12,705 research outputs found

    Valorization of chestnut shells for hydrogen production by Clostridium butyricum fermentation

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    Chestnut shell s (CS) is an agronomic waste generated from the peeling process of the chestnut fruit. It is well-known that the extract of CS contains high amounts of tannins, which are polyphenolic antioxidants1, but this agronomic residue also contains about 36% sugars in form of polysaccharides, and no utilization of chestnut shells as potential source of fermentable sugars has been considered so far. As consequence, this waste represents an interesting exploitable source for monosaccharides production, and in this study we evaluated the potential of biohydrogen production from CS hydrolyzate

    A novel β-xylosidase from Anoxybacillus sp. 3M towards an improved agro-industrial residues saccharification

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    ABSTRACT: An intracellular β-xylosidase (AbXyl), fromthe thermoalkaline Anoxybacillus sp. 3M,was purified and characterized. The homodimeric enzyme (140 kDa) was optimally active at 65 °C and pH 5.5, exhibited half life of 10 h at 60 °C, 78 and 88% residual activity after 24 h, at pH 4.5 and 8.0, respectively. Fe2+, Cu2+, Al3+, Ag+ and Hg2+inhibited the enzyme; the activity was moderately stimulated by SDS and not influenced by β-mercaptoethanol. In the presence of p-nitrophenyl-β-D-xylopyranoside, AbXyl exhibited Km of 0.19 mM, Kcat of 453.29 s−1, KcatKm−1 of 2322 s−1mMandwas moderately influenced by xylose (Ki 21.25mM). The enzyme hydrolyzed xylo-oligomers into xylose and catalyzed transxylosilation reactions also in presence of alcohols as acceptors, producing xylo-oligosaccharides and alkyl-xylosides. Finally AbXyl was applied towards a statistically optimized process of brewery's spent grain bioconversion, highlighting the important role of this biocatalyst in reaching high yields of fermentable sugars.info:eu-repo/semantics/publishedVersio

    Municipal sewage sludge variability: biodegradation through composting with bulking agent

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    Municipal sewage sludge is a waste with high organic load generated in large quantities that can be treated by biodegradation techniques such as composting to reduce its risk to the environment. This research studies the physicochemical variability of sewage sludge from treatment plants in the south of Galicia (Spain) and determines if it is possible to establish a protocol for the use of bulking agent depending on the composition of the sludge and the development of the composting process. Therefore, physicochemical analyses of 35 sewage sludge from different municipalities and 10 samples from the same treatment plant are discussed. Three different mixtures bulking agent:sewage sludge (3:1, 2:1, 1:1, v:v) were carried out in 30 L reactors in triplicate. Finally, proportion 2:1 was replicated six times in a 600 L reactor. High inter-sludge variability was observed specially in key parameters such as moisture and C/N ratio. Intra-variability was lower, and 2:1 proportion was the most suitable mixture since extending the thermophilic phase of the composting process at a greater degree. However, repeatability of the process at a higher scale showed different responses in the temperature evolution. Variability of sewage sludge makes difficult to establish treatment protocols although minimum requirements are necessary for proper composting

    Joint application of biological techniques for the remediation of waste contaminated with hydrocarbons

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    Cleaning the oil industry's fuel storage and management facilities generates high levels of hazardous waste. This research aims to assess the use of biological bioremediation treatments, most commonly used for decontaminating soil, by applying them to hydrocarbon-contaminated waste. Turned pile composting using food-derived sludge as a co-substrate and the necessary proportion of bulking agent enabled the bioremediation of the initial mixture via the succession of microbial populations (PLFAs), with a 70% lower TPH concentration obtained 6 months after the start of the process. Subsequent bioassays using the composted material showed survival rates of over 80% with earthworms (Eisenia andrei) and a larger decrease in TPH in the joint treatment with earthworms and plants (Pennisetum clandestinum). The composting process reduces the concentration of hazardous organic compounds, allowing for the proper development of fauna and flora in the compost by improving the biodegradation rate.Universidade de Vigo/CISU

    Municipal Sewage Sludge Variability: Biodegradation through Composting with Bulking Agent

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    Municipal sewage sludge is a waste with high organic load generated in large quantities that can be treated by biodegradation techniques such as composting to reduce its risk to the environment. This research studies the physicochemical variability of sewage sludge from treatment plants in the south of Galicia (Spain) and determines if it is possible to establish a protocol for the use of bulking agent depending on the composition of the sludge and the development of the composting process. Therefore, physicochemical analyses of 35 sewage sludge from different municipalities and 10 samples from the same treatment plant are discussed. Three different mixtures bulking agent:sewage sludge (3:1, 2:1, 1:1, v:v) were carried out in 30 L reactors in triplicate. Finally, proportion 2:1 was replicated six times in a 600 L reactor. High inter-sludge variability was observed specially in key parameters such as moisture and C/N ratio. Intra-variability was lower, and 2:1 proportion was the most suitable mixture since extending the thermophilic phase of the composting process at a greater degree. However, repeatability of the process at a higher scale showed different responses in the temperature evolution. Variability of sewage sludge makes difficult to establish treatment protocols although minimum requirements are necessary for proper composting

    Ressonância magnética cardíaca de perfusão em stress: a experiência de um centro nacional

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    INTRODUCTION AND OBJECTIVES: Myocardial ischemia can be assessed with cardiac magnetic resonance perfusion imaging (MRPI). This study aimed to analyze the clinical utility of MRPI in the diagnosis of significant coronary artery disease. METHODS: Fifty-five patients were examined with a 1.5 T MR scanner (Siemens Symphony), with a first pass of 0.10 mmol/kg gadolinium chelate, at rest and during adenosine vasodilatation (140μg/kg/min for 4min) using an inversion recovery steady-state free precession sequence. The results were compared with coronary angiography and with SPECT myocardial perfusion images. Agreement for qualitative diagnosis was measured by the kappa coefficient, taking statistical significance as 95%. Minimum clinical follow-up was 12 months. RESULTS: In 19 patients (34.5%) MRPI was negative for myocardial ischemia and necrosis, in 17 (30.9%) it was negative for ischemia but positive for necrosis, in 7 (12.7%) only ischemia was present and in 12 (21.8%) the ischemic area was larger than the necrotic area. The correlation between MRPI and coronary angiography for ischemia detection by coronary artery territory was very good: left anterior descending and right coronary - k=0.8571 (0.59-1), circumflex - k=0.8108 (0.59-1). By contrast, there was no correlation in terms of myocardial ischemia detection between MRPI and SPECT. CONCLUSIONS: MRPI is able to diagnose significant coronary disease in a high risk population, by detection of myocardial ischemia

    Depressão na pessoa idosa em diferentes contextos: Institucional, centro de dia, apoio domiciliário

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    Dissertação de Mestrado apresentada ao Instituto Superior de Psicologia Aplicada para obtenção de grau de Mestre na especialidade de Psicologia Clínica.Esta tese insere-se no contexto da psicologia do idoso, onde se incluirá o tema da depressão do idoso em contexto de lar, em contexto de centro de dia e em contexto de apoio domiciliário. Este estudo procurou conhecer a depressão no idoso, mediante o contexto em que está inserido. Foi utilizada a “Escala de Depressão Geriátrica” (autores: Paradela Emylucy Martins Paiva, Lourenço Roberto Alves, Veras Renato Peixoto). A principal conclusão sustenta que existe ainda, pouca informação sobre a depressão em geral, essencialmente no idoso, logo um distanciamento para a resolução deste mesmo problema, adiando uma melhor qualidade de vida na 3ª idade. O estudo mostrou perante as variáveis estudadas e analisadas estatisticamente, que são, a idade, o género, o estado civil, o contexto, o tempo de institucionalização e as habilitações literárias, não haver relação significativa com a depressão, a não ser o género. Existem significativamente mais mulheres idosas a apresentar depressão ligeira (41.2%) comparativamente ao género masculino. Foram inquiridas 82 pessoas, dessas 55, ou seja, 67 % de toda esta população apresentou, como resultados da escala aplicada, ausência de depressão.This thesis falls within the context of the psychology of the elderly, which will include the subject, depression in the elderly, in the context of, nursing home, day care and home support. This study aimed to know the depression in the elderly by the context in which it appears. Was used the “Escala de Depressão Geriátrica” (authors: Paradela Emylucy Martins Paiva, Lourenço Roberto Alves, Veras Renato Peixoto). The main conclusion contends that there is still little information about depression in general, mainly in the elderly, so there is a detachment to solve this same problem in order to provide better life quality in the 3rd age. The study showed through the variables, as age, gender, marital status, context, time of institutionalization and the qualifications, studied and analyzed statistically, that there is no significant connection with depression, except in the gender. There are significantly more elderly women to produce mild depression (41.2%) compared to males. The study surveyed 82 people, showing that 55 of them, or 67% of the entire population, presented as results by the scale applied, with absence of depression

    Apparent diffusion coefficient in the analysis of prostate cancer

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    The multiparametric magnetic resonance imaging (MPMRI) approach, has allowed the diagnostic performance in the detection and characterization of prostate cancer (PCa). Diffusion-weighted imaging (DWI), is an important technique in the MPMRI, that provides qualitative and quantitative biological information regarding water diffusivity in a non-invasive manner. The apparent diffusion coefficient (ADC) measures water mobility and can be quantified from the signal intensity loss between two or more b-values. Different studies reported that ADC values are directly associated with microvessel density and cellularity. One of the main aspects that is in discussion is the b-values that must be used in the DWI sequence in order to compute ADC.info:eu-repo/semantics/publishedVersio
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