Search Results (1,231)

This study was focused on addressing the performance degradation in core microstructures of ultra-heavy steel plates (thickness ≥ 50 mm) caused by non-uniform cooling during thermo-mechanical controlled processing. Using microalloyed DH36 steel as the research subject, we systematically investigated the effects of cooling rate on the nucleation and growth of acicular ferrite and its consequent microstructure-property relationships through an integrated approach combining in situ observation via high-temperature laser scanning confocal microscopy with multiscale characterization techniques. Results demonstrate that the cooling rate significantly affects acicular ferrite formation, with the range of 3–7 °C/s being most conducive to acicular ferrite formation. At 5 °C/s, the acicular ferrite volume fraction reached a maximum of 74% with an optimal aspect ratio (5.97). Characterization confirmed that TiOx-Al₂O₃·SiO₂-MnO-MnS complex inclusions act as effective nucleation sites for acicular ferrite, where the MnS outer layer plays a key role in reducing interfacial energy and promoting acicular ferrite radial growth. Furthermore, the interlocking acicular ferrite structure was shown to enhance microhardness by 14% (HV0.1 = 212.5) compared to conventional ferrite through grain refinement strengthening and dislocation strengthening (with a dislocation density of 2 × 10⁸ dislocations/mm²). These results provide crucial theoretical insights and a practical processing window for strengthening-toughening control of heavy plate core microstructures, offering a viable pathway for improving the comprehensive performance of ultra-heavy plates. Full article

(1) Background: The extracellular matrix (ECM) is a natural scaffold for cells, creating a three-dimensional architecture composed of fibrous proteins (mainly collagen) and proteoglycans, which are synthesized by resident cells. In this study, a physiological hypoxic environment was utilized to enhance ECM production by human mesenchymal stem cells (hMSCs), a process relevant to tissue engineering and regenerative medicine. (2) Methods: hMSCs were treated with deferoxamine (DFO), a pharmaceutical hypoxia-mimetic agent that induces cellular responses similar to low-oxygen conditions through stabilization of hypoxia inducible factor-1α (HIF-1α). The time points 0 h 24 h, 3 h 24 h, and 24 h 24 h refer to DFO being added immediately after cell seeding (before cells adhesion), 3 h after cell seeding (during initial cells attachment), and 24 h after cell seeding (after focal adhesions formation and actin organization), respectively, to evaluate the influence of cell adhesion on ECM deposition. hMSCs incubated in culture media were subsequently exposed to DFO for 24 h. Samples were then subjected to cell viability tests, scanning electron microscopy (SEM), atomic force microscopy (AFM) and laser scanning confocal microscopy (CLSM) assessments. (3) Results: Viability tests indicated that DFO concentrations in the range of 0–300 µM were non-toxic over 24 h. The presence of collagen fibers in the DFO-derived ECM was confirmed with anti-collagen antibodies under CLSM. Increased ECM secretion was observed under the following conditions: 3 μM DFO (24 h 24 h), 100 μM DFO (0 h 24 h) and 300 μM DFO (3 h 24 h). SEM and AFM images revealed the morphology of various stages of collagen formation with both collagen fibrils and fibers identified. (4) Conclusions: Our preliminary study demonstrated enhanced ECM secretion by hMSC treated with DFO at concentrations of 3, 100, and 300 µM within a short cultivation period of 24–48 h without significant affecting cell viability. By mimicking physiological processes, it may be possible to stimulate endogenous tissue regeneration, for example, at an injury site. Full article

Vibrio parahaemolyticus is a primary foodborne pathogen in seafood that endangers consumers’ health. It is vital to develop novel prevention and control strategies due to its extensive transmission and drug resistance. This work aimed to examine the antibacterial and anti-virulence efficiency of chlorogenic acid (CA) against V. parahaemolyticus. The minimum inhibitory concentration (MIC) of CA is 6 mg/mL. CA realized its antibacterial effect by damaging the cell wall and membrane, evidenced by the leakage of alkaline phosphatase, intracellular proteins and nucleic acids, potassium ion, and glucose, the increasing malondialdehyde and reactive oxygen species, as well as morphological observations under scanning and transmission microscopes and live and dead cell observations under laser confocal microscopy. When V. parahaemolyticus was treated with CA at sub-inhibitory doses, its hydrophobicity, extracellular polysaccharide synthesis, motility, and biofilm formation were all significantly inhibited. Moreover, CA effectively protected salmon from the contamination of V. parahaemolyticus with a prolonged shelf life. These findings indicate that CA possesses antibacterial activity against V. parahaemolyticus, suggesting its potential value for controlling V. parahaemolyticus-associated seafood infections. Full article

This study examines the pigments and materials used in Girolamo Romanino’s Musicians fresco (1537–1538), located in the Duomo Vecchio in Brescia, with the aim of identifying and analyzing the artist’s colour palette. Ten samples of the pictorial layer and mortar were collected from two frescoes and characterized using microscopic and spectroscopic techniques. Confocal laser scanning microscopy (CLSM) was used to define the best positions where single-point, spectroscopic techniques could be applied. Raman spectroscopy and micro-Fourier transform Infrared spectroscopy (micro-FTIR) were used to detect pigments and organic binders, respectively. X-ray powder diffraction (XRPD) provided additional insights into the mineral composition of the pigmenting layers, in combination with environmental scanning electron microscopy equipped with energy-dispersive spectroscopy (ESEM-EDS). The analysis revealed the use of traditional fresco pigments, including calcite, carbon black, ochres, and copper-based pigments. Smalt, manganese earths, and gold were also identified, reflecting Romanino’s approach to colour and material selection. Additionally, the detection of modern pigments such as titanium white and baryte points to restoration interventions, shedding light on the fresco’s conservation history. This research provides one of the most comprehensive analyses of pigments in Romanino’s works, contributing to a deeper understanding of his artistic practices and contemporary fresco techniques. Full article

Novel multifunctional fibrous materials were prepared by simultaneous dual spinneret electrospinning of two separate solutions differing in composition. This technique allowed for the preparation of materials built of two types of fibers: fibers from poly(vinyl alcohol) (PVA), chitosan (Ch), and rosmarinic acid (RA), and poly(L-lactide) (PLA) fibers containing lidocaine hydrochloride (LHC). Confocal laser scanning microscopy (CLSM) analyses showed that both types of fibers are present on the surface and in the bulk of the new materials. The presence of all components and some interactions between them were proven by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. RA and LHC were in an amorphous state in the fibers, and their presence affected the temperature characteristics and the crystallinity, as detected by differential scanning calorimetry (DSC) and X-ray diffraction analyses (XRD). The presence of PVA/Ch/RA fibers enabled the hydrophilization of the surface of the multifunctional fibrous materials (the water contact angle value was 0°). The newly developed materials demonstrated adequate mechanical properties, making them suitable for use in wound dressing applications. The RA-containing fibrous mats possessed high radical-scavenging activity (ca. 93%), and the combining with LHC led to an enhancement of this effect (ca. 98.5%). RA-containing fibrous mats killed all the pathogenic bacteria S. aureus and E. coli and decreased the titer of fungi C. albicans by ca. 0.4 log for a contact time of 24 h. Therefore, the new materials are prospective as antibacterial and atraumatic functional wound dressings, as systems for local drug delivery, and in medical skincare. Full article

In this study, the solidification behavior of 310S stainless steel was systematically investigated by combining high-temperature confocal laser scanning microscopy (HT-CLSM), microstructural characterization, and thermodynamic calculations. The focus was on the formation and transformation of ferrite, secondary-phase precipitation, and elemental segregation behavior, with comparisons made with 304 stainless steel. The effects of an Al addition and cooling rate were also explored. The results show that the solidification sequence of 310S stainless steel is L → L + γ → L + γ + δ → δ + γ, in which austenite nucleates early and grows rapidly, followed by the precipitation of a small amount of δ-ferrite in the later stages of solidification. In contrast, 304 stainless steel solidifies according to L → L + δ → L + δ + γ → δ + γ, with a rapid δ → γ transformation occurring after solidification. Compared with 304, 310S stainless steel exhibits a reduced ferrite fraction and a significantly increased σ phase content. The σ phase primarily precipitates directly from δ-ferrite (δ → σ), while M₂₃C₆ preferentially forms at grain boundaries and δ/γ interfaces, where δ-ferrite not only provides fast diffusion pathways for Cr but also nucleation sites. The solidification segregation sequence in 310S stainless steel is Cr > Ni > Fe, with Cr and Ni showing positive segregation and Fe showing negative segregation. The addition of Al does not alter the solidification mode of 310S stainless steel but refines austenite grains, reduces interdendritic solute enrichment, decreases segregation, lowers both the size and fraction of ferrite, and suppresses the precipitation of σ and M₂₃C₆ phases. This effect is mainly attributed to the reduction of δ/γ interfaces, which weakens the preferred nucleation sites for M₂₃C₆. Increasing the cooling rate enhances non-equilibrium solute segregation, promotes ferrite formation, inhibits the δ → γ transformation, and ultimately retains more ferrite; the intensified segregation further accelerates the δ → σ transformation. Full article

Background: The treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections is extremely challenging due to its antibiotic resistance, and the combination of plant active ingredients with antibiotics represents a potential strategy to address this issue. Methods: We determined the combinatorial relationship between baicalin (BA) and kanamycin (KM) using the checkerboard dilution method. The antibacterial activity of the baicalin–kanamycin (BA/KM) combination was evaluated through growth curve determination assays and scanning electron microscopy (SEM). The effects of the BA/KM combination on the cell membrane and cell wall of MRSA were analyzed using reactive oxygen species (ROS) detection assays, intracellular protein leakage experiments, alkaline phosphatase (AKP) activity assays, laser scanning confocal microscopy (LSCM) observations, and molecular docking simulations. The antibiofilm activity and related mechanisms of the BA/KM combination were elucidated via crystal violet staining, MTT assay, phenol-sulfuric acid method, congo red staining, staphyloxanthin determination assays, and quantitative real-time polymerase chain reaction (qPCR). The safety of the BA/KM combination was assessed through hemolytic activity analysis, and its anti-MRSA efficacy was evaluated on lettuce. Results: BA/KM combination showed a synergistic antibacterial effect on MRSA USA300. Mechanistic studies revealed that BA may interact with amino acid residues of peptidoglycan synthetase PBP2a to hinder peptidoglycan synthesis, thereby facilitating KM penetration through the cell wall. Subsequently, BA binds to amino acid residues of the membrane transporter NorA, leading to disruption of cell membrane homeostasis and enhancing KM’s ability to induce intracellular ROS accumulation in MRSA. Furthermore, the BA/KM combination reduced MRSA biofilm formation by 77.85% and decreased the metabolic activity of biofilm cells by 42.93% through inhibiting the synthesis of biofilm components EPS and PIA. Additionally, this combination suppressed the synthesis of staphyloxanthin and downregulated the expression of agrA and agrC genes. When 1/8 MIC BA was combined with 1/4 MIC KM, the count of MRSA on lettuce surfaces was reduced by 0.88 log CFU/cm², an effect comparable to that of 0.2% (v/v) hydrogen peroxide. Conclusions: According to these findings, the BA/KM combination may offer a promising option for enhancing antibacterial efficacy through synergism, reducing antibiotic usage concentrations, and limiting MRSA transmission in fresh agricultural products. Full article

Tubulin cytoskeleton rearrangements play an important role in the cell differentiation of symbiotic nodules in legumes. However, the organization of the tubulin cytoskeleton has been investigated only for four legume species forming determinate nodules (with limited nodule meristem activity). In this study, microtubule organization was studied in three species (Vigna radiata, V. unguiculata, and Lotus corniculatus) with determinate nodules using confocal laser scanning microscopy and quantitative analyses. Histological organization in young nodules of V. radiata and V. unguiculata resembled the recently reported zonation in young nodules of Glycine max. In addition, bacteroids in nodules of these species were significantly enlarged compared to free-living bacteria. Organization of endoplasmic and cortical microtubules in young infected cells and uninfected cells and that of cortical microtubules in nitrogen-fixing cells demonstrated general patterns for determinate nodules, whereas endoplasmic microtubules in nitrogen-fixing cells showed species-specific patterns. Thus, the presence of both general and species-specific patterns of tubulin cytoskeleton organization was confirmed in determinate nodules. Full article

Low energy N⁺ ion beam implantation has been used to create the novel rice mutant “shuangli”, which produces partially fertile spikelets containing double grains. Abnormal ovule development is a major cause of partial fertility and grain diversity in rice mutants. To elucidate the developmental mechanism of ovule diversity in shuangli, ovules undergoing development were stained using eosin Y and H33342 and observed using confocal laser scanning microscopy. Different developmental abnormalities were observed in the ovary, embryo sac, and ovule. Abnormal development was observed in 35.18% of the ovary structures, primarily manifesting as “tumor” like cell clusters, “false ovaries”, stamen degeneration, and double ovaries. In the embryo sac, abnormal development occurred in about 17.35% of the megaspore cells, including the formation of three nuclei, two daughter cells of asynchronously divided dyads, multiple megaspore tetrads, and “narrow and elongated” cavities. At the female gametogenesis stage, the abnormal development rate was 27.53%, mainly involving the degeneration of the central polar nucleus, egg apparatus, antipodal cell mass, or female germ unit. In shuangli, abnormal development occurred in 28.06% of the ovule structures, including lateral tissue, nucellar tissue, double ovules and double embryo sacs. Of the observed lateral tissues, 8.27% did not differentiate into sexual reproductive tissue, which affected the fertilization of the embryo sac, leading to atrophy and degeneration. A new abnormal tissue similar to the inner integument was found on both sides of the nucellar tissue, and the two specialized nucellar tissues appeared to have “staggered” growth within a single ovary. Of the examined ovules, 10.79% exhibited different types of double ovules, including heart-shaped, “anatropous”, “conjoined” structures. However, the double ovules typically developed synchronously, explaining the production of different sizes of the two grains in shuangli. In addition, “double” embryo sacs from two “twinborn” nucelli were found in one ovule, and the frequency of “double” embryo sacs was 3.60%. Therefore, ovule development diversity may result in fertilization or gradual degeneration after fertilization, explaining the lower fertility of shuangli at the embryological level. Full article

Surface roughness influences biofilm adhesion on denture base materials, impacting oral health. Despite advances in polymeric denture materials, the effects of common cleaning protocols on their surface texture remain inadequately characterized. This study investigated the influence of toothbrush abrasion on the surface texture of dimethyl methacrylate-based (DMA, printed: V-Print dentbase), polymethyl methacrylate (PMMA, milled: VITA Vionic Base, pressed: IvoBase Hybrid), polyamide (PA, pressed: Bre.flex), and polyether ether ketone (PEEK, milled: Juvora Disc). The specimens were fabricated as polished discs. The Vickers and Martens hardness, indentation modulus, elastic and plastic part of indentation work, and indentation creep were determined. Toothbrushing simulation and surface texture analysis were conducted in three steps: 1800, 1800, and 3600 cycles using water, dish detergent, or toothpaste slurry. The surface texture parameters Sa, Sal, Sdr, Sku, and Ssk were determined using confocal laser scanning microscopy and suitable filtering (S-F and S-L surface). Sa, Sal, and Sdr showed significant changes depending on the choice of medium and the material used. The duration had a small effect (three-way ANOVA; all p < 0.001). DMA showed minor surface changes. Milled and pressed PMMA exhibited similar surface deformities due to wide valleys that were not considered critical for biofilm adhesion. PA showed the lowest and PEEK the highest Vickers and Martens hardness. However, both PA and PEEK exhibited surface changes that could promote biofilm development. These findings suggest that denture cleaning recommendations should remain material-specific. Regular surface inspections and repolishing are necessary to reduce the risk of biofilm formation on PA or PEEK-containing dentures. Full article

DROSHA protein is widely known for its essential role in the microRNA (miRNA/miR) biogenesis pathway where, together with its co-factor DGCR8, it forms the “Microprocessor” complex and catalyzes the primary miRNA (pri-miRNA) processing in the nucleus. Nevertheless, DROSHA also seems to participate in several miRNA-independent cellular mechanisms, such as transcriptional regulation, RNA processing and genome integrity maintenance. Hence, the present study aims to further investigate novel miRNA-independent activities of DROSHA protein, with potentially regulatory roles in the oncogenesis of human cancer cells. Our results reveal a new, strong profile of microprocessor-independent DROSHA localization at the Golgi apparatus in several human cancer cell lines of different tissue origin, with hepatic carcinoma, thyroid cancer, urothelial bladder cancer, colon carcinoma and melanoma being the cellular model systems herein examined. Notably, oncogenic activity, malignancy grade and metastatic capacity are shown to be strongly associated with DROSHA’s compartmentalization at Golgi, a phenotype that does not seem to rely on p53 protein’s functionality. Taken together, through employment of advanced confocal laser scanning microscopy (CLSM) and molecular modeling, we herein unveil the ability of DROSHA, but not AGO2 and DICER, to reside at Golgi, where DROSHA can physically interact with the GM130 Golgi-specific component, thus indicating DROSHA’s engagement in non-canonical and miRNA-independent—but also Golgi apparatus-dependent—novel mechanisms that can be tightly coupled with malignancy dynamics and beneficially utilized as potential biomarkers and therapeutic targets for human cancer. Full article

Addressing the critical challenge in the differential diagnosis of severe inflammatory lung diseases, we propose a novel methodology for the analysis of macrophage surface receptors, CD68 and CD206, using specific non-antibody ligands. We developed a non-antibody alternative for the fluorometric detection of CD68+ cells, focusing on macrophages as key functional markers in inflammatory processes. Our marker based on dioleylphosphatidylserine (DOPS), a specific ligand to CD68, was incorporated into a liposomal delivery system. The specificity of this DOPS-based ligand can be precisely modulated by the liposome’s composition and the polyvalent presentation of the ligand. We synthesized a series of fluorescently-labeled DOPS-based ligands and developed a liposome-based sandwich fluorometric assay. This assay enables the isolation and quantification of CD68 receptor presence from bronchoalveolar lavage fluid (BALF). The results confirmed the specific binding of DOPS/lecithin liposomes to CD68+ cells compared to control lecithin systems. Furthermore, the incorporation of PEGylated ‘stealth’ liposomes significantly enhanced binding specificity and facilitated the generation of distinct binding profiles, which proved valuable in differentiating various inflammatory conditions. This approach yielded unique binding profiles of PS-based ligands to CD68+ cells, which varied significantly among a broad range of respiratory conditions, including primary ciliary dyskinesia, bronchial asthma, bronchitis, bacterial infection, pneumonia, and bronchiectasis. Confocal Laser Scanning Microscopy demonstrated selective binding and intracellular localization of the DOPS-based marker within CD68+ macrophages from BALF samples of patients with bronchitis or asthma. The binding parameters of this multivalent composite ligand with the CD68 receptor are comparable to those of antibodies. The inherent binding specificity of phosphatidylserine may offer a sufficient and viable alternative to conventional antibodies. Our results demonstrate the remarkable potential of this novel DOPS-based assay as a complementary tool for the developing non-antibody-based systems for the differential diagnosis of the respiratory diseases, warranting further investigation in larger clinical studies. Full article

Background/Objectives: Dental plaque, a biofilm composed of accumulated oral microorganisms, is a key contributor to various oral diseases. 6-shogaol, a bioactive compound of ginger, is known to have pharmacological activities, including anticancer, anti-inflammatory, and antimicrobial activities. Therefore, we aimed to determine the effects of 6-shogaol on dual-species biofilms of Streptococcus mutans (S. mutans) and Candida albicans (C. albicans). Methods: Dual-species oral biofilms were formed on hydroxyapatite (HA) disks for 42 h and exposed to 6-shogaol. The pH was measured in the experimental medium, and the biomass, colony-forming unit (CFU) of microbial cells, and insoluble extracellular polysaccharides (EPS) were quantified in the biofilm formed on the HA disk. Confocal laser scanning microscopy (CLSM) was used to assess biofilm morphology, and quantitative polymerase chain reaction was performed to analyze gtf gene expression. Results: 6-shogaol dose-dependently reduced insoluble EPS, CFU counts, and dry weight of biofilms. The pH was maintained above 5.5 in the 6-shogaol-treated group. CLSM images showed that S. mutans proliferation, C. albicans hyphal development, and EPS production were markedly inhibited in biofilms treated with 6-shogaol. The expression of gtfB and gtfC was significantly downregulated by 6-shogaol. Conclusions: These findings suggest that 6-shogaol has the potential to be a promising natural product for the prevention and management of oral biofilm-related oral diseases. Full article

Background: Accurate margin assessment during surgical treatment is essential to prevent recurrences of BCC. Mohs surgery or alternative peripheral and deep en-face margin assessment (PDEMA) based on conventional histopathology are considered the gold standard for excising high-risk BCC, as it allows stepwise and complete examination of peripheral and deep margins. However, it is labor-intensive and time-consuming. EVCM has emerged as a promising alternative, allowing rapid intraoperative evaluation of fresh excised tissue. Objective: To assess the diagnostic accuracy of EVCM in a PDEMA workflow of high-risk nodular BCCs. Methods: A retrospective monocentric study was conducted at the Lausanne University Hospital (CHUV) between March 2024 and May 2025. A total of 51 patients with histologically confirmed nodular BCCs considered as high-risk and thus addressed for EVCM-assisted excision were included, yielding 171 surgical margin samples. EVCM and conventional histology-based PDEMA analyses were compared. Results: EVCM achieved an overall sensitivity of 93.8% (95% CI: 71.7–98.9%) and specificity of 98.7% (95% CI: 95.2–99.7%) compared to conventional histology. The positive and negative predictive values were 88.2% (95% CI: 63.6–97.4%) and 99.4% (95% CI: 96.4–99.9%), respectively. Conclusion: EVCM demonstrates high diagnostic accuracy for the intraoperative PDEMA of high-risk, nodular BCC. Its integration in PDEMA surgical workflows may improve efficiency, although confirmatory studies are needed in broader clinical settings. Full article

Background/Objectives: The inner blood–retinal barrier (iBRB) is a specialized neurovascular interface essential for retinal homeostasis and visual function and is compromised in several vision-threating conditions. Therefore, the ability to model iBRB function and dysfunction in a controlled, reproducible and scalable manner is crucial for pharmaceutical research. However, the complex anatomy and physiology of the iBRB raise challenges for cell-based in vitro modeling. Methods/Results: This review follows the evolution of iBRB models—from simple monolayers of retinal endothelial cells (ECs) to sophisticated multicellular microphysiological systems (MPs). Advanced diverse microfluidic platforms aim to replicate key structural, biochemical and functional aspects of the iBRB, each incorporating distinct strategies regarding cell sourcing, device design, flow dynamics and functional readouts. Conclusions: Despite their limitations, these models are highly valuable for drug screening and mechanistic studies aimed at preserving or restoring barrier integrity while also helping to bridge the translational gap in ophthalmic drug discovery. Full article