Enhancement of spin orbit coupling at manganite surfaces

Spin orbit coupling in magnetic systems lacking inversion symmetry can give rise to nontrivial spin textures. Magnetic thin films and heterostructures are potential candidates for the formation of skyrmions and other noncollinear spin configurations as inversion symmetry is inherently lost at their surfaces and interfaces. However, manganites, in spite of their extraordinarily rich magnetic phase diagram, have not yet been considered of interest within this context as their spin orbit coupling is assumed to be negligible. We demonstrate here, by means of angular dependent x ray linear dichroism experiments and theoretical calculations, the existence of a noncollinear antiferromagnetic ordering at the surface of ferromagnetic La2 3Sr1 3MnO3 thin films whose properties can only be explained by an unexpectedly large enhancement of the spin orbit interaction. Our results reveal that spin orbit coupling, usually assumed to be very small in manganites, can be significantly enhanced at surfaces and interfaces adding a new twist to the possible magnetic orders that can arise in electronically reconstructed system

Genome-wide association analysis of dementia and its clinical endophenotypes reveal novel loci associated with Alzheimer's disease and three causality networks: The GR@ACE project

INTRODUCTION: Large variability among Alzheimer's disease (AD) cases might impact genetic discoveries and complicate dissection of underlying biological pathways. METHODS: Genome Research at Fundacio ACE (GR@ACE) is a genome-wide study of dementia and its clinical endophenotypes, defined based on AD's clinical certainty and vascular burden. We assessed the impact of known AD loci across endophenotypes to generate loci categories. We incorporated gene coexpression data and conducted pathway analysis per category. Finally, to evaluate the effect of heterogeneity in genetic studies, GR@ACE series were meta-analyzed with additional genome-wide association study data sets. RESULTS: We classified known AD loci into three categories, which might reflect the disease clinical heterogeneity. Vascular processes were only detected as a causal mechanism in probable AD. The meta-analysis strategy revealed the ANKRD31-rs4704171 and NDUFAF6-rs10098778 and confirmed SCIMP-rs7225151 and CD33-rs3865444. DISCUSSION: The regulation of vasculature is a prominent causal component of probable AD. GR@ACE meta-analysis revealed novel AD genetic signals, strongly driven by the presence of clinical heterogeneity in the AD series

Lopinavir/ritonavir plus nevirapine as a nucleoside-sparing approach in antiretroviral-experienced patients (NEKA study).

Contains fulltext : 48702.pdf (publisher's version ) (Closed access)OBJECTIVES: To compare the efficacy and safety of a nucleoside-sparing approach with a conventional highly active antiretroviral therapy (HAART) regimen in antiretroviral-experienced patients with prolonged viral suppression. METHODS: Pilot study including 31 antiretroviral-experienced patients with HIV RNA <80 copies/mL. Subjects were randomly assigned to lopinavir/ritonavir (LPV/rtv) 400/100 mg BID plus nevirapine (NVP) 200 mg BID (NVP group, n = 16) or LPV/rtv plus the 2 previous NRTIs (NRTI group, n = 15). The primary endpoint was the percentage of subjects who maintained viral suppression at week 48. Changes in lipid metabolism, mitochondrial parameters, and LPV trough levels were also assessed. RESULTS: All patients maintained viral suppression after 48 weeks. No subject discontinued therapy because of adverse events. HDL cholesterol increased by 28% at week 24 (P < 0.0001) and 10% after 48 weeks of follow-up (P = 0.319) in the NVP group. In the NRTI group, LDL cholesterol increased by 14% at week 48 (P = 0.076). Mitochondrial DNA/nuclear DNA ratio and mitochondrial respiratory chain complex IV activity showed a trend toward increasing in the NVP group. Mean (SD) LPV trough levels were 6340 (2129) ng/mL in the NRTI group and 5161 (2703) ng/mL in the NVP group (P = 0.140). CONCLUSIONS: In antiretroviral-experienced subjects with sustained viral suppression, dual therapy with NVP plus LPV/rtv at standard dosage was as potent and safe as standard-of-care HAART at 48 weeks of follow-up. This approach may reduce mitochondrial toxicity and improve LPV/rtv-associated lipid abnormalities. The results of this pilot study support the study of this approach in a larger, randomized trial