Search Results (3,770)

The increasing prevalence of multiclass pesticide residues in aquatic environments poses a significant threat to ecosystems and human health. To address this challenge, magnetic Fe₃O₄@Co₅Al-LDH nanoparticles were synthesized as high-performance, easily recoverable catalysts for the peroxymonosulfate (PMS)-mediated degradation of epoxiconazole, atrazine, and metalaxyl. Under optimized conditions (pH 7.0, 35 mg catalyst, and 4.0 mM PMS), the system achieved 100% degradation of the three coexisting pesticides within 15 min. Quenching experiments and electron paramagnetic resonance (EPR) spectroscopy confirmed that SO₄⁻ and ^•OH radicals were the primary reactive species driving the process. Liquid chromatography–mass spectrometry (LC-MS) analysis identified four intermediates for epoxiconazole, three for atrazine, and four for metalaxyl, facilitating the proposal of distinct degradation pathways. The degradation mechanism revealed that electron transfer between Fe/Co and PMS promoted the generation of reactive oxygen species, leading to dechlorination, hydroxylation, and dealkylation of the pesticides transiently adsorbed on the surface of Fe₃O₄@Co₅Al-LDH. In summary, this study demonstrates that Fe₃O₄@Co₅Al-LDH is an easily recoverable, reusable, and cost-effective catalyst for the simultaneous remediation of complex pesticide mixtures in water. Full article

A biological/synthetic hybrid graft copolymer was obtained by grafting poly(acrylic acid) (PAA, synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization) to amylopectin (AMP). The novel graft copolymer presents amphiphilic properties due to the inherent insolubility of AMP in water and was further utilized as a mediator for the synthesis of gold nanoparticles (AuNPs) following an environmentally friendly in situ procedure. The AMP-g-PAA copolymer formation by the interaction of the PAA end groups with the C(6)-OH groups on an AMP backbone was confirmed by Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) and 1D (proton (¹H NMR) and carbon (¹³C NMR) nuclear magnetic resonance, and Distortionless Enhancement by Polarization Transfer (DEPT)) and 2D (correlation (COSY) and heteronuclear single quantum coherence (HSQC)) spectroscopies. The calculated degree of substitution of 1.17 suggests that the grafting was done at one OH from the three in an anhydroglycosidic unit (AGU) (preferably at that in C6 position), with a mean grafting efficiency of 76%. Additional information obtained using thermogravimetric analysis shows that the thermal decomposition of AMP-g-PAA occurs in two steps, with a residual mass of ~16 wt% at 700 °C, higher than AMP or PAA, indicating increased thermal stability of the copolymer. Dynamic and electrophoretic light scattering (DLS and ELS) measurements were used to determine the hydrodynamic size and ionic charge of the AMP-g-PAA self-assemblies in aqueous solution as well as their stability. The AMP-g-PAA was subsequently tested as a reducing agent in the environmentally friendly synthesis of AuNPs in aqueous solution, at different incubation temperatures, reaction duration, and inorganic/polymer weight ratios. The development of the surface plasmon resonance band of AuNPs, observed in UV–vis spectra, was consistently monitored over the reaction time. DLS analysis indicated time-dependent changes in the AuNPs’ particle size distributions, while scanning transmission electron microscopy confirmed that the AuNPs formed at the inorganic/polymer weight ratio of 0.36 and at 60 °C were predominantly well-dispersed, spherical-shaped nanoparticles. The AuNPs synthesized in situ within the copolymer matrix did not introduce additional cytotoxicity compared to the parent copolymer alone, with the composites representing a promising safety baseline for further investigation in biomedical applications. Full article

In this study, a compound with a novel chemical skeleton was isolated and purified from the fermentation broth of Streptomyces canarius SN0246. Its structure was elucidated using nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HRMS), and the compound was named canakingmycin. The in vitro antifungal activity of canakingmycin was evaluated against common crop pathogenic fungi, Rhizoctonia solani. The bioassay results showed that canakingmycin exhibited notable inhibitory effects on the mycelial growth of the phytopathogen, with the EC₅₀ value of 76.13 μg/mL. This study enriches the structural diversity of secondary metabolites from Streptomyces and provides a promising lead molecule and scientific basis for the development of new bio-based fungicides. Full article

Municipal solid waste incineration (MSWI) fly ash contains soluble salts and heavy metals, which may cause leaching risks and durability deterioration when directly used in cement-based materials. This study aimed to investigate the synergistic effects of carbonated and hydrophobically modified municipal solid waste incineration fly ashes on the engineering performance and heavy-metal immobilisation of mortar. Mortars containing modified fly ashes were evaluated in terms of hydration behavior, compressive strength, water absorption, electrically accelerated corrosion resistance, heavy metal leaching, and microstructure. Carbonated fly ash promoted hydration through the nucleation and filling effects of CaCO₃, shortened setting time, increased cumulative hydration heat, and improved compressive strength by up to 4.5 MPa. Hydrophobic fly ash reduced particle wettability and capillary water transport, thereby reducing water uptake and mitigating visible corrosion-induced deterioration under accelerated conditions, although excessive dosage delayed hydration and reduced strength. The combined modification showed a clear synergistic effect, reducing water absorption by up to 39.9%. In particular, the C3H3 specimen, containing 75 kg·m⁻³ carbonated MSWI fly ash and 75 kg·m⁻³ hydrophobically modified MSWI fly ash, exhibited the lowest water absorption of 3.92% and effectively suppressed crack propagation and corrosion-product migration. The leaching concentrations of Cr, Cu, Zn, As, Cd, and Pb were below the GB 18598—2019 limits. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG), and low-field nuclear magnetic resonance (NMR) results indicated that the improved performance originated from a composite barrier involving carbonate filling, hydrophobic interfacial blocking, and heavy metal solidification/stabilization. Full article

Olive oil represents a precious resource for the agri-food sector, not just economically but also for its health properties due to the presence of bioactive compounds. The aim of this study is to evaluate the Nuclear Magnetic Resonance (¹H NMR)-based metabolomics profiles of monovarietal olive oils from Coratina, Ogliarola garganica and Peranzana, which are typically included in the “Dauno” PDO. Analysis by ¹H NMR metabolic profiling was carried out to develop a strategy for understanding the differences based on cultivar. NMR spectroscopy coupled with multivariate statistical analysis (MVA) revealed significant differences in fatty acid profiles and phenolic compounds according to cultivar. In particular, Coratina oils were higher in squalene, oleic acid and polyphenols than Ogliarola garganica and Peranzana. Conversely, the latter two showed higher contents of polyunsaturated fatty acids and lower levels of phenolic compounds. Furthermore, as the olive oils were influenced by several factors, in addition to cultivar, the effects of tree age on the chemical composition of Peranzana olive oils were investigated. MVA revealed different fatty acid and polyphenol contents between secular and young trees. These results may contribute to expanding the literature data on the ¹H NMR-based chemometric approach as a powerful tool for quality and authenticity control of olive oil. Full article

Oxidative stress has been recognized as a repeatedly validated pathophysiological factor in schizophrenia, but its mechanistic role and translational relevance remain incompletely defined. Prior work has advanced redox dysregulation, neuroinflammation, and NMDA receptor hypofunction as a putative central hub in schizophrenia. This narrative review proposes an evidence-weighted redox–mitochondria–immune framework that integrates peripheral biomarkers, magnetic resonance spectroscopy, postmortem findings, and preclinical mechanisms while explicitly distinguishing established observations from candidate pathways. Existing studies support increased oxidative damage and altered antioxidant buffering in schizophrenia, particularly involving the glutathione system. However, these abnormalities are neither uniform across disease stages nor equally represented across patient subgroups, and may be markedly prominent only in certain biological subgroups. Mechanistically, redox imbalance may interact with mitochondrial bioenergetic deficits and innate immune signaling; however, pathway-specific links such as cGAS-STING activation, nitrosative/peroxynitrite stress, and GPx4-ferroptosis should currently be treated as testable extensions rather than validated human mechanisms in schizophrenia. Importantly, the pathological consequences of oxidative stress are unlikely to be cell-type neutral. Parvalbumin-positive interneurons and oligodendrocyte lineage cells are more vulnerable because of their high metabolic load, limited antioxidant buffering capacity, and lipid/iron-related susceptibility, thereby providing a mechanistic bridge to excitation–inhibition imbalance, myelin abnormalities, and reduced circuit synchrony. Microglial redox–inflammatory signaling may further exacerbate these processes. On the basis of this framework, we argue that the key for future research is not to continue demonstrating the universality of oxidative stress, but to improve the translational efficiency. Biomarker-guided stratification, stage-sensitive study designs, and cell-type-informed therapeutic strategies may therefore provide a more productive path toward redox-targeted interventions in schizophrenia. Full article

Low-field benchtop nuclear magnetic resonance (NMR) spectroscopy has emerged as an accessible analytical platform for rapid, routine, and application-oriented analysis. However, its broader analytical adoption remains constrained by intrinsic limitations, including reduced spectral resolution, severe signal overlap, and lower sensitivity compared with conventional high-field instruments. To address these limitations, artificial intelligence (AI), including machine learning and deep learning approaches, has increasingly been explored alongside conventional chemometric strategies to enhance information extraction from low-field spectral data. This review examines recent developments in AI-assisted benchtop NMR across three major application domains: classification and authentication, quantitative analysis, and spectral processing or automated interpretation. Current evidence suggests that classification and authentication currently represent the most mature application area, whereas quantitative analysis shows promising but often condition-dependent performance. In contrast, spectral reconstruction and automated interpretation remain comparatively early-stage and exploratory, despite their potential long-term relevance for addressing intrinsic information limitations. Key challenges, including limited dataset diversity, poor model transferability, validation pitfalls, limited interpretability, and the lack of benchmarking and standardized workflows, are critically discussed. Future progress will likely depend not only on advances in AI algorithms, but also on the development of robust, reproducible, and analytically meaningful workflows. Overall, AI-assisted benchtop NMR is evolving from proof-of-concept applications toward a more structured analytical framework for extracting chemically meaningful information from spectrally constrained low-field data. Full article

Bisphenol A type epoxy resin has the problem of relatively high brittleness after curing. Although traditional polysiloxane toughening methods can improve toughness, they often come at the expense of strength. In this paper, methylphenyl dimethoxysilane (MPS) was used as a monomer to synthesize end-hydroxyl poly(methylphenyl)siloxane (PMPS), which was then used to modify E51 epoxy resin. The structure and reaction degree were characterized by infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry and viscosity tests. The mechanical test results show that when the PMPS content is 20 wt%, the tensile, flexural, compressive and impact strengths of the modified resin increase by 31.26%, 26.16%, 18.53% and 98.66%, respectively, compared with the unmodified resin, and the tensile and flexural elastic moduli increase by 38.36% and 32.25%, respectively. The fracture toughness increases by 60.29%, indicating that the strength, stiffness and toughness of the material have all been improved. Dynamic mechanical analysis shows that the glass transition temperature and crosslinking density of the system gradually decrease with increasing PMPS content. Thermogravimetric analysis shows that the introduction of PMPS increases the char yield and decreases the maximum thermal decomposition rate, thereby enhancing the thermal stability of the system. Microscopic morphology analysis by optical microscopy, scanning electron microscopy and atomic force microscopy shows that the system has good compatibility, and the internal different modulus phases are distributed in a network-like manner, forming a uniform co-continuous or bicontinuous phase structure. This structure effectively promotes stress transfer and energy dissipation, alleviates local stress concentration, and thus comprehensively improves the mechanical properties of the resin system. Full article

Natural polysaccharides from Siegesbeckia orientalis L. have been reported to exhibit promising bioactivities. To enhance extraction efficiency, low-temperature plasma-assisted extraction was optimized for S. orientalis L. polysaccharides using single-factor experiments and response surface methodology. Column chromatography purified a homogeneous SIE-III fraction, followed by structural characterization. Optimal parameters were 80 kV discharge voltage, 153 Hz frequency, and 109 s treatment time, under which the polysaccharide yield reached 15.68%, significantly higher than that of the conventional hot water extraction method. Plasma treatment loosened the raw material’s surface, potentially facilitating polysaccharide release. SIE-III had a molecular weight of 20.831 kDa and comprised mainly galactose (51.7%), rhamnose (19.1%), arabinose (11.3%), and galacturonic acid (9.9%). It featured typical rhamnogalacturonan-I (RG-I) domains and a triple-helix conformation. Fourier transform infrared spectroscopy and nuclear magnetic resonance confirmed both α- and β- glycosidic linkages, and methylation analysis revealed a highly branched →3,4)-Galp-(1→ structure. This study provides an effective extraction method for plant polysaccharides and valuable insights into their potential applications in the food and other industries. Full article

Chiang Mai, Thailand, experiences seasonal fine particulate matter (PM_2.5) pollution associated with metabolic diseases, but the underlying mechanisms remain unclear. This prospective observational study compared plasma metabolomes of 25 healthy adults in Samoeng District, a highly affected area, between low and high PM_2.5 exposure seasons using proton nuclear magnetic resonance (¹H-NMR) spectroscopy. Twenty-six metabolites differentiating haze and non-haze seasons were identified using PLS-DA (VIP > 1.5). During the haze season, 11 were elevated, whereas 15 were decreased. Among the elevated metabolites, the top five—maleylacetoacetic acid, deoxyribose 5-phosphate, betaine, 3-hydroxyanthranilic acid, and 1-methyladenosine—were associated with inflammation, increased reactive oxygen species, nitric oxide inhibition, and altered amino acid metabolism. The top five decreased metabolites—deoxyguanosine, D-arabitol, glycerophosphocholine, ophthalmic acid, and oxaloacetic acid—were involved in several metabolic pathways, particularly those involved in energy metabolism. A total of 56 metabolic pathways were altered by high PM_2.5 exposure, including pathways related to amino acids, lipids, sugars, nucleotides, vitamins, and energy metabolism. High PM_2.5 exposure disrupts metabolites and pathways, inducing inflammation, oxidative stress, impaired lipid/energy metabolism, insulin resistance, and high blood pressure. These alterations may increase the risk of metabolic and cardiovascular diseases, with dysregulated metabolites serving as potential biomarkers. These findings highlight the molecular impact of air pollution in affected populations and may support preventive strategies and public health policy development in affected regions. Further studies are needed to clarify these findings. Full article

Ultrastrong magnetic fields, ranging from 100 T to 1000 T, are generated exclusively by destructive pulsed magnets. While various generation methods exist, this review focuses on the Single-Turn Coil (STC) and Electromagnetic Flux Compression (EMFC) techniques, which provide optimal environments for high-precision measurements in materials science. First, we present recent technological breakthroughs in the EMFC method that have successfully achieved fields exceeding 1000 T. We then describe specialized measurement infrastructures for magneto-optics, magnetization, and magneto-transport, highlighting the development of miniaturized all-plastic cryostats and custom sample holders designed for the dual extremes of cryogenic temperatures and megagauss fields. Representative physical phenomena revealed through these techniques are discussed, including quantum phase transitions in frustrated magnets, Aharonov–Bohm effects in carbon nanotubes, and semiconductor-to-metal transitions in strongly correlated systems. Furthermore, we address emerging measurement platforms such as magnetostriction, specific heat, and ultrasound velocity. Throughout this review, we emphasize the instrumentation and experimental refinements that ensure reliable data acquisition in the ultrastrong pulsed field regime. Full article

This study investigated the covalent grafting of ferulic acid (FA) onto high-amylose corn starch (HACS) through controlled moist heat treatment as a strategy to regulate starch structure and digestibility. Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (¹H NMR) analyses confirmed the formation of ester linkages between HACS and FA. Scanning electron microscopy (SEM) revealed that FA grafting induced a rougher granule surface and increased porosity, while differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) indicated altered gelatinization behavior and thermal stability. In vitro digestion analysis showed that the rapidly digestible starch content decreased from 23% to 15%, whereas the resistant starch (RS) content increased to 48% after FA grafting. Molecular docking suggested that FA could interact with α-amylase and that covalent modification may reduce enzyme accessibility to starch chains, thereby limiting starch hydrolysis. These findings demonstrate that FA grafting effectively reshapes the structural and digestive properties of HACS and provides a promising approach for developing resistant starch-rich functional food ingredients. Full article

Natural microbial pigments offer important advantages and are widely studied for food applications. We investigated the biosynthetic pathways, characteristics, and bioactivities of the orange–red pigment produced by Bacillus velezensis YM–3, a strain isolated from the traditional Pixian Douban condiment. Whole-genome sequencing revealed complete pathways for melanin, phytoene, and heme biosynthesis. The purified extracellular pigment was characterized using ultraviolet–visible spectroscopy, Fourier-transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and ultra-performance liquid chromatography–high-resolution mass spectrometry; it was preliminarily characterized as melanin-like pigment. The pigment was highly soluble in alkaline solutions, moderately soluble in water, and insoluble in common organic solvents. It exhibited strong photostability and remained stable at low temperature, precipitated under acidic conditions, and showed high stability under alkaline environments. Furthermore, the pigment demonstrated in vitro free radical scavenging activity. Hence, this study provides a scientific foundation for exploring the potential utility of B. velezensis YM–3 and its pigment metabolites as functional agents. Full article

To investigate the corrosion resistance and deterioration mechanism of cast-in situ concrete incorporating iron ore tailings aggregate (IOT), specimens with IOT replacement ratios of 0%, 30%, and 50% were exposed to distilled water, endogenous Cl⁻-SO₄²⁻ corrosion, exogenous Mg²⁺-SO₄²⁻ corrosion, and endogenous-exogenous coupled corrosion. The evolution of mass, size, compressive strength, and flexural strength was evaluated, while Nuclear Magnetic Resonance (NMR), Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS), X-ray Diffraction (XRD), and Thermogravimetric Analysis/Derivative Thermogravimetry (TG/DTG) were used to characterize pore structure and phase transformation. Results show that distilled water causes limited variation, whereas exogenous and coupled corrosion accelerate product accumulation, size expansion, pore coarsening, and strength degradation. Under exogenous Mg²⁺-SO₄²⁻ corrosion, the peak compressive strengths of specimens with 0%, 30%, and 50% IOT reach 43.30 MPa, 45.60 MPa, and 46.93 MPa, respectively, with the 50% IOT specimen showing an 8.38% increase compared with the specimen without IOT. TG/DTG results show that the Ca(OH)₂ related mass loss decreases from 5.42% under distilled water immersion to 4.37% under exogenous Mg²⁺-SO₄²⁻ corrosion, confirming calcium consumption during sulfate–magnesium attack. Microstructural characterization reveals that sulfate reaction, chloride binding, and Mg²⁺-induced decalcification jointly promote the formation of gypsum, ettringite, Friedel’s salt, magnesium silicate hydrate (M-S-H), and magnesium-associated corrosion products. Overall, 30% IOT provides better pore refinement and mechanical stability under endogenous and exogenous corrosion, whereas 50% IOT improves residual skeleton support under coupled corrosion. These findings provide guidance for durability design and sustainable utilization of IOT aggregate in cast-in situ concrete. Full article

Mitochondrial dysfunction has been increasingly implicated in the pathobiology of neurodevelopmental conditions, particularly autism and attention-deficit/hyperactivity disorder (ADHD). Because the developing brain is critically dependent on sustained ATP production, impairments in oxidative phosphorylation, mitochondrial dynamics, and redox balance may disrupt neuronal maturation, synaptic development, and neural circuit refinement during sensitive developmental periods. This review examines evidence from postmortem neurochemistry, genomics, magnetic resonance spectroscopy, and biomarker research to characterize mitochondrial impairment across autism and ADHD. Studies in autism report an elevated burden of heteroplasmic mitochondrial DNA (mtDNA) variants, along with alterations in mtDNA copy number, respiratory chain capacity, fission–fusion dynamics, and antioxidant defenses. Postmortem data demonstrate reduced activity of electron transport chain Complexes I, III, and V in the frontal cortex, temporal lobe, and cerebellum. These bioenergetic abnormalities are accompanied by elevated oxidative stress markers alongside mitochondria-mediated immune activation. In vivo neuroimaging corroborates these findings through elevated cerebral lactate and reduced phosphocreatine-to-ATP ratios. Evidence in ADHD is limited, but similarly implicates mitochondrial dysfunction, consistent with the frequent co-occurrence of these conditions and their partially shared architecture. The available literature supports mitochondrial dysfunction as a transdiagnostic biological feature of neurodevelopmental conditions, with relevance to mechanistic biomarker identification and targeted therapeutic development. Full article