Perhaps you should try some spelling variations:
"significantly impaired decrease" » "significantly impairs decrease" (Expand Search), "significantly improved decrease" (Expand Search), "significantly improve decrease" (Expand Search), "significantly marked decrease" (Expand Search)
"significantly mediate decrease" » "significantly mediated decrease" (Expand Search), "significantly predicted decrease" (Expand Search), "significantly mitigated decrease" (Expand Search), "significantly mean decrease" (Expand Search), "significantly mediated defense" (Expand Search)

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

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