Thioglycolic acid corresponding disulfide (2-[(carboxymethyl)disulfanyl]acetic acid or dithiodiglycolic acid): Thioglycolic acid, usually as its dianion, forms complexes with metal ions. Such complexes have been used for the detection of iron, molybdenum, silver, and tin. Thioglycolic acid reacts with diethyl acetylmalonate to form acetylmercaptoacetic acid and diethyl malonate, the reducing agent in conversion of Fe(III) to Fe(II). Scientist David R. Goddard, in the early 1930s, identified TGA as a useful reagent for reducing the disulfide bonds in proteins, including keratin (hair protein), while studying why protease enzymes could not easily digest hair, nails, feathers, and such. He realized that while the disulfide bonds,
Artificial nails and his brother, Tom, patented a successful version and started the company Patti Nails. Fred Slack used his dental equipment and chemicals to replace his natural nail, but over time the process has significantly changed. In the late 20th century, artificial nails for women became widely popular all over the world. In today's time there are even nail styling competitions. Judges of these nail competitions look for consistency from nail to nail. They also judge whether or not the nails complement the model's hands. If the nails are beautiful, but too long for the model's hands, the judge will count