Perhaps you should try some spelling variations:
"40 na decrease" » "40 nn decrease" (Expand Search), "40 pa decreased" (Expand Search), "40 la decreased" (Expand Search), "40 n_ decrease" (Expand Search), "40 n_ decreased" (Expand Search), "40 n_ decreases" (Expand Search), "40 nm decrease" (Expand Search), "40 pa decrease" (Expand Search), "40 ns decrease" (Expand Search)
"50 ng decrease" » "50 nn decrease" (Expand Search), "50 _ decrease" (Expand Search), "50 we decrease" (Expand Search), "50 mg decrease" (Expand Search), "10 ng decrease" (Expand Search), "5 ng decrease" (Expand Search)
"50 a decrease" » "50 _ decrease" (Expand Search), "50 _ decreased" (Expand Search), "50 _ decreases" (Expand Search), "50 μ decrease" (Expand Search), "50 c 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: "((\"50 a decrease\") OR (((\"40 na decrease\") OR (\"50 ng decrease\"))))~".
• Removing quotes may allow a broader search: (( 50 a decrease ) OR ((( 40 na decrease ) OR ( 50 ng decrease ))))~.
• Adding a wildcard symbol may retrieve word variants: (("50 a decrease") OR ((("40 na decrease") OR ("50 ng decrease"))))*.