Search Results (161)

We present a simple method for customizing the optical characteristics of gold-core, silver-shell (Au@Ag) nanoparticles through controlled morphosynthesis via a seed-mediated chemical reduction approach. By systematically adjusting the concentration of cetyltrimethylammonium chloride (CTAC), we obtained precise control over both the thickness of the Ag shell and the particle shape, transitioning from spherical nanoparticles to distinctly defined nanocubes. Bright field and high-angle annular dark-field scanning transmission electron microscopy (BF-STEM and HAADF-STEM), and energy-dispersive X-ray spectroscopy (EDS) were employed to validate the structural and compositional changes. To link morphology with optical behavior, we utilized the Mie and Maxwell–Garnett theoretical models to simulate the dielectric response of the core–shell nanostructures, showing trends that align with experimental UV-visible absorption spectra. This research presents an easy and adjustable method for modifying the plasmonic properties of Ag@Au nanoparticles by varying their shape and shell, offering opportunities for advanced applications in sensing, photonics, and nanophotonics. Full article

Penile intraepithelial neoplasia (PeIN) is a rare but clinically significant condition that can progress to invasive squamous carcinoma. Early diagnosis is crucial but often challenging due to its heterogeneous clinical and dermoscopic presentation, which can mimic other benign or malignant lesions. In this study, we report two cases of pigmented penile lesions evaluated using non-invasive imaging techniques: reflectance confocal microscopy (RCM) and line-field confocal optical coherence tomography (LC-OCT). Both methods revealed characteristic features such as hyperkeratosis, parakeratosis, acanthosis, nuclear pleomorphism of keratinocytes, and the presence of bright intraepithelial dendritic cells, correlating closely with histopathological findings of high-grade basaloid PeIN. Our findings highlight the valuable role of RCM and LC-OCT in improving the differential diagnosis of genital lesions, potentially reducing the need for invasive diagnostic procedures and ensuring early, appropriate management. Full article

Obesity is a growing global health concern, contributing to diseases such as cancer, autoimmune disorders, and neurodegenerative conditions. Adipose tissue dysfunction, characterized by abnormal adipokine secretion and chronic inflammation, plays a key role in these conditions. Adipose-derived extracellular vesicles (ADEVs) have emerged as critical mediators in obesity-related diseases. However, the study of mature adipocyte-derived EVs (mAdipo-EVs) is limited due to the short lifespan of mature adipocytes in culture, low EV yields, and the low abundance of these EV subpopulations in the circulation. Additionally, most studies rely on rodent models, which have differences in adipose tissue biology compared to humans. To overcome these challenges, we developed a standardized approach for differentiating human preadipocytes (preAdipos) into mature differentiated adipocytes (difAdipos), which produce high-yield, human adipocyte EVs (Adipo-EVs). Using visceral adipose tissue from bariatric surgical patients, we isolated the stromal vascular fraction (SVF) and differentiated preAdipos into difAdipos. Brightfield microscopy revealed that difAdipos exhibited morphological characteristics comparable to mature adipocytes (mAdipos) directly isolated from visceral adipose tissue, confirming their structural similarity. Additionally, qPCR analysis demonstrated decreased preadipocyte markers and increased mature adipocyte markers, further validating successful differentiation. Functionally, difAdipos exhibited lipolytic activity comparable to mAdipos, supporting their functional resemblance to native adipocytes. We then isolated preAdipo-EVs and difAdipo-EVs using tangential flow filtration and characterized them using bulk and single EV analysis. DifAdipo-EVs displayed classical EV and adipocyte-specific markers, with significant differences in biomarker expression compared to preAdipo-EVs. These findings demonstrate that difAdipos serve as a reliable surrogate for mature adipocytes, offering a consistent and scalable source of adipocyte-derived EVs for studying obesity and its associated disorders. Full article

Pulmonary exposure to carbon nanotubes (CNTs) has been linked to a series of adverse respiratory effects in animal models, including inflammation, genotoxicity, fibrosis, and granuloma formation, the degree and characteristics of which are considered dependent upon the detailed physicochemical properties of the material as inhaled. To further explore the effect of variations in physicochemical properties on pulmonary effects, two different multi-walled CNTs (MWCNTs) were tested in vivo: a pristine MWCNT (pMWCNT) (NM-401) and a surface-modified MWCNT (MWCNT-COOH). Female Sprague–Dawley rats were whole-body exposed for 28 days to MWCNT aerosols (pMWCNT (0.5 and 1.5 mg/m³) and MWCNT-COOH (1.5 and 4.5 mg/m³)) and followed up to 1 year post-exposure. The inhalation exposures resulted in relatively low estimated lung deposition. Bronchoalveolar lavage fluid (BALF) analysis indicated inflammation levels broadly consistent with deposited dose levels. Lung histopathology indicated that both MWCNTs produced very limited toxicological effects; however, global mRNA expression levels in lung tissue and BALF cytokines indicated different characteristics for the two MWCNTs. For example, pMWCNT but not MWCNT-COOH exposure induced osteopontin production, suggestive of potential pre-fibrosis/fibrosis effects linked to the higher aspect ratio aerosol particles. This is of concern as brightfield and enhanced darkfield microscopy indicated the persistence of pMWCNT fibres in lung tissue. Full article

Color metallographic samples of H59 brass alloy have been prepared by aqua regia etching. In this paper, combined with XRD (X-ray diffraction), traditional metallographic analysis, FE-SEM (field emission scanning electron microscopy), and EBSD (electron backscattering diffraction), the effect of the color metallographic method on the microstructure characterization of the H59 brass alloy was analyzed. The experimental results showed that α phases and β phases could be distinguished clearly, and the phase morphology, distribution, and content could be expressed accurately with an average error value of 5.25% for the α phase and 4.71% for the β phase. The average error rate of the phase content characterization was 4.98% (less than 5%) with the color metallographic method. In addition, it was also found in the study that the brightness and darkness of the β phase would be related to the grain orientation, and the bright grains would correspond to the low-index surface, and the dark grains to the high-index surface. As a low-cost, fast, and efficient characterization technique, the experimental results show that color metallography (CM) could replace electron backscattering diffraction (EBSD) for the analysis of the phase composition, phase distribution, phase content, and grain orientation of brass alloys, which would provide an experimental basis for optimizing alloy properties and expanding applications. Full article

Vitamin D and its metabolites exert anti-cancer properties in various cancers; however, their effects on cervical cancer remain largely unexplored. To investigate this gap, we exposed HeLa adenocarcinoma cervical cells to physiological and the growth inhibition 20% (GI20) concentration of 25-hydroxycholecalciferol, the precursor hormone of active 1,25-dihydroxycholecalciferol. We then assessed its impact on cell health, and the expression of the genes and proteins involved in the activation and catabolism of vitamin D at the cellular level by autocrine vitamin D metabolism via the vitamin D metabolizing system (VDMS). Cell health was evaluated by crystal violet and alamarBlue assays, while cell cycle progression and apoptotic cell death markers were assessed by flow cytometry. Gross morphology and ultrastructure were observed using brightfield microscopy and transmission electron microscopy. Gene and protein analyses of the autocrine VDMS were assessed using reverse transcription polymerase chain reaction and Western blot, respectively. Our findings reveal that 25(OH)D₃ inhibits cell growth and induces apoptosis in HeLa cervical cells in a dose-dependent manner through the autocrine upregulation of CYP27B1 and VDR. These autocrine effects most likely promote the bioactivation of 25(OH)D₃ and intracellular signaling of pro-apoptotic genomic pathways by liganded VDR. Furthermore, the upregulation of CYP24A1 at GI20 treatment likely increases the catabolism of 25(OH)D₃ and 1,25(OH)₂D_3, and therefore may mitigate the anti-cancer action of the high-treatment dose. In summary, 25(OH)D₃ holds immense potential as a complementary therapeutic treatment for cervical cancer. Full article

We present a single-capture multimodal bright-field (BF) and quantitative phase imaging (QPI) approach that enables the analysis of large, connected, or extended samples, such as confluent cell layers or tissue sections. The proposed imaging concept integrates a fiber-optic Mach–Zehnder interferometer-based off-axis digital holographic microscopy (DHM) with an inverted commercial optical BF microscope. Utilizing 8-bit grayscale dynamic range multiplexing, we simultaneously capture both BF images and digital holograms, which are then demultiplexed numerically via Fourier filtering, phase aberration compensation, and weighted image subtraction procedures. Compared to previous BF-DHM systems, our system avoids synchronization challenges caused by multiple image recording devices, improves acquisition speed, and enhances versatility for fast imaging of large, connected, and rapidly moving samples. Initially, we perform a systematic characterization of the system’s multimodal imaging performance by optimizing numerical as well as coherent and incoherent illumination parameters. Subsequently, the application capabilities are evaluated by multimodal imaging of living cells. The results highlight the potential of single-capture BF-DHM for fast biomedical imaging. Full article

New therapeutic molecules for farm animals are needed to address worldwide problems in the food industry, like the rise of resistance among ruminant parasites and pathogenic microbes. Since in vivo testing would involve an excessive number of animals, with consequent ethical and economic issues, the generation of sheep intestinal organoids represents a promising close-to-reality in vitro model for veterinary drug development; however, the characterization and application of such organoids remain limited. In this study, ovine intestinal organoids were generated from adult LGR5+ stem cells from the intestinal crypts of freshly slaughtered lambs, and developed in an in vitro culture system. Morphological analysis via brightfield microscopy and immunocytochemical staining revealed a pseudostratified epithelium with multiple cell types, and distinct apical–basal polarity, while RNA sequencing validated the preservation of the physiological characteristics of the original organ. The development and characterization of a robust and reproducible protocol for culturing sheep duodenum intestinal organoids in a high-throughput screening (HTS) compatible format demonstrated reliability in HTS applications, with Z’-factor tests indicating robust assay performance. Dose–response studies using pre-identified compounds showed comparable pharmacodynamic profiles between mouse and sheep organoids. These findings establish sheep intestinal organoids as an innovative tool for veterinary pharmacology and toxicology, offering a cost-effective and sustainable platform to address challenges such as drug resistance and improve livestock health. Full article

The current work presents the influence of the magnesiothermic synthesis method on titanium carbide (TiC). In this method, powdered titanium precursors and two carbon sources—turbostratic carbon and carbon nanotubes—were employed in proportions of 10 wt.% and 20 wt.%. The refinement of the X-ray diffraction (XRD) patterns using the Rietveld method for TiC suggests suggested coexistence of two phases, cubic with Fm-3m space group and hexagonal with P3₁21 space group. In particular, for the sample with 20 wt.% of carbon sources, the XRD refinement revealed that the cubic phase accounted for 94% of the composition, in contrast to a secondary hexagonal phase, Ti₆C_3.75, which comprised 6%. The influence of carbon on the morphology (particle size and shape) and crystallite size was monitored through bright-field transmission electron microscopy (BF-TEM) imaging and XRD. In samples containing 20 wt.% carbon, a homogeneous morphology in both size (around 11 microns) and shape was observed, along with a reduction in crystallite size (from 22.7 to 17.8 nm). Raman band analysis further revealed vibrational modes indicating that carbon induced disorder in the TiC structure. The magnesiothermic synthesis method developed in this work offers a low-cost approach of interest in the aerospace and automotive industries. Additionally, the study provides significant insights for particles used as additives or reinforcing agents to enhance the mechanical properties of metal matrix composites (MMCs). Full article

We present an experimental procedure for determining the diameter of spherical gold nanoparticles (AuNPs) using a basic bright-field microscopy apparatus. We achieved high-contrast imaging by constructing a bright-field microscopy system with ultrabright LEDs (incorporating low-cost components), employing Köhler illumination near the coherence limit, and using digital processing to perform image averaging and background subtraction. Our system allows for the detection of 80 nm, 150 nm, and 300 nm diameter AuNPs immobilized on functionalized glass substrates. Through-focus images of the particles show characteristic contrast inversion, from where we find a nearly linear relationship between the minimum intensity contrast and particle diameter (as determined from scanning electron microscopy) for the three sizes studied and for three different illumination wavelengths covering the corresponding AuNP plasmon band (λ = 460 nm, 520 nm, and 620 nm). This behavior was found to be consistent with the corresponding scattering and absorption cross-sections of the AuNPs under the illumination wavelengths considered. Full article

Rapid urbanisation and industrialisation have intensified the Urban Heat Island (UHI) effect, significantly increasing energy demand for thermal comfort. Urban buildings consume considerable energy throughout the year, which can be reduced by incorporating Phase Change Materials (PCMs) into building materials. PCMs effectively regulate temperature by storing and releasing heat as latent heat during phase transitions. However, to prevent leakage, PCMs can be encapsulated in co-axial polymeric Phase Change Fibres (PCFs), representing an innovative approach in scientific research. This study optimised the coagulation bath and produced PCFs using commercial cellulose acetate as the sheath and polyethylene glycol (PEG 600 and 1000) as the core via the wet-spinning method. The first part of this work investigated the coagulation bath using Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) analyses of the characteristic peak areas. In contrast, the second part examined the PCFs’ morphological, chemical and thermal properties using Bright-field microscopy, ATR-FTIR, Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) techniques. The results demonstrated the successful production of PCFs with an optimised coagulation bath. Bright-field microscopy and ATR-FTIR confirmed the well-defined morphology and the presence of PEG in the fibre core. TGA analysis showed high thermal stability in the PCFs, with mass loss observed at high degradation temperatures, ranging from ~264 °C to 397 °C for the PCFs with PEG 600 and from ~273 °C to 413 °C for the PCFs with PEG 1000. Meanwhile, DSC analysis revealed melting points of ~12.64 °C and 11.04 °C, with endothermic enthalpy of ~39.24 °C and 30.59 °C and exothermic enthalpy of ~50.17 °C and 40.93 °C, respectively, for PCFs with PEG 600, and melting points of ~40.32 °C and 41.13 °C, with endothermic enthalpy of ~83.47 °C and 98.88 °C and exothermic enthalpy of ~84.66 °C and 88.79 °C, respectively, for PCFs with PEG 1000. These results validate the potential of PCFs for applications in building materials for civil engineering, promoting thermal efficiency and structural stability. Full article

In the field of histological analysis, one of the typical issues is the analysis of single cells contained in regions of interest (i.e., ROIs). Today, several commercial, freely available, and open-source software options are accessible for this task. However, the literature lacks recent extensive reviews that summarise the functionalities of the opportunities currently available and provide guidance on selecting the most suitable option for analysing specific cases, for instance, irregular freehand-defined ROIs on brightfield images. In this work, we reviewed and compared 14 software tools tailored for single-cell analysis within a 2D histological freehand-defined image ROI. Precisely, six open-source tools (i.e., CellProfiler, Cytomine, Digital Slide Archive, Icy, ImageJ/Fiji, QuPath), four freely available tools (i.e., Aperio ImageScope, NIS Elements Viewer, Sedeen, SlideViewer), and four commercial tools (i.e., Amira, Arivis, HALO, Imaris) were considered. We focused on three key aspects: (a) the capacity to handle large file formats such as SVS, DICOM, and TIFF, ensuring compatibility with diverse datasets; (b) the flexibility in defining irregular ROIs, whether through automated extraction or manual delineation, encompassing square, circular, polygonal, and freehand shapes to accommodate varied research needs; and (c) the capability to classify single cells within selected ROIs on brightfield images, ranging from fully automated to semi-automated or manual approaches, requiring different levels of user involvement. Thanks to this work, a deeper understanding of the strengths and limitations of different software platforms emerges, facilitating informed decision making for researchers looking for a tool to analyse histological brightfield images. Full article

Based on the potential of DPSCs as the most promising candidates for bone tissue engineering, we comprehensively investigated the time-dependent cellular and molecular changes that occur during their osteodifferentiation. To analyze this area in-depth, we used both cellular and molecular approaches. Morphological changes were monitored using bright-field microscopy, while the production of mineral deposits was quantified spectrophotometrically. The expression of a key mesenchymal stem cell marker, CD90, was assessed via flow cytometry. Finally, protein-level changes in whole cells were examined by fluorescence microscopy. Our results show successful long-term osteodifferentiation of the patient’s DPSCs within 25 days. In differentiated cells, mineralized extracellular matrix production gradually increased; in contrast, the expression of the specific stem cell marker CD90 significantly decreased. We observed dynamic changes in intracellular and extracellular proteins when collagen1 A1 and osteopontin appeared as earlier markers of osteogenesis, while apolipoprotein A2, bone morphogenetic protein 9, dentin sialophosphoprotein, and matrix metalloproteinase 8 were produced mainly in the late stages of this process. A decrease in actin microfilament expression indicated a reduction in cell proliferation, which could be used as another marker of osteogenic initiation. Our results suggest a coordinated process in vitro in which cells synthesize the necessary proteins and matrix components to regulate the growth of hydroxyapatite crystals and form the bone matrix. Full article

Ilhéus Virus (ILHV) was first detected in 1944 in Ilhéus, state of Bahia, northeast Brazil. During cellular infection, orthoflaviviruses induce cellular changes related both to the replication process, the formation of replication complexes, and to structures resulting from cellular damage. Although more detailed data are available in the literature for other orthoflaviviruses, the relationship between ILHV, the formation of these structures, its replication cycle, and cellular changes remains unknown. One of the main objectives of this study is to characterize the primary ultrastructural changes in green monkey kidney epithelial cell lineage (Vero cell) infected with ILHV, as well as to map its replication cycle, virion structure, and genome. To achieve these objectives, Vero cell monolayers were infected with an MOI of 0.01 and collected at different times post-infection. Cell monolayers were evaluated under bright-field microscopy and transmission electron microscopy. Ultrastructural analyses confirmed that ILHV can induce the formation of double-membrane vesicles, convoluted membranes, and vesicular packets. These structures, like those observed in zika (ZIKV) and dengue (DENV) viruses, form replication complexes that aid ILHV’s replication process in cells. Our preliminary results reveal that ILHV infection induces cytopathogenesis like that observed in vitro studies for other arboviruses. Full article

Background/Objectives: Although factors acting both prenatally and postnatally are taken into consideration, the etiopathogenesis of developmental defects of enamel (DDE) is not fully understood. Among the medications used for a variety of ailments, amoxicillin and cefaclor are indicated as having a part in the development of DDE. The objective of the present study was to reproduce DDE in the laboratory in rats by administering amoxicillin, ibuprofen, and cefaclor. These lesions were subsequently diagnosed using polarized light microscopy (PLM). Methods: This study was conducted on Wistar rats, which were given prenatally drugs possibly involved in the production of DDE. After macroscopic examination and identification of enamel defects, bright-field microscopy (BFM) and PLM examination were performed. Results: The group that received cefaclor was the most affected, according to the data gathered from this study. This group was followed by the groups that received amoxicillin in a double dose, ibuprofen, amoxicillin in a standard dose, and the control group. Conclusions: In the control group, DDE was identified in a reduced number, resulting in the fact that there are other factors involved, besides the drugs administered, in the development of DDE. Following this research, it was concluded that DDE in the form of demineralization was more frequently recorded in the cefaclor and ibuprofen groups, while DDE in the form of hypoplasia was more frequently recorded in the double-dose and standard-dose amoxicillin groups. Full article