| comet tail sign | In chest radiology, the curved appearance of pulmonary arteries and veins associated with round atelectasis, fibrosis associated with organizing pleurisy. Synonym: comet tail sign. (05 Mar 2000) |
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| artifact | Something artificial, a distortion that does not reflect normal anatomy or pathology, not usually found in the body. For example: in radiology, the appearance on an X-ray of a surgical metal clip that obscures the clear view of an anatomical structure. (16 Dec 1997) |
| chemical shift artifact | In magnetic resonance imaging, a dark band caused by a biochemical difference in resonant frequency of adjacent regions rather than a true anatomic separation. (05 Mar 2000) |
| comet sign | In chest radiology, the curved appearance of pulmonary arteries and veins associated with round atelectasis, fibrosis associated with organizing pleurisy. Synonym: comet tail sign. (05 Mar 2000) |
| artery of the pancreatic tail | Origin, splenic artery near the left gastroepiploic; distribution, the tail of the pancreas; anastomoses, with other pancreatic arteries. Synonym: arteria caudae pancreatis, caudal pancreatic artery. (05 Mar 2000) |
| boat-tail | <zoology> A large grackle or blackbird (Quiscalus major), found in the Southern United States. Source: Websters Dictionary (01 Mar 1998) |
| rat-tail | 1. <veterinary> An excrescence growing from the pastern to the middle of the shank of a horse. 2. <zoology> The California chimaera. See Chimaera. Any fish of the genus Macrurus. See Grenadier. Source: Websters Dictionary (01 Mar 1998) |
| mare's-tail | 1. A long streaky cloud, spreading out like a horse's tail, and believed to indicate rain; a cirrus cloud. See Cloud. "Mackerel sky and mare's-tails Make tall ships carry low sails." (Old Rhyme) 2. <botany> An aquatic plant of the genus Hippuris (H.vulgaris), having narrow leaves in whorls. Source: Websters Dictionary (01 Mar 1998) |
| viral tail proteins | Proteins found in the tail sections of DNA and RNA viruses. It is believed that these proteins play a role in directing chain folding and assembly of polypeptide chains. (12 Dec 1998) |
| poly A tail | <molecular biology> A sequence of adenine nucleotides that get added to the 3' end of some primary transcript messenger RNA molecules in eukaryotes during post-transcriptional processing. The added tail is believed to confer stability to the molecule. Histone mRNA do not have poly A tail. The poly A tail is added post transcriptionally to the primary transcript as part of the nuclear processing of RNA yielding hnRNAs with 60-200 adenylate residues in the tail. In the cytoplasm the poly A tail on mRNAs is gradually reduced in length. The function of the poly A tail is not clear but it is the basis of a useful technique for the isolation of eukaryotic mRNAs. The technique uses an affinity column with oligo(u) or oligo(dT) immobilised on a solid support. If cytoplasmic RNA is applied to such a column, poly A rich RNA (mRNA) will be retained. (13 Nov 1997) |
| hare's-tail | <botany> A kind of grass (Eriophorum vaginatum). See Cotton grass, under Cotton. Hare's-tail grass, a species of grass (Lagurus ovatus) whose head resembles a hare's tail. Source: Websters Dictionary (01 Mar 1998) |
| sperm tail | The posterior, filiform part of spermatozoa, which provides sperm motility. (12 Dec 1998) |
| split-tail | <zoology> A california market fish (Pogonichthys macrolepidotus) belonging to the Carp family. The pintail duck. Source: Websters Dictionary (01 Mar 1998) |
| daggle-tail | A slovenly woman; a slattern; a draggle-tail. Source: Websters Dictionary (01 Mar 1998) |
| dog's-tail grass | <botany> A hardy species of British grass (Cynosurus cristatus) which abounds in grass lands, and is well suited for making straw plait. Synonym: goldseed. Source: Websters Dictionary (01 Mar 1998) |