Addition Of Cations Research Articles

Establishment of a method to measure the intracellular potassium ion concentration of brain tissue using a simple device.

Intracellular potassium ion (K+) concentration is higher than extracellular K+ concentration. Some cells maintain intracellular potassium levels by taking up extracellular potassium. However, investigating these details requires techniques to measure intracellular potassium concentrations. We established a method to easily measure intracellular potassium concentrations using a simpler electrode. The LAQUAtwin K-11 was capable of linearly quantifying potassium concentrations and was not affected by cellular constituents other than nucleic acids; however, it did not tolerate low temperatures. Interference caused by a high concentration of nucleic acids was eliminated by the addition of cations. It was also suggested that the concentration of nucleic acids in the cell suspension was not sufficiently high to interfere with the measurements. Intracellular potassium concentrations increased and decreased in response to extracellular potassium concentrations. Exposure to valinomycin did not decrease the potassium concentration, suggesting that re-uptake of the potassium released outside the cells occurred immediately. Additionally, potassium concentrations could be measured in the brain tissue homogenates using the device. This measurement method can track the relative changes in potassium concentration in cells under various conditions and in tissues of various disease models.

Enhancement of the blue luminescence of phenylquinoline derivatives by cation addition

Enhancement of the blue luminescence of phenylquinoline derivatives by cation addition

STRUCTURAL FEATURES AND PROPERTIES OF MULTICOMPONENT SODIUM-CESIUM/RUBIDIUM ALUMINOBOROSILICATE MODEL MATRIX GLASSES OF BASIS COMPOSITION

Synthesis and study of the structure and various properties of Na-Cs and Na-Rb aluminoborosilicate model glasses with addition of the alkaline-earth cations have been carried out. Vibrational spectroscopy techniques have been used to establish the high degree of polymerization and noticeable structural similarity of all synthesized glasses at fixed ratio of modifying and network-forming cations. It has been shown that increasing fraction of large cations in the total content of modifying cations leads to changes in distribution of modifying cations between the silicate and borate structural units. The observed homogeneity with the similarity of anionic structure, at different content and various combinations of alkali and alkaline-earth cations, points at promising application of these glasses as a basis for synthesis of matrix materials for high-level radioactive waste disposal.

Radical promoted cationic RAFT polymerization by photo electron transfer reaction

A radical promoted cationic reversible addition–fragmentation chain transfer (RAFT) polymerization of various vinyl ethers via photo electron transfer reaction was developed and applied in photocuring.

Screening metal cation additives driven by differential capacitance for Zn batteries

The high-valence metal cation Ce4+ is used to compress the electric double layer on the Zn electrode surface, which improves Zn2+ deposition overpotential and reduces the Zn electrode corrosion rate.

Ion valence-gated photochromism of an aza-crowned diarylethene.

A non-photochromic diarylethene 2o with an N-phenylaza-15-crown-5 was synthesized. When the nitrogen atom in the aza-crown ring was protonated, it became photochromic due to the prevention of a twisted intramolecular charge transfer (TICT). Although addition of a monovalent metal cation (Li+, Na+, K+, Rb+, Cs+, Cu+, Ag+) in acetonitrile could not stop the TICT so that it was not photochromic, the addition of a multivalent metal cation (Mg2+, Ca2+, Sr2+, Ba2+, Fe2+, Ni2+, Al3+, Sb5+) changed 2o to be photochromic due to the strong attraction of the lone pair on the nitrogen atom. In the presence of excess Cu2+, 2o was oxidized to be EPR-detectable 2o·+, which was thermally unstable as well as inert towards visible-light irradiation. However, 2o·+ was further oxidized to be fairly stable 2o2+ by the irradiation of 365-nm light in the presence of Cu2+. ESI-MS measurements strongly suggested the generation of 2o·+ by mixing 2o with Cu(ClO4)2 in acetonitrile, and the transformation of 2o·+ to 2o2+ by successive 365-nm light irradiation. Fe3+ similarly worked as the oxidant, but the two-step oxidation of 2o to 2o2+ occurred more easily.

Study on the effect of cationic latex on the properties of cement stabilized iron tailings

This paper introduces the feasibility of replacing natural aggregates with iron tailings (after magnetic separation) in cement stabilized macadam (CSM) for the construction of base courses of motor road pavements. In this paper, the effects of cationic latexes Butonal NS 198 and Butonal 5126 as modifying additives on the structure, strength properties, frost resistance and crack resistance of cement stabilized iron tailing (CSIT) were studied. The possibility of introducing latex additives into CSIT was demonstrated by the technique of initially dissolving the cationic latex additives in water and obtaining solutions with the required thermodynamic properties. The results of the research showed that the unconfined compressive strengths and splitting strengths were not sufficient to comprehensively evaluate the effects of different concentrations of cationic latex additives on CSIT. At the same time, the experimental results proved that the introduction of cationic latex into CSIT resulted in a significant increase in the frost resistance, maximum structural strength, and temperature crack resistance index of the material.

Perovskite/silicon tandem solar cells-compositions for improved stability and power conversion efficiency.

Perovskite/Silicon Tandem Solar Cells (PSTSCs) represent an emerging opportunity to compete with industry-standard single junction crystalline silicon (c-Si) solar cells. The maximum power conversion efficiency (PCE) of single junction cells is set by the Shockley-Queisser (SQ) limit (33.7%). However, tandem cells can expand this value to ~ 45% by utilising two stacked solar cells to harvest the solar spectrum more efficiently. 33.9% PCE has already been achieved with PSTSCs. This perspective analyses recent advances in PSTSC technology, with an emphasis on optimal perovskite composition, the problem and mitigation of light-induced halide phase segregation, self-assembled hole transporting monolayers and additives that can improve and stabilise the perovskite. Top-performing compositions show three cationic components (Cs+, FA+, Pb2+) and three anionic (I-, Br-, Cl-) with a bandgap between 1.55 and 1.77eV and a theoretical maximum of 1.73eV (717nm). Anionic additives such as (Br3)- and SCN- reduce trap states and segregation. 2D-perovskite grain boundary interfaces are created with cationic alkylammonium additives such as methyl-phenethylammonium (MPEA) and result in improved performance. 2-, 3- or 4-terminal devices with a (partly) textured silicon heterojunction (SHJ) bottom cell are ideal. An ultra-thin interfacial recombination layer (~ 5nm) of indium tin oxide (ITO) or indium zinc oxide (IZO) containing a carbazole-based hole transporting self-assembled monolayer (Me-4PACz) is used for optimal 2-terminal tandem devices.

Effect of Cr cations addition on the structural, morphological, optical, and photocatalytic properties of Er-doped ZnO structures

In this work, we have investigated the effect of Cr3+ cations addition on the structural, morphological, optical, and photocatalytic properties of Er-doped ZnO structures. The Zn(1-(x-y))ErxCryO compound, where [(x; y) = (0.00; 0.00), (0.02; 0.01), (0.02; 0.02) and (0.02; 0.03)] was synthesized by the co-precipitation method and thermally treated at 100 °C for 6 h. The structural study showed that the dopant cations concentrations, cause variations in lattice constants, and increase the crystallite size and the strain in the ZnO crystal lattice. The structural atomic disorder was confirmed by Raman and photoluminescence spectroscopies, with VO, VO+, and VO++ type oxygen vacancy defects dominating. The samples exhibited different morphologies depending on the dopant concentration (plates-like, irregular hemispherical particles, and octahedrons-like structures). In the photocatalytic test, the methylene blue (MB) dye degradation under UV irradiation increased as a function of Cr3+ cations concentration, achieving a degradation rate of 37.4 ± 1.9% for the sample containing 2% of Er3+ cations and 3% of Cr3+ cations. In addition, the MB dye removal capacity by the Zn(1-(x-y))ErxCryO compound was incremented to above 85% using an optimized H2O2 concentration. Finally, the irradiated solution did not show toxicity against Artemia salina, indicating that the intermediate photoproducts formed are not toxic.

Effect of Metal Cations with Different Valences on the Humus Composition of Dark-Brown Soil Mixed with Tilia Wood Shavings

To clarify the contribution of the bridging effect from three metal cations (K+, Mn2+, and Fe3+) on the humification of lignin-rich Tilia wood shavings and further enrich the theory of lignin humification, an indoor incubation method with constant temperature and humidity was adopted. K+, Mn2+, and Fe3+ served as additives, with CK as the control for studying the differential influence of metal cations with different valences on the humus composition of dark-brown soil mixed with Tilia wood shavings. The change in the C contents of water-soluble substance (CWSS), humic-extracted acid (CHE) and humin (CHu), ∆logK value of HE, atomic ratio and FTIR spectra of humic acid (HA), and the ratio of C content of humic acid to fulvic acid (CHA/CFA) of dark-brown soil mixed with Tilia wood shavings were analyzed after 0, 30, 80, and 150 days of incubation, and the following conclusions were reached: (1) The addition of metal cations, regardless of their valence, could effectively improve the microbial utilization and consumption of WSS, and the effect was as follows: Fe3+ > Mn2+ > K+. The addition of three metal cations could effectively inhibit mineralization and reduce the loss of TOC, and the effect could be seen as follows: Fe3+ > Mn2+ > K+. (2) Although the CHE content first decreased and then increased with incubation, the addition of Fe3+ and Mn2+ ions increased the CHE content, showing that Fe3+ > Mn2+, and K+ ions had no significant effect. Throughout the incubation, the structure of HE molecules changed first via a complex process and then through a simple process. Comparing the change before and after the incubation, the overall structure of HE molecules tended to be simpler with the CK control, and HE became more complicated with the addition of Fe3+ and Mn2+; however, the addition of K+ had little effect on the structure of HE molecules. (3) At the end of the incubation, the addition of Fe3+, Mn2+, and K+ ions strengthened the molecular condensation of HA and its aromatization degree, while the CK control without any added metal cations caused HA molecules to decompose and obtain a greater aliphatic degree. In addition, the number of O-containing functional groups and N-containing compounds in HA molecules increased to varying degrees regardless of which metal cation was added. The decomposition of Tilia wood chips led to a partial entry of the decomposition products into the HA component, which was then reconsumed by continuous mineralization. After incubation, the polysaccharides in HA molecules were consumed only with the addition of Mn2+ ions. Fe3+ and Mn2+ ions had greater advantages in increasing the CHA/CFA ratio and improving the humus quality than K+ ions. (4) The addition of metal cations could effectively inhibit the mineralization and decomposition of the Hu component, among which Fe3+ ions had the most significant effect, followed by Mn2+ ions. Compared to monovalent cations (K+), polyvalent cations (Fe3+ and Mn2+) had the advantage of a bridging effect, and their addition promoted the microbial utilization of WSS, effectively reduced the loss of TOC, increased the CHE content, complicated its molecular structure, improved the humus quality, and inhibited the decomposition of Hu. Regardless of which metal cation was added, the degree of molecular polycondensation and aromatization of HA was enhanced, and the number of O-functional groups and N-containing compounds in HA molecules increased.

Characterizing digestibility of potato starch with cations by SEM, X-ray, LF-NMR, FTIR.

Cations can combine with starch and alter its physicochemical characteristics. The addition of cations may influence the in vitro digestion of potato starch. Scanning electron microscopy, X-ray diffraction, low-field nuclear magnetic resonance, and Fourier transform infrared spectroscopy were used to measure the microstructure, relative crystallinity, water distribution, and interaction of potato starch with cations and characterize its digestibility. The results showed that all cations decreased rapidly digestible starch (RDS) at a low concentration but increased the RDS with the addition of cations, especially trivalent cations. However, the resistant starch (RS) had the opposite trend. All cations increased the relative crystallinity of potato starch, except Ca2+. Fe3+, and Al3+ markedly decreased the mobility and hydrogen bonds in potato starch. In general, the addition of cations influenced the retrogradation of potato starch, resulting in a change in its digestibility.

About the possibility to liberate naturally present fixed cations from dioctahedral smectites by hydrothermal treatment

The chemical analysis of pure dioctahedral smectites exchanged by one of the typical CEC-index cations (e.g. Cu-trien) often shows significant Na-, Ca-, and K-contents which, in contrast to Mg, are not expected to occur in the octahedral sheet. They are supposed to occur in the interlayer but are not exchangeable - hence termed “fixed cations”. The aim of the study was to gain new evidence for the presence of naturally present fixed cations and find out if at least a part of these can be liberated by hydration after hydrothermal treatment.The methodological approach for cation liberation tests included different treatments with water at 60 °C and 150 °C, partly using an ultrasonic bath, and different reaction times prior to addition of the Cu-trien index cation for CEC analysis.The study proved that at least part of the naturally present fixed cations could be rendered exchangeable (liberated) by the hydrothermal treatment before an index cation is added. The differences were small but significant.Liberation of fixed cations was thought to increase the CEC but the increased amount of exchangeable cations was accompanied by a decrease of the CEC, which can probably be explained by partial smectite dissolution. This hypothesis was supported by measurements conducted at higher solid to liquid ratio in order to suppress smectite dissolution. The CEC decrease was less pronounced but at the same time less cations were liberated. In conclusion, the naturally present fixed cations are strongly bound and, supposedly, can only be liberated if the smectite structure is affected.Future work will be devoted to finding alternative methods which are suitable for quantification of naturally present fixed cations in bentonites/smectites.

Combining stable isotope ratios with elemental concentrations to improve the estimation of terrestrial carnivore diets

Stable isotopes of animal tissue have been used to estimate diet for many consumer species and places, but the ability to assign contributions to all food items is limited by the number of tracers used, and the separation of the tracer data among the dietary sources. We tested whether we could detect caribou (Rangifer tarandus) in the diet of individual predators in southwest Canada, where caribou are endangered. The separation between caribou tissue and that of other common prey was minimal using C13 and N15 isotope ratios and our confidence in assigning the caribou diet fraction correctly was low despite testing several fractionation values and priors. We measured the concentration of a suite of elements in the tissue of lichen, large prey and predators to investigate whether we could use an elemental concentration as a diet tracer and better assign the caribou diet fraction, because several of these elements were known to be more abundant in lichen, a major food for caribou in winter. Strontium and cesium had higher concentrations, when normalized by a common salt (we chose calcium), in caribou tissue than the other prey species we measured; this was also true for strontium isotope ratios. The elemental tracers appeared to overestimate caribou in the diet however, we suggest that the addition of either cation could yield finer and more accurate estimates of diet for large terrestrial predators after further investigation. The addition of a strontium isotope ratio tracer to a diet investigation may be equally informative and require less pre-work, because one ratio (Sr87/Sr86) has already been well studied.

Diffusion kinetics of molecular probe in thin poly(vinyl alcohol)-based films

We investigated the diffusion characteristics of a molecular probe in organic films of poly(vinyl alcohol) (PVA) that replicate formulations used as packaging materials. Diffusion kinetics of Rhodamine B (RhB) was measured in thin films of PVA containing glycerol and surfactants of various headgroup chemistry (cationic/nonionic/anionic) using fluorescence recovery after photobleaching and atomic force microscopy. Here we show how diffusion is determined by both molecular arrangement within the film and the nature/magnitude of intermolecular interactions. Addition of glycerol could improve the flexibility of PVA chains initially but imposed steric inhibition once the concentration exceeded the threshold of 44 wt%. In all investigated formulations, RhB exhibited diffusion-coupled mechanism. The presence of surfactants (at 6 wt%) reduced the diffusivity of RhB in PVA matrix for all types of surfactants used (by 30 %, 61 %, and 88 % for cationic, nonionic, and anionic surfactant addition compared to control sample, respectively). We conclude that steric inhibition effects underpin the diffusion of RhB in PVA thin films doped with nonionic surfactant. However, for PVA films with the addition of cationic or anionic surfactant, interactions between surfactant and fluorophore are likely responsible for the change in diffusivity of the molecular probe.

Blue LED light‐promoted CuCl2‐catalyzed three component reaction of styrenes, indoles, and diselenides

A three‐component reaction of olefins, indoles, and diaryl diselenides catalyzed by copper chloride under irradiation of blue LED light is disclosed. Various diaryl diselenides including diheteroaryl diselenides are suitable for this bifunctionalization of olefins. This protocol provides 26 examples of β‐(hetero)arylselenyl indoles in 60%–87% yields. The proposed mechanism involves activation of diaryl diselenides by coordination with copper chloride, generation of arylselenium cations by heterolysis of activated diaryl diselenides, electrophilic addition of arylselenium cations to styrenes, and then Friedel–Crafts‐type alkylation at the 3‐position of NH‐indoles.

How calcium and magnesium ions affect the stability of asphalt with anionic emulsifiers: A molecular dynamics study

Based on molecular dynamics, modelling and analysis of the state of salt-free ionic emulsified asphalt system with the addition of calcium ions and magnesium ions (Ca2+and Mg2+, respectively). The effect of calcium and magnesium ions on the stability of sodium dodecyl sulfate (SDS)-emulsified asphalt was investigated. To determine the effect of the metal cations on the stability of anionic emulsified asphalt, the interfacial morphological distribution, interaction of the emulsifier with water molecules, and mobility of water molecules in the emulsifier head group/metal cations was investigated. The results of the simulation analysis show that, compared to a salt-free environment, the addition of Ca2+ or Mg2+ to a salt-containing system induces aggregation between the head groups of the SDS emulsifier molecules and reduces the thickness of the SDS emulsifier headgroup distribution along the Z-axis. This, in turn, weakens the stability of the anionic emulsified asphalt. Compared to the Ca2+-emulsified asphalt system, the Mg2+-emulsifier headgroup molecules are more easily bound to water molecules and more difficult to dissociate from them. Thus, the addition of Mg2+ is more likely to reduce the stability of the emulsion. Furthermore, the results of the simulated data analysis indicate that the addition of cations to the emulsified asphalt system, particularly Mg2+, reduces the mobility of the water molecules surrounding the head group, thereby reducing the stability of the emulsion. The results of the molecular simulations are consistent with the experimental results in the literature. Thus, the validity of using molecular dynamics to analyze the effect of metal cations on anionic emulsified asphalt was verified.

Charge Transfer Kinetics of the Ti(IV)/Ti(III) Redox Couple in the Cesium Chloride-Cesium Fluoride Melt with Addition of Alkaline Earth Metal Cations

The electrochemical behavior of the Ti(IV)/Ti(III) redox couple in the CsCl-CsF(10 wt%)-K2TiF6 melt was studied by cyclic voltammetry. The diffusion coefficients of the Ti(IV) complexes were calculated using the Randles-Sevcik equation. The standard rate constants of charge transfer for the Ti(IV)/Ti(III) redox couple in the CsCl-CsF(10 wt%)-K2TiF6 melt without and with additions of alkaline Earth metal cations (Mg2+, Ca2+, Sr2+, Ba2+) were determined. It was found that the rate constants of charge transfer increase with increasing ionic potential of the addition, reaching a maximum value for complexes with outer-sphere cations of magnesium, and this dependence is rectilinear. The activation energies of the charge transfer process in melts with additions of alkaline Earth metal cations were calculated and these values are significantly lower than the activation energy of the initial system CsCl-CsF(10 wt%)-K2TiF6. The kinetic parameters of the Ti(IV)/Ti(III) redox couple in chloride-fluoride melts with different second coordination sphere composition of the complexes were compared.

Piezoelectric and Dielectric Properties in Bi0.5(Na,K)0.5TiO3-x Ag2O Lead-Free Piezoceramics.

Lead-free piezoceramics of Bi0.5(Na0.825K0.175)0.5TiO3 with varying concentrations of x mol% Ag2O (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, denoted as BNKT-xA) were fabricated using the solid-state technique. An extensive investigation was undertaken to analyze the structural, piezoelectric, and dielectric properties of these piezoceramics in the presence of Ag ions. There is no evidence of any secondary solid solution in the BNKT-xA piezoceramics. The ceramics with x mol% Ag2O in BNKT still demonstrate the presence of both rhombohedral (R) and tetragonal (T) phases. The addition of Ag+ is helpful to increase the relative density of the BNKT-xA piezoceramics. It is noteworthy that the BNKT-0.3 mol% A piezoceramics show remarkable improvements in their properties (d33 = 147 pC/N, kp = 29.6%, ε = 1199, tanδ = 0.063). These improvements may be ascribed to the denser microstructure and the preservation of morphotropic phase boundaries between R and T phases caused by the appropriate addition of Ag cations. The addition of Ag+ results in the relaxor behavior of the BNKT-xA ceramics, characterized by disorder among A-site cations. With the increase in temperature, the d33 value of BNKT-xA ceramics does not vary significantly in the range of 25 to 125 °C, ranging from 127 to 147 pC/N (with a change of d33 ≤ 13.6%). This finding shows that piezoelectric ceramics have a reliable performance over a certain operating temperature range.

Influence of various colloidal surfactants on the stability of MS2 bacteriophage suspension. The charge distribution on the PCV2 virus surface

To understand virus stability in aqueous solutions, the colloidal nanostructure and properties of a model virus, the MS2 bacteriophage, have been investigated by studying the effect of the addition of electrolytes and various colloidal surfactants to its water solution at physiological conditions. The charge of the virus particles influences their colloidal properties. It was found that the ζ-potential value is reduced from –35 mV to –10 mV in 0.01 M CaCl2 and 0.1 M NaCl solutions as well as at higher electrolytes concentrations, while the size of the MS2 aggregates was about 600 ÷ 900 nm with individual particles of size around 30 nm also recorded. The 2 :1 electrolyte causes destabilization of MS2 bacteriophage particles in an aqueous solution at a lower concentration. The addition of cationic, anionic, and non-ionic colloidal surfactants below and above critical micelle concentration to MS2 bacteriophage suspension caused the destabilization of MS2 particles. We also investigated the capsid’s surface of another virus, PCV2, using dynamic light scattering and laser Doppler electrophoresis. The hydrodynamic diameter and the ζ-potential of PCV2 empty capsid were found to be equal to 22 ± 1 nm and −41 ± 4 mV (using Ohshima approximations). The electrostatic potential of the surface was measured using acid-base probes and found to be equal to −91 ± 3 and +14 ± 2 mV for positively and negatively charged probes respectively, which indicate the ‘mosaic’ way of the charge distribution on the surface, similar to MS2′s surface studied previously. Our data provide new information about the virus surface, the complex process of virus aggregation-disaggregation and virus capsid disassembly.

Quantifying and Reducing Ion Migration in Metal Halide Perovskites through Control of Mobile Ions.

The presence of intrinsic ion migration in metal halide perovskites (MHPs) is one of the main reasons that perovskite solar cells (PSCs) are not stable under operation. In this work, we quantify the ion migration of PSCs and MHP thin films in terms of mobile ion concentration (No) and ionic mobility (µ) and demonstrate that No has a larger impact on device stability. We study the effect of small alkali metal A-site cation additives (e.g., Na+, K+, and Rb+) on ion migration. We show that the influence of moisture and cation additive on No is less significant than the choice of top electrode in PSCs. We also show that No in PSCs remains constant with an increase in temperature but μ increases with temperature because the activation energy is lower than that of ion formation. This work gives design principles regarding the importance of passivation and the effects of operational conditions on ion migration.