# expansion

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Related to clonal expansion: Clonal selection

## expansion,

in physics, increase in volume resulting from an increase in temperature. Contraction is the reverse process. When heat is applied to a body, the rate of vibration and the distances between the molecules composing it are increased and, hence, the space occupied by the body, i.e., its volume, increases. This increase in volume is not constant for all substances for any given rise in temperature, but is a specific property of each kind of matter. For example, zinc and lead undergo greater expansion in a one-degree rise in temperature than do silver or brass. Since solidssolid,
one of the three commonly recognized states in which matter occurs, i.e., that state, as distinguished from liquid and gas, in which a substance has both a definite shape and a definite volume.
have a definite shape, each linear dimension of the solid increases by a proportional amount for a given temperature increase. The amount that a unit length along any direction of a substance increases for a temperature increase of one degree is called the coefficient of linear expansion of the substance. Most liquids also expand when heated. However, since liquids do not have a definite shape, it is the expansion of their volume as a whole that is relevant rather than the increase in a linear dimension. The amount of expansion that a unit volume (e.g., a cubic centimeter or a cubic foot) of any substance undergoes per one-degree rise in temperature is called its volume coefficient or coefficient of cubical expansion and is listed as a property of that substance. The coefficient of linear expansion can be calculated by dividing the coefficient of cubical expansion of the substance by three. When the amount of expansion of a given length of a substance has been determined experimentally, the linear coefficient is calculated by dividing the total amount of expansion by the product of the original number of length units and the number of degrees of rise in temperature. Gases also exhibit thermal expansion. The coefficient of expansion is about the same for all the common gases at ordinary temperatures; it is 1-273 of the volume at 0°C; per degree rise in temperature. The Kelvin, or absolute, scale is based upon this behavior (see Kelvin temperature scaleKelvin temperature scale,
a temperature scale having an absolute zero below which temperatures do not exist. Absolute zero, or 0°K;, is the temperature at which molecular energy is a minimum, and it corresponds to a temperature of −273.
). Charles's law concerning the expansion of gases states that the volume of a gas is directly proportional to its absolute temperature (see gas lawsgas laws,
physical laws describing the behavior of a gas under various conditions of pressure, volume, and temperature. Experimental results indicate that all real gases behave in approximately the same manner, having their volume reduced by about the same proportion of the
). Liquids differ from each other as do solids in their expansion coefficients. Water, unlike most substances, contracts rather than expands as its temperature is increased from 0°C; to 4°C;; above 4°C; it exhibits normal behavior, expanding as the temperature increases.

## expansion

[ik′span·shən]
(electronics)
A process in which the effective gain of an amplifier is varied as a function of signal magnitude, the effective gain being greater for large signals than for small signals; the result is greater volume range in an audio amplifier and greater contrast range in facsimile.
(mathematics)
The expression of a quantity as the sum of a finite or infinite series of terms, as a finite or infinite product of factors, or, in general, in any extended form.
(mechanical engineering)
Increase in volume of working material with accompanying drop in pressure of a gaseous or vapor fluid, as in an internal combustion engine or steam engine cylinder.
(physics)
Process in which the volume of a constant mass of a substance increases.

## expansion

The increase in length or volume of a material, or a body, caused by temperature, moisture, or other environmental condition.

## expansion

1. Maths
a. the form of an expression or function when it is written as the sum or product of its terms
b. the act or process of determining this expanded form
2. the part of an engine cycle in which the working fluid does useful work by increasing in volume
3. Physics the increase in the dimensions of a body or substance when subjected to an increase in temperature, internal pressure, etc.
References in periodicals archive ?
Piceatannol, natural polyphenolic stilbene, inhibits adipogenesis via modulation of mitotic clonal expansion and insulin receptor-dependent insulin signaling in early phase of differentiation.
Hence, the monotypic nature (with respect to light chain expression) of the HHV8-infected large lymphoid cells does not reflect a clonal expansion or a lymphoma [9,10].
Franzin and colleagues (20) analyzed the clonal expansion of a B-cell population in HCV patients, demonstrating a high frequency of clonal Ig gene rearrangements.
The multiple somatic antigens, variety of antimicrobial drug-resistance scores, and variety of gene complements in this successful ST indicate multiple acquisitions of virulence markers, rather than clonal expansion from a single source (Table; online Technical Appendix Figure, http://wwwnc.
Her finding of the same 9;22 translocation in virtually all bone marrow cells from CML patients, and not in unaffected lymphocytes, indicated that this chromosomal rearrangement occurs as an acquired genetic change in a single bone marrow cell that is thereby afforded a proliferative advantage which, through clonal expansion, gives rise to leukemia," explained Dr.
Although implementation of BBDR models for low-dose risk estimation have thus far been limited mainly to cancer modeled using a two-stage clonal expansion framework, these problems are expected to be present in all attempts at BBDR modeling.
Immediately following stimulation of differentiation, these cells re-enter the cell cycle and undergo one or two rounds of mitotic clonal expansion for about 24-36 h, after which they permanently withdraw from the cell cycle and terminally differentiate.
8) It has been suggested that EBV infects the primitive pharynx and transforms the epithelial cells, leading to a clonal expansion of these cells.
Leflunomide is a pyrimidine synthesis inhibitor with a long half-life that blocks T cell clonal expansion.
This finding suggests that EBV was present before clonal expansion and probably played a role in pathogenesis of PBL.
Molecular epidemiology of KPCproducing Klebsiella pneumoniae isolates in the United States: clonal expansion of multilocus sequence type 258.

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