Search Results (25,489)

Repetitive temperature fluctuations during transportation and storage promote ice crystal formation in salmon flesh, leading to protein denaturation, lipid oxidation, and quality loss. Tuna skin, a major by-product of tuna processing, is a potential source of antifreeze peptides (AFPs) but remains underutilized. This study examined the cryoprotective effects of tuna skin-derived AFPs on salmon cubes subjected to repeated freeze–thaw cycles. Cubes treated with AFPs from three groups of protein hydrolysates prepared using trypsin, pepsin, or neutral protease were evaluated for texture, color, water holding capacity (WHC), volatile odor profiles, protein conformation, biochemical indices, and microstructure. AFP treatment improved textural properties, maintained color stability, and reduced thawing, cooking, and centrifugal losses. The neutral protease-treated group exhibited the optimal cryoprotective ability and it also limited aldehyde and sulfide accumulation, preserved the retention rate of α-helix structure at 49% which was higher than 39% in controls, and enhanced Ca²⁺-ATPase activity to 1.75 μmol Pi·mg⁻¹·h⁻¹ with a 45.8% increase compared to controls, and significantly inhibited protein and lipid oxidation. Microstructural analysis showed compact fibers and intact sarcolemma in the neutral protease-treated group samples, contrasting with severe disruption in controls. This study showed that tuna skin AFPs mitigate freeze–thaw damage in salmon cubes by stabilizing proteins and reducing oxidative deterioration, highlighting their potential as natural, healthy cryoprotectants for seafood preservation, meeting the growing demand of the food industry for clean-label, low-calorie preservation solutions, while advancing the circular economy of aquatic processing via the valorization of tuna skin by-products for high-value seafood applications. Full article

Hydrogels are widely investigated as drug carriers for cancer therapy due to their ability to provide sustained release and reduce systemic side effects. In this study, MeBSA–PNIPAm hydrogels were developed as dual-temperature and pH-responsive systems for gastrointestinal delivery of 5-FU. MeBSA was successfully synthesized using glycidyl methacrylate and confirmed by FTIR and ¹H-NMR analyses. Hydrogels with varying MeBSA/NIPA ratios were prepared via redox polymerization. DSC results showed that increasing MeBSA content shifted the phase transition temperature of hydrogels, while TGA analysis revealed enhanced thermal stability with higher MeBSA incorporation. Temperature-dependent swelling experiments further demonstrated that the VPTT slightly shifted depending on the surrounding pH, indicating that the thermoresponsive behavior of the hybrid network is influenced by the pH-dependent charge state of the protein component. Swelling studies performed at 30, 37, and 40 °C and at pH 1.2 and 7.4 confirmed dual-responsive behavior. Drug loading efficiencies above 70% were achieved for all formulations. In vitro release studies at 37 °C demonstrated distinct composition-dependent release profiles. During the first 2 h, all hydrogels exhibited controlled and limited release without burst behavior under acidic conditions. Following the transition to pH 7.4, a composition-dependent increase in drug release was observed. GEL 4 achieved the fastest and highest cumulative release (91%), whereas GEL 1 provided the most sustained release over 72 h (32%). Kinetic analysis indicated diffusion-controlled release, best described by the Weibull and Korsmeyer–Peppas models. Cytocompatibility tests showed that fibroblast viability improved with increasing MeBSA content. Overall, protein-modulated dual-responsive hydrogels offer tunable and biocompatible platforms for stimuli-responsive gastrointestinal drug delivery applications. Full article

The development of inks with suitable rheological, physicochemical, mechanical, and biological properties is crucial for the successful fabrication of functional scaffolds via extrusion-based 3D printing. In this study, collagen/chitosan hydrogels with varying polymer ratios were developed and characterized to evaluate their printability and suitability for cartilage tissue engineering. Rheological analyses revealed that all samples exhibited shear-thinning behavior and solid-like viscoelasticity, with the formulation of an 80:20 COL/CHI ratio (20CHI) demonstrating optimal filament formation and dimensional stability. Physicochemical analyses confirmed the preservation of the collagen triple helix and the formation of hydrogen bonding between chitosan and collagen. 20CHI scaffolds showed swelling capacity and high cohesiveness. In vitro studies confirmed the cytocompatibility of the scaffolds with murine fibroblasts and the ability of the scaffolds to promote adhesion, proliferation, and extracellular matrix production of both chondrocytes and adipogenic mesenchymal stem cells (aMSCs). Quantification of sulfated glycosaminoglycan (sGAG) indicated sustained matrix deposition over 28 days, particularly by chondrocytes. These findings demonstrate that 20CHI hydrogel is a promising candidate for 3D printing of biomimetic scaffolds for cartilage regeneration. Full article

Urban air quality is a key component of environmental sustainability and public health in large metropolitan areas. Following the substantial but temporary improvements in air quality observed during the COVID-19 lockdowns, it remains unclear whether structural changes in urban air pollution have persisted in the post-pandemic period. This study analyzes the temporal dynamics of major atmospheric pollutants in Mexico City between 2021 and 2024, including CO, NO₂, NO_x, O₃, PM₁₀, PM_2.5, and SO₂, using hourly data from the Mexico City Atmospheric Monitoring System (SIMAT). Annual and monthly median concentrations were computed to reduce the influence of extreme values and short-term pollution episodes. Station-level monotonic trends were evaluated using the non-parametric Mann–Kendall test, complemented by the use of Sen’s slope estimator to quantify the magnitude and direction of change. Absolute and relative changes between 2021 and 2024 were also analyzed to capture incremental variations not reflected by trend significance tests and performed together with hourly monthly analyses to characterize diurnal and seasonal patterns. Results indicate that no statistically significant monotonic trends were detected for any pollutant across the analyzed stations (p > 0.05), suggesting an overall stabilization of air quality levels during the post-pandemic period. Nevertheless, moderate increases in annual median concentrations were observed at specific locations, particularly for PM₁₀, PM_2.5, NO₂, and NO_x, with relative changes ranging from approximately 5% to 35%. Persistent diurnal and seasonal patterns were identified, closely associated with traffic activity, photochemical processes, and meteorological conditions. These findings suggest that, although no robust long-term trends are evident, incremental increases and stable temporal structures remain relevant from a sustainability perspective. Continued monitoring and targeted air quality management strategies are therefore necessary to support long-term urban environmental sustainability. Full article

This study investigates the key performance-related fuel properties of emulsifier–diesel solutions and ethanol-in-diesel microemulsions. This work begins with the in situ polymerization of long alkyl chain-substituted glycidyl methacrylate (R-GMA) in diesel and the optional presence of a second methacrylate monomer. The resulting diesel-soluble oligomer functions as a nonionic emulsifier. Controlled amounts of ethanol are subsequently incorporated into the emulsifier–diesel solution to form a stable microemulsion, referred to as E-Diesel. This study examines how the structure of the emulsifier influences key fuel properties, including (i) ethanol–diesel miscibility, (ii) gross calorific value, (iii) Ramsbottom carbon residue (% of fuel), (iv) entrapped polycyclic aromatic hydrocarbons (PAHs), and (v) fuel lubricity. Both the hydrophilic–hydrophobic balance and the structure of the emulsifier side chains are found to significantly affect these properties. Compared with neat diesel, oligomeric emulsifiers enable the substantial dispersion of ethanol in diesel (up to 18 wt.%). The resulting fuel exhibits a gross calorific value exceeding the theoretical sum of diesel and ethanol at the same composition (a synergistic effect) and achieves an enhancement in lubricity up to 49.5% relative to neat diesel at a 5% emulsifier loading. Although the presence of emulsifiers leads to an increase in the carbon residue by up to 54.7% compared to neat diesel during controlled pyrolysis, it simultaneously reduces the PAH content in the exhaust. Overall, this study establishes fundamental correlations among microemulsion stability, combustion synergy, carbon residue formulation, and fuel lubricity, which are governed by the structure of the emulsifier. Full article

This study examines the use of artificial intelligence (AI) in organizational decision-making processes (DMPs) related to investments in renewable energy sources (RESs). The research addresses the gap between AI’s technological capabilities and its actual application in investment practice. An empirical two-stage survey was conducted in 2025, and a comparative analysis was conducted to assess the stability of attitudes toward AI adoption. The findings indicate a low level of practical implementation of AI tools in investment decision-making, despite a clear perception of their potential usefulness, particularly for risk analysis and improving decision objectivity. Organizations tend to perceive AI primarily as analytical support rather than an autonomous decision-making mechanism. The results also reveal a persistent level of uncertainty and hesitation associated with trust in AI systems. Comparative analysis confirms that these attitudes remain stable across research stages, suggesting structural rather than temporary barriers to adoption. This study demonstrates that limited adoption of AI in renewable energy investment decisions results mainly from organizational readiness and trust-related factors rather than technological constraints. The paper contributes empirical evidence on the behavioral and organizational determinants of AI implementation in the context of sustainable energy transition. Full article

To address the current absence of targeted gradation design for porous asphalt pavements both domestically and internationally, this study employs the Coarse Aggregate Void Filling (CAVF) method to design the gradation of porous asphalt mixtures. Marshall stability tests, rutting tests, and scattering tests were conducted to investigate the relationship between coarse aggregate proportions and the structural stability of the mixture skeleton. An orthogonal experimental design was further utilized to examine the influence of three levels of fine aggregate gradation on the acoustic absorption characteristics of the mixture, and to analyze the effects of aggregate gradation on the primary pore diameter, connected pore diameter, and connected pore length. The results indicate that the coarse aggregate gradation predominantly governs the skeleton strength and overall pavement performance of the mixture, whereas the fine aggregate gradation exhibits significant effects on the interconnected void ratio, pore structure, and sound absorption performance. The optimal roughness range of coarse aggregates in porous asphalt mixtures is determined to be 0.46–0.52. The proportion of 0.6–1.18 mm aggregates has a pronounced influence on the primary pore diameter, connected pore diameter, and connected pore length. By integrating the design considerations for both coarse and fine aggregate gradations, a recommended gradation range for porous asphalt mixtures is proposed that achieves a balance between pavement performance and sound absorption/noise-reduction effectiveness. Full article

Carotenoproteins from marine sponges represent an underexplored class of pigment–protein complexes with distinctive structural and functional properties. Here, we report the isolation and biophysical characterization of a blue carotenoprotein from the sponge Tedania ignis, termed Ti-CP. The protein was purified and shown to consist of two closely related isoforms with molecular masses of approximately 27–29 kDa. Reverse-phase chromatography enabled separation of the apoprotein (ApoTi-CP) and its associated carotenoids, which were identified as oxygenated carotenoids consistent with astaxanthin and mytiloxanthin. Circular dichroism analysis revealed that both Ti-CP and ApoTi-CP are dominated by β-sheet secondary structure and display highly similar conformational profiles. In contrast, dynamic light scattering demonstrated that carotenoid binding is critical for protein stability, as the native form exhibited a compact and monodisperse organization, whereas ApoTi-CP showed pronounced aggregation. Isothermal titration calorimetry revealed that Ti-CP, but not ApoTi-CP, interacts with tetracycline, oxacillin, and streptomycin, indicating that pigment-mediated stabilization modulates ligand binding. Both Ti-CP and ApoTi-CP reduced bacterial viability and biofilm formation in a strain-dependent manner and enhanced antibiotic activity, including synergistic effects against resistant bacteria. Together, these results provide a comprehensive description of a previously uncharacterized sponge carotenoprotein and highlight the dual role of carotenoids in structural stabilization and antimicrobial modulation, reinforcing the biotechnological relevance of marine pigment–protein complexes. Full article

Virtual reality (VR)-based evacuation training provides a safe and immersive environment for participants to experience disaster scenarios. However, existing systems often prioritize the experience itself, leaving the critical stage of reflection—essential for refining and stabilizing evacuation knowledge—under-supported. This study presents a qualitative pilot investigation into an extended reflection support function for a VR-based evacuation training system. Unlike traditional replay functions that only visualize avatar movements, our system synchronizes spatialized environmental sounds and recorded verbal utterances, i.e., voices of the user and non-player characters (NPCs), with the visual replay. A preliminary experiment involving eight university students was conducted to evaluate how these auditory clues influence the reflection-on-action process. Qualitative results indicate that audio clues help participants recall their internal decision-making processes and provide essential context for understanding the actions of others (NPCs). The findings suggest that the integration of auditory information facilitates evacuation knowledge refinement, i.e., the transition from mere experience to the formulation of concrete survival concepts. Although limited by a small sample size, this study highlights the potential of multi-modal reflection support in VR-based evacuation training. Full article

Serotonin transporter (SERT) precisely regulates serotonin (5–HT) signaling in the central nervous system and is a major target of antidepressants for the treatment of major depressive disorder. Despite significant progress in characterizing its structure and transport mechanism, the regulation of SERT function by various modulators remains to be fully understood. In the present study, we focused on two potential cholesterol sites in human SERT to investigate cholesterol occupation at these sites and its functional relevance by biochemical approaches. Mutations of an intramolecular site (CHOL2) significantly decreased both specific transport activity and K_m for 5–HT and stabilized the transporter in an inward-facing conformation. In addition, our NanoBiT luminescent assay for protein–protein proximity demonstrated that cholesterol mediated the protomer–protomer interactions by residing in a site at the dimeric interface. Mutations of the interfacial site remarkably reduced the interactions between SERT protomers and substantially impaired their transport activity. The structural analysis indicated that the residues participating in cholesterol residing in the interfacial site were conformationally sensitive. Thus, we have proposed that cholesterol at these sites could play a vital role in the regulation of SERT function by a conformational mechanism. Our study has provided new insights into the molecular mechanism by which cholesterol can regulate SERT function and dimerization. Full article

Barley remains the fourth most cultivated cereal crop worldwide and is valued for its versatility in malting and brewing, animal feed, human nutrition, and dietary supplements. The identification of genotypes suitable for breeding or specific end-use applications requires multi-environment testing to evaluate agronomic performance, grain quality, and trait stability. In this study, a panel of 50 winter barley genotypes (two-row and six-row) originating from diverse genetic backgrounds was evaluated over three growing seasons (2021–2023) under the environmental conditions of southeastern Romania. Seven traits were analyzed, including three phenological traits (heading time, flowering time and plant height), grain yield, and three quality parameters (thousand-grain weight, protein content, and starch content). Environmental conditions had a strong influence on phenological development and grain yield, whereas grain quality traits showed relatively greater stability, indicating a stronger genetic control. Multivariate analyses (Principal Component Analysis (PCA) and Genotype plus Genotype-by-Environment interaction biplot (GGE biplots)) revealed clear relationships among traits and highlighted contrasting adaptive strategies between the two barley types. In two-row barley, genotypes such as Idra and Sandra combined favorable yield performance with stable grain quality traits and therefore represent promising candidates for breeding programs and large-scale cultivation. In six-row barley, SU-Ellen and LG Zebra showed high productivity and strong starch accumulation, making them valuable genetic resources for yield-oriented breeding, although further improvement in nitrogen use efficiency may be beneficial. The 2022–2023 growing season represented the most restrictive environment, emphasizing the importance of stability under stress conditions. Genotypes located close to the Average Environment Coordination axis (AEC axis) during that season, such as Ametist (six-row) and Lardeya (two-row), may represent promising material for breeding programs targeting drought resilience. Overall, the results expand the phenotypic characterization of winter barley germplasm and identify valuable genetic resources that can support pre-breeding efforts and the development of climate-resilient barley cultivars. Full article

Organic field-effect transistors (OFETs) incorporating a triple insulating layer of polymethyl methacrylate (PMMA), silicon dioxide (SiO₂), and zinc oxide (ZnO) were successfully fabricated on glass and on flexible PET substrates. The insulating layers significantly enhanced device performance, with the OFETs achieving field-effect mobility (µ) values more than twice as high as those reported in the literature. Specifically, mobility values of ~6.75 cm²/V·s were recorded on glass, ~7.14 cm²/V·s on flexible substrates before bending, and ~6.88 cm²/V·s on flexible substrates after bending. Threshold voltages (V_th) of −7 V and −9 V were estimated for the flexible OFETs before and after bending, respectively, along with a high on/off current ratio, exceeding 10³ for all devices. Minimal hysteresis in the transfer and output characteristics indicated excellent, trap-free interaction between the insulating layers and the pentacene. The high dielectric constant of the PMMA/SiO₂/ZnO triple insulating layers was identified as a critical factor driving the exceptional performance, stability, and low hysteresis of the OFETs. These results underscore the pivotal role of advanced insulating layers in optimizing OFET performance and durability. Full article

A multi-dimensional quantitative assessment of high-quality development (HQD) in China’s livestock industry and the identification of its main constraints are essential to understanding its current stage and future direction. Guided by global sustainability targets and the United Nations’ Sustainable Development Goals (SDGs), an evaluation system was constructed by this study. This system integrates five key aspects: product safety, output efficiency, resource conservation, environmental friendliness, and regulatory effectiveness. Using provincial panel data from China for 2013–2022, this research applies the entropy-weighted TOPSIS method, kernel density estimation (KDE), and an obstacle degree model for analysis, the goal is to support food security and foster environmentally sustainable growth. The findings indicate the following: (1) Notable inter-provincial disparities exist in the HQD of China’s livestock industry, revealing a spatial pattern of “leading in the east, stable in the center, and lagging in the west.” (2) The nationwide evolution exhibits a “convergence followed by divergence” pattern: from 2013 to 2017, the primary peak of the KDE rose and its width narrowed; from 2018 to 2022, the primary peak declined and its width widened, indicating that inter-provincial disparities first narrowed and then expanded. At the regional level, the development pattern is characterized by eastern polarization, central stability, and western lock-in. (3) Obstacle factor analysis identifies product safety and environmental friendliness as the principal constraints on HQD in the livestock industry. Addressing these bottlenecks is crucial for ensuring the supply of livestock products (SDG 2: Zero Hunger), promoting resource conservation and green production (SDG 12: Responsible Consumption and Production), and alleviating the ecological and environmental pressures of the livestock industry (SDG 15: Protection of Terrestrial Ecosystems). The challenges related to resources, the environment, and quality safety confronting China’s livestock industry are common among developing countries. Consequently, the evaluation framework established in this study can offer methodological references for relevant nations. Full article

Background/Objectives: Nanostructured biomaterials based on natural polymers have gained increasing attention in pharmaceutics due to their biocompatibility, multifunctionality, and diverse biomedical applications. This novel study aimed to biofabricate chitosan-doped zinc oxide nanocomposites (CS–ZnONCs) using Leucas aspera leaf extract and to evaluate their physicochemical properties and in vitro biomedical performance. Methods: CS–ZnONCs were synthesized using L. aspera leaf extract through a green precipitation approach, and the resulting nanocomposites were characterized by various spectroscopic techniques. The in vitro antioxidant, antibacterial, and anti-inflammatory activities were evaluated, while wound-healing potential was assessed using L929 fibroblast cell migration assays. Results: UV–visible analysis confirmed the formation of CS–ZnONCs, with a characteristic absorption peak at 362 nm, and FTIR spectra indicated the presence of various important functional groups. XRD results demonstrated the crystalline nature of ZnO within the chitosan matrix. Well-dispersed, quasi-spherical nanoparticles with an average size of 44 ± 3.1 nm were identified by HR-TEM, and a positive zeta potential (+9 mV) suggested considerable colloidal stability. CS–ZnONCs showed a high swelling capacity (88 ± 2.75% for 2%) and significant phytocompound release (65.38 ± 2.79% at pH 7.4). The CS–ZnONCs showed significant antioxidant activity (ABTS of 88.19 ± 1.59%), notable antibacterial efficacy against Staphylococcus aureus (18.78 ± 0.98 mm) and Escherichia coli (17.14 ± 0.96 mm), and significant anti-inflammatory activity (82.12 ± 1.47% membrane stabilization). In vitro biocompatibility and wound-healing assays revealed significant cytocompatibility in Vero cells, with 98.75 ± 1.17% cell viability observed, whereas the fibroblast migration assay demonstrated near-complete wound closure (96.55 ± 6.46%). Conclusions: The green-synthesized CS–ZnONCs exhibit favorable physicochemical properties, biocompatibility, and multifunctional biological activities, supporting their potential as a promising sustainable biomaterial nanomedicine for pharmaceutical formulations, wound healing, and regenerative medicine applications. Full article

Wellbore stability is one of the major challenges during drilling operations in shale gas formations. Drilling fluid seepage can significantly alter the pore pressure around the wellbore, thereby inducing wellbore instability. In this study, the Darcy pore fluid flow model was applied to both the mud cake and wellbore to predict pore pressure, which helps improve the accuracy of calculating collapse pressure and fracture pressure. Shale samples were collected from the Puguang Gas Reservoir, and their composition and physicochemical properties were systematically analyzed. The results indicate that the clay content in the formation can reach up to 35.5%, with distinct hydrophilic characteristics, and the maximum hydration expansion rate of the shale is 5.79%. The permeabilities of shale and mud cake were measured via the pore pressure transmission test. Specifically, shale samples from Sub-layer 1 exhibit the highest permeabilities for both rock and mud cake, which are 8.27 × 10⁻¹⁸ m² and 2.07 × 10⁻²⁰ m², respectively. In contrast, samples from Sub-layer 3 show the lowest permeability values, being 2.76 × 10⁻²⁰ m² and 1.66 × 10⁻²² m². The borehole tensile breakdown pressure and compressive collapse pressure were calculated using a poro-mechanical coupling model. The Sub-layer with the lowest cohesion strength after drilling fluid immersion presents the narrowest mud density window of 0.04 g/cm³, making it the most susceptible to wellbore stability failures; furthermore, the maintenance of wellbore stability requires strict control of the drilling mud density within the range. This study can provide guidance for accurate prediction of mud density window during drilling operations in shale formations. Full article