| 释义 |
-valent
[ad. L. valent-em, pres. pple. of valēre to be worth.]
A formative element occurring in a few words of general currency, as equivalent, prevalent (directly f. L.), ambivalent, and in various scientific contexts, being used with prefixes denoting number: (a) in Chem., usu. with pronunc. |-ˈveɪlənt|, forming adjs. denoting ‘having a valency of the specified number’ (valency 2); also used in an analogous sense in Immunol. (cf. multivalent a. b); also with arabic number prefixed; (b) in Cytology (usu. with pronunc. |ˈ-vələnt|) forming adjs. and ns. denoting ‘(a meiotic structure) composed of the specified number of chromosomes’ (cf. multivalent a. and n., quadrivalent a. and n., trivalent a. and n.).
This suffix was first used in its Chem. sense by L. Meyer 1864, in Mod. Theorien d. Chem. 67.
1977Lancet 25 June 1338/2 A double-blind controlled trial of a 14-valent pneumococcal polysaccharide vaccine was carried out. |