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The single H-bond capable N-H in triethylammonium triggers massive structural rearrangement in an inert Co(III) complex that tetraethylammonium cannot. The rearrangement provides a new way to distinguish two similar cations spectroscopically. The process is identical and instantaneous with labile iron(III) without any spectroscopic change. [ABSTRACT FROM AUTHOR]

Microporous aluminosilicate zeolites are useful industrial catalysts. However, their hydrothermal synthesis is a multistep process with complicated and unclear reactions, limiting their rational functional design. Herein, we compare the formation pathway and the structural and catalytic properties of several CHA zeolites to obtain fundamental knowledge for intentionally controlling the catalytic function of zeolites. Three CHA zeolites were synthesized using different starting silica/alumina sources in the presence of tetraethylammonium hydroxide as an inexpensive organic structure‐directing agent. FAU zeolite and an amorphous synthesis gel prepared using two different methods were used as starting materials. The obtained CHA zeolites were applied for exhaust gas purification (selective catalytic reduction of NOx with ammonia, NH3‐SCR), and their structural characteristics and formation pathways were investigated using a combination of analytical methods. Stepwise gel preparation (SGP), which divides the compositional control of the amorphous synthesis gel, promotes the decomposition of the initial additive (zeolite seed), resulting in the formation of CHA zeolites with abundant micropores and paired Al sites. This structural feature obtained using the SGP method improves the catalytic durability of the NH3‐SCR reaction. The present relationship, including different crystallization phenomena, structures, and catalytic abilities, provides useful insights into rational zeolite synthesis and its application. [ABSTRACT FROM AUTHOR]

Silica-rich Y (FAU topology) and EMC-2 (EMT topology) zeolites have been obtained in the presence of the tetraethylammonium (TEA+) cation as a structure-directing molecule and the corresponding protonic zeolites as seeds. In the presence of USY seeds, Y zeolites were fully crystallized after a few hours at 130 °C but they were unstable and rapidly converted into chabazite, a zeolite with CHA topology. Their stability could nonetheless be greatly improved by decreasing the temperature to 110 °C without significantly modifying the morphology of the crystals and the composition of the framework. Framework SiO2/Al2O3 ratios up to 13 could be obtained, which is the highest value ever reported for Y zeolites synthesized with TEA+ cations as the sole organic molecule. The use of H-EMC-2 as seeds generally led to FAU–EMT intergrowths in which the relative proportion of EMT depended on the composition of the seeds. However, a pure EMT zeolite could be obtained under specific conditions. With a framework SiO2/Al2O3 ratio of 11.2, it constitutes the first example of Si-rich EMT obtained in the absence of crown ether from conventional silica and alumina sources. [ABSTRACT FROM AUTHOR]

Three ionic liquids (ILs)(1-ethyl-2,3-dimethylimidazolium acetate, [EMMIM][AC]; tributyl-methylammonium acetate, [N4,4,4,1][AC]; and tetraethylammonium acetate, [N2,2,2,2][AC]) were chosen. The vapor–liquid equilibrium (VLE) data of ternary mixtures (acetate + ethanol + IL) were measured at 101.3 KPa. NRTL equation was used to correlate the data. From NRTL model, for [N2,2,2,2][AC], [EMMIM][AC], and [N4,4,4,1][AC], minimum mole fractions for completely eliminating azeotrope are 0.015, 0.020 and 0.022, respectively. From the average relative volatility and σ-profiles, it can be obtained that the separation ability order is [EMMIM][AC] > [N2,2,2,2][AC] > [N4,4,4,1][AC]. [ABSTRACT FROM AUTHOR]

Flat layers are usually considered as structurally rigid motifs in two-dimensional (2D) materials. In this work, we demonstrate that a flat honeycomb-layer composed of distorted tri-coordinate copper ions bridged with cyanidos in (tetraethylammonium)Cu2(CN)3 exhibits high in-plane flexibility. This resulted in an extremely large anisotropic 2D-thermal expansion. [ABSTRACT FROM AUTHOR]

The title compound, tetraethylammonium triazidotri-μ3-sulfido-[μ3-(trimethylsilyl) azanediido][tris(3,5-dimethylpyrazol-1-yl)hydroborato]triiron(+2.33)molybdenum(IV), (C8H20N)[Fe3MoS3(C15H22BN6)(C3H9NSi)(N3)3] or (Et4N)[(Tp*)- MoFe3S3(μ3-NSiMe3)(N3)3] [Tp* = tris(3,5-dimethylpyrazol-1-yl)hydroborate(1-)], crystallizes as needle-like black crystals in space group P1. In this cluster, the Mo site is in a distorted octahedral coordination model, coordinating three N atoms on the Tp* ligand and three μ3-bridging S atoms in the core. The Fe sites are in a distorted tetra-hedral coordination model, coordinating two µ3-bridging S atoms, one µ3-bridging N atom from Me3SiN2-, and another N atom on the terminal azide ligand. This type of heterometallic and heteroleptic single cubane cluster represents a typical example within the Mo-Fe-S cluster family, which may be a good reference for understanding the structure and function of the nitro-genase FeMo cofactor. The residual electron density of disordered solvent mol-ecules in the void space could not be reasonably modeled, thus the SQUEEZE [Spek (2015). Acta Cryst. C71, 9-18] function was applied. The solvent contribution is not included in the reported mol-ecular weight and density. [ABSTRACT FROM AUTHOR]

The title compound, tetraethylammonium triazidotri-μ3-sulfido-[μ3-(trimethylsilyl) azanediido][tris(3,5-dimethylpyrazol-1-yl)hydroborato]triiron(+2.33)molybdenum(IV), (C8H20N)[Fe3MoS3(C15H22BN6)(C3H9NSi)(N3)3] or (Et4N)[(Tp*)- MoFe3S3(μ3-NSiMe3)(N3)3] [Tp* = tris(3,5-dimethylpyrazol-1-yl)hydroborate(1-)], crystallizes as needle-like black crystals in space group P1. In this cluster, the Mo site is in a distorted octahedral coordination model, coordinating three N atoms on the Tp* ligand and three μ3-bridging S atoms in the core. The Fe sites are in a distorted tetra-hedral coordination model, coordinating two µ3-bridging S atoms, one µ3-bridging N atom from Me3SiN2-, and another N atom on the terminal azide ligand. This type of heterometallic and heteroleptic single cubane cluster represents a typical example within the Mo-Fe-S cluster family, which may be a good reference for understanding the structure and function of the nitro-genase FeMo cofactor. The residual electron density of disordered solvent mol-ecules in the void space could not be reasonably modeled, thus the SQUEEZE [Spek (2015). Acta Cryst. C71, 9-18] function was applied. The solvent contribution is not included in the reported mol-ecular weight and density. [ABSTRACT FROM AUTHOR]

Tetraethylammonium (TEA), a quaternary ammonium compound, is a wellknown blocker of potassium channels belonging to various subfamilies, such as KV1-3, KCa1, 2 and prokaryotic KcsA. In many cases, TEA acts from the extracellular side by open pore blockade. TEA can also block transient receptor potential (TRP) cation channels, such as TRPM7, in a voltagedependent manner. In human T lymphocytes, intracellular (cytosolic) TEA and its analog TMA (tetramethylammonium) inhibit TRPM7 channel currents in the outward but not inward direction. By contrast, intracellular Mg2+, protons and polyamines inhibit both outward and inward current components equally. Likewise, the majority of available pharmacological tools inhibit TRPM7 channels in a voltage-independent manner. Since TRPM7 is a steeply outwardly rectifying conductance, voltage-dependent blockers can be useful for studying the cellular functions of this channel. TRPM7 protein is endogenously expressed in diverse cell lines, including HEK, HeLa, CHO, RBL and Jurkat. Using patch-clamp electrophysiology, we found that incubating HEK293 and Jurkat T cells overnight in the presence of 20 mM TEA-Cl, resulted in the nearly complete blockade of whole-cell TRPM7 outward current, measured at breakin. By contrast, the inward current was unchanged in TEA-loaded cells. The blockade was fully reversible after washout of intracellular solution in whole-cell but not in perforated-patch recording configurations. Overnight incubation with 20 mM TMA-Cl resulted in a more modest blockade of the outward TRPM7 current. Internal 129 mM TMA and TEA eliminated most of the outward current. TEA uptake in transfected HEK293 cells led to blockade of recombinant murine TRPM7 and the Mg2+ and pH insensitive Ser1107Arg variant. Unexpectedly, Tris-HCl, a widely used pH buffer, could similarly be loaded into Jurkat and HEK cells, and preferentially blocked outward TRPM7 currents. 20 mM and 129 mM Tris in the internal solution blocked TRPM7 current in outward but not inward direction. Voltage-dependent channel blockade by TEA, TMA and Tris loading will be useful for studying the properties and functions of TRPM7- mediated ion transport in intact cells. [ABSTRACT FROM AUTHOR]

In response to both biotic and abiotic stresses, vascular plants transmit long-distance Ca2+ and electrical signals from localized stress sites to distant tissues through their vasculature. Various models have been proposed for the mechanisms underlying the long-distance signaling, primarily centered around the presence of vascular bundles. We here demonstrate that the non-vascular liverwort Marchantia polymorpha possesses a mechanism for propagating Ca2+ waves and electrical signals in response to wounding. The propagation velocity of these signals was approximately 1–2 mm s-1, equivalent to that observed in vascular plants. Both Ca2+ waves and electrical signals were inhibited by La3+ as well as tetraethylammonium chloride, suggesting the crucial importance of both Ca2+ channel(s) and K+ channel(s) in wound-induced membrane depolarization as well as the subsequent long-distance signal propagation. Simultaneous recordings of Ca2+ and electrical signals indicated a tight coupling between the dynamics of these two signaling modalities. Furthermore, molecular genetic studies revealed that a GLUTAMATE RECEPTOR-LIKE (GLR) channel plays a central role in the propagation of both Ca2+ waves and electrical signals. Conversely, none of the three two-pore channels were implicated in either signal propagation. These findings shed light on the evolutionary conservation of rapid long-distance Ca2+ wave and electrical signal propagation involving GLRs in land plants, even in the absence of vascular tissue. [ABSTRACT FROM AUTHOR]

Polyiodides present high bonding flexibility already at ambient conditions, and undergo significant pressure-induced structural deformations. Resonant Raman spectroscopy has been widely used to study I–I bonds in various polyiodides, but it carries a risk of photodecomposition due to the high visible-light absorption of iodine. In this study, tetraethylammonium (bis)diiodine triiodide (TEAI) has been investigated by resonant Raman spectroscopy up to 12.02(3) GPa. The effect of pressure on the intensities and positions of Raman bands has been evaluated and correlated with the interatomic I–I distances derived from high-pressure X-ray diffraction experiments. Pressure was shown to effectively stabilize TEAI against laser-induced photodecomposition, even after a long course of irradiation with the resonant laser light. Examination of a freshly exposed crystal surface revealed that TEAI superficially passivates with the layer of lower polyiodides, which prevents further iodine loss, and shows distinct pressure-induced behaviour. [ABSTRACT FROM AUTHOR]

Ciguatoxins (CTXs) are neurotoxins responsible for ciguatera poisoning (CP), which affects more than 50,000 people worldwide annually. The development of analytical methods to prevent CP is a pressing global issue, and the N2a assay is one of the most promising methods for detecting CTXs. CTXs are highly toxic, and an action level of 0.01 μg CTX1B equivalent (eq)/kg in fish has been proposed. It is desirable to further increase the detection sensitivity of CTXs in the N2a assay to detect such low concentrations reliably. The opening of voltage-gated sodium channels (NaV channels) and blocking of voltage-gated potassium channels (KV channels) are thought to be involved in the toxicity of CTXs. Therefore, in this study, we developed an assay that could detect CTXs with higher sensitivity than conventional N2a assays, using KV channel inhibitors as sensitizing reagents for N2a cells. The addition of the KV channel inhibitors 4-aminopyridine and tetraethylammonium chloride to N2a cells, in addition to the traditional sensitizing reagents ouabain and veratridine, increased the sensitivity of N2a cells to CTXs by up to approximately 4-fold. This is also the first study to demonstrate the influence of KV channels on the toxicity of CTXs in a cell-based assay. [ABSTRACT FROM AUTHOR]

The crystal structure of the tetraethylammonium salt of the non-steroidal antiinflammatory drug nimesulide (polymorph II) (systematic name: tetraethylammonium N-methanesulfonyl-4-nitro-2-phenoxyanilinide), C8H20N+-C13H11N2O5S-, was determined using single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic space group P21/c with one tetra-ethylammonium cation and one nimesulide anion in the asymmetric unit. In the crystal, the ions are linked by C--H … N and C--H … O hydrogen bonds and C--H … π interactions. There are differences in the geometry of both the nimesulide anion and the tetraethylammonium cation in polymorphs I [Rybczyiiska & Sikorski (2023). Sci. Rep. 13, 17268] and II of the title compound. [ABSTRACT FROM AUTHOR]

C44H108N20O12S4, monoclinic, P21/n (no. 14), a = 8.0480(3) Å, b = 18.6415(7) Å, c = 11.9008(4) Å, β = 103.242(2)°, V = 1737.97(11) Å3, Z = 4, Rgt(F) = 0.0471, wRref(F2) = 0.1422, T = 296(2) K. [ABSTRACT FROM AUTHOR]

We report a novel strategy for reversible modulation of the supramolecular chirality based on guest‐facilitated heteroleptic assembly of helical anionocages. Two triple‐stranded helical anionocages including a chiral cage 1 (A2L13) and a crown ether functionalized achiral cage 2 (A2L23) were synthesized by anion coordination of bis‐monourea‐based ligands and PhPO32−. Both cages exhibited favorable binding with tetraethylammonium TEA+ and cobaltocenium Cob+ (endo‐guest, bound in the cavity). Additionally, cage 2 could reversibly release and recapture the guests through binding the exo‐guest potassium ions (K+) in the crown ethers and subsequent removal of the K+ by [2,2,2]‐cryptand. The circular dichroism (CD) spectrum of cage 1 was not significantly affected by guest encapsulation or mixing with the "empty" cage 2. However, in the presence of both cage 2 and an endo‐guest/exo‐guest, the Cotton effects were reversed at 391 nm and significantly enhanced at 310 nm. This observation was attributed to the guest‐facilitated formation of heteroleptic cages that enabled effective chirality transfer from the chiral to the achiral ligands. The CD changes induced by K+ could be fully reversed by removing it with [2,2,2]‐cryptand. Sequential addition and removal of K+ allowed reversible modulation of the chirality for at least 10 cycles without significant attenuation. [ABSTRACT FROM AUTHOR]

Zeolitic imidazolate frameworks (ZIFs) are widely used MOFs because of certain characteristics, but also because they can be prepared at room temperature using water as the unique solvent. However, these a priori sustainable conditions inevitably entail a huge and somehow unusable excess of linker. Here, we present the formation of ZIFs at room temperature in water, starting from mixtures with a linker/metal ratio of two, that is, coinciding with the stoichiometry found in the final MOFs, in the presence of amines. ZIF-8 can be prepared with triethylamine (TEA), giving a yield of Zn of 96.6%. Other bases, like NaOH, tetraethylammonium hydroxide or ammonium hydroxide, do not lead to ZIF-8 under the same conditions. The so-obtained ZIF-8 contains TEA inside its cavities, making it less porous than its conventionally prepared counterparts. Amine can be removed by mild thermal treatments (200–250 °C). Such thermal treatments induce the generation of g-C3N4-like species which could give added value to these materials as potential photocatalysts, increasing their affinity to CO2, as proved in this work. This methodology can be successfully extended to other amines, like N,N-dicyclohexylmethylamine, as well as to other prepared ZIFs, like Co-based ZIF-67, isostructural to ZIF-8. [ABSTRACT FROM AUTHOR]

The present report demonstrates an efficient use of oxygen radical anion to promote the synthesis of N-substituted isatin derivatives (3a-j) under mild reaction conditions. The combination of potassium superoxide (KO2) and tetraethylammonium bromide (TEAB) generate the oxygen radical anion in situ that promote this synthetic transformation. This method offers a sustainable and direct access to the N-substituted isatin derivatives in good to excellent yields. [ABSTRACT FROM AUTHOR]

Organic–inorganic halocuprates based on monovalent copper are promising luminescent compounds for optoelectronic applications; however, their relaxation processes in the excited electronic state are severely underexplored. In this contribution, we prepare thin films of bis(tetraethylammonium) di-µ-bromo-dibromodicuprate(I) [N(C2H5)4]2[Cu2Br4], abbreviated (TEA)2Cu2Br4, which features a "molecular salt" structure containing discrete [Cu2Br4]2− anions. This compound, which has an absorption peak at 283 nm, displays a blue, strongly Stokes-shifted emission with a peak at 467 nm. Transient photoluminescence (PL) experiments using broadband emission detection and time-correlated single-photon counting (TCSPC) both find an excited-state lifetime of 57 μs at 296 K. UV–Vis transient absorption experiments at 296 K covering time scales from femto- to microseconds provide evidence for the formation of the T1 state through intersystem crossing from S1 with a time constant of 184 ps. The triplet state subsequently decays to S0 predominantly by phosphorescence. In addition, the time constants for carrier–optical phonon scattering (1.8 ps) and acoustic phonon relaxation (8.3 ns and 465 ns) of (TEA)2Cu2Br4 are provided. [ABSTRACT FROM AUTHOR]

In pursuit of understanding structure–property relationships for the melting point depression of binary eutectic mixtures, the influence of the anion on the solid–liquid (S–L) phase behavior was explored for mixtures of glutaric acid + tetraethylammonium chloride, bromide, and iodide. A detailed experimental evaluation of the S–L phase behavior revealed that the eutectic point is shifted toward lower temperatures and higher salt contents upon decreasing the ionic radius. The salt fusion properties were experimentally inaccessible owing to thermal decomposition. The data were inter- and extrapolated using various models for the Gibbs energy of mixing fitted to the glutaric-acid rich side only, which allowed for the assessment of the eutectic point. Fitting the experimental data to a two-parameter Redlich–Kister expansion with Flory entropy, the eutectic depth could be related to the ionic radius of the anion. The anion type, and in particular its size, can therefore be viewed as an important design parameter for the liquid window of other acid and salt-based deep eutectic solvents/systems. [ABSTRACT FROM AUTHOR]

Piper nigrum Linn. (Pepper) is a very well-known spice used for different purposes such as human dietaries, medicine and preservative. In Thai traditional medicine, white pepper is a component of herbal formulas used to treat many disorders including symptoms of dysmenorrhea. It is of interest to investigate the effect of methanolic extract of white pepper (MEWP) on the isolated rat uterus contractions induced by various uterine stimulants and the possible mechanism(s) involved. Strips of uterus were prepared from estrogen-primed female Wistar rats, fixed in the organ bath filled with an appropriate physiological solution with carbogen bubbled continuously at 37 °C. The measurement of isometric tension was then performed using force transducer attached to a polygraph. MEWP was tested its effect on the uterine contraction and found the inhibitory effects on the contraction induced by oxytocin, PGF2α and depolarizing solution. TEA inhibited the uterine relaxing effect of MEWP while glibenclamide had no effects when the uterus was induced to contract with oxytocin. Propranolol abolished the uterine relaxing effect of isoproterenol while it had no effects on the relaxing effect of MEWP. The results suggested that MEWP is likely to be a general uterine relaxant. The effects may be due to the interference on Ca2+ influx into the uterine muscle cells which may involve the opening of KCa channel. The effect was unlikely to occur via the KATP-channel and may not involve the interaction of MEWP on β-adrenergic receptor on the uterine muscle cells. [ABSTRACT FROM AUTHOR]

A mild, efficient one-pot three-component reaction of primary and secondary amines with carbon disulphide and a,b-unsaturated compounds providing dithiocarbamates has been developed employing in situ generated tetraethylammonium superoxide in aprotic solvent at room temperature. [ABSTRACT FROM AUTHOR]

Organic hybrid halide perovskite, which has excellent characteristics of low cost, nontoxicity, and high recognition, has attracted extensive attention in optical anticounterfeiting applications. In this paper, (TEA)2ZrCl6 (TEA = tetraethylammonium) single crystals (SCs) are synthesized by an easy‐to‐operate hydrothermal method, which exhibits excitation wavelength‐dependent emission at 254 and 365 nm, respectively. Moreover, the photoluminescence quantum yield of (TEA)2ZrCl6 SCs achieves 84.7%, with the introduction of Sb3+ ions. (TEA)2ZrCl6 and doped (TEA)2ZrCl6 patterns can be recognized with excitation by different wavelengths. In addition, as‐prepared (TEA)2ZrCl6 crystals show interesting radioluminescence for another anticounterfeiting model with the light yield of 17 709 photons per MeV. The experimental results indicate the novel (TEA)2ZrCl6 SCs have a huge potential for X‐ray imaging and anticounterfeiting. [ABSTRACT FROM AUTHOR]

Some of organic ammonium salts, namely: 2-((4-carboxyphenyl) carbamoyl) benzoate tetraethylammonium, B1, 4-oxo-4-(pyridin-3- ylamino)-2-butenoate tetraethylammonium, B2, 2-((4-carbamoylphenyl) carbamoyl) benzoate tetraethylammonium, B3, 4-((4- carbamoylphenyl)amino)-4-oxobutanoate tetraethylammonium, B4, are successfully synthesized as ionic liquids. By spectral techniques of FTIR, ¹H-NMR and 13C-NMR the structures of organic salts are confirmed. The thermal analysis by differential scanning calorimetry (DSC) has shown the thermal stability of the organic ammonium salts (B1-B4). A high conductivity characteristic as compared with that of NaCl has been detected in the aqueous solution [ABSTRACT FROM AUTHOR]

Background/aimsThe Amyloid Precursor Protein (APP) is involved in the regulation of multiple cellular functions via protein-protein interactions and has been most studied with respect to Alzheimer's disease (AD). Abnormal processing of the single transmembrane-spanning C99 fragment of APP contributes to the formation of amyloid plaques, which are causally related to AD. Pathological C99 accumulation is thought to associate with early cognitive defects in AD. Here, unexpectedly, sequence analysis revealed that C99 exhibits 24% sequence identity with the KCNE1 voltage-gated potassium (Kv) channel β subunit, comparable to the identity between KCNE1 and KCNE2-5 (21-30%). This suggested the possibility of C99 regulating Kv channels.MethodsWe quantified the effects of C99 on Kv channel function, using electrophysiological analysis of subunits expressed in Xenopus laevis oocytes, biochemical and immunofluorescence techniques.ResultsC99 isoform-selectively inhibited (by 30-80%) activity of a range of Kv channels. Among the KCNQ (Kv7) family, C99 isoform-selectively inhibited, shifted the voltage dependence and/or slowed activation of KCNQ2, KCNQ3, KCNQ2/3 and KCNQ5, with no effects on KCNQ1, KCNQ1-KCNE1 or KCNQ4. C99/APP co-localized with KCNQ2 and KCNQ3 in adult rat sciatic nerve nodes of Ranvier. Both C99 and full-length APP co-immunoprecipitated with KCNQ2 in vitro, yet unlike C99, APP only weakly affected KCNQ2/3 activity. Finally, C99 altered the effects on KCNQ2/3 function of inhibitors tetraethylammounium and XE991, but not openers retigabine and ICA27243.ConclusionOur findings raise the possibility of C99 accumulation early in AD altering cellular excitability by modulating Kv channel activity.

Introduction: slowly adapting mechanoreceptors in the skin provide vital tactile information to animals. The ionic channels that underlie their functioning is the subject of intense research. Previous work suggests that potassium channels may play particular roles in the activation and firing of these mechanoreceptors. Objective: We used a range of potassium channel blockers and openers to observe their effects on different phases of mechanoreceptor responses. Methods: Extracellular recording of neural activity of slowly adapting mechanoreceptors was carried out in an in vitro preparation of the sinus hair follicles taken from rat whisker pads. A range of potassium (K+) channel modulators were tested on these mechanoreceptor responses. The channel blockers tested were: tetraethylammonium (TEA), barium chloride (BaCl2), dequalinium, 4-aminopyridine (4-AP), paxilline, XE 991, apamin, and charybdotoxin. Results: Except for charybdotoxin and apamin, these drugs increased the activity of both types of slowly adapting units, St I and St II. Generally, both spontaneous and evoked (dynamic and static) activities increased. The channel opener NS1619 was also tested. NS1619 clearly decreased evoked activity (both dynamic and static) while leaving spontaneous activity relatively unaffected, with no clear discrimination of effects on the two types of St receptor Conclusion: These findings are consistent with the targets of the drugs suggesting that K+ channels play an important role in the maintenance of spontaneous firing and in the production of and persistence of mechanoreceptor activity.

Introduction and Objective. High blood pressure is an important risk factor for heart-related disease. Combining dietary adjustments with standard drugs in the therapy of heart diseases have gained attention. Genistein, a soy isoflavone, has many biological effects but its role in blood pressure is inconclusive. The aim of the study was to investigate the effect of genistein on blood pressure in normotensive rats pre-treated with standard drugs. Materials and method. Twenty healthy adult male Sprague Dawley rats (body weight 160-180g) were administered with genistein, and SBP, DBP, PP, MABP and HR were recorded. Subsequently, the rats (5 each) were treated with Indomethacin, a non-steroidal, anti-inflammatory and a cyclooxygenase (COX-2) enzyme inhibitor (5 mg/kg subcutaneously), methylene blue, an inhibitor of nitric oxide synthase and guanylate cyclase (7.5 mg/kg, by infusion), nifedipine, a calcium channel blocker (0.75 mg/kg intravenously), and tetraethylammonium, a voltage-gated K+ channels blocker (60 mg/kg intravenously). Genistein was administered intravenously in graded doses after the administration of these blockers. SPB, DBP, PP and MABP were significantly increased following genistein administration only, as well as in the methylene blue and tetraethylammonium groups each. Results. Higher doses of genistein significantly decreased SBP, DBP and PP after indomethacin treatment. Falling DBP and MABP were reversed in the nifedipine group. Conclusions. Results suggests that genistein elevates blood pressure in experimental normotensive male rats. This has implications for alternative therapy in the management of hypertension, and implications for blood pressure in cardiovascular related diseases. [ABSTRACT FROM AUTHOR]

To investigate faster crystallization of zeolite beta by the dry‐gel conversion method, the local structure of the dry gel before synthesis was quantitatively evaluated using in situ Raman spectroscopy during the drying process. The dry gel prepared from Si and Al sources, and tetraethylammonium hydroxide solution was crystallized after several hours by the dry‐gel conversion method. The conformational change of TEA+ cations was observed during the drying process by the deconvolution of the spectrum, and the conformational change was larger than that during the synthesis process. The rate of conformational change was increased with the drying temperature, and the apparent activation energy was estimated to be 68.2 kJ/mol. The generation and transformation of double three‐membered silicate rings (D3Rs) and 4‐2 type secondary building units (SBUs), which are essential for the crystallization of zeolite beta, were observed during the drying process. The transformation from D3R to 4‐2 SBU in the dry gel during drying process could be confirmed quantitatively by the difference of the time variation for the amounts of these silicate building units estimated by in situ observation. [ABSTRACT FROM AUTHOR]

Chemical modification is a reliable and efficient strategy for designing cellulose-based functional materials. Herein, porous quaternized cellulose beads (QCBs) as cationic superabsorbent were fabricated by homogeneous in-situ chemical grafting cellulose molecular chains with glycidyl trimethylammonium chloride (GTAC) in tetraethylammonium hydroxide (TEAOH)/urea aqueous solution followed by acetic acid induced regeneration. The influence of GTAC dosage on the physicochemical-structural properties of cationic QCBs was deeply investigated. Results revealed that cotton liner could well-dissolved in TEAOH/urea aqueous solution, leading to a homogeneous and efficient quaternization medium for cellulose, thereby giving the high DS and positive charge density for quaternized cellulose. NMR results demonstrated the main substitution of GTAC groups at 2-OH and 6-OH positions of the cellulose chains during quaternization reaction. With increasing GTAC dosage, the network skeleton of QCBs gradually transformed from thick fibrils to thin aggregates, as well as enhanced pore volumes and hydrophilicity. Accordingly, QCBs-1.5 with high pore volume (99.70 cm3/g) exhibited excellent absorption capacity and efficiency, absorbing 122.32 g of water and 0.45 g of moisture per gram of the beads in 20 min. This work not only offers a simple strategy for the homogeneous quaternization modification of cellulose, but also provides a porous cellulose-based cationic superabsorbent material. [Display omitted] [ABSTRACT FROM AUTHOR]

Fluorinated Room Temperature Ionic Liquids (FRTILs) are a branch of ionic liquids that is the object of growing interest for a wide range of potential applications, due to the synergic combination of specifically ionic features and those properties that stem from fluorous tails. So far limited experimental work exists on the micro- and mesoscopic structural organization in this class of compounds. Such a work is however necessary to fully understand morphological details at atomistic level that would have strong implications in terms of bulk properties. Here we use the synergy between X-ray and neutron scattering together with molecular dynamics simulations to access structural details of a technologically relevant FRTIL that is characterised by an anion bearing a long enough fluorinated tail to develop specific morphological features. In particular, we find the first experimental evidence that in FRTILs bearing an asymmetric bis(perfluoroalkyl)sulfonyl-imide anion, fluorous side chains tend to be spatially segregated into nm-scale spatial heterogeneities. This feature together with the well-established micro-segregation of side alkyl chains in conventional RTILs leads to the concept of triphilic ILs, whose technological applications are yet to be fully developed. [ABSTRACT FROM AUTHOR]

The new diaminoacetylene (DAA) dimorpholinoacetylene (3) was prepared from 1,1‐dimorpholinoethene (1) by bromination to form the dibromoketene aminal 2, which upon lithiation afforded 3 through a Fritsch‐Buttenberg‐Wiechell rearrangement. Heating 3 at elevated temperatures resulted in a complete conversion into the dimer 1,1,2,4‐tetramorpholino‐1‐buten‐3‐yne (4), which was used for the synthesis of four‐membered cyclic bent allene (CBA) transition‐metal complexes of the type [(CBA)MLn] (5‐7; MLn=AuCl, RhCl(COD), RhCl(CO)2; CBA=1,3,4,4‐tetramorpholino‐1,2‐cyclobutadiene; COD=1,5‐cyclooctadiene). The reaction of 3 with tetraethylammonium bromide gave 1,2,3,4‐tetramorpholinocyclobutenylium bromide (8), which reacted with bromine to form 1,2,3,4‐tetra(morpholino)cyclobutenediylium bis(tribromide) (9). Compound 9 represents the first fully characterized compound containing a tetraaminocyclobutadiene dication and displays a nearly planar C4N4 core as shown by X‐ray diffraction analysis. Detailed quantum chemical calculations were performed to assess the aromaticity of tetraaminocyclubutadiene dications by employing the Nucleus Independent Chemical Shift (NICS) method and current density analysis. [ABSTRACT FROM AUTHOR]

The bronchodilator effect of the Achillea fragrantissima essential oil (AFO) was studied in guinea pigs' tracheas and the influence of drying on the quantity and composition of AFO was studied using GC-MS and GC analyses. AFO produced a complete and potent relaxation against carbachol (CCh), while lower potency and partial efficacy were observed against high K+ (80 mM), thus producing dual inhibitory effects similar to dicyclomine. The anticholinergic-like action was further confirmed when pre-incubation tracheal tissues were used at lower concentrations with AFO displacing the CCh concentration-response curves (CRCs) to the right in a competitive manner similar to atropine. However, non-parallel shifts in CCh CRCs were observed with higher doses, similar to dicyclomine. Further confirmation of the CCB-like effect was obtained from the non-specific deflection of Ca++ CRCs toward the right using the pre-incubated tissues with AFO in Ca++ free medium, similar to verapamil. When AFO was tested against low K+-mediated contractions to explore the possible involvement of additional antispasmodic mechanism(s), AFO interestingly showed a complete inhibition with a higher potency. This inhibition was found to be sensitive to tetraethylammonium (TEA) and 4-aminopyridine (4-AP), whereas glibenclamide (Gb) remained inactive. These results show that AFO possesses bronchodilator effects predominantly from its anticholinergic and K+ channel activation followed by weak Ca++ channels inhibition. [ABSTRACT FROM AUTHOR]

Lippia alba is popularly known as lemon balm, with its essential oil (EO) cited for displaying antimicrobial, sedative, and vasorelaxant effects. Yet, its action on isolated human vessels has not been described in the literature. Thus, we evaluated the vasorelaxant effect of essential oil of L. alba (EOLa) on human umbilical arteries (HUA) isolated in organ baths. HUA rings were isolated, subjected to contractions induced by potassium chloride (KCl), serotonin (5-HT), or histamine (HIST) to record the isometric tension, and then treated with EOLa (30–1000 µg/mL). The EOLa showed a more prominent inhibitory effect on the pharmacomechanical coupling contraction via HIST with an EC50 value of 277.1 ± 8.5 µg/mL and maximum relaxant effect at 600 µg/mL. The addition of tetraethylammonium (TEA) or 4-aminopyridine (4-AP) in HUA preparations did not inhibit EOLa total relaxant effect at 1000 µg/mL. In the presence of gliblenclamide (GLI), the oil relaxed the HUA rings by 90.8% at maximum concentration. The EOLa was also investigated for its effects on voltage-operated calcium channels (VOCCs), where the HUA preincubation with this oil at 1000 μg/mL inhibited BaCl2 (0.1–30 mM)-induced contractions. This study demonstrates for the first time that EOla has a vasorelaxant effect on HUA and its particular blockade of VOCCs. [ABSTRACT FROM AUTHOR]

Supercapacitors are becoming the workhorse for emerging energy storage applications due to their higher power density and superior cycle life compared to conventional batteries. The performance of supercapacitors depends on the electrode material, type of electrolyte, and interaction between them. Owing to the beneficial interconnected porous structure with multiple conducting channels, vertical graphene nanosheets (VGN) have proved to be leading supercapacitor electrode materials. Herein, we demonstrate a novel approach based on the combination of surface activation and a new organo-aqueous hybrid electrolyte, tetraethylammonium tetrafluoroborate in H2SO4, to achieve significant enhancement in supercapacitor performance of VGN. As-synthesized VGN exhibits an excellent supercapacitance of 0.64 mF/cm² in H2SO4. However, identification of a novel electrolyte for performance enhancement is the subject of current research. The present manuscript demonstrates the potential of the hybrid electrolyte in enhancing the areal capacitance (1.99 mF/cm²) with excellent retention (only 5.4% loss after 5000 cycles) and Coulombic efficiency (93.1%). In addition, a five-fold enhancement in the capacitance of VGNs (0.64 to 3.31 mF/cm²) with a reduced internal resistance is achieved by the combination of KOH activation and the hybrid electrolyte. [ABSTRACT FROM AUTHOR]

In this paper, a highly effective and scalable polyol-based modified procedure is reported, yielding shape-controlled Pd nanoparticles (NPs) formed via two distinct growth mechanisms as a function of apparent pH. Starting from tetraethylammonium tetrahydroxypalladate (TEA)2[Pd(OH)4], a halide-free precursor, the resulting shape of the NPs ranged from highly defective worm-like nanostructures to well-defined polyhedra (tetrahedra, octahedra and 5-fold twins) as shown by TEM, HRTEM, and STEM. The effect of the different synthesis parameters was thoroughly investigated, finding that apparent pH – modulated by adding diluted HNO3 – is the key parameter in determining the final size and shape of Pd NPs, whose evolution was followed during the reaction. A rational explanation of the observed shape modification as a function of apparent pH was proposed. The as-prepared Pd NPs, once dried, were analysed by means of XRD. DRIFT spectroscopy was used to show how CO binds on the Pd NPs after deposition on γ-Al2O3 as catalytic support. [ABSTRACT FROM AUTHOR]

Background: Endometrial cancer is the most common gynecological cancer in developed countries. Potassium channels, which have many types, are suggested to play a major role in cancer progression. However, their role in endometrial cancer has not been fully investigated. We aimed to demonstrate whether the ATP-sensitive potassium channel blocker glibenclamide, voltage-sensitive potassium channel blocker 4-aminopyridine, non-selective (voltage-sensitive and calcium-activated) potassium channels blocker tetraethylammonium and potassium chloride (KCl) have any effect on the proliferation and migration of HEC1-A cells. Methods and results: Proliferation and migration were evaluated by real-time cell analysis (xCELLigence system) and wound healing assays, respectively. Proliferation was reduced by glibenclamide (0.1 and 0.2 mM, P < 0.05 and P < 0.01, respectively), 4-aminopyridine (10 and 20 mM, P < 0.001) and tetraethylammonium (10 and 20 mM, P < 0.01 and P < 0.001, respectively). However, KCl did not change the proliferation. Migration was reduced by glibenclamide (0.01, 0.1 and 0.2 mM, P < 0.001, P < 0.001 and P < 0.01, respectively) and 4-aminopyridine (10 and 20 mM, P < 0.05 and P < 0.01, respectively). Tetraethylammonium did not change migration. However, KCl reduced it (10, 25 and 50 mM, P < 0.05, P < 0.01 and P < 0.01, respectively). Both proliferation and migration were reduced by glibenclamide and 4-aminopyridine. However, tetraethylammonium only reduced proliferation and KCl only reduced migration. Conclusions: Potassium channels have an important role in HEC1-A cell proliferation and migration and potassium channel blockers needs to be further investigated for their therapeutic effect in endometrial cancer. [ABSTRACT FROM AUTHOR]

Herein, tetraethylammonium 1,2,3-triazolide ([Et4N][Tz]), 1,2,3-triazole (Tz), and ethylene glycol (EG) are used to form DESs for CO2 capture. Surprisingly, [Et4N][Tz]-EG DESs can react with CO2, but [Et4N][Tz]-Tz cannot react with CO2, although both of the two systems contain the same anion [Tz]−. Unexpectedly, with the addition of EG to [Et4N][Tz]-Tz, the formed ternary DESs [Et4N][Tz]-Tz-EG can react with CO2, although neither EG nor [Et4N][Tz]-Tz can react with CO2 before the combination of them. NMR, FTIR and theoretical calculation results disclose that the surprise CO2 absorption behavior mainly depends on the strength of hydrogen bonds (H-bonds) between the anion [Tz]− and H-bond donors (EG or Tz). The strength of the H-bond between [Tz]− and Tz is much stronger than that between [Tz]− and EG. The strong H-bond between [Tz]− and Tz in [Et4N][Tz]-Tz greatly reduces the basicity of [Tz]−, rendering the anion [Tz]− unreactive to CO2. In [Et4N][Tz]-Tz-EG ternary DESs, EG competes with Tz to form a H-bond with [Tz]−, which weakens the strength of the H-bond between [Tz]− and Tz. Moreover, H-bonds also impact the desorption behavior. [Et4N][Tz] : EG (1 : 2) is regenerated at 60 °C, whereas the chemisorbed CO2 by [Et4N][Tz] : Tz : EG (1 : 2 : 2) can be released even down to 30 °C. [ABSTRACT FROM AUTHOR]

The crystal structure and vibrational spectra of the tetraethylammonium salt of tribromotriphylphosphinonickel(II) is reported. Br-Ni-Br angles vary between 108° and 121°, deviating from perfect tetrahedral angles. [ABSTRACT FROM AUTHOR]

Solketal is one of the most promising additives improving the properties of motor fuels. Investigations related to process intensification of synthesis of solketal from glycerol and acetone is gaining importance. The present work illustrates the use of the microwave mode for intensification of this process in the presence of silicoaluminophosphates (SAPO) as catalysts. The main focus of the study was placed on tuning the textural, acidic, and catalytic properties of SAPO-34 and SAPO-5 via variation of the synthesis parameters, such as the nature of Al and Si sources and the structure-directing agent. The catalytic properties of SAPO materials were investigated in the synthesis of solketal from glycerol and acetone under microwave assistance at the acetone/glycerol molar ratio of 2.4 in a methanol solution (glycerol/methanol: 1 g/1 mL) and 56 °C. It was demonstrated that the selectivity towards solketal was 91.1–98.6 % in the presence of the studied materials. The activities of mesoporous SAPO-34 and SAPO-5 prepared in the presence of triethylamine were higher as compared with microporous SAPO-34 prepared in the presence of tetraethylammonium hydroxide due to the high mesoporosity and a larger content of acid sites. The 90.4 % conversion of glycerol and 98.6 % selectivity towards solketal were observed in the presence of mesoporous 7.6%SAPO-34 for 90 min. The advantage of using microwave technology is shown. The solketal yield in the reaction under microwave irradiation was 3 times higher than that in the process performed under thermal heating conditions. [Display omitted] • Synthesis of solketal from glycerol and acetone under microwave conditions was investigated. • Silicoaluminophosphates SAPO-5 and SAPO-34 were used as catalysts. • The source of Al and Si and template affect the structural, textural, acidic properties of catalysts. • The yield of solketal under microwave mode was 3 times higher compared to thermal heating. [ABSTRACT FROM AUTHOR]

With the aim of expanding the potential application scope of mulberries, eleven pH-switchable deep eutectic solvents were screened for the ultrasonic-assisted extraction of mulberry polysaccharides, and a salt/salt aqueous two-phase system was constructed for the efficient separation of mulberry polysaccharides by regulating the system pH. DES-9 (tetraethylammonium chloride: octanoic acid molar ratio = 1: 2) with a critical response pH value of approximately 6.1 was concluded to be the best extraction solvent for extracting mulberry polysaccharides. A maximum polysaccharide extraction yield of 270.71 mg/g was obtained under the optimal conditions. The maximum polysaccharide extraction efficiency was 78.09 % for the pH-driven tetraethylammonium chloride/K 2 HPO 4 aqueous two-phase system. An acidic β -pyran mulberry polysaccharide with a low-molecular weight of 9.26 kDa and a confirmed monosaccharide composition were obtained. This efficient and environmentally friendly polysaccharide separation method offers a new approach for the efficient extraction and utilization of other plant polysaccharides. • pH-switchable deep eutectic solvent was used for mulberry polysaccharides extraction. • This salt/salt aqueous two-phase system exhibited high extraction efficiency. • An acidic β -pyran polysaccharide with a molecular weight of 9.26 kDa was obtained. [ABSTRACT FROM AUTHOR]

[Display omitted] • SAPO-18/34 intergrowth zeolite was synthesized by solvent-free method. • Structure-directing role of co-template was necessary to form the intergrowth. • Lamellar structure was beneficial to improve catalytic conversion and stability. Lamellar SAPO-18/34 intergrowth zeolite has been successfully synthesized by solvent-free method employing N,N -diisopropylethylamine and tetraethylammonium hydroxide as co-template. Different framework structures (SAPO-34 or SAPO-18) could also be crystallized from identical gels under the guidance of a single template agent. The differences in structure, morphology, pore characteristics, chemical composition, and acidity of the prepared zeolite SAPO samples were investigated by XRD, SEM, N 2 adsorption–desorption, XRF, and NH 3 -TPD. In comparison to SAPO-18 and SAPO-34, the lamellar SAPO-18/34 intergrowth zeolite with suitable acidity exhibited better catalytic conversion and enhanced catalytic stability in the cracking of 1-butene. [ABSTRACT FROM AUTHOR]

This article, published in ChemCatChem, explores the synthesis, structure, and catalysis relations of CHA zeolites, which are important industrial catalysts. The authors investigate the crystallization mechanism of zeolites and aim to gain fundamental knowledge for controlling their function. They find that different starting materials lead to three different formation pathways for CHA zeolites, resulting in different properties. The study also provides insights into the origin of catalytic durability based on structural characteristics, crystallization mechanisms, and exhaust gas purification abilities. For more information, readers can refer to the research article by Nao Tsunoji and co-workers. [Extracted from the article]

Sn–Al-Beta zeolites with less silanol defects were synthesized in fluoride media. The effects of the amount of organic template (tetraethylammonium hydroxide, TEAOH), mineralizer (NH 4 F), Al and Sn on the synthesis, acidity and catalytic performance were systematically studied. The synthesized Sn–Al-Beta zeolites were characterized by XRD, SEM, 27Al MAS NMR, UV–vis DRS and FT-IR spectroscopy of hydroxy region and pyridine adsorption. The optimum values of n TEAOH / n Si and n F- / n Si were same (0.3) for synthesizing Sn–Al-Beta with high crystallinity at 140 °C for 7 d. Moreover, decreasing n F- / n Si facilitated the incorporation of Al into the framework. The crystallization rate of Sn–Al-Beta is similar with that of Sn-Beta. Sn was promoted to enter the framework with the increase of Al content, while elevating Sn content has no effect on the incorporation of Al into the framework. The catalytic performance of Sn–Al-Beta was investigated for conversion of glucose to 5-hydroxymethylfurfural in water-containing solvent. Sn–Al-Beta synthesized in fluoride media is more stable than the post-synthesized sample. [Display omitted] • Sn–Al-Beta with tunable B and L acidity is successfully synthesized in fluoride media. • The crystallization rate of Sn–Al-Beta is similar with that of Sn-Beta. • Decreasing n F- / n Si facilitates Al incorporation into the framework. • Increasing Al content promotes Sn incorporation into the framework. • Sn–Al-Beta is more stable than postsynthesized counterpart in water-containing solvent. [ABSTRACT FROM AUTHOR]

New Findings: What is the central question of this study?Does inhibition of K+ channels modulate the exercise‐training‐induced augmentation in cholinergic and thermal sweating?What is the main finding and its importance?Iontophoretic administration of tetraethylammonium, a K+ channel blocker, blunted sweating induced by a low dose (0.001%) of the cholinergic agent pilocarpine, but not heat‐induced sweating. However, no differences in the cholinergic sweating were observed between young endurance‐trained and untrained men. Thus, while K+ channels play a role in the regulation of eccrine sweating, they do not contribute to the increase in sweating commonly observed in endurance‐trained adults. Our findings provide important new insights into the mechanisms underlying the regulation of sweating by endurance conditioning. We evaluated the hypothesis that the activation of K+ channels mediates the exercise‐training‐induced augmentation of cholinergic and thermal sweating. On separate days, 11 endurance‐trained and 10 untrained men participated in two experimental protocols. Prior to each protocol, we administered 2% tetraethylammonium (TEA, K+ channels blocker) and saline (Control) at forearm skin sites on both arms via transdermal iontophoresis. In protocol 1, low (0.001%) and high (1%) doses of pilocarpine were administered at the TEA‐treated and Control sites over a 60‐min period. In protocol 2, participants were passively heated by immersing their lower limbs in hot water (43°C) until core (rectal) temperature (Tc) increased by 0.8°C above resting levels. Administration of TEA attenuated cholinergic sweating (P = 0.001) during the initial 20 min after the treatment of low dose of pilocarpine only whilst the response was similar between the groups (P = 0.163). Cholinergic and thermal sweating were higher in the trained relative to the untrained men (all P ≤ 0.033). Thermal sweating reached ∼90% of the response at a Tc elevation of 0.8°C during the initial 20 min of passive heating, which corresponds to the period wherein TEA attenuated cholinergic sweating in protocol 1. However, sweating did not differ between the Control and TEA sites in either group (P = 0.704). We showed that activation of K+ channels does not appear to mediate the elevated sweating response induced by a low dose of pilocarpine in trained men. We also demonstrated that K+ channels do not contribute to sweating during heat stress in either group. [ABSTRACT FROM AUTHOR]

The slow cooling technique was utilized to grow organic single crystals of tetraethylammonium L-tartarate dehydrate (EAT) with dimensions 20 × 4 × 4 mm3. The meta stable zone width was obtained via solubility curve. Structural confirmation was achieved using X-ray diffraction. EAT possesses noncentro symmetric P21 space group within the monoclinic crystal structure. Optical transmittance in the visible region reveals a strong transparency with lower cutoff wavelength of 261 nm. EAT crystal's refractive index is 1.611. The EAT compound's thermal stability was found to be 115 °C, measured by TG-DTA experiments. EAT's specific heat capacity is be 3.670 g−1K−1. The laser damage threshold of grown EAT crystal surface was measured at 0.3611 GW/cm2. Vicker's microhardness, Kurtz-Perry Powder Method evaluated the mechanical power, particle size based second harmonic generation efficiency (SHG) which identified phase matching in EAT. The SHG maker Fringes technique investigated the SHG of EAT. Optical limiting analysis showed transmitted output power rises linearly till 2.736 mW mm−2 of irradiance. [ABSTRACT FROM AUTHOR]

Nanocrystalline Ti−Beta zeolite with high hydrophilicity and a Ti−rich exterior was successfully prepared via a dissolution–recrystallization method. With the post−treatment of tetraethylammonium hydroxide (TEAOH) solution at elevated temperature, the Si and Ti species within the Ti−Beta matrix were partially dissolved and recrystallized on the outer surface of crystals, resulting in the Ti−rich exterior and higher hydrophilicity, which improved the accessibility of the active Ti sites and the enrichment of H2O2. Simultaneously, some of the closed Ti(OSi)4 species were transformed to more active open Ti(OSi)3OH or Ti(OSi)2(H2O)2(OH)2 species. The modified Ti−Beta zeolite exhibited greatly enhanced catalytic performance in the epoxidation of cyclohexene in comparison to the parent Ti−Beta. [ABSTRACT FROM AUTHOR]

Aim: To determine whether Na+ uptake in adult zebrafish (Danio rerio) exposed to acidic water adheres to traditional models reliant on Na+/H+ Exchangers (NHEs), Na+ channels and Na+/Cl− Cotransporters (NCCs) or if it occurs through a novel mechanism. Methods: Zebrafish were exposed to control (pH 8.0) or acidic (pH 4.0) water for 0‐12 hours during which 22Na+ uptake (JNain), ammonia excretion, net acidic equivalent flux and net K+ flux (JHnet) were measured. The involvement of NHEs, Na+ channels, NCCs, K+‐channels and K+‐dependent Na+/Ca2+ exchangers (NCKXs) was evaluated by exposure to Cl−‐free or elevated [K+] water, or to pharmacological inhibitors. The presence of NCKXs in gill was examined using RT‐PCR. Results: JNain was strongly attenuated by acid exposure, but gradually recovered to control rates. The systematic elimination of each of the traditional models led us to consider K+ as a counter substrate for Na+ uptake during acid exposure. Indeed, elevated environmental [K+] inhibited JNain during acid exposure in a concentration‐dependent manner, with near‐complete inhibition at 10 mM. Moreover, JHnet loss increased approximately fourfold at 8‐10 hours of acid exposure which correlated with recovered JNain in 1:1 fashion, and both JNain and JHnet were sensitive to tetraethylammonium (TEA) during acid exposure. Zebrafish gills expressed mRNA coding for six NCKX isoforms. Conclusions: During acid exposure, zebrafish engage a novel Na+ uptake mechanism that utilizes the outwardly directed K+ gradient as a counter‐substrate for Na+ and is sensitive to TEA. NKCXs are promising candidates to mediate this K+‐dependent Na+ uptake, opening new research avenues about Na+ uptake in zebrafish and other acid‐tolerant aquatic species. [ABSTRACT FROM AUTHOR]

Potassium ion signaling mediates microbial communication in electroactive biofilms within microbial fuel cells (MFCs), but its role in nitrogen removal remains unclear. This study investigated the impact of inhibiting potassium signaling on nitrogen removal in MFCs using tetraethylammonium chloride (TEA) as an inhibitor. Results demonstrated that 5 mM and 10 mM TEA reduced the maximum power generation of MFCs from 77.95 mW/cm 2 to 57.18 mW/cm 2 and 48.23 mW/cm 2 , respectively. Correspondingly, total nitrogen (TN) removal efficiency was decreased from 46.57 ± 1.01% to 35.93 ± 0.63% and 38.97 ± 0.74%, respectively. This decline was attributed to inhibited potassium ion signaling, which compromised the electrochemical performance of the MFC and hindered the nitrogen removal process. The relative abundance of exoelectrogen Geobactor decreased from 15.37% to 5.17% and 8.05%, while the relative abundance of cathodic nitrifying bacteria Nitrosomonas decreased from 17.87% to 4.92% and 3.63% under 5 mM and 10 mM TEA. These findings underscore the crucial role of potassium ion signaling in enhancing the bioelectrochemical nitrogen removal process in MFCs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Low threshold mechanoreceptors (LTMRs) are important for environmental exploration, social interaction, and tactile discrimination. Whisker hair follicles are mechanical sensory organs in non-primate mammals that are functionally equivalent to human fingertips. Several functional types of LTMRs have been identified in rodent whisker hair follicles, including rapidly adapting (RA), slow adapting type 1 (SA1), and slowly adapting type 2 (SA2) LTMRs. Properties of these LTMRs have not been fully characterized. In the present study, we have used pressure-clamped single-fiber recording technique to record impulses of RA, SA1, and SA2 LTMRs in mouse whisker hair follicles, and tested effects of 5-HT, Cd2+, tetraethylammonium (TEA), 4-aminopyridine (4-AP), and Ba2+ on the LTMR impulses. We show that 5-HT at 2 mM suppresses SA1 impulses but has no effects on RA and SA2 impulses. Cd2+ at 100 μM suppresses both SA1 and SA2 impulses but has no effects on RA impulses. TEA at 10 mM has no effects on RA and SA1 impulses but increased SA2 impulses. However, TEA at 1 mM and 200 μM decreases SA2 impulses. 4-AP at 1 mM suppresses both SA1 and SA2 impulses but has no effects on RA impulses. Ba2+ at 5 mM increases both RA and SA1 impulses but suppresses SA2 impulses. Collectively, RA, SA1, and SA2 LTMRs show distinct pharmacological properties, suggesting that these LTMRs may use different mechanisms to tune their mechanical signaling. [ABSTRACT FROM AUTHOR]

Species of Erythroxylum genus are popularly used as anti-inflammatories and in the treatment of renal and respiratory disorders. Although it has been reported that species from the Erythroxylum genus induce cardiovascular effects, E. passerinum had not been studied specifically in this respect. However, previous phytochemical studies of E. passerinum demonstrated the presence of compounds which can have potential activity on the cardiovascular system. In this study, phytochemical screening of the ethanol extract of E. passerinum (EEEP) detected polyphenols, but not alkaloids. EEEP caused hypotension, bradycardia and vasorelaxation in rats. The vasorelaxation was attenuated by Nw-nitro-L-arginine methyl ester (L-NAME) or L-NAME + indomethacin (INDO), but not by INDO alone. Vasorelaxation was also significantly attenuated after endothelium removal or after incubation with high K+, 4-aminopyridine, glibenclamide or tetraethylammonium, but was not affected by pre-contraction with serotonin. Thus, EEEP induces hypotension and endothelium-dependent and independent vasorelaxation, which seems to involve the nitric oxide and K+-channels. [ABSTRACT FROM AUTHOR]