| 释义 |
specificity|spɛsɪˈfɪsɪtɪ|
[ad. F. spécificité, or f. specific a. + -ity.]
1. a. The quality or fact of being specific in operation or effect.
1876Bartholow Mat. Medica (1879) 417 It is not an action of specificity—like quinia in intermittent and remittent fevers. 1884Trans. Victoria Inst. 37 note, The specificity of germs is still an unsettled question. 1922[see directedness]. 1946Scrutiny XIV. 109 George Eliot's genius appears in the specificity with which she exhibits the accomplishments in Gwendolen of the kind of conscious advantage she resembles Isabel in enjoying. 1977J. F. Fixx Compl. Bk. Running vii. 89 Few runners had supposed it could possibly be so hot on a mid-April day in Massachusetts, so practically nobody had trained properly. As a result, most people's times were terrible. The same specificity principle applies to terrain.
b. The narrowness of the range of substances with which an antibody or other agent acts or is effective.
1896Allbutt's Syst. Med. I. 888 He denies, from experiments of his own, the specificity of protective serum. 1904G. H. F. Nuttall Blood Immunity & Blood Relationship ix. 381 Wassermann..brought the question of specificity into greater prominence. Ibid. 443/1 (Index), Specificity of precipitins. 1935N. P. Sherwood Immunol. xii. 274 Two kinds of specificity can be demonstrated by immune reactions, one that applies to species and the second to type variation within a species. 1971Sci. Amer. July 26/1 The specificity, or narrow spectrum, of vaccines is a limitation; it means that a different vaccine is required for each virus or strain of virus.
c. Biol. The degree to which a parasite or symbiote is restricted in its range of hosts.
1924Rep. Brit. Assoc. Adv. Sci. 1923 453 They [sc. parasitic nematodes] may be divided broadly into a section with more or less strict ‘specificity’ and a section with members occurring in various hosts, often of quite distantly related groups. 1955Sci. Amer. July 77/1 It is also known that the protein coat determines the specificity of the virus, i.e., whether or not it will attack a certain bacterium. 1965B. E. Freeman tr. Vandel's Biospeleology xv. 245 This is more a case of parasitic or symbiotic specificity than cavernicolous specialisation.
2. The fact of being specific in character.
1879Brit. Med. Jrnl. 24 May 785 No one who has studied the clinical history of diphtheria can avoid grave doubts as to its specificity. 1894Lancet 3 Nov. 1058 The doctrine of the invariable specificity of the disease. 1897Allbutt's Syst. Med. III. 633 In determining the specificity of the rheumatic origin. 1928Hartshorne & May Studies in Deceit ii. xii. 221 (heading) Specificity of attitudes. 1958R. Williams Culture & Society iii. iii. 231 A principal virtue was always the specificity, not only of definition, but of illustration. 1981Times 16 July 6/1 They also want to avoid ‘specificity’ because they have not yet formulated fully-fledged policies.
Add:[1.] d. Med. The extent to which a diagnostic test is specific for a particular condition, trait, etc., calculated as the proportion of tests on individuals who do not have the condition, etc., that give negative results.
1954A. B. Kurlander et al. in Diabetes III. 216/1 Specificity may be defined as the ability of the test to classify as negative those who do not have the condition being screened for and is calculated as the percentage screening negative of those determined not to have diabetes. Ibid. 218/2 The specificity ratings of blood sugar tests by the Somogyi–Nelson and Wilkerson–Heftmann methods were satisfactory—98·0 and 96·8 per cent respectively. 1955Sci. Amer. Mar. 68/2 The three procedures represent an ascending scale of sensitivity and a descending scale of specificity. 1977I. M. Roitt Essent. Immunol. v. 131 As with most immunological techniques as sensitivity is increased, specificity becomes progressively reduced. 1987Oxf. Textbk. Med. (ed. 2) I. v. 442/2 This test has a sensitivity of up to 96 per cent and a specificity of 99 per cent. |