Search Results (11,417)

Photocatalysis is a promising strategy for the treatment of dangerous chemical pollutants in the ocean. In this work, a stable copper-based photocatalyst, i.e., {[Cu(BPA)₂]·2I₃}_n (1, BPA = 4,4′-bipyridinium-N-pentanoic acid), exhibited excellent degradation performance in dye pollutant in seawater. According to the structural analysis, this photocatalyst consists of 1-D cationic [Cu(BPA)₂]_n²ⁿ⁺ infinite chain and two I³⁻ polyiodide anions. In the [Cu(BPA)₂]_n²ⁿ⁺ chain, the distorted CuO₄N₂ octahedra are bridged by asymmetric viologen ligand (BPA), which result in a 1-D ladder-shaped chain. Strong C–H···O/I hydrogen bonds contribute to the formation of a 2-D layer along bc-plane, in which I³⁻ anions are stacked among the cationic chains. The strong adsorption from ultraviolet to visible regions together with its high charge separation efficiency implies its usage as excellent visible-light-driven catalysis. Interestingly, good photocatalytic performance for the degradation of Rhodamine B (RhB) in seawater can be observed by using this hybrid as photocatalyst. In detail, 90.6% degradation ratio of RhB can be achieved in 150 min under visible light, which was monitored on a UV–Vis spectrum. This work could pave the way for new ocean pollutant treatments for shipping accidents. Full article

Objective: The aim of our study was to investigate whether faecal concentrations of eosinophil cationic protein (fECP) and human β-defensins (HBD2s) are significantly elevated in children with cow’s milk-protein-induced allergic colitis (MPIAP) and whether a monthly milk-free diet reduces these markers. Materials and methods: This was a single-centre, prospective, observational cohort study involving 70 infants with MPIAP, aged 1–3 months, and 30 healthy controls of the same age. The concentrations of fECP and HBD2 were measured using the ELISA method (IDK^® Eosinophil Cationic Protein and β-Defensins ELISA Kit, Immunodiagnostik AG, Germany). Diagnosis of MPIAP was confirmed with an open milk challenge test. Results: The concentrations of fECP and HBD2 proved useful in evaluating MPIAP treatment with a milk-free diet, where the resolution of allergy symptoms and a significant (p = 0.0000) decrease in the concentrations of both biomarkers were observed after 4 weeks of following the diet. The concentrations of fECP and HBD2 were still higher than those in the control group. High concentrations of fECP can be helpful in diagnosing MPIAP (100% sensitivity), but the low specificity of the assay means that there is a risk of diagnosing MPIAP in one in six children who do not have the disease. The concentrations of HBD2 have low sensitivity, so one in four children with MPIAP will not be confirmed to have the disease using this indicator. Conclusions: fECP and HBD2 can be used to monitor the resolution of colitis in infants with MPIAP treated with a milk diet, indicating a slower resolution of allergic inflammation than the resolution of allergic symptoms. Therefore, neither of the parameters are useful for the diagnosis of MPIAP. Full article

Solute carrier family 12 (SLC12) encodes electroneutral cation-coupled chloride cotransporters responsible for transmembrane ion transport (Na⁺, K⁺, and Cl⁻), which play a critical role in aquatic osmoregulation. However, the SLC12 gene of Exopalaemon carinicauda (EcSLC12) has not been systematically identified or functionally characterized. In this study, six EcSLC12 genes were identified across the genome and classified into N(K)CC, KCC, CCC9, and CIP subfamilies. Three NKCC1 homologous genes (EcSLC12A2.1, EcSLC12A2.2, and EcSLC12A2.3) were reported for the first time in crustaceans. The EcSLC12 family exhibited distinct expression patterns in response to low-salinity, high-alkalinity, and saline–alkaline stress. EcSLC12A2.2 was highly expressed in the gill, and its expression was closely correlated with saline–alkaline acclimation. Additionally, EcSLC12A2.2 knockdown decreased E. carinicauda survival under saline–alkaline stress. Thus, EcSLC12A2.2 plays critical roles in osmotic regulation and saline–alkaline acclimation. This study provides crucial insights into E. carinicauda’s saline–alkaline tolerance mechanisms, and the discovery of multiple NKCC1 homologs fills a gap in the crustacean SLC12 gene family research. Full article

Background/Objectives: Severe asthma remains difficult to treat, even with the range of biologics we now have that target type 2 inflammation. Some patients do not respond well enough to the first biologic they try, which raises the question of whether switching to another option can help. In this study, we looked at how patients who had unsatisfactory therapeutic outcomes on other biologics responded—both clinically and at the biomarker level—after switching to dupilumab. Methods: We reviewed data from the Allergy and Clinical Immunology Unit of Fondazione Policlinico Universitario A. Gemelli-IRCCS, Rome, Italy, between January and June 2025. The study included fifteen adults with uncontrolled severe asthma who had previously been treated for at least six months with benralizumab, omalizumab, or mepolizumab before switching to dupilumab. We evaluated demographic, clinical and laboratory data. Lung function (Forced Expiratory Volume in 1 s (FEV₁)), blood eosinophils, total and specific IgE to staphylococcal enterotoxins, eosinophil cationic protein (ECP), free light chains (FLC), and FeNO were assessed at the time of the switch and again after 12 months. Comparisons were made using paired tests, and a p-value < 0.05 was considered statistically significant. Results: After a year on dupilumab, we saw clear improvements: mean FEV₁ went up by about 10.8% predicted (p = 0.002), FeNO dropped by an average of 22 ppb (p = 0.005), blood eosinophils fell by roughly 400 cells/µL (p = 0.003), and ECP levels decreased by 13 µg/L (p = 0.009). Kappa FLCs also showed a significant drop (p = 0.04). Clinically, 40% of patients met criteria for a meaningful response, and 20% achieved complete remission. Dependence on oral corticosteroids was notably reduced. Baseline levels of eosinophils, ECP, IgE, and FLCs correlated with response to treatment. Conclusions: Our study, despite the small sample size, highlights that in patients with severe asthma who do not show a good response to their first biologic, switching to dupilumab can lead to significant improvements. Markers of type 2 inflammation at baseline might help predict who benefits most. Larger, multi-center, prospective studies are needed to confirm these results. Full article

Persistent bacteria (PB) are a subpopulation of dormant cells that tolerate high antibiotic concentrations and cause chronic, hard-to-treat infections, posing a serious global health threat. In this study, the antibacterial efficacy of six cationic polymers, poly(hexamethylene guanidine) (PHMG), polyethyleneimines of different molecular weights, α-polylysine, ε-polylysine, and polyacrylamide, against persistent bacteria was systematically evaluated. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of these cationic polymers against susceptible and persistent methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), and Escherichia coli (E. coli) were determined using a microbroth dilution method, while cytotoxicity to mouse fibroblast (L929) cells was assessed via MTT assay. PHMG demonstrated superior antibacterial activity, with MBC values as low as 2 μg/mL against persistent MSSA, markedly outperforming the other polymers tested. The key novelties of this work are (i) the first establishment of a cationic polymer library with diverse structural parameters for persistent bacteria clearance, offering a potential strategy for treating recalcitrant infections; and (ii) the elucidation of quantitative correlations between polymer charge density and hydrophobic chain segments with antimicrobial efficacy through structure–activity relationship analysis, providing a theoretical basis for the rational design of anti-persistent materials. Full article

The technological potential and sustainability of red clays from the Taveiro region (Coimbra, Portugal) for structural ceramic applications have been investigated. Thirteen representative samples granulometric, mineralogical, chemical analysis, and technological characterization were conducted to determine the suitability for extrusion-based ceramics, aligned with circular economy and climate goals (e.g., PNEC2030, RNC2050). The samples exhibited a high fine fraction content (<0.002 mm up to 76%) and plasticity index (PI; up to 41%), associated with significant smectite, illite, and kaolinite content. Bulk mineralogy was dominated by Σ phyllosilicates (up to 77%) and quartz (12%–29%), while chemical analyses showed high SiO₂ and Al₂O₃ content, moderate Fe₂O₃, and low CaO/MgO, typical of aluminosilicate clays for red ceramics. High cation exchange capacity (CEC; up to 49 meq/100 g) and specific surface area (SSA; up to 83 m²/g) reflected smectite-rich samples. Firing tests at 900 and 1000 °C demonstrated decreasing water absorption and shrinkage with increased temperature, with some samples yielding lower porosity and higher strength (~12 MPa), confirming suitability for bricks and tiles. Two samples showed higher plasticity but greater shrinkage and porosity, suggesting applicability in porous ceramics or blends. This work highlights the role of mineralogical and technological indicators in guiding the eco-efficient use of georesources for ceramic manufacturing. Full article

The effect of adding 10% biochar (B) or sludgechar (SL) on the water regime and adsorption properties of soils was tested on composites prepared by mixing two standard soils of loamy and clay type with B or SL in a 90:10 weight ratio. Water-holding capacity was assessed as initial (2 h) and equilibrium (24 h). Water retention time was estimated by evaporation from saturated samples at 20 °C to a constant weight. The composites exhibited a 60–90% increase in water absorption compared to the individual soils, retaining water up to 3–6 days longer than the individual soils. The adsorption properties were tested for cation (Pb²⁺) and anion (Sb(OH)₆⁻) adsorption and for Pb²⁺ and Sb(OH)₆⁻ co-adsorption from model solutions under laboratory conditions. All samples showed higher selectivity for Pb²⁺, with the adsorption efficiency from 40% to 99%. Sb(OH)₆⁻ adsorption achieved a maximum efficiency of only 10%. Pb²⁺ and Sb(OH)₆⁻ co-adsorptions were efficient for Sb(OH)₆⁻ adsorption, reaching efficiency levels above 95%. At prolonged reaction times, the adsorption efficiency elevated by more than 20%. Only 10% wt. addition of biochar or sludgechar enhanced not only the water regime of soils but also their adsorption capacity for ionic contaminants. Full article

A novel series of multifunctional tacrine–quinoline hybrids were designed, synthesized, and evaluated as potential anti-Alzheimer’s agents. These compounds incorporate tacrine for cholinesterase’s inhibition and 8-hydroxyquinoline for metal chelation. Piperazine was selected as a linker to provide conformational flexibility and to create favorable cation–π interactions with residues in the mid-gorge region of AChE, enhancing dual-site binding with AChE to inhibit Aβ aggregation. In vitro studies demonstrated submicromolar inhibitory activity toward both AChE and BuChE, particularly for compounds 16e (IC₅₀ = 0.10 μM for AChE, 0.043 μM for BuChE) and 16h (IC₅₀ = 0.21 μM for AChE, 0.10 μM for BuChE). These compounds also exhibited potent inhibition of self-induced Aβ_1–42 aggregation (16e: 80.5% ± 4.4%, 16h: 93.2% ± 3.9% at 20 μM). Kinetic analyses revealed mixed-type inhibition, suggesting dual binding to both CAS and PAS of AChE. UV–vis spectrometry confirmed the chelation of Cu²⁺ and Zn²⁺ ions by the 8-hydroxyquinoline moiety. These findings highlight the tacrine–quinoline scaffold as a promising platform for the discovery of a multitarget-directed anti-AD drug. Full article

Lead-free A₂ZrX₆ “defect” perovskites hold significant potential for many optoelectronic applications due to their stability and tunable properties. Extending a previous work, we present a first-principles density functional theory (DFT) study, utilizing PBE and HSE06 functionals, to systematically investigate the impact of A-site cation and X-site halogen substitutions on the structural and electronic properties of these materials. We varied the A-site cation, considering ammonium, methylammonium, dimethylammonium, trimethylammonium, and phosphonium, and the X-site halogen, trying Cl, Br, and I. Our calculations reveal that both these substitutions significantly affect the band gap and the lattice parameters. Increasing A-site cation size generally enlarges the unit cell, while halogen electronegativity directly correlates with the band gap, yielding the lowest values for iodine-containing systems. We predict a broad range of band gaps (from ~4.79 eV for (PH₄)₂ZrCl₆ down to ~2.11 eV for MA₂ZrI₆ using HSE06). The (PH₄)₂ZrX₆ compounds maintain cubic crystal symmetry, unlike the triclinic of the ammonium-derived systems. Finally, our calculations show that the MA cation yields the smallest band gap among the ones studied, a result that is attributed to its size and the charges of the hydrogen atoms attached to nitrogen. Thus, our findings offer crucial theoretical insights into A₂ZrX₆ structure–property relationships, demonstrating how A-site cation and halogen tuning enables control over electronic and structural characteristics, thus guiding future experimental efforts for tailored lead-free perovskite design. Full article

Understanding surface charge behavior is essential for improving ion separation during lithium brine treatment. This paper investigates the performance of a three-compartment electrodialysis system designed for the selective removal of divalent cations (Mg²⁺ and Ca²⁺). The relationship between zeta potential and the recovery of Li⁺, Na⁺, and K⁺ is analyzed. Zeta potential measurements at various pH values showed that Mg(OH)₂ particles maintained a positive charge. The system facilitated the precipitation of Mg(OH)₂ and Ca(OH)₂ via electrochemically generated OH⁻ ions. The specific electrical energy consumption was evaluated for each operating condition. The results showed that the zeta potential of the precipitates was affected by both the current density and temperature. This influenced lithium losses due to brine entrapment within the precipitated solids. At 600 A/m² and 50 °C, more than 99% of Mg²⁺ and Ca²⁺ were removed, and more than 90% of lithium was recovered, with a specific electric energy consumption of 2.58 kWh per kilogram of Li recovered. The system also generates HCl as a valuable by-product, which improves the sustainability of the process. This study provides a new framework for improving the energy efficiency of lithium purification from brines and lithium recovery. Full article

In order to enhance the corrosion resistance of aluminum alloys, mussel adhesive protein (MAP) was intercalated into layered double hydroxide (LDH) grown onto an Al substrate. The results from X-ray diffraction (XRD), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and energy dispersive spectroscopy (EDS) measurements all confirmed that part of the positively charged MAP can be successfully intercalated into the LDH based on the strong second reactivity. MAP is able to form complexes with the metal cations and hydroxides, leading to less positive charges on the hydroxide layers of the LDH. The intercalation results in the removal of the previously intercalated anions from the interlayer space of the LDH, which maintains the charge balance and lamellar structure. The MAP intercalated LDH film can provide effective corrosion protection to the Al substrate. Full article

Background/Objectives: The growing threat of antibiotic resistance necessitates the development of novel antimicrobial agents that effectively target pathogenic microorganisms while minimizing toxicity. Methods: Two series DABCO-based cationic homopolymers (D-subs 1kDa, D-subs 5kDa, D-subs 15kDa) and DABCO–pyridinium-based copolymers (PyH-subs 5kDa_Dsubs 5kDa, PyH-subs 7kDa_Dsubs 3kDa, PyH-subs 3kDa_Dsubs 7kDa) were synthesized to mimic to host-defense cationic peptides via ring-opening metathesis polymerization (ROMP). The antimicrobial activities of these polymers were determined by their minimum inhibitory concentrations (MICs) against E. coli (Gram-negative bacteria), P. aeruginosa (Gram-negative bacteria), S. aureus (Gram-positive bacteria), and C. albicans (fungus). In vitro cytotoxicity assays revealed selective toxicity towards bacterial cells, with high selectivity indices for several copolymers. To gain insight into the mechanism of action, morphological changes in S. aureus upon exposure to D-subs 1kDa were examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results: The D-subs 15kDa homopolymer demonstrated the highest overall antimicrobial activity, particularly against S. aureus (MIC: 8 µg/mL), with all polymers exhibiting minimal hemolytic activity (HC₅₀ ≥ 1024 µg/mL). SEM and TEM results revealed membrane disruption indicative of polymer–bacteria interactions. Additionally, stability studies confirmed polymer integrity under physiological conditions for at least 28 days. Conclusions: These results support the potential of DABCO-based cationic polymers as a promising platform for next-generation antimicrobial therapeutics. Full article

Shallow gas reservoirs exhibit low formation pressure and gas injection levels, leading to low-resistivity contrast between gas-bearing reservoirs and fully water-saturated layers. Gas-bearing formation identification and water saturation estimation face great challenges. To improve the accuracy of shallow gas reservoir identification and logging evaluation, it is essential to analyze the genesis mechanisms underlying the low-resistivity contrast. This study used the HJ Formation, a typical shallow gas reservoir located in the BY Sag of the eastern South China Sea Basin as an example. Combining the results of nuclear magnetic resonance (NMR), full rock mineral analysis and X-ray diffraction of clay minerals in the laboratory, it was determined that the genesis mechanism for the low-resistivity contrast in the gas-bearing reservoir was due to the high irreducible water saturation (S_wi) and the cation-induced supplementary conductivity. Afterwards, we integrated three methods, density–neutron correlation, calculation of the apparent formation water resistivity, and cross-plots of conventional and gas-logging curves, to identify shallow gas reservoirs. In addition, we also established a Waxman–Smits-based model to estimate water saturation. Compared with the typical Archie’s equation, the predicted water saturation curve using the Waxman–Smits-based model was more reasonable. The established methods and models can be used in target shallow gas reservoir evaluations, and it also has reference value for other types of oilfields with similar physical characteristics. Full article

Background/Objectives: Lysozyme-based amyloid aggregates offer a promising platform for RNA delivery due to their stability, cationic nature, biocompatibility, and ability to form well-defined structures. In this study, we evaluated their potential as drug carriers, focusing on the delivery of polyinosinic–polycytidylic acid (Poly(I:C)), an immunostimulatory synthetic RNA. To validate RNA delivery capability and rule out the possibility that observed effects arose from the lysozyme–Poly(I:C) complex itself, small interfering RNA (siRNA) was also used to verify that the successful delivery of intact and functional RNA was the cause of the observed effects. Methods: The aggregates were characterized by particle size, zeta potential, morphology, and RNA encapsulation efficiency. Results: In vitro studies using RAW 264.7 macrophage-like cells demonstrated that Poly(I:C)-loaded aggregates improved RNA uptake and triggered significant immune activation without inducing toxicity. To further confirm the potential of lysozyme amyloids in RNA delivery, GFP siRNA-loaded aggregates were evaluated in A549-GFP cells. A notable decrease in GFP expression, confirmed through confocal microscopy and flow cytometry, confirmed successful intracellular delivery. Conclusions: These results highlight the potential of lysozyme amyloids as non-viral vectors for RNA delivery, with promising applications in immunotherapy. Full article

Samples of gel-type cation exchangers of the TOKEM nomenclature were tested for lithium extraction from multicomponent natural brines. The dependencies of the extraction of Li and other impurities—Na, Ca, and Mg—on the duration of the sorption process for the tested ion-exchange resins under static conditions are presented. Metal ions can be arranged according to the degree of extraction for each ion exchanger in a row: Ca²⁺ < Mg²⁺ < Li⁺, Na⁺. Testing of ion exchangers under static conditions on technological Li-containing solutions confirms the applicability of TOKEM-140 and TOKEM-160 cation exchangers for lithium extraction. For TOKEM-140, lithium extraction over time varies from 76.2% to 73.8% and for TOKEM-160—from 73.8% to 72.4%. The ionic background of natural brines has a significant effect on the capacity of ion exchangers for lithium and forms the following series Li⁺ << Mg²⁺ < Ca²⁺ << Na⁺ relative to the obtained concentrations of metal ions in natural brine. The overlay of IR spectra of TOKEM-140 and TOKEM-160 ion exchangers before and after saturation shows slight changes in their appearance, indicating that the lithium sorption process has occurred. The values of static exchange capacity (SEC) for TOKEM-140 and TOKEM-160 cation exchangers are identical. Full article