Extremely large perpendicular magnetic anisotropy of an Fe(001) surface capped by 5d transition metal monolayers: A density functional study

Significant enhancement of the magnetocrystalline anisotropy (MCA) of an Fe(001) surface capped by 4d and 5d transition metal monolayers is presented in this study using first principles density functional calculations. In particular, an extremely large perpendicular MCA of +10 meV/Ir was found in Ir-capped Fe(001), which originates not from the Fe but from the large spin-orbit coupling of the Ir atoms. From the spin-channel decomposition of the MCA matrix and electronic structure analyses, we find that strong 3d-5d band hybridization in the minority spin state is responsible for the sign changes of the MCA from parallel to perpendicular.open0

Identification of a gastritogenic epitope of the H/K ATPase β-subunit

We have previously shown that autoimmune gastritis can be elicited in mice by immunization with the gastric parietal cell H/K ATPase αβ heterodimer and that tolerance specifically induced to the H/K ATPase β-subunit protects mice from the development of gastritis. Here we have identified the immunodominant gastritogenic epitope of the H/K ATPase β-subunit (H/Kβ). Epitope mapping was carried out with a panel of 21 overlapping peptides that spanned the entire sequence of the gastric H/K ATPase β-subunit. T cells from gastric H/K ATPase-immunized mice responded to only one of the overlapping peptides, namely H/Kβ253–277. Furthermore, a single subcutaneous immunization of 6-week-old BALB/c mice with the ATPase β-subunit peptides resulted in a T-cell response to only H/Kβ253–277. Multiple immunization with the overlapping H/K ATPase peptides demonstrated that H/Kβ253–277 was capable of inducing a mononuclear infiltrate specifically within the gastric mucosa. We conclude that H/Kβ253–277 is the dominant gastritogenic epitope of the gastric H/K ATPase