| shadow corpuscle | A hypochromic, crescent-shaped erythrocyte, probably resulting from artifactual rupture of a red cell with loss of haemoglobin. Synonym: achromacyte, achromatocyte, ghost corpuscle, phantom corpuscle, Ponfick's shadow, shadow corpuscle, shadow, Traube's corpuscle. Origin: G. A-priv. + chroma, colour, + kytos, hollow (cell) (05 Mar 2000) |
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| shadow mask | <microscopy> Also Aperture mask. In colour video monitors, a finely perforated or striped metal plate that is located between the three electron guns and the phosphor screen. The mask ensures that the electron beams carrying the R, G, and B signals land on the corresponding phosphors at every point in the picture. (05 Aug 1998) |
| shadow nucleus | A nucleus that has lost its pigment and staining properties. (05 Mar 2000) |
| shadow test | <physiology> The study of the retina of the eye by means of the ophthalmoscope. Origin: Retina + -scopy. Source: Websters Dictionary (01 Mar 1998) |
| shadow-cast replica | <microscopy> A replica which has been shadowed. See: shadowing. (05 Aug 1998) |
| shadow-casting | Deposition of a film of carbon or certain metals such as palladium, platinum, or chromium on a contoured microscopic object in order to allow the object to be seen in relief with the electron microscope or sometimes with the light microscope. (05 Mar 2000) |
| shadowing | Procedure much used in electron microscopy, in which a thin layer of material, usually heavy metal or carbon, is deposited onto a surface from one side, in such a way as to cast shadows. Deposition is usually done by vapourising the metal on an electrode under vacuum. (18 Nov 1997) |
| shadowing (histology) | The technique of spraying a tissue specimen with a thin coat of a heavy metal such as platinum. The specimen is sprayed from an oblique angle, which results in the uneven deposition of the coating. The varying thicknesses create a shadow effect and give a three-dimensional appearance to the specimen. (12 Dec 1998) |
| shadowy | 1. Full of shade or shadows; causing shade or shadow. "Shadowy verdure." "This shadowy desert, unfrequented woods." (Shak) 2. Hence, dark; obscure; gloomy; dim. "The shadowy past." 3. Not brightly luminous; faintly light. "The moon . . . With more pleasing light, Shadowy sets off the face things." (Milton) 4. Faintly representative; hence, typical. "From sshadowy types to truth, from flesh to spirit." (Milton) 5. Unsubstantial; unreal; as, shadowy honor. "Milton has brought into his poems two actors of a shadowy and fictitious nature, in the persons of Sin and Death." (Addison) Source: Websters Dictionary (01 Mar 1998) |
| shadrach | <chemistry> A mass of iron on which the operation of smelting has failed of its intended effect; so called from Shadrach, one of the three Hebrews who came forth unharmed from the fiery furnace of Nebuchadnezzar. (See) Source: Websters Dictionary (01 Mar 1998) |
| shady | 1. Abounding in shade or shades; overspread with shade; causing shade. "The shady trees cover him with their shadow." (Job. Xl. 22) "And Amaryllis fills the shady groves." (Dryden) 2. Sheltered from the glare of light or sultry heat. "Cast it also that you may have rooms shady for summer and warm for winter." (Bacon) 3. Of or pertaining to shade or darkness; hence, unfit to be seen or known; equivocal; dubious or corrupt. "A shady business." "Shady characters, disreputable, criminal." (London Spectator) On the shady side of, on the thither side of; as, on the shady side of fifty; that is, more than fifty. To keep shady, to stay in concealment; also, to be reticent. Origin: Shadier; Shadiest. Source: Websters Dictionary (01 Mar 1998) |
| Shaffer, A | <person> U.S. Biochemist, 1881-1960. See: Shaffer-Hartmann method. (05 Mar 2000) |
| Shaffer-Hartmann method | An obsolete method for the quantitative determination of glucose in biological fluids, based on the reduction of copper by the reducing group of the sugar. (05 Mar 2000) |
| shaft | 1. The slender, smooth stem of an arrow; hence, an arrow. "His sleep, his meat, his drink, is him bereft, That lean he wax, and dry as is a shaft." (Chaucer) "A shaft hath three principal parts, the stele [stale], the feathers, and the head." (Ascham) 2. The long handle of a spear or similar weapon; hence, the weapon itself; anything regarded as a shaft to be thrown or darted; as, shafts of light. "And the thunder, Winged with red lightning and impetuous rage, Perhaps hath spent his shafts." (Milton) "Some kinds of literary pursuits . . . Have been attacked with all the shafts of ridicule." (V. Knox) 3. That which resembles in some degree the stem or handle of an arrow or a spear; a long, slender part, especially when cylindrical. <botany> Specifically: (a) The stem or midrib of a feather. The pole, or tongue, of a vehicle; also, a thill. The part of a candlestick which supports its branches. "Thou shalt make a candlestick of pure gold . . . His shaft, and his branches, his bowls, his knops, and his flowers, shall be of the same." (Ex. Xxv. 31) The handle or helve of certain tools, instruments, etc, as a hammer, a whip, etc. A pole, especially a Maypole. The body of a column; the cylindrical pillar between the capital and base. Also, the part of a chimney above the roof. Also, the spire of a steeple. A column, an obelisk, or other spire-shaped or columnar monument. "Bid time and nature gently spare The shaft we raise to thee. <machinery> " (Emerson) A solid or hollow cylinder or bar, having one or more journals on which it rests and revolves, and intended to carry one or more wheels or other revolving parts and to transmit power or motion; as, the shaft of a steam engine. 4. <zoology> A humming bird (Thaumastura cora) having two of the tail feathers next to the middle ones very long in the male; called also cora humming bird. 5. [Cf. G. Schacht. <chemical> A well-like excavation in the earth, perpendicular or nearly so, made for reaching and raising ore, for raising water, etc. 6. A long passage for the admission or outlet of air; an air shaft. 7. The chamber of a blast furnace. Line shaft, a furnace, in the form of a chimney, which is charged at the top and tapped at the bottom. Origin: OE. Shaft, schaft, AS. Sceaft; akin to D. Schacht, OHG. Scaft, G. Schaft, Dan. & Sw. Skaft handle, haft, Icel. Skapt, and probably to L. Scapus, Gr, a staff. Probably originally, a shaven or smoothed rod. Cf. Scape, Scepter, Shave. Source: Websters Dictionary (01 Mar 1998) |
| shaft horsepower | A measure of the actual mechanical energy per unit time delivered to a turning shaft. 1 shaft horsepower = 1 electric horsepower = 550 ft-lb/second. (05 Dec 1998) |