A proton NMR method for the determination of the solvation numbers of alkaline earth cations with dimethylsulfoxide (DMSO) in nitromethane as diluent is described. The method is based on the monitoring of the resonance frequency of DMSO protons as a function of DMSO to metal ion mole ratio while keeping the metal ion concentration constant. The average solvation number of cations at any...

STUDY DESIGN Prospective pilot study. OBJECTIVES The aim of this study was to measure titanium, niobium and aluminium levels in various intraoperative and postoperative samples to determine patterns of metal ion release that occur within the first month following instrumented spinal fusion. Raised serum metal ion levels are reported following instrumented spinal fusion in adolescent idiopathi...

Interaction of alkaline earth metal (magnesium, calcium, strontium and barium) ions with acetic and lactic acid in aqueous media was investigated by C NMR spectroscopy. In the acetate systems, signals whose chemical shifts were the averages of those of the free and bound acetate ions were observed. Downfield shifts of the carboxylate carbon signals with increasing metal ion concentration indica...

A proton NMR method for the drtermination of salvation numbers of alkaline earth cations with hexamethyl phosphoramide (HMPA) in nitromethane (NM) as diluents is described. The method is based on monitoring the resonance frequency of HMPA protons as a function of HMPA / metal ion molar ratio at constant metalion concentration. The average salvation number of cations,  , at any HMPA / metal ...

We have previously reported that metal ion binding could restrict the excited state rotation of a biaryl chromophore, suppressing intersystem crossing and leading to increased emission. We have now applied the restriction of excited state dynamics to suppression of the other fundamental nonradiative decay pathway, internal conversion, in biarylacetylenes. This indicates that both nonradiative d...

The structure and activity of nucleic acids depend on their interactions with metal ions. Fundamental to these interactions is the degree of specificity observed between the metal ions and nucleic acids, and a complete description of nucleic acid folding requires that we understand the nature of the interactions with metal ions, including specificity. The prior demonstration that high concentra...

Absrract: We have been concerned with the development of alternate strategies for achievinc; metalion recognition. An important aspect of this research has been to investigate meta! ion complexation over a range of related macrocycles, incorporating different macrocyclic rhg sizes, donor atom set combinations and/or degree of ring substitution and to search for stability rrnxima at different po...

Concerns have been renewed regarding the possible long-term effects of elevated circulating levels of cobalt and chromium as a direct result of implantation of large femoral head diameter metal-on-metal bearings. In order to establish whether metal ion levels remain persistently elevated, we compared metal ion levels before and after revision surgery in patients with large head diameter (greate...

' 'N the accompanying letter by Germer and Haworth, ~ evidence is presented to show that a positive ion in a high field (~107 volts/cm) must be able to eject several electrons from a metal. On the other hand, present theories of ejection by positive ions in low fields require that the ion be neutralized as the first step in the ejection process and, hence, that an ion be unable to eject more th...

a simple ion imprinted amino-functionalized sorbent was synthesized by coupling activated carbon with iminodiacetic acid, a functional compound for metal chelating, through cyanoric chloride spacer. the resulting sorbent has been characterized using fourier transform infrared spectroscopy (ft-ir), elemental analysis, thermogravimetric analysis (tga) and evaluated for the preconcentration and de...