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