pin-head pigmentation spot
| flying spot microscope | <instrument> A microscope in which a moving spot of light is imaged in the object plane, the energy transmitted by the specimen being detected with a photoelectric cell; the light source may be a cathode ray tube, a scanning disk or drum, or an oscillating mirror. (05 Mar 2000) |
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| focal spot | The site of bombardment by electrons and emission of X-rays from the anode of an X-ray tube. See: focal spot size. (05 Mar 2000) |
| focal spot size | The measured size of a focal spot, a function of its actual size and the angulation of the anode surface. See: focal spot. (05 Mar 2000) |
| forty-spot | <zoology> The Tasmanian forty-spotted diamond bird (Pardalotus quadragintus). Source: Websters Dictionary (01 Mar 1998) |
| Fuchs' black spot | An area of pigment proliferation in the macular region in degenerative myopia. (05 Mar 2000) |
| liver spot | A variably pigmented lentigo occurring on exposed skin of older Caucasians. Synonym: liver spot, solar lentigo. (05 Mar 2000) |
| acridine yellow | A faintly yellow solution with strong bluish-violet fluorescence; used as a topical antiseptic and as a fluorescent stain in histology. Synonym: 5-aminoacridine hydrochloride, 9-aminoacridine hydrochloride. (05 Mar 2000) |
| acute yellow atrophy of the liver | A lesion in which there is extensive and rapid death of parenchymal cells of the liver, sometimes with fatty degeneration of the size of the organ; the necrosis may result from fulminant viral infection or chemical poisoning; associated with jaundice. Synonym: acute parenchymatous hepatitis, Rokitansky's disease. (05 Mar 2000) |
| brilliant yellow | An indicator dye that changes from yellow to orange or red at pH 6.4 to 8.0. (05 Mar 2000) |
| butter yellow | C6H5N:NC6H4N(CH3)2;a fat-soluble yellow dye (MW 225) that has hepatic carcinogenic action in experimental animals; used as an indicator of pH (red, at pH 2.9, yellow at pH 4.0). Synonym: dimethylaminoazobenzene, methyl yellow. (05 Mar 2000) |
| martius yellow | C10H6N2O5; 2,4-dinitro-alpha-naphthol;an acid dye used as a plasma stain in plant and animal histology, and as a light filter for photomicrography. Origin: Karl A. Martius, Ger. Chemist, *1920 (05 Mar 2000) |
| Paris yellow | A fine yellow powder used in paints and dyes. Synonym: lead chromate, Leipzig yellow, lemon yellow, Paris yellow. (05 Mar 2000) |
| visual yellow | The orange retinaldehyde resulting from the action of light on the rhodopsin of the retina, which converts the 11-cis-retinal component of the rhodopsin to all-trans-retinal plus opsin. Synonym: trans-retinal, visual yellow. (05 Mar 2000) |
| metanil yellow | A monoazo acid dye, C18H14N3O3SNa, used as a cytoplasmic and connective tissue stain. (05 Mar 2000) |
| methyl yellow | C6H5N:NC6H4N(CH3)2;a fat-soluble yellow dye (MW 225) that has hepatic carcinogenic action in experimental animals; used as an indicator of pH (red, at pH 2.9, yellow at pH 4.0). Synonym: dimethylaminoazobenzene, methyl yellow. (05 Mar 2000) |