| addition | 1. The act of adding two or more things together; opposed to subtraction or diminution. "This endless addition or addibility of numbers." 2. Anything added; increase; augmentation; as, a piazza is an addition to a building. 3. <mathematics> That part of arithmetic which treats of adding numbers. 4. A dot at the right side of a note as an indication that its sound is to be lengthened one half. 5. A title annexed to a man's name, to identify him more precisely; as, John Doe, Esq.; Richard Roe, Gent.; Robert Dale, Mason; Thomas Way, of new York; a mark of distinction; a title. 6. Something added to a coat of arms, as a mark of honor; opposed to abatement. <geometry> Vector addition, that kind of addition of two lines, or vectors, AB and BC, by which their sum is regarded as the line, or vector, AC. Synonym: Increase, accession, augmentation, appendage, adjunct. Origin: F. Addition, L. Additio, fr. Addere to add. Source: Websters Dictionary (01 Mar 1998) |
|---|---|
| addition compound | Strictly, a complex of two or more complete molecules in which each preserves its fundamental structure and no covalent bonds are made or broken (e.g., hydrates of salts, adducts), loosely, association of acids with basic organic compound's (e.g., amines with HCl), more loosely, addition of two molecules without loss of any atom, but forming new covalent bonds (e.g., CH2==CH2 + Br2 → BrCH2-CH2Br). (05 Mar 2000) |
| addition-deletion mutation | <molecular biology> A type of mutation that results from insertion or deletion of a single nucleotide into, or from, an open reading frame in the normal DNA sequence. Normally, the genetic code is read in the wrong frame, three nucleotides at a time, and the entire sequence downstream of the mutation, is translated into a polypeptide with a garbled amino acid sequence from the mutated codon onwards. These mutations may be induced by certain types of mutagens or may occur spontaneously and usually result in the generation, downstream, of nonsense, chain termination codons. Synonym: addition mutation, addition-deletion mutation, deletion mutation, reading-frameshift mutation. (21 Jun 2000) |
| addition mutation | <molecular biology> A type of mutation that results from insertion or deletion of a single nucleotide into, or from, an open reading frame in the normal DNA sequence. Normally, the genetic code is read in the wrong frame, three nucleotides at a time, and the entire sequence downstream of the mutation, is translated into a polypeptide with a garbled amino acid sequence from the mutated codon onwards. These mutations may be induced by certain types of mutagens or may occur spontaneously and usually result in the generation, downstream, of nonsense, chain termination codons. Synonym: addition mutation, addition-deletion mutation, deletion mutation, reading-frameshift mutation. (21 Jun 2000) |
| addition polymer | <chemistry> A polymer which is formed from the fusion of two monomers which join completely without losing any small molecules. (15 Jan 1998) |
| addition reaction | <chemistry> Any reaction in which two chemicals combine to form a single chemical. (15 Jan 1998) |
| terminal addition enzyme | <enzyme> A non-template-directed DNA polymerase normally found in vertebrate thymus and bone marrow. It catalyses the elongation of oligo- or polydeoxynucleotide chains and is widely used as a tool in the differential diagnosis of acute leukaemias in man. Chemical name: Nucleoside-triphosphate:DNA deoxynucleotidylexotransferase Registry number: EC 2.7.7.31 (12 Dec 1998) |
| acidulated phosphate fluoride | <chemical> Phosphoric acid, mixt. With sodium fluoride (naf). A sodium fluoride solution, paste or powder, which has been acidulated to pH 3 to 4 and buffered with a phosphate. It is used in the prevention of dental caries. Pharmacological action: fluorides, topical. Chemical name: Phosphoric acid, mixt. With sodium fluoride (NaF) (12 Dec 1998) |
| calcium fluoride | <chemical> Calcium fluoride. Occurring in nature as the mineral fluorite or fluorspar. It is the primary source of fluorine and its compounds. Pure calcium fluoride is used as a catalyst in dehydration and dehydrogenation and is used to fluoridate drinking water. Chemical name: Calcium fluoride (CaF2) (12 Dec 1998) |
| phenylmethylsulfonyl fluoride | <chemical> Alpha-toluenesulfonyl fluoride. An enzyme inhibitor that inactivates irc-50 arvin, subtilisin, and the fatty acid synthetase complex. Pharmacological action: enzyme inhibitors, protease inhibitors. Chemical name: Benzenemethanesulfonyl fluoride (12 Dec 1998) |
| silver fluoride | AgF2-H2O;an antiseptic. (05 Mar 2000) |
| sodium fluoride | <chemical> Sodium fluoride (naf). A source of inorganic fluoride which has been used orally and topically to prevent dental caries. It is also effective as a pesticide and in the therapy of osteoporosis. Pharmacological action: fluorides, topical. Chemical name: Sodium fluoride (NaF) (12 Dec 1998) |
| stannous fluoride | A preparation containing not less than 71.2% of stannous tin and not less than 22.3% nor more than 25.5% of fluoride; used as a prophylactic against caries in dentistry. (05 Mar 2000) |
| fluoride | <chemical> The fluoride ion. Low levels of fluoride in drinking water markedly decrease the incidence of dental caries, probably because bacterial metabolism is much more sensitive to low fluoride levels. (18 Nov 1997) |
| fluoride number | The percent inhibition of pseudocholinesterase produced by fluorides; used to differentiate normal from atypical pseudocholinesterases. See: dibucaine number. (05 Mar 2000) |