| secondary X zone | An adrenocortical zone, situated in the inner zona fasciculata, that appears upon postpubertal gonadectomy in some male rodents, most notably the mouse; the development of this zone is believed to be stimulated by pituitary gonadotropins. (05 Mar 2000) |
|---|---|
| spectrometry, mass, secondary ion | A mass-spectrometric technique that is used for microscopic chemical analysis. A beam of primary ions with an energy of 5-20 kiloelectronvolts (kev) bombards a small spot on the surface of the sample under ultra-high vacuum conditions. Positive and negative secondary ions sputtered from the surface are analyzed in a mass spectrometer in regards to their mass-to-charge ratio. (12 Dec 1998) |
| dentin, secondary | Dentin formed and deposited in response to a normal or slightly abnormal stimulus, after the complete formation of the tooth. (12 Dec 1998) |
| immunization, secondary | Any immunization following a primary immunization and involving exposure to the same or a closely related antigen. (12 Dec 1998) |
| osteoarthropathy, secondary hypertrophic | Symmetrical osteitis of the four limbs, chiefly localised to the phalanges and the terminal epiphyses of the long bones of the forearm and leg, sometimes extending to the proximal ends of the limbs and the flat bones, and accompanied by dorsal kyphosis and joint involvement. It is often secondary to chronic conditions of the lungs and heart. (12 Dec 1998) |
| ABC process | Purification of water or deodorization of sewage by a mixture of alum, blood, and charcoal. (05 Mar 2000) |
| accessory process | A small apophysis at the posterior part of the base of the transverse process of each of the lumbar vertebrae. Synonym: processus accessorius, accessory tubercle. (05 Mar 2000) |
| acromial process | <anatomy> The lateral triangular projection of the spine of the scapula that forms the point of the shoulder and articulates with the clavicle. (27 Sep 1997) |
| activated sludge process | <procedure> A method of treating sewage and wastewater through microbial oxidation. Sewage previously treated in settling tanks is aerated to encourage the growth of nonpathogenic aerobic microorganisms (bacteria, yeasts, moulds and protozoans) which break the organic matter down into carbon dioxide, water and simple salts. After this activated sludge is produced, the wastewater undergoes further processing through anaerobic digestion, filtering and chlorination. (29 Dec 1997) |
| adiabatic process | <chemistry> A process in which the system does not exchange heat with the surroundings. (15 Jan 1998) |
| agene process | Bleaching of flour with nitrogen trichloride (prohibited in the United States). (05 Mar 2000) |
| alar process | A small lateral expansion of the ethmoid bone from the front of the crista galli on each side that articulates with the frontal bone and forms the foramen caecum. Synonym: ala cristae galli, alar process. (05 Mar 2000) |
| alveolar process | That portion of bone in either the maxilla or the mandible which surrounds and supports the teeth. (12 Dec 1998) |
| anterior process of malleus | A slender spur running anteriorward from the neck of the malleus toward the petrotympanic fissure. Synonym: processus anterior mallei, Folli's process, follian process, long process of malleus, processus gracilis, processus ravii, Rau's process, Ravius' process, slender process of malleus. (05 Mar 2000) |
| apical process | The dendritic process extending from the apex of a pyramidal cell of the cerebral cortex toward the surface. Synonym: apical dendrite. (05 Mar 2000) |