Composition and in vitro biocompatibility of corroding tungsten coils.

The purpose of the article is to evaluate composition and biocompatibility of corroding mechanically detachable spirals (MDS, Balt Extrusion, Montmorency, France). Analysis of the material composition of corroding MDS coils was assessed by inductively coupled plasma atomic emission spectroscopy, inductively coupled plasma mass spectroscopy, and wavelength-dispersive x-ray spectrometry. Toxicity assays were performed with human venous endothelial cells, venous smooth muscle cells and fibroblasts.

Degradation of tungsten coils implanted into the subclavian artery of New Zealand white rabbits is not associated with local or systemic toxicity.

Objective: To assess whether corrosion of tungsten coils is related to residual shunting and to evaluate whether elevated tungsten serum levels are associated with local or systemic toxicity.

Methods: Tungsten coils (SPI, Balt, France) were implanted into the subclavian artery of New Zealand white rabbits leading to a residual high-flow shunt in 5/10 rabbits. Serial serum tungsten levels, complete blood count and clinical chemistry were analysed prior to the implantation as well as 15 min, 2 and 4 months thereafter.

The nonequilibrium Lorentz gas.

We study the conductivity of a Lorentz gas system, composed of a regular array of fixed scatterers and a point-like moving particle, as a function of the strength of an applied external field. In order to obtain a nonequilibrium stationary state, the speed of the point particle is fixed by the action of a Gaussian thermostat. For small fields the system is ergodic and the diffusion coefficient is well defined.