marker or single-modality strategies. Together, these findings highlight the need for integrated, biologically informed imaging approaches to improve detection of residual disease and guide surgical decision making. Full article

Liquid infant formula has garnered increasing attention due to its mild thermal processing and superior retention of bioactive nutrients. Within such matrices, the lipid source is a critical determinant of protein digestion behavior, yet its influence on peptide bioavailability and intestinal homeostasis remains undefined. Given that efficient peptide absorption is vital for the systemic delivery of bioactivity in infants, understanding the lipid–protein synergy is essential for formula optimization. Moreover, excessive oxidative stress is closely associated with impaired intestinal health and developmental disorders in infants, making the regulation of oxidative stress crucial for maintaining intestinal function. The present study evaluated the effects of three distinct lipid sources—soybean oil (SM), bovine milk fat (BM), and goat milk fat (GM)—on the physicochemical stability, proteolytic digestion, peptide release, intestinal absorption, and oxidative stress modulation of goat-milk-based infant formula. An integrated approach combining physicochemical characterization, in vitro simulated infant digestion, and a Caco-2 intestinal epithelial cell model was employed. we demonstrate that all three lipids (3% w/w) formed stable emulsions with uniform spherical structures and mean particle diameters of 117–300 nm, as visualized by laser confocal microscopy. Following in vitro simulation of infant gastrointestinal digestion, the SM group exhibited the most extensive protein hydrolysis, yielding the highest total peptide content (4.28 ± 0.10 mg/mL) and generated the highest number of peptides identified by LC-MS/MS (474 types). Bioinformatic analysis predicted that peptides from all groups possess potential antihypertensive, hypoglycemic, and immunomodulatory activities. The Caco-2 monolayer cell model demonstrated that although the GM group produced fewer identified peptide species than the SM group (365 types), it achieved significantly higher intestinal peptide absorption rate (55.34 ± 1.05%). Furthermore, the GM digests provided superior protection against H₂O₂-induced oxidative stress in Caco-2 cells, markedly reducing reactive oxygen species levels and suppressing the expression of pro-inflammatory cytokines TNF-α and IL-6. Collectively, these findings reveal that while soybean oil promotes more extensive proteolysis, the use of homologous goat milk lipid enhances peptide bioaccessibility and confers potential cytoprotective effects on intestinal epithelial cells, underscoring its potential as a preferred lipid source in infant formula formulations. Full article

The methodical work describes all the necessary steps for establishing a stable oral ex vivo biofilm using saliva and crevicular plaque samples from periodontal healthy donors. First, cover slips were preconditioned with saliva supernatants and subsequently inoculated with crevicular plaque suspensions. Ex vivo biofilm formation was characterized by confocal laser scanning microscopy (cLSM) after 1, 4, 24, 48 and 72 h of anaerobic cultivation. Exemplarily, the inhibitory characteristics of blackcurrant fruit extracts [all-fruit juice (AFJ); alcoholic fraction from berry skins (AFBS)] were observed on 1, 4 and 24 h-aged ex vivo biofilms. Chlorhexidine (CHX, 0.2%) served as positive control. After direct contact (3 min), biofilms were dispersed, plated onto agar and anaerobically cultivated for 24 h. Early ex vivo biofilms (1 h-biofilm) showed scattered microbial colonies. After 4 h of cultivation, a multilayered biofilm was formed. Biofilm mass gradually increased, displaying a complex polymicrobial structure after 24 h. At 72 h, the biofilms had a dense three-dimensional appearance. Treatment with AFJ and CHX was more efficient in inhibiting biofilm growth compared to AFBS. Early biofilms (1 h, 4 h) were more susceptible to AFJ and CHX compared to 24 h-biofilms. The introduced model can be recommended for testing the efficiency of plaque-controlling agents. Full article

Background: Total glycosides of peony (TGP) have therapeutic potential for immune-related and inflammatory skin diseases, but their skin absorption is not satisfactory. This study aims to investigate how Evodia rutaecarpa volatile oil (VO-ER) enhances the permeability of TGP. Methods: Safety assessment was conducted through cell delivery and skin erythema tests. The chemical composition of VO-ER was identified via GC-MS. The study was conducted using modified Franz diffusion cells, microdialysis, confocal laser scanning microscopy (CLSM), attenuated total reflection–Fourier transform infrared spectroscopy (ATR-FTIR), molecular docking and molecular dynamics simulations (MD), laser Doppler flowmetry (LDF), and the western blotting method. Results: The study found that VO-ER promotes the permeation of total glycosides of peony in a concentration-dependent manner by disrupting the intercellular lipid tissue structure, downregulating the expression of claudin-1, claudin-7, and occludin, and improving local microcirculation, thereby promoting the absorption of TGP. Conclusions: VO-ER enhances the transdermal absorption of TGP through multiple mechanisms, such as disrupting the skin lipid barrier, downregulating tight junction proteins, and improving local skin microcirculation. This study provides a theoretical basis for VO-ER as a safe and effective new transdermal penetration enhancer, offering support for the development of topical preparations containing Evodia rutaecarpa and Paeonia lactiflora. Full article

This study proposes an innovative spacer design for use in spiral-wound membrane filtration systems as a high-performance alternative to conventional woven spacers. By eliminating interwoven filaments, this structure fundamentally reshapes flow patterns while maintaining mechanical support. A novel aspect of this methodology is the inaugural application of coupled computational fluid dynamics (CFD) and the discrete phase model (DPM) for modeling microbial particle transport and deposition dynamics, which has been a critical gap in prior studies that focused solely on hydrodynamic analysis without addressing biocolloid dynamics. Numerical simulations demonstrated that the novel design reduces stagnant zones by a significant amount compared to standard woven spacers and achieves a greater velocity uniformity. For all eight configurations of the novel design, the DPM-derived microbial distribution maps revealed a reduction of circa 65% in particle colonization density on the spacer surface, and this reaches a 77% reduction for the optimal design. These measurements directly linking structural geometry to antifouling efficacy provide mechanistic insight unattainable through conventional velocity field analysis alone. Experimental validation using optical coherence tomography (OCT) revealed a 40% reduction in TOC deposition, while confocal laser scanning microscopy (CLSM) quantified a 54% decrease in biofilm viability through adenosine triphosphate (ATP) measurements. The incorporation of the optimal spacer in the plate-and-frame test module demonstrated that the lower degree of fouling caused both a 23% increase in permeation flux together with 76% lower energy consumption compared to the commercial design. Full article

Traditionally, repairing coated substrates requires completely removing damaged, wear-resistant layers before recoating. This process leads to high costs, extended downtime, and material waste. Flexible brazing tapes, which are composed of alloy powder and an organic binder, offer an alternative to full coating removal for targeted repairs. Despite this, the process of vacuum brazing these tapes may lead to the formation of defects, including pores caused by trapped gases or residual binder, which compromise coating durability and corrosion resistance. This study focuses on the utilization of laser remelting as a method for post-processing nickel- and iron-based mixed alloy brazing tapes, with the aim of improving the integrity of the coating. Surface quality was assessed via microscopy and microhardness testing by systematically varying laser power, scanning speed, and hatch distance. Among the parameters studied, the most suitable laser parameter combination was found to be 350 W laser power, 250 mm/s scanning speed, and a hatch distance of 0.02 mm. These parameters yielded crack- and pore-free coatings with a remelting depth of 160.3 ± 17.2 µm and a microhardness of 701 ± 23 HV1, which is an 85% increase over as-brazed samples. Wear testing revealed a reduced coefficient of friction, and electrochemical corrosion tests showed lower corrosion current density and enhanced repassivation behavior in remelted coatings. These improvements demonstrate that laser remelting significantly enhances the microstructure, hardness, wear resistance, and corrosion performance of brazed coatings, providing an effective method for localized repair while minimizing material consumption and processing duration. Full article

Background/Objectives: Accurate determination of active pharmaceutical ingredient (API) particle size within dry powder inhaler (DPI) formulations is essential for ensuring effective pulmonary delivery but remains analytically challenging due to low API content and micronized particle size. Methods: In this study, scanning electron microscopy (SEM) coupled with energy-dispersive X-ray microanalysis (EDX) was used to directly identify and calculate the API particle size within several different commercial DPI products fit for purpose under regulatory constraints. The method exploits unique elemental markers inherent to each API, enabling reliable discrimination from excipients without prior sample modification or API extraction. Results: Large-area SEM–EDX mapping was used to localize API particles, followed by high-magnification imaging and confirmatory spot microanalysis. Particle sizes were manually measured for at least 50 API particles per formulation using image analysis software, and particle size distribution parameters were calculated from equivalent spherical diameters. Conclusions: The methodology was successfully applied to Spiriva^®, Anoro^® Ellipta, and Relvar^® Ellipta inhalation powders, revealing micronized APIs with distinct morphological features and verifying systematic application across products. Cross-validation against laser diffraction measurements of pure APIs demonstrated statistical equivalence, confirming the robustness and analytical utility of the proposed method for particle size assessment in DPI formulations. Full article

Laser Powder Bed Fusion for metals (PBF-LB/M) is a complex additive manufacturing process in which metal powder is selectively melted layer-by-layer to fabricate 3D parts. Process parameters critically influence the resulting microstructure in nickel alloys, with features such as melt pool marks, grain size and orientation, porosity, and cracks serving as key process signatures. These features are typically analyzed post-process to identify suboptimal conditions. This research aims to develop automated post-process measurement and analysis techniques using image processing, pattern recognition, and statistical learning to correlate process parameters with part quality. Optical microscopy images of build surfaces are analyzed using machine learning algorithms to evaluate porosity, grain size, and relative density in fabricated test coupons. Effect plots are generated to identify trends related to increasing energy density. A novel deep learning approach based on Mask R-CNN is used to detect and segment melt pool regions in optical microscopy images. From the segmented regions, melt pool dimensions—such as width, depth, and area—are extracted using bounding geometry coordinates. Manually labeled images (Type I and Type II) are used to train the model. A comparison between ResNet-50 and ResNet-101 backbones shows that the ResNet-50-based model (Model 2) achieves superior performance, with lower training loss (0.1781 vs. 0.1907) and validation loss (8.6140 vs. 9.4228). Quantitative evaluation using the Jaccard index, precision, and recall metrics shows that the ResNet-101 backbone outperforms ResNet-50, achieving about 4% higher mean Intersection-over-Union, with values of 0.85 for Type I and 0.82 for Type II melt pools, where Type I is detected more accurately due to its more regular morphology and clearer boundaries. By extending Faster R-CNNs with a mask prediction branch, the method allows for precise melt pool measurements, providing valuable insights into process quality and dimensional accuracy, and aiding in the detection of defects in PBF-LB-fabricated parts. Full article

This study proposes a four-dimensional Historical Building Defect Information Modeling (HBDIM) framework designed to support the documentation, diagnosis, and conservation of deteriorated historic stucco elements. The framework integrates multi-source digital documentation techniques, including terrestrial laser scanning (TLS), high-resolution photogrammetry, and automated total station measurements with laboratory-based material diagnostics to create a unified digital environment for defect detection and conservation assessment. The approach was applied to the Baron Empain Palace in Egypt as a representative case study of complex architectural heritage affected by material deterioration. Within the HBDIM workflow, point cloud processing and defect-oriented information modeling were used to identify and spatially localize deterioration features such as cracking, erosion, and material loss. Laboratory investigations—including computed tomography (CT), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray fluorescence (XRF)—were conducted to evaluate the effectiveness of calcium hydroxide nanoparticle consolidation treatments and to relate microstructural material behavior to spatially mapped defects within the digital model. Mechanical testing demonstrated a significant improvement in material performance, with treated stucco samples exhibiting an average compressive strength increase of approximately 69.06% compared to untreated specimens. The results demonstrate that integrating digital documentation, defect-oriented modeling, and material diagnostics within a four-dimensional framework provides a robust platform for linking geometric deterioration patterns with material-level conservation performance. By embedding diagnostic data and treatment outcomes within a temporally structured digital model, the HBDIM approach supports preventive conservation strategies, long-term monitoring, and data-driven decision-making in sustainable heritage management. Full article

This study presents experimental evidence of random magnetic behavior in modified barium hexaferrites. We demonstrate a significant shift in the magnetic properties of these materials upon the incorporation of divalent cations (Ni²⁺, Cu²⁺, Mn²⁺), which produces the formation of ceramic nanocomposites. X-ray diffraction, scanning electron microscopy, and laser diffraction reveal that these systems comprise micron-sized clusters formed by sintering polycrystalline nanoparticles. The cation incorporation occurs randomly across each sample, creating conditions conducive to random anisotropy magnetism. We confirm this behavior in our samples by fitting the magnetization data near saturation to a corresponding theoretical model. Additionally, we investigate the microwave absorption capabilities of these systems in the GHz range by calculating the reflection loss coefficient of mm-thick samples using transmission-line theory. The results predict broad (up to 2 GHz) and high (around 60 dB on average) absorption signals. In the case of the thinnest samples (1–2 mm), the Cu-substituted system presents broader absorption bandwidths than the pure hexaferrite and, therefore, proves to be more efficient for stealth applications in lightweight sectors. These findings suggest ceramic nanocomposites are promising candidates for random anisotropy magnets, highlighting their potential as efficient microwave absorbers, consistent with recent theoretical predictions. Full article

Tetrodotoxin (TTX), widely known as pufferfish venom, is a low-molecular-weight guanidinium neurotoxin. It can accumulate to extremely high concentrations in certain animals, including pufferfish, blue-ringed octopuses, flatworms, and nemerteans. However, the origin of TTX and the mechanisms that enable such extreme accumulation in these animals remain poorly understood. In this study, using confocal laser scanning microscopy combined with electron immunocytochemistry and ultrastructural analysis, we demonstrate the presence of TTX-positive bacteria associated with specialized cellular structures—type II phagosomes of gut enterocytes—in the highly toxic nemertean Cephalothrix cf. simula. We hypothesize that TTX production in C. cf. simula results from interactions between the nemertean host and its endosymbionts. These findings clarify the origin and accumulation of the toxin in nemerteans and have broader implications for other TTX-bearing species. Full article