| light chain-related amyloidosis | A form of primary amyloidosis in which the fibrillar amyloid deposits are derived from the amino terminal variable region of the light chains of immunoglobulin; seen in B-lymphocyte and plasma-cells dyscrasias. (05 Mar 2000) |
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| light coagulation | The coagulation of tissue by an intense beam of light, including laser (laser coagulation). In the eye it is used in the treatment of retinal detachments, retinal holes, aneurysms, haemorrhages, and malignant and benign neoplasms. (12 Dec 1998) |
| light-cured resin | A resin which uses visible or ultraviolet light to excite a photoinitiator which interacts with an amine to form free radicals and initiate polymerization. Used mainly in restorative dentistry. Synonym: light-activated resin. (05 Mar 2000) |
| light dependent reaction | The reaction taking place in the chloroplast in which the absorption of a photon leads to the formation of ATP and NADPH. (18 Nov 1997) |
| light difference | The difference in light sensitivity of the two eyes. Synonym: brightness difference threshold. (05 Mar 2000) |
| light differential threshold | The smallest difference in light intensity that can be appreciated. (05 Mar 2000) |
| light green SF yellowish | An acid arylmethane dye, used as a cytoplasmic stain in plant and animal histology; fades badly in bright light. (05 Mar 2000) |
| light harvesting system | Set of photosynthetic pigment molecules that absorb light and channel the energy to the photosynthetic reaction centre, where the light reactions of photosynthesis occur. In higher plants, contains chlorophyll and carotenoids and is present in two slightly different forms in photosystems I and II. (18 Nov 1997) |
| light-hearted | Free from grief or anxiety; gay; cheerful; merry. Light-heartedly, Light-heartedness. Source: Websters Dictionary (01 Mar 1998) |
| light-horseman | 1. A soldier who serves in the light horse. 2. <zoology> A West Indian fish of the genus Ephippus, remarkable for its high dorsal fin and brilliant colours. Source: Websters Dictionary (01 Mar 1998) |
| light-ion fusion | <radiobiology> Light-Ion-Beam-Driven Inertial Confinement fusion, using beams of light ions driven at implosion targets. Pulsed-power driven accelerators are relatively efficient and cost-effective, but beam-focusing is a technical hurdle for this approach. (09 Oct 1997) |
| light metal | A metal with a specific gravity of less than 4. (05 Mar 2000) |
| light microscope | <instrument> The most common type of microscope (a device used to magnify small objects or substances) used in laboratories. The device works by passing visible light through a condenser and an objective lens. (09 Oct 1997) |
| light microscopy | <procedure> In contrast to electron microscopy. See: bright field, phase contrast, interference, interference contrast, interference reflection, dark field, confocal and fluorescence microscopy. (18 Nov 1997) |
| light-near dissociation | A stronger near pupil response than light response; due to weak pupillomotor input, Argyll Robertson pupil, dorsal midbrain syndrome, or to misdirection of ciliary muscle fibres into the iris sphincter. Synonym: light-near dissociation. (05 Mar 2000) |