| 释义 |
monoˈphasic, a.
[f. prec. + -ic.]
a. Electr. = prec. Hence,
b. Applied to (a record of) a nerve impulse that is of the same sign throughout, and to experimental arrangements devised to give such records.
1883Phil. Trans. R. Soc. CLXXIII. 35 (table) Character of variation. Monophasic, -39·1. Diphasic, +11·7, -21·2. 1900Nature 26 July 290/2 So producing a monophasic variation of considerable E.M.F. 1915W. M. Bayliss Princ. Gen. Physiol. xii. 380 If electrode B is on a spot [of the nerve] which has been killed, the wave of negativity..disappears in the killed area, so that the only electrical effect seen is that due to the becoming negative of spot A and consists, therefore, of only the first half..of the diphasic response; it is..‘monophasic’. 1932Jrnl. Cellular & Compar. Physiol. I. 177 Local asphyxia at one of the leading-off electrodes renders a nerve potential record monophasic even more effectively than crushing does. 1950Jrnl. Gen. Physiol. XXXIII. 654 The problem of obtaining a monophasic lead, by which is meant one in which no membrane changes at the distal electrode are recorded, is one of great importance in view of the complexity of the potentials to be analyzed. Crushing or heating was so unsatisfactory that keeping the distal lead on intact nerve was a preferable arrangement. 1967L. A. Geddes in C. C. Brown Methods in Psychophysiol. xv. 441 As a result of the intermittent activity of a variety of cells and organs, short duration, asymmetrical (with respect to the time axis) or completely monophasic pulses are presented to the reproducing apparatus.
Hence monoˈphasically adv., by a technique yielding a monophasic record; monophaˈsicity, the property of being monophasic.
1928Amer. Jrnl. Physiol. LXXXVI. 187 The size of response was measured by the action current led off monophasically..from the peroneal nerve. 1932Jrnl. Cellular & Compar. Physiol. I. 178 Gerard argues that monophasicity results because the asphyxiated region of the nerve is completely depolarized, while a killed region, if supplied with oxygen, may partially repolarize to give a diphasic record. 1941S. H. Bartley Vision xii. 286 The monophasically recorded optic-nerve pattern produced by a flash of light on the retina, is a complex series of oscillations. 1950Jrnl. Gen. Physiol. XXXIII. 654 By the time at which the equilibrium period was completed the fibers were fully blocked. Monophasicity continued without further difficulty to the end of the experiment. 1972Science 2 June 1044/1 The excitability of primary afferent terminals was tested by stimulating the fibers through a low-resistance, glass microelectrode.., and the conducted antidromic volley was recorded monophasically. |