| pure random drift | That which has random components only with an average value of zero and no systematic effects. Brownian movement in a still container shows pure random drift but in the Mississippi shows a steady downstream tendency. (05 Mar 2000) |
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| pure red cell anaemia | Congenital nonregenerative, familial hypoplastic, or pure red cell anaemia; erythrogenesis imperfecta; Diamond-Blackfan syndrome; autosomal recessive normocytic normochromic anaemia resulting from congenital hypoplasia of the bone marrow, which is grossly deficient in erythroid precursors while other elements are normal; anaemia is progressive and severe, but leukocyte and platelet counts are normal or slightly reduced; survival of transfused erythrocytes is normal; minor congenital anomalies are found in some patients. Synonym: congenital nonregenerative anaemia, Diamond-Blackfan anaemia, Diamond-Blackfan syndrome, erythrogenesis imperfecta, familial hypoplastic anaemia, pure red cell anaemia. (05 Mar 2000) |
| pure red cell aplasia | A transitory arrest of red blood cell production which may occur in the course of a haemolytic anaemia, often preceded by infection, or as a complication of certain drugs; if the arrest persists anaemia may result. See: congenital hypoplastic anaemia. (05 Mar 2000) |
| pure tone audiogram | A chart of the threshold for hearing acuity at various frequencies usually expressed in decibels above normal threshold and usually covering frequencies from 128 to 8000 Hz. (05 Mar 2000) |
| pure-tone audiometer | An electroacoustical generator which produces pure tones of selected frequencies and calibrated output. (05 Mar 2000) |
| pure-tone audiometry | Audiometry utilizing tones of various frequencies and intensities as auditory stimuli to measure hearing, including comparisons of results from testing air conduction and bone conduction. (05 Mar 2000) |