Perhaps you should try some spelling variations:
"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 _g decrease" » "50 _ decrease" (Expand Search), "50 _ decreased" (Expand Search), "50 _ decreases" (Expand Search), "50 mg decrease" (Expand Search), "50 ng decrease" (Expand Search)
"50 n decrease" » "50 nn decrease" (Expand Search), "50 _ decrease" (Expand Search), "50 a decrease" (Expand Search), "50 ns decrease" (Expand Search), "50 ng decrease" (Expand Search), "50 μ decrease" (Expand Search)

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"5 ng decrease\") OR (\"50 _g decrease\"))) OR (\"50 n decrease\"))~".
• Removing quotes may allow a broader search: (((( 5 ng decrease ) OR ( 50 _g decrease ))) OR ( 50 n decrease ))~.
• Adding a wildcard symbol may retrieve word variants: (((("5 ng decrease") OR ("50 _g decrease"))) OR ("50 n decrease"))*.