introduction: salivary calcium and phosphate levels might have a relationship with dental caries severity. evaluation of different indexes such as alkaline phosphatase, which increases salivary phosphate levels, and hydroxyapatite ion activity, which reflects salivary calcium and phosphate levels, might help determine the risk of dental caries. the aim of the present study was to compare saliva...

the mössbauer spectra of nanoferrite materials such as ni0.25mn0.75fe2o4, co0.5mn0.5fe2o4 and ni0.4co0.6fe2o4 have been reported and the above materials were prepared by sol-gel combustion method using metal nitrates as source material and polyvinyl alcohol(pva) as agglomeration reducing agent. as the structural, thermal and magnetic properties (vsm) of the above ferrites have been published al...

Ion channels are naturally occurring pores through the proteins that regulate the passage of ions and thus maintain the concentration of ions inside and outside the cell. The ion channels control many physiological functions and they can show selectivity for a specific ion. Ion channels are mostly observed in nerve cells and muscle cells. The influx of ions into cells can be regulated by a gate...

the ion-pair association constant values, related to the reaction +  were determined by means of the nmr spectroscopy. the values of the thermodynamic functions of the ion pairing process were calculated on the basis of the nmr results. in addition, the association entropy was found to be dependent on the temperature. comparing the experimental data and the fuoss theory it is found that  ion-pa...

the interaction between some heavy metal ions such as of pb(ii), cd(ii) and cu(ii) ions from aqueous solution adsorbed by single walled carbon nanotube (swcnts) and carboxylate group functionalized single walled carbon nanotube (swcnt-cooh) surfaces were studied by atomic absorption spectroscopy. the effect of contact time, ph, initial concentration of ion, ionic strength and temperature on the...

in this study, a sensitive method of dispersive liquid phase microextraction based on ion-pair combined with the flame atomic absorption spectrometry was proposed for the determination of trace ni(ii) using aliquat 336-chloride as ion pair agent. several factors which have effect on  the microextraction efficiency of ni(ii), such as ph, extraction and dispersive solvent type and their volume, c...

the discharge of lead containing effluents into the environment and water bodies is harmful for the human, animals, aquatic flora and fauna. herein, a novel surface engineered magnetic nanoparticle for removing pb2+ ions was studied. after surface modification of the magnetite by 3-amino-propyltriethoxysilane (aptes) magnetic nanoparticles with covalently linked porphyrins were synthesized. two...

the main goal of this study is to investigate the capability of zeolites a and p synthesized from iranian natural clinoptilolite for uranium uptak. the removal of uranium(vi) from aqueous solution via ion exchange by zeolites in a single component system with various contact times,  temperatures and initial concentrations of uranium(vi) was investigated. the experimental results were fitted to ...