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.
If kidney function begins to decline, BUN and creatinine rise. A normal creatinine depends on muscle mass and age. In general, a normal creatine is 0.5 to 1.2 milligrams per deciliter (mg/dL). A normal BUN is 7 to 20 mg/dL.
Creatinine and BUN levels are important indexes to measure how well kidneys are functioning.If creatinine and BUN levels keep higher than normal for a long time, it may prove that your kidneys are not working well.n general,the normal BUN level ranges from 7 to 20mg/dL(2.5 to 7.1mmol/L).However, the normal BUN levels may vary with the lab, and your age. Urea nitrogen levels tend to increase with age. Infants have lower levels than other people do, and the range in children varies.