Novel Applications with Asphaltene Electronic Structure

Asphaltenes are the molecular components of Asphalts and have polyaromatic hydrocarbon (PAH) structures similar to nanographenes. Thus, organic-based dye sensitized solar cells can be produced from asphaltenes. In addition, graphene based structures doped with transition metals can be synthesized from asphaltenes. These materials are simple to synthesize and inexpensive relative to other methods for doping graphene. Thus, what is considered a “Waste Material - Tar” can now be utilized in several important applications. These novel materials from asphaltene are also termed Discotic Liquid Crystals (DLC) and now have great potential in many areas, because of novel and valuable properties, easy synthesis and low cost

L-Phenylalanine Transport in Saccharomyces cerevisiae: Participation of GAP1, BAP2, and AGP1

We focused on the participation of GAP1, BAP2, andAGP1 in L-phenylalanine transport in yeast. In order to study the physiological functions of GAP1, BAP2, and AGP1 in L-phenylalanine transport, we examined the kinetics, substrate specificity, and regulation of these systems, employing isogenic haploid strains with the respective genes disrupted individually and in combination. During thecharacterization of phenylalanine transport, we noted important regulatory phenomena associated with these systems. Our results show that Agp1p is the major transporter of the phenylalanine in a gap1 strain growing in synthetic media with leucine present as an inducer. In a wild type straiFil: Stella, Carlos Alberto. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chianelli, Monica Silvia. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Saenz, Daniel Alberto. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Atmospheric Nanoparticles in Photocatalytic and Thermal Production of Atmospheric Pollutants

Atmospheric aerosols which occur above heavily polluted areas such as Mexico City, are characterized and found to be complex materials that have the potential to accelerate important ozone-forming reactions photocatalytically and thermocatalytically. In addition, because the particles are respirable, they may represent a considerable health hazard. The aerosols consist of two intermixed components. The first component consists of amorphous carbonaceous materials of variable composition with fullerene like materials dispersed throughout. The second component is an inorganic material consisting of nanoparticles of oxides and sulfides supported on clay minerals. This inorganic component has all of the characteristics of an airborne photocatalyst. Nanoparticles of Fe2O3, MnO2 and FeS2 have demonstrated catalytic properties, particularly when they occur in the nanoparticle range, as they do in the subject aerosol materials. These materials have band-gaps that occur in the broad solar spectrum enhancing the photocatalytic adsorption of solar radiation beyond that of the wider band-gap aluminosilicate and titanate materials, which also occur in aerosols. In addition, the materials are acidic and probably are coated with moisture when suspended in air, further enhancing their catalytic ability to crack hydrocarbons and create free radicals

The flat phase of fixed-connectivity membranes

The statistical mechanics of flexible two-dimensional surfaces (membranes) appears in a wide variety of physical settings. In this talk we discuss the simplest case of fixed-connectivity surfaces. We first review the current theoretical understanding of the remarkable flat phase of such membranes. We then summarize the results of a recent large scale Monte Carlo simulation of the simplest conceivable discrete realization of this system \cite{BCFTA}. We verify the existence of long-range order, determine the associated critical exponents of the flat phase and compare the results to the predictions of various theoretical models.Comment: 7 pages, 5 figures, 3 tables. LaTeX w/epscrc2.sty, combined contribution of M. Falcioni and M. Bowick to LATTICE96(gravity), to appear in Nucl. Phys. B (proc. suppl.

Global and Ocular Hypothermic Preconditioning Protect the Rat Retina from Ischemic Damage

Retinal ischemia could provoke blindness. At present, there is no effective treatment against retinal ischemic damage. Strong evidence supports that glutamate is implicated in retinal ischemic damage. We investigated whether a brief period of global or ocular hypothermia applied 24 h before ischemia (i.e. hypothermic preconditioning, HPC) protects the retina from ischemia/reperfusion damage, and the involvement of glutamate in the retinal protection induced by HPC. For this purpose, ischemia was induced by increasing intraocular pressure to 120 mm Hg for 40 min. One day before ischemia, animals were submitted to global or ocular hypothermia (33uC and 32uC for 20 min, respectively) and fourteen days after ischemia, animals were subjected to electroretinography and histological analysis. Global or ocular HPC afforded significant functional (electroretinographic) protection in eyes exposed to ischemia/reperfusion injury. A marked alteration of the retinal structure and a decrease in retinal ganglion cell number were observed in ischemic retinas, whereas global or ocular HPC significantly preserved retinal structure and ganglion cell count. Three days after ischemia, a significant decrease in retinal glutamate uptake and glutamine synthetase activity was observed, whereas ocular HPC prevented the effect of ischemia on these parameters. The intravitreal injection of supraphysiological levels of glutamate induced alterations in retinal function and histology which were significantly prevented by ocular HPC. These results support that global or ocular HPC significantly protected retinal function and histology from ischemia/reperfusion injury, probably through a glutamatedependent mechanism.Fil: Salido E.Fil: Dorfman D.Fil: Bordone, Melina.Fil: Chianelli Mónica S.Fil: González Fleitas Mf.Fil: Rosenstein Re

Superconducting tantalum disulfide nanotapes; growth, structure and stoichiometry

Superconducting tantalum disulfide nanowires have been synthesised by surface-assisted chemical vapour transport (SACVT) methods and their crystal structure, morphology and stoichiometry studied by powder X-ray diffraction (PXD), scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and nanodiffraction. The evolution of morphology, stoichiometry and structure of materials grown by SACVT methods in the Ta-S system with reaction temperature was investigated systematically. High-aspect-ratio, superconducting disulfide nanowires are produced at intermediate reaction temperatures (650 degrees C). The superconducting wires are single crystalline, adopt the 2H polytypic structure (hexagonal space group P6(3)/mmc: a = 3.32(2) angstrom, c = 12.159(2) angstrom; c/a = 3.66) and grow in the <2<(1)over bar>(1) over bar0> direction. The nanowires are of rectangular cross-section forming nanotapes composed of bundles of much smaller fibres that grow cooperatively. At lower reaction temperatures nanowires close to a composition of TaS3 are produced whereas elevated temperatures yield platelets of 1T TaS2

99mTc-interleukin-2 scintigraphy in normal subjects and in patients with autoimmune thyroid diseases: a feasibility study

n/

Comida de santo: cultura e religiosidade da comida brasileira

Os negros foram trazidos para o Brasil nos navios em condições precárias e sub-humanas, sendo considerados "mercadorias" pelos colonizadores. Forçados a partir, deixaram para trás a sua terra, a sua família, seus pertences e as únicas coisas que sobreviveram nesse trajeto massacrante foram sua cultura e religião. Este trabalho tem como objetivo analisar a cultura e religiosidade da comida brasileira, com base em livros, artigos e entrevistas realizadas com 2 pais de santo do Candomblé da cidade do Rio de Janeiro, investigando a ritualização e a mistificação necessária para tornar os ingredientes do consumo diário da população brasileira um alimento sagrado e digno de uma divindade. Teve-se como conclusão que o alimento para o Candomblé é tão fundamental como é para sobrevivência do ser humano, não há Candomblé sem as oferendas que são uma forma de agradecimento, fé e renovação energética