Energías no convencionales : biocombustibles

Fil: Romano, Silvia Daniela. Universidad de Buenos Aires. Facultad de Ingeniería. Grupo de Energías Renovables; ArgentinaEntre los principales atractivos de los biocombustibles se encuentra el hecho de que se\nobtienen a partir de recursos renovables, generan menos emisiones, son\nbiodegradables y brindan la posibilidad de diversificar la matriz energética. Además,\nvarios de ellos se producen a partir de residuos o sustancias no alimenticias. La\nFacultad de Ingeniería de la UBA se constituyó en los últimos años como una de las\nprincipales fuentes de investigación sobre energías no convencionales. En su sede de\nPaseo Colón, ya se inauguró la primera planta piloto de biodiésel del país

Alternative Properties in Liquid Fuels and Blends

This work summarises the results of the research program at the Renewable Energy Group (GER) of the University of Buenos Aires on alternative properties for the characterization of liquid fuels. The study included fossil fuels: diesel fuel, gasoline, and methanol, and biofuels: biodiesel from different feedstocks and bioethanol. Blends of diesel fuel/biodiesel, gasoline/bioethanol, gasoline/methanol, biodiesel/butanol, and diesel fuel/biodiesel/butanol were also studied. The electrical, acoustical, and optical properties of fuels and blends were determined as a function of temperature and composition. From these results, the composition of blends was accurately estimated from measurements of permittivity and temperature. The research program included the study of correlations of the alternative properties with those indicated in the international quality standards for liquid fuels (kinematic viscosity, methanol content, flash point). These correlations make possible to verify the quality of liquid fuels with simpler and more convenient measurements in industrial settings, and also in the laboratory.Fil: Romano, Silvia Daniela. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Mecánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; ArgentinaFil: Sorichetti, P. A.. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física; Argentin

Biocombustibles Líquidos en La Argentina

Los biocombustibles líquidos de uso automotor han tomado relevancia en el siglo XXI. En particular, durante la última década se ha estado utilizando en numerosos países el corte obligatorio de nafta con bioetanol y gasoil con biodiesel, en distintas proporciones. Para que la implementación del uso de biocombustibles se pueda realizar es necesario que el país disponga de legislación que incluya requisitos de calidad del producto, de seguridad y control de efluentes en las instalaciones productoras, que asegure la disponibilidad de los biocombustibles para el mercado interno, que establezca una distribución adecuada, como también la clara determinación del precio de venta del biocombustible. El objetivo de este capítulo es presentar un breve panorama sobre la producción y el uso de los biocombustibles líquidos en Argentina, incluyendo el marco legal establecido para el desarrollo de los mismos.Fil: Romano, Silvia Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías del Hidrogeno y Energias Sostenibles; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería; Argentin

Isomin: a novel cytoplasmic intermediate filament protein from an arthropod species

<p>Abstract</p> <p>Background</p> <p>The expression of intermediate filaments (IFs) is a hallmark feature of metazoan cells. IFs play a central role in cell organization and function, acting mainly as structural stress-absorbing elements. There is growing evidence to suggest that these cytoskeletal elements are also involved in the integration of signalling networks. According to their fundamental functions, IFs show a widespread phylogenetic expression, from simple diblastic animals up to mammals, and their constituent proteins share the same molecular organization in all species so far analysed. Arthropods represent a major exception in this scenario. Only lamins, the nuclear IF proteins, have so far been identified in the model organisms analysed; on this basis, it has been considered that arthropods do not express cytoplasmic IFs.</p> <p>Results</p> <p>Here, we report the first evidence for the expression of a cytoplasmic IF protein in an arthropod - the basal hexapod <it>Isotomurus maculatus</it>. This new protein, we named it isomin, is a component of the intestinal terminal web and shares with IFs typical biochemical properties, molecular features and reassembly capability. Sequence analysis indicates that isomin is mostly related to the Intermediate Filament protein C (IFC) subfamily of <it>Caenorhabditis elegans </it>IF proteins, which are molecular constituents of the nematode intestinal terminal web. This finding is coherent with, and provides further support to, the most recent phylogenetic views of arthropod ancestry. Interestingly, the coil 1a domain of isomin appears to have been influenced by a substantial molecular drift and only the aminoterminal part of this domain, containing the so-called helix initiation motif, has been conserved.</p> <p>Conclusions</p> <p>Our results set a new basis for the analysis of IF protein evolution during arthropod phylogeny. In the light of this new information, the statement that the arthropod phylum lacks cytoplasmic IFs is no longer tenable.</p> <p>See commentary article: <url>http://www.biomedcentral.com/1741-7007-9-16</url>.</p

Use of water in the biodiesel purification process: optimization by controlling electrical properties of effluent

La producción sustentable de biodiesel requiere la optimización del consumo de agua. Este es un factor clave que debe tenerse en cuenta en la etapa de diseño y en la operación de las plantas. El impacto ambiental y la calidad del producto final dependen críticamente del correcto diseño del proceso de purificación y del control del mismo durante la producción. En plantas pequeñas y medianas el consumo de agua empleado respecto al volumen de biocombustible a purificar llega al 100% o 150%; la proporción cae al 35% en instalaciones grandes, en que se recupera la mayor parte del agua. Los efluentes de la producción de biodiesel consisten principalmente en el agua de lavado, que contiene cantidades variables de alcohol y catalizador. En consecuencia, un tratamiento deficiente de los efluentes involucra riesgos ambientales debidos a la contaminación de aguas subterráneas y superficiales, y sistemas de desagüe. En este trabajo se analiza la optimización del uso de agua en la producción de biodiesel, en particular durante la etapa de purificación. Se miden las propiedades eléctricas de los efluentes (permitividad, conductividad y factor de disipación), como función de la frecuencia y la temperatura. La reducción progresiva de los valores medidos constituye una indicación de la remoción del alcohol y los restos de catalizador del producto en las sucesivas etapas de lavado. Esto permite controlar el grado de avance del proceso y verificar su finalización. La purificación se considera adecuada cuando los valores medidos en los efluentes de la última etapa de lavado son cercanos a los del agua limpia empleada. Asimismo, los apartamientos respecto de los valores óptimos de los parámetros se detectan por comparación con valores de referencia. A diferencia de otras técnicas (cromatografía, espectrofotometría, etc.), las mediciones de propiedades eléctricas son rápidas, eficientes y económicas, y se adaptan bien a los sistemas de control automáticoSustainable production of biodiesel requires the optimization of water use. This is a key issue that must be considered at the design stage and during plant operation. The environmental impact and the quality of the final product depend critically on the correct design of the purification process and its control during production. In plants of small and medium size water consumption may reach 100% to 150% of the volume of the product to be purified; this ratio falls to 35% in large installations, where most of the water is recovered. Effluent from biodiesel production consists mainly of water from the washing steps, containing variable amounts of alcohol and catalyst. In consequence, the inadequate treatment of effluent involves serious environmental risks due to contamination of sewer systems and surface and underground water. In this work the optimization of water use in biodiesel production is analyzed, particularly during the purification stage. Electrical properties of effluent (permittivity, conductivity and dissipation factor) are measured as a function of frequency and temperature. The steady reduction of the measured values in the effluent indicates the removal of alcohol and catalyst remaining in the product at the successive washing steps. This makes possible to monitor the advance of the process and verify its completion. The purification is regarded as adequate when the measured values in the effluent of the last washing stage are close to those of the clean water used. Also, deviations from optimum parameter values are detected by comparison to reference values. Compared with other techniques (chromatography, spectrophotometry, etc.), electrical properties measurements are fast, efficient and economical, and adapt well to automated control systems.Comité de Medio Ambient

Draft genome sequences of four Yersinia enterocolitica strains, isolated from wild ungulate carcasses

This study describes the draft genome sequences of four Yersinia enterocolitica strains, originally isolated from ungulate carcasses. These isolates were typed biochemically and two were determined to be highly virulent (biotype 1B). The draft genome sequences had a mean size of 4.77 Mb and a mean G+C content of 47.1%

Peripheral Biomarkers in Manifest and Premanifest Huntington’s Disease

Huntington's disease (HD) is characterized by clinical motor impairment (e.g., involuntary movements, poor coordination, parkinsonism), cognitive deficits, and psychiatric symptoms. An inhered expansion of the CAG triplet in the huntingtin gene causing a pathogenic gain-of-function of the mutant huntingtin (mHTT) protein has been identified. In this review, we focus on known biomarkers (e.g., mHTT, neurofilament light chains) and on new biofluid biomarkers that can be quantified in plasma or peripheral blood mononuclear cells from mHTT carriers. Circulating biomarkers may fill current unmet needs in HD management: better stratification of patients amenable to etiologic treatment; the initiation of preventive treatment in premanifest HD; and the identification of peripheral pathogenic central nervous system cascades

Whole-Genome Shotgun Sequence of Salmonella bongori, First Isolated in Northwestern Italy

peer-reviewedThis study describes the whole-genome shotgun sequence of Salmonella bongori 48:z35:–, originally isolated from a 1-year-old symptomatic patient in northwest Italy, a typically nonendemic area. The draft genome sequence contained 4.56 Mbp and the G+C content was 51.27%

TNF-&#945;/TNF-R System May Represent a Crucial Mediator of Proliferative Synovitis in Hemophilia A

Hemophilic arthropathy (HA) typically begins with proliferative synovitis that shares some similarities with inflammatory arthritides, in which the proinflammatory cytokine tumor necrosis factor (TNF)-&alpha; has a crucial pathogenetic role. Inappropriate release of TNF-&alpha; was shown to contribute to arthropathy development following intra-articular bleeding in hemophilic mice. Here, we were interested in determining whether systemic levels of TNF-&alpha; and synovial tissue expression of the TNF-&alpha;/TNF receptor (TNF-R) system could be increased and related to joint damage in hemophilia A patients with severe HA. Serum levels of TNF-&alpha; measured by quantitative enzyme-linked immunosorbent assay (ELISA) were significantly increased in HA patients (n = 67) compared to healthy controls (n = 20). In HA patients, elevated TNF-&alpha; levels were significantly associated with the number of hemarthroses, the grade of synovial hypertrophy, and both the clinical World Federation of Hemophilia score and ultrasound score. The expression of TNF-&alpha;, TNF-R1, and TNF-R2 was strongly increased in HA synovium (n = 10) compared to the non-inflamed osteoarthritis control synovium (n = 8), as assessed by both immunohistochemistry and Western blotting. Increased protein levels of TNF-&alpha;, TNF-R1, and TNF-R2 were retained in vitro by HA fibroblast-like synoviocytes (n = 6) with respect to osteoarthritis control fibroblast-like synoviocytes (n = 6). Stimulation with TNF-&alpha; resulted in a significant increase in HA fibroblast-like synoviocyte proliferation quantified by the water-soluble tetrazolium (WST)-1 assay, while it had no relevant effect on osteoarthritis fibroblast-like synoviocytes. Quantification of active/cleaved caspase-3 by ELISA demonstrated that TNF-&alpha; did not induce apoptosis either in HA or in osteoarthritis fibroblast-like synoviocytes. The TNF-&alpha;/TNF-R system may represent a crucial mediator of proliferative synovitis and, therefore, a new attractive target for the prevention and treatment of joint damage in HA patients. Our findings provide the groundwork for further clinical investigation of anti-TNF-&alpha; therapeutic feasibility in hemophiliacs