Search Results (568)

Soil amendments play a critical role in improving soil health and supporting sustainable crop production, especially under declining soil fertility and climate-related stress. However, their impact varies because each amendment influences the soil through different biogeochemical processes rather than a single universal mechanism. This review synthesizes current knowledge on a wide range of soil amendments, including compost, biosolids, green and animal manure, biochar, hydrochar, bagasse, humic substances, algae extracts, chitosan, and newer engineered options such as metal–organic framework (MOF) composites, highlighting their underlying principles, modes of action, and contributions to soil function, crop productivity, and soil carbon dynamics. Across the literature, three main themes emerge: improvement of soil physicochemical properties, enhancement of nutrient cycling and nutrient-use efficiency, and reinforcement of plant resilience to biotic and abiotic stresses. Organic nutrient-based amendments mainly enrich the soil and build organic matter, influencing soil carbon inputs and short- to medium-term increases in soil organic carbon stocks. Biochar, hydrochar, and related materials act mainly as soil conditioners that improve structure, water retention, and soil function. Biostimulant-type amendments, such as algae extracts and chitosan, influence plant physiological responses and stress tolerance. Humic substances exhibit multifunctional effects at the soil–root interface, contributing to improved nutrient efficiency and, in some systems, enhanced carbon retention. The review highlights that no single amendment is universally superior, with outcomes governed by soil–crop context. Its novelty lies in its mechanism-based, cross-amendment synthesis that frames both yield and carbon outcomes as context-dependent rather than universally transferable. Within this framework, humic substances and carbon-rich materials show potential for climate-smart soil management, but long-term carbon sequestration effects remain uncertain and context-dependent. Full article

To address the challenge of treating refractory organic dyes in textile wastewater, this study synthesized a novel copper-based composite material (designated MEL-Cu-6HNA) via a supramolecular self-assembly–pyrolysis pathway. Its core component consists of CuO/Cu₂O(SO₄), which was applied to efficiently degrade the Reactive Red 3BS dye within a sodium bicarbonate-activated hydrogen peroxide (BAP) system. This material was applied to degrade the Reactive Red 3BS dye using a sodium bicarbonate-activated hydrogen peroxide system. The morphology, crystal structure, and surface chemistry of the material were systematically characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Electron paramagnetic resonance (EPR) was employed to identify reactive species generated during the reaction. The effects of dye concentration, H₂O₂ concentration, MEL-Cu-6HNA dosage, and coexisting substances in water on degradation efficiency were systematically investigated, with active species identified via EPR. This study marks the first application of the supramolecular self-assembled CuO/Cu₂O(SO₄)₂ composite material MEL-Cu-6HNA, prepared via pyrolysis, in a sodium bicarbonate-activated hydrogen peroxide system. It achieved rapid and efficient decolorization of the recalcitrant Reactive Red 3BS dye. The three-dimensional sulfate framework and dual Cu²⁺ sites of the material significantly enhanced the degradation efficiency. MEL-Cu-6HNA achieved rapid and efficient decolorization of the recalcitrant Reactive Red 3BS in a sodium bicarbonate-activated hydrogen peroxide system. The material’s three-dimensional sulfate framework and dual Cu²⁺ sites significantly enhanced interfacial electron transfer and Cu²⁺/Cu⁺ cycling activation capacity. ·OH served as the primary reactive oxygen species (ROS), with SO₄²⁻, ¹O₂, and ·O₂⁻ contributing to sustained radical generation. This system achieved 95% decolorization within 30 min, demonstrating outstanding green treatment potential and providing a reliable theoretical basis and practical pathway for efficient, low-energy treatment of dyeing wastewater. Full article

Perfluorooctane sulfonate (PFOS), a persistent and bioaccumulative perfluoroalkyl substance, poses significant environmental and human health risks due to the extraordinary stability of its C–F bonds. Conventional remediation strategies largely fail to achieve mineralization, instead transferring contamination or producing secondary waste streams. In this study, we investigate neutron irradiation as a potential destructive approach for PFOS remediation in both solid and aqueous matrices. Samples were exposed to thermal neutrons (flux: 3.2 × 10⁹ n·cm⁻²·s⁻¹, 0.0025 eV) at the Argonauta reactor for 6 h. Raman and FTIR spectroscopy revealed that PFOS in powder form remained largely resistant to degradation, with only minor structural perturbations observed. In contrast, aqueous PFOS solutions exhibited pronounced spectral changes, including attenuation of C–F and S–O vibrational signatures, the emergence of carboxylate and carbonyl functionalities, and enhanced O–H stretching, consistent with radiolytic oxidation and partial defluorination. Notably, clear peak shifts were predominantly observed for PFOS in aqueous solution after irradiation (overall displacement toward higher wavenumbers), whereas in powdered PFOS the main spectral signature of irradiation was the attenuation of CF₂ and S–O related bands with comparatively limited band relocation. To evaluate the biological relevance of these structural alterations, cell viability assays (MTT) were performed using human umbilical vein endothelial cells. Non-irradiated PFOS induced marked cytotoxicity at 100 and 50 μg/mL (p < 0.0001), whereas neutron-irradiated PFOS no longer exhibited significant toxicity, with cell viability comparable to the control. These findings indicate a matrix-dependent response: neutron scattering in solids yields negligible molecular breakdown, whereas radiolysis-driven pathways in water facilitate measurable PFOS transformation. The cytotoxicity assay demonstrates that neutron irradiation promotes sufficient molecular degradation of PFOS in aqueous media to suppress its cytotoxic effects. Although complete mineralization was not achieved under the tested conditions, the combined spectroscopic and biological evidence supports neutron-induced radiolysis as a promising pathway for perfluoroalkyl detoxification. Future optimization of neutron flux, irradiation duration, and synergistic catalytic systems may enhance mineralization efficiency. Because PFOS concentration, fluoride release (F⁻), and TOC were not quantified in this study, remediation was assessed through spectroscopic fingerprints of transformation and the suppression of cytotoxicity, rather than by mass-balance mineralization metrics. This study highlights neutron irradiation as a promising strategy for perfluoroalkyl destruction in contaminated water sources. Full article

Per- and polyfluoroalkyl substances (PFASs) represent a group of persistent environmental contaminants with known adverse health effects. This study assessed the presence and concentrations of PFASs in surface water across various locations along the Gunpowder River Watershed in Maryland, United States. Gunpowder RIVERKEEPER^® a 501(c)(3) nonprofit collected eleven surface water grab samples from the Gunpowder River Watershed for the study, including both drinking water sources and non-drinking tributaries. Of the 55 PFASs analyzed, multiple compounds, including PFOS, PFOA, PFBS, PFHxA, PFPeA, and PFHpA, were detected above reporting limits at all sampled locations. Total PFAS concentrations varied substantially across the watershed, ranging from 2.1 to 21.3 ng/L in drinking water source tributaries and 6.6–18.4 ng/L in non-drinking tributaries. Several sites exhibited PFOS and PFOA concentrations exceeding the 2022 U.S. EPA interim lifetime health advisory levels, indicating potential risk to downstream communities relying on these water sources. Short-chain PFASs (C ≤ 7) were more abundant than long-chain PFASs, reflecting their greater mobility and persistence in surface waters. These findings demonstrate watershed-wide PFAS contamination and highlight the potential for trophic transfer and bioaccumulation in fish species in these tributaries and subsequent human exposure. Continued monitoring, regulation, and remediation efforts are required to mitigate PFAS contamination and safeguard public health in vulnerable ecosystems and populations. Further research is needed to better understand the extent of PFAS exposure, associated health risks, and effective strategies for prevention and management. Full article

Ischemic–reperfusion injury represents an extremely serious problem in the human population. It mainly affects the elderly population and currently used treatments have poor results. However, in nature there is a much more effective and relatively well-studied mechanism known as the ischemic tolerance phenomenon. If an organism is exposed to adverse conditions that do not destroy it, it responds by producing substances capable of protecting it from severe damage or death in the event of a repeated encounter with the same or a different dangerous environment. The problem with its use in the clinic is that its effectiveness decreases in the elderly and is practically lost with associated diseases and their concurrent treatment. Based on experimental animal studies and findings, it can be assumed that the activation of full tolerance—through successive exposure to two stressors in young, healthy individuals—will result in the formation of effectors of tolerance, which are spread throughout the body through the blood. Blood plasma thus activated and administered to a recipient who is unable to otherwise acquire tolerance, should be used as an immediate treatment for ischemia–reperfusion injury and a wide range of impending injuries in all individuals, since activated plasma contains effectors of ischemic tolerance. The purpose of this work is to show the possibilities of using ischemic tolerance in the clinical practice. Complete tolerance can be transferred from young, healthy, unmedicated donors to patients who have lost their ability to build tolerance in their own bodies. Full article

Extracellular polymeric substances (EPSs) produced by actinomycetes of the genus Rhodococcus play crucial roles in their ecological success, metabolic versatility, and biotechnological value. This review summarizes existing studies of Rhodococcus EPSs, emphasizing the biochemical composition, functional attributes, and practical significance of EPSs, as well as their importance in biomedicine, bioremediation, and other applications (food industry, biomineralization) with respect to the EPS chemical composition and biological roles. Rhodococcus species synthesize complex EPSs composed primarily of polysaccharides, proteins and lipids that, like in other bacteria, support cell adhesion, aggregation, biofilm formation, and horizontal gene transfer (and can prevent exogenous DNA binding) and are highly important for resistance against toxicants and dissolution/assimilation of hydrophobic compounds. EPSs produced by different species of Rhodococcus exhibit diverse structures (soluble EPSs, loosely bound and tightly bound fractions, capsules, linear and branched chains, amorphous coils, rigid helices, mushroom-like structures, extracellular matrix, and a fibrillar structure with a sheet-like texture), leading to variations in their properties (rheological features, viscosity, flocculation, sorption abilities, compression, DNA binding, and interaction with hydrophobic substrates). Notably, the EPSs exhibit marked emulsifying and flocculating properties, contributing to their recognized role in bioremediation. Furthermore, EPSs possess antiviral, antibiofilm, anti-inflammatory, and anti-proliferating activities and high viscosity, which are valuable in terms of biomedical and food applications. Despite extensive industrial and environmental interest, the molecular regulation, biosynthetic pathways, and structural diversity of Rhodococcus EPSs remain insufficiently characterized. Advancing our understanding of these biopolymers could expand new applications in biomedicine, bioremediation, and biotechnology. Full article

Few hydrogeological studies have focused on possible per- and poly-fluoroalkyl substance (PFAS) contamination in groundwater with particular attention to the role of hydraulic interconnections and to the interdigitations present between shallow and deep aquifer layers in heterogeneous alluvial systems. In general, deeper groundwater is considered chemically safer and less impacted by contamination, especially in multilayer aquifers characterized by low permeability apparently confining horizons. Therefore, this research analyzed PFAS in groundwater at depths ranging from 20 to 120 m below ground level, combining stratigraphic, hydrogeological, and chemical data with GIS mapping to identify industrial activities potentially contributing to PFAS contamination using the cross-checking methodology. During the second survey, the monitoring network was extended along a hydrogeological transect, including two springs located upstream and downstream of the deep wells, to assess PFAS concentration in shallow groundwater and the possible transfer along the groundwater flow path. The intra-site comparative analysis reveals, for the same sampling locations, a differentiation in the PFAS profiles detected across the two monitoring campaigns, indicating a temporal evolution in the chemical composition. Furthermore, chemical results show the presence of PFAS exclusively in deep monitoring wells, confirming a spatially heterogeneous distribution within the aquifer system. These results highlight both the temporal and spatial evolution of PFAS concentration, suggesting a complex contaminant migration pathway along preferential gravel and sand horizons in deeper aquifer layers. The conceptual hydrogeological model confirmed hydraulic interconnections among aquifer layers and identified zones of higher vulnerability to contamination. The analysis of possible PFAS migration pathways at the basin scale raised some questions about the influence of wells features and management practices on PFAS distribution in shallow and deep groundwater. The findings of this research contribute to environmental sustainability, providing initial insights for measuring and managing the presence and pathways of PFAS in deep alluvial aquifers. Full article

Using reclaimed water for irrigation is an effective strategy in semi-arid regions facing water scarcity. However, this water may contain pharmaceutical residues, posing potential environmental and health risks. To ensure sustainable reuse, it is essential to study how these substances accumulate in soil and transfer to crops. The aim of this research was to develop and optimise a rapid Ultrasound-Assisted Extraction method combined with Ultra-High-Performance Liquid Chromatography–tandem Mass Spectrometry for quantifying 23 pharmaceuticals in non-cultivated soil. Following optimisation, 18 compounds were successfully extracted using a MeOH:H₂O ratio of 75:25. The detection and quantification limits were found to range from 0.52 to 0.5 ng·g⁻¹ and 1.75 to 35 ng·g⁻¹, respectively. The matrix effects and recoveries varied by compounds’ type and concentration, but most results were acceptable. The evidence suggested that some drugs underwent microbial degradation. Soil irrigated with reclaimed water via subsurface drip since 2012 occasionally contained four pharmaceuticals (caffeine, carbamazepine, tamoxifen, and venlafaxine) at low concentrations, while others were absent. This indicates the capacity of soil to act as a barrier, and highlights the importance of proper water management. The study concludes that reclaimed water reuse is safe if supported by efficient treatment and management, offering a promising approach for long-term sustainability in water-scarce regions. Full article

Magnetic biochars (MBCs) have been shown to inhibit the horizontal transfer of antibiotic resistance genes (ARGs) in soils, both with and without microplastics (MPs); however, the underlying molecular biological mechanisms remain unclear. This study examined the effects of MBCs and coexisting polybutylene adipate terephthalate microplastics (PBAT MPs) on the physiological characteristics of Serratia marcescens ZY01 (a host strain carrying the tet gene) and further investigated their relationships with the absolute abundance of the tet gene in soil. The results demonstrated that MBCs promoted prodigiosin synthesis in Serratia marcescens ZY01 by mediating the electron transfer process, the effect of which was further enhanced in the presence of PBAT MPs. In treatments without PBAT MPs, MBCs generally suppressed the production of both proteins and polysaccharides in the extracellular polymeric substances. In contrast, in treatments containing PBAT MPs, the protein content gradually decreased with decreasing iron-to-biochar ratios, while the polysaccharide content remained largely unchanged. MBCs also elevated intracellular ROS levels due to the increased oxidative stress, particularly in treatments with PBAT MPs. A positive correlation between intracellular ROS levels and cell membrane permeability indicates that intracellular ROS was the primary driver of the increased cell membrane permeability. The presence of MBCs and PBAT MPs generally provided favorable habitats for Serratia marcescens ZY01, thereby enhancing its cell viability. Mantel test analysis indicated that MBCs influenced Serratia growth in soil by modulating its cell viability. Furthermore, the increased intracellular ROS level was significantly positively correlated with the absolute abundance of the tet gene in soil, implying the horizontal transfer of the tet gene at the intra-genus level. These findings offer helpful insights for developing environmental remediation strategies based on biochar–iron composites. Full article

Background/Objectives: Advancing information on the key physicochemical properties of biologically active substances enables the development of formulations with reduced dosing, lower toxicity, and minimal adverse effects. This work addresses the knowledge gap concerning the pharmacologically relevant properties of harmaline (HML), with a focus on thermodynamic and kinetic aspects. New data were obtained on the compound’s solubility and distribution coefficients across a wide temperature range. Specifically, solubility was measured in aqueous buffers (pH 2.0 and 7.4), 1-octanol (OctOH), n-hexane (Hex), and isopropyl myristate (IPM), while distribution coefficients were determined in OctOH/pH 7.4, Hex/pH 7.4, and IPM/pH 7.4 systems. Methods: Three membranes—regenerated cellulose (RC), PermeaPad (PP) and polydimethylsiloxane-polycarbonate (PDS)—were used as barriers in permeability studies using a Franz diffusion cell. Results: At 310.15 K, the molar solubility of HML in the solvents decreased in the following order: OctOH > pH 2.0 > pH 7.4 > IPM > Hex. The distribution coefficient of HML showed a strong dependence on the nature of the organic phase, correlating with its solubility in the respective solvents. The OctOH/pH 7.4 distribution coefficient ranged from 0.973 at 293.15 K to 1.345 at 313.15 K, falling within the optimal range for potential drug bioavailability. The transfer of HML into OctOH (from either pH 7.4 or hexane) is thermodynamically spontaneous, whereas its transfer into Hex is unfavorable. Conclusions: Based on its permeability across the PP barrier, HML was classified as highly permeable. The distribution and permeation profiles of HML showed similar trends over 5 h in both the OctOH/pH 7.4–PP and IPM/pH 7.4–PDS systems. These systems were therefore proposed as suitable models for studying HML transport in vitro. Full article

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) have emerged as contaminants of global concern due to their persistence and potential health risks. PFASs pose potential pollution risks in mango cultivation and production. This study investigated pollution characteristics and conducted a comprehensive risk assessment of PFASs in soil–mango systems within the Nanfan District of Hainan, China. The results revealed that total PFAS concentrations in soil ranged from 0.18 to 1.07 ng/g, with PFHpA and PFHxA accounting for 24.9% and 21.0%, respectively. Total PFAS concentrations in mangoes ranged from 0.0019 to 0.0201 ng/g wet weight, where PFHxA and PFHpA accounted for 44.02% and 30.28%, respectively. For all PFASs, the bioaccumulation factor (BAF) in mangoes was <1, indicating limited transfer from soil to fruits. Regarding PFAS contamination sources, long-range atmospheric transport may serve as the primary pathway for PFAS contamination in soil and mangoes. Risk assessments indicated minimal ecological and dietary exposure risks, with soil ecological risk quotients (RQs) below 0.01 and edible exposure RQs below 1. This study highlights the unique contribution of short-chain PFAS to the quality and safety of tropical agricultural products and provides critical data for the safety regulation of PFASs in soil–fruit systems. Full article

Charge-transfer-type fluorochromes, which exhibit shifts in fluorescence intensity and emission wavelength in response to solvent polarity changes, have been widely employed to investigate solute–solvent interactions. Humic substances (HSs) are naturally occurring macromolecular organic acids derived from plant residues, with structural properties that vary depending on their origin and environmental conditions. The polarity of HSs is closely associated with the mobility and toxicity of environmental pollutants, making their chemical characterization essential. In this study, we developed a rapid and straightforward method to characterize HS polarity using fluorescent solvatochromism. The fluorescence peak shifts of four dyes—8-anilino-1-naphthalenesulfonic acid (ANS), acridine orange (AO), methylene blue (MB), and Rhodamine B (RhB)—were evaluated in the presence of humic acids (HAs), a major component of HSs. To assess environmental variability, a total of twelve HS samples were tested, including HSs derived from soils of different origins, compost, commercial reagents, and standard reference materials. Among these, AO and MB exhibited distinct spectral shifts without overlapping with the intrinsic fluorescence of HAs. Notably, MB displayed a consistent blue shift dependent on HA concentration, with the most stable response observed at 5 mg/L. The magnitude of this shift was significantly correlated with UV–Vis parameters associated with the aromaticity, humification degree, and polarity of HSs. Overall, this study demonstrates that MB-based fluorescent solvatochromism can function as an empirical and facile indicator for assessing the structural and microenvironmental characteristics of HSs, providing a rapid and complementary screening approach for HSs extracted and purified from environmental samples. Full article

Cheese consumption is steadily increasing worldwide, with a growing interest in cheese enriched with bioactive substances, including antioxidants. This study investigated the impact of adding blackcurrant wine to the curd (IC), enriching the curd with blackcurrant wine by soaking and ripening in salted blackcurrant wine (IOC), and cheese soaked and ripened in blackcurrant wine with 5% (w/w) NaCl (OC). The curd and added wine weight ratio (1.5:1, 3:1) effects were also studied. Physicochemical (dry matter, polyphenol content, antioxidant activity, radical-scavenging activity, anthocyanin content like delphinidin-3-rutoside and cyanidin-3-rutoside, ethanol content), microbiological, and sensory properties of the cheeses were evaluated. The results indicated that a week of soaking is sufficient to achieve the maximum antioxidant capacity and polyphenol content of the cheese. From a technological and sensory point of view, a 1.5:1 ratio of blackcurrant wine to curd was better. The maximum transfer rate of delphinidin-3-rutoside from wine was the most pronounced in IOC samples (20.44%). Blackcurrant wine inhibited the growth of lactic acid bacteria, and a longer soaking time can hinder the ripening process of cheese. During tasting, among the treated cheese, IC samples received the highest average acceptance scores for appearance, texture, creaminess, flavor, saltiness, bitterness, freshness and overall impressions. Full article

This study presents a theoretical framework for modeling sorption and release kinetics of substances in polymeric materials with planar, cylindrical, and spherical geometries. Fick’s second law was expressed in dimensionless variables and solved numerically using a finite-difference approach to generate universal profiles for mass transfer. These profiles were fitted with double-exponential equations, yielding explicit expressions that allow for straightforward estimation of diffusion coefficients from experimental data. The method was validated using literature data for films, fibers, and microspheres, showing excellent agreement with reported values. Unlike classical analytical solutions, which are limited to planar systems under ideal conditions, the proposed approach is applicable to diverse geometries commonly employed in packaging, biomedical devices, controlled-release formulations, and environmental technologies. Full article

Antibodies against low-molecular-weight compounds exhibit cross-reactivities (CRs) with their structural analogs, varying by orders of magnitude for different substances. This variability limits the informativeness of antibody applications as analytical reagents and for other aims when samples contain several members of the same family, their derivatives, or partial degradation products. Therefore, there is a demand to find some criteria for understanding the relationships between the structural characteristics of antigens of a given chemical class and their immunochemical activity. This study presents an experimental and theoretical investigation of the properties of a monoclonal antibody (MAb) against the S-stereoisomer of gatifloxacin, a member of the widely used (fluoro)quinolone (FQ) family of antibiotics, characterized by high structural diversity. The aim was to determine FQs that form complexes with MAb and suggest a methodology to predict their CRs in silico. For this, the interaction of MAb with 26 FQs was studied using the enzyme-linked immunosorbent assay and presented as CR values to the target antigen. The most pronounced CRs were observed for lomefloxacin, sarafloxacin, and ciprofloxacin. Molecular dynamics (MD) simulations were performed to identify differences in analyte interactions at the MAb antigen-binding site, which determines binding affinity. It has been shown that molecular docking fails to discriminate cross-reactive from non-cross-reactive compounds because FQs have similar cores. Therefore, advanced analysis of MD trajectories was carried out. It allowed for clarification of the dynamic features of analyte–antibody interactions responsible for binding. It was shown by the dynamical network analysis that the sum of betweenness centrality between a node corresponding to the quinolone ring and nodes representing MAb amino acids is higher for cross-reactive haptens. The found regularities can be transferred to other analyte–antibody systems as a binary classifier that discriminates cross-reactive and non-cross-reactive compounds. Full article