986 research outputs found

    Standard Unretrofitted Buildings and Net Zero-Energy Concept

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    There are many different possible combinations of building envelope, utility equipments and onsite energy generation equipments that can lead to net zero-energy performance. For instance, a building with standard design can offset its energy demand by adding a large amount of photovoltaic cells or by improving its energy efficiency rating first and then adding a smaller amount of photovoltaic cells. Despite the second strategy being considered the roadmap to net zeroenergy status, the first scenario is also possible in the actual Portuguese context where laws favor conditions for the installation of PV´s and solar thermal systems. This paper intends to discuss the implications of this fact from a national perspective coupled with the IEA SHC Task 40 - ECBCS Annex 52 vision where authors are active participants

    Production and Characterization of Energy Materials with Adsorbent Properties by Hydrothermal Processing of Corn Stover with Subcritical H2O

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    This work aims to investigate the effect of temperature on the process performance of hydrothermal processing (HTC) of corn Stover with subcritical H2O and on the morphology of solid products. The experiments were carried out at 200, 225 and 250 ºC, reaction time of 240 minutes, heating rate of 2.0 ºC/min, and biomass to water ratio of 1:10, using a pilot scale stirred tank reactor (STR) of 5 gallon, operating in batch mode. The process performance analyzed by computing the yields of solid and liquid reaction products (RLP). The aqueous phase (H2O + RLP) was physicochemical analyzed for pH and total carboxylic acids, expressed as total acetic acid content. The chemical compositions of carboxylic acids, furfural, and hydroxymethylfurfural (HMF) in the aqueous phase determined by GC-MS and HPLC. The results showed solid yields ranging from 57.39 to 35.82% (wt.), and liquid reaction products (RLP) yields ranging from 39.53 to 54.59% (wt.). The solid phase products were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). The chemically activated (2.0 M NaOH) solid phase energy material obtained by HTC at 250 °C, applied as adsorbent to investigate the capacity and/or efficiency to adsorb acetic acid from 1.0 to 4.0 g/L model solutions at 25 °C. The solid phase yield decreases along with the temperature, showing an inflection region between 200 and 225 °C, whereas a drastic change takes place, while that of liquid phase increases, showing also a drastic change between 200 and 225 °C. The total acetic acid content of aqueous phase varied from 4064 to 5387 mg/L, while the pH from 3.77 to 3.91. The GC analysis identified the presence of volatile carboxylic acids, particularly acetic acid, in concentrations between 4020 and 5040 mg/L. HPLC identified the presence of furfural and hydroxymethylfurfural, whose concentrations decrease exponentially and linearly along with the temperature between 686.7 and 0.0, and 443.9 and 0.0 mg/L, respectively, being both compounds not detectable at 250 °C. The elemental/ultimate analysis of solid products shows that carbon content increases, while the oxygen and hydrogen contents decrease, along with the temperature. The H/C and O/C ratios decrease linearly as process temperature increases, and the high heating value (HHV) of solid reaction products, an energy densified material, changes sharply between 200 and 225 °C, showing an increase with temperature. The SEM, EDX, and XDR indicates a change on the morphology and mineralogical phases present in solid reaction products with temperature, particularly at 250 °C. The activated solid phase has proven to be very selective to adsorb acetic acid, showing that recovery of acetic acid from hydrothermal carbonization/liquefaction aqueous solutions is feasible by using a multistage-stage adsorption process in series

    Schistosome and liver fluke derived catechol-estrogens and helminth associated cancers

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    Infection with helminth parasites remains a persistent public health problem in developing countries. Three of these pathogens, the liver flukes Clonorchis sinensis, Opisthorchis viverrini and the blood fluke Schistosoma haematobium, are of particular concern due to their classification as Group 1 carcinogens: infection with these worms is carcinogenic. Using liquid chromatography-mass spectrometry (LC-MS/MS) approaches, we identified steroid hormone like (e.g., oxysterol-like, catechol estrogen quinone-like, etc.) metabolites and related DNA-adducts, apparently of parasite origin, in developmental stages including eggs of S. haematobium, in urine of people with urogenital schistosomiasis, and in the adult stage of O. viverrini. Since these kinds of sterol derivatives are metabolized to active quinones that can modify DNA, which in other contexts can lead to breast and other cancers, helminth parasite associated sterols might induce tumor-like phenotypes in the target cells susceptible to helminth parasite associated cancers, i.e., urothelial cells of the bladder in the case of urogenital schistosomiasis and the bile duct epithelia or cholangiocytes, in the case of O. viverrini and C. sinensis. Indeed we postulate that helminth induced cancers originate from parasite estrogen-host epithelial/urothelial cell chromosomal DNA adducts, and here we review recent findings that support this conjecture.José M. Correia da Costa, Maria J. Gouveia, Mónica C. Botelho, Lúcio L. Santos, and Júlio H. Santos thank FCT for Pest- OE/AGR/UI0211/2011 and Strategic Project UI211-2011- 2013, Clínica Sagrada Esperança and Hospital Américo Boavida, Luanda, Angola. Nuno Vale thanks to Fundação para a Ciência e Tecnologia (FCT, Portugal) and FEDER (European Union) for funding through project grants CONCREEQ/275/QUI and PEstC/QUI/UI0081/2011. Nuno Vale also thanks FCT for Post-Doc grant SFRH/BPD/48345/2008. The research findings reviewed here were supported by award R01CA155297 (Paul J. Brindley, Gabriel Rinaldi, Banchob Sripa) from the National Cancer Institute, NIH and P50 P50AI098639 (Banchob Sripa, Paul J. Brindley) from the National Institute of Allergy and Infectious Diseases, NIH

    Prognostic value of Dna and Mrna E6/e7 of human papillomavirus in the evolution of cervical intraepithelial neoplasia grade 2

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    Objective: This study aimed at evaluating whether human papillomavirus (HPV) groups and E6/E7 mRNA of HPV 16, 18, 31, 33, and 45 are prognostic of cervical intraepithelial neoplasia (CIN) 2 outcome in women with a cervical smear showing a low-grade squamous intraepithelial lesion (LSIL).Methods: This cohort study included women with biopsy-confirmed CIN 2 who were followed up for 12 months, with cervical smear and colposcopy performed every three months.Results: Women with a negative or low-risk HPV status showed 100% CIN 2 regression. The CIN 2 regression rates at the 12-month follow-up were 69.4% for women with alpha-9 HPV versus 91.7% for other HPV species or HPV-negative status (P < 0.05). For women with HPV 16, the CIN 2 regression rate at the 12-month follow-up was 61.4% versus 89.5% for other HPV types or HPV-negative status (P < 0.05). The CIN 2 regression rate was 68.3% for women who tested positive for HPV E6/E7 mRNA versus 82.0% for the negative results, but this difference was not statistically significant.Conclusions: The expectant management for women with biopsy-confirmed CIN 2 and previous cytological tests showing LSIL exhibited a very high rate of spontaneous regression. HPV 16 is associated with a higher CIN 2 progression rate than other HPV infections. HPV E6/E7 mRNA is not a prognostic marker of the CIN 2 clinical outcome, although this analysis cannot be considered conclusive. Given the small sample size, this study could be considered a pilot for future larger studies on the role of predictive markers of CIN 2 evolution. © the authors.This study aimed at evaluating whether human papillomavirus (HPV) groups and E6/E7 mRNA of HPV 16, 18, 31, 33, and 45 are prognostic of cervical intraepithelial neoplasia (CIN) 2 outcome in women with a cervical smear showing a low-grade squamous intraepithelial lesion (LSIL).Methods: This cohort study included women with biopsy-confirmed CIN 2 who were followed up for 12 months, with cervical smear and colposcopy performed every three months.Results: Women with a negative or low-risk HPV status showed 100% CIN 2 regression. The CIN 2 regression rates at the 12-month follow-up were 69.4% for women with alpha-9 HPV versus 91.7% for other HPV species or HPV-negative status (P < 0.05). For women with HPV 16, the CIN 2 regression rate at the 12-month follow-up was 61.4% versus 89.5% for other HPV types or HPV-negative status (P < 0.05). The CIN 2 regression rate was 68.3% for women who tested positive for HPV E6/E7 mRNA versus 82.0% for the negative results, but this difference was not statistically significant.Conclusions: The expectant management for women with biopsy-confirmed CIN 2 and previous cytological tests showing LSIL exhibited a very high rate of spontaneous regression. HPV 16 is associated with a higher CIN 2 progression rate than other HPV infections. HPV E6/E7 mRNA is not a prognostic marker of the CIN 2 clinical outcome, although this analysis cannot be considered conclusive. Given the small sample size, this study could be considered a pilot for future larger studies on the role of predictive markers of CIN 2 evolution9152

    Efeito do treino de força na melhoria da performance muscular e funcional em mulheres idosas

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    Resumo: Estudos recentes têm dado primazia à realização de exercícios de força com velocidades de execução superiores às ditas tradicionais. Além disso, é sugerida a inclusão de exercícios que promovam a melhoria da capacidade funcional através da realização de acções motoras associadas às tarefas diárias, desde subir e descer degraus, sentar e levantar de uma cadeira, carregar sacos, etc. Desta forma, este estudo teve como objectivo examinar a resposta de um programa de treino de força com velocidades de execução máxima durante a fase concêntrica na melhoria da força muscular e capacidade funcional em mulheres idosas caucasianas. Método: Vinte e quatro mulheres foram distribuídas de forma aleatória para um grupo controlo (GC) (n=12; 63.3±5.9) e outro experimental (GE) (n=12; 60.3±9.3). O GE foi submetido a 3 sessões/semana de treino de força durante 12 semanas). O grupo de controlo não fez qualquer tipo de actividade física, tendo apenas sido submetida à recolha de dados no pré-teste (T1) e pós-teste (T12). A avaliação consistiu em exercícios de força: 1-repetição máxima no supino, 1-repetição máxima na extensão de pernas e em testes que avaliaram a aptidão funcional: sentar e levantar - 30 seg. (SL) e “go-up and go” (GUG), ambos da bateria de testes Rikly & Jones (1999). O plano de treino consistiu na realização de supino (SUP) e extensão de pernas bilateral (EP) com cargas progressivas (40%-75%) e realização de abdominais (3x12) e lombares (3x10). Resultados: O GC não apresentou melhorias nos testes durante teste período, tendo registado diferenças significativas no teste SL (-12,2%; p=0.029). Relativamente ao GE, foram observadas melhorias nos testes, 1RMSUP (38.6%; p=0.001), 1RMEP (24.6%p=0.00) e SL (17.1%; p=0.003). No entanto, embora no teste GUG tenhamos percebido uma diminuição no tempo de execução do percurso, esta não foi significativo (-4.3%; p=0.259). Conclusão: Um programa de treino de força com velocidades de execução máximas durante a fase concêntrica permite ganhos significativos no aumento dos índices de força nos membros superiores e inferiores. Além disso, esta metodologia contribui para o aumento da mobilidade e da autonomia funcional, aumentando também a coordenação neuromuscular e a potência, que em idades avançadas parecem contribuir significativamente para a diminuição do risco de queda e consequentemente para o aumento da independência funcional e da qualidade de vida

    The flavonoid agathisflavone modulates the microglial neuroinflammatory response and enhances remyelination

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    Myelin loss is the hallmark of the demyelinating disease multiple sclerosis (MS) and plays a significant role in multiple neurodegenerative diseases. A common factor in all neuropathologies is the central role of microglia, the intrinsic immune cells of the central nervous system (CNS). Microglia are activated in pathology and can have both pro- and anti-inflammatory functions. Here, we examined the effects of the flavonoid agathisflavone on microglia and remyelination in the cerebellar slice model following lysolecithin induced demyelination. Notably, agathisflavone enhances remyelination and alters microglial activation state, as determined by their morphology and cytokine profile. Furthermore, these effects of agathisflavone on remyelination and microglial activation were inhibited by blockade of estrogen receptor α. Thus, our results identify agathisflavone as a novel compound that may act via ER to regulate microglial activation and enhance remyelination and repair

    Urinary Estrogen Metabolites and Self-Reported Infertility in Women Infected with Schistosoma haematobium

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    Schistosomiasis is a neglected tropical disease, endemic in 76 countries, that afflicts more than 240 million people. The impact of schistosomiasis on infertility may be underestimated according to recent literature. Extracts of Schistosoma haematobium include estrogen-like metabolites termed catechol-estrogens that down regulate estrogen receptors alpha and beta in estrogen responsive cells. In addition, schistosome derived catechol-estrogens induce genotoxicity that result in estrogen-DNA adducts. These catechol estrogens and the catechol-estrogen-DNA adducts can be isolated from sera of people infected with S. haematobium. The aim of this study was to study infertility in females infected with S. haematobium and its association with the presence of schistosome-derived catechol-estrogens

    A mathematical analysis of the evolution of perturbations in a modified Chaplygin gas model

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    One approach in modern cosmology consists in supposing that dark matter and dark energy are different manifestations of a single `quartessential' fluid. Following such idea, this work presents a study of the evolution of perturbations of density in a flat cosmological model with a modified Chaplygin gas acting as a single component. Our goal is to obtain properties of the model which can be used to distinguish it from another cosmological models which have the same solutions for the general evolution of the scale factor of the universe, without the construction of the power spectrum. Our analytical results, which alone can be used to uniquely characterize the specific model studied in our work, show that the evolution of the density contrast can be seen, at least in one particular case, as composed by a spheroidal wave function. We also present a numerical analysis which clearly indicates as one interesting feature of the model the appearence of peaks in the evolution of the density constrast.Comment: 21 pages, accepted for publication in General Relativity and Gravitatio

    Extracción de aceite de bacaba (Oenocarpus bacaba) con CO2 supercrítico: Isotermas de rendimiento global, composición de ácidos grasos, calidad funcional, estabilidad oxidativa, perfil espectroscópico y actividad antioxidante

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    Bacaba is widely consumed by the Amazonian population, and is promising for the production of cooking oil. The objective of this research was to determine the parameters of bacaba oil extraction with supercritical CO2: the fatty acid composition, functional quality, oxidative stability, spectroscopic profile and antioxidant activity of the extracted oil. Extractions of bacaba (Oenocarpus bacaba) oil were performed with supercritical CO2 at temperatures of 40 and 60 ºC, with pressures varying from 120 to 420 bar. The highest mass yield was 60.39 ± 0.72% on a dry basis, obtained in the isotherm of 60 °C and 420 bar. Oleic acid was the major compound. The Infrared spectroscopic profile showed the predominance of unsaturated fatty acids. The results indicate that bacaba oil presents good functional quality.La bacaba es muy consumida por la población amazónica, constituyendo una promesa para una producción de aceite de cocina. El objetivo de esta investigación es determinar parámetros de la extracción de aceite de bacaba con CO2 supercrítico, la composición de ácidos grasos, evaluar su calidad funcional, la estabilidad oxidativa, el perfil espectroscópico y la actividad antioxidante del aceite. Las extracciones de aceite de bacaba (Oenocarpus bacaba) se realizaron con CO2 supercrítico a temperaturas de 40 y 60 ºC y presiones de 120 a 420 bar. El mayor rendimiento en masa fue de 60.39 ± 0.72% en base seca, obtenido en la isoterma de 60 °C y 420 bar. El ácido oleico fue el compuesto mayoritario. El perfil espectroscópico infrarrojo mostró el predominio de ácidos grasos no saturados. Los resultados indicaron que el aceite de bacaba presenta buena calidad funcional
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