Search results for "Potassium"
showing 10 items of 930 documents
Pyrogallarenes as alkali metal receptors: the role of cation-pi interactions in complexation.
2006
Crystallization studies of C-methyl pyrogallarene with potassium, rubidium and caesium bromides or chlorides resulted in a hydrogen bonded molecular cage in which the alkali metal cations are eta6 coordinated to aromatic rings via strong cation-pi interactions.
Sodium zirconium cyclosilicate: a new potassium binder for the treatment of hyperkalemia
2018
Hyperkalemia is one of the most common electrolyte disturbances, especially among some groups of patients, such as in those with chronic kidney disease, diabetes or heart failure. Hyperkalemia has been associated with increased risks of mortality, arrhythmias, hospitalization and costs, as well as the need to down titrate/discontinue renin-angiotensin-aldosterone system inhibitors (RAASIs), despite their well-known cardiovascular and nephroprotective benefits. Current potassium binders have limitations (slow onset of action, limited selectivity for potassium binding, risk of drug interactions or gastrointestinal intolerance). Sodium zirconium cyclosilicate (SZC) is a new potassium binder re…
Effect of serotonin and calcium in normal and sensitized guinea pig isolated trachea
1996
Tracheal strips from normal and actively sensitized guinea pigs were studied to determine the responses to serotonin (5-hydroxytryptamine, 5-HT ; 1 nM - 0.1 mM) and ouabain (0.1 μM - 0.1 mM), and the effects of increasing the extracellular calcium (Ca o ) concentration on tonic contractions elicited by 5-HT. Sensitized trachea exhibited an increased responsiveness and sensitivity to 5-HT and ouabain. Increases in Ca o to achieve final concentrations of 5, 10 and 20 mM caused concentration-related relaxations of normal and sensitized tissues contracted to a similar plateau level with 5-HT. Inhibition of the Na + /K + -ATPase by ouabain (10 μM) reversed the effects of Ca o from relaxation to …
Hydrolysis of DCNP (a Tabun mimic) catalyzed by mesoporous silica nanoparticles
2015
[EN] The hydrolysis of diethylcyanophosphonate, DCNP (a Tabun simulant) in the presence of mesoporous silica nanoparticles (MSN) has been studied in acetonitrile:water (99.5:0.5 v/v) mixtures using 31P NMR as a suitable technique to follow the DCNP hydrolysis. MSN alone was not capable to induce DCNP hydrolysis, yet MSN in combination with the presence of the bases potassium carbonate, triethylamine or DABCO enhanced DCNP degradation. When MSN was used combined with K2CO3, a hydrolysis of ca. 95% of the initial DCNP after 60 min was observed. In the presence of DABCO, MSN was able to induce the hydrolysis of ca. 90% of DCNP after the same time. However, the DCNP hydrolysis using MSN in the …
Comparative study on the inhibition of Na+, K+-activated ATPase activity by chlorpromazine, promazine, imipramine, and their monodesmethyl metabolites
1972
The inhibition of the sodium- and potassium-activated adenosine triphosphatase (Na-K-ATPase, EC 3.6.1.3) activity by chlorpromazine, promazine and imipramine was compared with that by the monodesmethyl metabolites of these drugs. The experiments were performed with a deoxycholate- and sodium iodide-treated microsomal enzyme preparation from rat brain. It was shown in dose-response curves as well as in double-reciprocal Lineweaver-Burk plots of Na-K-ATPase activity against KCl concentration that the monodesmethyl metabolites were stronger inhibitors than their parent compounds. The results obtained with the desmethyl metabolites and imipramine as inhibitors indicate competitive inhibition wh…
In vitro evaluation of poloxamer in situ forming gels for bedaquiline fumarate salt and pharmacokinetics following intramuscular injection in rats
2019
Graphical abstract
A novel high-spin heterometallic Ni12K4cluster incorporating large Ni–azide circles and an in situ cyanomethylated di-2-pyridyl ketone
2005
Reaction of di-2-pyridyl ketone (dpk) with nickel acetate and azide in the presence of potassium tert-butylate as a catalytic base generates the title compound, which contains the largest [Ni(m1,1-N3)]6 circles in the discrete ferromagnetically-coupled MII–azide cluster family, and shows an unprecedented in situ cyanomethylation of ketone. Clemente Juan, Juan Modesto, Juan.M.Clemente@uv.es
Insights on the Mechanism of Insoluble-to-Soluble Prussian Blue Transformation
2009
The electrochemical transformation of the soluble form of Prussian blue (PB) material from the insoluble form was monitored using electrochemical, gravimetric, acoustic, and spectroscopic techniques simultaneously. The described combination of in situ techniques represents an innovative tool for measurement in electrochemistry, which provides complementary information on the electrochemical systems. The insoluble-to-soluble PB transformation process takes place during the successive voltammetric cycles between the mixed valence form (PB) and the fully reduced form [Everitt's salt (ES)]. One of the processes that takes place is the exit of free Fe(CN) 4- 6 ions occluded in the vacancies of t…
Partialsynthese neuer Ergolinderivate aus Clavinalkaloiden, 4. Mitt. N-1-, C-2- und N-6-monosubstituierte Agroclavine
1985
Agroclavin (1) wird in flussigem Ammoniak/Kaliumamid mit Alkyliodid am Indolstickstoff alkyliert. 1 last sich mit N-Iodsuccinimid zu 2-Iod-1 (3) umsetzen. Mit der Bromcyan-Methode wird 6-Nor-1 (4b) gewonnen und danach an N-6 alkyliert. Partial Synthesis of New Ergoline Derivatives from Clavine Alkaloids, IV: Agroclavines Monosubstituted at N-1, C-2, and N-6 Agroclavine (1) is alkylated at the indole nitrogen with alkyl iodide in ammonia/potassium amide. It is convertible to 2-iodo-1 (3) with N-iodosuccinimide. Compound 6-nor-1 can be prepared by means of the cyanogen bromide method; alkylation at N-6 is described exemplarily for the ethyl derivative.
Synthesis and Characterization of New Keggin-Based Structure Tungstocobaltates: K9[Co3+W11O39] and its Vanadium Derivatives, K8[Co2+W11V4+O40], K7[Co…
1995
Abstract Good yield synthesis of the potassium salts of four new interrelated : olyoxometalates, [Co3+W11O39]9-(I), [Co2+W11V4+O4]8-(II), [Co2+W11V5+O40]7-(III), and [Co3+W11V5+O40]6-(IV), are reported. The title compounds have been characterized by IR and UV-Vis.-NIR spectroscopies, cyclic voltammetry and magnetic measurements. IR spectra confirm that I has the lacunary structure of an undecatungstate anion, while II through IV have a substituted α-Keggin structure with the vanadium atom located at an octahedral site replacing one tungsten atom. Optical data confirm the oxidation states for both, the Co and V atoms, as formulated for I through IV.