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Abstract: Background: Animal models of partial hepatic ischemia-reperfusion injury (IRI) have potential benefits for decision making and clinical management after liver transplantation or massive hepatic resection. We evaluated changes in apparent diffusion coefficient (ADC) in rabbits with partial hepatic IRI using 3.0 T magnetic resonance diffusion-weighted imaging (DWI). Methods: Rabbits underwent 60 minutes of left lobar ischemia followed by 0.5, 2, 6, 12, 24, or 48 hours of reperfusion (n = 6 each). DWI spin echo-echo planar imaging (SE-EPI) was performed with b values of 50, 100, 200, 300, 500, and 600 s/mm2. Results: There was a significant difference between the ADCs at 0.5 hour and sham groups when b values were <300 s/mm2 and between the six hour and sham groups with b = 50 and 100 s/mm2. The ADC values were lower in the 24-hour group with b values of 50, 100, 200, and 300 s/mm2 (all P < .01) but significantly increased in the 48-hour group when b = 500 and 600 s/mm2 compared with the sham group (all P < .01). ADC did not change significantly in the 2-hour and 12-hour groups compared with the control group. Conclusions: In this study 3.0 T DWI dynamically monitored the pathological processes of liver IRI, revealing the microvascular disorder with a perfusion-sensitive ADC at the lower b values (<300 s/mm2), particularly in the early stages. [Copyright &y& Elsevier]

The role of δ-Fe in hydrogen embrittlement (HE) of 17-4 PH steel is studied in this work. Scanning Kelvin probe force microscopy result indicates that δ-Fe is a hydrogen trapping site. Accordingly, δ-Fe can reduce the hydrogen concentration of surrounding martensite and prior austenite grain boundaries (PAGBs) and imped the brittle fracture along lath boundaries and PAGBs, which can be beneficial to the HE resistance improvement. However, a cleavage fracture of δ-Fe can occur under the synergetic action of hydrogen-enhanced localized plasticity (HELP) and hydrogen enhancement of the strain-induced generation of vacancies (HESIV). These findings indicate a new path to improving HE resistance of high strength martensitic steels. • SKPFM result shows that hydrogen tends to segregate in delta ferrite. • Delta ferrite acting as a hydrogen trapping site decreases the tendency of brittle fracture. • Hydrogen segregation in delta ferrite leads to a strain localization and a subsequent transgranular cleavage fracture. [ABSTRACT FROM AUTHOR]