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.
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.
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.
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.
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.
Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)
The sixth planet in order from the sun. It is one of the five outer planets of the solar system. Its twelve natural satellites include Phoebe and Titan.
The gaseous envelope surrounding a planet or similar body. (From Random House Unabridged Dictionary, 2d ed)
Tools or devices for generating products using the synthetic or chemical conversion capacity of a biological system. They can be classical fermentors, cell culture perfusion systems, or enzyme bioreactors. For production of proteins or enzymes, recombinant microorganisms such as bacteria, mammalian cells, or insect or plant cells are usually chosen.
High energy POSITRONS or ELECTRONS ejected from a disintegrating atomic nucleus.
Unstable isotopes of strontium that decay or disintegrate spontaneously emitting radiation. Sr 80-83, 85, and 89-95 are radioactive strontium isotopes.
Stable strontium atoms that have the same atomic number as the element strontium, but differ in the atomic weight. Sr-84, 86, 87, and 88 are the stable strontium isotopes.
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)
The amount of radiation energy that is deposited in a unit mass of material, such as tissues of plants or animal. In RADIOTHERAPY, radiation dosage is expressed in gray units (Gy). In RADIOLOGIC HEALTH, the dosage is expressed by the product of absorbed dose (Gy) and quality factor (a function of linear energy transfer), and is called radiation dose equivalent in sievert units (Sv).
The measurement of radiation by photography, as in x-ray film and film badge, by Geiger-Mueller tube, and by SCINTILLATION COUNTING.
A subclass of cannabinoid receptor found primarily on central and peripheral NEURONS where it may play a role modulating NEUROTRANSMITTER release.
Nanometer-sized particles that are nanoscale in three dimensions. They include nanocrystaline materials; NANOCAPSULES; METAL NANOPARTICLES; DENDRIMERS, and QUANTUM DOTS. The uses of nanoparticles include DRUG DELIVERY SYSTEMS and cancer targeting and imaging.
A trace element that constitutes about 27.6% of the earth's crust in the form of SILICON DIOXIDE. It does not occur free in nature. Silicon has the atomic symbol Si, atomic number 14, and atomic weight [28.084; 28.086].
Relating to the size of solids.
A class of devices combining electrical and mechanical components that have at least one of the dimensions in the micrometer range (between 1 micron and 1 millimeter). They include sensors, actuators, microducts, and micropumps.
Inorganic compounds that contain silicon as an integral part of the molecule.
The state of being free from intrusion or disturbance in one's private life or affairs. (Random House Unabridged Dictionary, 2d ed, 1993)
A loose confederation of computer communication networks around the world. The networks that make up the Internet are connected through several backbone networks. The Internet grew out of the US Government ARPAnet project and was designed to facilitate information exchange.
A plant genus of the family POLYGONACEAE that is used as an EDIBLE GRAIN. Although the seeds are used as cereal, the plant is not one of the cereal grasses (POACEAE).
The application of scientific knowledge to practical purposes in any field. It includes methods, techniques, and instrumentation.
Sequential operating programs and data which instruct the functioning of a digital computer.
Hafnium. A metal element of atomic number 72 and atomic weight 178.49, symbol Hf. (From Dorland, 28th ed)
Metals that constitute the group 2 (formerly group IIa) of the periodic table.
Emission of LIGHT when ELECTRONS return to the electronic ground state from an excited state and lose the energy as PHOTONS. It is sometimes called cool light in contrast to INCANDESCENCE. LUMINESCENT MEASUREMENTS take advantage of this type of light emitted from LUMINESCENT AGENTS.
An element of the alkaline earth family of metals. It has the atomic symbol Sr, atomic number 38, and atomic weight 87.62.
Screens which absorb the energy in the x-ray beam that has penetrated the patient and convert this energy into a light pattern which has as nearly as possible the same information as the original x-ray beam. The more light a screen produces for a given input of x-radiation, the less x-ray exposure and thus shorter exposure time are needed to expose the film. In most film-screen systems, the film is sandwiched between two screens in a cassette so that the emulsion on each side is exposed to the light from its contiguous screen.
Exclusive legal rights or privileges applied to inventions, plants, etc.