71 research outputs found

    Uso de morteros catalíticos sobre paneles, para el análisis de la reducción de partículas contaminantes en el aire

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    Trabajo de Investigación TecnológicaEste proyecto de grado se enfoca en la contaminación del aire y el uso de las nuevas tecnologías en la construcción para combatir este problema que genera afectaciones no solo ambientales, sino en la salud humana, en la flora y la fauna. La nanotecnología, es una rama que se desprende de las nuevas tecnologías y que se ha abierto paso en la industria de la construcción, por medio de la implementación de materiales y aditivos te tamaño nanométrico que mejoran y generan nuevas propiedades en los materiales comunes de construcción como el acero, concretos, morteros, pinturas, etc. En este proyecto se elaboró un concreto y mortero adicionando el Dióxido de titanio (TiO2), el cual actúa como un catalizador al combinarse con el cemento y los rayos ultra violeta, y su función principal es oxidar las partículas contaminantes suspendidas en el aire, por lo cual se categoriza como un descontaminante. Adicionalmente, el TiO2 puede mejorar las propiedades del concreto. Para comprobar el efecto del TiO2 en el concreto, se elaboraron cuatro cilindros de concreto común y de concreto adicionado, los cuales se fallaron en las edades típicas de falla y se compararon los resultados obtenidos. De igual manera, se fabricó un mortero adicionado, el cual se colocó sobre paneles y se dejó expuesto ocho días en un área de monitoreo de aire, y con los datos obtenidos se realizó el análisis correspondiente.1 INTRODUCCIÓN 2 ANTECEDENTES 3 PLANTEAMIENTO DEL PROBLEMA 4 OBJETIVOS 5 JUSTIFICACIÓN 6 DELIMITACIONES 7 MARCO DE REFERENCIA 8 METODOLOGÍA 9 DISEÑO METODOLÓGICO. 10 CONCLUSIONES 11 RECOMENDACIONES BIBLIOGRAFÍAPregradoIngeniero Civi

    A Novel Non-Lens βγ−Crystallin and Trefoil Factor Complex from Amphibian Skin and Its Functional Implications

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    In vertebrates, non-lens betagamma-crystallins are widely expressed in various tissues, but their functions are unknown. The molecular mechanisms of trefoil factors, initiators of mucosal healing and being greatly involved in tumorigenesis, have remained elusive.A naturally existing 72-kDa complex of non-lens betagamma-crystallin (alpha-subunit) and trefoil factor (beta-subunit), named betagamma-CAT, was identified from frog Bombina maxima skin secretions. Its alpha-subunit and beta-subunit (containing three trefoil factor domains), with a non-covalently linked form of alphabeta(2), show significant sequence homology to ep37 proteins, a group of non-lens betagamma-crystallins identified in newt Cynops pyrrhogaster and mammalian trefoil factors, respectively. betagamma-CAT showed potent hemolytic activity on mammalian erythrocytes. The specific antiserum against each subunit was able to neutralize its hemolytic activity, indicating that the two subunits are functionally associated. betagamma-CAT formed membrane pores with a functional diameter about 2.0 nm, leading to K(+) efflux and colloid-osmotic hemolysis. High molecular weight SDS-stable oligomers (>240-kDa) were detected by antibodies against the alpha-subunit with Western blotting. Furthermore, betagamma-CAT showed multiple cellular effects on human umbilical vein endothelial cells. Low dosages of betagamma-CAT (25-50 pM) were able to stimulate cell migration and wound healing. At high concentrations, it induced cell detachment (EC(50) 10 nM) and apoptosis. betagamma-CAT was rapidly endocytosed via intracellular vacuole formation. Under confocal microscope, some of the vacuoles were translocated to nucleus and partially fused with nuclear membrane. Bafilomycin A1 (a specific inhibitor of the vacuolar-type ATPase) and nocodazole (an agent of microtuble depolymerizing), while inhibited betagamma-CAT induced vacuole formation, significantly inhibited betagamma-CAT induced cell detachment, suggesting that betagamma-CAT endocytosis is important for its activities.These findings illustrate novel cellular functions of non-lens betagamma-cyrstallins and action mechanism via association with trefoil factors, serving as clues for investigating the possible occurrence of similar molecules and action mechanisms in mammals

    Preclinical Evaluation of Caprylic Acid-Fractionated IgG Antivenom for the Treatment of Taipan (Oxyuranus scutellatus) Envenoming in Papua New Guinea

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    articulo (arbitrado) -- Universidad de Costa Rica, Instituto de Investigaciones Clodomiro Picado, 2011Background: Snake bite is a common medical emergency in Papua New Guinea (PNG). The taipan, Oxyuranus scutellatus, inflicts a large number of bites that, in the absence of antivenom therapy, result in high mortality. Parenteral administration of antivenoms manufactured in Australia is the current treatment of choice for these envenomings. However, the price of these products is high and has increased over the last 25 years; consequently the country can no longer afford all the antivenom it needs. This situation prompted an international collaborative project aimed at generating a new, low-cost antivenom against O. scutellatus for PNG. Methodology/Principal Findings: A new monospecific equine whole IgG antivenom, obtained by caprylic acid fractionation of plasma, was prepared by immunising horses with the venom of O. scutellatus from PNG. This antivenom was compared with the currently used F(ab’)2 monospecific taipan antivenom manufactured by CSL Limited, Australia. The comparison included physicochemical properties and the preclinical assessment of the neutralisation of lethal neurotoxicity and the myotoxic, coagulant and phospholipase A2 activities of the venom of O. scutellatus from PNG. The F(ab’)2 antivenom had a higher protein concentration than whole IgG antivenom. Both antivenoms effectively neutralised, and had similar potency, against the lethal neurotoxic effect (both by intraperitoneal and intravenous routes of injection), myotoxicity, and phospholipase A2 activity of O. scutellatus venom. However, the whole IgG antivenom showed a higher potency than the F(ab’)2 antivenom in the neutralisation of the coagulant activity of O. scutellatus venom from PNG. Conclusions/Significance: The new whole IgG taipan antivenom described in this study compares favourably with the currently used F(ab’)2 antivenom, both in terms of physicochemical characteristics and neutralising potency. Therefore, it should be considered as a promising low-cost candidate for the treatment of envenomings by O. scutellatus in PNG, and is ready to be tested in clinical trials.This study was supported by Vicerrectoría de Investigación, Universidad de Costa Rica (project 741-A9-003); the PNG Office of Higher Education, CTP Limited (Milne Bay Estates), and the Australian Venom Research Unit (University of Melbourne), which is funded by the Australian Government Department of Health and Ageing, the Australia Pacific Science Foundation and Snowy Nominees. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP

    The observation of quasi-molecular ions from a tiger snake venom component (Mr 13 309) using 252Cf-plasma desorption mass spectrometry

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    AbstractA method involving fast heavy-ion bombardment of a solid sample called 252Cf-plasma desorption mass spectrometry has been used to study of a non-enzymatic, non-toxic phospholipase homolog from Australian tiger snake (Notechis scutatus) venom. The protein consists of 119 amino acids in a single polypeptide chain cross-linked by 7 disulfide bridges. The isotopically averaged molecular mass as determined by protein sequence analysis is 13 309 atomic mass units (amu). The mass distributions were studied by means of time-of-flight measurements. Quasi-molecular ions associated to the molecule and its dimer were observed. The mass of the quasi-molecular ion corresponding to the molecule was determined to be 13 285 ± 25 amu
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