critical oxygen requirement

(redirected from critical oxygen tension)

oxygen requirement, critical (COR) 

The minimum oxygen pressure at the epithelial surface required to prevent corneal swelling during the day. This value was initially assumed to be between 11 and 19 mmHg but it is nowadays considered to be at least 74 mmHg near the centre of the cornea (or 10% EOP or a Dk/L of about 25 ✕ 10−9 (cm2 ml O2)/(s ml mmHg) at 25ºC for daily wear. This figure increases to at least 90 ✕ 10−9 for overnight wear. Syn. critical oxygen tension. See hypoxia.
References in periodicals archive ?
Below the critical oxygen tension ([P.sub.crit]), [??][O.sub.2] drops rapidly, and animals increasingly rely on the less energy efficient anaerobic metabolism (Wieser 1986, Portner & Grieshaber 1993).
Critical oxygen tension of family P1 offspring was calculated by means of the smallest sum of the residual sum of squares of two linear regressions fitted to individual [??][O.sub.2] data using R (Yeager & Ultsch 1989).
Critical oxygen tensions, taken as the point at which animals could no longer maintain [??][O.sub.2], ranged from 22.7% [+ or -] 2.7% [O.sub.2]sat in fertilized eggs to 14.0% [+ or -] 1.0% [O.sub.2]sat in mid-veliger larvae.

Full browser ?