how many hours have it been since the last time patient 7112 began to stay in ward 52 on this hospital visit?
select 24 * ( strftime('%j',current_time) - strftime('%j',transfers.intime) ) from transfers where transfers.icustay_id in ( select icustays.icustay_id from icustays where icustays.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 7112 and admissions.dischtime is null ) ) and transfers.wardid = 52 order by transfers.intime desc limit 1