845 research outputs found

    Two-scalar-field model for the interaction of dark energy and dark matter

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    In this paper, we study the effects of an interaction between dark matter and dark energy through a two scalar field model with a potential V(ϕ,χ)=e−λϕP(ϕ,χ)V(\phi,\chi)=e^{-\lambda\phi}P(\phi,\chi), where P(ϕ,χ)P(\phi,\chi) is a polynomial. We show that the cosmic expansion dynamics of the Universe is reproduced for a large range of the bare mass of the dark matter field and that there exist solutions with transient accelerated expansion. A modification in the exponential behavior of the potential is studied, with important physical implications, including the possibility of more realistic transient acceleration solutions.Comment: Version to match the one published in Physical Review D, 8 pages, 11 figure

    Long-term survival in a patient with brain metastases of papillary thyroid carcinoma

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    We present the case of a 43-year-old woman who underwent total thyroidectomy with bilateral lymphadenectomy for a papillary thyroid carcinoma (PTC), solid variant (T4bN1bMx), with V600E BRAF mutation. After ablative therapy, she presented undetectable thyroglobulin (Tg) but progressively increasing anti-Tg antibodies (TgAbs). During follow-up, nodal, lung and brain metastases were identified. She was submitted to surgical excision of lung lesions, radiosurgery of brain metastases and five radioiodine treatments. The latest brain MRI showed no lesions, pulmonary CT showed stable micronodules and there was progressive reduction in TgAbs. This is a peculiar case of a PTC with lung and brain metastatic lesions detected through TgAbs. Initial histological and molecular study suggested a more aggressive clinical behaviour, which was eventually confirmed. Although PTC brain metastases are extremely rare and present poor prognosis, our patient presented a good response to treatment and longer survival than usually reported for similar cases.info:eu-repo/semantics/publishedVersio

    Nomear objetos: uma questão de idade?

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    Poster apresentado no 2º Congresso Internacional de Saúde do Instituto Politécnico de Leiria, 9-10 Maio 2014, Leiria

    Carcinoma da Tiróide em Crianças e Jovens Adultos: Revisão Retrospectiva de 19 Casos

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    Introduction: Thyroid carcinoma is rare in children and young adults. Most of management guidelines are based in data from adult population. Several controversies remain regarding the aggressiveness of clinical presentation and therapeutic approach. Objective: To evaluate all differentiated thyroid carcinoma patients with less than 20 years-old at presentation reflecting the experience of our unit in relation to diagnosis, treatment and follow-up of this clinical entity. Material and Methods: This is a retrospective review of clinical records of all children and young adults followed at Oncology Consultation of Department of Endocrinology of Centro Hospitalar e Universitário de Coimbra between 1996 and 2012. Results: Nineteen patients with mean age of 16 years old were followed, 13 girls and 6 boys. None of the patients had previous neck irradiation. A palpable cervical mass was the presenting complaint in 84.6%. FNA was performed in 15 patients and was diagnostic or suspicious of malignancy in 71.4%. Total thyroidectomy was performed in 18 cases (94.7%). Papillary carcinoma was identified in all. Vascular invasion and multicentry occurred in 21.1%. Mean tumor size was 2.5cm. Cervical lymph node involvement was diagnosed in 31.6% and distant metastases in 5.2%. The majority of patients (18 in 19) were classified as stage I disease. All patients received thyroxine suppressive therapy and postoperative radioiodine ablation was given to 84.2% (mean dose 85.7mCi). During mean follow-up of almost 6 years, 16 patients remain disease free. Conclusion: In our series, cervical lymph node and distant metastases rates were similar to that found in adult population. Overall prognosis was very good

    ShakeMap: Combinação de observações instrumentais e macrossísmicas

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    Since 2008, the Portuguese seismological service, has implemented the ShakeMap software package provided by U.S. Geological Survey (USGS), in order to obtain reliable maps of peak ground motion parameters and seismic intensities for mainland Portugal. These maps identify the area affected by the earthquake and estimate the severity of ground shaking, thus providing important information for emergency response planning and for the general public. The maps are produced based on regional constraints from instrumental ground motions and site amplifications. In late 2009, USGS released a new version (V3.5) of ShakeMap software with added features. The new approach introduces several changes in the existing ShakeMap methodology, allowing the combination of direct observations (observed peak ground motion and seismic intensities), observations converted parameters and estimates. Some results are presented and discussed in this work

    Direct determination of plant-growth related metabolites by capillary electrophoresis with spectrophotometric UV detection

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    The detection of plant hormones and growth regulators is of great interest for many biological studies especially in the determination of metabolites related to plan growth and differentiation. In this work, we propose a simple method based on capillary electrophoresis (CE) for the separation of different classes of plant growth regulators such as auxins, cytokinins, gibberelic acid and abscisic acid. CE with UV detection was used and the analytical conditions were as follows: phosphate buffer 25 mmol L-1, for all the measurements and the separation conditions pH 12 or 2.5, by hydrodynamic injection 5 s at 10 cm and separation voltage of 22 kV. The absorbance detection was fixed at either 220 nm or 270 nm depending on a given phytohormone class. Under these conditions, phytohormones (Indole-3-acetic acid (IAA), Gibberellic acid (GA3), Abscisic acid (ABA), picloram, zeatin and 6-Benzylaminopurine (BAP) were separated in approximately 3 to 5 min. The plant material used to verify the possibility of detection of hormone/plant growth regulators was citro (Citrus sinensis L. Osbeck) callus in the multiplication stage. In the plant tissue sample, zeatin was successfully detected. The results confirmed the potential use of CE as an efficient alternative and simple method to the classical procedures used for phytohormone detection in plant tissues.A detecção de hormônios e reguladores de crescimento em plantas é de grande interesse em uma enorme variedade de estudos biológicos. Visando este propósito nós desenvolvemos um método simples baseado em eletroforese capilar (CE) para a separação de diferentes classes de reguladores de crescimento de plantas como as auxinas, citocinina, ácidos giberélico e abscíssico. Foi utilizada CE, com detecção na região de UV; as condições de separação foram: fosfato de potássio como tampão, em concentração de 25 mmol L-1, pH 12 ou 2,5, tempo de injeção 5 s, elevando por sinfonamento o capilar, à altura de 10 cm e voltagem de separação de 22 kV. A absorbância foi fixada a 220 nm ou 270 nm, dependendo da classe do fitohormônio. Nestas condições os fitohormônios (IAA, GA3, ABA, picloram, zeatina e BAP) foram separados em um tempo de 3 a 5 min. O material oriundo de planta para verificar a possibilidade de detecção de hormônio/reguladores de crescimento de plantas foi a citro (Citrus sinensis L. Osbeck) callus no estágio de multiplicação. Na amostra de tecido de planta, a zeatina foi detectada com sucesso. Os resultados confirmaram a pontencialidade do uso de CE como um método eficiente, de baixo custo e alternativo para a detecção dessa classe de compostos em tecidos de plantas.FAPESPCNP

    The identification of multiple thrombophilic risk factors in an infant with cerebrovascular accident

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    We found 1 article: Rev Neurol. 2005 Apr 16-30;40(8):479-81. [The identification of multiple thrombophilic risk factors in an infant with cerebrovascular accident] [Article in Spanish] Neves J, Costa E, Branca R, Carrilho I, Barbot J, Barbot C. Servicio de Hematología, Hospital de Crianças Maria Pia, 4050-111 Porto, Portugal. Abstract INTRODUCTION: Neonatal stroke (NNS) incidence appears to be increasing over the last years. This is believed to be a consequence of diagnostic accuracy rather than a real amplification of this entity. Nowadays, NNS incidence is estimated to be 1:4000 full newborns. CASE REPORT: Child with left middle cerebral artery territory infarction in which several thromboembolic risk factors were documented both in the child (neonatal sepsis and factor V Leiden) and his mother (lupus anticoagulant, pre-eclampsy and factor V Leiden). CONCLUSIONS: This case supports the increasing evidence in recent reports that association of multiple prothrombotic risk factors (maternal and foetal) is present in NNS genesis. This way the authors agree that wide prothrombotic study may be of crucial interest in identifying subjacent thrombophilic disease, even when an exogenous risk factor is present. PMID: 15861329 [PubMed - indexed for MEDLINE
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