(Reuters) - Inventors based in the United States led the world in nanotechnology patent applications and grants in 2012, according to a new study by law firm McDermott Will & Emery. Nanotechnology involves manipulating matter that's measured at the tiny "nanometer" length level. The diameter of a human hair is between 40,000 and 60,000 nanometers, said Valerie Moore, a patent agent and one of the authors of the study. Nanotechnology patents come into play in everything from aerospace to medicine to energy, the study noted. ...