Perhaps you should try some spelling variations:
decrease shadowing » decrease owing (Expand search), decrease following (Expand search), decreases shedding (Expand search)
shadowing effect » shadowing effects (Expand search), shading effect (Expand search), shading effects (Expand search)
decrease during » increase during (Expand search), increases during (Expand search), increased during (Expand search)
during decrease » during increased (Expand search), during depressed (Expand search), during disease (Expand search)
decrease risk » decreased risk (Expand search), increase risk (Expand search), decrease in (Expand search)
risk decrease » risk decreases (Expand search), risk increase (Expand search), break decrease (Expand search)
decrease not » decrease of (Expand search), decrease akt (Expand search), decrease at (Expand search)
not decrease » to decrease (Expand search), not increase (Expand search), and decrease (Expand search)

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( decrease NOT decrease during decrease ) OR ( decrease risk decrease shadowing effect ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease not decrease during decrease ) OR ( decrease risk decrease shadowing effect ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease not decrease during decrease ) OR ( decrease risk decrease shadowing effect ))*.