1,315 research outputs found

    FILOU oscillation code

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    The present paper provides a description of the oscillation code FILOU, its main features, type of applications it can be used for, and some representative solutions. The code is actively involved in CoRoT/ESTA exercises (this volume) for the preparation for the proper interpretation of space data from the CoRoT mission. Although CoRoT/ESTA exercises have been limited to the oscillations computations for non-rotating models, the main characteristic of FILOU is, however, the computation of radial and non-radial oscillation frequencies in presence of rotation. In particular, FILOU calculates (in a perturbative approach) adiabatic oscillation frequencies corrected for the effects of rotation (up to the second order in the rotation rate) including near degeneracy effects. Furthermore, FILOU works with either a uniform rotation or a radial differential rotation profile (shellular rotation), feature which makes the code singular in the field.Comment: 6 pages, 5 figures. Astrophysics and Space Science (in press

    Lack of mutagenic effect by multi-walled functionalized carbon nanotubes in the somatic cells of Drosophila melanogaster

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    AbstractCarbon nanotubes (CNTs) are formed by rolling up a single graphite sheet into a tube. Among the different types of CNTs, the multi-walled carbon nanotubes (MWCNTs) comprise a set of concentric nanotubes with perfect structures. Several uses for MWCNTs have been suggested to be included in biological applications such as manufacturing of biosensors, carriers of drugs. However, before these materials can be put on the market, it is necessary to know their genotoxic effects. Thus, this study aims to evaluate the mutagenicity of multi-walled carbon nanotubes (MWCNTs) functionalized in somatic cells of Drosophila melanogaster, using the somatic mutation and recombination test (SMART). This assay detects the loss of heterozygosity of marker genes expressed phenotypically on the wings of the fly. Larvae of three days were used, resulting from ST cross, with basal levels of the cytochrome P450 and larvae of high metabolic bioactivity capacity (HB cross). They were treated with different concentrations of MWCNTs functionalized. The MH descendants, analyzed in both ST and HB crosses, had no significant effects on the frequency of mutant. Based on the results and on the experimental conditions mentioned in this study, it was concluded that MWCNTs were not mutagenic in D. melanogaster

    Substrate specificity and the effect of calcium on Trypanosomabrucei metacaspase 2

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    Metacaspases are cysteine peptidases found only in yeast, plants and lower eukaryotes, including the protozoa. To investigate the extended substrate specificity and effects of Ca<sup>2+</sup> on the activation of these enzymes, detailed kinetic, biochemical and structural analyses were carried out on metacaspase 2 from Trypanosoma brucei (TbMCA2). These results reveal that TbMCA2 has an unambiguous preference for basic amino acids at the P<sub>1</sub> position of peptide substrates and that this is most probably a result of hydrogen bonding from the P<sub>1</sub> residue to Asp95 and Asp211 in TbMCA2. In addition, TbMCA2 also has a preference for charged residues at the P<sub>2</sub> and P<sub>3</sub>positions and for small residues at the prime side of a peptide substrate. Studies into the effects of Ca<sup>2+</sup> on the enzyme revealed the presence of two Ca<sup>2+</sup> binding sites and a reversible structural modification of the enzyme upon Ca<sup>2+</sup> binding. In addition, the concentration of Ca<sup>2+</sup> used for activation of TbMCA2 was found to produce a differential effect on the activity of TbMCA2, but only when a series of peptides that differed in P<sub>2</sub> were examined, suggesting that Ca<sup>2+</sup>activation of TbMCA2 has a structural effect on the enzyme in the vicinity of the S2 binding pocket. Collectively, these data give new insights into the substrate specificity and Ca<sup>2+</sup> activation of TbMCA2. This provides important functional details and leads to a better understanding of metacaspases, which are known to play an important role in trypanosomes and make attractive drug targets due to their absence in humans

    Branding in the digital age : a '2020' vision for brand management

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    The proliferation of digital media, together with increasingly mobile internet connectivity, has arguably been the most significant influence on brands and brand management in the first two decades of this millennium. An important development in academic research on branding and marketing in this time has been the widening spectrum of research methods, as well as topics – ranging from qualitative and experiential to highly technical and (big)data-based approaches. In many ways, this development reflects that modern-day branding is a multidisciplinary scientific artform. Successful branding needs more than marketers; it needs ethnographers, designers, and data-scientists alike to overcome challenges and firmly grasp the opportunities that the digital age brings. What guidance can we provide to them for successful branding in the digital age? Combining the findings from the five papers included in this Internet Research special section and insights from leading practitioners, we present brands with a clearer ('20/20') vision for successful branding from the year 2020 onwards. We do so in this editorial essay by identifying and elaborating on four crucial foci for branding that are intrinsically associated with a brand’s identity: transparency, responsibility, connectivity, and creativity

    The Bronchiectasis Severity Index and FACED score for assessment of the severity of bronchiectasis

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    Bronchiectasis (BC) is a multidimensional and etiologically diverse disease and, therefore, no single parameter can be used to determine its overall severity and prognosis. In this regard, two different validated scores are currently used to assess the severity of non-cystic fibrosis bronchiectasis (NCFB): the FACED score and the Bronchiectasis Severity Index (BSI).info:eu-repo/semantics/publishedVersio

    Creation of antimicrobial biopolymers by the use of recombinant DNA technology

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    [Excerpt] The spread of antimicrobials resistant microorganisms has triggered the search for new ways to treat infections. One of these ways is the creation of antimicrobial devices and surfaces that kill or prevent the spread of microorganisms. In the present work we explored the properties of different antimicrobial peptides (AMPs) for the creation of biopolymers with broad antimicrobial activity. Antimicrobial recombinant protein-based polymers (rPBPs) were designed by cloning the DNA sequence coding for the different AMPs in frame with the N-terminus of the elastin-like recombinamer consisting of 200 repetitions of the pentamer VPAVG, here named A200. [...]This work was supported by the strategic programme UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569) funded by national funds through the FCT I.P. and by the ERDF through the COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI). By the Spanish Minister of Economy and Competitiveness (MAT2012-38043-C02-01) and Junta de Castilla y León-JCyL (VA152A12-2 and VA155A12-2), Spain. AC and RM, acknowledge FCT for SFRH/BD/75882/2011 and SFRH/BPD/86470/2012 grants, respectively

    Structural study of Cu2x_{2-x}Se alloys produced by mechanical alloying

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    The crystalline structures of superionic high temperature copper selenides Cu2x_{2-x}Se (0x0.250 \le x \le 0.25) produced by Mechanical Alloying were investigated using X-ray diffraction (XRD) technique. The measured XRD patterns showed the presence of the peaks corresponding to the crystalline superionic high temperature α\alpha-Cu2_2Se phase in the as-milled sample, and its structural data were determined by means of a Rietveld refinement procedure. After a heat treatment in argon at 200^\circC for 90 h, this phase transforms to the superionic high temperature α\alpha-Cu1.8_{1.8}Se phase, whose structural data where also determined through the Rietveld refinement. In this phase, a very low occupation of the trigonal 32(f) sites (3\sim 3%) by Cu ions is found. In order to explain the evolution of the phases in the samples, two possible mechanisms are suggested: the high mobility of Cu ions in superionic phases and the intense diffusive processes in the interfacial component of samples produced by Mechanical Alloying.Comment: 2 figures, submitted to Acta Crystallographic

    Estudo da mutação do recetor do fator de crescimento epidérmico, durante 5 anos, numa população de doentes com cancro do pulmão de não pequenas células

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    ResumoIntroduçãoEm 2006, a Unidade de Pneumologia Oncológica do Serviço de Pneumologia do Centro Hospitalar de Vila Nova de Gaia/Espinho iniciou a sequenciação da mutação do recetor do fator de crescimento epidérmico (EGFR) em doentes com CPNPC selecionados e desde 2010 realiza a sequenciação sistematicamente em todos os doentes, independentemente da histologia, hábitos tabágicos, idade ou sexo. O objetivo deste trabalho foi caracterizar o grupo de doentes que efetuou a sequenciação entre 2006-2010, determinar a frequência da mutação EGFR, avaliar as sobrevidas globais e após uso de inibidores da tirosina quinase (ITK), nos doentes que efetuaram esta terapêutica em 2.a e 3.a linha com conhecimento do estado da mutação do EGFR.MétodosAnálise estatística descritiva dos doentes que efetuaram sequenciação EGFR em 2006-2010 e sobrevida mediana global nos doentes que efetuaefetuaram ITK em 2.a e 3.a linha. Registo do material disponível para análise e demora média de resultado do exame, de acordo com o material enviado.ResultadosA sequenciação foi efetuada em 374 doentes, 71,1% sexo masculino, 67,1% não/ex-fumadores, 32,9% fumadores; 57,8% adenocarcinoma e 23,5% carcinoma epidermoide (CE). A mutação foi detetada em 49 doentes (13,1%). No total dos doentes estudados, a taxa de mutação foi de 9% no sexo masculino e 23% no sexo feminino. A sobrevida mediana global após o uso de erlotinib foi de 14 meses para os doentes com mutação positiva do EGFR versus 6 meses nos doentes não mutados (p = 0,003).ConclusãoO nosso grupo teve uma taxa de mutação global de 13,1%, com predomínio no sexo feminino, não fumadores, histologia adenocarcinoma. Em doentes selecionados (2006/2009), a taxa de mutação foi de 16%; nos doentes não selecionados (2010) foi de 10,4%. Este estudo tem vindo a permitir um melhor conhecimento da taxa de mutação do EGFR na população portuguesa, bem como avaliar os resultados das sobrevidas dos doentes após uso de inibidores da tirosina quinase (ITK), efetuada em 2.a e 3.a linha com conhecimento prévio do estado da mutação do EGFR, tendo sido encontradas diferenças nas sobrevidas nos 2 grupos de doentes (mutados e não mutados) com significado estatístico.A pesquisa mutação do EGFR deve ser efetuada em todos os doentes com CPNPC, dando possibilidade a um número considerável de doentes de poder efetuar um tratamento de 1.a linha com ITK (doentes mutados), bem como de poder usufruir de outros esquemas de quimioterapia, quando progredirem.AbstractIntroductionIn 2006, the Vila Nova de Gaia/Espinho Hospital Centre Pulmonary Oncology Unit started performing EGFR (Epidermal Growth Factor Receptor) mutation sequencing in selected patients with NSCLC and systematically in all patients since 2010, regardless of histology, smoking habits, age or sex. The aim of this study was to characterize the group of patients that carried out the sequencing between 2006-2010, to determine EGFR mutation frequency, to evaluate the overall survival and the survival after the use of tyrosine kinase inhibitors (TKI), in patients who performed this therapy in second and third line, knowing the EGFR mutation status.MethodsDescriptive statistical analysis of patients who did EGFR sequencing in 2006-2010 and of overall survival in patients treated with TKI as 2nd and 3rd line therapy. Record of the material available for analysis and average delay of exam results, according to the material submitted.ResultsThe sequencing was performed in 374 patients, 71,1% males, 67,1% non/ex-smokers, 32,9% smokers, 57,8% adenocarcinoma and 23,5% squamous cell carcinoma (SCC). The mutation was detected in 49 patients (13,1%). In all studied patients, the mutation rate was 9% in males and 23% in females. Median overall survival after erlotinib use of was 14 months for patients with positive EGFR mutation versus 6 months in not mutated patients (p = 0.003).ConclusionOur group had an overall mutation rate of 13.1% with female, non-smokers, adenocarcinoma histology predominance. In selected patients (2006/2009), the mutation rate was 16%, in not selected patients (2010) the mutation rate was 10.4%. This study has permitted a better understanding of the EGFR mutation rate in the Portuguese population as welll as an evaluation of the patients survival after the use of of tyrosine kinase inhibitors, in second and third line therapy with previous knowledge of the EGFR mutational status. Statistical significant differences in survival were found in the two patient groups (EGFR mutated and non mutated).The EGFR mutation research should be performed in all patients with NSCLC, giving the possibility to a considerable number of patients to perform a first line treatment with TKI (EGFR mutated patients) and the advantage of performing other chemotherapy schemes, when progression occurs

    C/EBPβ regulates homeostatic and oncogenic gastric cell proliferation

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    Cancer of the stomach is among the leading causes of death from cancer worldwide. The transcription factor C/EBPβ is frequently overexpressed in gastric cancer and associated with the suppression of the differentiation marker TFF1. We show that the murine C/EBP{beta} knockout stomach displays unbalanced homeostasis and reduced cell proliferation and that tumorigenesis of human gastric cancer xenograft is inhibited by knockdown of C/EBPβ. Cross-species comparison of gene expression profiles between C/EBPβ-deficient murine stomach and human gastric cancer revealed a subset of tumors with a C/EBPβ signature. Within this signature, the RUNX1t1 tumor suppressor transcript was down-regulated in 38% of gastric tumor samples. The RUNX1t1 promoter was frequently hypermethylated and ectopic expression of RUNX1t1 in gastric cancer cells inhibited proliferation and enhanced TFF1 expression. These data suggest that the tumor suppressor activity of both RUNX1t1 and TFF1 are mechanistically connected to C/EBPβ and that cross-regulation between C/EBPβ-RUNX1t1-TFF1 plays an important role in gastric carcinogenesis
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