Search Results (3,324)

An operationally simple procedure for the synthesis of 2-alkyl-4-quinolone N-oxides, relying on controlled platinum-catalyzed partial hydrogenation of 2-nitrobenzoyl enamines, has been developed. The Pseudomonas aeruginosa metabolite 2-heptyl-4-quinolone-N-oxide (HQNO) and four analogous products have been prepared in good yield and high purity by this method. All products showed ampholytic properties, with a tendency to form isolable organic-soluble hydrochlorides by switching from the N-hydroxy-4-quinolone to 4-hydroxyquinoline-N-oxide tautomeric form upon partitioning between dichloromethane and 1M aqueous HCl. In basic medium, on the other hand, water-soluble salts of the N-hydroxy-4-quinolone tautomers were formed. NMR measurements indicate pH-dependent equilibrium with fast exchange between the 4-quinolone and the protonated 4-quinolinol tautomer. Full article

In this study, an acid-tolerant and high-fermentation performance strain of Kazachstania humilis (K. humilis 3-8) was screened from sourdough isolates and co-cultured with Fructilactobacillus sanfranciscensis (F. sanfranciscensis 5) to prepare liquid sourdough, which was further applied in mantou production. The effects on physicochemical properties, nutritional characteristics, and microbial interactions were investigated. K. humilis 3-8 exhibited strong gas production and acid tolerance, achieving a dough volume increase of 72.19% after 3 h fermentation. In co-culture, F. sanfranciscensis 5 maintained stable growth, while its metabolites significantly inhibited the growth of K. humilis 3-8 during mid-fermentation. The co-fermented dough showed decreased pH and increased total titratable acidity. Metabolomic analysis indicated enhanced carbohydrate metabolism and amino acid metabolism, suggesting carbon–nitrogen metabolic interactions between the two strains. When applied to Mantou production, the optimized co-culture system substantially enhanced product functionality, increasing resistant starch content by 76.7% (from 23.02% to 40.68%). Total phenolic content and antioxidant capacity were markedly enhanced. These findings elucidate complex microbial interactions governing sourdough ecosystems and establish a scientific foundation for the targeted improvement of traditional fermented cereal products through rational strain selection and process optimization. Full article

The atypical proliferation of Sargassum (Sargassum spp.) in the tropical Atlantic and the Caribbean Sea over the past decade has triggered an unprecedented environmental and socioeconomic crisis along the Mexican coastline. Continuous beaching events of this macroalga on the Riviera Maya have caused coastal ecosystem degradation, severe impacts on the tourism sector, toxic gas emissions during decomposition, and high cleanup costs. To address this challenge, the valorization of Sargassum as a raw material for synthesizing functional materials represents a sustainable management strategy. In this study, a superabsorbent hydrogel was developed from Sargassum biomass (collected in Cancún, Quintana Roo, in 2025) using an innovative process that bypasses the conventional cellulose isolation step. The biomass was subjected to high-energy milling (15 and 30 min) to prepare Sargassum powder, which was subsequently carboxymethylated using monochloroacetic acid. This modified biomass was then crosslinked with citric acid, a process evaluated at three different citric acid/carboxymethylated Sargassum mass ratios. The hydrogel synthesized with the lowest crosslinking agent ratio achieved a maximum water absorption capacity of 1160 wt%, a value that exceeds the typical absorption capacities of 700–900% for biopolymer hydrogels. Successful material formation was confirmed by Fourier transform infrared spectroscopy (FTIR), which revealed the characteristic functional groups of CMC and the ester bonds formed during crosslinking. Additionally, scanning electron microscopy (SEM) analysis showed a well-defined porous structure with pore sizes ranging from 8.5 to 19.5 µm, which is essential for its high absorption performance. This study demonstrates the feasibility of producing high performance hydrogels from Sargassum through a simplified, cost-effective, and environmentally friendly process. These findings open a promising avenue for the integrated management of this problematic biomass, transforming it into value-added materials with potential applications in agriculture, hygiene, and environmental remediation. Full article

During thermal processing of the beech mushroom, water-soluble bitterness-related compounds migrate into the cooking liquor. Spermidine (SPD), one of the representative hydrophilic polyamines, has potential nutritional value, but its direct exposure may also contribute to bitterness. To improve its utilization while limiting the direct exposure of SPD, SPD recovered from beech mushroom cooking liquor was used as the core material to prepare soy protein isolate–dextran (SPI–Dex)/sodium alginate (SA) external gelation water-in-oil-in-water (W/O/W) emulsion and freeze-dried microcapsules. The study evaluated SPD recovery, emulsion stability, and the structural and encapsulation properties of the resulting microcapsules. The initial SPD concentration in the cooking liquor was 69.17 mg/L and increased to 520.10 mg/L after membrane filtration, low-temperature concentration, and food-grade enrichment, with an overall recovery of 72.16%. The emulsions showed a typical W/O/W multiple structure, with encapsulation efficiency (EE) and retention efficiency (RE) of 92.90–99.76% and 92.47–96.87%, respectively. SA improved emulsion structure, interfacial charge, and physical stability. After freeze-drying, the microcapsules showed a porous network structure, low water activity (0.2139–0.2279), and low moisture content (2.14–2.88%), with EE of 56.44–98.13% and RE of 70.21–89.12%. These results show that the SPI–Dex/SA system can effectively encapsulate and stabilize beech mushroom-derived SPD, and may provide a feasible strategy for limiting its direct exposure in food systems while improving the utilization of thermal processing by-products. Full article

Marine macroalgae are a rich source of bioactive natural products, although the application of many lipophilic compounds is limited by poor aqueous solubility and instability. This study investigated metabolites isolated from the South African brown seaweed Sargassum incisifolium and evaluated a solid lipid nanoparticle (SLN) system to improve their physicochemical properties and enable bioactivity studies. Five metabolites, including one previously unreported derivative and four known metabolites (including fucoxanthin), were isolated and characterized using standard chromatographic and spectroscopic techniques. SLNs composed of stearic acid and Poloxamer 188 were prepared via hot homogenization and characterized using dynamic light scattering, scanning electron microscopy, thermogravimetric analysis, and NMR, which confirmed the efficient encapsulation of the lipophilic compounds. Antimicrobial activity against clinically relevant bacterial and fungal pathogens was evaluated using a resazurin-based microdilution assay, with results expressed as percentage growth relative to untreated controls. The pure compounds exhibited moderate, concentration-dependent activity, while the SLN formulations improved dispersibility, and in several cases, reduced % growth or produced more consistent responses, particularly against Gram-positive bacteria and Candida auris. Although activity remained lower than that of conventional antimicrobials, these findings demonstrate that SLN-based delivery enables functional evaluation of hydrophobic marine metabolites and supports further development of Sargassum-derived natural products. Full article

Background: Maritime operations increasingly rely on integrated, secure, and resilient architectures, yet the associated body of knowledge remains fragmented across conceptual, operational, logical, methodological, and governance-oriented perspectives. Objective: Our aim is to systematically review the literature on maritime integrated systems architecture in order to identify dominant themes, methodological tendencies, enabling technologies, and unresolved research gaps. Eligibility criteria: Peer-reviewed studies published in English were included when they addressed integrated systems architecture, or closely related architectural approaches, in maritime or naval contexts. Studies centred exclusively on isolated components, non-maritime settings without clear architectural transferability, or insufficient technical or methodological detail were excluded. Information sources: ACM Digital Library, IEEE Xplore, SpringerLink, ScienceDirect, MDPI, and IMarEST. Searches were carried out between January and March 2025, with the final search update for all sources completed in March 2025. Methods: The review was conducted and reported in accordance with PRISMA 2020. Three reviewers independently screened titles, abstracts, and full texts. Two reviewers independently extracted data, assessed methodological limitations and risk of bias using a review-specific qualitative appraisal framework, and evaluated the risk of bias due to missing results at the synthesis level. Disagreements were resolved through discussion and consensus, with third-reviewer arbitration when necessary. The synthesis combined qualitative thematic analysis across eleven predefined analytical categories with descriptive bibliometric and thematic mapping procedures. Results: Of 300 identified records, 60 studies met the inclusion criteria. Across non-mutually exclusive analytical categories, the literature was concentrated in Integrated Systems Architecture (52 studies), Development Processes (42), and Conceptual Models (37), whereas Zachman-based Methodology (4) and Maturity Models (3) were only marginally represented. Three recurrent patterns were observed across the corpus: the central role of cybersecurity and risk governance in architectural design; the growing importance of information technology and operational technology convergence for resilient monitoring, coordination, and decision support; and the increasing use of model-based and model-driven approaches to address architectural complexity. Overall confidence in the principal synthesized findings was judged to be moderate. Limitations: The review was limited to six databases and English-language publications, and the included studies varied in reporting depth, methodological transparency, and degree of empirical validation. Conclusions: The review organizes the field into a multilevel taxonomy spanning conceptual and operational models, logical and layered views, development processes, reference architectures, enabling technologies, and maturity-related perspectives. Taken together, the findings suggest that research in this area has progressed more clearly in architectural representation and integration than in long-term evaluation, particularly with regard to the practical operationalization of Zachman-based approaches and the development of maritime-specific maturity assessment frameworks. Funding: This review received no external funding. Registration: The review was not prospectively registered, and no publicly accessible protocol was prepared. Full article

Limbal stem cell (LSC) transplantation is an important treatment for limbal stem cell deficiency (LSCD), but low efficacy in maintaining LSC stemness during in vitro expansion greatly affects its wider application. The primary contributing factors include a low proportion of stem cells and the lack of a stable, supportive microenvironment over prolonged culture. Rabbit corneal tissues preserved under deep cryogenic conditions for more than six months retain viable limbal stem cells (LSCs), and primary LSCs isolated from these tissues exhibit robust stem cell characteristics. It is noteworthy that the NLRP3/Caspase-1/IL-1β signaling axis was activated in corneal epithelial cells, and outer limbal layers preserved for one or two years. Based on these findings, a combined strategy integrating deep cryopreservation with IL-1β induction was established for the processing of limbal tissues. The combined cryogenic and IL-1β preconditioning yielded primary LSCs with maintained p63⁺ cell proportions, a reduction in K3⁺ differentiated cells from approximately 80% to 60%, and a 6.25-fold increase in colony-forming efficiency. In addition, an increased proportion of cells in the G2/M phase and enhanced proliferative capacity were observed. The enriched LSC population also exhibited improved stratified epithelial reconstruction potential. These findings identify an effective strategy for preserving and enriching LSCs from limbal tissue, providing a practical and efficient approach for LSC preparation prior to transplantation. Further in vivo studies will be important to validate the functional performance of these cells in ocular surface reconstruction. Full article

An isolated fish skull from the Early Eocene Green River Lagerstätte from southwestern Wyoming, USA was tentatively identified as a regurgitalite. It consists of a skull of the perciform moronoid Mioplosus labracoides and articulated vertebrae. After mechanical preparation, the specimen was studied in detail and it could represent a regurgitalite, a pabulite (remnant of predation) or a portion of a decayed fish. Fish decay rarely results in an isolated skull, so this specimen probably pertains to a bromalite (pabulite or regurgitalite). We consider that it most likely is a regurgitalite because of the breakage of bones and displacement of elements. Full article

This case report describes a digital workflow for the aesthetic rehabilitation of a 30-year-old male patient with unaesthetic anterior teeth. The treatment incorporated AI-assisted smile design software (SmileCloud Biometrics) for 2D/3D digital planning and patient communication. Six lithium disilicate veneers (IPS e.max CAD) were fabricated using CAD/CAM technology following mock-up-guided minimally invasive preparation (0.2–0.9 mm reduction). The restorations were adhesively cemented under rubber dam isolation. One-week follow-up confirmed aesthetic integration, occlusal harmony, and patient satisfaction. This case illustrates how digital workflows with AI-assisted tools can support veneer rehabilitation through data-informed planning and conservative preparation while maintaining aesthetic outcomes. Full article

Hydrodistillation of aromatic plants for essential oil production generates substantial amounts of solid and liquid residues that are commonly discarded despite their potential value as sources of bioactive compounds. In this study, the essential oil and post-distillation residues of Rhododendron tomentosum Harmaja were evaluated within a waste-to-value framework to recover phenolic compounds with antioxidant and antimicrobial properties. Dry extracts obtained from liquid (DEA) and solid (DEE) residues were characterized in terms of total phenolic and flavonoid contents, antioxidant capacity (DPPH assays), and antimicrobial activity against selected microorganisms. Quantitative HPLC–PDA analysis revealed multiple phenolic compounds. Extracts derived from solid residues exhibited significantly higher phenolic and flavonoid contents and stronger antioxidant activity than those obtained from liquid residues, indicating that solid by-products constitute a richer phenolic matrix. Antimicrobial assays revealed pronounced activity for extracts prepared from plant material harvested in October, particularly those based on propylene glycol and glycerin, which were effective against both Gram-positive bacteria and selected Gram-negative clinical isolates. The essential oil showed broad-spectrum antimicrobial activity, including inhibition of Aspergillus niger. Stability studies demonstrated that the phenolic composition and bioactivity of the dry extracts were largely preserved after one year of storage. These findings demonstrate that R. tomentosum hydrodistillation residues represent a promising source of natural antioxidants and antimicrobial agents, supporting their potential utilization as value-added ingredients in food and cosmetic applications and contributing to circular economy strategies. Full article

Industrial accident reporting systems provide the foundation for establishing future prevention strategies by collecting and analyzing accident-related data. While some industrial accidents occur as isolated events, many exhibit a process-oriented nature in which a sequence of temporally connected events accumulates and ultimately leads to a final accident. Nevertheless, a substantial proportion of accident reports are prepared by injured workers or employers who lack specialized safety knowledge. As a result, critical information about the conditions, procedures, and actions involved in accident progression is often insufficiently documented. Such information loss hinders a comprehensive understanding of accident causation and, consequently, reduces the effectiveness of preventive measures. To address this limitation, this study proposes an event-based accident information reporting framework that enables injured workers and employers without professional safety expertise to record accidents in a structured manner following their temporal sequence. The proposed framework defines the observed actions and conditions throughout the accident occurrence process as a series of discrete “events,” each of which is classified by an occurrence type. Furthermore, each occurrence type is linked to a corresponding object that reflects its characteristics, allowing accident components to be described in a standardized and systematic form. The framework is designed to be easily completed through a simple selection-and-entry process centered on occurrence types, thereby facilitating consistent and uniform reporting. When applied to 462 fatal industrial accident cases that occurred in South Korea in 2018, the proposed method indicated that approximately 55% of accidents involved multi-stage event sequences, highlighting the importance of process-related information that is not captured by conventional outcome-centered classification systems. In addition, the distribution of occurrence types differed substantially from patterns observed in existing reporting practices. The structured reporting approach proposed in this study may contribute to the preservation and accumulation of essential information on accident occurrence processes, thereby supporting more effective accident prevention efforts. This study does not propose a new investigation methodologies. Instead, it aims to improve accident reporting quality at the data input stage. Full article

The antioxidant activity of natural and semi-synthetic depsides and benzofurans—including R-(+)-usnic acid (1), dibenzoyl usnic acid (2), atranorin (3), 2,4-bis(benzoyloxy)atranorin (4), 4-O-methyl atranorin (5), decarboxythamnolic acid (6), thamnolic acid (7), and perlatolic acid (8)—was evaluated in this study. Natural compounds were isolated from selected lichen species, whilst semi-synthetic derivatives were prepared to investigate the influence of esterification and methylation on electronic properties and radical-scavenging capacity. Structural elucidation was performed using NMR spectroscopy and mass spectrometry (MS). Electronic and thermodynamic descriptors, including the bond dissociation energy (BDE) of the most reactive O–H group, HOMO and LUMO_r energies, the HOMO–HOMO-1 energy gap (ΔH(H-1)), polarisability, and logP, were calculated and correlated with experimentally determined antioxidant capacity using the TEAC assay. Multivariate partial least squares (PLS-1) analysis identified ΔH(H-1) and LUMO_r as the primary determinants of antioxidant activity, with BDE and ΔHf providing complementary contributions. Perlatolic acid (8) exhibited the highest radical-scavenging capacity (TEAC = 2.7), whereas R-(+)-usnic acid (1) and dibenzoyl usnic acid (2) were the least active compounds (TEAC ≈ 0.1). Antioxidant activity was found not to correlate with the number of hydroxyl groups, but rather to be governed by electronic redistribution, conjugation effects, and substituent modulation. Exclusion of the outlier decarboxythamnolic acid (6) improved model performance, explaining 79.8% of the variance in TEAC values (R²Y), with strong predictive ability (Q² = 0.724) using a single latent variable. Overall, these findings provide a robust basis for the prediction and rational design of new antioxidant compounds, highlighting the relevance of lichen-derived metabolites as structurally stable scaffolds with potential applications in pharmaceutical and nutraceutical development. Full article

The agricultural sector generates substantial waste that harms both the environment and human health. This study aimed to utilise Metschnikowia yeasts to convert native agricultural wastes without chemical pretreatment. Ten Metschnikowia isolates were assessed using API tests to identify their assimilation profiles and enzymatic activities. Yeast growth was evaluated via the plate count method. The culture media containing molasses, brewery spent grain, and postharvest sunflower parts were characterised chromatographically, and the in vitro impact on Verticillium tenerum phytopathogen was evaluated. The effect of the yeast preparations on Caco-2, IEC-6, and HaCaT cell lines was also investigated. Solid waste materials without preliminary chemical pretreatment supported yeast multiplication to 4.5 × 10⁷–1.3 × 10⁸ CFU/mL. The metabolite composition and enzymatic activity of lipase, glucosidase, and protease in post-culture media suggest that they may act as growth inhibitors of the Verticillium strain. For post-cultivation samples, inhibition coefficients were equal to 1.24–2.00, depending on the kind of substrate and yeast strain used. Antimicrobial activity was also noted in cell-free samples after yeast cultivation on sunflower stalks and brewery spent grain. The toxicological analysis showed that the yeast preparations did not cause toxic effects on the tested cell lines. This research offers a sustainable approach using Metschnikowia yeasts, highlighting the importance of a holistic method that combines microbiological, biochemical, and toxicological aspects for sustainable waste management and the development of new applications, such as feed supplements and biocontrol agents. Full article

Background: Intraoral scanning (IOS) errors seldom originate from a single-point failure; instead, they arise from interactions among hardware performance, reconstruction software, and operator-dependent acquisition behaviors. James Reason’s layered defense (Swiss-cheese) model provides a systems-oriented lens to trace how residual vulnerabilities can propagate into clinically relevant surface distortions. Objectives: To quantify within-scanner precision of IOS under repeatability conditions in a controlled in vitro setting and to propose a Reason-based framework that maps defensive layers, barriers, and residual failure modes along the IOS workflow. Methods: A controlled in vitro design was implemented to minimize clinical confounders. A standardized partially edentulous maxillary reference specimen was scanned repeatedly with three IOS systems under fixed environmental conditions using a standardized scanning strategy. Within each IOS, precision was quantified from repeated scans using surface deviation metrics, including root mean square (RMS) deviation, percentile-based dispersion, and the percentage of points within a predefined tolerance band. Residual vulnerabilities were organized into a systems-oriented error framework by defensive layer (hardware, software/processing, and acquisition/operator) and workflow stage (pre-scan preparation, acquisition, reconstruction/registration, and export/verification). Results: Deviation-based precision metrics revealed scanner-specific dispersion patterns, including differences in RMS magnitude and tail behavior (percentile spread), suggesting scanner-specific patterns of residual distortion under the tested conditions. Tolerance-based metrics further showed that threshold selection materially influences interpretability and perceived clinical relevance. In vitro IOS precision assessed under repeatability conditions should be interpreted as an emergent output of multiple interacting defensive layers rather than as the isolated performance of a single component. Coupling deviation-based precision metrics with Reason’s layered defense model yields a clinically actionable framework for quality control, helping anticipate where residual risk is most likely to accumulate and where mitigation checkpoints can be implemented. Conclusions: In vitro IOS repeatability should be interpreted as an emergent output of multiple interacting defensive layers rather than the isolated performance of a single component. Coupling repeatability metrics with Reason’s layered defense model supports a framework for quality-oriented interpretation, helping anticipate where residual risk is most likely to accumulate and where mitigation checkpoints can be implemented. Full article

Diseases caused by Fusarium spp. vary around the world. It is important to determine the causals agents and indigenous antagonists against these pathogens. Thus, this study aimed to (i) determine the pathogens of root rot and yellow leaf disease (RRYLD), (ii) select Trichoderma spp. strains to control the pathogens, and (iii) evaluate methods for preparing the antagonistic fungi. Diseased soil samples were collected from pomelo orchards in Ben Tre province, Vietnam. The experiment isolated 08 Fusarium spp. strains, with the fastest growth in PDA in FP-C16, FP-B18, FP-B16, and FP-B03 (8.33–17.3 mm) on day 4 of culture. They were identified as Fusarium fujikuroi FP-C16, F. verticillioides FP-B18, F. verticillioides FP-B16, and F. incarnatum FP-B03. On the other hand, 25 Trichoderma spp. strains were isolated from the pomelo rhizosphere. Among them, 13 Trichoderma spp. strains showed rapid growth and strong antagonistic activity against two Fusarium spp. strains under laboratory conditions. The two Trichoderma spp. strains TP-C40 and TP-G50 had antagonistic efficiencies against FP-C16 and FP-B16 at 47.7–63.5%. The two selected Trichoderma spp. strains were identified as Trichoderma asperellum TP-C40 and T. yunnanense TP-G50. The two Trichoderma spp. strains TP-C40 and TP-G50 reduced the number of leaves and roots infected by Fusarium spp. Full article