Perhaps you should try some spelling variations:
"50 ng decrease" » "50 nn decrease" (Expand Search), "50 _ decrease" (Expand Search), "50 a decrease" (Expand Search), "50 mg decrease" (Expand Search), "10 ng decrease" (Expand Search), "50 ns decrease" (Expand Search)
"5 ng decrease" » "5 nn decrease" (Expand Search), "5 _ decrease" (Expand Search), "5 a decrease" (Expand Search), "5 mg decrease" (Expand Search), "5 g decrease" (Expand Search), "5 nm decrease" (Expand Search)
"50 μ decrease" » "50 _ decrease" (Expand Search), "50 a decrease" (Expand Search), "50 _ decreased" (Expand Search), "10 μ decrease" (Expand Search), "5 μ 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 ng decrease") OR ("5 ng decrease"))) OR ("50 μ decrease"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"50 ng decrease\") OR (\"5 ng decrease\"))) OR (\"50 μ decrease\"))*".
• Removing quotes may allow a broader search: (((( 50 ng decrease ) OR ( 5 ng decrease ))) OR ( 50 μ decrease ))*.