ABSTRACT
Electrical control of magnetism has been a major technological pursuit of the spintronics community, owing to its far-reaching implications for data storage and transmission. Here, we propose and analyze a new mechanism for electrical switching of isospin, using chiral-stacked graphene multilayers, such as Bernal bilayer graphene or rhombohedral trilayer graphene, encapsulated by transition metal dichalcogenide (TMD) substrates. Leveraging the proximity-induced spin-orbit coupling from the TMD, we demonstrate electrical switching of correlation-induced spin and/or valley polarization, by reversing a perpendicular displacement field or the chemical potential. We substantiate our proposal with both analytical arguments and self-consistent Hartree-Fock numerics. Finally, we illustrate how the relative alignment of the TMDs, together with the top and bottom gate voltages, can be used to selectively switch distinct isospin flavors, putting forward correlated Van der Waals heterostructures as a promising platform for spintronics and valleytronics.
ABSTRACT
La telemedicina se define como el uso de la tecnología electrónica para la información y la comunicación de los profesionales de la salud con los pacientes, objetivando brindar y apoyar la atención médica a estos últimos fuera de las instituciones de salud. Esta revisión sistemática de la literatura durante la última década (2013-2022) investiga el uso de la telemedicina en pacientes con enfermedad pulmonar obstructiva crónica (EPOC). Identificamos 53 publicaciones relacionadas con: (1) telemonitorización domiciliaria; (2) teleeducación y autocuidados; (3) telerehabilitación, y (4) salud móvil (mHealth). Los resultados mostraron que, aunque la evidencia aún es débil en muchos de estos dominios, los resultados son positivos en términos de mejora del estado de salud, uso de recursos de atención médica, viabilidad y satisfacción del paciente. Destacamos que no se identificaron problemas de seguridad. Por lo tanto, la telemedicina puede considerarse actualmente como un complemento potencial a la atención sanitaria habitual. (AU)
Telemedicine is defined as the use of electronic technology for information and communication by healthcare professionals with patients (or care givers) aiming at providing and supporting healthcare to patients away from healthcare institutions. This systematic review over the last decade (20132022) investigates the use of telemedicine in patients with chronic obstructive pulmonary disease (COPD). We identified 53 publications related to: (1) home tele-monitorization; (2) tele-education and self-management; (3) telerehabilitation; and (4) mobile health (mHealth). Results showed that, although evidence is still weak in many of these domains, results are positive in terms of improvement of health-status, use of health-care resources, feasibility, and patient satisfaction. Importantly, no safety issues were identified. Thus, telemedicine can be considered today as a potential complement to usual healthcare. (AU)
Subject(s)
Humans , Health Status , Patient Satisfaction , Pulmonary Disease, Chronic Obstructive/therapy , TelemedicineABSTRACT
Telemedicine is defined as the use of electronic technology for information and communication by healthcare professionals with patients (or care givers) aiming at providing and supporting healthcare to patients away from healthcare institutions. This systematic review over the last decade (2013-2022) investigates the use of telemedicine in patients with chronic obstructive pulmonary disease (COPD). We identified 53 publications related to: (1) home tele-monitorization; (2) tele-education and self-management; (3) telerehabilitation; and (4) mobile health (mHealth). Results showed that, although evidence is still weak in many of these domains, results are positive in terms of improvement of health-status, use of health-care resources, feasibility, and patient satisfaction. Importantly, no safety issues were identified. Thus, telemedicine can be considered today as a potential complement to usual healthcare.
Subject(s)
Pulmonary Disease, Chronic Obstructive , Telemedicine , Humans , Pulmonary Disease, Chronic Obstructive/therapy , Health Status , Patient SatisfactionABSTRACT
La enfermedad pulmonar obstructiva crónica (EPOC) ha sido tradicionalmente entendida como una enfermedad autoinfligida por el hábito tabáquico que ocurre en adultos de más de 50-60 años. Este paradigma tradicional ha cambiado en los últimos 10 años por la aparición de nueva evidencia científica que muestra que existen otros muchos factores genéticos (G) y del entorno (E) asociados a baja función pulmonar, que varían, se acumulan e interaccionan con el tiempo (T), incluso desde antes del nacimiento (G×E×T). Esta nueva perspectiva abre nuevas ventanas de oportunidad temporal para la prevención, diagnóstico temprano y terapéutica personalizada de la EPOC. Esta revisión presenta esta nueva evidencia científica y discute las implicaciones prácticas que comporta, con especial énfasis en la importancia de una historia clínica que recoja posibles eventos tempranos en la vida y el uso de la espirometría forzada como marcador de salud global. (AU)
Chronic obstructive pulmonary disease (COPD) has been traditionally understood as a self-inflicted disease cause by tobacco smoking occurring in individuals older than 5060 years. This traditional paradigm has changed over the last decade because new scientific evidence showed that there are many genetic (G) and environmental (E) factors associated with reduced lung function, that vary, accumulate, and interact over time (T), even before birth (G×E×T). This new perspective opens novel windows of opportunity for the prevention, early diagnosis, and personalized treatment of COPD. This review presents the evidence that supports this proposal, as well as its practical implications, with particular emphasis on the need that clinical histories in patients with suspected COPD should investigate early life events and that spirometry should be used much more widely as a global health marker. (AU)
Subject(s)
Humans , Pulmonary Disease, Chronic Obstructive/diagnosis , Pulmonary Disease, Chronic Obstructive/etiology , Pulmonary Disease, Chronic Obstructive/prevention & control , Lung , Spirometry/adverse effects , NicotianaABSTRACT
Chronic obstructive pulmonary disease (COPD) has been traditionally understood as a self-inflicted disease cause by tobacco smoking occurring in individuals older than 50-60 years. This traditional paradigm has changed over the last decade because new scientific evidence showed that there are many genetic (G) and environmental (E) factors associated with reduced lung function, that vary, accumulate, and interact over time (T), even before birth (G×E×T). This new perspective opens novel windows of opportunity for the prevention, early diagnosis, and personalized treatment of COPD. This review presents the evidence that supports this proposal, as well as its practical implications, with particular emphasis on the need that clinical histories in patients with suspected COPD should investigate early life events and that spirometry should be used much more widely as a global health marker.
Subject(s)
Nicotiana , Pulmonary Disease, Chronic Obstructive , Humans , Lung , Pulmonary Disease, Chronic Obstructive/diagnosis , Pulmonary Disease, Chronic Obstructive/etiology , Pulmonary Disease, Chronic Obstructive/prevention & control , Spirometry/adverse effectsABSTRACT
Improved fabrication techniques have enabled the possibility of ballistic transport and unprecedented spin manipulation in ultraclean graphene devices. Spin transport in graphene is typically probed in a nonlocal spin valve and is analyzed using spin diffusion theory, but this theory is not necessarily applicable when charge transport becomes ballistic or when the spin diffusion length is exceptionally long. Here, we study these regimes by performing quantum simulations of graphene nonlocal spin valves. We find that conventional spin diffusion theory fails to capture the crossover to the ballistic regime as well as the limit of long spin diffusion length. We show that the latter can be described by an extension of the current theoretical framework. Finally, by covering the whole range of spin dynamics, our study opens a new perspective to predict and scrutinize spin transport in graphene and other two-dimensional material-based ultraclean devices.
ABSTRACT
We report an unconventional quantum spin Hall phase in the monolayer WTe_{2}, which exhibits hitherto unknown features in other topological materials. The low symmetry of the structure induces a canted spin texture in the yz plane, which dictates the spin polarization of topologically protected boundary states. Additionally, the spin Hall conductivity gets quantized (2e^{2}/h) with a spin quantization axis parallel to the canting direction. These findings are based on large-scale quantum simulations of the spin Hall conductivity tensor and nonlocal resistances in multiprobe geometries using a realistic tight-binding model elaborated from first-principle methods. The observation of this canted quantum spin Hall effect, related to the formation of topological edge states with nontrivial spin polarization, demands for specific experimental design and suggests interesting alternatives for manipulating spin information in topological materials.
ABSTRACT
Graphene is an excellent material for long-distance spin transport but allows little spin manipulation. Transition-metal dichalcogenides imprint their strong spin-orbit coupling into graphene via the proximity effect, and it has been predicted that efficient spin-to-charge conversion due to spin Hall and Rashba-Edelstein effects could be achieved. Here, by combining Hall probes with ferromagnetic electrodes, we unambiguously demonstrate experimentally the spin Hall effect in graphene induced by MoS2 proximity and for varying temperatures up to room temperature. The fact that spin transport and the spin Hall effect occur in different parts of the same material gives rise to a hitherto unreported efficiency for the spin-to-charge voltage output. Additionally, for a single graphene/MoS2 heterostructure-based device, we evidence a superimposed spin-to-charge current conversion that can be indistinguishably associated with either the proximity-induced Rashba-Edelstein effect in graphene or the spin Hall effect in MoS2. By a comparison of our results to theoretical calculations, the latter scenario is found to be the most plausible one. Our findings pave the way toward the combination of spin information transport and spin-to-charge conversion in two-dimensional materials, opening exciting opportunities in a variety of future spintronic applications.
ABSTRACT
Dirac materials such as graphene and topological insulators (TIs) are known to have unique electronic and spintronic properties. We combine graphene with TIs in van der Waals heterostructures to demonstrate the emergence of a strong proximity-induced spin-orbit coupling in graphene. By performing spin transport and precession measurements supported by ab initio simulations, we discover a strong tunability and suppression of the spin signal and spin lifetime due to the hybridization of graphene and TI electronic bands. The enhanced spin-orbit coupling strength is estimated to be nearly an order of magnitude higher than in pristine graphene. These findings in graphene-TI heterostructures could open interesting opportunities for exploring exotic physical phenomena and new device functionalities governed by topological proximity effects.
ABSTRACT
Since its discovery, graphene has been a promising material for spintronics: its low spin-orbit coupling, negligible hyperfine interaction, and high electron mobility are obvious advantages for transporting spin information over long distances. However, such outstanding transport properties also limit the capability to engineer active spintronics, where strong spin-orbit coupling is crucial for creating and manipulating spin currents. To this end, transition metal dichalcogenides, which have larger spin-orbit coupling and good interface matching, appear to be highly complementary materials for enhancing the spin-dependent features of graphene while maintaining its superior charge transport properties. In this review, we present the theoretical framework and the experiments performed to detect and characterize the spin-orbit coupling and spin currents in graphene/transition metal dichalcogenide heterostructures. Specifically, we will concentrate on recent measurements of Hanle precession, weak antilocalization and the spin Hall effect, and provide a comprehensive theoretical description of the interconnection between these phenomena.
ABSTRACT
Introducción. la transfusión feto-materna (TFM) o hemorragia feto-materna (HFM) es una causa infrecuente de anemia en recién nacidos que puede presentarse desde formas asintomáticas hasta otras con importante patología dependiendo del tiempo de instauración. Observación clínica. Recién nacido de minutos de vida, asintomático, que presenta intensa palidez cutánea. En el análisis inicial destacan valores de hemoglobina de 4.9 gr/dL y hematocrito de 16.3%. El test de Kleihauer materno confirman la sospecha diagnóstica de transfusión feto-materna. La terapia transfusional resulta clave para la resolución de la anemia. Comentarios. La TFM es una enfermedad de etiología poco clara que implica el paso de sangre fetal a la madre durante la gestación o en el momento del parto. La presentación clínica es muy diversa y variará según la severidad y rapidez de instauración de la hemorragia. La evolución y el pronóstico dependerán de un buen diagnóstico precoz y de la respuesta al tratamiento con transfusión de concentrado de hematíes. En nuestro caso, la cronicidad del cuadro y el tratamiento con la transfusión han proporcionado una buena evolución (AU)
Introduction. Fetomaternal transfusion (FMT) or fetomaternal hemorrhage (FMH) is a rare cause of neonatal anemia with a wide spectrum of clinical presentations, ranging from no symptoms to severe clinical deterioration, depending on the time of its occurrence. Clinical observation. Newborn with pallor and no other abnormal findings. Laboratory evaluation revealed hemoglobin of 4.9 g/dL and hematocrit of 16.3%. The Kleihauer test performed in the mother confirmed the diagnosis of FMT. Comments. FMT is a phenomenon of unclear etiology that results from the transfer of fetal blood into the mother during the pregnancy or at the time of delivery. The type and severity of the clinical presentation correlates with the amount and timing of the transfusion. An early diagnosis, a judicious use of transfusions of packed red blood cells, and the clinical response to replacement therapy are important prognostic factors. In the case presented here, the chronic nature of the condition and the early diagnosis and treatment resulted in a good outcome (AU)
