An autoantibody is an antibody (a type of protein) produced by the immune system that is directed against one or more of the individual's own proteins. Many autoimmune diseases (notably lupus erythematosus) are caused by such autoantibodies.
Perfluorooctanoic acid (PFOA), also known as C8 and perfluorooctanoate, is a synthetic perfluorinated carboxylic acid and fluorosurfactant.FOA has widespread applications. In 1976, PFOA was reported as a water and oil repellent in fabrics and leather and in the production of floor waxes and waxed papers ; however, it is believed that paper is no longer treated with perfluorinated compounds, but with fluorotelomers with less than 0.1% PFOA.
Hydrocarbon Double Bond. The way to tell is to count the number of carbons and the number of hydrogens attached to each. Remember that carbon is tetravalent. If it has a separate bond with each other element, there would be no double bonds. So, C3H8 would NOT have a double bond. Imagine 3 carbons in a row. The C on the left hand side has one bond to the next carbon, and three others - in this case, bonds to hydrogen. The middle carbon has a bond to the C on its left and a bond to the C on its right. So, it could bond to 2 hydrogens. The C on the left hand side has one bond to the C in the middle, and three bonds to hydrogen.