Antiferromagnetic spin coupling between rare earthadatoms and iron islands probed by spin-polarized tunneling

High-density magnetic storage or quantum computing could be achieved using small magnets with large magnetic anisotropy, a requirement that rare-earth iron alloys fulfill in bulk. This compelling property demands a thorough investigation of the magnetism in low dimensional rare-earth iron structures. Here, we report on the magnetic coupling between 4f single atoms and a 3d magnetic nanoisland. Thulium and lutetium adatoms deposited on iron monolayer islands pseudomorphically grown on W(110) have been investigated at low temperature with scanning tunneling microscopy and spectroscopy. The spin-polarized current indicates that both kind of adatoms have in-plane magnetic moments, which couple antiferromagnetically with their underlying iron islands. Our first-principles calculations explain the observed behavior, predicting an antiparallel coupling of the induced 5d electrons magnetic moment of the lanthanides with the 3d magnetic moment of iron, as well as their in-plane orientation, and pointing to a non-contribution of 4f electrons to the spin-polarized tunneling processes in rare earths.This work was supported by the Spanish MINECO (Grants MAT2010-15659 and MAT2012-31309), Gobierno de Aragón (Grant E81), University of Zaragoza (JIUZ-2013-CIE-12) and Fondo Social Europeo.Peer Reviewe

Structure and magnetism of Tm atoms and monolayers on W(110)

We investigated the growth and magnetic properties of Tm atoms and monolayers deposited on a W(110) surface using scanning tunneling microscopy and x-ray magnetic circular and linear dichroism. The equilibrium structure of Tm monolayer films is found to be a strongly distorted hexagonal lattice with a Moiré pattern due to the overlap with the rectangular W(110) substrate. Monolayer as well as isolated Tm adatoms on W present a trivalent ground-state electronic configuration, contrary to divalent gas phase Tm and weakly coordinated atoms in quench-condensed Tm films. Ligand field multiplet simulations of the x-ray absorption spectra further show that Tm has a $j =6,Jz=±4 and$j =6,Jz=±5 electronic ground state separated by a few meV from the next lowest substates $j =6,Jz=±6. Accordingly, both the Tm atoms and monolayer films exhibit large spin and orbital moments with out-of-plane uniaxial magnetic anisotropy. X-ray magnetic dichroism measurements as a function of temperature show that the Tm monolayers develop antiferromagnetic correlations at about 50 K. The triangular structure of the Tm lattice suggests the presence of significant magnetic frustration in this system, which may lead to either a noncollinear staggered spin structure or intrinsic disorder

Structure and magnetism of Tm atoms and monolayers on W(110)

Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).We investigated the growth and magnetic properties of Tm atoms and monolayers deposited on a W(110) surface using scanning tunneling microscopy and x-ray magnetic circular and linear dichroism. The equilibrium structure of Tm monolayer films is found to be a strongly distorted hexagonal lattice with a Moiré pattern due to the overlap with the rectangular W(110) substrate. Monolayer as well as isolated Tm adatoms on W present a trivalent ground-state electronic configuration, contrary to divalent gas phase Tm and weakly coordinated atoms in quench-condensed Tm films. Ligand field multiplet simulations of the x-ray absorption spectra further show that Tm has a |J=6,Jz=±5¿ electronic ground state separated by a few meV from the next lowest substates |J=6,Jz=±4¿ and |J=6,Jz=±6¿. Accordingly, both the Tm atoms and monolayer films exhibit large spin and orbital moments with out-of-plane uniaxial magnetic anisotropy. X-ray magnetic dichroism measurements as a function of temperature show that the Tm monolayers develop antiferromagnetic correlations at about 50 K. The triangular structure of the Tm lattice suggests the presence of significant magnetic frustration in this system, which may lead to either a noncollinear staggered spin structure or intrinsic disorder.This work was supported by the European Research Council (StG 203239 NOMAD), Agència de Gestió d’Ajuts Universitaris i de Recerca (2009 SGR 695), Spanish MINECO (Grants No. MAT2009-10040, No. MAT2010-15659, and No. MAT2012-31309), Gobierno de Aragón (Grant No. E81), Fondo Social Europeo, and the Swiss Competence Centre for Materials Science and Technology (CCMX).Peer Reviewe

Predicting Clinical Outcome with Phenotypic Clusters in COVID-19 Pneumonia: An Analysis of 12,066 Hospitalized Patients from the Spanish Registry SEMI-COVID-19

(1) Background: Different clinical presentations in COVID-19 are described to date, from mild to severe cases. This study aims to identify different clinical phenotypes in COVID-19 pneumonia using cluster analysis and to assess the prognostic impact among identified clusters in such patients. (2) Methods: Cluster analysis including 11 phenotypic variables was performed in a large cohort of 12,066 COVID-19 patients, collected and followed-up from 1 March to 31 July 2020, from the nationwide Spanish Society of Internal Medicine (SEMI)-COVID-19 Registry. (3) Results: Of the total of 12,066 patients included in the study, most were males (7052, 58.5%) and Caucasian (10,635, 89.5%), with a mean age at diagnosis of 67 years (standard deviation (SD) 16). The main pre-admission comorbidities were arterial hypertension (6030, 50%), hyperlipidemia (4741, 39.4%) and diabetes mellitus (2309, 19.2%). The average number of days from COVID-19 symptom onset to hospital admission was 6.7 (SD 7). The triad of fever, cough, and dyspnea was present almost uniformly in all 4 clinical phenotypes identified by clustering. Cluster C1 (8737 patients, 72.4%) was the largest, and comprised patients with the triad alone. Cluster C2 (1196 patients, 9.9%) also presented with ageusia and anosmia; cluster C3 (880 patients, 7.3%) also had arthromyalgia, headache, and sore throat; and cluster C4 (1253 patients, 10.4%) also manifested with diarrhea, vomiting, and abdominal pain. Compared to each other, cluster C1 presented the highest in-hospital mortality (24.1% vs. 4.3% vs. 14.7% vs. 18.6%; p 20 bpm, lower PaO2/FiO2 at admission, higher levels of C-reactive protein (CRP) and lactate dehydrogenase (LDH), and the phenotypic cluster as independent factors for in-hospital death. (4) Conclusions: The present study identified 4 phenotypic clusters in patients with COVID-19 pneumonia, which predicted the in-hospital prognosis of clinical outcomes

Spain

This chapter presents a review of the situation concerning the various geomorphological hazards in the country, including some information about existing programmes for research, control and mitigation. With its great variety of climatic, geological and morphodynamic environments, Spain is subject to every kind of natural hazard: tsunamis, floods, volcanism, and mass movements. The whole of the territory is prone to some kind of geomorphological hazard but it is in the eastern and southern coastal strips that the risks are greatest. One of the main problems for the mitigation of geomorphological hazards in Spain is the lack of an appropriate regulatory framework for the incorporation of natural hazard assessments into land-use planning and management at the macro-, meso- and micro-planning levels. The coverage of hazard mapping is still far from complete or adequate, and much work remains to be done. There has been considerable diversity in the methods used for risk assessment and for the cartographic representation of natural hazards. An urgent need is to establish common, accepted methodologies and criteria, based on indicators defined as clearly as possible, and to standardize map legends and scales for different planning levels. Information programmes for the general public also need to be considerably expanded

Spatiotemporal Characteristics of the Largest HIV-1 CRF02_AG Outbreak in Spain: Evidence for Onward Transmissions

Background and Aim: The circulating recombinant form 02_AG (CRF02_AG) is the predominant clade among the human immunodeficiency virus type-1 (HIV-1) non-Bs with a prevalence of 5.97% (95% Confidence Interval-CI: 5.41–6.57%) across Spain. Our aim was to estimate the levels of regional clustering for CRF02_AG and the spatiotemporal characteristics of the largest CRF02_AG subepidemic in Spain.Methods: We studied 396 CRF02_AG sequences obtained from HIV-1 diagnosed patients during 2000–2014 from 10 autonomous communities of Spain. Phylogenetic analysis was performed on the 391 CRF02_AG sequences along with all globally sampled CRF02_AG sequences (N = 3,302) as references. Phylodynamic and phylogeographic analysis was performed to the largest CRF02_AG monophyletic cluster by a Bayesian method in BEAST v1.8.0 and by reconstructing ancestral states using the criterion of parsimony in Mesquite v3.4, respectively.Results: The HIV-1 CRF02_AG prevalence differed across Spanish autonomous communities we sampled from (p < 0.001). Phylogenetic analysis revealed that 52.7% of the CRF02_AG sequences formed 56 monophyletic clusters, with a range of 2–79 sequences. The CRF02_AG regional dispersal differed across Spain (p = 0.003), as suggested by monophyletic clustering. For the largest monophyletic cluster (subepidemic) (N = 79), 49.4% of the clustered sequences originated from Madrid, while most sequences (51.9%) had been obtained from men having sex with men (MSM). Molecular clock analysis suggested that the origin (tMRCA) of the CRF02_AG subepidemic was in 2002 (median estimate; 95% Highest Posterior Density-HPD interval: 1999–2004). Additionally, we found significant clustering within the CRF02_AG subepidemic according to the ethnic origin.Conclusion: CRF02_AG has been introduced as a result of multiple introductions in Spain, following regional dispersal in several cases. We showed that CRF02_AG transmissions were mostly due to regional dispersal in Spain. The hot-spot for the largest CRF02_AG regional subepidemic in Spain was in Madrid associated with MSM transmission risk group. The existence of subepidemics suggest that several spillovers occurred from Madrid to other areas. CRF02_AG sequences from Hispanics were clustered in a separate subclade suggesting no linkage between the local and Hispanic subepidemics

Multiancestry analysis of the HLA locus in Alzheimer’s and Parkinson’s diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes

Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson’s disease (PD) and Alzheimer’s disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Propiedades magnéticas y electrónicas de materiales nanoestructurados determinadas mediante técnicas de microscopia de sonda local

En esta Tesis se van a estudiar sistemas nanoestructurados de dos metales magnéticos, pertenecientes a familias con propiedades magnéticas muy diferenciadas, que se manifiestan, por ejemplo, en la intensidad de las constantes de anisotropia y magnetoelásticas de estos materiales de tal forma que son mucho más elevadas en Tierras Raras que en metales 3d. El muy distinto origen del momento magnético, localizado en la capa electrónica 4f en las primeras y más deslocalizado en los segundos, permite explicar estas diferencias. El origen de la anisotropia magnética está en el acoplamiento de la parte procedente del espin del momento magnético con la forma del los orbitales electrónicos (acoplamiento espin-órbita VLS). Si el campo eléctrico local en el que se encuentra un átomo, conocido como campo cristalino Vcc, es de baja simetria y los orbitales de los electrones de enlace no son simétricos (Lz distinto de 0) habrá una interacción anisótropa de los orbitales del átomo con Vcc, provocando que haya direcciones energéticamente más favorables que otra a la orientación de las nubes de carga electrónicas del átomo. Así Vcc sera irrelevante para un átomo con momento orbital cero (L=0) dado que el orbital sera esférico y el acoplamiento espin-órbita nulo, por tanto el espin podrá tomar cualquier orientación respecto al cristal. En el caso de que el momento orbital no sea cero, los orbitales electrónicos sólo podrán estar en un posición libre si la simetria del campo cristalina es esférica, de no ser asi estos orbitales tendrán orientaciones preferenciales, ademas si L . S distinto de 0 el espin preferirá una de las orientaciones relativas respecto a L. En el caso de que el acoplamiento de L con el campo cristalino sea más fuerte que la interacción espin-órbita, el material mostrará solo una pequeña respuesta anisótropa, debido a que la parte orbital del momento magnético esta bloqueada, tal y como se observa en los elementos 3d como el Ni. Por otro lado, si VLS >Vcc, entonces la respuesta anisótropa sera mayor ya que al rotar el vector imanación es necesario reorientar los muy anisótropos orbitales atómicos correspondiente a los electrones 4f, lo que causa una elevada magnetostricción en el cristal, como es el caso del Tm. Dentro del escenario descrito anteriormente, los objetivos de esta Tesis son el estudio de la propiedades físicas de dos sistemas físicos: estructuras subnanométricas Tm sobre W(110) y nanohilos de Cu/Ni/Cu que combinan las características descritas. Asi, el estudio de Tm/W(110) corresponde con un metal magnético con momento localizado creado mediante procesos de autoorganización. Mientras que el estudio de nanohilos de Cu/Ni/Cu, responde a las características de un sistema fabricado mediante técnicas top-down con magnetismo itinerante. Para realizar su estudio y completa descripción se precisa el uso de las técnicas de microscopia de sonda local. A continuación presentamos los antecedentes en lo respectivo a los sistemas estudiados en esta Tesis.Peer Reviewe