5,553 research outputs found
Pure spin current manipulation in antiferromagnetically exchange coupled heterostructures
We present a model to describe the spin currents generated by ferromagnet/spacer/ferromagnet exchange coupled trilayer systems and heavy metal layers with strong spin-orbit coupling. By exploiting the magnitude of the exchange coupling (oscillatory RKKY-like coupling) and the spin-flop transition in the magnetization process, it has been possible to produce spin currents polarized in arbitrary directions. The spin-flop transition of the trilayer system originates pure spin currents whose polarization vector depends on the exchange field and the magnetization equilibrium angles. We also discuss a protocol to control the polarization sign of the pure spin current injected into the metallic layer by changing the initial conditions of magnetization of the ferromagnetic layers previously to the spin pumping and inverse spin Hall effect experiments. The small differences in the ferromagnetic layers lead to a change in the magnetization vector rotation that permits the control of the sign of the induced voltage components due to the inverse spin Hall effect. Our results can lead to important advances in hybrid spintronic devices with new functionalities, particularly, the ability to control microscopic parameters such as the polarization direction and the sign of the pure spin current through the variation of macroscopic parameters, such as the external magnetic field or the thickness of the spacer in antiferromagnetic exchange coupled systems.Fil: Avilés Félix, L.. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Butera, Alejandro Ricardo. Comision Nacional de Energía Atómica. Gerencia de Área Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Resonancias Magnéticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: González Chávez, D. E.. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Sommer, R. L.. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Gomez, Javier Enrique. Comision Nacional de Energía Atómica. Gerencia de Área Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Resonancias Magnéticas; Argentin
Testing for rational speculative bubbles in the Brazilian residential real-estate market
Speculative bubbles have been occurring periodically in local or global real
estate markets and are considered a potential cause of economic crises. In this
context, the detection of explosive behaviors in the financial market and the
implementation of early warning diagnosis tests are of critical importance. The
recent increase in Brazilian housing prices has risen concerns that the
Brazilian economy may have a speculative housing bubble. In the present paper,
we employ a recently proposed recursive unit root test in order to identify
possible speculative bubbles in data from the Brazilian residential real-estate
market. The empirical results show evidence for speculative price bubbles both
in Rio de Janeiro and Sao Paulo, the two main Brazilian cities
Influencia del sedentarismo en las desviaciones raquídeas de la población escolar de Léon
Nuestra investigación trata de evaluar los hábitos sedentarios, en los escolares de 10 y 14 años de una zona de León, y su influencia en las desviaciones raquídeas. Para la obtención de los hábitos nos basamos en el tets de Medoza, R. también se realizó una evaluación física de los niños para observar las desviaciones raquídeas. En el tratamiento de la información se utilizó el análisis de la varianza univariante y multivariante, además del análisis de componentes principales y análisis discriminante. Llegando a la conclusión, respecto al tiempo de televisión que el día de la semana que más tiempo dedican los niños a ver la televisión es discrimante de los escolares que tienen desviación raquídea
On the Formation Height of the SDO/HMI Fe 6173 Doppler Signal
The Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics
Observatory (SDO) is designed to study oscillations and the mag- netic field in
the solar photosphere. It observes the full solar disk in the Fe I absorption
line at 6173\AA . We use the output of a high-resolution 3D, time- dependent,
radiation-hydrodynamic simulation based on the CO5BOLD code to calculate
profiles F({\lambda},x,y,t) for the Fe I 6173{\AA} line. The emerging profiles
F({\lambda},x,y,t) are multiplied by a representative set of HMI filter
transmission profiles R_i({\lambda},1 \leq i \leq 6) and filtergrams
I_i(x,y,t;1 \leq i \leq 6) are constructed for six wavelengths. Doppler
velocities V_HMI(x,y,t) are determined from these filtergrams using a
simplified version of the HMI pipeline. The Doppler velocities are correlated
with the original velocities in the simulated atmosphere. The cross-
correlation peaks near 100 km, suggesting that the HMI Doppler velocity signal
is formed rather low in the solar atmosphere. The same analysis is performed
for the SOHO/MDI Ni I line at 6768\AA . The MDI Doppler signal is formed
slightly higher at around 125 km. Taking into account the limited spatial
resolution of the instruments, the apparent formation height of both the HMI
and MDI Doppler signal increases by 40 to 50 km. We also study how
uncertainties in the HMI filter-transmission profiles affect the calculated
velocities.Comment: 15 pages, 11 Figure
Impact of the coronavirus pandemic on maxillofacial trauma:a retrospective study in southern Spain
The coronavirus pandemic has impacted health systems worldwide, with Spain being one of the most affected countries. However, little is known about the extent to which the effects of staying home, social distancing, and quarantine measures have influenced the epidemiology of patients with maxillofacial trauma. The aim of this study was to analyze the impact of the coronavirus pandemic on the incidence, demographic patterns, and characteristics of maxillofacial fractures in the largest hospital in southern Spain. Data from patients who underwent surgery for maxillofacial fractures during the first year of the pandemic between 16 March 2020 and 14 March 2021 (pandemic group) were retrospectively compared with a control group during the equivalent period of the previous year (pre-pandemic group). The incidence was compared by weeks and by lockdown periods of the population. Demographic information, aetioloy, fracture characteristics, treatment performed, and days of preoperative stay were evaluated. Descriptive and bivariate statistics were calculated (p<0.05). During the first year of the pandemic, there was a 35.2% reduction in maxillofacial fractures (n=59) compared to the pre-pandemic year (n=91, p=0.040). A significant drop was detected during the total home lockdown period of the population (p=0.028). In the pandemic group, there was a reduction in fractures due to interpersonal aggressions, an increase in panfacial fractures, a significant increase in other non-facial injuries associated with polytrauma (p=0.037), a higher number of open reduction procedures with internal fixation, and a significantly longer mean preoperative stay (p=0.016). The first pandemic year was associated with a decline in the frequency of maxillofacial trauma and a change in the pattern and characteristics of fractures. Inter-annual epidemiological knowledge of maxillofacial fractures may be useful for more efficient planning of resource allocation and surgical practice strategy during future coronavirus outbreaks and population lockdowns
Expectations of patients awaiting lung transplantation: A qualitative study
Expectations; Lung transplant; Patient experienceExpectativas; Trasplante de pulmón; Experiencia del pacienteExpectatives; Trasplantament de pulmó; Experiència del pacientAim
The main aim of the present study is to examine the expectations and feelings of people awaiting lung transplantation.
Background
The assessment of the benefits of lung transplant should consider, among other things, the subjective perceptions of patients about the procedure, especially in relation to the context and to their values, goals and expectations. This is an issue that has not been studied in depth, especially in Spain.
Design
Exploratory qualitative study.
Methods
Data were collected through semi-structured interviews during the period of being on the waiting list for transplantation. Thematic analysis of the data was supported by the Atlas.ti software.
Results
The study population comprised 16 patients awaiting lung transplant, a number sufficient to reach data saturation. Four categories were identified to describe patients' feelings and expectations: (1) reasons for undergoing the transplant, (2) expectations about life post-transplant, (3) emotional state, and (4) relationship with the healthcare team.
Conclusions
Patients have high expectations of lung transplantation. They see it as offering them a second chance at life, although the future creates uncertainty. The healthcare professionals are identified as key actors, providing essential support and information throughout the various stages of the process. Future research should explore recipients' experiences of lung transplant at later stages.
Relevance to clinical practice
It is important to adapt care through all the lung transplant process, which is accompanied by intense and complex emotions since the beginning. Thus, providing social and psychological support from the beginning may contribute to their health status, helping them deal with all the emotions and feelings experienced, and find balance between expectations and reality.
Patient or public contribution
Sixteen patients awaiting lung transplant were interviewed. Interview transcripts were returned to participants to check for accuracy with their experiences
Potential Implication of Azole Persistence in the Treatment Failure of Two Haematological Patients Infected with Aspergillus fumigatus
Invasive aspergillosis (IA) is a major cause of morbidity and mortality in patients receiving allogeneic haematopoieticcell transplantation. The deep immunosuppression and a variety of potential additional complications developed in these patients result in IA reaching mortality rates of around 50-60%. This mortality is even higher when the patients are infected with azole-resistant isolates, demonstrating that, despite the complexity of management, adequate azole treatment can have a beneficial effect. It is therefore paramount to understand the reasons why antifungal treatment of IA infections caused by azole-susceptible isolates is often unsuccessful. In this respect, there are already various factors known to be important for treatment efficacy, for instance the drug concentrations achieved in the blood, which are thus often monitored. We hypothesize that antifungal persistence may be another important factor to consider. In this study we present two case reports of haematological patients who developed proven IA and suffered treatment failure, despite having been infected with susceptible isolates, receiving correct antifungal treatment and reaching therapeutic levels of the azole. Microbiological analysis of the recovered infective isolates showed that the patients were infected with multiple strains, several of which were persisters to voriconazole and/or isavuconazole. Therefore, we propose that azole persistence may have contributed to therapeutic failure in these patients and that this phenomenon should be considered in future studies.This research was funded by “Proyecto de I+D+I en salud-ISCIII 2022 de la Acción Estratégica en Salud Intramural (AESI)”, grant number “PI22CIII/00053”.S
Glucose-Nucleobase Pseudo Base Pairs: Biomolecular Interactions within DNA
Noncovalent forces rule the interactions between biomolecules. Inspired by a biomolecular interaction found in aminoglycoside-RNA recognition, glucose-nucleobase pairs have been examined. Deoxyoligonucleotides with a 6-deoxyglucose insertion are able to hybridize with their complementary strand, thus exhibiting a preference for purine nucleobases. Although the resulting double helices are less stable than natural ones, they present only minor local distortions. 6-Deoxyglucose stays fully integrated in the double helix and its OH groups form two hydrogen bonds with the opposing guanine. This 6-deoxyglucose-guanine pair closely resembles a purine-pyrimidine geometry. Quantum chemical calculations indicate that glucose-purine pairs are as stable as a natural T-A pair. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.We thank the Ministerio de Economía y Competitividad (CTQ2011-
15203-E, CTQ2012-35360, CTQ2014-52588-R, BFU2014-52864-R), the
Netherlands Organization for Scientific Research (NWO-CW and NWO-EW),
and the National Research School Combination—Catalysis (NRSC-C) for
financial support. E.V.C. thanks Ministerio de Educación, Cultura y Deporte
for a FPU fellowship and Cost Action CM1005 for a STSM grant.Peer reviewe
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