| spin density | The number of nuclear dipoles per unit volume. (05 Mar 2000) |
|---|---|
| spin echo | A commonly used technique to recover T2 relaxation signals in magnetic resonance imaging, by using a 180 |
| spin labelling | <chemistry, technique> The technique of introducing a grouping with an unpaired electron to act as an electron spin resonance (ESR) reporter species. This is almost invariably a nitroxide compound (N O) in which the nitrogen forms part of a sterically hindered ring. (18 Nov 1997) |
| spin labels | Molecules which contain an atom or a group of atoms exhibiting an unpaired electron spin that can be detected by electron spin resonance spectroscopy and can be bonded to another molecule. (12 Dec 1998) |
| spin trapping | A technique for detecting short-lived reactive free radicals in biological systems by providing a nitrone or nitrose compound for an addition reaction to occur which produces an electron spin resonance spectroscopy-detectable aminoxyl radical. In spin trapping, the compound trapping the radical is called the spin trap and the addition product of the radical is identified as the spin adduct. (free rad res comm 1990;9(3-6):163) (12 Dec 1998) |
| spin-lattice relaxation | In nuclear magnetic resonance, the return of the magnetic dipoles of the hydrogen nuclei (magnetization vector) to equilibrium parallel to the magnetic field, after they have been flipped 90 |
| spin-polarized fusion | <radiobiology> A method to enhance nuclear fusion reaction rates in some fusion fuels by polarizing the nuclear spins. (09 Oct 1997) |
| spin-spin relaxation | In nuclear magnetic resonance, the return of the magnetic dipoles of the hydrogen nuclei (magnetization vector) to equilibrium parallel to the magnetic field, after they have been flipped 90 |
| spina | Synonym: vertebral column. Origin: L. A thorn, the backbone, spine (05 Mar 2000) |
| spina angularis | A posterior and downward projection from the greater wing of the sphenoid bone on either side, located posterolateral to the foramen spinosum, so-named for its proximity to the sphenoidal spine; gives attachment to the sphenomandibular ligament. Synonym: processus spinosus, spina ossis sphenoidalis, alar spine, angular spine, spina angularis, spinous process. (05 Mar 2000) |
| spina bifida | A congenital limited defect in the spinal column, characterised by the absence of the vertebral arches through which the spinal membranes and spinal cord may protrude. (27 Sep 1997) |
| spina bifida aperta | A bony defect in the vertebral column through which the meningeal membranes that cover the spinal cord and part of the spinal cord protrude. An alternative term is meningomyelocele. (12 Dec 1998) |
| spina bifida cystica | A bony defect in the vertebral column through which the meningeal membranes that cover the spinal cord and part of the spinal cord protrude. An alternative term is meningomyelocele. (12 Dec 1998) |
| spina bifida manifesta | A bony defect in the vertebral column through which the meningeal membranes that cover the spinal cord and part of the spinal cord protrude. An alternative term is meningomyelocele. (12 Dec 1998) |
| spina bifida occulta | Literally, a hidden cleft in the spine. A bony defect in the vertebral column which remains hidden, covered by skin (12 Dec 1998) |