| REM | <radiobiology> The conventional unit of dose equivalent. The dose equivalent in rem is numerically equal to the absorbed dose, D, in rad multiplied by the quality factor Q. 1 rem = 0.01 sievert. (See sievert, rad). Note: for most medical applications involving X-ray or gamma emitters, the numerical values of the absorbed dose in rad, dose equivalent in rem and exposure in R are roughly equivalent numerically. (16 Dec 1997) |
|---|---|
| REM behaviour disorder | A disorder characterised by lack of the atonia of voluntary muscles that normally occurs in REM sleep. (05 Mar 2000) |
| REM stage sleep | <physiology> A stage of deep sleep that is accompanied by rapid eye movement and muscle paralysis. Vivid dreams can be recalled in over 80% of patients who awake from REM stage sleep. (27 Sep 1997) |
| REM syndrome | <syndrome> A reticular erythematous dermatitis of the upper trunk, more common in women, in which there is perivascular infiltrate of lymphocytes, few plasma cells, and upper dermal deposits of mucin; worsens on exposure to ultraviolet light. Synonym: reticular erythematous mucinosis. (05 Mar 2000) |
| sleep, rem | A stage of sleep characterised by rapid movements of the eye and low voltage fast pattern eeg. It is usually associated with dreaming. (12 Dec 1998) |
| bone density | Bone density is the amount of bone tissue in a certain volume of bone. It can be measured using a special X-ray called a quantitative computed tomogram. (12 Dec 1998) |
| bulk density | Weight per unit of volume, usually specified in pounds per cubic foot. (05 Dec 1998) |
| buoyant density | The density that allows a substance to float in some standard fluid. (05 Mar 2000) |
| vapor density | The mass per unit volume of a vapor; since the vapor density changes with temperature and pressure, it is commonly expressed as a specific gravity, i.e., the weight of the vapor divided by the weight of an equal volume of a reference gas (e.g., oxygen or hydrogen) at the same temperature and pressure. (05 Mar 2000) |
| very low density lipoprotein | <biochemistry> A lipoprotein substances (combination of a fat and a protein) which acts as a carrier for cholesterol and fats (particularly triglycerides) in the bloodstream. Elevations in very low density lipoprotein in the bloodstream are associated with an increased risk of atherosclerosis and coronary artery disease. Acronym: VLDL (18 Nov 1997) |
| centrifugation, density gradient | Separation of particles according to density by employing a gradient of varying densities. at equilibrium each particle settles in the gradient at a point equal to its density. (12 Dec 1998) |
| photon density | The number of counted events recorded in scintigraphy per square centimeter or per square inch of imaged area. Synonym: count density. (05 Mar 2000) |
| count density | The number of counted events recorded in scintigraphy per square centimeter or per square inch of imaged area. Synonym: count density. (05 Mar 2000) |
| population density | <epidemiology> Number of individuals in a population relative to space. (12 Dec 1998) |
| current density | <radiobiology> Amount of current flowing through a substance, per unit area perpendicular to the direction of current flow. (See also density) (09 Oct 1997) |