Search Results (6,539)

Understanding the anisotropic mechanical behavior and pore–fracture structure (PFS) evolution of bedded coal under mining disturbance is critical for gas extraction and hazard prevention in deep coal mining. This study employed low-field nuclear magnetic resonance (NMR) and fractal analysis to characterize the PFS of water-saturated coal samples with bedding angles of 0°, 30°, 45°, 60°, and 90°. The pore system was classified into adsorption and seepage pores according to pore size distribution. Real-time triaxial NMR tests were further conducted to reveal the coupled evolution of mechanical responses and PFS under different bedding orientations. Results show that bedding inclination controls pore distribution, connectivity, and structural complexity, while influencing coal strength, deformation, and failure through stress redistribution and bedding-plane activation. The mechanical response and PFS evolution exhibit strong anisotropic coupling during loading. A fractional-order porosity model was established by incorporating bedding orientation, anisotropy, and stress memory based on pore geometry and stress decomposition. Model verification confirms its effectiveness in describing anisotropic porosity and PFS evolution under varying bedding angles. This study provides theoretical support for permeability prediction, stability assessment, and hazard control in deep-bedded coal seams. Full article

Fucoidans are sulphated polysaccharides from brown macroalgae that have attracted considerable interest due to their diverse biological activities and potential applications in metabolic health. In this study, fucoidan-rich extracts were obtained from three South African brown macroalgal species, Ecklonia maxima, Ecklonia radiata, and Sargassum incisifolium, and comparatively characterised using biochemical and physicochemical analyses. The extracts were evaluated for carbohydrate, sulphate, L-fucose, protein, polyphenol, and uronic acid contents, while molecular weight distribution, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and proton Nuclear Magnetic Resonance (¹H NMR) spectroscopy were used to investigate structural characteristics. All extracts displayed features characteristic of fucoidans, including sulphated fucose-containing polysaccharides. Notable species-dependent differences were observed, with S. incisifolium exhibiting the highest sulphate (~24%) and polyphenol (~6.76%) contents, stronger sulphate-associated FTIR signals, greater molecular weight heterogeneity, and enhanced thermal stability. The fucoidan-rich extracts exhibited concentration-dependent pancreatic lipase and α-glucosidase inhibitory activities, together with DPPH radical-scavenging activity. At 1.0 mg/mL, S. incisifolium demonstrated approximately 66% DPPH radical scavenging and 49% pancreatic lipase inhibition. S. incisifolium and E. radiata exhibited strong α-glucosidase inhibition, with IC₅₀ values of ~29 and ~46 µg/mL, respectively, compared to ~354 µg/mL for acarbose. The findings highlight South African brown macroalgae as promising sources of fucoidans and contribute to understanding the relationships among fucoidan composition, structure, and bioactivity. Full article

We describe an experimental investigation of a nuclear spin oscillator based on ³He nuclei as a possible detector to search for exotic spin couplings. A magnetically shielded vapor cell comprising an alkali atom mixture ($95\%$ potassium and $5\%$ rubidium) and ³He gas is polarized via laser light resonant with the $D_1$ transition in rubidium in the presence of a dc magnetic field. The potassium atoms and ³He nuclei are polarized via spin-exchange collisions with the polarized rubidium atoms. The nuclear spins are tipped with a magnetic field applied perpendicular to the dc magnetic field. The resulting Larmor precession of the ³He nuclear spins is monitored via Faraday rotation of laser light near resonant with the $D_1$ transition in potassium. The Faraday rotation signal is filtered, amplified, and used to apply a magnetic field in a direction perpendicular to the dc magnetic field, resulting in a self-sustained oscillation of the nuclear spins at a frequency that is directly proportional to the dc magnetic field. We demonstrate a sensitivity to exotic spin couplings that is ≈5 times higher than the alkali atom magnetometers that have been used in the Global Network of Optical Magnetometers to Search for Exotic Physics collaboration. Full article

This preliminary within-animal study focuses on the comprehensive characterization of pork jowl (PJ) by comparing it with pork belly (PB), Boston butt (BB), and spare ribs (SR) collected from the same ten castrated Duroc × Landrace × Yorkshire (DLY) pigs; headspace volatile analysis used a matched subset of six pigs. Instrumental quality, proximate composition, amino-acid and fatty-acid profiles, low-field nuclear magnetic resonance (LF-NMR) water distribution and headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GC-MS) volatile profiles were evaluated. PB exhibited the lowest shear force, hardness, and chewiness. Across the four pork cuts, crude protein content ranged from 16.87% to 18.10%, whereas crude fat content ranged from 13.03% to 22.20%. BB had the lowest crude fat content (13.03%) and relatively high protein (18.10%) and amino-acid contents. PJ showed highest content of monounsaturated fatty acids (MUFAs) and the lowest numerical atherogenic (AI) and thrombogenic indices (TI), but also the highest n-6/n-3 polyunsaturated fatty acids (PUFA) ratio. LF-NMR showed that PJ had the highest T₂₃ and P23 values, consistent with its higher cooking and centrifugal losses. Sixty-five headspace volatile compounds were tentatively identified under the standardized 80 °C HS-SPME conditions. OPLS-DA differentiated the four cuts, and ten compounds meeting the combined criteria of VIP > 1, q < 0.05, and OAV > 1 were retained as candidate discriminant aroma-relevant compounds. Overall, the four cuts exhibited distinct quality profiles: PJ combined a MUFA-rich lipid fraction with greater free-water mobility and water loss, PB showed the greatest instrumental tenderness, BB had the lowest crude fat content and relatively high protein and amino-acid contents, and SR exhibited the greatest headspace volatile abundance. The data provide a reference for cut-specific utilization of pork raw materials. Full article

Solid electrolyte interphase (SEI) characterization is needed to interpret the performance, degradation, and lifetime of graphite and Si-containing carbon-based negative electrodes in lithium-ion batteries. However, SEI claims are often difficult to compare because measured signals, inferred assignments, sample history, and electrode architecture are not always clearly separated. This review presents a claim-bounded framework for SEI characterization that distinguishes direct observables from inferred chemical, molecular, structural, morphological, and functional information. Photoelectron spectroscopy methods provide chemical-state and relative-depth-sensitivity constraints; secondary-ion mass spectrometry methods provide fragment and isotope distributions; vibrational spectroscopies support functional-group and local vibrational evidence; nuclear magnetic resonance and molecular mass spectrometry provide molecular or product-level constraints; and microscopy, tomography, and atomic force microscopy provide morphology, architecture, local thickness, topography, and mechanical response. Across these methods, rinsing, drying, sputtering, beam exposure, extraction, and limited sampling can alter the observable and therefore the defensible claim. The review emphasizes the distinction between native electrode-associated SEI features and extracted, soluble, or electrolyte-phase products, and between morphology-only evidence and chemically assigned morphology. It concludes by proposing claim-driven correlative workflows and reporting guidance for reproducible interpretation on graphite, Si/graphite, Si/C, and carbon-coated Si architectures where directly studied or present. Full article

Agrochemicals are used worldwide in food production, but their use varies between countries due to the damage observed to nature and human health. Allelopathy is the primary pathway of chemical communication in plants, interfering with biome development through stimulation and/or inhibition mechanisms. Therefore, this study aimed to assess the biological activities of the ethanol extract (EE) and fractions of S. fluminensis leaves on monocotyledonous and eudicotyledonous models. The EE was obtained by percolation with ethanol, and the hexane (HEXF), dichloromethane (DCMF), ethyl acetate (EAF), and hydroethanol (HEF) fractions were obtained by liquid–liquid partition. The phytochemical characterization was performed by ¹H nuclear magnetic resonance (NMR). The allelopathic activity was evaluated on Allium cepa (onion) and Lactuca sativa (lettuce) seeds. The cytotoxic, genotoxic, and antigenotoxic effects on A. cepa meristematic cells were analyzed in vitro. Aliphatic compounds, saponins, and flavonoids derived from quercetin and kaempferol were characterized in the samples. All samples decreased the vigor, germination rate, and germination speed index (GSI) of A. cepa seeds. In contrast, they did not alter the vigor and viability of L. sativa seeds, but decreased the GSI, except for HEF. The samples inhibited the epicotyl and root growth of A. cepa and L. sativa, except HEXF, which stimulated the growth of epicotyls (750 µg/mL) and roots (750 and 1000 µg/mL). The cytotoxic assays showed that the EE and HEXF had cytotoxic action at low concentrations, and no sample showed a genotoxic effect. The following samples exhibited an antigenotoxic effect after pretreatment with atrazine (ATZ): EE (125 and 750 µg/mL), HEXF (750 and 1000 µg/mL), DCMF (125, 250, and 1000 µg/mL), EAF (at all tested concentrations), and HEF (125, 250, and 750 µg/mL). Furthermore, the EAF at 125 and 500 µg/mL and HEF at 125 µg/mL demonstrated the potential to reverse genetic damage induced by glyphosate (GLY). Full article

Ambient fine particulate matter (PM_2.5) is associated with oxidative stress, metabolic dysregulation, and cardiometabolic disease. However, systemic metabolic responses to contrasting real-world ambient air pollution exposure environments remain poorly characterized. In this cross-sectional study, untargeted proton nuclear magnetic resonance (¹H-NMR)-based urinary metabolomics was used to investigate metabolic signatures associated with contrasting ambient air pollution exposure environments in Thailand. Adults residing in Chiang Mai (high-exposure region; n = 51) and Songkhla (low-exposure region; n = 52) were recruited during a period of elevated regional air pollution, with long-term residence serving as a proxy for differential exposure to ambient air pollution environments. Partial least squares-discriminant analysis (PLS-DA) demonstrated separation between exposure groups (R² = 0.873, Q² = 0.447), indicating good model fit but only modest predictive ability. Eight urinary metabolites differed significantly (p < 0.05), implicating pathways related to tryptophan metabolism, nucleotide metabolism, energy metabolism, and host–microbial co-metabolism. L-arginine and L-cystathionine showed lower relative abundance in the high-exposure group, and six metabolites remained significant after Benjamini–Hochberg false discovery rate correction. Following covariate adjustment, L-tryptophan, hippuric acid, xanthine, and 5-hydroxyindoleacetic acid (5-HIAA) remained significantly associated with the high-exposure group. Contrasting ambient air pollution exposure environments, indexed by regional PM_2.5 concentrations, were associated with coordinated urinary metabolic alterations. Because long-term regional residence served as a proxy for individual-level exposure and diet and lifestyle differences between regions were not fully controlled, these findings should be interpreted as associations with contrasting regional exposure environments. Metabolite annotations remain putative and require validation in longitudinal studies with comprehensive pollutant characterization and individual-level exposure assessment. Full article

Using both laboratory and field samples, this paper investigates how zeolite concentration affects the hydrological connectivity of sandy-loam soil through Fast Field-Cycling Nuclear Magnetic Resonance relaxometry. Laboratory samples (LP) were prepared using four zeolite concentrations (0, 5, 10, and 15%), while field samples (FS) were collected in plots amended with the same concentrations to investigate the differences occurring during incubation time between LP and FS. For each zeolite concentration ZC, the results demonstrated that the F(T₁) distribution of the FS systematically shifts towards the right compared to LP. This “scaling” effect between LP and FS was addressed using a dimensionless variable T₁/σ(T₁), where σ(T₁) is the standard deviation of T₁ considering the effects of pore size variability. The developed analysis demonstrated that the highest values of the structural connectivity index SCI correspond to ZC = 10% for LP, while ZC = 15% is necessary for FS, even if similar performance corresponds to ZC = 10%. Differences in the functional connectivity index (FCI) of LP and FS, which can be explained by environmental effects, were recognized. In conclusion, for sandy-loam soil, ZC = 10% is sufficient to improve the physical soil characteristics (highest values of structural connectivity) for both samples, while for FS, a ZC = 10% assures the minimum FCI values (the highest water-holding capacity). Full article

Frozen seafood plays an important role in the global food supply, but maintaining its quality during frozen storage and cold-chain distribution remains a significant challenge. Although freezing effectively slows microbial growth and enzymatic activity, it cannot completely prevent quality deterioration. During frozen storage, seafood undergoes a series of interconnected physicochemical changes, including ice crystal growth, protein denaturation and oxidation, lipid oxidation, water redistribution, and texture deterioration. These changes gradually reduce sensory quality, nutritional value, and overall commercial acceptability. Conventional quality assessment methods, including destructive laboratory analyses and sensory evaluation, are still widely used. However, they are often labor-intensive, time-consuming, and unsuitable for rapid or real-time monitoring in modern cold-chain systems. As a result, increasing attention has been given to non-destructive sensing technologies that can evaluate seafood quality quickly and objectively. This review summarizes the major mechanisms responsible for quality deterioration in frozen seafood, together with recent advances in sensing technologies used to monitor these changes. The sensing approaches discussed include near-infrared (NIR) and Raman spectroscopy, hyperspectral and fluorescence imaging, low-field nuclear magnetic resonance (LF-NMR), electronic nose (E-nose), electronic tongue (E-tongue), colorimetric sensor arrays (CSAs), and biosensors. This review also discusses the growing role of artificial intelligence in frozen seafood quality assessment, including chemometrics, machine learning, deep learning, and multi-sensor data fusion. Particular attention is given to their applications in quality prediction, industrial implementation, and decision support. Finally, current challenges and future research needs are highlighted, with emphasis on the development of interpretable, transferable, and real-time monitoring systems that can support more reliable quality assurance throughout the frozen seafood supply chain. Full article

In contrast to honeybees, the Australian stingless bee Tetragonula carbonaria appears to be robust against microbial pathogens. Streptomyces sp. 127Q, isolated from T. carbonaria, inhibited the growth of Lysinibacillus sphaericus, which is the only microorganism reported to affect T. carbonaria. The antimicrobials were purified from Streptomyces sp. 127Q by bioassay-guided isolation using ethyl acetate extraction and Diaion HP20 chromatography, followed by reverse phase HPLC fractionation. The antimicrobial compounds were identified by high-resolution mass spectrometry, UV-Vis-spectroscopy, nuclear magnetic resonance spectroscopy, and genome mining as new members of the trioxacarcin/gutingimycin family having a 1,2-dihydroxyanthraquinone aromatic core structure. A closely related gutingimycin with a 1,2-dihydroxyanthraquinone moiety was previously observed in a crystallisation experiment of trioxacarcin A with an oligonucleotide. Streptomyces sp. 127Q produces a wide range of trioxacarcins/gutingimycins. At the onset of trioxacarcins production, Streptomyces sp. 127Q appeared to rapidly convert trioxacarcin epoxides with water, guanine, and nicotinic acid. The 1,2-dihydroxyanthraquinone trioxacarcins, trioxacarcin 692 and trioxacarcin 780, inhibited L. sphaericus with minimal inhibitory concentrations (MICs) of 37.5 μM and 75 μM, respectively. The MIC against Escherichia coli and Staphylococcus aureus was 75 μM and 150 μM, respectively. In the photoantimicrobial screening, the MIC for trioxacarcin 692 against E. coli and S. aureus decreased by 8-fold, and for trioxacarcin 780 by 4-fold. Following light pretreatment, trioxacarcin 692 (9.4 μM) inhibited E. coli and S. aureus at concentrations comparable to those of the established antibiotics ciprofloxacin and vancomycin. Neisseria gonorrhoeae was only inhibited at an MIC of ca. 18.8 μM after light preincubation. The 1,2-dihydroxyanthraquinone trioxacarcins constitute powerful antimicrobial compounds belonging to the trioxacarcin/gutingimycin family. Full article

The long-term durability of concrete exposed to marine environments is governed by progressive changes in transport behavior and pore network characteristics. Concrete mixtures incorporating fly ash (FA), slag (SG), silica fume (SF), and basalt fiber (BF) were subjected to natural tidal exposure, after which gas permeability and microstructural evolution were systematically characterized using nuclear magnetic resonance (NMR). Temporal trends in gas permeability were assessed in parallel with porosity and pore size distribution (PSD) measurements. Correlation analysis was subsequently performed to identify the pore characteristics that predominantly control gas transport. All investigated admixtures reduced gas permeability, although their effectiveness varied with exposure duration. Silica fume exhibited the greatest reduction during the early exposure stage, whereas fly ash became increasingly effective over prolonged exposure. Basalt fiber also contributed to improved gas transport resistance, while slag showed a comparatively weaker influence under the investigated conditions. The incorporation of admixtures strengthened the relationships between gas permeability and pore structure parameters. Among the investigated pore characteristics, the fraction of pores within the range of 100–500 nm exhibited the strongest correlation with permeability evolution. Furthermore, critical pore diameter and median pore diameter proved to be more representative indicators of gas transport resistance than mean pore diameter. Full article

Geogenic processes and human activities are both major causes of soil pollution. Soils can get toxic transition metals from the materials they are formed from, but most pollution comes from industrial and farming activities. The presence of these transition metals in soil can be shown through changes in chemical, biochemical, and microbial properties, as well as how plants react. This research aims to remove transition metals like chromium (Cr), manganese (Mn), iron (Fe), zinc (Zn), tungsten (W), and cadmium (Cd) from soil using a boron nitride (BN) nanocage. The electromagnetic and thermodynamic properties of these metals when trapped in BN were studied using materials modeling. The metals are captured through chemisorption. The research looked at how Cr, Mn, Fe, Zn, W, and Cd are trapped by BN to detect soil metal cations. BN was designed in the presence of these transition metals. The covalent characteristics of these complexes show similar energy levels and a view of the partial density of states between the p states of boron and nitrogen in BN and the d states of Cr, Mn, Fe, Zn, W, and Cd in B(X)N complexes. Also, nuclear magnetic resonance (NMR) analysis showed clear peaks around Cr, Mn, Fe, Zn, W, and Cd when they were trapped in BN during atomic detection and removal from soil, although there were some variations in chemical shielding for isotropic and anisotropic tensors. Based on these results, the ability of BN (as an atom sensor) to adsorb toxic metals, metalloids, and nonmetals is ordered as: Cd > Zn > Fe > Cr > Mn ≈ W. This article suggests that elements absorbed by BN could be used to develop and improve the optoelectronic properties of BN, helping to create photoelectric devices for soil cleaning. Full article

Reservoir stimulation through fracturing is essential for the commercial development of unconventional oil and gas resources. Supercritical CO₂ (scCO₂) combines liquid-like density with gas-like viscosity and compressibility, enabling efficient conversion of stored energy into shock waves and jet impacts. This study introduces an innovative scCO₂ shock fracturing technique, in which a downhole pressure-control valve rapidly releases compressed scCO₂ to generate transient shock pressures that induce rock fracture initiation and propagation. A series of scCO₂ shock fracturing experiments were conducted on sandstone and shale to evaluate the influence of different impact loads on both macroscopic and microscopic damage. Rock damage evolution was characterized using computed tomography (CT), nuclear magnetic resonance (NMR), mercury intrusion porosimetry (MIP), and quantitative analysis of fracture surface morphology. The results showed that increasing shock pressure enhanced fracture surface roughness, shear slip, and particle spalling in sandstone, producing rough tensile–shear fracture surfaces with a potential self-supporting tendency. NMR results indicated that sandstone mainly exhibited a single-peak T₂ response, and scCO₂ shock loading primarily affected pores and pore-fracture spaces larger than 0.08 µm. In contrast, shale showed a broader and more heterogeneous pore-fracture response, with preferential enlargement and connection of large pore-fracture spaces. The NMR-MIP-calibrated equivalent pore-fracture diameter distribution showed that scCO₂ shock fracturing mainly promoted pore-fracture spaces larger than 0.2 μm in shale; at 40 MPa, the volume of this pore-fracture range increased by approximately 6.75 times. However, the characteristic equivalent pore-fracture diameter decreased at 45 MPa, which is attributed to severe specimen fragmentation, fragment displacement, scCO₂ escape, and energy dissipation. These findings suggest that scCO₂ shock fracturing is a promising stimulation approach for enhancing macroscopic fracturing and microscopic pore-fracture reconstruction in unconventional reservoirs. Full article

This study addresses the limitations of traditional chemical flooding in low-permeability reservoirs by developing a nanofluid–surfactant binary flooding system (Has5/iNanoW1.0 binary flooding system) and investigating its microscopic mechanisms and enhanced oil recovery performance. The size of the nanofluid–surfactant binary flooding system reduces from 250 nm to 72 nm compared with pure surfactant; therefore it can enhance the ability to inject smaller pores. Core adsorption tests reveal that the addition of nanofluid can decrease surfactant adsorption by over 30%. The nanoscale synergistic effect of nanofluid (iNanoW1.0) and surfactant (Has5) and lower adsorption of surfactant allows more surfactant (Has5) to enter smaller pores for oil washing, significantly increasing oil recovery performance. Low-field nuclear magnetic resonance displacement experiments show that the binary system can significantly expand microscopic sweep efficiency (up to 14.9%) compared to pure surfactant or nanofluid flooding. Core flooding tests confirm that the binary system exhibits lower injection pressure (0.377 MPa), achieving 13.12% incremental oil recovery during post-water flooding, which is significantly better than the pure surfactant system (5.11%). The results demonstrate strong laboratory-scale potential and permit further pilot-scale evaluation. Full article

The structural and immunomodulatory properties of arabinogalactan proteins (AGPs) from edible medicinal plants remain largely unexplored. Here, A homogenous AG-II-like arabinogalactan protein (CTSP-W2, 9862 Da) was isolated from Cynanchum thesioides via hot-water extraction, ethanol precipitation, and column chromatography. Its structure was thoroughly characterized by high-performance gel permeation chromatography (HPGPC), Fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), Congo-red, scanning electron microscopy (SEM), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), methylation analysis. The mechanism of immune activity was examined using specific inhibitors, Western blotting, and molecular docking. It comprises galactose, arabinose, glucose, galacturonic acid, xylose, and 18 amino acids (asparagine-rich), with a backbone of →3,6)-Galp-(1→ and →6)-Galp-(1→. CTSP-W2 significantly enhanced macrophage proliferation, phagocytosis, and secretion of Nitric oxide (NO), Tumor necrosis factor-alpha (TNF-α), and Interleukin-6 (IL-6). Inhibitor assays showed that Toll-like receptor 4 (TLR4, TAK-242) and Toll-like receptor 9 (TLR9, E6446) antagonists markedly reduced CTSP-W2-induced TNF-α, IL-6, and NO in a dose-dependent manner, whereas Toll-like receptor 2 (TLR2) inhibition (C29) unexpectedly upregulated these mediators. Western blot revealed that CTSP-W2 upregulated TLR4 and TLR9 protein expression and increased phosphorylation of Inhibitor of nuclear factor kappa-B alpha (IκBα), nuclear factor kappa B (NF-κB p65), and p38, indicating activation of the TLR4/9–NF-κB–p38 mitogen-activated protein kinase (MAPK) signaling axis. Furthermore, Molecular docking analysis further indicated that CTSP-W2 forms extremely strong hydrogen-bonding and hydrophobic interactions with TLR4 through its galactose chains. This study elucidates the immunoregulatory mechanism of CTSP-W2 and establishes a molecular basis for arabinogalactan proteins as potential natural immunomodulators. Full article