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É um repositório para instituições de ensino e investigação produtoras de literatura científica cuja dimensão ainda não justifica a criação de um repositório próprio. Permite integrar instituições, grupos ou indivíduos na infra-estrutura do projecto, nomeadamente através das pesquisas do Portal RCAAP e da B-On.

Artigos científicos

Mostrando recursos 1 - 20 de 35

  1. A computerized tomography study of the morphological interrelationship between the temporal bones and the craniofacial complex

    Costa, Hélder Nunes; Slavicek, Rudolf; Sato, Sadao
    "The hypothesis that the temporal bones are at the center of the dynamics of the craniofacial complex, directly influencing facial morphology, has been put forward long ago. This study examines the role of the spatial positioning of temporal bones (frontal and sagittal inclination) in terms of influencing overall facial morphology. Several 3D linear, angular and orthogonal measurements obtained through computerized analysis of virtual models of 163 modern human skulls reconstructed from Cone-beam Computed Tomography (CBCT) images were analyzed and correlated. Additionally, the sample was divided into two subgroups based on the median value of temporal bone sagittal inclination [anterior rotation...

  2. Fsy1, the sole hexose-proton transporter characterized in Saccharomyces yeasts, exhibits a variable fructose:H+ stoichiometry

    Anjos, Jorge; Sousa, Helena Rodrigues de; Roca, Christophe; Cássio, Fernanda; Luttik, Marijke; Pronk, Jack T.; Salema-Oom, Madalena; Gonçalves, Paula
    "In the model yeast Saccharomyces cerevisiae, hexose uptake is mediated exclusively by a family of facilitators (Hxt, hexose transporters). Some other Saccharomyces species (e.g. Saccharomyces bayanus and Saccharomyces pastorianus) possess, in addition, a specific fructose transporter (Fsy1, fructose symporter) that has been previously described to function as a proton symporter. In the present work, we compared growth of a yeast strain in which FSY1 occurs naturally in anaerobic, fructose- and glucose-limited chemostat cultures. Especially at low specific growth rates, fructose-proton symport was shown to have a strong impact on the biomass yield on sugar. We subsequently employed energized hybrid plasma...

  3. Is menopause associated with an increased risk of tooth loss in patients with chronic periodontitis?

    Alves, Ricardo Castro; Félix, Sérgio Antunes; Rodriguez Archilla, Alberto
    "Objetivos: Analisar o possível efeito da menopausa sobre a perda dentária em mulheres com periodontite crónica. Materiais e Métodos: 102 mulheres entre os 35 e 80 anos com periodontite crónica e pelo menos seis dentes foram divididas em dois grupos: grupo de estudo (GE) constituído por 68 mulheres na menopausa e grupo controle (GC) constituído por 34 mulheres pré-menopáusicas. Foi aplicado um questionário onde se recolheram diversos dados sociodemográficos, história clínica geral e oral, antecedentes ginecológicos e hábitos. Adicionalmente, foram avaliados diversos parâmetros orais e periodontais incluindo: número de dentes, índice de placa, presença de tártaro, profundidade de sondagem, hemorragia à sondagem, recessão gengival e perda de inserção. Na análise estatística...

  4. Determinants of highly active antiretroviral therapy duration in HIV-1-infected children and adolescents in Madrid, Spain, from 1996 to 2012

    Palladino, Claudia; Briz, Verónica; Bellón, José María; Climent, Francisco J.; De Ory, Santiago J.; Mellado, María José; Navarro, María Luisa; Ramos, José T.; Taveira, Nuno; De José, María Isabel; Munõz-Fernandes, María Ángeles; CoRISpeS-Madrid Cohort Working Group
    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.

  5. Predictors of attrition and immunological failure in HIV- 1 patients on highly active antiretroviral therapy from different healthcare settings in Mozambique

    Palladino, Claudia; Briz, Verónica; Bellón, José María; Bártolo, Inês; Carvalho, Patrícia; Camacho, Ricardo; Munõz-Fernandes, M. Ángeles; Bastos, Rui; Manuel, Rolanda; Casanovas, José; Taveira, Nuno
    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:

  6. Evolution of the human immunodeficiency virus type 2 envelope in the first years of infection is associated with the dynamics of the neutralizing antibody response

    Rocha, Cheila; Calado, Rita; Borrego, Pedro; Marcelino, José Maria; Bártolo, Inês; Rosado, Lino; Cavaco-Silva, Patrícia; Perpétua, Gomes; Família, Carlos; Quintas, Alexandre; Skar, Helena; Leitner, Thomas; Barroso, Helena; Taveira, Nuno
    "Background: Differently from HIV-1, HIV-2 disease progression usually takes decades without antiretroviral therapy and the majority of HIV-2 infected individuals survive as elite controllers with normal CD4+ T cell counts and low or undetectable plasma viral load. Neutralizing antibodies (Nabs) are thought to play a central role in HIV-2 evolution and pathogenesis. However, the dynamic of the Nab response and resulting HIV-2 escape during acute infection and their impact in HIV-2 evolution and disease progression remain largely unknown. Our objective was to characterize the Nab response and the molecular and phenotypic evolution of HIV-2 in association with Nab escape in the first years of infection in...

  7. An ancestral HIV-2/simian immunodeficiency virus peptide with potent HIV-1 and HIV-2 fusion inhibitor activity

    Borrego, Pedro; Calado, Rita; Marcelino, José M.; Pereira, Patrícia; Quintas, Alexandre; Barroso, Helena; Taveira, Nuno
    "Objectives: To produce new fusion inhibitor peptides for HIV-1 and HIV-2 based on ancestral envelope sequences. Methods: HIV-2/simian immunodeficiency virus (SIV) ancestral transmembrane protein sequences were reconstructed and ancestral peptides were derived from the helical region 2 (HR2). The activity of one ancestral peptide (named P3) was examined against a panel of HIV-1 and HIV-2 primary isolates in TZM-bl cells and peripheral blood mononuclear cells and compared to T-20. Peptide secondary structure was analyzed by circular dichroism. Resistant viruses were selected and resistance mutations were identified by sequencing the env gene. Results: P3 has 34 residues and overlaps the N-terminal pocket-binding region and heptad repeat core of HR2. In contrast...

  8. The feasibility of wavelength dispersive X-ray fluorescence spectrometry for the assessment of lead concentration in animal bone powder

    Brito, José A. A. de; Cavaleiro, Inês I. B.; Fernandes, Tânia A. P.; Gonçalves, Luísa M. L.
    "This work demonstrates the feasibility of wavelength dispersive X-ray fluorescence for the assessment of lead in animal bone powder."

  9. Statistical and mathematical concepts and principles applicable to uncertainty calculations for the measurement of in vivo bone lead by 109Cd K X ray fluorescence

    Brito, José A. A. de
    "This work discusses the statistical and mathematical concepts and principles applicable to in vivo 109Cd K X Ray Fluorescence measurements (109Cd KXRF) of lead in human bone. The primary aim of this paper is to examine divergent views about the quantitative methods applied to estimate in vivo bone lead concentrations and their uncertainty when using the 109Cd KXRF technique. The emphasis is on the potential effect of covariance between quantities of interest on the result of an in vivo measurement of bone lead by 109Cd KXRF, a question which has received little attention in view of the long standing problem of why the average measurement...

  10. Different manifestations of class II division 2 incisor retroclination and their association with dental anomalies

    Pereira, Pedro Mariano; Ferreira, Afonso Pinhão; Tavares, Purificação; Braga, Ana Cristina
    "Objective: To investigate whether there is an association between dental development anomalies (DDAs) and the different manifestations of Class II Division 2 (CII/2) malocclusion incisor retroclination. This information may clarify whether the different CII/2 phenotypes, with regard to maxillary incisor retroclination, are a single clinical entity or etiologically different entities. Design: Retrospective comparative study. Setting: Private orthodontic practice in the regions of Lisbon and Porto, Portugal Subjects and Methods: The sample comprised 115 CII/2 malocclusions distributed into 2 groups on the basis of incisor retroclination: Group I composed of 48 CII/2 with retroclination exclusively of both maxillary central incisors; Group II composed of...

  11. Different manifestations of Class II Division 2 incisor retroclination – Morphologic study

    Pereira, Pedro Mariano; Ferreira, Afonso Pinhão; Tavares, Purificação; Braga, Ana Cristina
    "Introduction: The aim of the present study was to investigate whether there is a different transverse morphologic pattern of dental arches among the different manifestations of Class II Division 2 incisor retroclination and evaluate to what extent the pattern of smaller-than-average teeth in Class II Division 2 malocclusion is common to all groups studied. This information may clarify whether different Class II Division 2 phenotypes represent a single etiology or multiple etiologies. Methods: The sample comprised 108 Class II Division 2 malocclusions which were divided into two groups according to the type of incisor retroclination: Group I composed of 43...

  12. Associação da má oclusão de Classe II Divisão 2 com anomalias do desenvolvimento dentário

    Pereira, Pedro Mariano; Ferreira, Afonso Pinhão; Tavares, Purificação; Braga, Ana Cristina

  13. Enhanced bioproduction of poly-3-hydroxybutyrate from wheat straw lignocellulosic hydrolysates

    Cesário, M. Teresa; Raposo, Rodrigo S.; Almeida, M. Catarina M. D. de; Keulen, Frederik van; Ferreira, Bruno S.; Fonseca, M. Manuela R. da
    "Polyhydroxyalkanoates (PHAs) are bioplastics that can replace conventional petroleum derived products in various applications. One of the major barriers for their widespread introduction in the market is the higher production costs when compared with their petrochemical counterparts. In this work, a process was successfully implemented with high productivity based on wheat straw, a cheap and readily available agricultural residue, as raw material. The strain Burkholderia sacchari DSM 17165 which is able to metabolize glucose, xylose and arabinose, the main sugars present in wheat straw hydrolysates (WSH), was used. Results in shake flask showed that B. sacchari cells accumulated ca 70...

  14. Small electron transfer proteins as mediators in enzymatic electrochemical biosensors

    Silveira, Célia M.; Almeida, M. Gabriela
    "Electrochemical mediators transfer redox equivalents between the active sites of enzymes and electrodes and, in this way, trigger bioelectrocatalytic redox processes. This has been very useful in the development of the so-called second generation biosensors, where they are able to transduce the catalytic event into an electrical signal. Among other pre-requisites, redox mediators must be readily oxidized/reduced at the electrode surface and easily interact with the biorecognition component. Small chemical compounds (e.g. ferrocene derivatives, ruthenium or osmium complexes and viologens) are frequently used for this purpose, but lately, small redox proteins (e.g. horse heart cytochrome c) have also played the role of redox partners in biosensing applications. In general,...

  15. Probing the surface chemistry of different oxidized MWCNT for the improved electrical wiring of cytochrome c nitrite reductase

    Silveira, Célia M.; Pimpão, Marta; Pedroso, Humberto A.; Rodrigues, Patrícia R. S.; Moura, José J. G.; Pereira, Manuel F. R.; Almeida, M. Gabriela
    "This work reports the evaluation of a set of multi-walled carbon nanotubes (MWCNT) presenting different surface chemistries, as interfaces for the direct electrochemistry of the multihemic nitrite reductase (ccNiR) from Desulfovibrio desulfuricans ATCC27774 (Dd). The carbon nanotubes dispersions were prepared in aqueous media and deposited on pyrolytic graphite (PG) macroelectrodes, following a layer-by-layer methodology. The resulting MWCNT bed was coated with ccNiR and studied by cyclic voltammetry. Interestingly, although small non-catalytic cathodic waves were detected in all carbon nanotubes bioconjugates, the complexity of these electrochemical signals was partially deconvoluted in some materials, the less acidic ones emphasizing the contribution of the catalytic centre. Consistently, these MWCNT were the most...

  16. Effects of large pressure amplitude low frequency noise in the parotid gland perivasculo-ductal connective tissue

    Oliveira, Pedro; Brito, José; Mendes, João; Fonseca, Jorge da; Águas, Artur; Martins dos Santos, José
    "Introduction: In tissues and organs exposed to large pressure amplitude low frequency noise fibrosis occurs in the absence of inflammatory signs, which is thought to be a protective response. In the parotid gland the perivasculo-ductal connective tissue surrounds arteries, veins and the ductal tree. Perivasculo-ductal connective tissue is believed to function as a mechanical stabilizer of the glandular tissue. Material and Methods: In order to quantify the proliferation of perivasculo-ductal connective tissue in large pressure amplitude low frequency noise-exposed rats we used sixty Wistar rats which were equally divided into 6 groups. One group kept in silence, and the remaining five exposed to continuous large pressure...

  17. Osteotomy at low-speed drilling without irrigation versus high-speed drilling with irrigation: an experimental study

    Gaspar, João; Borrecho, Gonçalo; Oliveira, Pedro; Salvado, Francisco; Martins dos Santos, José
    "Introduction: Excessively traumatic surgery can adversely affect the maturation of bone tissue and consequently diminish the predictability of osseointegration so the mechanical and thermal damage should be minimized during surgical procedure. The purpose of this study is to evaluate immediate histological alterations in rabbit tibias, produced by low speed drilling (50 rpm) without irrigation and conventional drilling (800 rpm) under profuse irrigation. Material and Methods: Thirty-six implant osteotomies were created in the tibias of 6 White female rabbits. Drilling began with a 1.5 mm round bur, followed by 2.0 mm, 2.5 mm and 3.5 mm helical drills. The posterior tibial cortex was evaluated as the...

  18. Immunohistochemical evaluation of cardiac connexin43 in rats exposed to low-frequency noise

    Antunes, Eduardo; Borrecho, Gonçalo; Oliveira, Pedro; Brito, José; Águas, Artur; Martins dos Santos, José
    "Introduction: Low-frequency noise (LFN) leads to an abnormal proliferation of collagen and development of tissue fibrosis. It has been shown that myocardial fibrosis in association with gap junction remodeling occurs in several cardiac diseases and can be implicated in the development of ventricular tachyarrhythmias. We previously reported a strong development of myocardial fibrosis induced by LFN in rats but it is not known whether LFN induces any modification on cardiac connexin43 (Cx43). Objectives: The aim of this study was to evaluate modifications on cardiac Cx43 induced by LFN in Wistar rats. Methods: Two groups of rats were considered: A LFN-exposed...

  19. Effects of low-frequency noise on cardiac collagen and cardiomyocyte ultrastructure: an immunohistochemical and electron microscopy study

    Antunes, Eduardo; Borrecho, Gonçalo; Oliveira, Pedro; Matos, António P. Alves de; Brito, José; Águas, Artur; Martins dos Santos, José
    "Introduction: Low-frequency noise (LFN) leads to the development of tissue fibrosis. We previously reported the development of myocardial and perivascular fibrosis and a reduction of cardiac connexin43 in rats, but data is lacking concerning the affected type of collagen as well as the ultrastructural myocardial modifications. Objectives: The aim of this study was to quantify cardiac collagens I and III and to evaluate myocardial ultrastructural changes in Wistar rats exposed to LFN. Methods: Two groups of rats were considered: A LFN-exposed group with 8 rats continuously submitted to LFN during 3 months and a control group with 8 rats. The...

  20. Effects of industrial noise on circumpulpar dentin - a field emission scanning electron microscopy and energy dispersive spectroscopy analysis

    Cavacas, Maria Alzira; Tavares, Vitor; Oliveira, Maria João; Oliveira, Pedro; Sezinando, Ana; Martins dos Santos, José
    "Chronic exposure to Industrial Noise (IN), rich in Low Frequency Noise (LFN), causes systemic fibrotic transformation and sustained stress. Dental wear, significantly increased with exposure to LFN, affects the teeth particularly through the circumpulpar dentin. Our goal is to understand the consequences of IN exposure on the circumpulpar dentin of Wistar rats. 10 Wistar rats were exposed to IN for 4 months, according to an occupationally simulated time schedule and 10 animals were used as age-matched controls. The first and the second upper and lower molars of each animal were processed for observation by Field Emission Scanning Electron Microscopy (FESEM)...

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