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 w_ decrease" » "5 _ decrease" (Expand Search), "5 _ decreased" (Expand Search), "5 _ decreases" (Expand Search)
"5 wt decrease" » "5 _ decrease" (Expand Search), "_ wt decrease" (Expand Search), "5 ht decrease" (Expand Search), "2 wt decrease" (Expand Search)
"_ e decrease" » "_ _ decrease" (Expand Search), "_ _ decreased" (Expand Search), "_ _ 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 w_ decrease\") OR (\"5 wt decrease\"))) OR (\"_ e decrease\"))))~".
• Removing quotes may allow a broader search: (( 50 ng decrease ) OR ((((( 5 w_ decrease ) OR ( 5 wt decrease ))) OR ( _ e decrease ))))~.
• Adding a wildcard symbol may retrieve word variants: (("50 ng decrease") OR ((((("5 w_ decrease") OR ("5 wt decrease"))) OR ("_ e decrease"))))*.