[L. particula, a small piece, little bit, particle]

1. A very small piece or part of matter; a tiny fragment or trace.
2. Any of several subatomic components of the nuclei of radioactive elements, such as alpha and beta particles.
3. An attraction particle or centriole of the nucleus of a cell. SEE: 4. Virion.

alpha particle

A charged particle emitted from a radioactive substance made up of a helium nucleus consisting of two protons and two electrons. The particle has very low penetrability but an extremely high linear energy transfer.

beta particle

SEE: Beta ray.

charged particle

Any ion or subatomic particle that carries an electrical charge, e.g., in medicine, a proton used in radiation therapy. By convention, protons are positively charged particles; electrons, negatively charged.

Dane particle

SEE: Dane particle

elementary particle

The subatomic parts of the atomic nucleus.

large low-density lipoprotein particle

ABBR: large LDL particle A low density lipoprotein larger than 213 angstroms. The particles are thought to represent the least atherogenic fraction of the LDL molecule.

lipoviral particle

ABBR: LVP An infectious hepatitis C virus released from a hepatocyte, coated in low density lipoproteins.

neurodegenerative disease-associated particle

ABBR: NDAP Alpha-synnuclein, amyloid beta, or tau proteins. They accumulate in the central nervous system in patients with diseases such as Alzheimer dementia or Parknson disease.