a mild, efficient and fast method for the oxidation of alcohols and trimethylsilyl and tetrahydropyranyl ethers to their corresponding carbonyl compounds using cro3 in the presence of sulfonic acid functionalized ordered nanoporous na+-montmorillonite (sanm) and under solvent-free conditions is reported. all reactions were performed at room temperature in high to excellent yields. ease of the p...

abstract nowadays, environmental pollution by heavy metals is one of the most serious threats of the world which needs effective remediation actions. the aim of this study was to investigate the potential use of atriplex [atriplex verucifera], salicornia [salicornia europaea] and chenopodium album in simultaneous uptake and accumulation of na and cd or pb in two calcareous soils with different ...

introduction: ouabaine is a well-known atrioventricular (av) node depressant agent, but its effects on functional properties of the av node have not been cleared. the aim of the present study was to determine how ouabaine administration modifies the rate-dependent properties of the av node. methods: selective stimulation protocols were used to quantify independently electrophysiological propert...

Salinity is a major limitation ecological factor for plant development in arid and semi-arid regions. The ionic imbalance, deficiency of nutrients and degradation of plant metabolites are caused by saline conditions, are affected by the reduction ratio of potassium (K) then sodium (Na). In this research foliar applications of humic acid (HA) for improve the absorption of K under salt stress was...

In the present study we focused on the electronic and structural properties of Na and Mg adsorption on the surface of the (6, 6) armchair SiCNTs. The adsorption energy (Eads), band gap energy (Eg), partial density of state (PDOS), chemical potential (μ), global hardness (η), electrophilicity index (ω), global softness (S), work function values (φ) and work function change (Δφ) are calculated by...

Na+ reabsorption is regulated in proximal tubules by hormones that stimulate protein kinase C (PKC). To determine whether stimulation of PKC causes a reduction in intracellular Na+ concentration ([Na+]i) that might link Na+ pump activation to increased Na+ reabsorption, [Na+]i was measured in kidney cells loaded with the Na+-sensitive fluorescent indicator SBFI. Rapid digital imaging fluorescen...

To elucidate the role of intracellular Na(+) kinetics in the mechanism for ischemic preconditioning (IPC), we measured intracellular Na(+) concentration ([Na(+)](i)) using (23)Na-magnetic resonance spectroscopy in isolated rat hearts. IPC significantly delayed the initial [Na(+)](i) increase (d[Na(+)](i)/dt) compared with non-IPC control, resulting in attenuation of Na(+) accumulation (Delta[Na...

n-sodium acrylate-o-carboxymethyl chitosan [cmch-g-paa(na)] bound fe3o4 nanoparticles were developed as a novel magnetic nanoparticles with an ionic structure that can be potentially used in many fields. cmch-g-paa (na) was obtained by grafting of sodium polyacrylate on o-carboxymethyl chitosan, which is an amphiphilic polyelectrolyte with the biocompatibility and biodegradability properties. a...

We examined the kinetic properties of the interactions between inner and outer cation sites of the Na-Li countertransport system in human red blood cells. Li-stimulated Na efflux [V(Na)] was measured as a function of external Li [(Li)o] and internal Na [(Na)i] contents. At each (Li)o, a Hanes plot of (Na)i/V(Na) vs. (Na)i allowed us to calculate the apparent dissociation constant for internal N...