Perhaps you should try some spelling variations:
during depressed » during depressive (Expand search), during repressive (Expand search), feeling depressed (Expand search)
decrease during » increase during (Expand search), increases during (Expand search), increased during (Expand search)
depressed hiv » depressao hiv (Expand search), depressed i (Expand search), suppressed hiv (Expand search)
hiv decrease » via decrease (Expand search), hiv increase (Expand search), will 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)
decrease pcr » decrease or (Expand search), decrease pro (Expand search), decrease fear (Expand search)
pcr protocol » and protocol (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 during depressed hiv decrease ) OR ( decrease NOT decrease pcr protocol ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease during depressed hiv decrease ) OR ( decrease not decrease pcr protocol ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease during depressed hiv decrease ) OR ( decrease not decrease pcr protocol ))*.