13 resultados para C. Grandis L. Osbeck
em Universidade do Minho
Resumo:
The aim of this study was to characterize sweet cherry regarding nutritional composition of the fruits, and individual phytochemicals and bioactive properties of fruits and stems. The chromatographic profiles in sugars, organic acids, fatty acids, tocopherols and phenolic compounds were established. All the preparations (extracts, infusions and decoctions) obtained using stems revealed higher antioxidant potential than the fruits extract, which is certainly related with its higher phenolic compounds (phenolic acids and flavonoids) concentration. The fruits extract was the only one showing antitumor potential, revealing selectivity against HCT-15 (colon carcinoma) (GI50~74 μg/mL). This could be related with anthocyanins that were only found in fruits and not in stems. None of the preparations have shown hepatotoxicity against normal primary cells. Overall, this study reports innovative results regarding chemical and bioactive properties of sweet cherry stems, and confirmed the nutritional and antioxidant characteristics of their fruits.
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This paper presents a novel architecture of a bidirectional bridgeless interleaved converter for battery chargers of electric vehicles (EVs). The proposed converter is composed by two power stages: an ac-dc converter that is used to interface the power grid and the dc-link, and a dc-dc converter that is used to interface the dc-link and the batteries. The ac-dc converter is an interleaved bridgeless bidirectional boost-type converter and the dc-dc converter is a bidirectional buck-boost-type converter. The proposed converter works with sinusoidal grid current and with high power factor for all operating power levels, and in both grid-to-vehicle (G2V) and vehicle-to-grid (V2G) operation modes. In the paper is described in detail the proposed converter for EV battery chargers: the circuit topology, the principle of operation, the power control theory, and the current control strategy. Several simulation results for both G2V and V2G operation modes are presented.
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O presente artigo centra-se na análise do marketing socioambiental, promovido por empresas do setor energético, bem como o papel da sociedade civil, por intermédio, dos movimentos populares de reivindicação, contra os postes e linhas de alta e muito alta tensão em áreas residenciais na União Europeia e, especificamente, em Portugal. O processo de urbanização crescente e o modo de vida urbano desenfreado acarretaram mudanças substanciais no tecido urbano, sobretudo, no que diz respeito ao avanço das linhas aéreas de energia elétrica. Desde a década de 1960, uma série de estudos foram desenvolvidos sobre os efeitos destas infraestruturas tecnológicas em áreas residenciais. Apesar do intenso debate ainda não existem resultados consensuais quanto à sua influência na saúde das populações. Não obstante, diversos organismos internacionais, tais como, a Organização Mundia l de Saúde (OMS) e a Comissão Internacional de Proteção Contra Radiação Não - Ionizante (ICNIRP), já estabeleceram parâmetros de precaução, a partir da fixação de valores de exposição, tanto em termos ocupacionais , quanto para a população. Neste sentido, objetiva-se com a presente comunicação analisar o papel do marketing socioambiental, a partir da participação popular, dos movimentos internacionais e nacionais contra a alta tensão, sobretudo em Portugal. A pesquisa centrou-se numa abordagem qualitativa de fontes secundárias de dois blogues e cinco jornais nacionais que apresentavam notÃcias sobre a constituição e as manifestações realizadas pelo Movimento Nacional Contra Linhas de Alta Tensão em Zonas Habitadas. Este Movimento teve a sua origem no Sul de Portugal e difundiu-se por todo o paÃs recrutando indivÃduos preocupados com a instalação das novas e das já existentes linhas aéreas de energia elétrica. O Movimento ganhou força a nÃvel nacional com o apoio de partidos polÃticos. Também foi realizado trabalho de campo em junho de 2014.
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Artigo publicado a convite da Society for Polymer Engineers
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The importance of implementing sustainable practices in buildings is duly proved and understood by the majority of the population. However, its implementation is not yet a reality. Some studies have been performed with the goal of understand this lack of use of sustainable solutions, among building sector stakeholders. The conclusion is that one of the main factors contributing to this is related with economic constraints. Several studies have proven that many sustainable practices correspond to minor costs than traditional practices in a life cycle perspective. However, the building sector stakeholders are not aware of this and do not implement sustainable practices commonly. In this paper a costâ benefit methodology willing to cross this barrier and promote the sustainable practices implementation is presented.
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The use of thermal insulation materials for the achievement of energy efficient buildings intended, in most cases, the fulfilment of the required heating and cooling needs of the operational phase. The main goal of this paper is â by using exploratory methodology, namely literature review â identify more sustainable insulating materials and, concomitantly, exposing the paradoxical effect of other insulation materials with high Global Warming Potential (GWP) highlighting the role of the Life Cycle Assessment (LCA), Ecodesign and Environmental Product Declaration (EPD) tools for the framing, comparison and selection of materials. As a main conclusion, it is noticed the lack of environmental information from the producers which, together with acquisition prices that do not internalize Life Cycle Costs (LCC), has led to the use of insulation materials with high carbon footprint and to the "isolation paradox" as well.
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Colorectal cancer is one of the most common malignancies and a leading cause of cancer death worldwide. Molecular markers may improve clinicopathologic staging and provide a basis to guide novel therapeutic strategies which target specific tumourassociated molecules according to individual tumour biology; however, so far, no ideal molecular marker has been found to predict disease progression. We tested Ki-67 proliferation marker in primary and lymph node metastasis of CRC. We observed a statistical significant difference between the positive rates of neoplastic cells positively stained byKi-67 in both sites, with remarkable increased number of Ki-67 positive cells in primary tumor cells compared to cancer cells that invaded lymph nodes. We can speculate that the metastatic CRC in lymph node can be more resistant to the drugs that target cellular division.
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tThe main purpose of this work is to present and to interpret the change of electrical properties of TaxNyOzthin films, produced by DC reactive magnetron sputtering. Some parameters were varied during deposi-tion: the flow of the reactive gases mixture (N2and O2, with a constant concentration ratio of 17:3); thesubstrate voltage bias (grounded, −50 V or −100 V) and the substrate (glass, (1 0 0) Si or high speed steel).The obtained films exhibit significant differences. The variation of the deposition parameters inducesvariations of the composition, microstructure and morphology. These differences cause variation of theelectrical resistivity essentially correlated with the composition and structural changes. The gradualdecrease of the Ta concentration in the films induces amorphization and causes a raise of the resistivity.The dielectric characteristics of some of the high resistance TaxNyOzfilms were obtained in the sampleswith a capacitor-like design (deposited onto high speed steel, with gold pads deposited on the dielectricTaxNyOzfilms). Some of these films exhibited dielectric constant values higher than those reported forother tantalum based dielectric films.
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Tantalum oxynitride thin films were produced by magnetron sputtering. The films were deposited usinga pure Ta target and a working atmosphere with a constant N2/O2ratio. The choice of this constant ratiolimits the study concerning the influence of each reactive gas, but allows a deeper understanding of theaspects related to the affinity of Ta to the non-metallic elements and it is economically advantageous.This work begins by analysing the data obtained directly from the film deposition stage, followed bythe analysis of the morphology, composition and structure. For a better understanding regarding theinfluence of the deposition parameters, the analyses are presented by using the following criterion: thefilms were divided into two sets, one of them produced with grounded substrate holder and the otherwith a polarization of −50 V. Each one of these sets was produced with different partial pressure of thereactive gases P(N2+ O2). All the films exhibited a O/N ratio higher than the N/O ratio in the depositionchamber atmosphere. In the case of the films produced with grounded substrate holder, a strong increaseof the O content is observed, associated to the strong decrease of the N content, when P(N2+ O2) is higherthan 0.13 Pa. The higher Ta affinity for O strongly influences the structural evolution of the films. Grazingincidence X-ray diffraction showed that the lower partial pressure films were crystalline, while X-rayreflectivity studies found out that the density of the films depended on the deposition conditions: thehigher the gas pressure, the lower the density. Firstly, a dominant -Ta structure is observed, for lowP(N2+ O2); secondly a fcc-Ta(N,O) structure, for intermediate P(N2+ O2); thirdly, the films are amorphousfor the highest partial pressures. The comparison of the characteristics of both sets of produced TaNxOyfilms are explained, with detail, in the text.
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In this work it was studied the possible use of thin films, composed of Au nanoparticles (NPs) embedded in a TiO2 matrix, in biological applications, by evaluating their interaction with a well-known protein, Bovine Serum Albumin (BSA), as well as with microbial cells (Candida albicans). The films were produced by one-step reactive DC magnetron sputtering followed by heat-treatment. The samples revealed a composition of 8.3 at.% of Au and a stoichiometric TiO2 matrix. The annealing promoted grain size increase of the Au NPs from 3 nm (at 300 °C) to 7 nm (at 500 °C) and a progressive crystallization of the TiO2 matrix to anatase. A broad localized surface plasmon resonance (LSPR) absorption band (λ = 580–720 nm) was clearly observed in the sample annealed at 500 °C, being less intense at 300 °C. The biological tests indicated that the BSA adhesion is dependent on surface nanostructure morphology, which in turn depends on the annealing temperature that changed the roughness and wettability of the films. The Au:TiO2 thin films also induced a significant change of the microbial cell membrane integrity, and ultimately the cell viability, which in turn affected the adhesion on its surface. The microstructural changes (structure, grain size and surface morphology) of the Au:TiO2 films promoted by heat-treatment shaped the amount of BSA adhered and affected cell viability.
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BACKGROUND: The Cervical Cancer Database of the Brazilian National Health Service (SISCOLO) contains information regarding all cervical cytological tests and, if properly explored, can be used as a tool for monitoring and managing the cervical cancer screening program. The aim of this study was to perform a historical analysis of the cervical cancer screening program in Brazil from 2006 to 2013. MATERIAL AND METHODS: The data necessary to calculate quality indicators were obtained from the SISCOLO, a Brazilian health system tool. Joinpoint analysis was used to calculate the annual percentage change. RESULTS: We observed important trends showing decreased rates of low-grade squamous intraepithelial lesions (LSIL) and high-grade squamous intraepithelial lesions (HSIL) and an increased rate of rejected exams from 2009 to 2013. The index of positivity was maintained at levels below those indicated by international standards; very low frequencies of unsatisfactory cases were observed over the study period, which partially contradicts the low rate of positive cases. The number of positive cytological diagnoses was below that expected, considering that developed countries with low frequencies of cervical cancer detect more lesions annually. CONCLUSIONS: The evolution of indicators from 2006 to 2013 suggests that actions must be taken to improve the effectiveness of cervical cancer control in Brazil.
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Background: It is expected that, by 2020, 15 million new cases of cancer will occur every year in the world, one million of them in Africa. Knowledge of cancer trends in African countries is far from adequate, and improvements in cancer prevention efforts are urgently needed. The aim of this study was to characterize breast cancer clinically and pathologically at presentation in Luanda, Angola; we additionally provide quality information that will be useful for breast cancer care planning in the country. Methods: Data on breast cancer cases were retrieved from the Angolan Institute of Cancer Control, from 2006 to 2014. For women diagnosed in 2009 (5-years of follow-up), demographic, clinical and pathological information, at presentation, was collected, namely age at diagnosis, parity, methods used for pathological diagnoses, tumor pathological characteristics, stage of disease and treatment. Descriptive statistics were performed. Results: The median age of women diagnosed with breast cancer in 2009 was 47 years old (range 25–89). The most frequent clinical presentation was breast swelling with axillary lymph nodes metastasis (44.9 %), followed by a mass larger than 5 cm (14.2 %) and lump (12.9 %). Invasive ductal carcinoma was the main histologic type (81.8 %). Only 10.1 % of cancer cases had a well differentiated histological grade. Cancers were diagnosed mostly at advanced stages (66.7 % in stage III and 11.1 % in stage IV). Discussion: In this study, breast cancer was diagnosed at a very advanced stage. Although it reports data from a single cancer center in Luanda, Angola it reinforces the need for early diagnosis and increasing awareness. According to the main challenges related to breast cancer diagnosis and treatment herein presented, we propose a realistic framework that would allow for the implementation of a breast cancer care program, built under a strong network based on cooperation, teaching, audit, good practices and the organization of health services. Conclusion: Angola needs urgently a program for early diagnosis of breast cancer.
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Transparency document related to this article can be found online at http://dx.doi.org/10.1016/j.bbrc.2015.10.014