| differentiated | The similarity between a normal cell and the cancer cell, defines what degree of change has occurred. Cancer cells that are well differentiated are close to the original cell and are usually less aggressive. Poorly differentiated cells have changed more and are more aggressive. (09 Oct 1997) |
|---|---|
| differentiation | The distinguishing of one thing or disease from another. (18 Nov 1997) |
| differentiation antigen | Any large structural macromolecule that can be detected by immune reagents and that also is associated with the differentiation of a particular cell type or types. Many cells can be identified by their possession of a unique set of differentiation antigens. There should be no implication that the antigens cause differentiation. (18 Nov 1997) |
| difficult | 1. Hard to do or to make; beset with difficulty; attended with labour, trouble, or pains; not easy; arduous. Difficult implies the notion that considerable mental effort or skill is required, or that obstacles are to be overcome which call for sagacity and skill in the agent; as, a difficult task; hard work is not always difficult work; a difficult operation in surgery; a difficult passage in an author. "There is not the strength or courage left me to venture into the wide, strange, and difficult world, alone." (Hawthorne) 2. Hard to manage or to please; not easily wrought upon; austere; stubborn; as, a difficult person. Synonym: Arduous, painful, crabbed, perplexed, laborious, unaccommodating, troublesome. See Arduous. Origin: From Difficulty. Source: Websters Dictionary (01 Mar 1998) |
| difficulty | Origin: L. Difficultas, fr. Difficilis difficult; dif- = dis- + facilis easy: cf. F. Difficulte. See Facile. 1. The state of being difficult, or hard to do; hardness; arduousness; opposed to easiness or facility; as, the difficulty of a task or enterprise; a work of difficulty. "Not being able to promote them [the interests of life] on account of the difficulty of the region." (James Byrne) 2. Something difficult; a thing hard to do or to understand; that which occasions labour or perplexity, and requires skill perseverance to overcome, solve, or achieve; a hard enterprise; an obstacle; an impediment; as, the difficulties of a science; difficulties in theology. "They lie under some difficulties by reason of the emperor's displeasure." (Addison) 3. A controversy; a falling out; a disagreement; an objection; a cavil. "Measures for terminating all local difficulties." (Bancroft) 4. Embarrassment of affairs, especially financial affairs; usually in the plural; as, to be in difficulties. "In days of difficulty and pressure." (Tennyson) Synonym: Impediment, obstacle, obstruction, embarrassment, perplexity, exigency, distress, trouble, trial, objection, cavil. See Impediment. Source: Websters Dictionary (01 Mar 1998) |
| diffluence | The process of becoming fluid. Origin: L. Dif-fluo, to flow in different directions, dissolve (05 Mar 2000) |
| difform | Irregular in form; opposed to uniform; anomalous; hence, unlike; dissimilar; as, to difform corolla, the parts of which do not correspond in size or proportion; difform leaves. "The unequal refractions of difform rays." (Sir I. Newton) Origin: Cf. F. Difforme, fr. L. Dif- = dis- + forma form. Cf. Deform. Source: Websters Dictionary (01 Mar 1998) |
| diffraction | When a wave train passes an obstacle secondary waves are set up that interfere with the primary wave and give rise to bands of constructive and destructive interference. Around a point source of light, in consequence, is a series of concentric light and dark bands (coloured bands with white light), a diffraction pattern. (18 Nov 1997) |
| diffraction grating | <microscopy> An artificially produced periodic array of scattering centres capable of producing a pattern of diffracted energy, such as accurately ruled lines on a plane surface. (05 Aug 1998) |
| diffusate | <chemistry> Material which, in the process of catalysis, has diffused or passed through the separating membrane. Source: Websters Dictionary (01 Mar 1998) |
| diffuse | Not definitely limited or localised, widely distributed. Origin: L. Dis = apart, fundere = to pour (18 Nov 1997) |
| diffuse abdominal calcification | <radiology> Ovarian cystadenocarcinoma (psammomatous Calcium), pseudomyxoma peritonei, pseudomucinous cystadenoma of ovary, mucocele of appendix, undifferentiated abdominal malignancy, TB peritonitis, oil granulomata, meconium peritonitis (12 Dec 1998) |
| diffuse abscess | A collection of pus not circumscribed by a well-defined capsule. (05 Mar 2000) |
| diffuse aneurysm | An aneurysm that has enlarged and spread to the surrounding tissues in consequence of rupture of its walls. Synonym: consecutive aneurysm. (05 Mar 2000) |
| diffuse angiokeratoma | <disease> Lysosomal storage disease caused by a deficiency of alpha-galactosidase a and resulting in an accumulation of globotriaosylceramide in the renal and cardiovascular systems. The disease is characterised by telangiectatic skin lesions, renal failure, and disturbances of the cardiovascular, gastrointestinal, and central nervous systems. Inheritance: x-linked. (08 Mar 2000) |