Perhaps you should try some spelling variations:
patients risk » patient risk, patients links, patients si
lose patients » les patients, obese patients, care patients
wang wang » wang yang, wang liang, wang yong
yang yang » wang yang
among who » along who, among hr, wrong who
yang fan » zhang fan, yang dean, yang jin

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: ((wang wang) OR (wang yan)) ((yang fan) OR (yang yang)) lose patients risk among who ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((wang wang) or (wang yan)) ((yang fan) OR (yang yang)) lose patients risk among who ;~".
• Adding a wildcard symbol may retrieve word variants: ((wang wang) or (wang yan)) ((yang fan) OR (yang yang)) lose patients risk among who ;*.