Abstract: The invention relates to the use of dispersions of magneto-ionic particles consisting essentially of superparamagnetic solid particles and at least one polyelectrolyte as dispersing substance in water for the preparation of an MRI contrast medium.

Abstract: The present invention relates to a process for preparing solid, microcellular or expanded plastic molded items, characterized in that said molded items are produced in molds in which the internal surfaces consist of steel with the percentage composition:a) Fe: having a wt % greater than 0 wt % and less than 100 wt %;b) at least one element selected from the group consisting of W, Mo, or V, wherein if W is selected, W is present from a range greater than 0 wt % to 40 wt %; wherein if Mo is selected, Mo is present from a range greater than 0 wt % to 12 wt %; and if V is selected, V is present from a range greater than 0 wt % to 5 wt %;c) at least one element selected from the group consisting of Cr, Al, wherein if Cr is selected, Cr is present in a concentration of greater than 0 wt % to 15 wt %; and if Al is selected, Al is present in a concentration of greater than 0 wt % to 15 wt %;d) optionally, carbon at a concentration ranging from 0.1 to 1.5 wt %;e) optionally, cobalt at a concentration ranging from 0.