Search Results (203)

Nitrous oxide (N₂O) is a potent greenhouse gas with a global warming potential > 310 times that of CO₂. Owing to its rapid increase in atmospheric concentrations from industrial emissions, N₂O poses increasing environmental concerns. Among the various N₂O abatement technologies, catalytic decomposition can directly convert N₂O into harmless N₂ and O₂ without generating secondary pollutants. In this study, Co₃O₄ spinel catalysts were synthesized using a polymer-assisted precipitation method, using polyvinyl alcohol, polyvinylpyrrolidone, or polyethylene glycol (PEG) as N₂O decomposition catalysts. The PEG-mediated synthesis method yielded the most active catalyst with superior N₂O decomposition efficiency. Structural and surface analyses confirmed that PEG facilitated the formation of Co²⁺-enriched surface sites and abundant oxygen vacancies, which are crucial active sites for N₂O adsorption and activation. Moreover, these features improved the redox properties and electron transfer behavior of the resulting catalyst. In particular, the PEG-derived 5Co₃O₄/CeO₂ catalyst exhibited enhanced N₂O decomposition activity and stability even in the presence of coexisting N₂O and O₂, highlighting its potential for real-world applications. This study provides an effective synthetic route for Co₃O₄-based catalysts and potential opportunities for wide applications in industrial N₂O removal. Full article

Cholesterol blood levels in low-density lipoproteins (LDLs) are a key parameter for assessing the risk of cardiovascular diseases. Direct quantification of LDL cholesterol at the point of care would be possible if all other lipoproteins, particularly the high-density lipoproteins (HDLs), could be removed prior to measurement. Here, we investigated whether a molecularly imprinted membrane (MIM) could be used for the solid-phase affinity extraction (SPAE) of HDL in a paper-based lateral flow test. Samples traveled by capillarity through the MIM before reaching a detection zone where LDL cholesterol was quantified enzymatically. MIMs were produced by impregnation of the membrane with a dispersion of molecularly imprinted polymers (MIPs) selective for HDL. MIPs were synthesized using precipitation polymerization and exhibited good selectivity for HDL compared with LDL and an uptake capacity of 5.0–7.0 µg of HDL-C/mg of MIP. The MIM enabled the removal of HDL with an efficiency of typically 68%. However, quantification of LDL cholesterol suffered from strong non-specific binding of LDL, likely due to its inherent colloidal instability. Overall, our results highlight the challenges associated with SPAE of colloidal particles. Furthermore, our study demonstrates a novel, efficient, and potentially generic modality to integrate SPAE into paper-based POC diagnostic tests. Full article

Water pollution by heavy metals, dyes, and antibiotics is a serious environmental problem. Efficient and recyclable adsorbents are needed. Magnetic nanocomposite adsorbents (MNAs) offer a promising solution. They combine magnetic nanoparticles with various carriers. This gives them high adsorption capacity and easy magnetic separation. This review covers recent progress in MNAs. We focus on three carrier types: carbon-based materials, inorganic minerals, and natural polymers. We analyze common synthesis methods like co-precipitation and hydrothermal synthesis. The synergy between components enhances pollutant removal, however, challenges remain. These include poor selectivity in mixed pollutants and difficult large-scale production. Stability during reuse is also a concern. Future work should aim for greener synthesis and better stability. This review provides useful insights for designing high-performance MNAs for water treatment. Full article

Neurodegenerative disorders (NDs), including Alzheimer’s disease and Parkinson’s disease, pose a significant global health challenge characterized by progressive neuronal loss and limited therapeutic options. Early diagnosis remains a considerable hurdle due to the absence of reliable biomarkers and the restrictive nature of the blood–brain barrier (BBB), which complicates effective drug delivery. Magnetic nanoparticles (MNPs), particularly those based on iron oxide, have emerged as promising tools for both diagnostic and therapeutic applications in NDs, thanks to their superparamagnetism, biocompatibility, and customizable surfaces. This review examines various synthesis strategies for MNPs, encompassing physical methods (such as lithography, ball milling, and laser ablation) and chemical approaches (co-precipitation, thermal decomposition, hydrothermal synthesis, sol–gel processes, and polyacrylamide gel techniques), while highlighting how these techniques influence particle properties. This review also explores recent advancements in surface functionalization using polymers and coatings to enhance circulation time in the bloodstream and improve BBB penetration for targeted delivery. Furthermore, it emphasizes both in vitro and in vivo applications, showcasing MNPs’ effectiveness in enhancing imaging sensitivity and enabling targeted drug and gene delivery. By linking synthesis methods, functionalization techniques, and biomedical outcomes, this review illustrates the transformative potential of MNPs as next-generation theranostic agents in precision medicine for neurodegenerative diseases. Full article

This study presents the first investigation into the distribution of microplastics (MPs) in Sasebo City, Japan, using principal component analysis (PCA) in conjunction with water flow velocity and salinity variables. The mean MP abundance was 82.4 ± 47.7 items/m³ (SSB1–SSB4), showing no significant difference among sampling points. The fragment-to-fiber ratio was 76:24, and polypropylene and polyethylene (each 41%) were the main polymers. Fragment abundance increased with decreasing particle size, while fibers were rare below 700 μm. PCA indicated distinct MP polymer and shape distributions corresponding to stagnant water (SSB1), high-flow conditions (SSB2 and SSB3), and seawater (SSB4). Based on the literature, the study area represents a case of a small-scale aquatic system with limited anthropogenic influence due to moderate population, short river length, efficient effluent discharge, minimal industry, good water quality, and the absence of significant spatial variation in MP abundance. The infrequent precipitation during the sampling event supports the findings of the present study as a reliable baseline for objectively assessing MP contamination. Compared to aquatic systems of varying scales and anthropogenic influence, this baseline is applicable to both small-scale and large-scale aquatic systems with significant influences. This will serve as a valuable reference for future MP studies across diverse freshwater environments. Full article

Bacterial diseases are a major constraint to aquaculture productivity, driving extensive antibiotic use and raising concerns over antimicrobial resistance, environmental contamination, and food safety. Curcumin, a polyphenolic compound from Curcuma longa, exhibits broad-spectrum antimicrobial and immunomodulatory activities but is limited by poor water solubility, instability, and low bioavailability. This review was conducted through a literature search of Scopus, PubMed, Web of Science, and Google Scholar using targeted keywords, including curcumin nanoparticles, antibacterial, aquatic pathogens, nanotechnology, synthesis, and disease control. Titles and abstracts were screened for relevance, followed by full-text evaluation of selected studies. Key findings were critically analyzed and incorporated into the review. Findings from the literature indicate that curcumin nanoparticles, synthesized via milling, anti-solvent precipitation, ionic gelation, emulsification, spray drying, and metal/polymer nanocomposite formation, exhibit enhanced antibacterial activity against aquatic pathogens, including Aeromonas hydrophila, Vibrio parahaemolyticus, Escherichia coli, and Staphylococcus aureus. Optimally engineered curcumin nanoparticles (<100 nm, being mostly spherical, highly negatively charged) can penetrate bacterial membranes, disrupt biofilms, lower minimum inhibitory concentrations, and improve in vivo fish survival. Practical applications include dietary supplementation to boost fish immunity and growth, water disinfection to reduce pathogen loads, immersion therapy for external infections, and antimicrobial coatings for aquaculture equipment and surfaces, resulting in reduced infections and outbreaks, reduced mortality, improved water quality, and decreased antibiotic dependence. In conclusion, curcumin nanoparticles and curcumin-based nanocomposites present a versatile, eco-friendly approach to sustainable aquaculture disease management. However, further field-scale validation, safety assessment, and cost-effective production methods are necessary to enable commercial adoption. Full article

Magnetic nanoparticles (MNPs), especially iron oxide (Fe₃O₄), display distinctive superparamagnetic characteristics and elevated surface-area-to-volume ratios, facilitating improved physicochemical interactions with solutes and pollutants. These characteristics make MNPs strong contenders for use in water treatment applications. This research investigates the application of iron oxide MNPs synthesized via co-precipitation as innovative draw solutes in forward osmosis (FO) for treating synthetic produced water (SPW). The FO membrane underwent surface modification with sulfobetaine methacrylate (SBMA), a zwitterionic polymer, to increase hydrophilicity, minimize fouling, and elevate water flux. The SBMA functional groups aid in electrostatic repulsion of organic and inorganic contaminants, simultaneously encouraging robust hydration layers that improve water permeability. This adjustment is vital for sustaining consistent flux performance while functioning with MNP-based draw solutions. Material analysis through thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR) verified the MNPs’ thermal stability, consistent morphology, and modified surface chemistry. The FO experiments showed a distinct relationship between MNP concentration and osmotic efficiency. At an MNP dosage of 10 g/L, the peak real-time flux was observed at around 3.5–4.0 L/m²·h. After magnetic regeneration, 7.8 g of retrieved MNPs generated a steady flow of ~2.8 L/m²·h, whereas a subsequent regeneration (4.06 g) resulted in ~1.5 L/m²·h, demonstrating partial preservation of osmotic driving capability. Post-FO draw solutions, after filtration, exhibited total dissolved solids (TDS) measurements that varied from 2.5 mg/L (0 g/L MNP) to 227.1 mg/L (10 g/L MNP), further validating the effective dispersion and solute contribution of MNPs. The TDS of regenerated MNP solutions stayed similar to that of their fresh versions, indicating minimal loss of solute activity during the recycling process. The combined synergistic application of SBMA-modified FO membranes and regenerable MNP draw solutes showcases an effective and sustainable method for treating produced water, providing excellent water recovery, consistent operational stability, and opportunities for cyclic reuse. Full article

Aminotris(methylene phosphonic acid) (ATMP) and poly(acrylic acid) sodium salt (PAA) have shown favorable results in the treatment of porous building materials against weathering damage, showing promising potential as mixed-in additives during the production of lime-based mortars. This study investigates the impact of these additives on microstructure and mechanical properties. Additives were introduced in various concentrations to assess their influence on CaCO₃ crystallization, porosity, strength, and carbonation behavior. Results revealed significant modifications in the morphology of CaCO₃ precipitates, showing evidence of nanostructured CaCO₃ aggregates and vaterite stabilization, thus indicating a non-classical crystallization pathway through the formation of amorphous CaCO₃ phase(s), facilitated by organic occlusions. These nanostructural changes, resembling biomimetic calcitic precipitates enhanced mechanical performance by enabling plastic deformation and intergranular bridging. Increased porosity and pore connectivity facilitated CO₂ diffusion towards the mortar matrix, contributing to strength development over time. However, high additive concentrations resulted in poor mechanical performance due to the excessive air entrainment capabilities of short-length polymers. Overall, this study demonstrates that the optimized dosages of ATMP and PAA can significantly enhance the durability and mechanical performance of lime-based mortars and suggests a promising alternative for the tailored manufacturing of highly compatible and durable materials for both the restoration of cultural heritage and modern sustainable construction. Full article

This study presents an investigation on the potential of using one-year-old field-stored Medicago sativa (alfalfa) as a raw material for a multi-output biorefinery. The main objective was to fractionate the biomass into valuable components—crude protein, hemicellulose-derived polysaccharides, lignin, and cellulose—and to explore the latter’s suitability in papermaking. To this end, three pretreatment strategies (water, alkaline buffer, and NaOH solution) were applied, followed by soda pulping under varying severity conditions. Both solid and liquid fractions were collected and chemically characterized using FTIR, HPLC, and standardized chemical methods. Water-based pretreatment was most effective for protein extraction, achieving over 40% protein content in precipitated fractions. The harshest pulping conditions (20% NaOH, 160 °C, 60 min) yielded cellulose-rich pulp with high glucan content, while also facilitating lignin and hemicellulose recovery from black liquor. Furthermore, the pulps derived from alfalfa stems were tested for papermaking. When blended with old corrugated cardboard (OCC), the fibers enhanced tensile and burst strength by 35% and 70%, respectively, compared to OCC alone. These findings support the valorization of unexploited alfalfa deposits and suggest a feasible biorefinery approach for protein, fiber, and polymer recovery, aligned with circular economy principles. Full article

Magnetic zeolite nanocomposites (NCs) have emerged as a promising class of hybrid materials that combine the high surface area, porosity, and ion exchange capacity of zeolites with the magnetic properties of nanoparticles (NPs), particularly iron oxide-based nanomaterials. This review provides a comprehensive overview of the synthesis, characterization, and diverse applications of magnetic zeolite NCs. We begin by introducing the fundamental properties of zeolites and magnetic nanoparticles (MNPs), highlighting their synergistic integration into multifunctional composites. The structural features of various zeolite frameworks and their influence on composite performance are discussed, along with different interaction modes between MNPs and zeolite matrices. The evolution of research on magnetic zeolite NCs is traced chronologically from its early stages in the 1990s to current advancements. Synthesis methods such as co-precipitation, sol–gel, hydrothermal, microwave-assisted, and sonochemical approaches are systematically compared, emphasizing their advantages and limitations. Key characterization techniques—including X-Ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning and Transmission Electron Microscopy (SEM, TEM), Thermogravimetric Analysis (TGA), Nitrogen Adsorption/Desorption (BET analysis), Vibrating Sample Magnetometry (VSM), Zeta potential analysis, Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), and X-Ray Photoelectron Spectroscopy (XPS)—are described, with attention to the specific insights they provide into the physicochemical, magnetic, and structural properties of the NCs. Finally, the review explores current and potential applications of these materials in environmental and biomedical fields, focusing on adsorption, catalysis, magnetic resonance imaging (MRI), drug delivery, ion exchange, and polymer modification. This article aims to provide a foundation for future research directions and inspire innovative applications of magnetic zeolite NCs. Full article

Extracellular Vesicles (EVs) from seminal plasma have achieved attention due to their potential physiopathological role in male reproductive systems. This study employed a comprehensive proteomic and transcriptomic approach to investigate the composition and molecular signatures of EVs isolated from human seminal plasma. EVs from Normozoospermic (NORMO), OligoAsthenoTeratozoospermic (OAT), and Azoospermic (AZO) subjects were isolated using a modified polymer precipitation-based protocol and characterized for size and morphology. Comprehensive proteomic analysis, using both gel-free and gel-based approaches, revealed distinct protein profiles in each group (p<0.01), highlighting potential molecules and pathways involved in sperm function and fertility. The data are available via ProteomeXchange with identifiers PXD051361 and PXD051390, respectively. Transcriptomic analysis confirmed the trend of a general downregulation of AZO and OAT compared to NORMO shedding light on regulatory mechanisms of sperm development. Bioinformatic tools were applied for functional omics analysis; the integration of proteomic and transcriptomic data provided a comprehensive understanding of the cargo content and regulatory networks present in EVs. This study contributes to elucidating the key role of EVs in the paracrine communication regulating spermatogenesis. A full understanding of these pathways not only suggests potential mechanisms regulating male fertility but also offers new insights into the development of diagnostic tools targeting male reproductive disorders. Full article

Alkaline treatment is well suited for extracting high-molecular-weight hemicelluloses, specifically hardwoods xylans, which, due to their polymer structure and chemical characteristics, enable the production of films with desirable mechanical, barrier, and optical properties for packaging applications. Despite its relevance, the optimization of antisolvent addition has received little attention in the literature. This study explores the use of eucalyptus industrial residue as feedstock, utilizing a statistical design to determine the optimal extraction conditions for hemicelluloses while minimizing the lignin content in the recovered liquor. The process uses alkali loads that are compatible with those in conventional Kraft pulp mills. Optimal extraction conditions involve a temperature of 105 °C, 16.7% NaOH charge, and 45 min at maximum temperature. The resulting liquor was subjected to ethanol precipitation under varying pH conditions (initial pH, 9, 7, 5, and 2) and different ethanol-to-liquor ratios (1:1 to 4:1). The acidification was performed using hydrochloric, sulfuric, and acetic acids. Ethanol served as the main antisolvent, while isopropyl alcohol and dioxane were tested for comparison. Results show that 2.3 ± 0.2% of xylans (based on oven-dry biomass) could be extracted, minimizing lignin content in the liquor. This value corresponds to the extraction of 15.6% of the xylans present in the raw material. The highest xylan precipitation yield (78%) was obtained at pH 7, using hydrochloric acid for pH adjustment and an ethanol-to-liquor ratio of 1:1. These findings provide valuable insight into optimizing hemicellulose recovery through antisolvent precipitation, contributing to more efficient biomass valorization strategies within lignocellulosic biorefineries. Full article

Wastewater reinjection is an important measure for balancing the sustainable development of petroleum resources with environmental protection. However, the polymer-containing wastewater generated after polymer injection presents challenges such as reservoir damage and waterflooded zone identification in oilfields. To address this, this study systematically examined the impact of injection water with varying salinities on the flow characteristics and electrical responses of low-permeability reservoirs, based on rock-electrical and multiphase displacement experiments. Additionally, this study analyzed the factors influencing the damage to reservoirs during polymer-containing wastewater reinjection. Mass spectrometry, chemical compatibility tests, and SEM-based micro-characterization techniques were employed to reveal the micro-mechanisms of reservoir damage during the reinjection process, and corresponding protective measures were proposed. The results indicated the following: (1) The salinity of injected water significantly influences the electrical response characteristics of the reservoir. When low-salinity wastewater is injected, the resistivity–saturation curve exhibits a concave shape, whereas high-salinity wastewater results in a linear and monotonically increasing trend. (2) Significant changes were observed in the pore-throat radius distribution before and after displacement experiments. The average frequency of throats within the 0.5–2.5 µm range increased by 1.894%, while that for the 2.5–5.5 µm range decreased by 2.073%. In contrast, changes in the pore radius distribution were relatively minor. Both the experimental and characterization results suggest that pore-throat damage is the primary form of reservoir impairment following wastewater reinjection. (3) To mitigate formation damage during wastewater reinjection, a combined physical–chemical deblocking strategy was proposed. First, multi-stage precision filtration would be employed to remove suspended solids and oil contaminants. Then, a mildly acidic organic-acid-based compound would be used to inhibit the precipitation of metal ions and dissolve the in situ blockage within the core. This integrated approach would effectively alleviate the reservoir damage associated with wastewater reinjection. Full article

The continuous discovery of novel effective antibacterial agents using nano-based materials is of high significance. In this study, we utilized Polymerylated divalent-metal-doped ferrite nanoparticles (PMFe₂O₄ NPs) and studied their antibacterial inhibition effects. Different panels of PVP- and PEG-coated metal-doped MFe₂O₄ (M ≅ Co, Ni, and Zn) were prepared via the Ko-precipitation Hydrolytic Basic (KHB) methodology and thoroughly analyzed using TEM, XRD, FTIR, and VSM. The as-synthesized doped ferrites displayed stable quasi-spherical particles (7–15 nm in size), well-ordered crystalline cubic spinel phases, and high-saturation magnetizations reaching up to 68 emu/g. The antibacterial efficacy of the doped ferrites was then assessed against a Gram-negative E. coli bacterial strain. The results demonstrated that both metal doping and polymer functionalization influence the antimicrobial efficacies and performance of the ferrite NPs. The presence of the PVP polymer along with the divalent metal ions, particularly Co and Ni, resulted in the highest antibacterial inhibition and effective inactivation of the bacterial cells. The antibacterial performance was as follows: PVP-CoFe₂O₄ > PVP-NiFe₂O₄ > PVP-ZnFe₂O₄. Lastly, cell viability assays conducted on human breast fibroblast (HBF) cells confirmed the good safety profiles of the doped ferrites. These interesting results demonstrate the distinctive inhibitory features of the biocompatible metal-doped ferrites in enhancing bacterial killing and highlights their promising potential as effective antimicrobial agents, with possible applications in areas such as water disinfection, biomedical devices, and antimicrobial coatings. Full article

Mercury contamination in groundwater seriously affects human health and ecosystem security. The remediation of Hg-contaminated groundwater remains a challenging task. The applicability of an as-synthesized supramolecular polymer (SP) for low-concentration mercury in a high-salinity groundwater matrix has been verified through a batch process and column test. The remediation of mercury-contaminated groundwater, particularly in complex high-salinity environments, represents a significant and enduring challenge in environmental science. The batch test study demonstrated that the SP can efficiently adsorb Hg from groundwater with superior selectivity and a high uptake capacity (up to 926.1 ± 165.3 mg g⁻¹). Increasing the pH and dissolved organic matter (DOM) and reducing the ionic strength can facilitate Hg adsorption; the coexistence of heavy metal ions slightly weakens the removal. In terms of its performance as a permeable reactive barrier, the SP can intercept Hg in flowing groundwater with a capacity of up to 3187 mg g⁻¹. A low influent mercury concentration, low pore velocity, and high SP dosage can effectively extend the breakthrough time in column tests. Additionally, the Yan model (R² = 0.960−0.989) can accurately depict the whole dynamic interception process (150 PVs) of SPs in a fixed column, and the Adams–Bohart model (R² = 0.916−0.964) describes the initial stage (≤35 PVs) well. Considering the functional group in the SP and the Hg species in groundwater, complexation, electrostatic attraction, ion exchange, and precipitation/co-precipitation are the plausible mechanisms for mercury removal based on the characterization results of scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectrometer (FT-IR). These impressive features render the SP a promising candidate for the remediation of trace Hg in saline groundwater using permeable reactive barrier (PRB) technology. Full article