Perhaps you should try some spelling variations:
"50 pp decrease" » "50 _ decrease" (Expand Search)
"50 ng decrease" » "50 _ decrease" (Expand Search), "10 ng decrease" (Expand Search), "50 μg decrease" (Expand Search)
"50 cs decrease" » "50 _ decrease" (Expand Search)
"50 a decrease" » "50 _ decrease" (Expand Search), "50 _ decreased" (Expand Search), "50 _ decreases" (Expand Search), "5 a decrease" (Expand Search), "50 i decrease" (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: (("50 pp decrease") OR ((("50 ng decrease") OR ((("50 a decrease") OR ("50 cs decrease"))))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"50 pp decrease\") OR (((\"50 ng decrease\") OR (((\"50 a decrease\") OR (\"50 cs decrease\"))))))*".
• Removing quotes may allow a broader search: (( 50 pp decrease ) OR ((( 50 ng decrease ) OR ((( 50 a decrease ) OR ( 50 cs decrease ))))))*.