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Aluminum adjuvants (Alum), approved by the US Food and Drug Administration, have been extensively used in vaccines containing recombinant antigens, subunits of pathogens, or toxins for almost a century. While Alums typically elicit strong humoral immune responses, their ability to induce cellular and mucosal immunity is limited. As an alternative, layered double hydroxide (LDH), a widely used antacid, has emerged as a novel class of potent nano-aluminum adjuvants (NanoAlum), demonstrating advantageous physicochemical properties, biocompatibility and adjuvanticity in both humoral and cellular immune responses. In this review, we summarize and compare the advantages and disadvantages of Alum and NanoAlum in these properties and their performance as adjuvants. Moreover, we propose the key features for ideal adjuvants and demonstrate that LDH NanoAlum is a promising candidate by summarizing its current progress in immunotherapeutic cancer treatments. Finally, we conclude the review by offering our integrated perspectives about the remaining challenges and future directions for NanoAlum's application in preclinical/clinical settings. The next-generation layered double hydroxide nano-aluminum adjuvant reengineered from clinical drugs is a dual-functional adjuvant to amplify cancer immunotherapy by simultaneously serving as vaccine adjuvant and tumor microenvironment immunomodulator. [Display omitted] [ABSTRACT FROM AUTHOR]

Increasing water contamination from metal cations is a significant environmental challenge for humans. This has sparked extensive research into the development of adsorbents with superior removal efficiencies. This study assessed the adsorption capacity of crude and lignocellulosic fractions obtained from the pericarp of Quercus suber acorns, specifically focusing on the removal of Pb(II), Cd(II), Ni(II), and Cu(II) ions from aqueous solutions. The lignocellulosic fraction was separated from the crude fraction after extraction of cell wall polysaccharides using water and alkaline solutions. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the crude and lignocellulosic fractions. Data from equilibrium adsorption experiments were analyzed using the Langmuir and Freundlich isotherm models. The study found that the lignocellulosic fraction removed Pb(II) ions more efficiently than the crude fraction, with qmax values of 500.0 mg.g−1. Crude fractions exhibited a considerable retention potential for Cd(II), Ni(II), and Cu(II) ions with qmax values of 95.2 mg.g−1, 333.3 mg.g−1 and 200 mg.g−1 respectively. Crude and lignocellulosic fractions extracted from the acorn Q. suber pericarps could be environmentally friendly biosorbents for the removal of metal cations from aqueous solutions. [ABSTRACT FROM AUTHOR]

Abstract Background Antimicrobial agents (AMAs) are essential for treating infections. A part of AMAs chelate with metal cations (MCs), reducing their blood concentrations. That drug-drug interaction could lead to a reduction of therapeutic efficacy and the emergence of drug-resistant bacteria. However, prescriptions ordering concomitant intake (co-intake) of AMAs and MCs are frequently seen in clinical settings. A method for preventing such prescriptions is urgently needed. Methods We implemented pop-up alerts in the hospital's ordering and pharmacy dispensation support system to notify the prescriptions ordering co-intake of AMAs and MCs for physicians and pharmacists, respectively. To assess the effectiveness of the pop-up alerts, we investigated the number of prescriptions ordering co-intake of AMAs and MCs and the number of pharmacist inquiries to prevent co-intake of AMAs and MCs before and after the implementation of pop-up alerts. Results Before the implementation of pop-up alerts, 84.5% of prescriptions containing AMA and MCs ordered co-intake of AMAs and MCs. Implementing pop-up alerts time-dependently reduced the proportion of prescriptions ordering co-intake of AMAs and MCs to 43.8% and 29.5% one year and two years later, respectively. The reduction of tetracycline-containing prescriptions was mainly significant. Before the implementation of pop-up alerts, the proportion of prescriptions in which pharmacists prevented co-intake of AMAs and MCs was 3.4%. Implementing pop-up alerts time-dependently increased proportions of such prescriptions to 20.9% and 28.2% one year and two years later. Conclusion Implementing pop-up alerts reduced prescriptions ordering co-intake of AMAs and MCs and accelerated pharmacists to prevent co-intake of AMAs and MCs. The implementation of dual pop-up alerts in the hospital's ordering and pharmacy dispensation support system could help prevent co-intake of AMAs and MCs.

Background: Antimicrobial agents (AMAs) are essential for treating infections. A part of AMAs chelate with metal cations (MCs), reducing their blood concentrations. That drug-drug interaction could lead to a reduction of therapeutic efficacy and the emergence of drug-resistant bacteria. However, prescriptions ordering concomitant intake (co-intake) of AMAs and MCs are frequently seen in clinical settings. A method for preventing such prescriptions is urgently needed. Methods: We implemented pop-up alerts in the hospital's ordering and pharmacy dispensation support system to notify the prescriptions ordering co-intake of AMAs and MCs for physicians and pharmacists, respectively. To assess the effectiveness of the pop-up alerts, we investigated the number of prescriptions ordering co-intake of AMAs and MCs and the number of pharmacist inquiries to prevent co-intake of AMAs and MCs before and after the implementation of pop-up alerts. Results: Before the implementation of pop-up alerts, 84.5% of prescriptions containing AMA and MCs ordered co-intake of AMAs and MCs. Implementing pop-up alerts time-dependently reduced the proportion of prescriptions ordering co-intake of AMAs and MCs to 43.8% and 29.5% one year and two years later, respectively. The reduction of tetracycline-containing prescriptions was mainly significant. Before the implementation of pop-up alerts, the proportion of prescriptions in which pharmacists prevented co-intake of AMAs and MCs was 3.4%. Implementing pop-up alerts time-dependently increased proportions of such prescriptions to 20.9% and 28.2% one year and two years later. Conclusion: Implementing pop-up alerts reduced prescriptions ordering co-intake of AMAs and MCs and accelerated pharmacists to prevent co-intake of AMAs and MCs. The implementation of dual pop-up alerts in the hospital's ordering and pharmacy dispensation support system could help prevent co-intake of AMAs and MCs. [ABSTRACT FROM AUTHOR]

Background: Phosphorus in the soil is mostly too insoluble for plants to utilize, resulting in inhibited aboveground biomass, while Carex can maintain their aboveground biomass through the presence of dauciform roots. However, dauciform roots lead to both morphological and physiological changes in the root system, making their primary mechanism unclear. Methods: A greenhouse experiment was conducted on three Carex species, in which Al-P, Ca-P, Fe-P, and K-P were employed as sole phosphorus sources. The plants were harvested and assessed after 30, 60 and 90 days. Results: (1) The density of dauciform roots was positively correlated with root length and specific root length, positively influencing aboveground biomass at all three stages. (2) The aboveground phosphorus concentration showed a negative correlation with both dauciform root density and aboveground biomass in the first two stages, which became positive in the third stage. (3) Aboveground biomass correlated negatively with the aboveground Al concentration, and positively with Ca and Fe concentration (except Al-P). (4) Root morphological traits emerged as critical factors in dauciform roots' promotion of aboveground biomass accumulation. Conclusion: Despite the difference among insoluble phosphorus, dauciform roots have a contributing effect on aboveground growth status over time, mainly by regulating root morphological traits. This study contributes to our understanding of short-term variation in dauciform roots and their regulatory mechanisms that enhance Carex aboveground biomass under low available phosphorus conditions. [ABSTRACT FROM AUTHOR]

The influence of metal ions on the structure of amyloid- β (Aβ) protofibril models was studied through molecular dynamics to explore the molecular mechanisms underlying metal-induced Aβ aggregation relevant in Alzheimer's disease (AD). The models included 36-, 48-, and 188-mers of the Aβ42 sequence and two disease-modifying variants. Primary structural effects were observed at the N-terminal domain, as it became susceptible to the presence of cations. Specially when β-sheets predominate, this motif orients N-terminal acidic residues toward one single face of the β-sheet, resulting in the formation of an acidic region that attracts cations from the media and promotes the folding of the N-terminal region, with implications in amyloid aggregation. The molecular phenotype of the protofibril models based on Aβ variants shows that the AD-causative D7N mutation promotes the formation of N-terminal β-sheets and accumulates more Zn2+, in contrast to the non-amyloidogenic rodent sequence that hinders the β-sheets and is more selective for Na+ over Zn2+ cations. It is proposed that forming an acidic β-sheet domain and accumulating cations is a plausible molecular mechanism connecting the elevated affinity and concentration of metals in Aβ fibrils to their high content of β-sheet structure at the N-terminal sequence. [ABSTRACT FROM AUTHOR]

Context: Boron nitride nanotubes (BNNTs) provide an exceptional and sophisticated platform for detecting metal ions with high surface area and remarkable chemical stability. Metal cations tend to bind to the surface of BNNTs, which leads to significant changes in the electrical properties of nanotubes. BNNT-based metal ion sensors have shown promising results in various applications, including water quality monitoring, biomedical research, industrial quality control, and environmental monitoring. In the present study, we have explored the electronic sensitivity of the BNNT to metal ions (Si2+, Ge2+, Cu2+, Zn2+, Mg2+, and Ca2+). The interaction between the ions with the pristine BNNT is performed in the solution phase. The results show that ion adsorption on the nanotube surface is exothermic and favorable. The density of states calculation is presented to investigate the electronic properties of the nanotube during the adsorption process. The results display that an increase in the electrical conductivity of the complexes accompanies the reduction in the energy gap. Based on the obtained data, the Si2+ and Ge2+ cations adsorbed on the BNNT with satisfactory Eg changes (%ΔE) can be promising candidates for better sensing ability. Method: All calculations are conducted within the density functional theory (DFT) using the ωB97XD functional and 6-31G(d,p) basis set. The present approach incorporates the utilization of empirical atom–atom dispersion in conjunction with long-range correction. The calculations are performed using the quantum chemistry package GAMESS, and the obtained results are visualized by employing the GaussView 6.0.16 program. [ABSTRACT FROM AUTHOR]

A naphthylidene-diimine L2 was newly designed, and its structure was identified by elemental analysis and spectroscopic methods. The effect of temperature, acid–base and light on enol–keto tautomerism in this Schiff base was evaluated by colorimetry, UV–Vis and fluorescence spectroscopy. Under irradiation 365 nm, L2 emitted yellow, orange and strong green emission in pure, basic and aqueous DMSO media (v/v, 1/1), respectively. Its ionochromic behavior against various cations (Fe3+, Al3+, Cr3+, Cu2+, Co2+, Ni2+, Zn2+, Cd2+, Pb2+, Ba2+ and Ag+) and anions (F−, Cl−, CH3COO−, SO32–, S2O32−, HSO4−, H2PO4−, NO3−, CN−, and OH−) was investigated in aqueous DMSO media (v/v, 1/1) by UV–Vis and fluorescence experiments. Dark yellow color of L2 changed to colorless for Fe3+, Cr3+ and HSO4− ions, and turned to light yellow for Al3+ and Cu2+ ions, and to orange for CN− and OH− ions. According to UV–Vis data, the chemosensor displayed selective recognition towards Fe3+, Al3+, Cu2+, HSO4−, CN− and OH− with a 1:1 stoichiometric ratio. At the excitation wavelength of 365 nm, L2 gave strong yellowish white emission (λem = 445 and 539 nm) in the presence of Al3+, and the intensity increased about 12.5 times. On the other hand, the chemosensor displayed one emission band at 452 nm and 450 nm in the presence of CN− and OH− with 1.9 fold and 2.3 fold fluorescence enhancement, respectively. [ABSTRACT FROM AUTHOR]

The lack of low-cost methods to synthesize large-area graphene-based materials is still an important factor that limits the practical application of graphene devices. Herein, we present a facile method for producing large-area graphene oxide-metal (GO–M) films, which are size controllable and transferable. The sensor constructed using the GO–M film exhibited humidity sensitivity while being unaffected by pressure. The relationship between the sensor's resistance and relative humidity followed an exponential trend. The GO–Mg sensor was the most sensitive among all the tested sensors. The facile synthesis of GO–M films will accelerate the widespread utilization of graphene-based materials. [ABSTRACT FROM AUTHOR]

Due to its unique structure, chemical composition, physical and mechanical properties, grapes are one of the most valuable types of plant raw materials, the processing of which produces by-products: grape pomace, grape seeds, grape bunches, yeast sediments. The amount of grape pomace is about 20-25% of the total mass; if not used, this leads to an increase in production costs. Traditionally, grape pomace has been used as fertilizer or animal feed, but only the polyphenol content has been studied. Grape pomace is a complex natural composition of various components: skins, stems, grape seeds (seeds). Red wine marc is a by-product of fermentation, while white and rosé wine marc is removed before alcoholic fermentation, leaving the fermentable sugars in the marc. They contain organic acids, vitamins, microelements, and grape oil extracted from the seeds. The industry is expected to function as a natural ecosystem, with waste from one industry becoming the raw material for another. In order to rationally use natural raw materials, the main emphasis is on the development and implementation of new competitive high-tech safe technologies, as well as the search for new sources of biologically active substances from waste from food enterprises. The purpose of the research is to study the quality indicators of grape marc obtained using the white and red methods of processing grapes as raw materials for the production of functional soft drinks. It has been established that grape pomace is represented mainly by skins (84.8-87%). The main acids in grape pomace are tartaric («Firstborn of Magarach», «Cabernet Sauvignon») and malic. The main cation is potassium («Rkatsiteli»). The rich chemical composition provides enormous potential for the use of secondary grape processing products for the production of functional soft drinks.

Acid mine drainage (AMD) contains metals that have detrimental effects on crop growth if present in excess in plant-available form. The use of untreated AMD from coal mines for crop irrigation on strategically limed soils is considered a potential option for mine water management, especially in remote areas without access to water treatment infrastructure. However, leaf scorching and trace element enrichment of plant tissue are of potential concern, as these waters often contain high concentrations of potentially toxic, acid-generating metals (Al3+, Fe2+ and Mn2+) which may cause foliar damage and hyper-accumulate in plant tissue. The objectives of this trial were to quantify any foliar injury and metal accumulation in wheat (Triticum aestivum L.) and cowpea (Vigna unguiculata L.) vegetative material after foliar wetting with simulated AMD enriched with metal cations, and to ascertain if biomass production will be affected. In this trial, crop water requirements were not met through mine water irrigation, as this was only a foliar wetting investigation. Two pot experiments were set up, with wheat grown in the winter and cowpea in the summer season of 2021. Sulphuric acid was used to lower pH to 2, after the addition of low, intermediate and high concentrations of individual acid-generating metal cations, as well as a combination of all three cations. Areal foliar injury was greatest for cowpea (18.7%) with a combination of Al, Fe and Mn at the highest concentration. The crop was not able to recover at this injury level. No injury was recorded in wheat. Both crops accumulated only limited quantities of the metal cations. Calculated hazard quotient for cattle ranged from 0.022 to 0.53, indicating that such fodder would be safe to consume. It is concluded that there are large differences in crop specie susceptibility to leaf scorching after foliar wetting with acidic metal cation-rich mine waters. It is recommended, therefore, that because large volumes of mine water need to be managed, and centre pivot overhead irrigation is likely to be utilized to this end, that studies to screen more species to select crops tolerant to scorching through foliage wetting with mine water irrigation be conducted. Thereafter, studies to better understand root zone effects of irrigation with such waters need to be conducted on species that can tolerate foliar wetting with these waters.

2D perovskites have attracted wide attention for optoelectronic applications because of their unique layer structure and tunable outstanding optical/electrical properties. In addition, 2D Cs3Bi2Br9 nanoflakes possess large effective atomic number, high resistivity, high density as well as excellent stability, rendering it a promising material for X‐ray detection. Nevertheless, it is full of challenges to synthesize 2D Cs3Bi2Br9 nanoflakes by conventional inversion temperature crystallization (ITC) strategy due to the existence of Br‐ vacancies in the Cs3Bi2Br9 crystal nucleus. Herein, an Ag+ assisted ITC (SAITC) strategy to grow 2D Cs3Bi2Br9 nanoflakes is proposed. The synthesis mechanism revealed by both experiments and theoretical calculations can be mainly ascribed to the passivated Br− vacancies and enhanced structure stability by adding Ag+ which can effectively prevent the oxidation of 2D Cs3Bi2Br9 nanoflakes from growth of hybrid crystals. The synthesized high‐crystallinity 2D Cs3Bi2Br9 nanoflakes possess direct bandgap characteristic, and the mobility lifetime can reach 9.8 × 10−4 cm2 V−1. Excitingly, the fabricated device based on 2D Cs3Bi2Br9 nanoflakes demonstrates ultrahigh sensitivity of detecting X‐ray (1.9 CGyair−1cm−2) at very low driven voltage (0.5 V) due to the photoconductive gain mechanism. The 2D Cs3Bi2Br9 nanoflakes synthesized by SAITC method have great potential for developing highly sensitive optoelectronic devices. [ABSTRACT FROM AUTHOR]

Nata de coco produced via coconut water fermentation using Acetobacter xylinum was directly applied to remove metal cations in aqueous solutions without any further chemical modification. Bacterial cellulose, contributing just 0.8 wt % to nata de coco, were randomly distributed and interconnected, yielding a three‐dimensional framework with high crystallinity and porosity. Due to these characteristics and the abundant presence of electron‐rich hydroxyl groups, unmodified bacterial cellulose in nata de coco exhibited a strong affinity to metal cations in water. The adsorption efficiency of nata de coco can be significantly improved to ∼30 and ∼45 mg g−1 for Pb2+ and Fe3+, respectively, by decreasing its size by grinding to decrease its size. Notably, nata de coco can adsorb multiple cations and the uptakes were almost similar for a 100‐fold scaled‐up adsorption volume. [ABSTRACT FROM AUTHOR]

Reversed-phase dispersive liquid–liquid microextraction (RP-DLLME) was proposed in the present work to separate and preconcentrate metal cations in sesame oil before their detection through ion chromatography-conductivity detection (IC-CDD). This method facilitates the direct extraction of cations like Na+, Pb2+, K+, Mg2+, and Ca2+ from oil specimens into an aqueous micro-drop to inject into the chromatography column. Four parameters were included in the process as the pH of water, volume of water and THF, and centrifugation time through a response surface technique. Five replicated analyses were performed under optimized circumstances (1.5 mL THF as a disperser and 60 μL water at pH 9 as an extraction solvent). Thus, recoveries of 110%, 108%, 107.2%, 104.2%, and 106.8% were displayed with respective standard deviations of 10.3, 9.8, 7.3, 9.7, and 6.7 for K+, Na+, Mg2+, Pb2+, and Ca2+. The detection limits (3σ) for the method were 0.007 μg mL−1 for K+, 0.001 μg mL−1 for Na+, 0.011 μg mL−1 for Mg2+, 0.008 μg mL−1 for Pb2+, and 0.009 μg mL−1 for Ca2+. The method could successfully determine the existence of metal cations in four sesame oil specimens. [ABSTRACT FROM AUTHOR]

In lithium‐sulfur (Li−S) batteries, sulfur undergoes various changes. It switches between cyclic structure and linear structure. The charge on the sulfur varies between a neutral state and a negative charge‐bearing state. Due to these changes, the sulfur/polysulfide dissolves in the battery electrolyte. Furthermore, the kinetics of the sulfur redox reaction is sluggish. Therefore, a material that can suppress sulfur/polysulfide dissolution and electrocatalyze sulfur redox reaction is needed. We hypothesize that the polysulfide dissolution can be suppressed if the host exhibits polyvalent electrostatic attraction. Polysulfide is a negative charge‐bearing molecule; hence the host must comprise multiple positive charges. Nickel cations with other heteroatoms have been explored as a host in Li−S batteries. The heteroatoms impart additional interactions. The easier way to circumvent the effect of heteroatoms is the addition of metal salts. However, metal salts can either exhibit monovalent or divalent attraction with polysulfides. Those interactions are weak and we must have polyvalent interaction. Towards this objective, we have designed and synthesized a material that comprises multiple divalent cations that is also devoid of heteroatoms. The Li−S batteries fabricated using the metal cation immobilized graphene showed a maximum specific capacity of 1022 mAh/g at 0.1 C rate. Among the metal cations, nickel cations showed better performance than cobalt cations. Thus, we demonstrate that metal cations immobilized on Graphene can efficiently electrocatalyze the sluggish sulfur redox reaction and suppress the polysulfide dissolution. [ABSTRACT FROM AUTHOR]

Direct air capture of CO2 (DAC) has been increasingly recognized as a promising carbon‐negative technology. The challenge in deploying energy‐efficient DAC lies in effective sorbent materials. In this research, we comprehensively investigated the DAC behavior of LTA zeolites exchanged with different metal cations (Na+, K+, Mg2+, Ca2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Y3+, La3+, Ce3+, Eu3+, Tb3+, and Yb3+) by both static single‐component gas adsorption and dynamic mixture gas adsorptive separation tests. We found that a large charge‐to‐size ratio of cations is critical to imparting a high DAC capacity of LTA zeolites, which is ascribed to the enhanced electrostatic interaction and/or π‐back bonding toward CO2. Meanwhile, a detrimental effect is associated with an excessively large charge‐to‐size ratio, that is, a significant "shielding effect" of (pre‐) adsorbed contaminants (e.g., H2O and CO2) on cations (e.g., Mn2+ and Mg2+) reduce the accessible CO2 capacity. Ca‐LTA featuring Ca2+ with an appropriate charge‐to‐size ratio exhibits the highest DAC capacity (350 ppm CO2 in the air, 1.20 mmol/g) with fast kinetics and good reusability. These results provide valuable insights for the design of zeolites‐based physisorbents for DAC. [ABSTRACT FROM AUTHOR]

This review covers recent advances (from 2006 to date) in supramolecular systems based on fluorescent homooxacalixarenes, namely hexahomotrioxacalix[3]arenes, dihomooxacalix[4]arenes and tetrahomodioxacalix[4]arenes, focusing on fluorescence sensing using their intrinsic fluorescence (built-in mesitol-like groups) or the extrinsic fluorescence of organic fluorophores, either covalently linked to the calixarenes or forming supramolecular complexes with them. Sensing applications of ions, ion pairs and neutral molecules are discussed, as well as the potential measurement of temperature based on thermally activated delayed fluorescence.

Acorn pericarps of the Algerian holm oak (Quercus ilex) constitute a largely underexploited forestry co-product. In the aim of valorization, adsorption efficiencies of crude, parietal, and lignocellulosic fractions of acorn pericarps were evaluated towards lead, cadmium, nickel, and copper ions. The results were modeled using Langmuir and Freundlich isotherms. The best results were obtained with the lignocellulosic fraction towards lead and cadmium with qmax values of 370.37 and 303.03 mg.g−1, respectively. On the contrary, crude and parietal fractions showed the highest capacities for nickel and copper, with qmax values of 200 and 303.03 mg.g−1, respectively. This work thus provides the first trial of acorn pericarps of oaks growing in northwest Algeria as an efficient biosorbent for the removal of metallic cations from aqueous solutions, whose adsorption capacities surpass most of the previously described biosorbents. [ABSTRACT FROM AUTHOR]

Aminolysis of ester derivatives of 1,1′-dinaphthylmethane and rctt-calix[4]resorcinarene afforded a series of ligands differing in the molecular platform structure, the number of electron-donor sites, the nature of terminal amide component, the nature and size of the spacers connecting the polycyclic core with the amide group. Using liquid extraction method, the effect of ligand structural features on its ability to recognize and bind s-, p-, d-, and f-metal cations was investigated, and the stoichiometry of formed complexes was calculated. [ABSTRACT FROM AUTHOR]

Flocculation and dewatering of anaerobically digested sludge is known to be a major cost factor in the economy of wastewater treatment plants. Hence, several endeavors have been underway in search of affordable and effective alternatives. This study focuses on the effects of different metal cations, including FeCl3, CaCl2 and MgSO4, on the dewaterability of digested sludge. The effects of these metal flocculants were also investigated in the presence of co-polymers and surfactants, which can be considered the novelty of this study. The polymers and surfactants investigated in this study were emulsion polymer, CTAB and SDS. Sampling and characterization of digested sludge was conducted, and total solid (TS), volatile solid (VS), dewaterability in capillary suction time (CST), total dissolved solids (TDS), chemical oxygen demand (COD), pH and conductivity of the unconditioned digested sludge samples were determined. The dewaterability of FeCl3, CaCl2 and MgSO4 conditioned digested sludge samples were compared, and MgSO4 conditioned digested sludge showed better dewaterability compared to the other two metal conditioning agents at a pH of 6.8. The dewaterability was further improved by the addition of emulsion polymer (EMA 8854), cetyltrimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS). Fe Cl3 was found to perform better under an acidic pH of around 3. The dual conditioning using polymer and CTAB resulted in better dewaterability, with CaCl2 as metal conditioning agent. Moreover, the effects of pH, metal dose and polymer dose on the dewaterability of digested sludge were also investigated. The effects of metal and polymer conditioning on the particle size of the sludge flocs was also investigated. Optimum dewatering performance was achieved for metal doses of 0.16 v/v, 0.075 v/v and 0.16 v/v for FeCl3, CaCl2 and MgSO4, respectively, and a corresponding CTAB dose of 0.1 v/v and EMA dose of 15 kg/TDS were found to be the optimum. SDS as a polymer conditioning agent resulted in the deterioration of dewatering performance. [ABSTRACT FROM AUTHOR]

The influence of metal cations on corrosion behavior of aluminum alloy (AA2024-T3) in model freshwater was examined by immersion experiments, surface analysis, and electrochemical measurements. After long-time immersion, the corrosion rate of AA2024-T3 decreased as the corrosion indicator Y increased, and the corrosion rate of the alloy was reduced by Zn2+. The specimen immersed in Zn2+ containing solution showed less corrosion products which were observed by scanning electron microscopy (SEM). The results of X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) showed that Zn2+ attaches to aluminum alloys and forms protective layers. Electrochemical impedance spectroscopy (EIS) results suggested that Zn2+ reduced the area of defects in the passive film. [ABSTRACT FROM AUTHOR]

This study explores the impact of mediators and metal ions of laccase-mediated oxidation and ferrate(VI) oxidation for the simultaneous removal of tetracycline antibiotics (TCs) and sulfonamide antibiotics (SAs) and to effectively remove their antimicrobial activity. The results showed that the antimicrobial activity of tetracycline against Bacillus altitudinis and Escherichia coli was significantly reduced, and the antimicrobial activity of sulfamethoxazole against B. altitudinis disappeared completely after treatment with the laccase–ABTS system. The combination of 6.0 U/mL of laccase and 0.2 mmol/L of ABTS removed 100% of 20.0 mg/L of tetracycline after 1.0 min at pH 6.0 and 25.0 °C, whereas the removal ratio of 20.0 mg/L of sulfamethoxazole was only 6.7%. The Al3+ and Cu2+ ions promoted the oxidation, and the Mn2+ ion decelerated the oxidation of tetracycline and sulfamethoxazole by the laccase-mediator systems. In contrast, the antimicrobial activity of tetracycline against B. altitudinis and E. coli was shown to be significantly reduced, and the sulfamethoxazole still retained high antimicrobial activity against B. altitudinis after treatment with Fe(VI) oxidation. The removal ratio of 20.0 mg/L of tetracycline was 100% after 1.0 min of treatment with 982.0 mg/L of K2FeO4 at pH 6.0 and 25.0 °C, whereas the removal ratio of 20.0 mg/L of sulfamethoxazole was only 49.5%. The Al3+, Cu2+, and Mn2+ ions both decelerated the oxidation of tetracycline and sulfamethoxazole by Fe(VI) oxidation. In general, the combination of the laccase–ABTS system and Fe(VI) was proposed for the simultaneous treatment of TCs and SAs in wastewater and to effectively remove their antimicrobial activity. [ABSTRACT FROM AUTHOR]

Carbons prepared by pyrolysis of waste corn cobs or scrap tyres using different microwave power (200, 400, 600 W) are compared with carbons prepared by co-pyrolysis of corn:tyre mixtures in various mass ratios without/with activator (KOH, ZnCl 2 , K 2 CO 3 , NaOH in solid or liquid phase). Activation and co-pyrolysis of corn:tyre mixture was proved to be advantageous, prepared activated carbons showed enhanced xylene adsorption compared to non-activated. Activated carbons prepared from corn:tyre mixture at mass ratio of 4:1 and using ZnCl 2 in liquid and ZnCl 2 and K 2 CO 3 in solid phase showed the highest adsorption capacities (∼171, 139 and 104 mg xylene ·g−1, respectively) despite the opposite trend in their microporosity. Molecular modeling proved a preferential interaction of xylene with activated carbons porous structure through Zn2+, K+ and Na+ ions. The smallest cation with the highest positive charge, Zn2+, interacts the most strongly with xylene. The strength of cation-xylene interaction decreases as follows: Zn2+ > Na+ > K+. As the strongest were proved xylene interactions with Pore (5.2 Å)_Zn2+ > Pore (8.5 Å)_Zn2+ > Surface_Zn2+ > Pore (5.2 Å)_Na+ ∼ Pore (5.2 Å)_K+, which explains the highest adsorption capacities of ZnCl 2 -activated carbons despite of their lower microporosity compared to carbon activated by using K 2 CO 3 (s). [Display omitted] • Scrap tyres and corn cobs microwave co-pyrolysis completed in 30 min. • Activated carbons with ZnCl 2 and K 2 CO 3 are the best xylene adsorbents. • Adsorption determining factors: microporosity + cation charge and size. • The strength of cation-xylene interaction: Zn2+ > Na+ > K+. • With respect to pores: Pore(5.2 Å)_Zn2+ > Pore(8.5 Å)_Zn2+ > Surface_Zn2+ > Pore(5.2 Å)_Na+/K+. [ABSTRACT FROM AUTHOR]

Interactions between negatively charged aluminosilicate species and positively charged metal cations are critical to many important engineering processes and applications, including sustainable cements and aluminosilicate glasses. In an effort to probe these interactions, here we have calculated the pair-wise interaction energies (i.e., binding energies) between aluminosilicate dimer/trimer and 17 different metal cations Mn+ (Mn+ = Li+, Na+, K+, Cu+, Cu2+, Co2+, Zn2+, Ni2+, Mg2+, Ca2+, Ti2+, Fe2+, Fe3+, Co3+, Cr3+, Ti4+ and Cr6+) using a density functional theory (DFT) approach. Analysis of the DFT-optimized structural representations for the clusters (dimer/trimer + Mn+) shows that their structural attributes (e.g., interatomic distances) are generally consistent with literature observations on aluminosilicate glasses. The DFT-derived binding energies are seen to vary considerably depending on the type of cations (i.e., charge and ionic radii) and aluminosilicate species (i.e., dimer or trimer). A survey of the literature reveals that the difference in the calculated binding energies between different Mn+ can be used to explain many literature observations associated with the impact of metal cations on materials properties (e.g., glass corrosion, mineral dissolution, and ionic transport). Analysis of all the DFT-derived binding energies reveals that the correlation between these energy values and the ionic potential and field strength of the metal cations are well captured by 2nd order polynomial functions (R2 values of 0.99–1.00 are achieved for regressions). Given that the ionic potential and field strength of a given metal cation can be readily estimated using well-tabulated ionic radii available in the literature, these simple polynomial functions would enable rapid estimation of the binding energies of a much wider range of cations with the aluminosilicate dimer/trimer, providing guidance on the design and optimization of sustainable cements and aluminosilicate glasses and their associated applications. Finally, the limitations associated with using these simple model systems to model complex interactions are also discussed.

Double-PHD fingers 3 (DPF3) is a BAF-associated human epigenetic regulator, which is increasingly recognised as a major contributor to various pathological contexts, such as cardiac defects, cancer, and neurodegenerative diseases. Recently, we unveiled that its two isoforms (DPF3b and DPF3a) are amyloidogenic intrinsically disordered proteins. DPF3 isoforms differ from their C-terminal region (C-TERb and C-TERa), containing zinc fingers and disordered domains. Herein, we investigated the disorder aggregation properties of C-TER isoforms. In agreement with the predictions, spectroscopy highlighted a lack of a highly ordered structure, especially for C-TERa. Over a few days, both C-TERs were shown to spontaneously assemble into similar antiparallel and parallel β-sheet-rich fibrils. Altered metal homeostasis being a neurodegeneration hallmark, we also assessed the influence of divalent metal cations, namely Cu2+, Mg2+, Ni2+, and Zn2+, on the C-TER aggregation pathway. Circular dichroism revealed that metal binding does not impair the formation of β-sheets, though metal-specific tertiary structure modifications were observed. Through intrinsic and extrinsic fluorescence, we found that metal cations differently affect C-TERb and C-TERa. Cu2+ and Ni2+ have a strong inhibitory effect on the aggregation of both isoforms, whereas Mg2+ impedes C-TERb fibrillation and, on the contrary, enhances that of C-TERa. Upon Zn2+ binding, C-TERb aggregation is also hindered, and the amyloid autofluorescence of C-TERa is remarkably red-shifted. Using electron microscopy, we confirmed that the metal-induced spectral changes are related to the morphological diversity of the aggregates. While metal-treated C-TERb formed breakable and fragmented filaments, C-TERa fibrils retained their flexibility and packing properties in the presence of Mg2+ and Zn2+ cations. [ABSTRACT FROM AUTHOR]

Flavonoids are a group of food polyphenols that are delivered to the human body with plant foods. In recent years, these substances have attracted the attention of researchers due to their effectiveness in preventing a wide variety of diseases, including neurodegenerative, oncological, autoimmune, and cardiovascular. Similar pathologies may also occur with a lack of some first-row transition metals, including Cu(II), Zn(II), Mn(II), Fe(II/III). It is noteworthy that flavonoids are known as transition metal chelators. When a complex with these metals is formed, the therapeutic effect of flavonoids can be enhanced, assuming the possibility of synergy. Molecular models have shown that the lipophilicity of flavonoid-metal complexes can vary significantly depending on their binding stoichiometry. Therefore, a unique process of translocation of flavonoid-metal complexes of various lipophilicity through cell membranes is assumed, based on the possibility of their sequential association and dissociation, called "hitchhiking". It is expected that studies of the interaction of flavonoids with metals will improve the effectiveness of drugs based on flavonoids. [ABSTRACT FROM AUTHOR]

In recent decades, several abatement techniques have been proposed for organic dyes and metal cations. In this scenario, adsorption is the most known and studied. Clinoptilolite was considered, since it is a zeolite with a relatively low cost (200–600 $ tons−1) compared to the most well-known adsorbent used in wastewater treatment. In this work, Clinoptilolite was used for the adsorption of Methylene Blue (MB) at three different concentrations, namely, 100, 200, and 250 ppm. Furthermore, the adsorption capacity of the natural zeolite was compared with that of Activated Charcoal (250 ppm of MB). The two adsorbents were characterized by complementary techniques, such as N2 physisorption at −196 °C, X-ray diffraction, and field emission scanning electron microscopy. During the adsorption tests, Clinoptilolite exhibited the best adsorption capacities at 100 ppm: the abatement reached 98% (t = 15 min). Both Clinoptilolite and Activated Charcoal, at 250 ppm, exhibited the same adsorption capacities, namely, 96%. Finally, at 250 ppm MB, the adsorption capacity of Clinoptilolite was analyzed with the copresence of Zn2+ and Cd2+ (10 ppm), and the adsorption capacities were compared with those of Activated Charcoal. The results showed that both adsorbents achieved 100% MB abatement (t = 40 min). However, cation adsorption reached a plateau after 120 min (Zn2+ = 86% and 57%; Cd2+ = 53% and 50%, for Activated Charcoal and Clinoptilolite, respectively) due to the preferential adsorption of MB molecules. Furthermore, kinetic studies were performed to fully investigate the adsorption mechanism. It was evidenced that the pseudo-second-order kinetic model is effective in describing the adsorption mechanism of both adsorbents, highlighting the chemical interaction between the adsorbent and adsorbate. [ABSTRACT FROM AUTHOR]

A functionalized sodium alginate/polyvinyl pyrrolidone/zinc oxide @silica Schiff base (SA/PVP/ZnO@SiO2 SB) nanofiber membrane was prepared by electrospinning technique to study the single and binary adsorption of Cu(II) and Ni(II) cations from aqueous systems. Several analyses containing XRD, FTIR, FESEM, TEM, BET and TGA were applied to evaluate the structure of prepared samples. The mechanical strength and swelling tests were also investigated. To investigate the effect of Schiff base ligands and ZnO@SiO2 nanoparticles on the adsorption of Cu(II) and Ni(II) cations, the batch experiments were performed in a single batch system. It was found that Schiff base ligands play an important role in adsorption process. Furthermore, the effect of significant parameters such as solution pH, nanoparticle contents, contact time, initial cation concentration and adsorption temperature was studied. The double-exponential model was the best model to describe the kinetic data. The results of equilibrium isotherms showed that a monolayer adsorption was dominant. The maximum adsorption capacity of SA/PVP/ZnO@SiO2 Schiff base nanofiber membrane for Cu(II) and Ni(II) cations was 289.5 and 101.9 mg/g, respectively, at 45 °C. The endothermic and spontaneous adsorption was obtained from thermodynamic data. The SA/PVP/ZnO@SiO2 Schiff base nanofiber adsorbent was easily reused without remarkable decrease in adsorption capacity for both Cu(II) and Ni(II) cations after 5 steps. In a binary system, the adsorption capacity was reduced with increasing the other metal cation concentrations indicating an antagonistic adsorption effect. [ABSTRACT FROM AUTHOR]

Liquid crystals (LCs), when interfaced with chemically functionalized surfaces, can amplify a range of chemical and physical transformations into optical outputs. While metal cation-binding sites on surfaces have been shown to provide a basis for the design of chemoresponsive LCs, the cations have been found to dissociate from the surfaces and dissolve slowly into LCs, resulting in time-dependent changes in the properties of LC-solid interfaces (which impacts the reliability of devices incorporating such surfaces). Here, we explore the use of surfaces comprising metal-coordinating polymers to minimize the dissolution of metal cations into LCs and characterize the impact of the interfacial environment created by the coordinating polymer on the ordering and time-dependent properties of LCs. In particular, by combining theoretical (electronic structure calculations) and experimental (polarization-modulation infrared reflection-adsorption spectroscopy) results, we determine that the pyridine groups of a thin film of poly(4-vinylpyridine -co- divinylbenzene) (P(4VP- co -DVB)) coordinate with Ni 2+ when Ni(ClO 4 ) 2 is deposited onto the film. We provide evidence that the Ni 2+ -pyridine coordination weakens the binding of Ni 2+ with 4'- n -pentyl-4-biphenylcarbonitrile (5CB), a room-temperature nematic LC, as compared to Ni(ClO 4 ) 2 supported on glass, although binding is still sufficiently strong to induce a homeotropic (perpendicular) orientation of the LC. Exposure of the 5CB films supported on Ni(ClO 4 ) 2 -decorated P(4VP -co- DVB) substrates to parts-per-million vapor concentrations of dimethylmethylphosphonate (DMMP) was found to trigger orientational transitions (to planar (parallel) orientations) in the LC films. In contrast, 5CB supported on Ni(ClO 4 ) 2 -decorated glass surfaces exhibited no response, even though displacement of 5CB by DMMP is predicted by computations to be thermodynamically favored in both cases. We propose that the distinct LC responses measured on glass and the coordinating polymer substrates are governed by the kinetics of displacement of 5CB by DMMP, a proposal that is supported by measurements performed with increasing temperature. Importantly, by using Ni 2+ supported on P(4VP -co- DVB), we measured the ordering of 5CB to be stable and long-lived (>7 days), in contrast to unstable LC ordering (<14 h) when using Ni 2+ supported on glass under dry conditions and at room temperature. We further demonstrate the stability of Ni(ClO 4 ) 2 supported on P(4VP -co- DVB) toward higher temperatures and humidity using E7 as the LC. Overall, these results demonstrate that metal-coordinating polymer films are a promising class of substrates for fabricating robust and long-lived chemoresponsive LCs.

Metal cations are potent environmental pollutants that negatively impact human health and the environment. Despite advancements in sensor design, the simultaneous detection and discrimination of multiple heavy metals at sub‐nanomolar concentrations in complex analytical matrices remain a major technological challenge. Here, the design, synthesis, and analytical performance of three highly emissive conjugated polyelectrolytes (CPEs) functionalized with strong iminodiacetate and iminodipropionate metal chelates that operate in challenging environmental samples such as seawater are demonstrated. When coupled with array‐based sensing methods, these polymeric sensors discriminate among nine divalent metal cations (CuII, CoII, NiII, MnII, FeII, ZnII, CdII, HgII, and PbII). The unusually high and robust luminescence of these CPEs enables unprecedented sensitivity at picomolar concentrations in water. Unlike previous array‐based sensors for heavy metals using CPEs, the incorporation of distinct π‐spacer units within the polymer backbone affords more pronounced differences in each polymer's spectroscopic behavior upon interaction with each metal, ultimately producing better analytical information and improved differentiation. To demonstrate the environmental and biological utility, a simple two‐component sensing array is showcased that can differentiate nine metal cation species down to 500 × 10−12 m in aqueous media and to 100 × 10−9 m in seawater samples collected from the Gulf of Mexico. [ABSTRACT FROM AUTHOR]

In this study, thermogravimetric analysis (TGA) with a final temperature of 1000°C at a heating rate of 10°C/min and rapid pyrolysis are used to analyze the catalytic pyrolysis effect of CaCl2 and NiCl2 on lignite samples, mainly including pyrolysis reaction analysis and tar product distribution. To avoid the influence of minerals on the pyrolysis reaction, acid-washed coal is selected and mixed with metal cations for further analysis. The TGA results show that when mixed with 6 wt. % Ca or Ni, the weight loss rate of acid-washed lignite increases from 46.46% to 59.76% and 54.66%, respectively. At pyrolysis temperatures above 600°C, the performance on coal pyrolysis transformation of Ca is significantly better than that of Ni. The effect of the catalyst on coal pyrolysis could be divided into three stages. Due to catalysis, the pyrolysis of the most unstable structure of coal is advanced to the first stage, which makes the second stage show a certain catalytic inhibition. Kinetic analysis reveals that the activation energy of pyrolysis is obviously reduced by catalysts, and comparatively, the most energy is needed at the second stage. The tar mainly contains substances with 5 to 16 carbon atoms, and aromatic hydrocarbons, as the main components, account for more than 90% of the tar composition. The yield of light aromatic compounds increases with the catalysts Ca and Ni, while the yield of polycyclic aromatics decreases. [ABSTRACT FROM AUTHOR]

[Display omitted] • The acid–base properties of pregabalin were investigated under different conditions. • The findings indicate that at the pH of seawater (pH = 8.2), approximately 58 % of PGB is complexed with Cu2+ and ∼41 % exists as LH0 species. • For the Zn2+/PGB system, only the ∼28 % of PGB is complexed and ∼70 % of PGB exists as protonated species. The thermodynamics of the interaction between (S)-(+)-3-aminomethyl-5-methylhexanoic acid (pregabalin) and protons was studied potentiometrically at different temperatures (288.15 ≤ T /K ≤ 310.15), ionic strengths (0.16 ≤ I /mol kg−1(H 2 O) ≤ 0.97, NaCl), (0.11 ≤ I /mol kg−1(H 2 O) ≤ 1.11, (C 2 H 5) 4 NI), (0.10 ≤ I /mol kg−1(H 2 O) ≤ 1.03, NaClO 4 , only at T = 298.15 K). The protonation constants at infinite dilution and the corresponding enthalpy change values were determined, as well as their parameters for the dependence on the temperature and ionic strength. The results showed that the protonation reactions are exothermic, and that the entropic contribution is the driving force of the processes. Formation constants of pregabalin (L) with Zn2+, Cu2+, Ca2+, and Mg2+ were determined in NaCl(aq) at different ionic strength values, at 298.15 K. Different speciation models were proposed for the various metal/Pregabalin systems: ZnHL2+, ZnLOH0 (aq) , CuL+, CuL 2 0 (aq) , CaL+, CaHL2+, and MgL+, depending on the different acid–base properties of the metals and the possible formation of sparingly soluble species. The modelling of the thermodynamic formation parameters respect to the temperature and ionic strength variation was carried out by using both the Specific Ion Interaction Theory (SIT) and an extended Debye-Hückel type equation. Being Pregabalin an emerging contaminant, it was interesting to investigate its distribution in presence of the investigated metal cations in aqueous solution simulating both biological fluid (urine) and natural water (seawater). [ABSTRACT FROM AUTHOR]

Dopamine is the most essential monoaminergic neurotransmitter involved in the pathophysiology of neurodegenerative disorders, and its autoxidation has been recognized as one of the potential trigger factors for dopaminergic neuron loss. The cyclization of dopamine o-quinone was shown to be the irreversible and rate-limiting step of the autoxidation reaction at physiologic pH values. Furthermore, various metal ions such as Al3+, Fe3+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Pb2+, and Mn2+ have been clinically associated with neurodegeneration, especially Parkinsonism and dementia. It has been proposed that these metal ions could increase the rate of the dopamine autoxidation reaction; however, the exact mechanism has not yet been fully understood. Using advanced quantum chemical calculations with the inclusion of solvent effects we showed that except for Mn2+, the studied metal cations could form complexes with dopamine o-quinone and significantly increase the dopamine o-quinone cyclization rate in aqueous solution; first, by enabling the cyclization to proceed spontaneously without the attack of the unprotonated amino group by hydroxide ion; second, by decreasing the intrinsic activation energy; and third, by decreasing the free energy of protonated amino group deprotonation. The latter also decreases the protective effect of acidic pH on dopamine autoxidation found in synaptic vesicles. The results are fully consistent with experimental data and provide deeper understanding of the effects of metal cations on the dopamine autoxidation reaction at physiologic pH values.

The study aimed to develop inhibitive pigments based on the natural biopolymer tannin through metal complexation, as an effective and eco-friendly alternative to conventional inhibitive pigments in epoxy coatings for steel protection in marine environments. Initial screening of metal cations for tannin complexation was conducted via steel immersion tests in 3.5 wt% NaCl solution. The combination of tannin with Zn2+ and Ce3+ both exhibited outstanding corrosion inhibition performance. After a 14-day immersion period, the inhibition efficiency reached 79.0 % and 74.0 % respectively, compared to 53.9 % for pure tannin. The more uniform formation of iron-tannin complexes and the co-deposition of metal hydroxides/oxides are believed to contribute to a synergistic effect, as confirmed by ATR-FTIR and SEM-EDS analysis. Further, considering both inhibition efficiency and eco-friendliness, the cerium(III)-tannin complex (CeTA) pigment was successfully synthesized and incorporated into anticorrosive epoxy coatings. Salt spray exposure and electrochemical impedance spectroscopy (EIS) measurements consistently demonstrated improved pigment compatibility with the epoxy matrix and reinforced coating anticorrosive performance. [ABSTRACT FROM AUTHOR]

This review is devoted to ion spectroscopy studies of complexes relevant for the understanding of methane activation with metal ions and clusters. Methane activation starts with the formation of a complex with a metal ion. The degree of the interaction between an intact methane molecule and the ion can be monitored by the perturbations of C–H stretch vibrations in the methane molecule. Binding mediated by the electrostatic interaction results in a η3 type coordination of methane. In contrast, binding governed by orbital interactions results in a η2 type coordination of methane. We further review the spectroscopic characterization of activation products of metal–methane reactions, such as the metal–carbene and carbyne products resulting from the interaction of selected 5d metals with methane. The focus of recent research in the field has shifted towards the investigation of interactions between methane and metal clusters. We show examples highlighting that metal clusters can be more reactive in methane activation reactions. [ABSTRACT FROM AUTHOR]

The current research work demonstrates a simple, fast, and sensitive colorimetric approach for visual and spectroscopic detection of mercury (Hg (II)) ions using silver nanoparticles. The compound, N-(3,5-bis(trifluoromethyl)phenyl)-2-(4-chlorophenyl) hydrazine carbothioamide (ThAm), is synthesized, characterized and reacted with AgNO3 in the presence of sodium borohydride (NaBH4) used as reducing agent to produce AgNPs having mean particle size of approximately 11 nm. The stability of nanoparticles (NPs) is studied at different conditions such temperature, time, pH and salt concentration. The NPs are characterized by commonly available techniques including UV–Visible spectroscopy, atomic force microscopy (AFM), Fourier transformed infrared spectroscopy (FTIR) and thermogravimetric/differential analyzer (TG/DTA). The AgNPs are selective to detect Hg (II) among the sixteen metal ions considered in this study. The yellow color of AgNPs solution disappears quickly by addition of Hg (II), along with a substantial variation in surface plasmon resonance band (SPRB). The limit of detection (LOD) is 2.2 µM and that of quantification (LOQ) 7.5 µM. The sensor also responded to the trace amount of Hg (II) ions in spiked water samples and in human blood plasma. Recoveries study of spiked real water samples was in range of 95–98%. [ABSTRACT FROM AUTHOR]

Featured Application: The results of such studies will enable researchers to gain insight into the behavior of metals in wet depositions, which is fundamental knowledge to carry out atmospheric photochemistry studies and to model biogeochemical cycles of metal cations. Both inorganic and organic complexation of metal cations in clouds or rainwater is essential to describe the global biogeochemical cycles of metals, because complexation can increase metal solubility and stabilize some of their oxidation states. Within a Project of the National Research Program in the Antarctica, atmospheric depositions were collected during the Antarctic summer 2017–2018 in eight sampling sites. The main ionic components occurring in water extracts of these atmospheric depositions were quantified, and a chemical model was applied, in order to identify the main species occurring in the samples. The speciation study showed that most cations were present as aquoions, except for Fe, which occurred predominantly in hydrolytic forms. The model allowed us to foresee the effect of an increase in the concentration levels of all the solution components, by simulating what could happen when the original particles act as cloud condensation nuclei. The role of inorganic anions as complexing agents becomes important when increasing total concentrations of all the solutes by a factor >100 compared to the water extracts, while the presence of organic acids acquires significance for samples having organic acid concentration higher than 10−5 mol L−1. Moreover, it was possible to pinpoint the formation constants that mostly affect the chemical system, and to gain insight into the behavior of metals in wet depositions, which is fundamental knowledge in atmospheric photochemistry studies and in the modeling of the biogeochemical cycles of metal cations. [ABSTRACT FROM AUTHOR]

In this work, membranes for organic solvents nanofiltration (OSN) based on a natural polymer, sodium alginate, were fabricated. They are chemically stable in organic solvents, including aprotic polar solvents. The unique advantage of these membranes is the absence of toxic reagents and solvents during their production. This ensures the safety and environmental friendliness of the production process. It has been shown that an operation as simple as changing the cation in alginate (Cu2+, Fe3+, Cr3+, Al3+, Zn2+, Ca2+) makes it possible to control the transport and separating properties of membranes, depending on the organic solvent being separated. Therefore, to isolate RemazolBrilliant Blue with MM = 626 g·mol−1 from ethanol, membranes based on iron alginate with a rejection R = 97% and a permeability of 1.5 kg·m−2·h−1·bar−1 are the most efficient. For isolation of the same solute from DMF and MP, membranes based on calcium alginate with an R of about 90% and a permeability of 0.1–0.2 kg·m−2·h−1·bar−1 are the most efficient. The resulting membranes based on natural biodegradable sodium alginate are competitive compared to membranes based on synthetic polymers.

A new fluorescent chemosensor comprised of a pyridine functionalized pillar[5]arene (PyP5) and 1‐naphthol has been designed and utilized for the recognition of metal cations. The 1‐naphthol was encapsulated by the PyP5 cavity and formed a 1 : 1 host ‐ guest inclusion complex. Whilst free 1‐naphthol is known to be strongly fluorescent, this strong fluorescence was quenched in the inclusion complex 1‐naphthol@PyP5. Using the 1‐naphthol@PyP5 inclusion complex as a fluorescent probe, various metal cations have been detected. The experimental results revealed that the probe responded to both Ag+ and Fe3+, via an obvious fluorescence quenching or an incomplete quenching of fluorescence, respectively. As a result, a fluorescence method for the detection of two metal cations using a single system has been developed. On the other hand, 1‐naphthol is an important intermediate of fine chemicals, which is widely used in the synthesis and production of dyes, spices, oils, medicines and pesticides.[50–52] The oxygen atom of 1‐naphthol is sp2 hybridized and can form extensive π bonds, and can exhibit strong fluorescence. The successful preparation of water‐soluble pillar[5]arene can provide new opportunities for chemists working in the field of host–guest chemistry and the recognition of metal ions. Therefore, more and more research has centered on the synthesis of water‐soluble pillar[5]arenes.[53–56] On this basis, we have synthesized a pyridine functionalized pillar[5]arene. Pyridine functionalized pillar[5]arenes are extremely soluble in water and strongly bind 1‐naphthol in water, which is mainly driven by hydrophobic and electrostatic interactions. The probe system is constructed by encapsulating one equivalent of 1‐naphthol, which possess strong intrinsic fluorescence, into the hydrophobic cavity of PyP5. To this inclusion complex, namely 1‐naphthol@PyP5, were added metal ions. The addition of Ag+ led to incomplete quenching of fluorescence, whilst Fe3+ led to complete quenching of fluorescence. Based on the linear relationship between the fluorescence intensity and the concentration of Ag+ and Fe3+, a simple fluorescent probe method for the analysis of Ag+ and Fe3+ was constructed. The observed visual signals indicate the potential of this probe system in rapid assay applications. [ABSTRACT FROM AUTHOR]

In this manuscript, we propose a simple and versatile methodology to design nanosystems based on biocompatible and multicomponent mesoporous silica nanoparticles (MSNs) for infection management. This strategy relies on the combination of antibiotic molecules and antimicrobial metal ions into the same nanosystem, affording a significant improvement of the antibiofilm effect compared to that of nanosystems carrying only one of these agents. The multicomponent nanosystem is based on MSNs externally functionalized with a polyamine dendrimer (MSN-G3) that favors internalization inside the bacteria and allows the complexation of multiactive metal ions (MSN-G3-Mn+). Importantly, the selection of both the antibiotic and the cation may be done depending on clinical needs. Herein, levofloxacin and Zn2+ ion, chosen owing to both its antimicrobial and osteogenic capability, have been incorporated. This dual biological role of Zn2+ could have and adjuvant effect thought destroying the biofilm in combination with the antibiotic as well as aid to the repair and regeneration of lost bone tissue associated to osteolysis during infection process. The versatility of the nanosystem has been demonstrated incorporating Ag+ ions in a reference nanosystem. In vitro antimicrobial assays in planktonic and biofilm state show a high antimicrobial efficacy due to the combined action of levofloxacin and Zn2+, achieving an antimicrobial efficacy above 99% compared to the MSNs containing only one of the microbicide agents. In vitro cell cultures with MC3T3-E1 preosteoblasts reveal the osteogenic capability of the nanosystem, showing a positive effect on osteoblastic differentiation while preserving the cell viability. A simple and versatile methodology to design biocompatible and multicomponent MSNs based nanosystems for infection management is proposed. These nanosystems, containing two antimicrobial agents, levofloxacin and Zn2+, have been synthetized by external functionalization of MSNs with a polycationic dendrimer (MSNs-G3), which favours its internalization inside the bacteria and lead the complexation with metal ions through the amines of the dendrimer. The nanosystems offer a notable improvement of the antibiofilm effect (above 99%) than both components separately as well as osteogenic capability with positive effect on the osteoblastic differentiation and preserved cell viability. [Display omitted] [ABSTRACT FROM AUTHOR]

Metal cations play important roles in several industrial and biochemical processes. However, high levels of some cations are toxic and consequently cause serious health and environmental problems. Because of these features, the search for organic molecules capable of coordinating these analytes is an increasingly studied topic in the scientific community, especially those with optical responses (optical chemosensors). Following the research group’s interest in heterocyclic optical chemosensors for various ions, a sulfo-cyanine, which absorbs and emits in the NIR region, was studied as a chemosensor for the recognition of metal cations with biological and environmental relevance. Chemosensing studies showed that this sulfo-cyanine displayed a highly sensitive colorimetric response, from blue to colorless, for Cu2+ and Fe3+ in acetonitrile solution.

A carboxylic acid azo dye, Dabcyl, was synthesized and evaluated as a colorimetric chemosensor for metal cations with biological and environmental importance. The dye was prepared in high yield and characterized by 1H and 13C NMR and UV–Vis absorption spectroscopies. A preliminary chemosensing study showed that Dabcyl displayed a marked color change from light yellow to pink, for Hg2+, Fe2+, Pd2+, Sn2+ and Al3+ in acetonitrile solution. Consequently, spectrophotometric titrations were carried out for this dye with selected cations, which clearly indicated that Dabcyl has potential application as a chromogenic probe for the cations under study with remarkable sensitivity and with a marked color change.

With the extensive use of graphene oxide (GO) in research and application, the negative impact of water-soluble graphene oxide on the environment has to be considered. It is significant to find a suitable method to remove GO from water. In this study, sulfates were used as the coagulants for GO removal. The experimental results showed that cations as Mg2+, Al3+, Ca2+, Co2+, Ni2+, Cu2+, Zn2+, Mn2+ interacted with GO and GO would agglomerate then. However, low-concentration Na+, K+ and SO42– did not show any coagulation capacity. The temperature, equilibrium time and the initial concentration of cations and GO would affect the coagulation capacities. Among the selected sulfates, aluminum sulfate, calcium sulfate and copper sulfate had higher coagulation capacities, which were 4,772; 1,149 and 1,451 mg/g, respectively. In addition, the metallic cations mentioned were easy to obtain, so they were promising coagulants for the elimination of GO from water. [ABSTRACT FROM AUTHOR]

• The study on cationic sensitivity of inductance coil based contactless sensor. • Aqueous solutions of 16 metal cations are studied in a broad concentration range. • Sensitivity and linear response range parameters are characterized. • Response dependence of the radius and the charge of the cation are discussed. Contactless sensors for chemical analysis, based on inexpensive and widely available electronic components, are a promising alternative to existing routine laboratory methods. We have proposed a novel type of a contactless sensor, composed of three simple components: an alternate current generator, an inductance coil, and a receiver. The sample, placed into the coil as a core of the inductor, modifies the current passing through the coil. Previously, we have demonstrated that this contactless sensor may have numerous applications for chemical analysis. In this work, we have explored the performance of the coil-based measuring platform further and performed the first systematic study of the response of inductance coil sensor to metal cations in aqueous solutions. Sixteen metal cations with different charge and radii were studied. Linear response ranges, sensitivity values and the comparison between univariate and multivariate regression modeling are presented. The largest linear response range was observed for transition metal cations Ni2+, Cu2+, Pb2+ and Nd3+ (10-3 – 10-1 M), the narrowest – for Li+ and Gd3+ (10-2 – 3.2x10-1 M) with R2 values larger than 0.94. The dependence of the response on the radius and the charge of the cation are discussed. The analytical characteristics of the device show its potential in contactless and low-cost chemical analysis and set the ground for the future research. [ABSTRACT FROM AUTHOR]