A new simple and reliable method for rapid and selective extraction and determination of trace levels of Zn(II) ion is developed. Zn(II) ions are adsorbed quantitatively during passage of aqueous samples through PET-AA/AAm nano fiber modified. Almost all matrix elements were found to pass through the nano fiber to drain. Modified Poly (ethylene terephthalate)-grafted-Acrylic acid/Acryl amide Na...

A new simple and reliable method for rapid and selective extraction and determination of trace levels of Zn(II) ion is developed. Zn(II) ions are adsorbed quantitatively during passage of aqueous samples through PET-AA/AAm nano fiber modified. Almost all matrix elements were found to pass through the nano fiber to drain. Modified Poly (ethylene terephthalate)-grafted-Acrylic acid/Acryl amide Na...

A classification of kinetics of metalloporphyrin formation is presented according to the composition of the activated complex involved in the reaction. In the reaction of large metal ions, such as mercury(II) and cadmium(II) with porphyrins, these metal ions can not fit into the porphyrin nucleus and they are out—of-plane in the metalloporphyrin. In this case the reaction is relatively fast and...

A PVC membrane electrode based on 1-[({[(butylsulfunyl)carbothioyl]disulfanyl} carbothioyl)sulfanyl]butane as a suitable ion carrier for determination of lanthanum(III) ion was prepared. This electrode revealedsuch a good selectivity toward La3+ ion over a wide variety of other metal ions. Some experimental parametersuch as membrane composition, nature, and amount of plasticizer, the amount of ...

Dissolved trace metals are present in the environment as free ions and as complexes. Commonly used models to predict metal bioavailability consider the free ion as the major bioavailable species. However, increases in metal availability in the presence of metal complexes have repeatedly been found. We measured the uptake of cadmium (Cd) by spinach (Spinacia oleracea) from solution in absence or...

Metal ions play crucial roles in thermal stability and folding kinetics of nucleic acids. For ions (especially multivalent ions) in the close vicinity of nucleic acid surface, interion correlations and ion-binding mode fluctuations may be important. Poisson-Boltzmann theory ignores these effects whereas the recently developed tightly bound ion (TBI) theory explicitly accounts for these effects....

a new polyvinyl choloride (pvc) membrane sensor for cerium (iii) was prepared based on 4,13-didecyl-1,7,10,16-tetraoxa-4,13-diazacyclooctadecane (kryptofix22dd) as an ionophore. the sensor exhibites a linear concentration range of 1.0×10-6to 1.0×10-1m, with a nernstian slope of 18.0±1.0 mv/decade, and a detection limit of 9.7×10-7m. it has a fast response time (5 s) and can be used for two mont...

BACKGROUND Metal-on-metal prostheses undergo wear and corrosion, releasing soluble ions and wear particles into the surrounding environment. Reports described early failures of the metal-on-metal prostheses, with histologic features similar to a Type IV immune response. Mechanisms by which metal wear products and metal ion causing this reaction are not completely understood, and the effects of ...

Previously, we reported that the substrate shape recognition of the Escherichia coli ribonuclease (RNase) P ribozyme depends on the concentration of magnesium ion in vitro. We additionally examined the Bacillus subtilis RNase P ribozyme and found that the B. subtilis enzyme also required high magnesium ion, above 10 mM, for cleavage of a hairpin substrate. The results of kinetic studies showed ...