3041676 MHBS malignant hilar biliary strictures 4 3041675 MHBS Maternal history of bariatric surgery 1 3041667 MHBS methane gas from hydrate-bearing sands 1 3041674 MHBS Mexican-hat band structure 1 3041677 MHBS Migrant Health Behavior Survey 1 3041668 MHBS modified Hank's balanced salts solution 1