For this telescope, the lenses are a concave convex (one side curved out and the other curved in) and a plano concave (one flat side and one side curved in). The plano concave lens is used as the eyepiece with the plano (flat) side facing the eye.
BUN redirects here. For other uses, see Bun (disambiguation). The liver produces urea in the urea cycle as a waste product of the digestion of protein. Normal human adult blood should contain between 6 and 20 mg of urea nitrogen per 100 ml (6â20 mg/dL) of blood.
To convert BUN (Urea) from mmol/L to mg/dL, divide by 0.357 (or multiply by 2.8). To convert Creatinine from Âµmol/L to mg/dL, divide by 88.4. See Unit Conversion for more info and a calculator that will do the conversion for you.. Creatinine is the most specific test for kidney disease. When creatinine is elevated above the normal range (usually about 1.6 mg/dL, or 141 Âµmol/L), this generally means that there is a problem with the kidneys.