Search Results (1,849)

The surface chemistry of biochar plays a pivotal role in the adsorption and stabilization of soil organic carbon (SOC); however, sorption-mediated mechanisms remain insufficiently understood for biochars derived from invasive plants. In this study, Solanum rostratum biomass, an aggressive invasive weed in northern China, was pyrolyzed at 400–600 °C in 2023 to produce biochars with varying surface functionalities and structural features. FTIR, Raman, XPS, and SEM analyses revealed that increasing pyrolysis temperature led to decreased oxygen-containing functional groups and enhanced aromatic condensation, reflecting a transition from hydrogen bonding to π–π and hydrophobic sorption mechanisms. Soil incubation experiments using sandy loam soil showed that biochar produced at 500 °C significantly increased the stable carbon pool (SCP) to 52.4%, compared to 30.6% in unamended soils. It also reduced cumulative CO₂ release from 1.74 mg g⁻¹ to 1.21 mg g⁻¹ soil, indicating improved carbon retention. Bacterial 16S rRNA gene sequencing revealed that biochar amendments significantly altered community composition and increased deterministic assembly, particularly under 500 °C biochar, suggesting a sorption-driven niche filtering effect. These findings demonstrate that S. rostratum-derived biochar, especially at intermediate pyrolysis temperatures, enhances both carbon sequestration and microbial habitat structure. This has direct implications for improving degraded soils in arid farming regions, offering a dual strategy for invasive biomass management and climate-resilient agriculture. Full article

Patulin (PAT) is a fatal mycotoxin that exerts serious threats to human and animal health. Biodegradation of PAT is considered to be one of the promising ways for controlling its contamination. In this study, Lactiplantibacillus plantarum 6076 (LP 6076) with reliable removal efficiency on PAT was screened out from three lactic acid bacteria (LAB) strains. It was found that the PAT was eliminated through degradation by LP 6076, and the intracellular proteins played a crucial role in PAT degradation with the induction of PAT. The proteomic analysis showed that the response of LP 6076 to PAT was by a concerted effort to repair DNA damage, in parallel to adaptive changes in cell wall biosynthesis and central metabolism. Eleven differentially expressed proteins with high fold changes were picked out and identified as PAT degradation candidate enzymes. The 3D structures of the candidate enzymes were predicted, and molecular docking between the enzymes and PAT was performed. Five enzymes, including Acetoin utilization AcuB protein (AU), GHKL domain-containing protein (GHLK), Dihydroneopterin aldolase (DA), YdeI/OmpD-associated family protein (YDEL), and Transcription regulator protein (TR), could dock with PAT with lower affinity and shorter distance. Through molecular docking analysis, DA was ultimately identified as a potential key degrading enzyme. The choice of DA was substantiated by its superior combination of strong binding affinity and a productive binding pose with PAT. VAL84 and GLN51 residues of DA were likely the active sites, forming four hydrogen bonds with PAT. Our study could accelerate the commercial application of biodegradation toward PAT decontamination. Full article

Quercetin’s therapeutic potential is limited by its poor water solubility and rapid degradation. Natural clay minerals such as kaolinite present sustainable platforms for drug delivery, yet the molecular mechanisms of drug encapsulation are not fully understood. Specifically, the role of kaolinite’s structural polarity, its hydrophilic aluminol (001) and hydrophobic siloxane (00-1) basal surfaces, in selective drug adsorption remains unexplored. This study combines Monte Carlo sampling and Density Functional Theory (DFT) to provide the first quantitative, atomistic comparison of quercetin adsorption on both kaolinite surfaces. The results demonstrate a pronounced polarity-driven selectivity. Strong, exothermic adsorption (−206.65 kJ mol⁻¹) occurs on the hydrophilic (001) surface, stabilized by a network of five hydrogen bonds. In contrast, the hydrophobic (00-1) surface exhibits significantly weaker sorption (−147.16 kJ mol⁻¹), dominated by van der Waals interactions. Charge-transfer analysis shows that the hydrophilic (001) surface exhibits a net charge transfer of −0.198 e, approximately 2.4 times greater than that of the hydrophobic (00-1) surface (−0.083 e), consistent with differential electron density maps and partial density of states. By linking hydrogen bonding and charge transfer to adsorption energy, these results elucidate how surface polarity dictates drug encapsulation. This work establishes a predictive framework for designing kaolinite-based nanocarriers with optimized stability, bioavailability, and controlled release, guiding the development of sustainable drug delivery systems. It is noted that this DFT study models adsorption at 0 K using periodic slab models in a vacuum. Full article

This review explores the variety of diamond-based sensing applications, emphasizing their material properties, such as high Young’s modulus, thermal conductivity, wide bandgap, chemical stability, and radiation hardness. These diamond properties give excellent performance in mechanical, pressure, thermal, magnetic, optoelectronic, radiation, biosensing, quantum, and other applications. In vibration sensing, nano/poly/single-crystal diamond resonators operate from MHz to GHz frequencies, with high quality factor via CVD growth, diamond-on-insulator techniques, and ICP etching. Pressure sensing uses boron-doped piezoresistive, as well as capacitive and Fabry–Pérot readouts. Thermal sensing merges NV nanothermometry, single-crystal resonant thermometers, and resistive/diode sensors. Magnetic detection offers FeGa/Ti/diamond heterostructures, complementing NV. Optoelectronic applications utilize DUV photodiodes and color centers. Radiation detectors benefit from diamond’s neutron conversion capability. Biosensing leverages boron-doped diamond and hydrogen-terminated SGFETs, as well as gas targets such as NO₂/NH₃/H₂ via surface transfer doping and Pd Schottky/MIS. Imaging uses AFM/NV probes and boron-doped diamond tips. Persistent challenges, such as grain boundary losses in nanocrystalline diamond, limited diamond-on-insulator bonding yield, high temperature interface degradation, humidity-dependent gas transduction, stabilization of hydrogen termination, near-surface nitrogen-vacancy noise, and the cost of high-quality single-crystal diamond, are being addressed through interface and surface chemistry control, catalytic/dielectric stack engineering, photonic integration, and scalable chemical vapor deposition routes. These advances are enabling integrated, high-reliability diamond sensors for extreme and quantum-enhanced applications. Full article

Polyester fibers are extensively used in textiles, packaging, and industrial applications due to their durability and excellent mechanical properties. However, high-crystallinity polyester fibers represent a major challenge in plastic waste management due to their resistance to biodegradation. This study evaluated the biodegradation potential of environmental Bacillus isolates, obtained from mold-contaminated black bean plastic bags, toward polyethylene terephthalate (PET) and industrial-grade polyester fibers under mesophilic conditions. Among thirteen isolates, five (Bacillus altitudinis N5, Bacillus subtilis N6, and others) exhibited measurable degradation within 30 days, with mass losses up to 5–6% and corresponding rate constants of 0.04–0.05 day⁻¹. A combination of complementary characterization techniques, including mass loss analysis, scanning electron microscopy (SEM), gel permeation chromatography (GPC), and gas chromatography/mass spectrometry (GC/MS), together with Fourier-transform infrared spectroscopy (FTIR), thermogravimetric/differential scanning calorimetry (TGA/DSC), and water contact angle (WCA) analysis, was employed to evaluate the biodegradation behavior of polyester fibers. Cross-analysis of mass loss, surface morphology, molecular weight reduction, and degradation products suggests a surface erosion-dominated degradation process, accompanied by ester-bond hydrolysis and preferential degradation of amorphous regions. FTIR, TGA/DSC, and WCA analyses further reflected chemical, thermal, and surface property changes induced by biodegradation rather than directly defining the degradation mechanism. The findings highlight the capacity of mesophilic Bacillus species to partially depolymerize polyester fibers under mild environmental conditions, providing strain resources and mechanistic insight for developing low-energy bioprocesses for polyester fiber waste management. Full article

Ochratoxin A (OTA), a fungal secondary metabolite, is frequently detected in grains, herbal products, and other agricultural commodities, posing potential food safety risks. Among existing detoxification strategies, biological degradation is considered both specific and environmentally sustainable. In this study, a novel OTA-degrading bacterium, Brevibacillus parabrevis S09T2, was isolated from soil using OTA as the sole carbon source. The strain exhibited no hemolytic activity and carried no virulence or antibiotic resistance genes, indicating a favorable safety profile. S09T2 efficiently degraded OTA, removing over 93% of 5–8 μg/mL OTA within 24 h at 37 °C, and almost completely degrading OTA concentrations up to 10 μg/mL within 72 h. UPLC-HRMS analysis identified ochratoxin α (OTα) and phenylalanine as the only degradation products, confirming detoxification via amide bond hydrolysis. The intracellular enzyme responsible for this reaction displayed notable thermostability, achieving near-complete degradation of 1 μg/mL OTA at 50 °C within 6 h. Moreover, the cell lysate significantly reduced OTA levels in Plumeria rubra extract, a widely consumed functional food, demonstrating applicability in complex food matrices. Collectively, these findings highlight S09T2 as a promising candidate for OTA detoxification and support its potential use in food and feed safety applications. Full article

Antibiotics have become an integral part of human life and production. The presence of sulfachloropyridazine (SCP), one of the most ubiquitous antibiotics, in water has been a growing concern owing to its long persistence and the difficulty in removing it by conventional water treatment processes. This study introduced ozone (O₃)-activated sodium percarbonate (SPC) as an innovative technique of advanced oxidation processes (AOPs), and the degradation of SCP from water by this method was thoroughly investigated. The impact of a variety of parameters, such as the dosage of SPC, the dosage of O₃, the pH value, and water matrix constituents, on the removal of SCP was evaluated with regard to the pseudo-first-order kinetic model. It was found that the removal effectiveness of SCP improved initially and then decreased with the rising dosage of SPC, with an optimal SPC dose achieved at 20 mg/L. Moreover, •OH, ${\mathrm{O}}_2^{•-}$ and ¹O₂ played important roles during SCP degradation based on radical quenching tests and electron paramagnetic resonance (EPR) tests. The SCP degradation pathways were predicted using density functional theory (DFT), which primarily involves the cleavage of S-C or S-N bonds and Smiles-type rearrangements, accompanied by hydroxylation. Furthermore, the toxicity of degradation intermediates was evaluated by the ECOSAR 1.1 software in terms of acute toxicity and chronic toxicity, and most of them exhibited lower levels of toxicity. The results can expand the research scope of SPC and reveal significant insights for SPC’s application in controlling antibiotic contamination. Full article

In fixed orthodontic treatment, brackets are orthodontic attachments bonded to the tooth enamel, and their placement and removal may affect the underlying enamel surface. Enamel degradation is a critical factor for oral health, as it reduces the mechanical strength of teeth and increases susceptibility to caries and erosion. Accurate diagnosis of enamel changes is therefore essential for the evaluation of preventive and restorative treatments. In this study, enamel degradation was investigated via two integrated methods: energy-dispersive X-ray spectroscopy (EDS) and surface roughness measurement. The experimental protocol was performed in three stages: before bracket bonding, after bracket removal, and after applying a remineralization treatment. The experimental design included a repeated-measures structure, with stage (baseline, post-debonding, post-remineralization) as the within-tooth factor and bracket type (sapphire vs. metallic) as the between-tooth factor. Given the violation of the variance homogeneity assumption, group comparisons were ultimately performed using Welch ANOVA followed by Games–Howell post hoc tests, with Bonferroni-adjusted values used for pairwise comparisons. The presence of orthodontic brackets can influence enamel mineralization because the bonding and debonding procedures modify the enamel surface microtopography. These procedures can generate microcracks and surface irregularities, which may affect mineral exchange between enamel and the surrounding environment. In our study, bracket removal led to a significant decrease in the mean atomic percentages of Ca (from 32.65% to 16.37% for sapphire) and P (from 16.35% to 8.60% for sapphire), accompanied by a sharp increase in surface roughness. After remineralization, Ca and P levels increased, while roughness decreased. However, neither the mineral content nor the surface topography fully returned to the initial values, indicating that remineralization achieved only a partial recovery of enamel integrity. These findings highlight that the integrated EDS approach and roughness analysis offer a promising descriptive framework for assessing enamel degradation and monitoring the effectiveness of remineralization therapies. The generated mathematical model provides a powerful descriptive framework for the in vitro data obtained, correlating roughness with mineral composition and treatment stage. However, such a high goodness-of-fit (R² > 0.98) should be interpreted cautiously due to the risk of overfitting. Therefore, rigorous external validation is mandatory before this model can be considered a reliable predictive tool. It also highlights the importance of enamel remineralization therapies after orthodontic treatment, but also the importance of choosing personalized treatment strategies adapted to the enamel type. Full article

Background: Oral insulin improves compliance and convenience in patients with diabetes who require regular needle injections. However, the clinical application of oral insulin preparations has been limited due to instability and inefficient permeation through the gastrointestinal tract. In this study, a novel cationic polysaccharide nanodrug delivery platform was designed for efficient oral insulin delivery. Methods: The innovative thiolated trimethyl chitosan-grafted β-cyclodextrin (NCT) was synthesized by utilizing N-trimethyl chitosan (TMC) as the polymer backbone. This involved modifying TMC with thiol group-containing N-acetylcysteine and carboxymethyl-β-cyclodextrin that possesses hydrophobic cavities via an amide condensation reaction. Subsequently, this polymer was employed to construct the NCT nanoparticle system using an ionic cross-linking method. The physicochemical properties of the NCT nanoparticles were systematically analyzed, and their therapeutic efficacy was comprehensively evaluated in streptozotocin (STZ)-induced animal models. Results: The NCT nanoparticles demonstrated mucus adhesion, permeability, and pH sensitivity, which facilitated a slow and controlled release within the gastrointestinal microenvironment due to both ionic electrostatic interactions and disulfide bonding interactions. The experiments revealed in vivo that insulin/NCT nanoparticles extended the retention time of insulin in the small intestine. Blood glucose levels decreased to approximately 39% of the initial level at 5 h post-administration while exhibiting smooth hypoglycemic efficacy. Simultaneously, insulin bioavailability increased to 12.58%. Conclusions: The NCT nanoparticles effectively protect insulin from degradation in the gastrointestinal microenvironment while overcoming intestinal barriers, thereby providing a promising approach to oral biomolecule delivery. Full article

Multifunctional hydrogels with an interpenetrated network structure have shown great potential for biomedical and tissue-regeneration applications. In this work, the biomedical hydrogel was fabricated with an interpenetrated network based on dopamine grafted gelatin (DA-Gel), and genipin crosslinked quaternary ammonium chitosan (QCS), incorporating epigallocatechin gallate (EGCG). The EDC/NHS and Schiff-base bond connections occurred in the hydrogels, as confirmed by Fourier-transform infrared (FT-IR) analysis. The properties of the fabricated hydrogels, including microstructure, degradation rate, adhesive strength, mechanical strength, and rheological behavior, can be regulated by adjusting the DA-Gel/QCS ratio or by using different crosslinking approaches. In addition, the fabricated hydrogels exhibited self-healing properties and strong adhesion to various materials and organs. Furthermore, the hydrogels performed good antibacterial activity against the typical bacteria, Escherichia coli and Staphylococcus aureus. EGCG encapsulated hydrogels displayed excellent antioxidant activities and good hemocompatibility. The hydrogels also demonstrated excellent cytocompatibility and good cell migration ability. The above results provide a facile approach to fabricate the biomedical hydrogels with a regulated network structure and multifunctional characteristics with potential in biomedical applications. 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

Silica-rich dust intrusion is a persistent challenge for lubrication systems in agricultural machinery, where abrasive third-body particles can accelerate wear and shorten component service life. Here, molecular dynamics simulations are employed to elucidate how SiO₂ nanoparticle contamination degrades polyalphaolefin (PAO) boundary lubrication at the atomic scale. Two confined sliding models are compared: a pure PAO film and a contaminated PAO film containing 7 wt% SiO₂ nanoparticles between crystalline Fe substrates under a constant normal load and sliding velocity. The contaminated system exhibits a higher steady-state friction force, faster lubricant film disruption and migration, and consistently higher interfacial temperatures, indicating intensified energy dissipation. Substrate analyses reveal deeper and stronger von Mises stress penetration, increased severe plastic shear strain, elevated Fe potential energy associated with defect accumulation, and reduced structural order. Meanwhile, PAO molecules store more intramolecular deformation energy (bond, angle, and dihedral terms), reflecting stress concentration and disturbed shear alignment induced by nanoparticles. These results clarify the multi-pathway mechanisms by which abrasive SiO₂ contaminants transform PAO from a protective boundary film into an agent promoting abrasive wear, providing insights for designing wear-resistant lubricants and improved filtration strategies for particle-laden applications. Full article

The growing demand for biodegradable and functional packaging has driven research toward polysaccharide-based materials with improved performance. In this study, sodium alginate films were modified using natural deep eutectic solvents (NADES) and acorn polyphenolic extract to enhance their antimicrobial, mechanical, and thermal properties. The films were acquired by solvent casting and characterized through mechanical, spectroscopic, thermal, and microbiological analyses. Both NADES and the polyphenolic extract enhanced tensile strength and flexibility through additional hydrogen bonding within the alginate network, while the extract also introduced antioxidant functionality. Among all tested formulations, the A4E2 film exhibited the most balanced performance. FTIR spectra revealed hydrogen bonding between the film components, and thermogravimetric analysis showed an approximately 15 °C (F-EXT) and 20 °C (F-DES) shift in the main DTG degradation peak, indicating enhanced thermal stability. Controlled-release experiments demonstrated the gradual diffusion of phenolic compounds in aqueous, acidic, and fatty simulants, with an initial release phase within the first 6 h followed by sustained release up to 48 h, confirming the films’ suitability for various food environments. The combined modification reduced the growth of Escherichia coli and Staphylococcus aureus by 30–35%, with inhibition zone diameters reaching 27.52 ± 2.87 mm and 25.68 ± 1.52 mm, respectively, evidencing synergistic antimicrobial activity. These results highlight the potential of NADES- and extract-modified alginate films as sustainable materials for active food packaging applications. Full article

The deterioration of concrete hydraulic structures caused by chemical factors, seepage, and environmental stress necessitates advanced protective coatings that enhance durability, flexibility, and environmental sustainability. Conventional protective systems often exhibit limited durability under combined hydraulic, thermal, and chemical stress. In this study, a novel polyfluorosilicone-based coating system is presented, which integrates a deep-penetrating nano-primer for substrate reinforcement, a crack-bridging polymer intermediate layer for impermeability, and a polyfluorosilicone topcoat providing UV and weather resistance. The multilayer architecture addresses the inherent trade-offs between adhesion, flexibility, and durability observed in conventional waterproofing systems. Informed by a mechanistic study of interfacial adhesion and failure modes, the coating exhibits outstanding high mechanical and performance characteristics, including a mean pull-off bond strength of 4.56 ± 0.14 MPa for the fully cured triple-layer coating system, with cohesive failure occurring within the concrete substrate, signifying a bond stronger than the material it protects. The system withstood 2.2 MPa water pressure and 200 freeze–thaw cycles with 87.2% modulus retention, demonstrating stable mechanical and environmental durability. The coating demonstrated excellent resilience, showing no evidence of degradation after 1000 h of UV aging, 200 freeze–thaw cycles, and exposure to alkaline solutions. This water-based formulation meets green-material standards, with low volatile organic compound (VOC) levels and minimal harmful chemicals. The results validate that a multi-scale, layered design strategy effectively decouples and addresses the distinct failure mechanisms in hydraulic environments, providing a robust and sustainable solution. Full article

The structural application of Fiber-Reinforced Polymers (FRP) is significantly hindered by their inherent thermal sensitivity. This paper presents a comprehensive review of the fire performance of FRP materials and FRP-concrete systems, spanning from material-scale degradation to structural-scale response. Distinct from previous studies, this review explicitly distinguishes between the fire behavior of internally reinforced FRP-reinforced concrete members and externally applied systems, including Externally Bonded Reinforcement (EBR) and Near-Surface Mounted (NSM) techniques. The thermal and mechanical degradation mechanisms of FRP constituents—specifically reinforcing fibers and polymer matrices—are first analyzed, with a focused discussion on the critical role of the glass transition temperature T_g. A detailed comparative analysis of the pros and cons of organic (epoxy-based) and inorganic (cementitious) binders is provided, elaborating on their respective bonding mechanisms and thermal stability under fire conditions. Furthermore, the effectiveness of various fire-protection strategies, such as external insulation systems, is evaluated. Synthesis of existing research indicates that while insulation thickness remains the dominant factor governing the fire survival time of EBR/NSM systems, the irreversible thermal degradation of polymer matrices poses a primary challenge for the post-fire recovery of FRP-reinforced structures. This review identifies critical research gaps and provides practical insights for the fire-safe design of FRP-concrete composite structures. Full article