Cerium Radioisotopes: Unstable isotopes of cerium that decay or disintegrate emitting radiation. Ce atoms with atomic weights 132-135, 137, 139, and 141-148 are radioactive cerium isotopes.Cerium: An element of the rare earth family of metals. It has the atomic symbol Ce, atomic number 58, and atomic weight 140.12. Cerium is a malleable metal used in industrial applications.Radioisotopes: Isotopes that exhibit radioactivity and undergo radioactive decay. (From Grant & Hackh's Chemical Dictionary, 5th ed & McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Zinc Radioisotopes: Unstable isotopes of zinc that decay or disintegrate emitting radiation. Zn atoms with atomic weights 60-63, 65, 69, 71, and 72 are radioactive zinc isotopes.Cerium Isotopes: Stable cerium atoms that have the same atomic number as the element cerium, but differ in atomic weight. Ce-136, 138, and 142 are stable cerium isotopes.Metal Nanoparticles: Nanoparticles produced from metals whose uses include biosensors, optics, and catalysts. In biomedical applications the particles frequently involve the noble metals, especially gold and silver.Metals, Rare Earth: A group of elements that include SCANDIUM; YTTRIUM; and the LANTHANOID SERIES ELEMENTS. Historically, the rare earth metals got their name from the fact that they were never found in their pure elemental form, but as an oxide. In addition they were very difficult to purify. They are not truly rare and comprise about 25% of the metals in the earth's crust.Radioisotope Dilution Technique: Method for assessing flow through a system by injection of a known quantity of radionuclide into the system and monitoring its concentration over time at a specific point in the system. (From Dorland, 28th ed)Strontium Radioisotopes: Unstable isotopes of strontium that decay or disintegrate spontaneously emitting radiation. Sr 80-83, 85, and 89-95 are radioactive strontium isotopes.