Chemists are scientists who study matter to discover the elements of complex substances and develop new chemical compounds. They specialize in various sub-disciplines such as neurochemistry, biochemistry, theoretical chemistry, and nuclear chemistry. Forensic chemists assist law enforcement in criminal investigations, while biochemists focus on chemical reactions within living organisms to produce DNA therapies and pharmaceutical drugs. Neurochemists study molecules and other aspects of the biological nervous system, while nuclear chemists analyze the effects of radiation on living things to create treatments. Theoretical chemists explore lesser known chemical processes and reactions, including molecular dynamics, quantum chemistry, quantum mechanics, and statistical thermodynamics.