Search Results (89)

The persistent discharge of cationic dyes into aquatic systems necessitates advanced adsorbents with precisely tunable interfacial properties and high removal efficiency. Herein, we report for the first time the synthesis of composition-controlled sulfonated polymeric nanoparticles (NPs) based on polystyrene (PSt) and poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS) via a surfactant-free precipitation polymerization approach. Our findings showed that the NPs exhibited well-defined composition-dependent evolution in physicochemical properties, with hydrodynamic size decreasing from 1224 to 327 nm and surface charge rising from −36.1 to −51.0 mV with increasing PAMPS content. Furthermore, adsorption performance toward methylene blue (MB) and crystal violet (CV) demonstrated strong dependence on surface charge density, with removal efficiencies of 97–98% at low initial dye concentrations (10–20 mg L⁻¹) and still above 82–87% at a higher initial concentration (100 mg L⁻¹). At low initial dye concentrations (10–20 mg L⁻¹), the most highly sulfonated nanoparticles (NP-PSt/AMPS-50) reach equilibrium capacities of approximately 9.25–971 mg g⁻¹, while at 100 mg L⁻¹, the capacities increase to about 82–86 mg g⁻¹ for both MB and CV. Notably, the adsorption capacity (q_e) increases systematically with the sulfonation degree, reflecting enhanced ion-exchange capacity and accessibility of surface-exposed –SO₃⁻ functionalities. Rapid uptake behavior is observed, with >60–70% removal achieved within 15 min and equilibrium established within 100–120 min. Importantly, the enhanced adsorption performance of NPs can be attributed to their self-organized core–shell-like architecture. Considering this structure, hydrophobic PSt-rich domains form the particle interior, while PAMPS segments are localized at particle–water interface, creating a sulfonate-enriched surface layer. This enhances active-site accessibility and electrostatic interactions with cationic dyes. The composition-dependent evolution of sulfonate functional groups, as evidenced by FTIR spectroscopy, along with the systematic decrease in hydrodynamic size and increase in zeta potential magnitude with increasing AMPS content, collectively indicate the surface localization of charged PAMPS segments. Overall, our findings provide a mechanistic framework for the rational design of charge-regulated polymeric nano adsorbents and highlight the potential of PSt/PAMPS NPs as scalable and sustainable materials for cationic dye removal in wastewater treatment systems. Full article

The increasing prevalence of Alzheimer’s disease has created a substantial and urgent need for brain-healthy functional foods. The processing of Pacific white shrimp (Litopenaeus vannamei) generates considerable amounts of head waste, which is rich in bioactive compounds, including lipids and peptides, holding great promise for the development of nutraceuticals to support human brain health. However, traditional extraction methods are time-consuming and inefficient in fully utilizing these compounds. This study aimed to explore the functional properties of these shrimp head-derived ingredients using “one-step” three-phase partitioning (TPP) followed by successive proteolysis. The extracted polar lipid (PL-SH), protein (P-SH) and proteolytic peptidic product (Pep-SH) from shrimp heads were screened for their antioxidant, neuroprotective, and anti-neuroinflammatory activities. Antioxidant activities were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺), and hydroxyl free radical scavenging assays, all of which revealed strong antioxidant potential for all three products. Neuroprotective activities were assessed using HT-22 mouse hippocampal neuronal cells challenged with Aβ₂₅₋₃₅, and anti-neuroinflammatory activities were evaluated using BV-2 microglial cells stimulated with lipopolysaccharide (LPS). The results suggested that both PL-SH and Pep-SH exerted protective effects against Aβ₂₅₋₃₅-induced cell damage under the tested conditions, and PL-SH also reduced nitric oxide (NO) production induced by LPS, indicating potential anti-neuroinflammatory activity. However, further studies with additional biomarkers (e.g., ROS, apoptosis markers, and cytokines) are required to confirm these effects. The lipid composition of PL-SH was further characterized by thin-layer chromatography and LC-MS/MS-based lipidomics, revealing various classes of phospholipids. Furthermore, analysis of the molecular weight distribution and sequences of peptides in Pep-SH revealed peptide sizes ranging from 70 to 1700 Da and a high degree of homology to known antioxidant and neuroprotective peptide sequences. These findings suggest that lipids and peptides from Pacific white shrimp heads possess valuable functional properties, supporting their potential use in the development of functional foods for neuroprotection and anti-neuroinflammation. Full article

As lithium demand surges and primary resources face depletion, lithium-bearing wastewater from urban mines has become a crucial secondary resource. For highly alkaline (pH 9–12), low-lithium (Li⁺ 0.5–5 g/L), high-sodium (Na/Li mass ratio > 30) wastewater generated from the alkaline leaching-washing of spent lithium-ion batteries in urban mining, a single-component, synergist-free extraction process employing HBL121 in sulfonated kerosene was developed, and its extraction stoichiometry, reaction mechanism, and industrial feasibility were elucidated. Saponification significantly enhanced extraction under moderate alkalinity: the saponified system achieved over 99% extraction efficiency at pH 11.0, whereas the non-saponified system required pH > 13.5 for comparable performance, thereby lowering alkali consumption by 81%. Under optimal conditions (saponification degree 40%, 30% (v/v) HBL121 and 70% (v/v) sulfonated kerosene, organic-to-aqueous phase ratio O/A = 1:1, extraction time 5 min), single-stage extraction efficiency exceeded 99%. A McCabe-Thiele diagram was used to determine the theoretical stage number for lithium stripping, showing that essentially all lithium ions can be stripped via a three-stage countercurrent process. Using 3.0 mol/L H₂SO₄ at an aqueous-to-organic phase ratio of 1:4, the stripping efficiency exceeded 99% from the loaded organic. Slope analysis, FT-IR, and ESI-MS confirmed a coordination mechanism between HBL121 and metal ions, forming a stable anionic bisphosphonate complex [LiNa₂(C₂₈H₄₄O₇P₂)]⁻, whose neutral parent form is HLiNa₂(C₂₈H₄₄O₇P₂). Full article

In the present study, a series of isoxazole derivatives were severally evaluated for their antifungal activity against the yeast Candida albicans and molds such as Aspergillus niger, Aspergillus flavus, and Fusarium oxysporum. The results demonstrate that the isoxazole derivatives exhibit considerable antifungal potential, particularly isoxazole-sulfonate ester 4b (Ar= 4-(Cl)C₆H₄, Ar′= 4-(CH₃)C₆H₄), which was found to be active with significant inhibition zones; the diameters of the C. albicans and F. oxysporum samples were measured at 17.00 ± 0.00 mm and 14.00 ± 0.00 mm, respectively. Furthermore, compounds 4a (Ar= 4-(CH₃)C₆H₄, Ar′= 4-(CH₃)C₆H₄), 4c (Ar: 4-(Cl)C₆H₄, Ar′: 4-(NO₂)C₆H₄) and 4d (Ar: 4-(Cl)C₆H₄, Ar′: 3-(Cl)-2-(OCH₃)C₆H₃) demonstrated MIC and MFC values of 20 µg/mL against C. albicans. In addition, the anti-hemolytic activity of these derivatives was evaluated. Compounds 4a, 4e (Ar: 4-(Cl)C₆H₄, Ar′: 3,4-(OCH₃)₂C₆H₃) and aroylisoxazole 3a (Ar: 4-(CH₃)C₆H₄) demonstrated a high degree of anti-hemolytic activity (>99%) at all concentrations evaluated (10, 15, and 20 mg/mL). Molecular docking and molecular dynamics studies over 200 ns revealed protein–ligand complexes to have high affinity and stability, which agrees with the experimental results. The compounds 4d, 4e, and 3a have shown significant interaction with the target proteins of C. albicans, A. flavus, and F. oxysporum, respectively. The results have revealed that the major interaction sites are hydrogen bonding, hydrophobic interactions, and the presence of a water molecule, especially with key residues like TYR_84, ASP_120, SER_90, and THR_89. The crystal structure of compound 4a was also obtained. Full article

The application of natural polysaccharides and their sulfated derivatives have already been successfully implemented in the pharmaceutical and food industries, in particular. The present study is concerned with modifying a predominant polysaccharide in the composition of spruce wood, galactoglucomannan (GGM), by sulfation via a urea-sulfamic acid complex in a 1,4-dioxane medium. By varying the sulfation process duration from 30 to 180 min, six novel GGM sulfate samples with different degrees of substitution (DS) of 0.4–1.2 were obtained and studied with a combination of modern physicochemical methods: elemental analysis, Fourier transform infrared (FTIR) spectroscopy, and gel permeation chromatography (GPC). It has been revealed that the sulfation of GGM proceeds without degradation of the main polymer chain, as evidenced by the shift in the main peak toward the high-molecular-weight region in the GPC curves. Moreover, modification of the polysaccharide leads to a significant transformation of the molecular conformation from a dense sphere to a random coil (α from 0.30 to 0.76). Furthermore, it has been determined that sulfate-substituted groups of the GGM tended to decrease the scavenging capacity of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. However, the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assay showed an increase in the free radical inhibitory capacity of sulfated polysaccharides. This is attributed to the structural and conformational properties of the polysaccharide sulfate derivatives. The maximum anticoagulant activity (ACA) of sulfated GGM (SGGM) is 21.19 ± 2.89 IU/mg and increases with increasing sulfation duration. Full article

A low-permeability, high salinity reservoir entered the high-water-cut and high recovery degree stage in the middle and late stages of development, and it is difficult to tap the potential of water flooding. The overall water flooding recovery of the developed low-permeability reservoir is low, and the produced water has high oil content, many granular impurities, and high inorganic salt content. The polymer–surfactant binary system was studied according to the reservoir conditions. The polymer acrylic acid/polyacrylamide/2-acryloylamino-2-methyl-1-propanesulfonic acid was selected by viscosity measurement. The viscosity stability of the polymer and the effect of the flooding system were evaluated, and the salt-tolerant surfactant sulfonated betaine + amides and coco composite system were screened, and the viscosity, interfacial tension, and displacement effect were evaluated. Finally, the polymer–surfactant binary flooding system was formed. The system has good compatibility, the interfacial tension can still be reduced to 10⁻³ mN/m at 40 °C and 23,800 mg/L, and the viscosity of the polymer solution increased by 5.8% upon addition of the surfactant. The composite system can improve the oil displacement efficiency by 21.19%. The results of a parallel core displacement experiment with a 3.91 permeability ratio show that the oil displacement efficiency can be improved by 19.96%. The system has good performance in low-permeability oilfields and can effectively displace crude oil, which is of great significance for the displacement of low-permeability heterogeneous reservoirs. Full article

Freshwater cladocerans such as Daphnia magna (D. magna) are keystone grazers whose hormone-regulated life history traits make them sensitive sentinels of endocrine-disrupting chemicals (EDCs). The organophosphate flame-retardant tris(2-butoxyethyl) phosphate (TBOEP) and perfluoroethylcyclohexane sulfonate (PFECHS) now co-occur at ng L⁻¹–µg L⁻¹ in surface waters, yet their chronic sub-lethal impacts on invertebrate endocrine networks remain unclear. We analysed two publicly available 21-day microarray datasets (TBOEP: GSE55132; PFECHS: GSE75607) using gene ontology enrichment, STRING protein interaction networks, Drosophila phenotype mapping, and KEGG (Kyoto Encyclopaedia of Genes and Genomes)-anchored frameworks to build putative adverse outcome pathways (AOPs) for D. magna. Differentially expressed genes were clustered into functional modules and hub nodes were ranked by degree and betweenness. TBOEP suppressed moulting and growth, altering 1157 genes enriched for metabolism and membrane processes; hubs VRK1, MIB2, and adenylosuccinate synthetase formed a muscle anatomical development sub-network. PFECHS down-regulated vitellogenin and shifted 879 genes dominated by oxidative-stress and glutathione-metabolism signatures; central nodes UBC9, eIF4A-III, Tra-2α, and HDAC1 linked meiotic-cycle, oogenesis, and cyclic-compound binding. Despite chemical dissimilarity, both compounds converged on Wnt-signalling nodes—TBOEP via presenilin-1, and PFECHS via CK1ε/CK2—thereby reducing TCF/LEF-dependent transcription. Predicted outcomes include impaired oocyte maturation, reduced fecundity, and stunted body size, consistent with observed decreases in length and vitellogenin protein. Our network analysis, based on high-dose, sub-lethal exposures used in the underlying microarray studies, indicates that TBOEP- and PFECHS-induced perturbations can destabilise endocrine, developmental, and metabolic pathways in D. magna without overt lethality, and highlights Wnt-centred key events and hub genes as candidate biomarkers to be evaluated in future low-dose studies that use environmentally realistic exposure scenarios. Hub genes and Wnt-mediated key events emerge as sensitive biomarkers for monitoring mixed EDC exposure. Full article

Gold nanoparticles (AuNPs) are promising for biomedical applications, but their synthesis often requires toxic reagents. “Green” methods utilizing biopolymers offer a sustainable alternative. This study presents a novel synthesis of stable gold nanoparticles using a disulfide-crosslinked derivative of alginic acid (AA–S–S–AA) as both a reducing agent and stabilizer. The S–S-cross-linked alginate was synthesized with a degree of substitution of ~4.2% and reacted with HAuCl₄ in water at room temperature for just 10 min to give stable and polysaccharide in situ modified gold nanoparticles (AA-AuNPs). The resulting AA-AuNPs were characterized by a surface plasmon resonance peak at 539 nm and exhibited good colloidal stability over 14 days. Electron microscopy revealed spherical nanoparticles with a bimodal size distribution (10 nm and 75–100 nm) and a visible polysaccharide shell (5–9 nm), confirming effective stabilization. X-ray photoelectron spectroscopy confirmed the presence of metallic gold (Au⁰) and Au¹⁺. NMR analysis indicated the oxidation of disulfide groups to sulfonic acid during synthesis. The nanoparticles demonstrated a high negative zeta-potential of −53.9 mV, attributable to the polyanionic alginate corona, ensuring strong electrostatic stabilization. This work establishes sulfur-modified alginic acid as an efficient platform for the rapid synthesis of stable, hybrid nanoparticles for potential use in catalysis and biomedicine. Full article

This study examines the effects of extrusion cooking on the biofunctional, rheological, thermal, and structural properties of corn starch (CS)/whey protein isolate (WPI) blends (100/0, 50/50, 0/100 w/w, both raw and extruded) during in vitro gastrointestinal digestion. Extrusion and in vitro digestion increased antioxidant activity (2,2′-Azino-Bis (3-Ethylbenzothiazoline-6-Sulfonic Acid) Diammonium Salt and 2,2-Diphenyl-1-Picrylhydrazyl). Extrusion improved the bioaccessibility of angiotensin-converting enzyme (ACE-1) inhibitory peptides, leading to high inhibition (>90%) in the intestinal phase across all samples, with this effect consistent between raw and extruded samples during digestion. The in vitro digestion process changes the rheological behavior of the samples, from a non-Newtonian fluid (dilatant) to a Newtonian fluid. Notably, extruded CS maintained pseudoplastic behavior across all phases. Thermally, extrusion resulted in complete gelatinization of CS and denaturation of WPI, as evidenced by the absence of endotherms. Structurally, extrusion induced unfolding of WPI α-helix and β-sheet regions, leading to the formation of β-turns and random coils, which could enhance enzyme accessibility. For CS, a decrease in the degree of double helix and order was observed, indicating an alteration of its ordered molecular structure. Additionally, the extrusion process slightly increased the amount of resistant starch. This work shows that extrusion generates antioxidant compounds by bioactive peptide release. Full article

Purslane is highly suitable for intensive microgreen cultivation due to its rapid growth, high germination rate, and exceptional nutritional profile, including omega-3 fatty acids, essential vitamins, and minerals. While previous studies have mostly emphasized its basic composition, our research investigated additional functional traits, such as pigment accumulation and antioxidant activity. We also explored the cultivation potential of a wild purslane genotype (G2), naturally growing in the Botanical Garden of the Slovak University of Agriculture in Nitra, as a sustainable alternative to commercially available seeds (G1). This study examined how genotype and substrate interactions influence growth performance, pigment concentration, and antioxidant capacity in Portulaca oleracea microgreens. Both genotypes were grown on two different substrates: agar mixed with perlite and mineral wool. Although conserved DNA-derived polymorphism marker analysis revealed a high degree of genetic similarity between G1 and G2, significant phenotypic differences were observed. G1 exhibited greater fresh biomass and shoot length, making it more visually appealing for commercial microgreen production. In contrast, G2 showed higher dry matter content and enhanced accumulation of chlorophylls and carotenoids. Antioxidant activity, measured by DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), and FRAP (Ferric Reducing Antioxidant Power) assays, peaked in G1 cultivated on agar–perlite mix. These findings emphasize the importance of selecting the right genotype–substrate combination to optimize both quality and productivity in microgreen systems. Full article

Films of functionalised multiwalled carbon nanotubes (MWCNTs) were fabricated as interlayers (interfacial layers between the cathode and separator) in a lithium–sulfur battery (LSB). Phenylsulfonate functionalisation of commercial MWCNTs was achieved via diazotisation to attach lithium phenylsulfonate groups and was characterised by IR and XPS spectroscopies. SEM-EDX showed sulfur and oxygen colocations due to the sulfonate groups on the interlayer surface. However, CHNS elemental microstudies showed a low degree of functionalisation. Without an interlayer, the LSB produced stable cycling at a capacity of 600 mA h g⁻¹_sulfur at 0.05 C for 40 cycles. Using an unfunctionalised interlayer as a control gave a capacity of 1400 mA h g⁻¹_sulfur for the first cycle but rapidly decayed to the same 600 mA h g⁻¹_sulfur at the 40th cycle at 0.05 C, suggesting a high degree of polysulfide shuttling. Adding a lithium phenylsulfonated interlayer gave an initial capacity increase to 1100 mA h g⁻¹_sulfur that lowered to 800 mA h g⁻¹_sulfur at 0.05 C by the 40th cycle, showing an increase in charge storage (33%) relative to the other cells. This performance increase has been attributed to lessened polysulfide shuttling due to repulsion by the phenylsulfonate groups, increased conductivity at the separator-cathode interface and an increase in surface area. Full article

In view of the issues including the incomplete identification of alternatives and difficulty in tracing pollution sources in PFAS pollution monitoring in surface water, this study took typical surface waters with intensive human activities as the object to perform PFAS screening. A nontarget analysis based on high-resolution mass spectrometry was developed, coupled with a modified solid phase extraction pretreatment method, to achieve the comprehensive screening of 12 legacy carboxylic acids and sulfonic acids, as well as 2 novel alternatives in water. Surface water samples were collected from typical functional areas of human activity to reveal the spatial differential distribution of PFAS concentrations. The long-chain PFASs showed a high detected concentration, among which PFOS, PFUnDA, and PFOA concentrations were especially high in urban complex pollution areas, while PFDA, PFOS, and PFOA were the main components in agricultural areas. The two exposure patterns showed a certain degree of differentiation, which may be related to different pollution sources. PFASs with a long carbon chain, especially chlorine-substituted sulfonic acid, are high-persistent-risk substances. This study provided the data basis for the prevention and control of PFAS pollution in surface water, and supported the treatment of emerging pollutants in the region. Full article

Solution processing represents a widely adopted methodology for perovskite solar cell (PSC) fabrication. Nevertheless, the prevalent use of toxic solvents and anti-solvents in conventional approaches presents significant challenges for PSC commercialization. Water, as an environmentally benign solvent with exceptional Pb(NO₃)₂ solubility, offers a promising alternative for perovskite film preparation. However, the sluggish conversion kinetics of Pb(NO₃)₂ to perovskite often results in morphological imperfections and incomplete conversion, particularly detrimental to planar inverted PSCs derived from aqueous solutions, which currently exhibit limited power conversion efficiencies (PCE) of approximately 6%. To mitigate the Ostwald ripening effect induced by slow reaction kinetics and enhance the conversion efficiency of deep-layer Pb(NO₃)₂ and PbI₂, this study proposes a strategy of increasing the pore size in porous Pb(NO₃)₂ structures. Through the incorporation of sodium dodecyl sulfonate (SDS) surfactant into the Pb(NO₃)₂ precursor solution, we successfully fabricated high-quality perovskite films. Comprehensive characterization revealed that SDS doping effectively modified the surface properties of Pb(NO₃)₂ films, accelerating their conversion to perovskite. The optimized PSCs based on SDS-modified perovskite films demonstrated improved energy level alignment, enhanced charge carrier extraction, and suppressed non-radiative recombination. Consequently, the PCE of planar inverted aqueous PSCs increased significantly from 12.27% (control devices) to 14.82% following surfactant modification. After being stored in a nitrogen glove box for 800 h, the performance of the device still remained above 90% of its original level. It can still maintain 60% of its original performance after a 100 h heating aging test at 80 degrees. Full article

In this work, mesoporous silicas with two types of mesoporous structures were synthesized and functionalized with sulfonic acid groups: MCM-41-SO₃H (honeycomb-like hexagonal structure) and MSU-2-SO₃H (three-dimensional porous structure with wormhole pores). The synthesized materials were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, nitrogen adsorption–desorption, Fourier-transform infrared spectroscopy, ²⁹Si solid-state nuclear magnetic resonance spectroscopy, and elemental analysis. The obtained functionalized materials were evaluated as sorbents for strong cation-exchange solid-phase extraction (SPE) to determine their efficiency in the adsorption and desorption of tropane alkaloids (atropine and scopolamine). The loading solvents, loading volume, analyte concentration, and elution volume were studied, using 50 mg of both materials. Analyses were carried out by ultra-high performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry. The synthesized MCM-41-SO₃H material presented the highest recovery efficiency and has proven to be a promising sorbent for strong cation-exchange SPE of atropine and scopolamine in aqueous media. The high degree of functionalization of MCM-41-SO₃H and the high accessibility of the sulfonic groups for the target analytes, due to the regularity and uniformity of their pores, maximize the contact between the alkaloids and the sorbent, favoring efficient adsorption. Full article

Co-products from the frozen fish processing industry often lead to financial losses. Therefore, it is essential to transform these co-products into profitable goods. This study explores the production of fish protein hydrolysates (FPH) from three co-products: the heads and bones of black scabbardfish (Aphanopus carbo), the carcasses of gilthead seabream (Sparus aurata), and the trimmings of Nile perch (Lates niloticus). Four enzymatic hydrolysis systems were tested: an endopeptidase (Alcalase, A), an exopeptidase (Protana, P), two-stage hydrolysis with an endopeptidase followed by an exopeptidase (A + P), and a single stage with endo- and exopeptidase (AP). The results show that combined enzymatic treatments, especially single-stage Alcalase and Protana (AP), achieved high protein yields (80%) and enhanced degrees of hydrolysis (34 to 49%), producing peptides with lower molecular weights. FPH exhibited significant antioxidant activity, in 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays, with EC₅₀ values below 5 mg/mL. Additionally, AP hydrolysates demonstrated over 60% angiotensin-converting enzyme (ACE) inhibition at 5 mg/mL, indicating potential antihypertensive applications. Antidiabetic and anti-Alzheimer activities were present, but at relatively low levels. AP hydrolysates, especially from gilthead seabream, proved to be the most promising. This study highlights the value of fish co-products as sources of functional peptides, contributing to waste reduction, and their potential applications in food, agriculture, and nutraceuticals. Full article