Perhaps you should try some spelling variations:
"50 ng decrease" » "50 a decrease" (Expand Search), "50 we decrease" (Expand Search), "50 gy decreased" (Expand Search), "50 mg decrease" (Expand Search), "10 ng decrease" (Expand Search), "50 ns decrease" (Expand Search)
"5 ng decrease" » "5 a decrease" (Expand Search), "5 we decrease" (Expand Search), "5 gy decreased" (Expand Search), "5 mg decrease" (Expand Search), "5 g decrease" (Expand Search), "5 nm decrease" (Expand Search)
"50 nn decrease" » "50 a decrease" (Expand Search), "50 mean decrease" (Expand Search), "50 gy decreased" (Expand Search), "50 ns decrease" (Expand Search), "50 n decrease" (Expand Search), "59 nn decrease" (Expand Search)

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"50 _ decrease\") OR (((\"50 ng decrease\") OR (\"5 ng decrease\"))))) OR (\"50 nn decrease\"))~".
• Removing quotes may allow a broader search: (((( 50 _ decrease ) OR ((( 50 ng decrease ) OR ( 5 ng decrease ))))) OR ( 50 nn decrease ))~.
• Adding a wildcard symbol may retrieve word variants: (((("50 _ decrease") OR ((("50 ng decrease") OR ("5 ng decrease"))))) OR ("50 nn decrease"))*.