Endoscopic ultrasound features of autoimmune pancreatitis: The typical findings and chronic pancreatitis changes

BACKGROUND Few studies have fully described endoscopic ultrasound(EUS)features of newly diagnosed autoimmune pancreatitis(AIP)involving both typical findings and chronic pancreatitis(CP)features.The typical EUS findings are prevalent in the diffuse type AIP but may not be as common for the focal type,and the differences between the diffuse and focal AIP need to be specified.AIM To demonstrate the EUS features of newly diagnosed AIP and the difference between diffuse and focal AIP.METHODS This retrospective single center study included 285 patients of newly diagnosed type 1 AIP following the international consensus diagnostic criteria,with the EUS procedures accomplished before corticosteroid initiation.We explored the EUS features and compared the typical AIP and CP features between the diffuse and focal AIP cases.The Rosemont criteria were employed for CP features definition and CP change level comparison.RESULTS For the typical AIP features,there were significantly more patients in the diffuse group with bile duct wall thickening(158 of 214 cases,73.4%vs 37 of 71 cases,52.1%,P=0.001)and peripancreatic hypoechoic margin(76 of 214 cases,35.5%vs 5 of 71 cases,7.0%,P<0.001).For the CP features,there were significantly more patients in the focal group with main pancreatic duct dilation(30 of 214 cases,14.0%vs 18 of 71 cases,25.3%,P=0.03).The cholangitis-like changes were more prevalent in the focal cases with pancreatic head involvement.The CP change level was relatively limited for newly diagnosed AIP cases in both groups.CONCLUSION This study demonstrated the difference in the typical AIP and CP features between diffuse and focal AIP and indicated the limited CP change level in newly diagnosed AIP.

Temperature-Dependent Compressive Deformation Behavior of Commercially Pure Iron Processed by ECAP

To explore the temperature dependence of deformation behavior of BCC structural materials and the relevant effect of pre-annealing, commercially pure iron （CP Fe） produced by equal-channel angular pressing （ECAP） is selected as the experimental material. The influences of deformation temperature T and pre-annealing on deformation behavior, surface deformation characteristics and substructures of ECAP Fe were systematically studied. The results show that ECAP Fe undergoes a remarkable strain softening stage after a rapid strain hardening during uniaxial compression, and the softening degree and the yield strength avs first decrease and then increase with raising temperature. Pre-annealing at 400 ℃ effectively weakens the strain softening degree and increases trys. To understand the influence of deformation temperature on deformation behavior, as well as the relevant pre-annealing effect, deformation and damage characteristics and dislocation structures are studied in detail. In a word, the strain softening of ECAP Fe is associated not only with internal structural instability, but also with temperature, and pre-annealing at 400 ℃ improves high-temperature me- chanical properties of ECAP Fe.