Perhaps you should try some spelling variations:
"5 ng decrease" » "5 _ decrease" (Expand Search), "5 g decrease" (Expand Search), "5 μg decrease" (Expand Search)
"_ fe decrease" » "_ _ decrease" (Expand Search), "_ f_ decrease" (Expand Search), "_ f_ decreased" (Expand Search), "_ f_ decreases" (Expand Search)
"5 a decrease" » "5 _ decrease" (Expand Search), "5 _ decreased" (Expand Search), "5 _ decreases" (Expand Search)
"_ e decrease" » "_ _ decrease" (Expand Search), "_ _ decreased" (Expand Search), "_ _ decreases" (Expand Search)

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("5 a decrease") OR ("5 ng decrease"))) OR ((("_ e decrease") OR ("_ fe decrease"))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"5 a decrease\") OR (\"5 ng decrease\"))) OR (((\"_ e decrease\") OR (\"_ fe decrease\"))))".
• Removing quotes may allow a broader search: (((( 5 a decrease ) OR ( 5 ng decrease ))) OR ((( _ e decrease ) OR ( _ fe decrease )))).
• Adding a wildcard symbol may retrieve word variants: (((("5 a decrease") OR ("5 ng decrease"))) OR ((("_ e decrease") OR ("_ fe decrease"))))*.