Perhaps you should try some spelling variations:
significantly improved » significantly increased (Expand Search)
significantly impaired » significantly impairs (Expand Search), significantly improve (Expand Search), significantly impact (Expand Search)
improved decrease » improved urease (Expand Search), marked decrease (Expand Search)
impaired decrease » marked decrease (Expand Search)

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

• Removing quotes may allow a broader search: (( significantly improved decrease ) OR ( significantly impaired decrease ))*.