MBE growth of cubic AlxIn1-xN and AlxGayIn1-x-yN lattice matched to GaN

Ternary and quaternary cubic c-AlxIn1-xN/GaN and c-AlxGayIn1-x-y/GaN heterostructures lattice-matched to c-GaN on freestanding 3C-SiC substrates were grown by plasma-assisted molecular beam epitaxy. The c-AlxGayIn1-x-y alloy permits the independent control of band gap and lattice parameter. The ternary and quaternary films were grown at 620 C. Different alloy compositions were obtained by varying the Al and Ga fluxes. The alloy composition was measured by Energy Dispersive X-ray Spectroscopy (EDX) and Rutherford Backscattering Spectrometry (RBS). X-ray reciprocal space map of asymmetric (-1-13) reflex were used to measure the lattice parameters and to verify the lattice match between the alloy and the c-GaN buffer.Comment: 4 pages including 4 figure

A Neuroanatomical Signature for Schizophrenia Across Different Ethnic Groups

Schizophrenia is a disabling clinical syndrome found across the world. While the incidence and clinical expression of this illness are strongly influenced by ethnic factors, it is unclear whether patients from different ethnicities show distinct brain deficits. In this multicentre study, we used structural Magnetic Resonance Imaging to investigate neuroanatomy in 126 patients with first episode schizophrenia who came from 4 ethnically distinct cohorts (White Caucasians, African-Caribbeans, Japanese, and Chinese). Each patient was individually matched with a healthy control of the same ethnicity, gender, and age (±1 year). We report a reduction in the gray matter volume of the right anterior insula in patients relative to controls (P < .05 corrected); this reduction was detected in all 4 ethnic groups despite differences in psychopathology, exposure to antipsychotic medication and image acquisition sequence. This finding provides evidence for a neuroanatomical signature of schizophrenia expressed above and beyond ethnic variations in incidence and clinical expression. In light of the existing literature, implicating the right anterior insula in bipolar disorder, depression, addiction, obsessive-compulsive disorder, and anxiety, we speculate that the neuroanatomical deficit reported here may represent a transdiagnostic feature of Axis I disorders

Skin Disease in Liver and Kidney Transplant Recipients Referred to the Department of Dermatology and Venereology

Introdução: Foram descritas várias doenças cutâneas em doentes transplantados, em relação com a terapêutica imunossupressora instituída. Pretendemos caracterizar o espectro clínico das patologias dermatológicas e comparar os diagnósticos entre os doentes transplantados hepáticos e os doentes transplantados renais. Material e Métodos: Estudo descritivo e retrospectivo através da consulta de processos clínicos de todos os doentes submetidos a transplante hepático ou renal entre 2000 - 2010 referenciados à Consulta de Dermatologia e Venereologia. Resultados: Observámos 319 doentes transplantados (23,5%) e apurámos 410 diagnósticos (230 na sub-população com transplante hepático e 180 na sub-população com transplante renal), divididos em quatro grupos: 1) infecções cutâneas; 2) cancro cutâneo ou lesões precursoras; 3) manifestações cutâneas relacionadas com efeitos secundários de fármacos; 4) outras patologias dermatológicas não iatrogénicas. As infecções cutâneas foram as mais observadas (42,2%), em média 32,7 meses após o transplante. Este grupo incluiu 20,5% de infecções fúngicas, 12,7% virais e 8,5% bacterianas. Identificámos patologia tumoral e lesões precursoras em 11,7% dos casos, em média 44,8 meses após o transplante e assumindo maior importância na sub-população com transplante renal (20,6% vs 4,8% nos transplantados hepáticos; P < 0,001). Os transplantados renais apresentaram predomínio de carcinomas espinocelulares (CEC) sobre os casos de carcinomas basocelulares (CBC), numa razão CEC:CBC de 1,3:1 mas nos transplantados hepáticos verificou-se uma razão CBC: carcinomas de 3,5:1. Ocorreram efeitos secundários de fármacos em 10,5% dos casos e outras patologias dermatológicas não iatrogénicas em 35,6%. Discussão: Apesar da patologia tumoral ser a mais referida na literatura, as infecções cutâneas foram as mais observadas na nossa amostra. As diferenças significativas entre as duas sub-populações estudadas podem estar relacionadas com o maior grau de imunossupressão a que os doentes transplantados renais estão sujeitos. Conclusão: Dada a elevada frequência de patologia cutânea nestes doentes é essencial incluir o acesso a consultas de Dermatologia e Venereologia nos cuidados multi-disciplinares pós-transplante

White matter integrity as a predictor of response to treatment in first episode psychosis

The integrity of brain white matter connections is central to a patient's ability to respond to pharmacological interventions. This study tested this hypothesis using a specific measure of white matter integrity, and examining its relationship to treatment response using a prospective design in patients within their first episode of psychosis. Diffusion tensor imaging data were acquired in 63 patients with first episode psychosis and 52 healthy control subjects (baseline). Response was assessed after 12 weeks and patients were classified as responders or non-responders according to treatment outcome. At this second time-point, they also underwent a second diffusion tensor imaging scan. Tract-based spatial statistics were used to assess fractional anisotropy as a marker of white matter integrity. At baseline, non-responders showed lower fractional anisotropy than both responders and healthy control subjects (P < 0.05; family-wise error-corrected), mainly in the uncinate, cingulum and corpus callosum, whereas responders were indistinguishable from healthy control subjects. After 12 weeks, there was an increase in fractional anisotropy in both responders and non-responders, positively correlated with antipsychotic exposure. This represents one of the largest, controlled investigations of white matter integrity and response to antipsychotic treatment early in psychosis. These data, together with earlier findings on cortical grey matter, suggest that grey and white matter integrity at the start of treatment is an important moderator of response to antipsychotics. These findings can inform patient stratification to anticipate care needs, and raise the possibility that antipsychotics may restore white matter integrity as part of the therapeutic response

Perfeccionismo no transtorno obsessivo-compulsivo e nos transtornos alimentares

OBJETIVO: Este estudo tem dois objetivos principais. Primeiro, avaliar as dimensões do perfeccionismo no transtorno obsessivo-compulsivo e nos transtornos alimentares em comparação com duas amostras controle: psiquiátrica (depressão/ansiedade) e não clínica. Segundo, avaliar se o perfeccionismo é um traço de personalidade especificamente relacionado com estas diferentes condições clínicas. MÉTODO: 39 pacientes com transtorno obsessivo-compulsivo, 24 com transtornos alimentares, 65 com um diagnóstico de depressão e/ou ansiedade (todos estes pacientes encontravam-se em regime de ambulatório) e 70 controles não clínicos completaram a versão portuguesa da Multidimensional Perfectionism Scale. RESULTADOS: Comparativamente à amostra não clínica, todas as amostras clínicas apresentaram níveis significativamente mais elevados na Multidimensional Perfectionism Scale total, no Perfeccionismo Auto-Orientado e no Perfeccionismo-Socialmente-Prescrito. Não houve diferenças estatisticamente significativas no Perfeccionismo-Auto-Orientado e na Multidimensional Perfectionism Scale total nas três amostras clínicas. No entanto, a amostra com transtornos alimentares apresentou níveis significativamente mais elevados de Perfeccionismo-Socialmente-Prescrito, comparativamente à transtornos alimentares e à amostra psiquiátrica (depressão/ansiedade). CONCLUSÃO: O perfeccionismo revelou estar associado a uma grande variedade de condições psicopatológicas. Contudo, as diferenças encontradas entre a amostra de transtornos alimentares, de transtorno obsessivo-compulsivo e a psiquiátrica no Perfeccionismo-Socialmente-Prescrito necessitam de investigação subsequente no sentido de clarificar a especificidade desta dimensão com os transtornos alimentares

Modelling and analysis of time dependent processes in a chemically reactive mixture

In this paper, we study the propagation of sound waves and the dynamics of local wave disturbances induced by spontaneous internal fluctuations in a reactive mixture. We consider a non-diffusive, non-heat conducting and non-viscous mixture described by an Eulerian set of evolution equations. The model is derived from the kinetic theory in a hydrodynamic regime of a fast chemical reaction. The reactive source terms are explicitly computed from the kinetic theory and are built in themodel in a proper way. For both time-dependent problems, we first derive the appropriate dispersion relation, which retains the main effects of the chemical process, and then investigate the influence of the chemical reaction on the properties of interest in the problems studied here. We complete our study by developing a rather detailed analysis using the Hydrogen–Chlorine system as reference. Several numerical computations are included illustrating the behavior of the phase velocity and attenuation coefficient in a low-frequency regime and describing the spectrum of the eigenmodes in the small wavenumber limit.The paper is partially supported by the Research Centre of Mathematics of the University of Minho, with the Portuguese Funds from the Foundation for Science and Technology (FCT) through the Project UID/MAT/00013/2013. We wish to thank the anonymous Referees for their valuable comments and suggestions that helped us to improve the paper.info:eu-repo/semantics/publishedVersio