Biblioteca Digital

Experimentos de hidropirólise foram realizados em amostras de folhelho betuminoso da Formação Irati, Bacia do Paraná, Brasil, e em amostras de folhelho betuminoso e carvão da Bacia de Puertollano, Espanha, com o objetivo de estudar o potencial de geração de hidrocarbonetos, e determinar as mudanças na composição química e nos principais parâmetros geoquímicos e petrográficos, com o aumento da evolução térmica da matéria orgânica. O aumento do tempo nos experimentos de hidropirólise, usando a mesma temperatura máxima (350 ºC), promoveu uma maior transformação da matéria orgânica insolúvel em betume e óleo, em todas as amostras em estudo. Esta transformação parcial da matéria orgânica em hidrocarbonetos, foi evidenciada pelas tendências dos rendimentos obtidos dos produtos dos experimentos (betume e óleo), assim como pelas tendências observadas para os parâmetros geoquímicos de conteúdo de carbono orgânico total (COT), potencial de geração de hidrocarbonetos (pico S2), índice de hidrogênio (IH) e razão de tranformação da matéria orgânica em hidrocarbonetos (RT). Diferenças na concentração das frações saturadas e heteroatômicas (NSO) entre os betumes gerados durante a hidropirólise e os betumes originais das amostras de folhelho betuminoso em estudo...

Portugal e a maioria dos países da União Europeia são altamente dependentes da importação de fontes de energia que permitam manter os níveis de conforto e de qualidade de vida a que a sua população se habituou. Em virtude do tempo de vida limitado das reservas de petróleo, principal combustível fóssil utilizado, e face aos problemas políticos, sociais e económicos dos principais países produtores deste combustível, é urgente diversificar os processos de produção de energia, bem como encontrar fontes energéticas alternativas. Uma delas poderá ser a co-gasificação aplicada ao processamento de carvão misturado com resíduos com potencial energético, sendo este um dos aspectos inovadores deste trabalho, de forma a valorizar esses resíduos e simultaneamente reduzir a carga poluente a eles associada. Este trabalho teve como principal objectivo estudar o efeito das condições experimentais, de modo a seleccionar as variáveis que permitissem maximizar o rendimento e a qualidade do gás produzido por co-gasificação em leito fluidizado usando misturas de ar e vapor. Os resultados obtidos mostraram que a composição das misturas a co-gasificar, assim como o tipo e características dos resíduos a utilizar afectavam bastante a composição e o rendimento do gás obtido. No presente trabalho foi estudada a co-gasificação de um carvão...

Tese de doutoramento, Energia e Ambiente (Energia e Desenvolvimento Sustentável), Universidade de Lisboa, Faculdade de Ciências, 2014; Resíduos carbonosos (de leito e ciclone) resultantes da gasificação de pinho, carvão Puertollano e mistura destes, foram ativados com K2CO3, utilizando diferentes condições experimentais, levando à obtenção de amostras com áreas superficiais específicas atingindo 1500 m2g-1. A realização de pré-tratamentos não se mostrou uma opção viável pois não levaram a um maior desenvolvimento da porosidade (térmico), ou implicavam um processo mais longo e dispendioso (desmineralização). O desempenho de carvões provenientes do resíduo de pinho como adsorventes de fármacos em fase aquosa foi comparável, ou superior, ao de carvões comerciais. No caso da adsorção de cafeína, a afinidade do molécula é determinada pela química de superfície dos carvões. A capacidade de adsorção dos materiais é determinada pela existência de distribuições de microporos contínuas, que permitem maximizar o empacotamento da molécula na microporosidade. Relativamente à adsorção de paracetamol mostrou-se que a velocidade inicial do processo é determinada pela presença de supermicroporos e a afinidade pela existência de distribuições de tamanho de microporos com o máximo coincidente com a dimensão crítica do dímero (espécie predominante em solução). O estudo do efeito da temperatura (20-40C) demonstrou a complexidade do processo e importancia determinante da rede microporosa para justificar o aumento da quantidade adsorvida com a temperatura observado nas amostras obtidas a partir dos residuos de gasificação. Os resultados de adsorção de iopamidol provaram que a velocidade inicial do processo depende da presença de distribuições de mesoporos muito largas e a capacidade de adsorção está diretamente relacionada com o volume de meso+microporos. Um dos materais produzidos no laboratório atingiu uma capacidade da monocamada aproximadamente duas vezes superior à da amostra comercial testada. Tal justificou-se pela presença de uma distribuição de tamanho de microporos contínua em toda a gama de poros. A regeneração dos materais foi considerada apenas como uma primeira abordagem...

Tese apresentada à Universidade de Aveiro para obtenção do Grau de Doutor em Ciências Aplicada ao Ambiente; Portugal e a maioria dos países da União Europeia são altamente dependentes da importação de fontes de energia que permitam manter os níveis de conforto e de qualidade de vida a que a sua população se habituou. Em virtude do tempo de vida limitado das reservas de petróleo, principal combustível fóssil utilizado, e face aos problemas políticos, sociais e económicos dos principais países produtores deste combustível, é urgente diversificar os processos de produção de energia, bem como encontrar fontes energéticas alternativas. Uma delas poderá ser a co-gasificação aplicada ao processamento de carvão misturado com resíduos com potencial energético, sendo este um dos aspectos inovadores deste trabalho, de forma a valorizar esses resíduos e simultaneamente reduzir a carga poluente a eles associada. Este trabalho teve como principal objectivo estudar o efeito das condições experimentais, de modo a seleccionar as variáveis que permitissem maximizar o rendimento e a qualidade do gás produzido por co-gasificação em leito fluidizado usando misturas de ar e vapor. Os resultados obtidos mostraram que a composição das misturas a co-gasificar...

Nowadays there is a great interest in producing energy through co-gasification of low grade coals and waste blends to increase the use of alternative feedstocks with low prices. The experimental results showed that the viability of co-gasification to process such blends and that by the right manipulation of coal and biomass or waste blends, syngas treatment and upgrading may be simplified and the cost of the overall process may be reduced. Blends of three different coal grades (sub-bituminous coal from Puertollano mines, South African bituminous coal and German brown coal) with two different types of biomass (pine and olive oil bagasse) or polyethylene (PE) were co-gasified. Blend co-gasification showed to be beneficial to reduce the negative characteristics of some coals, such as the high ash and sulphur contents, especially of Puertollano coal. Syngas obtained by these blends was hot cleaned and undesirable syngas components (tar, NH3 and H2S) were measured along the hot treatment tested, which proved to be suitable to treat syngas produced by a wide range of feedstocks. Different routes for syngas cleaning were analysed to reduce unsuitable components to values required by most common end-uses. The results obtained showed that the type of feedstock to be gasified is a key outcome on initial syngas composition...

The MAL proteolipid has been recently demonstrated as being necessary for correct apical sorting of the transmembrane influenza virus hemagglutinin (HA) in Madin–Darby canine kidney (MDCK) cells. The fact that, in contrast to MDCK cells, Fischer rat thyroid (FRT) cells target the majority of glycosylphosphatidylinositol (GPI)-anchored proteins to the basolateral membrane provides us with the opportunity to determine the role of MAL in apical transport of membrane proteins under conditions in which the majority of GPI-anchored proteins are (MDCK cells) or are not (FRT cells) targeted to the apical surface. Using an antisense oligonucleotide-based strategy to deplete endogenous MAL, we have observed that correct transport of apical transmembrane proteins associated (HA) or not (exogenous neurotrophin receptor and endogenous dipeptidyl peptidase IV) with lipid rafts, as well as that of the bulk of endogenous apical membrane, takes place in FRT cells by a pathway that requires normal MAL levels. Even transport of placental alkaline phosphatase, a GPI-anchored protein that is targeted apically in FRT cells, was dependent on normal MAL levels. Similarly, in addition to the reported effect of MAL on HA transport, depletion of MAL in MDCK cells caused a dramatic reduction in the apical delivery of the GPI-anchored gD1-DAF protein...

The MAL proteolipid is a nonglycosylated integral membrane protein found in glycolipid-enriched membrane microdomains. In polarized epithelial Madin-Darby canine kidney cells, MAL is necessary for normal apical transport and accurate sorting of the influenza virus hemagglutinin. MAL is thus part of the integral machinery for glycolipid-enriched membrane–mediated apical transport. At steady state, MAL is predominantly located in perinuclear vesicles that probably arise from the trans-Golgi network (TGN). To act on membrane traffic and to prevent their accumulation in the target compartment, integral membrane elements of the protein-sorting machinery should be itinerant proteins that cycle between the donor and target compartments. To establish whether MAL is an itinerant protein, we engineered the last extracellular loop of MAL by insertion of sequences containing the FLAG epitope or with sequences containing residues that became O-glycosylated within the cells or that displayed biotinylatable groups. The ectopic expression of these modified MAL proteins allowed us to investigate the surface expression of MAL and its movement through different compartments after internalization with the use of a combination of assays, including surface biotinylation...

The MAL proteolipid, a component of the integral protein sorting machinery, has been demonstrated as being necessary for normal apical transport of the influenza virus hemagglutinin (HA) and the overall apical membrane proteins in Madin-Darby canine kidney (MDCK) cells. The MAL carboxy terminus ends with the sequence Arg-Trp-Lys-Ser-Ser (RWKSS), which resembles dilysine-based motifs involved in protein sorting. To investigate whether the RWKSS pentapeptide plays a role in modulating the distribution of MAL and/or its function in apical transport, we have expressed MAL proteins with distinct carboxy terminus in MDCK cells whose apical transport was impaired by depletion of endogenous MAL. Apical transport of HA was restored to normal levels by expression of MAL with an intact but not with modified carboxyl terminal sequences bearing mutations that impair the functioning of dilysine-based sorting signals, although all the MAL proteins analyzed incorporated efficiently into lipid rafts. Ultrastructural analysis indicated that compared with MAL bearing an intact RWKSS sequence, a mutant with lysine −3 substituted by serine showed a twofold increased presence in clathrin-coated cytoplasmic structures and a reduced expression on the plasma membrane. These results indicate that the carboxyl-terminal RWKSS sequence modulates the distribution of MAL in clathrin-coated elements and is necessary for HA transport to the apical surface.

Nutritional status may have significant importance for the immune system, and particularly, unsaturated fatty acids may serve as modulators of immune functions. Clinical and epidemiological studies have demonstrated that fatty acids are involved in the reduction of the inflammatory processes that occur in diseases characterized by an overactivation of the immune system. At the same time, an increase in susceptibility to infection has also been reported. The importance of immune system modulation by dietary lipids in the presence of an intracellular bacterial pathogen, such as Listeria monocytogenes, was evaluated in the present study. BALB/c mice were divided into four groups which were each fed a low-fat (2.5% by weight) diet, an olive oil (OO; 20% by weight) diet, a fish oil (FO; 20% by weight) diet, or a hydrogenated coconut oil (HCO; 20% by weight) diet for 4 weeks. In each group, lymphocye proliferation was measured, and a reduction in the stimulation index was observed in the FO and HCO groups. Cytotoxicity exerted by L. monocytogenes was increased in the groups fed diets containing OO and FO after 6 h of incubation with the bacterium. An important increase in the production of reactive oxygen species was found in the groups fed the HCO diet after 12 h of incubation with L. monocytogenes. Finally...

We previously demonstrated, using fluorescence recovery after photobleaching, that clathrin in clathrin-coated pits at the plasma membrane exchanges with free clathrin in the cytosol, suggesting that clathrin-coated pits are dynamic structures. We now investigated whether clathrin at the trans-Golgi network as well as the clathrin adaptors AP2 and AP1 in clathrin-coated pits at the plasma membrane and trans-Golgi network, respectively, also exchange with free proteins in the cytosol. We found that when the budding of clathrin-coated vesicle is blocked without significantly affecting the structure of clathrin-coated pits, both clathrin and AP2 at the plasma membrane and clathrin and AP1 at the trans-Golgi network exchange rapidly with free proteins in the cytosol. In contrast, when budding of clathrin-coated vesicles was blocked at the plasma membrane or trans-Golgi network by hypertonic sucrose or K+ depletion, conditions that markedly affect the structure of clathrin-coated pits, clathrin exchange was blocked but AP2 at the plasma membrane and both AP1 and the GGA1 adaptor at the trans-Golgi network continue to rapidly exchange. We conclude that clathrin-coated pits are dynamic structures with rapid exchange of both clathrin and adaptors and that adaptors are able to exchange independently of clathrin when clathrin exchange is blocked.

Sorting of transmembrane proteins and their ligands at various compartments of the endocytic and secretory pathways is mediated by selective incorporation into clathrin-coated intermediates. Previous morphological and biochemical studies have shown that these clathrin-coated intermediates consist of spherical vesicles with a diameter of 60–100 nm. Herein, we report the use of fluorescent imaging of live cells to demonstrate the existence of a different type of transport intermediate containing associated clathrin coats. Clathrin and the adaptors GGA1 and adaptor protein-1, labeled with different spectral variants of the green fluorescent protein, are shown to colocalize to the trans-Golgi network and to a population of vesicles and tubules budding from it. These intermediates are highly pleiomorphic and move toward the peripheral cytoplasm for distances of up to 10 μm with average speeds of ∼1 μm/s. The labeled clathrin and GGA1 cycle on and off membranes with half-times of 10–20 s, independently of vesicle budding. Our observations indicate the existence of a novel type of trans-Golgi network-derived carriers containing associated clathrin, GGA1 and adaptor protein-1 that are larger than conventional clathrin-coated vesicles...

The human mal gene, identified during a search for cDNAs selectively expressed during T-cell development, encodes a highly hydrophobic protein belonging to a group of proteins, termed proteolipids, characterized by their unusual property of being soluble in organic solvents used to extract cell lipids. To study the localization of the MAL protein we have prepared stable transfectants expressing the MAL protein tagged with a c-myc epitope (MAL/c-myc) using human epithelial A-498 cells. Immunofluorescence analysis suggested that MAL/c-myc is localized mainly to cholesterol-enriched structures with a post-Golgi location and, at low levels, in early endosomes. Moreover, extraction of A-498 cell membranes with Triton X-100 (TX100) and fractionation by centrifugation to equilibrium in sucrose gradients demonstrated the presence of MAL/c-myc in the detergent-insoluble buoyant fraction, known to be enriched in glycolipids and cholesterol. To compare the behaviour of MAL in T-cells with that in epithelial A-498 cells, we prepared stably transfected cells expressing MAL/c-myc using human Jurkat T-cells. When TX100 extracts from Jurkat cells were subjected to centrifugation to equilibrium in sucrose gradients we found MAL exclusively in the floating fractions...

Recent experimental observations have determined that long-chain n-3 polyunsaturated fatty acids suppress immune functions and are involved in the reduction of infectious disease resistance. BALB/c mice were fed for 4 weeks with one of four diets containing either olive oil (OO), fish oil (FO), hydrogenated coconut oil, or a low fat level. Interleukin-12p70 (IL-12p70), gamma interferon (IFN-γ), and tumor necrosis factor alpha (TNF-α) production in the sera of mice fed these diets and challenged with Listeria monocytogenes were determined by enzyme-linked immunosorbent assay. In addition, bacterial counts from spleens of mice were carried out at 24, 72, or 96 h of infection. Here, we quantified an initial diminution of production of both IL-12p70 and IFN-γ, which appear to play an important role in the reduction of host resistance to L. monocytogenes infection. In addition, an efficient elimination of L. monocytogenes was observed in spleens of mice fed a diet containing OO at 96 h of infection, despite reductions in IL-12p70 and TNF-α production, suggesting an improvement of immune resistance. Overall, our results indicate that the initial reduction of both IL-12 and IFN-γ production before L. monocytogenes infection represents the most relevant event that corroborates the impairment of immune resistance by n-3 polyunsaturated fatty acids during the different stages of infection. However...

RESUMEN. La llegada de una gran infraestructura como el AVE en 1992 a Ciudad Real y Puertollano, ciudades pequeñas tradicionalmente alejadas de los principales corredores de transporte españoles, ha provocado una serie de transformaciones territoriales en ambos núcleos. El artículo trata de descubrir los cambios demográficos, económicos e inmobiliarios a través de datos estadísticos existentes y la comparación, por un lado, con otras ciudades similares españolas que no se han beneficiado aún de esta infraestructura y, por otro lado, con núcleos representativos de la provincia de Ciudad Real. Además, se ha intentado establecer unas pautas de análisis para explorar o predecir los efectos del AVE en otras ciudades pequeñas y medianas parecidas.; ABSTRACT. The arrival in 1992 of a large infrastructure, namely the High Speed Train (HST), to Ciudad Real and Puertollano, small cities hitherto distant from the main Spanish transport corridors, has provoked a series of territorial transformations in both towns. This article sets out to reveal the demographic, economic and building changes by the use of the existing statistical data and by comparing these two cities firstly with similar Spanish cities that have not benefited from this infrastructure...

2 ej. de la misma obra; En portadilla dedicatoria ms. del autor para Eduardo Garc??a Duarte

[ES] Se presenta el estudio tecnológico de un nuevo depósito del Bronce Final aparecido en Puertollano (Ciudad Real). Compuesto exclusivamente por armas (14 espadas y puñales y un fragmento de regatón) constituye un deposito singular entre los conocidos en la Península ibérica. Se incluyen los análisis de composición mediante técnica PIXE que indican que todas las piezas son bronces binarios Cu-Sn con bajo nivel de impurezas. Se discute sobre la funcionalidad y uso práctico de estas producciones armamentísticas.; [EN] This paper deals with the technological study of a new Late Bronce Age hoard found in Puertollano (Ciudad Real). This hoard is a singular found in the context of Iberian Peninsula due to the number of items (14 swords and daggers and 1 fragment of ferrule) and all of them are weapons. Elemental analysis by PIXE shows a Copper- Tin alloy with very low impurity pattern. A general comment about the real use of this weapons is included.; Peer reviewed

Las áreas funcionales urbanas (FUA) de Ciudad Real y de Puertollano se estructuran a partir de ambas ciudades, funcionalmente diferentes pero que sostienen unas relaciones cada vez más intensas en el sector suroccidental de la región de Castilla-La Mancha, dentro de la provincia de Ciudad Real. Las interrelaciones se establecen en base a las infraestructuras de comunicación, principalmente la línea de alta velocidad ferroviaria. Este artículo caracteriza ambas áreas funcionales y determina las relaciones entre sus núcleos principales en base a una metodología que combina análisis estadístico (población, crecimiento real anual, población vinculada, etc.) y empírico, con las representaciones cartográficas de los principales indicadores. Los resultados obtenidos permiten abordar una caracterización conjunta de ambas áreas funcionales en el contexto del policentrismo aplicado a la región de Castilla-La Mancha y del importante papel articulador que las infraestructuras de alta capacidad tienen en este caso de estudio.; Les àrees funcionals urbanes (FUA) de Ciudad Real i de Puertollano s’estructuren entorn de totes dues ciutats, funcionalment diferents, però que mantenen relacions cada cop més intenses en el sector sud-oest de la regió de Castella-la Manxa...

Los ácidos grasos de naturaleza poliinsaturada ω-3 han recibido una gran atención en los últimos años como componentes de la dieta supresores de las funciones inmunes y por ello han sido aplicados en la resolución de diferentes desórdenes de naturaleza inflamatoria. Aunque la inhibición de algunas funciones inmunes por la acción de estos ácidos grasos ejerce efectos beneficiosos en la disminución de la respuesta inflamatoria del individuo, este estado puede conducir a una reducción significativa de la protección del individuo frente a microorganismos de naturaleza infecciosa (virus, bacterias, hongos y parásitos). Sin embargo, el aceite de oliva (constituido principalmente por ácidos grasos monoinsaturados y uno de los componentes principales de la dieta Mediterránea) modula también algunas de estas funciones, sin reducir de forma tan severa la resistencia inmune del individuo frente a agentes de naturaleza infecciosa. Bajo estas premisas podemos afirmar que la administración de aceite de oliva puede contribuir a la reducción de la actividad inflamatoria observada en algunas enfermedades crónicas caracterizadas por desórdenes inmunes, sin agravar la susceptibilidad del individuo a agentes patógenos. Por lo tanto...

Algunas dietas lipídicas están implicadas en la reducción de ciertas funciones inmunes. Sin embargo, la acción inmunosupresora de estas dietas puede tener efectos adversos sobre la resistencia inmune del individuo frente a enfermedades de naturaleza infecciosa. En el presente estudio tratamos de valorar el estado inmune de ratones alimentados con dietas lipídicas e infectados experimentalmente con una cepa virulenta de Listeria monocytogenes. Ratones de la raza Balb/c fueron divididos en cuatro grupos alimentados cada uno de ellos con su respectiva dieta: dieta baja en lípidos (control, 2,5%), dieta rica en aceite de oliva (AO, 20%), dieta rica en aceite de pescado (AP, 20%) y dieta rica aceite de coco (AC, 20%). Los animales fueron alimentados durante un mes y posteriormente infectados con L. monocytogenes por vía endovenosa. Los resultados han mostrado una reducción de la supervivencia en animales alimentados con AP, así como un incremento significativo en el número de bacterias viables aisladas a partir de bazo. Además hemos podido observar un aumento de la capacidad bactericida de células peritoneales procedentes de ratones alimentados con AO, aunque la invasividad de L. monocytogenes en este grupo fue mayor que en el resto. Finalmente...