Search Results (6,669)

Background/Objectives: Plant-mediated silver nanoparticles (AgNPs) are promising components for oral biomaterials because of their antimicrobial potential; however, their biological behavior depends strongly on the phytochemical matrix, physicochemical characteristics, and exposure concentration. This study aimed to evaluate silver nanoparticles formulations synthesized using turmeric powder-derived Curcuma longa ethanolic and aqueous extracts, with emphasis on physicochemical characterization, antibacterial activity against oral-relevant Gram-positive bacteria, cytocompatibility toward human gingival fibroblasts (HGF-1), and acute in ovo vascular compatibility. Methods: AgCUR-EtOH NPs and AgCUR-H₂O NPs were synthesized using CUR-EtOH and CUR-H₂O extracts as reducing and stabilizing matrices. The resulting formulations were characterized by UV–visible spectroscopy (UV-Vis), dynamic light scattering (DLS), zeta-potential analysis, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined against Streptococcus mutans, Streptococcus oralis, and Staphylococcus aureus. Cytocompatibility was evaluated in HGF-1 human gingival fibroblasts after 24 h exposure to 1–10 µg/mL using complementary viability, lysosomal, mitochondrial, and fluorescence-based assays. Acute vascular irritation was assessed using the hen’s egg test–chorioallantoic membrane (HET-CAM) assay. Results: Both formulations exhibited broad, polydisperse hydrodynamic distributions and negative apparent zeta potentials. AgCUR-H₂O NPs showed a lower Z-average diameter than AgCUR-EtOH NPs under their respective solvent-specific measurement conditions. XRD pattern revealed heterogeneous crystalline compositions dominated by residual AgNO₃, together with weaker contributions consistent with metallic Ag and a possible minor oxidized silver phase. FTIR spectra demonstrated extract-derived organic functional groups and prominent nitrate-associated bands. TEM/EDX confirmed Ag-containing nanostructures with approximate size ranges of 15–175 nm for AgCUR-EtOH NPs and 15–150 nm for AgCUR-H₂O NPs. S. mutans was the most susceptible microorganism, with MIC values of 9 and 7 µg/mL and MBC values of 88 and 62 µg/mL for AgCUR-EtOH NPs and AgCUR-H₂O NPs, respectively. AgCUR-H₂O NPs consistently showed lower MIC and MBC values against all tested strains, but also produced a more pronounced concentration-dependent reduction in HGF-1 viability. At 10 µg/mL, cell viability was 71.88% for AgCUR-EtOH NPs and 52.14% for AgCUR-H₂O NPs. Both formulations showed low acute irritation potential in ovo, with irritation scores of 1.06 and 0.69, respectively. Conclusions: The two CUR-AgNP formulations exhibited distinct physicochemical, antibacterial, and cellular response profiles under the tested conditions. At equivalent concentrations expressed as total dried formulation mass, AgCUR-H₂O NPs yielded lower MIC and MBC values against the tested bacterial strains, whereas AgCUR-EtOH NPs produced a less pronounced reduction in HGF-1 viability. Because the powders were not quantitatively normalized for total silver, extract-derived organic fraction, or residual precursor content, these differences cannot be attributed exclusively to nanoparticle properties or to the extraction solvent and should not be interpreted as evidence of the intrinsic superiority of either formulation. Both formulations showed low acute vascular irritation. Further quantitative compositional, silver-release, and biofilm assessments are required before incorporation into oral biomaterial platforms. Full article

This review aims to analyze defect-driven thermoelectric decoupling in pulsed laser deposition (PLD)-grown oxygen-deficient ${WO}_x$ and tungsten Magnéli thin films. While transition metal oxides offer a non-toxic, abundant alternative to conventional thermoelectrics, tungsten oxide stands out due to the profound impact of sub-stoichiometry on its transport properties. We systematically evaluate how ordered oxygen vacancies and crystallographic shear planes transform insulating ${WO}_3$ into sub-stoichiometric phases exhibiting metallic-like conductivity. Specifically, we analyze how the delocalization of W$5d$ electrons around defect-rich regions induces electronic states near the Fermi level, decoupling the Seebeck coefficient from electrical conductivity. Simultaneously, we discuss how these engineered defect networks and shear planes selectively enhance phonon scattering, drastically suppressing lattice thermal conductivity without hindering electronic transport. By establishing PLD as an effective approach for precise oxygen stoichiometry and defect architecture control, this review highlights the high-temperature potential of tungsten Magnéli phases and outlines future pathways to maximize their thermoelectric figure of merit ($ZT$). Full article

Temperature fluctuations in cold chain logistics accelerate protein degradation, lipid oxidation, and color deterioration of Litopenaeus vannamei, reducing product value and compromising food safety. To address this issue, this paper proposes a dynamic quality prediction method based on the Tad-Transformer neural network. First, storage experiments were conducted under six cold chain temperature conditions to collect multi-dimensional physicochemical and texture data. Core quality indicators were selected through temperature sensitivity analysis, and a time-series dataset was constructed. Second, an improved K-means++ clustering algorithm incorporating min-max constraints was applied for quality grading. Finally, the Tad-Transformer model was employed to predict quality indicators and temporal grade evolution. Comparative validation with Transformer, Informer and FEDformer on the self-constructed dataset demonstrates that, for the most challenging high-quality samples, the proposed model achieves both precision and recall exceeding 89%, representing improvements of 4.17–10.77% and 2.28–8.37%, respectively, over the comparison models. This method provides technical support for quality grading control and early warning of abnormal risks in cold chain logistics, offering a scientific reference for dynamic quality monitoring and intelligent evaluation of aquatic products. Full article

Tortillas are an essential food in Mexico, and they are usually packaged in low-density polyethylene (LDPE) bags, but these packages can release microplastics (MPs) into the food. On the other hand, MPs have been associated with conditions such as the release of toxic substances, damage to mitochondrial membranes, and the generation of oxidative stress and inflammation, among others. Currently, there are no studies on the presence of MPs in corn tortillas, so the objective of this work was to study samples of tortillas acquired at five points of sale in central Mexico, namely, supermarkets (A and B) and tortilla shops (C, D, and E), as well as to evaluate the presence of MPs and their identification by Fourier-transform infrared spectroscopy (FTIR), optical microscopy, and scanning electron microscopy (SEM). In addition, an abundance interval and an estimate of the consumption rate were established considering the available information on per capita consumption of tortillas in Mexico. The results show that the samples of tortillas purchased at sampling points A and B presented MPs in the form of films with an abundance between 155.56 and 177.78 MPs/kg of tortilla; however, no microplastics were identified in the samples of tortillas acquired at sites C, D, and E. The analysis suggests that the identified MPs may have come from the plastic bags in which tortillas are packaged. In addition, it was established that the daily consumption rate of microplastics per person is 2.48 to 5.15 pieces. Full article

Coumarins are compounds that are naturally found in various plants and are known for their potential pharmacological characteristics, such as anti-inflammatory, antibacterial, antiparasitic, and anticoagulant activities. Despite the potential pharmacological properties, structural modification of coumarins is important to enhance the biological activity, solubility, bioavailability, and various therapeutic characteristics. Microbial transformation is a promising method to modify coumarins since this method offers regioselective and stereospecific transformation, which is challenging to obtain through chemical synthesis. Various microorganisms, including bacteria and fungi, play an essential role in the microbial transformation of coumarins. These microorganisms employ enzymatic mechanisms involving various enzymes to catalyze several reactions, such as hydroxylation, oxidation, reduction, and demethylation. Among these microbial transformation processes, the demethylation process is a significant mechanism for altering the bioactivity of coumarins by converting methoxy groups into hydroxyl groups. Despite all the advantages, microbial transformation also has limitations such as low substrate specificity, contamination during inoculation, variable enzymatic activity, and challenges to scale up the production of bioactive coumarins. These challenges can be addressed through the optimization of the bioprocess to enhance the efficiency of microbial coumarin metabolism. This review provides a comprehensive overview of the microbial transformation of coumarins, highlighting the role of various microorganisms, enzymatic mechanisms, and the transformation processes. Full article

Efficient photocatalytic degradation of azo dyes requires coordinated control of nanostructure, surface chemical environment, and interfacial charge transport. In this work, rare-earth-modified copper-oxalate-derived CuO nanostructures (RE = Ce, Sm, Er, Tm, and Yb) were prepared through hydrothermal synthesis of a copper oxalate precursor, followed by calcination and ultrasonic-assisted RE modification. Structural, spectroscopic, optical, and electrochemical analyses show RE-associated apparent lattice perturbation, modified surface oxygen environments, stronger visible-region optical responses, higher apparent majority-carrier-density descriptors, and lower fitted interfacial charge-transfer resistance relative to pristine CuO. Among the samples, Ce-CuO exhibited the best performance, with a band gap of 1.48 eV, an apparent majority-carrier density of (1.94 ± 0.04) × 10²¹ cm⁻³, and a charge-transfer resistance of 216 Ω·cm². It achieved 91.59% methyl orange (MO) decolorization within 9 min under simulated solar irradiation, corresponding to a 23.7-fold higher apparent rate constant than pristine CuO, and retained 75.8% decolorization efficiency after eight cycles. Scavenger experiments suggested that h⁺ was the principal oxidative species under the investigated conditions, while ·OH and ·O₂⁻ also contributed to MO transformation. Overall, the results show that rare-earth modification is associated with changes in the structural, surface-chemical, optical, and interfacial electrochemical characteristics of copper-oxalate-derived CuO photocatalysts. Full article

Airborne fine particulate matter (PM_2.5) has been extensively identified as a major contributor to adverse health outcomes, including respiratory illnesses, cardiovascular diseases, and premature mortality. PM_2.5 poses an even greater threat due to the presence of environmentally persistent free radicals (EPFRs). It is, thus, important to study human exposure to EPFRs. Dust samples from residential areas in Al Ain, UAE, were tested, and free radicals were detected and quantified. ESR measurements showed distinct signals with g-factors around 2.004–2.006, typically associated with oxygen-centered EPFRs. Spin concentrations were quantified at approximately 2.64 × 10¹⁶ spins/g in Dust Sample 1 (DS1) and 2.36 × 10¹⁷ spins/g in Dust Sample 2 (DS2), values comparable to those reported in other regions. DS1 and DS2 were collected from two different locations in inhabited areas of the city of Al Ain. Fourier Transform InfraRed (FTIR) spectra revealed possible functional groups such as catechols and hydroquinones, while X-ray diffraction (XRD) confirmed mineral oxides that could stabilize these radicals. However, the spectra also displayed features consistent with the six-line hyperfine splitting of Mn. These findings confirm the presence of environmentally relevant paramagnetic species in dust, which have implications for human health. Full article

4-(2-Nitrobenzoyl)isoxazoles are readily available from 3,5-disubstituted 4-iodoisoxazoles through iodine–lithium exchange and trapping with 2-nitrobenzaldeyde, followed by Jones oxidation of the obtained secondary alcohols. Reductive ring transformation by means of treatment with iron in acetic acid gives 2-substituted 3-acyl-4-quinolones. The mechanism of the cyclization reaction was elucidated by using appropriately substituted isoxazole building blocks and 2D NMR investigation of the products. In contrast, catalytic hydrogenation leaves the isoxazole ring untouched, whereas reduction with NaBH₄/NiCl₂ gives 2-substituted 3-acylquinolines in an unprecedented reductive ring transformation. Full article

At low temperatures, the preferential removal of CO from the fuel feed of PEMFC is a critical factor for ensuring the optimal performance of fuel cells. In this study, Au/TiO₂-PD and Au/TiO₂-DP catalysts were synthesized via in situ photo-deposition and deposition–precipitation methods, respectively. The catalytic performance for CO preferential oxidation was evaluated in a hydrogen-rich atmosphere, and the effects of visible light irradiation on catalytic activity and selectivity were systematically investigated. The Au/TiO₂-DP catalyst exhibited a relatively low CO conversion under dark conditions in the hydrogen-rich atmosphere, while visible light irradiation significantly enhanced its CO oxidation activity and selectivity. In contrast, the Au/TiO₂-PD catalyst achieved a high CO oxidation conversion, but suffered from low CO oxidation selectivity; moreover, visible light exerted a weak inhibitory effect on its selectivity. Combined characterization results from temperature-programmed desorption (TPD), temperature-programmed surface reaction (TPSR), in situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) and in situ electron paramagnetic resonance (EPR) revealed that the Au/TiO₂-PD catalyst possessed stronger hydrogen adsorption, dissociation and oxidation capabilities than the Au/TiO₂-DP catalyst. The rapid dissociation of hydrogen molecules over the Au/TiO₂-PD catalyst accelerated the activation of adsorbed oxygen species and simultaneously promoted the formation of water via hydrogen oxidation. Excessive water accumulation on the catalyst surface occupied the active sites for CO oxidation, thereby imposing an overall inhibitory effect on CO preferential oxidation. Full article

Olive leaves, a major byproduct of olive processing, are generated in large quantities annually yet suffer from inefficient utilization and low added value. In this study, response surface methodology (RSM) was employed to optimize the extraction conditions of oleuropein from olive leaves. Additionally, the antioxidant activity of purified oleuropein and its protective effect against tret-butyl hydroperoxide (TBHP)-induced oxidative damage in the human embryonic kidney 293 (HEK-293) cell line were investigated. The optimal extraction conditions for oleuropein were determined as follows: extraction temperature of 71 °C, extraction time of 72 min, ethanol concentration of 58%, and solid–liquid ratio of 1:27 (mg/mL), yielding an oleuropein recovery of 44.5%. The extract was purified and identified as oleuropein via Fourier transform infrared spectroscopy (FTIR) and high-performance liquid chromatography (HPLC). Oleuropein exhibited remarkable antioxidant activity and mitigated TBHP-induced oxidative damage in HEK-293 cells by inhibiting apoptosis. TBHP treatment reduced cell viability by approximately 70%, while treatment with 100 and 200 μg/mL oleuropein restored the decreased cell viability to 100%. Morphological observations and 4′,6-diamidino-2-phenylindole (DAPI) staining revealed that TBHP induced apoptotic cell death characterized by nuclear condensation and fragmentation, and this effect was reversed by oleuropein treatment. Flow cytometry analysis showed that TBHP caused approximately 90% cell death, whereas co-treatment with oleuropein reduced cell death to only about 10%. TBHP downregulated the expression of p53, and oleuropein reactivated its expression, highlighting the role of oleuropein in the recovery of the cellular antioxidant system. This study possibly indicated the protective mechanism of oleuropein against oxidative damage-related diseases and provides a theoretical basis for the development of olive leaves as a potential ingredient in functional foods. Full article

Selenium nanoparticles (Se NPs) have shown potential for regulating cadmium (Cd) accumulation in rice; however, their particle-size-dependent effects in the paddy soil–rice system remain unclear. In this study, a whole-growth-period pot experiment was conducted to investigate the mechanisms of Se NPs with different particle sizes (50, 100, and 200 nm) applied at different rates (20 and 50 mg/kg) in regulating Cd accumulation in rice grown in Cd-contaminated paddy soil. Se NP application significantly altered rhizosphere pH and redox potential, decreased Cd concentrations in soil solution and DTPA-extractable Cd, and increased soil solution Se and KH₂PO₄-extractable Se. In the 20 mg/kg treatment, Se NPs promoted the transformation of Cd from exchangeable fractions to Fe–Mn oxide-bound fractions, indicating reduced Cd mobility. Se NPs also enhanced root iron plaque formation and increased the retention of Fe, Cd, and Se on the root surface. XPS analysis showed that 50 and 100 nm Se NPs increased the proportion of Fe(III) in root iron plaque, thereby strengthening Cd adsorption and immobilization at the root–soil interface. In addition, Se NP treatments reshaped rhizosphere microbial communities. The 50 nm treatment showed stronger effects on fungal taxa related to organic matter decomposition and Se activation, whereas the 100 nm treatment more effectively enriched bacterial groups associated with Fe and S cycling, including Thermodesulfobacteriota and Sideroxydans. Among all treatments, 100 nm Se NPs at 20 mg/kg reduced grain Cd from 0.466 to 0.050 mg/kg, representing an 89.27% reduction, while maintaining grain Se at 0.384 mg/kg, which is within the acceptable range for selenium-enriched rice. Overall, 100 nm Se NPs showed the best balance among Cd mitigation, Se biofortification, and ecological safety, suggesting their potential for application in safe rice production in Cd-contaminated paddy soils. Full article

Using balanced panel data for 30 Chinese provinces from 2014 to 2023, this study examines the relationship between digital village development and input-related agricultural carbon emissions in China. A composite digital village index is constructed from eight standardised indicators, and PCA diagnostics together with a PCA-based alternative index are used to assess index validity and sensitivity. Two-way fixed-effects models are used for empirical estimation. The results show that digital village development is significantly associated with lower agricultural carbon emissions after controlling for economic, fiscal, technological, regulatory, provincial, and temporal factors. The finding remains robust when using a rural e-commerce proxy and alternative specification checks. The lagged digital index has a negative coefficient but is less precisely estimated after the first-year observations are excluded. Heterogeneity analysis shows that the association is stronger in provinces with higher rural educational attainment, in Central China, and in major grain-producing areas, while the coefficient for grain-balanced areas is negative but not statistically significant. Mechanisation-based subgroup results further show that the negative association is more pronounced where agricultural mechanisation is relatively advanced. These findings suggest that rural digitalisation can support a low-carbon agricultural transition, particularly when digital infrastructure is transformed into effective industrial applications, public services, human capital development, and improved production organisation. This study focuses on input-related and field-operation-related agricultural carbon emissions rather than a complete agricultural greenhouse gas inventory including methane, nitrous oxide, and manure management and land use change emissions. Full article

Sickle Cell Disease (SCD) is a hereditary hemoglobinopathy arising from a single-nucleotide transversion (GAG → GTG) at codon six of the HBB gene on chromosome 11, substituting glutamic acid with valine in the β-globin chain and producing hemoglobin S (HbS). Under hypoxic conditions, HbS polymerizes and distorts erythrocytes into the characteristic sickle shape, initiating a cascade of vaso-occlusion, chronic hemolytic anemia, and progressive multi-organ damage that defines the clinical burden of this disease. Although SCD has ancient origins in sub-Saharan Africa, the Indian subcontinent, the Middle East, and the Mediterranean, regions where it conferred heterozygous resistance to malaria, the ease of human migration has long since made it a global health concern, affecting an estimated 300,000–400,000 newborns annually. Advances in molecular and genomic research have deepened our understanding of SCD pathophysiology, revealing the central contributions of hemoglobin polymerization, oxidative stress, endothelial inflammation, and nitric oxide depletion to disease progression. Current management rests on supportive pharmacological interventions, including hydroxyurea, chronic transfusion therapy, L-glutamine, and multimodal pain management, complemented by lifestyle modifications. Curative approaches have advanced substantially: hematopoietic stem cell transplantation (HSCT) remains the established standard of cure, while the regulatory approvals in late 2023 of the CRISPR/Cas9-based exagamglogene autotemcel (Casgevy) and the lentiviral vector-based lovotibeglogene autotemcel (Lyfgenia) represent the most transformative development in the history of SCD therapeutics. This review traces the disease from its ancient origins and molecular characterization through to its clinical manifestations, inheritance patterns, screening strategies, and the full spectrum of current and emerging therapies. Persistent challenges, prohibitive treatment costs, healthcare inequities, the ethical dimensions of genome editing, and the urgent need for long-term safety data, are examined critically, with a view to informing the research and policy agenda that must accompany these remarkable scientific advances. Full article

Horse mesenteric fat is a culturally significant and nutritionally valuable food product in Central Asia, yet the kinetics of its oxidative and hydrolytic deterioration under sub-optimal storage conditions remain poorly characterized. Raw mesenteric adipose tissue from ten free-grazing horses in Northern Kazakhstan was subjected to accelerated stress storage at 30 °C and 70% relative humidity for six days, with physicochemical and spectroscopic evaluation on days 0, 3, and 6. Parameters assessed included acid value, peroxide value, refractive index, density, melting point, sensory attributes, and Fourier-transform infrared attenuated total reflectance spectroscopy. The acid value increased markedly from 1.17 ± 0.46 to 32.60 ± 26.18 mg KOH/g by day 6, substantially exceeding the internationally accepted threshold of 2.0 mg KOH/g, while peroxide value rose progressively and density declined. Melting point decreased significantly between days 0 and 3, a physicochemical change that may be associated with hydrolytic and oxidative modification of the lipid matrix, as corroborated by infrared spectral analysis. These results demonstrate that raw horse mesenteric fat is highly susceptible to rancidity, reaching unacceptable quality thresholds within six days, underscoring the urgent need for cold-chain management and evidence-based handling guidelines for this product across the region. Full article

In this study, a series of xFe₂O₃–Na₂O–CaO–SiO₂ glass-ceramics containing 0–28 wt.% Fe₂O₃ were prepared via the conventional melt-quenching technique. The resulting samples, designated S1–S4, were subsequently subjected to thermal treatment and investigated with respect to their structural, thermal, and optical characteristics. Differential scanning calorimetry analysis revealed the influence of the Fe₂O₃ concentration on the glass transition temperature and crystallization behavior of the samples. Structural analysis of the samples revealed that crystalline silicate and iron oxide phases constituted the predominant crystalline phases, with their overall crystallinity being strongly dependent on the Fe₂O₃ content and thermal treatment. Fourier transform infrared spectroscopy evidenced structural modifications of the silicate network induced by iron incorporation, while ultraviolet–visible–near infrared spectroscopy highlighted the presence of Fe²⁺/Fe³⁺ ions and their associated electronic transitions. The results indicate that increasing the Fe₂O₃ content significantly affects the network structure, redox state, and thermal behavior of the glass-ceramic system, leading to enhanced absorption properties. Full article