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

(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.

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).

pre·cur·sor

(prē'kŭrs-ŏr)
That which precedes another or from which another is derived.
[L. praecursor, fr. prae-, pre- + curro, to run]
References in periodicals archive ?
But data collected through the years by researchers and intelligence agencies worldwide, including the United States' Drug Enforcement Agency, offer a composite sketch of the world's biggest source of drugs and drug precursors and the sketch showed China.
In the study, the researchers tackle this Alzheimer's disease mystery by devising a multi-functional reporter for amyloid precursor protein and tracking the protein's localization and mobility using quantitative imaging with unprecedented accuracy.
The year 2016 saw seizures of 215 MT narcotics and 25 MT precursor chemicals, 164 MT narcotics and 56 MT precursor chemicals
We are inviting every business engaged in trading of precursor chemicals to register with us and do business with registered companies only so that the misuse of chemicals could be stopped, a top official of Ministry of narcotics told the Nation.
[sup.1]H-NMR spectrum of PBz-eda precursor. [Color figure can be viewed at wileyonlinelibrary.com]
With the joint ventures, POSCO can secure its competiveness by sourcing a stable supply of precursors and materials such as cobalt, nickel and manganese.
In this article, we describe the multimodal imaging features of precursor RAP lesions, including optical coherence tomography angiography (OCTA), and present the results of long-term follow-up with B-scan spectral domain optical coherence tomography (SD-OCT) using high sampling density and eye-tracking mode.
The operation is focused on identification, monitoring and seizure of consignments of all illicit precursor chemicals especially Acetic Anhydride, Acetyl Chloride, Acetic Acid and Ammonium Chloride being transported to Afghanistan.
Our research demonstrates that precursor storms are the dominant cause of cyclone-related strong wind events over the British Isles for 850-hPa wind speeds exceeding 30 m [s.sup.-1] (60 knots or 69 mph).
Results of plate experiment demonstrated that precursor and Rhizobium inoculations improved the root / shoot length and mass as compared to control (Table 2).
In addition to ISSL, the INCB has developed a number of instruments to address the challenges of precursor chemicals:
This Phase 3, randomised, active-controlled, open-label TOWER study is investigating the efficacy of the company's BLINCYTO versus SOC chemotherapy in 405 adult patients with Ph- relapsed or refractory B-cell precursor ALL.