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