Novel model of negative secondary ion formation and its use to refine the electronegativity of almost fifty elements.

This study aimed to examine the recently proposed idea that the ionic contribution to atomic bonds is essential in determining the charge state of sputtered atoms. Use was made of negative secondary ion yields reported by Wilson for a large number of elements implanted in silicon and then sputter profiled by Cs bombardment. The derived normalized ion yields (or fractions) P vary by 6 orders of magnitude, but the expected exponential dependence on the electron affinity EA is evident only vaguely.

Excessive delivery of nanostructured matter to submersed cells caused by rapid gravitational settling.

With very few exceptions, previous nanotoxicity studies implicitly involved the assumption that the techniques developed for risk assessment of hazardous chemical substances can be applied in unchanged form to explore cell response in NP laden media. This misleading approach has the consequence that the actual dose of exposure is ill defined or, more often, completely unknown. Here the effect of gravitational settling on the dose of exposure was explored for commercially available engineered nanostructured matter (nanopowder).

Novel dose metric for apparent cytotoxicity effects generated by in vitro cell exposure to silica nanoparticles.

This study aimed at identifying the dose metric applicable to studies on the viability of cells exposed to nanoparticles (NPs) in vitro. A previously reported set of data was evaluated very carefully. The extent of cell death after 24-h exposure of three cell lines to suspended silica NPs (<30 nm) was quantified using four different viability/cytotoxicity assays.

In search of the most relevant parameter for quantifying lung inflammatory response to nanoparticle exposure: particle number, surface area, or what?

Background: Little is known about the mechanisms involved in lung inflammation caused by the inhalation or instillation of nanoparticles. Current research focuses on identifying the particle parameter that can serve as a proper dose metric.

Objectives: The purpose of this study was to review published dose-response data on acute lung inflammation in rats and mice after instillation of titanium dioxide particles or six types of carbon nanoparticles.