Potassium Chloride

Hygroscopic properties of potassium chloride and its internal mixtures with organic compounds relevant to biomass burning aerosol particles.[Pubmed:28240258]

Sci Rep. 2017 Feb 27;7:43572.

While water uptake of aerosols exerts considerable impacts on climate, the effects of aerosol composition and potential interactions between species on hygroscopicity of atmospheric particles have not been fully characterized. The water uptake behaviors of Potassium Chloride and its internal mixtures with water soluble organic compounds (WSOCs) related to biomass burning aerosols including oxalic acid, levoglucosan and humic acid at different mass ratios were investigated using a hygroscopicity tandem differential mobility analyzer (HTDMA). Deliquescence points of KCl/organic mixtures were observed to occur at lower RH values and over a broader RH range eventually disappearing at high organic mass fractions. This leads to substantial under-prediction of water uptake at intermediate RH. Large discrepancies for water content between model predictions and measurements were observed for KCl aerosols with 75 wt% oxalic acid content, which is likely due to the formation of less hygroscopic potassium oxalate from interactions between KCl and oxalic acid without taken into account in the model methods. Our results also indicate strong influence of levoglucosan on hygroscopic behaviors of multicomponent mixed particles. These findings are important in further understanding the role of interactions between WSOCs and inorganic salt on hygroscopic behaviors and environmental effects of atmospheric particles.

New approach for cystic fibrosis diagnosis based on chloride/potassium ratio analyzed in non-invasively obtained skin-wipe sweat samples by capillary electrophoresis with contactless conductometric detection.[Pubmed:28357484]

Anal Bioanal Chem. 2017 May;409(14):3507-3514.

A new approach for sweat analysis used in cystic fibrosis (CF) diagnosis is proposed. It consists of a noninvasive skin-wipe sampling followed by analysis of target ions using capillary electrophoresis with contactless conductometric detection (C4D). The skin-wipe sampling consists of wiping a defined skin area with precleaned cotton swab moistened with 100 muL deionized water. The skin-wipe sample is then extracted for 3 min into 400 muL deionized water, and the extract is analyzed directly. The developed sampling method is cheap, simple, fast, and painless, and can replace the conventional pilocarpine-induced sweat chloride test commonly applied in CF diagnosis. The aqueous extract of the skin-wipe sample content is analyzed simultaneously by capillary electrophoresis with contactless conductometric detection using a double opposite end injection. A 20 mmol/L L-histidine/2-(N-morpholino)ethanesulfonic acid and 2 mmol/L 18-crown-6 at pH 6 electrolyte can separate all the major ions in less than 7 min. Skin-wipe sample extracts from 30 study participants-ten adult patients with CF (25-50 years old), ten pediatric patients with CF (1-15 years old), and ten healthy control individuals (1-18 years old)-were obtained and analyzed. From the analyzed ions in all samples, a significant difference between chloride and potassium concentrations was found in the CF patients and healthy controls. We propose the use of the Cl(-)/K(+) ratio rather than the absolute Cl(-) concentration and a cutoff value of 4 in skin-wipe sample extracts as an alternative to the conventional sweat chloride analysis. The proposed Cl(-)/K(+) ion ratio proved to be a more reliable indicator, is independent of the patient's age, and allows better differentiation between non-CF individuals and CF patients having intermediate values on the Cl(-) sweat test. Figure New approach for cystic fibrosis diagnosis based on skin-wipe sampling of forearm and analysis of ionic content (Cl(-)/K(+) ratio) in skin-wipe extracts by capillary electrophoresis with contactless conductometric detection.

An Isolable Potassium Salt of a Borasilene-Chloride Adduct.[Pubmed:28328112]

Angew Chem Int Ed Engl. 2017 Apr 10;56(16):4593-4597.

Among the variety of isolable compounds with multiple bonds involving silicon, examples of compounds that contain silicon-boron double bonds (borasilenes) still remain relatively rare. Herein, we report the synthesis of the potassium salt of a chloride adduct of borasilene 1 ([2](-) ), which was obtained as an orange crystalline solid. Single-crystal X-ray diffraction analysis and reactivity studies on [2](-) confirmed the double-bond character of the Si=B bond as well as the reduced Lewis acidity, which is due to the coordination of Cl(-) to the boron center. A thermal reaction of [2](-) afforded a bicyclic product by formal intramolecular C-H insertion across the Si=B bond of 1, which was corroborated by a theoretical study.

Calcineurin inhibitors block sodium-chloride cotransporter dephosphorylation in response to high potassium intake.[Pubmed:28341239]

Kidney Int. 2017 Feb;91(2):402-411.

Dietary potassium intake is inversely related to blood pressure and mortality. Moreover, the sodium-chloride cotransporter (NCC) plays an important role in blood pressure regulation and urinary potassium excretion in response to potassium intake. Previously, it was shown that NCC is activated by the WNK4-SPAK cascade and dephosphorylated by protein phosphatase. However, the mechanism of NCC regulation with acute potassium intake is still unclear. To identify the molecular mechanism of NCC regulation in response to potassium intake, we used adult C57BL/6 mice fed a 1.7% potassium solution by oral gavage. We confirmed that acute potassium load rapidly dephosphorylated NCC, which was not dependent on the accompanying anions. Mice were treated with tacrolimus (calcineurin inhibitor) and W7 (calmodulin inhibitor) before the oral potassium loads. Dephosphorylation of NCC induced by potassium was significantly inhibited by both tacrolimus and W7 treatment. There was no significant difference in WNK4, OSR1, and SPAK expression after high potassium intake, even after tacrolimus and W7 treatment. Another phosphatase, protein phosphatase 1, and its endogenous inhibitor I-1 did not show a significant change after potassium intake. Hyperkaliuria, induced by high potassium intake, was significantly suppressed by tacrolimus treatment. Thus, calcineurin is activated by an acute potassium load, which rapidly dephosphorylates NCC, leading to increased urinary potassium excretion.