Search results for "Sodium"

Imaging synaptic zinc release in living nervous tissue

2001

Zinc enriched neurons have a pool of synaptic vesicles which contain free or loosely-bound zinc ions. The movement of the vesicular zinc ions into the synaptic clefts has been previously studied by microdialysis, fluorescence postmortem staining for zinc and radioactive zinc isotope. In this study the zinc fluorescence probe N-6-metoxy-p-toluensulfonamide quinoline (TSQ) has been applied as a tracer of synaptic release of zinc ions. This fluorochrome permeates cell membranes and when exposed to living brain slices gives rise to a staining pattern similar to that seen with autometallography. In the living brain slices, fluorescence emission persists after exposure to calcium saturated ethyle…

Energetics of Water−Dodecyl Surfactant−Macrocyclic Compound Ternary Systems

1996

Enthalpies of dilution and osmotic coefficients of sodium dodecyl sulfate (NaDS) and dodecyltrimethylammonium bromide (DTAB) in water + 18-crown-6 ether (CR) and water + β-cyclodextrin (CD) at a fixed cosolvent concentration were measured at 298 and 310 K, respectively, as functions of the surfactant concentration (mS). Enthalpies of transfer ΔH (W → W + S) of CR (0.03 m) from water to NaDS and DTAB aqueous solutions as functions of mS were also determined at 298 K. From the enthalpies of dilution the apparent (LΦ,S) and partial (L2,S) molar relative enthalpies of both surfactants were calculated. Despite CR forms inclusion complexes with the anionic surfactant only, the L2,S vs mS profiles…

Solution properties of polyelectrolytes—V. Viscometric study of mixed polyanions in pure water

1990

Abstract A viscometric study of sodium polystyrene sulphonate (NaPSS) and sodium poly( l -glutamate) (NaPLG) in salt-free water has been carried out as a function of the total concentration, cm, and the concentration of one polyelectrolyte at fixed concentration of the other. The influences of the molecular weight and concentration are considered in order to establish the degree of compatibility. For the first time, an equation is proposed to define the reduced viscosity of the NaPSS + NaPLG mixture in water. The viscometric interaction parameter, Bm, taking into account the electrostatic and thermodynamic interactions between both polyions, is defined as a geometrical mean of the contribut…

Heat capacities and volumes of suspensions in the presence of surfactants

2004

Abstract Density and heat capacity measurements of water–surfactant–silica ternary systems were carried out as functions of the silica and the surfactant concentrations at 298 K. From these properties, the apparent molar volume and heat capacity of the surfactant in a given water+silica mixture were evaluated. As well, the apparent specific volume and heat capacity of silica, at a given concentration, in the water+surfactant mixtures as functions of the surfactant concentration were calculated. Some surfactants (decyltrimethylammonium bromide, sodium octanoate, sodium decanoate, sodium dodecanoate, sodium decylsulfate, sodium perfluorooctanoate and N , N -dimethyldodecylamine- N -oxide) wer…

The role of the dual nature of ionic liquids in the reversed-phase liquid chromatographic separation of basic drugs.

2010

The cationic nature of basic drugs gives rise to broad asymmetrical chromatographic peaks with conventional C18 columns and hydro-organic mixtures, due to the ionic interaction of the positively charged solutes with the free silanol groups on the alkyl-bonded reversed-phase packing. Ionic liquids (ILs) have recently attracted some attention to reduce this undesirable silanol activity. ILs are dual modifiers (with a cationic and anionic character), which means that both cation and anion can be adsorbed on the stationary phase, giving rise to interesting interactions with the anionic free silanols and the cationic basic drugs. A comparative study of the performance of four imidazolium-based I…

Cellular cation exchange in arterial hypertension: Effects of insulin resistance

1993

Synthesis, structure and properties of new heterometallic octanuclear Li2Na2Cu4 and decanuclear Li2Zn8 complexes

2019

Abstract A carboxylate containing polydentate ligand in combination with exogeneous succinate (suc) has been used to stabilize heterometallic octanuclear [Li2Na2Cu4(cpdp)2(suc)2(CH3OH)2(H2O)4]Cl2·6H2O (1) and decanuclear Na(H3O)2[Li2Zn8(cpdp)4(suc)2(H2O)4]Cl2Br3·6MeOH·19H2O (2) complexes. The reaction of ligand H3cpdp (H3cpdp = N,N'-bis[2-carboxybenzomethyl]-N,N'-bis[2-pyridylmethyl]-1,3-diaminopropan-2-ol) with stoichiometric amounts of CuCl2/sodium succinate, and ZnCl2/sodium succinate, allowed isolation of complexes 1 and 2, respectively. Analyses of single crystal X-ray structures indicate that complex 1 is capped by two [Cu2(cpdp)]+ molecular building units and two succinate linkers, w…

NanoMORALs: Metal Nanoparticles Doped with Organic Molecules

2009

A new class of nanosized metal–organic alloys (MORALs) has been synthesized for the first time. Silver nanoparticles doped with Cu(II) and Fe(III) phthalocyanines were thus synthesized in the presence of sodium dodecyl sulfate (SDS). The resulting materials were characterized by means of XRD, SEM, TEM coupled to energy dispersive X-ray analysis, and thermogravimetric analysis. No leaching of the photoactive dopant species was observed in water or in common organic solvents.

Fullerene-ionic-liquid conjugates: a new class of hybrid materials with unprecedented properties.

2015

A modular approach has been followed for the synthesis of a series of fullerene-ionic-liquid (IL) hybrids in which the number of IL moieties (two or twelve), anion, and cation have been varied. The combination of C60 and IL give rise to new unique properties in the conjugates such as solubility in water, which was higher than 800 mg mL(-1) in several cases. In addition, one of the C60 -IL hybrids has been employed for the immobilization of palladium nanoparticles through ion exchange followed by reduction with sodium borohydride. Surprisingly, during the reduction several carbon nanostructures were formed that comprised nano-onions and nanocages with few-layer graphene sidewalls, which have…

Nanocomposites of bacterial cellulose/hydroxyapatite for biomedical applications.

2008

In the present work, a nanocomposite material formed by bacterial cellulose (BC) networks and calcium-deficient hydroxyapatite (HAp) powders was synthesized and characterized. The HAp nanoparticles were previously prepared by a wet chemical precipitation method, starting from aqueous solutions of calcium nitrate and di-ammonium phosphate salts. Energy-dispersive spectroscopy reveals that the prepared HAp corresponds to calcium-deficient hydroxyapatite. BC-HAp nanocomposites were prepared by introducing carboxymethylcellulose (CMC) into the bacteria culture media. HAp nanoparticles were then introduced and remained suspended in the culture medium during the formation of cellulose nanofibrils…