Perhaps you should try some spelling variations:
significantly improve » significantly improved (Expand Search)
significantly linked » significantly longer (Expand Search), significantly altered (Expand Search), significantly higher (Expand Search)
improve decrease » improve disease (Expand Search), improved urease (Expand Search), improves disease (Expand Search)
linked decrease » marked decrease (Expand Search), linear decrease (Expand Search)

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

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