Magnetoelectric properties of 500 nm Cr2O3 films

The linear magnetoelectric effect was measured in 500 nm Cr2O3 films grown by rf sputtering on Al2O3 substrates between top and bottom thin film Pt electrodes. Magnetoelectric susceptibility was measured directly by applying an AC electric field and measuring the induced AC magnetic moment using superconducting quantum interference device magnetometry. A linear dependence of the induced AC magnetic moment on the AC electric field amplitude was found. The temperature dependence of the magnetoelectric susceptibility agreed qualitatively and quantitatively with prior measurements of bulk single crystals, but the characteristic temperatures of the film were lower than those of single crystals. It was also possible to reverse the sign of the magnetoelectric susceptibility by reversing the sign of the magnetic field applied during cooling through the N\'eel temperature. A competition between total magnetoelectric and Zeeman energies is proposed to explain the difference between film and bulk Cr2O3 regarding the cooling field dependence of the magnetoelectric effect.Comment: accepted at Physical Review

Dimensionality dependence of optical nonlinearity and relaxation dynamics in cuprates

Femtosecond pump-probe measurements find pronounced dimensionality dependence of the optical nonlinearity in cuprates. Although the coherent two-photon absorption (TPA) and linear absorption bands nearly overlap in both quasi-one and two-dimensional (1D and 2D) cuprates, the TPA coefficient is one order of magnitude smaller in 2D than in 1D. Furthermore, picosecond recovery of optical transparency is observed in 1D cuprates, while the recovery in 2D involves relaxation channels with a time scales of tens of picoseconds. The experimental results are interpreted within the two-band extended Hubbard model.Comment: 10 pages, 4 figure

Finite-temperature reaction-rate formula: Finite volume system, detailed balance, T→0T \to 0 limit, and cutting rules

A complete derivation, from first principles, of the reaction-rate formula for a generic process taking place in a heat bath of finite volume is given. It is shown that the formula involves no finite-volume correction. Through perturbative diagrammatic analysis of the resultant formula, the detailed-balance formula is derived. The zero-temperature limit of the formula is discussed. Thermal cutting rules, which are introduced in previous work, are compared with those introduced by other authors.Comment: 35pages (text) plus 4pages (figures

Pathological activation of KIT in metastatic tumors of acral and mucosal melanomas

ArticleINTERNATIONAL JOURNAL OF CANCER. 124(4):862-868 (2009)journal articl

A new technique using a rubber balloon in emergency second trimester cerclage for fetal membrane prolapse

The definitive version is available at www.blackwell-synergy.comArticleJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH. 34(6):935-940 (2008)journal articl

Induced hyperlipaemia and immune challenge in locusts

Injections of immunogens, such as β-1,3-glucan or lipopolysaccharide (LPS), bring about a marked hyperlipaemia with associated changes in lipophorins and apolipophorin-III in the haemolymph of Locusta migratoria. These changes are similar to those observed after injection of adipokinetic hormone (AKH). The possibility that endogenous AKH is released as part of the response to these immunogens is investigated using passive immunisation against AKH-I, and measurement of AKH-I titre in the haemolymph after injection of immunogens. The data presented show that, despite the similarity of the changes brought about by the presence of immunogens in the haemolymph to those brought about by AKH, there is no release of endogenous AKH after injection of laminarin or LPS. A direct effect of the immunogens on release of neutral lipids by the fat body cannot be demonstrated in vitro, and the mechanism by which hyperlipaemia is induced during immune challenge remains uncertain

PCR-based Landmark Unique Gene (PLUG) markers are a useful tool for comparative genomic analysis and BAC clone screening in wheat

Dissertação de mestrado em Psicologia Clínica e Saúde (Psicopatologia e Psicoterapia Dinâmica), apresentada à Faculdade de Psicologia e Ciências da Educação da Universidade de CoimbraOs pacientes infetados pelo VIH têm sido objeto de interesse por parte dos profissionais de saúde mental pela dimensão do impacto psicológico do diagnóstico, evolução da infeção e a vulnerabilidade destes sujeitos. Seja como for, em traço de evolução da terapêutica, a infeção pelo vírus da imunodeficiência humana (VIH) é, atualmente, uma doença tendencialmente crónica. Entre as perturbações mentais, a depressão é descrita como uma das comorbidades mais frequentes nos indivíduos com VIH e que muitas vezes passa despercebida. Acompanha-se de elevada morbilidade e apresenta um impacto sócio-económico, sendo uma das causas mais frequentes de suicídio. Para além da incapacidade que se vai instalando progressivamente, os indivíduos são confrontados com o estigma social, carência de apoio social e isolamento. Neste sentido, este estudo foi realizado com o intuito de chamar a atenção para a necessidade de intervenção psicoterapêutica com esta população, através da exploração dos sintomas psicopatológicos mais prevalentes (com especial destaque para a depressão e para a ideação suicida), tendo em consideração a progressão da doença e a as caraterísticas socio-demográficas.Patients infected with HIV have been the object of interest on the part of mental health professionals due to the dimension of the psychological impact of the diagnosis, the course of infection and the vulnerability of these subjects. Anyway, in trait evolution of therapy, infection by the human immunodeficiency virus (HIV) is currently a chronic disease. Among mental disorders, depression is described as one of the most frequent comorbidities in individuals infected with HIV and which often goes unnoticed. It is accompanied by high morbidity and presents a socialeconomic impact, being one of the most frequent causes of suicide. Beyond the progressively established disability, individuals face social stigma, lack of social support and isolation. Thus, this study was conducted in order to draw attention to the need for psychotherapeutic intervention among this population, through the exploitation of the most prevalent psychopathological symptoms (with special emphasis on depression and suicidal ideation), taking into account the progression of this disease and the social-demographic characteristics

The fluctuation energy balance in non-suspended fluid-mediated particle transport

Here we compare two extreme regimes of non-suspended fluid-mediated particle transport, transport in light and heavy fluids ("saltation" and "bedload", respectively), regarding their particle fluctuation energy balance. From direct numerical simulations, we surprisingly find that the ratio between collisional and fluid drag dissipation of fluctuation energy is significantly larger in saltation than in bedload, even though the contribution of interparticle collisions to transport of momentum and energy is much smaller in saltation due to the low concentration of particles in the transport layer. We conclude that the much higher frequency of high-energy particle-bed impacts ("splash") in saltation is the cause for this counter-intuitive behavior. Moreover, from a comparison of these simulations to Particle Tracking Velocimetry measurements which we performed in a wind tunnel under steady transport of fine and coarse sand, we find that turbulent fluctuations of the flow produce particle fluctuation energy at an unexpectedly high rate in saltation even under conditions for which the effects of turbulence are usually believed to be small