| dark field stop | <microscopy> A central stop for obtaining a dark field effect for low-power objectives. It is customarily used with a high numerical aperture, bright field condenser. (05 Aug 1998) |
|---|---|
| dark-ground illumination | dark-field illumination |
| dark reaction | <biochemistry, plant biology> The reactions in photosynthesis that occur after NADPH and ATP production and that take place in the stroma of the chloroplast. By means of the reaction, carbon dioxide is incorporated into carbohydrate. (18 Nov 1997) |
| dark t2 lesion | <radiology> (short T2), acute haemorrhage (deoxyHb), haemosiderin, physiologic iron (basal ganglia, etc.), mucinous lesions (?) most abnormalities have long T1 and T2 (dark/bright). Compare: bright T1 lesion. (07 Mar 2000) |