Search Results (4,370)

This study aimed to systematically compare the functional properties of the four major components (albumin, globulin, prolamin, and glutelin) of protein from Yunnan deep-veined walnuts to screen for protein-based carrier materials with good processing adaptability and the ability to efficiently encapsulate the active ingredient rutin. In addition, the binding and molecular interactions between the preferred protein and rutin were analyzed. The results indicated that albumin exhibited superior performance compared to the other three components in solubility, emulsifying properties, foaming properties, and gel properties, and demonstrated the strongest processing applicability. Further analysis revealed that albumin possessed an excellent amino acid composition (essential amino acid content accounting for 42.30%) and antioxidant activity (with the highest ABTS scavenging rate reaching 85.71 ± 0.26%), which indicated its considerable potential as a functional carrier. Loading rutin onto albumin yielded a walnut albumin–rutin complex (WA@Rut), which significantly enhanced the thermal stability of albumin (with the thermal denaturation temperature elevated to 108.72 °C) and the storage stability of rutin (66.16 ± 5.05% retention after 22 days of storage). Combined analyses of FT-IR spectroscopy, intrinsic fluorescence spectroscopy, molecular docking, and molecular dynamics simulations confirmed that rutin primarily bound to albumin via hydrogen bonding and electrostatic interactions, and formed a stable complex structure. SEM images revealed that the composite surface was smooth and exhibited a flake-like morphology. In conclusion, walnut albumin is a protein resource with significant functional potential in Yunnan deep-veined walnuts, and it exhibits strong processing applicability and enables efficient encapsulation and protection of active ingredients. This study provides novel strategies and theoretical foundations for the high-value utilization of walnut protein. Full article

Fluorescence emission-excitation matrices for cow milk samples with different fat contents in the range of 0.05–10% and a constant protein content of 3%, as well as for butter and extracted milk components such as casein and lactose, have been measured using a spectrofluorometer. The influence of the increased fat content on the shape of the fluorescence spectra of milk has been studied. In addition, fluorescence spectra measured for serial dilutions of high-fat milk with water and skim milk, along with aqueous dilutions of skim milk, have shown that the fluorescence diagnostics of fat and protein content in milk can be implemented using excitation at only two wavelengths: 280 and 320 nm. The optimal spectral ranges proposed for detecting the content of milk components via fluorescence measurements can be useful when designing UV LED-based fluorescence analyzers of milk composition. Full article

The ultra-short-pulse (USP) laser joining of sapphire to iron is investigated by combining electron backscatter diffraction (EBSD) and ruby (Cr${}^{3+}$) R${}_1$ fluorescence mapping to resolve the joint microstructure and pressure distributions. Energy-dispersive X-ray spectroscopy (EDS) reveals Al, O, and Fe intermixing within the seam, consistent with the formation of thin Fe–Al–O reaction layers. R${}_1$ fluorescence yields a maximum internal pressure of $490\pm 80\mathrm{M}\mathrm{Pa}$ within the modified sapphire region and decays to near-zero within a few micrometres distance from the seam. EBSD data suggest a single-crystal sapphire lattice with localized disorientation adjacent to the joint, whereas the iron foil remains polycrystalline with rolling-induced misorientation without additional weld-induced grain refinement. These results demonstrate that USP joining of sapphire to iron produces localized interfacial reaction zones, with confined pressure predominantly occurring within sapphire. Full article

The environmental impacts of treated acid mine drainage on receiving river systems remain insufficiently understood. This study investigated four typical closed coal mines in northern Sichuan Province, China, by analyzing heavy metals, sulfate, pH, UV-Vis spectroscopy, and dissolved organic matter (DOM) characteristics at 24 sampling sites along the receiving reaches. Parallel factor analysis (PARAFAC) and two-dimensional correlation spectroscopy (2D-COS) were employed to examine the longitudinal response sequence of DOM components. Results showed that pollutant concentrations generally increased immediately after the inflow of treated acid mine drainage and then progressively attenuated downstream, although the dominant pollution factors varied significantly among the reaches. DOM composition exhibited spatial heterogeneity, with protein-like components dominating three reaches and humic-like components prevailing in one reach. Based on the co-variation characteristics of DOM and heavy metals along the river course, four response patterns were identified: rapid-recovery, slow-recovery, disturbance–oscillation recovery, and delayed-recovery patterns. The 2D-COS analysis validated the rationality of these four patterns and revealed differences in the sensitivity of various DOM components to longitudinal disturbances. This study provides a scientific basis for the environmental impact assessment of mine water from remediated closed coal mines. Full article

In the Iberian Pyrite Belt (IPB), long-term persistence of mine waste piles poses environmental challenges. The present work studies the Trimpancho Mining Complex in northern IPB with exposed mine waste and acidic waters in the proximity to the Chança River, a tributary of the Guadiana international river. A multidisciplinary approach is proposed, using hyperspectral reflectance spectroscopy, portable X-ray fluorescence (pXRF), multispectral Unmanned Aerial Vehicle (UAV) and Sentinel-2 images. Spectroscopic, geochemical and remote sensing methods were applied to characterise the mining area. Comparison of hyperspectral data with spectral libraries were used to validate mineralogy. Multispectral UAV data is used for custom band-ratios and adapted to Sentinel-2 images. Results grouped the samples into four groups. Spectroscopy is indicative of clays (white mica and smectite group), hematite/goethite, jarosite, and arsenopyrite and pyrite (exclusive to the Group 2); iron-rich samples reach maximum reflectance earlier than iron-poor samples. Geochemical studies show an increase in content of heavy metal such as As, Cu, Fe, Pb, and Zn from Group 1 < Group 3 ≈ Group 4 < Group 2, but Group 4 showed elevated Pb and Zn. Custom false colour composition highlighted the groups in UAV and satellite, thus constituting cost-effective tools for finding contamination sources. Full article

The emergence of a novel crumb rubber (CR)/SBS-polymerized pellet has simplified the complex preparation process of composite-modified asphalt. However, the effectiveness of CR/SBS-polymerized pellets in improving asphalt performance has not been confirmed. This study mainly investigated the performance and reinforcement mechanism of polymerized pellet-modified asphalt. First, polymerized pellet-modified asphalt samples with different contents (10%, 20%, 30% and 40% of the asphalt mass) were prepared. Then, the physical properties, rheological behavior, thermal stability, and aging resistance of the pellet-modified asphalt samples were systematically evaluated, using both base asphalt and a commercially available styrene–butadiene–styrene triblock copolymer (SBS)-modified asphalt as control groups for comparison. Finally, the modification mechanism was explored through Fourier transform infrared spectroscopy (FTIR) and fluorescence microscopy (FM). The findings demonstrated that the incorporation of polymerized pellets could effectively decrease the penetration, elevate the softening point, and enhance the viscosity of asphalt. In addition, the high- and low-temperature performance, as well as the aging resistance of the modified asphalt, were significantly improved. These enhancing effects became more pronounced with increasing modifier content. The performance of SBS-modified asphalt is between 20% pellets MA and 30% pellets MA. The pyrolysis temperature range of all asphalt samples is 220 °C~500 °C, and infrared spectroscopy indicated that CR/SBS pellet-modified asphalt is mainly a physical mixing process. This work provides a scientific basis for further engineering applications of CR/SBS pellets. Full article

Ready-to-eat sea cucumbers (RSC) cannot be preserved at room temperature due to autolysis, which is closely related to the instability of collagen resulting from the disruption of hydrogen bonds. To investigate the protective effect of N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) cross-linking against disruption of hydrogen bonds and its role in stabilizing RSC quality at room temperature, this study designed comparative experiments involving EDC/NHS cross-linking treatments with varying sequences of hydrogen bonds disruption. The results indicated that EDC/NHS positively affects the stabilization of the collagen structure in RSC. The various quality parameters of both groups of RSC that underwent cross-linking treatment before and after hydrogen bonds disruption were significantly better than those of the control group, which only experienced the breaking of hydrogen bonds. Notably, the Eb group, which underwent EDC/NHS cross-linking treatment prior to the disruption of the hydrogen bonds network, yielded even more favorable results. Preliminary analyses of textural properties and moisture content suggested that EDC/NHS helps delay the deterioration of RSC quality. The levels of soluble components and carbonyl groups indicated that prior cross-linking treatment is more effective in mitigating collagen degradation and oxidation. Differential scanning calorimetry revealed that the reduction in ΔH for the Eb group was only 2.4%. Furthermore, fluorescence spectroscopy, Fourier transform infrared spectroscopy, and circular dichroism spectroscopy, examined from the perspectives of secondary and tertiary structures respectively, indicated that the cross-linking mechanism of EDC/NHS involves the formation of a more robust network of amide bonds, thereby preventing the disruption of hydrogen bonds and enhancing collagen stability, enabling it to better resist the cleavage of hydrogen bonds due to urea. The scanning electron microscope and Van Gieson’s staining techniques offer a clearer illustration of this point from a microscopic perspective. Moreover, molecular docking simulations have indicated the cross-linking mechanism of EDC/NHS at the atomic level, thereby establishing a scientific foundation for the potential application and development of EDC/NHS in room-temperature storage technologies for RSC. Full article

The sustainability, crop production, and food safety of agriculture are increasingly challenged by microplastic pollution, as agricultural soils are the largest reservoirs and may serve as points of contact for plastic particles in the food chain. This review provides a comprehensive overview of plant materials, fate and uptake pathways, detection techniques, and the possible risks of microplastics in agriculture. Agroecosystems are also a source of microplastics, such as plastic mulch films, sewage sludge, compost and manure additives, wastewater irrigation, polymer-coated fertilizers, greenhouse materials, atmospheric deposition, and decomposition of discarded agricultural plastics. Their distribution and mobility in soil are controlled by polymer composition, particle size, morphology, density, surface ageing, soil texture, organic matter content, tillage practices, runoff, leaching, and soil biota. Recent data show that microplastics, especially smaller microplastics and nanoplastics, can attach to root surfaces, penetrate plants via cracks in roots, areas of lateral root development, and apoplastic pathways, and eventually move to tissues aboveground. Plant tissue detection is often accomplished by digestion of the sample, density separation, visual and fluorescence microscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, pyrolysis–gas chromatography mass spectrometry, and electron microscopy, but standardization of these methods remains a significant challenge. Microplastics can disrupt seed germination, root structure, nutrient absorption, photosynthesis, oxidative homeostasis, biomass buildup, yield development, and quality. Further, their capacity to transport additives, plasticizers, heavy metals, and persistent organic pollutants raises concerns about the transfer of contaminants to edible plant parts and their potential transfer to human diets. Further studies are needed focusing on field-realistic exposure conditions, long-term crop–soil interactions, nanoplastics behaviour, standardised analysis procedures, uptake and translocation pathways, edible crop risk assessments, and sustainable mitigation approaches to reduce microplastics in agroecosystems. Full article

Global food security and climate mitigation goals are placing unprecedented demands on agricultural systems to simultaneously improve soil productivity and reduce carbon emissions. Spent mushroom substrate (SMS), the mushroom industry’s principal waste stream, offers considerable recycling potential, yet its influence on dissolved organic carbon (DOC) chemistry and soil aggregate stability remains unclear. We tested four SMS return regimes on a medium-textured fluvo-aquic soil: CK, 0 t·ha⁻¹; ORS, 22.5 t/ha; ERS, 22.5 t/ha; and SRS, 45 t/ha in total, with 22.5 t/ha applied per SMS return event. It was found that SMS improved soil structural stability across all regimes, with SRS delivering the strongest effects. Compared with CK, SRS raised the proportions of >2 mm and 0.25–2 mm aggregates by 31.62% and 33.42%, while the mean weight diameter (MWD) and geometric mean diameter (GMD) increased by 23.25% and 22.68%. SMS also elevated aromatic carbon abundance, DOC concentration, UV254, and SUVA254. Fluorescence EEM-PARAFAC resolved DOC into three component: namely, two humic-like and one protein-like, and SMS expanded the relative contribution of the humic-like C1 fraction. Overall, under the tested fluvo-aquic soil and wheat–maize rotation conditions, SMS return was associated with changes in DOC composition, higher aggregate stability, and greater aggregate-associated carbon accumulation. These findings suggest that SMS return may be a promising strategy for improving soil structure and recycling agricultural waste under similar field conditions, but its broader applicability requires further validation. Full article

Mono- and bis-guanyl hydrazone-functionalized tricyclic compounds were here designed and investigated as putative G-quadruplex ligands in the context of anticancer drug development. The G-quadruplex on Controlled Pore Glass (G4-CPG) assay, a fast and easy screening method based on affinity chromatography for identifying potential G-quadruplex binders, together with biophysical techniques such as circular dichroism and fluorescence spectroscopy, demonstrated a higher selectivity of mono- with respect to disubstituted derivatives in recognizing G-quadruplexes from telomeric and oncogenic DNA regions vs. duplexes. Among the mono-substituted compounds, higher G-quadruplex selectivity was found for those containing the pyrido[3,4-b]indole and dibenzofuran scaffolds compared to the 9H-fluorene, 9H-carbazole, and dibenzothiophene ones. Molecular docking studies suggested that the investigated ligands bound the hybrid telomeric G-quadruplex model by adopting a coplanar arrangement of the core and guanyl hydrazone moieties, both stacked on the 5′-G-quartet, while in the interaction with the parallel oncogenic G-quadruplex model the guanyl hydrazone moieties pointed towards the grooves/loops. Finally, biological assays highlighted the higher potential of mono-guanyl hydrazone-derivatized tricyclic compounds as selective anticancer agents, showing higher anticancer activity and selectivity of action than the bis-guanyl hydrazone derivatives. Full article

Petroleum hydrocarbons contamination in soil is difficult to remediate due to strong adsorption and limited bioavailability. This study investigated the coupled remediation of diesel contamination in an alkaline kaolin-based model substrate using a silica gel-loaded, iron-catalyzed sodium percarbonate composite (SPC^SF) and Bacillus subtilis. The alkaline model substrate was used as a simplified representation of difficult-to-reclaim hydrocarbon- and reagent-impacted matrices that may occur at oil drilling or production sites. In this study, a combined remediation strategy integrating a silica gel-loaded, iron-catalyzed sodium percarbonate composite (SPC^SF) with Bacillus subtilis ATCC 11774 was developed for diesel-contaminated soil. The remediation performance of chemical oxidation, microbial remediation, and their combined application was systematically evaluated. The simultaneous SPC^SF–microbial treatment achieved the highest removal efficiency, reaching 65.1% after 31 d, which was markedly higher than that of chemical oxidation (22.5%) or microbial remediation alone (31.1%). Within the mineral model substrate used in this study, SPC^SF effectively regulated pH and oxidation–reduction potential, creating conditions more favorable for microbial activity. Spectroscopic analyses (three-dimensional fluorescence spectrum, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy) indicated that SPC^SF promoted the transformation of diesel hydrocarbons into bioavailable intermediates, which were further converted by microorganisms into carboxyl-rich organic matter. Bacillus subtilis was associated with a higher Fe(II) proportion in the coupled system, which may have favored maintenance of Fe redox activity and sustained Fenton-like reactivity. However, direct measurements of reactive oxygen species and Fe(II)/Fe(III) dynamics were not performed; therefore, this interpretation should be regarded as a plausible hypothesis based on indirect evidence. The specific microbial contribution to Fe redox transformation was inferred from indirect evidence and may also have been influenced by medium-derived components or microbial metabolites. This study presents a coupled supported sodium percarbonate and microbial remediation strategy providing mechanistic evidence for the compatibility of supported chemical oxidation and microbial degradation in diesel-contaminated soil. Full article

The purpose of this study was to investigate the effectiveness and mechanism of iron-based catalysts in the treatment of phenolic wastewater by catalyzing ozone oxidation. The removal rates of phenolics and COD were systematically examined using simulation experiments with water and actual wastewater, which involved analyzing the effects of reaction time, pH, ozone dosage, catalyst dosage, and initial concentration. The phenol and COD removal rates in the simulated wastewater were 95.9% and 93.5%, respectively, respectively, while the ozone dosage was 16 mg/L/min, pH was 6.7–6.8, and catalyst dosage was 0.3 g/L. The phenol and COD removal rates in the actual wastewater were 68.6% and 68.0%, respectively. The reaction time was 30 min. The system’s efficient removal ability for phenolic compounds, polycyclic aromatic hydrocarbons, and others was confirmed through three-dimensional fluorescence and ultraviolet spectroscopy. The iron-based catalyst generates ·OH through three pathways: adsorption of activated ozone on surface active sites, continuous production of free radicals by Fe²⁺/Fe³⁺ cycling, and direct activation of ozone by Fe²⁺. This mechanism analysis showed that the catalyst generates ·OH. These pathways convert pollutants into small molecules or mineralized by attacking the aromatic rings and conjugated structures of pollutants. Technical references for the deep treatment of phenol-containing wastewater are provided in this study. Full article

Hydroxypropyl methylcellulose hydrogels were designed as polymeric matrices for porphyrinic photosensitizer samples (5-(2-hydroxy-5-methoxyphenyl)-10,15,20-tris-(4-carboxymethylphenyl) porphyrin (P3.2) and 5,10,15,20-tetrakis-(4-carboxymethylphenyl) porphyrin (P3.1) to investigate their physicochemical behavior and structure–property relationships. Fourier transform infrared, UV–Vis, and fluorescence spectroscopy showed that both porphyrins remained monomerically dispersed in the polymeric matrix by establishing moderate interactions with HPMC by hydrogen bonding. X-ray diffraction and atomic force microscopy showed the uniform microstructural organization of the hydrogel matrix, while thermal analyses confirmed the stability of both studied systems. Rheological measurements demonstrated that the incorporation of porphyrins in the hydrogel network slightly modulates viscoelastic behavior. The swelling, density, and pH studies highlighted correlations between molecular interactions and macroscopic hydrogel properties. The swelling ratio determined after 6 h showed values of about 89% for the hydrogel of HPMC with P3.1. and about 92% for the hydrogel of HPMC with P3.2, respectively. The pH value was found to be 7.0 for both hydrogels. These results highlighted interfacial and physicochemical insights into polymer–porphyrin interactions in hydrogel matrices. All studies show that a controlled dispersion of chromophores preserves their monomeric state and controlled structure–property relationships. Full article

Porcine blood meal-derived hydrolysate peptides and hemin are natural antioxidants, and the formation of peptide–hemin conjugates can synergistically improve antioxidant performance. Ultrasonic (US) treatment facilitates the binding of different molecules. Therefore, in this study, the effects of ultrasonic power treatments on the antioxidant activity and binding behavior of peptide–hemin conjugates were investigated. The spatial structure of the peptide–hemin conjugates was characterized using endogenous fluorescence spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and circular dichroism (CD) spectroscopy, respectively. The results demonstrated that the peptide–hemin binding rate reached the highest value of 91.63% at 400 W US power, with structural changes in conjugates from α-helix to random coil structures. Additionally, US treatment increased the surface hydrophobicity and reduced the enthalpy change in conjugates. The antioxidant capacity was greatly improved and peaked at 400 W US, where DPPH and ABTS radical scavenging rates exceeded 55% and 65%, respectively. This study provided a scientific basis for the high-value utilization of US treatment on porcine blood meal resources. Full article

Indigenous clays are widely used for facial skincare in South Africa, yet their suitability for cosmetic incorporation remains poorly characterised, particularly with respect to elemental safety. This study assessed two traditionally applied clays for acne-prone skin (Umcako and Ibomvu) using a multi-analytical workflow encompassing colorimetry, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), pH measurement, in vitro sun protection factor (SPF) estimation, X-ray fluorescence (XRF), and inductively coupled plasma mass spectrometry (ICP-MS) of clay leachates. XRD showed both materials to be kaolinite-dominated, with higher kaolinite content in Umcako (92.5 wt%) than in Ibomvu (77.3 wt%); SEM revealed characteristic overlapping pseudo-hexagonal platelets, and FT-IR did not indicate prominent organic functional groups under the conditions tested. The clays were mildly acidic (pH 4.23–4.48), aligning with physiological skin pH, but exhibited low photoprotective performance when assessed alone (SPF ≈ 2.5–2.6). Elemental screening identified nutritionally relevant trace minerals but also detected regulated or sensitising metals, with Ibomvu showing elevated bulk Pb (53 ± 12 ppm), Ni (126 ± 71 ppm) and Zn (72 ± 26 ppm), while Umcako contained elevated bulk Cr (460 ± 140 ppm) and Pb (18 ± 6 ppm). Overall, although Umcako and Ibomvu display physicochemical properties compatible with clay-based cosmetic products, their heavy metal burden, together with the potential for dermal exposure highlighted by leachate analysis, indicates that purification, batch-to-batch monitoring and regulatory risk assessment are essential before safe cosmetic use. Full article