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