Tailoring magnetic anisotropy in epitaxial half metallic La0.7Sr0.3MnO3 thin films

We present a detailed study on the magnetic properties, including anisotropy, reversal fields, and magnetization reversal processes, of well characterized half-metallic epitaxial La0.7Sr0.3MnO3 (LSMO) thin films grown onto SrTiO3 (STO) substrates with three different surface orientations, i.e. (001), (110) and (1-18). The latter shows step edges oriented parallel to the [110] (in-plane) crystallographic direction. Room temperature high resolution vectorial Kerr magnetometry measurements have been performed at different applied magnetic field directions in the whole angular range. In general, the magnetic properties of the LSMO films can be interpreted with just the uniaxial term with the anisotropy axis given by the film morphology, whereas the strength of this anisotropy depends on both structure and film thickness. In particular, LSMO films grown on nominally flat (110)-oriented STO substrates presents a well defined uniaxial anisotropy originated from the existence of elongated in-plane [001]-oriented structures, whereas LSMO films grown on nominally flat (001)-oriented STO substrates show a weak uniaxial magnetic anisotropy with the easy axis direction aligned parallel to residual substrate step edges. Elongated structures are also found for LSMO films grown on vicinal STO(001) substrates. These films present a well-defined uniaxial magnetic anisotropy with the easy axis lying along the step edges and its strength increases with the LSMO thickness. It is remarkable that this step-induced uniaxial anisotropy has been found for LSMO films up to 120 nm thickness. Our results are promising for engineering novel half-metallic magnetic devices that exploit tailored magnetic anisotropy.Comment: 10 pages, 10 figures, 1 tabl

Chaotic saddles in nonlinear modulational interactions in a plasma

A nonlinear model of modulational processes in the subsonic regime involving a linearly unstable wave and two linearly damped waves with different damping rates in a plasma is studied numerically. We compute the maximum Lyapunov exponent as a function of the damping rates in a two-parameter space, and identify shrimp-shaped self-similar structures in the parameter space. By varying the damping rate of the low-frequency wave, we construct bifurcation diagrams and focus on a saddle-node bifurcation and an interior crisis associated with a periodic window. We detect chaotic saddles and their stable and unstable manifolds, and demonstrate how the connection between two chaotic saddles via coupling unstable periodic orbits can result in a crisis-induced intermittency. The relevance of this work for the understanding of modulational processes observed in plasmas and fluids is discussed.Comment: Physics of Plasmas, in pres

Avaliação formativa e feedback como ferramenta de aprendizado na formação de profissionais da saúde

The different assessment forms are major elements of any teaching and learning process in educational programs, and should be considered as a core component to be planned and implemented in all curriculums, especially in the health professions education. A regular and qualified students’ assessment is closely related to competence and skills of the professionals that will be delivered to society. In this context, formative assessment and well-trained staff to provide effective and regular feedback are essentials in the formation of the future generation of health professionals. This article focuses primarily on formative assessment, feedback and debriefing.As diferentes formas de avaliação são elementos centrais do processo de ensino-aprendizagem de qualquer programa educacional, e devem ser bem planejadas e implementadas em todas as propostas curriculares, especialmente na formação de profissionais na área da saúde. Uma avaliação do estudante adequada e de qualidade guarda estreita relação com a competência e capacitação do profissional que será entregue à sociedade. Neste contexto, a avaliação formativa e a capacitação dos professores para prover feedback efetivo, frequente, e de qualidade são fundamentais na formação dos futuros profissionais da saúde. Este artigo faz uma revisão sobre avaliação formativa, feedback e debriefing

Characterization of proteinases from the midgut of Rhipicephalus (Boophilus) microplus involved in the generation of antimicrobial peptides

Peer reviewedPublisher PD

Comorbid mood and anxiety disorders in victims of violence with posttraumatic stress disorder

OBJETIVO: Buscar estudos que avaliem a comorbidade entre transtorno de estresse pós-traumático e transtornos do humor, bem como entre transtorno de estresse pós-traumático e outros transtornos de ansiedade. MÉTODO: Revisamos a base de dados do Medline em busca de estudos publicados em inglês até abril de 2009, com as seguintes palavras-chave: "transtorno de estresse pós-traumático", "TEPT", "transtorno de humor", "transtorno depressivo maior", "depressão maior", "transtorno bipolar", "distimia", "transtorno de ansiedade", "transtorno de ansiedade generalizada", agorafobia", "transtorno obsessivo-compulsivo", "transtorno de pânico", "fobia social" e "comorbidade". RESULTADOS: Depressão maior é uma das condições comórbidas mais frequentes em indivíduos com transtorno de estresse pós-traumático, mas eles também apresentam transtorno bipolar e outros transtornos ansiosos. Essas comorbidades impõem um prejuízo clínico adicional e comprometem a qualidade de vida desses indivíduos. Comportamento suicida em pacientes com transtorno de estresse pós-traumático, com ou sem depressão maior comórbida, é também uma questão relevante, e sintomas depressivos mediam a gravidade da dor em sujeitos com transtorno de estresse pós-traumático e dor crônica. CONCLUSÃO: Os estudos disponíveis sugerem que pacientes com transtorno de estresse pós-traumático têm um risco maior de desenvolver transtornos afetivos e, por outro lado, transtornos afetivos pré-existentes aumentam a propensão ao transtorno de estresse pós-traumático após eventos traumáticos. Além disso, vulnerabilidades genéticas em comum podem ajudar a explicar esse padrão de comorbidades. No entanto, diante dos poucos estudos encontrados, mais trabalhos são necessários para avaliar adequadamente essas comorbidades e suas implicações clínicas e terapêuticas.OBJECTIVE: To review studies that have evaluated the comorbidity between posttraumatic stress disorder and mood disorders, as well as between posttraumatic stress disorder and other anxiety disorders. METHOD: We searched Medline for studies, published in English through April, 2009, using the following keywords: "posttraumatic stress disorder", "PTSD", "mood disorder", "major depressive disorder", "major depression", "bipolar disorder", "dysthymia", "anxiety disorder", "generalized anxiety disorder", "agoraphobia", "obsessive-compulsive disorder", "panic disorder", "social phobia", and "comorbidity". RESULTS: Major depression is one of the most frequent comorbid conditions in posttraumatic stress disorder individuals, but individuals with posttraumatic stress disorder are also more likely to present with bipolar disorder, other anxiety disorders and suicidal behaviors. These comorbid conditions are associated with greater clinical severity, functional impairment, and impaired quality of life in already compromised individuals with posttraumatic stress disorder. Depression symptoms also mediate the association between posttraumatic stress disorder and severity of pain among patients with chronic pain. CONCLUSION: Available studies suggest that individuals with posttraumatic stress disorder are at increased risk of developing affective disorders compared with trauma-exposed individuals who do not develop posttraumatic stress disorder. Conversely, pre-existing affective disorders increase a person's vulnerability to the posttraumatic stress disorder--inducing effects of traumatic events. Also, common genetic vulnerabilities can help to explain these comorbidity patterns. However, because the studies addressing this issue are few in number, heterogeneous and based on a limited sample, more studies are needed in order to adequately evaluate these comorbidities, as well as their clinical and therapeutic implications

Determinação simultânea de ácido ascórbico e ácido acetilsalicílico usando análise por injeção em fluxo com detecção amperométrica pulsada

A simple flow system with multiple pulse amperometric detection using a single working electrode is proposed for simultaneous determination of ascorbic (AA) and acetylsalicylic (AAS) acids in pharmaceutical formulations. The procedure is based on application of two potential pulses: 0.90 V/50 ms: oxidation and determination of AA without the interference of AAS; 1.35 V/50 ms: oxidation of both compounds and quantification of AAS by current subtraction using a correction factor. Sampling rate was estimated as 125 injections per hour and the limits of detection were 0.17 and 0.16 µmol L-1 for AA and AAS, respectively. Results for commercial samples agreed with those obtained using HPLC

Solar and Interplanetary Turbulence: Lagrangian Coherent Structures

Talk delivered in 22nd EGU General Assembly, held online 4-8 May, 2020, id.4289, https://meetingorganizer.copernicus.org/EGU2020/EGU2020-4289.html.-- https://www.egu2020.eu/The dynamics of solar and interplanetary plasmas is governed by coherent structures such as current sheets and magnetic flux ropes which are responsible for the genesis of intermittent turbulence via magnetic reconnections in solar supergranular junctions, solar coronal loops, the shock-sheath region of an interplanetary coronal mass ejection, and the interface region of two interplanetary magnetic flux ropes. Lagrangian coherent structures provide a new powerful technique to detect time- or space-dependent transport barriers, and objective (i.e., frame invariant) kinematic and magnetic vortices in space plasma turbulence. We discuss the basic concepts of Lagrangian coherent structures in plasmas based on the computation of the finite-time Lyapunov exponent, the Lagrangian averaged vorticity deviation and the integrated averaged current deviation, as well as their applications to numerical simulations of MHD turbulence and space and ground observations.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation SEV-2017-070