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 pH of a solution is a measure of the molar concentration of hydrogen ions in the solution and as such is a measure of the acidity or basicity of the solution.The letters pH stand for power of hydrogen and the numerical value is defined as the negative base 10 logarithm of the molar concentration of hydrogen ions.n pure water, the molar concentration of H + ions is 10 -7 M and the concentration of OH-ions is also 10 -7 M. Actually, when looked at in detail, it is more accurate to classify the concentrations as those of [H 3 O] + and [OH] - .