precursor


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precursor

 [pre-ker´ser]
something that precedes. In biological processes, a substance from which another, usually more active or mature substance, is formed. In clinical medicine, a sign or symptom that heralds another.

pre·cur·sor

(prē-kŭr'sŏr),
That which precedes another or from which another is derived, applied especially to a physiologically inactive substance that is converted to an active enzyme, vitamin, hormone, etc., or to a chemical substance that is built into a larger structure in the course of synthesizing the latter.
[L. praecursor, fr. prae-, pre- + curro, to run]

precursor

/pre·cur·sor/ (pre´kur-ser) something that precedes. In biological processes, a substance from which another, usually more active or mature, substance is formed. In clinical medicine, a sign or symptom that heralds another.precur´sory

precursor

(prĭ-kûr′sər, prē′kûr′sər)
n.
A biochemical substance, such as an intermediate compound in a chain of enzymatic reactions, from which a more stable or definitive product is formed: a precursor of insulin.

precursor

[-kur′sər]
Etymology: L, prae + currere, to run
1 something preceding, or coming before, another.
2 a prognostic characteristic or feature of a patient's health data, such as a radiographic or laboratory finding, that is associated with a higher or lower risk of death than the average.

pre·cur·sor

(prē'kŭrs-ŏr)
That which precedes another or from which another is derived, applied especially to a physiologically inactive substance that is converted to an active enzyme, vitamin, or hormone, or to a chemical substance that is built into a larger structure in the course of synthesizing the latter.
[L. praecursor, fr. prae-, pre- + curro, to run]

precursor

a form that precedes another. For example:
  1. (a) a substance that precedes and is involved in the synthesis of a compound, such as any of the intermediates in the synthesis of an AMINO ACID.
  2. (b) a cell from which other cells develop.
  3. (c) a molecule that is subjected to modification to provide an active molecule, such as the enzymic cleavage of TRYPSINOGEN to yield TRYPSIN (see ZYMOGEN).

precursor

physiologically inactive substance that converts to active form, e.g. provitamin; prohormone

pre·cur·sor

(prē'kŭrs-ŏr)
That which precedes another or from which another is derived.
[L. praecursor, fr. prae-, pre- + curro, to run]

precursor

something that precedes. In biological processes, a substance from which another, usually more active or mature substance is formed. In clinical medicine, a clinical sign or syndrome that heralds another.

precursor fragments
References in periodicals archive ?
At a Press conference held in the Dubai Police headquarters, Major-General Abdul Rahman Rafi, Director-General of the Department of Community Services, said the two-day forum, which will be held at the Dubai Police Officers Club, will look at issues of chemical precursors and cover legal and economic aspects, training and rehabilitation centres, international cooperation, international experiences and practices.
These amino acids changed how the reactions work and allowed only the naturally occurring RNA precursors to be generated in a stable form," said Hein.
Precursors for late preterm birth included spontaneous labor in 30% of cases, preterm premature rupture of membranes (PPROM) in 32% of cases, and medical indications for an obstetric, maternal, or fetal condition in 32% of cases.
Much of the world's precursor diversion happens at or when crossing international borders, and national authorities often find it difficult to verify the foreign buyer's legitimacy, particularly if exporting and importing countries' authorities are not cooperating on the issue.
However, as Borges makes clear when he speaks at the end of his essay of the way that "the first Kafka of Betrachtung [the early short stories] is less a precursor of the Kafka of the gloomy myths and terrifying institutions than is Browning or Lord Dunsany" (Total Library 365; OC 2: 89), any attempt to say what Kafka is is only to reduce him to one of his precursors.
In contrast, the approach the NRC actually used was a nonstandard approach for developing an RfD based on the inhibition of iodine uptake, a distant precursor to the critical effect.
However, although effectively managing precursors is challenging, choosing not to use precursor information to improve safety is unacceptable in high-hazard industries.
The model for the H7N3 hemagglutinin precursor is based on the 2.
The company reports the scientists' identification of the precise gestational window for timely procuring future heart, liver and pancreas in pigs has significant impact on Tissera's ability to begin the next stage of research on the establishment of embryonic precursor tissues as a new source for organ transplantation.
Encourage the Food and Drug Administration (FDA) to take more of a pro-active role in regulating the OTC supplement industry, especially with the advent of pro-steroids and precursor steroids.
Ground-level ozone, a precursor of smog linked to respiratory ailments in humans, is known to slow the growth of some plants.
2]-containing precursor films which are then converted to oxide superconductor through reaction with water-vapor.