Perhaps you should try some spelling variations:
"50 nn decrease" » "50 _ decrease" (Expand Search)
"10 ng decrease" » "10 _ decrease" (Expand Search), "100 ng decrease" (Expand Search), "10 μg decrease" (Expand Search)
"5 wt decrease" » "5 _ decrease" (Expand Search), "_ wt decrease" (Expand Search), "5 ht decrease" (Expand Search), "2 wt decrease" (Expand Search)
"_ a 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: (((("50 nn decrease") OR ("10 ng decrease"))) OR ((("5 wt decrease") OR ("_ a decrease"))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"50 nn decrease\") OR (\"10 ng decrease\"))) OR (((\"5 wt decrease\") OR (\"_ a decrease\"))))".
• Removing quotes may allow a broader search: (((( 50 nn decrease ) OR ( 10 ng decrease ))) OR ((( 5 wt decrease ) OR ( _ a decrease )))).
• Adding a wildcard symbol may retrieve word variants: (((("50 nn decrease") OR ("10 ng decrease"))) OR ((("5 wt decrease") OR ("_ a decrease"))))*.