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Sample records for acidos adenilico uridilico

  1. The preparation of nucleotides uniformly labelled with carbon-14 by biosynthetic methods. Isolation of adenylic, uridylic, cytidylic,and guanylic acids, from the alkaline hydrolysate of escherichia coli RNA; Preparacion de nucleiotidos uniformemente marcados con 14{sup C}, por via biosintetica. Aislamiento de los acidos adenilico, uridilico, citidilico y guanilico, procedentes de la hidrolisis alcalina de RNA de escherichia Coli.

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Pineda, M. D.; Pacheco Lopez, J.

    1978-07-01

    A method is described for the preparation and analysis of adenylic, uri dilic, cytidi- 11c and guanylic acids, labelled with 14{sup C}. Escherichia coli cells have been labelled by growing them in a medi dia containing glucose-14{sup C} as their only source of carbon. RNA is isolated from the cells, and after hydrolysis of the molecule the resulting nucleotides are separated by gel filtration and exchange chromatography. Chemical and radiochemical purity of the Isolated nucleotides is determined, and also its specific radioactivity. (Author) 30 refs.

  2. Cross linkage studies with the membranes of the vesicular stomatitis virus using radioactive 4-acido and 5-acido palmitic acid

    International Nuclear Information System (INIS)

    In the study described here the spatial arrangement of lipids and proteins in the VS virus was investigated on the basis of the covalent cross linkage technique. The formation of such cross linkages is brought about by the action of photosensitive acidosubstituted lipids, which permit acido functions to be introduced into a membrane in a previously defined position. Subsequently, photolysis helps to trigger the generation of radioactive nitrenes that react with the proteins and lipids in their immediate vicinity in a direct and non-selective way. The findings revealed by this study have raised questions as to the possibility of lipid-protein and lipid-lipid interactions, which is also discussed. (orig./MG)

  3. Respiration gating and Bloch fitting improve pH measurements with acidoCEST MRI in an ovarian orthotopic tumor model

    Science.gov (United States)

    Jones, Kyle M.; Randtke, Edward A.; Howison, Christine M.; Pagel, Mark D.

    2016-03-01

    We have developed a MRI method that can measure extracellular pH in tumor tissues, known as acidoCEST MRI. This method relies on the detection of Chemical Exchange Saturation Transfer (CEST) of iopamidol, an FDA-approved CT contrast agent that has two CEST signals. A log10 ratio of the two CEST signals is linearly correlated with pH, but independent of agent concentration, endogenous T1 relaxation time, and B1 inhomogeneity. Therefore, detecting both CEST effects of iopamidol during in vivo studies can be used to accurately measure the extracellular pH in tumor tissues. Past in vivo studies using acidoCEST MRI have suffered from respiration artifacts in orthotopic and lung tumor models that have corrupted pH measurements. In addition, the non-linear fitting method used to analyze results is unreliable as it is subject to over-fitting especially with noisy CEST spectra. To improve the technique, we have recently developed a respiration gated CEST MRI pulse sequence that has greatly reduced motion artifacts, and we have included both a prescan and post scan to remove endogenous CEST effects. In addition, we fit the results by parameterizing the contrast of the exogenous agent with respect to pH via the Bloch equations modified for chemical exchange, which is less subject to over-fitting than the non-linear method. These advances in the acidoCEST MRI technique and analysis methods have made pH measurements more reliable, especially in areas of the body subject to respiratory motion.

  4. Síntesis de óxidos tipo perovskita, mediante polimerización con acido cítrico y combustión con glicina.

    OpenAIRE

    Gómez Cuaspud, Jairo A; Valencia Ríos, Jesús S

    2011-01-01

    En este trabajo se describe la preparación de la perovskita La0.25 Sr 0.25 CO 0.5 Fe 0.5 O3 (LSCoF), mediante la polimerización con acido cítrico y combustión con glicina, con el propósito de obtener materiales para potenciales aplicaciones catalíticas, eléctricas y electroquímicas; para ellos los sólidos se caracterizaron mediante difracción de rayos X (DRX) y microscopia electrónica de barrido (SEM); obteniendo información acerca de la formación y pureza de fases, la morfología, la estructu...

  5. ANALISIS DEL CO-TRATAMIENTO PASIVO DE AGUAS RESIDUALES MUNICIPALES Y DRENAJE ACIDO DE MINAS EN CERRO RICO DE POTOSÍ, BOLIVIA

    Directory of Open Access Journals (Sweden)

    William H.J. Strosnider

    2015-01-01

    Full Text Available El drenaje acido de minas (DAM es un problema a nivel mundial. El co-tratamiento pasivo de DAM con aguas residuales municipales (ARM es una manera efectiva y de bajo costo que utiliza los nutrientes de ARM para tratar las concentraciones de metales y sulfato en DAM. Cerro Rico de Potosí, Bolivia es una de las grandes ciudades mineras en el mundo que tiene muchos problemas con el DAM. El objetivo de este estudio fue determinar velocidades de reacción de Al, Fe, Mn, Zn, y otros metales en DAM provenientes de un flujo de agua en Cerro Rico usando un sistema reactor de tres etapas. El DAM tenía un pH de 3.58, acidez de 1080 mg/L equivalente a CaCO3 conteniendo concentraciones de 12, 68, 17, y 550 mg/L de Al, Fe, Mn y Zn respectivamente. Las velocidades de reacción de Al, Fe, Mn y Zn fueron de 1.43, 2.09, 0.01 y 0.10 d-1, respectivamente.

  6. ESTUDIO DE LA ADSORCIÓN DE PROTEÍNAS SOBRE SUPERFICIES DE ACIDO POLILÁCTICO MEDIANTE TÉCNICAS GRAVIMÉTRICAS Y ELECTROQUÍMICAS

    Directory of Open Access Journals (Sweden)

    HUGO ARMANDO ESTUPIÑAN DURAN

    2011-01-01

    Full Text Available Metodos electroquimicos fueron utilizados para promover y evaluar la adsorcion orientada de albumina y colageno sobre superficies polimericas de acido polilactico (PLA mediante la aplicacion de un sobrepotencial anodico en un rango de 0 V a 0,45 V. La adsorcion fueestudiada usando mediciones simultaneas de espectroscopia de impedancia electroquimica (EIE y microbalanza de cristal de cuarzo (QCM, en un rango de temperaturas de 25°C a 45°C, con variaciones en proteina entre 5 y 20 ¿Êg/ml en solucion buffer de fosfato de pH 7,4. Con el aumento de la concentracion de proteinas en el electrolito, disminuye la resistencia a la transferencia de carga, exhibiendo asi una mayor adsorcion sobre la superficie, ademas de aumentar la magnitud de los cambios de masa. Se mejoro la hidrofilicidad del recubrimiento, mostrando una mayor afinidad con las soluciones de colageno y por lo tanto un aumento en la biocompatibilidad debido a la activacion superficial.

  7. Hydrogen sulfide corrosion of weld regions in API X52 steel; Corrosion por acido sulfhidrico de las regiones de soldadura en acero API X52

    Energy Technology Data Exchange (ETDEWEB)

    Arenas-Martinez, L.F [Universidad Autonoma de Coahuila, Coahuila (Mexico)]. E-mail: fernando.arenas@uadec.edu.mx; Garcia-Cerecero, G. [Corporacion Mexicana de Investigacion en Materiales S.A. de C.V., Saltillo, Coahuila (Mexico)]. E-mail: ggarcia@comimsa.com

    2012-10-15

    The corrosion behavior of gas metal arc welding (GMAW) regions has been studied using potentiodynamic polarization and polarization resistance (LPR) techniques. Experiments were conducted in hydrogen sulfide (H{sub 2}S)-containing brine and in H{sub 2}S-free brine. Welds were made on API 5L X52 steel. Due to differences in their microstructure, chemical composition and residual stress level, weld regions exhibited different responses under H{sub 2}S corrosion. Base metal exhibited the highest corrosion rate (CR) and the most cathodic corrosion potential. [Spanish] Se estudio el comportamiento ante la corrosion de las regiones de soldadura de un cordon realizado por arco metalico con gas (GMAW) sobre un acero grado API X52 mediante las tecnicas de polarizacion potencio dinamica y resistencia a la polarizacion (LPR). Los experimentos se realizaron utilizando salmuera con 300 ppm de acido sulfhidrico (H{sub 2}S) y salmuera libre de H{sub 2}S como electrolitos. Debido a las diferencias en su microestructura, composicion quimica y el nivel de esfuerzos residuales, las regiones de soldadura mostraron diferentes respuestas a la corrosion por H{sub 2}S. El metal base exhibio la velocidad de corrosion (VC) mas alta y el potencial de corrosion mas catodico.

  8. Determination of the load state of lead-acid batteries using neural networks; Determinacion del estado de carga de baterias plomo-acido utilizando redes neuronales

    Energy Technology Data Exchange (ETDEWEB)

    Cristin V, Miguel A; Ortega S, Cesar A [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2005-07-01

    The charge of lead-acid batteries (LAB), as in any other type of batteries, consists of replacing the energy consumed during the discharge. Nevertheless, as no physical or chemical process is good enough to totality recharge a battery, it is necessary to supply to it more than the 100% of the energy demanded during its discharge. A critical factor to make a suitable load control of the batteries is to determine its own state of load. That is to say, to have an efficient load control, it is necessary to count on means that allow to accurately determining the residual capacity of the battery to deliver load. This one is the one of the aspects of greater interest in the research centers around world. For this reason, in this work it was pretended to develop a calculation algorithm of the state of load of batteries based on a fuzzy-neural network that could calculate the state of load without using the battery current as an input. This is because one of the main problems for the designers of battery load controllers is the correct supervision of the current that circulates around the system in all the rank of operation of the same one because the sensors do not have a linear behavior. [Spanish] La recarga de baterias plomo-acido (BPA), como cualquier otro tipo de baterias, consiste en reponer la energia consumida durante la descarga. Sin embargo, como ningun proceso fisico o quimico es lo bastante eficiente para recargar a totalidad una bateria, es necesario suministrarle mas del 100% de la energia demandada durante su descarga. Un factor critico para realizar un adecuado control de carga de las baterias, es determinar su propio estado de carga. Es decir, para tener un control de carga eficiente, es necesario contar con un medio que permita determinar con precision la capacidad remanente de la bateria para entregar carga. Este es uno de los aspectos de mayor interes en los centros de investigacion alrededor el mundo. Por tal razon, en este trabajo se propuso

  9. Proposal to neutralize acid fluids from wells in the Los Humeros, Pue., geothermal field; Propuesta para la neutralizacion de fluidos acidos provenientes de pozos del campo geotermico de Los Humeros, Pue.

    Energy Technology Data Exchange (ETDEWEB)

    Flores Armenta, Magaly del Carmen; Ramirez Montes, Miguel; Garcia Cuevas, Juan Manuel [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)]. E-mail: magaly.flores@cfe.gob.mx

    2009-07-15

    Neutralizing an acidic fluid consists of adding a sodium hydroxide solution to neutralize the H group of acids, therefore increasing the pH. The injection of sodium hydroxide has to be continuous and at a proper depth inside the well to protect against the corrosion of casing and surface equipment. Neutralization is a common practice used in geothermal fields, such as at The Geysers in the US and Miravalles in Costa Rica-places where aggressive fluids cause problems for extracting and using geothermal fluids commercially. A zone surrounding wells H-4, H-16 and H-29 in the northern section of the Los Humeros, Pue., geothermal field, known as the Colapso Central, has shown evidence of aggressively acidic fluids. Several wells drilled in the area had to be repaired, thus plugging and isolating the deepest production zones. Well H-43 was drilled two years ago in the northern zone of the field, and even though it is not located in the aggressive-fluid zone, the well presents mineralogical features possibly indicating the presence of acidic fluids. Therefore, before producing this well it has been proposed we install a neutralization system with general characteristics presented in this paper. The system will prevent corrosion that up to now has prevented exploitation of the deep portion of Colapso Central, helping to develop the field in a more profitable way. [Spanish] Neutralizar un fluido acido consiste en agregarle una solucion de hidroxido de sodio. Esto neutraliza el grupo de acidos H y en consecuencia aumenta el pH. La inyeccion de hidroxido de sodio se realiza de manera continua y a una profundidad adecuada dentro del pozo para proteger a la tuberia y a todo el equipo superficial contra la corrosion. La neutralizacion es una practica comun que se viene realizando en campos como Los Geysers en Estados Unidos y en Miravalles, Costa Rica, donde la presencia de fluidos agresivos causa problemas en la extraccion y aprovechamiento del fluido geotermico con fines

  10. Synthesis and characterization of PdAg as a catalyst for oxygen reduction reaction in acid medium; Sintesis y caracterizacion de PdAg como catalizador para la reaccion de reduccion de oxigeno en medio acido

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Casillas, D. C.; Vazquez-Huerta, G.; Solorza-Feria, O. [Centro de Investigacion y de Estudios Avanzados del IPN, Mexico D.F. (Mexico)]. E-mail: dcmartinez@cinvestav.mx

    2009-09-15

    This work presents the synthesis of the binary compound PdAg and the electrochemical characterization for oxygen reduction reaction (ORR) in acid medium. The catalyst is obtained from the reduction of Pd(NO{sub 3}){sub 2}·2H{sub 2}O and AgNO{sub 3} with NaBH{sub 4} in THF. The synthesized compound was physically characterized with transmission electron microscopy (TEM), sweep electron microscopy (SEM) and x-ray diffraction (XRD) of powder. Electrochemical studies were conducted to determine the catalytic activity and intrinsic properties of the PdAg material for the ORR in acid medium using cyclic voltamperometry (CV), rotary disc electrode (RDE) and electrochemical impedance spectroscopy (EIS) in a solution of H{sub 2}SO{sub 4} 0.5 M at 25 degrees Celsius. The electrochemical current-potential responses were compared to those of palladium and platinum. The kinetic results showed an increase in the performance of the bimetallic electrocatalyst containing Ag as compared to pure Pd, but less than that obtained with nanometric Pt. The Tafel slopes obtained are roughly120 mV dec-1, similar to that reported for Pt and Pd and for other Ru-based electrocatalysts. [Spanish] En este trabajo se presentan la sintesis del compuesto binario PdAg y su caracterizacion electroquimica para la reaccion de reduccion de oxigeno (RRO) en medio acido. El catalizador se obtuvo a partir de la reduccion de Pd(NO{sub 3}){sub 2}·2H{sub 2}O y AgNO{sub 3} con NaBH{sub 4} en THF. El compuesto sintetizado se caracterizo fisicamente por microscopia electronica de transmision (MET), microscopia electronica de barrido (MEB) y difraccion de rayos X (DRX) de polvos. Se realizaron estudios electroquimicos para determinar la actividad catalitica y las propiedades intrinsecas del material de PdAg para la reaccion de reduccion de oxigeno (RRO) en medio acido, utilizando las tecnicas de voltamperometria ciclica (VC), electrodo disco rotatorio (EDR) y espectroscopia de impedancia electroquimica (EIE), en

  11. Changes of arterial blood pressure, heart rate, internal body temperature, and blood acido-basic balance in the unanaesthetized rabbit following whole-body gamma irradiation at a mean absorbed dose of 250 rads

    Energy Technology Data Exchange (ETDEWEB)

    Dufour, R.; Court, L.

    1973-09-01

    The general effects of whole-body gamma -irradiation at a mean absorbed dose of 250 rads were studied simultaneously in the unanaesthetized rabbit for 48 hours. They occurred early, with the following characteristics: arterial blood pressure decreased steadily as early as the 2nd hour and reached its minimum value on the 5th hour with a decrease of about 14%; it remained low during the following two days. Heart rate increased during the first hour, was the highest by the end of the second hour, and resumed normal value on the 24th hour. Internal body temperature increased during the 1st hour and was maximum by the end of the 2nd hour, with a mean increase of 1.2 deg C; hyperthermia steadily decreased between the 4th and the 6th hours and had completely disappeared by the 24th hour. Respiratory alkalosis is shown in the acido-basic balance by a raise of pH, a decrease of PCO/sub 2/ and arterial blood bicarbonates. These various changes seem to indicate a double origin, both central and peripheral. (FR)

  12. Results of test of acid fluids neutralization in the well H-43, Los Humeros geothermal field, Puebla; Resultados de la prueba de neutralizacion de fluidos acidos en el pozo H-43, campo geotermico de Los Humeros, Puebla

    Energy Technology Data Exchange (ETDEWEB)

    Flores Armenta, Magaly del Carmen; Ramirez Montes, Miguel; Sandoval Medina, Fernando; Rosales Lopez, Cesar [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)]. E-mail: magaly.flores@cfe.gob.mx

    2011-07-15

    The well H-43 was drilled in Los Humeros Geothermal Field, Pue., in 2007 and 2008. When well production was measured, it was found the well produced acid fluids with high corrosion potential. Then it was decided to try to neutralize the acidity of the H-43 fluids by adding a solution of sodium hydroxide. This is a basic substance used to neutralize mainly the acid groups H+, and the goal was to raise the pH of the fluids to minimize its corrosive features. First sodium hydroxide was injected into the well to protect the casing of 244.4 mm (9 5/8 in) against corrosion and then all the surface installations. It was possible to increase the pH of the well fluid from 5.2 up to 6.8 without altering the steam production, thus demonstrating the neutralization procedure is feasible. The approximate costs of the neutralization tests performed, including equipment for the proposed neutralization system, the neutralizer (NaOH), and drilling the well are about 71.4 million pesos (around 5.5 million USD). We estimate a benefit/cost ratio of 1.5 and a return on investment in five years, considering the income from energy sales at present value. [Spanish] El pozo H-43 fue perforado en el campo de Los Humeros, Pue., en 2007-2008, y al evaluar su produccion se encontro que producia fluidos acidos de alto potencial corrosivo. Se decidio por tanto realizar una prueba para neutralizar la acidez de los fluidos de este pozo, que consistio en agregarle una solucion de hidroxido de sodio. Esta es una sustancia basica que neutraliza principalmente los grupos acidos H+, con lo que se buscaba aumentar el pH del fluido lo necesario para reducir al maximo su caracter corrosivo. La inyeccion del hidroxido de sodio se realizo dentro del pozo a fin de proteger de la corrosion a la tuberia de revestimiento de 244.4 mm (9 5/8 pulgadas), y posteriormente a todos los equipos superficiales. Como resultado de la prueba, se logro aumentar el pH del fluido producido por el pozo de 5.2 a un maximo de 6

  13. Contenidos de isomeros trans de los acidos grasos en productos carnicos (I). Embutidos

    OpenAIRE

    Hernández, N.; Codony Salcedo, Rafael; Rafecas Martínez, Magdalena; Boatella Riera, Josep

    1991-01-01

    En este trabajo se determinan los contenidos de isómeros trans de la fracción de los ácidos grasos, en muestras de embutidos diversos (total 48 muestras), mediante extracción previa de la fracción grasa y posterior análisis por cromatografía de gases capilar, con columna CP Sil 88. Los resultados muestran una gran variabilidad, entre 0,14 y 1,63% de C18:1 t y entre 0,37 y 2,14% de formas trans totales.

  14. Acid Deposition Maps in Spain; Mapas de Deposito Acido en Espana

    Energy Technology Data Exchange (ETDEWEB)

    Artinano, B.; Cabal, H.; Garcia, C.

    1998-07-01

    Animal and monthly deposition velocity and total sulfur deposition maps have been performed for the peninsular Spain for 1992 by using the inferential method. To do this, updated databases with high space and time resolution, for land uses (CORINE) and meteorological information from analysis modelling for the same year, have been utilized. The final result are deposition maps in a 5x5 Km{sup 2} grid which allow to assess the methodology used in Europe to obtain the maps of excedances over the critical loads of pollutants. (Author) 32 refs.

  15. Terpenes and fatty acids from Dipteryx lacunifera Ducke; Terpenos e acidos graxos de Dipteryx lacunifera Ducke

    Energy Technology Data Exchange (ETDEWEB)

    Vieira Junior, Gerardo Magela; Silva, Hilris Rocha e; Bittencourt, Thais Chaves; Chaves, Mariana H. [Universidade Federal do Piaui (UFPI), Teresina (Brazil). Dept. de Quimica]. E-mail: mariana@ufpi.br; Simone, Carlos Alberto de [Universidade Federal do Alagoas (UFAL), Maceio, AL (Brazil). Inst. de Quimica e Biotecnologia

    2007-07-01

    This paper describes the isolation of the furanocassane-type diterpene, named vinhaticoic acid, along with b-farnesene and spatulenol from fruit shells of D. lacunifera. Structural determinations were accomplished by chemical derivatization and spectral analysis, including 1D and 2D NMR and X-ray crystallography. The fatty portion was extracted from the fruit kernels, transesterfied and analysed by HRGC/MS. Oleic acid (75.8 +- 4.3%) was the major component. Essential oil extracted from the fruit shells of D. lacunifera was analysed by HRGC/MS and nine sesquiterpenes were identified; beta-farnesene (48.6%) and spatulenol (21.61%) were the major constituents. (author)

  16. Acido, ergo sum: Holger Hydén--the neuroscientist in Cortázar's Hopscotch.

    Science.gov (United States)

    Delgado, Guillermo; Estañol, Bruno

    2013-06-01

    The fictional Italian author Morelli is throughout the novel "Hopscotch" (1963) Julio Cortázar's alter ego. This character proposes an unoriginal literary hypothesis in chapter 62. There is an allusion to a particular Swedish that 'is working on a chemical theory of thought.' The Swedish neuroscientist under analysis is Holger Hydén (1917-2000), by then professor and chairman of the Department of Histology at the University of Göteborg. Hydén, who was the first to work in neurobiological micromethods, is mentioned by Morelli due to his participation in a symposium held at the end of January 1961, in San Francisco. His pioneering work will never be completely forgotten, because Hydén's neuroscientific legacy lives and will live in Cortázar's "Hopscotch".

  17. Isolation of deoxyribonucleic acids (A Review); Aislamiento de los acidos desoxiribonucleicos. Revision Bibliografica

    Energy Technology Data Exchange (ETDEWEB)

    Garcia de Pineda, M. de

    1974-07-01

    The criteria of choice in this Review have been to gather some of the last advances in the methodology of DNAs isolation; also the description of the generally accepted procedures has been emphasized. Only papers published before March 1974 are reviewed, because this work has been finished during this month. (Author) 109 refs.

  18. Acido, ergo sum: Holger Hydén--the neuroscientist in Cortázar's Hopscotch.

    Science.gov (United States)

    Delgado, Guillermo; Estañol, Bruno

    2013-06-01

    The fictional Italian author Morelli is throughout the novel "Hopscotch" (1963) Julio Cortázar's alter ego. This character proposes an unoriginal literary hypothesis in chapter 62. There is an allusion to a particular Swedish that 'is working on a chemical theory of thought.' The Swedish neuroscientist under analysis is Holger Hydén (1917-2000), by then professor and chairman of the Department of Histology at the University of Göteborg. Hydén, who was the first to work in neurobiological micromethods, is mentioned by Morelli due to his participation in a symposium held at the end of January 1961, in San Francisco. His pioneering work will never be completely forgotten, because Hydén's neuroscientific legacy lives and will live in Cortázar's "Hopscotch". PMID:23828537

  19. Acid Deposition Maps in Spain; Mapas de Deposito Acido en Espana

    Energy Technology Data Exchange (ETDEWEB)

    Artinano, B.; Cabal, H.; Garcia, C. [CIEMAT. Madrid (Spain)

    1998-12-31

    Annual and monthly deposition velocity and total sulfur deposition maps have been performed for the peninsular Spain for 1992 by using the inferential method. To de this, updated database with high space and time resolution, for land uses (CORINE) and meteorological information from analysis modelling for the same year, have been utilized. The final result are deposition maps in a 5 x 5 km``2 grid which allow to assess the methodology used in Europe to obtain the maps of excedance over the critical loads of pollutants. (Author) 32 refs.

  20. Copper corrosion originated by volatile organic acid vapours; Corrosion del cobre por acidos organicos volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Cano, E.; Polo, J. L.; Kong, D. Y.; Mora, E. M.; Lopez-Caballero, J. A.; Bastidas, J. M.

    2004-07-01

    The corrosion of copper in the presence of volatile organic acids is frequent. Thus, for example, it is known that failures by corrosion of the copper tubes take place in the air conditioning equipment, caused by volatile organic acids emitted by oils used in their manufacturing. Another frequent case is the corrosion of copper objects caused by the acids emitted by the materials used in packing, wood and resins, amongst others. This communication presents the corrosion results of copper exposed to 100% relative humidity and different concentrations (10-300ppm) of formic (HCOOH), acetic (CH{sub 3}COOH), propionic (CH{sub 3}CH{sub 2}COOH) and butyric (CH{sub 3}(CH{sub 2}){sub 2}COOH) acid vapours, for short exposure times. the techniques used were gravimetric analysis, scanning electron microscopy (SEM) and X-ray diffraction (XRD). (Author) 9 refs.

  1. Naphthenic acid characterization and distribution in crude oils; Caracterizacao e distribuicao de acidos naftenicos em petroleos

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Regina C.L.; Gomes, Alexandre de O. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    Naphthenic acid corrosion was observed for the first time during the distillation process of some kind of crude oils in 1920. Recent reports about naphthenic acid corrosion have been found in China, India, Venezuela, Eastern Europe, Russia and the USA. In Brazil, heavy and acid crude oil processing is rising. Some brazilian crude oils have TAN around 3,0 mg KOH/g. The presence of relatively high levels of naphthenic acids in crude oils is a bane of petroleum refiners; and more recently, of producers as well, who have reported problems during production with calcium and sodium naphthenate . Essentially, these acids which are found to greater or lesser extent in virtually all crude oils are corrosive and tend to cause equipment failures, lead to high maintenance costs and may pose environmental disposal problems. In order to give these information to PETROBRAS, The Research and Development Center of PETROBRAS (CENPES) has been working in house and with brazilian universities developing analytical technicians to know better molecular structures and distribution of these acids compounds in crude oils. This work presents the actual methods and some results from these developments. (author)

  2. Quantification of uranyl in presence of citric acid; Cuantificacion de uranilo en presencia de acido citrico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia G, N.; Barrera D, C.E. [UAEM, Facultad de Quimica, 50000 Toluca, Estado de Mexico (Mexico); Ordonez R, E. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)]. e-mail: nidgg@yahoo.com.mx

    2007-07-01

    To determine the influence that has the organic matter of the soil on the uranyl sorption on some solids is necessary to have a detection technique and quantification of uranyl that it is reliable and sufficiently quick in the obtaining of results. For that in this work, it intends to carry out the uranyl quantification in presence of citric acid modifying the Fluorescence induced by UV-Vis radiation technique. Since the uranyl ion is very sensitive to the medium that contains it, (speciation, pH, ionic forces, etc.) it was necessary to develop an analysis technique that stands out the fluorescence of uranyl ion avoiding the out one that produce the organic acids. (Author)

  3. Avaliacao da seguranca de diferentes doses de suplementos de acido folico em mulheres do Brasil

    Directory of Open Access Journals (Sweden)

    Quenia dos Santos

    2013-10-01

    Full Text Available OBJETIVO Avaliar a distribuição da ingestão de ácido fólico e a segurança de diferentes doses de suplementos em mulheres em idade reprodutiva. MÉTODOS Foram utilizados dados de consumo a partir de dois dias não consecutivos de registro alimentar de 6.837 mulheres em idade reprodutiva (19 a 40 anos participantes do Inquérito Nacional de Alimentação, módulo da Pesquisa de Orçamentos Familiares 2008-2009. Médias e percentis de consumo habitual de folato natural e ácido fólico foram estimados utilizando o método do National Cancer Institute . Cinco cenários foram simulados somando-se diferentes doses diárias de fortificação (400 mcg, 500 mcg, 600 mcg, 700 mcg e 800 mcg ao ácido fólico oriundo dos alimentos consumidos pelas mulheres. Comparou-se o total de ácido fólico (dieta + suplemento com o nível máximo de ingestão tolerável (UL = 1.000 mcg para definir a dose segura de suplementação. RESULTADOS Mulheres com ingestão habitual de ácido fólico acima do nível máximo de ingestão tolerável foram observadas para doses de suplemento de 800 mcg (7,0% das mulheres. Abaixo desse valor, qualquer dose de suplementação mostrou-se segura. CONCLUSÕES O uso de suplementos de até 700 mcg de ácido fólico mostrou-se seguro.

  4. Modificazioni dei livelli di acido arachidonico e vitamina A in relazione alla attività anticancerogena attribuita all'apporto alimentare di burro naturalmente arricchito in acido linoleico a dieni coniugati (CLA)

    OpenAIRE

    Banni, Stefano; Angioni, E.; Carta, G.; Dessi, M. Assunta; Melis, M. Paola; Murru, E.; Scanu, P.; Spada, Sebastiano; Vargiolu, Silvana; Corongiu, Francesco P.

    2000-01-01

    Considerable attention has recently been directed to the naturally occurring trace fatty acid conjugated linoleic acid (CLA), based on its dual ability to act both as a preventive and therapeutic agent in a number of rodent and human tumor model systems. CLA, which is synthesized by rumen bacteria, is found in meat and dairy products, and is of particular interest since it is effective at low levels in the diet. Our research interest is to explore whether the mechanism of the anticarcinogenic...

  5. Estudios Cinéticos de la Disolución de Hidroboracita en Soluciones de Acido Clorhídrico y Acido Sulfúrico Dissolution Kinetics of Hydroboracite in Hydrochloric Acid and Sulphuric Acid Solutions

    Directory of Open Access Journals (Sweden)

    Graciela V Morales

    2008-01-01

    Full Text Available Se realizan estudios cinéticos de la disolución de hidroboracita en soluciones de ácido clorhídrico y ácido sulfúrico en un reactor tanque agitado discontinuo de acero inoxidable, a presión atmosférica. Se investiga el efecto de la temperatura, el tamaño de partícula, la relación sólido/líquido y la concentración de ácido sobre la velocidad de disolución. Los resultados experimentales permiten observar que la velocidad de disolución aumenta con el incremento de la concentración del ácido y de la temperatura, y disminuye con el aumento del tamaño de partícula y con la relación sólido/líquido. La energía de activación aparente calculada para la disolución de hidroboracita en soluciones de ácido clorhídrico es 44.9 kJ/mol, lo cual no permite inferir cual es la etapa controlante del proceso; mientras que la energía de activación aparente calculada para la disolución de hidroboracita en soluciones de ácido sulfúrico es 14.6 kJ/mol, lo cual permite inferir que el proceso ocurre con control difusivo.The dissolution kinetics of hydroboracite in hydrochloric acid and sulphuric acid solutions was investigated. The experiments were carried out in a steel batch reactor equipped with a mechanical stirrer, at atmospheric pressure. The effect of reaction temperature, particle size, solid/liquid ratio and acid concentration on the dissolution rate was determined. It was found that the dissolution rate increased with increasing the acid concentration and reaction temperature. However, the increase of particle size and solid/liquid ratio decreased the dissolution rate. The activation energy for the hydroboracite dissolution in hydrochloric acid was calculated as 44.9 kJ/mol, which does not permit to know the process controlling step. The activation energy for the hydroboracite dissolution in sulphuric acid was found to be 14.6 kJ/mol, which indicates that the dissolution is a diffusion controlled process.

  6. Effects of acido-basic support properties on the catalytic hydrogenation of acetylene on gold nano-particles

    Science.gov (United States)

    Manda, Abdullah Ahmed

    Metallic gold nanoparticles supported on gamma-Al2O 3 and magnesia-alumina mixed oxide, with different magnesia content have been prepared by sol-gel method and characterized by different techniques (inductive coupled plasma-mass spectroscopy (ICP-MS), XRD, BET surface area analysis, transmission electron microscopy (TEM), CO2 and NH 3 temperature programmed desorption (TPD), H2 temperature programmed reduction (TPR) and FTIR of adsorbed CO2). Such systems were found to produce catalysts with controllable acidity, varying from catalyst possessing large density of acidic and low density of basic sites, others with acidic and basic sites of equal strength and density, and others with large basic and low acid sites densities, respectively. The catalytic assessment of the generated acidity was carried out using 2-propanol decomposition as a test reaction. The results obtained indicate that the presence of magnesia and reduced gold nanopartilces has imparted the catalysts, 1%Au/4%Mg-Al 2O3 and 1%Au/8%Mg-Al2O3, with significant base-catalytic properties. Acetylene hydrogenation and formation of coke deposits were investigated on a gold catalyst supported on gamma-Al2O3 and gold supported on alumina-magnisia mixed oxide with different gold content; 1%Au/gamma-Al 2O3, 1%Au/15%Mg-Al2O3, 2%Au/15%Mg-Al 2O3 and 4%Au/15%Mg-Al2O3. The effect of the H2/C2H2 ratio was studied over a range of values. The catalytic activity and selectivity towards ethylene and other products were investigated at different reaction temperatures. Acetylene hydrogenation was investigated in the presence and absence of ethylene in stream. It is investigated that the adsorption of the triple bond is preferred over the double bond and during selective catalytic (SCR) of C2H2 the two hydrocarbons do not compete for the same adsorption sites. The deactivation of catalysts was studied by temperature programmed oxidation (TPO). Higher content of coke over 1%Au/Al2O3 catalyst was investigated in contrast to the other catalysts in which the basisity of magnesia-alumina supports could have played an important role in inhibiting the acidic carbon formation by possessing smaller number and/or weaker acid sites.

  7. Revisión de los niveles de acidos grasos trans encontrados en distintos tipos de alimentos

    Directory of Open Access Journals (Sweden)

    Vicario, I. M.

    2007-03-01

    Full Text Available In this paper a comprehensive review of trans-fatty acid levels reported in different types of food products is offered. The lowest levels are found in some types of bread (0,1% while the highest levels (up to 40% are found in fried potatoes. Some foods like shortenings, cakes and pastries may have up to 30% of these fatty acids. In milk and dairy products the reported levels are between 1.50% and 5.20%, in meat and derived products between 0.20% and 21,30%; in chocolates from 0% to 15, 70%. The greatest variability is found in margarines, where a variety has been reported from “trans-free products” to products containing up to 34. 30%. In relation to the trans-fatty acid profile, 18:1t is the most abundant fatty acid found in the majority of foods, followed by C18:2t, C18:3t, C18:1t y C14:1t. Due to the negative health effects of these fatty acids, there is a trend to reduce their levels in food products and to include them in the nutritional label of food packaging.En este trabajo se realiza una exhaustiva revisión bibliográfica de los contenidos en grasos trans en alimentos de distinto origen. Los niveles más bajos se encuentran en algunos tipos de pan (0,10%, y los más elevados (hasta 40%, en algunas muestras de patatas fritas. Alimentos tales como shortenings, algunos tipos de galletas y bollería contienen hasta el 30% de dichos ácidos grasos. En las leches y derivados se encuentran cantidades entre 1,50% y 5,20%; en carnes y derivados entre 0,20% y 21,30%; en chocolates desde cantidades nulas hasta 15,70%. La mayor variabilidad se registra en margarinas, entre las que se encuentran desde las “libres de trans”, hasta algunas con 34,30% de estos ácidos grasos. En cuanto a los distintos isómeros, el mayoritario es el C18:1t seguido del C18:2t, C18:3t, C18:1t y C14:1t. Debido a los efectos desfavorables que presentan sobre la salud se observa en los últimos años una tendencia a reducir este tipo de ácidos grasos en algunos alimentos y a incluirlos en el etiquetado nutricional de los alimentos.

  8. Contenidos de isomeros trans de los acidos grasos en productos carnicos. (III) Tejido adiposo y grasa intramuscular de vacuno

    OpenAIRE

    Lluch, M. C.; Roca de Vinyals, M.; Parcerisa Egea, Javier; Guardiola Ibarz, Francesc; Codony Salcedo, Rafael; Rafecas Martínez, Magdalena; Boatella Riera, Josep

    1993-01-01

    Se presentan los resultados obtenidos para la determinación de ácidos grasos en una serie de muestras de tejidos subcutáneo y muscular, procedentes de canales de vacuno, por aplicación de la cromatografía en fase gaseosa, para los que se obtuvieron unos valores medios de 58.7% de ácidos saturados, 39.1 % de monoinsaturados y 2.7% de polinsaturados, en el tejido adiposo, y de 44.7% de saturados, 46.1% de monoinsaturados y 9.4% de polinsaturados, en el tejido muscular. Los contenidos de ácidos ...

  9. New heterogeneous acid catalysts in the synthesis of biodiesel; Estudo de novos catalisadores heterogeneous acidos na sintese de biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Soldi, Rafael A.; Cesar-Oliveira, Maria Aparecida F. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Quimica. Lab. de Polimeros Sinteticos], e-mail: mafco@quimica.ufpr.br; Oliveira, Angelo R.S.; Ramos, Luiz P. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Quimica. Centro de Pesquisa em Quimica Aplicada (CEPESQ)

    2007-07-01

    In this work, sulfonated polystyrene compounds (PSS) were synthesized from linear polystyrene (PS). Several methods and experimental conditions were investigated for the sulfonation of PS, producing catalytically active polymeric materials with sulfonation degrees in the range of 5.0-6.2 mmol -SO{sub 3}H/g of dry polymer. The performance of these catalysts was evaluated in transesterification reactions of beef tallow and vegetable oils with ethanol and methanol. For the sake of comparison, the same reaction conditions employed for the PSS catalysts were also used for an Amberlyst 15 (3,7 mmol SO{sub 3}H/g - Aldrich). The PSS samples were shown to be insoluble in the reaction media, leading to conversion rates of 85%, 75% and 80% of the refined soybean oil, beef tallow and crude corn oil in to ethyl esters, respectively, and 94% of the refined soybean oil methyl esters. Amberlyst 15 was studied as an alternative to the process, but its conversion rate to alkyl esters was very low in the employed conditions. These results demonstrated that our synthetic PSS materials have a great potential to act as heterogeneous catalysts for transesterification. (author)

  10. Acido, ergo sum: Holger Hydén – the neuroscientist in Cortázar's Hopscotch

    Directory of Open Access Journals (Sweden)

    Guillermo Delgado

    2013-06-01

    Full Text Available The fictional Italian author Morelli is throughout the novel “Hopscotch” (1963 Julio Cortázar's alter ego. This character proposes an unoriginal literary hypothesis in chapter 62. There is an allusion to a particular Swedish that ‘is working on a chemical theory of thought.’ The Swedish neuroscientist under analysis is Holger Hydén (1917-2000, by then professor and chairman of the Department of Histology at the University of Göteborg. Hydén, who was the first to work in neurobiological micromethods, is mentioned by Morelli due to his participation in a symposium held at the end of January 1961, in San Francisco. His pioneering work will never be completely forgotten, because Hydén's neuroscientific legacy lives and will live in Cortázar's “Hopscotch”.

  11. Bacterias halotolerantes/alcalofilas productoras de acido indol acético (AIA asociadas a Arthrospira platensis (Cyanophyceae

    Directory of Open Access Journals (Sweden)

    Liliana Cecilia Gómez Gómez

    2012-08-01

    Full Text Available Título en ingles: Halotolerant alkalophilic and indolacetic acid producing acid producing bacteria associated with Arthrospira platensis (Cyanophyceae Resumen: Este trabajo tuvo como propósito contribuir al conocimiento de la interacción entre la cianobacteria alcalófila Arthrospira platensis y las bacterias que crecen asociadas a su mucilago. Se desarrolló un  medio de cultivo heterotrófico en el cual se aislaron cinco cepas bacterianas asociadas a un monocultivo de A. platensis. Se determinó la capacidad de estas cinco cepas para producir ácido 3- indol acético (AIA. La tipificación molecular de los aislamientos bacterianos permitió identificarlos como Exiguobacterium aurantiacum str. DSM 20416, Xanthomonas sp. ML-122, Halomonas sp. Ap-5, Bacillus okhensis str.  Kh10-101, Indibacter alkaliphilus, type str. LW1T; todas las cepas bacterianas obtenidas  son halotolerantes, alcalófilas y productoras de AIA. Los resultados aportan evidencia para sugerir una interacción benéfica entre A. platensis y sus bacterias asociadas,  quizá como estrategia evolutiva  de cooperación para desarrollarse en  un ambiente hipersalino.    Palabras claves: Bacillus okhensis, Exiguobacterium aurantiacum, Halomonas sp., Indibacter alkaliphilus. Xanthomonas sp. Abstract: The aim of this study was contribute to knowledge over alkalophilic cianobacteryum  Arthrospira platensis  and their  interaction with some associated bacteria growing in their mucilage. Heterotrophic culture medium was designed, in this medium were isolated five bacterial strains associated to single culture of A. platensis. It was measured the 3-indol acetic acid (IAA production by these bacterial strains. Molecular typing allowed identify these bacterial strains like Exiguobacterium aurantiacum str. DSM 20416, Xanthomonas sp. ML-122, Halomonas sp. Ap-5, Bacillus okhensis str. Kh10-101, Indibacter alkaliphilus, type str. LW1T; all these bacteria are halotolerant, alkalophilic and IAA producer.  The findings allow suggest a beneficial interaction between A. platensis and their associated bacteria, maybe as evolutionary strategy of cooperation to grow and develop in  hypersaline environments. Key words: Bacillus okhensis, Exiguobacterium aurantiacum, Halomonas sp., Indibacter alkaliphilus.Xanthomonas sp.

  12. Producción de acido láctico por Lactobacillus plantarum L10 en cultivos batch y continuo

    Directory of Open Access Journals (Sweden)

    Waldir Estela

    2013-04-01

    Full Text Available Se ha ensayado a escala de laboratorio la cepa Lactobacillus plantarum L10, para la producción de ácido láctico en cultivos batch y continuo; además se ha optimizado la composición del medio y las condiciones de cultivo para este propósito. Los mejores parámetros de producción de ácido láctico encontrados en cultivo batch fueron los siguientes: YP/S 86,1%; PP 5,4 g/L/h; unido a YX/S 13,2%; PX 1,2 g/L/h y μ = 0,2 h-1, el cultivo se ha llevado a cabo en un medio conteniendo glucosa 70 g/L; extracto de levadura 12,1 g/L; KH2PO4 1,2 g/L; (NH42HPO4 1,2 g/L; citrato de amonio 3,0 g/L; MgSO4. 7H2O 0,3 g/L y MnSO4. 4H2O 0,03 g/L. Así mismo los mejores parámetros de producción de ácido láctico encontrados en cultivo continuo fueron los siguientes: YP/S 96%; P´P 6,0 g/L/h; unido a YX/S 19 %; P´X 1,2 g/L/h; y tasa de dilución (D 0,46 h-1.

  13. Bacterias halotolerantes/alcalofilas productoras de acido indol acético (aia) asociadas a arthrospira platensis (cyanophyceae)

    OpenAIRE

    Liliana Cecilia Gómez Gómez; Nelson Valero Valero; Ever Morales Avendaño

    2012-01-01

    Título en ingles: Halotolerant alkalophilic and indolacetic acid producing acid producing bacteria associated with Arthrospira platensis (Cyanophyceae) Resumen: Este trabajo tuvo como propósito contribuir al conocimiento de la interacción entre la cianobacteria alcalófila Arthrospira platensis y las bacterias que crecen asociadas a su mucilago. Se desarrolló un  medio de cultivo heterotrófico en el cual se aislaron cinco cepas bacterianas asociadas a un monocultivo de A. platensis. Se determi...

  14. Gas chromatography of alkylphosphonic and dialkyl phosphinic acids; Cromatografia en fase gaseosa de acidos alquifosfonicos y dialquilfosinicos

    Energy Technology Data Exchange (ETDEWEB)

    Gasco Sanchez, L.; Barrera Peniero, R.; Ramirez Caceres, A.; Marin Munoz, M.

    1978-07-01

    After carrying out an optimization study on the separation conditions for the TMSr- derivatives, of the hexyl-, cyclohexyl-, heptyl-, and octyl-phosphonic acids; dihexyl dicyclohexyl-, heptyl-, and octyl-phosphinic acids, and dioctyl phosphine oxide, their retention indices (I) at two temperatures and on the OV-1 and OV-17 stationary phase were determined. Correlations between I and molecular structure were established. Calibration factors of these compounds in the flame ionization detector were studied, and the results analyzed taking into account the variables affecting the quantitative results, These results were unbiased but they had a lower precision than that usually achievable in gas chromatography. (Author) 24 refs.

  15. Removing volatile fatty acids during the anaerobic treatment of pig sewage; Remocion de acidos grasos volatiles durante el tratamiento anaerobio de aguas residuales porcicolas

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez Borges, E.; Mendez Novelo, R.; Magana Pietra, A.; Partinez Pereda, P.; Fernandez Villagomez, G. [Facultad de Ingenieria, Universidad Atuonoma de Yucatan. Mexico (Mexico)

    1997-06-01

    This study examined the behaviour of a hybrid anaerobic digester in treating pig farm sewage. The experimental model consisted of a 208-litre UASB reactor at the bottom and a 195-litre high-rate sedimentator at the top. The digester was installed on a pig farm and its efficiency in removing volatile (acetic and propionic) fatty acids (VFA) was determined with hydraulic retention time (HTR) as the critical parameter for evaluating the anaerobic system`s performance. The results obtained with the five different HRTs used during the experiment are reported. The highest removal rates were obtained with an HRT of 2.8 days: 98% in the UASB, 28% in the sedimentator and 98% in the digester as a whole. An HRT of 1 day gave VFA removal rates of 40%, 12% and 50% in the UASB reactor sedimentator and digest respectively. (Author) 16 refs.

  16. Study of the desphosphatization process. The impact of nitrilotriacetic acid trisodium salt (NTA). Estudio del proceso de defosfatacion. Impacto de la sal tisodica del acido nitrilotriacetico SNTA

    Energy Technology Data Exchange (ETDEWEB)

    Peisajovich, A.; El Falaki, K.; Martin, G.

    1993-07-01

    In this paper we examined the effects of NTA on the removal of phosphorus process. The biological phosphorus removal process has been studied in the batch tests. This process indicated that there is a perturbation level (DD) of the phosphorus removal which is situated at 40 mg/g MVLSS. A dynamic lab-scale study showed a reduction of the nitrogen and phosphorus removal efficiency, ten days after the introduction of NTA in the influent water in concentration lower than DD. The precipitation of phosphate from wastewater has been examined using the Jar-Test method. The resultants of phosphate precipitation employed iron (III), aluminium (III) or lime did not reveal any differences in the efficiency between the coagulants. The present of NTA did not show a reduction of efficiency in the removal phosphorus process. (Author) 32 refs.

  17. Disolución anodica del niquel en medio acido. Caracterización de probetas termoplasticas conductroras del tipo grafito/niquel-polipropileno.

    OpenAIRE

    Negrete Barrera, Faustino Antonio

    2009-01-01

    RESUMEN El objetivo científico de este trabajo se centra principalmente en la caracterización de un tipo composite basado en la dispersión aleatoria de polvos micrométricos de grafito y níquel en el interior de una matriz termoplástica de polipropileno. Se han utilizado también técnicas microscópicas convencionales, de SEM, EDAX y STM para analizar la morfología superficial de las probetas. El composite estudiado es un material de tipo híbrido elaborado con polvos de níquel y de grafito gr...

  18. Radioprotection potential of the ascorbic acid on the carrageenan used as food additive; Potencial radioprotetor do acido ascorbico sobre a carragenana utilizada como aditivo alimenticio

    Energy Technology Data Exchange (ETDEWEB)

    Aliste, Antonio Joao; Mastro, Nelida Lucia del [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: ajaliste@net.ipen.br; nlmastro@net.ipen.br

    2002-07-01

    Carrageenans are a group of natural carbohydrates that are present in the structure of certain varieties of red algae (Rhodophyceae). They are used in emulsions, for syneresis control and to grow up, to promote adhesiveness and dispersion. In the industry of foods they can be used for instance, as thickness and gelling agents, alone or together with other additives. The processing of foods by radiation is increasing considerably, because the efficiency of the process in the industrial decontamination of products. The objective of this work was to study the action of the ascorbic acid as potential radioprotector of the carrageenan against {sup 60} Co gamma radiation effects, using the viscosity as parameter. Samples of commercial carrageenan dissolved at 1,0% were irradiated in the presence or not of ascorbic acid, with doses of 0.0 kGy; 1.0 kGy; 2.5 kGy; 5.0 kGy and 10.0 kGy. After the irradiation the relationships viscosity/dose were established for the temperature of 60 deg C. For the dose of 10.0 kGy a better protecting effect of the ascorbic acid on the carrageenan was seen. The implications of the use of this antioxidant is discussed as a form of minimizing the effect of the radiation in irradiated foods. (author)

  19. The importance of the fatty acids in breast milk and in lacteal formulae; La importancia de los acidos grasos en la leche materna y en las formulas lacteas

    Energy Technology Data Exchange (ETDEWEB)

    Vega, S.; Gutierrez, R.; Radilla, M.; Ramirez, A.; Perez, J. J.; Schettino, B.; Ramirez, M. L.; Ortiz, R.; Fontecha, J.

    2012-11-01

    The best choice for feeding the newborn child is breast milk, and when it is not possible to breast feed a baby, the breast milk is replaced by lacteal formula, which is why numerous studies focus their attention on the analysis of the diverse components of baby formula as well as functions in the breast fed baby. Fatty acids are components of great nutritional importance in the fetus and in the newborn child. Nowadays it is estimated that the fetus, during the last trimester of the gestational period and the newborn child, during the first six months of life, need a great contribution of araquidonic and docosahexaenoic acids, due to the fact that the speed of transformation of the predecessors to the hepatic level are not sufficient to cover the metabolic requirements of these fatty acids and it is the mother who contributes them through placental transport during gestation and her milk during lactation. The Organization of Food and Agriculture (FAO), the World Health Organization (WHO), the European Society of Gastroenterology, Hepato logy and Pediatric Nutrition (ESPGHAN) and the American Academy of Pediatrics recommend that lacteal formula imitate the composition of the breast milk, especially in the fatty polyunsaturated acids (PUFA). (Author) 61 refs.

  20. Analytical methods for 2,4-D (Dichlorophenoxyacetic acid) determination; Metodos analiticos para la determinacion del 2,4-D (Acido diclorofenoxiacetico)

    Energy Technology Data Exchange (ETDEWEB)

    Martinez G, M.S.M

    1999-06-01

    The 2,4-D herbicide is one of the main pesticides for controlling the bad grass in crops such as the water undergrowth. In Mexico the allowed bound of this pesticide is 0.05 mg/l in water of 2,4-D so it is required to have methods trusts and exacts, which can used in order to detected low concentration of it. In this work we show some for the conventional techniques and for establishing the 2,4-D concentrations. The UV-Vis spectrometer and liquids chromatography due that they are the most common used nowadays. Beside, we introduce a now developed technique, which is based on the neutronic activation analysis. Though use of the UV-Vis spectrometer technique it was possible target the concentrations interval between 1 and 200 mg/l. In the liquids chromatography interval was between 0.1 and 0.9, and by the neutronic activation analysis the interval was between 0.01 and 200 mg/l. (Author)

  1. Natural Radiation in byproducts of the production of phosphoric acid; Radiacao natural em residuos gerados no processo de producao de acido fosforico

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, Marcilei A. Guazzelli da; Cardoso, L.L., E-mail: marcilei@fei.edu.br [Centro Universitario da FEI, Sao Bernardo do Campo, SP (Brazil); Medina, N.H. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Institutlo de Fisica

    2014-07-01

    Natural radiation is the largest source of radiation exposure to which man is subject. It is formed basically by cosmic radiation and the radionuclides present in the Earth crust, as {sup 40}K and the elements of the decay series of {sup 232}Th and {sup 238}U. Phosphate ores, which constitutes the raw material for the production of phosphoric acid, have a high rate of natural radiation from the decay series of {sup 232}Th and {sup 238}U. Phosphogypsum, which is naturally radioactivity, is a by-product of the production of phosphoric acid by the wet method. For each ton of phosphoric acid it is produced about 4.5 tons of phosphogypsum. This work presents the analysis of samples collected in all stages of the manufacturing process of phosphoric acid, which generates the phosphogypsum. Gamma-ray spectrometry was used to measure the concentration of the elements of the decay series of {sup 232}Th and {sup 238}U. All analyzed samples showed a high concentration of radionuclides, promoting the need for further steps in the process in order to reduce the presence of such radionuclides in the phosphogypsum. The results indicate the radionuclide {sup 238}U has higher contribution in some samples of the intermediate stages of the process. All samples exceeded the international average range of human exposure to terrestrial gamma radiation, which is 0.3 to 1.0 mSv/year. (author)

  2. EFECTO DE LA ADICION DE ACIDOS GRASOS POLIINSATURADOS SOBRE LA DINAMICA FOLICULAR, TASA DE GESTACIÓN Y RESPUESTA OVÁRICA EN OVEJAS PELIBUEY

    OpenAIRE

    J. Herrera Camacho

    2003-01-01

    El objetivo general del presente trabajo fue evaluar el efecto de la adición de ácidos grasos poliinsaturados en la dieta sobre la dinámica folicular, la tasa de fertilidad, prolificidad y respuesta superovulatoría en ovejas Pelibuey. Se realizaron tres experimentos. El experimento uno, se realizó en la Facultad de Medicina Veterinaria y Zootecnia durante el período julio-septiembre del año 2000. Se utilizaron 30 ovejas Pelibuey de condición corporal similar con el objeto de evaluar el efecto...

  3. Comparative experimental study on municipal wastewater disinfection with ozone and peracetic acid; Indagine sperimentale comparata sulla disinfezione di acque reflue urbane con ozono e acido peracetico

    Energy Technology Data Exchange (ETDEWEB)

    Andreottola, G.; Bertola, P.; Ziglio, G. [Trento Univ. (Italy). Dip. di Ingegneria Civile Ambientale

    1996-04-01

    The results of a pilot experimental study on the disinfection of treated municipal wastewater to be used in agriculture are presented. A comparative evaluation has been carried out on two parallel pilot-scale disinfection plants using respectively ozone and peracetic acid. After a preliminary sand filtration pilot unit. Both processes showed the capability of meeting the Italian standards for agricultural reuse, but the disinfection process with ozone required much higher doses than the one with peracetic acid, probably because of the higher reactivity of ozone, if compared to peracetic acid with the organic matter present in wastewater. Further research is needed in order to evaluate the efficiency of peracetic acid applied to microorganism different from the bacterial ones and to identify nature and consequences of possible disinfection by products.

  4. El acido esteárico: un posible sustituto para los ácidos grasos trans de origen industrial

    OpenAIRE

    Tavella, Marcelo; Delplanque, Bernadette; Valenzuela, Alfonso

    2011-01-01

    Trans isomers, contained in partially hydrogenated oils, which are used in the food industry, have been questioned and nowadays trends are heading towards reducing their consumption. The food industry is facing a dilemma, since in order to remove trans fatty acids, hydrogenated fats should be eliminated and replaced by fats rich in saturated fatty acids. Scientific research has shown that saturated fatty acids have negative effects on the lipid profile and its consumption is associated with a...

  5. Kraft pulp bleaching with molybdenum activated acid peroxide (P{sub Mo} stage); Branqueamento de polpa celulosica kraft de eucalipto com peroxido acido ativado por molibdenio

    Energy Technology Data Exchange (ETDEWEB)

    Rabelo, Marcos Sousa [Servico Nacional de Aprendizagem Industrial (SENAI), Lauro de Freitas, BA (Brazil). Dept. Regional da Bahia; Silva, Vanessa Lopes; Barros, Denise Pires de; Colodette, Jorge Luiz [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Engenharia Florestal; Sacon, Vera Maria; Silva, Marcelo Rodrigues da [Votorantim Celulose e Papel, Jacarei, SP (Brazil)

    2009-07-01

    Optimum conditions to run the P{sub Mo} stage for bleaching eucalyptus kraft pulp were 90 deg C, pH 3.5, 2 h, 0.1 kg/t Mo and 5 kg/t H{sub 2}O{sub 2}. The P{sub Mo} stage efficiency increased with decreasing pH (1.5-5.5) and increasing temperature (75-90 deg C), time (2-4 h), and hydrogen peroxide (3-10 kg/t) and molybdenum concentration (0.1-0.4 kg/t). The implementation of the P{sub Mo} stage, as replacement for the A stage, decreased total active chlorine demand of the OAZDP sequence by 6 kg/t to reach 90% ISO, both in laboratory and mill scale. Such practice resulted in decreased bleaching chemical costs to produce fully bleached pulp of 90% ISO. (author)

  6. Mechanical properties of poly(N-isopropylacrylamide-Co-itaconic acid) hydrogels; Propiedades mecanicas de hidrogeles de poli(N-sopropilacrilamida-Co-acido itaconico)

    Energy Technology Data Exchange (ETDEWEB)

    Valderruten, N. E.; Quintana, J. R.; Katime, I.

    2001-07-01

    It is well known that polymers of N-isopropylacrylamide (NIPA) show lower critical solution temperature (LCST) behavior in water and its gels have a volume phase transition at about 34 degree centigree in water. In this study, we reported the polymerization of NIPA in the presence of N,N methylenebisacrylamide (BIS). Poly(N-isopropylacrylamide) and poly(N-isopropylacrylamide-co-itaconic acid) hydrogels were obtained by swelling the resultant solid xerogels to equilibrium in water. The effects of monomer composition and concentration of added cross-linking agent on the swelling behavior and mechanical properties of these hydrogels at 22 and 37 degree centigree were investigated, the latter involving measurements of shear in a DMTA system. The storage moduli at 22 degree centigree lay within the range 9.08-5.08 KPa. At a fixed BIS concentration, an increase from 22 to 37 degree centigree resulted in an increase in the shear moduli and the effective crosslinking density (v{sub e}) and a decrease in the interaction parameter hydrogel/water, {chi}. (Author) 6 refs.

  7. Influence of state of charge in lead-acid batteries operating in PV systems; Comportamiento no repetitivo de las baterias de plomo-acido operando en sistemas FV.

    Energy Technology Data Exchange (ETDEWEB)

    Vela, N.; Chenlo, F.

    2004-07-01

    Correct determination of the overcharge cut-off voltage is a key point for both the optimal operation and maximum life-time of batteries in photovoltaic (PV) systems. This work presents the results of analysing the influence on charge voltage of different operation conditions, mainly current rate, temperature and state of charge (SOC). From the results obtained we have observed that voltage evolution during a charge process depends on its activation degree of the battery. The battery activation is reached when battery was previously fully charged. So, we can conclude that variation of the charge voltage with time as function of starting point (fully charged or fully discharged) together with current rate and temperature should be taking into account in the battery SOC determination and in the design of charge controllers. (Author)

  8. Modelado Cinético de la Disolución de Hidroboracita en Acido Clorhídrico Kinetics Modeling of Hydroboracite Dissolution in Hydrochloric Acid

    OpenAIRE

    Graciela V Morales; Oscar D Quiroga; Ebelia N Tolaba

    2010-01-01

    Se realizó el modelado cinético de la disolución de hidroboracita en soluciones de ácido clorhídrico. La disolución se llevó a cabo en un reactor tanque agitado discontinuo a presión atmosférica. Se investigó el efecto de la temperatura, el tamaño de partícula, la relación sólido/líquido, y la concentración del ácido sobre la velocidad de disolución del mineral. Se observa que la velocidad de disolución es muy rápida en todos los casos estudiados, aumenta con el incremento de la temperatura y...

  9. Polyesters production from the mixture of phthalic acid, terephthalic and glycerol; Producao de poliesteres a partir da mistura de acido ftalico, tereftalico e glicerol

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, A.L.S.; Oliveira, J.C.; Miranda, C.S.; Boaventura, J.S.; Jose, N.M., E-mail: adrianaequfba@gmail.co [Universidade Federal da Bahia (GECIM/UFBA), Salvador, BA (Brazil). Inst. de Quimica. Grupo de Energia e Ciencias dos Materiais; Carvalho, R.F. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Escola Politecnica. Curso de Mestrado em Engenharia Ambiental Urbana

    2010-07-01

    Glycerin, a byproduct of biodiesel is currently an environmental and economic problem for producers of this renewable fuel in Brazil and in others parts of the world. In order to offer new proposals for recovery, it is used for the manufacture of polyesters used in applications in diverse areas such as construction and automobile industry. This work reports the production of polymer from the mixture of terephthalic and phthalic acid in three different proportions. The polyesters showed good thermal stability, analyzed by TGA and DSC, with an increase proportional to the terephthalic acid content. The X-ray diffraction patterns show that the samples are semi crystalline polymers. The micrographs indicated the presence of a smoother surface in the polyester that has a larger amount of phthalic acid, as reported in the literature. Therefore, the materials showed good thermal properties and morphological characteristics, so it consists in a new alternative to use glycerin. (author)

  10. Determinacion de la configuracion E-Z de los acidos Fumarico y Maleico. Un experimento orientado a incentivar el desarrollo de la investigacion cientifica en alumnos de Pregrado

    Directory of Open Access Journals (Sweden)

    Bustos Carlos

    2000-01-01

    Full Text Available In this work we intend to eliminate the idea that laboratory exercises seem like cookbooks. That is, exercises shall be presented as a problematic situation. Based on observation and experimentation, the students should determine the E-Z configuration of maleic and fumaric acids. The basis of this laboratory exercise is the acid-catalyzed isomerization of maleic acid to fumaric acid. Students are given the starting material, reagents and the experimental procedure. They are told that the starting material is a dicarboxylic acid containing a C=C double bond of formula C4H4O4. Students determine melting points, solubilities, acidity and chromatographic patterns for both the starting material and the product, so that a configuration of each acid can be proposed. This type of experiment yields excellent results, because the students are left to deduce that maleic acid is less stable than fumaric acid. Additionally, they conclude that maleic acid is the "Z" isomer and fumaric acid is the "E" isomer. Finally, this laboratory exercise allows the students to develop simultaneously their critical-thinking skills with the respective laboratory techniques and not to see chemistry as recipes to be followed.

  11. Behaviour and reliability of lead-acid batteries in stand-alone photovoltaic systems; Comportamiento y durabilidad de baterias de plomo-acido en sistemas fotovoltaicos autonomos

    Energy Technology Data Exchange (ETDEWEB)

    Vela Barrionuevo, N.

    2007-07-01

    Vented stationary lead-acid batteries are currently the most commonly used type of accumulator in stand-alone PV systems. The state-of the art of the technology suggests that lead-acid batteries will maintain a predominant position in the PV market for the next years. Additionally to the specific operating requirements of batteries in PV systems, there are other questions not completely solved related to battery characterisation and testing methods for this type of application. The objective of this work is to contribute to the operational optimisation and reliability improvement of lead-acid batteries operating in stand-alone PV systems. This objective has been approached by means of eminently experimental works. These works are focused firstly on functional characterisation of batteries, with special emphasis on capacity and characteristic voltages study and secondly on degradation analysis of these batteries taking into account the specific working conditions of stand-alone PV systems which main characteristic is its wide variability of operational conditions (current rates, temperature and state of charge). In relation with battery characterisation, a procedure for the determination of the usable capacity of lead-acid batteries has been established and applied to a set of commercial batteries at different current rate and temperature conditions. From each battery experimental data and using a model equation describing the battery capacity as function of current rate and temperature, the corresponding parameters for each battery have been obtained. A comparative analysis of the model application to experimental data and data supplied by the manufacturer is included. Also, initial gassing voltage and end-of-charge voltage values have been measured at different current rate and temperature conditions for the whole set of batteries. Experimental values of voltage from each battery have been fitted with high degree of accuracy to simple mathematical expressions for both characteristic voltages as function of current rate and temperature. From the regression analysis, temperature coefficients have been obtained. To conclude the characterisation works, an study of charge voltage evolution and overall charge discharge efficiency at different operating conditions (current rate and temperature) combined with different initial test conditions and variations of state of- charge has been performed. It has been observed that battery voltage, in many cases, could not be indicative of its actual state of charge, instead of this a strong dependence on the voltage evolution on initial battery condition has been obtained. With respect to battery reliability, an analysis of failures and degradation mechanisms of lead-acid batteries under specific PV operation condition is presented. From this analysis we can conclude that the main causes of degradation of lead-acid batteries in PV systems are due to extended periods working at overcharge or over discharge conditions and typical cycling condition. Because of this, different accelerated battery tests have been developed to reproduce these degradation mechanisms. The objective of these procedures is to considerably reduce the tests duration without causing any alteration to the physical meaning of the actual degradation mechanism. Results of applying these accelerated degradation tests to two different batteries are presented. Finally, in basis of the obtained results, a general qualification test sequence for lead-acid batteries in PV stand-alone systems has been proposed. The proposed sequence includes individual specific test procedures for: technical specifications included in the documentation supplied with the battery, visual inspection, characterisation (full charge, capacity and efficiency) and reliability (overcharge, over discharge and cycling). (Author)

  12. Effect of the temperature and oxalic acid in the uranyl sorption in zircon; Efecto de la temperatura y acido oxalico en la sorcion de uranilo en circon

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez R, E.; Almazan T, M. G.; Garcia G, N. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Hernandez O, R., E-mail: eduardo.ordonez@inin.gob.mx [Instituto Tecnologico de Veracruz, Ingenieria Quimica, Miguel Angel de Quevedo No. 2779, 91860 Veracruz (Mexico)

    2012-10-15

    In this work the results of the temperature effect study are presented on uranyl solutions adsorbed on zirconium silicate (ZrSiO{sub 4}) and also on the compounds formed in surface with oxalic acid. The adsorption isotherms of uranyl on hydrated zircon with NaClO{sub 4} 0.5 M, show an increase of the uranyl sorption efficiency when increasing the temperature from 20 to 4 C with a sudden descent in this efficiency when changing the temperature at 60 C. The uranyl sorption efficiency increases to hydrate the zircon with a solution of oxalic acid 0.1 M, maintaining the same tendency regarding to the temperatures of the sorption in medium NaClO{sub 4} 0.5 M. The complex formation in the zircon surface with organic acids of low molecular weight increases the fixation of the uranyl in solution due to the formation of ternary systems, in the order Zircon/A. Organic/Uranyl, without altering their response to the temperature. (Author)

  13. Acidos húmicos y fúlvicos en la producción hidropónica de Chile Manzano (Capsicum pubescens R y P) en invernadero.

    OpenAIRE

    Hernández Hernández, Antelma

    2011-01-01

    Para determinar el efecto de substancias húmicas (SH) en el crecimiento del chile manzano (Capsicum pubescens R y P), en invernadero, se evaluaron tres niveles de presión osmótica de solución nutritiva Steiner (0.54, 0.72 y 0.90 atm) y tres concentraciones de aplicación foliar de substancias húmicas (0.5, 1, 1.5 ml.L-1 de agua de las SH). Las variables medidas fueron: diámetro ecuatorial (DE), diámetro polar (DP), volumen (VOL), grosor de pericarpio (GP), numero de frutos comerciales (NFRC), ...

  14. Acido-basic control of the thermoelectric properties of poly(3,4-ethylenedioxythiophene)tosylate (PEDOT-Tos) thin films

    DEFF Research Database (Denmark)

    Khan, Zia Ullah; Bubnova, Olga; Jafari, Mohammad Javad;

    2015-01-01

    in the nanoscale morphology due to anion exchange between tosylate and Cl- or OH-. But, we identified that changing the pH leads to a tuning of the oxidation level of the polymer, which can explain the changes in thermoelectric properties. Hence, a simple acid-base treatment allows finding the optimum...

  15. Evolution of biochemical parameters in irradiated fishes: Serum proteins and intestinal nucleic acids; Evolucion de parametros bioquimicos en peces irradiados: Proteinas en suero y acidos nucleicos en intestino

    Energy Technology Data Exchange (ETDEWEB)

    Garces, F.; Andres, P.; Davila, C. A.

    1976-07-01

    In sublethal gamma-irradiated C. auratus, a sudden decrease of total serum protein concentration and a preferential descent of the low molecular weight gamma-globulin fraction have been observed. These effects are transient and after different latent periods dependent on doses, normal values are recovered, A temporal failure of a vascular permeability regulation system is probably implied. The DMA depolymerization. observed in the intestine indicates the action of radio-induced DNA degradation mechanisms since this effect is independent on doses. (Author) 29 refs.

  16. Degradation of polylactic acid (Pla) at different doses of gamma radiation; Degradacion del acido polilactico (PLA) a diferentes dosis de radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Castillo R, Y.

    2015-07-01

    The excessive use of polymers such as polyethylene (PET), polystyrene (Ps) and recently the polylactic acid (Pla) that take more than 20 years to degrade, have caused great pollution in the environment. In this study the effects of gamma radiation in the Pla to different doses were studied, in order to reduce the degradation time of this polymer. The changes in physico-chemical structure of Pla during radiation were studied by thermo-gravimetric/Mass analysis; differential scanning calorimetry; scanning electron microscopy; X-ray dispersive analysis; infrared spectroscopy; X-ray diffraction and mechanical tests of hardness, elasticity and deformation. With scanning electron microscopy, the morphology of the Pla surface unirradiated was observed, in which an apparently smooth surface was observed, after changes that had the Pla when irradiated also was observed, where the effects of radiation were observed in form of scratch, agglomeration and small fractures. By X-ray dispersive analysis was determined and verified the elemental chemical composition of the Pla; as expected the tests showed only carbon, oxygen and hydrogen. With thermo-gravimetric/Mass analysis the decomposition temperatures of Pla were determined, identifying that the degradation compounds are CO, CO{sub 2} and CH{sub 4}. With infrared spectrometry the major peaks of Pla were observed before and after being irradiated with increasing of radiation dose the intensity of the bands decreased. Also by X-ray diffraction was observed that the polymer is an amorphous material. The mechanical tests indicate that the values of each of the tests decrease significantly with increasing the radiation dose. (Author)

  17. Myrsinoic A acid and its derivative: in vitro inhibitors of photosynthesis; Acido myrsinoico A e derivado: inibidores da fotossintese in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Burger, Marcela Carmen de M.; Oliveira, Gracielle S. de; Menezes, Antonio Carlos S. [Universidade Estadual de Goias, Anapolis, GO (Brazil). Unidade Universitaria de Ciencias Exatas e Tecnologicas; Vieira, Paulo Cezar; Silva, Maria Fatima das G.F. da [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Dept. de Quimica; Veiga, Thiago A.M., E-mail: tveiga@unifesp.br [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Inst. de Ciencias Ambientais, Quimicas e Farmaceuticas. Dept. de Ciencias Exatas e da Terra

    2012-07-01

    Myrsinoic A acid, isolated from Myrsine cuneifolia and its hydrogenated derivative had their effect on photosynthesis tested. The compounds inhibited the electron flow (basal, phosphorylating and uncoupled) from water to methyl viologen; therefore, they act as Hill reaction inhibitors in spinach thylakoids. They inhibited partial reactions of PSII electron flow from water to 2,5-dichloro-1,4-benzoquinone, from water to sodium silicomolybdate, and partially electron flow from diphenylcarbazide to 2,6-dichloroindophenol. Their inhibition sites were at the donor and acceptor sides of PSII, between P{sub 680} and Q{sub A}. Chlorophyll {alpha} fluorescence measurements confirmed the behavior of the compounds (pool of quinones). (author)

  18. Behaviour of the 1-Ascorbic as supporting Electrolyte. Influence of the Magnesium Ion; Comportamiento del acido 1-Ascorbico como electrolito soporte influencai del ion magnesio

    Energy Technology Data Exchange (ETDEWEB)

    Alonso Lopez, J.

    1962-07-01

    The behaviour of 1-ascorbic acid, as supporting electrolyte of the uranyl ion in a 0{sub 1}-0.7 M concentration range, and the influence of pH on the diffusion current and half wave potential of 0,1 M uranyl ion is studied. The cathodic waves from 0 to -2,5 volts, with mercury dropping electrode are studied in fresh 0,1 M aqueous solution in presence of Mg{sup 2}+ and at 2,0-12 pH range. A kinetic current with a half wave potential of 0,85 v. vs. Hg. b.e. is obtained at pH> 9,5 appears a tilth wave a -0,60 v. The pH variation does not influence these potentials. (Author) 18 refs.

  19. Spectrophotometric determination of titanium with ascorbic acid in aluminium alloys and other materials. Determinacion espectrofotometrica de titanio con acido ascorbico en aleaciones de base aluminio y otros materiales

    Energy Technology Data Exchange (ETDEWEB)

    Bosch Serrat, F. (Departamento de Quimica Analitica. Facultad de Qauimica. Valencia (Spain))

    1994-01-01

    A spectrophotometric determination of titanium with ascorbic acid in aluminium alloys and bauxite is described. The proposed procedures permit to determine levels of titanium down to 5.10 ''3% with a good accuracy and precision. (Author) 13 refs.

  20. PRODUCCIÓN DE ACIDO CLAVULÁNICO POR FERMENTACIÓN DE Streptomyces clavuligerus: EVALUACIÓN DE DIFERENTES MEDIOS DE CULTIVO Y MODELADO MATEMÁTICO

    Directory of Open Access Journals (Sweden)

    CLAUDIA PATRICIA SANCHEZ HENAO

    2012-01-01

    Full Text Available El ácido clavulánico (AC es un antibiótico b-lactámico con una potente capacidad inhibidora de la actividad b-lactamasa. En el presente trabajo se evaluaron cuatro medios de cultivo reportados en la bibliografía y uno propuesto por los autores, para la producción de AC. Se evaluó también la concentración de glicerol adecuada para el medio seleccionado y con base en los resultados obtenidos se realizó una evaluación de la producción de AC en un biorreactor de laboratorio. Se propuso un modelo matemático y se evaluó su ajuste a los resultados experimentales. Se observó que los medios complejos con presencia de una mezcla de aminoácidos libres, son adecuados para la producción de AC. El glicerol presentó un valor óptimo frente a la producción de AC en 50 g.L-1 y se observó el efecto inhibitorio a concentraciones de 100 g.L-1. Con el medio complejo y 50 g.L-1 de glicerol, la concentración de AC alcanzada fue de 994 mg.L-1. El modelo matemático propuesto que incluye una cinética tipo Contois para la biomasa y una cinética de formación de producto parcialmente asociado al crecimiento, presentan un ajuste significativo con un 95% de nivel de confianza.

  1. Sprayed microspheres of poly(lactic acid) obtained with calcium compounds; Microesferas aspergidas de poli(acido latico) obtidos com compostos de calcio

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Raquel P.; Picciani, Paulo H. de Souza; Dias, Marcos L., E-mail: raquelpires@ima.ufrj.br [Instituto de Macromoleculas - Universidade Federal do Rio de Janeiro - UFRJ, Rio de Janeiro, RJ (Brazil)

    2011-07-01

    In this work PLLA and PDLA were synthesized using calcium methoxide (Ca(OMe){sub 2}) as initiator. This compound shows good activity in the bulk polymerization of L-lactide (LLA) and D-lactide (DLA) producing polymers with average molecular weight up to 22,300 g/mol, but with microstructure containing a significant amount of estereoerros, as revealed by {sup 13} C NMR. Block copolymers containing blocks of L-and D-lactic acid were also prepared, using the method of sequential addition of LLA and DLA in an attempt to obtain stereo complexes. Analyses of scanning electron microscopy (SEM) revealed that the polymers obtained with catalysts of calcium produced PLA microspheres with diameters of around 5 {mu}m via electro spray technique. (author)

  2. Elution of nickel ions from alginate beads in an acid media; Elucion de iones de niquel desde esferas de alginato en un medio acido

    Energy Technology Data Exchange (ETDEWEB)

    Aracena, A.; Carcamo, F.; Jerez, O.; Constanzo, R.

    2016-05-01

    Elution of nickel ions from alginate beads was studied in a temperature range of 2 to 80 degree centigrade and a sulfuric acid concentration between 0.005 to 2.5 g L{sup -}1. The elution mechanism was established by ion exchange between nickel and ions protons, obtaining a value of 93% elution at a temperature of 80 degree centigrade and a H{sub 2}SO{sub 4} concentration of 0.25 g L{sup -}1. The influence of other acids on nickel elution was also studied. The nickel elution rate was significantly influenced by temperature and concentration of H{sub 2}SO{sub 4}. Elution kinetics of nickel ions was studied, and the 1-(1-α){sup 1}/3=k{sub a}ppt model properly described the kinetics of this reaction. The dependence of nickel elution on the sulfuric acid concentration was of the order of 0.33. Moreover, the intrinsic rate constants were determined and an activation energy value of 54.5 kJ mol{sup -}1 was obtained for the temperature range studied. The results indicated that the nickel elution is a process controlled by chemical reactions. (Author)

  3. Optimized Analytical Method to Determine Gallic and Picric Acids in Pyrotechnic Samples by Using HPLC/UV (Reverse Phase); Optimizacion del Metodo Analitico mediante HPLC/UV Operando en Fase Inversa para la Determinacion de Acido Galico y Acido Picrico en Muestras de Origen Pirotecnico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Alonso, S.; Perez Pastor, R. M.

    2013-10-01

    A study on the optimization and development of a chromatographic method for the determination of gallic and picric acids in pyrotechnic samples is presented. In order to achieve this, both analytical conditions by HPLC with diode detection and extraction step of a selected sample were studied. (Author)

  4. Impregnation of 12-tungstophosphoric acid on silica - part II: effect of different solvents on the impregnation and catalytic activity in methyl esterification of stearic acid; Impregnacao do acido 12-tungstofosforico em silica - parte II: efeito de diferentes solventes na impregnacao e atividade catalitica na esterificacao metilica de acido estearico

    Energy Technology Data Exchange (ETDEWEB)

    Scroccaro, Karine Isabel; Yamamoto, Carlos I., E-mail: karineisabel@yahoo.com.br [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Centro Politecnico. Departamento de Engenharia Quimica; Tanobe, Valcineide O. de A.; Oliveira, Alan Antonio de [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Departamento de Engenharia e Tecnologia Florestal; Wypych, Fernando [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Departamento de Quimica

    2014-04-15

    Materials obtained by the immobilization of 12-tungstophosphoric acid (PTA) on silica using the method of impregnation with excess solution in distinct solvents (aqueous HCl, methanol:H{sub 2}O, and acetonitrile) were evaluated for use as catalysts in the methyl esterification of stearic acid. Optimum conditions were established for the impregnation of 0.5 g (w/w) of PTA on amorphous silica, under stirring at 150 rpm for 24 h, using 20 mL of 0.1 mol L{sup -1} HCl as the solvent. After calcination at 200 deg C, high conversions were obtained under mild reaction conditions, resulting in high turnover numbers. The catalyst was evaluated in ten catalytic cycles of use, where the activity was reduced only slightly, attesting its stability and the possibility to apply it to industrial production of methylesters. (author)

  5. Marginal microleakage in vitro study on class V cavities prepared with Er:YAG laser and etched with acid or etched with Er:YAG laser and acid; Estudo in vitro da microinfiltracao marginal em cavidades classe V preparadas com laser de Er:YAG e condicionadas com acido ou com laser de Er:YAG e acido

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, Henrique Dutra Simoes

    2001-07-01

    Microleakage at the interface between the teeth and the restorative materials remains a problem with composite resin restorations. Microleakage at the gingival margins of class V cavities restorations still challenge as they are usually placed in dentin and/or cementum. Previous studies have shown that the cavity preparation with Er:YAG laser is possible. It has been reported that Er:YAG laser has ability to create irregular surface providing micromechanical retention for adhesive dental restorative materials and to improve marginal sealing. The purpose of this in vitro study was to evaluate the marginal microleakage on class V cavities prepared with Er:YAG laser and etched with acid or with Er:YAG laser and acid, in compared to those prepared and etched conventionally. Thirty human molars were divided into three groups, namely: group I - prepared with Er:YAG laser (KaVo KEY Laser II - Germany) and etched with 37% phosphoric acid; group II - prepared with Er:YAG laser and etched with Er:YAG laser and 37% phosphoric acid; group III (control group) - prepared with high speed drill and etched with 37% phosphoric acid. All cavities were treated with same adhesive system (Single Bond - 3M) and restored with the composite resin (Z100 - 3M), according to the manufacturer's instructions. The specimens were stored at 37 deg C in water for 24 hours, polished with Sof-Lex discs (3M), thermally stressed, sealed with a nail polish coating except for the area of the restoration and 1 mm around it, and immersed in a 50% aqueous solution of silver nitrate for 24 hours. After that, the specimens were rinsed in water, soaked in a photodeveloping solution and exposed to a fluorescent light for 8 hours. The teeth were embedded in an autopolymerizing resin and sectioned longitudinally using a diamond saw microtome under running water. The sections were photographed. The microleakage at the occlusal cavity and at the gingival margins of each specimen was evaluated with scores (0-3) by three calibrated examinators. Both results on occlusal and gingival margins have shown no statistic significant difference among the three groups evaluated (p>0.05). The Er:YAG laser have shown to be as effective as the conventional methods for cavity preparation and etching, suggesting its use for the class V cavity preparation and enamel etching. (author)

  6. Development of methodology for the synthesis of poly(lactic acid-co-glycolic acid) for use in the production of radioactive sources; Desenvolvimento da metodologia para sintese do poli(acido latico-co-acido glicolico) para utilizacao na producao de fontes radioativas

    Energy Technology Data Exchange (ETDEWEB)

    Peleias Junior, Fernando dos Santos

    2013-07-01

    According to World Health Organization (WHO), cancer is a leading cause of death worldwide. Prostate cancer is the second most common cancer in men. A method of radiotherapy which has been extensively used is brachytherapy, where radioactive seeds are placed inside the area requiring treatment. Iodine-125 seeds can be placed loose or stranded in bioabsorbable polymers. Stranded seeds show some advantages, since they reduce the rate of seed migration, an event that could affect the dosimetry of the prostate and cause unnecessary damage to healthy tissues or organs. For Iodine-125 stranded seeds, polyglactin 910 (poly(lactic-co-glycolic acid)) (PLGA), with a coverage of polyglactin 370 (Vicryl Registered-Sign ) is used. It was purposed in this dissertation, the study and development of the synthesis methodology for PLGA via ring-opening polymerization, as well as its characterization, with the objective of using the synthesized material to manufacture a material similar to RAPID Strand{sub Registered-Sign }. The results obtained show that it was possible to determine the optimal reaction parameters (time and temperature) for PLGA in 80/20 (lactide/glycolide) ratio. Using a temperature of 110 Degree-Sign C and reaction time of 24h, a yield of 86% was obtained, and increasing the reaction time to 72 hours, the yield was higher than 90%. The molecular mass values obtained from the samples are still very low compared to those obtained by other authors in the literature (about 20%). Failures in the sealing of vials, leaving them vulnerable to moisture and oxygen, or lack of an efficient stirring system might be possible explanations for these results. A suitable chemical reactor could solve the problem. Regarding polymer characterization, all techniques used not only confirmed the expected structure of the polymer, but also showed the highest proportion of lactide units compared to to glycolide units. (author)

  7. Development of methodology for the synthesis of poly(lactic acid-co-glycolic acid) for use in the production of radioactive sources; Desenvolvimento da metodologia para sintese do poli(acido latico-co-acido glicolico) para utilizacao na producao de fontes radioativas

    Energy Technology Data Exchange (ETDEWEB)

    Peleias Junior, Fernando dos Santos; Zeituni, Carlos Alberto; Rostelato, Maria Elisa Chuery Martins; Souza, Carla Daruich de; Mattos, Fabio Rodrigues de; Moura, Eduardo Santana de; Moura, Joao Augusto; Benega, Marcos Antonio Gimenes; Feher, Anselmo; Costa, Osvaldo Luiz da; Rodrigues, Bruna Teiga, E-mail: fernandopeleias@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP/CTR), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes; Fechine, Guilhermino Jose [Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil). Escola de Engenharia

    2015-05-15

    According to the World Health Organization, cancer is a leading cause of death worldwide. A radiotherapy method extensively used in prostate cancer is brachytherapy, where the area requiring treatment receives radioactive seeds. Iodine-125 seeds can be inserted loose or stranded in bioabsorbable polymers produced from poly(lactic-co-glycolic acid) (PLGA). We developed the synthesis methodology for PLGA and the results obtained show that it was possible to determine the optimal reaction parameters (time and temperature) for PLGA in 80/20 (lactide/glycolide) ratio. The yield was higher than 90% using a temperature of 110 °C and reaction time of 72 hours; however, the molecular weight values obtained are very low compared to those obtained by other authors. New tests using previously synthesized dimers and nitrogen atmosphere are being performed. These conditions could potentially increase the molar mass of PLGA. All techniques used confirmed the expected structure of the polymer. (author)

  8. Composicao quimica, perfil de acidos graxos e quantificacao dos acidos ƒ¿-linolenico, eicosapentaenoico e docosahexaenoico em visceras de tilapias (Oreochromis niloticus = Percentual composition, fatty acids and quantification of the LNA (Alfa-Linolenic, EPA (Eicosapentaenoic and DHA (Docosahexaenoic acids in visceras of Nile Tilapia (Oreochromis niloticus

    Directory of Open Access Journals (Sweden)

    Nilson Evelázio de Souza

    2005-01-01

    Full Text Available Foi avaliada a composição química de vísceras de tilápias (Oreochromis niloticus criadas em cativeiro Os teores de umidade, cinza, proteína bruta e lipídios totais foram de 64,4%; 1,3%; 6,3% e 18,0%, respectivamente, caracterizando alta concentração de lipídiostotais em relação a outros resíduos de peixes. Foram identificados 49 ácidos graxos, sendo majoritários os ácidos: oléico, (32,8%, seguido do palmítico, (19,9% e linoléico, (18,2%. As razões entre n-6/n-3 e ácidos poliinsaturados/saturados foram de 5,5 e 0,9, respectivamente. As quantificações dos ácidos graxos alfa-linolênico, eicosapentaenóico e docosahexaenóico, em mg/g de lipídios totais, foram de 10,4, 1,4 e 9,3, respectivamente. O elevado teor de lipídios totais das vísceras contribuiu significativamente para as quantidadesde ácidos graxos n-3. Todos os parâmetros analisados foram satisfatórios sob o ponto de vista nutricional e neste sentido as vísceras de tilápias poderão ser utilizadaa para alimentar peixes ou outros animais.The chemical composition was evaluated in visceras of tilapias raised in captivity. The moisture, ash, crude protein and total lipids contents were 64.4%; 1.3%; 6.3% and 18.0%, respectively, characterizing high total lipids concentration in relation other residues of fish. Forty nine fatty acids were detected, the major fatty acids were oleic (32.8%, palmitic (19.9% and linoleic-1 (18.2% and oleic (9.4%. The ratio n-6/n-3 and polyunsaturated/saturated fatty acids, showed the values 5.5 and 0.9, respectively. The quantifications of alfa-linolenic, eicosapentaenoic and docosahexaenoic acids (in mg/g of total lipids, were 10.4, 1.4 and 0.3, respectively. The higher contents of total lipids in visceras contributed significantly for amounts of n-3 fatty acids. All the parameters analyzed were shown nutritional value satisfactory in this sense visceras of tilapias can be used in the feed of fish and other animal.

  9. NCBI nr-aa BLAST: CBRC-PHAM-01-1048 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-PHAM-01-1048 ref|YP_003183601.1| hypothetical protein Aaci_0148 [Alicyclobacillus acido...caldarius subsp. acidocaldarius DSM 446] gb|ACV57212.1| hypothetical protein Aaci_0148 [Alicyclobacillus acido...caldarius subsp. acidocaldarius DSM 446] YP_003183601.1 6e-05 22% ...

  10. Composición molecular de acidos humicos evaluada mediante pirólisis -cromatografia de gases- masas e hidrólisis térmica asistida y metilación, en suelos altoandinos – colombia

    OpenAIRE

    Claudia Martinez; Isabel Bravo; Francisco Martin

    2014-01-01

    Se determinó la composición  molecular de ácidos húmicos (AH), extraídos del horizonte A de suelos altoandinos, Colombia dedicados a tres usos: bosque primario, cultivo y pastura. Los AH se obtuvieron mediante extracción secuencial de la materia orgánica humificada (MOH) con soluciones de tetraborato, pirofosfato e hidróxido de sodio (0,1N), y fueron purificados por diferentes procesos analíticos. Su composición molecular se determinó  por Py-GC/MS y THMA. Los diferentes productos de la pirol...

  11. Shyntesis and cytotoxicity evaluation in vitro of new compounds with hybrid structures of 8-flavoneacetic acid and quinolones; Sintesis y evaluacion citotoxica in vitro de nuevos compuestos con estructuras hibridas del acido 8-flavonacetico quinolonas

    Energy Technology Data Exchange (ETDEWEB)

    Biaa, M.F.; Castellano, J.M.; Emling, F.; Schlick, E. [Knoll, S.a., Madrid (Spain)

    1994-12-31

    Using the structural similarity between 8-flavoneacetic acid the antitumor quinolones, we have prepared some hybrid compounds on both systems and studied their cytotoxicity. None of the sinthesized compounds have shown sufficient interest for further development. 33 refs.

  12. Radiation characterization, physico-chemical and mineralogical materials associated with the production of phosphoric acid; Caracterizacion radiactiva, fisico-quimica y mineralogica de materiales asociados con la proudccion del acido fosforico

    Energy Technology Data Exchange (ETDEWEB)

    Pereira Ambrosio, E.; Gazquez Gonzalez, M.; Bolivar Raya, J. P.

    2011-07-01

    For over 20 years there is a clear awareness in the scientific community about the need to assess the occupational and environmental radiological impact caused by the activities of conventional nuclear industries (industries NORM). These are characterized either by use in their production processes raw materials rich in natural radionuclides, or by generating commercial products, by-products or residues enriched in these radionuclides. (Author)

  13. Obtention of Samarium and Gadolinium concentrates by solvent extraction using mono-2-ethylhexyl ester of 2-ethylhexyl phosphonic acid; Obtencao de concentrados de samario e gadolinio via extracao por solventes com o ester mono-2-etilhexil do acido 2-etilhexilfosfonico

    Energy Technology Data Exchange (ETDEWEB)

    Miranda Junior, Pedro

    1996-07-01

    The rare earth chlorides solution employed in this study, which is constituted by medium and heavy fractions, is derived from monazite processing accomplished by NUCLEMON-Mineroquimica (SP). This solution shows an acidity about 1.18 M and 189 g/L of rare earth oxides, containing as main constituents: Sm(34.55%), Gd(23.85%), Dy (6.82%), and Y (24.45%). It was used, as organic phase, 2-ethylhexyl phosphonic acid, mono-2-ethylhexylester diluted to 1 M in isododecane. (author)

  14. Cleaning of the diffusers with formic acid for aeration of an active sludge process; Limpieza con acido formico de los difusores demembrana para la aireacion en un proceso de fangos activos

    Energy Technology Data Exchange (ETDEWEB)

    Simon Andre, P.; Lardin Mifsut, C.; Abella Solar, M.; Marc Ponsoda, J.; Garcia del Real, A.; Perez Sanchez, P.

    2009-07-01

    Electric energy costs are one of the main issues inside the total amounts in a WWTP, being the aeration system consumption the highest one but also the most flexible and order to reduce the global costs. In this work it has been quantified the improvement obtained when formic acid is used to do periodic cleanness of the diffusers. When this is used, manual cleanness can be kept apart. During the cleanness processes with formic acid, it has been observed a reduction in the pressure drop, between 6 and 13%, and a reduction in the power demand, between 7 and 12% . These reduction have been correlated with the annual costs, reaching an annual saving of near 3%. (Author) 8 refs.

  15. Polymeric blends from post-consumer PET and polyester becoming of glycerol and phthalic acid; Misturas polimericas a partir do PET pos-consumo e poliesteres derivados do gliceraol e acido ftalico

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, C.S.; Brioude, M.; Fiuza, R.P.; Luporini, S.; Carvalho, R.F.; Jose, N.M., E-mail: cleidienesm@gmail.co [Universidade Federal da Bahia (GECIM/UFBA), Salvador, BA (Brazil). Inst. de Quimica. Grupo de Energia e Ciencias dos Materiais

    2010-07-01

    Preparation of physical mixture or polymer blends is a very important method to obtain a final product with excellent balance of properties, where one component can compensate for the poor property of another, and is often a modified low cost compared to development and synthesis of a new polymer. PET has become a major waste of post-consumer plastics and aiming to remedy this problem, this work aims to obtain blends from recycled PET and polyesters derived from glycerol and phthalic acid. The material with higher proportion of PET showed better thermal properties, observed by TGA and DSC, with a similar profile of pure PET. In XRD analysis showed a semicrystalline, while the SEM is a smooth surface on all materials, characteristic of pure polyester. The ratio of 50% its surface showed a probable immiscibility of polymers. (author)

  16. Influence of acids composition in the properties of poly(glycerol citrate-co-adipate); Influencia da composicao dos acidos nas propriedades do poli(glicerol citrato-co-adipato)

    Energy Technology Data Exchange (ETDEWEB)

    Brioude, M.M.; Pereira, R.; Fiuza, R.P.; Jose, N.M., E-mail: mbrioude@gmail.co [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica

    2010-07-01

    Synthetic polymers are highly resistant to degradation, being one of the greatest responsible for environment pollution. Consequently, an increase in biodegradable polymers research and development is happening. In this work we propose the synthesis and characterization of polyesters potentially biodegradable using glycerol, citric acid (CA) and adipic acid (AD). The polyesters were prepared by adding the reactants in molar ratio between glycerol:acids (1:1,5), but changing the acids ratio. The system was heated to 150-160 deg C, under nitrogen atmosphere and magnetic stirring, without catalyst adding. The samples were characterized by TGA, DSC, FTIR, XRD e SEM. The results show that the polymers prepared are amorphous polyesters, with two thermal events in 250 deg C and 450 deg C and the surfaces presents smooth and rough regions refers to bonds between glycerol and CA or AD, respectively. (author)

  17. COMPOSICIÓN MOLECULAR DE ACIDOS HUMICOS EVALUADA MEDIANTE PIRÓLISIS -CROMATOGRAFIA DE GASES- MASAS E HIDRÓLISIS TÉRMICA ASISTIDA Y METILACIÓN, EN SUELOS ALTOANDINOS – COLOMBIA

    Directory of Open Access Journals (Sweden)

    Claudia Martinez

    2014-07-01

    Full Text Available Se determinó la composición  molecular de ácidos húmicos (AH, extraídos del horizonte A de suelos altoandinos, Colombia dedicados a tres usos: bosque primario, cultivo y pastura. Los AH se obtuvieron mediante extracción secuencial de la materia orgánica humificada (MOH con soluciones de tetraborato, pirofosfato e hidróxido de sodio (0,1N, y fueron purificados por diferentes procesos analíticos. Su composición molecular se determinó  por Py-GC/MS y THMA. Los diferentes productos de la pirolisis se clasificaron atendiendo a la familia química a la que pertenecen,  prevalecieron los ácidos grasos (FA como el producto más abundante en los AH de todos los usos, mientras que  los fenoles, esteroles, S-compuestos y terpenos se encontraron en menor abundancia. Se presentaron diferencias en los porcentajes de abundancia relativa de los grupos identificados, demostrando que el cambio de uso de suelo influye en las propiedades físicas, químicas y biológicas del suelo por lo que se perciben diferentes grados de transformación, que afectan la composición de los AH y su reactividad en el suelo.

  18. Obtention and characterization of acrylic acid-i-polyethylene organometallic copolymers with Mo, Fe, Co, Zn, and Ni; Obtencion y caracterizacion de copolimeros organometalicos de acido acrilico-i-polietileno, con Mo, Fe, Co, Zn y Ni

    Energy Technology Data Exchange (ETDEWEB)

    Dorantes, G.; Urena, F.; Lopez, R. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Lopez, R. [Universidad Autonoma del Estado de Mexico (Mexico)

    1997-07-01

    In this study a graft acrylic acid (AA) in low density polyethylene (PEBD) copolymers were prepared, using as reaction initiator, gamma radiation at different doses. These copolymers were coordinated with molybdenum, cobalt, iron, zinc and nickel. the obtained polymeric materials were characterized by conventional analysis techniques. It was studied the measurement parameter variation of the positron annihilation when they inter activated with this type of materials and so obtaining information about microstructure of these polymers. (Author)

  19. Chemical characterization of composites developed from glycerol and dicarboxylic acids rein forced with piassava fiber; Caracterizacao quimica de compositos desenvolvidos a partir do glicerol e acidos dicarboxilicos reforcados com fibra de piacava

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Cleidiene S.; Oliveira, Jamerson C.; Guimaraes, Danilo H.; Jose, Nadia M., E-mail: cleidienesm@gmail.com [Universidade Federal da Bahia, Instituto de Quimica, GECIM - Programa de Pos-Graduacao em Engenharia Quimica, Salvador, BA (Brazil); Carvalho, Ricardo F. [Universidade Federal da Bahia, Escola Politecnica, Mestrado em Engenharia Ambiental Urbana, Salvador, BA (Brazil)

    2011-07-01

    In search of alternative technologies that enable the use of products with lower environmental impact, This study aims to develop a composite polymer-based piassava fiber. The sludge, waste and byproduct of commercial uses currently being used as reinforcement in polymer matrices, due to presence of lignocellulosic materials. The matrix polymer used was synthesized from glycerol with dicarboxylic acids, in order to open future perspectives on the use of glycerin generated from purified biodiesel production plastics. Composites with 2, 5, 10 wt% of piassava fiber cut into 5 mm raw and treated were obtained a mixture of solution. The materials were characterized by TGA, DSC, XRD and SEM. It was observed that the material under study is promising for the industrial market, because it has good compatibility with natural fibers allowing wider application of fiber natural and glycerol, producing semicrystalline composites and with good thermal properties. (author)

  20. Modified montmorillonite as a heterogeneous catalyst in (m)ethyl esterification reaction of lauric acid; Montmorilonita modificada como catalisador heterogeneo em reacoes de esterificacao (M)etilica de acido laurico

    Energy Technology Data Exchange (ETDEWEB)

    Zatta, Leandro; Nepel, Angelita; Barison, Andersson; Wypych, Fernando, E-mail: wypych@ufpr.br [Departamento de Quimica, Universidade Federal do Parana (UFPR), Curitiba , PR (Brazil)

    2012-07-01

    Montmorillonite was modified with zirconium polyoxycations in the presence of ammonium sulphate. The material was characterized and used as a catalyst in the esterification of lauric acid, the reactions being accompanied by 2{sup 3} factorial design. Conversions of up to 95.33 and 83.35% were observed for the methyl and ethyl esterification reactions respectively, proving superior to results obtained by thermal conversion. The material was submitted to three reaction cycles and similar conversions were observed, indicating the catalyst is not significantly deactivated after reuse. The catalyst was also tested under reflux conditions, yielding a maximum conversion of 36.86%. (author)

  1. Esterification of fatty acids using sulfated zirconia and composites activated carbon/sulfated zirconia catalysts; Esterificacao de acidos graxos utilizando zirconia sulfatada e compositos carvao ativado/zirconia sulfatada como catalisadores

    Energy Technology Data Exchange (ETDEWEB)

    Brum, Sarah S.; Santos, Valeria C. dos; Destro, Priscila; Guerreiro, Mario Cesar [Universidade Federal de Lavras, MG (Brazil). Dept. de Quimica

    2011-07-01

    In this work sulfated zirconia (SZr) and activated carbon/SZr composites produced by impregnation method with or without heating treatment step (CABC/SZr-I and CABC/SZr-I SC) and by the method of synthesis of SZr on the carbon (CABC/SZr-S) was used as catalysts in the esterification reactions of fatty acids. The SZr presented very active, conversions higher than 90% were obtained after 2 h of reaction. The activity of the composite CABC/SZr-I20%SC was up to 92%, however, this was directly related to time and temperature reactions. CABC/SZr-I and CABC/SZr-S were less active in esterification reactions, what could be attributed to its low acidity. (author)

  2. The elution of erbium from a cation exchanger bed by means of the N-hydroxyethyl-ethylene-diamine triacetic acid; Mecanismo de la elucion del erbio en un cambiador cationico con el acido n-hidroxietil-etilen-diamono-triacetico

    Energy Technology Data Exchange (ETDEWEB)

    Amer Amezaga, S.

    1963-07-01

    A physicochemical study of the phenomena resulting when erbium is eluted from a cation-exchanger bed at a steady by means of the N-hydroxyethyl-ethylene-diamine-triacetic acid (HEDTA) is made. Two different retaining beds are used, a hydrogen bed, in which no ammonium passes through, and a zinc bed, which leaks ammonium ion. Good agreement between experimental and calculated values by using the equations deduced for the concentrations of the main species has been achieved, with errors around 1-2% in most of the experiments. (Author) 69 refs.

  3. Crystal structure of ATVORF273, a new fold for a thermo- and acido-stable protein from the Acidianus two-tailed virus

    DEFF Research Database (Denmark)

    Felisberto-Rodrigues, Catarina; Blangy, Stéphanie; Goulet, Adeline;

    2012-01-01

    in the viral world. To understand this intriguing phenomenon, we have undertaken structural studies of ATV virion proteins and here we present the crystal structure of one of these proteins, ATV[Formula: see text]. ATV[Formula: see text] forms tetramers in solution and a molecular envelope is provided...... for the tetramer, computed from small-angle X-ray scattering (SAXS) data. The crystal structure has properties typical of hyperthermostable proteins, including a relatively high number of salt bridges. However, the protein also exhibits flexible loops and surface pockets. Remarkably, ATV[Formula: see text......] displays a new [Formula: see text] protein fold, consistent with the absence of homologues of this protein in public sequence databases....

  4. Oscillatory dynamics in systems containing bromate and 1,4-cyclohexanedione in acidic media. I. The effect of temperature; Dinamica oscilatoria em sistemas contendo bromato e 1,4-ciclo-hexanodiona em meio acido. I. Efeito da temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Hyrla C.L.; Oliveira, Tatiane B.; Varela, Hamilton, E-mail: varela@iqsc.usp.br [Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo (IQSC/USP), Sao Carlos, SP (Brazil)

    2012-07-01

    We present in this work the influence of temperature on the dynamics of homogeneous chemical systems containing bromate and 1,4-cyclohexanedione (1,4-CHD) in acidic media. In particular, the following systems were studied: bromate/1,4-CHD/acid, bromate/1,4-CHD/ferroin/acid and bromate/1,4-CHD/trisbipyridine ruthenium/acid. Investigations were carried out by means of an electrochemical probe, at five temperatures between 5 and 45 degree C. Activation energies (Ea) were estimated in different ways for the pre-oscillatory and oscillatory regimes. In any case, the Ea was found to depend on the catalyst, composition and initial concentrations. In addition, it was observed that ferroin and trisbipyridine ruthenium act as catalysts only during the transition between the induction period and oscillatory regime. (author)

  5. Acido tranexâmico e hemostasia em cirurgia de revascularização do miocárdio com circulação extracorpórea Tranexamic acid and hemostasis in myocardial revascularization with extracorporeal circulation

    Directory of Open Access Journals (Sweden)

    Guilherme F Vargas

    1992-12-01

    Full Text Available O antífibrinolítico sintético ácido tranexâmico (Transamin ® foi avaliado em seus efeitos hemostáticos e poupadores de transfusões homólogas, em pacientes submetidos a revascularização do miocárdio com circulação extracorpórea (CEC. Quarenta pacientes receberam placebo e 55 pacientes foram operados sob o efeito do ácido tranexâmico na dose de 10 g endovenosa no trans-operatório (2 g administrados na indução anestésica e os restantes 8 g nas 4 horas seguintes de cirurgia, de modo contínuo. O ácido tranexâmico, na dosagem utilizada, demonstrou possuir efeito hemostático impressionante, promovendo uma redução no débito pelos drenos torácicos da ordem de 47% nas 12 horas de P.O., 42,5% nas 24 horas de P. O. e 40,5% até a retirada dos drenos, em relação ao grupo-controle (pThe synthetic antif ibrinolytic drug tranexamic acid was evaluated in its hemostatic and blood saving effects, in patients submitted to myocardial revascularization with extracorporeal circulation. To 40 patients were administered placebo and to 55 tranexamic acid I.V. in a dosage of 10 g in the operative period (2 g in the anesthetic induction and the remaining 8 g in a continuous way during the operative procedure. Tranexamic acid, in this dosage, has proved to have a very impressive hemostatic effect, leadir g to a reduction in post operative bleeding of 47% in 12 h, 42,5% in 24 h and 40,5% when drains were taken off, related to the control group (p < 0.05. Tranexamic acid have led to less utilization for homologous paked red cells per patient, but statistical significance was found only in the 24 h of post operative period, with 1,025 units/patient in control group and 0,333 units/ patient in treated group. Concerning post operative complications, there have been more neurological alterations without sequelae (2.5% against 12.7% and creatinin alterations (5% against 10.9% in the tranexamic acid group. Such alterations were attributed to the high dosage used. As a conclusion, we do not recommend routine use of tranexamic acid to patients submitted to myocardial revascularization in the dosage of 10 g I.V., but, owing to the evident hemostatic effect of the drug, we recommend more investigations concerning the ideal dosage and way of administration.

  6. Phosphorus in chronosequence of burnt sugar cane in Brazilian cerrado: humic acid analysis by {sup 31}P NMR; Fosforo em cronossequencia de cana-de-acucar queimada no cerrado goiano: analise de acidos humicos por RMN de {sup 31}P

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Celeste Q.; Pereira, Marcos G.; Garcia, Andreas C., E-mail: mgervasiopereira@gmail.com [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil). Dept. de Solos; Perin, Adriano; Gazolla, Paulo R. [Instituto Federal de Educacao, Ciencia e Tecnologia Goiano, Rio Verde, GO (Brazil); Gonzalez, Antonio P. [Universidade de Coruna, ES (Spain). Faculdad de Ciencias

    2013-10-01

    The aim of this study was to identify, with the use of {sup 31}P NMR spectroscopy, organic P species in humic acids (HA) in samples from Oxisol cultivated in chronosequence with sugar cane, pasture and Cerrado. The main forms of P-type found were orthophosphate, monoester-P (phosphate sugars) and P-diester (orthophosphate). The {sup 31}P NMR technique proved capable of identifying changes in the areas studied as a function of sugar cane burning time. In areas with 1 and 5 years of burnt cane, a decrease in recalcitrant organic P in humic acids indicated the need for use of P-humic substances for plant nutrition (author)

  7. Gamma radiation effects at color, antioxidant capacity and fatty acid profile in peanut (Arachis hypogaea L.); Efeitos da radiacao gama na cor, capacidade antioxidante e perfil de acidos graxos em amendoim (Arachis hypogaea L.)

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, Adriano Costa de; Canniatti-Brazaca, Solange Guidolin; Mansi, Debora Niero; Domingues, Maria Antonia Calori [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Agroindustria, Alimentos e Nutricao; Arthur, Valter, E-mail: arthur@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2011-01-15

    Irradiation is efficient at extinction fungi contamination in peanuts. Peanuts have high biologic value protein, minerals, vitamin E, complex B, and high concentration of lipids. The objective of this research is to evaluate the gamma irradiation effect on color, total phenolic, antioxidant activity, and fatty acid profile in peanuts (Arachis hypogaea L.). Cultivars IAC-Tatu ST and IAC-Runner 886 were submitted to gamma radiation with doses of 5.0; 7.5; 10.0, and 15.0 kGy and storage at room temperature. There was no significant difference in the color of IAC-Tatu ST. However, significant difference was found in the luminosity and Chroma in IAC-Runner 886. Total fenolics differed from the control with 33.27 mg.g{sup -1} and treatment dose of 10.0 kGy with 58.60 mg.g{sup -1} in IAC-Tatu ST. This parameter not had significant difference in IAC-Runner 886 and the control with 51.59 mg.g{sup -1}. The antioxidant activity did not present significant difference with a dose of 10.0 kGy, recommended for the elimination of fungi in peanuts. The dose of 10.0 kGy showed a decrease in saturated fatty acids, increase in unsaturated fatty acids, and an increase in linolleic acid. The oleic/linoleic relation decreased justifying further research correlating storage and oxidative stability. (author)

  8. Bioethanol production by cashew apple bagasse (Anacardium occidentale L.): comparison of acid diluted and alkali pre-treatments; Producao de bioetanol a partir da fibra do caju (Anacardium occidentale L.): comparacao entre o pre-tratamento acido e alcalino

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Tigressa H.S.; Pinheiro, Alvaro D.T.; Goncalves, Luciana R.B. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil); Rocha, Maria V.P.; Macedo, Gorete R. de [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    Due to the growing environmental awareness on the negative impact resulting from utilization of fossil fuels, and in the search for renewable energy sources, biofuels' interest as Bioethanol has rapidly expanded recently. In this context, lignocellulosic compounds have become center of attention as an abundant and economic alternative source of carbohydrates for ethanol production. In this study, cashew's bagasse acid hydrolysis was initially studied for glucose synthesis and its fermentation towards ethanol production. Sulfuric acid concentration, solids concentration and time were some of the factors evaluated. The highest glucose productivity value (162,9 mg.g de bagaco{sup -1}) , was obtained for 0,6 mol.L{sup -1} of sulfuric acid in an autoclave at 121 deg C for 15 min. For the fermentation of the hydrolyzed material by S. cerevisiae containing 16 {+-} 2,0 g.L{sup -1} of glucose metabolic, the yield and productivity obtained were 0,63 g-g glucose{sup -1} and 1,43 g.L{sup -1}h{sup -1} respectively. Ethanol concentration after 6 h of fermentation of this hydrolyzed was 11 g.L{sup -1}. In the best conditions of acid hydrolysis, a second pre-treatment with diluted sulfuric acid was performed to evaluate availability of hemicelluloses at 160 deg C and 180 deg C. For comparative purposes, alkali pre-treatment was evaluated under the conditions of 0,6 mol.L{sup -1}, 30% p/v of bagasse thermically treated at 121 deg C for 15 minutes. However, concentration of sugars was not sufficient for fermentation. Also, nitrogen supplementation of the hydrolyzed fraction did not influence significantly ethanol production. The results demonstrate that the hydrolyzed fraction from the acid pre-treatment of cashew's bagasse could be utilized for ethanol production. (author)

  9. Evaluation of gamma irradiation effects on carotenoids, ascorbic acid and sugar contents of buriti fruit (Mauritia flexuosa L.); Avaliacao dos efeitos da radiacao gama nos teores de carotenoides, acido ascorbico e acucares do fruto Buriti do Brejo (Mauritia flexuosa L.)

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Antonio Luis dos Santos [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Quimica, Quimica Organica e de Produtos Naturais], e-mail: santoslima@ime.eb.br; Lima, Keila dos Santos Cople; Silva, Jaqueline Michele [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Nuclear. Irradiacao de Alimentos], e-mail: keila@ime.eb.br, e-mail: jaquelinefisica@bol.com.br; Coelho, Maysa Joppert [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Nuclear. Engenharia Ambiental], e-mail: maysa@ime.eb.br; Godoy, Ronoel Luiz de Oliveira [EMBRAPA Agroindustria de Alimentos, Rio de Janeiro, RJ (Brazil). Lab. de Cromatografia Liquida, Quimica Organica e de Produtos Naturais], e-mail: ronoel@ctaa.embrapa.br; Pacheco, Sidney [EMBRAPA Agroindustria de Alimentos, Rio de Janeiro, RJ (Brazil). Lab. de Cromatografia Liquida, Ciencia e Tecnologia de Alimentos], e-mail: sidney@ctaa.embrapa.br

    2009-07-01

    Buriti (Mauritia flexuosa L.), a typical fruit from the Northeast and Center-West Amazon of Brazil, is used in many regional dishes. It is considered an excellent source of carotenoids that are A vitamin precursors, showing a majority of beta-carotene. It also presents ascorbic acid and sugar contents. Many studies have indicated that the lack of A vitamin is the main cause of night blindness and xerophthalmia. Also, ascorbic acid deficiency may cause scorbutic disease. The use of food irradiation is growing and represents an economic benefit to agriculture through the reduction of post-harvesting losses while maintaining food nutritional quality. In this study, buriti in natura was treated with gamma irradiation with doses of 0.5 kGy and 1.0 kGy. The objective was to evaluate the irradiation effects on total carotenoids, ascorbic acid and sugars concentrations of buriti. The fruit was evaluated through the total carotenoids analysis, by spectrophotometry, and the carotenoids (alpha and beta-carotene and lutein), ascorbic acid and sugars were determined by high performance liquid chromatography (HPLC). The results showed that buriti is an excellent source of total carotenoids (44600 {mu}g/100 g). The irradiation of buriti with the dose of 0.5 kGy did not significantly change carotenoids and sugars contents. However, there was a reduction of ascorbic acid concentration with an increase of the dose, which may have been caused by irradiation or by intrinsic and extrinsic factors that alter ascorbic acid stability in food, converting ascorbic to dehydroascorbic acid, while keeping the C vitamin active form. (author)

  10. Dosimetric influence of hyaluronic acid in patients with prostate cancer treated with RT3D; Influencia dosimetrica del acido hialuronico en pacientes cancer de prostata tratados con RT3D externa+HDR braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, J.; Vazquez, J. A.; Garcia Blanco, A. S.; Gomez, F.; Montejo, A.; Raba, J. I.; Pacheco, M. T.; Cardenal Carro, J.; Mendigueren, M. A.

    2013-07-01

    This study aims to assess the influence on dosimetry by the introduction of hyaluronic acid and assess the need for the realization of a second CT scan and consequent re-planning of RT3D treatment. (Author)

  11. Exhaust lead-acid batteries recycling as a tool of the environmental protection policy. Energy, environmental and economic issues; Il riciclaggio delle batterie al piombo-acido esauste come strumento della politica di salvaguardia ambiental. Aspetti energetici, ambientali ed economici

    Energy Technology Data Exchange (ETDEWEB)

    Picini, P.; Battista, A. [ENEA, Divisione Caratterizzazione dell' Ambiente e del Territorio, Centro Ricerche Casaccia, S. Maria di Galeria, RM (Italy)

    2001-07-01

    Lead is an heavy metal that has a major impact on human health and his removal from the environment is an important action for its protection. The aim of the present work is to provide a framework of the Italian lead recycling with respect to the economic and environmental aspects of COBAT activities (COBAT is the Mandatory Consortium to collect and recycle the exhaust lead-acid batteries and lead wastes). In order to better understand the context in which COBAT works, some statistical data on the lead production, consumption and end uses in Italy and in the world are provided. An estimate of the energy consumptions and the environmental impact related to Italian lead production was also carried out. [Italian] Il piombo e' uno dei metalli pesanti a maggiore impatto ambientale e sanitario e la sua rimozione dall'ambiente costituisce un'importante azione di protezione e tutela della salute umana. Lo scopo del presente lavoro e' quello di fornire un quadro di riferimento relativo al riciclaggio del piombo in Italia evidenziandone gli aspetti ambientali ed economici in relazione alle attivita' condotte dal COBAT (Consorzio Obbligatorio delle Batterie Esauste e dei rifiuti piombosi). In tal senso, per disporre di una visione piu' completa del contesto in cui si inserisce l'attivita' del Consorzio, vengono forniti alcuni dati di carattere statistico sulla produzione, sul consumo e sugli utilizzi del piombo in Italia e nel mondo e viene effettuata una stima dei consumi energetici e dell'impianto ambientale associati alla produzione di piombo nazionale.

  12. Mechanical performance evaluation of bionanocomposites with polymeric matrix of poly(lactic acid)-PLA and organo clay; Avaliacao do comprtamento mecanico de bionanocompositos com patriz polimerica de poli(acido latico)-PLA e argila organofilica

    Energy Technology Data Exchange (ETDEWEB)

    Cavalcanti, Shirley N.; Melo, Tomas J.A. de; Araujo, Edcleide M.; Oliveira, Akidauana D.A.; Lima, Jessica C.C., E-mail: shirleynobre@gmail.com [Universidade Federal de Campina Grande - UFCG - Dept. de Engenharia de Materiais, Campina Grande, PB (Brazil)

    2011-07-01

    The aim of this study is to evaluate the influence of ethylene/methyl acrylate (EMA) and ethylene/glycidyl methacrylate (E-GMA) copolymers and organoclay on the mechanical properties of polymer PLA-poly (lactic acid), from the system PLA / organoclay. The clay was organophilized with the ionic surfactant praepagem and the mixtures were prepared in a modular twin screw extruder. The behavior of bionanocomposites was evaluated by tensile and impact tests. The results of FTIR and DR-X indicated that the process was efficient organophilization. The mechanical properties showed that the elastic modulus and tensile strength of bionanocomposites obtained decreased compared to PLA. On the other hand there was a gain for resistance to impact, for all systems except for system PLA/OMMT. (author)

  13. Viability of uses of fluoride 10% acid to removal paramagnetic ions in soil samples and its physic fractions; Viabilidade do emprego de acido fluoridrico 10% para a remocao de ions paramagneticos em amostras de solos e suas respectivas fracoes fisicas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Larissa Macedo dos; Simoes, Marcelo Luiz; Martin-Neto, Ladislau, E-mail: larissa@cnpdia.embrapa.b [EMBRAPA Instrumentacao Agropecuaria, Sao Carlos, SP (Brazil); Montes, Celia Regina [Universidade de Sao Paulo (IQ/USP), SP (Brazil). Inst. de Quimica; Melfi, Adolpho Jose [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil)

    2010-09-15

    Treated sewage effluent utilization for irrigation represents an antique, popular and attractive alternative to the common disposal of effluent to watercourses and includes three main purposes: effluent complementary treatment, water and nutrient source to the soil-plant system. However, because in Brazil no experiences in wastewater recycling exists consequently few scientific studies were carried out despite the importance of the subject. The present study aimed to evaluate by chemical and spectroscopy techniques the soil organic matter from soils irrigated with treated sewage effluent. Five treatments were evaluated: TSI (control) - irrigation with potable water and addition of the nitrogen as mineral fertilizer; T100, T125, T150 and T200 - irrigation with treated sewage sludge effluent and addition of the nitrogen as mineral fertilizer. The results obtained shown changes in the carbon contend and humification degree for the soils irrigated with treated sewage sludge effluent due to the increase activity of the decomposition of organic matter, stimulated by the increase of water in the soil. (author)

  14. Modificacion del Valor Nutrimental de Acidos Grasos en Semilla de la Halofita Salicornia bigelovii Torr. con la Interaccion de Bacterias Promotoras del Crecimiento de Plantas (Azospirillum halopraeferens y Klebsiella pneumoniae

    Directory of Open Access Journals (Sweden)

    Edgar Omar Rueda Puente

    2005-01-01

    Full Text Available Una especie vegetal a gran escala se presenta como una alternativa para la producción de ácidos grasos esenciales en nutrición humana por lo que su composición de ácidos grasos cobra especial importancia. Salicornia bigelovii una halófita que se desarrolla en ambientes áridos y costeros como las del estado de Sonora y de la península de Baja California Sur, México, presenta ser una especie alternativa en la producción de aceites comestibles. La fijación de N2 por bacterias asociadas con raíces de Salicornia bigelovii y halófitas similares son una fuente importante de nitrógeno disponible en ecosistemas costeros. La inoculación de Klebsiella pneumoniae y Azospirillum halopraeferens fue evaluada durante el desarrollo vegetativo de Salicornia bigelovii bajo condiciones de campo en dos genotipos (genotipo silvestre y cv. SOS-10, afectando positivamente variables como peso, longitud de plantas, rendimientos de producción y características bioquímicas como proteína total, ceniza, y contenido de lípidos totales en semilla producida. Nuestros resultados sugieren que ambos genotipos de S. bigelovii, bajo las condiciones de campo empleadas, pueden ser mejorados con la aplicación de K. pneumoniae y A. halopraeferens, mostrando una utilidad potencial para productores agrícolas de zonas semiáridas costeras.

  15. Evaluation of human dental loss caused by carbamide peroxide bleacher compared with phosphoric acid conditioning - radioactive method; Avaliacao da perda dental humana com o uso do clareador peroxido de carbamida comparado ao condicionamento com acido fosforico - metodo radiometrico

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Eduardo Makoto; Yousseff, Michel Nicolau [Sao Paulo Univ., SP (Brazil). Faculdade de Odontologia. Dept. de Dentistica; Saiki, Mitiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Lab. de Analise por Ativacao Neutronica

    2002-07-01

    The radiometric method was applied to the evaluation of dental loss caused by carbamide peroxide when it is applied on the surface layers of enamel and dentin tissues. Also the dental loss caused by the etching with 37% phosphoric acid procedure used in aesthetic restoration was assessed for comparison with those results obtained. The tooth samples irradiated with a P standard in a thermal neutron flux of the nuclear reactor were placed in contact with 10% carbamide peroxide or with 37% phosphoric acid solution. The radioactivity of {sup 32} P transferred from the radioactive teeth to the bleaching gel or to etching acid was measured using a Geiger Muller detector to calculate the mass of P removed in this treatment and losses were calculated after obtaining their P concentrations. Results obtained indicated that enamel and dentin exposed to carbamide peroxide bleaching agent lose phosphorus. The extent of enamel loss was smaller than that obtained for dentin. In the case of acid etching, there was no difference between the results obtained for enamel and dentin loss. Also the dentin loss obtained after a treatment of 30 applications of 10% carbamide peroxide was the same magnitude of that one application of 37% phosphoric acid. (author)

  16. Cyclopentenyl acids from sapucainha (Carpotroche brasiliensis Endl, Flacourtiaceae): the first antileprotic used in Brazil; Acidos ciclopentenicos do oleo da sapucainha (Carpotroche brasiliensis Endl, Flacourtiaceae): o primeiro antileprotico usado no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Adriana S.; Lima, Joselia A.; Rezende, Claudia M.; Pinto, Angelo C. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Centro de Tecnologia. Inst. de Quimica]. E-mail: crezende@iq.ufrj.br

    2009-07-01

    The chaoolmugra oil is one of the oldest medicines used for leprosy until the development of sulfas. In Brazil, it is known as sapucainha oil that is obtained from Carpotroche brasilienesis seeds (Flacourtiaceae). Chemical and medicinal studies of sapucainha oil were introduced in Brazil by Peckolt, Cole and Cardoso which showed that major ciclopentenyl fatty acids as chaulmoogric, hydnocarpic and gorlic were responsible for its bactericidal activity. In this work, a method for quantification of sapucainha oil acidic fraction by HRGC was established using methyl n-heptadecanoate as internal standard. The oil chemical stability was investigated by the use of GC-MS, IR, {sup 1}H and {sup 13}C NMR and showed that the main degradation products belong to the cyclopentenyl moiety oxidation. (author)

  17. Effect of the humic acids in the adsorption of U (Vi) in a Mexican natural zeolite; Efecto de los acidos humicos en la adsorcion de U (VI) en una zeolita natural mexicana

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval G, H. A.; Lopez del R, H.; Davila R, J. I.; Mireles G, F., E-mail: hlopezdelrio@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2012-10-15

    The uranium adsorption was studied in a Mexican natural zeolite of the clinoptilolite type in presence and absence of humic acids (Ha). The adsorption kinetics of the binary U-zeolite and ternary U-Ha-zeolite systems were compared, and the effect of the humic matter impregnated in the zeolite in the uranium removal in function of the solution ph was studied. The experiments were made to environmental conditions and lightly acid ph, with fixed concentrations of uranium and Ha of 1 x 10{sup -5} M and 20 ppm, respectively, and a reason m/V of 5 mg/ml. The uranium adsorption in absence of Ha was of 96% and decreased to 45% in the ternary system U-Ha-zeolite. The data of the binary system U-zeolite were analyzed with three kinetic models of adsorption (pseudo-first order, pseudo-second order and Elovich). By means of non lineal regression was found that the uranium adsorption obeys a kinetic of pseudo-second order. It was observed that the uranium adsorption in the zeolite impregnated with Ha is favored to more ph at 5. (Author)

  18. Synthesis and characterization of chitosan-graft-poly(acrylic acid)/rice husk ash hydrogels composites; Sintese e caracterizacao de hidrogeis compositos de cinza da casca de arroz e quitosana enxertada com poli(acido acrilico)

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Francisco H.A. [Universidade Estadual Vale do Acarau - UVA, Sobral, CE (Brazil); Lopes, Gabriel V.; Pereira, Antonio G.B.; Fajardo, Andre R.; Muniz, Edvani C. [Universidade Estadual de Maringa - UEM, PR (Brazil)

    2011-07-01

    According to environmental concerns, super absorbent hydrogel composites were synthesized based on rice husk ash (RHA), an industrial waste, and Chitosan-graft-poly(acrylic acid). The WAXS and FTIR data confirmed the syntheses of hydrogel composites. The effect of crystalline or amorphous RHA on water uptake was investigated. It was found that the RHA in crystalline form induces higher water capacity (W{sub eq}) of composites hydrogels due to the fact that the intra-interactions among silanol groups on RHA make available new sites in the polymer matrix, which could interact to water. (author)

  19. Preparation and characterization of polymer blends based on recycled PET and polyester derived by terephthalic acid; Preparacao e caracterizacao de blendas polimericas a base de PET reciclado e poliester derivado do acido tereftalico

    Energy Technology Data Exchange (ETDEWEB)

    Ohara, L.; Miranda, C.S.; Fiuza, R.P.; Luporini, S.; Carvalho, R.F.; Jose, N.M., E-mail: leandro.ohara@gmail.co [Universidade Federal da Bahia (GECIM/UFBA), Salvador, BA (Brazil). Inst. de Quimica. Grupo de Energia e Ciencias dos Materiais

    2010-07-01

    Environmentally friendly materials, made from industrial waste, are being increasingly used as a solution to the growing amount of waste generated by society, but also as a cheaper alternative to replace conventional materials for use in construction. In this work were investigated the properties of polymer blends based on recycled PET and a polyester derived from terephthalic acid and glycerin, a co-product of biodiesel. The samples were characterized by XRD, TGA, DSC, FTIR and SEM. The polyester synthesized showed a degradation event near 300 deg C. The blends with higher ratio of PET showed thermal behavior similar to pure PET. The X-ray diffraction showed that the polymer blends are semicrystalline materials. The micrographs presents the presence of a smooth surface, indicating the possibility of miscibility between the arrays. Therefore, the blending makes possible the fabrication of low-cost materials with applications in several areas. (author)

  20. 铌-酒石酸-邻硝基苯基萤光酮-CTMAB 多元络合物显色反应的研究%Colour Reaction of Multicomponent Complex Niobium-Tartaric Acido-Nitrophenylfluorone-CTMAB

    Institute of Scientific and Technical Information of China (English)

    沈含熙; 王连生

    1984-01-01

    @@铌的高灵敏显色反应,迄今报道甚少。以邻硝基苯基萤光酮为显色剂的氯仿萃取光度法[1],虽然具有较高的灵敏度(8=1.38×105),但由于使用有机溶剂进行萃取操作而感不便。我们考虑以胶束增敏反应在水溶液中进行铌的测定来代替萃取光度法,可能使实验操作简化。 试验结果表明,在酒石酸-盐酸介质中,铌(Ⅱ) 可以与邻硝基苯基萤光酮以及阳离子表面活性剂CTMAB形成具有四元组分的络合物,其最大吸收峰位于525nm,相应的摩尔吸光系数可达到1.63×105升·摩尔-1·厘米-1。有可能发展成为水相介质中测定微量铌的高灵敏分光光度法。

  1. Study of stability of humic acids from soil and peat irradiated by gamma rays; Estudo da estabilidade de acidos humicos extraidos de solo e turfa, frente a radiacao ionizante gama

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Wilson Tadeu Lopes da

    1995-07-01

    Humic acids samples (one deriving from a sedimentary soil and other from a peat), in aqueous media, were irradiated with gamma rays, in doses of 10, 50 and 100 kGy, in order to understand their chemical behavior after the irradiation. The material, before and after irradiation, was analyzed by Elemental Analysis, Functional Groups (carboxylic acids and phenols), UV/Vis Spectroscopy (E{sub 4}/E{sub 6} ratio), IR spectroscopy, CO{sub 2} content and Gel permeation Chromatography (GPC) ). The Elemental Analysis showed the humic acid derived from a peat had a most percentage quantity of Carbon and Hydrogen than the material from a sedimentary soil. From the UV/Vis Spectroscopy, it was observed a decrease of E{sub 4}/E{sub 6} ratio with an increase of the applied dose. The data from GPC are in agreement with this. The results showed that the molecular weight of the material increased by exposing it to a larger radiolitical dose. The peat material was less affected by the gamma radiation than the soil material. The carboxylic groups were responsible by radiochemical behavior of the material. (author)

  2. Impregnation of 12-tungstophosphoric acid on silica - part I: determination of impregnation parameters, characterization and evaluation of catalytic activity; Impregnacao do acido 12-fosfotungstico em silica - parte I: determinacao de parametros de impregnacao, caracterizacao e avaliacao da atividade catalitica

    Energy Technology Data Exchange (ETDEWEB)

    Scroccaro, Karine Isabel; Tanobe, Valcineide Oliveira de Andrade; Cocco, Lilian Cristina; Yamamoto, Carlos Itsuo, E-mail: karineisabel@yahoo.com.br [Universidade Federal do Parana, Curitiba, PR (Brazil). Centro Politecnico. Dept. de Engenharia Quimica; Wypych, Fernando [Universidade Federal do Parana, Curitiba, PR (Brazil). Centro Politecnico. Dept. de Quimica

    2012-07-01

    Catalyst based on Kegging-type heteropolyacids (H{sub 3}PW{sub 12}O{sub 40} - HPA), supported on SiO{sub 2} (H{sub 3}PW), were prepared by the impregnation method under different thermal treatment conditions. The materials were characterized by different instrumental techniques and used as catalysts in the methyl esterification reactions of stearic acid. Using the catalyst with 15% of HPA, conversions higher than 60% were obtained after 2 h of reaction at 65 deg C. Recovery studies using hot-filtration with ethanol at 75 deg C showed satisfactory activity for two additional reaction cycles. (author)

  3. Acido tranexâmico e hemostasia em cirurgia de revascularização do miocárdio com circulação extracorpórea Tranexamic acid and hemostasis in myocardial revascularization with extracorporeal circulation

    OpenAIRE

    Guilherme F Vargas; João Nelson R. Branco; Ana Hercília S Guimarães; Cecília Kobata; Espedito T. V. F Silva; Carlos Alberto Teles; Carlos Arnulfo A La Rotta; M. L. A Batista Filho; José Carlos S Andrade; Ênio Buffolo

    1992-01-01

    O antífibrinolítico sintético ácido tranexâmico (Transamin ®) foi avaliado em seus efeitos hemostáticos e poupadores de transfusões homólogas, em pacientes submetidos a revascularização do miocárdio com circulação extracorpórea (CEC). Quarenta pacientes receberam placebo e 55 pacientes foram operados sob o efeito do ácido tranexâmico na dose de 10 g endovenosa no trans-operatório (2 g administrados na indução anestésica e os restantes 8 g nas 4 horas seguintes de cirurgia, de modo contínuo). ...

  4. Poderá o carrapato transmitir a lepra?: isolamento e cultura dum bacilo acido-álcool resistente de sedimento de "Amblyomma cajennense" capturado em leproso: 2ª nota May ticks transmit leprosy?: Second Note

    Directory of Open Access Journals (Sweden)

    H. C. Souza-Araujo

    1942-01-01

    Full Text Available In this 2nd note upon the possibility of transmission of human leprosy by ticks, the A. relates his stepps to obtain the collaboration of his colleagues working in leprosaria in various States of Brazil, Argentina and Paraguay in such studies. Firstly the A. describes the positive results of examination of sediment of ticks, the cattle tick Boophilus microplus (Canestrini, 1888, received from Paraná (Leprosário São Roque , which were put on active lepers, two of them sucking during 9 days and one during 7 days. Two out of three were killed for examination and were very strongly positive for acid-fast bacilli. A series of tubes of Loewenstein medium was smeared with the sediment of such ticks. Secondly the A. relates his personnal experiment, carried out in Rio de Janeiro, trying to infect normal ticks in lepers. The experiment with Boophilus microplus was negative and was twicely positive the experiment with Amblyomma cajennense Fabricius, 1794. The experiment is being in progress and will be continued in other places of Brazil. Finally, after being given the general characteristics of Boophilus microplus, the A. describes the non-chromogenic culture of a acid-fast bacillus isolated by him from sediment of ticks (Amblyomma cajennense captured in lepers from Colônia Santa Isabel (Minas gerais, which parasitism was spontaneous. The first isolation was obtained in Loewenstein medium after 62 days incubation at 37°C. The culture is pure and the bacillus is permanent acid-fast. The plate1, in full color, represents this culture in its four generations. The colonies are pearl-white in color, dry, elevated and rough, developing slowly and beginning as white pinhead points scattered upon the surface of the medium. The culture is not yet rich enough to be inoculated into laboratory animals, which will be done when possible.

  5. Modeling of an immobilized lipase tubular reactor for the production of glycerol and fatty acids from oils; Modelado de un reactor tubular de lipasas inmovilizadas para la produccion de glicerol y acidos grasos a partir de aceites

    Energy Technology Data Exchange (ETDEWEB)

    Oddone, S.; Grasselli, M.; Cuellas, A.

    2010-07-01

    Advances in the design of a bioreactor in the fats and oils industry have permitted the hydrolysis of triglycerides in mild conditions and improved productivity while avoiding the formation of unwanted byproducts. The present work develops a mathematical model that describes the hydrolytic activity of a tubular reactor with immobilized lipases for the production of glycerol and fatty acids from the oil trade. Runge Kuttas numerical method of high order has been applied, considering that there is no accumulation of the substratum in the surface of the membrane, where the enzyme is. At the same time, different equations based on the kinetic model of Michaelis Mentens and the Ping-Pong bi-bi mechanism were examined. Experimental data in discontinuous systems are the basis for the development of the quantitative mathematical model that was used to simulate the process computationally. The obtained results allow for optimizing both the operative variables and the economic aspects of industrial processes. (Author)

  6. Synthesis and reactions with a midines of derivates cycles and of open chain of 2-bromo-3, 4-dioxobutanoic; Sintesis y reacciones con amidinas de derivados ciclicos y de cadena abierta del acido 2-bromo-3, 4-dioxobutanoico

    Energy Technology Data Exchange (ETDEWEB)

    Ancos, B. de; Delgado, F.; Martin, M.R. [Departamento de Quimica Organica, Facultad de Ciencias, Universidad Autonoma, Madrid (Spain)

    1995-12-31

    Bromination of enaminoesters 1 and 5, in appropriate conditions, affords in good yield enamines of the corresponding 2-bromo-3.4-dioxobutanoic acid derivatives 2-3 and 6 or dibromocompounds 4 and 6. The open chain enaminoesters (1-3) are more easily hydrolyzed that enaminofuranones 5 and 6. Prolongated treatment of 6 with hydrochloric acid affords the chlorinated enamine 11. The synthesis of 3-Bromo-4-hydroxy-5-methoxyfuran-2(5H)-one 10 can be achieved by bromination of 12, obtained by hydrolysis of 5. The reaction of methyl 3-bromo-4, 4-dimethoxy-3-oxobutanoate with amidines is a good method for the synthesis of 5-bromo-6-(dimethoxymethyl) pyrimidine-4(3H)-ones substituted at 2 position. Under the same conditions the reaction of furanone 10 with benzamide does not lead to the corresponding imidazoline. (Author) 12 refs.

  7. Effect of glycerin and formic acid in the efficiency of deposit on Zn-Ni, obtained by electrodeposition; Efeito da glicerina e do acido formico na eficiencia de deposito da liga Zn-Ni, obtido atraves de eletrodeposicao

    Energy Technology Data Exchange (ETDEWEB)

    Pedroza, G.A.G.; Souza, C.A.C.; Lima, L.R.P.A.; Ferreira, D.M. [Universidade Federal da Bahia - Escola Politecnica, BA (Brazil)

    2010-07-01

    Additives are added to the electrodeposition of metal coatings to improve the characteristics of the deposit. However, the objective was to investigate the effect of adding glycerin and formic acid in the deposition efficiency and deposit structure of zinc-nickel alloy obtained by electrodeposition. The depositions were made at a galvanostatic current density of 10 mA/cm{sup 2} to obtain a deposit of about 5 mm in thickness. The deposition efficiency was determined through measures of mass, chemical composition of the deposit in the presence and absence of additives was examined by X-ray Spectrometer Fluorescence (XRF) and surface characterization of coatings was performed by Scanning Electron Microscopy (SEM). The high levels of glycerin (0,07 M) and formic acid (0,26 M) in bath deposition increased the deposition efficiency of around 10% to 12% by mass, respectively. (author)

  8. Behavior of uranium isotopes along a tidal cycle in a study affected by acid mine drainage; Comportamiento de los isotopos de uranio a lo largo de un ciclo mareal en un estuario afectado por denaje acido de minas

    Energy Technology Data Exchange (ETDEWEB)

    Hierro, A.; Martin, J. e.; Olias, M.; Garcia, C.; Bolivar, J. P.

    2013-07-01

    The Tinto and Odiel rivers converge in an estuarine system known as the Ria de Huelva, which is an ecosystem of great interest, conditioned by hydrochemical facts. The main objective of this study was to analyze the behavior of uranium isotopes in the waters of the Red River estuary in a tidal cycle under hydrochemical conditions of high gradients of salinity and pH generated by the acidic waters of the Rio Tinto and seawater. (Author)

  9. Labelling of 5-ethyl-5-phenylbarbituric acid with Technetium-99m: biodistribution study in Swiss mice; Marcacao do acido 5-etil-5-fenilbarbiturico com tecnecio-99m: estudo da biodistribuicao em camundongos Swiss

    Energy Technology Data Exchange (ETDEWEB)

    Simoes, Susana B.E.; Oliveira, Marcia B.N. de; Gutfilen, Bianca; Bernardo-Filho, Mario [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Biologia. Dept. de Biofisica e Biometria; Alves, Andreia Coelho; Machado-Silva, Jose R. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Biologia. Dept. de Parasitologia

    1996-07-01

    The 5-ethyl-5-phenylbarbituric acid (phenobarbital) is used as a sedative, hypnotic and anticonvulsant drug. We decided to label it with technetium-99m. In order to determine the optimal conditions, different concentrations of this drug were incubated with various stannous chloride solutions. Then, {sup 99m}Tc was added and chromatography was performed using 0.9% NaCl solution, acetone and n-butyl alcohol as the mobile phase. Using a solution of 0.01 mg/ml stannous chloride and 1.0 mg/ml phenobarbital over 92% of the radioactivity bound to phenobarbital {sup 99m}Tc-phenobarbital. In the biodistribution study, {sup 99m}Tc-phenobarbital was administered in mice intraperitoneal. The main uptake of the labeled drug was in the liver, blood, kidneys, spleen and stomach. The phenobarbital is also used as anesthetic drug in animals. Earlier studies confirm that this drug can dislocate the adult worms of Schistosoma mansoni to mesenteric vein towards the liver and portal vein, so that we used infected animals, radioactivity was not found in isolated worms and we can conclude that the phenobarbital has an indirect action in relation to the displacement of the worms. (author)

  10. Morphology and thermal degradation study of poly(lactic acid)/synthetic mica composites; Estudo da morfologia e da degradacao termica de compositos de poli(acido latico)/mica sintetica organofilica

    Energy Technology Data Exchange (ETDEWEB)

    Souza, D.H.S.; Dias, M.L., E-mail: diegosaboya@ima.ufrj.b [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano

    2010-07-01

    Poly(lactic acid) (PLA)/synthetic mica composites has been little studied in the literature. In this work, an organophilic synthetic mica was used to prepare PLA nanocomposites. The composites were obtained at an internal mixer containing 3, 5, 7 and 10 wt% of mica. The materials were analyzed by x-ray diffraction, thermogravimetric analysis and gel permeation chromatography. (author)

  11. Resistencia a la insulina inducida por acidos grasos en células de músculo esquelético L6E9: papel de la carnitina palmitoiltransferasa I (CPT-I)

    OpenAIRE

    Sebastián Muñoz, David

    2006-01-01

    La resistencia a la insulina es un estado patológico que se define como la incapacidad del organismo de responder normalmente a las acciones de la insulina. Este estado está ligado a la obesidad, al estilo sedentario de vida y es responsable en gran medida de la aparición de la diabetes de tipo 2. Aunque tradicionalmente el estudio de esta patología se había centrado en el metabolismo de carbohidratos, en las últimas décadas se ha producido un cambio hacia el estudio del metabolismo de ácidos...

  12. Evaluation of the physicochemical properties of structured materials: metallic, polymeric and ceramic, for the treatment of sour gases; Evaluacion de las propiedades fisicoquimicas de materiales estructurados: metalico, polimerico y ceramico, para el tratamiento de gases acidos

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, A.; Chavez, R. H. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Olea, O.; Solis, D., E-mail: rosahilda.chavez@inin.gob.mx [Universidad Autonoma del Estado de Mexico, Facultad de Quimica, Cerro de Coatepec s/n, Ciudad Universitaria, 50100 Toluca, Estado de Mexico (Mexico)

    2013-07-01

    in this work the physicochemical properties of three structured materials: metallic, polymeric and ceramic, from Sulzer Brothers Limited brand, are studied in order to removal sour gases, by absorption process, in aqueous solution of Monoethanolamine (Mea), at 30% weight. Mechanical properties, chemical composition, morphology and corrosion resistance were determined, using different characterization techniques, such as: 1) mechanically, according to standard procedures Astm E-384-1990, 2) chemically, by the corrosion resistance in the presence of an electrochemical cell, in aqueous solution of H{sub 2}SO{sub 4}, 1 N by Astm G-5-1999, 3) morphologically by scanning electron microscopy technique, and 4) efficiency of separation, by the gas chromatography technique in order to determine the chemical absorption of CO{sub 2} by Mea. The ceramic material was the hardest with 700 Hk value and tensile strength of 90 MPa, likewise showed resistance to corrosion of 10.28 m py, separation efficiency of 74% CO{sub 2}, at 10 minutes. The metallic material had a hardness of 190 Hk and it was the most resistant of tension, with 831 MPa, and corrosion resistance of 780.4 x 10{sup -6} m py, likewise promoted CO{sub 2} separation efficiency of 90% during the evaluation. The polymeric material presented hardness of 20 Hk and 35 MPa and it was not suffered surface change with electrochemical attack, with 282.4 x 10{sup -6} m py, and separation efficiency of 88%. Therefore the polymer was the most ductile, with smooth surface and greater resistance with H{sub 2}SO{sub 4}. The metal material was more resistant to plastic deformation and more corrugated surface and the second resistance in the presence of acid medium in aqueous solutions. For all the above, the metallic material is recommended by its greater separation in the reduction of acid gases and the polymer due to its greater chemical resistance. (Author)

  13. FORMULATION D'UN GEL OXYDANT À MATRICE ORGANIQUE APPLICABLE À LA DÉCONTAMINATION NUCLÉAIRE : PROPRIÉTÉS RHÉOLOGIQUES, ACIDO-BASIQUES ET OZONOLYSE DE LA MATRICE

    OpenAIRE

    Rouy, Emmanuel

    2003-01-01

    Un gel fortement acide et oxydant, à matrice purement organique, a été formulé dans l'objectif de l'appliquer sur des parois métalliques contaminées par des radioéléments. Les propriétés rhéologiques pertinentes au regard de l'application envisagée (caractère rhéofluidifiant, thixotropie, seuil d'écoulement...) ont été analysées dans différents milieux : purement aqueux, acide (HNO3 2 mol/kg), acide et cérique ( (NH4)2Ce(NO3)6 1 mol/kg). La matrice organique utilisée, le xanthane, présente po...

  14. Characterization of commercial ceramic adsorbents and their application on naphthenic acids removal of petroleum distillates; Caracterizacao de adsorventes ceramicos comerciais e sua aplicacao na remocao de acidos naftenicos de destilados de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Silva, J.P.; Senna, L.F. de; Lago, D.C.B. do; Silva Junior, P.F. da; Figueiredo, M.A.G. de; Dias, E.G. [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil)], e-mail: julia_psi@yahoo.com.br; Chiaro, S.S.X. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2006-07-01

    One denominates 'naphthenic acids' to the mixture of carboxylic acids that is present in petroleum oil, and is directly responsible for its acidity and corrosiveness in liquid phase during the refine process. These acids are also presents in distilled fraction of petroleum, causing several problems in final products quality. A possible way to remove them from petroleum distilled fractions is the adsorption in porous materials. However, the published results indicate that ion exchange resins would be the best adsorbents for this process, which would probably increase its cost. In this work, two commercial adsorbents (clay and activated alumina) were characterized by a set of physical-chemistry techniques and evaluated concerning their capacity of removing naphthenic acids from a light petroleum fraction. It was also verified the influence of a previous thermal treatment to the adsorption in their physical-chemistry characteristics and its properties. (author)

  15. Modification of zirconium diphosphate with salicylic acid and its effect on the uranium (Vi) sorption; Modificacion del difosfato de circonio con acido salicilico y su efecto sobre la sorcion de uranio (VI)

    Energy Technology Data Exchange (ETDEWEB)

    Almazan T, M. G.; Garcia G, N. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Simoni, E., E-mail: guadalupe.almazan@inin.gob.mx [Universidad Paris Sud, Instituto de Fisica Nuclear, Georges Clemenceau No. 15, Orsay (France)

    2014-10-15

    The surface of zirconium diphosphate (ZrP{sub 2}O{sub 7}) was modified with salicylic acid and its effect was evaluated on the uranium (Vi) sorption. The modified surface of the material was analyzed with different analytical techniques among which are included the atomic force microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy. This analysis allowed showing that the salicylic acid is being held on the surface of the zirconium diphosphate. The reactivity of modified zirconium diphosphate compared with uranium (Vi) was investigated using the classical method of batch sorption. The analysis of sorption isotherms shows that the salicylic acid has an important effect in the uranium (Vi) sorption. According to the study conducted, the interaction among the uranium (Vi) and the surface of zirconium diphosphate modified with the salicylic acid most likely leads to the complexes formation of binary (U(Vi)/ZrP{sub 2}O{sub 7}) and ternary (U(Vi)/salicylate/ZrP{sub 2}O{sub 7}) surface. (Author)

  16. Influence of the temperature in the uranyl sorption in zirconium diphosphate modified with salicylic acid; Influencia de la temperatura en la sorcion de uranilo en difosfato de circonio modificado con acido salicilico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia G, N.; Solis C, D. A. [Universidad Autonoma del Estado de Mexico, Facultad de Quimica, Paseo Colon y Paseo Tollocan s/n, 50000 Toluca, Estado de Mexico (Mexico); Ordonez R, E., E-mail: nidgg@yahoo.com.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (MX)

    2011-11-15

    In this work the experimental conditions were established to evaluate the uranium (Vi) sorption to 20 and 40 C on the surface of the zirconium diphosphate (ZrP{sub 2}O{sub 7}) modified with a solution of salicylic acid 0.1 M. The modification of the ZrP{sub 2}O{sub 7} was produced during the hydrate process, taking advantage that these are formed complexes between the carboxyl and hydroxyl groups of salicylic acid and amphoteric species of the interface solid/liquid. The method is used by lots to elaborate the isotherms that explain the behavior of this sorption in different ph conditions and temperature, the quantity of the uranium reaction is analyzed with the fluorescence technique. The results indicated that in the temperature increases the uranium sorption on the material and is more efficient to low ph values. (Author)

  17. Composti perfluorurati: Valutazione degli effetti biologici e molecolari in modelli cellulari

    OpenAIRE

    Pirini, Francesca

    2014-01-01

    L’acido perfluorottanoico (PFOA) e l’acido perfluoronanoico (PFNA) sono composti perfluorurati (PFCs) comunemente utilizzati nell’industria, negli ultimi 60 anni, per diverse applicazioni. A causa della loro resistenza alla degradazione, questi composti sono in grado di accumularsi nell’ambiente e negli organismi viventi, da cui possono essere assunti in particolare attraverso la dieta. Le esistenti evidenze sugli effetti dell’esposizione negli animali, tra cui la potenziale cancerogenicità, ...

  18. Ácido graxo a-linolênico causa o mesmo efeito que seus derivados de cadeia longa em ratos portadores de tumor de Walker 256?

    OpenAIRE

    Schiessel, Dalton Luiz

    2012-01-01

    Resumo: Alteracoes na dieta estabelecidas nos ultimos 200 anos causaram reducao no consumo de acidos graxos poliinsaturados (AGPI) n-3, aumento do consumo de gordura total, saturada e rica em AGPI n-6. Estas mudancas foram fatores determinantes para o aumento da incidencia de doencas cronicas nao transmissiveis entre estas o cancer. Estima-se que um terco de todos os canceres pode ser prevenido pelo estilo de vida saudavel e dieta saudavel. AGPI n-3, em especial o acido graxo eicosapentaenoic...

  19. Phosphategypsum wastes in Venice lagoon. Radiological impact; Le discariche di fosfogessi nella laguna di Venezia. Valutazioni preliminari dell'impatto radiologico

    Energy Technology Data Exchange (ETDEWEB)

    Belli, M; Blasi, M; Guogang, J.; Rosamilia, S.; Sansone, U. [Agenzia Nazionale per la Protezione dell' Ambiente, Rome (Italy); Biancotto, R.; Bidoli, P.; Sepulcri, D. [Agenzia Regionale di Prevenzione e Protezione del Veneto, Venice (Italy). Dipt. provinciale di Venezia; Cavolo, F. [Smilax, Mira, VE (Italy)

    2000-07-01

    The phosphoric minerals utilized in phosphoric acid production, presents high concentrations of radioactive materials: U238, Th 232, K 40. The phosphogypsum is the waste material obtained in the phosphoric acid production in wet process. This type of production method is employed for many years in Venice lagoon (Porto Marghera chemical plants). In this paper are reported evaluations of radiological impact on aquatic environment of lagoon. [Italian] Con il termine di fosfogessi si intende comunemente il materiale di risulta che si ottiene nella produzione di acido fosforico attraverso la via umida (attacco acido). Questa tipologia di produzione che ha operato per diversi decenni a Porto Marghera, e' finalizzata allo scopo di ottenere acido fosforico principalmente per l'industria dei fertilizzanti e quindi come prodotto intermedio per la chimica e per le preparazioni alimentari. Il fosforo, elemento principale della reazione, era ricavato da rocce fosfatiche di origine sedimentaria marina provenienti per lo piu' dall'Africa settentrionale. Il sistema produttivo utilizzato negli impianti di Porto Marghera era basato su una reazione principale, che partendo dal minerale attraverso un attacco acido, produceva acido fosforico: Ca{sub 3}(PO{sub 4}){sub 2} (Minerale Fosforico) + 3H{sub 2}SO{sub 4} (Acido Solforico) + 3H{sub 2}O (Acqua) {yields} 2H{sub 3}PO{sub 4} (Acido fosforico) + 3CaSO{sub 4}H{sub 2}O (Solfato di calcio (gesso)). In particolare il minerale era preventivamente macinato e vagliato, quindi si procedeva alla sua miscelazione con l'acido fosforico ed alla successiva reazione del composto ottenuto.

  20. Alessandri_Buffer_rev1.xls

    OpenAIRE

    S. Alessandri

    2006-01-01

    Applicazione Excel per la simulazione delle caratteristiche chimiche di una miscela acquosa composta da un acido debole, un suo sale, un acido forte ed una base forte. L'applicazione produce risultati ottenuti con tre livelli di approssimazione, documentati e descritti, e la soluzione esatta degli equilibri in gioco. Il calcolo del pH all'equilibrio viene restituito in forma di piaccametro simulato.

  1. Use of probabilistic safety analysis for design of emergency mitigation systems in hydrogen producer plant with sulfur-iodine technology, Section II: sulfuric acid decomposition; Uso de analisis probabilistico de seguridad para el diseno de sistemas de mitigacion de emergencia en planta productora de hidrogeno con tecnologia azufre-iodo, Seccion II: descomposicion de acido sulfurico

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza A, A.; Nelson E, P. F.; Francois L, J. L. [Facultad de Ingenieria, Departamento de Sistemas Energeticos, UNAM, Paseo Cuauhnahuac 8532, 62550 Jiutepec, Morelos (Mexico)], e-mail: iqalexmdz@yahoo.com.mx

    2009-10-15

    Over the last decades, the need to reduce emissions of greenhouse gases has prompted the development of technologies for the production of clean fuels through the use of primary energy resources of zero emissions, as the heat of nuclear reactors of high temperature. Within these technologies, one of the most promising is the hydrogen production by sulfur-iodine cycle coupled to a high temperature reactor initially proposed by General Atomics. By their nature and because it will be large-scale plants, the development of these technologies from its present phase to its procurement and construction, will have to incorporate emergency mitigation systems in all its parts and interconnections to prevent undesired events that could put threaten the plant integrity and the nearby area. For the particular case of sulfur-iodine thermochemical cycle, most analysis have focused on hydrogen explosions and failures in the primary cooling systems. While these events are the most catastrophic, is that there are also many other events that even taking less direct consequences, could jeopardize the plant operation, the people safety of nearby communities and carry the same economic consequences. In this study we analyzed one of these events, which is the formation of a toxic cloud prompted by uncontrolled leakage of concentrated sulfuric acid in the second section of sulfur-iodine process of General Atomics. In this section, the sulfuric acid concentration is near to 90% in conditions of high temperature and positive pressure. Under these conditions the sulfuric acid and sulfur oxides from the reactor will form a toxic cloud that the have contact with the plant personnel could cause fatalities, or to reach a town would cause suffocation, respiratory problems and eye irritation. The methodology used for this study is the supported design in probabilistic safety analysis. Mitigation systems were postulated based on the isolation of a possible leak, the neutralization of a pond of sulfuric acid and finally washing the same; later some scenarios and modifications were analyzed to determine their impact on the likelihood of failure system and provide feedback design with the information produced in the probabilistic safety analysis. (Author)

  2. The speciation of products from the reaction of {sup 51} Cr(VI) with mineral acids by high efficiency liquid chromatography; Especiacao dos produtos da reacao entre {sup 51} Cr(VI) e acidos minerais por cromatografia liquida de alta eficiencia

    Energy Technology Data Exchange (ETDEWEB)

    Pezzin, Sergio H.; Collins, Carol H.; Collins, Kenneth E. [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica; Archundia, Cielita [Universidad Nacional Autonoma de Mexico, Mexico DF (Mexico). Inst. de Ciencias Nucleares

    1996-07-01

    The speciation of the products from the reaction of {sup 51} Cr(VI) with concentrated acids (HClO{sub 4}, HCl e HF) was carried out by ion chromatography. The separation was made on a Partisil SCX (10 {mu}m) column, using HClO{sub 4} and Ca(ClO{sub 4}){sub 2} solutions as eluents. The eluates were measured by {gamma}-counting. The results for the reaction (1h) of carrier-free {sup 51} Cr(VI) with HCl show that 96.4% from the {sup 51} Cr is not retained on the column (anionic and/or neutral species). A similar result (92.7% not retained) is observed in a Cr(VI)-HF system. However, for the reaction with HClO{sub 4}, 82% of the {sup 51} Cr was observed as a +3 species and only 5.9% as anionic and/or neutral species. (author)

  3. Synthesis of zeolites coal ash in surfactant modified in application and removal of orange 8 acid solution: study in batch, fixed bed column and evaluation ecotoxicological; Sintese de zeolitas de cinzas de carvao modificada por surfactante e aplicacao na remocao de acido laranja 8 de solucao aquosa: estudo em leito movel, coluna de leito fixo e avaliacao ecotoxicologica

    Energy Technology Data Exchange (ETDEWEB)

    Magdalena, Carina Pitwak

    2015-09-01

    In this study, synthesized zeolitic material from coal ash and modified cationic surfactant was used for removing the acid dye Orange 8 (AL8) by adsorption process using moving bed and fixed-bed column. The raw material and adsorbents were characterized by different techniques, such as X-ray diffraction, X-ray fluorescence spectroscopy, among others. The adsorption of AL8 was performed by moving bed in order to optimize the results when they are launched in a fixed bed. The effects of adsorption on zeolite AL8 were compared: (1) Effect of counterions Br{sup -} and Cl{sup -} surfactant used in the modification of the zeolite; (2) effect of type of coal ash used as raw material in the synthesis of zeolites (fly and bottom). The following adsorbents were used in the study: fly and bottom zeolite modified by surfactant hexadecyltrimethylammonium bromide (ZLMS-Br-Br and ZPMS-Br) and fly zeolite modified by surfactant hexadecyltrimethylammonium chloride (ZLMS-Cl). The pseudo-second-order kinetic described the adsorption of the dye on all adsorbents. The equilibrium time was reached 40, 60 and 120 min for ZLMS-Br, ZLMS-Cl and ZPMS-Br, respectively. The adsorption equilibrium was analyzed by the equations of the models of linear and nonlinear isotherms of Langmuir, Freundlich, Temkin and Dubinin- Radushkevivh (DR) and the criterion of best fit was evaluated using the error functions.The DR model was adjusted better to the experimental data for the system AL8 / ZLMS-Br, the Freundlich model for AL8 / ZLMS-Cl and Langmuir for AL8 / ZPMS. According to the Langmuir maximum adsorption capacity was 4.67, 1.48 and 1.38 mg g{sup -1} for ZLMS-Br, ZLMS-Cl and ZPMS-Br, in order. In studies employing fixed bed columns, the effects of inlet concentration (20- 30 mg L{sup -1}), flow rate (4.0 -5.3 mL min{sup -1}) and the bed height (5, 5 - 6.5 cm) above the breakthrough curves characteristics in the adsorption system were determined. The Adams-Bohart, Thomas, Yoon-Nelson models were applied to experimental data to predict the breakthrough curves and to determine the parameters that characterize the column. The mathematical models of Thomas and Yoon-Nelson adjusted well to the data of breakthrough curves. The highest bed capacity of 5.3 mg g{sup -1} was obtained using 30 mg L{sup -1} inlet Acid Orange 8 concentration, 5.5 cm bed height and 5.3 mL min{sup -1} flow rate. Acute ecotoxicity tests using Daphnia similis microcrustacean with wastewater (AL8) and after treatment with surfactant modified zeolite were carried out with the purpose of evaluating evidence of possible contamination when launched on the receiving water body. The results of this study showed that samples AL8 dye in aqueous solution does not show any toxic effect, and the treated samples showed toxicity with ZLMS-Br. (author)

  4. Electrocatalytical activity of Pt, SnO{sub 2} and RuO{sub 2} mixed electrodes for the electrooxidation of formic acid and formaldehyde; Atividade eletrocatalitica de eletrodos compostos por Pt, RuO{sub 2} e SnO{sub 2} para a eletrooxidacao de formaldeido e acido formico

    Energy Technology Data Exchange (ETDEWEB)

    Profeti, L.P.R.; Profeti, D.; Olivi, P. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Quimica

    2005-07-01

    The electrocatalytical activity of binary electrodes of Pt and SnO{sub 2} and ternary electrodes of Pt and SnO{sub 2} and RuO{sub 2} for the electrooxidation of formic acid and formaldehyde was investigated by cyclic voltammetry and chronoamperometry techniques. The electrode materials were prepared by the thermal decomposition of polymeric precursors at 400 deg C. The cyclic voltammetry results showed that the methanol electrooxidation process presents peak potentials for those electrodes approximately 100 mV lower than the values obtained for metallic platinum electrodes. The Pt{sub 0.6}Ru{sub 0.2}Sn{sub 0.2}O{sub y} electrodes presented the highest current density values for potentials lower than the peak potential values. The chronoamperometric experiments also showed that the addition of SnO{sub 2} and RuO{sub 2} contributed for the enhancement of the electrode activity in low potential values. The preparation method was found to be useful to obtain high active materials. (author)

  5. Utility of the dimercapto succinic acid pentavalent ({sup 99m} Tc- DMSA V) in the diagnostic of secondary bone leisure at metastasis of diverse primary tumours. Preliminary study; Utilidad del acido dimercapto succinico pentavalente ({sup 99m} Tc-DMSA V) en el diagnostico de lesiones oseas secundarias a metastasis de diversos tumores primarios. Estudio preliminar

    Energy Technology Data Exchange (ETDEWEB)

    Ortega L, N. [Hospital de Especialidades ' Dr. Antonio Fraga Mouret' Centro Medico Nacional ' La Raza' , IMSS Mexico D.F. (Mexico); Pichardo R, P.A. [Medico Nuclear adscrito al servicio de Medicina Nuclear del Hospital de Oncologia, Centro Medico Nacional Siglo XXI, IMSS, Mexico D.F. (Mexico); Marquez H, A. [Departamento de Medicina Nuclear, IMSS, Mexico D.F. (Mexico)

    2005-07-01

    The more used method in the diagnosis of secondary bone lesions to become cancerous it is by means of having derived of phosphates like it is the {sup 99m}Tc- MDP. The reason of acquiring searching with the radiopharmaceutical {sup 99m}Tc- DMSA V is with the purpose to find other bone lesions that are not visualized with the gammagraphy with diphosphonate and therefore to increase the specificity of the study. (Author)

  6. Optimization of labelling conditions of 15-p-iodophenyl pentadecanoic acid with {sup 123}I and its pharmacokinetics evaluation; Otimizacao das condicoes de marcacao do acido 15-p-iodo fenil pentadecanoico com {sup 123/131} I e sua avaliacao farmacocinetica

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Ione Caselato; Colturato, Maria Tereza; Araujo, Elaine Bortoleti de; Barbosa, Marycel Figols de; Muramoto, Emiko; Pereira, Nilda Petrona Sosa de; Silva, Constanca Pagano Goncalves da; Almeida, Maria Aparecida T.M. de [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1996-07-01

    The 15-p-iodo-phenyl pentadecanoic acid (IPPA) labelled with {sup 123} I is an important radiopharmaceutical for use in cardiology, due to its favorable physical characteristics and its labelling stability. The labelling procedure studies for the preparation of IPPA {sup 123/131} I was according to the procedures described by Dougan et col. The optimization of the labelling of the labelling condition and product stability were evaluated by radiochemical controls and by biological distribution study using animal models. (author)

  7. Teores de gordura e acidos graxos de clones de cacau nas condições do Vale do Ribeira (SP Fat and fatty acids content of cocoa clones under the conditions of Vale do Ribeira, State of São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Maria Luiza Sant'Anna Tucci

    1996-01-01

    Full Text Available O Estado de São Paulo é uma das regiões em que se cultiva o cacaueiro (Theobroma cacao L. mais afastadas do equador, com características climáticas distintas daquelas registradas nas regiões tradicionais de cultivo. A manteiga de cacau apresenta características físico-químicas peculiares, estreitamente relacionadas aos teores dos ácidos graxos que a constituem, os quais são influenciados pelas condições climáticas, especialmente a temperatura do ar. No presente trabalho, caracterizaram-se treze genótipos de cacau, da coleção do Instituto Agronômico, em Pariquera-Açu a 24°43' S, 47°53' W e 25 m de altitude, com base no teor de gordura e na composição em ácidos graxo. Os clones estudados foram os seguintes: SCA 6, SCA 12, IAC 1, ICS 39, ICS 60, ICS 95, UF29, UF 613, UF 667, UF 668, UF 677, P 7 e IMC 67. Houve diferenças significativas entre os clones quanto ao teor de gordura, que variou de 50,7%, para o ICS 95, a 57,6%, para o IAC 1. A composição de ácidos graxos diferiu significativamente entre os clones, exceto para o ácido araquídico. A relação entre ácidos graxos saturados e insaturados variou de 1,37 a 1,74: os clones SCA 12, SCA 6 e P 7 diferiram estatisticamente dos clones ICS 39, 60, 95, IMC 67 e UF 668.The State of São Paulo (Brazil represents the farthest region from the equator in which cocoa (Theobroma cacao L. is cultivated, with different climatic conditions from those observed in the traditional growing areas. Cocoa butter shows peculiar physical and chemical characteristics closely related to fatty acids balance, which are influenced by climatic conditions, mainly air temperature. This paper deals with the characterization of 13 clones of cocoa, growing in the State of São Paulo, based on fat content and fatty acid composition for the climatic conditions of Pariquera-Açu Experimental Station, at 24°43' S, 47°53' W and 25 m of altitude. The clones studied were: SCA 6, SCA 12, IAC 1, ICS 39, ICS 60, ICS 95, OF 29, OF 613, OF 667, OF 668, OF 677, P 7 e IMC 67. Significant differences were found for fat content, which varied from 50.7% for ICS 95 to 57.6% for IAC 1. Fatty acid composition differed significantly among the clones, except for araquidic acid. The saturated and unsaturated fatty acids ratio varied from 1.37 to 1.74, and the clones of SCA 12, SCA 6 and P 7 differed statistically for ICS 39, ICS 60, ICS 95, IMC 67 and OF 668 clones.

  8. Characterization and corrosion behavior of phytic acid coatings, obtained by chemical conversion on magnesium substrates in physiological solution; Caracterizacion y comportamiento frente a la corrosion de recubrimientos de acido fitico, obtenidos por conversion quimica, sobre substratos de magnesio en solucion fisiologica

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Alvarado, L. A.; Lomeli, M. A.; Hernandez, L. S.; Miranda, J. M.; Narvaez, L.; Diaz, I.; Garcia-Alonso, M. C.; Escudero, M. L.

    2014-10-01

    In order to improve the corrosion resistance of biodegradable magnesium and AZ31 magnesium alloy implants, a phytic acid coating has been applied on both substrates and their protective effect against corrosion has been assessed. The morphology and the chemical nature of the conversion coating were analyzed by SEM/EDX, XRD and FTIR. The spectra showed that the conversion coating was amorphous, and it was composed of Mg, O, and P on magnesium surface, along with Al, Zn and C on AZ31 alloy. The main coating components were chelate compounds formed by phytic acid and metallic ions. The corrosion resistance of bare and coated samples was evaluated by potentiodynamic polarization technique in Hank's solution at 37 degree centigrade. The results indicate that phytic acid conversion coatings provided a very effective protection to the magnesium substrates studied. (Author)

  9. Seguimiento de la producción del aroma del yogurt durante la fermentación acido láctica mediante nariz electrónica y evaluación sensorial / Monitoring aroma production of yogurt during lactic fermentation by electronic nose and sensory evaluation

    OpenAIRE

    Rúales Guzmán, Bertha Viviana

    2012-01-01

    El yogurt es una de las bebidas fermentadas más consumidas en el mundo por sus propiedades nutricionales, funcionales y sensoriales, por lo tanto la calidad final del producto será de gran importancia para satisfacer las necesidades del consumidor y obtener un posicionamiento en el mercado. El seguimiento de la fermentación es la clave para obtener todas estas propiedades, por tal razón, en la presente investigación se propuso el seguimiento de la producción de aroma como un método alternativ...

  10. Influence of the acid and basic properties of rhenium oxide supported on alumina catalyst on the catalytic performance in olefin metathesis; Influence des proprietes acido-basiques de l`oxyde de rhenium supporte sur les performances catalytiques en metathese des olefines

    Energy Technology Data Exchange (ETDEWEB)

    Nahama, F.

    1996-11-30

    The aim of this work is to study the influence of the acid-basic properties of rhenium oxide supported on alumina catalyst on the catalytic performance in olefin metathesis. The literature data indicate that the environment of the active site does possess acid properties. However, the nature of the acid sites is still matter of debate. Concerning the Re O{sub x} - Al{sub 2}O{sub 3} interactions, we have shown that perrhenate ions are electrostatically absorbed on alumina. The uptake of rhenium is favoured at acidic pH (below 4), and the absorbed rhenium is in equilibrium with rhenium in solution. The results of rhenium extraction by water strongly suggest that the surface compounds of the calcined Re{sub 2}O{sub 7}/Al{sub 2}O{sub 3} materials is aluminium perrhenate. Characterization of surface acidity of the catalyst by infrared spectroscopy reveals that the initiation of the metathesis reaction is governed essentially by Lewis acidity. This strongly supports the role of Lewis acidity, which is exalted by the increase of the rhenium content and the calcination temperature. Finally, we point out by ammonia adsorption-thermodesorption a band at 1320 cm{sup -1} characteristic of the Lewis acidity of aluminium perrhenate. This result is a second indication of the presence of aluminium perrhenate on the Re{sub 2}O{sub 7}/Al{sub 2}O{sub 3} catalyst surface. (author)

  11. Chemical recycling of post-consumer PET: structural characterization of terephthalic acid and the effect of Alkaline Hydrolysis at low temperature; Reciclagem quimica do PET pos-consumo: caracterizacao estrutural do acido tereftalico e efeito da hidrolise alcalina em baixa temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Talitha Granja; Almeida, Yeda Medeiros Bastos de; Vinhas, Gloria Maria, E-mail: gmvinhas@yahoo.com.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Engenharia Quimica

    2014-09-15

    Due to the environmental impact caused by PET packaging disposal, this material recycling has been thoroughly discussed and evaluated. In particular, chemical recycling enables achievement of the monomers that are used in PET resin manufacture: ethylene glycol (EG) and terephthalic acid (PTA). Therefore, studies for this process optimization are important from environmental and economic points of view. The present study investigated certain parameters that influence the depolymerization reaction of PET post-consumer via alkaline hydrolysis in order to obtain PTA. Assays were performed at 70 °C by varying the concentration of sodium hydroxide and the reaction time. The best results were obtained at 10.82 mol L{sup -1} NaOH and 9 h reaction time. Consequently, it was possible to prove this process viability, once analyses by infrared and nuclear magnetic resonance confirmed that PTA was obtained in all reactions performed. (author)

  12. Influence of method of preparation of Pt Ru/C electrocatalysts on the catalytic activity for the ethanol oxidation reaction in acidic medium; Influencia do metodo de preparacao de eletrocatalisadores PtRu/C sobre a atividade catalitica frente a reacao de oxidacao de etanol em meio acido

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Walber dos Santos; Silva, Uriel Lean Valente; Souza, Jose Pio Iudice de, E-mail: jpio@ufpa.br [Universidade Federal do Para, (UFPA), Belem, PA (Brazil). Instituto de Ciencias Exatas e Naturais. Faculdade de Quimica

    2013-09-01

    In this work the influence of variations in the borohydrate reduction method on the properties of Pt Ru/C electrocatalysts was investigated. The electrocatalysts were prepared using 1:1 ; 2:1; 5:1; 50:1 and 250:1 molar ratios of NaBH{sub 4} to metals. The reduction was also performed by dripping or by fast addition of the solution. The results showed that Pt Ru nanoparticles obtained by fast addition had the smallest crystallite sizes. It was also noted that the catalytic activity increased as the borohydrate:metal molar ratio increased. The Pt Ru/C electrocatalysts (50:1) obtained by fast addition presented the best catalytic activity for ethanol electro-oxidation. (author)

  13. Efectividad del Acido Peracético sobre la reducción de la carga de Esporas de Mohos causantes de Pudrición Poscosecha de Frutas y Hortalizas Effectiveness of Peracetic Acid on fungal Spores reduction of Moulds causing rotting in Fruits and Vegetables

    Directory of Open Access Journals (Sweden)

    María V Kyanko

    2010-01-01

    Full Text Available Se evaluó in vitro la efectividad del ácido peracético sobre la reducción de la carga de esporas de mohos micotoxicogénicos causantes de pudrición de frutas y hortalizas, para determinar su potencial aplicación al control poscosecha de esta patología. Se evaluó tres concentraciones de ácido (0.05%, 0.1 % y 0.3% para determinar su capacidad antifúngica frente a Alternaria alternata, Fusarium graminearum, Aspergillus ochraceus, A. níger, A. flavus, Penicillium roqueforti y P. expansum. Se observó una reducción de la carga de esporas aún a la más baja concentración ensayada, efecto que incrementó con el aumento de la concentración del tratamiento. A una concentración del 0.3 % se logró una mucho mayor reducción de la carga de esporas viables de A. alternata, F. graminearum y A. ochraceus, respectivamente. El ácido peracético podría resultar una alternativa de tratamiento no contaminante para el control poscosecha de la pudrición fúngica.The objective of this work was to determine in vitro the effectiveness of peracetic acid on the load reduction of mould spores that are responsible for rotting in fruits and vegetables to evaluate its potential application to post-harvest control. Three concentrations of peracetic acid (0.05%, 0.1% and 0.3% were used to evaluate its anti-fungal capacity against Alternaria Alternata, Fusarium graminearum, Aspergillus ochraceus, A. niger, A. flavus, Penicillium roqueforti and P. expansum. It was observed reduction of the load of spores using the lowest concentration. This effect was increased with a higher concentration of peracetic acid. It was extremely effective at a concentration of 0.3% against A. alternata, F. graminearum and A. ochraceus. It is concluded that the peracetic acid is a nonpolluting alternative treatment for post-harvest rotting control of fruits and vegetables

  14. Assessment of micro, macro, toxic elements (Cd, Hg, Pb) and fatty acids profile in consumed fish commercially available in Cananeia and Cubatao, Sao Paulo State; Avaliacao de micro e macroelementos, elementos toxicos (Cd, Hg e Pb) e acidos graxos, em peixes disponiveis comercialmente para consumo em Cananeia e Cubatao, Estado de Sao Paulo

    Energy Technology Data Exchange (ETDEWEB)

    Curcho, Michel Rodrigues da Silva Morales

    2009-07-01

    Aside from their nutritional importance, fish are considered one of the most important bio indicators in aquatic systems for the estimation of pollution levels by toxic metals. This is so, since fish can bio accumulate these elements and they occupy different trophic levels and present different sizes and age. The purpose of the present study was to contribute with important data for the knowledge of nutritional and toxic constituents in muscles of the most consumed fish species from two coastal regions, Cananeia and Cubatao. Cananeia fish species analyzed were: Micropogonias furnieri (Corvina), Macrodon ancylodon (Pescada), Centropomus undecimalis (Robalo peba) and Mugil platanus (Tainha). From Cubatao, Micropogonias furnieri (Corvina), Macrodon ancylodon (Pescada), Menticirrhus americanus (Perna de moca), Sardella braziliensis (Sardinha) and Mugil liza (Tainha). For this study, analytical methodologies were developed and validated, regarding precision and accuracy, by means of certified reference materials. Micronutrients (Ca, Fe, K, Na, Se and Zn) and some trace elements (As, Br, Co, Cr, Rb) in fish muscle were determined by means of neutron activation analysis (NAA). Cold Vapor Atomic Absorption Spectrometry (CV AAS) was used for total Hg determination and Electrothermal Atomic Absorption Spectrometry (ET AAS) for Cd and Pb determinations. Proximate composition determinations according to AOAC methodologies and fatty acids profiles by gas chromatography were done in these muscle fish samples. Regarding fatty acids profile from the {omega}-6 family, Tainha species pool presented the highest values (8.9%) and Pescada species pool the lowest ones (4.4%) for Cananeia species. Fatty acids from the {omega}-3 family, Sardinha pool species presented the highest values (31.8%) for all species analyzed. Regarding micronutrients content great concentration variations between individual of the same species and between different species were observed. Discriminate analysis was used for the values for micronutrient content for all fish species analyzed in order to identify samples of similar chemical composition and respective food habits. Concerning populational risk to toxic elements exposure, in this case As and Hg, it was possible to conclude that Corvina and Pescada from Cananeia and Corvina, Sardinha and Tainha from Cubatao presented the highest values for As exceeding the Brazilian legislation limits for this contaminant. For Hg, all the species analyzed did not exceed the Brazilian legislation limits for predatory and non predatory species. Results from this study also suggest that Corvina species can be used as a bioindicator since this species bioaccumulate metals and remains in the estuary until it reaches adulthood. Thus, Corvina can be considered as a good indicator of the conditions of the coastal region where it inhabits. (author)

  15. Study of conformational and acid-base properties of norbadione A and pulvinic derivatives: Consequences on their complexation properties of alkaline and alkaline earth cations; Etude des proprietes conformationnelles et acido-basiques de la norbadione A et de derives pulviniques: consequences sur leurs proprietes complexantes de cations alcalins et alcalino-terreux

    Energy Technology Data Exchange (ETDEWEB)

    Kuad, P

    2006-01-15

    This work deals with the study of norbadione A, a pigment extracted from mushrooms and known to complex cesium cations. The study of the acid-base properties of norbadione A has allowed to determine the relative acidity of the seven protonable functions of the molecule and to reveal a reversible isomerization of the double exocyclic bond of the pulvinic moieties. The observed change of configuration is induced by a hydrogen bond of the H-O-H type and by electrostatic interactions. Moreover, the microscopic protonation mechanism of the norbadione A has been analyzed, considering three different study media where the acid-base properties of the norbadione A are compared. In the presence of 0.15 mol.l{sup -1} of NaCl, it has been observed a remarkable cooperativity in the protonation of the enol groups. At last, the use of different analytical methods (NMR, potentiometry and calorimetry) has allowed to study the complexing properties of the norbadione A towards cesium and other alkaline and rare earth cations. (O.M.)

  16. Evaluation of mitomycin-C effect on biodistribution of {sup 99m}Tc-dimercaptosuccinic acid in BALB/C mice; Avaliacao do efeito da mitomicina-c na biodistribuicao do radiofarmaco acido dimercaptosuccinico marcado com tecnecio-99m em camundongos BALB/C

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Maria Luisa; Britto, Deise Mara de M.; Freitas, Rosimeire de S.; Bernardo-Filho, Mario [Instituto Nacional do Cancer, Rio de Janeiro, RJ (Brazil). Centro de Pesquisa Basica; Braga, Ana Cristina de S.; Bezerra, Roberto Jose A.C. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Biologia Roberto Alcantara Gomes. Dept. de Biofisica e Biometria

    1999-11-01

    The many desirable characteristics of technetium-99m have stimulated the development of labeling techniques for different molecular and cellular structures. It is accepted that a variety of factors such the drug chemotherapy can alter the biodistribution of radiopharmaceuticals. The unknowledge of these factor may result in an unexpected behavior of the radiopharmaceuticals. Since patients on chemotherapeutic treatment can be submitted to a nuclear medicine procedure, we have studied in mice, the effect of mitomycin-C on the {sup 99m} Tc-DMSA used for kidney scintigraphy. Mitomycin-C is an antineoplastic agent obtained from Streptomyces caesptosus. The metabolism of this drug produces different toxic and inactive metabolites. Mitomycin-C 0.15 mg was administered in Balb/c female with an interval of 72 hours. After one hour of the last dose, 0.3 ml of 9{sup 9m}c-DMSA (7.4 MBq) were injected and after 0.5 h the animals were sacrificed. The organs were isolated and counted in a well counter. The percentage of radioactivity (%ATI) were calculated and statistical analysis were performed (Wilcoxon Test). The results have shown that the %ATI: has increased in stomach and uterus, has decreased in kidney and ovary; has not altered in pancreas, spleen, lung, heart, liver, thymus, thyroid, bone and brain. The increase of % ATI could be justified by the metabolic process or the therapeutical effect of mitomycin-C. As an effect of this drug is observed in the uptake of the {sup 99m} Tc-DMSA by the kidney, probably an alteration in the kidney scintigraphy is expected. However, the increase of %ATI of this radiopharmaceutical in other organs by the mitomycin-C could be evaluated carefully. (author) 12 ref., 2 tabs.

  17. Evolution evidence of a basic fluid to an acid based in the analysis of hydrothermal alteration of the geothermic field of the Azufres, Michoacan; Evidencias de evolucion de un fluido basico a acido a partir del analisis de la alteracion hidrotermal del campo geotermico de los Azufres, Michoacan

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Partida, Eduardo [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2000-07-01

    Hydrothermal alteration at the Los Azufres geothermal field is mostly composed of calc-silicate minerals that define a propylitic alteration zone, which shows progressive dehydration with depth and temperature increase. A generalized zoning of the calc-silicate zone can be observed, with zeolites in the upper part and epidote-clinozoisite at the deepest levels. An argillic alteration zone overlies the calc-silicate zone and is the dominant surface manifestation of the hydrothermal alteration. In some parts, there is a mineral assemblage composed of kaolinite-alunite-native sulfur-quartz (advanced argillic zone) formed by the interaction of vapor and shallow groundwater. The proto-fluid at the Los Azufres geothermal system is related to a neutral sodium chlorine brine, which favors deep propyllitic alteration (productive zone). This zone is characterized by secondary permeability due to fracturing. At depth the geothermal field is dominated by a pressurized liquid, yielding to vapor at more shallow zone. The gradual change from a liquid to a vapor phase occurs through boiling at depths between 1,200 and 1,500 m, and is accompanied by changes in the hydrothermal alteration mineralogy. The type of alteration passes from proylitic to argillic by means of an oxidation-acidification process, which includes the participation of a gas, particularly CO{sub 2}. Considering the physicochemical characteristic of the brine and the evolution of the paragenetic sequence, the Los Azufres geothermal field could de considered a model for hydrothermal behavior at ore deposits which develop by boiling and oxidation of low sulfidation fossil hydrothermal fluids. [Spanish] En el campo geotermico de Los Azufres la zona de alteracion hidrotermal esta formada en su mayor parte por calcosilicatos (que definen una zona paragenetica del tipo propilitico), los cuales muestran una deshidratacion progresiva conforme se va profundizando e incrementandose la temperatura. Se puede generalizar un zoneamiento evolutivo para los calcosilicatos predominando las zeolitas hacia la cima y la epidota-clinozoicita en los niveles mas profundos. Le sobreyace una zona de argilitizacion que domina las manifestaciones hidrotermales superficiales. En algunas zonas, se tiene la asociacion caolinita-alunita-azufre nativo-cuarzo (zona argilica avanzada) formada por la interaccion vapor-acuifero someros. En el sistema geotermico de Los Azufres el protofluido esta ligado a una salmuera clorurado-sodica de caracter neutro que propicia una alteracion hidrotermal propilitica profunda (zona productoras) y se caracteriza por tener una permeabilidad secundaria debido al fracturamiento. A profundiad el yacimiento es a liquido dominante presurizado para evolucionar a vapor en su parte mas somera. El cambio gradual de la fase liquida a vapor se da por ebullicion a profundidades del orden de 1,200 a 1,500 m, y esta acompanado por cambios igualmente presentes en la mineralogia de alteracion hidrotermal. Ella pasa de propilitica a argilica por un proceso de oxidacion-acidificacion, en donde la participacion de gases, principalmente de CO{sub 2}, es importante. De acuerdo a las caracteristicas fisicoquimicas de la salmuera y la evolucion en las fases parageneticas, el yacimiento de Los Azufres pudiera ser un modelo de comportamiento hidrotermal en el deposito de las menas que se dan por ebullicion y oxidacion de los fluidos hidrotermales fosiles de baja sulfidacion.

  18. Preparation of manganese salts of carboxylic acids labelled with ''54Mn and comparison with ''54 MnCl{sub 2} in liquid scintillation counting; Preparacion de sales manganosas de acidos alifaticos monocarboxilicos marcados con ''54 MnCl{sub 2} en medidas por centelleo liquido

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Barquero, L.; Arcos Merino, J. M. los; Grau Malonda, A.

    1992-07-01

    Procedures for liquid scintillation sample preparation of manganese dimethylbutirate, decanoate and palmitate, labelled with 54 Mn are described. their quenching effect, spectral evolution and counting stability along several weeks are analysed in liquid scintillation measurements with Toluene. HISafe II. PCS, instagel. Dioxane-naphtalene and Toluene-alcohol. For comparison, Inorganic 54 MnCl-2 samples are also studied, resulting in acceptable counting stability but showing greater quenching and signs of little spectral degradation against the organic samples. (Author)

  19. Characterization of ZrP{sub 2}O{sub 7} modified with oxalic acid and thermodynamic analysis associated to the uranyl (Vi) sorption; Caracterizacion de ZrP{sub 2}O{sub 7} modificado con acido oxalico y analisis termodinamico asociado a la sorcion de uranilo (VI)

    Energy Technology Data Exchange (ETDEWEB)

    Garcia G, N.; Ordonez R, E. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Solis C, D. A. [Universidad Autonoma del Estado de Mexico, Facultad de Quimica, Paseo Colon y Paseo Tollocan, 50120 Toluca, Estado de Mexico (Mexico); Simoni, E.; Drot, R.; Jeanson, A., E-mail: eduardo.ordonez@inin.gob.mx [Universite Paris-Sud, Institut de Physique Nucleaire, Georges Clemenceau No. 15, Orsay (France)

    2013-10-15

    Several physical and chemical tests were carried out to evaluate the influence of the oxalic acid in the uranium (Vi) sorption on the surface of the zirconium diphosphate. The physical analyses consist of atomic force microscopy (AFM) and total organic coal, and the chemists are the calculation of the reaction heat for the hydrate and sorption processes, the reaction speed constant and the sorption yield in the sodium perchlorate systems and of oxalic acid; these tests allow to corroborate that the oxalic acid influences positively in the uranium (Vi) sorption forming a ternary system of ZrP{sub 2}O{sub 7}/(C{sub 2}O{sub 4})/U(Vi), with a single configuration along the ph interval studied. (Author)

  20. Oxidizing gel formulation for nuclear decontamination: rheological and acidic properties of the organic matrix and its ozonolysis; Formulation d'un gel oxydant a matrice organique applicable a la decontamination nucleaire: proprietes rheologiques, acido-basiques et ozonolyse de la matrice

    Energy Technology Data Exchange (ETDEWEB)

    Rouy, E

    2003-10-15

    An acidic and oxidizing gel was formulated with a purely organic matrix, xanthan gum, at low concentrations (1 to 2 wt %). This polymer gel was investigated in various media (aqueous, acidic and ceric) by means of rheology: shear thinning behaviour, thixotropy, yield stress... Evidences of unexpected rheological properties in highly concentrated media show that xanthan is quite convenient for industrial projection of this type of gel on metallic walls in nuclear plants, notwithstanding its time-limited resistance to oxidation (about a few hours). Complexation mechanisms between ceric species and polar sites of the polymer led us to characterise acidic properties of our xanthan sample by potentiometric titration and {sup 1}H NMR techniques. The matrix was finally treated by ozonolysis to suppress organic residues, as required to handle nuclear wastes. In acidic medium, ozonolysis of the gel was achieved successfully while in acidic and ceric medium this process showed limited efficiency, needing further investigation to be clarified. (author)

  1. Crystallochemical study of amides derived from 6{alpha}, 7{beta}-diidroxivoacapan-17{beta}-oic acid by X-ray diffraction; Estudo cristaloquimico de amidas derivadas do acido 6{alpha}, 7{beta}-di- hidroxivouacapan-17 {beta}-oico por difracao de raios-X

    Energy Technology Data Exchange (ETDEWEB)

    Branco, Marcello Cardoso; Prado Gambardella, Maria Teresa do [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Quimica. Dept. de Quimica e Fisica Molecular

    1995-12-31

    Abstract. The 6{alpha}, 7{beta}-diidroxivoacapan-17{beta}-oic acid (DVA) is a Furane-diterpene isolated from Peterodon genus. It has anti inflammatory and analgesic properties. The purpose of this work is the characterization of amides derived from DVA, in order to understand the relationship between Chemical Structure and Biological Activity of Vouacapanes. The structures of DVA derivatives will be solved by single-crystal X-ray diffraction. (author) 15 refs., 2 figs.

  2. Crystallochemical study of esters derived from 6{alpha}, 7{beta}-diidroxivouacapan-17{beta}-oic acid by x-ray diffraction; Estudo cristaloquimico de esteres derivados do acido 6{alpha}, 6{beta}-di-hidroxivouacapan-17{beta}-oico por difracao de raios-X

    Energy Technology Data Exchange (ETDEWEB)

    Abrahao Junior, Odonirio [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Quimica

    1995-12-31

    The 6{alpha}, 7{beta}-diidroxivoacapan-17{beta}-oic acid (DVA) is a Furane-diterpene isolated from Peterodon genus. It has anti-inflammatory and analgesic properties. The purpose of this work is the characterisation by x-ray single crystal diffraction technique of esters derived from DVA, to understand the relationship between chemical structure and biological activity of vouacapanes. (author) 15 refs.

  3. Comparison of the efficacy of carbamazepine, haloperidol and valproic acid in the treatment of children with Sydenham´s chorea: clinical follow-up of 18 patients Comparación de la eficacia de carbamazepina, haloperidol y acido valproico en el tratamiento de niños con corea de Sydenham: seguimiento clínico de 18 pacientes

    Directory of Open Access Journals (Sweden)

    Joaquín Peña

    2002-06-01

    Full Text Available In order to compare and contrast the efficacy of haloperidol, carbamazepine, and valproic acid in the treatment of Sydenham´s chorea a prospective study including 18 cases of this disorder was undertaken. Age of patients ranged from 7 to 15 years. Ten children were female and 8 were male. All but one had generalized, either symmetric or asymmetric chorea. The patients were divided in three equal groups, and were given a standardized dose of each of the drugs built-up over a week. Following therapy, the six children receiving valproic acid showed remarkable improvement, without side effects. Five patients receiving carbamazepine showed improvement without side effects. Only three of the patients that received haloperidol improved. In the 4 cases that did not show clinical improvement after one week of treatment, therapy with valproic acid led to disappearance of the symptoms in a lapse that ranged from 4 to 7 days. Recurrence related to discontinuation of treatment was observed in two patients. In view of the present results we recommend valproic acid as the first choice drug to treat Sydenham chorea.A fin de comparar y contrastar la eficacia de haloperidol, carbamazepina y ácido valproico en el tratamiento de la corea de Sydenham, se realizó un estudio prospectivo que incluyó 18 casos de esta patología. La edad de los pacientes varió de 7 a 15 años. Diez de los niños eran varones y el resto hembras. A excepción de uno de ellos, todos tenían corea generalizada, simétrica ó asimétrica. Los pacientes fueron divididos en tres grupos iguales, a cada uno de los cuales se le administró una dosis estandarizada de los medicamentos mencionados durante una semana. Luego del tratamiento, los seis pacientes que recibieron ácido valproico mostraron mejoría notable sin efectos colaterales. Cinco de los seis pacientes que recibieron carbamazepina exhibieron mejoría sin efectos colaterales. Solo tres de los pacientes que recibieron haloperidol mejoraron. En los cuatro casos que luego de recibir estas dos últimas drogas sin experimentar mejoría clínica luego de una semana, se instaló terapia con ácido valproico, lo que llevó a desaparición de la sintomatología en un lapso de 4 a 7 días. Se observó recaída relacionada con tratamiento discontinuado en dos de los pacientes. A la vista de nuestros resultados, recomendamos el ácido valproico como droga de primera elección en el tratamiento de la corea de Sydenham.

  4. Estabilidad de un análogo de capsaicina : Efecto del pH sobre la reacción de descomposición térrnica de vainillilamida del acido pelargónico (N-[4-hidroxi-3-metoxifenil-metil] nonanamida) en solución hidroalcohólica

    OpenAIRE

    Matias, Rossana L.; Sein, Gustavo O.; González, Miriam; Mandrile, Eloy L.; Cafferata, Lázaro F.R.

    1998-01-01

    La vainillilamida del ácido pelargónico ("capsaicina sintética"), un análogo del compuesto natural N[{4-hidroxi-3-metoxifenil)-metil]-8-metil-(E)-6-nonenamida), es hidrolizada rápidamente en soluciones metanólicas acuosas con valores de pH de 6,O, 8,5 y 10,5 y en un ámbito de temperaturas comprendido entre 50ºC y 100ºC. El análisis cualitativo de los principales productos de la reacción fue realizado utilizando CG-EM. La cinética de la reacción, medida utilizando espectroscopía ultra- violeta...

  5. Radiomimeticity of the system H{sub 2}O{sub 2}/Fe(II) on nucleic acid components. Kinetics study; Radiomimeticidad del sistema H{sub 2}O{sub 2}/Fe(II) sobre components de Acidos Nucleicos. Estudio Cinetico

    Energy Technology Data Exchange (ETDEWEB)

    Cirauqui, R.; Mingot, F.; Davila, C. A.

    1974-07-01

    The kinetic study of the action of a redox system on DNA monomers allowed us to make criticisms on radiomimetic character of this system. Assuming that in both cases, gamma radiolysis of aerated aqueous solutions and action of H{sub 2}O{sub 2} / Fe(II) system in the same conditions, the reactive species is the OH radical, we propose the kinetic expressions that are confirmed by our experimental results. Some of the accepted G-values are corrected in view of our results. Al so these results put in evidence mechanisms of molecular repair after radical attack. (Author) 79 refs.

  6. Polarographic study of the Cu(II)/Cu(I) system in the presence of 1-ascorbic acid and 0,1 M ClK; Estudio polarografico del sistema Cu(II)/Cu(I) en presencia del acido 1-ascorbico y en ClK 0,1 M

    Energy Technology Data Exchange (ETDEWEB)

    Alonso Lopez, J.

    1969-07-01

    While studying the catalytic effect of Cu{sup {down_arrow}}2 ions on the oxidation process of 1-ascorbic acid, it has been observed that, in a 0,1 M solution of K1 at a pH 6 to 7, the above acid gives rise in the presence of Cu{sup {down_arrow}}2 ions to a polarographic wave of half-wave potential of -0,41 V (vs. S.C.E.). (Author) 14 refs.

  7. Determination of the extractive capacity of para-tert butyl calix[8]arene octa-phosphinoylated towards uranyl ions from an aqueous-acidic-salty medium; Determinacion de la capacidad extractiva del p-ter-butilocalix[8]areno octa-fosfinoilado hacia iones uranilo de un medio acuo-acido salino

    Energy Technology Data Exchange (ETDEWEB)

    Serrano V, E. C.

    2011-07-01

    The extraction properties of octa-phosphinoylated para-tert butyl calix[8]arene (prepared in the laboratory) in chloroform towards uranyl ions from an aqueous-acidic-salty medium (HNO{sub 3}-3.5 NaNO{sub 3}) containing uranyl nitrate salt, was investigated. Two spectroscopic techniques UV/Vis and Luminescence were used for this study. The latter permitted analyze the fluorescence from the uranyl ions influenced by the surrounding medium. Both permitted to learn about the power of this calixarene as extractant towards the mentioned ions. Its extraction ability or capability using this calixarene at 5.91 x 10{sup -4} M towards the uranyl ions was 400% as determined by UV/Vis while fluorescence revealed 100% of uranyl ion extraction. A closed analysis of the results obtained by using these techniques revealed that the stoichiometry of the main extracted species was 1calixarene:2 uranyl ions. The loading capacity of the calixarene ligand towards the uranyl ions was also investigated using both techniques. UV/Vis resulted to be inadequate for quantifying exactly the loading capacity of the calixarene whereas luminescence was excellent indeed, using a 5.91 x 10{sup -4} M calixarene concentration, its loading capacity was 0.157 M of free uranyl ions from 0.161 M of uranyl ions present in the aqueous-acidic-salty medium. The extracts from the ability and capacity studies were concentrated to dryness, purified and the dried extracts were analyzed by infrared and neutron activation analysis. By these techniques it was demonstrated that during the extraction of the uranyl ions by the calixarene ligand they form thermodynamically and kinetically stable complexes, since in the solid state, the 1:2, calixarene; uranyl ions stoichiometry was kept with the minimum formula: (UO{sub 2}){sub 2}B{sub 8}bL{sup 8}(NO{sub 3}){sub 4}(H{sub 2}O){sub 4}CHCl{sub 3}(CH{sub 3}OH){sub 3} the methanol molecules come from its purification. It is proposed that B{sub 8}bL{sup 8} calixarene in chloroform medium is a good extractant for the treatment of nuclear wastes or radioactive wastes containing uranium in a rich aqueous-acidic-salty medium. (Author)

  8. Usefulness of the dimercapto succinic pentavalent acid ({sup 99m} Tc- Dmsa-V) in the diagnostic of the bone metastases illness; Utilidad del acido dimercapto succinico pentavalente ({sup 99m} Tc- DMSA-V) en el diagnostico de la enfermedad osea metastasica

    Energy Technology Data Exchange (ETDEWEB)

    Ortega L, N

    2005-07-01

    The objective of this study was to determine the utility of {sup 99m} Tc-(V)- Dmsa whole body planar scan in the diagnostic of skeletal metastases. Nineteen patients were studied, having a recent {sup 99m} Tc-HDP bone scan reporting different pathologies (3 normal scans, 5 equivocal scans and 11 with disseminated bone metastases). 72 hours later, a whole body planar scan was obtained at 3 and 24 hours after the i.v. administration of {sup 99m} Tc-(V)-Dmsa. Counts per pixel were determined in regions of interest drawn over metastases sites and in normal tissue, and were correlated with the bone scan. Statistical analysis was carried out by using the Kruskal-Wallis analysis of variance followed by Mann Whitney U test. Other comparisons were done with Momios, chi square and t Student tests. 273 lesions were studied in the whole body bone scan and 184 lesions in the {sup 99m} Tc-(V)-Dmsa scintigraphy (t Student test n.s.). The tumor to normal tissue ratios were 3.3 (+/- 0.521) and the soft to normal tissue ratios were 1.01 (+/- 0.01), Mann Whitney p< 0.01. The study sensitivity was 92% an overall specificity was 97%. As conclusions we have that {sup 99m} Tc-(V)-Dmsa scintigraphy is an useful choice in the diagnostic of bone metastases when the whole body planar bone scan ({sup 99m} Tc- HDP) is equivocal or abnormal. It also points out other lesions such as in bone and in soft tissue. (Author)

  9. The sealing of second mandibular temporary molar pits and fissure with the laser of Nd: YAG, phosphoric acid and the glass ionomer cement; Selamento de fossulas e fissura de segundo molar deciduo inferior com laser de Nd: YAG, acido fosforico e cimento de ionomero de vidro

    Energy Technology Data Exchange (ETDEWEB)

    Toda, Maria Aparecida

    2003-07-01

    The main of our study was to check the sealing of second mandibular temporary molar pits and fissure, in vitro, with the laser of Nd: YAG, phosphoric acid at 37% and the glass ionomer cement (CIV, Fuji IX GC).The proposal was to check the structural morphologic changes in the laser irradiation upon the enamel surface to watch the pits and fissure sealing with the glass ionomer cement use after the laser irradiation and to verify the efficiency of the 'double conditioning' (phosphoric acid + Nd: YAG). At the same time we watch the evolution of the temperature in the pulp chamber's inside. Our desire was to achieve a therapeutic alternative technic to prevent the dental caries. The Nd: YAG laser parameters were the same: 79 mJ of energy per pulse; frequency of 5 Hz; mean power of 0,4 W; optical fiber on contact of 320 {mu}m diameter; fluency of 99,52 J/ cm{sup 2}, assuming that the only differential was the time of the laser application on the enamel surface. The samples were prepared with this way: Laser Nd: YAG (53 second) + acid + CIV (Fuji IX); Laser Nd: YAG (53 s); Laser Nd: YAG (20 s + 20 s) + acid + CIV; Laser Nd: YAG (20 s + 20 s); Acid + CIV; Control. Through the scanning electron microscopy (MEV) we noticed fusion and resolidification regions due to the laser irradiation and a better adaptation of the glass ionomer cement when we did the 'double conditioning'. Concerning the temperature increase we can conclude that the echeloned period was the best recommended because the temperature was found in a pattern that would not cause any damage to the dental pulp. For future studies we suggest a longer relaxing time between the laser irradiation, a comparative study of this method with other lasers, the use of other sealing materials and the study with the permanent teeth. (author)

  10. Study of the temperature influence during the uranium (Vi) sorption on surface of ZrP{sub 2}O{sub 7} in presence of oxalic and salicylic acid; Estudio de la influencia de la temperatura durante la sorcion de uranio (VI) en la superficie del ZrP{sub 2}O{sub 7} en presencia de acidos oxalico y salicilico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia G, N.

    2013-07-01

    This work studies the effect of temperature on the uranium (Vi) sorption onto zirconium diphosphate in the presence of organic acids (oxalic and salicylic acids). Zirconium diphosphate was synthesized by a chemical condensation reaction and characterized using several analytical techniques, in order to check its purity. This point is very important because the presence of any impurities or secondary phases may interfere with the hydration and sorption process. Prior to the sorption experiments, three batches of zirconium diphosphate were pre-equilibrated with NaClO{sub 4}, oxalic acid or salicylic acid solutions. The hydrated solids were washed and dried and then again characterized in order to study the interactions between organic acids and zirconium diphosphate surface. Uranium sorption onto zirconium diphosphate (pre-equilibrated with NaClO{sub 4}, oxalic acid and salicylic acid solutions) was investigated as a function of ph, organic acid and temperature (20, 40 y 60 grades C). Thermodynamic parameters for the sorption reactions (enthalpy change, entropy change and Gibbs free energy change) were determined from temperature dependence of distribution coefficient by using the Vant Hoff equation. Solids characterization after hydration shows that exist an interaction between organic acids and ZrP{sub 2}O{sub 7}. This fact was confirmed with the microcalorimetry study, the reaction heat for hydration of zirconium diphosphate in NaClO{sub 4} solution was exothermic (-269.59 mJ) and for hydration of zirconium diphosphate in oxalic acid solution was endothermic (53.64 mJ). The experimental results showed important differences in the sorption mechanisms for the reaction of Uranium with ZrP{sub 2}O{sub 7} in the presence and absence of organic acids. For the zirconium diphosphate hydrated with oxalic acid, the sorption percentage was 50% from lowest ph values. For the zirconium diphosphate hydrated with salicylic acid, the initial concentration of uranium was 6 x 10{sup -4} M and a percentage of 10% was observed in the initial reaction and it reached 100% at ph 5.5. A similar behavior was observed for the zirconium diphosphate hydrated with NaClO{sub 4}, but the initial concentration of uranium was 5 x 10{sup -4} M. The temperature had an important effect on the sorption of uranium onto ZrP{sub 2}O{sub 7}. The reaction of uranium with the solid hydrated with NaClO{sub 4} was exothermic from 20 to 60 grades C, and the reaction with the solid hydrated with organic acids was exothermic from 20 to 40 grades C and endothermic from 40 to 60 grades C. In conclusion, the thermodynamic study indicated that the sorption process was activated chemisorption s. (Author)

  11. Innovation in sodium erythorbate production. The use of membrane-reactors

    Energy Technology Data Exchange (ETDEWEB)

    Spigno, G. [Piacenza Univ. Cattolica del S. Cuore, Piacenza (Italy). Ist. di Enologia e Ingegneria Alimentare

    2001-04-01

    Isoascorbic or erythorbic acid is a stereoisomer of ascorbic acid acting as a preservative against oxidation and decoloration, recently approved for food use also in the European Market. Actually erythorbate is produced by means of a complex and long process after bio-fermentation of dextrose. In order to simplify and improve this process a membrane system was conceived able to induce acid 2-ketogluconic diffusion from fermentation broth directly into methanol where it esterficates. Acid 2-ketogluconic methyl ester is the intermediate for erythorbic acid. The principal problem was to perfectly separate water methanol to avoid saponification instead of esterification. [Italian] L'acido eritorbico o isoascorbico, recentemente approvato per uso alimentare anche in Europa, e' uno stereoisomero dell'acido ascorbico e agisce come antiossidante e preservante del colore. Attualmente viene prodotto con un complicato processo dopo fermentazione del destrosio. Per semplificare e migliorare questo processo, e' stato studiato un sistema a membrane in grado di trasferire direttamente l'acido 2-chetogluconico dal brodo di fermentazione al metanolo, dove esterifica. L'estere metilico dell'acido 2-chetogluconico e' l'intermedio dell'acido eritorbico. Il problema maggiore era quello di mantenere separati l'acqua ed il metanolo, per evitare la saponificazione al posto della esterificazione.

  12. Regeneracion adventicia de somaclones de uchuva (physalis peruviana)

    OpenAIRE

    Santana, Gloria E.; Angarita, Antonio

    2011-01-01

    Hipocoti1os de uchuva (Physalis peruvjana L.) fueron utilizados en la inducción de callos y regeneración de plántulas. El medio basal de Murashige y Skoog (MS) fue suplementado con bencil amino purina (BAP) de 0 a 5,0 ppm, acido giberelico (GA3 0 Y 1,0 ppm) en combinacion con acido naftalenoacetico (ANA de 0 a 1.0 ppm) o con acido 2,4 diclorofenoxiacetico (2,4-D  de 0 a 1.0 ppm). La inducción de callos dependió de las interacciones hormonales y condiciones de luz. La regeneración de plántulas...

  13. EFECTO NEFROPROTECTOR DEL ÁCIDO ASCÓRBICO EN UN MODELO DE DAÑO RENAL INDUCIDO POR GENTAMICINA EN CONEJOS

    Directory of Open Access Journals (Sweden)

    Javier Antonio Padilla Funes

    2013-08-01

    Full Text Available Objetivo. Uno de los efectos secundarios mas notables de la Gentamicina es su nefrotoxicidad. En este estudio se propone el posible efecto nefroprotector del acido ascorbico como barredor de radicales libres de oxigeno. Metodología. Se ejecuto un estudio experimental en 24 conejos machos, raza Nueva Zelanda, cuyo peso fue de 1,5 +/- 0,5 Kg. Los sujetos experimentales fueron distribuidos en tres grupos. El grupo Control se manejo con Gentamicina a dosis de 80 mg/Kg/dia por via IM. El grupo Acido Ascorbico se trato a dosis de 200 mg/kg/dia via IP y Gentamicina 80mg/Kg/dia IM. El grupo Sham se manejo con SSN 0,9% por via IP e IM, durante cinco dias consecutivos, para cada grupo. Se determinaron los siguientes parametros: creatinina serica, N-Acetil s-D glucosaminidasa urinaria (NAG-U, diuresis e histopatologia de las muestras renales. Resultados. La creatinina serica fue significativamente mayor para el grupo Control respecto al grupo Acido Ascorbico (p<0,05. Respecto a la diuresis, se observo una tendencia a la poliuria en el grupo Control. En cuanto a NAG-U, se observo inhibicion completa de la actividad enzimatica en el grupo Acido Ascorbico. El analisis histopatologico demuestra hallazgos de necrosis tubular aguda en el 100% del grupo control, mientras que en el grupo Acido Ascorbico se obtuvo en un 50% de los sujetos unicamente detritos intraluminales. Conclusiones. La administracion concomitante de Acido Ascorbico con Gentamicina, disminuye significativamente el dano tubular renal, evidenciado en los valores de creatinina serica, NAG, diuresis e histopatologia renal.

  14. A method for the determination of ascorbic acid using the iron(II)-pyridine-dimethylglyoxime complex

    Energy Technology Data Exchange (ETDEWEB)

    Arya, S. P.; Mahajan, M. [Haryana, Kurukshetra Univ. (India). Dept. of Chemistry

    1998-05-01

    A simple and rapid spectrophotometric method for the determination of ascorbic acid is proposed. Ascorbic acid reduces iron (III) to iron (II) which forms a red colored complex with dimethylglyoxime in the presence of pyridine. The absorbance of the resulting solution is measured at 514 nm and a linear relationship between absorbance and concentration of ascorbic acid is observed up to 14 {mu}g ml{sup -1}. Studies on the interference of substances usually associated with ascorbic acid have been carried out and the applicability of the method has been tested by analysing pharmaceutical preparations of vitamin C. [Italiano] Si propone un rapido e semplice metodo spettrofotometrico per la determinazione dell`acido ascorbico. L`acido ascorbico riduce il ferro(III) a ferro(II) che forma con la dimetilgliossima, in presenza di piridina, un complesso colorato in rosso. L`assorbanza della soluzione risultante e` misurata a 514 nm e si ottiene una relazione lineare tra assorbanza e concentrazione dell`acido ascorbico fino a 14 {mu}g ml{sup -1}. Si sono condotti studi sugli interferenti usualmente associati all`acido ascorbico ed e` stata valutata l`applicabilita` del metodo all`analisi di preparati farmaceutici di vitamina C.

  15. Inhibition of fructan-fermenting equine fecal bacteria and Streptococcus bovis by hops (Humulus lupulus L.) ß-acid

    Science.gov (United States)

    Aims: The goals were to determine if the '-acid from hops (Humulus lupulus L.) could be used to control fructan fermentation by equine hindgut microorganisms, and to verify the antimicrobial mode of action on the Streptococcus bovis, which has been implicated in fructan fermentation, hindgut acidos...

  16. Disease: H00243 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available iology of renal tubular acidosis. Curr Genomics 10:51-9 (2009) PMID:11045400 (gene) Rodriguez-Soriano J New ...rol 14:1121-36 (2000) PMID:12138150 (gene, env_factor, marker, drug) Rodriguez Soriano J Renal tubular acido

  17. Revista de revistas

    OpenAIRE

    Revista, Facultad de Medicina

    2011-01-01

    The Lancet. Vol. I, 1947: 775-811. Londres, junio 7 de 1947 / Aspectos sociales de la epilepsia. Tylor Fox; Lingfield Epilecptic Colony, Surrey. Pp: 775-778 / Virus y enfermedad (Editorial). P: 793-794 / Acido fólico (Editorial). Pp. 795-797

  18. In vitro activity of 2-pyridinecarboxylic acid against trypanosomes of the subgenus Schizotrypanum isolated from the bat Phyllostomus hastatus = Atividade in vitro do ácido 2-piridinocarboxílico em tripanossoma do subgênero Schizotrypanum isolado do morcego Phyllostomus hastatus

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Ceridóreo Corrêa

    2011-09-01

    Full Text Available The effect of 2-pyridinecarboxylic acid (picolinic acid on trypanosomes of the subgenus Schizotrypanum isolated from the bat Phyllostomus hastatus was determined in this study. Picolinic acid, at 50 ƒÊg mL-1, inhibited epimastigote growth by 99% after 12 days incubation. In addition, trypomastigote motility decreased by 50% after 6h and completely after 24h in the presence of 50 ƒÊg mL-1 picolinic acid. The 50% cytotoxic concentration on HEp-2 cell line was275 ƒÊg mL-1 after 4 days incubation. Altogether, these results indicate higher toxicity against trypanosomes. The inhibitory effect of picolinic acid on epimastigote growth can be partially reversed by nicotinic acid and L-tryptophan, suggesting a competitive inhibition. Furthermore, two anti-Trypanosoma (Schizotrypanum cruzi drugs were also evaluated with regard to bat trypanosome growth. Benznidazole, at 50 ƒÊg mL-1, inhibited epimastigote growth by 90% after 12 days incubation. Nifurtimox, at the same concentration, caused 96% growth inhibition after four days incubation. Corroborating a previous study, bat trypanosomes are a good model for screening new trypanocidal compounds. Moreover, they can be used to study many biological processes common to human pathogenic trypanosomatids.O efeito do acido 2- piridinocarboxilico (acido picolinico sobre um tripanossoma do subgenero Schizotrypanum isolado do morcego Phyllostomus hastatus foi determinado neste estudo. O acido picolinico, na concentracao de 50 ƒÊg mL-1, inibiu 99% do crescimento de epimastigotas apos 12 dias de incubacao. Alem disso, houve um decrescimo de 50 e 100% na mobilidade dos tripomastigotas apos 6 e 24h, respectivamente, em presenca de acido picolinico na concentracao de 50 ƒÊg mL-1. A concentracao citotoxica 50% para celulas HEp-2 foi de 275 ƒÊg mL-1 apos quatro dias de incubacao. Esses resultados indicam maior toxicidade contra os tripanossomas. O efeito inibitoriodo acido picolinico sobre o crescimento de

  19. Identificação de exopolissacarídeos em presença de iões nitrito e nitrato

    OpenAIRE

    Oliveira, Rosário; Azeredo, Joana

    1994-01-01

    A identificação de exopolissacarídeos em presença de iões nitrito e nitrato não pode ser feita pela aplicação direta do método do fenol-acido sulfúrico, uma vez que há forte interferência por parte destes iões. Isto torna-se particularmente relevante quando se pretende estudar a produção de exopolissacarídeos por microorganismos nitrificantes e desnitrificantes. O interesse da utilização do método do fenol-acido sulfúrico, inicialmente descrito por Dubois et al. (1956), reside na sua simplici...

  20. Influence of cysteamine and A.E.T. on cerebral activity of irradiated adult rabbit

    International Nuclear Information System (INIS)

    The radioprotective action of cysteamine and A.E.T. on the central nervous system of rabbits exposed to a whole-body gamma irradiation (650 rads) was studied. The rabbits were given intravenous injection of cysteamine (100 mg/kg) and A.E.T. (50 mg/kg), 20 minutes before irradiation. Modifications of behavior, arousal, electrical activities of different cerebral structures and blood acido-basic equilibrium were used as criteria. It was concluded that cysteamine and A.E.T. had a pronounced radioprotective action on central nervous system. Arousal was normal. Radiation induced hyperexcitability was reduced. Blood acido-basic equilibrium modifications did not appear to play an important role in radiation induced cerebral hyperexcitability

  1. Síntesis de Derivados Fotoactivos de Ácidos Biliares para Aplicaciones Biológicas

    OpenAIRE

    Rohacova ., Jana

    2010-01-01

    Los acidos biliares son esteroides biosintetizados en el higado que actuan como tensoactivos, facilitando la digestion de los lipidos. Para ello, circulan y se reutilizan en un movimiento conocido como circulacion enterohepatica, un proceso muy complejo en el que no todas las etapas estan perfectamente entendidas. Con el proposito de estudiar algunos aspectos relacionados con la circulacion enterohepatica, en la presente Tesis Doctoral se planteo preparar derivados fotoactivos de ...

  2. Síntese de esteres poliméricos a partir do poli(álcool vinílico) para aplicação como filtros solares

    OpenAIRE

    Sakae, George Hideki

    2013-01-01

    Resumo: O presente trabalho apresenta o desenvolvimento de esteres polimericos com propriedades de absorcao na regiao do UV, obtidos atraves da reacao do poli(alcool vinilico) (PVAl) parcialmente hidrolisado (87-89%) e os anidridos dos acidos cinamico, anisico e p-metoxicinamico, buscando sua utilizacao na composicao de formulacoes fotoprotetoras. Para a modificacao quimica do polimero foram testadas algumas metodologias, assim denominadas neste trabalho: "One-pot", Aduto de Vilsmeier e Anidr...

  3. Molluscicidal activity of various solvent extracts from Solanum nigrum var. villosum L. aerial parts against Galba truncatula

    OpenAIRE

    Hammami H.; Mezghani-Jarraya R.; Damak M.; Ayadi A.

    2011-01-01

    Molluscicidal activity of Solanum nigrum var. villosum (morelle velue) extracts and their fractions were tested against the mollusca gastropoda Galba truncatula intermediate host of Fasciola hepatica. The results indicated that the hydro-methanol (MeOH-H2O) immature fruit extract possess the highest molluscicidal activity (LC50 = 3.96 mg/L) against Galba truncatula compared with other tested compounds. After acido-basic treatment, the methanolic extract fraction isolated from the immature fru...

  4. El ensayo del ácido 2-tiobarbitúrico (atb) para medir la degradación autooxidativa de aceites vegetales comestibles

    OpenAIRE

    Vicario Romero, Isabel María

    1993-01-01

    En esta memoria se lleva a cabo un estudio general sobre el ensayo del acido 2-tiobarbiturico (atb) y su aplicacion a la determinacion de la degradacion autooxidativa de aceites vegetales comestibles. la recopilacion de todo el material cientifico disponible sobre este ensayo hasta el presente nos permite conocer las caracteristicas de la reaccion y su importancia en la valoracion de la degradacion autooxidativa de alimentos y otros sistemas biologicos, asi como las tecnicas empleadas y las a...

  5. Evaluación de la mezcla de un prebiótico y un ácido orgánico en la salud intestinal y parámetros productivos de pollos de engorde

    OpenAIRE

    Jaramillo Benavides, Alvaro Hugo

    2011-01-01

    El objetivo del presente trabajó de investigación fue evaluar el efecto de un ácido orgánico (Acido fumárico) y un prebiótico comercial (Fortifeed®), y la combinación de éstos frente a un antibiótico promotor de crecimiento (Bacitracina de Zn) y un control, en el alimento de pollos de engorde, determinando los parámetros productivos y salud intestinal.

  6. Mejoramiento del valor nutritivo de residuales azucareros mediante el enriquecimiento con deyecciones de gallinas ponedoras (Improvement of nutritious value of sugar residual by the enrichment with egg-laying hens manures)

    OpenAIRE

    Gutberto Solano Silvera, Pedro L. Fonseca, Luís Escalona y Ricardo Ramírez

    2007-01-01

    RESUMEN El trabajo tiene como objetivo emplear una un nivel del consumo y digestibilidad de la mezcla seca de cachaza, bagacillo, residual materia seca aceptable así como en la azucarado y residual acido (REINAZ), de la ganancia diaria de peso vivo. Se sugiere industria azucarera como absorbente de las tener en cuenta esta nueva alternativa para deyecciones excretadas por gallinas mejorar el valor nutritivo del REINAZ lo que ponedoras situadas en jaulas, par...

  7. DMTMM, un nuovo reattivo di "coupling" per la sintesi di ammidi in fase solida ed in fase omogenea

    OpenAIRE

    Falchi, Alessandro; Giacomelli, Giampaolo; Porcheddu, Andrea; Taddei, Maurizio

    2000-01-01

    La formazione di un legame ammidico é la reazione per la quale esistono forse più metodi disponibili in letteratura. Nonostante tale abbondanza di metodi, non sono molti i reattivi che formano un legame ammidico direttamente a partire dall’acido carbossilico e dalla ammina, che funzionano sia su fase solida che su fase omogenea senza la formazione di molti sottoprodoti e che limitano la possibilità di racemizzazione allorquando si lavori con α-amminoacidi. Molto versatile é ris...

  8. [Hypomyelination with atrophy of the basal ganglia and cerebellum. Contribution of two new cases to a recently reported entity].

    Science.gov (United States)

    Tomás-Vila, Miguel; Menor, Francisco; Ley-Martos, Myriam; Jumillas-Luján, M José; Marco-Hernández, Ana V; Barbero, Pedro

    2014-02-16

    Introduccion. La hipomielinizacion con atrofia de ganglios basales y de cerebelo (H-ABC) es una rara entidad descrita recientemente. Se presentan dos nuevos casos pertenecientes a una misma familia. Casos clinicos. Caso 1: niño de 17 meses con retraso grave en todas las areas, ausencia de lenguaje y de contacto visual. En la exploracion destacaba una microcefalia con tetraparesia espastica. En la resonancia magnetica cerebral se apreciaba atrofia cerebelosa de predominio vermiano con perdida de volumen de ambos nucleos del putamen y la cabeza del caudado, y patron de hipomielinizacion de la sustancia blanca. En la electromiografia se objetivo un patron de polineuropatia cronica de predominio motor. Presento un descenso de los valores de acido homovalinico y de acido 5-hidroxindolacetico. El tratamiento con levodopa/carbidopa no fue efectivo. Caso 2: niña de 11 meses, hermana del caso anterior. Presentaba un retraso grave en todas las areas y en la exploracion clinica se detecto una microcefalia con tetraparesia espastica. La resonancia magnetica cerebral mostro hallazgos superponibles a los del hermano, con hipomielinizacion, atrofia cerebelosa y afectacion putaminal y de ambos caudados; en la electromiografia, hallazgos compatibles con polineuropatia motora de caracter desmielinizante. Presento un descenso de los valores de acido homovalinico y acido 5-hidroxindolacetico en el liquido cefalorraquideo. El tratamiento con levodopa/carbidopa resulto ineficaz. Conclusiones. Estos dos nuevos casos ayudan a caracterizar mejor esta entidad y refuerzan la hipotesis del origen genetico del sindrome, dado que se trata de dos casos pertenecientes a una misma familia.

  9. Estudo de permeaçao cutânea in vitro do ácido kójico

    OpenAIRE

    Gomara, Fernanda de Lacerda

    2013-01-01

    Resumo: Desordens no processo melanogenico podem causar as hiperpigmentacoes, sendo a de maior frequencia o melasma. O acido kojico e um dos despigmentantes topicos utilizados no tratamento destas hipercromias. A acao de um produto dermatologico deve ser topica, nao devendo atingir niveis sistemicos. Um dos fatores que pode definir o nivel de acao, topica ou sistemica, e o veiculo. Neste contesto, o presente trabalho teve por objetivo avaliar o grau de permeacao cutanea in vitro, celula de F...

  10. [CONSUMPTION OF OMEGA- 3 FATTY ACIDS AND DEPRESSIVE SYMPTOMS IN COLLEGE STUDENTS FROM SONORA, MEXICO].

    Science.gov (United States)

    Rubi Vargas, María; González Lomelí, Daniel; Terrazas Medina, Efraín A; Peralta Peña, Sandra L; Jordán Jinez, Ma Lourdes; Ruiz Paloalto, Ma Laura; Cupul Uicab, Lea A

    2015-10-01

    Introducción: estudios recientes sugieren que los niveles bajos de acidos grasos poliinsaturados omega-3 se relacionan con una mayor prevalencia de depresion; sin embargo, los resultados no son concluyentes. Objetivo: evaluar la asociacion entre el bajo consumo de acidos grasos omega-3 y la presencia de sintomas depresivos en jovenes universitarios del noroeste de Mexico. Métodos: se realizo un estudio transversal en una muestra de 706 universitarios de 18 a 24 anos de edad de ambos sexos. La presencia de sintomatologia depresiva se estimo con la escala de Depresion del Centro de Estudios Epidemiologicos (CES-D) empleando un punto de corte ≥ 24. El consumo semanal de acidos grasos alfalinolenico (ALA) y de eicosapentaenoico (EPA) mas docosahexaenoico (DHA) en mg/g de alimento se estimo por medio de un cuestionario de frecuencia de consumo de alimentos validado para la poblacion mexicana. La asociacion del consumo de omega-3 con la presencia de sintomas depresivos se evaluo con modelos de regresion logistica. Resultados: el 67% de los participantes fueron mujeres; en general, el 16,6% presentaron sintomatologia depresiva. El consumo bajo de ALA y EPA + DHA no se asocio con mayor prevalencia de sintomatologia depresiva antes y despues de ajustar por confusores. En aquellos casos con sintomatologia depresiva, los niveles ALA derivados solo de las nueces fueron significativamente menores. Conclusiones: en esta poblacion no se observo asociacion entre el bajo consumo de acidos grasos omega-3 y la sintomatologia depresiva. La posible asociacion entre el consumo de nueces y la sintomatologia depresiva requiere de mas estudios.

  11. Determinazione del fosforo: metodo spettrofotometrico in assorbimento molecolare

    OpenAIRE

    Tartari, Gabriele A.

    2012-01-01

    Metodo analitico interno al laboratorio di idrochimica del CNR-ISE di Verbania per la determinazione del fosforo reattivo al molibdato. L'ortofosfato reagisce con l'ammonio molibdato ed il potassio antimonio tartrato con formazione del complesso antimonio fosfomolibdico, a sua volta ridotto dall'acido L-ascorbico al colorante blu di molibdeno il cui spettro di assorbimento presenta il massimo di assorbanza a 890 nm.

  12. Evaluation studies of cleaning methods for artworks: from chelating agents on inorganic substrates to Dry cleaning treatments on contemporary surfaces

    OpenAIRE

    Selva Bonino, Valentina Emanuela

    2015-01-01

    Il progetto di tesi presenta due studi riguardanti, un intervento di pulitura, cosiddetto tradizionale su supporti inorganici e dipinti murali e una nuova applicazione di metodi a secco per il trattamento di pulitura di superficie (Dry cleaning). In particolare, il primo riguarda l'applicazione di soluzioni di agenti chelanti, in particolare il sale trisodico diidrato dell'acido etilendiamminotetraacetico e il sale tribasico diidrato del citrato di sodio, su substrati inorganici, cioè carb...

  13. Design and Synthesis of Immunoconjugates and Development of an Indirect ELISA for Rapid Detection of 3, 5-Dinitrosalicyclic Acid Hydrazide

    OpenAIRE

    Yuan-Ming Sun; Yue-Ming Jiang; Zhi-Li Xiao; Hong Wang; Hong-Tao Lei; Shi-Wei Zhang; Yu-Dong Shen

    2008-01-01

    In this study novel immunoconjugates were designed, synthesized and then used to develop a rapid, specific and sensitive indirect ELISA method to directly detect residues of 3,5-dinitrosalicyclic acid hydrazide (DNSH), a toxic metabolite of nifursol present in chicken tissues. The hapten DNSHA was first designed and used to covalently couple to BSA to form an immunogen which was immunized to rabbits to produce a polyclonal antibody against DNSH. Furthermore, a novel 3,5-dinitrosalicylic acido...

  14. Fotólise do ácido salicílico na presença de ciclo dextrina = Photolisys of the salicylic acid in the presence of â-cyclodextrin

    Directory of Open Access Journals (Sweden)

    Reinaldo Aparecido Bariccatti

    2005-01-01

    Full Text Available Neste trabalho, utilizou-se a espectroscopia de UV/VIS para estudar afotodegradacao por luz UV do acido salicilico em cavidade de ƒÀ-ciclo dextrina. Verificou-se uma reducao na velocidade de fotodegradacao do acido salicilico de 34,5% em pH 7 e de 17,5% em pH 4 quando se adiciona a ƒÀ-ciclo dextrina na solucao. O valor obtido para aconstante de dissociacao do complexo acido salicilico e ƒÀ-ciclo dextrina foi de 4,3}0,5 L10-3 mol/L.In this work the UV/VIS spectroscopy was used to study the photo degradation by UV light of the salicylic acid in cavity of ƒÀ-cyclodextrin. A reduction in the speed of degradation of thesalicylic acid of 34.5% in pH 7 and of 17.5% in pH 4 was observed when ƒÀ-cyclodextrin is added to the solution. The obtained value to the constant of dissociation of the salicylic acid complex and of the ƒÀ-cyclodextrin was of 4.3}0.5x10-3 mol/L.

  15. Residualidad del ácido sulfúrico aplicado como enmienda, y calculado de acuerdo con la CIC y con la suma de bases, sobre la estabilidad de los agregados en dos suelos salino-sódicos de la zona de Palmaseca, Valle del Cauca Residualidad del acido sulfúrico aplicado como enmienda, y calculado de acuerdo con la c 1c y con la suma de bases, sobre la estabilidad de los agregados en dos suelos salino-sódicos de la zona de palma seca, Valle del Cauca

    Directory of Open Access Journals (Sweden)

    Charry Calle Jairo

    1988-12-01

    Full Text Available Los dos suelos salino-sódicos se cultivaron sucesivamente con algodón (Gossypium hirsutum var. Gossica P-21, soya (Glycine max var. ICA- Tunía y fríjol (Phaseolus vulgaris var. ICA- Gualí. La estabilidad de los agregados para los suelos, tratamientos y cultivos, se comparó calculando el área localizada debajo de cada una de las curvas aditivas porcentuales de los agregados, entre los parámetros menor de 025 mm y 0.42-0.84 mm.Residuality of sulfuric acid applied as amendment and calculated according to CEC and Sum of Exchangeable Bases (Ca, Mg, Na and K on the aggregate stability of two saline-sodic soils from Palmaseca zone , Cauca Valley, successively cultivated in cotton (Gossypium hirsutum var. Gossica P- 211. soybean (Glycine max var. ICA Tunía and bean (Phaseolus vulgaris var. ICA-Gualí was studied. The aggregate stability for two soils, treatments and crops, was compared by calculating the area located below each one of the accumulative percentage curves of aggregates, between less than 025 mm and 0.42-084 mm parameters. The results showed: A percent increase up to 56% in the aggregate stability of both soils, in treatments calculated according to CEC cultivated in soybean, and Sum of Exchangeable Bases cultivated in bean. The characteristic roots do not have a pronounced effect on aggregation. The initial and final chemical analysis of soils cultivated in cotton, bean and soybean showed in general, a 90 to 98% reductions of levels of sulphate, exchangeable sodium and exchangeable sodium percentage.

  16. Influence of Isosacarinic acid on the sorption of {sup 2}38Pu, {sup 1}52 Eu, {sup 7}5Se, {sup 6}0Co, {sup 6}3Ni and {sup 1}09Cd on CSH phases of relation different CaO / SiO{sub 2}; Influencia del acido isosacarinico (ISA) en la sorcion de {sup 2}38Pu, {sup 1}52Eu, {sup 7}5Se. {sup 6}0Co, {sup 6}3Ni y {sup 1}09Cd sobre fases CSH de diferente relacion Cao/SiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Gutierrez, M.; Missana, T.; Mingarro, M.; Morejon, J.; Gil, P.; Galan, H.

    2014-07-01

    The storage of radioactive waste on the surface are the main barrier to the migration of radionuclides in concrete and mortar. The alkaline environment created by these materials produce degradation compounds cellulose, from the paper, wood, cotton, etc .., widely present in the contaminated material as waste, to acid isosacarinic. (Author)

  17. [Status epilepticus in paediatrics: a retrospective study and review of the literature].

    Science.gov (United States)

    Moreno-Medinilla, Esther E; Negrillo-Ruano, Rocío; Calvo-Medina, Rocío; Mora-Ramírez, M Dolores; Martínez-Antón, Jacinto L

    2015-05-01

    Introduccion. El estado epileptico (EE) es la emergencia neurologica mas frecuente en pediatria. Dada la posibilidad de secuelas neurologicas y mortalidad asociadas, requiere un tratamiento agresivo precoz. Pacientes y metodos. Estudio descriptivo retrospectivo a traves de la revision de historias clinicas de pacientes ingresados en nuestro hospital entre 2010-2013 con diagnostico de EE. El objetivo fue describir las caracteristicas epidemiologicas y el manejo de estos pacientes, asi como revisar la bibliografia disponible sobre este tema. Resultados. Hemos recogido 39 pacientes (25 varones) y 51 episodios de EE. Edad media: 4,8 años. Tenian enfermedad de base 22 pacientes. Dieciocho eran epilepticos conocidos y cinco tuvieron un EE previo. De los 51 episodios de EE, 33 fueron sintomaticos, 15 febriles y tres criptogenicos. Los tipos de EE fueron: 25 parciales (de ellos, 16 complejos) y 26 generalizados. El tratamiento de primera eleccion fue benzodiacepinas en 47 pacientes (40, diacepam), fenitoina en tres y acido valproico en uno. Veintisiete pacientes precisaron farmacos de segunda linea: 16, acido valproico; ocho, fenitoina; dos, fenobarbital; y uno, levetiracetam. Diez pacientes precisaron farmacos de tercera linea para la induccion del coma: el midazolam fue el mas utilizado en nuestro centro, seguido del tiopental y el propofol. Dos EE superrefractarios requirieron inmunoglobulinas y corticoides sistemicos por presentarse en el curso de encefalitis autoinmunes. Conclusiones. Debe plantearse el esquema terapeutico del EE desde el inicio de cualquier crisis convulsiva. El tratamiento es escalonado, con benzodiacepinas en la primera etapa, antiepilepticos de amplio espectro y disponibilidad intravenosa en la segunda (acido valproico, levetiracetam en el EE generalizado y fenitoina en el EE focal), mientras que el tercer nivel varia en funcion de la experiencia de cada equipo.

  18. Multímetro como sistema de medición alternativo en las valoraciones potenciométricas

    Directory of Open Access Journals (Sweden)

    José de Jesús Pérez-Saavedra

    2015-09-01

    Full Text Available En el presente trabajo, experimentalmente se demuestra que las valoraciones potenciométricas usuales en química analítica (acido-base, redox, complejométricas y de halogenuros pueden llevarse a cabo utilizando como sistema indicador de punto de equivalencia, un multímetro en vez del potenciómetro, mediante la prueba estadística de t de Student; y se posibilita con esto que los laboratorios de docencia se puedan equipar mejor y a bajo costo, con multímetros en vez de potenciómetros.

  19. Soil decontamination at the Montevecchio-Levante mine site with experimental washing and leaching techniques

    Energy Technology Data Exchange (ETDEWEB)

    Dessi, R. [Progemisa SpA, Cagliari (Italy); Fadda, S.; Peretti, R.; Zucca, A. [CSGM, Centro Studi Germinerari e Mineralurgici del CNR, Cagliari (Italy); Serci, A. [Digita, Dipt. di Geoingegneria e Tecnologie Ambientali, Cagliari (Italy)

    2000-12-01

    The soils in the neighbourhood of the Rio Montevecchio-Sitzerri, a stream that flows in the valley below the tailings pond of the Montevecchio-Levante mineral processing plant (SW Sardinia, Italy) are severely contaminated by heavy metals, to the extent that traditional land uses are compromised. Consequently urgent measures are needed both to abate the pollution at source and rehabilitate the contaminated land. This paper is concerned with the problem of soil decontamination using washing and leaching techniques. Laboratory experiments have been conducted in mechanically agitated reactors, using citric acid and acetic acid solutions and brine of hydrochloric acid and calcium chloride. The influence of both reagent concentration and solid-to-liquid ratio has been assessed, and in the most significant cases, the attack kinetics has been determined. The tests showed the brine to be the most effective for removing metals from the soils. Based on the findings of the investigations, the possibility of decontamination by heap leaching has been simulated in the laboratory using the column technique. [Italian] I suoi circostanti il Rio Montevecchio-Sitzerri, che scorre a valle del bacino di decantazione degli sterili dell'impianto di trattamento dei minerali di Montevecchio-Levante (Sardegna Centro-Occidentale), sono caratterizzati da un elevato contenuto di metalli pesanti, che ne pregiudicano gli usi tradizionali. Si rende percio' improrogabile sia la necessita' di intervenire sulle cause all'origine della contaminazione, sia di bonificare i suoli in questione al fine di recuperarli a nuovi usi. La memoria intende portare un contributo alle relative problematiche affrontando la possibilita' di decontaminazione mediante tecniche di lavaggio e lisciviazione. La sperimentazione di laboratorio e' stata condotta in reattori ad agitazione meccanica, utilizzando soluzioni con acido citrico, acido acetico ed una salamoia costituita da acido

  20. Intoxicación por fluoroacetato de sodio

    OpenAIRE

    Juliana Granada; Diego Andrés Rodríguez

    2014-01-01

    El fluoroacetato de sodio es conocido como compuesto 1080, fue descubierto por químicos alemanes durante la segunda guerra mundial. Es un compuesto inodoro e insaboro, soluble en agua, la dosis letal 50 en humanos es de 2 a 4 mg/kg. Debido a su letalidad, ha sido retirado del mercado en algunos países incluyendo Colombia. Este compuesto causa efectos bioquímicos y fisiológicos como acumulación de citrato, alteración de los trasportadores mitocondriales del citrato, acumulación de acido láctic...

  1. Efeito da aplicação foliar de fosfonato potássico na protecção das raízes do castanheiro (Castanea sativa Mill.) inoculadas com Phytophthora cinnamomi Rands

    OpenAIRE

    Gouveia, Eugénia; Coelho, Valentim; Fonseca, Felícia; Nunes, Luís; Monteiro, Maria do Loreto

    2008-01-01

    Phytophthora cinnamomi é um parasita cujo ciclo de vida ocorre integralmente no ambiente solo causando podridões das raízes e colo em muitas espécies vegetais. O castanheiro (Castanea sativa Mill) é muito susceptível às espécies do género Phytophthoro e os sintomas da Doença da Tinta rapidamente se manifestam. Recentemente, verificou-se que as formas aniónicas do acido fosfónico evidenciam elevada eficácia no combate as doenças radiculares associadas a Phytophthoro.

  2. Inclusión de AINEs en distintas matrices inorgánicas. Estudios de solubilidad y liberación

    OpenAIRE

    Fernández Díez, Alicia

    2008-01-01

    Se han incorporado diversos AINEs (acido mefenámico y meclofenámico, naproxeno y fenbufen) en distintas matrices inorgánicas: hidroxidos dobles laminares (LDHs de MgAl y de MgAlFe), sílice mesoporosa ordenada (MCM-41) y silicato cálcico para evaluar su posible aplicación como nuevas formulaciones farmacéuticas de liberación modificada. La síntesis de los distintos sistemas matriz-AINEs preparados se ha realizado utilizando distintas condiciones de temperatura, composición del medio de disoluc...

  3. Utilización de la biomasa residual del cultivo de la piña (Ananas Comosus) para la desproteinización enzimática de desechos de la actividad camaronera

    OpenAIRE

    Javier Rodrigo Alpízar Cordero; Luis Roberto Villegas Peñaranda; Sergio Madrigal Carballo; María Sibaja Ballestero

    2013-01-01

    Se realizó un estudio para comprobar la capacidad desproteinizante de extractos proteicos obtenidos a partir de desechos de rastrojo de piña a diferentes concentraciones sobre los sub-productos de la actividad camaronera. El extracto proteolítico de los desechos de rastrojo de piña se obtuvo a partir de desechos de tallos utilizando un buffer de acido sulfúrico. Este extracto se caracterizó al determinar el contenido de proteína, de azucares totales y su actividad enzimática, contra un patrón...

  4. Comparative Studies on Biochemical Properties of Protein Synthesis of an Archae-Bacteria Thermoplasma-Sp

    Science.gov (United States)

    Ohba, Masayuki; Oshima, Tairo

    1982-12-01

    An acido-thermophillic archaebacteria,Thermoplasma strain KO-2, produced poly(A) containing RNA. The isolated poly(A)RNA showed the messenger activity in a cell-free extract of rabbit reticulocyte, indicating that the RNA is mRNA of the archaebacteria. 7-Methylgluanosine 5'-phosphate did not inhibit the reaction, suggesting that the cap structure is not present in the messenger. These results may suggest that poly(A) containing messenger arised at very early stage of evolution prior to the divergence between archaebacteria and eukaryotes.

  5. Efecto de Lactobacillus casei, Saccharomyces Rhodopseudomona palustris (microorganismos eficientes em) y melaza en la ganancia de peso de tilapias (Oreochromis sp) en condiciones de laboratorio

    OpenAIRE

    Guillermo Ladino-Orjuela; José A. Rodríguez-Pulido

    2009-01-01

    La combinación de una bacteria acido láctica, una bacteria fototrófica y una levadura también conocida como EM (effective microorganisms), se le reconoce capacidad sinérgica, sintrópica y metabiotica para disminuir de la capacidad contaminante de las aguas servidas. La MO de los estanques acuícolas la cual, normalmente sevierte, podría ser utilizada como sustrato para el crecimiento de los EM. Los microorganismos pueden servir de alimento a los peces y disminuir tanto los vertimientos a los c...

  6. Diseño y elaboración de un software a medida para la interpretación de gases sanguíneos

    OpenAIRE

    Junco González, José Luis

    2013-01-01

    El análisis de los gases sanguíneos se ha convertido en un reto para el personal médico, realizar una interpretación completa en muchos casos suele ser difícil y algunos profesionales no logran hacerlo de una forma adecuada, con el diseño, y desarrollo de un software, que asista a los intensivistas para la interpretación de gases sanguíneos, el cual comprenda oxigenación, ventilación, acido-base y perfusión, se contribuirá a un mejor proceso diagnostico, monitoreo y tratamiento de pacientes e...

  7. CLA as a nutraceutical molecule: concentration in foods, estimation of intake in Italy and genetic factors affecting thesynthesis in animal tissue

    OpenAIRE

    CICOGNINI, FRANCESCA MARIA

    2014-01-01

    Gli isomeri del CLA (Acido Linoleico Coniugato) potrebbero avere effetti benefici sulla salute in relazione al raggiungimento di un determinato intake, ma, per quanto ci è dato sapere, non esiste letteratura in Italia riguardante l'effettiva quantità di CLA negli alimenti e al relativo intake nell'uomo. Quindi è stata condotta una quantificazione degli isomeri c9,t11 e t10,c12 negli alimenti disponibili sul mercato italiano, seguita da una stima dell'intake di questi isomeri in una coorte del...

  8. Yogurt funcional alto CLA

    OpenAIRE

    Massa Grilli, Elisa

    2012-01-01

    La presencia de compuestos bioactivos en la grasa láctea ha despertado gran interés ya que se le atribuyen efectos preventivos frente a enfermedades de alto impacto en la población. Se ha demostrado que los sistemas de alimentación basados en pastoreo incrementan la presencia de ácidos grasos poliinsaturados y específicamente del acido linoleico conjugado, obteniéndose un alimento funcional que presenta propiedades beneficiosas sobre la salud. El objetivo del presente ...

  9. Aislamiento, selección y caracterización de una bacteria ácido láctica porcina como probiótico en lechones post destete

    OpenAIRE

    Rebolledo Londoño, Ángelo

    2014-01-01

    Con el objetivo de identificar y caracterizar bacterias acido lácticas BAL de origen porcino asociadas al estado de sanidad intestinal de los lechones posdestete, se llevó a cabo un experimento donde se aislaron 38 cepas de BAL para evaluar su potencial de colonización del tracto gastrointestinal a través de la prueba de in vitro de adhesión y aglutinación a mannosa. Se seleccionó la BAL L605 y se evaluó su capacidad para fermentar alimentos balanceados basados en maíz y soya, utilizados en l...

  10. Química de especies del genero espeletia Espeletia killipii - Espeletia tunjana

    Directory of Open Access Journals (Sweden)

    Rubén Darío Torrenegra

    2010-07-01

    Full Text Available De las partes aéreas de 2 especies del género Espeletia se aislaron compuestos del tipo diterpeno Acido (-i-Kaur-9( 11, 16-dien-19-oico, el (-Kaur-16-en-19-ol, los terpenos friedeiina, sitosterol-estigmasterol, y dos sesquiterpenlactonas del tipo melampólido, Acetato de Longipilin y Polimatin B. Los últimos compuestos no reportados hasta el momento en la química del género Espeletia. Del extracto etanólico se identificaron dos flavonoides: Quercetina y 3-metoxiquercetina.

  11. Mecanismos de ação envolvidos no efeito gastroprotetor do extrato etanólico de Arctium Lappa L. em úlceras gástricas crônicas induzidas por ácido acético em ratos.

    OpenAIRE

    Silva, Luísa Mota da

    2011-01-01

    Resumo: A Arctium lappa L. é uma planta da família Asteraceae (Compositae), conhecida popularmente como bardana. Estudos anteriores realizados no Departamento de Farmacologia da Universidade Federal do Paraná, demonstraram os efeitos gastroprotetores desta planta na úlcera gástrica induzida por acido acético em ratos. No entanto, o mecanismo de ação envolvido neste efeito não ficou esclarecido. Dessa forma, o presente estudo teve como objetivo avaliar o mecanismo pelo qual o extrato etanólico...

  12. COMPARACIÓN DEL PERFIL VITAMÍNICO EN JUGOS ULTRAPASTEURIZADOS DE MANZANA Y SU IMPACTO TÉRMICO DE DEGRADACIÓN

    OpenAIRE

    Juan Guillermo Ayala Soto; León Raúl Hernández Ochoa; Néstor Gutiérrez Méndez; David Chávez Flores

    2015-01-01

    La manzana contiene azúcares provenientes principalmente de la fructosa y, en menor grado, de la glucosa y la sacarosa. Además, tiene acido málico y ácido ascórbico, este último agente nutrimental que por lo general se cuantifica. Aproximadamente hay 10 mg de ácido ascórbico en cada 100 g de manzana, aunque eso depende de la calidad y la clase de esta fruta. El ácido ascórbico es un nutrimento esencial que se puede hallar en frutas y verduras; sin embargo, el hombre no puede almacenarlo e...

  13. Protección frente a la tinción dentaria en dientes tratados con tetraciclinas al aplicar un antioxidante (ácido ascórbico)

    OpenAIRE

    Bermúdez Semprún, María Esther; Beltri Orta, Paola; Bartolomé Villar, Begoña

    2014-01-01

    En la presente investigación pretendemos optimizar los resultados, evitando la coloración coronal, en procedimientos odontológicos donde sea imprescindible el uso de tetraciclinas así como evaluar la disminución de las coloraciones coronales, al aplicar un antioxidante (Acido Ascórbico) en dientes tratados con tetraciclinas (Minociclina y Doxiciclina). En los dientes tratados con minociclina y doxiciclina observamos cambios en la coloración dentaria apreciables tanto en corona como en la raíz...

  14. 3-substituted and 1, 3-disubstituted pyrroles synthesis from {alpha}, {beta} insaturated Nitriles. Formal total synthesis of Danaidona; Sintesis de pirroles 3-sustituidos y 1, 3-disustituidos a partir de Nitrilos {alpha}, {beta}- insaturados. Sintesis total formal de la Danaidona

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Hector; Flores, Blas; Leon, Fernando; Mendez, Jose Manuel [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    1996-02-01

    We describe a short method to obtain 3-substituted and 1, 3-disubstituted pyrroles from {alpha}, {beta}-insaturated nitriles. We obtained the corresponding substituted succinonitriles from 1, 4-addition of hydrogen cyanide to {alpha}, {beta}-insaturated nitriles. [Spanish] Se describe un metodo corto para obtener pirroles 3-sustituidos y 1, 3-disustituidos a partir de nitrilos {alpha}, {beta}-insaturados. Se obtuvieron los correspondientes succinonitrilos sustituidos a partir de la adicion 1, 4 de acido cianhidrico a nitrilos {alpha}, {beta}-insaturados.

  15. Lewis acidic zn(ii) schiff base complexes in homogeneous catalysis

    OpenAIRE

    Anselmo, Daniele

    2013-01-01

    El trabajo descrito en esta tesis muestra estudios hacia nuevas aplicaciones de complejos derivados de bases de Schiff en catálisis homogénea. En concreto, se han investigadoligandos “salen” (incluyendo sistemas quelantes N2S2) ytambiénse han examinado otros aspectos que generalmente se consideran importantes en el contexto del aumento de la sostenibilidad de los procesos químicos. Estudios sobre el uso de estos compuestos acidos de Lewis en la catálisis de la fijación de dióxido de carbono, ...

  16. Bacterias ácido-lácticas que se desarrollan en leche de soja y activan las isoflavonas, producto que las contiene y sus aplicaciones

    OpenAIRE

    Delgado, Susana; Mayo Pérez, Baltasar

    2012-01-01

    La presente invención hace referencia a una cepa bacteriana del acido láctico perteneciente al género Lactobacillus, caracterizada porque presenta actividad Į-galactosidasa y actividad ȕ- glucosidasa, para la producción de isoflavonas activas. Así mismo, la presente invención hace referencia al uso de al menos una cepa bacteriana del ácido láctico perteneciente al género Lactobacillus para la elaboración de un producto fermentado funcional a base de leche d...

  17. First principle study of the surface reactivity of layered lithium oxides LiMO2 (M = Ni, Mn, Co)

    Science.gov (United States)

    Vallverdu, Germain; Minvielle, Marie; Andreu, Nathalie; Gonbeau, Danielle; Baraille, Isabelle

    2016-07-01

    LiNixMnyCo1 - x - yO2 compounds (NMC) are layered oxides widely used in commercial lithium-ion batteries at the positive electrode. Nevertheless surface reactivity of this material is still not well known. As a first step, based on first principle calculations, this study deals with the electronic properties and the surface reactivity of LiMO2 (M = Co, Ni, Mn) compounds, considering the behavior of each transition metal separately in the same R 3 ̅ mα-NaFeO2-type structure, the one of LiCoO2 and NMC. For each compound, after a brief description of the bare slab electronic properties, we explored the acido-basic and redox properties of the (110) and (104) surfaces by considering the adsorption of a gaseous probe. The chemisorption of SO2 produces both sulfite or sulfate species associated respectively to an acido-basic or a reduction process. These processes are localized on the transition metals of the first two layers of the surface. Although sulfate species are globally favored, a different behavior is obtained depending on both the surface and the transition metal considered. We conclude with a simple scheme which describes the reduction processes on the both surfaces in terms of formal oxidation degrees of transition metals.

  18. Determinação de ferro (III em produtos farmacêuticos por titulação fotométrica = Determination of iron (III in pharmaceutical products by photometric titration

    Directory of Open Access Journals (Sweden)

    Airton Vicente Pereira

    2011-01-01

    Full Text Available Este trabalho descreve a montagem de um sistema de titulacao fotometrica simples e de baixo custo para a determinacao de ferro (III em produtos farmaceuticos. O sistema de titulacao fotometrica foi construido utilizando-se a bomba peristaltica de um espectrofotometro convencional. O procedimento e baseado na titulacao de ferro (III com EDTA e acido salicilico como indicador. A absorcao do complexo ferro (III-acido salicilico foi monitorada espectrofotometricamente em 525 nm. O limite de quantificacao foi de 5 ƒÝg de ferro (III. O procedimento de titulacao fotometrica foi aplicado para a determinacao de ferro (III em amostras contendo sulfato ferroso e hidroxido ferrico polimaltosado. O procedimento mostrou sensibilidade, reprodutibilidade e precisao para a utilizacao em analise rotineira de ferro (III em produtos farmaceuticos.This paper describes a simple, precise and low-cost photometrictitration method for iron (III determination in pharmaceutical preparations. The photometric titration system was constructed using the peristaltic pump of a conventional spectrophotometer. The method is based on titration of iron (III with EDTA using salicylic acid as indicator. The absorption of the iron (III-salicylic acid complex wasmonitored spectrophotometrically at 525 nm. The limit of quantification was 5 ƒÝg of iron (III. The photometric titration procedure was applied for the determination of iron (III in samples of ferrous sulfate and ferric hydroxide polymaltose complex. The procedure showed sensibility, reproducibility and accuracy for use as a method for the routine analysis of iron (III in pharmaceutical formulations.

  19. Synthesis and characterization of magnetic nanoparticles of oxides for dual MnFe{sub 2}O{sub 4} bioseparation, stabilized in fatty acid and the system chitosan - Eu(TTA){sub 3}(TPPO){sub 2}. Studies on the influence of doping with Gd{sup 3+}, Tb{sup 3+}, Ho{sup 3+} e Eu{sup 3+} in structural and magnetic properties; Sintese e caracterizacao de nanoparticulas magneticas de oxidos duplos de MnFe{sub 2}O{sub 4} para biosseparacao, estabilizadas em acido graxo e recobertas pelo sistema quitosana - Eu(TTA){sub 3}(TPPO){sub 2}. Estudo da influencia da dopagem com Gd{sup 3+}, Tb{sup 3+}, Ho{sup 3+} e Eu{sup 3+} nas propriedades estruturais e magneticas

    Energy Technology Data Exchange (ETDEWEB)

    Kovacs, Thelma Antunes Rodrigues

    2014-07-01

    This work was synthesized and characterized ferrite magnetic nanoparticles manganese, using the chemical coprecipitation method. By varying the heating time under 98°C (0, 10,20,40,60 3 80 minutes), the molar percentage of doping (1, 3, 5, 7, and 10%), gadolinium, europium, terbium and holmium. Magnetic ferrite nanoparticles and manganese ferrite doped with manganese were synthesized by coprecipitation method starting with chloride solutions of metals (iron (III), manganese (II), europium (III), gadolinium (III), terbium (III) and holmium (III)) and NaOH 5mol.L{sup -1} as precipitating agent. The magnetic nanoparticles were characterized by scanning electron microscopy, infrared spectroscopy, X-ray diffraction, magnetization curves, and thermal analysis. Most of manganese ferrite particles showed superparamagnetic behavior. After the characterization it was found that the samples synthesized manganese ferrite with more than 40 minutes heating time, crystal structure showed the characteristic pattern of the inverted manganese ferrite spinel type. The stabilization of the samples in oleic acid nanoparticles produced with a hydrophobic outer layer and facilitated by coating chitosan biopolymer, since this has a positive charge. Among the doped samples there was no significant change in the magnetic behavior. Several techniques for characterizing these materials have been used such as X-ray diffraction spectrum in the infrared region, magnetization curves and thermal analysis. The resins were tested as magnetic material for the separation of biological materials. In this paper, are used as biological targets separation of bovine serum albumin. (author)

  20. Supported liquid membrane stability in chiral resolution by chemically and physically modified membranes

    Energy Technology Data Exchange (ETDEWEB)

    Molinari, R.; Argurio, P. [Arcavata di Rende Univ. of Calabria, Arcavata di Rende, CS (Italy). Dept. of Chemical and Materials Engineering

    2001-04-01

    In the present work some stability studies on Supported Liquid Membranes (SLMs) to be used for chiral separations were realized. In particular, primary aim was to determine how a modification of the support surface influences the SLM stability. First, the procedure for support modification was optimised, making a screening of various compounds (sulphuric acid, nitric acid, chromic acid, sodium dodecyl sulphate (SDS), glycerol, oleic alcohol, propylene glycol (PPG), bovine serum albumin (BSA)) and testing their performance by means of contact angle measurements. Next, a second screening was realized by permeation tests in a stirred cell. Finally, to compare the stability of modified with unmodified support in a process of interest for chemical and/or biochemical industries, some permeation tests for resolution of DNB-DL-Leucine were realized in a re-circulation system. Results showed a better surface hydrophilization of chemically modified support and better stability of the sulphonated support. However, in operating conditions a little high stability of the unmodified support was obtained. [Italian] Nel presente lavoro sono stati realizzati degli studi di stabilita' di Membrane Liquide Supportate (SLMs) da impiegare in separazioni chirali. In particolare, obiettivo principale e' stato quello di determinare l'influenza che una modifica della superficie del supporto ha sulla stabilita' della SLM. Cosi', in un primo momento, e' stata ottimizzata le procedura di modifica del supporto, facendo una selezione tra vari composti (acido solforico, acido nitrico, acido cromico, sodio dodecil solfato (SDS), glicerolo, alcool oleico, glicole propilenico (PPG), siero di albumina bovina (BSA)) basata su misure dell'angolo di contatto. Successivamente, e' stata realizzata una seconda selezione mediante prove di permeazione in una cella agitata. Infine, con lo scopo di confrontare la stabilita' della SLM con supporto modificato rispetto

  1. Mejoramiento del valor nutritivo de residuales azucareros mediante el enriquecimiento con deyecciones de gallinas ponedoras (Improvement of nutritious value of sugar residual by the enrichment with egg-laying hens manures

    Directory of Open Access Journals (Sweden)

    Gutberto Solano Silvera, Pedro L. Fonseca, Luís Escalona y Ricardo Ramírez

    2007-05-01

    Full Text Available RESUMEN El trabajo tiene como objetivo emplear una un nivel del consumo y digestibilidad de la mezcla seca de cachaza, bagacillo, residual materia seca aceptable así como en la azucarado y residual acido (REINAZ, de la ganancia diaria de peso vivo. Se sugiere industria azucarera como absorbente de las tener en cuenta esta nueva alternativa para deyecciones excretadas por gallinas mejorar el valor nutritivo del REINAZ lo que ponedoras situadas en jaulas, para posibilita emplearlo en la aumentar el contenido de nutrientes y suplementación de raciones para ovejos en utilizarla en la alimentación de rumiantes. ceba. El producto se le oferto a ovejos Pebuey en los que se determino el consumo, digestibilidad y el comportamiento de la ceba respectivamente. Los resultados muestran un incremento del nivel de proteína bruta

  2. Herbicides synthesis and biological tests to determine its activity on the weeds; Sintesis de herbicidas y pruebas biologicas para determinar su actividad sobre la maleza

    Energy Technology Data Exchange (ETDEWEB)

    Romero M, Artemisa [Universidad Autonoma Metropolitana-Xochimilco, Mexico, D. F. (Mexico); James M, Guillermo [Universidad Autonoma Metropolitana-Xochimilco, Mexico, D. F. (Mexico); Miramontes F, Benjamin [Universidad Autonoma Metropolitana-Xochimilco, Mexico, D. F. (Mexico); Haro C, Jorge [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D.F. (Mexico)

    1995-02-01

    Four derivatives of Dicamba (2-methoxy-3, 6-dichlorobenzoic acid) were obtained: 2-methoxy-3, 6-dichlorobenzyl alcohol, 2-methoxy-3, 6-dichlorobenzaldehyde, 2-methoxy-3, 6-dichlorobenzaldoxime, tested on weed, and 2-methoxy-3, 6-dichlorobenzylamine. The weeds were Taraxacum officinale Weber, Amaranthus silvester and Sonchus oleraceus L. The oxime did not show activity on Amaranthus silvester, all the substances were active on the other two weeds. [Spanish] Se sintetizaron cuatro derivados del herbicida Dicamba (acido 2-metoxi-3, 6-diclorobenzoico), y se hicieron pruebas de la actividad de tres de ellos sobre maleza de Xochimilco. Se probaron el alcohol 2-metoxi-3, 6-diclorobencilico, 2-metoxi-3, 6-diclorobenzaldehido, 2-metoxi-3, 6-diclorobenzaldoxima. La maleza fue Taraxacum officinale Weber (Diente de leon), Amaranthus silvester (Amaranto silvestre) y Sonchus oleraceus L. (Sonchus). En amaranto, la oxima fue el unico que no presento actividad. En diente de leon y Sonchus, todas las sustancias probadas presentaron actividad.

  3. Zinc and cadmium monosalicylates

    Energy Technology Data Exchange (ETDEWEB)

    Kharitonov, Yu.Ya.; Tujebakhova, Z.K. (Moskovskij Khimiko-Tekhnologicheskij Inst. (USSR))

    1984-06-01

    Zinc and cadmium monosalicylates of the composition MSal, where M-Zn or Cd, Sal - twice deprotonated residue of salicylic acid O-HOC/sub 6/H/sub 4/COOH (H/sub 2/Sal), are singled out and characterized. When studying thermograms, thermogravigrams, IR absorption spectra, roentgenograms of cadmium salicylate compounds (Cd(OC/sub 6/H/sub 4/COO) and products of their thermal transformations, the processes of thermal decomposition of the compounds have been characterized. The process of cadmium monosalicylate decomposition takes place in one stage. Complete loss of salicylate acido group occurs in the range of 320-460 deg. At this decomposition stage cadmium oxide is formed. A supposition is made that cadmium complex has tetrahedral configuration, at that, each salicylate group plays the role of tetradentate-bridge ligand. The compound evidently has a polymer structure.

  4. [Epidemiological aspects of tuberculosis in middle west of Madagascar].

    Science.gov (United States)

    Rakotondramarina, D; Razafimalala, F; Andrianaivo, P; Rabeson, D; Andriatsiva, R; Andrianavalomahefa, W

    2000-01-01

    We conducted a 5-year (1989-1993) retrospective analysis on a series of patients screened and treated for tuberculosis in order to determine the epidemiological aspects of the disease in mid-western Madagascar. Pulmonary forms affected 97% of patients, and predominantly men (sex ratio: 1.4); 83% of patients with pulmonary tuberculosis were coughing up acido-alcoholo-resitant bacilli. Haemoptysis and general deterioration, the most frequently met pathological signs, were observed respectively in 62% and 24% of cases. This explains the high rate of hospitalisation (42%), especially for patients with difficult access to services. Significantly, in terms of socio-professional category, live-stock breeders and farmers represented 32% of notified cases, and cattle-traders 18%. We draw attention to the possible role played by Mycobacterium bovis in human case-findings in a region characterised by cattle-breeding.

  5. Atividades analgésica e/ou antiinflamatória da fração aquosa do extrato etanólico das folhas da Spiranthera odoratissima A. St. Hillaire (manacá

    Directory of Open Access Journals (Sweden)

    L.G. Matos

    2003-01-01

    Full Text Available Os testes de contorção abdominal induzida por acido acético, de edema de orelha induzido por óleo de Croton e de peritonite induzida por carragenina foram usados para o estudo de atividades analgésicas e/ou antiinflamatórias da fração aquosa do extrato etanólico das folhas de Spiranthera odoratissima. A fração aquosa inibe o número de contorções abdominais, reduz o edema de orelha e a migração de leucócitos. Os resultados sugerem que as folhas de Spiranthera odoratissima contêm compostos com atividade antiinflamatória.

  6. Evaluación de la extracción del aceite de la Triportheus magdalenae y análisis del perfil lipídico del aceite crudo

    OpenAIRE

    Denilson Padilla Cerpa; Jose Luis. Beleño Quiroz; Rodrigo Rene Cuello Marín; Carmelo Segundo Pérez Yance

    2012-01-01

    Se evaluó el rendimiento en la extracción química del aceite de la especie íctica Arenca (Triportheus magdalenae) mediante la aplicación previa de dos tipos de digestión (ácida y acido-alcohólica), a través de un diseño experimental de bloques completamente al azar (DBCA). La extracción del aceite fue realizada por el método químico soxhlet; (adaptado del método, 960.39-AOAC para carnes) y el análisis del perfil lipídico del aceite crudo fue realizado por cromatografía Gaseosa, demostrando qu...

  7. Caracterización de los ácidos húmicos extraídos de cuatro lombricompuestos y su efecto sobre la germinación de semillas de maíz Zea mays L., algodón Gossypium hirsutum y tomate Lycopersicon esculentum L.

    Directory of Open Access Journals (Sweden)

    Gómez Zambrano Jairo

    1996-12-01

    Full Text Available

    The work perfomed to characterize the elemental composition and functional groups of humic acids extracted from four lombricompost cow dung, filter press cake of sugar cane, coffee pulp and grass residue the total content of essential elements and its distribution in the humic and no humic fractions were determined. It was evalued the effect of two concentrations of humic acids (150 and 300 ppm upon seed germination of maize, cotton and tomat. There were found differences in the elemental composition (CHON and functional groups (COOH, OH phedic and carbony of the humic acids atributed to variations in composition of the original substrates. The lombricompost of cow dung showed higher oxidation values (O/H = 0.49 than the lombricompost of filter press cake of sugar cane (0.40 sugering a higher grade of humification of the first. The grass residue showed higher contribution to the CIC (COOH + OH = 9. O me/g than the coffe pulp (7. 1 me/g the total essential elements were concentrated in the remanent residue, with lower content in the water and 0.1M HCL solutions; the fulvic and humic fractions had very low content of these elements. The humic acid at the concentrations tested did not have any effect on the germination of maize and cotton, and depressed the germination of tomato seeds.

    El trabajo se realizó con el fin de caracterizar por su composición elemental y contenido de grupos funcionales, los acidos húmicos extraídos de cuatro lombricompuestos (bovinaza, cachaza, pulpa de café y residuo de prado. Se determinó el contenido y distribución de los elementos esenciales totales en las fracciones húmicas y no de acidos húmicas. Se evaluó el efecto de dos concentraciones de acidos húmicos (150 y 300 ppm sobre la germinación de semillas de maíz, algodón y tomate. Se encontraron diferencias en el contenido elemental (CHON y grupos funcionales (COOH, OH fenólico y carbonilo atribuido a variaciones en la composición de los

  8. Ácido linoléico conjugado - CLA en alimentos / Conjugated linoleic acid - CLA in foods

    OpenAIRE

    Paz Cabrera, Rafael Alberto

    2009-01-01

    El acido linoléico conjugado CLA, es un compuesto químico de gran importancia en la naturaleza, por la actividad biológica en el organismo. Químicamente es un isómero de ácido linoléico obtenido, obtenido básicamente por tres mecanismos; el primero por bioconversión del ácido linoleico, presente en el rumen de los animales, segundo por producción de metabolitos intermedios en la producción de ácido esteárico y finalmente por la fermentación de la leche mediante algunas cepas de microorganismo...

  9. Estudo da relação entre o indice de Apgar do primeiro minuto de vida com valores bioquimicos de sangue de cordão umbilical

    OpenAIRE

    Figueiredo, Carmen Silvia Martimbianco de

    1992-01-01

    Resumo: No presente trabalho foi avaliada a relação de variáveis gasométricas e do conteúdo de acido láctico, do sangue de artéria e veia do cordão umbilical, com o índice de Apgar do primeiro minuto de vida e com os sinais que o compõem: FC, ER, ER, T, C. A analise de variância das variáveis gasométricas com o índice de Apgar do primeiro minuto de vida mostrou que a exceção do BICv (bicarbonato do sangue de veia umbilical), todos as demais apresentam relação estatisticamente significativa co...

  10. Mécanismes d'adsorption des métaux lourds par les exopolysaccharides bactériens : Le système Xanthane-Cuivre comme modèle d'étude

    OpenAIRE

    Causse, Benjamin

    2009-01-01

    Les ExoPolySaccharides (EPS) bactériens constituent une fraction réactive du sol vis-à-vis des Eléments Traces Métalliques (ETM). Le système xanthane-cuivre est étudié comme modèle de complexation des ETM par les EPS. L'étude à l'échelle macroscopique, par titrages acido-basiques, détermine les valeurs des pKa du xanthane (pKmoyenI=0.1M=2.5) et propose un modèle électrostatique à condensateur cylindrique pour expliquer les variations de pKa en fonction de la force ionique. Les titrages en pré...

  11. Emissions monitoring in conveyed gas flow: (a) sulfur oxides and nitrogen oxides expressed respectively as SO{sub 2} and NO{sub 2}, (b) inorganic chlorine and fluorine compounds as gases and vapours expressed as HCl and HF; Rilevamento delle emissioni in flussi gassosi convogliati: (a) ossidid di zolfo e ossidi di azoto espressi rispettivamente come SO{sub 2} e NO{sub 2}, (b) composti inorganici del cloro e del fluoro sotto forma di gas e vapore espressi rispettivamente come HCl e HF

    Energy Technology Data Exchange (ETDEWEB)

    Ziemacki, G.; Viviano, G. [ed.] [Isituto Superiore di Sanita`, Rome (Italy). Gruppo di lavoro `Modifiche per il rilevamento delle emissioni in atmosfera da impianti industriali`

    1998-03-01

    The method (a) enables the determination of sulfur oxides (SO{sub 2}) and nitrogen oxides (NO{sub 2}) in conveyed atmospheric emissions. A stream of flue gas is a sampled by a heated with a filter housing and absorbed by an alkaline solution of potassium permanganate. The absorption solution is analyzed by ion-exchange chromatography for the determination of sulfate ion and nitrate ion as SO{sub 2} and NO{sub 2}. The method (b) enables the determination of hydrochloric acid (HCl) and hydrofluoric acid (HF) in conveyed atmospheric emissions. A stream of flue gas is sampled by a heated probe with a filter housing and absorbed by an alkaline solution (NaOH). The absorption solution is analyzed by ion-exchange chromatography for the determination of chloride ion and fluoride ion as HCl and HF. [Italiano] Il metodo a) consente la determinazione, in emissioni atmosferiche convogliate, degli ossidi di zolfo (SO{sub 2}) e degli ossidi di azoto (NO{sub 2}). Il campionamento viene effettuato mediante sonda riscaldata, munita di sistema filtrante, e sistema di assorbimento in soluzione alcalina di permanganato di potassio. La soluzione di assorbimento viene analizzata mediante cromatografia a scambio ionico, determinando le concentrazioni di ioni solfato e nitrato come SO{sub 2} ed NO{sub 2}. Il metodo b) consente la determinazione, in emissioni atmosferiche convogliate, dell`acido cloridrico (HCl) e dell`acido fluoridrico (HF). Il campionamento viene effettuato mediante sonda riscaldata, munita di sistema filtrante, e sistema di assorbimento in soluzione alcalina (NaOH). La soluzione alcalina viene quindi analizzata mediante cromatografia a scambio ionico, deter,mminando le concentrazioni di ioni cloro e fluoro come HCl e HF.

  12. Synthesis and evaluation of polystyrene membranes for use in fuel cells; Sintesis y evaluacion de membranas base poliestireno para uso en celdas a combustible

    Energy Technology Data Exchange (ETDEWEB)

    Benavides, R. [Centro de Investigacion en Quimica Aplicada (CIQA), Saltillo, Coahuila (Mexico)] e-mail: robertob@ciqa.mx; Paula, M.M.S.; Da Silva, L.; Fiori, M.; Coronetti, J.C.; Silvano, W.F. [Lasicom, Universidade do Extremos Sul Catarinense (UNESC), Criciuma, S.C. (Brasil); B.M. Huerta [Centro de Investigacion en Quimica Aplicada (CIQA), Saltillo, Coahuila (Mexico)

    2009-09-15

    Polymeric membranes were prepared using mass copolymerization of acrylic/styrene with weight proportions of 90/10, 92/8 and 94/6 %, while using the cross-linked divinylbenzene (DVB) monomer with weight proportions of 0.1 and 0.001 % to improve the mechanical properties. The copolymers obtained were sulfonates with sulfuric acid concentrated for 0, 30, 85 and 120 minutes to improve its ionic exchange capacity. The materials were characterized using infrared spectroscopy, thermal analysis (TGA and DSC), cross-linked level with% Gel and acidity using titration with sodium hydroxide. The IR spectrum of the membranes before sulfonating shows the existence of traditional polymer bands used with two signals from homopolymers that are lost and two new signals appearing, corroborating the copolymerization reactions. The thermogravimetry shows a higher decomposition temperature for the cross-linked DVB membranes, while the DSC is not very useful for observing transitions due to the hygroscopicity of the membranes. Finally, the percentage of gel is related to the amount of DVB used and the acidity of the membranes increases with increasing amounts of acrylic acid, sulfonation time and DVB percentage, although this value depends a good deal on the ease of solubilizing the material. The ionic properties of the membranes with better mechanical properties were evaluated with a fuel cell prototype. [Spanish] Se prepararon membranas polimericas mediante la copolimerizacion en masa del estireno/acido acrilico en proporciones de 90/10, 92/8 y 94/6 % en peso, al mismo tiempo que se utilizo el monomero entrecruzante divinilbenceno (DVB) en proporciones de 0.1 y 0.001 % en peso, para mejorar sus propiedades mecanicas. Los copolimeros obtenidos fueron sulfonados con acido sulfurico concentrado durante periodos de tiempo de 0, 30, 85 y 120 minutos para mejorar su capacidad de intercambio ionico. Se caracterizaron los materiales mediante espectroscopia infraroja, analisis termicos (TGA y

  13. Energy alternative for the use of organic waste (swine feces) in the state of Tabasco; Alternativa energetica para el aprovechamiento de los desechos organicos (excretas de ganado porcino) en el estado de Tabasco

    Energy Technology Data Exchange (ETDEWEB)

    Ramon Garcia, E.; Angles Falconi, S.I.; Vazquez Magana, L.R.; Tun Perez, A.C. [Instituto Tecnologico de Villahermosa, Villahermosa, Tabasco (Mexico)]. Email: bioleliza_ramgar@hotmail.com; sergio_falcorp@hotmail.com

    2009-09-15

    Biogas is obtained from decomposing organic material due to the action of four types of bacteria, in the absence of oxygen: hydrolytic, producers of moncarbonate compounds and acidogenics, producing organic fatty acids and other polycarbonate compounds; acetogenic, producers of hydrogen and CO{sub 2}; homoacetogenic, that can convert a considerable amount of multicarbonate or monocarbonate compounds into acetic acid and; metanogenic, producers of methane gas, the principal component of biogas. To design and build the pilot equipment proposed for this research, a 20-liter container was used with 10 kg of swine feces with identical volumes of inoculates. The aerobic fermentation process was immediate begun, followed by the anaerobic process; metabolic reactions were conducted. A total of 0.119 m3 of biogas was obtained from the anaerobic fermentation of 10 kg of swine feces, 60% (0.0714 m{sup 3}) of which was methane gas and the remaining 40%(0.0476 m{sup 3}) hydrogen sulfide (HS). During this investigation, it was concluded that obtaining this by-product (methane biogas), which can be used as a biofuel, provides an economically and ecologically sustainable alternative that reduces organic discharges (swine feces) into rivers and reduces the energy expenditures of swine farms. Because of the high generation of RSM, the creation of a biogas production plant in Tabasco is proposed. [Spanish] El biogas se obtiene al descomponerse la materia organica debido a la accion de cuatro tipos de bacterias, en ausencia de oxigeno: las hidroliticas, que producen compuestos monocarbonados, las acidogenicas producen acidos grasos organicos y otros compuestos policarbonados; las acetogenicas productoras de Hidrogeno y CO{sub 2}; las homoacetogenicas, que pueden convertir una cantidad considerable de compuestos multicarbonados o monocarbonados en acido acetico; y las metanogenicas, productoras del gas metano, principal componente del biogas. Para el diseno y construccion del equipo

  14. The Mediterranean diet and micronutrient levels in depressive patients.

    Science.gov (United States)

    Ibarra, Olga; Gili, Margalida; Roca, Miguel; Vives, Margalida; Serrano, María Jesús; Pareja, Antonio; García-Campayo, Javier; Gómez-Juanes, Rocío; García-Toro, Mauro

    2014-10-03

    Introducción: Se ha comunicado una correlación inversa entre depresión y el nivel sérico de algunos micronutrientes (selenio, zinc, hierro, magnesio, vitamina B y acido fólico). Además, otros estudios han señalado que la suplementar de estos micronutrientes puede mejorar la depresión. La dieta mediterránea proporciona una suficiente cantidad de los micronutrientes mencionados, aunque ningún estudio ha probado si la prescripción de dicha dieta puede incrementar los niveles de micronutrientes en pacientes depresivos. Objetivo: Examinar el impacto de recomendar un patrón dietético mediterráneo en los niveles de micronutrientes de pacientes deprimidos. Material y Métodos: 77 pacientes ambulatorios se aleatorizaron entre un grupo de intervención (recomendaciones higiénico-dietéticas sobre dieta, ejercicio, sueño y exposición solar) y un grupo control. La evolución fue evaluada antes y después de los seis meses del periodo de intervención. Resultados: Los niveles de selenio y de zinc fueron ligeramente bajos en la determinación basal y el nivel de selenio correlacionaba inversamente con la severidad de la depresión (r=-0.233; p=0.041). El grupo activo evolucionó mejor de la clínica depresiva. Sin embargo, no se observaron diferencias significativas en los niveles de micronutrientes después de la prescripción del patrón de dieta mediterránea probablemente a causa de una insuficiente adherencia. Conclusión: Los niveles séricos de selenio, zinc, hierro, magnesio vitamina B12 y acido fólico no aumentaron en pacientes depresivos seis meses después de prescribir un patrón de dieta mediterránea.

  15. Synthesis and electrochemical characterization of highly tolerant Pd electrocatalysts as cathodes in direct ethylene glycol fuel cells (DEGFC)

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Varela, F.J.; Fraire Luna, S. [Cinvestav, Unidad Saltillo, Ramos Arizpe, Coahuila (Mexico)] e-mail: javier.varela@cinvestav.edu.mx; Savadogo, O. [Laboratoire d' Electrochimie et de Materiaux Energetiques, Ecole Polytechnique de Montreal, Montreal, QC (Canada)

    2009-09-15

    Highly selective Pd electrocatalysts were synthesized by the formic acid method and evaluated as cathodes for DEGFC applications. In rotating disc measurements in acid medium, the Pd/C cathode showed important catalytic activity for the Oxygen Reduction Reaction (ORR). In the presence of ethylene glycol (EG, C{sub 2}H{sub 6}O{sub 2}), Pd/C exhibited an excellent electrochemical behavior and full tolerance to the organic molecule. No current density peaks associated to the EG oxidation reaction emerged and the shift in onset potential for the ORR (Eonset) toward more negative potentials was negligible on this cathode. Moreover, the evaluation of Pd/C in a DEGFC operating at 80 degrees Celsius demonstrated its high performance as cathode. As a comparison, commercial Pt/C was tested under the same conditions showing a limited selectivity for the ORR. The detrimental effect of EG on the Pt electrocatalysts resulted in high intensity current density peaks due to the oxidation of EG and a significant shift in Eonset. Given these results, it is expected that highly efficient Pd-based cathodes can find application in DEGFCs. [Spanish] Se sintetizaron electrocatalizadores altamente selectivos mediante el metodo de acido formico y se evaluaron como catodos en aplicaciones de CCGED. En mediciones de disco rotatorio en medio acido, el catodo Pd/C mostro importante actividad catalitica en la reaccion de reduccion de oxigeno (RRO). En la presencia de glicol de etileno (GE, C{sub 2}H{sub 6}O{sub 2}), Pd/C exhibio un excelente comportamiento electromecanico y tolerancia total a la molecula organica. No surgieron picos de densidad de corriente asociados con la reaccion de oxidacion de GE y el corrimiento en el potencial de inicio para la RRO (Einicio) hacia potenciales mas negativos fue despreciable en este catodo. Como comparacion, se probo un Pt/C bajo las mismas condiciones y se observo una selectividad limitada para el RRO. El efecto perjudicial de GE en el electrocatalizador

  16. Caracterización y estudio de la fermentación espontánea del suero costeño producido en Montería

    Directory of Open Access Journals (Sweden)

    Mónica Simanca S

    2010-04-01

    Full Text Available Objetivo. Caracterizar el proceso fermentativo del suero costeño elaborado en Montería. Materiales y métodos. Se caracterizó fisicoquímica y bromatológicamente el producto elaborado artesanalmente en Montería; se evaluó durante 24 horas la fermentación espontánea del producto elaborado en las microempresas, se determinó pH, acidez total, concentración de lactosa y mesófilos aerobios cada tres horas. Se aislaron y seleccionaron los microorganismos involucrados en la fermentación, teniendo en cuenta las propiedades de interés tecnológico y se identificaron bioquímicamente por API 50CH (BioMérieux. Resultados. El suero costeño de contenido medio en grasa, presentó una humedad de 76%, extracto etéreo (11.65%, proteína (5.09%, lactosa (4.36%, cenizas (2.88%, cloruros (2.34%, pH (3.94 y acidez (1.4% acido láctico. En la fermentación espontánea se observó un comportamiento inversamente relacionado entre el pH y la acidez, alcanzando al final del estudio un valor de 4.69 y 0.67% de ácido láctico respectivamente; se encontró un porcentaje de lactosa de 4.44% y una población de mesófilos aerobios de 2x109 UFC/mL. Se aislaron tres cepas de bacterias acido lácticas (BAL identificadas como Enterococcus faecium y Lactobacillus brevis. Conclusiones. Las características fisicoquímicas y bromatológicas del suero costeño elaborado en la ciudad de Montería, no presentaron diferencias estadísticamente significativas entre los productos. En la fermentación espontanea hubo consumo de lactosa, aumento de la concentración de mesófilos aerobios y se presentó una relación inversa entre pH y acidez. Se aislaron e identificaron BAL con la posibilidad de ser utilizadas como cultivos iniciadores.

  17. Inhibición del Oscurecimiento con Mucílago de Nopal (Opuntia ficus indica en el Secado se Plátano Roatán Inhibition the Darkening with Cactus Mucilage (Opuntia ficus indica during Drying of Banana Roatán

    Directory of Open Access Journals (Sweden)

    Laura V Aquino

    2009-01-01

    Full Text Available El objetivo de este estudio fue inhibir el oscurecimiento durante el deshidratado de plátano Roatán (Musa cavendish, usando una solución de mucílago de nopal (Opuntia ficus indica combinado con diferentes concentraciones de acido cítrico y bisulfito de sodio. El tratamiento se aplicó siguiendo un diseño experimental 2³, siendo los factores y niveles: pre-tratamiento (mucílago-acido cítrico-bisulfito de sodio y concentración (alta y baja. Para el secado se usaron cortes transversales de plátano de un espesor de 5 mm; una temperatura de 50 °C y una velocidad de aire de 2 ms-1. Se midió el color antes y después del secado y se consideró como variable respuesta. La combinación de mucílago con ácido cítrico y bisulfito de sodio a altas concentraciones tuvo un efecto sinérgico que favorece en la disminución del oscurecimiento del plátano durante el secado. El mucílago formó una cubierta protectora en la superficie que proporcionó brillo al material deshidratado.The object of this study was inhibiting the browning process during the drying of banana Roatán (Musa Cavendish using a solution of cactus mucilage (Opuntia ficus indica blend with different concentrations of citric acid and sodium bisulphite. The treatment was applied following an experimental design 2³, using the following factors and levels: pre-treatment (mucilage, citric acid, sodium bisulphate and concentration (high and low. For the drying cross sections of banana with thickness of 5 mm, temperature of 50 °C and air velocity of 2 ms-1 were used. Color before and after drying was determined and was consider as the response variable. The combination of mucilage, citric acid and sodium bisulphite at high concentrations had a synergic effect that diminished the browning of bananas during drying. The mucilage formed an edible coating in the surface that gives shine to the dried material.

  18. Vitamina C, carotenoides, fenólicos totais e atividade antioxidante de goiaba, manga e mamão procedentes da Ceasa do Estado de Minas Gerais = Vitamin C, carotenoids, phenolic compounds and antioxidant activity of guava, mango and papaya from Ceasa of Minas Gerais State

    Directory of Open Access Journals (Sweden)

    Daniela da Silva Oliveira

    2011-01-01

    Full Text Available Este estudo teve como objetivo analisar o conteudo de compostos antioxidantes (acido ascorbico - AA, acido desidroascorbico - ADA, vitamina C total, licopeno, £]-caroteno, £]-criptoxantina e estimativa de compostos fenolicos e avaliar a atividade antioxidante, em goiaba, manga e mamao. A analise de carotenoides e vitamina C foi realizada por Cromatografia Liquida de Alta Eficiencia (CLAE. O teor de fenolicos totais foi determinado utilizando o reagente de Folin-Ciocalteu e leitura espectrofotometrica. A atividade antioxidante foi avaliada pelo Teste do 2,2-diphenil-2-picril-hidrazil (DPPH¡E e do Poder Redutor. A Anova (ƒÑ = 0,05 foi utilizada para a analise dos dados. Os teores dos constituintes antioxidantes diferiram entre as tres frutas, mas a goiaba foi a fruta que apresentou teores mais elevados de compostos fenolicos, vitamina C total, ADA e licopeno, alem dos maiores valores para atividade antioxidante. Foi constatada forte correlacao entre os testes que avaliaram a atividade antioxidante e o teor de fenolicos totais, demonstrando serem estes os principais compostos antioxidantes a contribuirem para a atividade antioxidante das frutas analisadas, em ambos os testes. E importante incentivar a utilizacao das frutas avaliadas neste estudo, tanto em nivel domestico quanto em estabelecimentos de alimentacao coletiva para aumentar o consumo de antioxidantes naturais pela populacao.This study aimed to analyze the content of antioxidant compounds (ascorbic acid - AA, dehydroascorbic acid - DHA, total vitamin C, lycopene, £]-carotene, £]-cryptoxanthin and phenolic compounds and to evaluate the antioxidant activity in guava, mango and papaya.The analysis of carotenoids and vitamin C was performed by high performance liquid chromatography (HPLC. The content of phenolic compounds was determined using the Folin-Ciocalteu reagent and spectrophotometric reading. Antioxidant activity was evaluated by testing the 2.2-diphenyl-2-picryl

  19. Comparison of energy expenditure and closed-loop performance of thermal and reactive distillation sequences coupled for biodiesel production; Comparacion de gasto energetico y desempeno a lazo cerrado de secuencias de destilacion reactiva y termicamente acopladas para produccion de biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Cornejo-Jacob, J.L [Universidad Michoacana de San Nicolas de Hidalgo, Morelia, Michoacan (Mexico); Vazquez-Ojeda, M; Segovia-Hernandez, J.G; Hernandez, S [Universidad de Guanajuato, Guanajuato, Guanajuato (Mexico); Maya-Yescas, R. [Universidad Michoacana de San Nicolas de Hidalgo, Morelia, Michoacan (Mexico)]. E-mail: rmayay@umich.mx

    2013-03-15

    Biodiesel is the common name for fatty acid methyl esters, obtained by esterification (basic catalysis) or trans-esterification (acid catalysis) of vegetable or animal oils with alcohols, and used as liquid fuel. Production involves the reaction, under mild conditions, between the oil and, typically, excess of methanol. Traditional production of biodiesel exhibits some handicaps, such as the shift of equilibrium to fatty acids by using excess of alcohol that must be separated and recycled. As alternative, it is possible to integrate reaction/separation operations into a single intensified unit, a reactive distillation column, followed by a second separation unit. These configurations exhibit several advantages such as shifting equilibrium in the reactive region and, because of the thermal integration with the second unit, energy savings during products separation. In order to design these production sequences taking advantage of steady state knowledge (energy savings) and considering dynamic performance, this work performs a controllability analysis for six possible configurations; open-loop control properties, evaluated by single value decomposition, are probed by implementing PI controllers to the system. The reactive distillation column coupled to a stripper, without reboilers, shows to be the best option in terms of closed-loop performance and energy savings. [Spanish] Biodiesel es el nombre comun dado a metil esteres de acidos grasos obtenidos por esterificacion (catalisis basica) o trans-esterificacion (catalisis acida) de aceites animales o vegetales con alcoholes, y usados como combustibles liquidos. Su produccion involucra la reaccion entre el aceite y, tipicamente, exceso de metanol a condiciones moderadas. La produccion tradicional de biodiesel exhibe algunas desventajas como el desplazamiento del equilibrio hacia acidos grasos debido al exceso de alcohol, que debe ser separado y reciclado. Alternativamente, es posible integrar las operaciones reaccion

  20. Molluscicidal activity of various solvent extracts from Solanum nigrum var. villosum L. aerial parts against Galba truncatula

    Directory of Open Access Journals (Sweden)

    Hammami H.

    2011-02-01

    Full Text Available Molluscicidal activity of Solanum nigrum var. villosum (morelle velue extracts and their fractions were tested against the mollusca gastropoda Galba truncatula intermediate host of Fasciola hepatica. The results indicated that the hydro-methanol (MeOH-H2O immature fruit extract possess the highest molluscicidal activity (LC50 = 3.96 mg/L against Galba truncatula compared with other tested compounds. After acido-basic treatment, the methanolic extract fraction isolated from the immature fruits and the richest in alkaloids was the most toxic (LC50 = 1.65 mg/L. The fractions richest in saponosides obtained from the hydromethanolic and methanolic extracts of immature fruits showed interesting molluscicidal activities (LC50 = 6.15 mg/L and LC50 = 7.91 mg/L, respectively. The observed molluscicide activity could be attributed to the presence of alkaloids or saponosides. So, the immature fruits of Solanum nigrum var. villosum could be substrates of choice for molluscicide activity. In addition, total alkaloids and saponosides present in this plant deserve further investigations in order to identify the active principles and demonstrate their activities on mollusks in their natural habitat. According to the World Health Organization’s guidelines on screening for plant molluscicides, use of these fractions may add to the arsenal of methods to control snail transmitting fasciolosis in tropical and Third World countries where fasciolosis is a common disease.

  1. Origin of highly active metal-organic framework catalysts: defects? Defects!

    Science.gov (United States)

    Canivet, J; Vandichel, M; Farrusseng, D

    2016-03-14

    This article provides a comprehensive review of the nature of catalytic sites in MOFs. In the last decade, a number of striking studies have reported outstanding catalytic activities of MOFs. In all cases, the authors were intrigued as it was unexpected from the ideal structure. We demonstrate here that (surface) defects are at the origin of the catalytic activities for the reported examples. The vacancy of ligands or linkers systematically generates (surface) terminations which can possibly show Lewis and/or Brønsted acido-basic features. The engineering of catalytic sites at the nodes by the creation of defects (on purpose) appears today as a rational approach for the design of active MOFs. Similarly to zeolite post-treatments, post-modifications of MOFs by linker or metal cation exchange appear to be methods of choice. Despite the mild acidity of defective MOFs, we can account for very active MOFs in a number of catalytic applications which show higher performances than zeolites or benchmark catalysts. PMID:26584043

  2. [Benign myoclonic epilepsy in infancy: natural history and behavioral and cognitive outcome].

    Science.gov (United States)

    Domínguez-Carral, Jana; García-Peñas, Juan José; Pérez-Jiménez, M Ángeles; Fournier-Del Castillo, M Concepción; Carreras-Sáez, Inmaculada; Jiménez-Echevarría, Saioa

    2014-02-01

    Introduccion. La epilepsia mioclonica benigna del lactante (EMBL) es un sindrome electroclinico de caracteristicas homogeneas y bien definidas, considerado clasicamente de buen pronostico. Sin embargo, en los ultimos años se han publicado estudios con resultados variables en cuanto a evolucion neuropsicologica. Objetivo. Analizar la evolucion natural y el pronostico neurocognitivo y conductual de los pacientes con EMBL. Pacientes y metodos. Estudio retrospectivo de 10 pacientes con EMBL, con un periodo de seguimiento de mas de cinco años, durante los cuales se realizo una evaluacion neurocognitiva y conductual. Resultados. En el 60% de los pacientes las crisis se controlaron con acido valproico en monoterapia, y el 80% no presento nuevas crisis durante su seguimiento. El cociente intelectual de la cohorte se situo entre 74 y 93; tres pacientes tuvieron un cociente intelectual en rango de inteligencia limite, y seis, en rango de inteligencia media-baja. Nueve pacientes cumplieron criterios de trastorno por deficit de atencion/hiperactividad y dos asociaban otro trastorno del aprendizaje, uno de ellos trastorno de aprendizaje no verbal, y el otro, trastorno especifico de la lectoescritura. Todos los pacientes presentaron datos de pobre coordinacion motriz y visuoespacial, y tres fueron diagnosticados de trastorno de conducta. Conclusiones. El termino 'benigno' en la EMBL debe utilizarse con precaucion en cuanto a su pronostico neurocognitivo y conductual. El inicio precoz y un peor control de las crisis podrian suponer factores de riesgo de evolucion neuropsicologica desfavorable.

  3. Theoretical Studies on the Isomerization of Peroxynitrite to Nitrate Mediated by Peroxynitrous Acid

    Institute of Scientific and Technical Information of China (English)

    LIU Yong-Dong; ZHONG Ru-Gang

    2008-01-01

    The conversion of peroxynitrite(ONOO-)to nitrate(NO3-)mediated by peroxy-nitrous acid(ONOOH)has been investigated at the CCSD/6-311G(d)//B3L YP/6-311+G(d,P)level.Two kinds of pathways for the title reaction were found.The results show that the energy barrier ofisomerization through pathway 1 is around 25 kcal/mol in the gas phase.This value is significantly lower than that of isomerization without any catalysts.Thus,it indicates that ONOOH definitely makes the conversion from ONOO- to NO3- feasible.Although pathway 2 does not decrease the energy barrier of this isomerization,peroxynitric acid(O2NOOH)Was obtained;moreover,this is a new pathway for this formation.In view of the results that peroxynitrate anion Can decompose into nitrite and dioxygen.we conclude that our results are consistent with the experimental observation that nitrate,nitrite,and dioxygen are the main final products of the decay of peroxynitrite around pH7.

  4. Light-induced copper(II) coordination by a bicyclic tetraaza chelator through a ligand-to-metal charge-transfer reaction.

    Science.gov (United States)

    Holm-Jørgensen, Jacob R; Jensen, Mikael; Bjerrum, Morten J

    2011-12-19

    To enable utilization of the broad potential of copper isotopes in nuclear medicine, rapid and robust chelation of the copper is required. Bowl adamanzanes (bicyclic tetraaza ligands) can form kinetically stable copper complexes, but they are usually formed at low rates unless high pH values and high temperatures are applied. We have investigated the effects of the variation in the pH, different anions, and UV irradiation on the chelation rate. UV spectra of mixtures of Cu(2+) and [2(4).3(1)]adz in water show the existence of a long-lived two-coordinated copper(II) intermediate (only counting coordinated amine groups) at pH above 6. These findings are supported by pH titrations of mixtures of Cu(2+) and [2(4).3(1)]adz in water. Irradiation of this complex in the ligand-to-metal charge-transfer (LMCT) band by a diode-array spectrophotometer leads to photodeprotonation and subsequently to formation of the four-coordinated copper(II) complex at a rate up to 7800-fold higher at 25 °C than in the dark. Anions in the solution were found to have three major effects: competitive inhibition due to Cu(II) binding anions, inhibition of the photoinduced transchelation from UV-absorbing anions, and photoredox inhibition from acido ligands capable of acting as electron donors in LMCT reactions. Dissolved O(2) was also found to result in photoredox inhibition.

  5. Intoxicación por fluoroacetato de sodio

    Directory of Open Access Journals (Sweden)

    Juliana Granada

    2014-01-01

    Full Text Available El fluoroacetato de sodio es conocido como compuesto 1080, fue descubierto por químicos alemanes durante la segunda guerra mundial. Es un compuesto inodoro e insaboro, soluble en agua, la dosis letal 50 en humanos es de 2 a 4 mg/kg. Debido a su letalidad, ha sido retirado del mercado en algunos países incluyendo Colombia. Este compuesto causa efectos bioquímicos y fisiológicos como acumulación de citrato, alteración de los trasportadores mitocondriales del citrato, acumulación de acido láctico, alteración de la regulación de la glucosa y alteraciones hidrioelectroliticas (principalmente en los niveles de calcio. Las manifestaciones clínicas de intoxicación por esta sustancia son inespecíficas, lo que dificulta su identificación y tratamiento oportuno, aumentando su letalidad. El etanol aumenta el nivel de acetato, ofreciendo así un sustrato alterno al ciclo de Krebs y puede ofrecer beneficios en el tratamiento agudo de estos pacientes. Sin embargo, el manejo de soporte es el pilar fundamental del manejo de estos casos. Se presenta un caso de ingestión intencional en un adolescente con diagnóstico tardío y con desenlace satisfactorio.

  6. Operation of the ISO-DALT system: Seventh edition

    Energy Technology Data Exchange (ETDEWEB)

    Tollaksen, S.L.; Anderson, N.L.; Anderson, N.G.

    1984-05-01

    The ISO-DALT system of two-dimensional electrophoresis was developed as a series of modifications of the original technique of O'Farrell. We have written a series of recipes and more detailed laboratory procedures that incorporate refinements and ''tricks of the trade'' as they have developed during our use of the system. The present collection is the seventh version in this series and represents the state of art as of May 1984. The seventh edition has been prepared to incorporate the changes that we have found helpful, as well as to add a few new sections such as silver staining, transfer gels, ACIDOs, and BASOs. Although these directions are specific for our laboratory, we hope that they will be helpful in other laboratories as well. Although some disagreement still exists, we recommend that gel patterns be oriented with acid isoelectric points (pIs) to the left and high sodium dodecyl sulfate (SDS) molecular weights at the top. This results in a system of pI and molecular weight values that run according to the Cartesian convention and facilitates the use of the charge and molecular weight standards described herein. 67 refs., 14 figs.

  7. [Phenotypic variations in Aicardi-Goutieres syndrome caused by RNASEH2B gene mutations: report of two new cases].

    Science.gov (United States)

    Ortiz-Madinaveitia, Saturnino; Conejo-Moreno, David; López-Pisón, Javier; Peña-Segura, José Luis; Serrano-Madrid, M Luisa; Durán-Palacios, Ingrid C; Peláez-Cabo, Pilar

    2016-02-16

    Introduccion. El sindrome de Aicardi-Goutieres es un trastorno inmunitario raro debido a mutaciones en siete genes que codifican proteinas llamadas TREX1, el complejo ribonucleasa H2, SAMHD1, ADAR e IFIH1 (MAD5), las cuales estan implicadas en el metabolismo de los acidos nucleicos. A continuacion se presentan dos nuevos casos por mutacion en el gen RNASEH2B, uno de los cuales presenta una mutacion no descrita hasta la fecha. Casos clinicos. Caso 1: varon que consulto porque desde los 5 meses, coincidiendo con cuadros febriles de repeticion, presentaba perdida de los items madurativos adquiridos hasta la fecha. Caso 2: niño de 4 meses que desde los 2 meses mostraba gran irritabilidad con dificultades en la alimentacion, asociado a un grave retraso psicomotor. En ambos casos se constato un aumento de las pterinas en el liquido cefalorraquideo, principalmente de la neopterina, con calcificaciones en los ganglios basales. El diagnostico se confirmo mediante secuenciacion del gen RNASEH2B; el caso 2 presentaba una mutacion no descrita en la literatura medica. Conclusiones. Los casos corresponden a la descripcion clasica realizada por Aicardi-Goutieres. Debe tenerse en cuenta este sindrome ante un paciente con un cuadro de encefalopatia subaguda de comienzo en el primer año de vida, distonia/espasticidad en grado variable e importante afectacion/regresion del desarrollo psicomotor, especialmente si asocia aumento de las pterinas (neopterina) en el liquido cefalorraquideo y calcificaciones en los ganglios basales.

  8. Lupus vulgaris: Isolation of Mycobacterium tuberculosis from the affected skin scraping and mucous membranes

    Directory of Open Access Journals (Sweden)

    Jovanović Marina

    2006-01-01

    Full Text Available Introduction. In the second half of the last century skin tuberculosis has become a rarity. With the appearance of resistance to different kinds of pathogenes, HIV-immunodeficiency and decreasing standard of living, the incidence of skin tuberculosis increses. Lupus vulgaris is a chronic form of the secondary tuberculosis of the skin. Case report. This is a case report of a 66-year-old woman who presented with a growing, painless, brownish-red, slab-shaped, jelly, cutanesous mass, 2.5 centimeters in diameter, on the tip of her nose, reaching the mucous membrane of the nose. Results. Apart from accelerated erythrocyte sedimentation rate (43/73 and a positive tuberculosis test (Mantoux 10 TU=25x25 mm, all relevant findings were within reference values. Using Ziehl-Neelsen staining, no acido-resistent bacilli were found. The skin scraping sample, taken from the affected skin and the mucous membrane, was cultivated in Lowenstein medium base, and this resulted with cultivation of Mycobacterium tuberculosis. Using three-drug combination therapy for ten months, complete remission was achieved. Conclusion. Successful cultivation of pathogens represents an absolute diagnostic criterion. We present a case of a woman with lupus vulgaris, because there is a small number of cases documented around the world where the diagnosis was confirmed by culture of Mycobacterium tuberculosis. .

  9. Actualización de la Fisiología Gástrica

    Directory of Open Access Journals (Sweden)

    David Rodríguez Palomo

    2010-09-01

    Full Text Available La fisiología gástrica constituye una compleja y dinámica interacción entre estructuras anatómicas, sus secreciones, el ambiente circundante y los factores exógenos aportados por el individuo. Este trabajo pretende hacer una breve revisión actualizada sobre la fisiología de la secreción y la motilidad gástricas. Se expondrá la función de las principales células de la mucosa gástrica, sus secreciones y aquellas sustancias, hormonas y neurotransmisores que las estimulan, modulan o inhiben, haciendo especial énfasis en los mecanismos de producción del acido gástrico. Además, se tratará específicamente el tema de la motilidad gástrica con idéntica metodología.Gastric physiology constitutes a complex and dynamic interaction between anatomic structures, their secretions, the environment around and the exogenous factors provided by the individual. This work pretends to offer a brief actualized literature review about the physiology of the gastric secretions and gastric motility. We will expose the function of the main gastric mucosa cells, its secretions and the substances, hormones and neurotransmitters that enhance, modify and inhibit them, making special emphasis in the gastric acid secretion. Moreover, the subject of gastric motility, specifically, will be explained with identical methodology.

  10. Monocapas de ácidos grasos. I. Ácido esteárico sobre disoluciones acuosas de etanol

    Directory of Open Access Journals (Sweden)

    Rodríguez Patino, J. M.

    1991-04-01

    Full Text Available The structure and stability of fatty acid monolayers spread on aqueous solutions with ethanol has been studied. The experiments were carried out isothermically using a commercial Langmuir balance (Lauda. Monolayers exhibit solid or condensed liquid structure depending of the ethanol concentration in the subphase. Temperature has not a significant influence on the monolayer. Structure there is a loss of stearic acid film through solution into the adjacent subphase. This loss is increased with the temperature and ethanol concentration in the subphase.

    Monocapas de ácidos grasos. I. Acido esteárico sobre disoluciones acuosas de etanol. Se ha estudiado la estructura y estabilidad de monocapas de ácido esteárico esparcidas sobre disoluciones acuosas que contienen etanol. Las experiencias se han realizado en una balanza de superficie comercial tipo Langmuir y se ha operado en condiciones isotérmicas. Las monocapas presentan estructuras de tipo sólida o de líquido condensado en función de la concentración de etanol en la subfase. La estructura que adopta la monocapa es prácticamente independiente de la temperatura. La pérdida de moléculas de ácido esteárico de la monocapa por disolución en la subfase se incrementa a los valores más elevados de temperatura y de concentración de etanol.

  11. CO{sub 2} sequestration technologies

    Energy Technology Data Exchange (ETDEWEB)

    Ketzer, Marcelo [Brazilian Carbon Storage Research Center (Brazil)

    2008-07-15

    In this presentation the importance of the capture and sequestration of CO{sub 2} is outlined for the reduction of gas discharges of greenhouse effect; then the principles of CO{sub 2} storage in geologic formations are reviewed; afterwards, the analogs for the CO{sub 2} storage are commented, such as the storage of the acid gas, the natural gas storage and the natural CO{sub 2} deposits. Also it is spoken on the CO{sub 2} storage in coal, in water-bearing saline deposits and in oil fields, and finally the subject of the safety and monitoring of the CO{sub 2} storage is reviewed. [Spanish] En esta presentacion se expone la importancia de la captura y secuestro de CO{sub 2} para la reduccion de emisiones de gases de efecto invernadero; luego se tratan los principios de almacenamiento de CO{sub 2} en formaciones geologicas; despues se comentan los analogos para el almacenamiento de CO{sub 2} como el almacenamiento del gas acido, el almacenamiento de gas natural y los yacimientos naturales de CO{sub 2}. Tambien se habla sobre el almacenamiento de CO{sub 2} en carbon, acuiferos salinos y yacimientos petroliferos y por ultimo se toca el tema de la seguridad y monitoreo del almacenamiento de CO{sub 2}.

  12. Mechanochemical process to recover heavy metals from industrial ash; Procedimenti meccanochimici per l'estrazione di metalli pesanti da ceneri industriali

    Energy Technology Data Exchange (ETDEWEB)

    La Barbera, A.; Bimbi, C.; De Francesco, M.; Padella, F. [ENEA Centro Ricerche Casaccia, Rome (Italy). Dipt. Innovazione; Ranaldi, E. [ENEA Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente

    1999-07-01

    An innovative mechanochemical process has been conceived to recover heavy metals from industrial ashes. The low environmental impact process is based on the transformation of heavy metals oxides into soluble salts. In particular high energy ball milling has been successfully applied on real samples from iron electrometallurgy. Heavy metals extractions higher than the ones resulting from the typical acid attack were obtained. [Italian] A partire da simulazioni termidinamiche, e' stato ideato un innovativo processo meccanochimico a basso impatto ambientale per il recupero di metalli pesanti da ceneri pericolose di origine industriale. Il processo, che prevede la conversione in fasi solubili di metalli pesanti presenti nelle ceneri sotto forma di ossidi misti insolubili, e' stato sperimentato con successo sia su campioni di laboratorio che su campioni reali. In particolare la macinazione ad alta energia e' stata applicata a campioni di cenere provenienti da elettrometallurgia del ferro, con un elevato contenuto di zinco, ottenendo risultati migliori di quelli ottenibili da un tradizionale attacco acido.

  13. Dietary potential renal Acid load in venezuelan children.

    Science.gov (United States)

    López-Sayers, Mayerling; Bernal, Jennifer; López, Michelle

    2015-05-01

    Objetivo: Determinar y analizar la carga acida potencial renal de la dieta (Potential Renal Acid Load PRAL) y el patron de alimentacion de ninos entre 1 a 6 anos aparentemente sanos. Métodos: Se seleccionaron segun conveniencia a padres de 52 ninos asistentes a una consulta de ninos sanos. La calidad de la dieta y el patron de alimentacion se evaluo mediante un recordatorio de 24 horas y un cuestionario de frecuencia de alimentos. Se calculo la ingesta de macronutrientes y grupos de alimentos, como carnes, lacteos, frutas y verduras. La ingesta de nutrientes se comparo con las recomendaciones de energia y nutrientes. El PRAL se determino segun el metodo de Remer y Manz, para determinar la carga acida de la dieta. Se aplico estadistica descriptiva y correlaciones entre el PRAL, nutrientes y grupos de alimentos. Resultados: La ingesta de proteinas, de leche y de carnes fue elevada, mientras que la ingesta de rutas y hortalizas fue baja. El PRAL fue positivo en 92% de los ninos, se asocio con mayor ingesta de energia, proteinas, grasas, carne y lacteos. La ingesta de proteinas fue > 2,5 g/kg/ dia en 46,2% de los ninos. Los grupos de alimentos con mayor desequilibrio debido a exceso fueron la carne y los productos lacteos, mientras que por deficit fue el grupo de frutas y hortalizas. Conclusión: La dieta se caracteriza por una elevada carga de acido o PRAL, lo que aumenta el riesgo de acidosis sistemica y sus consecuencias metabolicas.

  14. An analytical method for determination of mercury by cold vapor atomic absorption spectroscopy; Determinazione di mercurio. Metodo per spettrometria di assorbimento atomico a vapori freddi (CV-AAS)

    Energy Technology Data Exchange (ETDEWEB)

    Campanella, L. [Rome Univ. La Sapienza, Rome (Italy); Mastroianni, D.; Capri, S.; Pettine, M. [CNR, Rome (Italy). Ist. di Ricerca sulle Acque; Spezia, S.; Bettinelli, M. [ENEL, Unified Modelling Language, Piacenza (Italy)

    1999-09-01

    An analytical procedure for the determination of total mercury in wastewaters and natural waters is described. Aqueous samples are fast digested with nitric acid by using the microwave-oven technique; the analysis of mercury is then performed by cold vapor atomic absorption spectrometry (CV-AAS) using two possible instrumental apparatus (batch system or flow injection). Sodium borohydride is used as the reducing agent for mercury in solution (Method A). The use of amalgamation traps on gold for the preconcentration of mercury lowers the detection limit of the analyte (Method B). [Italian] Viene descritta una procedura analitica per la determinazione del mercurio totale in acque di scarico e naturali. Il campione acquoso viene sottoposto a mineralizzazione con acido nitrico in forno a microonde e analizzato mediante spettroscopia di assorbimento atomico a vapori freddi (CV-AAS) in due possibili configurazioni strumentali (sistema batch oppure flow injection), utilizzando sodio boro idruro come agente riducente del mercurio (metodo A). L'impiego della trappola di oro per la preconcentrazione del mercurio mediante amalgama consente di determinare l'analita a livelli di pochi ng/L (metodo B).

  15. An environmentally friendly method to remove and utilize the highly toxic strychnine in other products based on proton-transfer complexation

    Science.gov (United States)

    Adam, Abdel Majid A.; Refat, Moamen S.; Saad, Hosam A.; Hegab, Mohamed S.

    2015-12-01

    The study of toxic and carcinogenic substances represents one of the most demanding areas in human safety, due to their repercussions for public health. There is great motivation to remove and utilize these substances in other products instead of leaving them contaminate the environment. One potentially toxic compound for humans is strychnine (Sy). In the present study, we attempted to establish a quick, simple, direct and efficient method to remove and utilize discarded Sy in other products based on proton-transfer complexation. First, Sy was reacted with the acido organic acceptors PA, DNBA and CLA. Then, the resultant salts were direct carbonized into carbon materials. Also, this study provides an insight into the structure and morphology of the obtained products by a range of physicochemical techniques, such as UV-visible, IR, 1H NMR and 13C NMR spectroscopies; XRD; SEM; TEM; and elemental and thermal analyses. Interestingly, the complexation of Sy with the PA or DNBA acceptor leads to a porous carbon material, while its complexation with CLA acceptor forms non-porous carbon product.

  16. Structures of nitrato-(2-hydroxybenzaldehydo) (2,2′-bipyridyl)copper and nitrato-(2-hydroxy-5-nitrobenzaldehydo)(2,2′-bipyridyl)copper

    International Nuclear Information System (INIS)

    Nitrato-(2-hydroxy-5-nitrobenzaldehydo)(2,2′-bipyridyl)copper (I) and nitrato-(2-hydroxybenzaldehydo)(2,2′-bipyridyl)copper (II) were synthesized and characterized by X-ray diffraction. The coordination polyhedron of the central copper atom in complex I can be described as a distorted tetragonal pyramid whose base is formed by the phenol and carbonyl oxygen atoms of the monodeprotonated 2-hydroxy-5nitrobenzaldehyde molecule and the nitrogen atoms of the 2,2′-bipyridyl ligand and whose apex is occupied by the oxygen atom of the nitrato group. In the crystal structure, complexes I are linked by the acido ligands and the NO2 groups of the aldehyde molecule into infinite chains. In complex II, the central copper atom is coordinated by 2-hydroxybenzaldehyde, 2,2′-bipyridyl, and the nitrato group, resulting in the formation of centrosymmetric dimers. The coordination polyhedron of the central copper atom can be described as a bipyramid (4 + 1 + 1) with the same base as in complex I. The axial vertices of the bipyramid are occupied by the oxygen atom of the nitrato group and the bridging phenol oxygen atom of the adjacent complex related to the initial complex by a center of symmetry. In the crystal structure, complexes II are hydrogen bonded into infinite chains.

  17. Operation of the ISO-DALT system: Seventh edition

    International Nuclear Information System (INIS)

    The ISO-DALT system of two-dimensional electrophoresis was developed as a series of modifications of the original technique of O'Farrell. We have written a series of recipes and more detailed laboratory procedures that incorporate refinements and ''tricks of the trade'' as they have developed during our use of the system. The present collection is the seventh version in this series and represents the state of art as of May 1984. The seventh edition has been prepared to incorporate the changes that we have found helpful, as well as to add a few new sections such as silver staining, transfer gels, ACIDOs, and BASOs. Although these directions are specific for our laboratory, we hope that they will be helpful in other laboratories as well. Although some disagreement still exists, we recommend that gel patterns be oriented with acid isoelectric points (pIs) to the left and high sodium dodecyl sulfate (SDS) molecular weights at the top. This results in a system of pI and molecular weight values that run according to the Cartesian convention and facilitates the use of the charge and molecular weight standards described herein. 67 refs., 14 figs

  18. [The essence of essential tremor: neurochemical bases].

    Science.gov (United States)

    Gironell, A; Marin-Lahoz, J

    2016-06-01

    Introduccion. El temblor esencial es el trastorno del movimiento mas frecuente en el adulto. Se ha considerado una enfermedad benigna, pero puede ocasionar una importante discapacidad fisica y psicosocial. El tratamiento farmacologico sigue siendo poco satisfactorio. Su etiologia, fisiopatologia y anatomia siguen sin conocerse del todo. Objetivo. El conocimiento de las bases neuroquimicas es fundamental para el desarrollo de terapias mas eficaces. Se revisan los conocimientos actuales en este campo a fin de incentivar nuevas investigaciones e ideas que permitan mejorar la comprension de la enfermedad y que fomenten el desarrollo de nuevas terapias farmacologicas. Desarrollo. Se revisan los trabajos realizados hasta la fecha en humanos y en modelos animales de neurotransmisores (acido gamma-aminobutirico, glutamato, noradrenalina, serotonina, adenosina), proteinas y otros fenomenos neuroquimicos, como los canales de calcio de tipo T en el temblor esencial. Conclusiones. Se han descrito cuatro disfunciones neuroquimicas que acontecerian basicamente en el cerebelo y el nucleo olivar inferior: alteracion del sistema gabergico, aumento del rebote postinhibitorio mediante corrientes de calcio de tipo T, disminucion de los mecanismos de inhibicion neuronal y aumento de la actividad de los neurotransmisores excitatorios. Estas disfunciones neuroquimicas comportarian un aumento de la actividad de las neuronas profundas cerebelosas con actividad oscilatoria, que se trasladaria al nucleo del talamo y a la corteza motora, y comportarian la aparicion del temblor. Son necesarios nuevos estudios para poder confirmar estas hipotesis y seguir avanzando para conseguir tratamientos farmacologicos mas eficaces para los pacientes con temblor esencial.

  19. Lignin recovery. A resource to value; La lignina: una risorsa da valorizzare

    Energy Technology Data Exchange (ETDEWEB)

    Zimbardi, P.; Cardinale, G.; Demichele, M.; Nanna, F.; Viggiano, D. [ENEA, Centro Ricerche Trisaia, Rotondella, MT (Italy). Dipt. Energia; Bonini, C.; D' Alessio, L.; D' Auria, M.; Teghil, R.; Tofani, D. [Basilicata Univ., Potenza (Italy). Dipt. di Chimica

    1999-07-01

    In the present paper, the effects of the steam explosion (ES) pretreatment conditions on recovery and chemical structure of wheat straw lignin are reported. The experimental data of lignin recovery by caustic extraction, followed by acid precipitation, have been interpolated to obtain the dependence on the time and temperature of SE. The lignin has been characterised by using several methods. Preliminary results on the synthesis of copolymers lignin-styrene are also reported. [Italian] Si ripotano i risultati piu' rilevanti di un'attivita' di ricerca condotta dall'ENEA e dall'universita' della Basilicata, finalizzata alla valorizzazione della lignina. Sono stati indagati gli effetti del trattamento con vapore d'acqua ad alta pressione (processo steam explosion) sulla struttura chimica della lignina e la possibilita' di isolarla con alte rese di estrazione dalla paglia di grano. La lignina, estratta dalla biomassa trattata con una soluzione acquosa di idrossido di sodio ed isolata acidificando la soluzione con acido solforico, e' stata analizzata con diverse tecniche microscopiche, spettroscopiche e cromatografiche. Sono riportati i dati sperimentali interpolati ottenendo la relazione empirica che lega la resa di recupero alla temperatura e alla durata del trattamento di steam explosion.

  20. Analytic techniques to quantify Tetrachlorohydroquinone and Chloranil; Tecnicas analiticas para cuantificar Tetraclorohidroquinona y Cloranilo

    Energy Technology Data Exchange (ETDEWEB)

    Castillo Escobedo, Ma. Teresa; Gutierrez de Gonzalez, Luz Ma; Gojon Zorrilla, Gabriel [Universidad Autonoma de Nuevo Leon, Monterrey, Nuevo Leon (Mexico)

    1995-02-01

    Tetrachlorohydroquinone (TCHQ) was determined by two methods: iodometry and cerimetry. Tritation with aqueous ceric ammonium sulphate using potentiometric end-point detection proved to be the method of choice on account of its coefficient of variation (CV=0.475%) and its excellent accuracy. Chloranil (TCQ) was quantified by titration with aqueous ascorbic acid in acetone-water-hexamethylene tetramine (HMT), the golden-yellow color of the TCQ-HMT complex disappearing at the end point. This method is accurate and has CV=0.396%. [Spanish] Se cuantifico la tetraclorohidroquinona (TCHQ) mediante una tecnica yodometrica y un metodo potenciometrico, basado en el uso de sulfato cerico amoniacal. Se concluyo que el metodo potenciometrico es el mejor, ya que tiene un coeficiente de variacion (CV) de 0.475%, y una exactitud muy aceptable. Se desarrollo un tecnica para cuantificar el Cloranilo (TCQ) por titulacion con Acido Ascorbico en presencia de Hexametilentetramina (HMT) en medio acetona-agua; el punto final se determino por la separacion del color amarillo oro del complejo TCQ-HMT. Esta tecnica presenta un coeficiente de variacion (CV) de 0.396% y una exactitud aceptable. Se realizaron pruebas de hipotesis para verificar la exactitud de los metodos elegidos.

  1. Análisis del tratamiento ideal usando baños termotratados para la separación de cal de los residuos de descarne en curtiembres

    Directory of Open Access Journals (Sweden)

    Yelitza Aguas Mendoza

    2016-07-01

    Full Text Available Se analizó el tratamiento ideal usando baños termotratados para la separación de cal de los residuos de descarne, del proceso de curtición semiartesanal desarrollado en Sampués, Departamento de Sucre (Colombia. Para su desarrollo se seleccionó una muestra de carnaza representativa, homogénea y con menos tiempo de almacenamiento. Dicha muestra se redujo al tamaño de 1 cm2 y se conservó refrigerada para posteriormente realizar los análisis de grasa, pH y presencia de cal. Los baños termotratados de desencalado se realizaron a tres temperaturas diferentes (26, 30 y 35 ºC. Se utilizó como agente desencalante el acido sulfúrico en tres concentraciones (3, 2 y 1 N. Además se usó un sistema de agitación simulando el bombo en proceso industrial. Se llevaron a cabo nueve pruebas con tres repeticiones para mayor confiabilidad de los datos, en donde se determinó la correlación existente entre las variables independientes, temperatura y concentración, sobre la cal impregnada y los resultados de grasa en cada una de las muestras en un tiempo de 4 y 8 h.

  2. Effect of co-culture and nutrients supplementation on bioremediation of crude petroleum sludge

    Energy Technology Data Exchange (ETDEWEB)

    Devi, Mamilla Prathima; Reddy, Motakatla Venkateswar; Sarma, Ponnapalli Nageswara; Mohan, Srinivasula Reddy Venkata [Bioengineering and Environmental Centre, Indian Institute of Chemical Technology, Hyderabad (India); Juwarkar, Asha [Environmental Biotechnology Division, National Environmental Engineering Research Institute, Nehru Marg, Nagpur (India)

    2011-10-15

    Ex-situ bioremediation of real-field crude petroleum sludge was evaluated to elucidate the role of co-culture (bioaugmentation) and external nutrients supplementation (biostimulation) under anaerobic microenvironment. Maximum removal of total petroleum hydrocarbons (TPH) was observed by integrating biostimulation with bioaugmentation (R5, 44.01%) followed by bioaugmentation alone (R4, 34.47%), co-substrate supplemented operations [R6, 23.36%; R3, 16.5%; R2, 9.88%] and control (R1, 4.36%). Aromatics fraction showed higher degradation in all the conditions studied. Fate of six selected polycyclic aromatic hydrocarbons (PAHs) was evaluated during bioremediation. Among these, four ring PAHs compounds showed good degradation by integration of biostimulation with bioaugmentation (R5) while bioaugmentation alone (R4) documented good degradation of three ring PAHs. Lower ring PAHs compounds showed good degradation with the application of biostimulation (R6). Fluorescent in situ hybridization (FISH) detected the presence of known PAHs degrading microorganisms viz., Bacillus, Pseudomonas, Acido bacteria, Sulphur reducing bacteria Firmicutes, etc. Application of biostimulation and bioaugmentation strategies alone or in combinations documented noticeable influence on the degradation of petroleum sludge. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. pH as a Driver for Ammonia-Oxidizing Archaea in Forest Soils.

    Science.gov (United States)

    Stempfhuber, Barbara; Engel, Marion; Fischer, Doreen; Neskovic-Prit, Ganna; Wubet, Tesfaye; Schöning, Ingo; Gubry-Rangin, Cécile; Kublik, Susanne; Schloter-Hai, Brigitte; Rattei, Thomas; Welzl, Gerhard; Nicol, Graeme W; Schrumpf, Marion; Buscot, Francois; Prosser, James I; Schloter, Michael

    2015-05-01

    In this study, we investigated the impact of soil pH on the diversity and abundance of archaeal ammonia oxidizers in 27 different forest soils across Germany. DNA was extracted from topsoil samples, the amoA gene, encoding ammonia monooxygenase, was amplified; and the amplicons were sequenced using a 454-based pyrosequencing approach. As expected, the ratio of archaeal (AOA) to bacterial (AOB) ammonia oxidizers' amoA genes increased sharply with decreasing soil pH. The diversity of AOA differed significantly between sites with ultra-acidic soil pH (4.5, regardless of geographic position and vegetation. These OTUs could be related to the Nitrosotalea group 1.1 and the Nitrososphaera subcluster 7.2, respectively, and showed significant similarities to OTUs described from other acidic environments. Conversely, none of the major OTUs typical of sites with a soil pH >4.6 could be found in the ultra- and extreme acidic soils. Based on a comparison with the amoA gene sequence data from a previous study performed on agricultural soils, we could clearly show that the development of AOA communities in soils with ultra-acidic pH (<3.5) is mainly triggered by soil pH and is not influenced significantly by the type of land use, the soil type, or the geographic position of the site, which was observed for sites with acido-neutral soil pH. PMID:25501889

  4. CARACTERIZACIÓN DE POLVOS DE ACERÍA ELÉCTRICA PRODUCIDOS EN VENEZUELA Y EVALUACIÓN PRELIMINAR DE SU LIXIVIABILIDAD CON ÁCIDOS ORGÁNICOS DILUIDOS

    Directory of Open Access Journals (Sweden)

    PEDRO DELVASTO

    2011-01-01

    Full Text Available Se estudiaron polvos de aceria cuyo analisis quimico revelo un contenido (en peso de: 27,0 % de Fe; 7,1 % de Mg; 4,9 % de Zn; 4,0 % de Ca y 0,5 % de Pb. La difraccion de rayos X y la espectroscopia infrarroja, permitio identificar en los polvos las siguientes fases: espinelas, Fe3O4, CaCO3, SiO2, ZnO y PbO. El analisis microscopico de estos residuos indico que estan formados por agregados de particulas esferoidales cuyo tamano varia entre 120 y 0,25 ¿Êm. La lixiviabilidad de los mismos se evaluo durante 28 dias en columnas de percolacion, empleando agua y disoluciones de acidos organicos como agentes lixiviantes. El objetivo fue evaluar el comportamiento del residuo bajo condiciones similares a las que generan los microorganismos naturales del suelo. Se encontro que la lixiviabilidad de Zn y Pb vario entre 80 y 16 mg mensuales por kilogramo de polvo de aceria.

  5. Kinetics of oxidation of acidic amino acids by sodium N-bromobenzenesulphonamide in acid medium: A mechanistic approach

    Indian Academy of Sciences (India)

    Puttaswamy; Nirmala Vaz

    2001-08-01

    Kinetics of oxidation of acidic amino acids (glutamic acid (Glu) and aspartic acid (Asp)) by sodium N-bromobenzenesulphonamide (bromamine-B or BAB) has been carried out in aqueous HClO4 medium at 30°C. The rate shows firstorder dependence each on [BAB]o and [amino acid]o and inverse first-order on [H+]. At [H+] > 0 60 mol dm-3, the rate levelled off indicating zero-order dependence on [H+] and, under these conditions, the rate has fractional order dependence on [amino acid]. Succinic and malonic acids have been identified as the products. Variation of ionic strength and addition of the reaction product benzenesulphonamide or halide ions had no significant effect on the reaction rate. There is positive effect of dielectric constant of the solvent. Proton inventory studies in H2O-D2O mixtures showed the involvement of a single exchangeable proton of the OH- ion in the transition state. Kinetic investigations have revealed that the order of reactivity is Asp > Glu. The rate laws proposed and derived in agreement with experimental results are discussed.

  6. Mathematical modeling of the hydrogen evolution reaction using HClO{sub 4} and H{sub 2}SO{sub 4} as electrolytes; Modelacion matematica de la reaccion de evolucion del hidrogeno utilizando HClO{sub 4} y H{sub 2}SO{sub 4} como electrolitos

    Energy Technology Data Exchange (ETDEWEB)

    Ortega Chavez, Laura; Herrera Peraza, Eduardo; Alonso Nunez, Gabriel [Centro de Investigacion en Materiales Avanzados, Chihuahua, Chihuahua (Mexico); Manzanarez Papayanopoulos, Luisa [PROFEPA, Mexico D.F. (Mexico); Verde Gomez, Ysmael [Instituto Tecnologico de Cancun, Cancun, Quintana Roo (Mexico); Keer Rendon, Arturo [Centro de Investigacion en Materiales Avanzados, Chihuahua, Chihuahua (Mexico)

    2008-01-15

    tecnologia, se ha visto limitada por factores tales como el elevado costo de los distintos componentes que conforman una celda de combustible. Por ejemplo, el platino empleado por excelencia como el mejor catalizador para llevar a cabo la reaccion quimica entre hidrogeno y oxigeno, responsable de la produccion de energia electrica. En la busqueda de la optimizacion o sustitucion del platino, es importante contar con una metodologia que permita realizar un diagnostico in situ del estado de dicho catalizador. Este diagnostico involucra aspectos tales como la determinacion de los sitios activos y la carga y la degradacion que el catalizador puede ir sufriendo durante el funcionamiento de la celda. El presente trabajo consiste en el desarrollo de un modelo matematico que alimentado con las constantes de velocidad y los fenomenos involucrados en la reaccion de la evolucion del hidrogeno, produce como datos de salida, las curvas de polarizacion (E vs I) y de espectroscopia de impedancia electroquimica para dicha reaccion. Se considero para la modelacion, al Pt monocristalino preferenciado en las direcciones (111) y (100) como catalizador y usando diversos acidos como electrolitos. Las curvas obtenidas con el algoritmo matematico muestran una correlacion de la influencia del tipo y concentracion de los acidos usados como electrolitos y la densidad de corriente electrica debido a la evolucion del H{sub 2}. Finalmente, este modelo deja abierta la posibilidad de explorar el efecto del cambio en los valores de las variables involucradas en las reacciones de una celda de combustible, lo que nos permitira evaluar in situ el estado y comportamiento del catalizador.

  7. Guidelines for specialized nutritional and metabolic support in the critically-ill patient: Update. Consensus SEMICYUC-SENPE: Septic patient Recomendaciones para el soporte nutricional y metabólico especializado del paciente crítico: Actualización. Consenso SEMICYUC-SENPE: Paciente séptico

    Directory of Open Access Journals (Sweden)

    C. Ortiz Leyba

    2011-11-01

    consecuencias de la desnutrición, proveer el adecuado aporte de nutrientes y prevenir el desarrollo de complicaciones secundarias como la sobreinfección y el fracaso multiorgánico. Al igual que en el resto de pacientes críticos, cuando la ruta enteral es insuficiente para asegurar las necesidades caloricoproteicas, la asociación de nutrición parenteral ha demostrado ser segura en este subgrupo de pacientes. Los estudios que evalúan el efecto de farmaconutrientes específicos en el paciente séptico son escasos y no permiten establecer recomendaciones al respecto. Respecto a las dietas enterales con mezcla de sustratos con diferente capacidad farmaconutriente, su uso no parece aportar, hasta el momento actual, beneficios claros sobre la evolución de la sepsis respecto a las dietas estándar, aunque tampoco hay clara evidencia de que sean perjudiciales. A pesar de que no hay suficiente evidencia para recomendar el empleo de glutamina en el paciente septico que recibe nutricion parenteral, este podria beneficiarse de su uso, dados los buenos resultados y la ausencia de efectos adversos atribuible a la glutamina en los diferentes estudios llevados a cabo en el conjunto de pacientes criticos. No se puede recomendar el empleo rutinario de acidos grasos ω-3 hasta que dispongamos de mayor evidencia, aunque debe evitarse en estos pacientes el empleo de emulsiones lipidicas con alto contenido en acidos grasos ω-6. El paciente septico debe recibir un adecuado aporte de oligoelementos y vitaminas. El empleo de selenio a dosis altas requiere de mas estudios para poder recomendarlo.

  8. Ripe fruits of Bromelia antiacantha: investigations on the chemical and bioactivity profile Quimica e atividade in vitro da banana-do-mato (Bromelia antiacantha Bertol., Bromeliaceae

    Directory of Open Access Journals (Sweden)

    Vanessa N. C. Santos

    2009-06-01

    -DAD. Nenhuma citotoxicidade foi observada em fibroblastos L929 para extratos aquoso, metanólico e lipídico entre 500 e 0,01 µg/ml, assim como baixa genotoxicidade (1000 µg/mL quando comparados aos controles negativo e positivo (MMS. Abundantes cristais de oxalato de cálcio e de sacarose foram observados e caracterizados por RMN e difração de Raios-X respectivamente, e a composição centesimal do fruto indicou abundantes carboidratos (45% e lipídeos (18%. A analise de carboidratos encontrou componentes monosacarídicos ácidos e foram encontrados acido palmítico e linoléico em quantidades similares (30% cada e 20% de acido oléico, entre outros ácidos graxos através de CG-DIC. A viscosidade da sub-fração polissacarídica solúvel em água (5 g/L foi semelhante a da água.

  9. Qualidade da carne do músculo longissimus dorsi de novilhos superjovens Aberdeen Angus de biótipo pequeno e médio abatidos com o mesmo estágio de acabamento na carcaça = Meat quality of the longissimus dorsi muscle of Aberdeen Angus steers of small and medium frame score, slaughtered at the same carcass finishing stage

    Directory of Open Access Journals (Sweden)

    Miguelangelo Ziegler Arboitte

    2011-04-01

    Full Text Available O objetivo deste trabalho foi verificar a influencia do biotipo pequeno e medio de novilhos Aberdeen Angus superjovens na composicao da carne do longissimus dorsi (LD. Foram utilizadas seccoes do LD de oito novilhos com biotipo pequeno e dez com biotipo medio, confinados por 158 dias, apresentando ao abate idade e peso vivo medio de 456 dias e 429 kg. A alimentacao foi constituida de silagem de sorgo e concentrado na relacao 60:40 nos primeiros 63 dias e apos 50:50 ate o abate. O biotipo foi calculado por meio da formula: B = -11,548 +(0,4878 x h - (0,0289 x ID + (0,0000146 x (ID2 + (0,0000759 x h x ID; h = altura em polegadas e ID=idade em dias. A carne do LD apresentou gordura intramuscular media (10,11 pontos; p = 0,7034, coloracao vermelha (4,33 pontos; p = 0,3724, textura com tendenciaa muito fina (4,61 pontos; p = 0,3075 e forca ao cisalhamento de 2,72 kgf cm-2 (p = 0,4009. A carne apresentou 72,27% (p = 0,4355 de umidade, 19,34% (p = 0,4150 de proteina bruta, 3,96% (p = 0,9071 de lipidios, 4,43% (p = 0,9842 de minerais e 0,25 mg 100g-1 de carne(p = 0,2375 de colesterol. Os biotipos nao influenciaram na concentracao dos acidos graxos palmitico (p = 0,0790, estearico (p = 0,2455, oleico (p = 0,3046, linoleico (p = 0,9456, ocorrendo alteracao na participacao do acido graxo miristico (. = 1,85 + 0,12B; p = 0,043. O estudo do biotipo na composicao da carne e importante para a identificacao de melhores caracteristicas nutraceuticas.The objective of this work was to assess the influence of small and medium frame scores in the meat composition of the longissimus dorsi (LD muscle of Abredeen Angus steers. We used LD sections from eight small-framed steers and ten medium-framed steers, confined for 158 days, with mean slaughter age of 457 days and 429 kg live weight. The feed was composed of sorghum silage and concentrate in a 60:40 ratio for the first 63 days, and 50:50 thereafter until slaughter. Frame wascalculated using the formula: F=-11

  10. Synthesis and evaluation of Pt-alloys supported on MWCNTS as ethylene glycol-tolerant ORR cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Morales-Acosta, D.; Arriaga, L.G. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, Pedro Escobedo, Queretaro (Mexico); Alvarez-Contreras, L. [Centro de Investigacion en Materiales Avanzados S. C., Chihuahua, Chihuahua (Mexico); Fraire Luna, S.; Rodriguez Varela, F.J. [Cinvestav, Unidad Saltillo, Ramos Arizpe, Coahuila (Mexico)]. E-mail: javier.varela@cinvestav.edu.mx

    2009-09-15

    In this work, a Pt-Co/MWCNT alloy (atomic ratio 70:30) was synthesized and evaluated as oxygen reduction reaction (ORR) cathode for Direct Ethylene Glycol Fuel Cells (DEGFC) applications. The alloy showed good performance for the ORR in acid medium, while in the presence of 0.125M EG (C{sub 2}H{sub 6}O{sub 2}) the MWCNTs-supported electrocatalyst showed a very high selectivity for the cathodic reaction and a high degree of tolerance to the organic fuel, i.e., a very small shift in the onset potential for the ORR, Eonset, and no peak current densities associated to the oxidation of EG, a detrimental effect of organic fuels normally observed in the case of Pt-alone electrocatalysts. [Spanish] En este trabajo, se sintetizo y evaluo una aleacion Pt-Co/NTCMP (razon atomica 70/30) como catodo de reaccion de reduccion de oxigeno (RRO) para aplicaciones de celdas de combustible de glicol de etileno directo (CCGED). La aleacion mostro buen desempeno para la RRO en medio acido, en tanto que la presencia de 0.125M de GE (C{sub 2}H{sub 6}O{sub 2}) del electrocatalizador soportado por NTCMP mostro una muy alta selectividad para la reaccion catodica y un alto grado de tolerancia al combustible organico, es decir, un corrimiento muy pequeno del potencial de inicio para la RRO, Einicio, y no densidades de corriente asociadas a la oxidacion del GE, efecto perjudicial de los combustibles organicos que se observa en el caso del electrocatalizadores solo de Pt.

  11. Effects of some sesquiterpenes on the stored-product insect Tenebrio molitor (Coleoptera: Tenebrionidae Efectos de algunos sesquiterpenos sobre el insecto de productos almacenados, Tenebrio molitor (Coleoptera: Tenebrionidae

    Directory of Open Access Journals (Sweden)

    Matías García

    2003-12-01

    Full Text Available In order to evaluate the allelochemical activity of some sesquiterpenes isolated from the native plant Tessaria absinthioides (Hook. et Arn. DC, and some semi synthetic derivatives against Tenebrio molitor L. larvae, we have developed bioassays directed to quantify repellency, larval mortality, and its effects on the development. Although costic aldehyde caused the maximum repellent effect, all the compounds showed a significant effect at some dose or time, indicating behavioral avoidance. The topical application of costic aldehyde produced the largest increase on the duration of the pupal stage. Tessaric acid exhibited the highest toxicity by topical application at the experiment closure. Both eremophilane-1(10,2,11(13-triene-12-oic, and -costic acids induced some morphological deformities.Con el objeto de evaluar sesquiterpenos aislados de la planta nativa Tessaria absinthioides (Hook et Arn y algunos derivados semisintéticos frente a larvas de Tenebrio molitor L., se desarrollaron bioensayos orientados a la cuantificación de la repelencia, mortalidad de larvas y efectos sobre el desarrollo. Aldehído cóstico produjo el mayor incremento en la duración del estado pupal por aplicación tópica. Acido tessárico exhibió el más alto porcentaje de mortalidad al finalizar el período de experimentación. Los productos eremophilan-1(10,2, 11(13-trien-12-oico y ácido -cóstico dieron lugar al mayor número de malformaciones. Si bien aldehído cóstico mostró la máxima actividad de repelencia, todos los compuestos evaluados produjeron efectos significativos en el ensayo de elección.

  12. [Electrical status epilepticus during sleep: a retrospective multi-centre study of 29 cases].

    Science.gov (United States)

    Lorenzo-Ruiz, María; Miguel-Martin, Beatriz; García-Pérez, Asunción; Martínez-Granero, Miguel A; Aguilera-Albesa, Sergio; Yoldi-Petri, M Eugenia; Sánchez-Ruiz de Gordoa, Javier; Castro-De Castro, Pedro; Sánchez-Carpintero, Rocío

    2015-02-01

    Introduccion. El estado epileptico electrico durante el sueño (ESES) es un sindrome epileptico caracterizado por la presencia de descargas epilepticas tipo punta-onda lenta de manera muy persistente durante el sueño no REM. En la actualidad, el manejo de esta patologia es heterogeneo y no hay estudios controlados con los tratamientos utilizados, ni se ha comprobado si estos mejoran la evolucion cognitiva de los pacientes. Pacientes y metodos. Se revisan los pacientes diagnosticados de ESES durante 15 años en cuatro centros hospitalarios, se recoge la presentacion clinica, el manejo terapeutico y la evolucion clinica, y se compara con la bibliografia. Resultados. Se seleccionaron 29 pacientes con ESES, 20 de ellos idiopatico y 26 de ellos generalizado. Los farmacos con los que se consiguio mayor control de la actividad electrica fueron los corticoides/hormona adrenocorticotropa (ACTH), el clobazam y el levetiracetam. La mediana de duracion del ESES en los casos primarios fue de seis meses, y en los secundarios, el doble. El 45% de los pacientes mantuvo un cociente intelectual normal y un 40% presento en la evolucion discapacidad cognitiva de diferente grado. Conclusiones. El pronostico neuropsicologico evolutivo suele ser desfavorable y la evolucion cognitiva parece estar en relacion con la duracion del ESES y el area donde este concentrada la actividad epileptica, lo que sugiere que el mal pronostico, si se trata precozmente, se puede evitar. Los antiepilepticos mas frecuentemente utilizados son el acido valproico, la etosuximida y el levetiracetam, y en nuestra muestra tambien se utilizaron con frecuencia el clobazam y la lamotrigina. Los farmacos mas eficaces para el control del ESES fueron los corticoides/ACTH, el clobazam y el levetiracetam.

  13. Efecto de las Variables de Proceso sobre la Cinética de Acidificación, la Viabilidad y la Sinéresis del Suero Costeño Colombiano Effect of the Process Variables on the Kinetics of Acidity, Viability and Syneresis of the Colombian Coastal Whey

    Directory of Open Access Journals (Sweden)

    Diofanor Acevedo

    2010-01-01

    Full Text Available En el presente estudio se analizaron los efectos simultáneos de la temperatura de fermentación, el nivel de sólidos totales y la concentración del inóculo sobre la acidificación, la sinéresis y la viabilidad del Suero Costeño, un producto lácteo fermentado tradicional de Colombia. Para ello se usó la metodología de superficie de respuesta con tres variables y cinco niveles. La fermentación se realizó con las bacterias lácticas Lactococcus lactis Subs. Lactis (ATCC29146 y Lactobacillus Paracasei Subs paracasei (ATCC 334. El tratamiento estadístico dio lugar a la generación de modelos matemáticos, con los cuales se determino que los sólidos totales disminuyen la velocidad máxima de acidificación y la sinéresis del suero, mientras la temperatura afecta significativamente la viabilidad de las bacterias acido lácticas.In the present study the simultaneous effect of fermentation temperature, milk total solid level and total inoculums concentration on the acidification process, syneresis and viability of Colombian coastal whey, a fermented milk product, traditional of Colombia. For this the response surface methodology with three variables and five levels was employed. Fermentation was done using the bacteria Lactococcus lactis Subs. Lactis (ATCC29146 and Lactobacillus Paracasei Subs paracasei (ATCC 334. The statistical analysis allowed generating mathematical models that were used to determine that the total solids significantly decreased the maximum rate of acidification and syneresis of costal whey, while the temperature significantly affects the viability of lactic acid bacteria.

  14. The Villas Carrousel PV-Wind Hybrid Project

    Energy Technology Data Exchange (ETDEWEB)

    Huacuz, Jorge M. [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    A pilot project was carried out to supply electrical services for an ecological hotel (eco-hotel), using solar and wind energy in Southeast Mexico. Fifteen small photovoltaic-wind hybrid systems were designed and built by researchers of the Electrical Research Institute of Mexico (IIE), as part of a cooperation agreement with the mexican company Carrousel Operadora Turistica, aimed at developing a technology package to supply electrical services to similar hotels sited in remote areas. Each hybrid system includes one wind generator of 500W nominal capacity, one PV panel ranging in power from 150W to 320 Watts peak, one lead-acid battery bank of 570 ampere-hour in capacity, and an electronic charge controller. This paper describes the systems and summarizes the results from the first twelve months of operation. [Espanol] Se llevo a cabo un proyecto piloto para el suministro de servicios electricos a un hotel ecologico (eco-hotel), utilizando energia solar y energia del viento en el Sudeste de Mexico. Investigadores del Instituto de Investigaciones Electricas de Mexico, disenaron y construyeron quince pequenos sistemas hibridos fotovoltaicos-viento, como parte de un acuerdo de cooperacion con la compania mexicana Carrousel Operadora Turistica, orientado al desarrollo de un paquete tecnologico para proporcionar servicios de energia electrica a hoteles similares ubicados en areas remotas. Cada sistema hibrido incluye un aero-generador con capacidad nominal de 500W un panel foto-voltaico con una potencia que varia entre los 150W y los 320W pico, una banco de baterias de plomo-acido de 570 amperes-hora de capacidad y un controlador electronico de carga. Este articulo describe los sistemas y presenta un resumen de los resultados de los primeros doce meses de operacion.

  15. COMPOSTOS FENÓLICOS E ATIVIDADE ANTIOXIDANTE DE GENÓTIPOS DE CIRIGUELAS (SPONDIA PURPUREA L.

    Directory of Open Access Journals (Sweden)

    Quésia Jemima da SILVA

    2012-01-01

    Full Text Available Com o objetivo de determinar em frutos de 11 genótipos de cirigueleiras o teor de fenólicos totais e o potencial antioxidante foram preparados extratos hidrometanólicos e hidroacetônicos por extração sequencial. A ação antioxidante foi analisada utilizando dois ensaios: sequestro do radical DPPH● (1,1-difenil-2-picrilhidrazil e do radical ABTS+• (2,2’-azino-bis-(3-etilbenzotiazolina-6- acido sulfônico. O extrato obtido do genótipo IPA-10 apresentou maior teor de fenólicos totais (862,31mg EAG.g-1 de polpa, superando, estatisticamente, os extratos dos demais genótipos. Em relação ao percentual de sequestro do radical DPPH●, os extratos dos frutos de todos os genótipos apresentaram forte capacidade antioxidante, tendo em vista que os valores determinados foram superiores a 70%. O comportamento cinético dos extratos dos frutos dos genótipos IPA-2, IPA-3, IPA-4, IPA-5, IPA-6, IPA-7, IPA-8, IPA- 10 e IPA-11 foram classificados como rápidos (TEC50<5 minutos, no entanto, apenas o genótipo IPA-7 apresentou eficiência antirradical super alta. Com relação ao radical ABTS+• todos os genótipos apresentaram apreciável ação antioxidante com destaque para o extrato do genótipo IPA- 10 que demonstrou uma ação superior aos demais genótipos(6.633,87μM TEAC.g-1.

  16. Actividad antioxidante de compuestos naturales nitrogenados

    Directory of Open Access Journals (Sweden)

    Maestro-Durán, R.

    1993-06-01

    Full Text Available As a continuation of the study of natural antioxidants, this third part deals with nitrogeneous compounds, classified in the following groups.

    Amino acids and proteins.
    Products of the Maillard reaction.
    Phospholipids (with choline or ethanolamine and their heating products.
    Riboflavin.
    Chlorophylls and porphyrins.
    Uric acid and derivatives.
    Their behaviour as inhibitors of the chain reaction of prooxidant radicals, by irreversible reaction or by sequestration of those radicals, as well as their synergistic action with primary antioxidants is discussed. Finally, the patents registered during the last years for these kind of compounds, their derivatives and synergists in food and other uses are cited.

    Continuando el estudio de los antioxidantes naturales, se incluyen en esta tercera parte los compuestos nitrogenados, clasificados en los siguientes grupos:
    Aminoácidos y proteínas.
    Productos de la reacción coloreada de Maillard.
    Fosfolípidos (con las bases colina y etanolamina y sus productos de calentamiento.
    Riboflavina.
    Clorofilas y porfirinas.
    Acido úrico y sus derivados.
    Se discute su comportamiento como inhibidores de la reacción en cadena de los radicales prooxidantes, por reacción irreversible o por secuestro de estos radicales, así como su acción sinergista con antioxidantes primarios. Finalmente, se citan las patentes registradas en los últimos años para estos tipos de compuestos, sus derivados y sinergistas, en productos alimentarios o en otros usos.

  17. Evaluation of a process for the removal of gases contained in geothermal steam through condensation and re-evaporation; Evaluacion de un proceso de remocion de gases contenidos en el vapor geotermico, por medio de la condensacion y de revaporacion

    Energy Technology Data Exchange (ETDEWEB)

    Angulo C, Raul; Lam Rea, Luis; Garmino, Hector; Jimenez, Humberto [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1985-12-31

    The Cerro Prieto I Geothermal Field, developed and operated by the Comision Federal de Electricidad (CFE), has currently an installed electric power generation capacity of 180 MW and is at a very advanced stage in the development of Cerro Prieto II and III, which will allow to raise the generation capacity to 620 MW. During the exploitation of a geothermal field, in producing steam with the purpose of generating electricity, brines and waste gases are obtained. The hydrogen sulfide exhaust to the environment implies pollution problems, for this reason processes have been developed for the oxidation of these gases downstream the turbogenerator either in the flow of separated gases in the steam condensation or in the condensate produced. The Instituto de Investigaciones Electricas (IIE) has collaborated with CFE in the evaluation of the environmental impact of this gas and in the development of the processes for its abatement. [Espanol] El campo geotermico de Cerro Prieto I, desarrollado y operado por la Comision Federal de Electricidad (CFE), actualmente tiene una capacidad instalada de generacion de energia electrica de 180 MW, y se encuentra en etapa muy avanzada, el desarrollo de Cerro Prieto II y III, lo que permitira incrementar la capacidad de generacion a 620 MW. Durante la explotacion de un campo geotermico, al producir vapor con el proposito de generar electricidad, se obtienen salmueras y gases de desecho. La descarga de acido sulfhidrico a la atmosfera implica problemas de contaminacion, por esta razon se han desarrollado procesos para la oxidacion de este gas aguas abajo de la turbina generadora, ya sea en la corriente de gases que se separan en la condensacion del vapor o en el condensado producido. El Instituto de Investigaciones Electricas (IIE) ha colaborado con la CFE en la evaluacion del impacto ambiental de este gas y en el desarrollo de sus procesos de abatimiento.

  18. Microbiota de jamones de cerdo cocidos asociada al deterioro por abombamiento del empaque

    Directory of Open Access Journals (Sweden)

    Juliana Ossa

    2010-08-01

    Full Text Available Objetivo. Caracterizar la diversidad microbiana y calidad microbiológica e higiénico sanitaria de diferentes marcas de jamones de cerdo cocidos abombados y no abombados comprados en varios supermercados de Bogotá D.C. Materiales y métodos. Se analizaron 10 marcas diferentes de jamones de cerdo cocidos comprados en tres supermercados, refrigerados bajos las mismas condiciones del consumidor, durante 45 días. Se realizó los recuentos en placa de microorganismos de interés en la industria de alimentos y de inocuidad en las muestras con o sin distensión del empaque e identificación por pruebas bioquímicas y PCR para determinar la diversidad de la microbiota. Se aislaron cepas productoras de biopelículas provenientes de la superficie de una planta de alimentos de una de las marcas de los jamones investigadas. Resultados. Se identificaron un total de 139 cepas aisladas del producto terminado, de las cuales un 99% (137 cepas pertenecen al grupo de Bacterias Acido Lácticas (BAL, el 1% restante son levaduras. De las 31 cepas aisladas de las superficies en la zona de tajado, el 97% (30 cepas presentaron formación de biopelículas. Se determinó ausencia de patógenos tanto en el producto terminado como en las muestras de las superficies.Conclusiones. El deterioro causado por abombamiento del empaque fue asociado a la presencia de BAL, debido a que fueron encontradas en la zona de tajado y en el producto terminado, de este último únicamente se aislaron BAL, en mayor proporción cepas correspondientes al género de Lactobacillus sp.

  19. Efecto citoprotector del camu-camu Myrciaria dubia en tres líneas celulares de ratón expuestos in vivo a bromato de potasio

    Directory of Open Access Journals (Sweden)

    Alvis Rafael

    2011-05-01

    Full Text Available Se evaluó in vivo la capacidad citoprotectora del fruto de Myrciaria dubia (Kunth McVaugh Camu-camu frente al daño mutagénico producido por bromato de potasio (68,5 mg/k sobre tres líneas celulares de ratón (hígado, riñón y células sanguíneas. Se utilizó ratones (n= 120 divididos en tres grupos los cuales bebieron ad libitum: TI= control negativo (solo agua y el grupo TIII (control positivo; El grupo TII bebió el extracto acuoso (2% p/v del fruto de camu-camu. A los diez días se inyectó una dosis única de KBr03 (68,5 mg/kg peso corporal vía intraperitoneal, a los grupos TII y TIII. El tratamiento con camu-camu continuo 35 días más, luego los ratones fueron eutanizados para determinar la frecuencia del daño al DNA mediante el protocolo del ensayo cometa alcalino. El grupo TII mostró en todas las líneas celulares el efecto citoprotector del camu-camu (p< 0,05. El efecto dañino al DNA por la acción oxidativa del KBrO3 es inhibido por el extracto acuoso del fruto de camu camu, probablemente por la presencia de los agentes antioxidantes como el Acido ascórbico y los flavonoides.

  20. Guidelines for specialized nutritional and metabolic support in the critically-ill patient: Update. Consensus SEMICYUC-SENPE: Respiratory failure Recomendaciones para el soporte nutricional y metabólico especializado del paciente crítico: Actualización. Consenso SEMICYUC-SENPE: Insuficiencia respiratoria

    Directory of Open Access Journals (Sweden)

    T. Grau Carmona

    2011-11-01

    Full Text Available Severe acute respiratory failure requiring mechanical ventilation is one of the most frequent reasons for admission to the intensive care unit. Among the most frequent causes for admission are exacerbation of chronic obstructive pulmonary disease and acute respiratory failure with acute lung injury (ALI or with criteria of acute respiratory distress syndrome (ARDS. These patients have a high risk of malnutrition due to the underlying disease, their altered catabolism and the use of mechanical ventilation. Consequently, nutritional evaluation and the use of specialized nutritional support are required. This support should alleviate the catabolic effects of the disease, avoid calorie overload and, in selected patients, to use omega-3 fatty acid and antioxidant-enriched diets, which could improve outcome.La insuficiencia respiratoria aguda grave que precisa ventilacion mecanica es una de las causas mas frecuentes de ingreso de los pacientes en UCI. Entre las etiologias mas frecuentes se encuentran la reagudizacion de la enfermedad pulmonar obstructiva cronica y la insuficiencia respiratoria aguda con lesion pulmonar aguda o con criterios de sindrome de distres respiratorio agudo. Estos pacientes presentan un riesgo elevado de desnutricion por su enfermedad de base, por la situacion catabolica en la que se encuentran y por el empleo de la ventilacion mecanica. Ello justifica que estos pacientes deban ser valorados desde el punto de vista nutricional y que el uso de soporte nutricional especializado sea necesario. El soporte nutricional especializado debe paliar los efectos catabolicos de la enfermedad, evitar la sobrecarga de calorias y utilizar, en casos seleccionados, dietas especificas enriquecidas con acidos grasos ω-3 y antioxidantes que podrian mejorar el pronostico.

  1. Effect of the ascorbic acid treatment on the NADHd-positive myenteric neurons of diabetic rats proximal colon

    Directory of Open Access Journals (Sweden)

    Jacqueline Nelisis Zanoni

    2007-01-01

    Full Text Available The aim of this work was to study the effect of the ascorbic acid on the myenteric neurons of diabetic rats proximal colon. Fifteen rats (90 days old were divided into three groups: control, untreated diabetic and treated diabetic with ascorbic acid (DA. After 120 days of daily treatment with ascorbic acid, the intestinal segments were submitted to the NADH-diaphorase (NADHd histochemistry technique to expose the myenteric neurons. The group DA showed a higher neuronal density (33.4 % when compared to the untreated diabetic animals (p O efeito do ácido ascórbico sobre neurônios mioentéricos do colo proximal de ratos diabéticos foi avaliado. Quinze ratos com 90 dias foram divididos nos grupos: controle, diabéticos e diabéticos tratados com ácido ascórbico (DA. Após 120 dias de tratamento diário com ácido ascórbico os segmentos intestinais foram submetidos à técnica histoquímica NADH-diaforase (NADHd. A densidade neuronal, em uma área de 14,11 mm² para cada segmento, e o perfil do corpo celular de neurônios (500 neurônios/grupo foram avaliados. O grupo DA apresentou maior densidade neuronal (33.4 % em relação aos animais diabéticos (p < 0.05. Da mesma forma, a área do corpo celular dos neurônios foi significativamente maior no grupo DA (17.3 % quando comparado com o grupo diabético (p < 0.05. Concluímos que o acido ascórbico apresentou um efeito neuroprotetor sobre os neurônios mioentéricos NADHd do colo proximal de ratos diabéticos.

  2. Contribution to the study of sorption mechanisms at solid-liquid interfaces: application to the cases of apatites and oxy-hydroxides; Contribution a l'etude des mecanismes de sorption aux interfaces solide-liquide: application aux cas des apatites et des oxy-hydroxydes

    Energy Technology Data Exchange (ETDEWEB)

    Duc, M

    2002-11-15

    Sorption-desorption phenomena play an important role in the transport of toxic and radioactive elements in surface and underground water in contact with solid matter. Selenium, which is one of the long-lived radionuclides present in radioactive waste, is characterized by several oxidation states and by anionic species in aqueous solutions. In order to predict its transport, we need a good knowledge of its sorption processes. We have studied the sorption of Se(IV) and Se(VI) on two types of solids present in natural media or which have been proposed as additives to active barriers: hydroxy-apatites, fluoro-apatite and iron oxi-hydroxides (goethite and hematite). Sorption mechanisms have been studied through an approach including several different and complementary methods: titrimetry, zeta-metry, scanning and transmission electron microscopy, infrared spectroscopy, X-ray diffraction, X-ray photo electron spectroscopy, etc... Results showed that Se(VI) is much less sorbed than Se(VI) on both types of solids. For Se(IV) the sorption mechanisms are different for iron oxides and apatites. On oxides, sorption increases when pH decreases. It can be interpreted by a surface complexation model, essentially through an inner sphere complex (monodentate or bidentate). Modelling of Se sorption curves was performed after the determination of acido-basic properties of oxides. However, the determination of the intrinsic properties of oxides is disturbed by several parameters identified as impurities, evolution of the solid in solution, kinetic and solubility of the solid. For apatites, selenium sorption proceeds by exchange with superficial groups, with a maximum of fixation at approximately pH 8. Thanks to XPS measurements and the elaboration of a mathematical model, we could determine the depth of penetration of both selenium and cadmium on apatites. (author)

  3. Utilización de la biomasa residual del cultivo de la piña (Ananas Comosus para la desproteinización enzimática de desechos de la actividad camaronera

    Directory of Open Access Journals (Sweden)

    Javier Rodrigo Alpízar Cordero

    2013-03-01

    Full Text Available Se realizó un estudio para comprobar la capacidad desproteinizante de extractos proteicos obtenidos a partir de desechos de rastrojo de piña a diferentes concentraciones sobre los sub-productos de la actividad camaronera. El extracto proteolítico de los desechos de rastrojo de piña se obtuvo a partir de desechos de tallos utilizando un buffer de acido sulfúrico. Este extracto se caracterizó al determinar el contenido de proteína, de azucares totales y su actividad enzimática, contra un patrón de bromelina comercial. Los resultados obtenidos indicaron que el uso del extracto crudo de rastrojo de piña en forma directa logró desproteinizar el 97% de los desechos de camarón, el cual resultó más efectivo que cualquier dilución de esta misma, en un tiempo de 24 horas. Los resultados sugieren que los desechos de la comercialización de la piña pueden ser considerados como potenciales bioagentes para la desproteinizacion de desechos de camarón. Con esto se genera una alternativa biotecnológica para sustituir los procesos químicos tradicionales que utilizan hidróxido de sodio. Esta novedosa metodología promoverá nuevas aplicaciones para los desechos del cultivo de la piña y reducirá los costos y la contaminación del proceso de producción de quitina y quitosano.

  4. Tuberculose pulmonaire à Brazzaville en hospitalisation pneumologique: impact du diagnostic tardif à l’infection au VIH sur les anomalies radiographiques

    Science.gov (United States)

    Bemba, Esthel Lee Presley; Bopaka, Régis Gothard; Moyikoua, Régis; Ossibi-Ibara, Rolland; Ebenga-Somboko, Norela Bibiane; Toungou, Syn Nerval; Matondot, Paunel God’hervé; Ossale-Abacka, Boris Kevin; Okemba-Okombi, Franck Hardain; Mboussa, Joseph

    2016-01-01

    L’objectif de notre étude était de décrire les différents aspects radiographiques de la tuberculose pulmonaire selon le degré de l’immunodépression chez les patients VIH. Nous rapportons une étude rétrospective de 80 patients VIH positif non traités présentant une tuberculose pulmonaire, hospitalisés dans le service de Pneumo-phtisiologie de Brazzaville de Janvier 2013 à Janvier 2014. Notre échantillon était composé de 44 femmes (55%) et 36 hommes (45%) soit un sex ratio de 0,81. La moyenne d’âge était de 37,5±9,17ans, la moyenne du Taux de CD4 était de 153,13±86,6cell/mm3. La microscopie des expectorations à la recherche des bacilles acido-alcoolo-résistants était positive dans 75% des cas chez les patients ayant un taux de lymphocytes T CD4>200cell/ mm3. Les adénopathies médiastinales, les atteintes moyennes, inferieures du champ pulmonaire et la miliaire étaient plus fréquentes chez les patients ayant un taux de lymphocytes T CD4< 200cell/ mm3. L’immunodépression sévère est significativement associée à la présentation radiographique atypique de la tuberculose. PMID:27800112

  5. [Control of epilepsy in adult patients with tuberous sclerosis].

    Science.gov (United States)

    Gallardo-Tur, Alejandro; García-Martín, Guillermina; Chamorro-Muñoz, María Isabel; Romero-Godoy, Jorge; Romero-Acebal, Manuel

    2013-06-01

    Introduccion. La esclerosis tuberosa es una enfermedad genetica cuyas manifestaciones principales son la formacion de tumores neuroectodermicos, que asocia epilepsia secundaria muy frecuentemente. Objetivo. Describir el perfil epileptico, el control, la frecuencia de crisis y la efectividad del tratamiento en pacientes adultos con esclerosis tuberosa. Pacientes y metodos. Estudio descriptivo en el que se han incluido pacientes adultos (mayores de 14 anos) con diagnostico confirmado de esclerosis tuberosa. Se ha analizado la frecuencia y tipos de crisis. Se ha realizado un estudio y contabilizacion de los diferentes farmacos antiepilepticos en cada paciente, la frecuencia de uso de cada principio activo y un estudio comparativo entre control de crisis y tipo de terapia. Resultados. De 19 adultos estudiados, tuvieron crisis epilepticas 16 (84%). Presentaron control de crisis completo, crisis esporadicas y crisis frecuentes el 44%, 25% y 31%, respectivamente. Hubo frecuencia de crisis focales, generalizadas y ambas en el 38%, 6% y 25%, respectivamente. Estaban en tratamiento con farmacos antiepilepticos en monoterapia, biterapia y triterapia el 38%, 44% y 19%, respectivamente. El mas consumido globalmente fue el levetiracetam, seguido de la carbamacepina y el acido valproico. En monoterapia, el mas frecuente fue la carbamacepina, con mayor proporcion de control completo. Conclusiones. La epilepsia en la esclerosis tuberosa es relativamente benigna, y se consigue un aceptable control en la mayoria de casos con un numero de antiepilepticos acorde con lo aconsejado en las guias de tratamiento. Se observa estabilidad de lesiones, y no hay malignizacion en nuestra serie. El bajo numero de la muestra limita el estudio, pero se observan proporciones similares de efectividad del tratamiento respecto a otra serie publicada.

  6. Evolución estructural de la zona de transición entre las fajas plegadas y corridas de Aconcagua y Malargüe Provincia de Mendoza

    Directory of Open Access Journals (Sweden)

    S. Broens

    2005-12-01

    Full Text Available En el presente trabajo se describe brevemente la estratigrafía y la estructura de los Andes en la zona de transición entre las fajas plegadas y corridas del Aconcagua y Malargüe. Las rocas aflorantes corresponden a un basamento volcánico acido permotriásico, sedimentitas mesozoicas de la cuenca neuquina y efusiones volcánicas y depósitos continentales neógenos. Estructuralmente se reconocen de oeste a este, cuatro segmentos denominados: zona de inversión tectónica, zona de pliegues apretados, zona central o de imbricación y anticlinal del Carrizalito. Se construyeron dos secciones estructurales que se ajustan a los datos de campo recogidos en las zonas de imbricación, de pliegues apretados y del flanco dorsal del anticlinal del Carrizalito, que permitieron describir las estructuras presentes en el área. Lineamientos regionales de orientación noroeste-sureste podrían estar actuando como zonas de transferencia de rechazos. Pueden reconocerse dos o tres pulsos deformacionales según se considere la edad relativa de las estructuras respecto al levantamiento de la Cordillera Frontal. Para el caso en que el cordón del Carrizalito haya actuado como un alto de basamento se proponen dos pulsos, uno de piel fina y otro posterior que levanta a la Cordillera Frontal basculando la secuencia previamente deformada. Si en cambio la estructuración del anticlinal del Carrizalito hizo que este se comporte como punto de fijación (sticking point podria sumarse un tercer episodio deformacional con corrimientos fuera de secuencia.

  7. Evaluación de la extracción del aceite de la Triportheus magdalenae y análisis del perfil lipídico del aceite crudo

    Directory of Open Access Journals (Sweden)

    Denilson Padilla Cerpa

    2012-02-01

    Full Text Available Se evaluó el rendimiento en la extracción química del aceite de la especie íctica Arenca (Triportheus magdalenae mediante la aplicación previa de dos tipos de digestión (ácida y acido-alcohólica, a través de un diseño experimental de bloques completamente al azar (DBCA. La extracción del aceite fue realizada por el método químico soxhlet; (adaptado del método, 960.39-AOAC para carnes y el análisis del perfil lipídico del aceite crudo fue realizado por cromatografía Gaseosa, demostrando que los dos tipos de digestión aplicadas producen un aumento en el rendimiento de la extracción química del aceite, obteniéndose mayor rendimiento con la digestión ácida, según la Diferencia Media Significativa (DMS con una p<0,05. Se determinó que la T. magdalenae, presenta una cantidad de aceite crudo en promedio de 3,23%, predominado por ácidos grasos insaturados (AGI, en un 56,77%, con proporción en ácidos grasos esenciales de la serie Omega 3 (ω-3 y omega 6 (ω-6, entre los que sobresalen el Eicosapentaenoico (EPA, el Docosapentaenoico (DPA y el Linolénico para ω-3; el linoleíco y el araquidónico para ω-6. Los resultados obtenidos permiten considerar la especie estudiada como viable para la obtención de aceites, de características farmacéuticas y medicinales.

  8. New heterocycles having double characters; as antimicrobial and surface active agents.

    Directory of Open Access Journals (Sweden)

    El-Sayed, R.

    2004-12-01

    Full Text Available Fatty acids isothiocyanate (1 was used as a starting material to synthesize some important heterocycles such as triazoles, oxazoles, thiazoles, benzoxazoles and quinazolines by treating with different types of nucleophiles such as nitrogen nucleophiles, oxygen nucleophiles, and sulfur nucleophiles. The produced compounds were subjected to propylene oxide in different moles (n = 3, 5 and 7 to produce novel groups of nonionic compounds having the double function as antimicrobial and surface active agents which can be used in the manufacturing of drugs, cosmetics, pesticides or can be used as antibacterial and/or antifungal. The physical properties as surface and interfacial tension, cloud point, foaming height, wetting time, emulsification power and the critical micelle concentration (CMC were determined, antimicrobial and biodegradability were also determined.Isocianatos de acidos grasos se utilizaron como material de partida para la síntesis de importantes heterociclos tales como triazoles, oxazoles, thoazoles, benzoxazoles y quinazolinas mediante el tratamiento de los mismos con diferentes tipos de nucleofilos tales como nucleofilos nitrogenados, oxigenados, o azufrados. Los compuestos producidos se trataron con oxido de propileno a diferentes concentraciones molares (n = 3, 5 y 7 para producir nuevos grupos de compuestos no iónicos que tuvieran la doble función de ser compuestos antimicrobianos y agentes de superficie, que se pudieran usar en la fabricación de medicinas, cosméticos, pesticidas o como antibacterianos o antifúngicos. Se determinaron sus propiedades tales como tensión superficial e interfacial, punto de turbidez, altura de espuma, tiempo de mojado, poder de emulsificación y concentración micelar crítica (CMC, asi como sus propiedades antimicrobianas y de degradabilidad.

  9. [The prevalence of obesity and metabolic syndrome in paediatric patients with epilepsy treated in monotherapy with valproic acid].

    Science.gov (United States)

    Carmona-Vazquez, C R; Ruiz-Garcia, M; Pena-Landin, D M; Diaz-Garcia, L; Greenawalt, S R

    2015-09-01

    Introduccion. El acido valproico (VPA) es un antiepileptico util para controlar diferentes tipos de epilepsia. Tiene efectos colaterales y se asocia a incremento del peso corporal y a alteraciones metabolicas y endocrinas, entre ellas sindrome metabolico. Objetivo. Conocer la prevalencia de la obesidad y el sindrome metabolico en pacientes pediatricos con epilepsia tratados en monoterapia con VPA. Pacientes y metodos. Estudio transversal, observacional, analitico. Se estudiaron pacientes tratados con VPA entre 2010-2014, y se midio el indice de masa corporal (IMC), el perimetro abdominal, la presion arterial, la glucosa, los trigliceridos y las lipoproteinas de alta densidad (HDL), en busqueda de obesidad y sindrome metabolico. La obesidad se definio con un IMC mayor del percentil 95; el sindrome metabolico, con al menos tres de los siguientes criterios: perimetro abdominal mayor del percentil 90, presion arterial sistemica mayor del percentil 90, trigliceridos mayores de 110 mg/dL y HDL menor de 40 mg/dL. Resultados. Se estudiaron 47 pacientes con una edad media de 10,1 ± 4 años; el 51,06% eran varones. Ocho (17%) desarrollaron obesidad y, de ellos, dos (25%), sindrome metabolico. Tres pacientes desarrollaron sobrepeso (6%). Observamos diferencias estadisticamente significativas de media de edad comparados con los grupos de IMC, donde los pacientes obesos eran adolescentes (ANOVA; p = 0,0001), y aquellos que tomaban mas VPA al dia eran los obesos (ANOVA; p = 0,024). Conclusiones. Los pacientes tratados con VPA que se convierten en obesos pueden desarrollar sindrome metabolico. Requieren una monitorizacion cuidadosa y, ante la presencia de ganancia de peso, se debera valorar la retirada del farmaco.

  10. Contribution to the study of sorption mechanisms at solid-liquid interfaces: application to the cases of apatites and oxy-hydroxides

    International Nuclear Information System (INIS)

    Sorption-desorption phenomena play an important role in the transport of toxic and radioactive elements in surface and underground water in contact with solid matter. Selenium, which is one of the long-lived radionuclides present in radioactive waste, is characterized by several oxidation states and by anionic species in aqueous solutions. In order to predict its transport, we need a good knowledge of its sorption processes. We have studied the sorption of Se(IV) and Se(VI) on two types of solids present in natural media or which have been proposed as additives to active barriers: hydroxy-apatites, fluoro-apatite and iron oxi-hydroxides (goethite and hematite). Sorption mechanisms have been studied through an approach including several different and complementary methods: titrimetry, zeta-metry, scanning and transmission electron microscopy, infrared spectroscopy, X-ray diffraction, X-ray photo electron spectroscopy, etc... Results showed that Se(VI) is much less sorbed than Se(VI) on both types of solids. For Se(IV) the sorption mechanisms are different for iron oxides and apatites. On oxides, sorption increases when pH decreases. It can be interpreted by a surface complexation model, essentially through an inner sphere complex (monodentate or bidentate). Modelling of Se sorption curves was performed after the determination of acido-basic properties of oxides. However, the determination of the intrinsic properties of oxides is disturbed by several parameters identified as impurities, evolution of the solid in solution, kinetic and solubility of the solid. For apatites, selenium sorption proceeds by exchange with superficial groups, with a maximum of fixation at approximately pH 8. Thanks to XPS measurements and the elaboration of a mathematical model, we could determine the depth of penetration of both selenium and cadmium on apatites. (author)

  11. Catalytic mechanism of the dehydrogenation of ethylbenzene over Fe–Co/Mg(Al)O derived from hydrotalcites

    KAUST Repository

    Tope, Balkrishna B.

    2011-11-01

    Catalytic mechanism of ethylbenzene dehydrogenation over Fe-Co/Mg(Al)O derived from hydrotalcites has been studied based on the XAFS and XPS catalyst characterization and the FTIR measurements of adsorbed species. Fe-Co/Mg(Al)O showed synergy, whereas Fe-Ni/Mg(Al)O showed no synergy, in the dehydrogenation of ethylbenzene. Ni species were stably incorporated as Ni2+ in the regular sites in periclase and spinel structure in the Fe-Ni/Mg(Al)O. Contrarily, Co species exists as a mixture of Co3+/Co2+ in the Fe-Co/Mg(Al)O and was partially isolated from the regular sites in the structures with increasing the Co content. Co addition enhanced Lewis acidity of Fe3+ active sites by forming Fe3+-O-Co 3+/2+(1/1) bond, resulting in an increase in the activity. FTIR of ethylbenzene adsorbed on the Fe-Co/Mg(Al)O clearly showed formations of C-O bond and π-adsorbed aromatic ring. This suggests that ethylbenzene was strongly adsorbed on the Fe3+ acid sites via π-bonding and the dehydrogenation was initiated by α-H+ abstraction from ethyl group on Mg2+-O2- basic sites, followed by C-O-Mg bond formation. The α-H+ abstraction by O2-(-Mg 2+) was likely followed by β-H abstraction, leading to the formations of styrene and H2. Such catalytic mechanism by the Fe 3+ acid-O2-(-Mg2+) base couple and the Fe 3+/Fe2+ reduction-oxidation cycle was further assisted by Co3+/Co2+, leading to a good catalytic activity for the dehydrogenation of ethylbenzene. © 2011 Elsevier B.V. All rights reserved.

  12. CO{sub 2} electroreduction: conversion into formic acid and mechanistic aspect in aqueous medium; Electroreduction du CO{sub 2}: conversion en acide formique et aspect mecanistique en milieu aqueux

    Energy Technology Data Exchange (ETDEWEB)

    Innocent, B.; Pasquier, D.; Ropital, F. [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France); Hahn, F.; Leger, J.M.; Kokoh, B. [Poitiers Univ., LaCCO, Equipe Electrocatalyse, UMR 6503 CNRS, 86 (France)

    2007-07-01

    The CO{sub 2} release reduction is nowadays considered as a necessity to limit the climatic change phenomena due to the greenhouse effect. For that, a part of CO{sub 2} could be transformed by its electrochemical reduction on a hydrogen overvoltage electrode as lead. According to the nature of the electrode material and of the electrolyte, CO{sub 2} can be electro catalytically hydrogenated or dimerized. In the conditions presented here (basic aqueous medium, lead electrode), the reagent is in majority reduced into formate, the parasite faradic reaction being the solvent transformation into dihydrogen. The studies carried out by cyclic voltametry have shown that the reducible form of CO{sub 2} is the hydrogeno-carbonate ion; its reduction begins at -1.2 V and reaches a maximum for an electrode potential of -1.6 V vs. ECS. Long intentiostatic electrolyses have then been carried out in an electrolytic circulation cell of 'filter-press' type. The cathode is a lead sheet of 20 cm{sup 2} and a current intensity of -100 mA has been imposed. The chromatographic analyses of the electrolytic solution have allowed to show that the formate selectivity is of 90%. The electroreduction process induces an acido-basic disequilibrium which induces a decrease of the reaction yield. A pH correction is then necessary to obtain great conversions of CO{sub 2} in alkaline medium (pH{>=}7) as follows: HCO{sub 3}{sup -} + H{sub 2}O + 2e{sup -} {yields} HCOO{sup -} + 2 HO{sup -}. In situ reflexion infrared spectroscopy studies, carried out in deuterated aqueous medium and by chrono-amperometry, have shown characteristic bands due to the hydrogeno-carbonate ion (weakly adsorbed) and to the formate produced, required for the understanding of the reactional mechanism. (O.M.)

  13. Monitoring and control system for the charging of batteries in photovoltaic applications; Sistema para monitorizar y controlar la carga de baterias en aplicaciones fotovoltaicas

    Energy Technology Data Exchange (ETDEWEB)

    Ortega S, Cesar A; Pacheco A, Maria Jojutla; Orozco V, Jaime A; Cristin V, Miguel A [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2004-07-01

    The appropriate monitoring and control of the charging of lead-acid (LAB) batteries is an increasing necessity in an industry that demands systems with low maintenance costs and high availability. The problem of extending the batteries useful life becomes more complex when the batteries are charged through photovoltaic panels. The purpose of the present article is to offer the description of the system for monitoring and control for the charging of batteries developed at the Instituto de Investigaciones Electricas (IIE). This system performs a continuous monitoring of the charging state of the battery and of the main operation parameters. With the extracted information of the data, the fine tuning algorithm control can be made. The data are acquired in a personal computer through a serial connection. Once stored, they are presented to the user in a graphical way so that they can be analyzed. [Spanish] El adecuado monitoreo y control de carga de baterias plomo-acido (BPA) es una necesidad creciente en una industria que demanda sistemas con bajos costos de mantenimiento y alta disponibilidad. El problema de extender la vida util de las baterias se vuelve mas complejo cuando las baterias son cargadas a traves de paneles fotovoltaicos. La intencion del presente articulo es ofrecer la descripcion del sistema para monitoreo y control de carga de baterias desarrollado en el Instituto de Investigaciones Electricas (IIE). Este sistema realiza un monitoreo continuo del estado de carga de la bateria y de los principales parametros de operacion. Con la informacion extraida de los datos, se puede hacer la sintonizacion fina del algoritmo de control. Los datos se adquieren en una computadora personal a traves de un enlace serial. Una vez almacenados, se presentan al usuario de manera grafica para que puedan ser analizados.

  14. [Folate and iron in fertile age women from a Venezuelan community affected by incidence of neural tube defects].

    Science.gov (United States)

    Mariela, Montilva; Jham, Papale; Nieves, García-Casal María; Yelitza, Berné; Yudith, Ontiveros; Lourdes, Durán

    2010-06-01

    The objective of this transversal study was to determine folate and iron nutritional status of women in fertile age from Municipio Jiménez, Lara State, Venezuela. The sampling was probabilistic by conglomerates from the urban and rural areas, selecting 15 conglomerates from which women between 12 and 45 years (269), were studied. After signing informed consent, participating were interviewed for personal data, antecedents related to folate and iron, socioeconomic data (Graffar-Mendez Castellano method and unsatisfied basic needs). In blood sample was determined Hemoglobin, and Erythrocytic Folate (FE). Serum was obtained to determine Ferritin and Serum Folate (FS). 53.53% of the sample presented low FS levels, 10.78% were FS deficient. Severe FE deficiency was present in 80.7% of the cases, moderate deficiency affected 5.9%. For both tests, median was higher for women in treatment with Acido Fólico or pregnant (p = 0.000), median for FE was higher for adults (p = 0.001) and in non poor women (p = 0.011). There were no significant differences for coffee, alcohol, anticonceptive consumption, urban or rural resident or socioeconomic strata. The prevalence of anemia was 11.2% being significantly more frequent in adults than in adolescents (p = 0.029) and in urban women (p = 0.042). Low ferritin were found in 37.3% of the sample, the effect of different variables was not statistically significant. In conclusion, there is a high prevalence of iron and folate deficiencies in women of fertile age from Municipio Jiménez, which could constitute a conditioning factor for the appearance of neural tube defects. PMID:21427880

  15. Metabolic Mechanism of Acid Production by Streptococcus bovis in Rumen and Its Regulation%牛链球菌在瘤胃中产酸的代谢机制及调控

    Institute of Scientific and Technical Information of China (English)

    陈连民; 沈宜钊; 王洪荣

    2016-01-01

    Streptococcus bovis ( S.bovis) is usually a major lactate producing bacterium in the rumen, and is recognized its’ contribution to development of rumen acidosis when ruminants are fed high concentrate diets. Previous work indicates that carbohydrate metabolism in S.bovis is mainly affected by the way of glucose trans membrane transport, and enzymes and intermediate metabolites in glycolytic pathway.In addition, the factors, environmental pH, growth stage, and control protein catabolism ( CcpA) , etc., also have significant impacts. In this paper, metabolic mechanism and influence factors of carbohydrate fermentation and acid production by S.bovis were reviewed in purpose to provide references for further insight into the mechanism of rumen acido-sis caused by lactic acids.%牛链球菌( S.bovis)是瘤胃主要的乳酸产生菌,在饲喂高精料饲粮导致瘤胃乳酸中毒进程中扮演重要角色。已有研究证实S.bovis利用碳水化合物代谢产酸主要受葡萄糖转运方式、酵解产酸途径中酶和中间代谢物调控。另外,研究也发现环境pH、增殖生长阶段及分解代谢控制蛋白( CcpA)等对其产酸速率和模式也有显著影响。本文对近年来有关S.bovis利用饲料中碳水化合物发酵产酸代谢途径及影响因素研究加以综述,为从微生物代谢角度解析瘤胃乳酸中毒机制提供参考。

  16. Avaliação da atividade antioxidante e antimicrobiana do extrato etanólico bruto e frações orgânicas obtidas a partir da casca do caule da espécie Guettarda uruguensis Cham, & Scthdl, (Rubiaceae

    Directory of Open Access Journals (Sweden)

    Ana Flávia Schvabe Duarte

    2014-09-01

    Full Text Available Este trabalho teve como objetivo avaliar o potencial antioxidante e antimicrobiano do extrato bruto e frações obtidas das cascas do caule da espécie Guettarda uruguensis, Os ensaios antioxidantes indicaram alto potencial antioxidante, No ensaio de redução de fosfomolibdênio, a fração acetato de etila apresentou atividade antioxidante de 41,67% em relação ao padrão de ácido ascórbico e superou em 35,21% a atividade do padrão rutina, No ensaio de redução do DPPH (2,2-diphenyl-1-picrylhydrazyl, a fração acetato de etila apresentou um IC50 de 10,91 µg mL-1, valor próximo ao do ácido ascórbico (IC50 = 4,78 µg mL-1 e da rutina (IC50 = 6,62 µg mL-1, Pelo ensaio de TBA (acido tiobabitúrico o extrato bruto (IA = 71,48% e a fração hexano (IA = 47,85% apresentaram índices superiores ao controle de BHT (butil hidroxi tolueno (IA = 42,66, Através do ensaio de microdiluição em placas, foi observado que o extrato bruto e frações apresentaram atividade antimicrobiana, O estudo fitoquímico qualitativo revelou a presença de alcaloides, cumarinas, esteroides e/ou triterpenos, heterosídeos saponínicos, taninos e aminogrupos.

  17. Phytochemical study of Mikania pseudohoffmanianna G. M. Barroso ex W. C. Holmes Estudo fitoquímico de Mikania pseudohoffmanianna G. M. Barroso ex W. C. Holmes

    Directory of Open Access Journals (Sweden)

    Janaina Moreira de Souza

    2006-06-01

    Full Text Available This work describes the fractionation of methanol and dichloromethane extracts of aerial parts from the Mikania pseudohoffmanniana G. M. Barroso ex W. C. Holmes. The phytochemical study of extracts led to isolation and the identification of 16 known compounds, including: steroids: campesterol, stigmasterol and beta-sitosterol, diterpenes: ent-15beta-E-cinnamoyloxy-kaur-16-en-19-oic acid, ent-15beta-Z-cinnamoyloxy-kaur-16-en-19-oic acid and ent-kaur-16-en-19-oic acid, triterpenes: alpha-amyrin, beta-amyrin, alpha-amyrin acetate, beta-amyrin acetate, lupeol, lupeol acetate and friedelin, coumarin: scopoletin, flavonoid: quercetin and caffeoyl quinic acid derivative: 4,5-di-O-[E]-caffeoyl quinic acid.O fracionamento dos extratos diclorometânico e metanólico das partes aéreas de Mikania pseudohoffmanniana G. M. Barroso ex W. C. Holmes resultou na identificação de 16 substâncias: os esteróides: campesterol, estigmasterol e beta-sitosterol; os diterpenos: ácido ent-15beta-E-cinamoiloxi-caur-16-en-19-óico, ácido ent-15beta-Z-cinamoiloxi-caur-16-en-19-óico e ácido ent-caur-16-en-19-óico; os triterpenos: alfa-amirina, beta-amirina, acetato de alfa-amirina, acetato de beta-amirina, lupeol, acetato de lupeol e friedelina; a cumarina: escopoletina; o flavonóide: quercetina e o derivado do ácido cafeoilquínico: 4,5-di-O-[E] -cafeoilquínico.

  18. [Characteristics of patients with refractory epilepsy attended in a tertiary referral center in Costa Rica].

    Science.gov (United States)

    Sanabria-Castro, A; Henriquez-Varela, F; Lara-Maier, S; Monge-Bonilla, C; Sittenfeld-Appel, M

    2016-07-16

    Introduccion. El 30% de los pacientes con epilepsia presenta convulsiones recurrentes, porcentaje que representa aproximadamente a 15 millones de personas en el mundo y constituye una poblacion escasamente descrita. Objetivo. Caracterizar sociodemografica y clinicamente la poblacion de pacientes diagnosticados con epilepsia refractaria en un hospital terciario de Costa Rica. Pacientes y metodos. Se analizan los registros medicos de los pacientes con epilepsia refractaria valorados en la unidad de epilepsia del Hospital San Juan de Dios de la Caja Costarricense del Seguro Social desde agosto de 2012 a octubre de 2014. Resultados. Se incluyen los expedientes clinicos de 91 pacientes. La edad media de inicio fue de 13,1 ± 11,1 años. Las crisis secundariamente generalizadas constituyen el tipo predominante (81,3%), la etiologia mas frecuente es la esclerosis mesial temporal (48,3%) y la mayoria de los pacientes presentaba examenes neurologicos normales y valoraciones neuro­psicologicas normales o bajas. Alrededor de la mitad (48,8%) de los pacientes habia sido medicada con un rango de 4-6 farmacos antiepilepticos, y los mas prescritos fueron lamotrigina, carbamacepina, acido valproico y fenitoina. Las principales recomendaciones en estos pacientes fueron: optimizacion de tratamiento, neurocirugia y reingreso. Se observan diferencias entre la edad de inicio y el sexo, la frecuencia de las crisis y el sexo, el tiempo de evolucion de la patologia y la cantidad de tratamientos fallidos, y el tiempo de evolucion de la enfermedad y la ocupacion. Conclusiones. Las caracteristicas sociodemograficas, el manejo de los pacientes, los farmacos antiepilepticos utilizados y las diferencias encontradas son similares a las descritas en otras latitudes.

  19. [Prevalence, type of epilepsy and use of antiepileptic drugs in primary care].

    Science.gov (United States)

    Fernández-Suárez, Elena; Villa-Estébanez, Rubén; Garcia-Martinez, Alberto; Fidalgo-González, José A; Zanabili Al-Sibbai, Ahmad A; Salas-Puig, Javier

    2015-06-16

    Introduccion. La epilepsia es una enfermedad con gran repercusion social y economica. La prevalencia deberia ser usada como la base mas importante para planificar la prevencion secundaria y terciaria. Objetivos. Identificar los pacientes con diagnostico de epilepsia en un centro de atencion primaria y determinar la prevalencia, las caracteristicas demograficas, el tipo de sindrome epileptico y el uso de los farmacos antiepilepticos. Pacientes y metodos. Estudio descriptivo transversal retrospectivo. Incluyo 196 pacientes con diagnostico de epilepsia pertenecientes a un centro de salud y revision de la historia clinica hospitalaria, con el estudio de las variables sociodemograficas y clinicofarmacologicas. Resultados. Prevalencia de epilepsia: 8,4/1.000 habitantes. Edad media: 50,3 años. Sexo: 52,6%, hombres. Ambito: 79,6%, urbano. Antecedentes familiares de epilepsia: 14,8%. Tipo de epilepsia: focal sintomatica por ictus (14,3%), generalizada idiopatica (13,8%), focal criptogenica (8,7%), no clasificada (31,1%). Edad media al inicio de la crisis: 31,6 años. Comorbilidad neurologica o psiquiatrica: 62,8%. Ultima revision: el 18,9% sin tratamiento antiepileptico, el 56,6% en monoterapia y el 24,5% en politerapia. Libres de crisis: 76,5%. Farmacos mas prescritos: acido valproico, carbamacepina, fenitoina, lamotrigina y levetiracetam. Un 78,6% sin efectos secundarios. Fallecimiento: 4,1%. Conclusiones. La prevalencia de pacientes con epilepsia fue de 8,4/1.000 habitantes y predomina la focal sintomatica por ictus. Casi un tercio de los pacientes referia algun factor desencadenante de crisis, principalmente consumo de alcohol o fiebre. Predomina la monoterapia, los efectos secundarios son escasos y, en la ultima revision, la mayoria se hallaba libre de crisis.

  20. Evaluación del potencial de dos peróxidas para su aplicación en biorremedación de compuestos orgánicos recalcitrantes

    Directory of Open Access Journals (Sweden)

    Caicedo Nelson

    2001-12-01

    Full Text Available El presente trabajo demuestra el promisorio futuro que presentan las enzimas cloroperoxidasa del hongo Caldariomyces fumago (CPO y la peroxidasa de palma real (Roystonea regia, PPR, dos peroxidasas de diferente fuente (microbiana y vegetal, usadas como biocatalizadores para aplicación en biorremediación de compuestos orgánicos recalcitrantes. Para este estudio, se evaluó la actividad catalítica tipo peroxidasa, en sistemas de fase orgánica, de cada una de las enzimas empleando diferentes compuestos modelos tales como: PAH's (pireno y antraceno, órgano nitrogenados (difenilamina, moléculas monoaromáticas tipo fenólicas (guayacol, y colorantes [(naranja de metilo y ABTS (2.2´ Azinabis (6- acido surfonic-3- etilbenzotinzolina]. Los sistemas de reacción estuvieron compuestos por mezclas monofásicas de agua: solvente orgánico miscible (metanol, etanol, isopropanol, acetonitrilo, tetrahidrofurano, dimetil sulfóxido, etc., sobre los cuales se evaluó la actividad catalítica de ambas peroxidasas. En la mayoría de los ensayos se observó actividad catalítica de las dos enzimas sobre los sustratos evaluados. Sin embargo, para el caso del naranja de metilo y algunos PAH's, la PPR no mostró capacidad de oxidación biocatalítica. A su vez, fue la enzima que mostró mayor tolerancia a los solventes evaluados, bajo los cuales vio mejorada apreciablemente su actividad cuando se emplearon sustratos de baja hidrofobicidad. Con los datos experimentales se calculó el kcat, como parámetro cinético, el cual sirvió para comparar el desempeño biocatalítico de cada enzima sobre los sustratos.

  1. Cardiovascular risk factors in children and adolescents with anxiety disorders and their association with disease severity.

    Science.gov (United States)

    Cheuiche Pires, Gabriela; Camboim Rockett, Fernanda; Abrahão Salum Júnior, Giovanni; Gus Manfro, Gisele; Bosa, Vera Lúcia

    2005-01-01

    Introducción: Evidencias sugieren que la ansiedad es una prediciente independiente de los eventos cardiovasculares adversos. Entretanto, pocos estudios evaluaron la presencia de factores de riesgo (FR) para estas enfermedades en ninos y adolescentes. Objetivos: Identificar la prevalencia de FR cardiovasculares en ninos y adolescentes diagnosticados con disturbio de ansiedad y su asociacion con la gravedad de la enfermedad. Metodología: Estudio transversal que avaluo FR nutricional, antropometricos, % de gordura corporal (CG), presion arterial (PA), nivel de actividad fisica y escalas de sintomas y gravedad de la ansiedad. Resultados: 65 ninos y adolescentes (8.6 } 1.7 anos) fueron incluidos en el estudio. Cuanto a los FR, el consumo excesivo de acidos grasos saturados (52.3%), indice de masa corporal alto (50.8%), PA alterada (50.8%) y la falta de ejercicio fisico (50.0%) fueron los mas prevalecientes. Hubo asociacion significativa entre la mayor gravedad del disturbio y el acumulo de ≥ 6 FR (p=0,026), exceso de gordura abdominal medida por la circunferencia de cintura (p=0.019) y por el indice de conicidad (p=0.053) y exceso en el % GC (p=0.044). Conclusión: Los resultados encontrados indican que hay una alta prevalencia de FR cardiovascular en la amuestra estudiada y los pacientes mas graves presentaron mayor riesgo. La caracterizacion del perfil de riesgo en las poblaciones con predisposicion a las enfermedades cardiovasculares es crucial para la elaboracion de estrategias de intervencion que oportunicen la reduccion en la prevalencia de estas enfermedades.

  2. [Mango: agroindustrial aspects, nutritional/functional value and health effects].

    Science.gov (United States)

    Wall-Medrano, Abraham; Olivas-Aguirre, Francisco J; Velderrain-Rodriguez, Gustavo R; González-Aguilar, A; de la Rosa, Laura A; López-Díaz, Jose A; Álvarez-Parrilla, Emilio

    2014-11-01

    Objetivo: Revisar y discutir la información más reciente sobre el valor agroindustrial, funcional y nutricional de uno de los frutos de mayor cultivo, exportación y consumo en México: el Mango. Métodos: Se realizó una búsqueda en diversas bases de datos (PubMed, Cochrane, ScienceDirect) y documentos de libre acceso (Google Scholar) sobre Mangifera indica L. Esta información fue posteriormente sub-clasificada en aspectos agroindustriales, nutricionales, funcionales y efectos a la salud. Resultados: Uno de cada veinte mangos consumidos mundialmente, es mexicano. “Ataulfo” es la variedad la de mayor importancia agronómica. El procesamiento mínimo de su pulpa (MP) genera residuos de cáscara (MC) y semilla con alto potencial nutracéutico. MP y MC son buenas fuentes de ascorbato, fructosa, fibra dietarias soluble (MP, almidones y ramnogalacturonanos) e insoluble (MC, ligninas y hemicelulosa) y lípidos funcionales (MP). MP y MC poseen un perfil de compuestos fenólicos (CF) monoméricos (MP) como el acido gálico y el protocatehuico y poliméricos (MC) como la -PGG asociados con efectos anti-obesigénicos, anti-inflamatorios, anti-cancerigenos y anti-diabeticos. Estos beneficios son dependientes de la bioaccesibilidad (liberación de su matriz alimentaria) y destino metabólico (biodisponibilidad) de estos CF. Discusión: El mango resulta una valiosa fuente de compuestos antioxidantes con comprobado beneficio a la salud. Sin embargo, factores como la variedad, temporalidad de cultivos, tratamientos pre y post-cosecha, extracción de bioactivos y algunas barreras fisiológicas pueden modificar su potencial nutracéutico.

  3. Use of a lactic acid plus lactoserum intimate liquid soap for external hygiene in the prevention of bacterial vaginosis recurrence after metronidazole oral treatment Uso do ácido láctico com lactoserum em sabonete líquido íntimo para higiene externa na prevenção da recorrência de vaginose bacteriana após tratamento oral com metronidazol

    Directory of Open Access Journals (Sweden)

    M. Valeria Bahamondes

    2011-08-01

    uso de acido láctico com lactoserum em sabonete líquido iniciado imediatamente após o tratamento com metronidazol oral e qualidade de vida das participantes. MÉTODOS: Um total de 123 mulheres com dianóstico de VB com ao menos três dos seguintes critérios: 1 leucorreia vaginal homogênea sem inflamação de vagina ou vulva; 2 pH vaginal ≥ 4,5; 3 teste positivo de Whiff; e 4 "clue cells" em mais de 20% das células epiteliais na vagina. O escore de Nugent ≥ 4 na bacterioscopia vaginal também foi usado. Após o diagnóstico de VB, metronidazol 500 mg oral foi ministrado durante 7 dias. Pacientes curados da VB foram instruídos a usar 7,5 a 10 mL de acido láctico com lactoserum em sabonete líquido uma vez ao dia para higiene da genitália externa. Três visitas de controle foram agendadas (30, 60 e 90 dias; ± 5 dias. Um questionário foi aplicado na forma de escala visual análoga (EVA em todas as visitas sobre: 1 nível de conforto na região genital; 2 mau odor na genitália; 3 conforto na relação sexual; 4 satisfação com higiene íntima; e 5 autoestima. RESULTADOS: Noventa e duas (74,8% mulheres iniciaram o uso de ácido láctico com lactoserum líquido na visita 1. Na visita 2, 3 e 4 foram 84, 62 e 42 mulheres para avaliação, respectivamente. A taxa de recorrência da VB foi 19,0%, 24,2% e 7,1%, respectivamente nas três visitas e candidíase vaginal foi observada em cinco mulheres. Qualidade de vida foi avaliada em 42 mulheres que completaram as quatro visitas agendadas e houve uma melhora significativa nos cinco domínios avaliados. CONCLUSÃO: O uso de acido láctico com lactoserum em sabonete líquido para higiene externa intima pode ser uma opção para a prevenção da recorrência de VB após tratamento e cura com metronidazol oral

  4. Monitoring system for individual cells in energy backing banks; Sistema para monitorizar las celdas individuales en bancos de respaldo de energia

    Energy Technology Data Exchange (ETDEWEB)

    Ortega S, Cesar A; Pacheco A, Maria Jojutla; Orozco V, Jaime A; Cristin V, Miguel A [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2004-07-01

    relatively smaller investment compared with the cost of a fault in the energy supply system. [Spanish] Las baterias plomo-acido (BPA) son ampliamente utilizadas en la industria para almacenar energia quimica y liberarla en forma de electricidad. Los fenomenos que ocurren en el interior de una BPA -durante sus ciclos de carga y descarga - afectan la vida util de la bateria a largo plazo. En este sentido, se han realizado diversas investigaciones alrededor del mundo; no obstante, dichos estudios han arrojado solo dos conclusiones: a) La seleccion de un algoritmo de carga adecuado puede extender la vida util de la bateria. b) Un monitoreo continuo del banco puede ayudar a estimar el estado de salud de las baterias y a detectar los elementos del banco que estan mas proximos a fallar. Una bateria plomo-acido esta formada por un conjunto de celdas plomo-acido conectadas en serie. A mayor numero de celdas, mayor el voltaje de la bateria. Las BPA que se utilizan para formar bancos de respaldo de energia son dispositivos sumamente delicados cuya vida util depende fuertemente de factores como: temperatura de operacion, regimen de descarga, regimen de carga. Las BPA se conectan, en serie, para elevar el voltaje, o bien, en paralelo, para elevar la corriente suministrada por el banco. Con una combinacion de arreglos serie-paralelo es posible lograr casi cualquier especificacion de voltaje y corriente. Por otro lado, la operacion confiable de un arreglo de celdas requiere que todos los elementos de este funcionen correctamente. Si una celda falla en un arreglo serie, el resto deja de funcionar, lo que ocasiona costos de mantenimiento ademas de reducir la confiabilidad del sistema de respaldo. Para incrementar la confiabilidad de los arreglos de celdas Pb-A, es necesario un monitoreo individual y continuo de las celdas. Ello permite determinar cuales son las que tienen mayor probabilidad de falla y, entonces, poder reemplazarlas. Entre los principales beneficios de un sistema de monitoreo

  5. Monitoring system for individual cells in energy backing banks; Sistema para monitorizar las celdas individuales en bancos de respaldo de energia

    Energy Technology Data Exchange (ETDEWEB)

    Ortega S, Cesar A; Pacheco A, Maria Jojutla; Orozco V, Jaime A; Cristin V, Miguel A [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2004-07-01

    relatively smaller investment compared with the cost of a fault in the energy supply system. [Spanish] Las baterias plomo-acido (BPA) son ampliamente utilizadas en la industria para almacenar energia quimica y liberarla en forma de electricidad. Los fenomenos que ocurren en el interior de una BPA -durante sus ciclos de carga y descarga - afectan la vida util de la bateria a largo plazo. En este sentido, se han realizado diversas investigaciones alrededor del mundo; no obstante, dichos estudios han arrojado solo dos conclusiones: a) La seleccion de un algoritmo de carga adecuado puede extender la vida util de la bateria. b) Un monitoreo continuo del banco puede ayudar a estimar el estado de salud de las baterias y a detectar los elementos del banco que estan mas proximos a fallar. Una bateria plomo-acido esta formada por un conjunto de celdas plomo-acido conectadas en serie. A mayor numero de celdas, mayor el voltaje de la bateria. Las BPA que se utilizan para formar bancos de respaldo de energia son dispositivos sumamente delicados cuya vida util depende fuertemente de factores como: temperatura de operacion, regimen de descarga, regimen de carga. Las BPA se conectan, en serie, para elevar el voltaje, o bien, en paralelo, para elevar la corriente suministrada por el banco. Con una combinacion de arreglos serie-paralelo es posible lograr casi cualquier especificacion de voltaje y corriente. Por otro lado, la operacion confiable de un arreglo de celdas requiere que todos los elementos de este funcionen correctamente. Si una celda falla en un arreglo serie, el resto deja de funcionar, lo que ocasiona costos de mantenimiento ademas de reducir la confiabilidad del sistema de respaldo. Para incrementar la confiabilidad de los arreglos de celdas Pb-A, es necesario un monitoreo individual y continuo de las celdas. Ello permite determinar cuales son las que tienen mayor probabilidad de falla y, entonces, poder reemplazarlas. Entre los principales beneficios de un sistema de monitoreo

  6. Ionic composition and levels of acidity in rainfall in Maracaibo, Venezuela, between 1989 and 2001; Composicion ionica y niveles de acidez de las lluvias en Maracaibo, Venezuela, entre 1989 y 2001

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Ligbel; Morales, Jose; Velasquez, Harvi; Portillo, Dennis; Cano, Yulixis; Montilla, Brinolfo; Iriarte, Nelkis, Mesa, Johan [Universidad del Zulia, Maracaibo (Venezuela)]. E-mail: ligbels@hotmail.com

    2009-08-15

    de emision naturales y antropicas, se incorporan en las gotas de lluvia a traves de varios procesos fisicoquimicos durante los eventos de precipitacion. El conocimiento de la composicion quimica de las precipitaciones es critico para el entendimiento de la contaminacion regional y local y sus efectos sobre los ecosistemas. Entre las sustancias acidas o potencialmente acidas envueltas en la formacion de la lluvia acida, se puede senalar los compuestos de azufre, nitrogeno y cloro. Un factor importante en las caracteristicas acido-base de la lluvia es la emision de materiales alcalinos como carbonato de calcio, magnesio y amoniaco, que se encuentran generalmente como un vapor capaz de neutralizar los acidos sulfurico y nitrico. Los datos de la quimica de las lluvias, en este trabajo, provienen de varios sitios de la ciudad de Maracaibo, las muestras de agua de lluvia fueron recolectadas en tres periodos repartidos entre los anos 1989 y 2001, con equipos de muestreo manuales y automaticos. Para los diferentes analisis realizados se utilizaron un espectrometro de absorcion atomica modalidad llama, Perkin-Elmer 3110 y un cromatografo ionico con detector de conductividad, marca Dionex 2000i/SP. El pH-PPV en la lluvia de Maracaibo es 4.8, indicativo de una atmosfera ligeramente acida e influenciada por: SO{sub 4}{sup -2}, Cl{sup -} y NO{sub 3}{sup -} en 86 %. La especie neutralizante mas importante es el NH{sub 3}, aunque las concentraciones de Ca{sup +2} y Mg{sup +2} son aportes adicionales al proceso de neutralizacion atmosferica. El mayor flujo de depositacion humeda fue exhibido por: NH{sub 4}{sup +}, SO{sub 4}{sup -2}, Cl{sup -} y NO{sub 3}{sup -} con 67.5 %. Estadisticamente, se evidencio una alta correlacion entre SO4{sup *}, Cl{sup *} y NO{sub 3}{sup -} con el ion H{sup +} (p<0.05), ratificando su influencia en la acidez de las lluvias de Maracaibo. Se concluye que solo una pequena fraccion de los iones potencialmente acidos contribuyen a la acidez libre de las

  7. Biomarkers for environmental and occupational exposure to aromatic mutagens and carcinogens from emissions of oil shale petrochemistry. Report of the EC PECO programme, project CIPA-CT92-3016

    Energy Technology Data Exchange (ETDEWEB)

    Carere, A.; Crebelli, R. [eds.] [Istituto Superiore di Sanita`, Rome (Italy). Lab. di Tossicologia Comparata ed Ecotossicologia

    1998-03-01

    di ricerca, coordinato dall`Istituto Superiore di Sanita`, sui biomarcatori di esposizione a cancerogeni aromatici nella lavorazione degli scisti bituminosi. Le ricerche condotte hanno dimostrato la possibilita` di valutare l`esposizione individuale a livelli relativamente bassi di policicli aromatici e benzene attraverso la determinazione dell`idrossipirene ed acido trans, trans-mucotico urinari, rispettivamente, e del benzene ematico. E` stato sviluppato anche un nuovo, promettente metodo per la determinazione del benzene addotto alla emoglobina, ed ulteriormente raffinata e validata la metodologia per l`analisi di addotti sul DNA basata sulla post-marcatura con {sup 32}P. I risultati dlele analisi citogenetiche condotte hanno messo in luce la maggiore sensibilita` delle nuove tecniche molecolari basate sulla ibridazione in situ rispetto ai metodi convenzionali, prospettandone il possibile ruolo nella sorveglianza della esposizione a cancerogeni.

  8. Sonochemical synthesis of a PdAg/C electrocatalyst for oxygen reduction reaction; Sintesis sonoquimica de un electrocatalizador de PdAg/C para la reaccion de reduccion de oxigeno

    Energy Technology Data Exchange (ETDEWEB)

    Godinez-Garcia, A.; Perez-Robles, J.F. [Centro de Investigacion y de Estudios Avanzados del IPN. Santiago de Queretaro, Queretaro (Mexico)]. E-mail: jperez@qro.cinvestav.mx; Solorza-Feria, O. [CINVESTAV-IPN, Mexico, D.F. (Mexico)

    2009-09-15

    tecnica resulta interesante porque produce nanoparticulas muy dispersas y ya soportadas en carbon, con superficies muy limpias lo que la hace interesantes para su estudio. Cada electrocatalizador se evaluo para la reaccion de reduccion de oxigeno (ORR) en medio acido, por volta-amperometria ciclica (VC) y electrodo de disco rotatorio (EDR). El electrocatalizador fue caracterizado por difraccion de rayos X y microscopia electronica de transmision (TEM). La caracterizacion fisica nos revela que el electrocatalizador esta compuesto de agregados bimetalicos nanometricos. Una caracteristica importante de la aleacion PdAg/C obtenida por ultrasonido es que presenta una mayor actividad respecto a aquella obtenida por reduccion con NaBH{sub 4}.

  9. Determinación de frecuencia cardiaca, frecuencia respiratoria, lactato deshidrogenasa, creatinkinasa y ácido láctico en caballos durante competencia de salto en la Sabana de Bogotá

    Directory of Open Access Journals (Sweden)

    Paula Andrea Guerrero Nieto

    2009-06-01

    Full Text Available El estudio presenta los primeros resultados de investigación en variables fisiológicas y sus cambios por el ejercicio en equinos en competencia de salto en el país. Se utilizaron 24 ejemplares de las razas Silla Argentina, PSI y mestizo de la Escuela de Equitación del Ejército Nacional de Colombia, que participaron en pruebas de salto (1,10 – 1,20 m en diferentes centros ecuestres de la Sabana de Bogotá. Se determinó frecuencia cardiaca, frecuencia respiratoria y enzimas musculares (creatinquinasa (CK, lactato deshidrogenasa (LDH y el ácido láctico.. Se tomaron tres muestras: reposo, inmediatamente después del ejercicio y a las 6 horas posejercicio. Para la frecuencia cardiaca se utilizó un monitor POLAR S625; la frecuencia respiratoria se determinó mediante fonendoscopio; y las enzimas y el ácido láctico se analizaron en laboratorio. Se utilizó el método estadístico ANAVA para enzimas musculares y acido láctico y estadística descriptiva para frecuencia cardiaca y respiratoria. En los resultados se encontró un comportamiento estadísticamente significativo (p < 0.05 del ácido láctico y la enzima creatinkinasa, a diferencia del comportamiento de la enzima lactato deshidrogenasa, que fue no significativo. Las frecuencias cardiaca y respiratoria se elevaron de manera significativa posejercicio y regresaron a lo normal alrededor de las 6 seis horas. El ácido láctico se incrementó posejercicio y disminuyó a las 6 horas, contrario a lo reportado por otros autores. Se concluye que una vez analizadas estas variables, hay diferencias con los valores obtenidos por otros autores, que pueden deberse a la altitud, al tipo y tiempo de ejercicio realizado. Por tanto es indispensable continuar haciendo estudios en este campo.

  10. El aceite de oliva virgen y la distribución y movimiento transmembrana del colesterol en la membrana de eritrocito humano

    Directory of Open Access Journals (Sweden)

    Muriana, F. J. G.

    1998-04-01

    significativamente la presión arterial sistólica y diastólica de pacientes hipertensos. Estas experiencias parecen indicar que mediante una dieta enriquecida con aceite de oliva virgen es posible controlar y/o prevenir parcialmente la alteración de distintos parámetros de interconexión patogénica relacionados con la hipertensión arterial humana y de clara Influencia sobre la Patología Cardiovascular. Estos procesos no pueden adscribirse exclusivamente al contenido de acido oleico en el aceite de oliva virgen.

  11. Volatile Compounds in Honey Produced in the Central Valley of Ñuble Province, Chile Compuestos Volatiles en Miel Producida en el Valle Central de la Provincia de Ñuble, Chile

    Directory of Open Access Journals (Sweden)

    María Pía Gianelli Barra

    2010-03-01

    encontraron en un mayor porcentaje de área fueron etanol, acido acético, 1-hidroxi-2-propano, 3-hidroxi-2-butano y furfural; sin embargo, las muestras analizadas no presentan un perfil aromático característico.

  12. Methanotrophic activity and bacterial diversity in volcanic-geothermal soils at Pantelleria island (Italy)

    Science.gov (United States)

    Gagliano, A. L.; D'Alessandro, W.; Tagliavia, M.; Parello, F.; Quatrini, P.

    2014-04-01

    Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic/geothermal soils are source of methane, but also sites of methanotrophic activity. Methanotrophs are able to consume 10-40 Tg of CH4 a-1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria island (Italy), Favara Grande, whose total methane emission was previously estimated in about 2.5 t a-1. Laboratory incubation experiments with three top-soil samples from Favara Grande indicated methane consumption values up to 950 ng g-1 dry soil h-1. One of the three sites, FAV2, where the highest oxidation rate was detected, was further analysed on a vertical soil profile and the maximum methane consumption was measured in the top-soil layer but values > 100 ng g-1 h-1 were maintained up to a depth of 15 cm. The highest consumption rate was measured at 37 °C, but a still recognizable consumption at 80 °C (> 20 ng g-1 h-1) was recorded. In order to estimate the bacterial diversity, total soil DNA was extracted from Favara Grande and analysed using a Temporal Temperature Gradient gel Electrophoresis (TTGE) analysis of the amplified bacterial 16S rRNA gene. The three soil samples were probed by PCR using standard proteobacterial primers and newly designed verrucomicrobial primers targeting the unique methane monooxygenase gene pmoA; the presence of methanotrophs was detected in sites FAV2 and FAV3, but not in FAV1, where harsher chemical-physical conditions and negligible methane oxidation were detected. The pmoA gene libraries from the most active site FAV2 pointed out a high diversity of gammaproteobacterial methanotrophs distantly related to Methylococcus/Methylothermus genera and the presence of the newly discovered acido-thermophilic methanotrophs

  13. Methanotrophic activity and diversity of methanotrophs in volcanic geothermal soils at Pantelleria (Italy)

    Science.gov (United States)

    Gagliano, A. L.; D'Alessandro, W.; Tagliavia, M.; Parello, F.; Quatrini, P.

    2014-10-01

    Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic or geothermal soils are not only a source of methane, but are also sites of methanotrophic activity. Methanotrophs are able to consume 10-40 Tg of CH4 a-1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria (Italy), Favara Grande, whose total methane emission was previously estimated at about 2.5 Mg a-1 (t a-1). Laboratory incubation experiments with three top-soil samples from Favara Grande indicated methane consumption values of up to 59.2 nmol g-1 soil d.w. h-1. One of the three sites, FAV2, where the highest oxidation rate was detected, was further analysed on a vertical soil profile, the maximum methane consumption was measured in the top-soil layer, and values greater than 6.23 nmol g-1 h-1 were still detected up to a depth of 13 cm. The highest consumption rate was measured at 37 °C, but a still detectable consumption at 80 °C (> 1.25 nmol g-1 h-1) was recorded. The soil total DNA extracted from the three samples was probed by Polymerase Chain Reaction (PCR) using standard proteobacterial primers and newly designed verrucomicrobial primers, targeting the unique methane monooxygenase gene pmoA; the presence of methanotrophs was detected at sites FAV2 and FAV3, but not at FAV1, where harsher chemical-physical conditions and negligible methane oxidation were detected. The pmoA gene libraries from the most active site (FAV2) pointed to a high diversity of gammaproteobacterial methanotrophs, distantly related to Methylocaldum-Metylococcus genera, and the presence of the newly discovered acido-thermophilic Verrucomicrobia methanotrophs. Alphaproteobacteria of the genus Methylocystis were isolated from enrichment cultures under a methane

  14. ENRIQUECIMIENTO DE HUEVOS CON ÁCIDOS GRASOS OMEGA-3 MEDIANTE LA SUPLEMENTACIÓN CON SEMILLA DE LINO (Linum usitatissimum EN LA DIETA

    Directory of Open Access Journals (Sweden)

    Gonzalo Díaz

    2009-04-01

    Full Text Available Objetivo. Enriquecer los huevos de gallina con ácidos grasos omega-3 (n-3 mediante la inclusión de semillas de lino en la dieta. Materiales y métodos. La dieta de las aves fue formulada con niveles de 0 (L0, 10 (L10, 15 (L15 y 20% (L20 de linaza. Se determinó la composición de ácidos grasos por cromatografía de gases y se evaluó la producción y calidad del huevo. Resultados. El porcentaje de producción de huevo fue superior en los grupos L0 y L15 (p<0.05 con 93,0 y 91,5% de producción comparada con 86,0 % en los grupos L10 y L20. La mejor conversión de alimento se presentó también en los grupos L0 y L15. Con la inclusión de semilla de lino, se incrementó el contenido de ácidos grasos n-3 desde 3,0 % en el grupo L0 hasta 12,6 % en el grupo L20, siendo los ácidos grasos n-3 á-linolénico (C18:3, n-3 y docosahexahenóico (DHA, C22:6, n-3 los hallados en mayor concentración. Con la inclusión de linaza en la dieta de las gallinas ponedoras se redujo el contenido de acido linoleico (C18:2n-6, lo cual resultó en una disminución en la relación n-6: n-3. Conclusiones. Con base en la evaluación económica se concluye que es posible enriquecer la yema de huevo de gallina hasta con un 10,1 % de ácidos grasos n-3 mediante la inclusión de un 15 % de linaza en la dieta de las gallinas, sin embargo, esto representó un sobrecosto de producción del 12%.

  15. Effects of budesonide and probiotics enemas on the systemic inflammatory response of rats with experimental colitis Efeito de enemas contendo budesonida e probióticos na resposta inflamatória sistêmica de ratos com colite experimental

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    Mardem Machado de Souza

    2007-01-01

    Full Text Available PURPOSE: The aim of this study was to investigate the effect of enemas containing probiotics and budesonide on the systemic inflammatory response in experimental colitis. METHODS: Fifty male Wistar rats with experimental colitis induced by 10% acetic acid enema were randomized to five groups (10 rats each according to the treatment: group 1 - saline solution, group 2 - budesonide (0.75 mg/kg/day, group 3 - probiotics (1mg/day, group 4 - probiotics plus budesonide, and group 5 - control, with not-treated rats. The following variables were studied: body weight, serum levels of albumin, C-reactive protein and interleucine-6 (IL-6. RESULTS: All animals lost weight between the beginning and the end of the experiment (280+ 16 mg versus 249+21 mg, p0.05. Only probiotic rats presented a significant decrease of IL-6 than controls (0,30±0,08 mg/dL vs. 0,19±0,03 mg/dL; pOBJETIVO: Investigar o efeito da administração retal de probióticos e budesonida na resposta inflamatória de ratos com colite experimental. MÉTODOS: Cinqüenta ratos Wistar com colite experimental induzida pelo acido acético à 10% foram randomizados em 5 grupos (n=10 por grupo para diferentes tratamentos: grupo 1 - solução fisiológica; grupo 2 budesonida (0,75mg/kg/dia; grupo 3 - probióticos (1 g/dia; grupo 4 - probióticos associados a budesonida; e finalmente grupo 5 - controle, composto por ratos sem tratamento. As seguintes variáveis foram estudadas: peso corporal, dosagens séricas de albumina, proteína C reativa (PCR e interleucina-6 (IL-6. RESULTADOS: Todos os animais perderam peso entre o inicio e o fim do experimento (280±16 vs 249±21g; p0.05. As comparações entre o grupo controle (0,30±0,08 mg/dL e outros mostraram que houve uma queda significante nos níveis de IL-6 apenas no grupo probiótico (0,19±0,03 mg/dL; p<0.01. CONCLUSÃO: Probióticos são efetivos na diminuição do estado inflamatório mediado pela IL-6 na colite experimental.

  16. Actividad antioxidante de extractos de diez basidiomicetos comestibles en Guatemala

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    Karen Belloso

    2015-11-01

    Full Text Available Los antioxidantes son esenciales en el cuerpo humano para prevenir el daño oxidativo. Estas substancias pueden obtenerse de diversas fuentes como frutas, plantas y hongos. En Guatemala, diversas especies de hongos comestibles son comercializadas y consumidas, sin embargo su actividad antioxidante no ha sido documentada en el país. El objetivo de este estudio fue determinar la actividad antioxidante de extractos acuosos y etanólicos obtenidos de diez especies de basidiomicetos comestibles (Agaricus aff. bisporus, Agaricus brunnescens, Armillariella polymyces, Amanita garabitoana, Boletus edulis, Cantharellus lateritius, Laccaria amethystina, Lactarius deliciosus, Neolentinus ponderosus y Pleurotus ostreatus. Se utilizó un método cualitativo por cromatografía en capa fina (CCF y tres ensayos macrométricos in vitro de cuantificación de fenoles totales, reducción del radical 1,1-difenil-2-pricrilhidrazilo (DPPH y decoloración del radical catiónico del reactivo ácido 2,2’-azinobis-(acido-3-etilbenzotiazolina-6-sulfónico (ABTS. Los extractos acuosos mostraron mayor actividad antioxidante que los extractos etanólicos en todas las técnicas cuantitativas realizadas. La especie que mostró mayor actividad antioxidante en ambos extractos fue B. edulis, cuyos resultados fueron: fenoles totales del extracto acuoso 93.46 ± 18.17 mg/g y 42.70 ± 3.48 mg/g, DPPH CI50 del extracto acuoso 0.93 mg/mL (IC95 0.65-1.28 y 2.75 mg/mL (IC95 2.46-3.07 del extracto etanólico; y en ABTS CI50 del extracto acuoso 0.96 mg/mL (IC95 0.63-1.35 y 4.13 mg/mL (IC95 2.67-5.88 del extracto etanólico. Por la actividad antioxidante de los extractos acuosos de algunas de las especies de basidiomicetos, pueden promoverse como alimentos funcionales.

  17. Fatty acid profiles of varietal virgin olive oils (Olea europaea L. from mature orchards in warm arid valleys of Northwestern Argentina (La Rioja

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    Rousseaux, M. C.

    2011-12-01

    cuando crecieron en el noroeste de Argentina versus el Mediterráneo. Para Arbequina, el contenido de oleico disminuyó con la temperatura durante la síntesis y acumulación lipídica (-2 % por °C. La clasificación varietal por acido oleico debe ser útil para seleccionar aceites para mezclas correctivas y variedades para futuras plantaciones que cumplan con la normativa del COI. Diferencias en los perfiles de ácidos grasos entre el noroeste de Argentina y el Mediterráneo indican una interacción genotipo x ambiente, y el efecto negativo de la alta temperatura media estacional durante la síntesis de lípidos requerirá mayor investigación.

  18. The role of extremophile in the redox reaction of Fe and As relating with the formation of secondary phase mineral in extreme environment, Norris Geyser Basin, Yellowstone National Park, USA

    Science.gov (United States)

    Koo, T. H.; Kim, J. Y.; Park, K. R.; Jung, D. H.; Geesey, G. G.; Kim, J. W.

    2015-12-01

    Redox reaction associated with microbial elemental respiration is a ubiquitous process in sediments and suspended particles at various temperatures or pH/Eh conditions. Particularly, changes in elemental redox states (structural or dissolved elemental form) induced by microbial respiration result in the unexpected biogeochemical reactions in the light of biotic/abiotic mineralization. The objective of the present study is, therefore to investigate the secondary phase mineralization through a-/biogeochemical Fe and As redox cycling in the acido-hyperhtermal Norris Geyser Basin (NGB) in Yellowstone National Park, USA, typical of the extreme condition. X-ray diffraction, scanning electron microscope with energy dispersive x-ray spectroscopy, X-ray absorption near edge structure, inductively coupled plasma-atomic emission spectrometer and liquid chromatography with ICP-mass spectroscopy with filtrated supernatant were performed for the mineralogical and hydro-geochemical analysis. The clay slurry collected from the active hot-spring of the NGB area (pH=3.5 and Temperature=78 ℃) was incubated with ("enrichment") or without the growth medium ("natural"). The control was prepared in the same condition except adding the glutaraldehyde to eliminate the microbial activity. The secondary phase mineral formation of the oxidative phase of Fe and As, and K identified as 'Pharmacosiderite' only appeared in the enrichment set suggesting a role of extremophiles in the mineral formation. The considerable population of Fe-oxidizer (Metallosphera yellowstonensis MK-1) and As-oxidizer (Sulfurihydrogenibium sp.) was measured by phylogenetic analysis in the present study area. The inhibition of As-oxidation in the low pH conditions was reported in the previous study, however the As-redox reaction was observed and consequently, precipitated the Pharmacosiderite only in the enrichment set suggesting a biotic mineralization. The present study collectively suggests that the microbial

  19. Using short-lived nuclides of the U- and Th-series to probe the kinetics of colloid migration in forested soils

    Science.gov (United States)

    Rihs, Sophie; Prunier, Jonathan; Thien, Bruno; Lemarchand, Damien; Pierret, Marie-Claire; Chabaux, François

    2011-12-01

    The recent chemical dynamics of a podzolic forest soil section (from the Strengbach watershed, France) was investigated using U- and Th-series nuclides. Analyses of ( 238U), ( 230Th), ( 226Ra), ( 232Th), ( 228Ra) and ( 228Th) activities in the soil particles, the seepage waters, and the mature leaves of the beech trees growing on this soil were performed by TIMS or gamma spectrometry. The simultaneous analysis of the different soil ( sl) compartments allows to demonstrate that a preferential Th leaching over Ra must be assumed to explain the ( 226Ra/ 230Th), ( 228Ra/ 232Th) and ( 228Th/ 228Ra) disequilibria recorded in the soil particles. The overall Ra- and Th- transfer schemes are entirely consistent with the prevailing acido-complexolysis weathering mechanism in podzols. Using a continuous open-system leaching model, the ( 226Ra/ 230Th) and ( 228Ra/ 232Th) disequilibria measured in the different soil layers enable dating of the contemporary processes occurring in this soil. In this way, we have determined that a preferential Th-leaching from the shallow Ah horizon, due to a strong complexation with organic colloids, began fairly recently (18 years ago at most). The continual increase in pH recorded in precipitations over the last 20 years is assumed to be the cause of this enhanced organic complexation. A lower soil horizon (50-60 cm) is also affected by preferential Th leaching, though lasting over several centuries at least, with a much smaller leaching rate. The migration of Th isotopes through this soil section might hence be used as a tracer for the organic colloids migration and the induced radioactive disequilibria demonstrate to be useful for assessing the colloidal migration kinetics in a forested soil. Ra and Th isotopic ratios also appear to be valuable tracers of some mineral-water-plant interactions occurring in soil. The ( 228Ra/ 226Ra) ratio enables discrimination of the Ra flux originating from leaf degradation from that originating from mineral

  20. Physicochemical and microbiological study of “shmen”, a traditional butter made from camel milk in the Sahara (Algeria: isolation and identification of lactic acid bacteria and yeasts

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    Mourad, Kacem

    2006-06-01

    Full Text Available Microorganisms (aerobic bacteria, coliforms, lactic acid bacteria, psychrotrophs, lipolytic bacteria and yeasts were isolated from 20 samples of shmen, a traditional clarified butter made from sour camel milk in the Algerian Sahara. The values of pH, titratable acidity, NaCl, total solid, moisture, and fat content ranged from : 3.11-4.97, 0.19-0.36%, 1.04-2.15%, 64.03-65.11%, 34.40-34.99%, and 49.90-56% respectively. A total of 181 isolates of lactic acid bacteria were identified as Lactobacillus plantarum (40 strains, Lactobacillus delbrueckii ssp. bulgaricus (35 strains, Lactococcus lactis ssp. lactis biovar diacetylacti (22 strains, Lactococcus lactis ssp. cremoris (18 strains, Lactobacillus paracasei ssp. paracasei (10 strains, Leuconostoc pseudomesenteroides (9 strains and Leuconostoc gelidum (12 strains Enterococcus faecium (35 strains. Yeasts were isolated from all samples (55 isolates. Of these, 40 were identified as Saccharomyces cerevisiae and 15 isolates were identified as Saccharomyces sp.Se aislaron los microorganismos (bacterias aeróbicas, coliformes, bacterias acido lácticas, bacterias lipolíticas y levaduras de 20 muestras de “shmen”, una matequilla tradicional del Sahara argelino hecha a partir de leche de camella. Los valores de pH, acidez, libre, Nacl, solidos totales, humedad y grasa oscilaron entre 3,11-4,97, 0,19-0,36%, 1.04-2,15%, 64,03-65,11%, 34,40-34,99% y 49,90-56,00%, respectivamente. Entre los 181 cultivos puros de bacterias lácticas se identificaron Lactobacillus plantarum (40 cepas, Lactobacillus delbrueckii ssp. bulgaricus (35 cepas, Lactococcus lactis ssp. lactis biovar diacetylacti (22 cepas, Lactococcus lactis ssp. cremoris (18 cepas, Lactobacillus paracasei ssp. paracasei (10 cepas, Leuconostoc pseudomesenteroides (9 cepas and Leuconostoc gelidum (12cepas Enterococcus faecium (35 cepas. Asimismo, se detectaron levaduras en todas las muestras (55 cultivos puros. De estos, 40 se identificaron como

  1. Cinética de degradación del naftaleno por células inmovilizadas húmedas de Bacillus alcalophilus cepa IDO-225

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    Roberto Rafael Núñez Moreira

    2004-01-01

    Full Text Available Numerosas han sido las investigaciones sobre el estudio de la biorremediación para su aplicación en la lucha para combatir la contaminación ambiental por hidrocarburos. El Instituto de Oceanología del Ministerio de Ciencia, Tecnología y Ambiente, ha trabajado desde 1988 en el aislamiento y conservaci ón de bacterias marinas que sean capaces de degradar el petróleo. Actualmente, cuenta con cuatro bioproductos degradadores de petróleo en medio marino denominados BIOIL, K-BIOIL, BIOIL-FC e IDO-225. En el presente trabajo, se demuestra por Espectroscopia Infrarroja de las muestras extraídas a los 3, 6, 9, 12 y 15 d de contacto de las células húmedas inmovilizadas de Bacillus alcalophilus cepa IDO-225 en el medio de degradación con el naftaleno, un hidrocarburo del petróleo, que estas son capaces de degradar el naflateno como única fuente de carbono y energía. La degradación de este hidrocarburo por las células inmovilizadas de esta cepa se lleva a cabo mediante un mecanismo que se basa en un modelo cinético de segundo orden correspondiente a un mecanismo de metil-oxidación y b-oxidación, al igual que las células libres de dicha cepa, pero con la diferencia de que en el caso de las células inmovilizadas, el término cuadrático (metil-oxidación es mayor y el término lineal (b-oxidación es menor que en las células libres. En este mecanismo se produce acetil-CoA, el cual se incorpora al ciclo de los acidos tricarboxílicos para formar dióxido de carbono, agua y coenzimas reducidas, las cuales se dirigen a la cadena de transporte electrónica para obtener energía en forma de ATP y garantizar la síntesis de compuestos esenciales y la obtención de energía.

  2. Deficiência hídrica e aplicação de ABA nas trocas gasosas e no acúmulo de flavonoides em calêndula (Calendula officinalis L. = Water deficit and ABA application on leaf gas exchange and flavonoid content in marigold (Calendula officinalis L..

    Directory of Open Access Journals (Sweden)

    Ana Cláudia Pacheco

    2011-04-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos da deficiencia hidrica e aplicacao de acido abscisico (ABA sobre aspectos fisiologicos e teor de flavonoides em plantas de calendula. Oexperimento foi instalado em condicoes de casa-de-vegetacao com plantas envasadas. No inicio do florescimento de plantas de calendula, foram aplicados quatro intervalos de suspensao da irrigacao (irrigacao diaria; tres; seis e nove dias sem irrigar, acompanhados por tres doses de ABA (0, 10 e 100 ƒÊM. Avaliou-se o conteudo relativo de agua na folha (CRA e as trocas gasosas, utilizando-se um analisador portatil por infravermelho (A: fotossintese liquida, gs: condutancia estomatica, E: transpiracao, Ci: concentracao intercelular de CO2 e EUA: eficiencia de uso daagua. Aos nove dias sem irrigacao ocorreram reducoes significativas em todas as variaveis de trocas gasosas analisadas, independente da aplicacao de ABA. Concluiu-se que o efeito principal do ABA foi o de causar diminuicao na gs, a qual foi acompanhada de reducao em A somente quando as plantas estavam desidratadas. As intensidades de deficiencia hidrica testadas nao causaram interferencia no acumulo de flavonoides nas inflorescencias. Entretanto, o ABA restringiu a biossintese de flavonoides, tanto nas plantas-controle como nas plantas submetidas a deficiencia hidrica.The goal of this study was to evaluate the effects of water deficit and abscisic acid (ABA application on physiological parameters and flavonoid production in marigold plant. The experiment was performed under nursery conditions with potted plants. It was tested water deficit by withholding water (control . diary irrigation, 3, 6 and9 days without irrigation followed by 3 ABA concentrations (0, 10 e 100 ƒÊM applied in the beginning of blooming. It was evaluated the relative water content and the leaf gas exchange using a portable infrared gas analyzer (A: net photosynthesis, gs: stomatal conductance, E: transpiration, Ci: CO2 intercellular

  3. Antibacterial effect of Turkish black cumin ( Nigella sativa L. oils

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    Gecgel, Umit

    2005-12-01

    Full Text Available A series of five different oils from Turkish black cumin ( Nigella sativa used in foods mainly for their flavour, preservation and natural therapies were screened for their antibacterial effects at 0.5 %, 1.0 % and 2.0 % concentrations using the agar diffusion method against twenty four pathogenic, spoilage and lactic acid bacteria (LAB. All tested oils showed antibacterial activity against all the bacteria used in the assay. The oils at 2.0 % concentration were more effective than of the other concentrations. The most sensitive bacterium against all of the oil concentrations was Aeromonas hydrophila, while the most resistant was Yersinia enterocolitica. Generally, lactic acid bacteria had more resistance than pathogenic and spoilage bacteria against black cumin oils. Consequently, black cumin oil may be used as an antimicrobial agent in food products to prevent spoilage.Se ensayaron un total de cinco aceites diferentes de comino negro turco ( Nigella sativa L., que se utilizan habitualmente en alimentos para darles sabor, ayudar a la conservación o por sus efectos terapéuticos, para estudiar sus propiedades antimicrobianas a concentraciones de 0.5 %, 1.0 %, y 2 %. Para ello se utilizó el método de difusión en agar, frente a veinticuatro microorganismos patógenos, causantes de alteraciones o bacterias ácido lácticas (LAB. Todos los aceites ensayados mostraron actividad antimicrobiana contra todos los microorganismos ensayados, siendo las concentraciones del 2 % las concentraciones más eficaces. Aeromonas hydrophyla fue el microorganismo mas sensible a todas las concentraciones mientras que Yersinia enterocolitica fue la más resistente. Generalmente las bacterias acido lácticas tuvieron más resistencia que los gérmenes patógenos y las bacterias que causan alteraciones. En consecuencia, el aceite de comino negro turco se puede utilizar como agente antimicrobiano en productos alimenticios para evitar su alteración.

  4. Nutritional changes in powdered red pepper upon in vitro infection of Aspergillus flavus Alterações nutricionais em pimenta vermelha em pó após infecção in vitro com Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Smita Tripathi

    2009-03-01

    Full Text Available Quantitative losses in various biochemical constituents like capsaicin, carotenes, ascorbic acid, polyphenols, mineral matter, sugars (soluble and insoluble, protein and fat were estimated after the successful growth of Aspergillus flavus for 30 days on powdered red pepper. The fungal biomass was measured by ergosterol content and Aflatoxin B1 by HPLC. Amongst the various nutritional constituents evaluated for nutritional losses and changes the highest nutritional loss was reported in total carotenoids (88.55% followed by total sugars (85.5%. The protein content of the infected sample increased from 18.01% to 23%. The nutritional profile of chilli powder (Capsicum annum var. sannam L. shows highest share of total soluble sugars (32.89% and fiber content (21.05%, followed by protein (18.01% and fat (13.32% making it an ideal solid - substrate for mould growth. At the end of incubation the fungal biomass was 192. 25 mg / 100 gram powder, total plate count 17.5 X 10 4 CFU/g and Aflatoxin B1 content was 30.06 µg / kg.Foram avaliadas as perdas de vários constituintes bioquímicos como capsaicina, carotenos, acido ascórbico, polifenóis, matéria orgânica, açucares (solúveis e insolúveis, proteína e gordura em pimenta vermelha em pó após a multiplicação de Aspergillus flavus por 30 dias. A biomassa fúngica foi mensurada pelo conteúdo de ergosterol e aflatoxina por HPLC. Entre os vários constituintes avaliados, a maior perda foi a de carotenóides totais (88,55%, seguido de açucares totais (85,5%. O conteúdo protéico da amostra infectada aumentou de 18,01% para 23%. O perfil nutricional da pimenta em pó (Capsicum annum var. sannam L. indica alto teor de açucares totais (32,89% e fibras (21,05%, seguido de proteína (18,01% e gordura (13,32%, tornando-a um substrato ideal para crescimento de fungos. Ao final dos 30 dias, a biomassa fúngica foi 192,25 mg/100g, a contagem total em placas foi 17,5 x 10(4 CFU/g e o conteúdo de

  5. Oligoanalgesia in pronto soccorso: da un audit retrospettivo a un percorso clinico-assistenziale

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    Edoardo Pennacchio

    2012-08-01

    Full Text Available Background. Nonostante il dolore acuto rappresenti il sintomo più frequente di presentazione in pronto soccorso, numerosi studi hanno riportato un’elevata prevalenza di oligoanalgesia (insufficiente riconoscimento o trattamento del dolore in questo setting assistenziale. Obiettivi. Stimare la frequenza della oligoanalgesia nel pronto soccorso dell’Azienda Ospedaliera San Carlo di Potenza e identificare le cause per correggere il problema. Metodi. Un audit team multidisciplinare ha effettuato un audit retrospettivo sui primi 3000 accessi in pronto soccorso del 2011, con interrogazione del sistema informatico aziendale. Sono stati esclusi i pazienti di età < 12 anni e quelli con dolore toracico o addominale, cefalea severa, politrauma. Risultati. Sono stati identificati 580 pazienti con dolore potenzialmente trattabile (M/F 333/247; età media 44,5 anni; 11,7% con dolore severo, 88,3% con dolore moderato. In tutti i pazienti è stata valutata l’intensità del dolore con scala verbale; sono stati trattati con analgesici il 33,8% dei pazienti con dolore grave e il 18,9% di quelli con dolore moderato; sono stati usati i seguenti farmaci: paracetamolo, ketoprofene, tramadolo, diclofenac, tiocolchicoside, fluoroglucinolo, lorazepam, betametasone, acido acetilsalicilico, metilprednisolone, ossigeno; il timing medio di somministrazione degli anagesici è stato di 90’ nei pazienti con dolore severo e di 93’ nei pazienti con dolore moderato; il 39% dei pazienti con dolore severo è stato trattato dopo oltre 20’ dall’accettazione; il 50,5% dei pazienti con dolore moderato è stato trattato dopo oltre 60’ dall’accettazione; nessuno dei pazienti ha ricevuto una rivalutazione del dolore; al 59,4% dei pazienti con dolore severo e al 63,5% di quelli con dolore moderato sono stati prescritti analgesici alla dimissione. Limiti. Non è stato possibile valutare l’impatto di interventi non farmacologici abitualmente utilizzati, quali l

  6. Development program of electrical vehicles of batteries in the UNAM; Programa de desarrollo de vehiculos electricos de baterias en la UNAM

    Energy Technology Data Exchange (ETDEWEB)

    Carmona Paredes, G.; Chicurel Uziel, R.; Chicurel Uziel, E.; Gutierrez Martinez, F. [Instituto de Ingenieria, UNAM, Mexico, D.F. (Mexico)

    2002-09-01

    en el Instituto de Ingenieria y el Centro de Diseno Mecanico de la Facultad de Ingenieria. Se ha contado tambien con la colaboracion del Centro de Investigaciones en Diseno Industrial de la Facultad de Arquitectura, el Centro de Instrumentos y la Facultad de Quimica. Otros aspectos complementarios en los que se esta trabajando, incluyen el desarrollo de un cargador inteligente para grandes paquetes de baterias y de un controlador electronico dual, el estudio del desempeno dinamico de baterias de plomo-acido, el diseno de un sistema de monitoreo de baterias y la busqueda de nuevas alternativas de baterias.

  7. Influência da embalagem e estocagem no conteúdo de betacaroteno e ácido ascórbico em suco de manga “Ubá” industrializado = Influence of package and storage on the content of beta-carotene and ascorbic acid in industrialized “Ubá” mango juice

    Directory of Open Access Journals (Sweden)

    Daniela da Silva Oliveira

    2010-07-01

    Full Text Available Este trabalho investigou o conteudo e avaliou a estabilidade de doisantioxidantes naturais - β-caroteno e acido ascorbico (AA - em suco de manga "Uba" industrializado e armazenado em diferentes tempos de estocagem e correlacionou as recomendacoes de vitaminas A e C com o teor encontrado nos sucos. O β-caroteno e o AA foram analisados nos sucos comercializados em embalagem tetra pak, em cinco tempos de estocagem (1 a 5 meses e em embalagem de vidro, em tres tempos de estocagem (apos 3, 4 e 5 meses de armazenamento. A analise foi realizada por Cromatografia Liquida de Alta Eficiencia (CLAE. Nao foram detectadas diferencas estatisticamente significativas (α = 5% entre os diferentes tempos de estocagem, para ambos os componentes analisados, tanto em embalagens tetra pak quanto em embalagens de vidro. Alem disso, nao foram observadas diferencas significativas entre o conteudo de β-caroteno dos sucos comercializados nas duas embalagens. No entanto, houve diferenca significativa no teor de AA entre as diferentes embalagens, e a embalagem de vidro apresentou maior teor em relacao a embalagem tetrapak. Assim, as perdas ocasionadas especialmente pela permeabilidade da embalagem ao oxigenio deveriam ser alvo de atencao das industrias de alimentos.This work investigated the content and stability of two natural antioxidants . β-carotene and ascorbic acid (AA - in mango juice industrialized and stored during different storage times, correlating the recommendations of vitamins A and C with the content found in the juice. β-carotene and AA were analyzed in juice sold in tetra pak packaging, during five storage times (1 to 5months and in glass containers, during three storage times (after 3, 4 and 5 months of storage. The analysis was carried out using High Performance Liquid Chromatography (HPLC. No statically differences (α = 5 % were found between the different times of storage for both compounds analyzed, both in tetra pak package and glass container

  8. Acidovorax avenae subsp.Citrulli 危害新寄主籽瓜和病菌的快速检测%Edible Seed Watermelon as a New Host of Acidovorax avenae subsp. Citrulli and Rapid Detection of this Pathogen

    Institute of Scientific and Technical Information of China (English)

    任毓忠; 李国英; 李晖; 孙岚春

    2007-01-01

    Through observation of field symptoms,identification of the isolated bacterial strains based on biological characteristics, biochemical and physiological tests including Gram reaction,catalase,oxidase and oxygen requirement test,and by Polymerase Chain Reaction (PCR) detection,Acidovorax avenae subsp.Citrulli was first reported infecting edible seed watermelon (citrullus lanatus var.Lanatus) in Xinjiang province of China.This pathogen mainly infected fruit and cotyledon of edible seed watermelon,especially causing spots with black and star-shaped cracks in fruit.To control this disease,rapid detection method of A.avenae subsp.Citrulli in plant seed was studied.It was shown that pecific primer PCR could detect the pathogen in seed rapidly and sensitively.Seed suspension could be directly used as PCR template when seed infection was more than 4%. When extracted DNA from seed suspension was used as template,target pathogen could be easily detected with seed infection at or less 2%.%根据病原菌的生物学特性、生理生化特性包括革兰氏染色反应、氧化酶反应、过氧化氢酶反应、氧需求等和特异性PCR扩增结果,以及病原菌危害造成的田间症状,发现燕麦嗜酸菌属西瓜亚种(Acidovorax avenae subsp.Citrulli)可在新寄主-籽瓜上造成严重危害.该病菌在田间主要侵染籽瓜的果实和子叶,症状在果实上尤为明显,形成黑色的星状开裂.为了控制该病的发生,对种子携带病原菌的快速检测方法进行了研究.结果表明,特异性PCR作为检测种传病原菌具有快速、准确和灵敏的特点.当种子浸出液为PCR反应的模板时,可检测出的种子带菌率极限最低为4%;当以种子浸出液提取的DNA为模板时,种子带菌率检测极限为2%甚至更低.

  9. Neurotoxins in the polar fraction of the seaweed Galaxaura marginata (Rhodophyta, Nemaliales Neurotoxinas na fração polar da alga marinha Galaxaura marginata (Rhodophyta, Nemaliales

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    Enrique E. Rozas

    2008-06-01

    Full Text Available Neurotoxic activity of polar substances extracted from the red seaweed Galaxaura marginata was investigated in pharmacological assays, using seaweed collected at São Sebastião channel (45º25' W; 26º49' S in the northern coast of the State of São Paulo, Brazil. High concentration of the polar fraction (PF and PF filtered through a membrane (1000 Da intraperitoneally (IP injected in mice were lethal, inducing ataxia, disorientation, and severe muscle atonia prior to death. The same symptoms preceding death were described in mice and rat tested with neuroexcitatory amino acids (NEA, suggesting that some PF components cross the blood-brain barrier, the same as NEA. However, the HPLC and mass spectrometric analysis did not show the presence of the known neuroexcitatory amino acids, kainic acid, domoic acid and NMDA. We conclude that G. marginata possess substances with neurotoxic and lethal activities.A atividade neurotóxica das substâncias polares extraídas da alga vermelha Galaxaura marginata foi estudada por meio de ensaios farmacológicos, utilizando-se algas coletadas no canal de São Sebastião (45º25' W; 26º49' S, litoral norte do estado de São Paulo, Brasil. Altas concentrações da fração polar (PF e da PF filtrada em membrana de 1000 Da, injetadas intraperitonealmente em camundongos, foram letais. Induzindo os animais à ataxia, desorientação e severa atonia muscular prévias à morte. Sintomas similares foram descritos para camundongos e ratos testados com aminoácidos neuroexcitatórios (NEA, sugerindo que alguns dos componentes da PF atravessam a barreira Hematoencefálica, da mesma forma que os NEA. No entanto, a análise da PF no HPLC e no espectro de massa não mostraram a presença dos aminoácidos neuroexcitatórios conhecidos, ácido Caínico, acido Domóico e NMDA. Assim concluímos que G. marginata possui substâncias com atividade letal e neurotóxica, diferentes às antes, descritas.

  10. APLICACIÓN DE LA TECNICA DE IV GAMA PARA LA ELABORACIÓN DE ENSALADAS EVALUATION OF IV GAMA TECHNIQUE TO PREPARE VEGETABLE SALADS

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    Auris Damely García Méndez

    2008-12-01

    Full Text Available El propósito de la aplicación de la técnica de IV Gama en la elaboración de ensaladas listas para el consumo fresco, esta dirigido al control del deterioro en lechuga americana (Lactuca sativa, zanahoria (Daucus carota L., radicchio (Cichorium intybus L. y escarola (Cichorium endivia L., destinadas a preparar ensaladas tipo “Mediterránea y Cheff”. La metodología permitió seleccionar y evaluar la técnica de IV Gama, así como las buenas prácticas de manufactura para extender la vida comercial de las ensaladas y garantizar la seguridad alimentaria para la población potencialmente consumidora. La aplicación combinada de soluciones de cloruro de calcio al 1%, acido cítrico a 0,1% y oxido de magnesio al 0,5% contribuyo a mantener la calidad de las ensaladas por un período de 16 días bajo refrigeración a 5 + 1 °C y 95 + 5% HR. En conclusión las técnicas ensayadas, posibilitaron extender el valor comercial de estos productos.The purpose of applying the fresh-cut technique in preparing vegetable salads ready for fresh consumption, was aimed to control the damage American lettuce (Lactuca sativa; carrot (Daucus carota L; Radicchio (Cichorium intybus L and endive (Cichorium endivia L.“ Mediterranean and Cheff” style salads were prepared for evaluation. The methodology allowed selecting and evaluating fresh-cut technique as well as good manufacturing practices, to extend the commercial life, and guarantee alimentary food safety to people. Use of 1% calcium chloride; 0.1% citric acid and 0.5% magnesium oxide solutions; allowed to maintain the quality of the salads for a period of 16 up to days, under refrigeration at 5± 1ºC and 95 ± 5 % RH. Finally the assays techniques let to extend the commercial value of these vegetables.

  11. Cyanic acid, Phytic acid, total tannin and aflatoxin contents of a Brazilian (Natal multimistura preparation Conteúdos de ácido cianídrico, ácido fítico, tanino total e aflatoxina em uma preparação brasileira (Natal de multimistura

    Directory of Open Access Journals (Sweden)

    Francisca Sônia CÂMARA

    2001-04-01

    Full Text Available The utilization of a "multimistura" as food supplement, in nutritional improvement programs for the low-income population in Brazil, represents a low-cost and easy-to-use food preparation alternative, presentig reasonable nutritive value and satisfying local taste preferences. This is based on the fact that the "multimistura" is made up of non-conventional ingredients/foods and of agroindustrial by-products, rich in different nutrients. This paper was designed to determine some toxic and/or antinutritional factors of a "Multimistura" utilized as food supplement in institutional programs to prevent malnutrition by the Department of Welfare and Social Affairs of the City of Natal, RN. The product studied had the following formulation: 30% of wheat bran; 30% of wheat flour; 30% of corn meal; 3% of powder from cassava leaves; 4% of pumpkin seeds powder; and 3% of eggshell powder. The analysis of the main toxic and/or antinutritional factors showed very low concentrations of phytates and tannins and no detectable levels of aflatoxin and cyanic acid.O uso da "multimistura" como suplemento alimentar, em programas de intervenção nutricional para populações brasileiras carentes, vem se apresentando como uma alternativa alimentar de valor nutritivo razoável, baixo custo, preparo rápido e paladar regionalizado. Isto resulta do fato desta ser constituída principalmente de alimentos não convencionais e/ou subprodutos agro-industriais ricos em diferentes nutrientes. Este trabalho teve como objetivo dosar alguns fatores tóxicos e/ou antinutricionais de uma "multimistura" utilizada como suplemento alimentar em programas institucionais no combate à desnutrição da Secretaria Municipal de Promoção Social da cidade de Natal. O produto analisado tinha a seguinte formulação: 30% de farelo de trigo; 30% de farinha de trigo; 30% de fubá de milho; 3% de pó de folha de mandioca; 4% de pó de semente de jerimum; 3% de pó de casca de ovo. As an

  12. The Biogas from bio-energy electrical power plant of Nuevo Leon; Central electrica de biogas de bioenergia de Nuevo Leon

    Energy Technology Data Exchange (ETDEWEB)

    Arvizu F, Jose L [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Saldana M, Jaime L [Sistemas de Energia Internacional S.A. de C.V. (Mexico)

    2005-07-01

    de agua, hidrogeno, nitrogeno, oxigeno, acido sulfhidrico y otros gases en cantidades minimas.

  13. Epilepsias generalizadas idiopáticas diagnosticadas incorretamente como epilepsias parciais

    Directory of Open Access Journals (Sweden)

    Mory Susana B.

    2002-01-01

    Full Text Available A epilepsia generalizada idiopática (EGI frequentemente não é diagnosticada corretamente em adultos, com sérias consequências para os pacientes. O objetivo deste estudo foi avaliar os fatores mais frequentemente associados a dificuldades no diagnóstico diferencial entre epilepsias parciais e generalizadas em adultos. Avaliamos 41 pacientes com diagnostico de crises parciais complexas com elementos de anamnese e EEG indicando um possível diagnóstico diferencial. Foi possível a mudança do diagnóstico de epilepsia parcial para EGI em 25 pacientes: 22 (88% com EMJ; um com ausência juvenil, um com síndrome de ausências com mioclonias periorais e um com ausência com mioclonias palpebrais. Mioclonias, uma das características da EMJ e outras formas de EGI, geralmente não eram espontaneamente relatadas pelos pacientes. Abalos mioclônicos unilaterais eram confundidos com crises parciais motoras. Ausências breves e pouco frequentes e anormalidades focais no EEG contribuíram para o não reconhecimento de EGI. Todos os 25 pacientes apresentavam crises sem controle adequado antes da revisão diagnóstica. Após o diagnóstico correto e mudança para monoterapia com acido valpróico ou valproato de sódio, 19 (76% ficaram livre de crises e seis (24% dos 25 pacientes apresentaram melhora significativa. A associação de lamotrigina em três destes pacientes propiciou redução significativa da frequência de crises. Em conclusão, anamnese detalhada e questionamento direcionado para determinar a presença de mioclonias e crises tipo ausência e a sua interpretação no contexto clínico são fundamentais para o diagnóstico correto das EGI em adultos.

  14. Estudio bromatológico y de digestibilidad in-situ dela gramínea chusque (Chusquea scandens K a diferentes edades de corte .

    Directory of Open Access Journals (Sweden)

    Fernando Dueñas-Tamayo

    2011-02-01

    Full Text Available El  chusque  es un planta que hace parte de  los sistemas silvopastoriles naturales en el  trópico alto y, por ende, es aprovechada como alimento para los animales que pastan en dichos sistemas; no obstante, esta planta no cuenta con ningún reporte científico  que  indique  el  valor  y  los  aportes nutricionales que brinda a  los  rumiantes que  la consumen.  Con  esta  investigación  se  logró determinar  la  calidad  nutricional  del  chusque (Chusquea scandens, KUNTH por medio de un análisis bromatológico, digestibilidad aparente de la materia seca,  egradabilidad  in  situ  de  la proteína  (P,  fibra en detergente neutro  (FDN,  fibra en detergente acido  (FDA, contenido celular  (CC, complejo  lignina-celulosa  (CLC ý cenizas (C, a diferentes edades de corte del rebrote  (30, 45 y 60 días. Se empleó como testigo positivo (forraje de buena calidad alfalfa cortada a una edad de rebrote de 25 días y como  testigo negativo (forraje de mala calidad el kikuyo de más de 120 días. La unidad experimental estuvo constituida por dos muestreos con periodos de incubación en rumen de 96, 72, 48, 24, 12 y 0 h. Luego de  la realización del  trabajo  de  campo  y  de  las  pruebas  de laboratorio,  los  resultados  determinaron que  el chusque presenta un alto contenido de P, pero éste no es asimilable por efecto del complejo lignina-celulosa que  se encuentra elevado en  las muestras estudiadas. De  igual manera se encontró que el chusque  tiene un alto grado de FDN-FDA, además es  un  alimento  con  alto  contenido  celular transformándolo en un forraje energético.

  15. Inflamación celular en pacientes sometidos a cirugía electiva tratados con carbohidratos de baja carga glicémica, ácidos grasos omega 3 y antioxidantes

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    Lucrecia Arceo-Giorgana

    2016-03-01

    Full Text Available Antecedentes y Objetivos. La creciente complejidad de la Especialidad de Cirugía Plástica, ha inducido a su ramificación en varias subespecialidades. Una de las limitantes de la Cirugía Plástica ha sido la obesidad, enfermedad que conlleva complicaciones, aumenta el riesgo de inconvenientes y hace insuficiente el resultado proyectado para la estética y la función. El objetivo del presente trabajo es mostrar la importancia de la evaluación de la inflamación celular en la preparación de pacientes sometidos a cirugía electiva, previamente tratados con dieta con carbohidratos de baja carga glicémica, ácidos grasos omega 3 y 6 y antioxidantes. Material y Método. Realizamos un estudio longitudinal prospectivo cuasi-experimental no aleatorio de 23 pacientes que solicitaron intervenciones de Cirugía Plástica y aceptaron entrar en el protocolo de diagnóstico y tratamiento de inflamación celular. Primero realizamos el cuestionario de Reporte de Inflamación Celular "RIS" y tomamos a los pacientes pruebas de inflamación celular y de ácido eicosapentaenóico (EPA, ácido decosaexaenóico (DHA, acido araquidónico (AA y ácido dihomogamalinoléico (DGLA al ingreso y antes de la cirugía. Analizamos los datos con estadística descriptiva y comparamos los rangos con la prueba McNemar y de hipótesis t de student, del sistema SPSS. Resultados. Tras aplicar el RIS a los 23 pacientes antes de la preparación con dieta y tras un periodo de 1 a 3 meses, evaluamos las respuestas de cada uno de los cuestionarios a través de las pruebas no paramétricas, encontrando diferencia significativa en los 14 items. Se mejoró considerablemente a la alza el EPA; el DHA y el AA sin cambios significativos; y el DGLA disminuyó considerablemente. Con t de student encontramos variación significativa en los fosfolípidos del plasma y no hubo diferencia significativa entre los DHA y AA. Conclusiones. Demostramos así la efectividad de la dieta de los omegas

  16. Nitrous oxides reduction pathways induced during nitrified leachate recirculation in bioreactor landfill; Voies de reduction des oxydes d'azote lors de leur injection dans un massif de dechets menagers et assimiles: contribution a l'etude de la recirculation de lixiviat nitrifie dans une installation de stockage de dechets menagers et assimiles bioactive

    Energy Technology Data Exchange (ETDEWEB)

    Vigneron, V.

    2005-12-15

    Nitrified leachate recirculation in bioreactor landfill has been proposed to avoid ammonium accumulation. We worked on the identification of nitrous oxides reduction pathways induced when nitrified leachate is recirculated during waste degradation. Batch reactors (1.1 liter, 40 g of reconstituted Municipal Solid Waste, MSW) were operated at 35 deg C and saturated with leachate. Injections of 250 mg N-NO{sub x}.10{sup -1} were performed during different phases of waste biodegradation. Nitrate reduction during acido-genic and active methanogenic phases, with an easily available carbon source in leachate, was mainly attributed to heterotrophic denitrification. However, H{sub 2}S concentration up to 0.7 % in the biogas (corresponding to 0.5 mmol of free H{sub 2}S per liter of leachate) led to prevalent DNRA (Dissimilatory Nitrate Reduction to Ammonium) over denitrification. This reaction hindered the release of nitrogen outside of the system. This observation was confirmed with experiments performed with {sup 15}N enriched nitrate. During late methanogenic phase, without any available carbon source in leachate, nitrate was reduced by autotrophic denitrification with sulfide as an electron donor. No free metal was detected in the leachate. N{sub 2}O transient accumulation was detected during both DNRA and autotrophic denitrification. A second set of experiments was conducted in a MSW pilot scale column (0.2 m{sup 3}, 80 kg of reconstituted waste) in methanogenic phase. 113 % and 203 % of nitrate were converted into N{sub 2} when a synthetic KNO{sub 3} solution (280 mg N.day{sup -1} during 77 days) or nitrified leachate (61 mg N.day{sup -1} during 54 days) were respectively injected into the system. The downward movement of a denitrification front passing through the waste mass was followed using 3 redox probes inserted at different levels of the pilot. Even if N{sub 2}O was never detected, a small production of this gas could not be totally excluded. It was established

  17. Avaliação da atividade antioxidante e alelopática do extrato etanólico e frações das cascas do caule de Zanthoxylum rhoifolium Lam., Rutaceae

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    Joelle de Melo Turnes

    2014-08-01

    Full Text Available Este trabalho teve como objetivo o estudo das atividades antioxidante e alelopática das cascas do caule de Zanthoxylum rhoifolium Lam., Rutaceae, de modo a conduzir à descoberta de substâncias biologicamente ativas. O material vegetal foi submetido à extração etanólica e este extrato foi fracionado obtendo as frações (hexano, clorofórmio, acetato de etila e hidroalcoólica. Para a avaliação da atividade antioxidante, empregaramse os métodos de redução do complexo fosfomolibdênio, de redução do radical DPPH e das substâncias reativas ao acido tiobarbitúrico (TBARS. Quanto à alelopatia, as amostras foram testadas em quatro concentrações sobre a germinação e o desenvolvimento de radícula e hipocótilo das sementes de Lactuca sativa. As amostras evidenciaram atividade antioxidante significativa frente ao método de redução do complexo fosfomolibdênio quando comparada à rutina, e do TBARS quando comparado ao BHT, assim como a atividade alelopática, uma vez que estimularam tanto a germinação como o crescimento das sementes. A fração clorofórmica e acetato de etila demonstraram melhor potencial antioxidante com 204,17% e 127,11% em relação à rutina no método de formação do complexo fosfomolibdênio, e o extrato bruto e a fração hexano com 64,2% e 60,9%, em relação ao BHT, no método TBARS. No ensaio alelopático, destaca-se a fração clorofórmica, pois foi a única amostra que estimulou o crescimento do hipocótilo e radícula na maioria das concentrações, variando de 41 a 144%, e a fração acetato de etila que apresentou a maior porcentagem de estímulo nesse bioensaio, demonstrando estímulo de 274% do crescimento do hipocótilo. Este é o primeiro trabalho que demonstra a atividade antioxidante e alelopática de Z. rhoifolium.

  18. Design and construction of a go-kart hybrid PEM fuel cell / rechargeable battery; Diseno y construccion de un go-kart hibrido pila de combustible PEM / bateria recargable

    Energy Technology Data Exchange (ETDEWEB)

    Suarez Alcantara, Karina; Rodriguez Castellanos, Andres; Soloza Feria, Omar [Centro de Investigacion y de Estudios Avanzados del IPN, Mexico D.F. (Mexico)]. E-mail: k.suarez.alcantara@gmail.com

    2008-11-15

    An hybrid Polymer Electrolyte Membrane Fuel Cell, PEMFC-Rechargeable Battery Go-kart has been designed and manufactured using AutoCAD software for the design and a CNC mechanical machine for the manufacture of components of the fuel cell. The membrane-electrode assemblies, MEAs, were integrated with a Gore-Select membrane and carbon cloth with Pt (20 wt % /C) 0.5 mg/cm{sup 2} anode and cathode electrode catalysts loading. High density graphite collector plates with 5mm thickness were used as collector plates. The estimated weigh of the go-kart with a driver is about 120 kg. The demand of the motor of the go-kart is 20 V and 5 A (100W), supplied by an hybrid system integrated by three 30Watts PEMFC. The commercially available Pb/acid rechargeable battery supplies energy for peripheral equipment. [Spanish] En este trabajo se presenta el diseno y la construccion de un go-kart hibrido pila de combustible con membrana de conduccion protonica tipo PEM (Proton Exchange Membrane, por sus siglas en ingles) y pila recargable. El diseno de los colectores de corriente de la pila se realizo utilizando el programa AutoCAD y la construccion mediante una fresadora con control numerico, CNC. Los ensambles membrana-electrocatalizador de la pila estan formados por membranas Gore-Select y por electrodos de Pt soportado en tela de carbon al 20 %peso/C con carga de 0.5 mg /cm{sup 2}, en anodo y catodo. Los platos colectores de corriente fueron manufacturados en grafito de alta densidad con espesor de 5 mm. La caracterizacion de la pila de combustible se realizo mediante ensayos de polarizacion potenciostatica. El peso total del go-kart y una persona a bordo es de 120 kg. La potencia del go-kart es generada por un motor de corriente directa de 20 V y 5 A (100 Watts). Para tal efecto, se construyeron tres pilas de combustible de 30 W cada una, con un respaldo de baterias recargables comerciales de Pb/acido para energizar equipos perifericos.

  19. Applications of hydrogen peroxide in electrochemical technology

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez Gallegos, Alberto Armando

    1998-12-01

    reproducible results and indicating that under the experimental conditions studied the reticulated vitreous carbon cathode and the cell components were chemically and electrochemically stable. [Espanol] Se demuestra que el peroxido de hidrogeno se puede producir con una eficiencia de corriente del 40-70% por reduccion catodica del oxigeno en un electrodo reticulado de carbon vitreo en una celda de flujo dividido usando los catolitos que consisten en un medio acuoso de cloruro o de sulfato, pH 2. El electrolito que utiliza no influye en la eficiencia de la corriente para el H{sub 2}O{sub 2} o su regimen de produccion. La eficiencia de la corriente para el H{sub 2}O{sub 2} no es una funcion importante del potencial y de esto sugiere que la reduccion de 2e- y del 4e- del oxigeno ocurre en paralelo en diversos sitios de la superficie del carbon. Los experimentos voltametricos mostraron que (a) la respuesta del I-E para la reduccion del oxigeno a un pH 2 es una funcion de la superficie del electrodo y/o del electrolito que utiliza; (b) tanto el desprendimiento del H{sub 2} y la reduccion del oxigeno se retardan en el carbon con el aumento de fuerza ionica; (c) la presencia de iones ferrosos conduce a la descomposicion homogenea del H{sub 2}O{sub 2} lejos de la superficie del catodo pero su eficacia como catalizador para esta descomposicion depende de su evolucion en la solucion que cambia durante una electrolisis. El uso de un electrodo tridimensional fabricado de carbon vitreo reticulado permite que el reactivo de Fenton sea electroproducido a un regimen practico que haga posible el retiro de substancias organicas en un medio acuoso ligeramente acido. Una amplia gama de las moleculas organicas altamente toxicas (fenol, catecol, hidroquinona, p-benzoquinona, acido oxalico, anilina, cresol y amaranto) se han oxidado en condiciones moderadas y una fraccion significativa del carbon organico se desprende como CO{sub 2}. En todos los casos estudiados la demanda quimica inicial de

  20. CARACTERIZACIÓN FISICOQUÍMICA Y ORGANOLÉPTICA DEL FRUTO DE AGRAZ (Vaccinium meridionale Swartz PHYSIOCHEMICAL AND ORGANOLEPTIC CHARACTERIZATION OF ANDEAN BLUEBERRY FRUIT (Vaccinium meridionale Swartz STORED AT 2ºC

    Directory of Open Access Journals (Sweden)

    Hernán Guillermo Ávila Rodríguez

    2007-12-01

    Full Text Available Con el propósito de hallar algunas características fisicoquímicas del fruto del agraz, del cual existen pocos conocimientos sobre su calidad, se recolectaron frutos provenientes de Chiquinquirá (Boyacá los cuales fueron empacados en cajas plásticas de 125 g y almacenados durante 9 días en un cuarto frío a una temperatura de 2ºC, con una humedad relativa del 90 %. Cada 3 días fueron medidas las variables sólidos solubles totales (SST, pH, acidez total titulable (ATT, ácidos cítrico, málico y ascórbico, diámetro del fruto y pérdida de peso. La mayoría de los cambios fisicoquímicos fueron de muy poca magnitud, las siguientes mediciones presentaron una tendencia permanente a la disminución: el peso fresco (de 0,58 a 0,55 g, el diámetro del fruto (de 0,99 a 0,93 cm y el pH (de 3,12 a 3,05, mientras que aumentaron la ATT (de 1,44 a 1,52 % y los SST (de 14,13 a 14,73 ºBrix. Los análisis con HPLC arrojaron que el ácido predominante fue el acido cítrico, seguido por el acido málico (1.899 mg y 1.396 mg/100 g fruto, respectivamente los cuales aumentaron a partir del día 6 de almacenamiento. El ácido ascórbico (8 mg/100 g presentó una leve disminución durante los días 3 a 6 del almacenamiento. Es posible que el aumento de los SST, la ATT y los ácidos orgánicos hacía el día 9 del almacenamiento haya sido debido a un efecto de concentración. En el análisis sensorial, se identificó que los frutos frescos obtuvieron una buena aceptación tanto en apariencia, aroma, sabor y en textura, mientras que los almacenados durante 9 días aún calificaron en aroma y sabor.With the purpose to find out some physiochemical characteristics of Andean blueberry fruits from which exist few knowledge about its quality, fruits were collected from Chiquinquirá (Boyacá, and packed in plastic boxes of 125 g and stored during 9 days (at 2ºC and 90% relative humidity. Each 3 days variables as total soluble solids (TSS, pH, total titratable

  1. Exercício resistido vs jogging em fatores de risco metabólicos de mulheres com sobrepeso/obesas Ejercicio resistido versus jogging en factores de riesgo metabólicos de mujeres con sobrepeso/obesas Circuit weight training vs jogging in metabolic risk factors of overweight/obese women

    Directory of Open Access Journals (Sweden)

    Carlos Alexandre Fett

    2009-11-01

    Full Text Available FUNDAMENTO: Exercícios resistidos e aeróbicos são recomendados para reduzir o peso e melhorar a saúde, mas ainda não foi definido qual dos dois tipos é o melhor. OBJETIVO: O objetivo do presente estudo foi comparar o exercício resistido e jogging (JOGG na doença cardiovascular múltipla (DCV, nos fatores de risco metabólicos e aptidão física de mulheres obesas ou com sobrepeso [composição corporal, perfil lipídico, acido úrico, glicose, equivalente metabólico (MET, frequência cardíaca, pressão arterial, flexibilidade, gasto de energia em repouso (GER e balanço de nitrogênio (BN]. MÉTODOS: Cinquenta mulheres foram aleatoriamente divididas em dois grupos, mas apenas 26 terminaram o estudo: exercício resistido (ER (n=14; 36±12 anos; índice de massa corporal, IMC=32±7 kg/m² e JOGG (n=12; 37±9 anos; IMC=29±2. O primeiro mês de treinamento consistiu em 60 min x 03 dias/semana e o segundo mês de treinamento consistiu em 04 dias/semana para ambos os protocolos, mais reeducação alimentar. RESULTADOS: Ambos os grupos apresentaram diminuição da massa corporal total, IMC, acido úrico plasmático e aumento do MET (pFUNDAMENTO: Ejercicios resistidos y aeróbicos se recomiendan para reducir el peso y mejorar la salud, pero todavía no se definió cuál de los dos tipos es el mejor. OBJETIVO: El objetivo del presente estudio fue comparar el ejercicio resistido y el jogging (JOGG en la enfermedad cardiovascular múltiple (ECV, en los factores de riesgo metabólicos y la aptitud física de mujeres obesas o con sobrepeso [composición corporal, perfil lipídico, ácido úrico, glucosa, equivalente metabólico (MET, frecuencia cardiaca, presión arterial, flexibilidad, gasto de energía en reposo (GER y balance de nitrógeno (BN]. MÉTODOS: Cincuenta mujeres se dividieron en dos grupos, de modo aleatorio, pero solamente 26 terminaron el estudio: ejercicio resistido (ER (n=14; 36±12 anos; índice de masa corporal, IMC=32±7 kg

  2. Immunomodulatory effect of fibres, probiotics and synbiotics in different life-stages Efecto inmunomodulador de la fibra, probióticos y simbióticos en las diferentes etapas de la vida

    Directory of Open Access Journals (Sweden)

    J. Romeo

    2010-06-01

    herramienta prometedora en la modulación del sistema inmune en diferentes poblaciones. Los efectos saludables de la fibra dietética y los probióticos han sido documentados en numerosos estudios epidemiológicos y de intervención, especialmente sus efectos beneficiosos sobre la microbiota del intestino con implicaciones clínicas importantes en la prevención y/o tratamiento de enfermedades infecciosas e inflamatorias. Los mecanismos incluyen la modulación de las propiedades funcionales de la microbiota, células epiteliales, dendríticas e inmunológicas. Se han estudiado en profundidad cómo los prebióticos afectan a la composición de la microbiota del intestino, estimulando beneficiosamente a otros comensales además de las bacterias acido lácticas, abriendo así una futura línea de investigación con nuevas cepas de probióticos y combinaciones de sinbióticos. Por otro lado, están bien establecidos los cambios en la fisiología del intestino, microbiota y respuesta inmune atribuidos al envejecimiento están bien establecidos. Además, las agresiones externas en los primeros días de vida, la alimentación con formulas infantiles, el tratamiento con probióticos, las enfermedades gastrointestinales y el estrés, también alteran el desarrollo y equilibrio de la microbiota intestinal. Por todo ello, esta revisión ofrece una visión actual sobre los aspectos mas relevantes del efecto de la fibra, probióticos y simbióticos sobre el sistema inmune en las diferentes etapas de la vida.

  3. The antibiotic activity of some Brazilian medicinal plants Atividade antibiótica de algumas plantas medicinais brasileiras

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    Maria R. Ferreira de Lima

    2006-09-01

    extrato etanólico das folhas de L. pacari mostrou valores de concentração inibitória mínima (CIM na faixa entre 312,5 a 2500 mg/mL, 250 mg/mL, 625 mg/mL, e 1250 mg/mL, respectivamente, contra oito diferentes variedades de Staphylococcus aureus Gram-positivas, Proteus mirabilis Gram-negativas e os bacilos acido-resistentes Mycobacterium phlei, M. fortuitum e M. smegmatis. O extrato etanólico do caule de L. pacari apresentou valores de CIM de 625 mg/mL contra S. aureus. Análise química revelou que os extratos brutos continham taninos, esteróides, fenóis, flavonóides, triterpenos e saponinas: as atividades foram altas o suficiente para possibilitar o isolamento guiado pelo bioensaio e a identificação futura dos compostos ativos.

  4. Manejo de la neumonía comunitaria del adulto en el Servicio de Salud Viña del Mar-Quillota. Abril - Septiembre de 2003 Management of community-acquired pneumonia by general practitioners in Viña del Mar and Quillota Health Service, Chile

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    Juana Pavié G

    2006-03-01

    Full Text Available La neumonía adquirida en la comunidad (NAC constituye una causa frecuente de consulta ambulatoria y hospitalización en la población adulta. Objetivos: describir el manejo de la NAC del adulto en el Servicio de Salud de Viña del Mar y Quillota durante la Campaña de Invierno de 2003. Resultados: Entre Abril y Septiembre, se atendieron 3.701 consultas por neumonía comunitaria del adulto, 73% en los servicios de urgencia y 27% en los consultorios de atención primaria. El 14% de los episodios de NAC requirieron hospitalización en el área de Viña del Mar y 21% en el área de Quillota. Se examinó una cohorte prospectiva de 229 adultos inmunocompetentes con NAC (± DE = 56 ± 21 años de edad de bajo riesgo y manejo ambulatorio según las recomendaciones de la Sociedad Chilena de Enfermedades Respiratorias, quienes fueron atendidos en los hospitales de Quillota, Viña del Mar y Limache durante el período de otoño-invierno. El 40% de los episodios correspondieron a NAC tipo I y 60% a NAC tipo II. Los pacientes con NAC tipo I fueron manejados con Claritromicina (67,4% o Amoxicilina (32,6% y los pacientes con NAC tipo II fueron manejados con Amoxicilina-Acido clavulánico (74,5% o Levofloxacina (24,8% durante 10 días. El 98,7% de los casos evolucionaron favorablemente sin requerir hospitalización, y sólo tres pacientes fueron admitidos al hospital debido a fracaso del tratamiento ambulatorio. Los tres pacientes fallecieron debido a la infección pulmonar y/o descompensación de una comorbilidad (1,3%. Conclusión: La mayoría de los enfermos con NAC, sin criterios de gravedad, pueden ser manejados en el medio ambulatorio con bajos índices de hospitalización, riesgo de complicaciones y muerteCommunity-acquired pneumonia (CAP is a potentially serious infection that results in numerous general practitioner visits and hospital admissions each year. Objective: to evaluate the clinical management of CAP by general practitioners in the emergency

  5. Performance of a small stand alone photovoltaic-wind system at El Oyameyo D.F., Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Juarez, A.; Campos, J. [Centro de Investigacion en Energia, UNAM, Mexico, D. F. (Mexico); Tiburcio Silver, A. [Instituto Tecnologico de Toluca-Division de Posgrado, Toluca (Mexico)

    1997-12-31

    hibrido fotovoltaico-viento. La potencia electrica instalada para los sistemas FV autocontenidos estan en el rango de 48 W-p hasta 768 W-p. Entre estos hay 4 sistemas FV que estan configurados en sistemas regulados de CD y otros 6 son sistemas regulados de CA. Todos estos sistemas utilizan bancos de baterias de plomo-acido (selladas o ventiladas) para almacenar la energia producida diariamente por los sistemas. El sistema hibrido FV-Viento esta formado actualmente por un aerogenerador de 5.0 Kw, un arreglo FV de 768 W-p, un banco de baterias de almacenamiento de 37.8 Kw-h y un inversor de DC/AC de 5.0 Kw. En este articulo se reporta la electricidad generada, el patron de carga y el comportamiento general del sistema hibrido fotovoltaico-viento. Se presentan tambien las caracteristicas tecnicas, las pruebas de energia del sistema hibrido y la experiencia obtenida del manejo de la energia y del mantenimiento del sistema para todos los sistemas. Se encontro que todos los sistemas habian demostrado buen desempeno a satisfaccion del usuario.

  6. Effet de la substitution du cuivre par du lithium sur les proprietes de l'oxyde spinelle lithium(x)cuivre(y-x)cobalt(3-y)oxygen(4) etudie pour l'electrocatalyse de la reaction de degagement de l'oxygene en milieu alcalin

    Science.gov (United States)

    Fatih, Khalid

    L'electrolyse de l'eau demeure la seule technologie industrielle de generation de l'hydrogene et de l'oxygene tres purs sans rejet de CO2 dans l'atmosphere, ce qui le rend tres attrayant par rapport a la combustion de carburants fossiles qui provoque presentement de serieux problemes environnementaux. Dans le but d'ameliorer le rendement de ce procede, nous avons developpe de nouveaux materiaux d'anode peu couteux, a base de l'oxyde mixte CuyCo3-yO 4, qui possedent une cinetique rapide pour la reaction de degagement de l'oxygene (RDO). Cette reaction suscite un interet particulier en raison de la surtension d'activation relativement elevee a l'anode qui cause la principale perte de rendement du procede. Une etude systematique a ete effectuee sur la substitution du Cu par du Li (0 a 40%), afin d'elucider les proprietes electrocatalytiques des oxydes LixCuy-xCo3-yO4. Ces oxydes, prepares sous forme de poudres par decomposition thermique des nitrates precurseurs entre 300 et 500°C, ont montre (DRX et FTIR) une structure spinelle inverse non-stcechiometrique avec une diminution du volume de la maille cristalline. La surface specifique par BET est d'environ 6 m2 g-1. Le pcn, obtenu par titrage acido-basique, a indique une diminution de la force du lien M-OH avec le taux du Li dans l'oxyde. Les analyses par XPS, realisees sur des films d'oxyde prepares par nebulisation reactive sur un substrat lisse de nickel, revelent un enrichissement de la surface en Cu a partir de 30% Li, et la presence des cations de surface Co2+, Co3+, Cu +, Cu2+ et Cu3+. La concentration de ce dernier montre un maximum a 10 et 20% Li. Suite a la substitution du Cu par du Li, la compensation de la charge serait assuree principalement par la formation d'especes Cu3+ pour les oxydes contenant jusqu'a 20% Li, et par la formation d'especes Co3+ aux taux de substitution superieurs. Les micrographies MEB montrent une morphologie hemispherique des particules d'oxyde reparties uniformement sur le substrat

  7. Methanotrophic activity and bacterial diversity in volcanic-geothermal soils at Pantelleria island (Italy

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    A. L. Gagliano

    2014-04-01

    Full Text Available Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic/geothermal soils are source of methane, but also sites of methanotrophic activity. Methanotrophs are able to consume 10–40 Tg of CH4 a−1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria island (Italy, Favara Grande, whose total methane emission was previously estimated in about 2.5 t a−1. Laboratory incubation experiments with three top-soil samples from Favara Grande indicated methane consumption values up to 950 ng g−1 dry soil h−1. One of the three sites, FAV2, where the highest oxidation rate was detected, was further analysed on a vertical soil profile and the maximum methane consumption was measured in the top-soil layer but values > 100 ng g−1 h−1 were maintained up to a depth of 15 cm. The highest consumption rate was measured at 37 °C, but a still recognizable consumption at 80 °C (> 20 ng g−1 h−1 was recorded. In order to estimate the bacterial diversity, total soil DNA was extracted from Favara Grande and analysed using a Temporal Temperature Gradient gel Electrophoresis (TTGE analysis of the amplified bacterial 16S rRNA gene. The three soil samples were probed by PCR using standard proteobacterial primers and newly designed verrucomicrobial primers targeting the unique methane monooxygenase gene pmoA; the presence of methanotrophs was detected in sites FAV2 and FAV3, but not in FAV1, where harsher chemical-physical conditions and negligible methane oxidation were detected. The pmoA gene libraries from the most active site FAV2 pointed out a high diversity of gammaproteobacterial methanotrophs distantly related to Methylococcus/Methylothermus genera and the presence of the newly discovered acido

  8. 小儿轮状病毒肠炎176例临床特点分析%Clinical manifestations of 176 infants with rotavirus enteritis

    Institute of Scientific and Technical Information of China (English)

    阮善; 庄丽宝; 徐玉珍; 陆定

    2008-01-01

    Objective To improve the clinical understanding of rotavirus gastroenteritis(RV) and pro-vide evidences for prevention and therapy of the disease in children. Methods From October 2005 to Septem-ber 2007 data of 176 patients with acute rotavirus gastroenteritis in our paediatric department were analyzed ret-rospectively. Results Comparing the exent of dehydration with the feeding pattern in infant with RV under one years old, there was significant difference between the artificial feeding group and the breast feeding group (P<0.01). Same to the mixed-feeding group(P<0.05). Comparing the degree of dehydration and metabolic acido-sis, the difference between 0-12 months group and 13-24 months group was also significant(P<0.05). Ihe num-ber of patients with isoosmotic, hypoosmotic, hyperosmotic dehydration was 127,38 and 11 respectively. The number of patients with hyponatremia in mild dehydration group and moderate to severe dehydration group was 14 (15.1%) and 24 (28.9%) respectively. The difference between them was significant (P<0.05). Conclu-sion Breast feeding can relieve the condition of infant with RV. The incidence of metabolic acidosis was high in infant with serious dehydration. Infants with RV usually got iso-osmotic dehydration. If the dehydration aggrava-ted,the number of hypoosmotic dehydration was apparently increased.%目的 提高对小儿轮状病毒肠炎的临床认识,为防治轮状病毒肠炎提供依据.方法 对本院儿科2005年10月至2007年9月收治的急性轮状病毒肠炎176例进行回顾性分析.结果 婴儿轮状病毒肠炎不同喂养方式的脱水程度比较,人工喂养组与母乳喂养组差异有极显著性(P<0.01),与混合喂养组差异有统计学意义(P<0.05).0~12月组和13~24月组患儿脱水程度、代谢性酸中毒比较差异均有显著性(P<0.05).本文患儿等渗性脱水127例,低渗性脱水38例,高渗性脱水11例,轻度与中~重度脱水组发生低血钠的分别为14例(15.1%)、24

  9. Evolución estructural de la zona de transición entre las fajas plegadas y corridas de Aconcagua y Malargüe Provincia de Mendoza Structural evolution of the transition zone between the Aconcagua and Malargûe fold and thrust belts, province of Mendoza

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    S. Broens

    2005-12-01

    Full Text Available En el presente trabajo se describe brevemente la estratigrafía y la estructura de los Andes en la zona de transición entre las fajas plegadas y corridas del Aconcagua y Malargüe. Las rocas aflorantes corresponden a un basamento volcánico acido permotriásico, sedimentitas mesozoicas de la cuenca neuquina y efusiones volcánicas y depósitos continentales neógenos. Estructuralmente se reconocen de oeste a este, cuatro segmentos denominados: zona de inversión tectónica, zona de pliegues apretados, zona central o de imbricación y anticlinal del Carrizalito. Se construyeron dos secciones estructurales que se ajustan a los datos de campo recogidos en las zonas de imbricación, de pliegues apretados y del flanco dorsal del anticlinal del Carrizalito, que permitieron describir las estructuras presentes en el área. Lineamientos regionales de orientación noroeste-sureste podrían estar actuando como zonas de transferencia de rechazos. Pueden reconocerse dos o tres pulsos deformacionales según se considere la edad relativa de las estructuras respecto al levantamiento de la Cordillera Frontal. Para el caso en que el cordón del Carrizalito haya actuado como un alto de basamento se proponen dos pulsos, uno de piel fina y otro posterior que levanta a la Cordillera Frontal basculando la secuencia previamente deformada. Si en cambio la estructuración del anticlinal del Carrizalito hizo que este se comporte como punto de fijación (sticking point podria sumarse un tercer episodio deformacional con corrimientos fuera de secuencia.In this work we describe briefly the stratigraphy and the structure of the Andes in the transition zone between the Aconcagua and Malargüe fold and thrust belts. The outcrops are a Permotriasic volcanic acid basement, Mesozoic sediments of the Cuenca Neuquina and Neogene volcanic rocks and continental deposits. Structuraly we distinguish from west to east four segments: a tectonic inversion zone, a tight folds zone, a

  10. Double blind randomized clinical trial controlled by placebo with an alpha linoleic acid and prebiotic enriched cookie on risk cardiovascular factor in obese patients Ensayo clínico aletorizado doble ciego controlado con placebo con una galleta enriquecida en ácido alfa linoleico y prebióticos en el patrón de riesgo cardiovascular de pacientes obesos

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    D. A. de Luis

    2011-08-01

    Full Text Available Introduction: Inulin and FOS are prebiotics with potential benefit in cardiovascular risk factors. Alpha linolenic acid (ALA is the metabolic precursor of the long chain n-3 fatty acid eicosapentaenoic acid (20: 5n-3, this fatty acid has anti-inflammatory properties. The aim of our study was to evaluate the response of the cardiovascular risk profile in obese patients after inclusion in the diet of an ALA, FOS and inulin enriched-cookie. Material and methods: 36 patients were randomized in both branches: group I (inulin, FOS and ALA enriched cookie Gullon SL® and group II (control cookie. Previous and after 1 month of the treatment, a nutritional and biochemical study was realized. Results: 15 patients finished the procotol in each group. In group I, a significantly increase in soluble fiber (2.3 ± 0.8 g/day vs 7.7 ± 0.8 g/day: p Introducción: La inulina y los FOS son prebióticos con potenciales efectos beneficiosos a nivel cardiovascular. El acido alfa linolénico (ALA es el precursor del ácido eicosapentaenoico (20: 5n-3, presentando propiedades antinflamatorias. El objetivo de nuestro trabajo es evaluar la respuesta del perfil de riesgo cardiovascular en pacientes obesos tras la inclusión en la dieta de una galleta enriquecida en inulina, FOS y ALA. Material y métodos: Un total de 36 pacientes fueron randomizados a una de las siguientes ramas: galleta I (enriquecida con inulina, FOS y ALA y galleta II (galleta control (Gullón SL. Cada paciente recibió un total de 2 galletas al día (70 gramos de producto. Antes de iniciar el tratamiento y al mes, se realizó una valoración nutricional y analítica. Resultados: Finalizaron el protocolo un total de 15 pacientes en cada grupo. En el grupo I se produjo un aumento significativo en la ingesta de fibra soluble (2,3 ± 0,8 g/día vs 7,7 ± 0,8 g/día: p < 0,05 (inulina y FOS, así como ALA (0,6 ± 0,5 g/día vs 3,8 ± 0,5 g/día; p < 0,05. Se detectó en los pacientes varones que

  11. Influência do método de síntese no processo de pilarização com titânio de uma esmectita da região amazônica Influence of the synthesis method on the process of pillarization of smectite from the amazonic region with titanium

    Directory of Open Access Journals (Sweden)

    D. L. Guerra

    2006-12-01

    Full Text Available Amostras de argila esmectítica provenientes do município de Serra Madureira no Estado do Acre foram utilizadas no processo de pilarização. As matrizes natural e pilarizada foram caracterizadas por difração de raios X, espectroscopia no infravermelho com transformada de Fourier, análises térmicas diferencial e gravimétrica, microscopia eletrônica de varredura, espectroscopia de raios X por energia dispersiva e análise textural. As soluções pilarizantes de titânio, Ti(OC2H54 e TiCl4, foram analisadas por espectroscopia no infravermelho com transformada de Fourier. O íon intercalante foi obtido através da reação química entre as soluções de Ti(OC2H54 e HCl na proporção aproximada de HCl/Ti=1 e soluções de TiCl4 em reação com etanol com relação Ti/argila= 25 mmol Ti/g. A intercalação da notronita foi efetuada utilizando-se de dois métodos: com a solução de acido clorídrico incorporada paulatinamente na solução de etóxido de titânio, e utilizando o cloreto de titânio em solução de etanol, com vigorosa agitação a 25 ºC durante 3 h e com calcinação a 450 ºC e 600 ºC. Os resultados de difração de raios X do processo de pilarização mostraram alterações no espaçamento basal de 15,30 Å para 18,76 Å, e na área de superfície específica de 44,37 m²/g para 188,72 m²/g. A estabilidade térmica da argila natural foi otimizada com o processo de pilarização.Smectite clays of the State of Acre, Brazil, were used for the pillarization process. The natural and pillarized matrices were characterized by X-ray diffraction, Fourier transform infrared spectroscopy (FTIR, thermal analysis, scanning electron microscopy, energy dispersive spectroscopy and textural analysis. The titanium pillarized solutions Ti(OC2H54 and TiCl4 were analyzed by FTIR. The intercalation ion was obtained by reacting Ti(OC2H54 with HCl (HCl/Ti ~ 1 and TiCl4 with ethanol (Ti/clay ~ 25 mmol Ti/g. The notronite intercalation was

  12. Rhizosphere competent Mesorhizobiumloti MP6 induces root hair curling, inhibits Sclerotinia sclerotiorum and enhances growth of Indian mustard (Brassica campestris Mesorhizobium loti MP6 rizosférico competente induz encurvamento do pelo daraiz, inibe Sclerotinia sclerotiorum e estimula o crescimento de mostarda indiana (Brassica campestris

    Directory of Open Access Journals (Sweden)

    Shikha Chandra

    2007-03-01

    Full Text Available The bacterial strain Mesorhizobium loti MP6, isolated from root nodules of Mimosa pudica induced growth and yield of Brassica campestris. The isolate MP6 secreted hydroxamate type siderophore in Chrom-Azurol Siderophore (CAS agar medium. Production of hydrocyanic acid (HCN, indole acetic acid (IAA and phosphate solubilizing ability was also recorded under normal growth conditions. Root hair curling was observed through simple glass-slide technique. In vitro study showed a significant increase in population of M. loti MP6 in rhizosphere due to root exudates of B. campestris. In dual culture technique the strain showed a strong antagonistic effect against Sclerotinia sclerotiorum, a white rot pathogen of Brassica campestris. The growth of S. sclerotiorum was inhibited by 75% after prolonged incubation. Efficient root colonization of mustard seedlings was confirmed by using a streptomycin-resistant marker M. loti MP6strep+. The M. loti MP6 coated seeds proved enhanced seed germination, early vegetative growth and grain yield as compared to control. Also, a drastic decline (99% in the incidence of white rot was observed due to application of M. loti MP6.A cepa bacteriana Mesorhizobium loti MP6 isolada de nódulos de raiz de Mimosa pudica induziu o crescimento e o rendimento de Brassica campestris. A cepa MP6 secretou sideróforo do tipo hidroxamato em meio sólido Chrom-Azurol Siderophore (CAS. Em condições normais de crescimento, a cepa foi também capaz de produzir de ácido cianídrico (HCN e acido indolacético (AIA e solubilizar fosfato. O encurvamento do pelo da raiz foi observado usando a simples técnica de lâmina e lamínula. Estudos in vitro mostraram um aumento significativo na população de M. loti MP6 na rizosfera devido aos exsudatos de B. campestris. Empregando-se técnica de co-cultura, a cepa mostrou um grande efeito antagônico contra o fungo Sclerotinia sclerotiorum, o patógeno da podridão branca de Brassica campestris. Ap

  13. Synthesis of structured triacylglycerols containing medium-chain and long-chain fatty acids by interesterification with a stereoespecific lipase from Mucor miehei.

    Directory of Open Access Journals (Sweden)

    Nieto, Susana

    1999-06-01

    Full Text Available The preparation of structured triacylglycerols sn-1, sn-3 dilauryl, sn-2 eicosapentaenoyl glycerol and sn-1, sn-3 dilauryl, sn-2 docosahexaenoyl glycerol by enzymatic interesterification under restricted water availability is described. Laurie acid, one of the substrates for interesterification, was obtained by the controlled hydrolysis of coconut oil by a non-specific lipase obtained from Candida cylindracea. The fatty acid was separated from the hydrolysis products by silverresin column chromatography and converted to methyl ester, sn-2 Eicosapentaenoyl glycerol and sn-2 docosahexaenoyl glycerol were prepared by the hydrolysis of fish oil by the sn-1, sn-3 stereospecific immobilized lipase Lipozyme IM-20 obtained from Mucor miehei as described in the accompanying paper. The interesterification was carried out in a water jacketed glass reactor and the triacylglycerol products were separated and recovered through aluminum oxide column chromatography The interesterification procedure described allows to obtain In laboratory scale structured triacylglycerols containing medium-chain fatty acids at the sn-1 and sn-3 positions and long-chain polyunsaturated fatty acid from marine origin at the sn-2 glycerol position.

    Se describe la preparación de triacilgliceroles estructurados sn-1, sn-3 dilauril, sn-2 ecosapentaenoil glicerol y sn-1, sn-3 diiauril, sn-2 docosahexaenoil glicerol por interesterificación enzimática bajo disponibilidad de agua reducida. Acido láurico, uno de los sustratos para la interesterificación, se obtuvo mediante hidrólisis controlada del aceite de coco por una lipasa no-específica obtenida de Candida cylindracea. Los ácidos grasos se separaron de los productos de hidrólisis mediante cromatografía en columna de resina de plata y convertidos en sus esteres metílicos, sn-2 Eicosapentaenoil glicerol y sn-2 docosahexaenoil glicerol se prepararon mediante hidrólisis de aceite de pescado por la sn-1, sn

  14. Lipid lowering effect of policosanol and omega-3 fatty acids combined therapy in hypercholesterolemic patients

    Directory of Open Access Journals (Sweden)

    José Illnait

    2010-01-01

    Full Text Available Aunque el colesterol de las lipoproteinas de baja densidad (LDL-C continua siendo el principal objetivo en el manejo de la dislipidemia, la prevencion de la enfermedad coronaria incluye ademas, la modificacion de otros indicadores tales como la disminucion del colesterol no unido a las lipoproteinas de alta densidad y los trigliceridos sericos (TG, asi como el incremento de las HDL-C. Se reconoce que los aceites de pescado ricos en acidos grasos omega 3 (AG-OMEGA3, los cuales reducen los TG sericos y el colesterol no unido a HDL, pueden disminuir el riesgo de los eventos cardiovasculares a traves de estos efectos y a traves de otros efectos no relacionados con los lipidos (reduccion de la frecuencia cardiaca, efectos antiarritmicos, discreta reduccion de la hipertension arterial y de la agregacion plaquetaria. El efecto de AG-OMEGA3 sobre las HDL y el colesterol total (CT puede ser variable y en ocasiones tiende a incrementar las concentraciones de las LDL-C en el suero. El policosanol ha demostrado que reduce las LDL-C y CT mientras que incrementa las HDL-C en individuos normocolesterolemicos e hiperlipidemicos, con un efecto marginal e inconsistente sobre los trigliceridos. El policosanol administrado concomitantemente con OMEGA-3-FA durante un corto periodo demostro que reduce la LDL-C y el CT mientras que aumenta las HDL-C mas que el placebo AG-OMEGA3 + placebo, sin afectar el efecto reductor de los TG de los AG-OMEGA3. No se ha reportado, sin embargo, la persistencia de tales efectos. Este estudio investiga si los beneficios de la administracion de AG-OMEGA3 + policosanol (AG-OMEGA3-poli persisten despues de una terapia mas prolongada (24 semanas. Despues de un periodo de dieta solamente, 60 pacientes se distribuyeron, aleatoriamente y a doble ciegas, en dos grupos. Uno de los grupos fue tratado con AG-OMEGA3 (1 g/d + placebo (AG-OMEGA3-pla mientras que el otro recibio AG-OMEGA3 (1 g/d + policosanol 10 mg/d . Las variables de laboratorio

  15. Softwood forest thinning as a biomass source for ethanol production: A feasibility study for California

    Energy Technology Data Exchange (ETDEWEB)

    Kadam, Kiran L; Wooley, Robert J; Aden, Andrew; Nguyen, Quang A; Yancey, Mark A; Ferraro, Francis M [Colorado(United States)

    2000-07-01

    hidrolisis de acido diluido de dos etapas para la produccion de etanol a partir de madera de coniferas, y la lignina residual se utiliza para generar vapor y electricidad. Para una planta que procesa 800 toneladas secas por dia de materia prima, el caso de una planta vecina es un concepto economicamente atractivo. El capital total estimado de inversion es de aproximadamente $70 millones en el caso de la instalada una junto a otra. La tasa interna de retorno resultante es de cerca del 24% utilizando un 25% de financiamiento equitativo. Por consiguiente, este tipo de planta de conversion de biomasa a etanol parece ser una proposicion atractiva para California, con el etanol reemplazando gradualmente al eter metil butil-terciario que esta destinado a desaparecer.

  16. Propagação vegetativa de cedo-australiano (Toona ciliata M. Roemer por miniestaquia Vegetative propagation of Toona ciliata M. Roemer by the minicutting technique

    Directory of Open Access Journals (Sweden)

    Jonicélia Cristina Araújo Vieira de Souza

    2009-04-01

    Full Text Available O método de propagação usual do cedro-australiano (Toona ciliata é via seminal, entretanto a oferta sazonal das sementes e sua curta viabilidade ao longo do tempo representam um problema para a produção contínua de mudas destinadas à implantação de povoamentos. Este trabalho foi conduzido com o objetivo de avaliar a viabilidade da propagação vegetativa da espécie por miniestaquia e a necessidade da aplicação de acido indolbutírico (AIB para o enraizamento das miniestacas. A partir de um banco de estacas de origem seminal, foram obtidas brotações para produção de mudas clonais, em três diferentes épocas de coleta (2,5; 4,5; e 5,5 meses após a recepa das mudas. Antes do estaqueamento, as miniestacas tiveram suas bases imersas em quatro concentrações de AIB (0; 1.500; 3.000; e 4.500 mg L-1. Durante o experimento, obtiveram-se 100% de sobrevivência das minicepas e das miniestacas. Houve 100% de enraizamento das miniestacas nas três coletas, não ocorrendo diferença no comprimento de raízes em função das doses de auxina aplicadas. Quanto maior o intervalo entre as coletas e quanto maiores as brotações que originaram as miniestacas, maior a velocidade de crescimento das mudas. Miniestacas de cedro-australiano possuem capacidade de enraizamento, e mudas recepadas apresentam brotação, possibilitando a clonagem da espécie pelo processo de miniestaquia.Sexual propagation is the method commonly used for the Australian Red Cedar Toona ciliata. However, seasonal seed availability and short viability are a concern for the continuous offer of seeds for implantation. The objectives of this study were to evaluate the viability of vegetative propagation of this species through minicutting and to test indolbutiric acid (IBA application for rooting of minicuttings. Sprouts for clonal minicutting production were obtained from a miniclonal garden established from seeds, in three different harvest times (2.5; 4.5 and 5.5 months

  17. Assessment of a sequential extraction protocol by examining solution chemistry and mineralogical evolution

    Science.gov (United States)

    Maubec, Nicolas; Pauwels, Hélène; Noël, Hervé; Bourrat, Xavier

    2015-04-01

    of them are able to leach several solid phases. In this context, the aim of the present study is to investigate the effectiveness and the selectivity of different reagents for metal extraction from target geochemical fraction. It is based on solid analyses with the use of X-ray diffraction and a scanning electron microscopy (SEM) coupled to a microRaman spectrometer in conjunction with chemical analyses of extracting solutions at each step. This methodology provides the opportunity to assess more accurately the effect of each reagent. The study focuses on extraction of Cu and Zn from sediment samples collected at two sites from river banks and characterized by presence of Quartz, Feldspar K, Micas, Kaolinite but with differences regarding accessory phases (pyrite, organic matter, iron oxy- hydroxide, calcite). The interaction of the samples with eight different reagents was assessed and compared (Ca(NO3)2 and CaCl2 for the exchangeable fraction; buffered solutions of sodium acetate/acetic acid at pH = 5.5 and pH = 5 for the acido-soluble fraction; hydroxylamine hydrochloride and a solution of ammonium oxalate/oxalic acid for reducible fraction; hydrogen peroxide and sodium hypochlorite for the oxidizable fraction. In-depth characterization of solid residue at each step allowed proposing the best protocol for both metals. Anderson, P., Davidson, C. M., Duncan, A. L., Littlejohn, D., Ure, A. M., and Garden, L. M. (2000). Column leaching and sorption experiments to assess the mobility of potentially toxic elements in industrially contaminated land. Journal of Environmental Monitoring, 2. Arey, J. S., Seaman, J. C., and Bertsch, P. M. (1999). Immobilization of uranium in contaminated sediments by hydroxyapatite addition. Environmental Science & Technology, 33, 337-342. Brannon, J. M., and Patrick, W. H. (1987). Fixation, transformation, and mobilization of arsenic in sediments.Environmental Science & Technology, 21, 450-459. Cornu, S., and Clozel, B. (2000). Extractions

  18. Búsqueda y selección de una proteasa fúngica con potencial aplicación en la restauración de documentos históricos en el Archivo de Bogotá

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Cruz Ramírez

    2012-08-01

    Full Text Available Normal 0 21 false false false ES-CO X-NONE X-NONE MicrosoftInternetExplorer4 Título en ingles: Screening for a fungal protease with potential in the biorestoration of historical valuable documents in Bogota Archive Resumen: Se ha buscado y seleccionado sistemáticamente una proteasa que pudiese ser usada en la eliminación “limpia” de encolantes sobre soportes documentales con valor de patrimonio histórico de forma eficiente y económica, a partir de la colección de hongos filamentosos del Archivo de Bogotá. De 74 morfotipos viables evaluados sobre placas selectivas, 32 morfotipos presentaron formación de halos de hidrólisis evidentes sobre placas diferenciales. De ellos, se evaluó el perfil isoenzimático de 8 morfotipos provenientes de muestreos documentales directos y de 2 morfotipos proteolíticos promisorios provenientes de un trabajo previo. Los 10 morfotipos seleccionados fueron representativos de los géneros Penicillium, Stachybotrys, Chaetomium, y Eladia. Luego de inducir la producción de proteasas extracelulares en medios líquidos diferenciales bajo tres fases de fermentación, se realizaron isoelectroénfoques analíticos tendientes a la observación de isoformas en el gradiente de pH establecido (3.0-10.0. Solo los morfotipos 8D (Chaetomium sp. y 21D (Eladia saccula presentaron una isoforma alcalina extrema, de puntos isoeléctricos 8.5 y 8.8, respectivamente, susceptible de selección con miras a su purificación y caracterización parcial de forma económica y eficiente. Los demás morfotipos, representativos de los géneros Penicillium sp., y Stachybotrys sp., presentaron unicamente isoformas proteolíticas en el rango acido de pH con puntos isoeléctricos que oscilan entre 4.0 y 5.0. Palabras clave: biodeterioro; hongo filamentoso; proteasa; halo de hidrólisis; punto isoeléctrico. Abstract: Studies on a protease as an efficient, environmental friendly and relatively economical remover of residual proteins for

  19. Estudos sobre o xanthoma: biochimica e pathogenia Studies in xanthoma: biochemistry and pathogenesis

    Directory of Open Access Journals (Sweden)

    Gilberto G. Villela

    1935-12-01

    Full Text Available 1. No presente trabalho são descriptos dois casos de xanthelasmatose (xanthoma com perturbações accentuadas do metabolismo dos lipides e esteroes. 2. Um dos casos apresentou notavel cholesteroluria não mostrando o doente lesões renaes, ao passo que o outro caso sendo portador de pyelonephrite não eliminava cholesterol. 3. Foram feitas dosagens de cholesterol, acidos graxos totaes e lecithina, no sangue, urina e tumores, obtendo-se valores muito elevados. As demais provas (histo-chimicas, polarização microscopica confirmaram a presença de abundante infiltração de lipides e cholesterol nos tecidos. 4. A prova de carga de Bürger feita no caso I demonstrou diminuição da tolerancia para o cholesterol. 5. A therapeutica insulinica fez baixar o cholesterol e a glycose do sangue sem, comtudo, offerecer melhora clinica do paciente. No caso II houve baixa da cholesterolemia e da glycemia com desapparecimento dos tumores, evidenciando a diversidade das formas clinicas destes casos. 6. A intradermo-reacção feita com o cholesterol no caso I produziu reacção positiva, suggerindo um estado de hypensensibilidade para as substancias de infiltração no xanthelasma (xanthoma. 7. Os aspectos clinico-morphologicos dos casos estudados indicam tambem a ocorrencia de processos de sensibilisação cutanea. 8. As lipidoses são encaradas neste trabalho como toxicodermias hematogenicas, sendo proposto para seu estudo os mesmos methodos de exploração cutanea.1. In the present paper two cases of xanthelasmatosis (xanthoma with marked changes in lipid and sterol metabolism are studied. 2. One of the cases without injuries shows accentuated cholester-oluria, while the other with renal injuries presented pyelonephritis without cholesteroluria. 3. Cholesterol, total fatty acids and lecithine give high values in both cases. Histo-chemical and polariscopic researches confirmed a real infiltration of cholesterol and lipids in tissues. 4. Burger's test in case

  20. Geohydrology model of the geothermal reservoirs at Los Humeros, Puebla, Mexico; Modelo hidrogeologico de los yacimientos geotermicos de los Humeros, Puebla, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Cedillo Rodriguez, Fidel [Comision Federal de Electricidad, Perote, Veracruz (Mexico)

    1999-12-01

    the regional lateral water recharge. On the other hand, the circular faults of the collapsed calderas of Los Humeros and Los Petreros form impermeable barriers to lateral water flow. Geothermal reservoir recharge only occurs inside the collapsed Los Humeros caldera. [Spanish] Los estudios de petrologia de agua y gases, e ingenieria de yacimientos de los pozos geotermicos, indican la existencia de dos yacimientos geotermicos. Las correlaciones petrograficas estructurales y el estado de las tuberias de produccion de los pozos geotermicos reparados, desviados y no invertidos, confirma la presencia de dos yacimientos, uno superior no agresivo con pH neutro y fluido bicarbonatado-sodico alojado en andesitas de augita; el otro, inferior, de alta temperatura y pH acido, contenido en andesitas de hornblenda y basaltos con fluidos clorurados-sodicos, ambos separados por un horizonte de tobas vitreas. Las grandes elevaciones de los niveles potenciometricos de los pozos geotermicos impide inferir la direccion de flujo de los fluidos geotermicos profundos. Los resultados litologicos y piezometricos de los pozos geothermohidrologicos perforados dentro de la caldera de Los Humeros, tambien muestra la existencia de dos acuiferos superficiales, uno relativamente frio y otro caliente. Debido a las grandes distancias entre estos pozos, y al medio geologico en que se encuentran, tampoco en ellos es posible inferir la direccion de flujo. Los estudios regionales de hidrogeologia, geofisica, hidrogeoquimica y geologico- estructurales, permiten afirmar que los acuiferos (frio y caliente) no tienen comunicacion hidraulica, ni relacion geoquimica o geologica con los pozos, norias y manantiales de los alrededores de la region de Los Humeros. Por consiguiente, la recarga de los acuiferos frio y caliente ocurre dentro de la cuenca cerrada de la caldera de Los Humeros, delimitada por el parte aguas orografico. Estos acuiferos recargan a los yacimientos geotermicos a traves de fallas y fracturas

  1. Caracterização e extração de compostos voláteis de resíduos do processamento de maracujá (Passiflora edulis Sims f. flavicarpa degener Characterization and extraction of volatile compounds from passion fruit (Passiflora edulis Sims f. flavicarpa degener processing waste

    Directory of Open Access Journals (Sweden)

    Lília Calheiros de Oliveira

    2012-12-01

    Full Text Available Este estudo objetivou extrair e identificar compostos voláteis presentes nos resíduos de processo de maracujá. Obtiveram-se destilados a partir de resíduos de maracujá através das técnicas de hidrodestilação simples e hidrodestilação com arraste de gás nitrogênio. Os compostos voláteis presentes nos destilados foram capturados por microextração em fase sólida, empregando-se fibra Carboxen/DVB/DMS, e identificados por cromatografia gasosa acoplada com espectrômetro de massa, usando a coluna capilar de sílica fundida CP WAX 52. Foram identificados trinta e um compostos voláteis no extrato obtido pela técnica de hidrodestilação simples, sendo os principais compostos: neral (26,19%, cinamato de metila (18,52%, linalol (16,82%, 1-undecanol (5,60%, cis-óxido de linalol (4,41%, benzaldeído (3,92% e 1-hexanol (3,48%. Para a hidrodestilação com arraste de gás nitrogênio, trinta compostos foram identificados, sendo que, em maior porcentagem de área, destacaram-se: cinamato de metila (30,41%, neral (24,46%, β-ionona (13,81%, linalol (4,0% e acido butanoico (2,19%. O presente estudo revelou que os resíduos de maracujá apresentam compostos voláteis que podem ser extraídos na forma de aromas, apresentando potencial para gerar essências naturais com valor agregado.The aim of this study was to extract and identify volatile compounds from passion fruit residues generated during processing. Distillates of passion fruit residues were obtained from the techniques of simple hydrodistillation and hydrodistillation by passing nitrogen gas. The volatile compounds present in the distillates were captured by solid phase microextraction with Carboxen/DVB/DMS fiber. The volatile compounds were indentified by gas chromatography with mass spectrometry using a fused sillica capillary column with a CP WAX 52 stationary phase. Thirty one compounds were indentified by simple hydrodistillation technique. The main compounds were: neral (26

  2. Electrochemical study of oxygen reduction reaction in Pt/C catalysts synthesized by photo-deposition; Estudio electroquimico de la reaccion de reduccion de oxigeno en catalizadores de Pt/C sintetizados por fotodeposito

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Galindo, J. A.; Ruiz-Camacho, B.; Valenzuela-Zapata, M. A.; Gonzalez-Huerta, R. G. [IPN, ESIQIE, Mexico, D.F. (Mexico)]. E-mail: rosgonzalez_h@yahoo.com.mx

    2009-09-15

    interaccion entre estos dos componentes ha recibido mucha atencion en los ultimos anos. Esta interaccion es considerada como la responsable en los efectos de crecimiento de la estructura y la disminucion de la dispersion de las particulas del metal sobre el soporte, provocando un bajo desempeno global y un menor tiempo de vida util de la pila. Las propiedades del soporte se ven acentuadas en los catalizadores catodicos, donde se lleva a cabo la reaccion de reduccion de oxigeno por las condiciones de operacion que se tienen, actualmente se estan investigando sintesis que mejoren la interaccion metal-soporte y asi aumentar el tiempo de vida de la pila de combustible. En este trabajo se presenta el estudio electroquimico de catalizadores de tamano nanometrico de platino soportado en carbon (Pt/C) sintetizados por el metodo de Foto-deposito Quimico para determinar su efecto catalitico y estabilidad en la reaccion de reduccion de oxigeno en medio acido. Se utilizo como precursor de platino el C{sub 10}H{sub 14}O{sub 4}Pt (Pt(acac)2). El estudio electroquimico se realizo con las tecnicas de voltamperometria ciclica y electrodo de disco rotatorio observando que los catalizadores sintetizados presentan un comportamiento similar al Pt ETek. El estudio cinetico mostro un potencial a circuito abierto de 0.96 V, con una pendiente de Tafel de 73 mV dec-1 y a una corriente de 0.1 mA cm-2 se tiene un potencial de 0.91 V. Los autores agradecen el apoyo al ICYTDF (proyecto PICS08-37) y al IPN (Proyecto SIP-20090433).

  3. Ground level chemical analysis of air transported from the 1998 Mexican-central american fires to the southwestern USA

    Energy Technology Data Exchange (ETDEWEB)

    Villanueva Fierro, Ignacio [Departmento de Ciencias Ambientales, COFAA, CIIDIR-IPN Unidad Durango, Durango, Durango (Mexico)]. E-mail: ifierro62@yahoo.com; Popp, Carl J. [Department of Chemistry, New Mexico Tech, NM (United States); Dixon, Roy W. [Department of Chemistry, California State University at Sacramento, Sacramento, CA (USA); Martin, Randal S. [Department of Civil and Environmental Engineering, Utah State University, Logan, UT (United States); Gaffney, Jeffrey S. [Department of Chemistry, University of Arkansas at Little Rock, Little Rock, AR(United States); Marley, Nancy A. [Graduate Institute of Technology, University of Arkansas at Little Rock, Little Rock, AR (United States); Harris, Joyce M. [Office of Oceanic and Atmospheric Research, ERL/CMDL, NOAA, Boulder, CO (United States)

    2009-02-15

    km desde la fuente de los incendios. Las mediciones de varios marcadores quimicos fueron tomadas antes y durante la incursion del humo en Socorro, NM. Dias antes de que llegara la contaminacion a NM, grandes areas de Texas, Louisiana y la parte baja del valle del Rio Mississippi fueron cubiertas por el humo de los incendios. La suma de compuestos carbonilicos vario, antes del humo de 5.6 ppbv, a 15.5 ppbv durante la incursion del humo; la suma de acidos carboxilicos vario de 7.2 ppbv a 8.6 ppbv; los hidrocarburos con 1 y 2 carbonos de 270 ppbv a 133 ppbv; los NO{sub 3}{sup -} en particulas de 0.1 a 1.3 {mu}g/m{sup 3}; los SO{sub 4}{sup -2} variaron de 1.2 a 3.4 {mu}g/m{sup 3}; las PM10 se mantuvieron en el intervalo de antes de la incursion (15-20 {mu}g/m{sup 3}). Los resultados indican un impacto significativo en un sitio rural del transporte de larga distancia de contaminantes de humo primarios y secundarios provenientes de eventos de quema de biomasa y la importancia de estas especies se debe principalmente al intervalo de tamano gaseoso y de aerosol fino. Estos aerosoles finos son importantes como agentes coadyuvantes al cambio climatico y afectan la calidad del aire y visibilidad.

  4. Ethylene, Enzymatic and Respiratory Pattern Evolution in Loquat (Eriobotrya japonica (Thunb. Lindl. cv. Golden Nugget in the Last four Sequential Stages of Maturation Evolución del Patrón Respiratorio, Enzimático y de Etileno del Níspero Japonés (Eriobotrya japonica (Thunb. Lindl. cv. Golden Nugget en los Últimos Cuatro Estadios Secuenciales de Madurez

    Directory of Open Access Journals (Sweden)

    Pedro L Undurraga M

    2011-12-01

    (PG, y celulasa. Los resultados muestran que el etileno incrementó su concentración al momento de quiebre de color, lo cual no fue equivalente en el cambio de la tasa respiratoria. La actividad de la enzima peroxidasa se incrementó desde el color verde al quiebre de color, mientras que las enzimas PME, celulasa, y PG mostraron una reducción constante desde el color verde hasta el color anaranjado y la PPO no se vió alterada en los cuatro estadios estudiados. Respecto a la calidad, a partir del quiebre de color se incrementaron los sólidos solubles hasta 11,8 °Brix y se redujo la acidez titulable desde 0,67 a 0,28 g L-1 de acido málico. Basado en estos resultados, se concluye que hacia el término de su desarrollo el fruto de níspero cv. Golden Nugget presenta un comportamiento enzimático y del etileno similar al que muestran frutos de tipo climatérico.

  5. Developments in the technology for the combustion of water emulsions in Mexican fuel oil; Desarrollos en la tecnologia para la combustion de emulsiones agua en combustoleo mexicano

    Energy Technology Data Exchange (ETDEWEB)

    Diego, Antonio Marin; Martinez Flores, Marco A.; Tamayo Flores, Gustavo; Alarcon Quiroz, Ernesto; Melendez Cervantes, Carlos [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2001-07-01

    The residual petroleum oil (fuel oil) is the most used fuel in boilers of electrical and industrial power stations. Nevertheless, the use of this fuel can generate diverse problems such as the elevated particle emissions, that affect the boiler efficiency, darken the visibility by the smoke that leaves the chimneys and is emitted to the Environment. In addition, sulfur trioxide is produced, which reacts with the water present in the combustion gases, forming sulfuric acid that, when emitted, also affects the visibility of the plume and can be condensed, originating corrosion and increased accumulation of deposits in the boilers. The experimental research was made in a comparative base, between combustion tests of fuel oil, with emulsions where the water concentration and the size of the drops of this one was varied. A diagram of the supply of fuel and preparation of emulsions in a pilot furnace is shown. The article contains graphs of the effect of the water concentration of the emulsions in the particulate emission. The article contains figures of the cenospheres produced by the fuel oil combustion (500 x) and the ones produced by the combustion with 5% of water (500 x). Also shows graphs of the effect of the water drop size of emulsions in the particulate emission, of the reduction of the sulfur trioxide with soluble magnesium products in the water of emulsions, and of the free particle acidity with neutralizers of water emulsions of soluble magnesium. [Spanish] El aceite residual de petroleo (combustoleo) es el combustible mas utilizado en calderas de centrales electricas e industriales. Sin embargo, el uso de este combustible puede generar diverso problemas como las emisiones elevadas de particulas, que afectan la eficiencia de una caldera, obscurecen la visibilidad pero el humo que sale de las chimeneas y se emiten al medio ambiente. Ademas se produce trioxido de azufre, el cual reacciona con el vapor de agua presente en los gases de combustion, formado acido

  6. Oxygen reduction using platinum electrocatalysts prepared by liquid phase photo-deposition; Reduccion de oxigeno mediante electrocatalizadores de platino preparados por foto-deposicion en fase liquida

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Camacho, B.; Perez-Galindo, J. A.; Valenzuela, M. A.; Gonzalez-Huerta, R. G. [Instituto Politecnico Nacional, ESIQIE, Mexico D.F. (Mexico)]. E-mail: rosgonzalez_h@yahoo.com.mx

    2009-09-15

    This work presents the synthesis and characterization of nanometric-sized Pt/C electrochemical catalysts using impregnation and liquid phase photo-deposition methods. Two platinum precursors were used, C{sub 10}H{sub 14}O{sub 4}Pt (Pt acetylacetonate, Pt(acac){sub 2}) and H{sub 2}PtCl{sub 6} (hexachloroplatinic acid) to study the effect on the particle size and the electrocatalytic behavior in the oxygen reduction reaction. The characterization of the catalysts was done using x-ray diffraction, hydrogen chemisorption and transmission electron microscopy. The electrochemical study was conducted with cyclic voltamperometry and rotary disc electrode (RDE) techniques. Pt (E-tek) was used as a reference catalyst. The peaks of the platinum were identified based on the x-ray diffraction results, and correspond to crystalline phases (111) and (200), whose intensity was greater when using H{sub 2}PtCl{sub 6} versus Pt(acac){sub 2}. The hydrogen chemisorption and transmission electron microscopy tests found that the larger-sized particle (1-5 nm) and greater metallic dispersion was obtained using Pt(acac){sub 2} as a platinum precursor and liquid phase photo-deposition. It was also found that this material presented the best electrochemical response, showing a open-circuit potential of 0.96 V and over-potential of 0.05 V with respect to H{sub 2}PtCl{sub 6} and of 0.22 V with respect to the catalyst obtained using impregnation. [Spanish] En este trabajo se presenta la sintesis y caracterizacion electroquimica de catalizadores de tamano nanometrico de Pt/C empleando los metodos de impregnacion y foto-deposicion en fase liquida. Se utilizaron dos precursores del platino C{sub 10}H{sub 14}O{sub 4}Pt (acetil-acetonato de Pt, Pt(acac){sub 2}) y H2PtCl6 (acido hexacloroplatinico), para estudiar el efecto que tienen sobre el tamano de particula y el comportamiento electrocatalitico en la reaccion de reduccion de oxigeno. La caracterizacion de los catalizadores se realizo mediante

  7. Evolution of the geothermal system in Acoculco, Pue., Mexico: Study based on petrography of well EAC-2 and other information; Evolucion del sistema geotermico de Acoculco, Pue., Mexico: un estudio con base en estudios petrograficos del pozo EAC-2 y en otras consideraciones

    Energy Technology Data Exchange (ETDEWEB)

    Viggiano Guerra, Julio Cesar [Universidad Michoacana de San Nicolas de Hidalgo, Michoacan (Mexico)]. E-mail: cesar.viggiano@live.com; Flores Armenta, Magaly; Ramirez Silva, German R. [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)

    2011-01-15

    Acoculco, Pue., geothermal area is located 180 km away from Mexico City. It includes two hydrothermally altered areas with acid sulfate cold springs and some mofettes, associated with a complex structural framework presented in an area 2000 m thick of Tertiary-Quaternary volcanic rocks, Cretaceous metamorphized limestone and even Cretaceous granite. The field seems to resemble kaipohan type geothermal fields. Two exploratory wells have been drilled in the area. In 1995, well EAC-1 was drilled to a depth of 1810 m and in 2008 well EAC-2 was drilled to a depth of 1900 m. We discuss results and interpretations of petrographic studies made on the second well, and how some information from the first well is used to interpret the evolution of the hydrothermal system. It can be concluded the Acoculco geothermal area is in its final hydrothermal stage, since a change in the hydrothermal regime from convective to forced-convective or conductive has occurred, according to studies of hydrothermal mineralogy and other considerations. It is notable that the system is not recycling, perhaps because the rocks have not allowed it to, and therefore is ending. This, of course, has not been an obstacle to the presence of large volumes of hot (300 degrees Celsius) hornfels and granite opening up possibilities for the exploitation of an Enhanced (or Engineered) Geothermal System (EGS). The possibility of improving reservoir rocks permeability (hornfels and granite) by conventional means remains to be investigated. [Spanish] La zona geotermica de Acoculco, Pue., se localiza a 180 km de distancia de la ciudad de Mexico, D.F. Exhibe dos areas alteradas hidrotermalmente con descargas acido-sulfatadas frias y algunas mofetas, asociadas a una red estructural compleja configurada en un espesor de 2000 m de rocas volcanicas del Cuaternario-Terciario, calizas metamorfizadas del Cretacico e incluso granitos del Cretacico. Esta particularidad parece encajar conceptualmente en los denominados

  8. Efeito da fortificação alimentar com ácido fólico na prevalência de defeitos do tubo neural Efecto de la fortificación alimentaria con ácido fólico en la prevalencia de defectos del tubo neural Effects of folic acid fortification on the prevalence of neural tube defects

    Directory of Open Access Journals (Sweden)

    Sâmya Silva Pacheco

    2009-08-01

    Full Text Available OBJETIVO:Analisar o efeito de alimentos fortificados com ácido fólico na prevalência de defeitos de fechamento do tubo neural entre nascidos vivos. MÉTODOS: Estudo longitudinal de nascidos vivos do município de Recife (PE entre 2000 e 2006. Os dados pesquisados foram obtidos do Sistema Nacional de Informações de Nascidos Vivos. Os defeitos de fechamento do tubo neural foram definidos de acordo com o Código Internacional de Doenças-10ª Revisão: anencefalia, encefalocele e espinha bífida. Compararam-se as prevalências nos períodos anterior (2000-2004 e posterior (2005-2006 ao período mandatório à fortificação. Analisou-se a tendência temporal das prevalências trimestrais de defeitos do fechamento do tubo neural pelos testes de Mann-Kendall e Sen's Slope. RESULTADOS: Não se identificou tendência de redução na ocorrência do desfecho (Teste de Mann-Kendall; p= 0,270; Sen's Slope =-0,008 no período estudado. Não houve diferença estatisticamente significativa entre as prevalências de defeitos do fechamento do tubo neural nos períodos anterior e posterior à fortificação dos alimentos com acido fólico de acordo com as características maternas. CONCLUSÕES: Embora não tenha sido observada redução dos defeitos do fechamento do tubo neural após o período mandatório de fortificação de alimentos com ácido fólico, os resultados encontrados não permitem descartar o seu benefício na prevenção desta malformação. São necessários estudos avaliando maior período e considerando o nível de consumo dos produtos fortificados pelas mulheres em idade fértil.OBJETIVO:Analizar el efecto de alimentos fortificados con ácido fólico en la prevalencia de defectos del cierre del tubo neural entre nacidos vivos. MÉTODOS: Estudio longitudinal de nacidos vivos del municipio de Recife (Noreste de Brasil, entre 2000 y 2006. Los datos pesquisados fueron obtenidos del Sistema Nacional de Informaciones de Nacidos Vivos. Los

  9. Sequenciamento e análise dos genes das subunidades alfa e beta do hormônio folículo estimulante de bovino (Bos taurus indicus Sequencing and analysis of subunits alpha and beta of the follicle stimulating hormone from bovine (Bos taurus indicus

    Directory of Open Access Journals (Sweden)

    Luci Sayori Murata

    2008-07-01

    Full Text Available

    Este trabalho relata uma clonagem e seqüenciamento das subunidades alfa e beta do hormônio folículo estimulante de Bos taurus indicus. Também apresenta os resultados de comparação realizada das seqüências gênicas dessas cadeias com as seqüências das cadeias alfa e beta do FSH de suínos e da cadeia beta de bovinos Bos taurus taurus já presentes no GenBank. Na comparação das seqüências de nucleotídeos e de aminoácidos predita da cadeia αFSH de Bos taurus indicus com as cadeias αFSH de outras espécies como suínos e búfalo (Bubalis bubalis, observou-se que as seqüências são bastante similares. A comparação da seqüência da subunidade αFSH de Bos taurus indicus com a de suíno demonstrou diferenças em três resíduos de aminoácidos. Na comparação com ßFSH, registrou-se modificação na primeira base do codon que levou à alteração no resíduo do aminóacido 83, que, em Bos taurus indicus, é uma glicina, ao invés da serina presente em Bos taurus taurus. Confirmaram-se essa modificação e todas as outras identificadas na seqüência dos cDNA das cadeias αFSH e βFSH em outra clonagem. A modificação Ser para Gly na posição 83 foi a única que alterou a identidade do resíduo de aminoácido na comparação entre as subunidades beta do FSH de Bos taurus indicus e Bos taurus taurus. Contudo, ela não deve alterar significativamente as propriedades fisiológicas do FSH, uma vez que o resíduo de glicina encontrado nessa posição também é encontrado na cadeia βFSH suína. Trata-se, portanto, de uma modificação particular que distingue as cadeias βFSH de B. taurus taurus e B. taurus indicus.

     

    PALAVRAS-CHAVES: Bovino, clonagem, FSH, hormônio.

    The aim this work was to promove the cloning and analysis sequencing

  10. Technical feasibility of using silver and copper ions electro generated in the microbiological control of cooling systems; Factibilidad tecnica para emplear iones plata y cobre electrogenerados en el control microbiologico de los sistemas de enfriamiento

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Susana M; Martinez Meza, Esteban; Alvarez Gallegos, Alberto [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2001-07-01

    sistema continuo el pH se mantuvo en el intervalo de pH de 7 a 8 mediante la adicion de acido sulf

  11. Biohydrogen production from diary processing wastewater by anaerobic biofilm reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rios-Gonzalez, L.J.; Moreno-Davila, I.M.; Rodriguez-Martinez, J.; Garza-Garcia, Y. [Universidad Autonoma de Coahuila, Saltillo, Coahuila (Mexico)]. E-mail: leopoldo.rios@mail.uadec.mx

    2009-09-15

    to be employed for hydrogen production. [Spanish] Este articulo describe la produccion biologica de hidrogeno a partir de agua residual diaria via fermentacion anaerobica utilizando choque termico pretratado (100 grados centigrados, 30 min.) y procedimientos de tratamiento acido para enriquecer selectivamente el hidrogeno produciendo consorcios mezclados antes de la inoculacion de reactores por lote. El biorreactor empleado para el consorcio de inmovilizacion se opero a temperatura mesofilica (ambiente) (20{+-}3 grados centigrados), bajo condiciones acidofilicas (pH 4.0-4.5), HRT (2h), y un soporte natural para generar hidrogeno produciendo biopelicula de consorcios mezclados: Opuntia imbricata. El reactor se opero inicialmente con sorbitol (5g/L) durante 60 dias de operacion. Las pruebas de lote se llevaron a cabo empleando 20{+-}0.02g de soporte natural con biopelicula. Los experimentos de lote se realizaron para investigar el efecto de la DQO ((2.9-21.1 g-DQO/L), a pH inicial de 7.0, 32{+-}1 grados centigrados. La produccion maxima de hidrogeno se obtuvo a 21.1 g-COD/L. Se efectuaron experimentos del efecto del pH empleando una concentracion de sustrato optima (21.2 g-COD/L), a pH de 4 a 7 y 11.32 (pH de agua residual diaria) y 32{+-}1 grados centigrados. Los resultados de los experimentos indican que el cultivo inicial optimo fue de pH 4.0, pero podemos considerar tambien una produccion estable de hidrogeno a pH 11.32 (pH de agua residual diaria), por lo que se pudo evitar ajustar el pH, y usar agua residual diaria como queda en el proceso de produccion de queso. El pH operacional de 4.0 esta 1.5 unidades por debajo del reportado antes correspondiente al hidrogeno que producen los organismos. La influencia del efecto de la temperatura se realizo usando la concentracion de sustrato optima (21.2 g-COD/L), dos niveles de pH: 4.0 y 11.32, y cuatro diferentes temperaturas: 16{+-}3 grados centigrados (temperatura ambiente), 32{+-}1 grados centigrados, 45{+-}1 grados

  12. Technical feasibility of using silver and copper ions electro generated in the microbiological control of cooling systems; Factibilidad tecnica para emplear iones plata y cobre electrogenerados en el control microbiologico de los sistemas de enfriamiento

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Susana M; Martinez Meza, Esteban; Alvarez Gallegos, Alberto [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2001-07-01

    sistema continuo el pH se mantuvo en el intervalo de pH de 7 a 8 mediante la adicion de acido sulfurico y se conservo un delta de temperatura de 10 (27 {+-} 5 ). El pH, la conductividad y la temperatura se midieron en forma continua. Se muestran graficas de efecto de iones plata/cobre sobre el aniquilamiento de bacterias coliformes totales y coliformes fecales se da como figura el efecto de la concentracion del ion metalico plata sobre el aniquilamiento de bacterias relacionadas con fierro. Se puede concluir que los sistemas de planta, plata/cobre y cobre estudiados resultaron ser una buena alternativa con un minimo impacto ambiental para sustituir el cloro en los sistemas de enfriamiento. Estos sistemas lograron abatir a las poblaciones bacterianas promotoras de la corrrosion influenciada microbiologicamente y del ensuciamiento biologico a niveles de 1000 ufc/mL y menores compitiendo con los tratamientos de aguas de enfriamiento convencionales. (abstract truncated)

  13. DYNAMICS OF THE RUMINAL FERMENTATION IN SHEEP FEEDING WITH RATION CONTAINING DIFFERENT LEVELS OF CASHEW BY-PRODUCTS (Anacardium occidentale Efecto de la inclusion en los níveles crescentes del subproducto de caju (Anacardium occidentale L. en la dinámica de la fermentacion ruminal de ovinos DINÂMICA DA FERMENTAÇÃO RUMINAL EM OVINOS ALIMENTADOS COM RAÇÕES CONTENDO DIFERENTES NÍVEIS DE COPRODUTOS DE CAJU (Anacardium occidentale

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    Marcos Cláudio Rogério

    2009-07-01

    Full Text Available

    The study aimed to evaluate the inclusion of cashew by-product (Anacardium occidentale L. on the ammoniac nitrogen concentrations (N-NH3, pH and vollatile fatty acids concentrations (VFA of the ruminal fluid, in sheep that received diets containing the cited by-product. Twenty male, entire sheep had been distributed in four treatments with different levels of cashew by-product inclusion (zero; 19%; 38%; 52% in a randomized block design, in a split-plot project, having in the parcels the diets and the sub-parcels the times of collection (zero, two, five, eight hours after-feeding with five replications. PH was remained inside of the normal standards cited by same literature in the raised cashew by-product inclusions. Diets with zero and 52% had gotten the biggest concentrations of N-NH3. The molar ratio of the AGV in the ruminal liquid in the diets with cashew by-product was typical of rich diets in voluminous. The relation acetate: propionate was not affected by the inclusion of the cashew by-product. The inclusion of the cashew by-product in up to 19 % of the dietary total presented better resulted in that it says respect to the parameters analyzed in this work.

    KEY WORDS: Ammoniac nitrogen, Ovis aries, pH, parameters ruminate, ruminants, volatile fatty acids.

    El estudio apunto evaluar la inclusión del subproducto de caju (Anacardium occidentale en la concentración de nitrogeno amoniacal (N-NH3, el pH y las concentraciones de los acidos grasos vollatiles (AGV en el liquido ruminal de ovinos lnteracciones de la respuesta del eje somatotrófco en la amenorrea hipotalámica funcional relacionada con la desnutrición The activity of the somatotrophic function in Functional Hypothalamic Amenorrhea (FHA related to undernourishmant

    Directory of Open Access Journals (Sweden)

    L Fiszlejder

    2011-03-01

    Full Text Available La función somatotrófica en la amenorrea hipotalámica funcional (AHF exhibe un aumento central de su actividad y paradojalmente, el comportamiento hormonal periférico, el metabolismo intermedio y varios aspectos clínicos pueden ser compatibles con los observados en la insuficiencia del eje somatotrófico. Los niveles basales y la secreción diaria de GH son altas, pero su perfil pulsátil es irrregular. En virtud de ello, se produce una resistencia a la GH, con disminución de los receptores de la hormona, que, sumado al descenso de la proteína ligadora de GH (GH binding protein, GHBP, alteran su capacidad de estimular en el hígado las síntesis de IGF-I, IGFBP-3 y la de la subunidad acido-lábil. Ello disminuye la disponibilidad de IGF-I libre en los tejidos. Por otro lado, los IGFBP-1 y IGFBP-2 aumentan significativamente. Si bien estos péptidos son regulados por la GH, aparentemente resulta ser más importante su correlación inversa con la actividad de la insulina (que se encuentra disminuida en estas pacientes y con el bajo aporte proteico de las dietas. El aumento de los niveles séricos de estos péptidos también contribuye al descenso de la IGF-I libre. Las alteraciones en la dinámica de secreción inducen a una reducción de la concentración de la leptina (una adipokina y al aumento de la ghrelina (la cual, a su vez, facilita la secreción de GH y presentan una destacada incidencia en el metabolismo intermedio de estas pacientes desnutridas. Estos cambios hormonales pueden ser interpretados como un mecanismo de adaptación homeostática tendiente a preservar la disponibilidad de los nutrientes energéticos. En relación a ello, existe inicialmente un predominio de la lipólisis, seguido de proteólisis a nivel muscular. Si la restricción dietética continúa, se desarrolla en el hígado y en el tejido muscular, un proceso de neoglu-cogénesis utilizando como sustrato, las proteínas y los NEFA. Ello es seguido por la glugen

  14. Sensorial, biochemical and microbiological evaluations of guacamole, an avocado based product, under cold storage and added with ascorbic acidAvaliações sensoriais, bioquímicas e microbiológicas do guacamole, um produto à base de abacate, sob armazenamento a frio e com adição de ácido ascórbico

    Directory of Open Access Journals (Sweden)

    Lídia Raquel de Carvalho

    2011-07-01

    peroxidase (POD, EC 1.11.1.7 e polifenoloxidase (PPO, EC 1.10.3.1 do guacamole adicionado de ácido ascórbico e conservado sob frio elaborado, usando-se abacate da variedade Hass. Produtos acondicionados em embalagens de polietileno+nylon com e sem aplicação de vácuo foram submetidos ao congelamento lento e rápido (-18ºC e armazenados em freezer (-18ºC. Avaliações foram realizadas no momento da elaboração do produto (t0 e aos 3, 7 e 30 dias após armazenamento, sendo que no t30 as amostras foram mantidas sob refrigeração (4 ±1ºC e avaliadas após 3, 5 e 7 dias. Após 30 dias de armazenamento, a - 18ºC sob congelamento, seguido de descongelamento e mantendo-se à 4ºC±1 por 7 dias, as notas para os parâmetros sensoriais diminuram. A peroxidase foi totalmente inibida no produto elaborado e a atividade da enzima polifenoloxidase diminuiu consideravelmente no guacamole (20,07 mM de catecol/g massa fresca em relação ao fruto (58,31 mM de catecol/g massa fresca, porém sem variação significativa durante o armazenamento (à -18ºC. As amostras apresentaram-se microbiologicamente estáveis nas condições do estudo. A adição de acido ascórbico contribuiu para conservação do produto de abacate congelado diminuindo a atividade enzimática. No entanto, os parâmetros sensoriais são prejudicados com o descongelamento e armazenamento à 4±1oC.

  15. Methodical characterization of rice ( Oryza sativa bran oil from Pakistan

    Directory of Open Access Journals (Sweden)

    Mahmood, Zahid

    2005-06-01

    for the establishment of a globalized database of this valuable crop.El contenido de aceite, extraído con hexano, del salvado de cuatro variedades de arroz (Oryza sativa viz. Super Kernel, 386, 385 y Basmati, varió entre el 14.70 y el 19.10 %. Otros parámetros físicos y químicos de los aceites extraídos fueron respectivamente: Indice de yodo: 112.40, 109.80, 105.1 y 103.70; índice de refracción ( 40 °C : 1.4650, 1.4680, 1.4657 y 1.4660; densidad ( 40 °C 0.919, 0.913, 0.909 y 0.911; índice de saponificación: 183, 177, 186 y 190; insaponificable: 6.15, 5.60, 4.98 y el 5.40 %. Los tocoferoles ( α, γ, δ en los aceites fueron, respectivamente: 284.00, 175.12, 180.42, 300.06; 83.40, 98.70, 120.70, 90.60; 75.16, 57.20, 39.32 y 83.00 mg/kg. El contenido de tocotrienoles ( α, γ, δ en los aceites fue: 120.30, 106.00, 95.20, 135.74; 196.00, 125.00, 210.0, 276.41; 72.50, 20.00, 39.30 y 64.00 mg/kg, respectivamente. En los aceites estudiados se encontró una concentración de γ -oryzanol que varió entre 415.12 y 802.05 µg/g . Los periodos de inducción (Rancimat, 20 L/h, 120 °C de los aceites crudos fueron 6.81, 5.99, 6.39 y 7.40 h, respectivamente. Las fracciones principales de esteroles en los aceites se componían de: campesterol (10.10-19.20 %, stigmasterol (14.00-19.28 %, b -sitosterol (49.30-58.20 % y Δ5 ,avenasterol (8.14-13.05 %. Las variedades investigadas ( Super Kernel, 386, 385 and Basmati de aceite de salvado de arroz contenían elevados niveles de acido oleico 42.67, 38.59, 40.68 y 36.78 % seguido por los ácidos linoleico y palmítico 31.58, 33.80, 28.70, 30.51; 17.00, 14.88, 19.63 y 20.00 %, respectivamente. Los contenidos en ácidos mirístico, esteárico y araquídico fueron 1.50, 2.02, 4.28, 1.00; 2.64, 2.87, 4.02, 7.48; 1.28, 3.00, 1.00 y 1.00 % resp

  16. Laser induced spectroscopy breakdown (LIBS) application to heavy metal detection in soils; Applicazioni della tecnica Laser induced breakdown spectroscopy (LIBS) alla determinazione dei metalli pesanti nei suoli

    Energy Technology Data Exchange (ETDEWEB)

    Barbini, R.; Fantoni, R.; Palucci, A.; Ribezzo, S.; Colao, F. [ENEA, Centro Ricerche Frascati, Frascati, RM (Italy). Div. Fisica Applicata; Capitelli, F. [Bari, Univ., Bari (Italy). Dipt. di Biologia e Chimica Agroforestale ed Ambientale

    2000-07-01

    composizione elementale del campione e, mediante l'utilizzo di emissioni di campioni a concentrazione nota, di risalire alle concentrazioni delle singole specie del campione. Il grande vantaggio di questa tecnica e' che non e' richiesto alcun trattamento del campione (come invece e' il caso in tecniche spettroscopiche tradizionali quale l'ICP, Inductively Coupled Plasma, che richiede la mineralizzazione del campione tramite attacco acido con acqua regia), se non il semplice compattamento tramite pressa meccanica. I risultati ottenuti dall'applicazione della tecnica LIBS al centro ricerche ENEA di Frascati sui campioni di suolo sono stati analizzati per confronto con i risultati ottenuti con una tecnica tradizionale quale l'ICP. Si osserva una sistematica sovrastima del valore LIBS rispetto a quello ICP, probabilmente imputabile alle differenze di matrice litologiche tra i campioni analizzati e quelli usati come riferimento. (abstract truncated)

  17. Pathogenia da anemia na Ancylostomose: II - causas determinantes dos phenomenos regenerativos e degenerativos nessa anemia e contribuições para elucidar o seu mechanismo intimo Pathogenesis of Anaemia in Hookworm Disease: II - causes wich determine the regenerative and degenerative phenomena in this anaemia and contributions towards the elucidation of their inmost mechanism

    Directory of Open Access Journals (Sweden)

    W. O. Cruz

    1934-12-01

    ausentes, os normoblastos, as hematias com restos nucleares e as hematias polychromaticas. A reticulose oscilla em torno de 3%. Este aspecto é constante nos casos graves, sendo entretanto variavel na unidade de volume o numero destas hematias acima caracterisadas. A média dessa ultima cifra em numerosos casos é de 2,50 M., o que determina uma taxa de Hb. egual a 23%. Ao analysarmos certas observações, que descrevem aspectos hematologicos differentes daquelles aqui descriptos, concluimos pela existencia nesses casos anomalos, de superposições de outras doenças, cuja etio-pathogenia nada tem a ver com os factores que determinam o apparecimento da anemia ancylostomotica. A regeneração hematica processa-se na Ancylostomose unicamente após a administração de ferro em dóses variaveis, conforme o sal empregado. Mostraram-se inactivas nos casos aqui observados, as administrações de figado crú, triptophano, hystidina, lecithina, Vit. B, saes de arsenico, manganez, cobalto, cobre e a alimentação com dietas ricas em ferro. Em virtude dos resultados que obtivemos com a administração isolada de ferro, concluimos pela inefficiencia da administração de substancias pyrrholicas, da fracção hepatica sensivel nas anemias hypochromicas, e da associação ao ferro de acido chlorhydrico. Todas essas substancias, e tambem a elimanação simples dos helminthos parasitos, não só mostraram-se isoladamente sem acção sobre o sangue, como não auxiliaram a regeneração provocada pelo ferro...We studied 25 selected cases of anchylostomiasis, endeavouring to determine the factors which induce the hematic regeneration and investigating the mechanism of this regeneration as well as the development of the anemiant process. We preferred to select a small number of cases and accompany them for a long period, some of them having been underobservation during 1 to 1 year and a half. Apart from 568 routine examinations (count of red cells, dosage of Hb., determination of the

  18. The extreme environments and their microbes as models for extraterrestrial life

    Science.gov (United States)

    Seckbach, J.; Oren, A.; Chela-Flores, J.

    2008-09-01

    Life exists almost everywhere on Earth. Presence of liquid water is a prerequisite for life (Oren, 2008). Living organisms are not only found in `normal' habitats (from the anthropocentric view). Many types, especially of microorganisms, not only tolerate harsh environmental conditions, but even thive in them. Such organisms that resist very harsh physical and chemical conditions in their habitats are termed `extremophiles'. Some extremophilic microorganisms are able to overcome more than one type of extreme conditions in their environment. For example, some `polyextremophiles' grow under hundreds of atmospheres of hydrostatic pressure (barophiles) and at very low, or alternatively at very high temperatures. In many hot springs there are acido-thermophiles that tolerate elevated temperatures and very low pH levels (e.g. the Cyanidium caldarium group, see Seckbach 1994). Members of Cyanidium are able to thrive in pure CO2, a condition not tolerated by most algae (Seckbach et al., 1970). Some thermophilic Archaea grow at temperatures up to 1130C and possibly even higher. In the Arctic and Antarctic regions and in the permafrost region in Siberia there are cold-loving microorganisms (psychrophiles) which are able to grow at -200C. Many types of Bacteria and Archaea tolerate extreme dryness, and spores of Bacillus and relatives that have been encapsulated within salt crystals may have survived in a dormant state for thousands and even millions of years, and still can be revived today. Other extremophiles tolerate salt concentrations up to saturation. Halophilic microorganisms such as found in the Dead Sea or in the Great Salt Lake have developed different strategies to cope with the high osmotic pressure of their environment. Some (e.g. the unicellular green alga Dunaliella salina) balance the salts in their medium by accumulating organic compounds such as glycerol. Others (halophilic Archaea of the order Halobacteriales, as well as a few representatives of the

  19. El HTLV-I y la PET/HAM un modelo de investigación en virología y biología molecular

    Directory of Open Access Journals (Sweden)

    Felipe García Vallejo

    2004-03-01

    ="MsoNormal">Además, el derivado del acido cafeíco, el 3,5 dicafeoilquinico (3,5DCQA, se constituye en potencial inhibidor irreversible de la integrasa viral. De manera integral nuestros resultados han permitido tener una visión mucho mas detallada sobre la biología molecular del HTLVI y de una de sus enfermedades asociadas, la PET/MAH del Pacífico colombiano, cuya incidencia es una de las

    mayores del mundo.

    Nuestros estudios continúan con el fin de poder desarrollar novedosas estrategias terapéuticas antirretrovirales, empleando principios activos derivados del café como una aproximación al abordaje de nuevas y más baratas estrategias antirretrovirales, que pueden ser extrapolables a la infección con el VIH-1 y otros virus humanos.

     

    REFERENCIAS

    1. GARCÍA VALLEJO F. Molecular and immunological characteristics in the pathogenesis of tropical spastic paraparesis HTLV-I-associated myelopathy (TSP/HAM. J. Ciencia e Cultura 1996; 48 :351-358.

    2. DOMÍNGUEZ M C, CASTILLO A, CABRERA J, EIZURU Y, AKIBA S, GARCÍA-VALLEJO F. Envelope sequence variation and phylogenetic relations of human T-Cell Lymphotropic Virus (HTLV Type I from endemic areas of Columbia. AIDS Res Hum Retroviruses 2002; 18: 887- 890.

    3. BALCÁZAR N, SÁNCHEZ G, GARCÍA-VALLEJO F. Sequence and phylogenetic analysis of Human T-Lymphotropic Virus type 1 from Tumaco, Colombia. Mem Inst Oswaldo Cruz 2003; 98