64 research outputs found
Inhibition of HIV cell-to-cell fusion by antiretroviral drugs and neutralizing antibodies
Poster presented at the 7th iMed.ULisboa Postgraduate Students Meeting. Lisbon, 15 July 2015"Inhibition of HIV cell entry by antiretroviral drugs and neutralizing antibodies (NAbs) is typically measured in assays where cell-free virions enter reporter cell lines. However, direct Env-mediated cell-to-cell transmission is a major mechanism of HIV infection that also needs to be targeted. In this work we aimed to determine the ability of anti-HIV compounds in clinical or research use to inhibit HIV mediated cell-to-cell fusion (syncytia formation)."Fundação para a Ciência e a Tecnologia - Portugal ; European Unio
Hybrid moulds : the use of combined techniques for the rapid manufacturing of injection moulds
"Virtual modeling and rapid manufacturing : advanced research in virtual and rapid prototyping : proceedings of the 2nd International Conference on Advanced Research and Rapid Prototyping, Leiria, Portugal, 28 September - 1 October, 2005 (VR@P 2005)". ISBN 0-415-39062-1Injection moulding is the major polymer processing technique. The mould is a key element of
this process and its characteristics have a key importance on the parts produced. The fabrication of products
with higher added value, especially in terms of production time and costs, is essential for the success of the
mouldmaking industry within a global competitive environment.
This paper presents the concept of hybrid mould, a recent concept for injection moulding of prototype and
short series. Direct and indirect rapid tooling technologies can be used for the fabrication of these moulds.
Hence, new design guidelines need to be defined to produce these moulds as well to assess its performance.
Epoxy tooling and selective laser sintering are the two rapid tooling technologies explored to produce inserts
for hybrid-moulds. This work studies the fabrication of hybrid-moulds through these rapid tooling technologies,
as well its mechanical and thermal behaviour.(undefined
Aferição de uma bateria de provas de raciocínio diferencial para utilização nas atividades de orientação vocacional dos alunos do ensino secundário
The study presents the principal results of a standardizationstudy concerning the utilization of "Battery of Differential ReasoningTests" for vocational guidance of secondary students. Some theoreticalaspects of this kind of tests are discussed; for example, its relation withgeneral and group factors of intelligence. The results on each subtest(numerical, abstract, verbal, spatial, and mechanical reasoning) areanalysed concerning sensibility, reliability and validity. The statisticalvalues obtained are in accord with the theoretical and practicalpurposes. The factor analysis shows an important and general factor(next 60% of total variance) that may be related with the generalreasoning ability of subjects evaluated in each subtest.Apresentam-se os principais resultados de um trabalho deaferição da "Bateria de Provas de Raciocínio Diferencial" junto dosalunos portugueses do ensino secundário. Esta prova, destinada a serusada no âmbito da orientação vocacional destes alunos, constitui-secomo uma boa integração dos elementos teórico-práticos decorrentesdas teorias do fator geral e dos fatores de grupo da realizaçãointelectual. Os resultados em cada uma das provas (raciocínio numérico,abstrato, verbal, espacial e mecânico) são analisados quanto à suasensibilidade, fidelidade e validade. Os valores estatísticos obtidosadequam-se às exigências teóricas e práticas deste tipo de instrumento.Numa análise fatorial das intercorrelações dos resultadosnas cinco provas verificou-se a presença de um importante fator geral(explicando cerca de 60% da variância total dos resultados), que emtermos de explicação se poderá tomar como "fator geral de raciocínio",pois que subjacente à realização de qualquer uma das cinco provas
Processo de sobremoldação de vedante numa tampa plástica
O objeto da presente patente é o processo de sobremoldação de uma tampa
Plástica com vedante incorporado, na qual é injetado o material de maior dureza sobre o
De menor dureza. Este processo de sobremoldação é aplicado somente em bi-injecção
(utilização de dois materiais ou mais), em tampas plásticas rígidas para embalagens de
Forma redonda ou outras. A solução adotada passou por proteger o vedante (3) do fluxo
(9) do material da tampa (2) de modo a evitar que este cause deformações no vedante (3)
Durante o processo de enchimento. A forma de orientação precisa do fluxo (9) do sobre o
Material de menor dureza (3) evita a deformação deste ultimo recorrendo aos diferenciais
De pressão conjugados com a velocidade. Desta forma é possível injetar sobre um
Material de menor dureza (3), um material de maior dureza (2)
Severe community-acquired pneumonia in the intensive care unit
Introduction Community-acquired pneumonia remains a common condition worldwide. It is associated with significant morbidity and mortality. The aim of this study was to evaluate conditions that could predict a poor outcome
A CAE approach for the stress analysis of gear models by 3D digital photoelasticity
The use of numerical and experimental methods to determine the stress field of mechanical components is well known. In particular, 3D photoelasticity can be considered the only experimental technique for the complete stress state evaluation of 3D components. The advent of rapid prototyping techniques has allowed the manufacturing of complex models in a matter of hours by using birifrangent materials. The present paper is focused on the description of a Computer Aided Engineering (CAE) approach which combines Finite Element (FE) simulations and automatic photoelastic investigations for the stress analysis of face gear drives, made by stereolithography. Computer Aided Design (CAD) geometries, used to manufacture the stereolithographic models, are directly used to perform FE analyses, thus allowing the stress analysis process to become simpler and easier. The substantial agreement observed between experimental and numerical results proved the potentialities of the adopted approach and the usefulness of FE simulations to optimize photoelastic analyses through cost- and time-effective experiments even for complex 3D shapes
The molecular epidemiology of HIV-1 in the Comunidad Valenciana (Spain): analysis of transmission clusters
HIV infections are still a very serious concern for public heath worldwide. We have applied molecular evolution methods to study the HIV-1 epidemics in the Comunidad Valenciana (CV, Spain) from a public health surveillance perspective. For this, we analysed 1804 HIV-1 sequences comprising protease and reverse transcriptase (PR/RT) coding regions, sampled between 2004 and 2014. These sequences were subtyped and subjected to phylogenetic analyses in order to detect transmission clusters. In addition, univariate and multinomial comparisons were performed to detect epidemiological differences between HIV-1 subtypes, and risk groups. The HIV epidemic in the CV is dominated by subtype B infections among local men who have sex with men (MSM). 270 transmission clusters were identified (>57% of the dataset), 12 of which included ≥10 patients; 11 of subtype B (9 affecting MSMs) and one (n = 21) of CRF14, affecting predominately intravenous drug users (IDUs). Dated phylogenies revealed these large clusters to have originated from the mid-80s to the early 00 s. Subtype B is more likely to form transmission clusters than non-B variants and MSMs to cluster than other risk groups. Multinomial analyses revealed an association between non-B variants, which are not established in the local population yet, and different foreign groups
Origin and Epidemiological History of HIV-1 CRF14_BG
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Users must also make clear the license terms under which the work was published. CC BY Licence: http://creativecommons.org/licenses/by/4.0/Background: CRF14_BG isolates, originally found in Spain, are characterized by CXCR4 tropism and rapid disease
progression. This study aimed to identify the origin of CRF14_BG and reconstruct its epidemiological history based on new
isolates from Portugal.Methodology/Principal Findings: C2V3C3 env gene sequences were obtained from 62 samples collected in 1993–1998
from Portuguese HIV-1 patients. Full-length genomic sequences were obtained from three patients. Viral subtypes, diversity,
divergence rate and positive selection were investigated by phylogenetic analysis. The molecular structure of the genomes
was determined by bootscanning. A relaxed molecular clock model was used to date the origin of CRF14_BG. Geno2pheno
was used to predict viral tropism. Subtype B was the most prevalent subtype (45 sequences; 73%) followed by CRF14_BG (8;
13%), G (4; 6%), F1 (2; 3%), C (2; 3%) and CRF02_AG (1; 2%). Three CRF14_BG sequences were derived from 1993 samples.
Near full-length genomic sequences were strongly related to the CRF14_BG isolates from Spain. Genetic diversity of the
Portuguese isolates was significantly higher than the Spanish isolates (0.044 vs 0.014, P,0.0001). The mean date of origin of
the CRF14_BG cluster was estimated to be 1992 (range, 1989 and 1996) based on the subtype G genomic region and 1989
(range, 1984–1993) based on the subtype B genomic region. Most CRF14_BG strains (78.9%) were predicted to be CXCR4.
Finally, up to five amino acids were under selective pressure in subtype B V3 loop whereas only one was found in the
CRF14_BG cluster.Conclusions: CRF14_BG emerged in Portugal in the early 1990 s soon after the beginning of the HIV-1 epidemics, spread to
Spain in late 1990 s as a consequence of IVDUs migration and then to the rest of Europe. CXCR4 tropism is a general
characteristic of this CRF that may have been selected for by escape from neutralizing antibody response
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