The phrasal verb “look up” consists of the verb “look” and the adverbial 'particle' “up.”
There is 'not a particle of' evidence to support their claim.
There is 'not a particle of' truth in what he said.
(..) degrees Celsius... the approximate temperature of the young lady in the front row. Mr. Wolowitz, this is your second warning. A sigma particle. Yes, assuming the hypothetical planet has a mass greater than the Earth. Correct! Ladies and gentlemen, I hold in my hand the final question. (..)2008 TvShow: The Big Bang Theory Title: The Bat Jar Conjecture Season: 1 Episode 13