Perhaps you should try some spelling variations:
significantly improves » significantly improved (Expand Search), significantly improve (Expand Search), significant improvements (Expand Search)
significantly weaker » significantly greater (Expand Search), significantly better (Expand Search), significantly related (Expand Search)
improves decrease » improves disease (Expand Search), improve disease (Expand Search), improved urease (Expand Search)
weaker decrease » greater decrease (Expand Search), teer decrease (Expand Search), water decreases (Expand Search)

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

• Removing quotes may allow a broader search: (( significantly weaker decrease ) OR ( significantly improves decrease ))~.