Perhaps you should try some spelling variations:
"5 ng decrease" » "5 _ decrease" (Expand Search), "5 g decrease" (Expand Search), "5 μg decrease" (Expand Search)
"5 nm decrease" » "5 _ decrease" (Expand Search), "6 nm decrease" (Expand Search)
"50 n decrease" » "50 _ decrease" (Expand Search), "50 _ decreased" (Expand Search), "50 _ decreases" (Expand Search), "50 i decrease" (Expand Search)
"50 a decrease" » "50 _ decrease" (Expand Search), "50 _ decreased" (Expand Search), "50 _ decreases" (Expand Search), "5 a decrease" (Expand Search), "50 i decrease" (Expand Search)

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("50 n decrease") OR ((((("5 ng decrease") OR ("5 nm decrease"))) OR ("50 a decrease"))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"50 n decrease\") OR (((((\"5 ng decrease\") OR (\"5 nm decrease\"))) OR (\"50 a decrease\"))))*".
• Removing quotes may allow a broader search: (( 50 n decrease ) OR ((((( 5 ng decrease ) OR ( 5 nm decrease ))) OR ( 50 a decrease ))))*.