(fāz )

[Gr. phasis, an appearance]

1. A stage of development.
2. A transitory appearance.
3. In chemistry, a distinct component of a larger, heterogeneous system, as oil or water when the two are mixed.

aqueous p.The water portion of a mixture of liquids and solids or of immiscible liquids and of gases.

circulatory p. of cardiac arrest That phase of cardiac arrest when the heart is not contracting (beating) forcefully enough to circulate blood to vital organs.

continuation p.In diseases that require prolonged treatment (such as cancers or tuberculosis), the phase of therapy that follows induction and lasts several months. In cancer treatment, this phase is also known as consolidation chemotherapy.

SEE: consolidation chemotherapy .

continuous p.The state of a substance in a heterogeneous system in which particles are continuous, e.g., the water particles in which oil has been dispersed.

death p.In cellular biology, the period that begins when cells in culture exhaust their nutrient supply and begin to die.

disperse p.The state of a substance in a heterogeneous system in which particles are separated from each other, e.g., oil particles in water.

eclipse p.The phase of the viral life cycle during which a virus enters a cell to parasitize it. The phase includes the attachment of the virus to the cell membrane, penetration of the cell by the virus, and the uncoating of the virus once it has entered the cytoplasm. During this phase in its life cycle, no progeny virus is found within the cell and the infected patient is not infectious.

isometric contraction p.The first phase in contraction of the ventricle of the heart in which ventricular pressure increases but there is no decrease in volume of contents because semilunar valves are closed.

lag p.Lag (2).

latent p.Incubation (1).

log p.That portion of the bacterial growth curve at which bacteria are reproducing at an exponential rate.

metabolic p. of cardiac arrest The period in cardiac arrest after the heart resumes normal pacing and muscle contraction, when tissue damage results from inflammation, insufficient oxygen, reperfusion injury, or the accumulation of cellular toxins.

roll-in p.In the investigation of a new technology or treatment, a period during which the researchers gain experience and proficiency in the use of the device.