| 释义 |
▪ I. coma1|ˈkəʊmə|
[a. Gr. κῶµα (κωµατ-) deep sleep, lethargy: cf. κοιµά-ειν to put to sleep.]
Pathol. ‘A state of unnatural, heavy, deep and prolonged sleep, with complete unconsciousness and slow, stertorous, often irregular, breathing’ (Syd. Soc. Lex.), due to pressure on the brain, to the effect of certain poisons, or other causes, and frequently ending in death; stupor, lethargy.
1646Sir T. Browne Pseud. Ep. iv. ix. 200 Sneezing..is..of good signality in Lethargies, Apoplexies, Catalepsies, and Coma's. 1782Heberden Comm. vii, When the scarlet fever proves fatal, a coma will sometimes show itself. 18..Hooper Physic. Vade M. §914 It is often important to distinguish the coma of drunkenness from that of apoplexy. 1877Roberts Handbk. Med. I. 13 Death beginning at the brain is said to be by coma.
b. coma vigil: Applied in earlier medical treatises to a condition anterior to fevers: see quots. 1708–1834; but by Sir W. Jenner to a lethargic condition in which a typhus fever patient lies with wide open eyes, totally unconscious, but muttering in delirium.
1708J. Harris Lex. Techn., Coma Vigil, waking Drowsiness, is a Disease wherein the Patients are continually inclined to Sleep, but scarce can sleep, being affected with a great Drowsiness. 1748Hartley Observ. Man i. i. 55. 1758 R. Brookes Gen. Pract. Physic II. 113 A Coma Vigil..they have a strong inclination to sleep, and yet either don't sleep at all, or, if they do, awake immediately with little Relief, but have no delerium..Generally a Fore⁓runner of a Phrenzy in acute Fevers. 1834J. M. Good Study Med. (ed. 4) III. 446. 1871 Sir T. Watson Princ. Physic (ed. 5) II. 869. 1886 Fagge Princ. Med. I. 145 In a peculiar state to which Jenner has appropriated the term Coma vigil.
c. fig.
1876Gladstone in Pall Mall Budget (1887) 14 Apr. 6/2 Honour, duty, compassion, and I must add shame, are sentiments never in a state of coma.
▪ II. coma2|ˈkəʊmə|
Pl. comæ |-miː|.
[a. L. coma, a. Gr. κόµη hair of the head, also applied to foliage, etc., and to the tail of a comet.]
1. Bot.
a. A tuft of silky hairs at the end of some seeds, as those of Epilobium.
b. A tuft of bracts occurring beyond the inflorescence, as in the pine-apple; ‘the crown of sterile flowers on the top of some forms of inflorescence’ (Syd. Soc. Lex.).
c. The arrangement of the leafy branches forming the ‘head’ of a tree.
1669Rowland tr. Schroder's Chymical Dispens. 2 Coma, in plants, signifies the tops. 1770C. Milne Bot. Dict. s.v. Bractea, Large bracteæ, which, from their resemblance to a bush of hair, are denominated coma. 1830Lindley Nat. Syst. Bot. 236 Cyrtandraceæ ..Seeds..naked, or with a coma. 1870Bentley Bot. 102 The head of a tree is called a coma. 1872Oliver Elem. Bot. ii. 172 The silky coma surrounding the top of the seeds of the Willow-herbs.
2. Astron. The nebulous envelope surrounding the nucleus of a comet, and forming the outer portion of the ‘head’.
1765Maty in Phil. Trans. LV. 307 The nucleus could not be distinguished from the coma. 1878Newcomb Pop. Astron. iii. v. 365 The tail is a continuation of the coma.
fig.1815W. Taylor in Monthly Mag. XXXIX. 309 It is not everywhere possible for the most ingenious critic to distinguish..the nucleus from the coma.
3. The blurred appearance surrounding an object seen under a microscope when the lens is not free from spherical aberration.
1867J. Hogg Microsc. i. ii. 64 If the greater expansion or coma be when the object is without the focus. |