beta particle

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be·ta par·ti·cle

an electron, either positively (positron, β+) or negatively (negatron, β-) charged, emitted during beta decay of a radionuclide.
See also: cathode rays.
Synonym(s): beta ray

beta particle

an electron emitted from the nucleus of an atom during radioactive decay of the atom. Beta particles have a range of 10 m in air and 1 mm in soft tissue. Also called beta ray. See beta rays.

beta particle

An ionising electron or positron which is emitted from decaying radioactive nuclei during beta decay or beta emission. Beta particles are equal in mass and charge to electrons.


the second letter of the Greek alphabet, B or β; used to denote the second position in a chemical classification system. Often used in names of chemical compounds to distinguish one of two or more isomers or to indicate the position of substituent atoms or groups in certain compounds. Also used to distinguish types of radioactive decay; brain rhythms or waves; adrenergic receptors; secretory cells of the various organs of the body that stain with basic dyes, such as the beta cells of the pancreas; and the type of hemolysis induced by bacteria that results in a zone of complete hemolysis when grown on blood agar, except for staphylococci.

beta adrenergic
beta-adrenergic receptors,
β-adrenergic receptors specific sites on effector cells that respond to epinephrine. There are two types: β1-receptors, found in the heart and small intestine, and β2-receptors, found in the bronchi, blood vessels and uterus.
beta agonists
beta barrels
a form of secondary structure of a polypeptide in which β strands of amino acids are wound into a super secondary structure; usually interconnected by α helical regions of the polypeptide on the outside of the molecule.
a drug that blocks the action of epinephrine at beta-adrenergic receptors on cells of effector organs. There are two types of these receptors: β1-receptors in the myocardium and β2-receptors in the bronchial and vascular smooth muscles. The principal effects of beta-adrenergic stimulation are increased heart rate and contractility, vasodilation of the arterioles that supply the skeletal muscles, and relaxation of bronchial muscles.
beta brain waves
those having a frequency of more than 10 hertz (pulsations per second); seen during wakefulness. See also electroencephalography.
beta-carboline indoleamine alkaloid
poisoning causes a nervous syndrome of hyper- or hypomotility, muscle tremor, flexed paresis of fore- or hindlimbs, hypermetria, walking backwards, convulsions. A plant poison found in Peganum, Tribulus, Kallstroemia spp.
beta carbon
carbon-3 of a molecule or the carbon atom two on from the function group of a molecule, the carbon(s) of which are not included in the lettering.
hormone secreted by central nervous system, hypothalamus, gastrointestinal tract. See also endorphin.
beta fibrillosis
beta-folded domains
compact, locally folded region of tertiary structure containing the β-sheets or β-turns.
beta hemolysin
is a sphingomyelinase and is produced by staphylococci. It produces partial hemolysis of sheep and cattle erythrocytes. It appears to have little pathogenic effect. See also beta hemolysis.
beta-hydroxy-beta-methylglutaryl coenzyme A
1. intermediate in the formation of ketones.
2. key starting compound in the synthesis of cholesterol.
salt of the major circulating ketone body in animals, formed from the reduction of acetoacetic acid.
beta-hydroxybutyrate dehydrogenase
mitochondrial enzyme catalyzing the NADH-linked-reduction of acetoacetate to β-hydroxybutyrate.
beta-ketobutyric acid
beta particle
an electron emitted from a nucleus.
beta radiation
see radiation injury, radiotherapy.
beta sheet (β-sheet)
a common structural feature of many proteins in which the single polypeptide chain is folded back and forth upon itself with each folded section running in an opposite direction to its nearest neighbors. The folded sections are held together by hydrogen bonds and the arrangement which occurs, particularly in the core of proteins, confers great stability on the molecule.
beta subunit
second-named chain (or subunit) occurring in the functional organization of macromolecules, usually proteins, containing two or more chains.
References in periodicals archive ?
chemically similar to calcium and emits beta particles, accumulates in
Some of the earliest bind iodine-131, an isotope that emits low-energy gamma radiation along with a beta particle.
It emits a photon in coincidence with a beta particle.
If a particular atom broke down to emit an alpha or beta particle, it would seem that a definite energy source had been broached, and particles of definite energies ought to be given off.
The researchers monitored the emission of alpha and beta particles.
Moe and his colleagues have spent the last few years looking for a form of radioactivity known as neutrinoless double-beta decay, characterized by the simultaneous emission of two beta particles, or electrons.
To determine the neutrino mass, Stoeffl and his co-workers use a special apparatus to measure the energies of beta particles, or electrons, emitted by the decay of a radioactive form of hydrogen known as tritium.
For each atomic isotope, these beta particles emerge from nuclei with a characteristic distribution, or spectrum, of energies.
The rarest of all observed radioactive event sinvolves the simultaneous decay of two neutrons within an unstable atomic nucleus to form two protons, accompanied by the emission to two beta particles (electrons) and two neutrinos.
Simpson of the University of Guelph in Ontario reported a tiny anomaly in his measurements of the energies of beta particles, or electrons, emitted during the radioactive decay of tritium atoms.