jute modified has been used for adsorption of cr (vi), cd (ii) and pb (ii) ions over a range ofinitial metal ion concentration. adsorption process is done in batch mode. adsorption isotherms ofthe heavy metals on adsorbents prepared were determined and correlated with common isothermequations. it was found that the freundlich isotherm is better than langmuir for explaining thebehavior of adsorp...

It is well-known that metal ion complexes are essential in various biological systems, including those with adenosine nucleotides which are substrates for a large number of enzymatic processes. The interactions of various metal ions with adenosine nucleotides have been intensively studied by multinuclear NMR spectroscopy. Nucleotides are polydentate ligands with various potential binding sites,...

the complexation reactions between tl+ and pb2+ ions and crown ethers 12-crown-4(12c4), 15-crown-5 (15c5), benzo-15-crown-5 (b15c5), 18-crown-6 (18c6), dicyclohexyl-18-crown-6 (dc18c6) and aza-18-crown-6 (a18c6) were studied in 90% acetonitrile and 90% ethanol solutions at 25 °c, using an a.c. polarographic technique. the stoichiometry and stability of the complexes were determined by monitorin...

Previously, we reported that the substrate shape recognition of the EScherichia coli ribonuclease (RNase) P ribozyme depends on the eoncentration of magnesium ion in vitro. We additional]y examined the Bacillvs subtilts RNase P ribozyme and found that the B. subti1ts enzyme also required high mag"esium ion, aboye 10 mM, for cleavage of a hairpin substrate. The results of kinetic studies showed ...

The removal of the chromium (VI) ion from aqueous solutions with the Lewatit FO36 ion-exchange resin is described at different conditions. The effects of adsorbent dose, initial metal concentration, contact time and pH on the removal of chromium (VI) were investigated. The batch ion exchange process was relatively fast and it reached equilibrium after about 90 min of contact. The ion exchange p...

The hydrolysis of the thorium(IV) ion in various concentrations of magnesium, calcium, strontium and barium chloride media was studied by the emf method at 25 °c. The data show that the extent of thorium hydrolysis decreases with increasing concentration and hydration energy of the medium ions. The contribution of the concentration of the medium ions to the total medium effect is higher than th...

Increased concentrations of metal ions after metal-on-metal resurfacing arthroplasty of the hip remain a concern. Although there has been no proven link to long-term health problems or early prosthetic failure, variables associated with high metal ion concentrations should be identified and, if possible, corrected. Our study provides data on metal ion levels from a series of 76 consecutive pati...

Heavy metals released by a number of industrial processes are major pollutants in marine, ground, industrial and even treated waste waters. Biosorption is a process that utilizes biological materials as adsorbents and several researchers have studied this method as an alternative technique to conventional methods for heavy metal removal from wastewaters. In this study, the efficiency of tea was...

a binding study of nickel ions by a new recombinant human growth hormone (hgh), produced as an injected drug, has been done at 27˚c in nacl solution (50 mm) using an isothermal titration calorimetry. there is a set of three identical and non-interacting binding sites for nickel ions. the intrinsic dissociation equilibrium constant and the molar enthalpy of binding are 40 μm and -16.5 kj/mol, re...

Background and purpose - Large metal-on-metal (MoM) articulations are associated with metal wear and corrosion, leading to increased metal ion concentrations and unacceptable revision rates. There are few comparative studies of 28-mm MoM articulations with conventional metal-on-polyethylene (MoP) couplings. We present a long-term follow-up of a randomized controlled trial comparing MoM versus M...