Magnetic textures and singularities in ferri ferromagnetic multilayers

The stacking of ferrimagnetic and ferromagnetic films leads to a competition between magnetic interactions that can stabilize Bloch points and other singularities at the interfaces. In this work, GdxCo1 x NdCo5 GdyCo1 y tri layers, with different thicknesses, have been prepared. By tuning the stoichiometry of the Gd Co outer layers, the Co magnetic sublattice dominates in one layer, whereas the opposite side is Gd dominated. In this way, in depth magnetization domain walls can be created due to the balance between exchange and magnetostatic interactions. In addition, the weak perpendicular magnetic anisotropy of the Nd Co central layer induces a stripe domain pattern, supporting the formation of Bloch points, meron like textures, and vortex antivortex pairs. The interaction between both types of structures, in depth domain walls and magnetic singularities, has been studied by a combination of macroscopic Magneto Optical Kerr Effect and Vibrating Sample Magnetometry measurements with microscopic Magnetic Force Microscopy and element selective magnetic Transmission soft X ray Microscopy imaging. The results confirm marked changes in the magnetic properties of the trilayers, as compared with those single NdCo5 films, and the formation of complex magnetic textures, associated with partial magnetization reversal, where magnetic singularities are forme

Transportin-SR2 mediates nuclear import of phosphorylated SR proteins

Serine/arginine-rich proteins (SR proteins) are a family of nuclear factors that play important roles in both constitutive and regulated precursor mRNA splicing. The domain rich in arginine/serine (RS) repeats (RS domain) serves as both a nuclear and subnuclear localization signal. We previously identified an importin β family protein, transportin-SR2 (TRN-SR2), that specifically interacts with phosphorylated RS domains. A TRN-SR2 mutant deficient in Ran binding colocalizes with SR proteins in nuclear speckles, suggesting a role of TRN-SR2 in nuclear targeting of SR proteins. Using in vitro import assays, we here show that nuclear import of SR protein fusions requires cytosolic factors, and that the RS domain becomes phosphorylated in the import reaction. Reconstitution of SR protein import by using recombinant transport factors clearly demonstrates that TRN-SR2 is capable of targeting phosphorylated, but not unphosphorylated, SR proteins to the nucleus. Therefore, RS domain phosphorylation is critical for TRN-SR2-mediated nuclear import. Interestingly, we found that the RNA-binding activity of SR proteins confers temperature sensitivity to their nuclear import. Finally, we show that TRN-SR2 interacts with a nucleoporin and is targeted not only to the nuclear envelope but also to nuclear speckles in vitro. Thus, TRN-SR2 may perhaps escort SR protein cargoes to nuclear subdomains

Bendamustine as part of conditioning of autologous stem cell transplantation in patients with aggressive lymphoma: a phase 2 study from the GELTAMO group

We conducted a phase 2 trial to evaluate the safety and efficacy of bendamustine instead of BCNU (carmustine) in the BEAM (BCNU, etoposide, cytarabine and melphalan) regimen (BendaEAM) as conditioning for autologous stem-cell transplantation (ASCT) in patients with aggressive lymphomas. The primary endpoint was 3-year progression-free survival (PFS). Sixty patients (median age 55 [28-71] years) were included. All patients (except one who died early) engrafted after a median of 11 (9-72) and 14 (4-53) days to achieve neutrophil and platelet counts of >0.5 x 10(9) /l and >20 x 10(9) /l, respectively. Non-relapse mortality at 100 days and 1 year were 3.3% and 6.7%, respectively. With a median follow-up of 67 (40-77) months, the estimated 3-year PFS and overall survival (OS) were 58% and 75%, respectively. Patients in partial response at study entry had significantly worse PFS and OS than patients who underwent ASCT in complete metabolic remission, and this was the only prognostic factor associated with both PFS (Relative risk [RR], 0.27 [95% confidence interval {CI} [0.12-0.56]) and OS (RR, 0.40 [95% CI 0.17-0.97]) in the multivariate analysis. BendaEAM conditioning is therefore a feasible and effective regimen in patients with aggressive lymphomas. However, patients not in complete metabolic remission at the time of transplant had poorer survival and so should be considered for alternative treatment strategies