Search Results (11,773)

Microplastics (MPs) are emerging contaminants that have been detected in human blood and tissues, raising concerns regarding systemic exposure and potential health effects. Internal MP burden mitigation techniques, nevertheless, are yet largely unexplored. We evaluated whether oral administration of chitosan derived from Procambarus clarkii (PCC) could reduce circulating MPs in humans via gastrointestinal sequestration in this pilot-controlled study. 11 healthy adults received PCC supplementation (0.8 g/day) for 15 days, while 10 matched controls received a placebo. Using stereomicroscopy, scanning electron microscopy (SEM), and micro-Fourier transform infrared spectroscopy (µFTIR), blood MP concentrations were quantified and characterised according to size, shape, and polymer type. At baseline, MPs were found in every subject. Following PCC supplementation, mean MP concentrations decreased from 1.84 ± 0.28 µg/mL to 1.34 ± 0.20 µg/mL (−26.3%, p < 0.01, paired analysis). The control group observed no significant differences. While polymer-resolved analysis consistently indicated reductions across major polymer classes, size-resolved analysis indicated preferential reductions in intermediate particle fractions (11–50 µm). The circulating MPs’ estimated mean residence time (MRT) was 58 ± 28 days. These findings provide preliminary evidence that chitosan-based gastrointestinal sequestration could potentially reduce the systemic MP burden in humans. Full article

Green synthesis of gold nanoparticles is an effective approach to create biocompatible nanomaterials. In this study, gold nanoparticles (BC-AuNPs) were prepared by reducing chloroauric acid with black corncob (BC) extract at relatively low temperatures. The optimal preparation conditions were obtained through a single-factor experiment, which included 5 mL of black corncob extract and 0.12 mL of 3% HAuCl₄ solution at a pH of 5.0, and the reaction was carried out at 50 °C in a water bath for 3 h. The prepared BC-AuNPs were characterized by ultraviolet–visible (UV-Vis) spectroscopy, Fourier-transform infrared (FTIR) analysis, transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), dynamic light scattering (DLS), and Zeta-potential measurement, which showed that they were dispersed spherical particles with an average size of approximately 23.0 nm and their surfaces were covered with various black corncob active components. The photothermal performance test indicated a good photothermal effect with a conversion efficiency of 41.3%. Antibacterial experiments revealed that BC-AuNPs had excellent antibacterial activity. The minimum inhibitory concentrations (MICs) for E. coli and Salmonella were 25.00 and 50.00 µg/mL, respectively. Overall, this study proved a potential application for gold nanoparticles in photothermal antibacterial fields. Full article

To enhance the interfacial bonding between bamboo and the polymer matrix in natural fiber composites (NFCs), vacuum heat treatment was applied to moso bamboo strips at temperatures ranging from 140 to 180 °C with holding times of 4 and 6 h. The effects of treatment conditions on the surface characteristics and chemical composition of bamboo were systematically investigated. Scanning electron microscopy (SEM), contact angle measurements, and Fourier transform infrared spectroscopy (FTIR) were employed to evaluate the changes in microstructure, surface wettability, and the main functional groups including α-cellulose, hemicellulose, and lignin. The results indicate that the severity of heat treatment (temperature–time combination) significantly influences the physicochemical properties of bamboo. Hemicellulose, which exhibited the lowest thermal stability, underwent pronounced degradation above 140 °C and showed the most substantial compositional variation. Although the relative contents of α-cellulose and lignin increased with increasing treatment severity, their absolute contents decreased. The vacuum environment was found to retard the degradation of α-cellulose to some extent. At 180 °C, severe disruption of the cell wall structure was observed, accompanied by the deformation and collapse of cell lumens. In addition, heat treatment increased the surface contact angle, indicating enhanced hydrophobicity, with temperature exerting a more pronounced effect than treatment time. FTIR analysis revealed a marked reduction in the intensity of the C=O stretching vibration of hemicellulose (~1730 cm⁻¹) and the O–H stretching vibration (~3400 cm⁻¹), while the aromatic structure of lignin remained relatively stable. Overall, vacuum heat treatment effectively enhanced the surface hydrophobicity of bamboo, providing a theoretical basis and technical support for the development of bamboo-reinforced natural fiber composites. Full article

Insufficient oxidative capacity can limit humification during municipal sludge composting. This study comparatively evaluated two Fenton-like amendment systems, a homogeneous copper-based treatment (CH) and a heterogeneous nano-iron-based treatment (NFH), for their effects on composting performance, humification-related indices, spectroscopic characteristics, and bacterial community succession. Both amended treatments improved composting performance relative to the control, reaching higher peak temperatures (68.5 °C for CH and 70.3 °C for NFH) and prolonging the thermophilic phase. NFH also showed stronger moisture removal, with the final moisture content decreasing to 58.1%, compared with 65.1% in CH and 64.1% in the control. CH showed the highest apparent humic acid accumulation (1173 mg kg⁻¹), whereas NFH exhibited spectroscopic features commonly associated with lower E₄/E₆ ratios and more pronounced humic-like fluorescence characteristics. Ultraviolet–visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), and excitation–emission matrix fluorescence spectroscopy (EEM) analyses collectively indicated progressive transformation toward more aromatic and humified organic matter in the amended treatments. Bacterial community succession also differed across treatments, and several enriched taxa, including Rhodanobacter and Thermobifida, showed positive associations with reactive oxygen species (ROS)-related variables and humification indices. These results describe treatment-linked dynamics in humification and suggest corresponding changes in microbial succession during sludge composting, with potential implications for process outcomes. Full article

The purpose of this study was to examine the utilization of 0–45 μm aluminum hydrate fraction (gibbsite) manufactured by Alum SA Tulcea, as a precursor in the hydrothermal synthesis process of nanosize boehmite from gibbsite suspensions. Furthermore, the use of the produced material as adsorbent of lanthanum (III) ions was investigated using aqueous solutions. Thermogravimetric analysis (TG), Fourier Transform InfraRed Spectroscopy (FT-IR), Wide-Angle X-Ray Scattering (WAXS), and atomic force microscopy (AFM) were used to demonstrate the preparation of the required material. Additionally, the material point of zero charge (pHpzc) and material specific surface (using BET approach) were evaluated. By conducting adsorption studies, the specific parameters for the lanthanum adsorption process were evaluated. The effects of pH, the ratio of adsorbent material to La(III) quantity from aqueous solution, contact time, and La(III) initial concentration were also assessed. Based on the obtained experimental data, it was proved that the maximum adsorption capacity of 97.7 mg/g was obtained for a solid:liquid ratio = 0.1 g:25 mL, pH between 3 and 6, temperature of 298 K, and contact time of 90 min. The studied adsorption process is most effectively described by the Sips model, suggesting an intricate interaction among the adsorbent material and La (III) ions. The prepared adsorbent exhibited a good desorption capacity (higher than 93%) when 20% HCl was used for desorption. Full article

The Iulia Felix is a 2nd-century AD Roman shipwreck that was discovered off the coast of Grado in 1986. Following its recovery, the hull was dismantled and treated with high concentrations of PEG 4000 at elevated temperatures. This process was completed in 2003. The elements were then stored for over 20 years. During this prolonged storage period, salt efflorescence developed on some surfaces, raising concerns about ongoing degradation and prompting an investigation into the composition of the wood and how environmental conditions influence it. The efflorescence was analysed using scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), X-ray powder diffraction (XRPD) and Fourier transform infrared spectroscopy (FTIR). To evaluate the impact of environmental factors, samples were exposed to controlled humidity levels of 35% and 85% until equilibrium was achieved. The analyses identified iron- and sulphur-based compounds, including hydrated ferrous sulphates, calcium sulphate and hydrated iron oxides. These findings suggest a corrosion-related degradation process that originates in a marine burial environment and progresses in humid, oxygen-rich conditions after recovery. The presence of PEG within the efflorescence indicates that environmental conditions after treatment promoted its gradual migration to the surface. Climate testing revealed that PEG 4000 significantly reduced hygroscopic exchange with the environment. Under dry conditions, dimensional changes were minimal, with less than 1% variation in mass and surface area. In contrast, prolonged exposure to high humidity resulted in a 11% increase in mass due to moisture uptake, as well as a roughly 5% increase in surface area. This was accompanied by minor cracking and, in some cases, structural failure. This study highlights the long-term conservation challenges posed by waterlogged archaeological wood treated with high-molecular-weight PEG. It emphasises the importance of continuous environmental monitoring to mitigate degradation processes and preserve structural integrity, providing valuable insights for future museum conservation strategies. Full article

Carbon dots (CDs), including carbon quantum dots (CQDs), are ultra-small carbon-based nanomaterials, typically below 10 nm, with tunable photoluminescence, high aqueous dispersibility, favorable biocompatibility, low toxicity, and abundant surface functional groups. These properties make CDs promising multifunctional platforms for nanomedicine, particularly in bioimaging, biosensing, targeted drug/gene delivery, photodynamic therapy (PDT), photothermal therapy (PTT), antimicrobial treatment, and theranostic applications. This review critically examines recent advances in CD fabrication, including top-down, bottom-up, green biomass-derived, microwave-assisted, hydrothermal, and emerging hybrid strategies, with emphasis on how precursor selection, heteroatom doping, surface passivation, and polymer/ligand functionalization regulate optical performance, biological interaction, and therapeutic efficiency. The review discusses structural classification, including CQDs, graphene quantum dots (GQDs), carbon nanodots, and carbonized polymer dots (CPDs), together with major characterization approaches such as ultraviolet–visible (UV–Vis) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and high-resolution transmission electron microscopy (HRTEM). Particular attention is given to red/near-infrared (NIR) emission, renal clearance, drug-loading behavior, reactive oxygen species (ROS) generation, toxicity mechanisms, biodistribution, and long-term biosafety. This review also highlights key translational barriers, including batch-to-batch variability, limited standardization, scalable manufacturing, regulatory uncertainty, and incomplete pharmacokinetic evaluation. It considers artificial intelligence (AI) and machine learning (ML) as emerging tools for reproducible CD design. CDs represent versatile and clinically promising nanoplatforms, but their translation requires standardized synthesis, rigorous safety assessment, and application-specific regulatory validation. Full article

People suffering from gout and hyperuricemia have limited consumption of soy products because of their high purine content, even though soybean is a nutrient-rich crop. This study developed a combined purine reduction process: ultrasonic-assisted soaking to promote purine dissolution and isoelectric point precipitation to separate purines with minimal protein loss. A high-performance liquid chromatography (HPLC) method for rapid purine determination was first established (R² > 0.9999, RSD < 0.23%), thereby providing technical support for process optimization. Using soybean powder as the raw material, optimal ultrasonic conditions (58 °C, 250 W, 58 min) were identified, achieving a purine removal rate of 61.15% with a protein recovery of 94.23%. Scanning electron microscopy (SEM) and Fourier-transform infrared (FTIR) spectroscopy analyses revealed that ultrasonic treatment altered the microstructure of the soybean powder, thereby facilitating purine dissolution. Low-purine soymilk prepared from the resulting soybean powder exhibited a unique flavor, with enhanced electronic nose response signals of its flavor compounds. This process effectively reduces purine content while preserving soy protein and flavor, offering a feasible technical solution for the development and industrial application of low-purine soy products. However, challenges remain in process scale-up and in optimizing the balance between purine removal and nutrient retention. Full article

The increasing prevalence of drug-resistant microorganisms has prompted research into novel antimicrobial compounds, with 2-thiophene carboxylic acid thiourea derivatives showing promise for future therapeutic applications. However, the poor water solubility of these compounds limits their practical use. This study investigates the formation and characterization of inclusion complexes between 2-hydroxypropyl-β-cyclodextrin (HPβCD) and 2-thiophene carboxylic acid-halogenated (chlorine-, bromine-, and iodine-) thiourea derivatives, seeking to improve their physicochemical properties. The dynamic light scattering (DLS) measurements and UV-Vis spectroscopy provided information related to thiourea–HPβCD aggregates and stoichiometry. Solid-state inclusion compounds and physical mixtures were prepared in two different molar ratios (thioureas:HPβCD = 1:1 and 1:2), and the morphology of the resulting powders was observed by scanning electron microscopy (SEM). Thermogravimetry (TG) and differential scanning calorimetry (DSC) (TG-DSC) coupled analysis were used to analyze thermal profiles in the temperature range of 25 °C to 600 °C, while the spectral data obtained by Fourier transform infrared spectroscopy (FTIR) provided the characteristic vibrational bands of the pure guest molecules and data corresponding to the structural and chemical changes in the host–guest systems. The structural and thermal analyses revealed significant interactions between the host and thioureas molecules, with evidence of possible interactions involving two cyclodextrin molecules. The results demonstrate the presence of intermediate stoichiometry in the inclusion compounds, with possible enhancement of the therapeutic potential of these thiourea derivatives. Full article

Biochar produced from natural organic waste has attracted considerable attention as a promising resource for odor control due to its porous structure. In this study, the potential application of commercially available biochar as an adsorbent for ammonia (NH₃) and hydrogen sulfide (H₂S) removal was investigated. Among the tested samples, HT800 biochar pyrolyzed at 800 °C exhibited the highest adsorption capacity, showing superior performance compared to conventional activated carbon. Surface modification produced contrasting effects on the adsorption efficiencies of activated carbon and biochar, with ferrate-modified biochar demonstrating the highest adsorption performance. Fourier transform infrared spectroscopy (FT-IR) analysis confirmed that ferrate modification significantly enhanced Fe–O functional groups on the biochar surface. These findings suggest that the improved ammonia removal performance may be attributed not only to acid–base interactions associated with surface functional groups, but also to the direct oxidation of odor-causing compounds by iron oxide species. Full article

This work investigates the Mode I fracture behavior of adhesive joints manufactured from unidirectional carbon fiber-reinforced epoxy composites (CFRP) under static and fatigue loading. Specimens were exposed to two degradation environments: hygrothermal conditions (60 °C, 70% RH) and saline conditions (35 ± 2 °C, 89% RH), for 1 and 12 weeks, and compared with non-exposed material. Double Cantilever Beam (DCB) tests were conducted to evaluate the influence of aging on fracture toughness. Thermal (Differential Scanning Calorimetry, DSC) and spectroscopic (Fourier Transform Infrared Spectroscopy, FTIR) analyses were performed to identify degradation mechanisms. DSC results showed no significant variation in glass transition temperature (T_g) under saline exposure, whereas hygrothermal aging increased T_g, indicating post-curing effects. FTIR analysis revealed moisture uptake and oxidation under saline conditions, while hygrothermal exposure mainly led to structural rearrangement. Critical energy release rate (G_IC) values were used to define fatigue test conditions, enabling the construction of fatigue initiation (ΔG–N) and crack propagation (G–da/dN) curves. A Weibull-based model was applied to describe fatigue initiation behavior. Results show that saline exposure promotes progressive degradation, whereas hygrothermal conditions may enhance performance due to post-curing effects. Full article

In this study, zinc-modified biochar (ZBC) was prepared from rose willow, and NiCoMn-LDHs@ZBC composites were synthesized using a hydrothermal method. The composites were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area analysis, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The adsorption mechanism of As(V) from aqueous solution onto NiCoMn-LDHs@ZBC was investigated through a series of arsenic adsorption experiments. The effects of various experimental parameters (including adsorbent composition and ratio, adsorbent dosage, solution pH, contact time, temperature, and coexisting ions) on the adsorption capacity were evaluated. Additionally, adsorption model fitting and kinetic analysis were conducted. The results indicate that the adsorption process follows the pseudo-second-order kinetic model (linear correlation coefficient R² = 0.99), while the isothermal adsorption process adheres to the Langmuir model, with a maximum adsorption capacity of 159.780 mg/g. The adsorption process is primarily dominated by chemisorption and involves three pathways: first, electrostatic attraction between the material surface and arsenic-containing ions; second, ion exchange between arsenic-containing ions and interlayer carbonate ions; and third, coordination reactions between the surface hydroxyl groups (-OH) of NiCoMn-LDHs@ZBC and As, forming As-O-M inner-sphere complexes as adsorption proceeds. Furthermore, the NiCoMn-LDHs@ZBC composite exhibits relatively stable reusability, demonstrating significant potential for the treatment of arsenic pollution in water bodies. Full article

The development of durable and practical polymer-supported photocatalytic materials that are suitable for use in continuous-flow systems has become an increasingly pressing issue in the field of water treatment. In this study, FeTiO₃/BiOCl heterojunction structures were synthesized at different ratios and integrated into a poly(vinylidene fluoride) (PVDF) matrix to develop photocatalytic thin-film systems. The resulting materials were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and UV–visible diffuse reflectance spectroscopy (UV-DRS) analyses. In photocatalytic experiments conducted under visible light, a 66.3% removal of doxycycline was achieved for pristine FeTiO₃ within 180 min, whilst the FTO@BiOCl(III) composite reached 74.4%. In the PVDF-based thin-film system, the film catalyst demonstrated a removal efficiency of 68.9%. When the pH effect was investigated, the highest total removal of 90.3% was achieved under pH 6.0 conditions. Radical scavenging experiments revealed that superoxide radicals were the predominant active species (a decrease to 30.5% in the presence of benzoquinone (BQ). In experiments conducted in the air-lift reactor system, the P-FTO@BiOCl(III) film achieved approximately 65% removal after 9 h and maintained its structural stability. The PVDF-supported FeTiO₃/BiOCl heterojunction thin-film system offers a noteworthy alternative for environmental applications due to its suitability for continuous systems, structural stability and effective photocatalytic performance. Full article

Diesel engines are commonly used in transportation and power generation, but their operation is associated with incomplete combustion and emissions. In this research, four different nanocatalyst additives including Ag, Ag/TiO₂, Ce/TiO₂, and Ag/CeO₂/TiO₂ were studied as diesel fuel additives to improve combustion efficiency and minimize regulated emissions. These nanoparticles were synthesized and characterized by employing X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) techniques. The prepared fuel blends were tested in a single-cylinder diesel engine at additive concentrations of 50, 75, and 100 ppm under varying engine loads. Among the tested formulations, the ternary Ag/CeO₂/TiO₂ blend demonstrated the highest performance. When compared with the baseline diesel fuel, it reduced CO emissions by 32.5%, HC emissions by 27.8%, and NO_x emissions by 29.4%. At the same time, the amount of CO₂ emission has increased by 18.81%, which shows that the combustion is more complete. Also, the same formulation has decreased brake-specific fuel consumption (BSFC) by 18.7% and increased brake thermal efficiency (BTE) by 16.3%. The improved performance is due to the cooperative effect of CeO₂ oxygen buffering, TiO₂ surface-assisted oxidation, and oxidation activity of the silver species. The findings show that the ternary nanocatalyst formulation is an effective approach for optimizing diesel fuel combustion and emissions. Full article

Alginate hydrogels offer mild ionic gelation and tunable porosity for drug delivery, yet their hydrophilic, macroporous networks suffer from rapid initial burst release of water-soluble payloads. Here we introduce a hierarchical barrier-engineering strategy in which poly(D,L-lactide-co-glycolide)/poly(ethylene glycol) (PLGA/PEG) blend coatings are applied via dip-coating to Ca²⁺-cross-linked alginate beads (~1 mm) and microgels (~100 µm). For beads, three-cycle PLGA/PEG multilayer coating suppressed the initial swelling rate (dQ/dt) by ~50% and reduced 1 h burst release from >85% to ~60%, functioning as an “early-burst buffer” rather than a long-term depot. For microgels, a single PLGA/PEG layer partially attenuated burst release; however, an additional PLGA outer shell (double-barrier architecture) shifted the release-governing mechanism from swelling-dominated to diffusion-barrier-dominated control, limiting 10 min release to <10%. Core–shell formation was verified by confocal laser scanning microscopy (CLSM), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS); thermogravimetric analysis (TGA) showed ~73–79% coating retention after 9 days in phosphate-buffered saline (PBS, 37 °C). A vacuum re-loading process further improved encapsulation efficiency (>50% for beads, >20% for microgels) without compromising gel integrity. In beads, burst control was governed by swelling suppression; in microgels, the additional PLGA shell shifted control to diffusion-barrier-dominated release, demonstrating that barrier architecture must be adapted to particle scale. Full article