| B1 | induced field in magnetic resonance imaging; radiofrequency magnetic field in nuclear magnetic reson... |
|---|---|
| B0 | constant magnetic field in nuclear magnetic resonance |
| Bo | constant magnetic field in a magnetic resonance scanner |
| MR | Maddox rods; magnetic resistance; magnetic resonance; mandibular reflex; mannose-resistant; may repe... |
| LD | labor and delivery; laboratory data; labyrinthine defect; lactate dehydrogenase; laser Doppler; lear... |
| circular sulcus of Reil | A saemicircular fissure demarcating the insula from the opercula above, below, and behind. Synonym: sulcus circularis insulae, circular sulcus of Reil, limiting sulcus of Reil. (05 Mar 2000) |
|---|---|
| covalently closed circular DNA | <molecular biology> A circular molecule of double-stranded DNA which is supercoiled, or coiled up on itself due to internal tensions, because there are no breaks in the phosphate backbone (upon which the nucleotide bases are mounted) to relieve the tensions and allow it to form an open circle. (09 Oct 1997) |
| DNA, circular | Any of the covalently closed DNA molecules found in bacteria, many viruses, mitochondria, plastids, and plasmids. Small, polydisperse circular DNA's have also been observed in a number of eukaryotic organisms and are suggested to have homology with chromosomal DNA and the capacity to be inserted into, and excised from, chromosomal DNA. It is a fragment of DNA formed by a process of looping out and deletion, containing a constant region of the mu heavy chain and the 3'-part of the mu switch region. Circular DNA is a normal product of rearrangement among gene segments encoding the variable regions of immunoglobulin light and heavy chains, as well as the T-cell receptor. (12 Dec 1998) |
| magnetic | 1. A magnet. "As the magnetic hardest iron draws." (Milton) 2. Any metal, as iron, nickel, cobalt, etc, which may receive, by any means, the properties of the loadstone, and which then, when suspended, fixes itself in the direction of a magnetic meridian. Source: Websters Dictionary (01 Mar 1998) |
| magnetic attraction | The force that draws iron or steel toward a magnet. (05 Mar 2000) |
| magnetic axis | <physics> This typically refers to the location of the innermost flux surface in a toroidal device, the one which encloses no volume and has therefore degenerated from a flux surface into a single field line. Roughly, the circle through the middle of the dough of the donut. Additionally, in systems with magnetic islands (see entry below), each island has a local magnetic axis, distinct from the overall magnetic axis of the torus. (09 Oct 1997) |
| magnetic confinement | <physics> Use of magnetic fields to confine a plasma. (Confinement involves restricting the volume of the plasma and/or restricting particle or energy transport from the centre of the plasma to the edge.) (09 Oct 1997) |
| magnetic confinement fusion | <physics> Method of fusion which uses magnetic fields / magnetic bottles to confine a hot plasma until fusion occurs. (09 Oct 1997) |
| magnetic field | The sphere of influence of a magnet. (05 Mar 2000) |
| magnetic field gradient | In magnetic resonance imaging, a magnetic field that varies with location, superimposed on the uniform field of the magnet, to alter the resonant frequency of nuclei and allow recovery of their spatial position. Synonym: field gradient. (05 Mar 2000) |
| magnetic implant | A tissue-tolerated, magnetised metal placed within the bone to aid in denture retention; a similar magnet is placed in the overlying denture to complete the field. (05 Mar 2000) |
| magnetic inertia | <physics> A lagging or retardation of the effect, when the forces acting upon a body are changed, as if from velocity or internal friction; a temporary resistance to change from a condition previously invuced, observed in magnetism, thermoelectricity, etc, on reversal of polarity. Origin: NL, fr. Gr. To be behind, to lag. Source: Websters Dictionary (01 Mar 1998) |
| magnetic island | <physics> A magnetic topology near a rational surface where the flux surface is broken up into tubes which are not connected with each other poloidally. Islands may develop in non-ideal magnetohydrodynamic fluids, where electrical resistance becomes important and magnetic field lines are no longer frozen-in to the fluid. Then magnetic tearing and reconnection may allow field lines to link up and form islands with a local magnetic axis in a narrow region near a rational surface. (See also magnetohydrodynamic, frozen-in law). The development of islands may be caused by a small perturbation, whether internal or external, whether deliberate or accidental, and is usually associated with enhanced transport (i.e., reduced confinement). The centres of the islands are magnetic O-points, while the boundaries between islands are marked by X-points. (09 Oct 1997) |
| magnetic mach number | <physics> A dimensionless number equal to the ratio of the velocity of a fluid to the velocity of Alfven waves in that fluid. (13 Nov 1997) |
| magnetic moment | <physics> (a) A vector associated with a magnet, current loop, or particle, the cross product of this vector with the magnetic field is equal to the torque which the field exerts on the system. (b) The adiabatic invariant associated with the rapid gyromotion of a charged particle in a slowly varying magnetic field. (The value of the magnetic moment in sense (b) is the magnitude of the vector in sense (a).) (13 Nov 1997) |