NFKB1 and pancreatitis: Observation: 1, 3, 6 h; Pancreatitis severity: pancreas wet/dry ratio, HE score (Rongione); Inflammation/oxidative stress: serum TNF‐α, IL‐6, IL‐10, HO‐1; MPO, MDA, SOD; NF‐κB, IkB expression