March 24, 2006 -- A torn ACL in the knee can be replaced -- but it can't be healed.A new technique now shows promise to change this. Doctors long ago gave up trying to repair a torn ACL (anterior cruciate ligament).arch 24, 2006 -- A torn ACL in the knee can be replaced -- but it can't be healed.
In chemistry, pH (/piËËeÉªtÊ/) is a numeric scale used to specify the acidity or basicity of an aqueous solution. It is approximately the negative of the logarithm to base 10 of the molar concentration, measured in units of moles per liter, of hydrogen ions.
The concentration of a substance is the amount (mass or volume) of a substance divided by the total volume of the mixture. It is commonly applied to solutions. In chemistry, it is measured as the number of moles per liter.