Perhaps you should try some spelling variations:
"50 ng decrease" » "50 _ decrease" (Expand Search), "10 ng decrease" (Expand Search), "50 μg decrease" (Expand Search)
"5 we decrease" » "5 _ decrease" (Expand Search), "5 w_ decrease" (Expand Search), "5 w_ decreased" (Expand Search), "5 w_ decreases" (Expand Search), "_ we decrease" (Expand Search)
"_ fe decrease" » "_ _ decrease" (Expand Search), "_ f_ decrease" (Expand Search), "_ f_ decreased" (Expand Search), "_ f_ decreases" (Expand Search), "_ e decrease" (Expand Search)
"5 e decrease" » "5 _ decrease" (Expand Search), "5 _ decreased" (Expand Search), "5 _ decreases" (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 ng decrease\") OR (((((\"5 we decrease\") OR (\"5 e decrease\"))) OR (\"_ fe decrease\"))))~".
• Removing quotes may allow a broader search: (( 50 ng decrease ) OR ((((( 5 we decrease ) OR ( 5 e decrease ))) OR ( _ fe decrease ))))~.
• Adding a wildcard symbol may retrieve word variants: (("50 ng decrease") OR ((((("5 we decrease") OR ("5 e decrease"))) OR ("_ fe decrease"))))*.