Abstract: The present invention is directed to particles comprised of a magnetically responsive material and a dispersant, said particles having a particle size range of about 2 to about 10 nm. The present invention is also directed to a method for the preparation of such particles comprising admixing a magnetically responsive material with a dispersant to form an admixture, and contacting said first admixture with a base for a time period and under conditions appropriate to form a magnetically responsive material-dispersant particle. In a preferred embodiment, the magnetically responsive material is magnetite, the dispersant is dextran, and the base is ammonium hydroxide. In a further preferred embodiment, the admixture is suspended in a gel phase. The present invention is further directed to a method of diagnosis comprising administering to a mammal a contrast effective amount of these particles suspended or dispersed in a physiologically tolerable carrier and generating an NMR image of said mammal.

Abstract: Stable particles comprising a core consisting of a water-insoluble ester or amide of 3,5-diacetamido-2,4,6-triiodobenzoic acid encapsulated with methyl cellulose, such particles having an average particle size of less than about 10 .mu.m, dispersions containing such particles, and methods for the preparation thereof are disclosed. The particles are particularly useful as contrast agents for use in x-ray and ultrasound diagnostic imaging compositions and methods.

Abstract: Particles having an average diameter of less than about 12 microns comprising fatty acid cores encapsulated with human serum albumin and methods for their preparation are disclosed. These materials are useful as contrast agents in ultrasonic imaging, having scattering intensities that are equivalent to or greater than those obtain from dispersed microbubbles but being much more stable, both in storage and when used in vivo, than are contrast agents based on dispersed microbubbles.

Abstract: A method of increasing the hardness of a polyurethane medium containing a polyisocyanate, such as a magnetic tape or disk, by contacting the medium with an aldehyde and an acid.

Abstract: Stable, encapsulated superparamagnetic magnetite particles having a narrow particle size distribution with average particle diameters in the range of from about 50 .ANG. to about 350 .ANG. are prepared by forming an aqueous dispersion of magnetite particles having the above particle size characteristics in the presence of a surfactant, coacervating a mixture of gelatin and a carboxyl containing hydrophilic polymer such as gum arabic to form a thin coating of coacervate on the magnetite particles and crosslinking the coacervate coating with a gelatin hardener such as glutaraldehyde.

Abstract: For use in magnetic recording tapes and for other purposes, iron and iron alloy materials are passivated and protected against oxidative corrosion by treatment with a solution of a non-hygroscopic salt of bis(triphenylphosphoranylidene) ammonium cation with an anion such as nitrite or chromate.

Abstract: For use in magnetic recording tapes and for other purposes, iron and iron alloy materials are passivated and protected against oxidative corrosion by treatment with a solution of a non-hygroscopic salt of bis(triphenylphosphoranylidene) ammonium cation with an anion such as nitrate or chromate.

Abstract: In a method for determining macromolecules in polyacrylamide gels comprising the steps of forming a latent stain image by nucleating the macromolecules in the gel with a palladium tetramine salt and developing the latent stain image by treating the gel with a physical developing solution comprising dimethylamine borane and a transition metal salt, the improvement comprises contacting the developed latent stain image with a 1-phenyl-2-tetrazoline-5-thione or a salt of 1-phenyl-1H-tetrazole-5-thiol.

Abstract: A method for determining macromolecules in polyacrylamide gels comprises forming a latent stain image by nucleating the gel with a palladium tetramine salt and developing the latent stain image by treating the gel with a physical developing solution comprising dimethylamine borane and a member selected from the group consisting of a transition metal salt and a tetrazolium salt.