Search Results (5,138)

Background: Persistent endodontic infections involving Enterococcus faecalis and Candida albicans are a major cause of root canal treatment failure. Although conventional irrigants, such as sodium hypochlorite and chlorhexidine (CHX), exhibit strong immediate antimicrobial activity, microbes may survive and recover from the initial antimicrobial effect, hence limiting their effectiveness, especially in complex root canal anatomies and in the apical terminus of the tooth. Antibacterial dressing techniques were not proven satisfactory due to depletion of the antibacterial component or difficulty in spreading it evenly along the entire root canal. This study aimed to develop and evaluate the antimicrobial efficacy and release characteristics of a novel sustained-release device (SRD), delivering CHX via gutta-percha points coated with a sustained-release formulation used as a temporary intracanal medicament. Methods: Gutta-percha points were coated with two sustained-release CHX varnishes (CHX1 and CHX2) or a placebo and assessed in vitro. Antimicrobial activity against E. faecalis and C. albicans was evaluated using agar diffusion assays over time. Release kinetics were analyzed using Rhodamine-labeled SRD in a 3D-printed acrylic molar tooth model via fluorescence microscopy. Additionally, biofilm-infected acrylic molar teeth were treated with a placebo, a single 2% CHX irrigation, or SRD-coated gutta-percha points placed as an intracanal dressing prior to obturation. Microbial viability was quantified by colony-forming unit (CFU/mL) analysis from root canals and gutta-percha points. Statistical analysis was performed using one-way ANOVA followed by Tukey’s post hoc multiple comparison test (p < 0.05). Results: SRD-coated gutta-percha points demonstrated sustained antimicrobial activity for up to 21 days against E. faecalis and 19 days against C. albicans. Fluorescence analysis, in an acrylic tooth model, confirmed continuous release for up to 15 days, with pronounced diffusion in the isthmus and palatal canals. In biofilm-infected acrylic teeth models, SRD treatment resulted in a significant reduction of 2–3 log₁₀ CFU/mL compared to placebo groups (p < 0.001) and prevented microbial rebound over the 14-day observation period. In contrast, a single application of 2% CHX solution showed only transient reduction followed by regrowth. Conclusions: Sustained-release CHX delivery via polymer-coated gutta-percha points provided prolonged antimicrobial activity against bacterial and fungal biofilms compared to conventional single-dose CHX application in this in vitro model. These findings support the potential use of coated gutta-percha points as a removable intracanal drug delivery platform prior to final obturation, although further studies incorporating direct-release quantification and in vivo validation are required before clinical translation. Full article

Neurodegenerative diseases feature diverse pathological protein aggregates, including Lewy bodies in Alzheimer’s disease (AD) and skein-like filaments in amyotrophic lateral sclerosis (ALS). The physical mechanisms underlying this morphological diversity remain unclear. Here, we demonstrate that aggregation of the prion-like domain of hnRNPA1 (A1PrD), implicated in AD and ALS, is driven by solution composition and phase transition dynamics. Utilizing 3D timelapse and fluorescence lifetime imaging microscopy, we show that solution conditions modulate phase separation, gelation, and fibrillation, resulting in distinct structures such as fibril, gel, and starburst morphologies. Homotypic and heterotypic interactions between A1PrD and RNA were observed to shift the balance between pathological and physiological condensates. Importantly, amyloid-rich starbursts displayed prion-like infection capabilities toward amyloid-poor condensates. Our findings highlight how the interplay between solution composition and kinetic balances of liquid-liquid phase separation, gelation, and fibrillation shapes the diverse pathological aggregate morphologies characteristic of neurodegenerative diseases. Full article

Background/Objectives: Ovarian cancer is the most lethal gynecologic malignancy, largely due to late diagnosis and the high prevalence of malignant ascites, a hallmark of advanced disease that is difficult to control and contributes to immune suppression and treatment failure. Despite advances in standard care, durable responses are rare. This study investigates a novel immunotherapeutic strategy designed to overcome the suppressed peritoneal microenvironment using an oncolytic vaccinia virus engineered to express a decoy-resistant IL-18 mutein. Methods: We generated a vaccinia virus (vvDD-nsmDR-18) expressing a non-secreted, mature, decoy-resistant IL-18. Viral expression was validated via RT-qPCR and fluorescence microscopy, while cytotoxicity was confirmed using CCK-8 assays. The antitumor efficacy of vvDD-nsmDR-18 was evaluated in the aggressive murine ID8a ovarian cancer model. The underlying mechanisms of action were investigated using flow cytometry and transcriptional profiling. Results: Treatment with vvDD-nsmDR-18 significantly prolonged survival and was associated with reduced abdominal distension consistent with decreased ascites burden. Immune analyses indicated enhanced T cell activation across multiple anatomical compartments, including tumors, peritoneal cavity, and spleens, the latter recently suggested to serve as a reservoir for tumor-reactive T cells. This systemic activation was characterized by increased IFN-γ and perforin expression. In addition, vvDD-nsmDR-18 treatment was associated with expansion of CD39⁺CD103⁺CD8⁺ tumor-reactive T cells and a shift toward a lower PD-1 expression phenotype within this population. Conclusions: These findings demonstrate that nsmDR-18-expressing oncolytic viruses can remodel the immunosuppressive landscape of advanced ovarian cancer, suggesting this approach is a promising candidate for further clinical development. Full article

In order to achieve rapid and qualitative detection of soluble heavy metal ions, nitrogen-doped fluorescent carbon quantum dots (N-CQDs) were synthesized using chitin extracted from shrimp and crab shells as the carbon source. The structural, morphological, and optical properties of the synthesized N-CQDs were systematically characterized using transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), Raman, X-ray photoelectron spectroscopies (XPS), ultraviolet-visible (UV-Vis) absorption spectroscopy and fluorescence spectroscopy. The resulting N-CQDs exhibited a carbonization yield of 54.46% and a fluorescence quantum yield of 34.33%. Their morphology, structure and optical properties were thoroughly characterized using a range of analytical techniques. The synthesized N-CQDs exhibited excellent fluorescence properties, and remarkable stability. When applied for metal ion detection, the N-CQDs displayed a distinct and selective fluorescence quenching response exclusively toward Fe³⁺ ions. The detection limit for Fe³⁺ at room temperature was 4.04 μmol/L. Furthermore, due to the inherent nitrogen present in the acetyl amino groups of chitin, nitrogen doping was achieved without the need for external dopants during the hydrothermal synthesis process. Owing to their high stability, low cost and low toxicity, the N-CQDs synthesized in this study provide a promising fluorescence sensing platform with excellent selectivity for Fe³⁺ detection, achieved through precise control of surface functional groups. Full article

Short-wavelength ultraviolet radiation can impair biological systems by causing DNA damage, oxidative stress, and disruption of photosynthetic processes. Although ultraviolet C (UVC) at 254 nm is widely used as a controlled laboratory stressor, the extent to which trophic condition influences repeated UVC tolerance in phototrophic protists remains unclear. Here, we examined the response of Euglena gracilis grown under photoautotrophic or ethanol-supported mixotrophic conditions and exposed to daily UVC pulses for five days. Cell growth, photosynthetic pigments, intracellular oxidative stress measured by 2′,7′ dichlorodihydrofluorescein diacetate fluorescence, and lipid peroxidation estimated as thiobarbituric acid reactive substances equivalent malondialdehyde were assessed, together with qualitative fluorescence microscopy. Repeated UVC exposure reduced cell density in both trophic conditions, with stronger inhibition under photoautotrophy. Photoautotrophic UVC-treated cultures showed the highest oxidative stress signal, whereas malondialdehyde displayed only a non-significant directional increase. Mixotrophic cultures maintained higher cell density under UVC and showed lower oxidative stress signals than photoautotrophic UVC-treated cultures. Pigment responses also differed between trophic conditions, with increased chlorophyll a and carotenoids per cell under photoautotrophic UVC treatment, while mixotrophic pigment levels remained comparatively stable. These findings show that trophic condition shapes repeated UVC stress responses in E. gracilis and that ethanol-supported mixotrophy is associated with improved physiological robustness under the present experimental conditions. Full article

Background/Objectives: Early embryonic arrest during the cleavage stage (days 2–4) accounts for a substantial proportion of developmental failure in in vitro fertilization. This phenomenon remains poorly understood at the molecular level, even in chromosomally normal embryos identified by preimplantation genetic testing. This review aims to redefine cleavage-stage arrest from a passive energy deficit to a checkpoint-regulated endpoint caused by inadequate coordination among metabolism, transcriptome integrity, and stress-response pathways. Methods: We integrate evidence from long-read transcriptomics, metabolomics, epigenetics, and immunobiology relevant to pre-blastocyst development. These data are assembled into a unifying mechanistic framework and a clinically oriented stratification model, together with candidate multimodal readouts for early classification. Results: We propose a three-axis model linking: (i) metabolic–epigenetic insufficiency, including defective histone lactylation and impaired alpha-ketoglutarate-dependent DNA demethylation; (ii) isoform-level abnormalities, including intron retention and retrotransposon activation within a hidden transcriptomic landscape better resolved by long-read sequencing; and (iii) stress-related immune signaling, in which NLRP7 links alternative splicing and DNA-damage-response dysfunction with mitochondrial stress and p53-associated arrest. Within this framework, we distinguish three molecular arrest states: an early transition failure marked by defective maternal-to-embryonic reprogramming and severe splicing disruption; a metabolically quiescent state that may retain a limited rescue window; and a later stress-associated state characterized by senescence-like features, oxidative stress, and broad transcriptomic and genomic instability. Conclusions: Early embryo arrest should no longer be viewed as a nonspecific developmental failure, but as a mechanistically stratifiable condition with distinct metabolic, transcriptomic, and stress-associated trajectories. A diagnostic platform combining fluorescence lifetime imaging microscopy, long-read sequencing, and digital polymerase chain reaction may improve early mechanistic classification, help identify embryos with possible reversibility, and reduce uncertainty in embryo selection during in vitro fertilization. Full article

The aim of this study was to investigate which physicochemical and structural properties of cationic peptides P1–P6 may determine their selective anticancer activity against melanoma cells and their interactions with tumor cell membranes. An integrated approach was applied, including characterization in solution (osmotic pressure, NaCl stability, surface tension); cytotoxicity evaluation against Me45, B16F10, and HaCaT cells; analysis of interactions with phosphatidylglycerol (POPG) model membranes using isothermal titration calorimetry and steady-state fluorescence spectroscopy; membrane permeability assays; and F-actin staining. Anticancer activity depended on positively charged residues, hydrophobic amino acids, and sequence arrangement. Tryptophan-rich peptides P2 and P5 exhibited strong membrane interactions and high efficacy after 72 h. Highly hydrophobic P4, containing long C₁₂ chains with a relatively low net charge, caused nonselective lysis. P3 showed reduced activity due to insufficient amphipathicity, whereas P6, with excessive WWW and KKKK motifs, exhibited weak or nonselective effects. Thermodynamic and fluorescence analyses indicated that P2 and P5 initially bind POPG membranes via entropy-driven electrostatic interactions, followed by hydrophobic insertion of tryptophan residues, evidenced by increased fluorescence intensity and a blue shift of the emission maximum. P2, P4, and P5 induced actin cytoskeleton reorganization and increased membrane permeability, emphasizing the role of balanced amphipathicity and charge–hydrophobicity in designing selective anticancer peptides. Full article

Background: Multiple myeloma (MM) is characterised by clonal expansion of plasma cells (PCs) in the bone marrow (BM). Disease assessment and monitoring typically rely on invasive, single-site procedures, such as BM biopsies (BMBs), which may inadequately capture intra- and extra-medullary spatial heterogeneity. Circulating plasma cells (CPCs), enriched from peripheral blood (PB), may represent a minimally invasive alternative or adjunct for molecular profiling. Objectives: This study aimed to evaluate the feasibility of using CPCs, enriched from PB, for mRNA analysis in plasma cell dyscrasia, including MM. A secondary objective was to assess whether mRNA expression levels of the endoplasmic reticulum (ER) stress sensors X-box-binding protein 1 (uXBP1) and activating transcription factor 6 (ATF6), and the chaperone-mediated autophagy marker Lysosomal-Associated Membrane Protein 2 (LAMP2A) by droplet digital PCR (ddPCR), were associated with resistance to the second-generation proteasome inhibitor (PI) carfilzomib (Cfz). Methods: Multiple myeloma (MM) cell lines (H929 and U266) and their carfilzomib-adapted derivatives were used to establish and validate droplet digital PCR (ddPCR) assays targeting ER stress (uXBP1, ATF6) and autophagy-related (LAMP2A) transcripts. Solid tumour cell lines, including serum-starved HeLa cells, served as biological controls to support assay specificity and sensitivity. Total RNA was extracted and reverse-transcribed to complementary DNA prior to analysis. Transcript levels were normalised to those of β-actin or GAPDH, as appropriate. ddPCR was performed using the BioRad QX200 system, with results reported as the normalised transcript copy number per microlitre of reaction. Matched bone marrow aspirate (BMA) and peripheral blood (PB) samples were collected at a single clinical time point from adults undergoing investigation for plasma cell dyscrasia between January 2021 and December 2023. Samples were obtained as part of standard clinical care and/or during treatment with Bortezomib (Btz) or Cfz. Mononuclear cells were isolated by density gradient centrifugation, and CD138⁺ plasma cells were enriched by fluorescence-activated cell sorting. Enrichment purity was assessed qualitatively by immunofluorescence microscopy using CD138 and CD117 markers. Samples yielding fewer than 1000 CD138⁺ plasma cells were excluded, resulting in 10 evaluable matched patient pairs. Results: Carfilzomib-adapted MM cell lines demonstrated reduced levels of uXBP1, ATF6, and LAMP2A mRNA compared to treatment-naïve cells. In matched BM and PB samples, uXBP1 mRNA levels were consistently lower in circulating PCs than in BM-derived PCs, whereas ATF6 mRNA levels were concordant between compartments. LAMP2A mRNA levels exhibited marked inter-patient heterogeneity. Conclusions: This study demonstrates the feasibility of using CPCs as a minimally invasive source for mRNA-based biomarker assessment and highlights ddPCR as a sensitive platform for quantifying ER stress and chaperone-mediated autophagy related transcripts in CPCs. Cfz adaptation was associated with reduced levels of uXBP1 and LAMP2A mRNA in MM cell lines. Future prospective studies evaluating the clinical utility of ER stress and chaperone-mediated autophagy associated transcripts in CPCs as predictors of resistance to PI are warranted. Full article

This study assesses indicative technical correspondences and divergences between Francisco de Zurbarán’s painting practices and those observed in the seventeenth-century Óbidos workshop (Baltazar Gomes Figueira and Josefa d’Óbidos). We focus on the composition and function of priming layers, the shadow-to-light painting sequence, and pigment/binder usage. A multi-analytical approach was employed: portable X-ray Fluorescence (XRF), Optical Microscopy on polished cross-sections (OM), Scanning Electron Microscopy in backscattered mode with Energy-Dispersive X-ray analysis (SEM-BSE/EDS), Micro-Confocal Raman Spectroscopy (µ-Raman), and Micro-Fourier Transform Infrared Spectroscopy (µ-FTIR). Rather than treating single pigments as diagnostic, we compare patterns of application and stratigraphic behaviour—notably a two-layer priming, in which a finer, Fe-rich upper layer is actively used to build shadows, and a consistent exploitation of the priming as a value layer in a shadow-to-light sequence. Materials largely overlap, while priming compositions differ, plausibly reflecting local resources. Given the small corpus (two works by Zurbarán, one by Baltazar, and one by Josefa), conclusions are presented as indicative and contextualized within Iberian workshop practice. Full article

Broccoli (Brassica oleracea var. italica) is an important crop valued for its nutritional and health-promoting properties, yet its biotechnological improvement is limited by low effectivity and genotype-dependent transformation protocols. The absence of reliable transient expression systems further constrains functional genomics and genome-editing applications. Here, we optimized regeneration and transformation protocols for different broccoli genotypes. Endoreduplication patterns in young tissues were analyzed by flow cytometry to identify suitable explants, and combinations of plant growth regulators were tested to develop an efficient organogenic medium. Stable transformation was achieved via Agrobacterium tumefaciens using nptII and eGFP markers. Cotyledons and hypocotyls up to day 7 showed similar endoreduplication patterns, with abundant 2n cells, but hypocotyls exhibited higher regeneration capacity. The optimized medium supported efficient organogenesis while maintaining diploidy. Transformation efficiency reached 10.4% in ‘S1’ and 2.8% in ‘Naxos’, highlighting genotype dependence. In parallel, a transient expression system was established using cotyledon-derived protoplasts and electroporation-mediated DNA delivery. GFP expression was confirmed through fluorescence microscopy, confocal imaging, and Western blotting. These protocols provide a robust toolkit for broccoli genetic manipulation, facilitating molecular biology studies in the native plant, functional genomics and genome-editing strategies, including CRISPR-based approaches. Full article

Effects of gastric acid and antiacid medications on the surface and optical properties of resin-based restorative materials were evaluated. A hybrid-CAD/CAM block, a 3D-printed resin, a paste-type composite, and a flowable composite were investigated (n = 9). Samples were prepared (1 mm thickness) and polished. All samples were exposed to gastric acid for 6 days, followed by a second exposure to distilled water, antiacid medication, or gastric acid for 56 min. Surface roughness, translucency, and fluorescence were assessed at baseline (T₀), after gastric acid exposure (T₁), and after the second exposure (T₂). Surface morphology was examined by scanning electron microscopy. Data were analyzed with a significance level of p < 0.05. Gastric acid exposure caused a significant increase in surface roughness and a significant reduction in translucency in all materials (p < 0.05). CAD/CAM and paste-type composites exhibited significantly higher roughness values than the 3D-printed and flowable composites (p < 0.001). Fluorescence changes were observed in all groups, but the highest ΔE₀₀ values were observed in the 3D-printed and flowable composites (p < 0.001). Gastric acid adversely affected the surface and optical properties of resin-based restorative materials, while antiacid medication showed limited, material-dependent protective effects. Full article

Synergistic diagenetic evolution of sandstones and shales significantly impacts the quality of associated tight oil and shale oil reservoirs. Using integrated petrographic (thin sections, fluorescence thin sections, scanning electron microscopy with energy dispersive spectroscopy), mineralogical (X-ray diffraction), geochemical (stable carbon–oxygen isotopes, electron microprobe), organic petrologic, and petrophysical analyses, combined with basin burial and thermal history reconstruction, this study investigates the mechanisms and processes of synergistic diagenesis in the tight sandstone-shale assemblages of the 7th and 8th Members of the Yanchang Formation (Middle-Late Triassic) in the western Zhidan area, Ordos Basin, China. Controlled by basin evolution, the interbedded sandstones and shales, under shared burial-thermal conditions, exhibit strong synergy in four coupled processes: compaction, clay mineral evolution, shale fluid expulsion coupled with sandstone carbonate cementation, and shale hydrocarbon expulsion coupled with sandstone secondary porosity generation. This “fluid supply-response modification” relationship strongly influences diagenetic pathways and reservoir space evolution in sandstones, leading to variable reservoir quality among different sandstone-shale assemblages. Thicker-bedded sandstones interbedded with thinner-bedded shales represent potential targets for high-quality tight sandstone reservoirs. These findings provide a possible theoretical and methodological basis for identifying high-quality tight sandstone reservoirs in lacustrine-deltaic sandstone-shale assemblages. Full article

The concentration of heavy metals in the environment has been steadily increasing, raising concerns about their adverse effects on ecosystems and human health. Fine-grained particulate matter is of particular concern due to its enhanced mobility, bioavailability, and potential for inhalation exposure. Facilities involved in the mechanical processing of electronic waste (e-waste) represent a significant potential source of metal-containing fine particles. In this study, crushed e-waste components containing precious metals were separated into particle-size fractions ranging from 3.0 to 0.15 mm using a vibratory sieving system. The elemental composition of the individual fractions was determined by energy-dispersive X-ray fluorescence spectrometry (ED-XRF), while the spatial distribution of selected metals in fine fractions was further investigated using scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM–EDS). The results demonstrate that e-waste contains a wide range of heavy non-ferrous metals whose distribution is strongly dependent on particle size. A pronounced enrichment of metals was observed in the finest fractions, particularly below 0.25 mm. Compared to the coarse fraction (>3 mm), the zinc concentration increased by approximately one order of magnitude, while chromium, nickel, and cadmium exhibited increases of up to approximately 20-fold. Lead showed particularly high enrichment, reaching approximately 2 wt.% in the finest fraction (<0.15 mm), corresponding to nearly fiftyfold enrichment relative to the coarse fraction. Tin concentrations also increased markedly, in some cases by up to two orders of magnitude. Trace amounts of arsenic and selenium were detected in the finest fractions, whereas mercury was not detected. The combined ED-XRF and SEM–EDS results confirm that fine-grained e-waste fractions are the dominant carriers of hazardous metals and respirable particles generated during mechanical processing. These findings highlight the dual character of fine fractions as both a critical environmental and occupational risk and a potentially valuable secondary resource. The study emphasizes the importance of controlled handling, effective dust management, and targeted processing strategies to minimize human exposure while enabling efficient recovery of valuable metals from e-waste. Full article

The goal of this review is to bring to the attention of the scientific community the opportunities of transmission electron microscopy for analyses of biological subjects and resolving complicated cases of data interpretation. Although procedures for electron microscopy are in general more elaborate (particularly for simultaneous immunolabeling of multiple antigens) compared to fluorescent microscopy, they can help view cellular morpho-functional features undetectable using other methods. In this review, we consider several unexpected and serendipitous discoveries made in our laboratory and fulfilled using unique opportunities provided by electron microscopy of ultrathin sections. We are deliberating the following topics: interpretation of unusual results of immunolabeling; a novel method for in situ identification of cells undergoing mitochondrial disorder and necrosis-like death; the sequence of organelles’ reorganization in dying cells; simultaneous rupture of nuclear and plasma membranes in migrating neurons; and the role of cytoskeleton in lateral expansion of the cerebral cortex. Full article

The performance of recycled hot-mix asphalt mixtures (RHAM) is strongly governed by the extent and uniformity of interactions between the aged binder in reclaimed asphalt pavement (RAP) and the virgin binder. However, in current engineering practice, it remains difficult to accurately evaluate the blending degree of aged and virgin asphalt during RHAM production, where the blending degree refers to the extent and uniformity of binder interaction during hot mixing. Moreover, influenced by various construction-related factors, the uniformity of interfacial diffusion between the two asphalt layers is also hard to control, which compromises the durability of RHAM. To address these issues, fluorescence microscopy was used to quantitatively characterize the blending behavior of aged and virgin asphalt, and Fourier transform infrared spectroscopy (FTIR) was employed to investigate the interfacial diffusion process and its evolution under time-temperature coupling conditions from plant production to field paving. The results indicate that, owing to the fluorescent characteristics of the Styrene-butadiene-styrene block copolymer (SBS) modifier in polymer-modified asphalt, the blending behavior during hot mixing can be quantitatively characterized by the fluorescent area and its areal proportion, providing a rapid solution for quantitative evaluation during RHAM production. Increasing the preheating temperature of RAP, extending mixing time, raising mixing temperature, and adopting Mixing Sequence I reduced the proportion of fluorescent area, suggesting improved blending between aged and virgin asphalt. After blending, the interfacial diffusion between aged and virgin asphalt occurs within the RHAM; the uniformity of this diffusion becomes more pronounced as the elapsed duration from production to paving increases. Nevertheless, excessively long duration may induce secondary aging of the blended binder. Accordingly, the duration is recommended to be controlled at approximately 90 min and should not exceed 180 min. By elucidating the blending and diffusion behaviors of aged and virgin asphalt, this study provides practical guidance for contractors in controlling production-process parameters for RHAM. Full article