Search Results (1,558)

Effective induction of antigen-specific cytotoxic T lymphocyte responses requires delivery systems that enable both the intracellular delivery of peptide antigens to antigen-presenting cells and the intracellular release of antigen-derived species compatible with major histocompatibility complex (MHC) class I-mediated presentation. In this study, we synthesized three type of reduction-responsive self-assembling peptide, Cys-EG₁₂, SS1-EG₁₂, and SS2-EG₁₂, which differ in the number and design of disulfide-containing linkages, and investigated how these structural differences affect nanofiber formation and antigen presentation. Thioflavin T assay, transmission electron microscopy, and circular dichroism measurements showed that EG₁₂, SS1-EG₁₂, and SS2-EG₁₂ formed β-sheet-rich nanofibers, whereas Cys-EG₁₂ formed particulate assemblies. Under reducing conditions, SS1-EG₁₂ and SS2-EG₁₂ nanofibers released epitope-containing fragments. Flow cytometry and confocal laser scanning microscopy confirmed cellular uptake of EG₁₂, SS1-EG₁₂, and SS2-EG₁₂ nanofibers by JAWS II dendritic cells, although uptake of SS1-EG₁₂ and SS2-EG₁₂ was lower than that of EG₁₂. Despite this lower uptake, JAWS II cells treated with SS2-EG₁₂ nanofibers exhibited enhanced MHC class I-mediated antigen presentation compared with cells treated with EG₁₂ and SS1-EG₁₂ nanofibers. These findings suggest that designing disulfide linkages to enable the reductive release of epitope-containing species in a form more favorable for MHC class I-mediated presentation is an important strategy for antigen delivery systems based on self-assembling peptide nanofibers. Full article

The growing demand for structural coloration methods that simultaneously exhibit an iridescent sheen effect and a base color on transparent substrates calls for a single-step fabrication procedure capable of periodic and localized modulation of thin-film structure. In this work, a composite thin-film structure consisting of aluminum nitride-aluminum (AlN-Al)-soda-lime glass substrate is designed, deposited, and subsequently processed using burst-mode femtosecond laser. By systematically varying the number of sub-pulses, the pulse-to-pulse distance, and the average laser power while maintaining a fixed single-sub-pulse energy (1 μJ), the precise control over thermal accumulation and surface protrusion morphology is achieved, resulting in a series of highly transparent structural colors with iridescent sheen effects. Reflectance spectra, transmittance data, confocal microscopy, scanning electron microscopy and coupled energy dispersive spectrometer analyses, and the finite-difference time-domain simulations reveal that the observed color variation originates from laser-induced air gaps between the Al and AlN layers, rather than from compositional changes, and that the resulting periodic surface protrusion structures govern the iridescent sheen effect. The proposed method enables large-scale patterning while preserving high transmittance, as demonstrated by the desired hue, saturation, and iridescent sheen. This burst-mode laser processing strategy offers a material- and production line-compatible route for realizing coupled interference- and diffraction-based structural colors, with promising applications in decorative purposes with anti-counterfeiting or encryption purposes, where both angle-independent base color and angle-dependent iridescent sheen effect are required. Full article

This study was performed to elucidate the mechanism underpinning the nodal swelling induced by equinatoxin II (EqtII), a cation-selective pore-forming toxin derived from the sea anemone Actinia equina. Experiments were conducted using frog myelinated nerve fibers as a model system. Application of EqtII led to an approximately two-fold increase in the nodal volume of myelinated axons, but only when extracellular Ca²⁺ was present. Replacing extracellular Cl⁻ with isethionate had no measurable effect on this response, whereas substitution of NaCl with either sucrose or LiCl, an established Na⁺/Ca²⁺ exchanger (NCX) inhibitor, abolished the swelling. The persistence of the effect in the presence of tetrodotoxin indicates that voltage-gated Na⁺ channels are not involved in the underlying mechanism. Our data suggest that Ca²⁺ influx through EqtII-induced membrane pores raises intracellular Ca²⁺ levels, thereby stimulating the NCX in its forward-operating mode. This process promotes Ca²⁺ extrusion in exchange for Na⁺ entry. The resulting accumulation of intracellular Na⁺ increases osmotic pressure within the axon, leading to water influx and nodal swelling. Full article

Alginate hydrogels offer mild ionic gelation and tunable porosity for drug delivery, yet their hydrophilic, macroporous networks suffer from rapid initial burst release of water-soluble payloads. Here we introduce a hierarchical barrier-engineering strategy in which poly(D,L-lactide-co-glycolide)/poly(ethylene glycol) (PLGA/PEG) blend coatings are applied via dip-coating to Ca²⁺-cross-linked alginate beads (~1 mm) and microgels (~100 µm). For beads, three-cycle PLGA/PEG multilayer coating suppressed the initial swelling rate (dQ/dt) by ~50% and reduced 1 h burst release from >85% to ~60%, functioning as an “early-burst buffer” rather than a long-term depot. For microgels, a single PLGA/PEG layer partially attenuated burst release; however, an additional PLGA outer shell (double-barrier architecture) shifted the release-governing mechanism from swelling-dominated to diffusion-barrier-dominated control, limiting 10 min release to <10%. Core–shell formation was verified by confocal laser scanning microscopy (CLSM), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS); thermogravimetric analysis (TGA) showed ~73–79% coating retention after 9 days in phosphate-buffered saline (PBS, 37 °C). A vacuum re-loading process further improved encapsulation efficiency (>50% for beads, >20% for microgels) without compromising gel integrity. In beads, burst control was governed by swelling suppression; in microgels, the additional PLGA shell shifted control to diffusion-barrier-dominated release, demonstrating that barrier architecture must be adapted to particle scale. Full article

Sparganium stoloniferum tubers (SL), known medicinally as Sparganii Rhizoma, are commonly considered superior at the winter-harvest stage, when they show the traditional quality traits of heavy weight and firm texture. However, the developmental basis of this quality phenotype remains insufficiently understood. This study aimed to determine how tissue organization, cell-wall architecture, starch deposition, and related transcriptional patterns are associated with winter-harvest quality in SL. By comparing SL at different developmental stages, we found that maturation was accompanied by reduced moisture content, increased tuber density, higher parenchyma cell density, progressive cell-wall thickening, and marked starch accumulation. Laser scanning confocal microscopy (LSCM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) observations further revealed thickened multilamellar cell walls and abundant clustered or compound-like starch bodies in mature SL. Starch isolated from mature SL displayed an A-type crystalline pattern, short-range order, and high gelatinization and pasting temperatures, indicating an ordered and thermally stable starch matrix. Cell-wall Fourier-transform infrared spectroscopy (FTIR) and solid-state nuclear magnetic resonance (NMR) analyses showed a predominantly polysaccharide-rich framework with subtle maturation-associated changes in aromatic- and methoxy-associated wall signals. Transcript-guided pathway analysis, supported by reverse transcription quantitative polymerase chain reaction (RT–qPCR)validation, suggested developmental shifts in carbohydrate metabolism, lipid-related metabolism, and gibberellin-associated transcriptional patterns. Together, these findings indicate that winter-harvest quality in SL is associated with coordinated tissue consolidation, cell-wall maturation, starch deposition, and transcriptional reprogramming, providing a structural and molecular framework for understanding the traditional firm-texture trait of S. stoloniferum. Full article

Background/Objectives: Complete excision of squamous cell carcinoma (SCC) while preserving healthy tissue relies on accurate diagnosis and assessment of tumor margins. Ex vivo confocal laser scanning microscopy (EVCM) allows rapid, high-resolution visualization of freshly excised tissue. This study was conducted to comprehensively assess the diagnostic accuracy of EVCM for SCC diagnosis in tissue specimens and margin assessment in margin-controlled (micrographic) surgery using conventional histopathology as the reference standard. Methods: A systematic literature search of MEDLINE and Embase was conducted on 1 January 2026, in accordance with PRISMA guidelines. Pooled sensitivity and specificity were estimated using bivariate random-effects models. The QUADAS-2 and GRADE frameworks were applied to assess risk of bias and certainty of evidence. Results: Six studies comprising a total of 288 specimens were included. For SCC diagnosis in tissue specimens, the pooled sensitivity was 85.1% (95% confidence interval [CI]: 71.6–92.8) and the pooled specificity was 95.5% (95% CI: 90.9–97.8), with low between-study heterogeneity and moderate certainty of evidence. For margin assessment, pooled sensitivity and specificity were 89.9% (95% CI: 51.6–98.7) and 96.1% (95% CI: 85.8–99.0), respectively, with low heterogeneity but also low certainty of evidence owing mainly to the limited number of included studies and specimens. Conclusions: EVCM demonstrates moderate sensitivity and high specificity for the diagnosis of SCC in tissue specimens and may be used selectively as an adjunct to conventional histology, for example as a rapid confirmatory diagnostic tool capitalizing on its high specificity. Current evidence for margin assessment, although promising, remains limited. Full article

To improve the functional performance and digestibility of casein-rich ingredients, this study investigated the effects of trisodium citrate (TC) chelation and spray drying on the functional properties and in vitro digestibility of micellar casein isolate (MCI). TC chelation improved the foaming, emulsifying, gelling, and digestive properties of casein to different extents. Compared with MCI, trisodium citrate-chelated casein (TCC) exhibited significantly enhanced foaming capacity; specifically, the foaming capacities of TCC-40 and TCC-60 increased to 58.0% and 60.0%, respectively. TC reduced particle size, leading to increased foam volume, whereas foam stability decreased at higher chelation levels. In terms of emulsifying properties, TCC-10 exhibited optimal performance, with most emulsion droplet diameters distributed within 1–5 μm. TC chelation induced a significant negative shift in zeta potential (p < 0.05), suggesting improved emulsion stability. Gelation behavior was linked with concentration, showing TCC-40 induced the shortest gelation time (3.98 min) and the highest storage modulus. TC significantly enhanced casein digestibility in both adult and elderly in vitro digestion models, with digestion efficiency in the elderly model approaching that of the adult model. Confocal laser scanning microscopy (CLSM) pictures indicated that calcium chelation reduced gastric floc compactness, facilitating enzymatic access and improving protein hydrolysis efficiency. The study reveals the advantage of calcium chelation on the functional properties and digestibility of casein-based powder. Full article

Candida albicans is the causal agent of invasive candidiasis, which might be lethal in immunocompromised patients. Biofilm formation is considered a key virulence factor of C. albicans and is associated with its elevated resistance to antifungals. C. albicans and bacteria like E. coli are frequently found to form mixed biofilms on biotic or abiotic surfaces, rendering them more refractory to existing antifungals. To investigate how E. coli endogenous indole interplaying with exogenous IAA exerts modulatory effects on dual-species biofilm with C. albicans, an E. coli strain deficient in the indole biosynthetic gene tnaA was constructed, and the enzyme TnaA inhibitor was administered to block the indole production in E. coli monoculture and/or E. coli–C. albicans dual culture. Phenotypic assay revealed that indole deficiency attenuated E. coli mono-species biofilm by 12% (tnaA∆ versus WT E. coli), and the lack of indole in the E. coli cell-free culture filtrate abolished the ability to promote C. albicans biofilms, evidenced by the fact that the treatment with WT E. coli culture supernatants exhibited a 1.7-fold promotive effect, while treatment with tnaA∆ displayed no significant difference from the broth control towards C. albicans biofilms. Furthermore, impaired E. coli indole production might disrupt E. coli–C. albicans biofilm, as examined by confocal laser scanning microscopy (CLSM). Moreover, indole-3-acetic acid (IAA) was found to exhibit more potent biofilm-modulatory activity than indole by CLSM imaging with dual biofilms of WT E. coli–C. albicans, in contrast to those of E. coli tnaA∆–C. albicans post-supplemented with exogenous IAA. This study provides evidence for indole as a signaling molecule mediating bacterial–fungal communication during mixed-biofilm formation. Indole and its derivatives, particularly in combination with existing antifungals, have potential in the development of anti-biofilm strategies to eradicate refractory fungal infections. Full article

In this study, poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) films embedded with silver nanoparticles were fabricated to investigate their antibacterial performance against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Inspired by the nanoscale topographies of natural antibacterial surfaces, such as dragonfly and cicada wings, microstructured pillars were introduced onto the polymer surface to enhance its bactericidal activity by increasing the effective contact area. Surface morphology was characterised using scanning electron microscopy (SEM), including higher-magnification imaging of micropillar surfaces, while energy-dispersive X-ray spectroscopy confirmed the presence of silver. Higher-magnification SEM revealed nanoscale surface features on the micropillars, attributed to embedded or surface-associated silver nanoparticles. Antibacterial performance was evaluated using confocal laser scanning microscopy with live/dead staining. The PVDF-HFP/Ag films exhibited a significant reduction in bacterial viability, particularly against S. aureus (reducing viability to 0.6% ± 1.1%), while showing moderate activity against E. coli (41.0% ± 3.7% viability). While the fabricated micropillars (~5 µm) are larger than bacterial cells and unlikely to induce direct mechanical rupture, they increase surface interaction. To further investigate the theoretical antibacterial mechanism of scaled-down features, finite element analysis (FEA) was performed to model the mechanical interaction between bacterial cells and nanostructured pillars. The simulation results indicated localised stress concentrations that could compromise bacterial membrane integrity, suggesting a possible mechanobactericidal contribution if the microstructures are further reduced to the nanoscale, in addition to the primary biochemical effects of silver nanoparticles. FEA results do not aim to explain the experimentally observed antibacterial performance and should be interpreted only as a conceptual investigation. These findings demonstrate the potential of bio-inspired PVDF-HFP/Ag films as antibacterial materials for food packaging and related applications, subject to future comprehensive toxicity and quantitative microbiological evaluations. Full article

Rapid growth in fossil-fuel consumption has amplified the severity of global climate issues, making the deployment of renewable energy solutions increasingly imperative. Among candidate approaches, adsorption-based technologies are attractive; however, the limited adsorption capacity and kinetic performance of traditional adsorbents constrain composite-cycle efficiency and hinder large-scale implementation. In this work, we develop and evaluate a new class of composite adsorbents prepared by impregnating metal–organic frameworks (MOFs) with hygroscopic chloride salt solutions (LiCl, CaCl₂, and MgCl₂). Owing to their enhanced sorption characteristics, the resulting materials support an integrated adsorption cycle in which one device can simultaneously realize refrigeration, space heating, seawater desalination, and power generation. Under standard operating conditions, experiments demonstrate that MOF–vermiculite composites deliver a cooling coefficient of performance (COP) of 0.71, a heating COP (COP_h) of 1.30, a specific power-generation output of 27.2 kJ/kg, and a desalination yield of 0.71 g/g. Collectively, these metrics outperform the majority of previously published results, indicating that composite adsorbents can substantially improve the efficiency and practicality of renewable energy conversion systems. Full article

(1) Background: Nitric oxide (NO) serves as a crucial signaling molecule in plant abiotic stress responses. Although its role in enhancing drought resistance in cotton has been recognized, the specific mechanisms underlying this physiological and molecular regulation remain largely unexplored. This study aims to elucidate the multi-layered mechanisms by which NO modulates drought resistance in cotton; (2) Methods: Cotton seedlings were subjected to drought stress with the application of the NO donor sodium nitroprusside (SNP). A combination of confocal laser scanning microscopy, transcriptional expression analysis, biochemical assay of enzyme activity, virus-induced gene silencing (VIGS), and in vitro protein modification assays was applied to characterize the effects of NO on the drought stress response in cotton; (3) Results: Exogenous NO significantly reinforced drought resistance in cotton seedlings by improving leaf water retention capacity and photosynthetic efficiency, eliminating excessive drought-induced reactive oxygen species (ROS), upregulating the transcription and enzymatic activity of antioxidant enzymes, and promoting stomatal closure. Mechanistically, NO triggered S-nitrosylation of the plasma membrane H⁺-ATPase isoform GhHA2, thereby enhancing its protein stability; (4) Conclusions: These findings reveal that exogenous NO orchestrates cotton drought tolerance via multiple interconnected physiological and molecular pathways, in which the activation of the antioxidant defense system and the modulation of stomatal closure serve as central regulatory mechanisms. Full article

Copper-bearing low-carbon high-strength steels are widely employed in marine engineering. However, the microstructural homogeneity, strength–toughness matching, and low-temperature toughening mechanisms of such steels at high copper contents remain unclear. Existing studies have predominantly focused on the Cu content range of 1–2 wt.%, lacking systematic comparisons regarding microstructural evolution and property regulation throughout the entire rolling-heat treatment process at higher Cu levels. To clarify the influence of Cu content on the microstructural evolution and mechanical properties of CuxNi2.7Mn steels during processing and heat treatment, and to fully exploit the Cu precipitation strengthening effect while suppressing its embrittlement drawback, this study investigates CuxNi2.7Mn steels with Cu contents of 1.35 wt.%, 3.1 wt.%, and 6 wt.%. The specimens were fabricated via vacuum melting and two-stage rolling. Combining in situ observation using a high-temperature laser confocal microscope, optical microscopy, scanning electron microscopy, X-ray diffraction, and mechanical property tests, the effects of different Cu contents on the microstructure, conventional mechanical properties, and low-temperature toughness at −40 °C of the steels in both as-rolled and optimally heat-treated states (solid solution at 900 °C for 1 h + aging at 540 °C for 2 h) were systematically investigated. The results demonstrate that in the as-rolled condition, with increasing Cu content, the Vickers microhardness (HV1) of the steel increases from 183.9 HV1 to 271.9 HV1, the yield strength rises from 556.55 MPa to 852.87 MPa, and the tensile strength increases from 758.53 MPa to 1162.59 MPa. Nevertheless, excessive Cu content induces austenitic grain coarsening, aggregation of Cu-rich precipitates, and stress concentration, resulting in significant deterioration of ductility and toughness. Following optimal heat treatment, the banded structure is completely eliminated, the microstructural homogeneity is substantially improved, and the ductility and toughness are remarkably enhanced compared with the as-rolled state. Meanwhile, the strength continues to increase with rising Cu content, with the 6 wt.% Cu steel achieving a yield strength of 922.51 MPa and a tensile strength of 955.17 MPa. In terms of low-temperature toughness, the 3.1 wt.% Cu steel exhibits the poorest performance (90.8 J), whereas the 6 wt.% Cu steel presents a sharply increased low-temperature impact energy of 152.6 J. This is attributed to the precipitation of particulate phases such as TiC and MnS, which effectively disperse low-temperature stress and hinder crack propagation. Overall, the CuxNi2.7Mn steel with 6 wt.% Cu possesses the highest strength as well as excellent low-temperature toughness after optimal heat treatment, providing theoretical and experimental foundations for the composition design and heat treatment process optimization of high-copper steels for marine applications. Full article

Differential enrichment of shale oil hydrocarbon fractions exerts a fundamental control on the spatial distribution of “sweet spots” and the efficiency of unconventional resource recovery. This study investigates the continental shales of the Upper Es4 Member in the Dongying Sag, Bohai Bay Basin, through an integrated analytical framework combining Laser Scanning Confocal Microscopy (LSCM), Scanning Electron Microscopy (SEM), and high-pressure mercury intrusion. By moving beyond qualitative observations, we characterize the micro-scale partitioning of light and heavy fractions and establish a deterministic hierarchy of controlling factors. Our results indicate the following. (1) Mineral composition functions as a “primary geochemical filter,” where carbonate minerals exhibit a preferential adsorption affinity for light fractions (≤C₁₈), while clay minerals facilitate the selective retention of heavy components (>C₁₈). (2) Pore–throat architecture acts as a “secondary mobility modulator.” A statistically significant linear correlation (R² = 0.72, p < 0.05) was identified between mean pore diameter and the light-to-heavy fluorescence ratio, suggesting that interconnected macropores in carbonate laminae provide low-resistance conduits for light oil accumulation, whereas isolated mesopores in argillaceous matrices promote heavy-component sequestration. (3) Thermal maturity (Ro) drives a progressive shift in the light-to-heavy ratio, enhancing oil fluidity and regulating the transition from adsorption-dominated to migration-dominated enrichment. This study clarifies the lithofacies-dependent coupling mechanisms between mineral diagenesis and pore-scale fractionation, providing a semi-quantitative conceptual model for shale oil sweet-spot prediction in complex lacustrine basins. Full article

Background and Objectives: Invasive cutaneous squamous cell carcinoma (cSCC) and actinic keratosis (AK) are growing burdens on ageing societies and mainly arise from chronic sun exposure. Distinguishing between carcinoma and carcinoma in situ is often clinically challenging but essential for decision-making with respect to targeted therapy. Ex vivo confocal laser scanning microscopy (CLSM) allows histologic examination of native tissue using tissue reflection and nuclear fluorescence staining. The digital staining process almost perfectly mimics conventional haematoxylin and eosin (HE) staining. While the use of CLSM for basal cell carcinoma (BCC) diagnosis is well described, data on cSCC remain scarce. The aim of this study was to compare CLSM with conventional histology in diagnosing and distinguishing cSCC and AK in routine clinical practice. Materials and Methods: Between August 2022 and March 2024, 63 patients with clinically suspected invasive cSCC or AK were enrolled. Biopsy or excision specimens were examined by ex vivo confocal laser scanning microscopy (VivaScope^® 2500 M-G4) followed by acridine orange staining. All samples underwent subsequent routine histopathology, which served as the reference. Two dermatologists independently compared the CLSM findings with the histopathological diagnoses. Results: Eighty-one lesions suspected to be cSCC were assessed using CLSM. The diagnostic accuracy was high across specimen types: cSCC was correctly identified in 24/26 cases (92.3%), AK/Morbus Bowen in 16/17 cases (94.1%), cSCC filia (cutaneous squamous cell carcinoma metastases) in 3/3 cases (100%), and basal cell carcinoma in 9/9 cases (100%). The absence of a tumour was correctly recognized in 19/21 cases (90.5%). In five cases (6.2%), AK and early invasive cSCC could not be differentiated, reflecting the histopathological results. Conclusions: CLSM with digital HE staining is well suited for rapid cSCC and AK diagnosis and differentiation in clinical practice. Full article

Fretting wear significantly limits the service life of metal O-rings operating under harsh conditions. To address this limitation, this study investigates the wear behavior of metal O-rings under equivalent accelerated reciprocating motion and establishes an accelerated life prediction model based on similarity theory. Fretting wear experiments were conducted using Inconel 718 alloy and 304 stainless steel to replicate service conditions in a controlled laboratory environment. Wear morphology was characterized using laser scanning confocal microscopy, revealing a progressive transition from mild abrasive and adhesive wear to severe abrasive wear accompanied by material spalling. Based on the experimental results, regression analysis was performed to estimate the acceleration model coefficients, leading to the formulation of an equivalent acceleration equation capable of predicting seal wear life under practical service conditions. The resulting equivalent acceleration model can establish a quantitative connection between the acceleration test and the operating conditions. This model can shorten the testing time and can be used to predict parameters related to the surface morphology of static seals, providing a theoretical and experimental basis for reliable life assessment. This provides a practical basis for improving the reliability and safe operation of metal O-ring seals in critical applications, including nuclear energy and chemical processing systems. Full article