1) Programmable network access 
A substance that contains the same bases as those found in biological nucleic acids but whose backbone is held together by amide bonds. PNAs are currently of interest in discussions about the chemical precursors of DNA and RNA.1, 2 PNAs form double-stranded complexes that clos...
Pennsylvania Nurses Association
Any of numerous complex hydrocarbon compounds consisting of three or more benzene rings in a compact molecular arrangement. Some types of PNA`s are formed in fossil fuel combustion and other heat processes, such as catalytic cracking.
Programmable Network Access
Performance Needs Analysis