The atmosphere is comprised of gases which are considered to be permanent (gases which remain essentially constant by percent) and gases considered to be variable (gases which have changing concentrations over a finite period of time).he atmosphere is comprised of gases which are considered to be permanent (gases which remain essentially constant by percent) and gases considered to be variable (gases which have changing concentrations over a finite period of time).
, also known as heavy hydrogen) is one of two stable isotopes of hydrogen. The nucleus of deuterium, called a deuteron, contains one proton and one neutron, whereas the far more common hydrogen isotope, protium, has no neutron in the nucleus. Deuterium has a natural abundance in Earth's oceans of about one atom in 7003642000000000000â 6420 of hydrogen.
Using this method, de novo lipogenesis in the liver could be observed in individuals on high-carbohydrate diets â even without net fat synthesis. Deuterium is also used to quantitate the relative proportions of dietary and newly synthesized triglyceride fatty acids. Measuring de novo lipogenesis by deuterium incorporation is considered to be a safe, precise and highly sensitive method which can be used with short measurement periods (i.e. less than 24 hours).