Somerville (MA) hospital's intensive care unit will be closed, surgery will be performed only between 7:30 a.m. and 4:30 p.m., and the Somerville Transitional Care Unit will be closed, according to a report. The hospital's curtailing of services comes as the healthcare system it belongs to faces financial problems. Somerville Hospital is part of publicly funded Cambridge Health Alliance, a group facing a potential loss of $25 million to $35 million for the year.