Disorder-induced trapping and anti-trapping of vortices in type-II superconductors

We study the features of the superconductivity nucleation and vortex configurations in superconductors with modulated disorder. Using the Ginzburg-Landau-type theory with spatially varying diffusion coefficient, we uncover and explain the switching between the vortex-defect attraction to the repulsion upon the increase in the external magnetic field. It is shown that for rather weak applied magnetic fields, a superconducting nucleus localized near the region with the suppressed diffusion coefficient possesses a nonzero vorticity whereas the increase in the magnetic field can lead to a transition into the state with zero winding number. We demonstrate the manifestations of this switching phenomenon in superconductors with a large number of defects by performing numerical simulations of the vortex structures in superconductors with periodic spatial profiles of the diffusion coefficient. The obtained results clarify the physics of the vortex arrangement in several classes of the superconducting materials including one-dimensional superlattices and nanopatterned superconductors with regular arrays of the defects characterized by the increased concentration of nonmagnetic impurities.Comment: 13 pages, 9 figure

Efficacy and Safety of Intravenous Ferric Carboxymaltose Treatment of Iron Deficiency Anaemia in Patients with Corpus Atrophic Gastritis: A Retrospective Study

Corpus Atrophic Gastritis (CAG) is characterised by iron malabsorption leading to iron deficiency anaemia (IDA), which rarely responds to oral therapy. Ferric carboxymaltose (FCM), shown to be a safe and effective intravenous iron therapy in other diseases, has not been investigated yet in CAG. Thus, we aimed to assess the safety and efficacy of FCM in CAG-related IDA. A retrospective study on 91 patients identified CAG as the only cause of IDA treated with FCM. Twenty-three were excluded for incomplete follow-up. Sixty-eight were evaluated for safety and efficacy, while three were evaluated for safety only due to infusion interruption for side effects. Haemoglobin and iron storage were evaluated pre-infusion (T0), at 4 weeks (T4) and 12 weeks (T12) after infusion. An eventual IDA relapse was analysed. Two cases reported mild side effects. Haemoglobin significantly increased at T4, and T12, reaching +3.1 g/dL. Ferritin increased at T4, decreasing at T12, while transferrin saturation increased progressively until reaching a plateau. IDA relapsed in 55.4% of patients at a mean of 24.6 months. The only factor associated with relapse was female gender [OR (95% CI): 6.6 (1.5-28.6)]. FCM proved to be safe and effective in treating CAG-related IDA, ensuring quick and long-lasting recovery