263 research outputs found

    Approach of a class of discontinuous dynamical systems of fractional order: existence of the solutions

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    In this letter we are concerned with the possibility to approach the existence of solutions to a class of discontinuous dynamical systems of fractional order. In this purpose, the underlying initial value problem is transformed into a fractional set-valued problem. Next, the Cellina's Theorem is applied leading to a single-valued continuous initial value problem of fractional order. The existence of solutions is assured by a P\'{e}ano like theorem for ordinary differential equations of fractional order.Comment: accepted IJBC, 5 pages, 1 figur

    Influence of cross section geometry on the confinement of reinforced concrete columns with CFRP composites

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    Comunicação apresentada em International Symposium Polymers in Concrete (ISPIC 2006), Guimarães, 2006Confinement effectiveness of externally bonded FRP jackets depends on different parameters namely type of concrete, steel reinforcement, FRP jacket stiffness (type of FRP, number of plies and design of wrap), shape of cross section, radius of corners for non-circular sections, and loading conditions. In order to investigate the effect of some of these parameters on the axial behavior of columns under compression and to quantify the level of confinement exerted on the concrete core, an experimental program has been developed. The experimental research consisted of a sequence of axial compressive tests on cylinders and square prisms. Prisms were divided into three representative groups: sharpedged sections and sections with rounded corners with corner radii equal to either 20mm or 38mm. The results presented in this paper are for the columns which were wrapped with two plies of unidirectional carbon fibers

    Consulta de Diabetes Ocular. Primeiros Resultados do Rastreio da Retinopatia Diabética por Câmara Não Midriática

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    Introdução: a retinopatia diabética (RD) é, nos países industrializados, uma das principais causas de cegueira. A perda de visão na RD diminui com o diagnóstico precoce e instituição terapêutica2 adequada possibilitados por programas de rastreio sistemático. O rastreio efectuado por fotografias do polo posterior com câmara não midriática é simples e apresenta boa sensibilidade e especificidade3. Material e Métodos: estudo prospectivo, observacional, dos doentes diabéticos sem seguimento oftalmológico regular, seguidos na consulta de Medicina do Centro Hospitalar de Lisboa Central desde Setembro de 2008 a Julho de 2009. Incluíram-se 86 doentes. Um ortoptista fez a aquisição de imagens do polo posterior com uma câmara não midriática e a impressão de fotografias compostas, coloridas, que foram posteriormente analisadas por um oftalmologista da consulta de Diabetes Ocular. Resultados: foram excluídos 7 olhos (4,2%) por não existir qualidade de imagem. Identificou-se a existência de RD em 26% dos 165 olhos incluídos ( 28% dos doentes), apresentando 21% RD não proliferativa e 5% proliferativa. Apurou-se uma relação estatisticamente significativa entre a existência de RD, a idade (p= 0,253 x 10-1) e a duração da diabetes (p= 7,16 x 10-5). Relativamente ao encaminhamento, 57,8% foram referenciados para rastreio anual e 42,2% para a Consulta Geral de Oftalmologia. Todos os excluídos foram igualmente encaminhados para a Consulta Geral de Oftalmologia. Conclusões: a percentagem de doentes rastreados que apresentou RD foi elevada (28%). O rastreio sistemático da população diabética com câmara não midriática pareceu-nos ser um método simples e eficaz no despiste da RD

    Cuidados parentais à criança hospitalizada em situação de doença aguda

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    Introdução: A participação dos pais nos cuidados à criança hospitalizada constitui, actualmente, um elemento central nos cuidados de Enfermagem. Os estudos que identificam as acções parentais a partir do relato dos pais são escassos, historicamente datados, e culturalmente marcados. Em particular, são poucos os estudos que, no contexto português, analisaram de forma sistemática os comportamentos de participação de pais de crianças em situação de internamento hospitalar por situação de doença aguda. Objectivos: O presente estudo teve como objectivos: (1) identificar os comportamentos de participação dos pais nos cuidados à criança hospitalizada por situação de doença aguda; (2) desenvolver uma taxonomia de classificação dos comportamentos de participação dos pais nos cuidados; (3) aferir a representatividade relativa das diversas categorias e sub-categorias de comportamentos de participação, diferenciando comportamentos realizados de comportamentos não-realizados mas desejados. Metodologia: O estudo foi conduzido em serviços de pediatria médica de dois hospitais da sub-região de Lisboa, após parecer das Comissões de Ética e autorização dos Conselhos de Administração. Participaram 92 pais de crianças com idades compreendidas entre os três e os nove anos. Solicitou-se aos pais que indicassem, num questionário de auto-preenchimento, as acções de cuidados que realizaram, e que poderiam ter realizado durante o internamento hospitalar. As respostas a estas duas perguntas foram analisadas com recurso à técnica de análise de conteúdo, nomeadamente, análise categorial e de ocorrências. Resultados: Os resultados revelaram que o exercício da parentalidade no hospital envolve a realização de múltiplas actividades que procuram dar resposta às necessidades da criança. A taxonomia de classificação dos comportamentos de participação dos pais desenvolvida assentou em três categorias principais de cuidados (i.e., emocionais, físicos e técnicos), especificadas em 26 subcategorias. As acções de cuidados emocionais revelaram maior expressão, seguidas das acções de cuidados físicos e com menor expressão, as acções de cuidados técnicos. A comparação entre os comportamentos realizados e não-realizados mas nomeados como desejados, sugere que os pais consideram dispor de competências para uma maior intervenção nos cuidados à criança, nomeadamente na área das acções técnicas. Conclusões: Os resultados obtidos contribuem para a compreensão do fenómeno da participação parental nos cuidados à criança hospitalizada no contexto português. Em específico, permitiram identificar os cuidados técnicos como área potencial de intervenção no sentido da promoção da participação parental nos cuidados, o que coloca algumas questões à reflexão ética da partilha de responsabilidades entre enfermeiros e pais. Adicionalmente, o desenvolvimento de uma taxonomia de comportamentos de participação favorece a clarificação conceptual no domínio da intervenção parental nos cuidados, e oferece um suporte ao desenvolvimento de um instrumento de aferição da participação parental de formato fechado ou semi-fechado, de aplicação rápida

    Metabolism of a Lipid Nanoemulsion Resembling Low-Density Lipoprotein in Patients with Grade III Obesity

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    INTRODUCTION: Obesity increases triglyceride levels and decreases high-density lipoprotein concentrations in plasma. Artificial emulsions resembling lipidic plasma lipoprotein structures have been used to evaluate low-density lipoprotein metabolism. In grade III obesity, low density lipoprotein metabolism is poorly understood. OBJECTIVE: To evaluate the kinetics with which a cholesterol-rich emulsion (called a low-density emulsion) binds to low-density lipoprotein receptors in a group of patients with grade III obesity by the fractional clearance rate. METHODS: A low-density emulsion was labeled with [14C]-cholesterol ester and [³H]-triglycerides and injected intravenously into ten normolipidemic non-diabetic patients with grade III obesity [body mass index higher than 40 kg/m²] and into ten non-obese healthy controls. Blood samples were collected over 24 hours to determine the plasma decay curve and to calculate the fractional clearance rate. RESULTS: There was no difference regarding plasma levels of total cholesterol or low-density lipoprotein cholesterol between the two groups. The fractional clearance rate of triglycerides was 0.086 ± 0.044 in the obese group and 0.122 ± 0.026 in the controls (p = 0.040), and the fractional clearance rate of cholesterol ester (h-1) was 0.052 ± 0.021 in the obese subjects and 0.058 ± 0.015 (p = 0.971) in the controls. CONCLUSION: Grade III obese subjects exhibited normal low-density lipoprotein removal from plasma as tested by the nanoemulsion method, but triglyceride removal was slower

    Comprehensive translational assessment of human-induced pluripotent stem cell derived cardiomyocytes for evaluating drug-induced arrhythmias

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    Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CM) hold promise for assessment of drug-induced arrhythmias and are being considered for use under the comprehensive in vitro proarrhythmia assay (CiPA). We studied the effects of 26 drugs and 3 drug combinations on 2 commercially available iPSC-CM types using high-throughput voltage-sensitive dye and microelectrode-array assays being studied for the CiPA initiative and compared the results with clinical QT prolongation and torsade de pointes (TdP) risk. Concentration-dependent analysis comparing iPSC-CMs to clinical trial results demonstrated good correlation between drug-induced rate-corrected action potential duration and field potential duration (APDc and FPDc) prolongation and clinical trial QTc prolongation. Of 20 drugs studied that exhibit clinical QTc prolongation, 17 caused APDc prolongation (16 in Cor.4U and 13 in iCell cardiomyocytes) and 16 caused FPDc prolongation (16 in Cor.4U and 10 in iCell cardiomyocytes). Of 14 drugs that cause TdP, arrhythmias occurred with 10 drugs. Lack of arrhythmic beating in iPSC-CMs for the four remaining drugs could be due to differences in relative levels of expression of individual ion channels. iPSC-CMs responded consistently to human ether-a-go-go potassium channel blocking drugs (APD prolongation and arrhythmias) and calcium channel blocking drugs (APD shortening and prevention of arrhythmias), with a more variable response to late sodium current blocking drugs. Current results confirm the potential of iPSC-CMs for proarrhythmia prediction under CiPA, where iPSC-CM results would serve as a check to ion channel and in silico modeling prediction of proarrhythmic risk. A multi-site validation study is warranted

    Pulsed Radiofrequency Rhizotomy of the Genicular Nerves of the Knee Guided by Radioscopy and Ultrasonography: Step-By-Step Technique

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    Osteoarthritis (OA) of the knee is highly prevalent and causes pain, stiffness, and harms the quality of life of millions of patients. Scientific evidence about radiofrequency ablation or rhizotomy of genicular nerves has been presented with increasing frequency in the literature for the treatment of chronic pain related to knee OA as an alternative to total knee arthroplasty. The main indication for this procedure is symptomatic OA unresponsive to conservative treatment, regardless of the disease evolution, although more common indications are in Kellgren-Lawrence grade III or IV, in post-total knee arthroplasty residual pain without an identified cause, in patients with comorbidities and high surgical risk, and those who do not want to undergo surgery. The aim of this study is to describe the step-by-step rhizotomy technique with pulsed radiofrequency of the 3 genicular nerves, guided by radioscopy and ultrasonography.info:eu-repo/semantics/publishedVersio

    Erratum to “Gastroenteropancreatic Neuroendocrine Neoplasia Characterization in Portugal: Results from the NETs Study Group of the Portuguese Society of Endocrinology, Diabetes and Metabolism”

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    In the article titled "Gastroenteropancreatic Neuroendocrine Neoplasia Characterization in Portugal: Results from the NETs Study Group of the Portuguese Society of Endocrinology, Diabetes and Metabolism"[1], the affiliation for I. Claro was labeled incorrectly. The correct affiliation of the author I. Claro is Instituto Portugûes de Oncologia de Lisboa, Francisco Gentil (IPOLFG), 1099-023 Lisboa, Portugal

    Gastroenteropancreatic Neuroendocrine Neoplasia Characterization in Portugal: Results from the NETs Study Group of the Portuguese Society of Endocrinology, Diabetes and Metabolism

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    Background: The incidence of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) has been increasing in the last five decades, but there is no large-scale data regarding these tumours in Portugal. We conducted a cross-sectional, multicentric study in main Portuguese centers to evaluate the clinical, pathological, and therapeutic profile of GEP-NENs. Methods: From November, 2012, to July, 2014, data from 293 patients diagnosed with GEP-NENs from 15 centers in Portugal was collected and registered in an online electronic platform. Results: Median age at diagnosis was 56.5 (range: 15-87) years with a preponderance of females (54.6%). The most frequent primary sites were the pancreas (31.1%), jejunum-ileum (24.2%), stomach (13.7%), and rectum (8.5%). Data regarding hormonal status was not available in most patients (82.3%). Stratified by the tumour grade (WHO 2010 classification), we observed 64.0% of NET G1, 24.7% of NET G2, and 11.3% of NEC. Poorly differentiated tumours occurred mainly in older patients (p = 0.017), were larger (p < 0.001), and presented more vascular (p = 0.004) and lymphatic (p = 0.001) invasion. At the time of diagnosis, 44.4% of GEP-NENs presented metastatic disease. Surgery (79.6%) and somatostatin analogues (30.7%) were the most frequently used therapies of GEP-NENs with reported grading. Conclusion: In general, Portuguese patients with GEP-NENs presented similar characteristics to other populations described in the literature. This cross-sectional study represents the first step to establish a national database of GEP-NENs that may aid in understanding the clinical and epidemiological features of these tumours in Portugal. Methods: From November, 2012, to July, 2014, data from 293 patients diagnosed with GEP-NENs from 15 centers in Portugal was collected and registered in an online electronic platform. Results: Median age at diagnosis was 56.5 (range: 15-87) years with a preponderance of females (54.6%). The most frequent primary sites were the pancreas (31.1%), jejunum-ileum (24.2%), stomach (13.7%), and rectum (8.5%). Data regarding hormonal status was not available in most patients (82.3%). Stratified by the tumour grade (WHO 2010 classification), we observed 64.0% of NET G1, 24.7% of NET G2, and 11.3% of NEC. Poorly differentiated tumours occurred mainly in older patients (p = 0.017), were larger (p < 0.001), and presented more vascular (p = 0.004) and lymphatic (p = 0.001) invasion. At the time of diagnosis, 44.4% of GEP-NENs presented metastatic disease. Surgery (79.6%) and somatostatin analogues (30.7%) were the most frequently used therapies of GEP-NENs with reported grading. Conclusion: In general, Portuguese patients with GEP-NENs presented similar characteristics to other populations described in the literature. This cross-sectional study represents the first step to establish a national database of GEP-NENs that may aid in understanding the clinical and epidemiological features of these tumours in Portugal.This study was industry-sponsored by the pharmaceutical company Ipsen Portugal. João Vinagre (CEECIND/00201/2017) and Paula Soares receive funding from the Operational Program for Competitiveness and Internationalization (POCI), Portugal 2020; Portuguese funds through FCT (Fundação para a Ciência e a Tecnologia)/Ministério da Ciência, Tecnologia e Inovação in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274) and the project “Advancing Cancer Research: From Basic Knowledge to Application” (NORTE-01-0145-FEDER-000029); and “Projetos Estruturados de I&D&I,” funded by Norte 2020—Programa Operacional Regional do Norte. Further funding was from the European Regional Development Fund (ERDF) through the Operational Program for Competitiveness and Internationalization (COMPETE 2020) and Portuguese national funds via FCT (Fundação para a Ciência e a Tecnologia), under the project “POCI-01-0145-FEDER-016390: CANCEL STEM.” Maria João Bugalho and João Vinagre were funded by the Sociedade Portuguesa de Endocrinologia, Diabetes e Metabolismo through the Study Group for Neuroendocrine Tumours.info:eu-repo/semantics/publishedVersio
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