Sample records for acido dimercapto succinico

  1. Evaluacion de las propiedades mecanicas de poliesteramidas derivadas de los acidos tartarico y succinico

    Perez-Rodriguez, Angel T; Fernandez-Santin, Jose M; Alla, Abdellilah; Munoz-Guerra, Sebastian


    ...% de ester, obtenidas a partir de los acidos tartarico y succinico. Las mismas constituyen polimeros que presentan potencial aplicacion en el sector biomedico por su posible utilizacion en intervenciones quirurgicas para hilos de sutura...

  2. 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

    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)


    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)

  3. 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

    Ortega L, N


    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)

  4. Effect of succinic acid concentration in poly(glycerol citrate/succinate) properties; Efeito da concentracao do acido succinico nas propriedades do poli(glicerol citrato/succinato)

    Brioude, Michel M.; Guimaraes, Danilo H.; Fiuza, Raigenis P.; Jose, Nadia M. [Universidade Federal da Bahia - UFBA, Instituto de Quimica, Salvador, BA (Brazil)


    In this work were prepared and characterized polymer based on glycerol, citric and succinic acid, in three different ratios to evaluate the effect of succinic acid concentration in materials properties. The polymers were obtained by polycondensation reaction between polyol and poly acids, and were characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning differential calorimetry (DSC), scanning electron microscopy (SEM). The materials are amorphous polyesters and its thermal and morphological properties change depending on the succinic acid concentration. (author)

  5. Genotoxicity of meso-2,3-dimercapto succinic acid-coated silver sulfide quantum dot

    Deniz Özkan Vardar


    Full Text Available Nanotecnology products have been used in wide applications in chemistry, electronics, energy generation, and medicine. Despite significant interest in developing quantum dots (QDs for biomedical applications, many researchers are convinced that QDs will never be used for the treatment of patients because of their potential toxicity. In various in vitro cell culture studies, the cytotoxic properties of some QD have been demonstrated and they have been suggested to be toxic in humans. In this study, the cytotoxic properties of Ag2S-(Meso-2,3-Dimercapto Succinic acid nanomaterials in V79 cells (Chinese lung fibroblast cell line were determined by MTT assay. The genotoxic effects of Ag2S-(Meso-2,3-Dimercapto Succinic acid were evaluated by the alkaline single cell gel electrophoresis. The cells were treated with Ag2S-(Meso-2,3-Dimercapto Succinic acid at the concentrations of 5- 2000 µg/ml. No cytotoxic effect of Ag2S-(Meso-2,3-Dimercapto Succinic acid at all concentrations studied was observed. No significant increases in DNA damage were found at the studied concentrations when compared to negative control in V79 cells. In conclusion, further in vitro and in vivo studies are required to determine the safety doses of Ag2S-(Meso-2,3-Dimercapto Succinic acid.

  6. Hidrolisis enzimatica del acido pectico con una endopoligalacturonasa de levadura: Cinetica y distribucion de masas moleculares

    Serrat-Diaz, Manuel; Dume-Arias, Richard A; Del-Todo-Martinez, Yuniesky; Rodriguez-Gamez, Odalys; Almenares-Verdecia, Juan F; Machado-Garcia, Roberto G


    .... En este trabajo se presenta la cinetica de la hidrolisis enzimatica del acido pectico con una endopoligalacturonasa de levadura, asi como la caracterizacion de la distribucion de masas moleculares en el hidrolizado...

  7. Concentraciones de acido urico e hiperuricemia en pacientes con hipertension arterial sistemica

    Lopez-Rosado, Ivonne; Luz-Araujo, Hedy; Guerra-Velasquez, Mery; Reyna-Villasmil, Eduardo; Mejia Montilla, Jorly; Reyna-Villasmil, Nadia; Torres-Cepeda, Duly


    El objetivo de la investigacion fue relacionar las concentraciones de acido urico y la presencia de hiperuricemia con la presion arterial en pacientes con diagnostico de hipertension arterial sistemica...

  8. Prebiotic Polymerization: Oxidative Polymerization of 2,3 Dimercapto-1- Propanol on the Surface of Iron(III) Hydroxide Oxide

    Weber, Arthur L.


    The oxidation of 2,3-dimercapto-1-propanol by ferric ions on the surface of iron(III) hydroxide oxide (Fe(OH)O) yielded polydisulfide oligomers. This polymerization occurred readily at low dithiol concentration under mild aqueous conditions. Polydisulfide polymers up to the 15-mer were synthesized from 1 mM dithiol in 5 ml water reacted with iron(III) hydroxide oxide (20 mg, 160 micromole Fe) for 3 days under anaerobic conditions at 40 C and pH 4. About 91% of the dithiol was converted to short soluble oligomers and 9% to insoluble larger oligomers that were isolated with the FE(OH)O phase. Reactions carried out at the same ratio of dithiol to FE(OH)O but at higher dithiol concentrations gave higher yields of the larger insoluble oligomers. The relationship of these results to prebiotic polymer synthesis is discussed.

  9. Prebiotic polymerization: Oxidative polymerization of 2, 3-dimercapto-1-propanol on the surface of iron(III) hydroxide oxide

    Weber, Arthur L.


    The oxidation of 2, 3-dimercapto-1-propanol by ferric ions on the surface of iron(III) hydroxide oxide (Fe(OH)O) yielded polydisulfide oligomers. This polymerization occurred readily at low dithiol concentration under mild aqueous conditions. Polydisulfide polymers up to the 15-mer were synthesized from 1 mM dithiol in 5 ml water reacted with iron(III) hydroxide oxide (20 mg, 160 micromole Fe) for 3 days under anaerobic conditions at 40 C and pH 4. About 91% of the dithiol was converted to short soluble oligomers and 9% to insoluble larger oligomers that were isolated with the Fe(OH)O phase. Reactions carried out at the same ratio of dithiol to Fe(OH)O but at higher dithiol concentrations gave higher yields of the larger insoluble oligomers. The relationship of these results to prebiotic polymer synthesis is discussed.

  10. Topical efficacy of dimercapto-chelating agents against lewisite-induced skin lesions in SKH-1 hairless mice

    Mouret, Stéphane, E-mail: [Département de Toxicologie et Risques Chimiques, Institut de Recherche Biomédicale des Armées, Centre de Recherches du Service de Santé des Armées, 24 avenue Maquis du Grésivaudan, 38700 La Tronche (France); Wartelle, Julien; Emorine, Sandy; Bertoni, Marine; Nguon, Nina; Cléry-Barraud, Cécile [Département de Toxicologie et Risques Chimiques, Institut de Recherche Biomédicale des Armées, Centre de Recherches du Service de Santé des Armées, 24 avenue Maquis du Grésivaudan, 38700 La Tronche (France); Dorandeu, Frédéric [Département de Toxicologie et Risques Chimiques, Institut de Recherche Biomédicale des Armées, Centre de Recherches du Service de Santé des Armées, 24 avenue Maquis du Grésivaudan, 38700 La Tronche (France); Ecole du Val-de-Grâce, 1 place Alphonse Laveran, Paris (France); Boudry, Isabelle [Département de Toxicologie et Risques Chimiques, Institut de Recherche Biomédicale des Armées, Centre de Recherches du Service de Santé des Armées, 24 avenue Maquis du Grésivaudan, 38700 La Tronche (France)


    Lewisite is a potent chemical warfare arsenical vesicant that can cause severe skin lesions. Today, lewisite exposure remains possible during demilitarization of old ammunitions and as a result of deliberate use. Although its cutaneous toxicity is not fully elucidated, a specific antidote exists, the British anti-lewisite (BAL, dimercaprol) but it is not without untoward effects. Analogs of BAL, less toxic, have been developed such as meso-2,3-dimercaptosuccinic acid (DMSA) and have been employed for the treatment of heavy metal poisoning. However, efficacy of DMSA against lewisite-induced skin lesions remains to be determined in comparison with BAL. We have thus evaluated in this study the therapeutic efficacy of BAL and DMSA in two administration modes against skin lesions induced by lewisite vapor on SKH-1 hairless mice. Our data demonstrate a strong protective efficacy of topical application of dimercapto-chelating agents in contrast to a subcutaneous administration 1 h after lewisite exposure, with attenuation of wound size, necrosis and impairment of skin barrier function. The histological evaluation also confirms the efficacy of topical application by showing that treatments were effective in reversing lewisite-induced neutrophil infiltration. This protective effect was associated with an epidermal hyperplasia. However, for all the parameters studied, BAL was more effective than DMSA in reducing lewisite-induced skin injury. Together, these findings support the use of a topical form of dimercaprol-chelating agent against lewisite-induced skin lesion within the first hour after exposure to increase the therapeutic management and that BAL, despite its side-effects, should not be abandoned. - Highlights: • Topically applied dimercapto-chelating agents reduce lewisite-induced skin damage. • One topical application of BAL or DMSA is sufficient to reverse lewisite effects. • Topical BAL is more effective than DMSA to counteract lewisite-induced skin damage.

  11. Topical efficacy of dimercapto-chelating agents against lewisite-induced skin lesions in SKH-1 hairless mice.

    Mouret, Stéphane; Wartelle, Julien; Emorine, Sandy; Bertoni, Marine; Nguon, Nina; Cléry-Barraud, Cécile; Dorandeu, Frédéric; Boudry, Isabelle


    Lewisite is a potent chemical warfare arsenical vesicant that can cause severe skin lesions. Today, lewisite exposure remains possible during demilitarization of old ammunitions and as a result of deliberate use. Although its cutaneous toxicity is not fully elucidated, a specific antidote exists, the British anti-lewisite (BAL, dimercaprol) but it is not without untoward effects. Analogs of BAL, less toxic, have been developed such as meso-2,3-dimercaptosuccinic acid (DMSA) and have been employed for the treatment of heavy metal poisoning. However, efficacy of DMSA against lewisite-induced skin lesions remains to be determined in comparison with BAL. We have thus evaluated in this study the therapeutic efficacy of BAL and DMSA in two administration modes against skin lesions induced by lewisite vapor on SKH-1 hairless mice. Our data demonstrate a strong protective efficacy of topical application of dimercapto-chelating agents in contrast to a subcutaneous administration 1h after lewisite exposure, with attenuation of wound size, necrosis and impairment of skin barrier function. The histological evaluation also confirms the efficacy of topical application by showing that treatments were effective in reversing lewisite-induced neutrophil infiltration. This protective effect was associated with an epidermal hyperplasia. However, for all the parameters studied, BAL was more effective than DMSA in reducing lewisite-induced skin injury. Together, these findings support the use of a topical form of dimercaprol-chelating agent against lewisite-induced skin lesion within the first hour after exposure to increase the therapeutic management and that BAL, despite its side-effects, should not be abandoned.

  12. Toxicity induced by Hg2+ on choline acetyltransferase activity from E. electricus (L.) electrocytes: the protective effect of 2,3 dimercapto-propanol (BAL).

    Nunes-Tavares, Nilson; Valverde, Rafael Hospodar Felippe; Araújo, Glauce Maria Nunes; Hassón-Voloch, Aida


    The effect of mercury (Hg(2+)) on the activity of choline acetyltransferase (ChAT) from electrocytes of Electrophorus electricus (L.) was studied due to the importance of this enzyme and acetylcholine in many neurochemical functions such as arousal, learning, and memory. Mercury, which has affinity to thiol groups, acted as a potent inhibitor of ChAT, which was obtained by differential centrifugation and ammonium sulfate precipitation, at 80%, from the main electric organ homogenate. Mercury inhibition presents different kinetic behaviors for both enzyme substrates: noncompetitive to choline and of mixed type to AcCoA, with inhibition constants on the order of 0.5 to 1.0 microM. The enzyme activity was recovered using 2,3 dimercapto-propanol (BAL), a well-known chelate for sulphydryl groups and metals, which acted as a protecting agent and was able to revert the Hg(2+) inhibition at a concentration of 10 (-6) M. After treatment with this metal and in the presence of 2,3 dimercapto-propanol, 70% of the enzyme activity was recovered for AcCoA and 80% for choline. The observed inhibition is likely due to direct protein interaction, because the addition of BAL reversed the effects of HgCl(2) on ChAT activity. The results cast new light on the mechanisms of mercurial neurotoxicity.

  13. Poly(2,5-dimercapto-1,3,4-thiadiazole) as a Cathode for Rechargeable Lithium Batteries with Dramatically Improved Performance

    Gao, Jie


    Organosulfur compounds with multiple thiol groups are promising for high gravimetric energy density electrochemical energy storage. We have synthesized a poly(2,5-dimercapto-1,3,4-thiadiazole) (PDMcT)/poly(3,4-ethylenedioxythiophene) (PEDOT) composite cathode for lithium-ion batteries with a new method and investigated its electrochemical behavior by charge/discharge cycles and cyclic voltammetry (CV) in an ether-based electrolyte. Based on a comparison of the electrochemical performance with a carbonate-based electrolyte, we found a much higher discharge capacity, but also a very attractive cycling performance of PDMcT by using a tetra(ethylene glycol) dimethyl ether (TEGDME)-based electrolyte. The first discharge capacity of the as-synthesized PDMcT/PEDOT composite approached 210 mAh g -1 in the TEGDME-based electrolyte. CV results clearly show that the redox reactions of PDMcT are highly reversible in this TEGDME-based electrolyte. The reversible capacity remained around 120 mAh g -1 after 20 charge/discharge cycles. With improved cycling performance and very low cost, PDMcT could become a very promising cathode material when combined with a TEGDME-based electrolyte. The poor capacity in the carbonate-based electrolyte is a consequence of the irreversible reaction of the DMcT monomer and dimer with the solvent, emphasizing the importance of electrolyte chemistry when studying molecular-based battery materials. The nature of the electrolyte has a dramatic effect on the performance of poly(2,5-dimercapto-1,3,4-thiadiazole) (PDMcT) as a cathode material in lithium-ion batteries. Whereas the use of an ethylene/diethyl carbonate (EC/DEC)-based electrolyte resulted in very poor performance, the use of a tetra(ethylene glycol) dimethyl ether (TEGDME)-based electrolyte dramatically improved the performance in terms of both the discharge capacity and capacity retention (see scheme). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Extração/pré-concentração de íons cobre no ponto nuvem explorando a formação de complexos com DMIT [4,5-dimercapto-1,3-ditiol-2-tionato


    The present study proposes a method for cloud point preconcentration of copper ions at pH 2.0 based on complexes formed with [4,5-dimercapto-1,3-dithyol-2-thionate] and subsequent determination by flame atomic absorption spectrometry (FAAS). Under optimal analytical conditions, the method provided limits of detection of 0.84 and 0.45 µg L-1, by preconcentrating 12.0 and 24.0 mL of sample, respectively. The method was applied for copper determination in water samples, synthetic saliva, guarana...

  15. Some Biochemical Properties of an Acido-Thermophilic Archae-Bacterium Sulfolobus Acidocaldarius

    Oshima, Tairo; Ohba, Masayuki; Wagaki, Takayoshi


    To elucidate the phylogenic status of archaebacteria, some basic cellular components of an acido-thermophilic archaebacterium,Sulfolobus acidocaldarius, were studied. Poly(A) containing RNA was present in the cells, and performed the role of mRNA in a cell-free extract of reticulocyte or the archaebacteria. Poly(A) containing RNA was also found in other archaebacterial cells. The absence of cap structure was suggested in these RNAs. The cell-free protein synthesis using the archaebacterial extract was inhibited by anisomycin, a specific inhibitor for eukaryotic ribosomes. Two unique membrane-bound ATPases were detected. Based on resistance to H+-ATPase inhibitors, these enzymes seemed not to be F0F1-ATPase.

  16. Extração/pré-concentração de íons cobre no ponto nuvem explorando a formação de complexos com DMIT [4,5-dimercapto-1,3-ditiol-2-tionato

    Bruna Fabrin Somera


    Full Text Available The present study proposes a method for cloud point preconcentration of copper ions at pH 2.0 based on complexes formed with [4,5-dimercapto-1,3-dithyol-2-thionate] and subsequent determination by flame atomic absorption spectrometry (FAAS. Under optimal analytical conditions, the method provided limits of detection of 0.84 and 0.45 µg L-1, by preconcentrating 12.0 and 24.0 mL of sample, respectively. The method was applied for copper determination in water samples, synthetic saliva, guarana powder, tea samples and soft drinks and the accuracy was assessed by analyzing the certified reference materials Dogfish Liver (DOLT-4 and Lobster Hepatopancreas (TORT-2.

  17. Trastornos acido base en una unidad de cuidados intensivos pediátrica de Bogotá

    Vásquez Hoyos, Pablo


    Objetivo: Describir la frecuencia de presentación de los trastornos acido base en una unidad de cuidado intensivo pediátrico de la ciudad de Bogotá utilizando 3 métodos de análisis ampliamente reconocidos. Población: Pacientes pediátricos hospitalizados entre febrero y abril de 2001, por más de 24 horas en la unidad de cuidado intensivo del hospital entre el periodo a estudio. Método: Se recoge de manera sistemática prospectiva todo paciente que ingresa a la unidad, se hacen laboratorios de i...


    Raisa NASTAS


    Full Text Available Au fost precizate unele aspecte metodologice ale tehnicilor de titrare vizuală (metoda Boehm şi electrometrică (titrări alcalimetrice şi acidimetrice pentru stabilirea proprietăţilor acido-bazice ale adsorbanţilor carbonici. Pe suprafaţa cărbunilor activi obţinuţi prin metoda fizico-chimică predomină grupările funcţionale bazice, pentru determinarea conţi­nutului lor fiind recomandată metoda titrării conductometrice acidimetrice. De rând cu grupările bazice, pe suprafaţa acestor cărbuni există şi grupări funcţionale acide, pentru determinarea lor fiind recomandată metoda titrării pH-metrice indirecte. Pe suprafaţa cărbunilor activi obţinuţi prin metoda chimică predomină grupările funcţionale acide, pentru de­ter­­minarea conţinutului lor fiind recomandă metoda titrării conductometrice alcalimetrice. Pentru determinarea grupări­lor bazice pe suprafaţa acestor cărbuni se recomandă metoda titrării pH-metrice indirecte.EVALUATION OF ACTIVE CARBONS ACID-BASIC PROPERTIESThe methodological peculiarities of visual titration method (Boehm method and electrometric (alkalimetric and acidimetric titrations for researching of acid-basic properties of carbonaceous adsorbents have been specified. On the surface of active carbons obtained by physical-chemical method of activation the basic sites predominate being recom­mended acidimetric conductometric titration for their determination. Besides of such groups there are also acidic sites being recommended alkalimetric pH-metric back titration for their determination. On the surface of active carbons obtained by chemical activation the acidic groups predominate being recommended alkalimetric conductometric titration for their determination. Besides of such groups there are also basic sites being recommended acidimetric pH-metric back titration for their determination.

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

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


    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.

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

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


    study the variation in the thermoelectric properties by a simple acido-basic treatment. The emphasis of this study is to elucidate the chemical changes induced by acid (HCl) or base (NaOH) treatment in PEDOT-Tos thin films using various spectroscopic and structural techniques. We could identify changes...... 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...

  1. Peracetic acid as disinfectant of municipal wastewaters; L'acido peracetico nella disinfezione dei reflui urbani

    Funari, E. [Istituto Superiore di Sanita' , Laboratorio di Igiene Ambientale, Reparto di Medicina Ambientale, Rome (Italy); Lopez, A. [Consiglio Nazionale delle Ricerche, Istituto di Ricerca sulle Acque, Reparto di Chimica e Tecnologia delle Acque, Bari (Italy)


    Based on the currently available literature, this paper is aimed at providing a sort of the <> on the use of peracetic acid (C{sub 3}COOOH{identical_to} Paa) as disinfectant of biologically treated municipal wastewater: the growing interest for this substance, used since many years in other sectors (e.g., food-industry, breweries, etc.) is mainly due to the claimed limited formation, if any, of harmful disinfecting by-products (Dbp) with consequent lack of toxicity in Paa treated wastewaters. Such features are just the opposite of those of chlorine, i.e. the most used disinfectant for municipal wastewater. During chlorine-disinfecting, in fact, numerous harmful organo-chlorinated Dbp are formed and, accordingly, the toxicity of chlorinated effluents results very high. In spite of the above reported <> properties of Paa, its use at large scale facilities is still restricted and this not only because of its costs but even for the limited knowledge concerning: the actual disinfecting effectiveness towards different pathogens, the nature and the toxicological properties of its potential Dbp, and the disinfecting performances at large scale facilities. The present paper, besides reporting an extensive and useful collection of references concerning Paa, provides a critical review on the current knowledge regarding specific Paa features such as: its disinfecting effectiveness towards different pathogenic micro-organisms, the nature and the toxicity of its disinfecting by-products, the environmental impact of Paa treated effluents, and the operative conditions used at large scale wastewater treatment plants. [Italian] Il presente lavoro, basandosi sui dati disponibili in letteratura, si propone di fare il punto sull'impiego dell'acido peracetico (CH{sub 3}COOOH{identical_to} PAA) come disinfettante di reflui urbani depurati. Il crescente interesse nei confronti di questa sostenza, gia' nota come disinfettante in

  2. Wastewater disinfection with peracetic acid and UV; La disinfezione di acque reflue con acido peracetico e raggi ultravioletti

    Caretti, C.; Lubello, C. [Florence Univ., Florence (Italy). Dipt. di Ingegneria Civile


    Was investigated the synergy between UV and peracetic acid (PAA) through a five months on-site experimental study in a pilot plant fed by the secondary effluent of the central wastewater treatment plant of Pistoia, Italy. This experiment is a part of a larger research project on advanced treatment for municipal wastewater reuse in agriculture. Because of Italy's strict limits on unrestricted wastewater reuse in agriculture (2 CFU total coliform/100 ml), a very high degree of disinfection is necessary. In the investigated experimental conditions, it has been impossible to meet such values through an exclusive use of UV irradiation (the UV unit reaches at most 4 Log inactivation). Low levels of PAA greatly enhance the decline of indicator levels, but higher unsustainable doses are required to hit the Italian limit. Through a poor amount of information on the subject was available in literature, it was tried to find out how the disinfection efficiency could improve by simultaneously using UV and PAA. It was found out that a combined treatment is satisfactory and that it is more advantage of the hydroxyl radicals formation due to the PAA photo lysis. The application of 2 ppm of PAA with an UV dose of 192 mWscm{sup -}2 is enough to meet the Italian limit. [Italian] Nel presente articolo si riportano i risultati di uno studio sulla sinergia tra acido peracetico (PAA) e raggi ultravioletti nella disinfezione delle acque reflue secondarie; le prove sono state effettuate su scala pilota, presso l'impianto centrale di Pistoia. Tale sperimentazione fa parte di un piu' ampio progetto di ricerca sulla possibilita' di riutilizzare le acque reflue a scopo irriguo; per rispettare i limiti estremamente stringenti imposti dalla normativa italiana per l'irrigazione (2 CFU Coliformi totali/100 ml, nel caso di irrigazione illimitata), e' necessario garantire efficienze di disinfezione molto elevate. Nelle condizioni sperimentali considerate, non e




    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.


    William H.J. Strosnider


    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.

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

    Arenas-Martinez, L.F [Universidad Autonoma de Coahuila, Coahuila (Mexico)]. E-mail:; Garcia-Cerecero, G. [Corporacion Mexicana de Investigacion en Materiales S.A. de C.V., Saltillo, Coahuila (Mexico)]. E-mail:


    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.

  6. Evaluation of DMIT [4,5-Dimercapto-1,3-Dithyol-2-Thionate] as chelating agent in a cloud point extraction procedure for Pb2+ determination in water samples - doi: 10.4025/actascitechnol.v35i2.18076

    Naiara Vieira Godoy


    Full Text Available The present study proposes a new method for cloud point preconcentration of Pb2+ ions based on complex formed with [4,5-dimercapto-1,3-dithyol-2-thionate] and posterior determination by flame atomic absorption spectrometry (FAAS. The preconcentration of Pb2+ was carried at pH 5.0 under following conditions: time and temperature of batch at 15 min. and 70oC, respectively, 0.1% (v/v Triton X-114, 0.003 mol L-1 acetate/acetic acid buffer solution, 1.0 x 10-5 mol L-1 DMIT and 0.5% (m/v NaCl. Under the best analytical conditions the method provided a limit of detection of 2.85 mg L-1 by preconcentrating 10.0 mL of sample and calibration curve ranging from 0 up to 650 mg L-1 (r = 0.99945. The applicability of proposed method for Pb2+ determination in natural waters without interferences was checked through addition/recovery tests.  

  7. The use of peracetic acid in drinking water systems: flow tests; L'acido peracetico in potabilizzazione: prove in flusso

    Ragazzo, P. [Consorzio per l' Acquedotto del Basso Piave, San Dona' di Piave, VE (Italy); Navazio, G. [Padua Univ., Padua (Italy). Dipt. dei Processi Chimici dell' Ingegneria; Cavadone, A. [Solvay Chimica Italia S.p.A., Milan (Italy)


    In a previous research, a preliminary study was carried out on the disinfection efficiency of peracetic acid (PAA), comparing it to that of other disinfectants that are typically used, in batch tests with dosage values ranging from 0.5 to 5 ppm. The study was carried out on samples of water collected from several significant points of the treatment process at the main water treatment plant in Jesolo (Venice, Italy). On the basis of results (basically positive at that time) obtained from these tests, a 400 litre/hour pilot plant was built, as a lower scale reproduction of the drink water treatment system mentioned earlier, in order to study the characteristics of PAA even in tests that could more realistically simulate the flow of water along the process. These tests essentially confirmed the kinetics of the spontaneous hydrolysis to CH{sub 3} COOH+H{sub 2}O{sub 2} and those of dismutation to CH{sub 3}COOH+O{sub 2}, with half-life time values ranging from 3 to 12 hours, depending on the characteristics of the water (especially the pH factor) and the PAA concentration values. [Italian] In un precedente lavoro e' stato effettuato un preventivo studio sull'efficienza disinfettiva dell'acido peracetico, anche in confronto con gli altri piu' usuali disinfettanti, in prove condotte in batch, con dosaggi compresi tra 0.5 e 5 ppm, su campioni di acqua prelevati dai diversi punti significativi della linea di trattamento della centrale di Jesolo (Torre Caligo), gestita dal Consorzio Acquedottistico del Basso Piave di S. Dona' di Piave (Venezia). Sulla base dei risultati, sostanzialmente positivi, e' stato costruito un impianto pilota da 400l/h, riproducente, in scala, la linea di potabilizzazione su ricordata, per studiare le caratteristiche del PAA anche in prove piu' probanti condotte in flusso. In tali prove sono state sostanzialmente riconfermate le cinetiche delle reazioni spontanee di dirolisi a CH{sub 3}COOH+H{sub 2}O{sub 2} e di

  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

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


    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.

    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:


    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

    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:


    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. 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

    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:


    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




    Full Text Available Las bacterias ácido lácticas han sido importantes en los alimentos por siglos por su considerable contribución al valor de los productos. Debido a varias de sus propiedades metabólicas, las bacterias ácido lácticas desempeñan un papel importante en la industria alimentaria, por su contribución significante al sabor, olor, textura, características sensoriales, propiedades terapéuticas y valor nutricional de los productos alimentarios. Este grupo está compuesto de un número de géneros incluyendo Lactococcus, Lactobacillus, Enterococcus, Streptococcus, Leuconostoc y Pediococcus. Algunos de los metabolitos producidos por las este tipo de bacterias son ácidos orgánicos, sustancias preservantes, polisacáridos, vitaminas, endulzantes, olores y sabores entre otros. Esta revisión se enfoca en estudiar la importancia de las bacterias acido lácticas en los alimentos.As bacterias ácido lácticas têm sido importantes nos alimentos por séculos pela sua considerável contribuição ao valor dos produtos. Devido a varias das suas propriedades metabóllcas, as bacterias ácido lácticas desempenham um papel importante na industria alimentar, pela sua contribulção significante ao sabor, cheiro, textura, características sensoriais, propriedades terapêuticas e valor nutrlcional dos produtos alimentar. Este grupo está constituido de um número de gêneros incluindo Lactococcus, Lactobaclllus, Enterococcus, Etreptococcus, Leuconostoc e Pediococcus. Alguns dos metabolltos produzidos por este tipo de bacterias são ácidos orgãnicos, sustãncias preservadoras, poli-sacáridos, vitaminas, adoçantes, cheiros e sabores entre outros. Esta revisão se enfoca em estudar a importãncia das bacterias ácido lácticas nos alimentos.Lactic acid bacteria have been important in food for centuries for their significant contribution to product value. Because several of its metabolic properties, lactic acid bacteria play an important role in the food

  13. Utilisation of chlorine-dioxide and peracetic acid as disinfectants of effluents from Bologna waste water treatment plant; Sperimentazione di tecniche di disinfezione mediante biossido di cloro e acido peracetico applicate alle acque reflue dell'impianto di trattamento della citta' di Bologna

    Mancini, M.L. [Bologna Univ., Bologna (Italy). Dipt. di Ingegneria delle Strutture, dei Trasporti, delle Acque, del Rilevamento e del Territorio; Sorrentino, M.


    The necessity to optimize the disinfection phase in the treatment plant of waste water of Bologna made possible an experimental survey about the efficacy of two disinfectant agents utilized: chlorine-dioxide and peracetic acid. Object of the survey is to verify the possibility of utilize, full scale, also peracetic acid as disinfection agent. The experimentation regarded the reals flows adduced and discharged from the plant and it may be an useful reference to verify performance of post-treatment constructed wetlands. Particularly it has been possible to assay the efficacy of the different treatment in waste water with residual concentrations of suspended solids. [Italian] La necessita' di ottimizzare la fase di disinfezione nell'impianto di trattamento acque reflue della citta' di Bologna, sia per il miglioramento delle rese di inattivazione, sia per la riduzione dei costi di esercizio, ha reso necessaria un'indagine sperimentale sull'efficacia di due agenti disinfettanti utilizzati: il biossido di cloro e l'acido peracetico. Scopo dell'indagine e' quello di verificare la possibilita' di impiegare, a scala reale, per il refluo tipico dell'impianto di Bologna, anche l'acido peracetico quale agente di disinfezione. La sperimentazione, condotta ha interessato le portate reali addotte e scaricate dall'impianto e puo' costituire un riferimento utile verificare la fattibilita' igienico-sanitaria di post-trattamenti di lagunaggio o fertirrigazione. In particolare si e' potuta saggiare l'efficacia dei diversi sistemi di trattamento sui reflui aventi concentrazioni residue non trascurabili di solidi sospesi.

  14. Determinación del acido abscisico en papa (Solanum sp. como respuesta a bajas temperaturas Abscisic acid determination in potato (Solanum sp. as a response to low temperature

    Ortiz Luz Yineth


    Full Text Available En Colombia, existen importantes áreas con amplio potencial
    agrícola, las cuales presentan restricciones ambientales para su utilización durante determinadas épocas del año, a causa de las heladas que provocan las bajas temperaturas. Éste es el caso del Altiplano Cundiboyasence, en el cual el fenómeno en mención afecta, drásticamente, los cultivos hasta ocasionar disminución del rendimiento o perdidas totales. El presente trabajo tuvo como finalidad detectar la presencia de Acido Abscísico (ABA en las siguientes variedades de papa de la especie Solanum sp.: 'Capiro', 'Única', 'Chitagá', 'Morita', 'Pastusa', 'ICA-Zipa' y 'Nativa' (silvestre. El análisis se hizo en el estadio de prefloración bajo condiciones de temperatura ambiente (-20°C y expuestas a una simulación de helada (-4°C. Para la extracción de ABA, se recolectaron hojas del tercio superior de la planta y se sometieron a extracción Líquido-Líquido y, para su cuantificación, se utilizó el bioensayo de la inhibición del coleóptilo de trigo (Triticun tensa vulgare L., el cual se realizó por cromatografía de capa fina. Entre las variedades estudiadas, se obtuvieron dos grupos de respuesta: susceptibles y tolerantes, las cuales están asociadas con la posible ausencia o presencia de ABA. En las variedades 'ICA-Zipa' y 'Chitagá' no se detectó la presencia de ABA, como tampoco, se observó tolerancia a las bajas temperaturas. En las variedades 'Capiro', 'Pastusa', 'Nativa', 'Única' y 'Morita', se observó mayor tolerancia a las bajas temperaturas.
    There are many important geographical areas in Colombia with a high agricultural potential. They have environmental
    constrains, however, to be used in certain periods during the
    year because of the low temperature. This happens in the
    Cundiboyasence plateau, in which, this phenomenon affects
    dramatically the growing of potato crops up to the point of
    causing a decrease in production or

  15. Acido vainillin mandelico, disonancia cognoscitiva y autoevaluacion

    Angel Rodriguez Kauth


    Full Text Available An. esperíment waa performed in arder to ltudy the rdationlhip among cogititive dillOnance. lelf-evaluation. and excretiOft of VáinllUn liJandelicadd. Subjetetl were 90 Itudentl with no training in lOdal pl Cho- 1081. A lICIl1eof Idf·evahiation wu applled. and IUbjecu placed in grou~ according to higb. medium or lowlCOreI. A IIgnificant difference wu found: IUbjectl with hígher ICOreI in Idf-evaluation ae:ted lO lOive the cognitive dissonance, and had differcntial excretion rates in the acid.

  16. Genotoxicity of meso-2,3-dimercapto succinic acid-coated silver sulfide quantum dot

    Deniz Özkan Vardar; ibrahim Hacıoğlu; Sevtap Aydin; Funda Yağcı


    Nanotecnology products have been used in wide applications in chemistry, electronics, energy generation, and medicine. Despite significant interest in developing quantum dots (QDs) for biomedical applications, many researchers are convinced that QDs will never be used for the treatment of patients because of their potential toxicity. In various in vitro cell culture studies, the cytotoxic properties of some QD have been demonstrated and they have been suggested to be toxic in humans. In this ...

  17. Registro Nazionale Malattie Rare: malformazioni congenite e acido folico

    Pierini, Anna; Bianchi, Fabrizio; Salerno, Paolo; Taruscio, Domenica


    It is estimated that in Italy at least 3% of babies are born with some congenital malformation. Scientific evidence demonstrates that the intake of folic acid by a woman prior the conception and during the early stages of pregnancy plays a role in preventing neural tube defects and severe birth anomalies due to the lack of neural tube closure at either the upper or lower end during the third and fourth week of pregnancy. The intake of folic acid during the periconception period can reduce the...

  18. Acidos y ésteres diterpenicos de Mikania banisteriae

    Cecilia Espitia de Pérez


    Full Text Available De la fracción soluble en diclorometano, del extracto etanólico de la parte aérea de Mikania banisteriae se aislaron y purificaron por métodos cromatográficos cinco compuestos cuyas estructuras fueron determinadas por métodos espectroscópicos. Las estructuras aisladas corresponden a los ácidos kaurénico y grandiflórico y a tres esteres: benzoato, cinamato e isobutirato del ácido grandiflórico. Estos resultados contrastan con los obtenidos previamente para la misma especie, procedente de diferente zona geográfica, de la cual se aislaron otros diterpenos derivados del kaurano.

  19. Diabetic acido-ketosis revealing thiamine-responsive megaloblastic anemia.

    Bouyahia, O; Ouderni, M; Ben Mansour, F; Matoussi, N; Khaldi, F


    Thiamine-responsive megaloblastic anemia (TRMA) is a rare autosomal recessive disorder characterized by megaloblastic anemia, diabetes mellitus and progressive sensorineural deafness. We report the cases of two infants, aged 4 and 5 months, hospitalized for diabetic ketoacidosis requiring insulin therapy. Laboratory tests revealed megaloblasic anemia, thrombocytopenia and normal thiamine level. Neurosensorial investigations showed bilateral deafness and ophthalmic involvement. Treatment with oral thiamine normalized hematological disorders and controlled diabetes; however, thiamine therapy had no impact on neurosensorial disorders.

  20. Acidos graso de Prochilodus lineatus (Val.) (Pisces, Curimatidae)

    Bayo, V.; Cordiviola de Yuan, E.


    Les acides gras des dépots graisseux du mésenlère de #Prochilodus lineatus$ ont été analysés pour saisons (été et hiver). Les poissons étudiés ont été capturés dans le cours principal du Parana moyen (Argentine). Les acides les plus importants sont l'acide oléique (18:1) avec 27,15%, l'acide palmitique (16:6) avec 23,99% et l'acide palmitoleique (16:1) avec 13,90%. Ces acides sont plus abondants en hiver. Les acides supérieurs (en carbone et en insaturation) sont moins abondants en hiver (16,...




    Full Text Available The use of antibiotics to treat bovine mastitis, produces antibiotic residues in milk and decreased quality of dairy products. Lactic acid bacteria have been proposed as an alternative to avoid the use of antibiotics. This paper reports the antimicrobial activity against pathogens responsible of bovine mastitis, of 4 lactic acid strains isolated from cattle in a state of acidosis ruminal. It also evaluated the specific growth rate (m and antimicrobial activity of one of the strains, using two concentrations of carbon source (20 and 60 gl-1 in the commercial substrate MRS. The strains were biochemically identified as Lactobacillus acidophilus, Lactobacillus brevis, Lactobacillus fermen-tum and Weissella confusa. Weissella confusa showed the best antimicrobial activity against the major pathogens responsible of bovine mastitis. When has been used 60 gl-1 of total sugars in the fermentation substrate, was obtained diameter of inhibition of 31 mm for Staphylococcus aureus and 36 mm for Streptococcus agalactiae. The antimicrobial activity of Weissella confusa is superior antimicrobial activity reported by many other lactic acid bacteria, therefore Weissella confusa could potentially be used to prevent bovine mastitis.El uso de antibióticos para el tratamiento de mastitis bovina, genera residuos de antibióticos en la leche y disminuye la calidad de los subproductos lácteos. Las bacterias ácido lácticas se han propuesto como una alternativa para evitar el uso de antibióticos. En este artículo se reporta la actividad antimicrobiana contra patógenos productores de mastitis bovina, de 4 cepas acido lácticas aisladas de bovinos en estado de acidosis ruminal. Se evaluó además la velocidad especifica de crecimiento (m y la actividad antimicrobiana de una de las cepas, utilizando dos concentraciones de fuente de carbono (20 y 60 gl-1 en el sustrato comercial MRS. Las cepas se identificaron bioquímicamente como Lactobacillus acidophilus

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

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


    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.

  3. Proteine chiave dei processi metabolici indotti dall’acido indolo-3-acetico (IAA) in Rizobio


    I batteri del suolo gram-negativi dei generi Rhizobium, Bradyrhizobium, Azorhizobium, Mesorhizobium e Sinorhizobium, collettivamente chiamati rizobi, sono microrganismi azotofissatori simbionti delle radici delle Leguminose. Nel processo di simbiosi i rizobi inducono la divisione cellulare delle cellule corticali della radice con la formazione dei cosiddetti noduli radicali, all’interno dei quali i batteroidi, ossia i batteri differenziati, riducono l’azoto atmosferico ad ammonio (P. van Rhij...




    Diariamente, las industrias textiles descargan grandes volúmenes de aguas que contienen altas concentraciones de colorantes y aditivos, los cuales ocasionan daños considerables al medio ambiente. Muchos de estos colorantes son estables a la luz y a la biodegradación, siendo considerados como compuestos orgánicos persistentes (COPs). Es por esto que es necesario aplicar métodos que permitan la eliminación de estos contaminantes desde las aguas. Una metodología efectiva para la eliminación de C...




    En el presente trabajo de tesis se ha estudiado la enzima ácido acetohidroxi sintasa (AHAS), mediante el uso de métodos químico-computacionales, como dinámica molecular y QM/MM, fundamentalmente. La AHAS es una enzima que participa en la biosintesis de aminoácidos de cadena ramificada (valina, leucina e isoleucina) en plantas, hongos y bacteria. Por lo cual, esta enzima ha sido considerada como el principal blanco de acción de herbicidas.




    En el presente trabajo de tesis se ha estudiado la enzima ácido acetohidroxi sintasa (AHAS) , mediante el uso de métodos químico-computacionales, como dinámica molecular y QM/ MM, fundamentalmente. La AHAS es una enzima que participa en la biosíntesis de aminoácidos de cadena ramificada (valina, leucina e isoleucina) en plantas, hongos y bacteria. Por lo cual, esta enzima ha sido considerada como el principal blanco de acción de herbicidas. En el presente trabajo de tesis se ha...

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

    Garcia de Pineda, M. de


    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.

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

    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:


    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)

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

    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:; Simone, Carlos Alberto de [Universidade Federal do Alagoas (UFAL), Maceio, AL (Brazil). Inst. de Quimica e Biotecnologia


    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)

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

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


    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.

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

    Delgado, Guillermo; Estañol, Bruno


    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".

  12. Hidrolisis enzimatica del acido pectico con una endopoligalacturonasa de levadura: Cinetica y distribucion de masas moleculares

    Serrat-Diaz, Manuel; Dume-Arias, Richard A; Del-Todo-Martinez, Yuniesky; Rodriguez-Gamez, Odalys; Almenares-Verdecia, Juan F; Machado-Garcia, Roberto G


    Los oligogalacturonidos se erigen como prometedoras biomoleculas para uso agricola, en la biotecnologia vegetal y en la elaboracion de alimentos funcionales, debido a su potente y diversa actividad...

  13. Equilibrio de fases de sistemas compostos por oleos vegetais, acidos graxos e etanol hidratado.

    Cintia Bernardo Gonçalves


    Resumo: Este trabalho de tese de doutoramento teve como objetivo avaliar vários aspectos do processo de extração líquido-líquido (ELL) como uma rota alternativa para a desacidificação de óleos vegetais. O conhecimento do equilíbrio de fases do sistema de interesse é essencial para o bom planejamento e desenvolvimento do processo de ELL. O presente trabalho apresenta dados de equilíbrio para sistemas compostos por óleos vegetais (milho/palma), ácidos graxos (oléico/ palmítico) e solvente (etan...

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

    Quenia dos Santos


    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.

  15. Uso del acido etilendiaminotetraacetico para evaluar la biodisponibilidad de metales pesados en lechuga

    Cordero, Y; Guridi, F


    ...) en la extraccion de metales pesados en un suelo contaminado por residuos industriales liquidos. Para ello, se estudiaron dos disoluciones de EDTA a concentraciones de 0.025 y 0.05 mol [L.sup.-1...




    Los ácidos grasos poliinsaturados de cadena larga n-3 (AGPICL) son nutrientes esenciales que tienen una función anti-inflamatoria y disminuyen el riesgo de enfermedad cardiovascular. Esta tesis examina el efecto de AGPICL n-3 comparado los AG saturados sobre la expresión de los principales efectores moleculares que están involucrados en los procesos aterogénicos previo al desarrollo de la arteriosclerosis como enfermedad. 48 ratones machos C57BL/6 (12 semanas de edad) fueron asignados e...


    Álvarez F., Pedro P.; Centro Nacional de Control de Calidad, Instituto Nacional de Salud (Perú).; Santiago Ch., Carlos A.; Centro Nacional de Alimentación y Nutrición, Instituto Nacional de Salud (Perú).


    En el verano del 2003 se produjo un fenómeno calificado como «marea roja» en un espejo de agua de los Pantanos de Villa de Lima, Perú. Con el objetivo de explicar el posible incremento de muerte de aves acuáticas, se analizó el agua en busca de la biotoxina ácido domoico. Se obtuvo una muestra de agua de color rojo y se analizó para ácido domoico por cromatografía líquida de alta performance (HPLC). El equipo empleado fue un cromatógrafo Shimadzu modelo LC-10A, con inyector automático y detec...

  18. Aislamiento y rendimiento del GMP mediante precipitacion de lactosuero con acido tricloroacetico

    Rojas V., Evelin; Valbuena C., Emiro; Torres F., Gabriel; Garcia de H., Aiza; Pinero G., Maria; Galindo A., Luz Mila


    ...) que se libera al lactosuero. El GMP presenta una estructura quimica particular donde predominan los aminoacidos con cadena lateral ramificada, no presenta aminoacidos aromaticos y contiene carbohidratos unidos a residuos de treonina...

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

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


    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)

  20. Cementation of wastes with boric acid; Cimentacao de rejeitos contendo acido borico

    Tello, Cledola C.O.; Haucz, Maria Judite A. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil); Alves, Lilian J.L.; Oliveira, Arno H. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear


    In nuclear power plants (PWR) are generated wastes, such as concentrate, which comes from the evaporation of liquid radioactive wastes, and spent resins. Both have boron in their composition. The cementation process is one of the options to solidify these wastes, but the boron has a negative effect on the setting of the cement mixture. In this paper are presented the experiments that are being carried out in order to overcome this problem and also to improve the efficiency of the process. Simulated wastes were cemented using additives (clays, admixtures etc.). In the process and product is being evaluated the effect of the amount, type and addition order of the materials. The mixtures were selected in accordance with their workability and incorporated waste. The solidified products are monolithic without free water with a good mechanical resistance. (author)

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

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


    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.

  2. Valutazione farmacoeconomica della prevenzione con picotamide vs acido acetilsalicilico dei pazienti diabetici con vasculopatia periferica

    Sergio Iannazzo


    Full Text Available Type 2 diabetes mellitus (DM and peripheral arterial disease (PAD are two very relevant cardiovascular (CV risk factors, which can often be found concurrently in the same patient. The DAVID trial, a double-blind, randomized, aspirin(ASA-controlled study, has demonstrated that the use of picotamide, a thromboxane A2 synthase and receptor dual inhibitor, is associated with lesser CV morbidity and mortality in this type of patients in comparison to ASA, considered the standard antiplatelet agent. In order to estimate clinical and economic impacts of picotamide in the Italian health care setting, we developed a pharmacoeconomic model based on clinical data from DAVID and national economic parameters and demographics. The base case scenario, which reflects current prices and reimbursement policy (i.e. ASA fully paid for, picotamide out-of-pocket for patients yielded an incremental cost/effectiveness ratio (ICER of about 8,500 euro/year of life (YOL saved, which falls below conventionally adopted willingness to pay thresholds. This cost, however, is totally born by the patient, while the savings on health care expenditures for avoided events (and less ASA benefit the national health service (NHS. These results may help the physician in explaining the consequences of this choice to his/her patients, facilitating a fully-informed choice. The availability of a theoretical model allowed to explore some alternative scenarios, that indicate that the ICER can be further lowered and the economical burden better distributed through policy changes. In conclusion, the pharmacoeconomic model indicated that picotamide is likely to be a cost/effective option for CV mortality and morbidity prevention in patients with concurrent type 2 DM and PAD and that the level of adoption of this strategy will depend on willingness to pay and policy priorities of the NHS and patients themselves.

  3. Controle eletroquimico de acido humico e algas usando um reator com eletrodo de filme de diamante

    Andrea Alexandra Junior


    Resumo: A presença de ácidos húmico e o crescimento de algas em água de abastecimento e de piscinas geram subprodutos que são prejudiciais à saúde. Para controlar a concentração de ácidos húmico e algas, este trabalho apresenta um processo de eletro-oxidação usando anodos de diamante dopado com boro (DDB). Neste tratamento, a solução aquosa é percolada através de um reator tipo filtro-prensa, com anodo de DDB polarizado a corrente constante. Para caracterizar a eficiência do tratamento, foram...

  4. Acido, ergo sum: Holger Hydén – the neuroscientist in Cortázar's Hopscotch Acido, ergo sum: Holger Hydén – o neurocientista em O Jogo da Amarelinha, de Cortázar

    Guillermo Delgado


    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”.O autor italiano de ficção Morelli atua, no romance “Jogo da Amarelinha” (1963, como o alter ego de Julio Cortázar. Este personagem propõe uma hipótese literária sem originalidade no capítulo 62. Há uma alusão a um sueco em particular que “está trabalhando em uma teoria química do pensamento”. O neurocientista sueco em questão é Holger Hydén (1917-2000, então professor e diretor do Departamento de Histologia da Universidade de Gotemburgo. Hydén, que foi o primeiro no uso de métodos para a microdissecção de neurônios individuais, é mencionado por Morelli devido a sua participação em um simpósio realizado em São Francisco, no final de janeiro de 1961. Seu trabalho pioneiro nunca será esquecido completamente porque seu legado neurocientífico vive e vai viver em “Jogo da Amarelinha”, de Cortázar.

  5. Acid—base behavior of aluminum and silicon oxides — a combination of two approaches: XPS and Lewis acido-basicity; rest potential and Brönsted acido-basicity

    Casamassima, M.; Darque-Ceretti, E.; Etcheberry, A.; Aucouturier, M.


    In the frame of an investigation on adhesion phenomena between elastomers and oxide substrates, X-ray photoelectron spectroscopy (XPS) and rest electrochemical potential measurements have been used in order to attempt a characterization of the reactivity of various oxides. The first step of the study is a definition of donor/acceptor properties for a solid surface in an interactive model such as the Lewis one. In this case, the Fermi level is an appropriate parameter. An experimental approach is developed to estimate this parameter through photoelectronical data obtained by XPS. As proposed by Mullins and Averbach in 1988 in the case of Al and Si oxides, XPS allows an estimation of the Fermi energy EF, defined as the energy difference between the Fermi level and the upper occupied valence band. A classification of EF values is obtained for different samples of aluminum and silicon oxides; the donor (acceptor) behavior increases for decreasing (increasing) EF. The second step is the validation of the EF classification obtained by XPS. A potentiometric method is used to estimate the rest potential Eo in aqueous solution. The relationship between the Eo and the solution pH is a Nernst law for a large range of pH values, which means that the system is governed by acid-base interactions in Brönsted definition in the interfacial area. When the nature of the oxide substrate is modified, the translation of the Eo versus pH line can be correlated with the EF classification obtained previously. This confirms the relationship already reported between point of zero charge and EF. It can also be considered as a validation of the idea that XPS allows the classification of EF values for those oxides.

  6. Uranium accumulation in Brassica rapa L. and effect of citric acid and humic acids as chelating agents; Acumulacion de uranio en Brassica rapa L. y efecto del acido citrico y acidos humicos como agentes quelantes

    Lopez del R, H.; Perez C, G. A.; Davila R, J. I.; Mireles G, F. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas, Zac. (Mexico); Rodriguez H, G., E-mail: [Universidad Autonoma de Zacatecas, Unidad Academica de Agronomia, Carretera Zacatecas-Guadalajara Km 15.5, Cieneguillas, Zacatecas (Mexico)


    Phyto extraction is a technique that makes use of plants for the remediation of soils contaminated with heavy metals. In this study the uranium incorporation in the Brassica rapa L. species was evaluated, in artificially contaminated inert soils with 40 mg U/kg, and the effect of adding of the natural chelating agents citric acid and humic acids in the accumulation of uranium was analyzed. Soil free of organic matter and biologically inert was obtained by controlled calcination s of natural soil. Cultures in the prepared soil consisted of five growth treatments: 1) cultivation without uranium or additives; 2) cultivation in the uranium presence; 3) cultivation with uranium and citric acid (2 g/kg); 4) cultivation with uranium and humic acids (10 g/kg); 5) uranium cultivation and combination of citric and humic acids at the same concentrations. There was no adverse effect on plant growth with the presence of uranium at the given concentration. Regarding the controls, the total biomass in the presence of uranium was slightly higher, while the addition of humic acids significantly stimulated the production of biomass with respect to the citric acid. The combined action of organic acids produced the highest amount of biomass. The efficiency of phyto extraction followed the order Humic acids (301 μg U/g) > Non-assisted (224 μg U/g) >> Citric acid + Humic acids (68 μg U/g) > Citric acid (59 μg U/g). The values of uranium concentration in the total biomass show that the species Brassica rapa L. has the capacity of phyto extraction of uranium in contaminated soils. The addition of humic acids increases the uranium extraction while the addition of citric acid disadvantages it. (Author)

  7. 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

    Graciela V Morales


    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.

  8. Actividad antimicrobiana del acido acetico y el cepillo Colgate 360[grados] antibacterial[R]: un estudio in vitro

    Caballero Romero, Stephanny Gissell; Sandoval, Laura Viviana Herrera; Torres Pinzon, Harold; Martinez Lopez, Carmen Alodia; Claro Numa, Andrea


    Introduccion: el cepillo dental se convierte en una fuente potencial de patogenos orales cuando no se hace un proceso de desinfeccion despues de su uso, sobre todo en pacientes con infecciones en el sistema...

  9. Nefrotoxicidade experimental por ciclosporina : efeito protetor da normalização dos niveis de acido urico

    Fernanda Cristina Mazali


    Resumo: Objetivo: Hiperuricemia é uma complicação freqüente da terapêutica com ciclosporina (CsA). Estudos anteriores demonstraram que a hiperuricemia exacerba a lesão intersticial e vascular no modelo experimental de nefrotoxicidade por CsA (CsA ntx). O presente estudo tem como hipótese que a normalização da uricemia preveniria o desenvolvimento da nefropatia crônica por CsA. Metodologia: A nefropatia crônica por CsA foi induzida em ratos machos, Sprague Dawley, através da injeção subcutânea...

  10. Nanofibras de Poli (L-Alanina-Dodecanodiol-L-Alanina-Acido Sebácico) [PADAS] elaboradas por electrospinning. Actividad antibacteriana


    El electrospinning es una técnica para producir fibras poliméricas con diámetros de entre 50- 5000 nanómetros empleando fuerzas electrostáticas. Con esta metodología se han elaborado micro y nanofibras de polímeros como poliésteres, poliamidas, poliuretanos y otros. Sin embargo, se han publicado muy pocos trabajos sobre la elaboración de nanofibras de Poliesteramidas. PADAS es una Poliesteramidas derivada de 1,12-dodecanodiol, L-alanina y ácido. Sebácico, que se obtiene con ...

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

    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:; 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)


    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)

  12. Properties of microalloyed steels used for sour gas transportation; Propiedades de aceros microaleados utilizados para el transporte de gas acido

    Saldana, E.; Castro, H.; Rodriguez, C.; Belzunce, J.


    The aim of this work was to evaluate the hydrogen induced damage on the microstructure and mechanical properties of API steels (X-52 and X-65 grades). Both steels were characterized in the as-rolled state and after being submitted to NACE TM 284/87, pH 3.5, test. Microstructure, mechanical properties and fracture behaviour have been determined along with the internal cracking due to hydrogen. The appearance of these cracks were located in reference to the geometry of the plate and the way they propagate through the steel microstructure was also assessed. (Author) 6 refs.

  13. Contribución de los Acidos Grasos Omega-3 para la Memoria y la Función Cognitiva

    Dan L. Waitzberg

    Full Text Available Una disminución de la función cognitiva y de la memoria se considera que es una consecuencia normal del envejecimiento. Los ácidos grasos omega-3 poliinsaturados son cada vez más propuestos como suplementos dietéticos con la capacidad de reducir el riesgo de deterioro cognitivo, incluyendo la enfermedad de Alzheimer (EA. Objetivo: Estudiar el efecto de los omega-3 en el deterioro cognitivo a través de la revisión de estudios recientes de observación, intervención y experimentales. Métodos: Se realizó una búsqueda en PubMed, Medline, Cochrane y Embase para los estudios epidemiológicos y clínicos en la literatura internacional que utilizan combinaciones de las siguientes palabras clave: "la enfermedad de Alzheimer", "deterioro cognitivo leve", "función cognitiva", "factores dietéticos", "ácidos grasos omega-3", "EPA y DHA". Conclusiones: Los estudios han demostrado el papel protector de los ácidos grasos omega-3 en el deterioro cognitivo leve, demencia y en el riesgo y la progresión de la enfermedad de Alzheimer en los adultos mayores. Se necesitan más estudios para comprender el mecanismo de acción de los ácidos grasos omega-3 sobre la cognición. Las dosis, la composición de cápsulas de EPA y DHA y el tiempo de suplementación deben ser explorados.

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

    Liliana Cecilia Gómez Gómez


    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.

  15. Stability constant of the lanthanum complex with humic acid; Constante de estabilidad del complejo de lantano con acido humico

    Jimenez R, M.; Solache R, M. J. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico)


    The work described here is a study on the formation of trivalent lanthanum complex with humic acid. Commercial humic acid was purified and then characterized by various analytical techniques. The stability constant determined by a radiochemical method has a worth of log {beta}{sub La},{sub AHA} = 13.6. (Author)

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

    Guillermo Delgado


    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”.

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

    Vicario, I. M.


    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.

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

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


    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.

  19. Descripción del estado acido base en pacientes con quemaduras térmicas agudas: serie de casos

    nieto angel, maria victoria; cortes puentes, luis arcadio; Linares Mendoza, Gerardo; navarrete, norberto; fernandez, federico


    Introducción: Los pacientes con lesiones térmicas presentan alteraciones fisiológicas complejas que hacen difícil la caracterización del estado ácido-base y así mismo alteraciones electrolíticas e hipoalbuminemia que pudieran estar relacionados con un peor pronóstico. Se ha estudiado la base déficit (BD) y el lactato, encontrando una gran divergencia en los resultados. Por lo anterior, el análisis físico-químico del estado ácido-base podría tener un rendimiento superior a los métodos tradic...

  20. Estudio de pacientes con aciduria glutarica tipo II, mediante la incubacion de fibroblastos con acidos palmitico y miristico tritiados

    Osorio Orozco, Jose Henry


    Introduccion: la aciduria glutarica tipo II, o deficiencia multiple de acil-CoA deshidrogenasas, es un trastorno causado por deficiencia de la flavoproteina de transferencia de electrones, de su oxidorreductasa o de ambas...

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

    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.

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

    Waldir Estela


    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.

  3. Efeitos de oxigenio singlete gerado fotoquimica e enzimaticamente sobre o acido ribonucleico de transferencia de E. coli

    Maria Cristina Marcucci


    Resumo: O malonaldeído e o ácido indol-3-acético são oxidados aerobicamente pela peroxidase, produzindo oxigênio singlete em ambos os processos, e no último caso também indol-3-aldeído excitado. Estes processos são chamados de biofotoenergizados. Entretanto, existem outras vias de geração de oxigênio singlete como processos fotoquímicos, pelo uso de sensibilizadores. Foi comprovada a similaridade entre os efeitos de oxigênio singlete gerado fotoquimica e enzimaticamenle sobre o ácido ribonucl...

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

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


    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 ...

  5. Volatile fatty acid degradation kinetics in anaerobic process; Cinetica de la degradacion de acidos grasos volatiles en procesos anaerobios

    Riscado, S.; Osuna, B.; Iza, J.; Ruiz, E. [Universidad del Pais Vasco. Bilbao (Spain)


    While searching for the optimal substrate load for anaerobic toxicity assays, the inhibition caused by the propionic acid has been addressed. Lab scale experiments have been carried out to assess the effects of different loads and acid ratios. Results bad been subjected to kinetic analysis and show the degradation follows a first order kinetic, and acetic is easier to degrade than propionic acid. The optimal load for a 100 ml vial assay is composed of 158 mg COD of the 3:1:1 HAc:HPr:HBu mixture. (Author) 9 refs.

  6. Contenidos de isomeros trans de los acidos grasos en productos carnicos (II). Tejidos adiposo y grasa intramuscular del cerdo

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


    Se presentan los resultados obtenidos en la determinación de ácidos grasos trans en una serie de muestras de tejidos subcutáneo y muscular, procedentes de canales de cerdo, mediante cromatografía en fase gaseosa. Ambos tipos de grasas presentan valores similares y relativamente bajos, con un valor medio del 0.6% de 018:1 t. Se detecta una marcada influencia de la alimentación, puesta de manifiesto por las diferencias significativas obtenidas para los contenidos de C18:1 trans, en función del ...




    El desarrollo del fruto es un proceso complejo regulados por hormonas vegetales y que involucra varios cambios metabólicos y fisiológicos coordinados. Mientras etileno actúa en etapas tardías de la maduración de frutos climatéricos tales como tomate, nuevas evidencias señalan una posible función de la fitohormona ácido abscísico (ABA) en etapas más tempranas de la inducción de la maduración. ABA es conocida por regular el desarrollo y maduración de semillas y estar involucrada en conferir...

  8. Detalhes sobre a historia geologica da Bacia Sergipe/Alagoas a partir de biomarcadores acidos e sintese de biomarcadores

    Pericles Barreto Alves


    Resumo: Este trabalho é dividido em três partes distintas. A primeira parte envolve o estudo de nove (9) óleos da bacia Sergipe-Alagoas originados das formações Coqueiro Sêco, Carmópolis e Muribeca do Apitiano (97-113m.a.). A análise dos constituíntes neutros permitiu caacterizar esses óleos como de origem marinha evaporítica e pouco evoluídos termicamente. Os níveis de biodegradação destes óleos a partir da alteração de determinadas classes de biomarcadores, variam entre os níveis de biodegr...

  9. Unusual structure-related magnetism in the organic conductor TSF(Ni(dmit)2)3 (tetraselenafulvalenium-tri-(bis-(4,5-dimercapto-1,3-dithiole-2-thione)nickel)-ate)

    Johannsen, Ib; Bechgaard, Klaus; Rindorf, G.


    TSF(Ni(dmit)2)3 crystallizes in the triclinic space group PI with unit cell dimensions a = 5.875(1), B = 11.846(1), C = 18.873(1) Å, α = 71.35(1), β = 81.63(1), γ = 78.16(1)°. Thermopower and electrical conductivity measurements show semiconducting behaviour localized in the Ni(dmit)2 network. A...

  10. Investigação da influência de 2,5-dimercapto-1,3,4-tiadiazol nas propriedades eletroquímicas de polipirrol e nanotubos de carbono


    Atualmente a quantidade de aparelhos eletrônicos cada vez menores vem crescendo e exigindo dispositivos de armazenamento de energia, como supercapacitores, compatíveis com seus tamanhos. Neste âmbito, compósitos constituídos de polímeros condutores e nanotubos de carbono (NTC) tem sido bastante estudados para utilização como eletrodos em supercapacitores, em que polímeros condutores colaboram para o aumento da condutividade eletrônica do compósito final e os NTC reforçam mecanicamente e estab...

  11. Sensibilidad a la amoxicilina de bacterias anaerobias de pacientes con periodontitis agresiva.(Articulo de Investigacion: Cientifica y Tecnologica)(Perspectiva general del medicamento)

    Cardona, Dora; Hernan Henao, Jorge; Aberto Aristizabal, Juan; Catalina Catano, Laura; Hernando Sanabria, Jairo


    .... La amoxicilina y la amoxicilina/ acido clavulanico son algunos de los mas utilizados. Establecer el tipo de bacterias y su sensibilidad a la amoxicilina y a la amoxicilina/acido clavulanico en pacientes con periodontitis agresiva...

  12. Caracterización y estudio de ácidos arildentiobarbitúricos formados por reacción entre el ácido 2-tiobarbitúrico (atb) y aldehídos aromáticos

    Guillén Sanz, Remedios


    En esta memoria se ha realizado un estudio de la reaccion acido 2-tiobarbiturico-aldehido a traves de la sintesis de los derivados: acido 5-(anisiliden)-2-tiobarbiturico acido 5-(p-dimetilaminobenciliden)-2-tiobarbiturico y acido 5-(saliciliden)bis-2-tiobarbiturico. Este estudio comprende la preparacion de los tiobarbituricos su caracterizacion espectral estabilidad y determinacion de constantes fisico-quimicas importantes (pka coeficiente de particion en distintos sistemas disolventes pa...

  13. Determinación espectrofluorimétrica de fitohormonas derivadas del indol y del naftaleno

    Blanc García, María del Rosario


    Se realiza el estudio de las propiedades fluorescentes y la puesta a punto de metodología espectrofluorimétrica en disolución y en fase sólida para la determinación en aguas, suelos y formulaciones comerciales de las fitohormonas derivadas del indol: acido indol-3-acetico. acido indol-3-butirico, acido indol-3-propinoico y acido 5-hidroxiindol-3-acetico; y del naftaleno: acido 1-naftilacetico y 1-naftilacetamida. se lleva a cabo la determinación individual de cada una de las fitohormonas as...

  14. Production and characterization of an acido-thermophilic, organic solvent stable cellulase from Bacillus sonorensis HSC7 by conversion of lignocellulosic wastes

    Fatemeh Azadian


    Full Text Available The acidophilic and thermophilic cellulase would facilitate the conversion of lignocellulosic biomass to biofuel. In this study, Bacillus sonorensis HSC7 isolated as the best thermophilic cellulose degrading bacterium from Gorooh hot spring. 16S rRNA gene sequencing showed that, this strain closely related to the B. sonorensis. CMCase production was considered under varying environmental parameters. Results showed that, sucrose and (NH42SO4 were obtained as the best carbon and nitrogen sources for CMCase production. B. sonorensis HSC7 produced CMCase during the growth in optimized medium supplemented with agricultural wastes as sole carbon sources. The enzyme was active with optimum temperature of 70 °C and the optimum CMCase activity and stability observed at pH 4.0 and 5.0, respectively. These are characteristics indicating that, this enzyme could be an acidophilic and thermophilic CMCase. Furthermore, the CMCase activity improved by methanol (166%, chloroform (152%, while it was inhibited by DMF (61%. The CMCase activity was enhanced in the presence of Mg+2 (110%, Cu+2 (116%, Triton X-100 (118% and it retained 57% of its activity at 30% NaCl. The compatibility of HSC7 CMCase varied for each laundry detergent, with higher stability being observed in the presence of Taj® and darya®. This enzyme, that is able to work under extreme conditions, has potential applications in various industries.

  15. Study of the interaction of enzyme Heparanase 1 (HPSE1) active with deoxyribonucleic acids; Estudo de interacao da enzima Heparanase 1 (HPSE 1) ativa com acido desoxirribonucleicos

    Cid, Gisele da Silva


    The human heparanase 1 (HPSE 1) is a protein with multiple functions and has emerged as a promising therapeutic target in the context of antitumor therapy. This fact is due to its clinical relevance in the tumor development and progression, as determined by their enzymatic ability to degrade heparan sulfate (HS), the main constituent of the extracellular matrix, providing a tumor microenvironment to tumor dissemination. In addition, this protein plays a significant role in the increase of tumor cells migration ionizing radiation dose delivery in radiotherapy from the increase in the expression levels of HPSE1. In order to evaluate in more detail the functions of active HPSE1, it has been proposed to characterize the interaction of human heparanase protein 1 with deoxyribonucleic acids. Our results are original and point to a new function of HPSE1 of the endonuclease type. (author)

  16. 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.

    Vela, N.; Chenlo, F.


    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)

  17. Detection of fluorescent labelled oligonucleotides using oxalate chemiluminiscence. Estudio de la deteccion de oligonucleotidos marcados con compuestos fluorescentes utilizando la quimioluminiscencia de los esteres del acido oxalico

    Eritia, R. (Barcelona Univ. (Spain). Dept. de Quimica Organica); Johnson, D.; Paige, J.; Walker, P.; Kaplan, B. (Beckman Research Institute of City of Hope, CA (USA))


    The preparation and characterization of oligonucleotides containing fluorescent compounds at the 5' terminus is described together with the utilization of oxalate chemiluminiscence for their detection. (Author)




    Hasta el momento se han identificado dos sistemas que median el transporte de vitamina C en células de mamíferos . La forma oxidada de esta vitamina (ácido deshidroascórbico) ingresa a la célula por los transportadores facilitativos de hexosas (GLUTs), en tanto que la forma reducida (ácido ascórbico) lo hace a través de una familia de proteínas denominadas SVCTs, de los cuales se han descrito dos miembros hasta el momento, SVCTI y SVCT2. Estos últimos transportadores se caracterizan por...

  19. 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

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


    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.


    Hugo A Rodríguez


    Full Text Available El glifosato es un herbicida no selectivo,ampliamente utilizado en el mundo para controlar malezas anuales y perennes. Su principal metabolito en suelos y aguas es el ácido aminometilfosfónico (AMPA formado por la acción de microorganismos. Este herbicida se utiliza en Colombia en altas dosis para la erradicación de cultivos ilícitos de coca y amapola, y como madurante en caña de azúcar, constituyendo un problema ambiental y social en el país, y haciéndose necesaria la evaluación de residuos de glifosato y su metabolito en diferentes matrices. En este trabajo se validó una metodología analítica para determinar residuos de glifosato y de su metabolito AMPA en aguas de influencia de algunas regiones colombianas. El procedimiento experimental comprende dos pasos principales: el primero es un paso de limpieza, extracción y concentración en fase sólida; el Segundo corresponde a la separación, identificación y cuantificación de los compuestos mediante Cromatografía Líquida de Alta Eficiencia (CLAE con derivación poscolumna y detección por fluorescencia. Los resultados de la validación muestran que la metodología es específica, selectiva, precisa y robusta en un rango lineal entre 10 y 750 /xg/L, con límites de detección de 0,8 /xg/L y límites de cuantificación de 2 /ig/L para los dos analitos. Las recuperaciones se encuentran en el orden del 73% para glifosato y del 70% para el AMPA. Además, se muestran los resultados de análisis de aguas tomadas en algunas zonas del país donde se aplica glifosato en diferentes dosis con diferentes propósitos, encontrándose residuos del herbicida y de su metabolito en concentraciones por encima de los valores permitidos en aguas potables para plaguicidas de categoría toxicológica IV, caso del glifosato, de acuerdo con la legislación colombiana

  1. The dynamics of acetic acid in the anaerobic treatment of abattoir sewage; Dinamica del acido acetico en la depuracion anaerobia de aguas residuales de mataderos

    Vazquez Borges, E.; Acosta Viana, K. [Universidad Autonoma de Yucatan. Mexico (Mexico)


    The purpose of this experiment was to examine the production and consumption of acetic acid during the anaerobic treatment of sewage from a municipal abattoir. The experiment studied a 20-litre UASB reactor under three hydraulic retention time (HRT) conditions-4 days, 2.5 days and 1.6 days-measuring the acetic acid concentration in the reactor in fluent and effluent. The results obtained during the experiment with the three different HRTs are reported. The highest percentages of acetic acid removed ( an average of 44%) were obtained with an HRT of 4 days. The amount of acetic acid removed with and HRT of 2.5 days was 27%. (Author) 18 refs.

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

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


    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.

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

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


    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)

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

    Castillo R, Y.


    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)

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

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


    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.

  6. Estudio experimental para la obtención de dióxido de titanio a partir de ilmenita vía acido clorhídrico

    Pedro Hernández


    Full Text Available Una ilmenita colombiana con un tamaño de partícula que pasa malla 100, se lixivió con soluciones de ácido clorhídrico cuyas concentraciones oscilaron entre 17% y el 41% (p/v, en relaciones estequiométricas de 1.0 a 2.5 veces, temperaturas entre 75°C y lOrC y tiempos de 1 a 5 horas. La mezcla resultante se filtró obteniéndose un licor que contenía entre 70% y 80% del TiO^ presente en la ilmenita, el cual se hidrolizó térmicamente. El producto final fue obtenido por calcinación a 900°C y posee un contenido de TiO^ mayor del 97%.

  7. 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

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


    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.

  8. Ação do acido pteroílglutâmico sobre o peso e a fosfatase alcalina do rim

    Gilberto G. Villela


    Full Text Available O APG ministrado subcutaneamente a camondongos normais em injeção unica após 24 hs produz um aumento do peso total dos rins e uma baixa da fosfatase alcalina destes orgãos. Os valores normais foram baseados em experiencias feitas em 54 camondongos e comparados com outros obtidos com 88 camondongos injetados com doses crescentes de APG (0,5~500mg/k. A fosfatase alcalina foi determinada por uma modificação do metodo colorimetro de King & Armstrong. A retenção e precipitação do APG nos estudosrenais parece ser responsavel pelo aumento de peso e a abaixa das fosfatase dos rins.PGA when administered subcutaneously into normal mice in a single injection produces after 24 hours an affective increase of the total weight and a decrease of the "alkaline" phosphatase of the kidneys. Normal values based on 54 mice are reported and compared with those obtained from 88 mice injected with graded doses of PGA (0.5mg/Kg to 500mg/Kg body weight. The "alkaline" phosphatase was determined by a slight modification of the colorimetric method of king & Armstrong using disodium phenylphosphate as a substrate. It is suggested that the retention and precipitation of PGA in the renal tubuli could be responsible for the increased weight and decreased phosphatase activity of the kidneys.

  9. 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

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


    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)




    La enfermedad de hígado graso no alcohólico (HGNA) es de etiología multifactorial que incluye la participación de factores como aumento del estrés oxidativo y preexistencia de anormalidades metabólicas, incluyendo un metabolismo alterado de los ácidos gra 61p.

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

    Carvalho, A.L.S.; Oliveira, J.C.; Miranda, C.S.; Boaventura, J.S.; Jose, N.M., E-mail: [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


    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)

  12. Efecto de enjuagues de acido hipocloroso en el pH de la saliva: estudio in vitro.(CIENCIAS BASICAS, BIOTECNOLOGIA Y BIOINFORMATICA)

    Lafaurie Villamil, Gloria Ines; Buitrago Ramirez, Diana Marcela; Gualtero Escobar, Diego Fernando; Trujillo Perez, Diego Alejandro; Calderon Robles, Justo


    .... El potencial uso de enjuagues con HOCl debe valorarse para establecer si afecta el pH y las propiedades amortiguadoras de la saliva que favorezcan procesos de desmineralizacion dental. Objetivo...




    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.

  14. 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

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


    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.

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

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


    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)


    Guerrero Linares, Israel


    La hipertermia activa mecanismos de protección que podrían tener un beneficio terapéutico, en particular en aquellas enfermedades que comparten como factor común una falla crónica en al metabolismo energético (Karunanithi et al., 1999; Franklin et al., 2005; Neal et al., 2006). El ácido 3-nitropropiónico (3-NP) es un inhibidor del complejo II de la cadena transportadora de electrones mitocondrial, que tiene la capacidad de inactivar irreversiblemente la enzima succinato desh...

  17. p-Coumaric acid biodegradation improvement by bacterial selection; Estrategia para la mejora de la degradaciond el acido p-cumarico mediante seleccion bacteriana

    Otal, E.; Arnaiz, C.; Gutierrez, J. C.; Lebrato, J. [Universidad de Sevilla, Sevilla (Spain)


    Over the last years, the treatment of wastewaters containing recalcitrant organic compounds by means of integrated chemical-biological processes has received a lot of attention. Nevertheless, studies with synthetic waters with acid p-coumaric showed that the chemical treatment before the biological one did not improve its degradation. In this work, we have selected several bacterial strain in order to obtain an inoculum with a high degradative potential of this compound and its intermediates from the chemical pre-treatment. (Author) 10 refs.

  18. 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

    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: [Instituto Tecnologico de Veracruz, Ingenieria Quimica, Miguel Angel de Quevedo No. 2779, 91860 Veracruz (Mexico)


    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)

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

    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: [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Inst. de Ciencias Ambientais, Quimicas e Farmaceuticas. Dept. de Ciencias Exatas e da Terra


    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)

  20. Canaric acid (3,4-seco-lupane derivative) isolated from propolis of Ceara, BR; Acido canarico (3,4-seco derivado do lupano) em propolis do Ceara

    Albuquerque, Irineu L. de; Alves, Leonardo A.; Lemos, Telma L.G.; Monte, Francisco J.Q. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Quimica Organica e Inorganica]. E-mail:; Braz-Filho, Raimundo [Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacazes, RJ (Brazil). Centro de Ciencias e Tecnologia. Setor de Produtos Naturais


    Phytochemical investigation of a propolis sample from Alto Santo - Ceara, Brazil, allowed identification of triterpenes (lupeol, lupenone, germanicone, Canaric acid) and flavonoids (quercetin, kaempferol and acacetin), which were identified by spectroscopic data (IR, MS, and NMR, including 2D techniques). This is the first report of Canaric acid in propolis. Propolis extract and flavonoids showed antioxidant activity using a DPPH radical scavenging assay. (author)

  1. Estudio experimental para la obtención de dióxido de titanio a partir de ilmenita vía acido clorhídrico

    Pedro Hernández; Andrés Hurtado; Luis Peñaloza; Jacqueline Romero


    Una ilmenita colombiana con un tamaño de partícula que pasa malla 100, se lixivió con soluciones de ácido clorhídrico cuyas concentraciones oscilaron entre 17% y el 41% (p/v), en relaciones estequiométricas de 1.0 a 2.5 veces, temperaturas entre 75°C y lOrC y tiempos de 1 a 5 horas. La mezcla resultante se filtró obteniéndose un licor que contenía entre 70% y 80% del TiO^ presente en la ilmenita, el cual se hidrolizó térmicamente. El producto final fue obtenido por calcinación a 900°C y po...

  2. Oxidative stability of biodiesel from soybean oil fatty acid ethyl esters; Estabilidade oxidativa de biodiesel de esteres etilicos de acidos graxos de soja

    Ferrari, Roseli Ap.; Oliveira, Vanessa da Silva; Scabio, Ardalla [Universidade Estadual de Ponta Grossa (UEPG), PR (Brazil). Dept. de Engenharia de Alimentos]. E-mail: ferrarir@uepg


    Biodiesel consists of long-chain fatty acid esters, derived from renewable sources such as vegetable oils, and its utilization is associated to the substitution of the diesel oil in engines. Depending on the raw material, bio diesel can contain more or less unsaturated fatty acids in its composition, which are susceptible to oxidation reactions accelerated by exposition to oxygen and high temperatures, being able to change into polymerized compounds. The objective of this work was to determine the oxidative stability of bio diesel produced by ethanolysis of neutralized, refined, soybean frying oil waste, and partially hydrogenated soybean frying oil waste. The evaluation was conducted by means of the Rancimat equipment, at temperatures of 100 and 105 deg C, with an air flow of 20 L h{sup -1}. The fatty acid composition was determined by GC and the iodine value was calculated. It was observed that even though the neutralized, refined and waste frying soybean oils presented close comparable iodine values, bio diesel presented different oxidative stabilities. The bio diesel from neutralized soybean oil presented greater stability, followed by the refined and the frying waste. Due to the natural antioxidants in its composition, the neutralized soybean oil promoted a larger oxidative stability of the produced bio diesel. During the deodorization process, the vegetable oils lose part of these antioxidants, therefore the bio diesel from refined soybean oil presented a reduced stability. The thermal process degrades the antioxidants, thus the bio diesel from frying waste oil resulted in lower stability, the same occurring with the bio diesel from partially hydrogenated waste oil, even though having lower iodine values than the other. (author)

  3. Selection of refractory materials for acid tanks at the CSN continuous pickling line; Selecao de materiais refratarios para tanques de acido das linhas de decapagem continua da CSN

    Silva, Sidiney Nascimento; Marques, Oscar Rosa; Bueno, Mauricio Chaves [Companhia Siderurgica Nacional, Volta Redonda, RJ (Brazil); Longo, Elson; Silva Pinheiro, Adriano da [Sao Carlos Univ., SP (Brazil). Dept. de Quimica


    Aiming at the revamping of the CSN continuous pickling line 4 acid tanks, a Post Mortem study of the refractory lining was carried out. The collected samples were characterized through techniques such as chemical analysis, mercury porosimetry, X-ray diffraction and scanning electronic microscopy. Trying to reproduce the operational conditions closely, laboratorial simulations were carried out. Such simulations lead to the addition of some alterations on the test method proposed by ABNT. Primarily, the sulfuric acid was substituted by hydrochloric acid (30%), containing iron in solution (130g/l). As result, it was concluded that acid resistant refractories containing a smaller alumina and /or corundum and mullite concentrations, presenting a smaller open porosity and average pore diameter, have a better performance face to corrosion due to hydrochloric acid solution. In addition, abrasion wear resistance tests, according to the ASTM-G65-85 standard were carried out in order to select different materials to the acid tanks cells. (author) 3 refs., 5 figs., 12 tabs.

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

    Martinez G, M.S.M


    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)

  5. Use of chemical pre-treatment based chromic acid; Uso de pre-tratamento quimico a base de acido cromico. Beneficios versus desvantagens

    Campos, Paulo Henrique Leite [TENARIS CONFAB S.A., Pindamonhangaba, SP (Brazil); Bibiano, Paulo de Tarso [SOCO-RIL do Brasil S.A., Pindamonhangaba, SP (Brazil); Koebsch, Andre; Mollica, Eduardo de Oliveira [PETROBRAS, Rio de Janeiro, RJ (Brazil)


    In this work were going compared the polyethylene and FBE coatings performances in triple layer for tubes done with and without the presence of the pre-treatment chemist with chromic acid of the tube surface. The performance test chosen for accomplishes the comparison was the cathodic disbondment and hot water soak, for being this the test that has objective to improve the performance with the chromic acid application. The obtained results were going extracted of a factory database of TENARIS CONFAB S.A. in Pindamonhangaba - Sao Paulo. The adopted technical specification like reference for the tried coatings belonged to PETROBRAS S.A. Were compared also tests results of jobs using chromate and jobs that were not used pre-treatment. (author)

  6. 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

    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)


    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)

  7. Radiological assessment occupational radionuclides in a phosphoric acid plant; Evaluacion radiologica ocupacional y distribucion de radionucleidos en una planta de acido fosforico

    Bolivar, J. P.; Garcia-Tenorio, R.


    On the frame of a research project devoted to the control of the exposure due to natural radiation in several NORM industries located at the South of Spain, a detailed to the production of phosphoric acid has been performed. In addition, the behaviour along the mentioned process of the different radionuclides involved has been analysed. It has been concluded that the effective dose which can be received by the workers of the plant is clearly below 1 mSv/year. And it has been demonstrated that the main route of occupational exposure corresponds to the external radiation due mainly to the permanent presence of a radioactive contamination source in different zones of the plant. This contamination source is associated to the presence of scales in the inner surfaces of pipes and equipment as well as to the presence of sludges in the phosphoric acid storage tanks, which in both cases contain elevated concentrations of 226{sup R}a. Moreover, the 222{sup R}n concentrations inside the plant do not overpass 100 Bq/m{sup 3}, which not constitutes a radiological problem. (Author) 9 refs.

  8. Efecto de dos citoquininas, acido ascorbico y sacarosa en la obtencion de plantas in vitro de Sorghum bicolor para la formacion de callos

    de Jesus Martinez Medina, Silvio; Gomez Kosky, Rafael; Posada Perez, Laisyn; Barbon Rodriguez, Raul; Acosta Suarez, Maira; Reyes Vega, Maritza; Perez Benitez, Martha; Torres Rodriguez, Damaris; Pons Corona, Mileidys; La O Cardenas, Mariana; Aguilera Chavez, Annerys; Tejeda Gonzalez, Miguel


    .... Se tomaron semillas maduras de plantas que crecian en condiciones controladas, las que se desinfectaron y fueron colocadas a germinacion en un medio de cultivo con las sales MS, mioinositol 100 mg [L.sup.-1], sacarosa 3...

  9. Description and implementation of acid/base titrimetric techniques for process monitoring; Descripcion e implementacion de tecnicas titrimetricas acido/base para la monitorizacion de procesos

    Marcelino Represa, M.; Guisasola i Canudas, A.; Casa Alvero, C.; Lafuente Sancho, F. J.


    The basis of titrimetric techniques is that the proton production (or consumption) rate can be indirectly measured with the amount of base (or acid) dosage necessary to maintain the pH at a certain setpoint value. Titrimetric measurements are very useful for the monitoring of any process that influences pH with simple equipment (an accurate pH control loop). This work describes the theoretical basis of titrimetric measurements and shows three examples of the application of titrimetric techniques for the process monitoring: CO{sub 2} absorption, nitrification and biological organic matter removal. (Author)

  10. Electrodialytic separation of Cu(II) and As(V) in acidic electrolytes; Separacion electrodialitica de Cu(II) y As(V) en electrolitos acidos

    Ibanez, J. P.; Ipinza, J.; Cifuentes, L.


    The separation of copper and arsenic from acidic electrolytes by electrodialysis was investigated at room temperature. the effect of current density and pH was studied in a batch cell during 3 hours. The kinetic parameters showed that Cu(II) transport rate was 0.75 mol/m''2/h and the As(V) transport rate was 0.002 mol/m''2/h. An efficient separation between Cu(II) and As(V) was achieved; Generating a concentrated solution of copper with no arsenic, which was obtained independently of the electrolyte acidity and current density used. The effect of the arsenic speciation with pH is discussed as well. (Author) 23 refs.

  11. 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

    Alonso Lopez, J.


    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.

  12. Formation mechanism of manganese compounds in acidic electrolytes of copper; Mecanismo de la formacion de compuestos de manganeso en electrolitos acidos

    Ipinza, J.; Ibanez, J. P.; Pagliero, A.; Vergara, F.


    The formation mechanism of manganese compounds in acidic electrolytes (180 g/l of H{sub 2}SO{sub 4}) was studied by potentiostatic experiments at 50 degree centigree. In the oxide layer on a PbCaSn anode, amorphous MnOOH was formed XRD showed that anodic slimes collected from the cell bottom after 3 h was made up of: {gamma}-MnO{sub 2} and {epsilon}-MnO{sub 2}. It was proved that the {epsilon} type oxide was formed by an electrochemical process and the {gamma} type oxide was formed by a pure chemical precipitation, the last one depends on the MnO{sub 4} concentration in the electrolyte. The electrochemical formation of MnOOH only depends on the concentrations of Mn''3+ in the electrolyte, and this amorphous compounds in the intermediate specie for generating {epsilon}-MnO{sub 2}. Fe''2+, in the presence of Mn''2+. inhibited the formation of both MnO{sub 2} oxides, and in the anode interface reduces PbO{sub 2} to PbSO{sub 4}, that reports in the anodic slime. furthermore, the presence of ferrous ion resulted in a better distribution of the manganese compounds and originates PbSO{sub 4} precipitates, which report on the slime. (Author) 25 refs.

  13. The impact of heavy and acid oil production in PETROBRAS downstream area; A influencia dos petroleos pesados e acidos no parque de refino da PETROBRAS

    Perisse, Juarez Barbosa; Oddone, Maria Regina Rezende; Bela, Donizeti Aurelio Silva [PETROBRAS, Rio de Janeiro, RJ (Brazil)


    PETROBRAS is facing a great challenge processing heavy and acid oils. The low API of the more recent offshore discoveries leads to an increase in vacuum residue yields which is one important component of the fuel oil's 'pool'. The fuel oil demand is expected to decrease along the next years due to natural gas substitution and to environmental issues, generating exceeding fuel oil exportation at low prices. This paper will discuss World and PETROBRAS technological choices to process these oils meeting the required future demand and quality. A comparison among various residue conversion technologies is also presented in this paper focused on the reduction of fuel oil production and on the improvement of diesel / gasoline rate. Another important issue that will be discussed in this paper is related to the different solutions implemented all over the world to deal with the crude acidity problem and the solutions adopted by PETROBRAS. (author)

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

    Silveira, Marcilei A. Guazzelli da; Cardoso, L.L., E-mail: [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


    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)

  15. 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

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


    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.

  16. Efeito do acido borico sobre a reação de formação da oxima da benzoina

    Dal Magro,Jacir


    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciencias Fisicas e Matematicas A reação entre a hidroxilamina e benzoína ocorre em duas etapas: formação de um intermediário de adição e a desidratação deste à oxima. A reação na presença de ácido bórico (0,01M) a pH 8,5 apresenta um aumento no valor de kobs em até l5 vezes. Este valor é maior na presença de ácido fenil bórico, onde a diferença atinge 28 vezes. Tampões que possuem pKas semelhantes não apresentam ne...

  17. Evaluation of ultrasonic technique to characterize the concentration of boric acid in liquid medium; Avaliacao de tecnica ultrassonica para medida de concentracao de acido borico em meio liquido

    Kohara, Richard Yuzo Ramida


    This dissertation is to analyze the viability of using ultrasonic technique to characterize the concentration of boric acid in liquid medium non-invasively, therefore, ultrasonic tests were performed relating different boric acid concentrations with the travel time of the ultrasonic wave, also were evaluated factors able to mask the characterization of these concentrations by ultrasonic technique. The results showed that the ultrasonic technique allows the characterization of boric acid concentrations in liquid medium in very simple terms by the ultrasonic wave travel time, requiring further studies in complex conditions. (author)

  18. Hydrogen embrittlement in superaustenitic stainless steels welded unions in sulfuric acid; Fragilizacao por hidrogenio em juntas soldadas de acos inoxidaveis superausteniticos em acido sulfurico

    Berthier, T. [Parana Univ., Curitiba, PR (Brazil). Lab. de Materiais e Tratamento de Superficies (LaMaTS)]. E-mail:; Kuromoto, N.K. [Parana Univ., Curitiba, PR (Brazil). Lab. de Nanopropriedades Mecanicas; Paredes, R.S.C. [Instituto de Tecnologia para o Desenvolvimento (LACTEC), Curitiba, PR (Brazil)


    The embrittlement of the austenitic stainless steel by hydrogen has been known for more than four decades. Researches done into the behavior of the hydrogenated homogeneous structures, under cathodic charging at room temperature, have shown that the hydrogen induces phase transformations and nucleation of retarded superficial cracks during the outgassing which is followed by the end of the hydrogenation. The results obtained upon austenitic and superaustenitic stainless steels are few considering the changes produced in welded unions. The aim of this work is to evaluate mechanical properties of material and its relation to the nucleation of the cracks in the austenitic steels welds type AISI 904L submitted to hydrogenated solutions. The samples have been welded through the process MIG/MAG; the hydrogenation has been made catholically in a sulfuric acid solution of 1N, with variable time of 1 to 4 hours at the room temperature. An anode of platinum in and density of current 1000 A/m{sup 2} has been used. The outgassing has occurred at the room temperature. Many retarded superficial cracks with different morphologies have been observed. Regarding the hardness measure, major alterations in all the regions of the sample have not been noticed. (author)

  19. The influence of acid and base waste on the activated sludge system; Influencia de vertidos acidos y basicos sobre el sistema de fangos activados

    Coello Oviedo, M. D.; Sales Marquez, D.; Quiroga Alonso, J. M.


    A study has been made of the effect of acid and base waste on the microorganisms in the activated sludge reactor. This effect was monitored using the classical control parameters (SVS and the percentage of organic matter eliminated) and by measuring the activity of the microorganisms (specific breathing rate and percentage of active cells). The results obtained indicate that the macrobiotic is affected at the extremes of the pH range (pH 4,5 and pH 10.5). The system's performance worsens and therefore the quality of the effluent fails to comply with European Directive 91/271/EEC. In the tests carried out with pH 6 and 9, the microorganisms activity declined at first,but the system eventually recovered and returned to levels of activity similar to those prior to the test. It was also found that deviations of the supply towards acid pH had a greater negative effect on the reactor than identical deviations towards baseness. (Author) 12 refs.

  20. Acid formic effect in zinc coatings obtained by galvanostatic deposition; Efeito do acido formico em revestimentos de zinco obtidos por deposicao galvanostatica

    Lopes, C.; David, M.; Souza, E.C., E-mail: [Universidade Federal da Bahia (UFBA), BA (Brazil). Escola Politecnica. Departamento de Engenharia Quimica


    Zinc deposits obtained from electrodeposition is widely used for the purpose of protecting steel substrates from corrosion. They are generally added to Zn deposition bath many additives for improving certain characteristics of the deposit. As far as is known there is no information in literature about the effect of formic acid in corrosion resistance of a Zn deposit. Because it is an acid additive, it has the use of cyclohexylamine, in order for the electrolytic bath continue with a pH equal to the one used commercially, around 5. The main goal of this study is analyze the effect of the formic acid addition in the corrosion resistance of an Zn electrodeposition obtained by galvanostatic deposition. The results obtained by performance tests, cyclic voltammetry and X-ray diffraction showed that the formic acid addition may be promising in combating the corrosion of materials. (author)

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

    Vela Barrionuevo, N.


    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)

  2. 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

    Scroccaro, Karine Isabel; Yamamoto, Carlos I., E-mail: [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


    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)

  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

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


    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. 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

    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: [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


    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)

  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

    Tavares, Henrique Dutra Simoes


    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. 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

    Nilson Evelázio de Souza


    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.

  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

    Peleias Junior, Fernando dos Santos


    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)

  8. Liquid-liquid extraction (LLE) of Fe(III) and Ti(IV) by bis-(2-ethyl-hexyl) phosphoric acid (D2EHPA) in sulfuric acid medium; Extracao liquido-liquido de ferro (III) e titanio (IV) pelo acido bis-(2-etil-hexil) fosforico (D2EHPA) em meio de acido sulfurico

    Silva, Glauco Correa da; Cunha, Jose Waldemar Silva Dias da [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil). Dept. de Quimica e Materiais Nucleares; Dweck, Jo [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica. Dept. de Processos Inorganicos; Afonso, Julio Carlos [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica. Dept. de Quimica Analitica]. E-mail:


    This work presents a study on the separation of Fe(III) and Ti(IV) from sulfuric acid leaching solutions of ilmenite (FeTiO{sub 3}) using liquid-liquid extraction with D2EHPA in n-dodecane as extracting agent. The distribution coefficients (K{sub D}) of the elements related to free acidity and concentration of Fe(III) and Ti(IV) were determined. Free acidity was changed from 3x10{sup -2} to 11.88 mol L{sup -1} and D2EHPA concentration was fixed at 1.5 mol L{sup 1}. Recovery of final products as well as recycling of wastes generated in the process were also investigated. The LLE process as a feasible alternative to obtain high-purity TiO{sub 2}. (author)

  9. Esterificacion quimioselectiva de fitosteroles de madera mediante lipasas

    Illanes, Andres; Alvarez, Lorena; Alvaro, Gregorio


    .... Ambas sustancias son muy similares, lo que impide su separacion por metodos fisicos, siendo la esterificacion selectiva de esta mezcla con esteres de acidos grasos mediante lipasas quimioselectivas...

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

    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% ...

  11. NCBI nr-aa BLAST: CBRC-PHAM-01-1744 [SEVENS

    Full Text Available CBRC-PHAM-01-1744 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 4e-17 40% ...

  12. 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

    Silva, Wilson Tadeu Lopes da


    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)

  13. Estudio de las propensiones conformacionales del amino acido l-glutamato en regiones altamente estructuradas de proteínas resueltas por cristalografía de rayos x

    Hincapié Parra, Dalia Andrea


    Aunque el estudio de la conformación en biomoléculas es fundamental para el entendimiento de sus funciones biológicas, la información concerniente a estudios estructurales y conformacionales de las estructuras de macromoléculas a partir de los datos reportados experimentalmente resonancia magnética nuclear (RMN) y cristalografía de rayos X (DRX) y de los estados estructurales preferenciales particularmente para proteínas y los residuos de aminoácidos que las constituyen son limitados y en muc...

  14. Niobium (V) doped bioceramics: evaluation of the hydrothermal route modified with citric acid and urea to obtain modified hydroxyapatite; Bioceramicas aditivadas com niobio (V): avaliacao da rota hidrotermica modificada com acido citrico e ureia para obtencao de hidroxiapatitas modificadas

    Simomukay, E.; Souza, E.C.F. de; Antunes, S.R.M.; Borges, C.P.F.; Michel, M.D.; Antunes, A.C. [Universidade Estadual de Ponta Grossa (UEPG), Ponta Grossa, PR (Brazil)


    Synthetic hydroxyapatite (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}; HA) has become a widely used ceramic material for bone reconstruction due to its biocompatibility with the bone tissue. This biocompatibility as well as other physical and chemical properties of the hydroxyapatite can be modified by the addition of different ions to its structure. Niobium (V) ion has not been commonly used in the hydroxyapatite synthesis. The objective of this study was to evaluate the use of hydrothermal route in the niobium (V) doped hydroxyapatite synthesis. The route used the niobium ammonium oxalate (NH{sub 4}H{sub 2}[NbO(C{sub 2}O{sub 4}){sub 3}].3H{sub 2}O) complex as a niobium (V) ion precursor. The addition of citric acid and urea in the hydrothermal route is used for the control of synthesis pH and precipitation rate. Pure sample and sample added with 5.3 ppm of niobium (V) ion were prepared. The coexistence of other phases besides the hydroxyapatite was not observed in any of the samples through the use of X-ray diffraction and infrared spectroscopy (FTIR) techniques. The FTIR technique revealed the presence of hydroxyapatite characteristic functional groups. The scanning electron microscopy analysis showed the formation of agglomerates composed of round particles, confirmed by the transmission electron microscopy technique. The X-ray fluorescence spectroscopic analysis detected the presence of niobium in the doped sample. The results showed that niobium (V) doped hydroxyapatite can be synthesized by means of hydrothermal route, which may be considered as huge potential for future application in bioceramics. (author)

  15. 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

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


    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)

  16. Se trata de determinar la eficacia y seguridad del acido tranexamico frente a placebo en la reduccion de las perdidas sanguineas asociadas a la cirugia de reemplazo total de cadera | EU Clinical Trials Register [EU Clinical Trials Register

    Full Text Available reduccion de las perdidas sanguineas asociadas a la cirugia de reemplazo total de cadera MedDRA edad que se les vaya a realizar cirugia de reemplazo total de cadera (CRT)---ASA I-III-Sin alergias al ác

  17. Estabilidad oxidativa y calidad sensorial de carne de pollo enriquecida con acidos grasos n-3 proveniente de fuentes de origen vegetal y animal, protegida con vitamina E y selenio orgánico.



    [EN] Despite people attitudes concerning healthy eating, western diets still show a low intake of n-3 polyunsaturated fatty acid (PUFA). Among Argentinean people the consumption of fish meat is relatively poor, being beef and chicken meat their main sources of protein. A viable way of increasing the consumption of n-3 PUFA is to raise the intake of products enriched with them. Chicken meat is rated in second place in the consumption of meat in Argentina. This meat, like others, is a nutrit...

  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)

    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)


    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. 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

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


    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)

  20. 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

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


    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.

  1. Evaluation of oil ducts wettability by measurements of contact angle. Effect of asphaltenes and naphtenic acids; Avaliacao da molhabilidade de oleodutos atraves de medidas de angulo de contato. Efeitos de asfaltenos e acidos naftenicos do petroleo

    Santos, Ronaldo G. dos; Mokamed, Rahoma S. [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Quimica; Loh, Watson [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica


    The recent interest of the petroleum companies for heavy crude oils reserves have been increased in the last decades. Rheological properties of these oils interferes with their economical production and transportation. Technologies based on the flow of lubricated oil through an aqueous film (Core Flows) represent an alternative way to improve of the flow efficiency and viability of the recovery of these heavy oils. In the systems, the pressure drop caused from the high values of viscosity can be reduced to values similar to those encounter in single aqueous flow. The progressive accumulation oil on the pipeline walls is, however, the major problem for the implementation of core flow. For oil accumulation to take place, pipeline surface would need to be oil-wet. This work examines the wettability of pipeline surfaces and the effect of oil phase polar constitute such as asphaltenes and naphtenic acids in the possible alteration of these surfaces from water-wet to oil-wet. The effect of crude oil fractions on the wettability is shown by measurements of contact angle. Commercial and carbon steel are tested. The results show that the wettability of the surfaces depend on oil composition and can be rectified by components in aqueous phase. (author)

  2. 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

    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: [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (MX)


    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)

  3. LF-NMR study of effect the octadecylamine addition in the copolymerization process between acrylic acid and styrene monomers; Estudo por RMN de baixo campo do efeito da adicao de octadecilamina na copolimerizacao dos monomeros de acido acrilico e estireno

    Pedroza, Oscar J.O.; Tavares, Maria I.B. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano]. E-mail:,


    The copolymer content at least two monomer units that are the repetitive unities in the polymeric chains. The use of Low Field Nuclear Magnetic Resonance (LF-NMR), MARAN ultra 23, was applied to measure the proton spin-lattice relaxation time values. The process of copolymerization between the acrylic acid (A) and the styrene (S) monomers was studied with the addition of the octadecylamine (D) in the acrylic acid monomer. These materials were submitted at reflux by 24 hours. After this process the polymerization was carried out at room temperature. The values of the relaxation parameter are showed in Table 1. The co polymerizations between acrylic acid and styrene monomers were influenced by the octadecylamine addition. The results showed that an increase in the amine concentration promotes flexibility in the final material. This can be explained in terms of chains size after amine addition, which promotes an increasing in the free space among the polymer chains. (author)

  4. 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

    Miranda Junior, Pedro


    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)

  5. 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

    Amer Amezaga, S.


    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.

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

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


    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....

  7. 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

    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:


    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)

  8. 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

    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.


    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)

  9. 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.)

    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)


    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)

  10. 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

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


    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.

  11. 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

    Rossi, Celeste Q.; Pereira, Marcos G.; Garcia, Andreas C., E-mail: [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


    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)

  12. Study of the reaction between {sup 51}CrO{sub 3} and concentrated nitric acid by radio chromatographic methods; Estudo da reacao entre {sup 51}CrO{sub 3} e acido nitrico concentrado por metodos radiocromatograficos

    Pezzin, Sergio H. [Univesidade do Estado de Santa Catarina (UDESC), Joinville, SC (Brazil). Centro de Ciencias Tecnologicas; Collins, Carol H.; Collins, Kenneth E. [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica


    The objective of the present work is to verify the reduction of CrO{sub 3} in concentrated nitric acid, using {sup 51}Cr as a tracer. For the study, {sup 51}CrO{sub 3} (ca. 200,000 cpm/mg) was added to 65% HNO{sub 3} and maintained under agitation at 20 deg C for specified time periods. Aliquots (100 {mu}) were analyzed by open column cation (AG50Wx8, 100-200 mesh, Na{sup +} form) chromatography, either immediately or after dilution to approximately pH 2 and storage for specified time periods. The separations, which were made by stepwise elution using HClO{sub 4} and Ca(ClO{sub 4}){sub 2} solutions as effluents with fraction collection, followed by counting with a NaI(Tl) detector and a single channel analyzer. It was verified that ca. 3.5% of Cr(III) is obtained after 15 min of reaction. The major reaction product is hexaaquo chromium(III), with minor concentrations of mononitrate penta-aquochromium(III), [Cr(H{sub 2}O){sub 5}NO{sub 3}]{sup 2+}, a product which undergoes watering at pH 2 to produce, after 360 h, [Cr(H{sub 2}O){sub 6}]{sup 3+}. (author)

  13. Study of the nitric acid influence on the production of Ce O{sub 2} with high specific surface area; Estudo da influencia do acido nitrico na obtencao de CeO{sub 2} com alta area superficial especifica

    Albanez, Nelma Kunrath; Bressiani, Jose Carlos [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)


    The cerium oxide (Ce O{sub 2}) main characteristics for use as catalyst in an exhaust gases purification system are: high specific surface area (approximately 30 m{sup 2}/g after calcination at 800 deg C/ 2 hs), and thermal stability. The Ce O{sub 2} powders obtained by conventional route, i.e., precipitation, and submitted high temperature (800 deg C) heat treatments, showed low specific surface area. In this work nitric acid effects on the Ce O{sub 2} surface area values were investigated. The variables studied were nitric acid concentration, humidity content in the raw material, re pulp after leaching, addition of hydrogen peroxide (H{sub 2} O{sub 2}) and starting material specific surface area. By this process, it was possible to obtain powders with specific surface area larger than 40 m{sup 2}/g, after treatment at 800 deg C during two hours. (author) 8 refs., 3 figs., 1 tab.

  14. 15-demethylisoplumieride acid, a new iridoid isolated from the bark of Plumeria rubra and latex of Himatanthus sucuuba; Acido 15-desmetilisoplumierideo, um novo iridoide isolado das cascas de Plumeria rubra e do latex de Himatanthus sucuuba

    Barreto, Alaide de Sa; Amaral, Ana Claudia F. [Fundacao Inst. Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil). Instituto de Tecnologia em Farmacos -Farmanguinhos. Lab. de Plantas Medicinais e Derivados; Silva, Jefferson Rocha de A. [Universidade Federal do Amazonas, Manaus, AM (Brazil). Dept. de Quimica]. E-mail:; Schripsema, Jan [Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacazes, RJ (Brazil). Setor de Quimica de Produtos Naturais; Rezende, Claudia M.; Pinto, Angelo C. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica


    Himatanthus sucuuba and Plumeria rubra are used in folk medicine in Brazil to treat various ailments. The isolation of the new iridoid 15-demethylisoplumieride from the bark of Plumeria rubra L. var. acutifolia (Ait) Woodson and latex of Himatanthus sucuuba (Spruce) Woodson is reported. Other iridoid glycosides were obtained from both plants. The structures of these substances were elucidated by spectral analysis and comparison with data already reported. (author)

  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

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


    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. 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

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


    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)

  17. 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)

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


    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)

  18. 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

    Scroccaro, Karine Isabel; Tanobe, Valcineide Oliveira de Andrade; Cocco, Lilian Cristina; Yamamoto, Carlos Itsuo, E-mail: [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


    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)

  19. 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

    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


    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)

  20. 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

    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


    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)

  1. Resistance to acid attack of portland cement mortars produced with red mud as a pozzolanic additive; Resistencia ao ataque acido de argamassas de cimento Portland produzido com residuo de bauxita como aditivo pozolanico

    Balbino, Thiago Gabriel Ferreira; Fortes, Gustavo Mattos; Lourenco, Rafaela Roberta; Rodrigues, Jose de Anchieta [Universidade Federal de Sao Carlos (DEMa/PPGCEM/UFSCar), SP (Brazil). Programa de Pos-Graducao em Ciencia e Engenharia de Materiais. Departamento de Engenharia de Materiais; Montini, Marcelo [Alcoa Aluminio S.A., Pocos de Caldas, MG (Brazil)


    Portland cement structures are usually exposed to aggressive environments, which requires the knowledge of the performance of these materials under deleterious conditions. In this study, it was evaluated the resistance to acid attack of mortars that contain ordinary (CPI) and compost (CPII-Z) Portland cements, adding to the first red mud (RB) as a pozzolanic additive in different conditions: without calcination, calcined at 400 ° C and at 600 ° C. The specimens were subjected to HCl and H{sub 2}SO{sub 4} solutions, both with concentration of 1.0 Mol L{sup -1} for 28 days, monitoring the weight loss and leached material nature by atomic emission inductively coupled plasma (ICP). The hydration products were studied by thermogravimetric analysis (TGA) and X-ray diffraction (XRD) of the hydrated cement pastes. It was observed a reduction of portlandite amount in the RB containing cement pastes, indicating a possible pozzolanic activity of the red mud. The mortars prepared with RB were more resistant to HCl, while that ones with calcined RB present a better performance in H{sub 2}SO{sub 4} attack. (author)

  2. Efeito da concentração de acido, umidade e temperatura na hidrolise de amido de mandioca por extrusão termoplastica visando a produção de alcool


    Resumo: Tem-se conhecimento que a produção de álcool a partir de amido de mandioca tornou-se economicamente inviável, devido ao processo requerer um alto consumo de energia e uso de grande quantidade de água e de enzima α-amilase e amiloglicosidase na etapa de gelatinização, liquefação e sacarificação do amido. Entretanto, a extrusão termoplástica é considerada uma tecnologia que permite a gelatinização e dextrinização de materiais amiláceos a seco com baixo consumo de energia. Portanto, o ob...

  3. Preparation of polymer blends from glycerol, fumaric acid and of poly(ethylene terephthalate) (PET) recycled; Preparacao de blendas polimericas a partir do glicerol, acido fumarico e do politereftalato de etileno (PET) pos consumo

    Medeiros, Marina A.O.; Guimaraes, Danilo H.; Brioude, Michel M.; Jose, Nadia M. [Instituto de Quimica, Universidade Federal da Bahia, Salvador, BA (Brazil); Prado, Luis A.S. de A. [Institut fuer Kunststoffe und Verbundwerkstoffe - Technische Universitaet Hamburg-Harburg, Hamburg (Germany)


    Polymer blends based on recycled poly(ethylene terephthalate) (PET) and poly(glycerol fumarate) polyesters were prepared in different PET concentrations. The PET powder was dispersed during the poly(glycerol fumarate) synthesis at 260 deg C. The resulting blends were characterized by X-ray diffraction. The thermal stability of the materials was evaluated by thermogravimetric analysis and differential scanning calorimetry. The morphology was studies by scanning electron microscopy. The blends were clearly immiscible. The possibility of (interfacial) compatibilization of the PET domains, caused by transesterification reactions between PET and glycerol were discussed. (author)

  4. Aspectos moleculares da fração acida de querosene de aviação : sintese de padrões (fenolicos, acidos carboxilicos e neutros) para analise em cromatografia gasosa acoplada a espectrometria de massas

    Joana D'Arc Felix de Sousa


    Resumo: O petróleo Cabiúnas, proveniente da Bacia de Campos, possui um índice de acidez considerável (IA = 1,0), classificando-o como petróleo de acidez média para alta. Sabemos que as frações do petróleo, Querosene de Aviação (QAV) e Gasolina, são obtidas numa faixa de ebulição (250-300°C) semelhante à faixa de destilação dos ácidos naftênicos (200-370°C). Este fato nos motivou a estudar a fração ácida do Querosene de Aviação em uma confirmação de resultados anteriores, deste laboratório. A ...

  5. Sterols and fatty acids analysis at the Llobregat River for a wastewater dumping episode; Analisis de esteroles y acidos grasos en el rio Llobrgat por un vertido de aguas residuales

    Romero-Lacal, J.; Garcia-Mendi, C.; Vega, A.; Pujadas, M.


    The study by gas chromatography (HRGC) and mass spectrometry (MS) of fatty acids and sterols of water samples from Anoia and Llobregat River, allowed to rule out the hypothesis of the Anoia River as the cause of dumping episode and even to determine that the episode was not associated to the faecal or residual contamination. Nevertheless, it has permitted us to have a better knowledge of these families of organic compounds in the basin of the Llobregat River. In the acidic fraction, saturated and unsaturated fatty acids of 14, 16 and 18 atoms of carbon from oil fish, animal fat or hydrogenated oils with industrial and domestic use were found. The application of different sterols indices (coprostanol, cholesterol, cholestanol, stigmasterol, stigmastadienol and sitosterol) permitted us to study the role of the sterols and the significance of the contamination from animal sterols, fitosterols in the studied samples. (Author) 19 refs.

  6. 基于BP神经网络的污泥酸性发酵过程预测%Prediction of Sludge Acido-Genic Fermentation Process Based on BP Neural Network

    石杰; 宋秀兰; 李亚新



  7. ({sup 1} H, {sup 13} C and {sup 31} P) NMR of phosphonic acid derivatives; Ressonancia magnetica nuclear ({sup 1} H, {sup 13} C, {sup 31} P) de derivados do acido fosfonico

    Campos, Valdevino; Costa, Valentim E. Uberti [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Quimica


    In the last years the development of phosphates analogues in the medical and agricultural pesticides has being very expressive. {sup 1} H, {sup 13} C and mainly {sup 31} P NMR are used for stereochemical and conformational analysis, and reactivity studies on the compounds resulting from those chemical processes 2 refs., 4 figs., 1 tab.

  8. Characterization of peat and humic acid in the margins of Mogi-Guacu river, Sao Paulo state, Brazil; Caracterizacao da turfa e dos acidos humicos das margens do rio Mogi-Guacu, SP

    Prado, Alexandre G.S.; Rezende, Mara O. de O. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Quimica. Lab. de Radioquimica e Quimica Ambiental


    The slow chemical and microbiological decomposition of flooded soils form a material with high proportion of organic matter known as peat. The presence of favorable areas for peat formation is a characteristic of the Brazilian territory; even so, the potential of this material is seldom used. Peat can be used as a fertilizer complement in agriculture, as source of energy, and as a pollutant extractor. The peat samples studied were collected in the margins of the Mogi Guacu river, in Sao Paulo state. The peat samples and the humic acids extracted from peat were characterized by several techniques. The results showed that the material can be applied in agriculture and presents a great potential for removal of environmental contaminants, besides being a good source of humic acids. (author)

  9. 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

    Miranda, Cleidiene S.; Oliveira, Jamerson C.; Guimaraes, Danilo H.; Jose, Nadia M., E-mail: [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)


    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)

  10. 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

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


    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)

  11. Influence of several nonferrous metals in the treatment of residual liquors from hydrochloric acid pickling processes. Influencia de diversos metales no ferreos en el tratamiento de lejias residuales de decapado con acido clorhidrico

    Negro, C.; Cobos, M.A.; Latorre, R.; Dufour, J.; Formoso, A.; Lopez, F.


    In the oxiprecipitation of waste liquors from siderurgical processes of pickling with hydrochloric acid, several kinds of iron oxides and oxihydroxides are obtained: alpha-FeOOH, gamma-FeOOH, Fe[sub 3]O[sub 4], gamma-Fe[sub 2]O[sub 3]. Fe[sub 2]O[sub 3].1,2H[sub 2]O, etc. These products can be used like pigments in the painting industry and like raw materials for the obtaining of ferrites. Varying the operation conditions, the presence of these products can be changed greatly, obtaining different mixtures of them. The presence of non-ferrous metals catalyzes and modifies the mechanism of the reaction, yielding pure products. This simplifies their later industrial applications. The aim of this work is to determine the influence of Cu(II), Zn(II), Mo(VI) and Al(III) on the oxiprecipitation of residual liquors from hydrochloric acid pickling processes, selecting the most favourable operation conditions at which it is possible to obtain products for industrial applications.

  12. 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

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


    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)

  13. 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)

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


    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)

  14. Treatment effect with hydrogen peroxide and/or stannous chloride in incubate cell culture with glucoheptonic acid; Efeito do tratamento com peroxido de hidrogenio e/ou cloreto estanoso em cultura celular encubada com acido glucoheptonico

    Assis, M.L.B.; Silva, F.C.P. da; Caldeira de Araujo, A.; Valsa, J.O. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Biologia; Bernardo Filho, M. [Instituto Nacional do Cancer, Rio de Janeiro, RJ (Brazil). Centro de Pesquisa Basica


    The stannous salt (Sn Cl{sub 2}) can be found in an associated form with another molecules, as in the kits for the production of {sup 99m} technetium labeled radiopharmaceuticals, widely employed in nuclear medicne procedures. Here, it was described the results obtained with treatment of an Escherichia coli AB1157 culture with Sn CL{sub 2} [5,5 x 10{sup -5} M] associated to the radiopharmaceuticals glucoheptonic acid (GHA). Our results show a culture`s protection in differents concentrations of GHA [2 x 10{sup -}2 M], [4 x 10{sup -2} M], [1 x 10{sup -1} M] and [2 x 10{sup -1} M], eliminating, almost completely, the lethal effect of the Sn CL{sub 2}. The culture survival was not affected when submitted only to GHA (control) solution. When the culture was submitted to hydrogen peroxide (H{sub 2} O{sub 2}) [2 x 10{sup -2} M] associated to the same concentration of GHA, we did not obtain protection, suggesting, a chelating action of GHA on the stannous ions. Further experiments associating Sn Cl{sub 2} [5,5 x 10{sup -5} M] + H{sub 2} O{sub 2} [2 x 10{sup -2} M] + GHA [4 x 10{sup -2} M] tend to confirm this result, as well as to suggest the sinergistic effect between the Sn Cl{sub 2} and the H{sub 2} O{sub 2}. (author). 20 refs, 3 figs.

  15. Combustion synthesis by reaction and characterization of nano ferrites: study of fuel aniline, citric and its mixture; Sintese por reacao de combustao e caracterizacao de nanoferritas Ni-Zn: estudo dos combustiveis anilina, acido citrico e sua mistura

    Silva, M.C. da; Coutinho, J.P.; Costa, A.C.F.M., E-mail: [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais; Kiminami, R.H.G.A. [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Engenharia de Materiais; Freitas, N.L. de [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Tecnologia do Desenvolvimento


    The present study aims to evaluate the influence of aniline and citric acid used alone and combined in a ratio of 50% each in the characterization of NiZn ferrite synthesized by combustion reaction method in a muffle furnace. Measurements were made of temperature and reaction time. The nano-powders were characterized by XRD, EDX, textural analysis and SEM. The highest temperature was achieved by the reaction using the mixture of fuel and increased reaction time using citric acid. The nano ferrites using different fuels, and the mixture changed phases, the crystallite size and decreased surface area of the samples with aniline, citric acid and a mixture of both, respectively. The powder morphology ranged from presenting the formation of irregular blocks for the use of citric agglomerated in the form of skeins with aniline and a mixture to agglomerate larger particles. (author)

  16. Influence of zeolite treated with sulphuric acid and sodium hydroxide on the coagulation-flocculation process of drainage. Influencia de la zeolita tratada con acido sulfurico y con hidroxido de sodio en el proceso de coagulacion floculacion en aguas superficiales

    Gutierrez Duque, M.; Herrera Vasconcelos, T.; Laria Piedra, N.


    The present paper has had as objective the treatment of natural zeolite from Tasajera with sulfuric acid and sodium hydroxide (residuals acid and basic from the regeneration of cationic and anionic resins of the ''Otto Parallada'' thermoelectric plant) at different times and concentrations, with a further comparison and testing of the effectiveness of the obtained zeolite in respect to the natural one as a coadyuvant of the coagulation-flocculation process in the treatment of superficial water. (Author)

  17. Hydrometallurgical route to recover molybdenum, nickel, cobalt and aluminum from spent hydrotreating catalysts in acid medium; Rota hidrometalurgica de recuperacao de molibdenio, cobalto, niquel e aluminio de catalisadores gastos de hidrotratamento em meio acido

    Valverde Junior, Ivam Macedo; Paulino, Jessica Frontino; Afonso, Julio Carlos [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica. Dept. de Quimica Analitica]. E-mail:


    This work describes a hydrometallurgical route for processing spent commercial catalysts (CoMo and NiMo/Al{sub 2}O{sub 3}). Samples were preoxidized (500 deg C, 5 h) in order to eliminate coke and other volatile species present. The calcined solid was dissolved in concentrated H{sub 2}SO{sub 4} and water (1:1 vol/vol) at 90 de C; the insoluble matter was separated from the solution. Molybdenum was recovered by solvent extraction using tertiary amines at pH around 1.8. Cobalt (or nickel) was separated by addition of aqueous ammonium oxalate at the above pH. Phosphorus was removed by passing the liquid through a strong anion exchange column. Aluminum was recovered by neutralizing the solution with NaOH. The route presented in this work generates less final aqueous wastes because it is not necessary to use alkaline medium during the metal recovery steps. (author)

  18. 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

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


    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)

  19. 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.)

    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:; 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:, e-mail:; Coelho, Maysa Joppert [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Nuclear. Engenharia Ambiental], e-mail:; 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:; Pacheco, Sidney [EMBRAPA Agroindustria de Alimentos, Rio de Janeiro, RJ (Brazil). Lab. de Cromatografia Liquida, Ciencia e Tecnologia de Alimentos], e-mail:


    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)

  20. {sup 1} H and {sup 13} C NMR studies on the enoling of 5-benzyl barbituric acids; Estudos por H-1 e C-13 RMN da enolizacao de acidos 5-benzil barbituricos

    Villar, Jose Daniel Figueroa; Santos, Nedina Lucia dos; Cruz, Elizabete Rangel [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Quimica


    This work shows that the derivatives of the 5-benzyl barbituric acids hydroxylated at the ortho position of the aromatic ring only exist in the enol form. and that the alkylation of this hydroxyl gives products which exist mainly in the ketone form of the DMSO 5 refs., 2 figs., 2 tabs.

  1. 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

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


    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)

  2. Influence of the addition of bentonite clay in poli (butylene adipate co-terephthalic) / poly(lactic acid) membranes; Influencia da adicao de argila bentonita em membranas de poli(butileno adipato co-tereftalico)/poli(Acido latico)

    Morais, D.D.S.; Medeiros, K.M.; Araujo, E.M.; Melo, T.J.A. [Universidade Federal de Campina Grande (UAEMa/UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais; Barbosa, R., E-mail: [Universidade Federal do Piaui (CT/UFPI), PI (Brazil). Centro de Tecnologia


    The processes of membrane separation have been used in many different sectors of industrial activity, ranging from the chemical industry, food, pharmaceutical, medical and biotech. In this paper, a bentonite clay was added by melt intercalation in a poly(butylene adipate-co-terephthalic acid)/poly(lactic acid) blend at levels 1 and 3 wt% of clay. After that, membranes were produced by solvent evaporation technique. From the XRD results, it was verified the possible formation of exfoliated/partially exfoliated structures in the membranes. By DSC, it was observed that the addition of clay did not promote alterations in glass transition temperature and crystalline melting of the PBAT/PLA matrix. The morphology of the membranes were observed by SEM and it was verified the clay formation of porous membranes. (author)

  3. Influence of -tocopherol on arachidonic acid deposition and peroxidation in Atlantic salmon (Salmo salar L.) fingerlings/Influencia del -tocoferol en la incorporacion y peroxidacion del acido araquidonico en alevines parr de salmon del Atlantico (Salmo salar L.)

    Dantagnan, Patricio; Dominguez, Astrid; Borquez, Aliro; Alcaino, Javier; Pavez, Claudio; Hernandez, Adrian


    The synergistic effect of arachidonic acid (ARA) (20:4n-6) and [alpha]-tocopherol on the accumulation of fatty acids and the peroxidation of lipids in liver and muscle was evaluated in Atlantic salmon (Salmo salar) juveniles...

  4. Effect of niobium addition to the Fe-17% Cr alloy on the resistance to generalized corrosion in sulfuric acid; Efeito da adicao de niobio a liga Fe-17% Cr sobre a resistencia a corrosao generalizada em acido sulfurico

    Alonso, Neusa; Wolynec, Stephan


    The aim of present work was to investigate the influence of Nb upon the corrosion resistance to o.5 M H2 SO{sub 4} cf 17% Cr ferritic stainless steels, to which it was added in amounts larger than those necessary for the stabilization of interstitial elements. The performance of Fe-17% Cr alloys containing 0.31%, 0.58%, 1.,62% Nb was compared to that of two other Fe-17% Cr alloys containing 0.31%, 0.58% and 1.62% Nb was compared to that of two other Fe-175 Cr alloys, one without additions and another containing 0.93% Nb. Through weight and electrochemical measurements and through morphologic examination of corroded surface it was found that in o.5 M H{sub 2} SO{sub 4} solution the corrosion of these alloys, with the exception of that containing molybdenum, products in two different stages. In the first stage (up to about 60 minutes) the rate practically does not change with time, the lower rates being displayed by alloys containing larger mounts of Nb. In the second stage (for immersion times larger than 60 minutes) the corrosion rate increases with time. the corrosion rate of Mo containing alloy is constant with time so that for longer immersion times this alloy becomes the most resistant. The first stage was discussed in terms of electromechanical properties of Nb and its ability to combine with steel impurities, while the second stage was considered as affected by corrosion products formed on the surface of these alloys after certain time of immersion. (author) 24 refs., 1 fig., 3 tabs.

  5. 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

    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:; Chiaro, S.S.X. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)


    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)

  6. 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

    沈含熙; 王连生


    @@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。

  7. Impact of acid mine drainage from mining exploitations on the Margajita River basin and the Hatillo reservoir (Dominican Republic); Impacto del drenaje acido de explotaciones mineras en la cuenca del Rio Margajita y Embalse de Hatillo (Republica Dominicana)

    Grandia, F.; Salas, J.; Arcos, D.; Archambault, A.; Cottard, F.


    Mining of the Pueblo Viejo high-sulphidation epithermal deposit (Dominican Republic) leads to environmental impact due to the formation of acid mine drainage associated with the oxidative dissolution of sulphides and sulpho salts. In addition to the very low pH, the acid waters are capable of transporting away from the mining areas high concentrations of metals and metalloids in solution. In the present work, a geochemical study of sediments deposited in the Hatillo reservoir is carried out. This reservoir is fed by the Margajita and Yuna streams which transport leachates from the Pueblo Viejo and Falcondo-Bonao (Cr-Ni) mining areas, respectively. The results show that these sediments have very high concentrations of Fe, Al and sulphate, along with significant amounts of As, Zn and Te, which are of especial environmental concern. The main contributor to this metal discharge into the reservoir is the Margajita stream, whereas the Yuna stream does not transport significant amounts of metals in solution due to its neutral pH, although it is likely that metals such as Mn, Cr, Ni and Co can be mobilised as a particulate. (Author) 5 refs.

  8. 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)

    Edgar Omar Rueda Puente; Enrique Troyo Dieguez; Thelma Castellanos Cervantes; Bernardo Murillo-Amador; Bertha Olivia Arredondo Vega; Jose Luis Díaz de Leon Alvarez; Mario Antonio Tarazon Herrera


    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 raíce...

  9. 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

    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)


    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)

  10. 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

    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)


    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)

  11. Un nuevo Método para Mejorar el Proceso de Producción de Acido Bórico A New Method to Improve the Production Process of Boric Acid

    Orlando J Domínguez; Emilio M Serrano; Jorge E Flores; Raquel L Michel


    En este trabajo se propone una modificación al proceso tradicional para obtener ácido bórico, con el agregado fraccionado del ácido lixiviante, para lograr un producto altamente soluble, como el pentaborato de sodio. Con esto se consigue la disolución del mineral en frío con menor cantidad de reactivo lixiviante, ahorrando así energía. Al líquido clarificado se le disminuye el pH logrando así la precipitación del ácido bórico. La ganga se agota con diferentes etapas de precipitación y filtrac...

  12. Effect of organoclays content and modify the impact on mechanical properties of of bionanocomposites poly (lactic acid ) - PLA; Efeito do teor de argilas organofilicas e modificador de impacto nas propriedades mecanicas de bionanocompositos de poli (acido latico)-PLA

    Cavalcanti, Shirley N.; Alves, Amanda M.; Agrawal, Pankaj; Silva, Moacy P. da; Araujo, Aylanna P.M.; Araujo, Edcleide M.; Melo, Tomas J.A., E-mail: [Universidade Federal de Campina Grande (UFCG), Campina Grande, PB (Brazil). Departamento de Engenharia de Materiais


    Until recently, it has become important to develop more durable plastic materials to meet the needs of the market, which have wide range of applications. But these materials are from non-renewable sources cause environmental impact due to the large amount of waste they produce. In order to evaluate the effect of organoclay (Brasgel PA and vermiculite) and impact modifier (EMA-GMA) were developed PLA bionanocomposites / Clays through the merge process by melting and rated the content (1, 3 and 5pcr) the mechanical properties of these clays. The clays were organophilizated using a percentage of surfactant based on the capacity of cation exchange. The bionanocomposites were prepared by extrusion followed the injection molding step of the specimens. The clays were characterized by X-ray diffraction (XRD).The bionanocomposites were characterized by the mechanical properties of impact and traction. The techniques of X-ray diffraction showed that organophilization process used was efficient. The mechanical properties were changed, and the impact strength showed considerable gain when the PLA was blended with the copolymer and the organoclay. (author)

  13. 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

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


    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.

  14. Adição de IN3 a derivados de acidos -alquil cinamicos : obtenç2o de 2-alquil-3-fenil-1-azirinas e 3-azido-2-azetidinonas

    Cintia Maria Rubo de Souza Nobre


    Resumo: O presente trabalho iniciou-se com a preparação da 2- fenil-3-carbometoxi-1-azirina (16) onde se pretendia o estudo da reatividade dos dois centros eletrófilos existentes no carbono da ligação imino e na carbonila do éster. . Reação entre o sistema 16 com hidrazina em benzeno, conduz a o 4-aminopirazol-3-ona (26) interceptado primeiramente com a adição ao meio reacional, de benzaldeído e depois acetil acetona através da obtenção respectivamente, da base de Schiff 37 e enaminona 38 cor...

  15. 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

    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


    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)

  16. Influence of several non ferrous metals in the treatment of residual liquors from sulfuric acid picking processes. Influencia de diversos metales no ferreos en el tratamiento de lejias residuales de decapado con acido sulfurico

    Negro, C.; Gonzalez, A.; Latorre, R.; Dufour, J.; Formoso, A.; Lopez-Mateos, F. (Departamento de Ingenieria Quimica. Facultad de Ciencias Quimicas, Universidad Complutense, Madrid (Spain))


    In the oxiprecipitation of waste liquors from sulfuric picking processes several kinds of ferrous oxides and oxihydroxides are obtained which can be used like raw materials for the chemical industry. Generally, in this process different mixtures of then are obtained and only in the most drastic conditions, pure products can be obtained. The presence of non-ferrous metals catalyzes and modifies the mechanism of the reaction, yielding pure products. The aim of this work is to determine the influence of Cu(II), Al(III), Zn(II) and Mo(VI) on the oxiprecipitation of residual liquors from sulfuric acid picking processes, selecting the most favorable operation conditions at which it is possible to obtain products for industrial applications. (Author) 20 refs.

  17. Avaliação histometrica da regeneração periodontal obtida com o uso de membranas reabsorviveis de acido polilactico em defeitos periodontais em cães

    Enilson Antonio Sallum


    Resumo: O objetivo deste estudo foi avaliar o uso das membranas reabsorvíveis (GUIDOR `MARCA REGISTRADA´) no tratamento de defeitos periodontais em cães, utilizando análise histométrica, comparando com o uso da terapia convencional. Deiscências ósseas vestibulares (3x5mm) foram criadas nas raízes distais dos terceiros pré-molares mandibulares (P3) em 5 cães e uma tira matriz metálica tipo Toffelmire foi fixada na área. Três meses após a fabricação do defeito, as bandas metálicas foram removid...

  18. 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

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


    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)


    Claudia Martinez


    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.

  20. 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

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


    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)

  1. Synthesis of high refractive spiro heterocyclic derivatives through thioacetalization of multi-carbonyl compounds

    Ye, Jim Young; Maheswara, Muchchintala; Do, Jung Yun [Pusan National Univ., Busan (Korea, Republic of)


    Preparation of several new spirocyclic mercaptol derivatives is described. Thiol protection on multi-carbonyl compounds allows of high sulfur content necessary to induce high refractive index. Condensation of 1,3-dimercapto-2-propanol and cyclohexanone followed by successive oxidation and thioacetalization affords a dispiro cycle with four sulfurs. Selective S,S-protection of cyclohexane-1,4-dione is achieved with 1,3-dimercapto-2-propanol and 2,3-dimercapto-1-propanol to provide dispiro cycles with four sulfurs. Olefineoxidation of norbornene gives a useful dialdehyde intermediate which is transformed to 1,3-dithiolane for a linearly-bound-cyclic molecule. Refractive index of linearly-bound-cycles was below 1.60 and dispiro cycles exhibited high refractive index of 1.57-1.69.

  2. Bioquímica: pH and Equilibrios ácido – base, 2010-11

    González-Núñez, Verónica


    I. Materiales de clase: 1. Introducción. Conceptos previos; 2. Curvas de titulación de ácidos and bases; 3. Aminoácidos. Propiedades ácido – base; 4. Curvas de titulación de aminoácidos; 5. Problemas sobre equilibrios acido - base and aminoácidos; 6. Mantenimiento del pH en el medio extracelular; 7. Estudio del equilibrio acido-base de un paciente; 8. Casos prácticos de alteraciones del equilibrio acido-base. II. Bibliografía. III. Materiales complementarios El objetivo general de esta asi...

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

    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)


    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.




    La sicurezza e la qualità degli alimenti sono tutt’ora un problema critico per i paesi in via di sviluppo. Le diete a basso contenuto di acido folico, per esempio, possono causare gravi problemi di salute, soprattutto nei bambini. Gravi disturbi legati al tubo neurale (DTN) nei neonati possono derivare infatti da madri che hanno insufficiente apporto di acido folico (400-600 g / giorno) durante il periodo di gravidanza. Inoltre, se non adeguatamente protetti o trattati, I prodotti alimentari ...

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

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


    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.

  6. 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

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


    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)

  7. 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 Determination of the E-Z fumaric and maleic acids configuration. An experiment designed to develop scientific research abilities in undergraduates students

    Carlos Bustos


    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.

  8. 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

    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:


    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)

  9. 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

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


    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)

  10. Effect of support on the crystalline structure, the acid-base properties and activity of iron based systems in the CO + H{sub 2}O reaction; Influence du support sur la structure cristalline, les proprietes acido-basiques et l'activite des systemes a base de fer en reaction CO + H{sub 2}O

    Bouarab, R. [Ecole nationale Polytechnique, Dept. des Sciences Fondamentales, Alger (Algeria); Bouarab, R.; Boudjemaa, A.; Trari, M. [Faculte de Chimie, USTHB, Lab. C. G. N. et L. S. V. E. R., Alger (Algeria); Bennici, S.; Auroux, A. [Institut de Recherches sur la Catalyse et l' Environnement de Lyon, UMR 5256, CNRS-UCB Lyon1, 69 - Villeurbanne (France)


    The water gas shift reaction was studied in the temperature range of 350-450 C over iron based catalysts exempt of Cr{sub 2}O{sub 3}. The basic properties and CO conversion of these catalysts are given in the following sequence: Fe{sub 3}O{sub 4}/MgO {>=} Fe{sub 3}O{sub 4}/TiO{sub 2} {>=} Fe{sub 3}O{sub 4} {>=} Fe{sub 3}O{sub 4}/SiO{sub 2}. The basic catalysts are consequently more active than acid ones. On the other hand, the DRX results showed a strong crystalline fraction of MgO in the Fe{sub 3}O{sub 4}/MgO catalyst calcined at 400 C. Hence, Fe{sub 3}O{sub 4}/MgO generates an MgO reservoir able to feed the catalyst surface with formate species during the water gas shift reaction. (authors)

  11. 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

    Alonso Lopez, J.


    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.

  12. 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

    Rouy, E


    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)

  13. Trimerization process of vegetables oils and fats and its application in additives for synthetic fluids used in the perforation of petroleum well bore; Processo de trimerizacao de oleos vegetais e acidos graxos e sua aplicacao em aditivos para fluidos sinteticos utilizados na perfuracao de pocos de petroleo

    Moreira, Viviane X.; Souza, Roberta C.R.; Coelho, Anderson S.; Lopes, Grazielle; Yoshida, Renan O.; Goncalves, Gizelle de Fatima G.D.V.; Silva, Sandra Regina da [Centro Tecnico Aeroespacial (CTA), Sao Jose dos Campos, SP (Brazil). Centro de Tecnologia; Poland Quimica Ltda., Macae, RJ (Brazil)


    Derivatives of vegetable oils and fatty acids such epoxides, polyols and fatty acid dimmers are industrially used for a variety of polymer applications, such as additives for plastics and composites and in filtration control aid in in perforation fluids as well as in the synthesis of polyamides and polyurethanes. In this article a vegetable oil was chemically modified by trimerization and used as filtration control and in a paraffin based perforation fluid. The rheology and filtration parameters were studied and the results were compared to desired specifications to maintenance of stability of well bore. (author)

  14. 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.

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


    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.

  15. 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

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


    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)

  16. 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

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


    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.

  17. 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

    Magdalena, Carina Pitwak


    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)

  18. Enrichment of nitrogen-15 by Nitrox system. Part 2: determination of the fractionation factor, height of an equivalent theoretical plate and production of nitric acid enriched in nitrogen-15; Enriquecimento de nitrogenio-15 pelo sistema Nitrox. Parte 2: determinacao do fator de fracionamento, altura equivalente de uma placa teorica e producao de acido nitrico enriquecido em nitrogenio-15

    Ducatti, Carlos [UNESP, Botucatu, SP (Brazil). Inst. de Biociencias. Dept. de Fisica e Biofisica; Matsui, Eichii [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)


    The expression S = f(alpha, P,L,N{sub o},N{sub p}) showed here, allows the simultaneous determination of the isotopic fractionation factor ({alpha}) by Nitrox System and the number of theoretical plates (s) of the column in countercurrent. For the experimental conditions utilized, room temperature, atmospheric pressure, column packing with stainless steel. Gauze spiral type of ({theta} o,4x h 0,4) cm, feed flow (1,4{+-}0,2) cm{sup 3}/min, feed concentration (4,7 {+-} 0,2)M and (0,369{+-} 0,001) atoms % {sup 15}N, the isotopic fractionation factor of HNO{sub 3}/NO system was {alpha} = 1,062 {+-} 0,001. The total number of theoretical plate (s) and height of an equivalent theoretical plate (HETP) of the isotopic exchange column was 45,3 {+-} 7,1 and (9,1 {+-} 1,6) cm, respectively. It was also vefified that the production of H {sup 15} NO{sub 3} in the isotopic exchange column shows a comprise relationship subject to the same time interval, which means to withdrow little quantity of H{sup 15} NO{sub 3} subject to low concentration (130 cm{sup 3} H{sup 15} NO{sub 3}/week; 2.0 atoms % {sup 15} N). (author). 7 refs., 6 tabs., 3 figs.

  19. Enrichment of nitrogen-15 by nitrox system. Part 1: countercorrent column of aqueous nitric acid and nitrogen oxides in gaseous phase; Enriquecimento de nitrogenio-15 pelo sistema Nitrox. Parte 1: coluna de contracorrente entre solucao de acido nitrico e oxidos de nitrogenio na fase gasosa

    Ducatti, Carlos [UNESP, Botucatu, SP (Brazil). Inst. de Biociencias. Dept. de Fisica e Biofisica; Bonassi, Jose A.; Matsui, Eichii [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)


    In this paper described the operational mode of countercurrent column of aqueous nitric acid and nitrogen oxides (Nitrox System) for the production of nitric acid in the concentration of 5% atoms of {sup 15} N in laboratory. (author). 8 refs., 2 tabs., 1 fig.

  20. Synthesis of polyaniline catalysed by Cu(I), Ni(II) and Fe(II) supported on the polyethylene-i-acrylic acid copolymer; Sintesis de polianilina catalizada por Cu(I), Ni(II) y Fe(II), soportados en el copolimero polietileno-i-acido acrilico

    Hernandez, L.; Urena, F.; Lopez, R. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)


    In this study the active sites of acrylic acid (AA) were grafted in low density polyethylene (PEBD) using gamma radiation. Subsequently, the graft copolymer PEBD-i-AA was coordinated with different metals such as copper, nickel and iron. The organometallic copolymers so formed were used as catalysts in the aniline polymerization reaction. Finally, it was realized the characterization of the obtained products, determining their thermal properties, copolymer graft percentage, quantification of the metal contained in the complex as well as polymerization and electric conductivity percentages of the poly aniline film. (Author)

  1. 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

    Kuad, P


    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.)

  2. Bactérias do acido láctico e leveduras associadas com o queijo-de-minas artesanal produzido na região da Serra do Salitre, Minas Gerais Lactic acid bacteria and yeasts associated with the artisanal Minas cheese produced in the region of Serra do Salitre, Minas Gerais

    C.D.L.C. Lima


    Full Text Available Em 10 fazendas da região da Serra do Salitre, MG, foram coletadas amostras de leite, soro fermentado (pingo, coalhada e queijo frescal para avaliar a microbiota de bactérias láticas e leveduras presentes. Uma diversidade menor de bactérias láticas foi observada durante a produção do queijo quando comparada à de leveduras. As espécies de bactérias láticas mais freqüentes foram Lactococcus lactis, Enterococcus spp., Enterococcus faecalis e Streptococcus agalactiae e de leveduras foram Debaryomyces hansenii e Kluyveromyces lactis. Apenas as populações de Enterococcus spp., Enterococcus faecalis e Leuconostoc mesenteroides apresentaram aumento significativo durante a produção do queijo. As espécies de bactérias láticas e leveduras encontradas nos diferentes substratos estudados podem ser responsáveis pelas características de aroma e sabor do queijo artesanal da Serra do Salitre.Samples of milk, curd, cheese whey, and cheese were collected in 10 farms located at the region of Serra do Salitre, Minas Gerais state. These samples were studied in relation to their lactic acid bacteria and yeast populations. The diversity of lactic acid bacteria species was lower than the diversity of yeasts in these samples. The isolated lactic acid bacteria were Lactococcus lactis, Enterococcus spp., Enterococcus faecalis, and Streptococcus agalactiae; and the yeasts were Debaryomyces hansenii and Kluyveromyces lactis. Only the species Enterococcus spp., Enterococcus faecalis, and Leuconostoc mesenteroides showed an increase in their populations during the production of the artisanal cheese. Lactic acid bacteria and yeasts found in this study could be responsible by the sensorial characteristics of the artisanal cheese produced in the region of Serra do Salitre.

  3. Increase resolution of {sup 13}C NMR spectra of humic acids in solution by previous treatment with 0,03 mol L{sup -1} KCl; Aumento da resolucao de espectros de RMN {sup 13}C de acidos humicos em solucao atraves do tratamento previo com KCl 0,03 mol L{sup -1}

    Canellas, Luciano Pasqualoto; Guridi, Fernando; Santos, Gabriel de A. [Universidade Federal Rural do Rio de Janeiro, RJ (Brazil). Dept. de Solos; Rumjanek, Victor Marcos [Universidade Federal, Rio de Janeiro, RJ (Brazil). Dept. de Quimica; Braz-Filho, Raimundo [Universidade Estadual do Norte Fluminense, Campos, RJ (Brazil). Setor de Quimica dos Produtos Naturais


    High levels of Fe and Mn present in some soils and compost organic matter decrease the resolution of {sup 13} C NMR spectra of humic substances. Addition of K Cl up to a concentration of 0,03 mol L{sub -}{sup 1} to humic substances extracts followed by centrifugation is an efficient method of eliminating clays and minerals containing high levels of paramagnetic metals such as Fe and Mn thus increasing the resolution of {sup 13} C NMR spectra. (author)

  4. Poderá o carrapato transmitir a lepra?: mais quatro amostras de culturas de bacilos acido-alcool resistentes obtidas de carrapatos (2 de "Amblyomma cajennense"e 2 de "Boophilus microplus" infectados em leprosos do Paraná: 3ª nota May leprosy be transmitted by ticks?: third note

    H. C. de Souza-Araujo


    Full Text Available The AA. carried out experiments in the leprosarium São Roque, State of Paraná, South Brazil, to verify if the cattle tick Boophilus microplus could be experimentally infected in lepers, which was true. The AA. Tried also to be ascertained if Boophilus microplus and Amblyomma cajennense could change of hosts during their feedings which was true, both ticks continue feeding, the last species for many days, after being transferred from one to another leper. The junior A. describes in full their experiments and also a dermatites caused by tick bites. The senior A. brought to Rio de Janeiro most of the infected ticks for examination, which revealed a very high positivity. He smeared the sediments of lots of both species of ticks in Loewenstein medium and after a variable periode of incubation at 37° C. he obtained four new samples of cultures of acid-fast organisms, two from Amblyomma cajennense and two from Boophilus microplus. These cultures are being studied and will be inoculated into laboratory animals. The senior A. inoculated new batches of white rats with sediments of many ticks infected in lepers. Various hypotheses of both previous notes upon the subject now are verified facts. The A. is accumulating facts to draw the conclusions in the future. He also suggested the leprosy workers in the interior of the country to cooperate with him in such important studies, specially in the habitat of lepers in the rural zones of various States.

  5. 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

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


    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)

  6. 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

    Toda, Maria Aparecida


    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)

  7. 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

    María V Kyanko


    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

  8. Synthesis of aluminum oxide by the polymer precursor method (Pechini) in 4: 1 ratio of citric acid: metal cation: calcination temperature effect; Sintese do oxido de aluminio pelo metodo dos precursores polimericos (Pechini) na relacao 4:1 de acido citrico: cation metalico: efeito da temperatura de calcinacao

    Silva, M.C.; Lira, H.L.; Ribeiro, P.C.; Freitas, N.L., E-mail: [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais


    The technology field is nanopowders prominent in science since these materials fall in various sectors regarding their applications. This work aims at the synthesis of aluminum oxide by polymeric precursors in 4:1 ratio of citric acid:metal cation and evaluate the influence of calcination temperature on their structural and morphological characteristics. The samples after reaction were characterized by XRD and thermal analysis. After calcination 500-1200°C the samples were characterized by XRD, SEM and particle size distribution. The results showed that the variation of the calcination temperature is sufficient to achieve a same material with different structural and morphological characteristics. The most stable phase aluminum oxide arose only after calcination at 1100°C, below 900°C, the amorphous material appeared. As regards the morphology, the change was not as significant as compared to the structure. (author)

  9. 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)

    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: [Universite Paris-Sud, Institut de Physique Nucleaire, Georges Clemenceau No. 15, Orsay (France)


    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)

  10. Evaluation and characterization of ceramic membranes based on Pdms/SiC containing phosphotungstic acid as electrolytes for PEM-FC; Avaliacao e caracterizacao de membranas ceramicas condutoras a base de PDMS/SiC contendo acido fosfotungstico como eletrolito para PEM-FC

    Lima, Marcelo de Oliveira; Guimaraes, Danilo Hansen; Boaventura Filho, Jaime Soares; Jose, Nadia Mamede [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica. Grupo de Energia e Ciencias dos Materiais; Barbosa, Diego Augusto Batista; Paschoal, Carlos William de Araujo [Universidade Federal do Maranhao (DF/UFMA), Sao Luis, MA (Brazil). Dept. de Fisica; Almeida, Rafael Mendonca; Tanaka, Auro Atsushi [Universidade Federal do Maranhao (DQ/UFMA), Sao Luis, MA (Brazil). Dept. de Quimica


    This work presents the development of membranes with potential use in Proton Exchange Fuel Cells (PEM-FC), consisting of hybrid materials based on poly(dimethylsiloxane), crosslinked with tetraethyl orthosilicate (TEOS), and reinforced with silicon carbide and phosphotungstic acid. The membrane series PDMS/TEOS/SiC/PWA were prepared by the reaction of PDMS and TEOS, 70/30% proportions in mass, catalyzed by dibutyltin dilaurate. SiC was incorporated in a 25% proportion, and PWA in varied proportions (5, 10, 15 and 20%), by weight. The membranes were characterized by Thermo-Gravimetric Analysis (TGA), X-ray Diffraction, Scanning Electron Microscopy and impedance spectroscopy. SiC and PWA addition to the membrane increased both structure organization and material crystallinity. The insertion of PWA provided an increase in the conductivity. However, maximum conductivity was obtained with concentration levels above 10%. The insertion of SiC associated with the PWA did not influence the conductivity for concentrations between 10 and 20%. (author)

  11. 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

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


    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.

  12. Synthesis of chromatographic standards and establishment of a method for the quantification of the fatty ester composition of biodiesel from babassu oil; Sintese de padroes cromatograficos e estabelecimento de metodo para dosagem da composicao de esteres de acidos graxos presentes no biodiesel a partir do oleo de babacu

    Urioste, Daniele; Castro, Matheus B.A.; Biaggio, Francisco C.; Castro, Heizir F. de [Universidade de Sao Paulo (USP), Lorena, SP (Brazil). Escola de Engenharia]. E-mail:


    Several alkyl esters were synthesized, purified, characterized by {sup 1}H NMR and employed as standards for establishing chromatographic methods to monitor their formation in the synthesis of biodiesel. The efficiency of the chromatographic methods was confirmed with the products of enzymatic transesterification of babassu oil with different alcohols (C{sub 2} to C{sub 4}), using Lipozyme as catalyst. (author)

  13. 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

    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


    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.

  14. 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

    María V Kyanko; Mara L Russo; Mariela Fernández; Graciela Pose


    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 obse...

  15. Determination of uranium and {sup 2}10Po in the river Odiel to assess the radioactive impact of acid mine drainage; Determinacion de uranio y {sup 2}10Po en el rio Odiel para valorar el impacto radiactivo de los drenajes acidos mineros

    Manjon, G.; Lehritani, M.; Mantero, J.; Diaz Frances, I.; Garcia-Tenorio, R.


    Since 1986 this research group has been monitoring of radioactive environmental impact in the estuary of the river Odiel, generated by the factories of production of phosphoric acid from Huelva, that emitting NORM waste. Once closed factories, is observed a second source of contamination: mining drains. To verify this source have been studied concentration levels of natural radionuclides in the waters and sediments of the river Odiel, in areas that are incorporated drains. (Author)

  16. 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

    Curcho, Michel Rodrigues da Silva Morales


    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)

  17. 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

    Serrano V, E. C.


    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)

  18. Influencia del [alpha]-tocoferol en la incorporacion y peroxidacion del acido araquidonico en alevines parr de salmon del Atlantico (Salmo salar L.)/Influence of [alpha]-tocopherol on arachidonic acid deposition and peroxidation in Atlantic salmon (Salmo salar L.) fingerlings

    Patricio Dantagnan; Astrid Domínguez; Aliro Bórquez; Javier Alcaíno; Claudio Pavez; Adrián Hernández


      The synergistic effect of arachidonic acid (ARA) (20:4n-6) and a-tocopherol on the accumulation of fatty acids and the peroxidation of lipids in liver and muscle was evaluated in Atlantic salmon (Salmo salar) juveniles...

  19. 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

    Maria Luiza Sant'Anna Tucci


    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.

  20. 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

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


    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.

  1. 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

    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


    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)

  2. 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

    Nahama, F.


    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)

  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

    Joaquín Peña


    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. 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

    Garcia G, N.


    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)

  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

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


    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. 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

    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)


    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)


    Javier Antonio Padilla Funes


    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.

  8. Metal chelate process to remove pollutants from fluids

    Chang, Shih-Ger T.


    The present invention relates to improved methods using an organic iron chelate to remove pollutants from fluids, such as flue gas. Specifically, the present invention relates to a process to remove NO.sub.x and optionally SO.sub.2 from a fluid using a metal ion (Fe.sup.2+) chelate wherein the ligand is a dimercapto compound wherein the --SH groups are attached to adjacent carbon atoms (HS--C--C--SH) or (SH--C--CCSH) and contain a polar functional group so that the ligand of DMC chelate is water soluble. Alternatively, the DMC' is covalently attached to a water insoluble substrate such as a polymer or resin, e.g., polystyrene. The chelate is regenerated using electroreduction or a chemical additive. The dimercapto compound bonded to a water insoluble substrate is also useful to lower the concentration or remove hazardous metal ions from an aqueous solution.

  9. Metal chelate process to remove pollutants from fluids

    Chang, S.G.T.


    The present invention relates to improved methods using an organic iron chelate to remove pollutants from fluids, such as flue gas. Specifically, the present invention relates to a process to remove NO[sub x] and optionally SO[sub 2] from a fluid using a metal ion (Fe[sup 2+]) chelate wherein the ligand is a dimercapto compound wherein the --SH groups are attached to adjacent carbon atoms (HS--C--C--SH) or (SH--C--CCSH) and contain a polar functional group so that the ligand of DMC chelate is water soluble. Alternatively, the DMC is covalently attached to a water insoluble substrate such as a polymer or resin, e.g., polystyrene. The chelate is regenerated using electroreduction or a chemical additive. The dimercapto compound bonded to a water insoluble substrate is also useful to lower the concentration or remove hazardous metal ions from an aqueous solution. 26 figures.

  10. Enriquecimiento de huevos con ácidos grasos omega-3 mediante la suplementación con semilla de lino (linum usitatissimum) en la dieta

    Betancourt Fernández, Liliana; Díaz, Gonzalo


    ... de huevo, se puede ver afectada por cambios en la composicion de la dieta (2). La grasa saturada y monoinsaturada tiene un menor efecto sobre el perfil de acidos grasos del huevo (3), que la grasa rica en acidos grasos poliinsaturados, la cual puede causar mayores cambios en el perfil (4), permitiendo de esta manera, la manipulacion de la composicion de los lipidos de la yema para cubrir los requerimientos nutricionales de los humanos. El interes sobre la relacion entre la dieta y la salud humana, proveen ...

  11. Influencia de dos aceites ricos en ácido oleico sobre el transporte e incorporación tisular de los triglicéridos

    Perona, Javier S


    Existe una sobrada evidencia de que la denominada Dieta Mediterránea está asociada con una disminución de la incidencia de enfermedades cardiovasculares. Este efecto ha sido tradicionalmente atribuido al acido oleico, procedente del aceite de oliva. Sin embargo, el aceite d ... e oliva virgen, pero no otro aceite muy rico en acido oleico, como es el aceite de girasol alto-oleico, reduce la presión arterial en sujetos sanos y pacientes hipertensos. Entre estos dos aceites destacan las diferenc...

  12. Desenvolvimento e caracterização de fosfato de cálcio fluoretado em esmalte dentário

    Marise de Oliveira


    Uma alternativa ao condicionamento acido do esmalte para a retencao dos adesivos ou para restaurar caries em esmalte e o crescimento de cristais na superficie do mesmo. Uma tecnica nova de crescimento de cristais, que utiliza uma pasta com solucao de peroxido de hidrogenio e acido fosforico adicionada ao po de fosfato de calcio fluoretado (F-CaP), FHA 110, F-HA 900 ou F-ÀTCP, foi aplicada a superficie do esmalte para a obtencao de recobrimento. Esse procedimento foi feito por 8 vezes na tecni...

  13. Influencia de dos aceites ricos en ácido oleico sobre el transporte e incorporación tisular de los trigliceridos

    Perona, Javier S.


    Existe una sobrada evidencia de que la denominada Dieta Mediterránea está asociada con una disminución de la incidencia de enfermedades cardiovasculares. Este efecto ha sido tradicionalmente atribuido al acido oleico, procedente del aceite de oliva. Sin embargo, el aceite d ... e oliva virgen, pero no otro aceite muy rico en acido oleico, como es el aceite de girasol alto-oleico, reduce la presión arterial en sujetos sanos y pacientes hipertensos. Entre estos dos aceites destacan las diferenc...

  14. 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

    Laura V Aquino; Juan Rodríguez; Lilia L Méndez; Kenia F Torres


    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 pl...

  15. Disease: H00241 [KEGG MEDICUS

    Full Text Available H00241 Combined proximal and distal renal tubular acidosis (RTA type 3) Renal tubular (RTA) is characterized by metabolic acidosis, a severe disturbance of extracellular pH homeostas...0 PMID:11045400 (gene) Rodriguez-Soriano J New insights into the pathogenesis of renal tubular acidosis--fro...m functional to molecular studies. Pediatr Nephrol 14:1121-36 (2000) PMID:17557941 (gene) Fry AC, Karet FE Inherited renal acidos...riguez Soriano J Renal tubular acidosis: the clinical entity. J Am Soc Nephrol 13

  16. Renal Toxicity of Mercuric Chloride at Different Time Intervals in Rats

    W.A. Al-Madani


    Full Text Available This study was undertaken to study the renal toxicity of mercuric chloride in rats at different periods of time. The following groups of rats were studied: i control, ii placebo, iii rats injected with a single ip dose of 100 mg/kg body weight of 2, 3 dimercapto- 1-propanesulfonic acid, iv rats injected with a single ip dose of 100 mg/kg body weight of 2, 3 dimercapto-1-propanesulfonic acid (DMPS followed by a single dose ip of 2.0 mg HgCl2/kg body weight one hour after DMPS injection v rats injected with a single ip dose of 2.0 mg HgCl2/kg body weight. Results indicate that mercuric chloride was more toxic after 48 hours of its administration when compared to 24 hours. Mercuric chloride administration caused an impairment of renal function which was evident from a significant decrease in urine volume, urinary excretion of urea, creatinine and glomerular filteration rate (P < 0.001 when compared to other treated groups. There was an increased excretion of protein, albumin and γ—glutamyltransferase in the urine of mercuric chloride treated rats. Administration of 2, 3 dimercapto-1-propanesulfonic acid before mercuric chloride treatment caused the altered indices to return to near normal levels.

  17. Selective copper(II acetate and potassium iodide catalyzed oxidation of aminals to dihydroquinazoline and quinazolinone alkaloids

    Matthew T. Richers


    Full Text Available Copper(II acetate/acetic acid/O2 and potassium iodide/tert-butylhydroperoxide systems are shown to affect the selective oxidation of ring-fused aminals to dihydroquinazolines and quinazolinones, respectively. These methods enable the facile preparation of a number of quinazoline alkaloid natural products and their analogues.

  18. NCBI nr-aa BLAST: CBRC-DMEL-01-0033 [SEVENS

    Full Text Available CBRC-DMEL-01-0033 ref|YP_987846.1| methyl-accepting chemotaxis sensory transducer [Acido...vorax sp. JS42] gb|ABM43770.1| methyl-accepting chemotaxis sensory transducer [Acidovorax sp. JS42] YP_987846.1 5.0 27% ...

  19. A Cielo o que e de Cesar: obtido em Roma, o recorde mundial dos 100 metros, a prova mais nobre da natacao, poe Cesar Cielo nos verbetes de enciclopedias do esporte e na historia dos poucos idolos mundiais brasileiros

    Altman, Fabio


    ... lancinante que so tem um remedio: a vitoria. So o primeiro lugar no podio de um campeonato mundial, com o melhor tempo da historia, ou o ouro olimpico, como o dos 50 metros em Pequim, sao capazes de aliviar a sensacao de queimadura interna provocada pelo acumulo de acido latico no sangue quando ele e produzido em esforcos musculares sobre-humanos....

  20. Efficacy and safety of alendronic acid in the treatment of osteoporosis in children.

    Martín Siguero, Alberto; Áreas Del Águila, Vera Lucía; Franco Sereno, María Teresa; Fernández Marchante, Ana Isabel; Pérez Serrano, Raúl; Encinas Barrios, Carmen


    Objetivos: describir la efectividad y seguridad del uso de acido alendronico en el tratamiento de la osteoporosis en ninos y adolescentes, en condiciones distintas a las autorizadas en la ficha tecnica. Métodos: estudio retrospectivo (2008-2014) de todos los pacientes menores de 18 anos a los que se dispenso acido alendronico para esta indicacion. Los criterios para iniciar tratamiento fueron: densidad mineral osea con puntuacion Z-score ≤ -2,5 DE, antecedentes de fracturas oseas sin traumatismo previo y dolor persistente. Las variables recogidas fueron: demograficas, de tratamiento, clinicas y de seguridad. Se considero efectividad del tratamiento al aumento de la densidad mineral osea hasta obtener Z-score > -2,5 DE. Resultados: un total de 12 pacientes, 8 varones, con una media de edad de 11 anos (} 3 DE), fueron tratados con acido alendronico. Tras un tiempo medio de tratamiento de 2,15 anos (} 1,2 DE), se produjo aumento de la densidad mineral osea en todos los pacientes, 9 de los cuales obtuvieron Z-score > -2,5 DE, por lo que el farmaco se considero efectivo en el 75% de los casos. Ningun paciente presento fracturas oseas ni manifesto efectos adversos durante el tratamiento. Conclusiones: el acido alendronico incremento la densidad mineral osea y se tolero bien en todos los pacientes, por lo que se podria considerar como opcion terapeutica en el tratamiento de la osteoporosis infantil.

  1. AcEST: BP914988 [AcEST

    Full Text Available ctase OS=Delftia acido... 37 0.081 sp|Q9M7D0|TPSD9_ABIGR Terpinolene synthase, chloroplastic OS=Abi... 31 4....LERLQELRDS 210 >sp|Q9M7D0|TPSD9_ABIGR Terpinolene synthase, chloroplastic OS=Abies grandis GN=ag9 PE=1 SV=1

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

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


    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.

  3. NCBI nr-aa BLAST: CBRC-TBEL-01-0326 [SEVENS

    Full Text Available CBRC-TBEL-01-0326 ref|YP_872485.1| NADH/Ubiquinone/plastoquinone (complex I) [Acido...thermus cellulolyticus 11B] gb|ABK52499.1| NADH/Ubiquinone/plastoquinone (complex I) [Acidothermus cellulolyticus 11B] YP_872485.1 0.90 39% ...

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

    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...

  5. Condensed aromatic rings and E{sub 4}/E{sub 6} ratio: humic acids in gleysoils studied by NMR CP/MAS{sup 13}C, and dipolar dephasing; Aneis aromaticos condensados e relacao E{sub 4}/E{sub 6}: estudo de acidos humicos de gleissolos por RMN de {sup 13}C no estado solido utilizando a tecnica CP/MAS desacoplamento defasado

    Saab, Sergio da Costa [Universidade Estadual de Ponta Grossa, PR (Brazil). Dept. de Fisica]. E-mail:; Martin-Neto, Ladislau [Empresa Brasileira de Pesquisa Agropecuaria, Sao Carlos, SP (Brazil)


    In this work, seven samples of humic acids extracted from gleysoils were investigated. These studies, using NMR CP/MAS {sup 13}C techniques, did not show significant correlation between the E{sub 4}/E{sub 6} ratio and the degree of aromaticity. However, dipolar dephasing (DD) measurements of condensed aromatic or substituted carbons showed a negative correlation of 0.94. Also, there was a good correlation between the amount of semiquinone free radicals measured by the EPR technique and condensed aromatic rings measured by NMR CP/MAS {sup 13}C with the DD technique. The content of semiquinone free radicals was quantified by EPR spectroscopy and was correlated with the humification (degree of aromaticity) of the humic substances. The results indicated that the E{sub 4}/E{sub 6} ratio identifies the degree of aromatic rings condensation. It was also found that the degree of aromaticity, measured by NMR, as frequently presented in the literature (by conventional CP/MAS), underestimates aromatic rings in condensed structures. (author)

  6. Study of behaviour of Biobeds SM No.7 and Amberlite XAD No.7 chromatographic resins containing di-2-ethyl-hexilphosphoric acid in Eu{sup 3+} and Am{sup 3+} extraction and concentration; Estudo do comportamento das resinas cromatograficas bio-beds SM No.7 e amberlite XAD No.7 contendo o acido di-2-etilexilfosforico na extracao e concentracao de Eu{sup 3+} e Am{sup 3+}

    Kuada, Terezinha A.; Felinto, Maria Claudia F. Cunha; Yamaura, Mitiko; Lobao, Afonso S.T. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)


    The extraction of Eu(III) and Am (III) in extraction chromatograpy has been investigated on the basis of partition and infrared studies. The stationary phases were DHEPA supported on Biobeads SM7 and Amberlite XAD7 and the mobile phase was nitric acid solutions. The system seems to be very good for extraction of Eu and Am. The results obtained shown that the capacity factor of these columns were 251.95 and 3039.15 for Eu and Am respectively for DEHPA/Amberlite XAD No.7 and 349.69 and 3132.79 for Eu and An respectively for DEHPA/Biobeads SM No.7. (author)

  7. 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

    Paulo Roberto Ceridóreo Corrêa


    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


    Adriane de Andrade Silva


    Full Text Available A rocha verdete é uma fonte possível de utilização como fertilizante potássico. Porém há uma limitação para melhorar sua disponibilização, sendo assim objetivou-se caracterizar o verdete quanto ao potencial de utilização agrícola, observar se ocorrerá aumento da disponibilidade de potássio, cálcio, magnésio quando o verdete for submetido a diferentes doses de ácido húmico e ácido fosfórico. Os testes de incubação foram realizados em potes de poliuretano com uso de LATOSSOLO VERMELHO de textura argilosa, o qual foram incubados tratamentos de diferentes doses de acido fosfórico; acido fosfórico+ acido húmico; acido humico. O ensaio foi conduzido por 90 dias, foram realizadas 2 coletas, aos 45 dias e 90 dias após a incubação. Realizou-se a determinação dos teores de potássio Houve efeito na disponibilização de potássio nos diferentes tratamentos e dosagens dos ácidos. A liberação de potássio foi maior quando se utilizou o ácido húmico de forma exclusiva. Porém houve efeito da utilização do acido fosfórico e do acido fosfórico + acído húmico. O cálcio, em relação ao tratamento controle observou-se um incremento de  53 a 75%. E o magnésio apresentou comportamento similar ao cálcio.  Sendo assim concluiu-se que o verdete apresentou-se uma fonte de potássio com aumento da solubilização quando submetido a ataque dos ácidos testados. O ácido húmico foi a fonte de ácido que melhor disponibilizou o K.  Há efeito das doses de ácido na disponibilização do K, Ca e Mg pela Rocha verdete.

  9. The adsorption of 2,5-dimer- capto-1,3,4-thiadiazole (DMTD) on copper surface and its binding behavior


    The interaction mechanism of 2,5-dimercapto- 1,3,4-thiadiazole (DMTD) on copper surface was studied by surface-enhanced Raman scattering (SERS), infrared (IR) and X-ray photoelectron spectroscopy (XPS) techniques. The SERS spectra were obtained. We found that DMTD bound with the copper via its two-excocyclic mercapto groups. The monosulphide salt was formed. At the same time, DMTD coordinated with the Cu+ ion through the excocyclic mercap-to groups and polymerized via the Cu+ ion into a one- dimen-sional polymer chain on the copper surface.

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

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


    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.

  11. Chemical Stockpile Disposal Program Final Programmatic Environmental Impact Statement Volume 3: Appendices A-S


    exposures produce behavioral and cardiovascular symptoms in man. Methylene chloride tested positive for carcinogenicity in rats (Fund. Appl. Toxicol... Cardiovascular Effects of Anticholinesterase Medications," Am. J. Med. Sci. 293(l), 18-23. Auerbach, C. H. 1950. "Differences Between Effects of Chemical...1, 1371-74. B-185 Ghiringhelli, L., and Di Fabio, A. 1957. ." Patologia da acido acetico: osservazioni negli animali da esperimento e nell’uomo

  12. Sintese de derivados do esteviosideo


    Resumo: 0 estudo descrito nesta disserta~ao refere-se a sintese de compostos derivados do esteviosideo. 0 esteviosideo e urn glicosideo extraido da Stevia rebaudiana, fornecido pela Esteviafarma Inga Industrial S.A.. Da hidr6lise enzimatica deste composto foi obtido o esteviol, urn diterpeno acido tetraciclico com esqueleto caurenico, do qual foram obtidos alguns derivados. A bibliografia revisada mostrou que muitos diterpenos tetraciclicos naturais apresentam efeitos biol6gicos. Poucos foram...


    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


    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.

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

    Jaramillo Benavides, Alvaro Hugo


    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.

  15. Determinación simultánea de metales con el ácido dietilenotriaminopentaacético (ADTP) por espectrofotometría derivada

    Pérez Iglesias, Julia



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

    Rohacova ., Jana


    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 ...

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

    Vicario Romero, Isabel María


    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...

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

    Reinaldo Aparecido Bariccatti


    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.

  19. [Use of fish oil lipid emulsions in hospitalized patients under 18 years old with abnormal results in liver tests associated with total parental nutrition].

    Giraldo Villa, Adriana; Henao Roldan, Catherine; García Loboguerrero, Fanny; Martínez Volkmar, María Isabel; Contreras Ramírez, Mónica María; Ruiz Navas, Patricia


    Introducción: La Nutricion Parental Total (NPT) prolongada esta asociada con complicaciones potencialmente mortales en la poblacion pediatrica como lo es la colestasis. Dentro del soporte nutricional, la fuente de acidos grasos, el contenido de fitoesteroles y la dosis de lipidos se han relacionado con el desarrollo de esta complicacion. Objetivo: Describir el comportamiento de las pruebas hepaticas en pacientes pediatricos con NPT en quienes se uso lipidos a base de acidos grasos omega 3 (omegavenR). Métodos: Estudio retrospectivo, en menores de 18 anos con tratamiento intravenoso por minimo 8 dias con acidos grasos omega 3. Los pacientes fueron inicialmente clasificados en dos grupos: colestasis y alteracion de pruebas hepaticas. Se evaluo el comportamiento de la transaminasa glutamico oxalacetica (TGO), transaminasa glutamico piruvica (TGP), bilirrubina total (BT), bilirrubina directa, gama glutamil transferasa (GGT) y fosfatasa alcalina (FA) antes y despues del tratamiento con omegaven R. Resultados: 33 pacientes cumplieron los criterios de inclusion. Al finalizar la administracion de omegavenR, 82,4% de los pacientes que presentaron inicialmente colestasis mostraron resolucion o mejoria. En el grupo de pacientes con alteracion de pruebas hepaticas 18,8% progresaron a colestasis. Conclusiones: Nuestro estudio sugiere que el uso de omegaven R en pacientes pediatricos con NPT y BD ≥ 2 mg/dL, parece revertir o mejorar la colestasis, mientras que en pacientes con alteracion de pruebas hepaticas aun no se tiene claro su efecto.

  20. Ensamble, diseño y ensayo de un potenciometro computarizado

    Rocio Bojacá B.


    Full Text Available Se ha ensamblado una unidad potenciométrica (U.P. para mediciones de pH y fuerza electromotriz en procesos estáticos y de titulación. La reproducibilidad en mediciones de pH es de 0.013 unidades de pH y 0.01 mi en volumen. El potenciómetro consta de un acoplador de impedancias, un amplificador de ganancia variable y una interfase (convertidor análogico/Digital. El computador utilizado es un Kaypro II y et graficador es Phillips 8154. El software desarrollado incluye tos programas calibra (estandarización de la U.P. en dos pH diferentes, titula, tit140 y Tit1400 (titulaciones ácido-base y Redox y Ajus (cálculos de volimen como función de pH o potencial. En los ensayos de la U.P. se insiste en las diferencias que se observan en las gráficas cuando se titula un Acido Fuerte o un Acido Débil. En el primer caso se propone la denominación Zona Estabilizadora y en et segundo Zona Buffer o amortiguadora, donde se forma el típico sistema Acido/Sal.

  1. Metal exposure in the physically and mentally challenged children of Punjab, India

    Blaurock-Busch, E.; Friedle, Albrecht; Godfrey, Michael; Schulte-Uebbing, Claus E.E.


    ABSTRACT We collected 149 hair samples at the Baba Farid Centre at Faridkot in Punjab, India to evaluate the trace and toxic metal concentration via ICP-MS. A total of 53 elements were tested. The hair of the children tested showed high values for Ba, Cd, Mn, Pb and U, signifying long-term exposure. Urine baseline testing supported hair analysis findings for all the elements listed above; a DMSA (Dimercapto Succinic Acid) challenge test raised urinary values for lead. Testing of six randomly selected water samples showed concentrations above the European maximum contaminant level for uranium (U) in three samples and lead (Pb) in one. Research aim: To evaluate if hair analysis and/or urine provocation confirm or refute long term metal intoxication. To support or refute that hair mineral analysis confirms urine challenge test results. To support or refute that a DMSA urine challenge test provides a valuable treatment option for metal exposure in children. Conclusion: Our results documented that hair and urine mineral analysis results are supportive of each other, and are both useful diagnostic tools in chelation therapy. We also documented that a DMSA challenge test confirms long term exposure as detected through hair mineral analysis. This indicates that the chelating agent DMSA (Dimercapto succinic acid) provides a safe and valuable treatment option for lead overexposure. PMID:21977132

  2. 三维网状冠醚配合物(Bu4N){[K(18-C-6)][Cd4(dmit)2(dmt)3]}的合成与结构%Synthesis and Crystal Structure of a Novel Three-dimensional Network Crown Ether Complex (Bu4N) {[K(18-C-6)][Cd4(dmit)2(dmt)3]}

    王大奇; 窦建民; 牛梅菊; 李大成; 刘颖



  3. 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}

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


    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)

  4. 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

    Charry Calle Jairo


    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.

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

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


    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.

  6. Modeling boron separation from water by activated carbon, impregnated and unimpregnated

    Ristic, M.; Grbavcic, Z. [Belgrade Univ., Belgrade (BA). Faculty of Technology and Metallurgy; Marinovic, V. [Belgrade Univ., Belgrade (BA). Ist. of Technical Science of the Serbian Academy of Science and Arts


    The sorption of boron from boric acid water solution by impregnated activated carbon has been studied. Barium, calcium, mannitol, tartaric acid and citric acid were used as chemical active materials. All processes were performed in a chromatographic continuous system at 22{sup 0} C. Experimental results show that activated carbon impregnated with mannitol is effective in removing boron from water. The separation of boron from the wastewater from a factory for producing enameled dishes by activated carbon impregnated with mannitol was also performed. Two models have been applied to describe published and new data on boron sorption by impregnated activated carbon. Both of them are based on the analysis of boron concentration response to the step input function. This led to a mathematical model that quite successfully described impregnation effects on adsorption capacities. [Italian] E' stato studiato l'assorbimento del boro, mediante carbone attivo impregnato, da soluzioni acquose di acido borico. Quali materiali chimici attivi sono stati utilizzati: bario, calcio, mannitolo, acido tartarico ed acido citrico. Tutti i processi sono stati condotti in un sistema cromatografico continuo a 22{sup 0}C. I risultati sperimentali mostrano che il carbone attivo impregnato con mannitolo e' efficace nella rimozione del boro dall'acqua. E' anche stata effettuata la separazione del boro da acque di scarico di un'industria per la produzione di piatti smaltati mediante carbone attivo impregnato con mannitolo. Sono stati applicati due modelli per descrivere i risultati, pubblicati e nuovi, dell'assorbimento del boro mediante carbone attivo impregnato. Entrambi sono basati sull'analisi della risposta alla concentrazione di boro successivamente incrementata a stadi. Cio' porta ad un modello matematico che descrive abbastanza soddisfacentemente gli effetti dell'impregnazione sulla capacita' di assorbimento.

  7. Accumulation of Tc99m-DMSA-3 in the spleen in a case of multiple myeloma with associated amyloidosis

    Barai Sukanta


    Full Text Available We describe a case of a 58-year-old male with longstanding hypertension and Type 2 diabetes mellitus who developed sudden onset renal impairment. The first clue to the possible presence of amyloidosis in this case was provided by the radionuclide renal cortical scan performed with trivalent dimercapto succinic acid (Tc99m-DMSA-3, which revealed intense tracer uptake in the spleen suggesting amyloid deposit. Further workup to ascertain the cause of amyloidosis led to the diagnosis of multiple myeloma. We conclude that in cases of extra-renal or splenic accumulation of Tc99m-DMSA-3, a diagnosis of amyloidosis should be considered, in an appropriate clinical setting.

  8. Radiographic Evaluation of Children with Febrile Urinary Tract Infection: Bottom-Up, Top-Down, or None of the Above?

    Michaella M. Prasad


    Full Text Available The proper algorithm for the radiographic evaluation of children with febrile urinary tract infection (FUTI is hotly debated. Three studies are commonly administered: renal-bladder ultrasound (RUS, voiding cystourethrogram (VCUG, and dimercapto-succinic acid (DMSA scan. However, the order in which these tests are obtained depends on the methodology followed: bottom-up or top-down. Each strategy carries advantages and disadvantages, and some groups now advocate even less of a workup (none of the above due to the current controversies about treatment when abnormalities are diagnosed. New technology is available and still under investigation, but it may help to clarify the interplay between vesicoureteral reflux, renal scarring, and dysfunctional elimination in the future.

  9. Sondas fluorescentes acuosolubles para metales tóxico

    Vázquez González, Margarita


    En la presente memoria se describe la síntesis de puntos cuánticos (PCs) CdTe acuosolubles utilizando como ligandos estabilizantes el ácido tioglicólico (TGA), el ácido 2,3-dimercaptosuccínico (DMSA) y el ácido 2,3-dimercapto-1-propanosulfónico (DMPS) y su posterior recubrimiento con corazas ZnS o CdS. En primer lugar se obtuvieron PCs DMPS-CdTe (PC1). Posteriormente, el empleo conjunto de DMPS y TGA permitió preparar PCs mixtos TGA·DMPS-CdTe (PC2) con mejores propiedades ópticas que PC1. ...

  10. Prebiotic Oxidative Polymerization of 2,3 Dimercaptopropanol on the Surface of Iron(III) Hydroxide Oxide

    Weber, Arthur L.


    The oxidation of 2,3-Dimercapto-1-propanol by ferric ions on the surface of iron (III) hydroxide oxide yielded polydisulfide polymers. This polymerization occured readily at low dithiol concentration under mild aqueous conditions. Polydisulfide polymers up to the 15-mer were synthesized from 1 mM dithiol in 5 ml water reacted with iron (III) hydroxide oxide (20 mg, 160 micro mole Fe) for 3 days under anaerobic conditions at 40 C and pH 4. About 91% of the dithiol was converted to short soluble oligomers and 9% to insoluble larger oligomers that were isolated with the mineral phase. Reactions at higher dithiol concentrations with the same ratio of dithiol to mineral gave a higher yield of the larger insoluble oligomers. The relationship of these results to prebiotic polymer synthesis will be discussed.

  11. The influence of the electroactive PDMcT hybrid HDL / polyaniline and its application as an adsorbent of the pesticide endosulfan (ES); Estudo da influencia do PDMcT no hibrido eletroativo HDL/PAni, e sua aplicacao como adsorvente do pesticida endosulfan (ES)

    Freitas, L.L. de; Nunes, B.N.; Santana, L.K.; Amaral, F. A. do; Canobre, S.C., E-mail: [Universidade Federal de Uberlandia (LAETE/UFU), MG (Brazil). Instituto de Quimica


    By the method of co-precipitation at constant pH was possible to perform the chemical synthesis of hybrid materials with HDLs bridging agent having as 2,5-dimercapto 1,3,4-thiadiazole (DMcT) and organic material capable of intercalating and polymerization (PAni). From the results of X-ray can be concluded that there was obtained the desired lamellar structure for collating the conductive polymer. From SEM micrographs, it was observed that the composite HDL / PDMcT / polyaniline, has a large number of compact crystallites various characteristic shapes and PDMcT polyaniline nanofibers. The VC of the ternary composite showed a significant increase of anodic charge. Given the results of adsorption of 98% of the pesticide in the composite polyaniline / PDMcT / HDL, it can contribute significantly to the removal of pesticide endosulfan contaminated water.(author)

  12. Chelation therapy in intoxications with mercury, lead and copper

    Cao, yang; Skaug, Marit Aralt; Andersen, Ole;


    mobilize deposits of mercury as well as of lead into the urine. These drugs can be administered orally and have relatively low toxicity compared to the classical antidote dimercaptopropanol (BAL). d-Penicillamine has been widely used in copper overload, although 2,3-dimercaptosuccinic acid......In the present review we provide an update of the appropriate use of chelating agents in the treatment of intoxications with compounds of mercury, lead and copper. The relatively new chelators meso-2,3-dimercaptosuccinic acid (DMSA) and 2,3-dimercapto-propanesulphonate (DMPS) can effectively...... or tetrathiomolybdate may be more suitable alternatives today. In copper-toxicity, a free radical scavenger might be recommended as adjuvant to the chelator therapy...

  13. 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

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


    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. Coloraciones histológicas vs microscopia electrónica de transmision para detección de Biopeliculas en pacientes con Rinosinusitis Crónica en el Hospital Universitario de la Samaritana en el año 2011

    Reyes Gelves, Camilo Andres; Gutierrez Guauque, Omar Alberto; Andrade Perez, Rafael Enrique; Contreras Villa, Dimas Dennis


    Objetivo: Determinar la concordancia entre microscopia de luz vs microscopia electrónica de transmisión para la detección de Biopeliculas en pacientes con Rinosinusitis Crónica Diseño: Estudio de concordancia. Materiales y Métodos: Analizamos 34 muestras de pacientes llevados a Cirugía Endoscópica Funcional por Rinosinusitis Crónica. Fueron procesadas para valoración mediante microscopia de luz usando Hematoxilina-Eosina, Gram, Acido Peryódico de Schiff, Giemsa y Microscopia Electrónica...

  16. Valoraci??n del estatus de tiamina en un colectivo andaluz y su relaci??n con otros par??metros


    INTRODUCCI??N: Las vitaminas del grupo B (piridoxina, riboflavina, cianocobalamina, acido f??lico, etc.) se relacionan estrechamente como componentes de coenzimas que intervienen en procesos de obtenci??n de energ??a para llevar a cabo reacciones metab??licas b??sicas para el organismo como el ciclo de Krebs, el ciclo de pentosa-P, etc... La vitamina B1 es, en ocasiones, desestimada de la lista de sustancias valoradas en una determinada poblaci??n, por descartar la posible deficie...

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


    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...

  18. Estudio del etiquetado de los alimentos funcionales

    Delgado González, Patricia


    El estudio del etiquetado de los alimentos, fundamentalmente de los alimentos funcionales, se basa en el estudio previo de éstos. Dentro de este grupo podemos encontrarnos distintos componentes como polioles, aminoácidos, ácidos grasos insaturados, fitoesteroles, vitaminas, minerales, bacterias ácido-lácticas, fibra, entre otros. Los probióticos son microorganismos vivos, bacterias acido lácticas saprófitas para nuestro organismo y que nos ayudan a mejorar ciertas funciones como las gastro...


    Laura Angélica Hurtado Fino


    Full Text Available Normal 0 21 false false false ES-CO X-NONE X-NONE Objetivos: Evaluar el efecto en la adhesión sobre cerámica de zirconio de diferentes tratamientos en ensayos de cizalla. Métodos: 160 cilindros de resina fueron unidos a especímenes de cerámica de zirconio, cerámica feldespática y metal siguiendo diferentes protocolos. Se utilizaron 4 tipos de cemento y se utilizaron 16 diferentes métodos de adhesión. Los cilindros se almacenaron por 24 horas en ambiente húmedo a 37ºC y luego sometidos a prueba de resistencia al corte. El análisis estadístico fue realizado con el análisis de varianza (ANOVA a una y dos vías; procedimiento de diferencia mínima significativa (LSD de Fisher bajo un nivel de significancia del 5% y prueba de Kruskal-Wallis. Resultados: el zirconio tratado, luego de la cerámica feldespática fue el que presentó mayor resistencia de unión al corte. La media general más grande de los grupos de cerámica de zirconio fue el grupo 5 (acido fluorhídrico 8.0859 Mpa, seguida del grupo 8 (coral experimental, 7.62965 Mpa, el grupo 7 (acido nítrico, 6.7618 Mpa, el grupo 6 (acido sulfúrico, 6.24245 Mpa y el grupo 4 (zirconio tratado únicamente con silano, 3.66635 Mpa. En general para la cerámica de zirconio con los diferentes tratamientos superficiales se observa un mejor comportamiento en promedio del cemento RelyX® U100 (3M (8.00428 Mpa que el Multilink® (IVOCLAR (4.95018 Mpa con una diferencia estadísticamente significativa. Conclusión: Los tratamientos superficiales como el acido nítrico a temperatura ambiente y coral experimental sobre la cerámica de zirconio, son una alternativa de fácil manipulación para mejorar valores de adhesión.


    Watanabe Velásquez, Romel Armando; Magister Profesor Asociado Departamento Académico Estomatología Rehabilitadora. Facultad de Odontología. UNMSM.


    With the purpose to observe the variations the dimensions of the eptely and the caver of the cornea, as well as the grade of querationation of the tipper mucous for the use of complete prothesys. Biopsip of tippermucous were done before the work and 60 daip after the installation of the complete prothesys the samples of the biopsip were fixed in metodo from and colouned urtle Hematoxilina and acido peryodico. The measurem were alone, using a micrometric ocular and the results were subject to ...

  1. Estudio del etiquetado de los alimentos funcionales

    Delgado González, Patricia


    El estudio del etiquetado de los alimentos, fundamentalmente de los alimentos funcionales, se basa en el estudio previo de éstos. Dentro de este grupo podemos encontrarnos distintos componentes como polioles, aminoácidos, ácidos grasos insaturados, fitoesteroles, vitaminas, minerales, bacterias ácido-lácticas, fibra, entre otros. Los probióticos son microorganismos vivos, bacterias acido lácticas saprófitas para nuestro organismo y que nos ayudan a mejorar ciertas funciones como las gastro...

  2. “uso y evaluación de dos aceites esenciales (canela y clavo de olor) para control de las pudriciones fungosas y determinación de la vida útil mediante películas protectoras comestibles en papaya (carica papaya c.v.hawaiana)”

    Martínez Martínez, Leovina Ingrid


    La alta demanda de los consumidores por productos con características naturales y larga vida ha determinado el estudio de nuevas técnicas de preservación y, entre ellas, el estudio de la formulación y desarrollo películas con el fin de ser utilizadas como recubrimiento de alimentos para aumentar su vida útil. Los objetivos del presente trabajo fueron determinar el efecto de la aplicación de una película comestible (almidón de maíz, acido esteárico, glicerol, agua)con diferentes concentracione...

  3. Síntesis y caracterización espectroscópica de sulfatos de hierro: implicaciones en astrobiología y la exploración de Marte


    Hay una serie de aspectos que fundamentan la necesidad y el interés de las investigaciones que en este proyecto de tesis se recogen. Por un lado, el interés por los sulfatos de hierro. Estos sulfatos tienen unas características físico químicas y estructurales que suponen un autentico mundo a descubrir y describir, con variadas composiciones, variados comportamientos acido-base y redox, diferentes grados de hidratación y diferentes disposiciones estructurales para mismas composiciones. La ...

  4. Inspección visual con ácido acético (IVAA) en la detección precoz del cancer de cuello uterino :

    Foresi, Ana María del Valle


    Tesis Doctor en Medicina y Cirugía -- Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. La Inspección Visual con Acido Acético (IVAA) constituye una alternativa frente a la citología Exfoliativa en el examen de detección del cuello de útero en lugares de escasos recursos o como complemento de papanicolaou en zonas de mediano recursos. OBJETIVOS: Examinar la sensibilidad, especiaficidad, valor predictivo positivo y negativo de los tres métodos de pesquisa (inspección visual con...

  5. Estudio de adsorción de boro con amberlite IRA 743

    Marín Martínez, Alberto J.


    Este proyecto estudia los equilibrios y las cinéticas de adsorción de boro en forma de acido bórico en medio acuoso, mediante Amberlite IRA743, una resina de políestireno copolimerizado con divinilbenceno. Se realizan equilibrios a diferentes concentraciones para obtener una isoterma de adsorción y su ecuación corresponiente. Se hacen ensayos a distintas concentraciones de cinéticas de adsorción en batch y mediante balances de materia, la ecuación de equilibrio de la isoterma hayada y l...

  6. Rani neurološki ishod novorođenčadi s intrauterinim zastojem u rastu

    Starčević, Mirta


    Uvod: intrauterini zastoj u rastu (IUGR) se smatra osobitim čimbenikom rizika za pojavu neurorazvojnih odstupanja i nepovoljan dugoročni neurorazvojni ishod. Ciljevi istraživanja: utvrditi prediktivnu vrijednost doplerskih parametara fetalne cirkulacije, te parametara acido-baznog statusa iz krvi pupkovine za rani neurološki ishod novorođenčadi s IUGR-om. Odrediti optimalne granične vrijednosti praćenih parametara fetalne cirkulacije koji ukazuju na rizik neuroloških posljedica...

  7. Yogurt funcional alto CLA

    Massa Grilli, Elisa


    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 ...

  8. Uso del ácido 2-formilbezoico en la obtención de sistemas heterocíclicos fusionados de interés biológico


    En este trabajo se presenta el uso del acido 2- formilbenzoico en la obtención de nuevos sistemas heterocíclicos con potencial actividad biológica. Dichos sistemas están formados por la unión del sistema isocumarínico al sistema imidazolico por medio dos átomos compartidos; la síntesis de las isocumarinas fue realizada por la metodología reportada por Opatz1 a partir de una reacción multicomponentes. Una vez sintetizada la isocumarina se intentó realizar la síntesis One Pot del sistema fus...

  9. Expresiones del CD44 en tejidos periapicales inflamados.

    Siragusa, Martha; Dietrich, Gustavo; Pisterna, Gabriela; D'Arrigo, Mabel


    Recibido: Noviembre 2011 - Aceptado: Marzo 2012 El granuloma periapical es una lesión inflamatoria crónica causada por una infección poli bacteriana. Las moléculas de adhesión del CD44 están fuertemente expresadas en células variadas tales como los leucocitos, células parenquimatosas e incluyendo células endoteliales, en células epiteliales y en células musculares. Tiene interacción con el Acido Hialurónico, con el colágeno, lamininas y fibronectina y juega un rol importante en la migraci...

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

    José de Jesús Pérez-Saavedra; Sonia Rincón-Arce; Miguel Ángel Cisneros-Valladares


    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.

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

    Rodríguez Patino, J. M.; de la Fuente Feria, J.; Gómez Herrera, C.


    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 iaalanza 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 subíase. La estructura...

  12. El aceite de pescado atenua las crisis convulsivas inducidas por hipertermia en ratas neonatas

    Leopoldo E. Flores M.; Miguel A. Guevara; Alfredo Feria-Velasco; Luís Cerdán S.; Marisela Hernández-González


    Un alto porcentaje (50-60%) del cerebro en los mamíferos son principalmente grasas o lípidos, de éstos, el 35% son ácidos grasos esenciales, en particular los llamados omegas (O), como el Acido Docosahexanoico (DHA) y el Eicosapentanoico (EPA) llamados omega 3 (O-3). Diversos estudios han mostrado beneficios en la salud con la implementación de los O-3 como agentes terapéuticos en alteraciones cardiovasculares, renales, dérmicas, metabólicas, neurodegenerativas e inmunológicas. Evidencias ...

  13. Impacto del arsénico en yacimientos auríferos

    Hidalgo Velasco, María del Rosario


    El presente trabajo tiene por objeto expresar los mecanismos naturales de generación del arsénico en la minería su movilidad y su solubilidad en ambientes acuosos como el Drenaje Acido de Roca (DAR) y agua de los ríos. Para lo cual se plantea alternativas de remoción y mitigación del arsénico en diferentes escalas de caudal; para aguas que satisfagan la Ley General de Aguas (LGA) clase III y la ley del agua potable. The present thesis trys to explain the natural process for Acid Drainage c...

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

    Junco González, José Luis


    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...

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

    Rubén Darío Torrenegra


    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.


    William H.J. Strosnider; Freddy S. Llanos; Cristina E. Marcillo; Ruben R. Callapa; Robert W. Nairn


    La minería intensiva y el procesamiento del cuerpo mineralizado del Cerro Rico de Potosí (Bolivia) ha ocurrido desde 1545. Para avanzar la investigación sobre descargas de drenaje acido de minas (DAM) y su conexión a la contaminación río abajo, se generaron datos en dos muestreos durante la temporada más extrema de lluvia y sequía. Las concentraciones en el DAM y arroyos receptores de Ag, B, Ba, Mo, Sb, Se, Sn, y V fueron superiores a los límites de descarga permitidos por la legislación Boli...

  17. Utilização de um novo material mesoporoso funcionalizado PABA-MCM-41 na remoção de hidrocarbonetos policíclicos aromáticos (HPAs)

    Costa, José Arnaldo Santana


    Este trabalho descreve a sintese e caracterizacao do material mesoporoso MCM-41 e do novo material mesoporoso funcionalizado PABA-MCM-41 para serem utilizados como materiais adsorventes na remocao dos HPAs benzo[k]fluoranteno (B[k]F), benzo[a]pireno (B[a]P) e benzo[b]fluoranteno (B[b]F). Os dois materiais foram sintetizados pelo metodo hidrotermal, sendo que PABA-MCM-41 foi sintetizado pelo metodo hidrotermal/co-condensacao, o qual foi funcionalizado pelo acido 4-aminobenzoico modificado. Os ...

  18. Prevalência de anemia ferropriva em adolescentes da "Vila Princesa" - lixão em Porto Velho - RO

    França, Maria das Graças Guedes de


    As anemias nutricionais resultam da carência simples ou combinada de nutrientes como ferro, o acido fólico e a vitamina B12, podendo também ser causadas por outros fatores mais raros como a deficiência de piridoxina, riboflavina e proteína. Apesar de muitos nutrientes e co-fatores estarem envolvidos na manutenção da síntese normal de hemoglobina, a deficiência de ferro é a causa mais comum de anemia carencial no mundo, constituindo-se a carência nutricional de maior abrangência, afetando prin...

  19. Determinación y diferenciación de Pantoea agglomerans y patógenos por medio de perfiles de ácidos grasos a partir de aislamientos de 5 variedades de semillas de Allium cepa L.

    Rafael Mallaupoma, Zeny C.


    Por medio de metil acido esteres (FAMES), fueron analizados 382 aislamientos pertenecientes a cinco variedades de semillas de Allium cepa L. (S1, S2,S3,S4,S5). Se determino que el 20% afecta a cultivos de interés económico, el 36% pertenecen a patógenos que afectan humanos, el 4% afectan a animales y el 40% son del ambiente. A los aislamientos se les identifico por medio de perfiles de ácidos grasos usando un cromatógrafo HP 5890 serie II y una columna capilar agilent ultra 2, software MIDI ,...

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

    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)


    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

  1. Estudio espectroscópico y teórico del ácido valproico y algunos compuestos derivados con actividad antiepiléptica

    Comelli, Nieves Carolina


    Con base en nuestro supuesto acerca de que variaciones en la actividad anticonvulsiva de Suvpd, Chvpd, Etvpd, Dmvpd, Vpd, Ipvpd, Vpa, Prvpa podrían ser explicadas a partir del estudio de los efectos del sustituyente acilo (R2) y del solvente sobre las propiedades electrónicas del grupo O=C-O/N, en este trabajo de tesis doctoral se propone estudiar, usando herramientas experimentales y computacionales, la hipersuperficie de energía potencial del Acido Valproico (Vpa) y derivados funcionales co...

  2. [Simultaneous pulmonar, laryngeal and lingual affectation by Mycobacterium tuberculosis].

    Díaz Manzano, J A; Castillo Romero, J L; Padilla Romero, M J; Sánchez Laínez, J J; Castillo Aguilar, C; Cegarra Navarro, M F


    The incidence of tuberculosis has lately increased in developed countries. The most frequent affectation is the pulmonar one and in the ORL area the laryngeal. The lingual affectation is exceptional. We present a case of a man 39 years old, with bilateral pulmonar, left vocal cord and mobile tongue affectation, negative Mantoux, positive spit culture and presence of acido-alcohol resistent bacillus in lingual and laryngeal biopsies. After antituberculosis treatment during 6 months the laryngeal and lingual lesions disappeared. We have only found two cases published of simultaneous tuberculosis in these three localisations in the last 30 years.

  3. Intoxicación por fluoroacetato de sodio


    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...

  4. Development and characterization of cellulose acetate nanofibers for controlled release of drugs

    Silvia Vaz Guerra Nista


    Resumo: Este projeto foi desenvolvido em duas fases, usando a tecnologia de eletrofiação. A primeira fase foi dedicada a obtenção de membranas eletrofiadas com acetato de celulose, as quais formaram nanofibras que foram carregadas com Sulfato de gentamicina, na segunda fase, para estudos da liberação controlada deste fármaco. Na primeira fase as membranas de nanofibras de Acetato de Celulose, chamadas de nanomembranas, foram produzidas utilizando-se quatro misturas de solventes (Acido Acético...

  5. Disease: H00429 [KEGG MEDICUS

    Full Text Available H00429 Proximal renal tubular acidosis (RTA type 2) Renal tubular acidosis (RTA) is... characterized by metabolic acidosis, a severe disturbance of extracellular pH homeostasis, due to renal imp...4278 PMID:11045400 (gene) Rodriguez-Soriano J New insights into the pathogenesis of renal tubular acidosis--...from functional to molecular studies. Pediatr Nephrol 14:1121-36 (2000) PMID:17557941 (gene) Fry AC, Karet FE Inherited renal acidos...(gene, env_factor, marker) Rodriguez Soriano J Renal tubular acidosis: the clinical entity. J Am Soc Nephrol

  6. Disease: H00428 [KEGG MEDICUS

    Full Text Available H00428 Distal renal tubular acidosis (RTA type 1) Renal tubular acidosis (RTA) is c...haracterized by metabolic acidosis, a severe disturbance of extracellular pH homeostasis, due to renal impai...a DM, Oliveira EA, Silva AC Molecular pathophysiology of renal tubular acidosis. Curr Genomics 10:51-9 (2009...) PMID:11045400 (gene) Rodriguez-Soriano J New insights into the pathogenesis of renal tubular acidos...1 (gene) Fry AC, Karet FE Inherited renal acidoses. Physiology (Bethesda) 22:202-11 (2007) PMID:12138150 (ge

  7. Temas de bioquímica básica (DIAPOSITIVAS)

    Correa Quiroz, Jorge Alberto


    A continuación se da a conocer el trabajo preparado y organizado por el docente Jorge Alberto Correa Quiroz durante el periodo de su año sabático, los temas a exponer son: Metabolismo y bioenergética, Metabolismo de carbohidratos, Ciclo del acido cítrico y del glioxilato, Transporte de electrones y fosforilación oxidativa, Metabolismo de lípidos y ácidos grasos, metabolismos del amoniaco y compuestos nitrogenados, Fotosíntesis. / Abstract. Then we explain the work planned and organized by...

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

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


    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.

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

    Airton Vicente Pereira


    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.

  10. [Aetiology and treatment of epilepsy in a series of 1,557 patients].

    Torres-Ferrús, Marta; Toledo, Manuel; González-Cuevas, Montserrat; Seró-Ballesteros, Laia; Santamarina, Esteban; Raspall-Chaure, Miquel; Sueiras-Gil, María; Cambrodí-Masip, Roser; Sarria, Silvana; Álvarez-Sabín, José; Salas-Puig, Javier


    Introduccion. La etiologia de la epilepsia es un determinante importante del tratamiento y el pronostico. Los avances diagnosticos y terapeuticos hacen pensar que la distribucion causal, el tratamiento y el pronostico de la poblacion con epilepsia se hayan podido ver modificados. Objetivo. Describir la distribucion sindromica, etiologica y el tratamiento farmacologico en los pacientes con epilepsia. Pacientes y metodos. Estudio descriptivo transversal de pacientes con epilepsia atendidos de manera consecutiva en la consulta de nuestra unidad de epilepsia. Se recogieron datos demograficos, de sindrome, etiologia y tratamiento farmacologico en el momento de la inclusion. Se analizaron los datos de modo conjunto y por grupos de edad. Resultados. Se incluyeron 1.557 pacientes, el 54% varones. El 73% de la muestra tenia una epilepsia focal, que era secundaria a una lesion estructural en el 56%. Las epilepsias generalizadas representaron el 20%. El 5% fue inclasificable. Por edad, la etiologia vascular predominaba en practicamente todos los grupos y su prevalencia aumentaba en relacion con la edad. Los farmacos antiepilepticos mas utilizados fueron acido valproico (29%), levetiracetam (27%) y carbamacepina (20%). El 70% de las epilepsias generalizadas y el 57% de las focales seguian tratamiento en monoterapia. Conclusiones. La prevalencia por grupos de edad fue similar a la descrita en paises desarrollados aunque se observo una menor prevalencia de epilepsias criptogenicas. Mas del 60% de los pacientes seguia monoterapia y el acido valproico fue el mas utilizado.

  11. 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

    Kovacs, Thelma Antunes Rodrigues


    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)

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

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


    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

  13. Chronic lead intoxication; Chronische Bleiintoxikation

    Wieseler, B.; Leng, G. [Duesseldorf Univ. (Germany). Inst. fuer Hygiene; Lenz, S.; Schultz, C. [Klinikum Remscheid GmbH, Remscheid (Germany); Wilhelm, M. [Bochum Univ. (Germany). Inst. fuer Hygiene, Sozial- und Umweltmedizin


    The case of a female 68 years old patient is described. Here, a chronic lead intoxication was diagnosed after a two year old medical history with increasing attacks of colic-like abdominal pain often described as life-threatening. After repeated hospitalizations and intensive search for the cause of the symptoms, porphyria and anemia was found to be a sign of a chronic lead poisoning. The blood lead concentrations were always about a level of 600 {mu}g/L. The source of exposure could not be found by now. Neither home inspection nor environmental investigations have shown a recent source of lead intake by the patient. However, a possible occupational source of lead exposure at a blast furnace was established by anamnesis for 1952 to 1962. Thus, osteoporosis induced lead mobilisation was suspected. Noticeable are the results of the six abdominal survey radiographies taken during hospitalization within one year; three radiographies were taken following clinical admission and three before discharge of the patient. In comparison, the course shows a chronic relapsing alimentary supply from metallic particles of unknown genesis. The patient was treated with the sodium salt of 2,3-dimercapto-1-propansulfonic acid (DMPS, Dimaval{sup TM}). She was free of complain afterwards. Following therapy, the blood lead concentrations fell under a level of 400 {mu}m/L, but after several weeks the lead level raised up to the original level of 600 {mu}g/L. (orig.) [Deutsch] Es wird eine 68jaehrige Patientin vorgestellt, bei der nach fast zweijaehriger Krankengeschichte, die gekennzeichnet war durch rezidivierende, teils als lebensbedrohlich geschilderte Bauchkoliken, eine chronische Bleiintoxikation diagnostiziert wurde. Erst nach wiederholten stationaeren Krankenhausaufenthalten mit intensiver Suche nach der Krankheitsursache wurden das Krankheitsbild und die Laborwerte durch Zusatzuntersuchungen ergaenzt, so dass sich in der festgestellten Porphyrie und Anaemie die Diagnose der

  14. 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.

    Gómez Zambrano Jairo


    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

  15. Reporte de un caso clínico de encefalocele frontal

    Pablo Hoyos; Gustavo Vásquez; José Restrepo-Avenia


    El encefalocele es una malformación congénita caracterizado por una herniación del tejido nervioso debido a alteraciones del cierre del tubo; neural (5-6 semanas), la mayoría de las veces se asocia a deficiencia de acido fólico. La incidencia de esta patología es 1-3/1000 nacidos; vivos y varía según las características geográficas, la población y la utilización y/o el contacto con agentes teratógenicos. Producto de madre; primigestante (29,5 semanas de gestación), procedente de área...

  16. Níveis de substituição da DL-metionina pela metionina hidróxi análoga em base equimolar, em dietas para frangos de corte

    Visentini Paulo; Lopes Juarez; Toledo Geni Salete de; Costa Paulo Tabajara


    Este trabalho objetivou testar o efeito de níveis de substituição da DL-Metionina (DL-Met) por Metionina Hidróxi Análoga acido livre (MHA-FA) como fonte do aminoácido metionina para frangos de corte de 1 a 44 dias de idade. Foram utilizados 700 pintos de corte de um dia de idade, machos, da linhagem Ross. O delineamento experimental foi em blocos para evitar o efeito ambiental, constituído de cinco tratamentos com sete repetições de 20 aves.Substituiu-se em base equimolar a DL-Met por MHA-FA ...

  17. Homocisteína como fator de risco para doenças cardiovasculares

    Sthefano Atique Gabriel


    Full Text Available Elevadas concentrações plasmáticas de homocisteína têm sido identificadas como um fator de risco independente para aterosclerose cerebral, coronariana e periférica. Os efeitos danosos da homocisteína sérica são fruto de suas características aterogênicas e trombogênicas. O tratamento mais eficaz para hiperhocisteinemia consiste na redução da homocisteína plasmática, através da fortificação alimentar com suplementos vitamínicos, ricos em vitamina B6, vitamina B12 e, principalmente, acido fólico. A dose recomendada é de 400 microgramos de folato por dia, sendo esta medida uma poderosa redutora da morbidade e mortalidade cardiovascular, além de prevenir possíveis defeitos de fechamento do tubo neural.

  18. 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

    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)


    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.

  19. 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

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


    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

  20. Zinc and cadmium monosalicylates

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


    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.

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

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


    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.

  2. [Hepatic tuberculosis of the pseudotumoral form].

    Diouf, M L; Dia, D; Ka, E H; Diouf, B; Mbengue, M; Moreira-Diop, T


    The authors report a case of a 30 years old immunocompetent woman with liver tuberculosis with an unusual pseudotumoral presentation and secondary occurrence of abcedation with cutaneous fistulization. The diagnosis was based on the bacteriological positivity for acido-alcoolo resistant bacillus in pus of the abscess obtained by ponction guided by ultrasonographic examination. The authors emphasize in the differential diagnosis with the other causes of liver abscess (amibiasis and pyogenic microorganisms) and liver carcinoma. They also note the importance of the function guided by ultrasonographic examination permitting histologic and bacte+ériologic study in the diagnosis of this unusual presentation of liver tuberculosis. The patient was treated by antibacillary antibiotics and evacuation function. The prognostic was good with 6 months of follow-up.

  3. Caracterización del citocromo b-559 de cloroplastos de espinaca localización y función en la cadena fotosintética de transporte de electrones

    Ortega Rodríguez, José María


    En este trabajo se ha abordado el estudio de la localización y función del citocromo b-559 en la cadena fotosintética de transporte de electrones. En primer lugar, se ha llevado a cabo una caracterización, sobre todo desde el punto de vista redox y acido-base, de este citocromo en partículas del fotosistema II. Los resultados obtenidos en este sentido, así como los extraídos de la purificación y el análisis de algunas propiedades físico-químicas de esta proteína, nos ha permitido establecer q...

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

    L.G. Matos


    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.

  5. Methane production from plant biomass

    Zauner, E.


    Methane fermentations of plant biomass were performed to increase basic knowledge necessary for development of suitable conversion technologies. Effects of bacterial inoculants, substrate compounds and varied process conditions were analyzed in batch and continuous fermentation experiments. Use of enriched bacterial populations precultured and adapted to plant materials was proved to be advantageous for inoculation. Methane yields and productivities as well as chemical and bacterial composition of digester fluids were determined at various loading rates and retention times during fermentation of different grass and maize silages. Recycling for favorable amounts of decomposed effluent for neutralization of supplied acid raw materials was important to achieve high methane yields. Quantity and composition of acido-, aceto- and methanogenic bacteria were not essentially influenced by changed fermentation conditions. Results of these laboratory examinations have to be completed by long run and scale up experiments to develop control parameters for plant biogas digesters.

  6. Coagulation Changes to Systemic Acidosis and Bicarbonate Correction in Swine


    a decrease in respiration successfully lowered arterial pH to 7.1 (Acido- sis, Table 2) and significantly elevated PaCO2 and HCO3 and lowered PaO2 ...PaCO2, PaO2 , and BE to near their prehemorrhage levels. CaCl2 was injected i.v. during reinfusion of citrated blood (1 mg/mL of blood), so that the plasma...3.1* 55.0 3.2 PaO2 (mm Hg) 479.8 26.2 464.5 26.1 455.4 16.6 HCO3 (mmol/L) 33.2 0.7 16.2 1.8* 31.4 1.5 BE (mmol/L) 7.0 0.7 -12.5

  7. Concordancia entre métodos de valoración de imbalance del estado ácido-base en la unidad de cuidado intensivo pediátrico

    López Cubillos, Juan Francisco


    Las alteraciones del estado ácido base son comunes en los pacientes en estado crítico y se consideran marcador tanto de gravedad como de pronóstico. (1,2) Existen varios métodos de valoración del estado acido base. El primero es el tradicional denominado aproximación de Henderson-Hasselbach (HH) el cual basa los cambios de pH en la concentración de bicarbonato y la presión de CO2 en el organismo. El segundo es la aproximación de Stewart que se basa en el concepto de electro-neutralidad y en l...

  8. Thermal and spatial effects in chemisorption measurements; Effetti termici e spaziali nelle misure di chemisorbimento

    Marengo, S. [Stazione sperimentale per i Combustibili, S.Donato Milanese, Milano (Italy)


    A new application of infrared thermography in catalyst characterization is described, in which an experimental set-up featuring high spatial resolution and capability of revealing dynamic effects and performing real time image analysis is adopted. Some significant results obtained in the study of acid-base properties of catalysts and solid materials, metal dispersion, reaction mechanism and deactivation processes are discussed. [Italiano] Viene illustrata una nuova applicazione della tecnica di termografia infrarossa, attuata con un`apparecchiatura ed un assetto sperimentale che presentano caratteristiche peculiari quali: elevata risoluzione spaziale, descrizione accurata di fenomeni dinamici, analisi delle immagini in tempo reale. Vengono presentati alcuni esempi significativi di impiego nei seguenti campi: catatterizzazioni di catalizzatori e materiali solidi in termini di proprieta` acido-base e di dispersione dei metalli supportati; studi cinetici-meccanicistici, studio della disattivazione del letto catalitico.

  9. Concordancia entre métodos de valoración de imbalance del estado ácido-base en la unidad de cuidado intensivo pediátrico

    López Cubillos, Juan Francisco


    Las alteraciones del estado ácido base son comunes en los pacientes en estado crítico y se consideran marcador tanto de gravedad como de pronóstico. (1,2) Existen varios métodos de valoración del estado acido base. El primero es el tradicional denominado aproximación de Henderson-Hasselbach (HH) el cual basa los cambios de pH en la concentración de bicarbonato y la presión de CO2 en el organismo. El segundo es la aproximación de Stewart que se basa en el concepto de electro-neutralidad y en l...

  10. Comparing the Spectroscopic and Molecular Characteristics of Different Dissolved Organic Matter Fractions Isolated by Hydrophobic and Anionic Exchange Resins Using Fluorescence Spectroscopy and FT-ICR-MS

    Morgane Derrien


    Full Text Available Despite the environmental significance of dissolved organic matter (DOM, characterizing DOM is still challenging due to its structural complexity and heterogeneity. In this study, three different chemical fractions, including hydrophobic acid (HPOA, transphilic acid (TPIA, and hydrophilic neutral and base (HPIN/B fractions, were separated from bulk aquatic DOM samples, and their spectral features and the chemical composition at the molecular level were compared using both fluorescence excitation emission matrix-parallel factor analysis (EEM-PARAFAC and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS. The HPIN/B fraction was distinguished from the two acidic fractions (i.e., HPOA and TPIA by the EEM-PARAFAC, while the TPIA fraction was discriminated by using the molecular parameters derived from the FT-ICR MS analyses. Statistical comparison suggests that the spectral dissimilarity among the three chemical fractions might result from the acido-basic properties of DOM samples, while the differences in molecular composition were more likely to be affected by the hydrophobicity of the DOM fractions. The non-metric multidimensional scaling map further revealed that the HPOA was the most heterogeneous among the three fractions. The number of overlapping formulas among the three chemical fractions constituted only <5% of all identified formulas, and those between two different fractions ranged from 2.0% to 24.1%, implying relatively homogeneous properties of the individual chemical fractions with respect to molecular composition. Although employing chemical fractionation achieved a lowering of the DOM heterogeneity, prevalent signatures of either acido-basic property or the hydrophobic nature of DOM on the characteristics of three chemical isolated fractions were not found for this study.

  11. Atividades antinociceptiva e antiinflamatória do extrato etanólico de Luehea divaricata


    Full Text Available RESUMO Considerando os diferentes usos etnofarmacológicos apresentados pela planta Luehea divaricata, realizou-se este estudo com o objetivo de avaliar as atividades antinociceptiva e antinflamatória do extrato etanólico de suas folhas, em modelo animal, nas dosagens de 20, 40, 80 e 160 mg/Kg, por via oral. Foram realizados os seguintes testes: contorções abdominais induzidas pelo acido acético, placa quente, formalina e edema de pata induzido por carragenina. Foram utilizados camundongos Swiss (20-25 g para os três primeiros testes e ratos Wistar (180-250 g, para o último, divididos em seis grupos de oito animais, totalizando 48 animais em cada parâmetro de avaliação. Os resultados foram analisados estatisticamente pela análise de variância a 5% de probabilidade, para verificar quais os tratamentos que diferiram entre si, e estes foram submetidos aos testes de Kruskall-Wallis e Student-Newman-Keuls. O extrato etanólico das folhas de L. divaricata (EEtOH-Ld, nas diferentes doses estudadas, apresentou significativa atividade antinociceptiva sobre a dor induzida quimicamente por injeções intraperitoneal de acido acético e intraplantar de formalina. Na dosagem de 160 mg/Kg, esse extrato apresentou ação analgésica central, aos 120 minutos de observação, no teste de placa quente e reduziu o edema de pata induzido pela administração de carragenina, uma hora após a administração do agente inflamatório, semelhante ao efeito produzido pelo fármaco padrão.

  12. Evaluación de la educación nutricional y un suplemento para prevenir la anemia durante la gestación.

    Beatriz Elena Parra


    Full Text Available Introducción. Las deficiencias de hierro y acido fólico son la causa de graves problemas de salud en la mujer gestante y en el niño, con implicaciones negativas para el desarrollo económico y social de los países. Objetivos. Evaluar los cambios de conocimientos sobre funciones, alimentos fuentes y biodisponibilidad del hierro y folatos, el consumo y la tolerancia de un suplemento y el comportamiento de los índices globulares en gestantes del programa prenatal de la Empresa Social del Estado Hospital Gilberto Mejía Mejía de Rionegro, Antioquia, Colombia, entre abril de 2002 y abril de 2003. Materiales y métodos. Estudio cuasi experimental en una muestra de 42 madres, seleccionada por conveniencia, con una confianza del 95%. La intervención fue un programa de educación nutricional y el suministro de un suplemento con 60 mg de hierro elemental, 400 J.g de acido fólico y 70 mg de vitamina C, elaborado para la investigación por el Laboratorio Profesional Farmacéutico, LAPROFF. El efecto de la intervención se midió en los cambios de conocimientos relacionados con las practicas que modifican la biodisponibilidad y el consumo de alimentos fuentes de estos nutrientes, en la tolerancia y la adherencia al suplemento y en la modificación de variables hematológicas: hemoglobina, hematocrito y ferritina. Resultados. Hubo cambios positivos de conocimientos sobre cómo mejorar las practicas alimentarias y la ingestión del suplemento; el 94,4% de las participantes no presentó anemia al finalizar la gestación. Conclusión. Estos resultados concuerdan con otros provenientes de poblaciones similares; se justifica implementar esta estrategia integrada en los programas de control prenatal de Colombia.

  13. 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

    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`


    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.

  14. Determination of monomethylarsonous acid, a key arsenic methylation intermediate, in human urine.

    Le, X C; Ma, M; Cullen, W R; Aposhian, H V; Lu, X; Zheng, B


    In this study we report on the finding of monomethylarsonous acid [MMA(III)] in human urine. This newly identified arsenic species is a key intermediate in the metabolic pathway of arsenic biomethylation, which involves stepwise reduction of pentavalent to trivalent arsenic species followed by oxidative addition of a methyl group. Arsenic speciation was carried out using ion-pair chromatographic separation of arsenic compounds with hydride generation atomic fluorescence spectrometry detection. Speciation of the inorganic arsenite [As(III)], inorganic arsenate [As(V)], monomethylarsonic acid [MMA(V)], dimethylarsinic acid [DMA(V)], and MMA(III) in a urine sample was complete in 5 min. Urine samples collected from humans before and after a single oral administration of 300 mg sodium 2,3-dimercapto-1-propane sulfonate (DMPS) were analyzed for arsenic species. MMA(III) was found in 51 out of 123 urine samples collected from 41 people in inner Mongolia 0-6 hr after the administration of DMPS. MMA(III )in urine samples did not arise from the reduction of MMA(V) by DMPS. DMPS probably assisted the release of MMA(III) that was formed in the body. Along with the presence of MMA(III), there was an increase in the relative concentration of MMA(V) and a decrease in DMA(V) in the urine samples collected after the DMPS ingestion. PMID:11102289

  15. Synthesis,Crystal Structure and Properties of a New Thiadiazolen Two-dimensional Polymer of H2ADTZ with Mn(Ⅱ)%一个新的噻二唑衍生物H2ADTZ与锰的二维聚合物的合成与晶体结构

    娄新华; 朱玉; 高辉; 朱爱新; 樊耀亭; 侯红卫; 卢会杰


    A new 1,3,4 thiadiazole-derivative ligand 2,5-(s-acetic acid) dimercapto-1,3,4 thiadiazole (H2ADTZ)and its one-dimensional manganese polymer Mn(ADTZ). 4H2O had been synthesized and structurally characterized by X-ray single crystal diffraction in this paper. The Mn(Ⅱ) ion is coordinated with a distorted octahedron by two oxygen atoms from neighboring two deprotonated ligands ADTZ2- and other four oxygen atoms from four coordinated water molecules. The structural feature of the title compound is the formation of one-dimensional manganese chains polymer through the bridging of dioxygen O-O units. In the solid state structure of the complex,one-dimensional manganese chains are joined together by the weak intermolecular hydrogen bonds and vander Waals interactions forming a two-dimensional supramolecular compound. Furthermore, the UV spectra and electro-chemical properties of the title compound were also investigated. CCDC: 260532.

  16. Risk factors for renal scarring in children with primary vesicoureteral reflux disease

    Sevgi Mir


    Full Text Available To determine the incidence of renal scarring among patients with primary vesicoureteral reflux (VUR and the possible risk factor(s, we studied 90 children (60 girls and 30 boys with VUR followed in the Pediatric Nephrology Unit at the Ege University Hospital from 1998 to 2003. All the patients were assessed for VUR grade by voiding cystoureterography and for presence of renal scarring by (99 m technetium dimercapto-succinic acid scintigraphy. All infants with VUR were given low-dose prophylactic antibiotics and followed-up until resolution of the reflux. Grade of reflux and number of urinary tract infection (UTI episodes (≥3 were found to be statistically significant risk factors for renal scarring (P 0.05. Similarly, there was no statistically significant difference of frequency of renal scarring among the different age groups (P >0.05. We conclude that recurrences of UTI and VUR severity are significant risk factors for renal scarring in children with VUR. Therefore, identification of VUR at an early age may offer the opportunity to prevent episodes of UTI and possible formation of renal scars that may result in end-stage renal failure.

  17. Chelation in metal intoxication

    Aaseth, Jan; Skaug, Marit Aralt; Cao, yang


    The present review provides an update of the general principles for the investigation and use of chelating agents in the treatment of intoxications by metals. The clinical use of the old chelators EDTA (ethylenediamine tetraacetate) and BAL (2,3-dimercaptopropanol) is now limited due to the incon......The present review provides an update of the general principles for the investigation and use of chelating agents in the treatment of intoxications by metals. The clinical use of the old chelators EDTA (ethylenediamine tetraacetate) and BAL (2,3-dimercaptopropanol) is now limited due...... to the inconvenience of parenteral administration, their own toxicity and tendency to increase the neurotoxicity of several metals. The hydrophilic dithiol chelators DMSA (meso-2,3-dimercaptosuccinic acid) and DMPS (2,3-dimercapto-propanesulphonate) are less toxic and more efficient than BAL in the clinical treatment...... of heavy metal poisoning, and available as capsules for oral use. In copper overload, DMSA appears to be a potent antidote, although d-penicillamine is still widely used. In the chelation of iron, the thiols are inefficient, since iron has higher affinity for ligands with nitrogen and oxygen, but the new...

  18. Structures, energy bands and conductivities of (Me3NEt)[Pd(dmit)2]2 and (NEt4)[Pd(dmit)2]2

    方奇; 张斌; 雷虹; 孙岳明; 刘陟; 麦松威


    The electrical conductive molecular crystals (Me3NEt)[Pd(dmit)2]2 and (NEt4)[Pd (dmit)2]2 (dmit = 4,5-dimercapto-1,3-dithiole-2-thione) have been prepared, and their crystal structures and conductivity-temperature curves have been determined. The fact that the conductivity at room temperature of (Me3NEt)[Pd(dmit)2]2 (a = 58 Ω· cm-1) is much higher than that of (NEt4)-[Pd(dmit)2]2(cr= 2.2 Q~1 ?cm’1) has been rationally explained by the results of energy band calculations. (MeNEt3)[Pd(dmit)2]2 belongs to monoclinic system, P21/m space group and (NEt4)[Pd (dmit)2]2 belongs to triclinic system, P1 space group. The structural conducting component of the crystals is the planar coordinative anion [Pd(dmit)2]05- which forms the face-to-face dimmer [Pd(dmit)2]2-. These dimers have been further constructed to be a kind of two-dimensional (2-D)conductive molecular sheet by means of S…S intermolecular interactions. The tiny difference of the above 2-D molecular sheets of the two title crystals has resulted in one

  19. Synthesis of RNAs with up to 100 Nucleotides Containing Site-Specific 2-methylseleno Labels for use in X-ray Crystallography

    Hobartner,C.; Rieder, R.; Kreutz, C.; Puffer, B.; Lang, K.; Polonskaia, A.; Serganov, A.; Micura, R.


    The derivatization of nucleic acids with selenium is a new and highly promising approach to facilitate their three-dimensional structure determination by X-ray crystallography. Here, we report a comprehensive study on the chemical and enzymatic syntheses of RNAs containing 2'-methylseleno (2'-Se-methyl) nucleoside labels. Our approach includes the first synthesis of an appropriate purine nucleoside phosphoramidite building block. Most importantly, a substantially changed RNA solid-phase synthesis cycle, comprising treatment with threo-1, 4-dimercapto-2, 3-butanediol (DTT) after the oxidation step, is required for a reliable strand elongation. This novel operation allows for the chemical syntheses of multiple Se-labeled RNAs in sizes that can typically be achieved only for nonmodified RNAs. In combination with enzymatic ligation, biologically important RNA targets become accessible for crystallography. Exemplarily, this has been demonstrated for the Diels-Alder ribozyme and the add adenine riboswitch sequences. We point out that the approach documented here has been the chemical basis for the very recent structure determination of the Diels-Alder ribozyme which represents the first novel RNA fold that has been solved via its Se-derivatives.

  20. [Metal poisoning].

    Ferrer, A


    Metals are amongst the oldest toxic substances known to man. In today's industrialized world the sources of exposure to metals are ubiquitous both in the field of work and from polluted water, foodstuffs and the environment. Their toxicity is characterized by the metallic element in question, but this is modified by the type of compound, whether organic or inorganic, and its characteristics of hydrosolubility and liposolubility, which determines its toxicokinetics and thus the possibilities of it reaching its targets. The biomolecules most affected by metals are the proteins with enzymatic activity, which is why their pathology is multisystemic. The principal systems affected are the gastrointestinal, central and peripheral neurological, haematic and renal. Some metallic compounds are carcinogenic. Metals's treatment is conditioned by their chemical reactivity. They can be deactivated and eliminated by the administering of chelating agents that produce complex molecules, which are non-toxic and can be excreted. The principal chelating agents are: BAL (British Anti-Lewisite or dimercaprol) DMPS (2,3-Dimercapto-1-propanesulfonic Acid) and DMSA (meso-2,3-Dimercaptosuccinic or Succimer), EDTA, Penicilamine (b,b-dimethylcysteine) and Deferoxamine. Toxicokinetic characteristics, mechanism of action, clinical picture and treatment of some of the most relevant metals and metalloids: lead, mercury and arsenic, are considered.

  1. Lead, mercury, and arsenic poisoning due to topical use of traditional Chinese medicines.

    Wu, Ming-Ling; Deng, Jou-Fang; Lin, Kon-Ping; Tsai, Wei-Jen


    Metal poisonings through a mucocutaneous route are reported rarely in the literature. We report 2 cases of heavy metal intoxication from inappropriate use of Chinese mineral medicines confirmed by toxicologic investigations. A 51-year-old man developed perianal gangrene and a high fever after a 2-week anal use of hong-dan herbal mixtures for anal fistula. He presented gastrointestinal and constitutional symptoms, followed by skin rash, anemia, hair loss, peripheral neuropathy, and muscle atrophy. Elevated urine arsenic and mercury confirmed the heavy metal poisonings. The hong-dan mixture contained lead tetraoxide, arsenic, and mercury. He was treated with 2,3-dimercapto-1-propanesulfonic acid, with partial improvement, but peripheral neuropathy persists 4 years later. A 75-year-old man developed anorexia, weight loss, headache, dizziness, nausea, vomiting, constipation, weakness, and anemia after a 3-month use of an herbal patch for chronic leg ulcer. His blood lead concentration was 226 μg/dL, and the lead content of the herbal patch was 517 mg/g. Chelation with ethylene diamine tetraacetic acid and dimercaptosuccinic acid was followed by clinical recovery. These cases documented serious systemic poisoning after the short-term use of traditional Chinese medicines containing heavy metals in damaged or infected tissue. Copyright © 2013. Published by Elsevier Inc.

  2. Synthesis,Structure and Conductivity of Molecular Conductor (PyMe)[Ni(dmit)2]2%分子导体(PyMe)[Ni(dmit)2]2的合成、结构与导电性

    许文; 方奇; 薛刚; 于文涛; 刘国群; 雷虹


    合成了一种新的导电分子晶体(PyMe)[Ni(dmit)2]2 (Py=pyridine, dmit=(C3S5)2-=4,5-dimercapto-1,3-dithiole-2-thio~nato),并用四圆X射线衍射方法确定了结构,该晶体属于三斜晶系,P-1空间群;晶胞参数为:a=0.74837(9) nm, b=1.15479(16) nm, c=1.9775(3) nm, α=99.268(12)°, β=99.140(10)°, γ=99.673(11)°; V=1.6320(4) nm3, Dc=2.029 g/cm3, Z=2. 导电组元[Ni(dmit)2]0.5-沿[-110]方向堆积成柱(column),柱与柱之间进一步借助于大量的S...S分子间相互作用形成二维导电层,测得在(001)面上的室温电导率为10-1~10-4 Ω-1·cm-1.用结构参数和分子间重叠积分相结合的方法,分析了导电性与结构的关系.

  3. 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

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


    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

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

    Benavides, R. [Centro de Investigacion en Quimica Aplicada (CIQA), Saltillo, Coahuila (Mexico)] e-mail:; 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)


    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

  5. Intoxicación por metales Metal poisoning

    A. Ferrer


    Full Text Available Los metales están entre los tóxicos más antiguos conocidos por el hombre. En el industrializado mundo actual las fuentes de exposición a metales son ubicuas tanto en el campo laboral como a partir de agua, los alimentos o el ambiente contaminados. Su toxicidad está caracterizada por el elemento metálico en cuestión pero se ve modificada por el tipo de compuesto, orgánico o inorgánico y sus características de hidro o liposolubilidad, que determina su toxicocinética y por tanto sus posibilidad de alcanzar sus dianas. Las biomoléculas más afectadas por los metales son las proteínas con actividad enzimática por lo que su patología es multisistema. Los principales sistemas afectados son el gastrointestinal, neurológico central y periférico, hemático y renal. Algunos de los compuestos metálicos son carcinógenos. Los metales se benefician de un tratamiento condicionado por su reactividad química. Pueden ser inactivados y eliminados mediante la administración de substancias quelantes que producen con ellos moléculas complejas, atóxicas y excretables. Los principales agentes quelantes son: BAL (British Anti-Lewisite o dimercaprol, DMPS (ácido 2,3-dimercapto-1-propanosulfonico y DMSA (ácido meso-2,3-dimercatosuccínico o Succimer, EDTA, Penicilamina (ß,ß-dimetilcisteína y Desferoxamina. Se exponen a continuación las características toxicocinéticas, mecanismo de acción, clínica y tratamiento de alguno de los metales y metaloides más relevantes: plomo, mercurio y arsénico.Metals are amongst the oldest toxic substances known to man. In today’s industrialized world the sources of exposure to metals are ubiquitous both in the field of work and from polluted water, foodstuffs and the environment. Their toxicity is characterized by the metallic element in question, but this is modified by the type of compound, whether organic or inorganic, and its characteristics of hydrosolubility and liposolubility, which determines its

  6. 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

    Laura V Aquino


    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.

  7. 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

    Daniela da Silva Oliveira


    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

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

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


    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

  9. Lewis acid catalyzed transformations of Z-ligustilide

    Rios, Maria Yolanda [Universidad Autonoma del Estado de Morelos, Cuernavaca, Morelos (Mexico); Delgado, Guillermo [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)


    Some Lewis acid mediated reactions of Z-ligustilide (1), a bioactive constituent of the medicinal species Ligusticum porteri, were investigated. These reactions provided varying mixtures of Z-butylidenephthalide (7), E-butylidenephthalide (8), n-butyphthalide (13), and novel linear dimeric phthalides (9-12) as the main products. The formation of the dimers occurred in low yields and with regio and situ-selectivity. Initial competitive O- and C- complexation of the Lewis acid with Z-ligustilide promoted the formation of the dimers occurred in low yields and with regio and situ- selectivity. Initial competitive O- and C- complexation of the Lewis acid with Z-ligustilide promoted the formation of carbocations at C(8), C(6) and C(7), which were stabilized by the addition of the C(6')-C(7') olefin of a second unit of the starting material, to provide cations at C(6') and C(7'). Subsequent isomerizations and elimination of the catalyst afforded the dimeric products 9-12. The yields and structure of the products are quite dependent on variations of the reaction conditions and the catalyst employed. [Spanish] Se investigaron algunas reacciones de Z-ligustilidas (1), un constituyente bioactivo de la planta medicinal Ligusticum porteri, catalizadas por acidos de Lewis. Estas reacciones produjeron mezclas variables de Z-butilidenftalida (7), E-butilidenftalida (8), n-butilftalida (13), y ftalidos dimetricos lineales novedosos (9-12) como productos principales. La formacion de los dimeros procedio en rendimientos bajos y con regio- y situ-selectividad. La O- y C- complejacion competitiva inicial del acido de Lewis con Z-lingustilida promueve la formacion de cationes en C(8), C(6) y C(7), los cuales son estabilizados por la adicion de la olefina C(6')-C(7') de una segunda unidad de la materia prima para generar los cationes en C(6')-C(7'). Isomerizaciones subsecuentes y la eliminacion del catalizador conducen a los productos dimericos 9

  10. 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

    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:


    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




    Full Text Available


    In the present study, a kinetic model for the biocatalytic synthesis of esters using Rhizopus oryzae resting cells is proposed. The kinetic study has been made in a range of 30-50 °C and atmospheric pressure. The Influence of operating variables, water content, pH, amount of mycelium was studied. Different values of temperature, initial mycelium concentration and acid/alcohol molar ratio were tested. Initial rates were estimated from the slope of the concentration of palmitic acid, or their corresponding ester at conversions of less than 10%, versus time and reported as mmol l-1 min -1. The values of kinetic constants were computed using the freeware program SIMFIT (http:\\

    Key words: bound lipase, esterification, fungal resting cells, Rhizopus oryzae, palmitic acid, propanol.


    En el presente estudio, un modelo cinético para la síntesis de esteres usando Rhizopus oryzae resting cells es propuesto. El estudio cinético fue realizado en un rango de temperatura de 30-50 ºC a presión atmosférica reducida. La influencia de las variables de operación tales como temperatura, pH y contenido de agua fueron estudiadas. Diferentes valores de concentración de micelio y relación molar de ácido/alcohol son ensayadas, Las velocidades iníciales se estimaron de la curva de concentración de acido palmítico, y su correspondiente conversión a ester en menos del 10%, frente a tiempo y reportadas en mmol I-1 min -1. Los valores de las constantes cinéticas fueron calculados usando el programa freeware SIMFIT (http:\\

    Palabras clave: Lipasas, esterificación, resting cells, Rhizopus oryzae, acido palmítico, propanol.

  12. Adaptations respiratoires et circulatoires de l'esturgeon sibérien à une hypoxie environnementale



    Full Text Available Les adaptations respiratoires, acido-basiques et quelques effets circulatoires ont été étudiés chez l'esturgeon sibérien Acipenser baeri lors d'une hypoxie progressive ou d'un choc hypoxique, et du retour en normoxie. Au cours d'une hypoxie progressive, ce poisson est capable, en hyperventilant, de maintenir constante sa consommation d'oxygène jusqu'à une valeur critique de pression partielle d'oxygène dans l'eau située entre 20 et 40 mmHg. Le retour en normoxie est caractérisé par le paiement d'une dette d'oxygène, indiquant qu'un recours au métabolisme anaérobie a été nécessaire durant l'hypoxie. L'hypoxie progressive provoque initialement une alcalose ventilatoire associée ensuite à une acidose métabolique. Le choc hypoxique induit un état de stress comme en témoignent les valeurs élevées des taux plasmatiques de catécholamines. L'hyperventilation initiale est suivie d'une importante dépression ventilatoire. L'hypertension observée dans un premier temps, bien que modérée, représente un effet d'une augmentation du taux de catécholamines plasmatiques. Cet effet est ensuite atténué par une bradycardie d'origine vraisemblablement vagale, concomitante de l'hypoventilation. Les conséquences sur l'équilibre acido-basique, bien qu'amplifiées, sont comparables à celles d'une hypoxie progressive. Cependant, la libération très importante de lactate dans le sang lors du retour en normoxie n'entraîne qu'une faible diminution de pH du fait d'une augmentation concomitante du taux de sodium plasmatique. Ainsi l'esturgeon Acipenser baeri, bien que considéré comme un poisson archaïque, a développé les mêmes réponses adaptatives à l'hypoxie que les téléostéens.

  13. Correlacion entre metodos de analisis de Zn disponible en cuatro ordenes de suelos de Costa Rica

    Eloy Molina


    Full Text Available Se realizo una comparación entre métodos analisis del Zn disponible en 4 ordenes de sue- Analytilos de Costa Rica (Ultisoles, Vertisoles, Andisoles Inceptisoles, 25 de c/u, utilizando las siguientes soluciones extractoras: Olsen Modificado, Meh- lich 3, Morgan Modificado, DTPA y HC1. Las cantidades de Zn extrafdas dependieron de la natu- raleza qufmica de la solucion extractora. El HCl presento los contenidos mas altos de Zn en los chasuelos, excepto en Vertisoles. Las soluciones que hicontienen el agente quelante EDTA (Olsen Modi- ficado y Mehlich`3, extrajeron niveles interme- Modidios de Zn, en tanto que los metodos que contie- Den el quelato DTPA (Morgan Modificado y DT - PA, obtuvieron los valores mas bajos. Las corre- laciones de Zn extrafble entre los 5 metodos fue- signifirOD significativas en la mayona de los casos, tanto nivel de orden de suelos como en el conjunto de indivilos 100 suelos analizados. Los coeficientes de co- rrelacion mas altos, se presentaron entre Mehlich Morgan Modificado y DTPA. Las correlaciones Modifueron consistentes en los 4 ordenes, 10 que indica que estas soluciones poseen un amplio margen de adaptacion a diferentes tipos de suelo, siendo una caractenstica ventajosa para la selección de un metodo de analisis. El Olsen Modificado fue mas slighteficiente para la extraccion de Zn en suelos de pH ligeramente acido 0 neutro (Vertisoles e Inceptiso- les, que en suelos acidos (Ultisoles y Andisoles. EI HCI extrajo cantidades muy aItas de Zn que Moraparentementestan relacionadas con formas no disponibles para lag plantas. Se concluye que lag soluciones Mehlich 3, Morgan Modificado y DT - PA son semejantes en la forma de extraer Zn dispo- Dible, y podrian seT una altemativa para sustituir el metoda tradicional de Olsen Modificado utilizado en Costa Rica. Sin embargo,la eficiencia de ellas no puede seT establecida sino a traves de log estudios de correlacion contra rendimiento en invernadero y campo.

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

    Mónica Simanca S


    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.

  15. Glass transition of adsorbed stereoregular PPMA by inverse gas chromatography at infinite dilution

    Hamieh, T.; Rezzaki, M.; Grohens, Y.; Schultz, J.


    In this paper, we used inverse gas chromatography (IGC) at infinite dilution that proved to be a powerful technique to determine glass transition and other transitions of PMMA adsorbed on α-alumina. We highlighted the glass transition temperature of the system PMMA/α-Al2O3 with defined polymer tacticity at various covered surface fractions. Thus, the Tg of the adsorbed isotactic PMMA increases strongly as compared to the bulk value. The study of the physical chemical properties of PMMA/α-alumina revealed an important difference in the acidic and basic behaviour, in Lewis terms, of aluminium oxide covered by various concentrations of PMMA. It appears that there is a stabilisation of the physical chemical properties of PMMA/α-Al2O3 for a surface coverage above 50%. This study also highlighted an important effect of the tacticity of the polymer on the acid-base character of the system PMMA/Al2O3. Dans cet article, nous montrons que la chromatographie gazeuse inverse (CGI) à dilution infinie se révèle être une technique très intéressante pour la détermination de la transition vitreuse de polymères stéréoréguliers adsorbés sur des substrats solides tels que l'alumine. Nous avons mis en évidence des transitions attribuées aux phénomènes de relaxation béta, transition vitreuse et autres transitions des systèmes PMMA/Al2O3 de tacticité définie à différents taux de recouvrement. Ainsi, la Tg du PMMA isotactique adsorbé augmente de façon significative par rapport a celle du polymère massique. L'étude des propriétés physico-chimiques du système PMMA/Al2O3, révèle une différence importante dans le comportement acido-basique, au sens de Lewis, de l'alumine pour de taux de recouvrement en PMMA variables. Il apparaît qu'il y a stabilisation des propriétés physico-chimiques de PMMA/Al2O3 pour un taux de recouvrement en PMMA supérieur à 50 %. Cette étude a montré également une influence importante de la tacticité du polymère sur le

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

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


    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.

  17. Adsorption mechanism of acids and bases in reversed-phase liquid chromatography in weak buffered mobile phases designed for liquid chromatography/mass spectrometry.

    Gritti, Fabrice; Guiochon, Georges


    The overloaded band profiles of five acido-basic compounds were measured, using weakly buffered mobile phases. Low buffer concentrations were selected to provide a better understanding of the band profiles recorded in LC/MS analyses, which are often carried out at low buffer concentrations. In this work, 10 microL samples of a 50 mM probe solution were injected into C(18)-bonded columns using a series of five buffered mobile phases at (SW)pH between 2 and 12. The retention times and the shapes of the bands were analyzed based on thermodynamic arguments. A new adsorption model that takes into account the simultaneous adsorption of the acidic and the basic species onto the endcapped adsorbent, predicts accurately the complex experimental profiles recorded. The adsorption mechanism of acido-basic compounds onto RPLC phases seems to be consistent with the following microscopic model. No matter whether the acid or the base is the neutral or the basic species, the neutral species adsorbs onto a large number of weak adsorption sites (their saturation capacity is several tens g/L and their equilibrium constant of the order of 0.1 L/g). In contrast, the ionic species adsorbs strongly onto fewer active sites (their saturation capacity is about 1g/L and their equilibrium constant of the order of a few L/g). From a microscopic point of view and in agreement with the adsorption isotherm of the compound measured by frontal analysis (FA) and with the results of Monte-Carlo calculations performed by Schure et al., the first type of adsorption sites are most likely located in between C(18)-bonded chains and the second type of adsorption sites are located deeper in contact with the silica surface. The injected concentration (50 mM) was too low to probe the weakest adsorption sites (saturation capacity of a few hundreds g/L with an equilibrium constant of one hundredth of L/g) that are located at the very interface between the C(18)-bonded layer and the bulk phase.

  18. Intoxicación por metales

    A. Ferrer

    Full Text Available Los metales están entre los tóxicos más antiguos conocidos por el hombre. En el industrializado mundo actual las fuentes de exposición a metales son ubicuas tanto en el campo laboral como a partir de agua, los alimentos o el ambiente contaminados. Su toxicidad está caracterizada por el elemento metálico en cuestión pero se ve modificada por el tipo de compuesto, orgánico o inorgánico y sus características de hidro o liposolubilidad, que determina su toxicocinética y por tanto sus posibilidad de alcanzar sus dianas. Las biomoléculas más afectadas por los metales son las proteínas con actividad enzimática por lo que su patología es multisistema. Los principales sistemas afectados son el gastrointestinal, neurológico central y periférico, hemático y renal. Algunos de los compuestos metálicos son carcinógenos. Los metales se benefician de un tratamiento condicionado por su reactividad química. Pueden ser inactivados y eliminados mediante la administración de substancias quelantes que producen con ellos moléculas complejas, atóxicas y excretables. Los principales agentes quelantes son: BAL (British Anti-Lewisite o dimercaprol, DMPS (ácido 2,3-dimercapto-1-propanosulfonico y DMSA (ácido meso-2,3-dimercatosuccínico o Succimer, EDTA, Penicilamina (ß,ß-dimetilcisteína y Desferoxamina. Se exponen a continuación las características toxicocinéticas, mecanismo de acción, clínica y tratamiento de alguno de los metales y metaloides más relevantes: plomo, mercurio y arsénico.

  19. Chelating compounds as potential flash rust inhibitors and melamine & aziridine cure of acrylic colloidal unimolecular polymers (CUPs)

    Mistry, Jigar Kishorkumar

    Waterborne coatings on ferrous substrates usually show flash rusting which decreases the adhesion of the coating and the corrosion products can form a stain. Chelating compounds were investigated as potential flash rust inhibitors. Compounds being evaluated include amine alcohols, diamines and sulfur containing amines. A new corrosion inhibitor 2,5-bis(thioaceticacid)-1,3,4-thiadiazole (H2ADTZ) was synthesized and its performance characteristics were evaluated. It was noted that the observed structure of 1,3,4-thiadiazolidine-2,5-dithione (also known as 2,5-dimercapto-1,3,4-thiadiazole (DMTD or DMcT)) has been previously reported in three different tautomeric forms including -dithiol and -dithione. The relative stability of each form as well as the synthesis and characterization of the structures of mono- and dialkylated forms of 5-mercapto-1,3,4-thiadiazole-2(3H)-thione (MTT) were examined. The methods of X-ray crystallography, NMR spectroscopy and ab-initio electronic structure calculations were combined to understand the reactivity and structure of each compound. Polymers were synthesized with a 1:7 or 1:8 ratio of acrylic acid to acrylate monomers to produce an acid rich resin. The polymers were reduced and solvent stripped to produce Colloidal Unimolecular Polymers (CUPs). These particles are typically 3-9 nanometers in diameter depending upon the molecular weight. They were then formulated into a clear coating with either a melamine (bake) or an aziridine (ambient cure) and then cured. The melamine system was solvent free, a near zero VOC and the aziridine system was very low to near zero VOC. The coatings were evaluated for their MEK resistance, adhesion, hardness, gloss, flexibility, wet adhesion, abrasion and impact resistance properties.

  20. Longterm outcome of Macroplatique injection for treatment of vesicoureteral reflux in children

    Elrahmany A. Mohamed


    Full Text Available Background: This study examined our experience with one year follow-up of 20 cases of vesicoureteric reflux in children after treatment with Macroplastique ® injection. Patient and Methods: A total of 20 children (31 ureters with primary grades II to V vesicoureteral reflux were treated with subureteral Macroplastique ® injection from 2010 to 2011 and followed for an average of 12 months (range 3 to 24. Vesicoureteral reflux was grade II in 3, III in 7, IV in 9 and V in 12 ureters. Each child underwent pre-operative voiding cystourethrography, abdominopelvic ultrasound, urine analysis/culture, S. creatinine and CBC. Dimercapto-succinic acid scan (DMSA scan and magnetic resonance urography (MRU were done in some patients. Voiding cystourethrography at 3 months was done to rule out persistent reflux. Results: Overall, reflux was corrected in 11 (35.5% ureters and 9 (45% children after a single injection. With repeat injection, reflux was corrected in 16 (51.6% ureters and 11 (55% children, reflux improved/downgrade in 4 (12.9% ureters and 2 (10% children. Correction by grade was 100%, 100%, 9.7%, 9.7% for grades II to V, respectively. There were no surgical complications. None of the cured patients had recurrent reflux during follow-up. There were 9 (45% children who required open ureteral re-implantation for failed injection. Conclusion: Sub-ureteral Macroplastique ® injection therapy could be a primary treatment for low grade VUR (grade III or less in children because it is simple, safe, effective, less invasive, decreased.

  1. Successful Splenectomy for Hypersplenism in Wilson’s Disease: A Single Center Experience from China

    Chen, Huai-Zhen; Wu, Yun-Hu; Fang, Xiang; Zhang, Jing; Wang, Zhen; Han, Yong-Sheng; Wang, Yu


    Splenomegaly and pancytopenia are common in Wilson’s disease (WD) and splenectomy is one of the conventional treatments for splenomegaly and the associated pancytopenia. However, splenectomy remained controversial for hypersplenism in WD as it was reported that splenectomy leaded to serious emotional and neurological deterioration in WD patients with hypersplenism. In the current study, we present our experiences in 70 WD patients with hypersplenism who had undergone splenectomy, outlining the safety and efficacy of splenectomy in WD. The clinical database of 70 WD patients with hypersplenism who had undergone splenectomy in our hospital between 2009 and 2013 were reviewed and followed-up regularly. Before splenectomy, all the patients accepted a short period of anti-copper treatment with intravenous sodium 2, 3-dimercapto-1-propane sulfonate (DMPS). All the patients demonstrated a marked improvement in platelet and leucocyte counts after splenectomy. No severe postoperative complication was observed. In particular, none of the 37 patients with mixed neurologic and hepatic presentations experienced neurological deterioration after splenectomy, and none of the patients with only hepatic presentations newly developed neurological symptoms. During the one year follow-up period, no patient presented hepatic failure or hepatic encephalopathy, no hepatic patient newly developed neurological presentations, and only 3 patients with mixed neurologic and hepatic presentations suffered neurological deterioration and these 3 patients had poor compliance of anti-copper treatment. Quantative analysis of the neurological symptoms in the 37 patients using the Unified Wilson’s Disease Rating Scale (UWDRS) showed that the neurological symptoms were not changed in a short-term of one week after splenectomy but significantly improved in a long-term of one year after splenectomy. Additionally, compared to that before splenectomy, the esophageal gastric varices in most patients

  2. Successful Splenectomy for Hypersplenism in Wilson's Disease: A Single Center Experience from China.

    Liang-Yong Li

    Full Text Available Splenomegaly and pancytopenia are common in Wilson's disease (WD and splenectomy is one of the conventional treatments for splenomegaly and the associated pancytopenia. However, splenectomy remained controversial for hypersplenism in WD as it was reported that splenectomy leaded to serious emotional and neurological deterioration in WD patients with hypersplenism. In the current study, we present our experiences in 70 WD patients with hypersplenism who had undergone splenectomy, outlining the safety and efficacy of splenectomy in WD. The clinical database of 70 WD patients with hypersplenism who had undergone splenectomy in our hospital between 2009 and 2013 were reviewed and followed-up regularly. Before splenectomy, all the patients accepted a short period of anti-copper treatment with intravenous sodium 2, 3-dimercapto-1-propane sulfonate (DMPS. All the patients demonstrated a marked improvement in platelet and leucocyte counts after splenectomy. No severe postoperative complication was observed. In particular, none of the 37 patients with mixed neurologic and hepatic presentations experienced neurological deterioration after splenectomy, and none of the patients with only hepatic presentations newly developed neurological symptoms. During the one year follow-up period, no patient presented hepatic failure or hepatic encephalopathy, no hepatic patient newly developed neurological presentations, and only 3 patients with mixed neurologic and hepatic presentations suffered neurological deterioration and these 3 patients had poor compliance of anti-copper treatment. Quantative analysis of the neurological symptoms in the 37 patients using the Unified Wilson's Disease Rating Scale (UWDRS showed that the neurological symptoms were not changed in a short-term of one week after splenectomy but significantly improved in a long-term of one year after splenectomy. Additionally, compared to that before splenectomy, the esophageal gastric varices in most

  3. Post-translational Activation of Glutamate Cysteine Ligase with Dimercaprol: A Novel Mechanism of Inhibiting Neuroinflammation in vitro.

    McElroy, Pallavi B; Sri Hari, Ashwini; Day, Brian J; Patel, Manisha


    Neuroinflammation and oxidative stress are hallmarks of various neurological diseases. However, whether and how the redox processes control neuroinflammation is incompletely understood. We hypothesized that increasing cellular glutathione (GSH) levels would inhibit neuroinflammation. A series of thiol compounds were identified to elevate cellular GSH levels by a novel approach i.e. post-translational activation of glutamate cysteine ligase (GCL), the rate-limiting enzyme in GSH biosynthesis. These small thiolcontaining compounds were examined for their ability to increase intracellular GSH levels in a murine microglial cell line (BV2), of which dimercaprol [2,3-dimercapto-1-propanol (DMP)] was found to be the most effective compound. DMP increased GCL activity, decreased LPS-induced production of pro-inflammatory cytokines and iNOS induction in BV2 cells in a concentrationdependent manner. DMP's ability to elevate GSH levels and attenuate LPS-induced proinflammatory cytokine production was inhibited by buthionine sulfoximine, an inhibitor of GCL. DMP increased the expression of GCL holoenzyme without altering the expression of its subunits or Nrf2 target proteins (NQO1 and HO-1), suggesting a post-translational mechanism. DMP attenuated LPS-induced mitogen activated protein (MAP) kinase activation in BV2 cells suggesting the MAP kinase pathway as the signaling mechanism underlying DMP's effect. Finally, DMP's ability to increase GSH via GCL activation was observed in mixed cerebrocortical cultures and N27 dopaminergic cells. Together, the data demonstrate a novel mechanism of GSH elevation by posttranslational activation of GCL. Post-translational activation of GCL offers a novel targeted approach to control inflammation in chronic neuronal disorders associated with impaired adaptive responses.

  4. Effects of Zinc Chelators on Aflatoxin Production in Aspergillus parasiticus

    Wee, Josephine; Day, Devin M.; Linz, John E.


    Zinc concentrations strongly influence aflatoxin accumulation in laboratory media and in food and feed crops. The presence of zinc stimulates aflatoxin production, and the absence of zinc impedes toxin production. Initial studies that suggested a link between zinc and aflatoxin biosynthesis were presented in the 1970s. In the present study, we utilized two zinc chelators, N,N,N′,N′-tetrakis (2-pyridylmethyl) ethane-1,2-diamine (TPEN) and 2,3-dimercapto-1-propanesulfonic acid (DMPS) to explore the effect of zinc limitation on aflatoxin synthesis in Aspergillus parasiticus. TPEN but not DMPS decreased aflatoxin biosynthesis up to six-fold depending on whether A. parasiticus was grown on rich or minimal medium. Although we observed significant inhibition of aflatoxin production by TPEN, no detectable changes were observed in expression levels of the aflatoxin pathway gene ver-1 and the zinc binuclear cluster transcription factor, AflR. Treatment of growing A. parasiticus solid culture with a fluorescent zinc probe demonstrated an increase in intracellular zinc levels assessed by increases in fluorescent intensity of cultures treated with TPEN compared to controls. These data suggest that TPEN binds to cytoplasmic zinc therefore limiting fungal access to zinc. To investigate the efficacy of TPEN on food and feed crops, we found that TPEN effectively decreases aflatoxin accumulation on peanut medium but not in a sunflower seeds-derived medium. From an application perspective, these data provide the basis for biological differences that exist in the efficacy of different zinc chelators in various food and feed crops frequently contaminated by aflatoxin. PMID:27271668

  5. Early discontinuation of antibiotic prophylaxis in patients with persistent primary vesicoureteral reflux initially detected during infancy: outcome analysis and risk factors for febrile urinary tract infection.

    Moriya, Kimihiko; Mitsui, Takahiko; Kitta, Takeya; Nakamura, Michiko; Kanno, Yukiko; Kon, Masafumi; Nishimura, Yoko; Shinohara, Nobuo; Nonomura, Katsuya


    We retrospectively assessed the incidence of and risk factors for febrile urinary tract infection in children during active surveillance after early discontinuation of antibiotic prophylaxis. We retrospectively evaluated 9 females and 61 uncircumcised males diagnosed with primary vesicoureteral reflux before age 1 year who had persistent reflux on followup voiding cystourethrogram and were subsequently followed under active surveillance without continuous antibiotic prophylaxis. Patients with secondary vesicoureteral reflux or associated urological abnormality were excluded. Clinical outcomes, including incidence of febrile urinary tract infection and new scar formation, were evaluated. Risk factors for febrile urinary tract infection were also analyzed. Mean age at stopping continuous antibiotic prophylaxis was 21 months, and mean followup was 61 months. During active surveillance 21 patients had febrile urinary tract infection, and the 5-year infection-free rate under active surveillance was 67.5%. One or 2 foci of minimal new scarring developed in 4 of 16 patients who underwent followup dimercapto-succinic acid scan after febrile urinary tract infection. On multivariate analysis dilated vesicoureteral reflux on followup voiding cystourethrogram was the only significant risk factor for febrile urinary tract infection. This study revealed that about two-thirds of patients with persistent vesicoureteral reflux were free of febrile urinary tract infection during 5 years of active surveillance. Those with dilated vesicoureteral reflux on followup voiding cystourethrogram are at significantly greater risk for febrile urinary tract infection. Accordingly active surveillance, especially in patients with nondilated vesicoureteral reflux on followup voiding cystourethrogram, seems to be a safe option even in children who have not yet been toilet trained. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights

  6. Tailoring activated carbon by surface chemical modification with O, S, and N containing molecules

    Rachel RibeiroVieira Azzi Rios


    Full Text Available In this work the surface of activated carbon was chemically modified in order to introduce O, S and N containing groups. The activated carbon surface was selectively oxidized with concentrated HNO3 under controlled conditions. Characterization by thermogravimetric analyses, infrared spectroscopy and NaOH titration suggested the formation of mainly -COOH and small amounts of -OH groups, with concentration of approximately 4.10(21 groups/g of carbon. These -COOH functionalized carbons showed high adsorption capacity for metal cations in aqueous solution in the following order: Pb+2>Cu+2>Ni+2 >Cd+2~Co+2>Ca+2 , suggesting a cation exchange mechanism via a surface complex [COO-M+2]. These -COOHsurf groups can be reacted with SOCl2 to produce a surface acylchloride group, -COCl. This surface -COCl group proved to be a very reactive and versatile intermediate for the grafting of different S and N containing molecules onto the carbon surface, such as 1,2-ethaneditiol (EDT-, HSCH2CH2SH 1,7-dimercapto-4-thioheptane (DMTH-HSCH2CH2CH2SCH2CH 2CH2SH or 1,2-ethylenediamine (EDA- NH2CH2CH2NH2 and triethyltetraamine, TEA (H2NCH2CH2NHCH2CH 2NHCH2CH2 NH2. The characterization of these materials was carried out by TG, IR and TPDMS (Temperature Programmed Decomposition Mass Spectrometry experiments suggesting the formation of thioesther and amide surface groups, i.e. -COSR and -CONHR, with yields of approximately 50 and 75% for the reaction with DME and EDA, respectively. Preliminary adsorption experiments showed that these materials can efficiently remove metals such as Pb+2, Cu+2 and Ni+2 from aqueous medium.

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

    Rodríguez Patino, J. M.


    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.

  8. Bio-Hydrogen Potential Of Easily Biodegradable Substrate Through Dark Fermentation

    Baris Calli; Wesley Boenne; Karolien Vanbroekhoven [Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol, (Belgium)


    For hydrogen production through dark fermentation of glucose, a continuously stirred 1-liter bioreactor was inoculated with yard waste compost and operated at 55 C with fed-batch runs. The reducing pH was regulated automatically by using pH transmitter and kept constant at 5.4. In this way, no methane was generated in any of the fed-batch runs and H{sub 2} yield in the range of 0.25 to 1.75 mol H{sub 2}/mol glucose consumed was obtained by inhibiting methanogenic H{sub 2} consumption. Astonishingly, the highest H{sub 2} yield was achieved with fresh inoculum which was neither heat treated nor acclimated. However, yield was not steady and decreased due to shift in metabolic pathway from acido-genesis to ethanol fermentation subsequent to high H{sub 2} partial pressure. Effluent ethanol concentrations above 400 mg/l after high H{sub 2} yielding runs were indication of this metabolic shift. (authors)

  9. Cd, Cu and Zn mobility in contaminated sediments from an infiltration basin colonized by wild plants: the case of Phalaris arundinacea and Typha latifolia.

    Saulais, M; Bedell, J P; Delolme, C


    Infiltration basins are shallow reservoirs in which stormwater is temporarily collected in order to reduce water volume in downstream networks. The settling of stormwater particles leads to a contaminated sediment layer. Wild plants can colonize these basins and can also play a role on the fate of heavy metals either directly by their uptake or indirectly by modification of physico-chemical characteristics of the sediment and therefore by modification of the mobility of heavy metals. The aim of this study, carried out in a vegetated infiltration basin, is to assess Cd, Cu and Zn mobility in two zones colonized by different species, Phalaris arundinacea and Typha latifolia. The study was carried out using three single chemical extractions: CaCl2 for the exchangeable phase, acetate buffer for the acido-soluble fraction and diethylenetriamine-pentaacetic acid (DTPA) for the fraction associated to the organic matter. Zn and Cd are mainly associated to carbonated and organic matter phases of the sediment. Moreover, acetate buffer-extractable Zn contents are strongly correlated to carbonates content in the sediment. DTPA-extractable Cu contents are strongly correlated with organic carbon sediment contents. We have also noted that extractable contents were significantly different between both zones whatever the metal.

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

    Puttaswamy; Nirmala Vaz


    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.

  11. Actividad antioxidante de extractos metanólicos y acuosos de distintas variedades de maíz mexicano

    Leticia Xochitl López Martínez


    Full Text Available En este estudio se determinó la actividad antioxidante y capacidad de inhibir la formación y acción de radicales libres, y contenido de compuestos fenólicos totales y antocianinas de extractos acuosos y metanólicos de distintas variedades de maíz mexicano. El contenido de compuestos fenólicos varió de entre 65.75 a 3400 mg/100 g y las antocianinas entre 1.5 a 2052.75 mg/100 g de harina de maíz. Las variedades "AREQ516540TL" y "Veracruz 42" fueron las que mostraron la mayor capacidad de inhibir la oxidación de ABTS.+ (2-2'azino-bis-etilbenziatoline- 6-acido sulfónico mediada por persulfato de sodio y la inhibición del blanqueamiento del B- caroteno acoplado a ácido linoléico, los mismos extractos fueron los más eficientes para reducir el radical catión DDPH (1,1-difenil-2-picrilhidrazil.

  12. Intoxicación por fluoroacetato de sodio

    Juliana Granada


    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.

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

    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


    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.

  14. Dietary potential renal Acid load in venezuelan children.

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


    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.


    Rog\\u00E9rio Luiz da Silva


    Full Text Available El objetivo de este trabajo fue evaluar la eficiencia de la técnica de miniestaca para la propagación clonal de la especie forestal guanandi (Calophyllum brasiliense. Para esto, se estableció un minijardín clonal en cajas de arena, del cual se obtuvo brotes para utilizar como miniestacas, buscando hacer 2 experimentos: en un ensayo se evaluó 2 tipos de miniestacas (apical e intermedia tratadas con diferentes dosis de acido indolbutírico (0, 2000, 4000 y 8000 mg.l-1; en el otro, las miniestacas fueros sembradas en 3 tipos de sustrato (vermiculita, cascarilla de arroz quemada y sustrato agrícola (corteza de pino compostada. Los índices de enraizamiento no variaron en el primer ensayo; en el segundo, hubo una reducción en el tiempo de permanencia en invernadero usando vermiculita como sustrato. De manera general, la técnica de miniestaca es una eficiente estrategia para la propagación clonal de guanandi.


    Cindy Lucía Martínez


    Full Text Available El Trabajo de Grado titulado: “Aislamiento, caracterización y conservación de bacterias acido-acéticas a partir de productos fermentados tradicionales” se desarrolló determinando los géneros bacterias ácido-acéticas Acetobacter sp. y Gluconobacter sp., aisladas a partir de productos fermentados tradiciones como son la chicha de maíz y el masato de arroz, para verificar estas bacterias se realizó un bioproceso a pequeña escala demostrando la producción de ácido acético característica propia de estos microorganismos. Finalmente se establecieron métodos de conservación que aseguran la estabilidad genética, bioquímica y morfológica de las bacterias ácido-acéticas aisladas para la introducción en el Cepario del Departamento de Biología de la Universidad Pedagógica Nacional (CDBUPN con el fin de ser utilizadas por los docentes y estudiantes de Biología de la Universidad Pedagógica Nacional como herramienta para la enseñanza de conceptos relacionados con temáticas frente a procesos de orden biológico.

  17. Self-powered biosensor for ascorbic acid with a Prussian blue electrochromic display.

    Zloczewska, Adrianna; Celebanska, Anna; Szot, Katarzyna; Tomaszewska, Dorota; Opallo, Marcin; Jönsson-Niedziolka, Martin


    We report on the development of a nanocarbon based anode for sensing of ascorbic acid (AA). The oxidation of AA on this anode occurs at a quite low overpotential which enables the anode to be connected to a biocathode to form an ascorbic acid/O2 biofuel cell that functions as a self-powered biosensor. In conjunction with a Prussian blue electrochromic display the anode can also work as a truly self-powered sensor. The oxidation of ascorbic acid at the anode leads to a reduction of the Prussian blue in the display. The reduced form of Prussian blue, called Prussian white, is transparent. The rate of change from blue to colourless is dependent on the concentration of ascorbic acid. The display can easily be regenerated by connecting it to the biocathode which returns the Prussian blue to its oxidized form. In this way we have created the first self-powered electrochromic sensor that gives quantitative information about the analyte concentration. This is demonstrated by measuring the concentration of ascorbic acid in orange juice. The reported quantitative read-out electrochromic display can serve as a template for the creation of cheap, miniturizable sensors for other relevant analytes.




    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.

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

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


    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.

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

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


    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.

  1. Degradation of recalcitrant organic pollutants by mixed catalysts; Degradazione di inquinanti organici recalcitranti mediante catalizzatori misti

    Campanella, L.; Marturano, S.; Sammartino, M. P. [Rome Univ. La Sapienza, Rome (Italy). Dipt. di Chimica


    The photodegradation of two well known recalcitrant compounds was studied. At this aim, a photosystem constituted by titanium dioxide and polyaniline, both immobilised in a PVC membrane, and a sunlight simulating irradiation source was used. The optimisation of the experimental conditions, ph, ionic strength and, when operating on soils, humic acid concentration, allowed the photodegradation of Paraquat at a nearly 100% extent, while, an oxidation by hypochlorite was needed to degrade cyanuric acid. [Italian] E' stata studiata la fotodegradazione di due composti notoriamente recalcitranti a questo tipo di rimozione. Con un sistema fotocatalitico costituito da biossido di titanio e polianilina immobilizzati in una membrana di PVC ed operando con luce solare simulata e' possibile, ottimizzando le condizioni sperimentali di pH, forza ionica e - operando su terreno - concentrazione di acidi umici, ottenere la degradazione del paraquat fino a valori assai prossimi al 100%. Per l'acido cianurico e' invece necessario, ai fini della degradazione, procedere tramite ossidazione con ipoclorito.

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

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


    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. Operation of the ISO-DALT system: Seventh edition

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


    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.




    Full Text Available .En el presente estudio, un modelo cinético para la síntesis de esteres usando Rhizopus oryzae resting cells es propuesto. El estudio cinético fue realizado en un rango de temperatura de 30-50 oC a presión atmosférica reducida. La influencia de las variables de operación tales como temperatura, pH y contenido de agua fueron estudiadas. Diferentes valores de concentración de micelio y relación molar de ácido/alcohol son ensayadas, Las velocidades iníciales se estimaron de la curva de concentración de acido palmítico, y su correspondiente conversión a ester en menos del 10%, frente a tiempo y reportadas en mmol I-1 min -1. Los valores de las constantes cinéticas fueron calculados usando el programa freeware SIMFIT (http:\\\\

  5. Molecular epidemiology of human cases of tuberculosis by Mycobacterium bovis in Mexico.

    Milián-Suazo, Feliciano; Pérez-Guerrero, Laura; Arriaga-Díaz, Camila; Escartín-Chávez, Minerva


    The purpose of this study was to evaluate the role of Mycobacterium bovis in human cases of tuberculosis (TB) in an endemic area of the disease in cattle. Sputum, urine and other tissue samples were obtained from: (1) TB-symptomatic patients, (2) dairy farm workers and (3) abattoir workers. Samples of macroscopic lesions suspicious of TB were also obtained from cattle at slaughter in the same geographic area. A total of 562 human samples were collected: 255 from symptomatic patients, 218 from farm workers and 93 from abattoir workers. Samples were analysed by the bacillus acido-alcohol resitant (BAAR) and polymerase chain reaction (PCR) tests and cultured in Stonebrink and Löwenstein-Jensen. Spoligotyping was performed in all isolates obtained by culture and the DNA obtained by PCR. From the total number of human cases, 34 (6%) showed M. bovis spoligotype; eight spoligotypes from cattle showed an identical pattern to three spoligotypes from humans; a different set of spoligotypes from cattle (n = 8) had only one spacer difference to a set of spoligotypes from humans (n = 2). These results provide further evidence that infected cattle represent a risk to public health and support previous reports about the role of M. bovis in Mexican patients. There is no doubt that genotyping M. bovis isolates collected from cattle may have a substantial impact on our understanding of the epidemiology of TB.

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

    Gironell, A; Marin-Lahoz, J


    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.

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

    Yelitza Aguas Mendoza


    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.

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

    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)


    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)

  9. Diferenciación de ácido acetilsalicílico utilizando la técnica de espectroscopia Raman y el análisis de componentes principales

    José Luis González-Sólis


    Full Text Available Recientemente la técnica de espectroscopia Raman ha sido aplicada en áreas como médicas, farmacéuticas y nanotecnología para determinar las concentraciones y diferencias en las soluciones de compuestos orgánicos e inorgánicos. En éste trabajo se analizaron las diferencias respecto a las concentraciones de los compuestos de una forma farmacéutica derivada del ácido acetilsalicílico comercial en forma de comprimido fabricado por 5 diferentes laboratorios. Los datos en bruto se obtuvieron a partir del acido acetil salicílico como principio activo, y 5 muestras de diferentes laboratorios fueron también analizadas. El bloque espectral se obtuvo utilizando un equipo de microscopia Raman Horiba-JY HR800 con una fuente de excitación de 830 nm y 17 mW de potencia. El algoritmo del PCA fue desarrollado en MatLab y aplicado al bloque espectral. Concluyendo que la aplicación de la espectroscopia Raman a la farmacología ofrece información sobre la efectividad farmacológica del ácido acetilsalicílico como analgésico y antipirético.

  10. Actualización de la Fisiología Gástrica

    David Rodríguez Palomo


    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.

  11. Learning Chemistry with candies

    Rodríguez Rodríguez, José Manuel


    Full Text Available Las golosinas (caramelos, chicles, nubes, palotes, papas fritas, etc. nos gustan a casi todos y gozan de una imagen positiva, a pesar de sus efectos secundarios si no se consumen con moderación. Aprovechándonos de esa buena imagen y de la gran variedad de golosinas que existen en el mercado, hemos diseñado una serie de experimentos con los que podemos explicar distintos tipos de reacciones químicas (acido-base, oxidación-reducción, endotérmicas…, la actuación de un indicador e, incluso, podemos comparar cantidades de vitamina C. En todas las actividades se persigue explicar algún aspecto de la Química que, en general, el público desconoce, captando su atención, por ejemplo, mediante cambios de color espectaculares y con las golosinas como protagonistas. Así mismo, estas experiencias pueden emplearse como recursos didácticos para alumnos de 4o E.S.O. y Bachillerato, apoyando los contenidos teóricos del currículum.

  12. Inhibition of Neutral red photolysis with different antioxidants.

    Rimpapa, Zlatan; Sofić, Emin; Sapcanin, Aida; Toromanović, Jasmin; Tahirović, Ismet


    Neutral red is a dye the azine structure which has been used as an acido-base indicator and a dye in histochemistry. In 1960 Goldhaber introduced Neutral red into the medium of resorbing bone cultures to localize the osteoclast in the living cultures. Using time-lapse microcinematography in order to follow the osteoclasts, he reported excellent contrast could be obtained with Neutral red due to the avidity of osteoclasts for this dye. Unfortunately, however, the photodynamic effect resulting from subsequent exposure of these cultures to light precluded this approach, and again in 1963. it was observed that the death of the osteoclasts was probably due to a photodynamic effect related to the dye in the cell, the presence of oxygen and the frequent exposure of light by our time-lapse photography. VIS and UV irradiation induced photolysis of Neutral red, and from Neutral red cation produced with photons a Neutral red radical. This Neutral red radical can be inhibited with action of an antioxidant, such as melatonin, glutathione, ascorbic acid, E vitamin, etc. We developed an assay with Neutral red photolysis which utilizes a VIS and UV irradiation technique for quantification the inhibition of photolysis with action of an antioxidant. In this method Neutral red acts double, as a free radical generator and as a photosensitizer.

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

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


    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.

  14. Curvas de titulación potencio métrica ácido-base de una bentonita

    Liz Adriana Pinilla Cuenca


    Full Text Available Se estudió el comportamiento acido- base de una bentonita colombiana proveniente del Valle del Cauca, medianteexperimentos de titulación potenciométrica. Se escogió el método de titulación por retroceso, ya que la técnica de titulación continua no produce una curva única de valoración.La curva de titulación muestra tres puntos de inflexión, establecidos mediante los máximos en la curva derivada, envalores de pH de 4,8; 6,2 y 6,8, que indican tres tipos de sitios ácidos, identificados con los mecanismos de intercambioiónico presentes en la bentonita. El primer sitio ácido, y el más fuerte, se manifiesta como un mecanismo de sustitución de los iones interlaminares, de la estructura 2: 1, por iones H +. El segundo y el tercero son consecuencia de sitios de enlaces rotos o defectos de la red cristalina localizados en bordes y aristas, que originan sitios de acomplejamientosuperficial de dos tipos: silanol (=SiOH y aluminol (=A10H

  15. Photo catalytic membrane processes for degradation of various types of organic pollutants and micropollutants in water

    Molinari, R.; Borgese, M.; Drioli, E. [Rende Univ. of Calabria, Rende, CS (Italy). Dipt. di Ingegneria Chimica e dei Materiali; Palmisano, L.; Schiavello, M. [Palermo Univ., Palermo (Italy). Dipt. di Ingegneria Chimica dei Processi e dei Materiali


    Degradation test in a photocatalytic membrane system have been carried out using TiO{sub 2} (Degussa P25) as catalyst and humic acid, organic dyes, 4-nitrophenol as pollutants. The influence of UV radiation and initial concentration of pollutant on the photodegradation rate were investigated in discontinuous and continuous systems. Experimental results, showed that it is possible to obtain an efficient photocatalytic membrane process, but various parameters (e. g. p H) should be optimised to obtain high reaction rate and high membrane rejection of pollutants and their by-products. [Italian] Prove di degradazione in un sistema fotocatalitico a membrana sono state condotte utilizzando TiO{sub 2} (Degussa P25) come catalizzatore e acido umico, coloranti organici, 4-nitrofenolo, come inquinanti. E' stata studiata l'influenza della radiazione UV e della concentrazione iniziale dell'inquinante sulla velocita' di fotodegradazione in sistemi continui, che discontinui. I risultati sperimentali hanno mostrato che e' possibile ottenere un efficiente proesso fotocatalitico a membrana, ma e' necessario ottimizzare vari parametri (per es. il pH) se si vuole ottenere un'elevata velocita' di fotodegradazione ed un'altrettanta elevata reiezione della membrana verso gli inquinanti da fotodegradare ed i loro sottoprodotti.

  16. 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)

    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)


    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).

  17. CO{sub 2} sequestration technologies

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


    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}.

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

    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


    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.


    William H.J. Strosnider


    Full Text Available La minería intensiva y el procesamiento del cuerpo mineralizado del Cerro Rico de Potosí (Bolivia ha ocurrido desde 1545. Para avanzar la investigación sobre descargas de drenaje acido de minas (DAM y su conexión a la contaminación río abajo, se generaron datos en dos muestreos durante la temporada más extrema de lluvia y sequía. Las concentraciones en el DAM y arroyos receptores de Ag, B, Ba, Mo, Sb, Se, Sn, y V fueron superiores a los límites de descarga permitidos por la legislación Boliviana y las directrices sobre arroyos receptores del DAM, tal como las normas de agricultura internacionales. Concen traciones elevadas de elementos de tierras raras han sido documentados en esta ubicación. Los resultados del estudio indican que la contaminación por minería impactan significativamente el río estudiado, y pone de manifiesto la importancia de su remediación.

  20. Glomerular filtration rate measured by 51Cr-EDTA clearance: evaluation of captopril-induced changes in hypertensive patients with and without renal artery stenosis

    Anna Alice Rolim Chaves


    Full Text Available INTRODUCTION: Renal artery stenosis can lead to renovascular hypertension; however, the detection of stenosis alone does not guarantee the presence of renovascular hypertension. Renovascular hypertension depends on activation of the renin-angiotensin system, which can be detected by functional tests such as captopril renal scintigraphy. A method that allows direct measurement of the baseline and post-captopril glomerular filtration rate using chromium-51 labeled ethylenediamine tetraacetic acid (51Cr-EDTA could add valuable information to the investigation of hypertensive patients with renal artery stenosis. The purposes of this study were to create a protocol to measure the baseline and post-captopril glomerular filtration rate using 51Cr-EDTA, and to verify whether changes in the glomerular filtration rate permit differentiation between hypertensive patients with and without renal artery stenosis. METHODS: This prospective study included 41 consecutive patients with poorly controlled severe hypertension. All patients had undergone a radiological investigation of renal artery stenosis within the month prior to their inclusion. The patients were divided into two groups: patients with (n=21 and without renal artery stenosis, (n=20. In vitro glomerular filtration rate analysis (51Cr-EDTA and 99mTc-DMSA scintigraphy were performed before and after captopril administration in all patients. RESULTS: The mean baseline glomerular filtration rate was 48.6±21.8 ml/kg/1.73 m² in the group wuth renal artery stenosis, which was significantly lower than the GFR of 65.1±28.7 ml/kg/1.73m² in the group without renal artery stenosis (p=0.04. Captopril induced a significant reduction of the glomerular filtration rate in the group with renal artery stenosis (to 32.6±14.8 ml/kg/1.73m², p=0.001 and an insignificant change in the group without RAS (to 62.2±23.6 ml/kg/1.73m², p=0.68. Scintigraphy with technetium-99m dimercapto-succinic acid (DMSA did not show

  1. Serum levels of interleukin-6 and interleukin-8 as diagnostic markers of acute pyelonephritis in children

    Abolfazl Mahyar


    Full Text Available &lt;b&gt;Purpose:&lt;/b&gt; Early diagnosis and treatment of acute pyelonephritis in children is of special importance in order to prevent serious complications. This study was conducted to determine the diagnostic value of serum interleukin (IL-6 and IL-8 in children with acute pyelonephritis. &lt;b&gt;Methods:&lt;/b&gt; Eighty seven patients between 1 month to 12 years old with urinary tract infection (UTI were divided into 2 groups based on the result of 99m-technetium dimercapto-succinic acid (DMSA renal scan: acute pyelonephritis (n=37 and lower UTI (n=50 groups. White blood cell (WBC count, neutrophil (Neutl count, erythrocyte sedimentation rate (ESR, C-reactive protein (CRP concentration, platelet count, and serum IL-6 and IL-8 concentrations of both groups were measured and compared . &lt;b&gt;Results:&lt;/b&gt; There was a significant difference between two groups regarding WBC count, Neutl count, ESR, and CRP concentration (P&lt;0.05. In addition, the difference between the two groups regarding serum IL-6 and IL-8 concentrations was not significant (IL-6, 60 and 35.4 pg/mL and IL-8, 404 and 617 pg/mL, respectively. The sensitivity and specificity of serum IL-6 and IL-8 for diagnosis of acute pyelonephritis were 73%, 42% and 78%, 32%, respectively. Sensitivity, specificity, negative and positive predictive values of serum IL-6 and IL-8 were less than those of acute phase serum reactants such as CRP. &lt;b&gt;Conclusion:&lt;/b&gt; This study showed that there was no significant difference between acute pyelonephritis and lower UTI groups regarding serum IL-6 and IL-8 levels. Therefore, despite confirming results of previous studies, it seems that IL-6 and IL-8 are not suitable markers for differentiating between acute pyelonephritis and lower UTI.

  2. {sup 99m}TcO(BAT-NI), a novel nitroimidazole tracer: in vivo uptake studies in ischaemic myocardium

    Hoffend, J.; Linke, G.; Mohammed, A.; Haberkorn, U. [Department of Radiology, Division of Nuclear Medicine, University of Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg (Germany); Tiefenbacher, C.P. [Department of Internal Medicine, Division of Cardiology, University of Heidelberg, Heidelberg (Germany); Eisenhut, M. [German Cancer Research Centre, Heidelberg (Germany)


    Myocardial perfusion single-photon emission tomography (SPET) performed with cationic technetium-99m complexes indicates ischaemic areas as cold lesions. By contrast, nitroimidazole derivatives labelled with fluorine-18 or {sup 99m}Tc have recently shown promising results for hot spot imaging of ischaemic myocardium. This study evaluates {sup 99m}TcO(BAT-NI), a new {sup 99m}Tc complex comprising the nitroimidazole ligand, 2,10-dimercapto-2,10-dimethyl-4,8-diaza-6-[4-(2-nitroimidazolyl)butyl]undecane, in a low-flow in vivo model of myocardial ischaemia in thoracotomised rats. To elucidate the influence of the 2-nitroimidazole group on ischaemia-induced uptake, comparisons with ligand derivatives were performed where (a) the 2-nitro group was deleted [{sup 99m}TcO(BAT-I)], (b) the 2-nitroimidazole functionality was replaced by a Br atom [{sup 99m}TcO(BAT-Br)] and (c) the {sup 99m}TcO(BAT) moiety was replaced by an iodine-125 iodophenoxybutyl ligand ({sup 125}IP-NI). The radiolabelled compounds were i.v. injected 15 min after reducing resting myocardial blood flow by 50-60% and the uptake of radioactivity was assessed 90 min post injection. Autoradiography of left ventricular short-axis slices showed median uptake ratios of ischaemic/non-ischaemic myocardium (I/N) of 3.4, 4.5 and 3.4 for {sup 99m}TcO(BAT-NI), {sup 99m}TcO(BAT-I) and {sup 99m}TcO(BAT-Br), respectively. In contrast, {sup 125}IP-NI was not preferentially taken up by ischaemic myocardium. Accumulation of {sup 99m}TcO(BAT-NI) in ischaemic heart regions was comparable to that in the liver. Biodistribution studies showed a median uptake of 0.65% ID/g of {sup 99m}TcO(BAT-NI) in ischaemic tissue and an I/N of 3.3. On planar images of the thorax and upper abdomen the ischaemic hearts were visualised faintly; the median heart to lung count ratio for {sup 99m}TcO(BAT-NI) was 1.7, and the median heart to liver count ratio was 1.0. We conclude that uptake of {sup 99m}TcO(BAT-NI) in ischaemic myocardium does not

  3. Fabrication of novel gold nanorod/polymer nanocomposite fibers and their application in heavy metal ion sensing

    Tang, Wenqiong

    NR/PCL fibers with metal ion binding ligands of 2,5-dimercapto-1,3,4-thiadiazole dimer and trimercaptotriazine, respectively. The changes in the SERS spectral features of the ligands before and after heavy metal ion coordination were indicative for the detection of target ions. Based on the above design, the resultant sensors exhibited not only high selectivity, but also the capability for quantitative analysis of the target ion concentration.

  4. Glomerular Filtration Rate Measured by 51Cr-EDTA Clearance: Evaluation of Captopril-Induced Changes in Hypertensive Patients with and without Renal Artery Stenosis

    Chaves, Anna Alice Rolim; Buchpiguel, Carlos Alberto; Praxedes, Jose Nery; Bortolotto, Luiz Aparecido; Sapienza, Marcelo Tatit


    INTRODUCTION: Renal artery stenosis can lead to renovascular hypertension; however, the detection of stenosis alone does not guarantee the presence of renovascular hypertension. Renovascular hypertension depends on activation of the renin-angiotensin system, which can be detected by functional tests such as captopril renal scintigraphy. A method that allows direct measurement of the baseline and post-captopril glomerular filtration rate using chromium-51 labeled ethylenediamine tetraacetic acid (51Cr-EDTA) could add valuable information to the investigation of hypertensive patients with renal artery stenosis. The purposes of this study were to create a protocol to measure the baseline and post-captopril glomerular filtration rate using 51Cr-EDTA, and to verify whether changes in the glomerular filtration rate permit differentiation between hypertensive patients with and without renal artery stenosis. METHODS: This prospective study included 41 consecutive patients with poorly controlled severe hypertension. All patients had undergone a radiological investigation of renal artery stenosis within the month prior to their inclusion. The patients were divided into two groups: patients with (n=21) and without renal artery stenosis, (n=20). In vitro glomerular filtration rate analysis (51Cr-EDTA) and 99mTc-DMSA scintigraphy were performed before and after captopril administration in all patients. RESULTS: The mean baseline glomerular filtration rate was 48.6±21.8 ml/kg/1.73 m2 in the group wuth renal artery stenosis, which was significantly lower than the GFR of 65.1±28.7 ml/kg/1.73m2 in the group without renal artery stenosis (p=0.04). Captopril induced a significant reduction of the glomerular filtration rate in the group with renal artery stenosis (to 32.6±14.8 ml/ kg/1.73m2, p=0.001) and an insignificant change in the group without RAS (to 62.2±23.6 ml/kg/1.73m2, p=0.68). Scintigraphy with technetium-99m dimercapto-succinic acid (DMSA) did not show significant

  5. Glomerular filtration rate measured by {sup 51}Cr-EDTA clearance: evaluation of captopril-induced changes in hypertensive patients with and without renal artery stenosis

    Chaves, Anna Alice Rolim; Buchpiguel, Carlos Alberto; Praxedes, Jose Nery; Bortolotto, Luiz Aparecido; Sapienza, Marcelo Tatit, E-mail: [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Medicina. Dept. de Neurologia


    Introduction: renal artery stenosis can lead to renovascular hypertension; however, the detection of stenosis alone does not guarantee the presence of renovascular hypertension. Renovascular hypertension depends on activation of the renin-angiotensin system, which can be detected by functional tests such as captopril renal scintigraphy. A method that allows direct measurement of the baseline and post-captopril glomerular filtration rate using chromium-51 labeled ethylenediamine tetraacetic acid ({sup 51}Cr-EDTA) could add valuable information to the investigation of hypertensive patients with renal artery stenosis. The purposes of this study were to create a protocol to measure the baseline and post-captopril glomerular filtration rate using {sup 51}Cr-EDTA, and to verify whether changes in the glomerular filtration rate permit differentiation between hypertensive patients with and without renal artery stenosis. Methods: this prospective study included 41 consecutive patients with poorly controlled severe hypertension. All patients had undergone a radiological investigation of renal artery stenosis within the month prior to their inclusion. The patients were divided into two groups: patients with (n=21) and without renal artery stenosis, (n=20). In vitro glomerular filtration rate analysis ({sup 51}Cr-EDTA) and {sup 99m}Tc-DMSA scintigraphy were performed before and after captopril administration in all patients. Results: the mean baseline glomerular filtration rate was 48.6+-21.8 ml/kg/1.73 m{sup 2} in the group with renal artery stenosis, which was significantly lower than the GFR of 65.1+-28.7 ml/kg/1.73m{sup 2} in the group without renal artery stenosis (p=0.04). Captopril induced a significant reduction of the glomerular filtration rate in the group with renal artery stenosis (to 32.6+-14.8 ml/kg/1.73m{sup 2}, p=0.001) and an insignificant change in the group without RAS (to 62.2+-23.6 ml/kg/1.73m{sup 2}, p=0.68). Scintigraphy with technetium-99m dimercapto

  6. Lipolytic activity of ricin from Ricinus sanguineus and Ricinus communis on neutral lipids.

    Lombard, S; Helmy, M E; Piéroni, G


    The present study was carried out with a view of determining ricin lipolytic activity on neutral lipids in emulsion and in a membrane-like model. Using 2,3-dimercapto-1-propanol tributyrate (BAL-TC(4)) as substrate, the lipolytic activity of ricin was found to be proportional to ricin and substrate concentrations, with an apparent K(m) (K(m,app)) of 2.4 mM, a k(cat) of 200 min(-1) and a specific activity of 1.0 unit/mg of protein. This work was extended to p-nitrophenyl (pNP) fatty acid esters containing two to twelve carbon atoms. Maximum lipolytic activity was registered on pNP decanoate (pNPC(10)), with a K(m,app) of 3.5 mM, a k(cat) of 173 min(-1) and a specific activity of 3.5 units/mg of protein. Ricin lipolytic activity is pH and galactose dependent, with a maximum at pH 7.0 in the presence of 0.2 M galactose. Using the monolayer technique with dicaprin as substrate, ricin showed a lipolytic activity proportional to the ricin concentration at 20 mN/m, which is dependent on the surface pressure of the lipid monolayer and is detectable up to 30 mN/m, a surface pressure that is of the same order of magnitude as that of natural cell membranes. The methods based on pNPC(10) and BAL-TC(4) hydrolysis are simple and reproducible; thus they can be used for routine studies of ricin lipolytic activity. Ricin from Ricinus communis and R. sanguineus were treated with diethyl p-nitrophenylphosphate, an irreversible serine esterase inhibitor, and their lipolytic activities on BAL-TC(4) and pNPC(10), and cytotoxic activity, were concurrently recorded. A reduction in lipolytic activity was accompanied by a decrease in cytotoxicity on Caco2 cells. These data support the idea that the lipolytic activity associated with ricin is relevant to a lipase whose activity is pH and galactose dependent, sensitive to diethyl p-nitrophenylphosphate, and that a lipolytic step may be involved in the process of cell poisoning by ricin. Both colorimetric tests used in this study are sensitive

  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

    C. Ortiz Leyba


    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. 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

    Miguelangelo Ziegler Arboitte


    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

  9. 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

    Vanessa N. C. Santos


    -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.

  10. 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

    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)


    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.

  11. The completely annotated genome and comparative genomics of the Peptoniphilaceae bacterium str. ING2-D1G, a novel acidogenic bacterium isolated from a mesophilic biogas reactor.

    Tomazetto, Geizecler; Hahnke, Sarah; Langer, Thomas; Wibberg, Daniel; Blom, Jochen; Maus, Irena; Pühler, Alfred; Klocke, Michael; Schlüter, Andreas


    The strictly anaerobic Peptoniphilaceae bacterium str. ING2-D1G (=DSM 28672=LMG 28300) was isolated from a mesophilic laboratory-scale completely stirred tank biogas reactor (CSTR) continuously co-digesting maize silage, pig and cattle manure. Based on 16S rRNA gene sequence comparison, the closest described relative to this strain is Peptoniphilus obesi ph1 showing 91.2% gene sequence identity. The most closely related species with a validly published name is Peptoniphilus indolicus DSM 20464(T) whose 16S rRNA gene sequence is 90.6% similar to the one of strain ING2-D1G. The genome of the novel strain was completely sequenced and manually annotated to reconstruct its metabolic potential regarding anaerobic digestion of biomass. The strain harbors a circular chromosome with a size of 1.6 Mb that contains 1466 coding sequences, 53 tRNA genes and 4 ribosomal RNA (rrn) operons. The genome carries a 28,261bp prophage insertion comprising 47 phage-related coding sequences. Reconstruction of fermentation pathways revealed that strain ING2-D1G encodes all enzymes for hydrogen, lactate and acetate production, corroborating that it is involved in the acido- and acetogenic phase of the biogas process. Comparative genome analyses of Peptoniphilaceae bacterium str. ING2-D1G and its closest relative Peptoniphilus obesi ph1 uncovered rearrangements, deletions and insertions within the chromosomes of both strains substantiating a divergent evolution. In addition to genomic analyses, a physiological and phenotypic characterization of the novel isolate was performed. Grown in Brain Heart Infusion Broth with added yeast extract, cells were spherical to ovoid, catalase- and oxidase-negative and stained Gram-positive. Optimal growth occurred between 35 and 37°C and at a pH value of 7.6. Fermentation products were acetate, butanoate and carbon dioxide. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    Denilson Padilla Cerpa


    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.

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

    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:


    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.

  14. Mechanical properties and total hydroxycinnamic derivative release of starch/glycerol/Melissa officinalis extract films

    Letícia Mello Rechia


    Full Text Available The aim of this study was to investigate the mechanical properties of starch/glycerol/Melissa officinalis, a topical drug delivery system for labial herpes treatment. Four films were prepared with different concentrations of starch, glycerol, and Melissa officinalis extract. The results revealed that increasing the glycerol concentration in the film reduced elasticity modulus and tensile strength, exhibiting a plasticizing effect. The increase in free volume resulted in increased release of hydroxycinnamic derivatives expressed as rosmarinic acid.O objetivo deste trabalho foi estudar as propriedades mecânicas e o mecanismo de liberação de um sistema tópico de liberação prolongada para o tratamento do Herpes labial a partir de filmes de amido/glicerol/extrato de Melissa officinalis, planta com comprovada atividade antiviral. Foram obtidos quatro filmes poliméricos com diferentes concentrações de amido, glicerol e extrato de Melissa officinalis os quais foram caracterizados mecanicamente e determinado o perfil de liberação de derivados hidroxicinâmicos. Os resultados demonstraram que o aumento da concentração de glicerol no filme produz uma redução no módulo de elasticidade e na tensão de deformação como conseqüência do efeito plastificante. O aumento no volume livre do polímero resultou em aumento da liberação dos derivados hidroxicinâmicos expressos como ácido rosmarínico.

  15. 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

    Duc, M


    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)

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

    Juliana Ossa


    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.

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

    Javier Rodrigo Alpízar Cordero


    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.

  18. 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

    Ana Flávia Schvabe Duarte


    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.

  19. Rendimiento y valor nutritivo de forraje de alfalfa (Medicago sativa L. con diferentes dosis de estiércol bovino

    Cirilo Vázquez-Vázquez


    Full Text Available El presente trabajo se realizó en la Comarca Lagunera, estado de Coahuila, México. El objetivo fue evaluar la producción y el valor nutritivo del forraje de tres variedades de alfalfa tratamientos de fertilizado con estiércol de bovino y con riego por goteo subsuperficial. Se determinó la composición del N, P, K, Ca y Mg en el tejido vegetal como un indicador de los volúmenes de extracción para cada nutrimento. Las variedades fueron: CUF 101, Sandor y Altaverde. Se aplicaron cinco tratamientos de estiércol (0, 40, 80, 120, 160 t ha-1 y uno de fertilizante químico (30-100 kg ha-1 de N y P como testigo. Respecto al forraje seco se presentaron diferencias significativas entre los tratamientos de estiércol pero no para variedades. Los valores de producción más altos se observaron en los cortes marzo, abril y junio en los tratamientos de estiércol de 80, 120 y 160 t ha-1 con valores superiores de 4 t ha-1 de forraje seco. En las variables de valor nutritivo del forraje (proteína cruda, fibra acido detergente, fibra neutro detergente y energía, tampoco se detectaron diferencias significativas entre variedades ni entre tratamientos de fertilización. Con respecto a la extracción de N, P, K, Ca y Mg por las plantas, en los cortes 5º al 8º es donde se presentó la mayor extracción de dichos elementos con aproximadamente 160 kg ha-1 de nitrógeno, 12-14 kg ha-1 de fósforo y 125 kg ha-1 de potasio.

  20. 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

    Diofanor Acevedo


    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.

  1. 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

    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)


    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.)

  2. 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

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


    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.

  3. Uso de aditivos biológicos na ensilagem de forrageiras / Use of biological addictive in ensiling of forage

    Marcos Rogério Oliveira


    Full Text Available ResumoOs inoculantes biológicos por meio de microrganismo objetivam acelerar a queda do pH, induzindo a exclusão competitiva de microrganismos indesejáveis, reduzindo a perda de nutrientes durante o metabolismo fermentativo e refermentativo. Os aditivos enzimáticos possuem principais atividades de catalase e hemicelulase. Já os bacterianos são culturas tanto homofermentativas, que são efetivos na produção de acido lático, quanto cepas heterofermentativas, que produzem além do ácido lático o ácido acético para auxiliar na estabilidade aeróbica. Resultados são controversos sobre os seus benefícios no decréscimo do pH, no teor de nitrogênio amoniacal, na redução na fração fibrosa, na digestibilidade e consumo de matéria seca, indicando a existência de variação entre a natureza do inóculo biológico e a forragem a ser ensilada.AbstractThe biological inoculants through microorganisms aim at accelerating the decrease of pH, inducing the competitive exclusion of undesirable microorganisms, reducing the loss of nutrients during the fermentative metabolism. The enzyme addictives are the main activities of catalase and hemicellulase. On the other hand, the bacterial ones are homofermentatives cultures, which are effective in the production of lactic acid, and heterofermentatives stumps, that produce the lactic acid and also the acetic acid to aid the aerobics stability. The results are controversial on their benefits in decreasing the pH, in the content of ammonium nitrogen, in the reduction in the fibrous fraction, in the digestibility and dry matter intake, indicating the variation existence between the nature of the biological inoculum and the forage to be ensiled.

  4. Asymmetric electrooptic response in a nematic liquid crystal

    Dascalu, Constanta [Politechnica University of Bucharest, Bucharest (Romania)


    An asymmetric electrooptic response in nematic liquid crystal (LC) has been obtained. The liquid crystal hybrid cell was made by using a standard configuration. One of the ITO (Indium Tin Oxide) electrodes was covered with a surfactant, which induces a homeotropic alignment. The second of the indium tin oxide electrodes was covered by a thin layer of photopolymer, which was previously mixed with an acid, which favours a process of release of protons. Such cations are responsible of electrochemical process in the LC leading to an asymmetric electrooptic response, which depend on the polarity of the applied electric field. This fact is due to an internal field, which change the effective voltage thresholds for the reorientation of the liquid crystal. During the anodic polarization, the optical switching is inhibited because the effective field decreases below the threshold value. On contrary for the opposite polarization the effective field is enough to determine a homeotropic alignment. [Spanish] Se ha obtenido una respuesta electro-optica asimetrica en cristales liquidos neumaticos. La celula hibrida de cristal liquido fue construida utilizando una configuracion estandar. Uno de los electrodos ITO fue cubierto con una pelicula delgada de material organico para inducir una alineacion homeotropa. El otro electrodo ITO fue cubierto con una pelicula delgada de fotopolimero anteriormente mezclada con un acido para favorecer la emision de protones. Estos cationes son responsables del proceso electroquimico en LC, conduciendo a una respuesta electro-optica asimetrica que depende de la polaridad del campo electrico aplicado. Este efecto es originado por un campo interno que cambia el umbral efectivo del voltaje para la reorientacion del cristal liquido. Durante la polarizacion anodica, la conmutacion optica se inhibe debido a que el campo efectivo disminuye abajo del valor del umbral. Por el contrario, para la polarizacion opuesta el campo efectivo es suficiente para

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

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


    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.

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

    Tope, Balkrishna B.


    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.


    Quésia Jemima da SILVA


    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.

  8. Desequilibrio hidroelectrolítico y ácido-base en la diarrea

    Raúl L Riverón Corteguera


    Full Text Available Se realiza una revisión de los principios básicos del equilibrio hidromineral y acido-básico y se profundiza en los mecanismos homeostáticos más frecuentes en la edad pediátrica relacionados con las enfermedades diarreicas agudas. Se describe la clasificación y el manejo de la deshidratación con las sales de rehidratación oral (SRO (planes A y B y soluciones endovenosas (plan C, así como la fisiología y el tratamiento con bicarbonato de sodio en la acidosis metabólica. Se exponen los elementos relacionados con la regulación del sodio, del potasio y del equilibrio ácido-básico. Se hace referencia a la predisposición a la translocación bacteriana que presenta la hipovolemia mantenida más de 8 horas.A review of the basic principles of water-mineral and acid-base balance was made aand the most frequent homeostatic mechanisms in pediatric ages, which are related to acute diarrheal diseases were studied in depth. The classification and management of dehydration using oral rehydration salts (ORS (plans A and B and intravenous solutions (plan C as well as physiology and treatment of metabolic acidosis with sodium bicarbonate were described. The elements related to sodium and potassium control and acidd-base balance were set forth. Reference is mae to predisposition to bacterial translocation found in sustained hypovolemia for more than 8 hours.

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

    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


    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

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

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


    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.

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

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


    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.

  12. [Learning disorders in neurofibromatosis type 1].

    Garcia-Penas, J J


    Introduccion. Los deficits neurocognitivos y las dificultades de aprendizaje representan las complicaciones neurologicas mas frecuentes de la neurofibromatosis tipo 1 (NF1) en la edad pediatrica y son responsables de una importante morbilidad evolutiva. Los niños con NF1 muestran alteraciones en atencion, percepcion visual, lenguaje, funciones ejecutivas, logros academicos y conducta. Los estudios en modelos animales sugieren que las alteraciones de aprendizaje en la NF1 se relacionan con una potenciacion de la actividad Ras que conduce a un incremento de la inhibicion mediada por el acido gamma-aminobutirico (GABA) y a una disminucion de la potenciacion sinaptica a largo plazo. Objetivo. Describir la frecuencia, gravedad, tipologia y evolucion natural de los deficits neurocognitivos especificos de la NF1. Desarrollo. Los trastornos neurocognitivos y conductuales afectan al 50-80% de los niños con NF1. Se pueden definir tres subtipos de perfiles cognitivos en la NF1, incluyendo trastorno de aprendizaje global, trastorno especifico de aprendizaje y trastorno por deficit de atencion/hiperactividad aislado. Los deficits cognitivos mas frecuentes se relacionan con la alteracion visuoespacial, aunque tambien son importantes las alteraciones de la memoria de trabajo y de la funcion ejecutiva asociadas con la disfuncion de la corteza prefrontal. Conclusiones. Existe una gran frecuencia global de problemas cognitivos en la NF1, lo cual implica que la disfuncion neurocognitiva sea la mayor complicacion medica que afecta la calidad de vida de estos pacientes. El diagnostico y el tratamiento precoces de los trastornos de aprendizaje en estos niños son basicos para conseguir un mejor desempeño academico.



    Full Text Available Este trabajo tuvo como objetivo principal evaluar la producción de etanol de nueve levaduras aisladas y caracterizadas en el Valle con un testigo de un ingenio brasilero. La evaluación de las variables como temperatura, oxígeno, dióxido de carbono y etanol durante el proceso de fermentación se realizó con la ayuda del equipo Ecochamber y la técnica HPLC para contrastar los valores encontrados. El diseño experimental correspondió al modelo unifactorial, y el tiempo de observación fue transversal en 48 horas, la unidad muestral fue de 600 mL de solución de melaza con una concentración de 16°Brix cuyo pH se ajustó a 4,5 con adición de acido cítrico. Los resultados se analizaron con el programa estadístico STATGRAPHICS 5.1, mediante ANOVA con un nivel de significancia de 0,05 y las diferencias con prueba de Tuckey. Como resultados relevantes se encontró que las variables temperatura y oxígeno no presentaron diferencias estadísticas con valores entre 24 a 32°C y 6,7 a 20% de manera respectiva, mientras que las cepas IC1, IP3, IP4, IP5 mostraron los mayores valores en producción de dióxido de carbono. En lo concerniente a la variable etanol, las cepas con mayor producción fueron T, IC1, IP3, IP4, IP6, IP5.

  14. 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

    T. Grau Carmona


    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.

  15. KINETIC STUDY OF PALMITIC ACID ESTERIFICATION CATALYZED BY Rhizopus oryzae RESTING CELLS Estudio cinético de la esterificación del ácido palmítico catalizado por células en reposo de Rhizopus oryzae


    Full Text Available In the present study, a kinetic model for the biocatalytic synthesis of esters using Rhizopus oryzae resting cells is proposed. The kinetic study has been made in a range of 30-50 °C and atmospheric pressure. The Influence of operating variables, water content, pH, amount of mycelium was studied. Different values of temperature, initial mycelium concentration and acid/alcohol molar ratio were tested. Initial rates were estimated from the slope of the concentration of palmitic acid, or their corresponding ester at conversions of less than 10%, versus time and reported as mmol l-1 min -1. The values of kinetic constants were computed using the freeware program SIMFIT (http:\\ el presente estudio, un modelo cinético para la síntesis de esteres usando Rhizopus oryzae resting cells es propuesto. El estudio cinético fue realizado en un rango de temperatura de 30-50 ºC a presión atmosférica reducida. La influencia de las variables de operación tales como temperatura, pH y contenido de agua fueron estudiadas. Diferentes valores de concentración de micelio y relación molar de ácido/alcohol son ensayadas, Las velocidades iníciales se estimaron de la curva de concentración de acido palmítico, y su correspondiente conversión a ester en menos del 10%, frente a tiempo y reportadas en mmol I-1 min -1. Los valores de las constantes cinéticas fueron calculados usando el programa freeware SIMFIT (http:\\

  16. 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

    陈连民; 沈宜钊; 王洪荣


    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。

  17. The Villas Carrousel PV-Wind Hybrid Project

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


    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.

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

    Jacqueline Nelisis Zanoni


    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.

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

    S. Broens


    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.

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

    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


    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.

  1. Pyrochemical reprocessing of molten salt fast reactor fuel: focus on the reductive extraction step

    Rodrigues Davide


    Full Text Available The nuclear fuel reprocessing is a prerequisite for nuclear energy to be a clean and sustainable energy. In the case of the molten salt reactor containing a liquid fuel, pyrometallurgical way is an obvious way. The method for treatment of the liquid fuel is divided into two parts. In-situ injection of helium gas into the fuel leads to extract the gaseous fission products and a part of the noble metals. The second part of the reprocessing is performed by ‘batch’. It aims to recover the fissile material and to separate the minor actinides from fission products. The reprocessing involves several chemical steps based on redox and acido-basic properties of the various elements contained in the fuel salt. One challenge is to perform a selective extraction of actinides and lanthanides in spent liquid fuel. Extraction of actinides and lanthanides are successively performed by a reductive extraction in liquid bismuth pool containing metallic lithium as a reductive reagent. The objective of this paper is to give a description of the several steps of the reprocessing retained for the molten salt fast reactor (MSFR concept and to present the initial results obtained for the reductive extraction experiments realized in static conditions by contacting LiF-ThF4-UF4-NdF3 with a lab-made Bi-Li pool and for which extraction efficiencies of 0.7% for neodymium and 14.0% for uranium were measured. It was concluded that in static conditions, the extraction is governed by a kinetic limitation and not by the thermodynamic equilibrium.

  2. [Long-term effect of policosanol on the functional recovery of non-cardioembolic ischemic stroke patients: a one year study].

    Sanchez, J; Illnait, J; Mas, R; Mendoza, S; Fernandez, L; Mesa, M; Vega, H; Fernandez, J; Reyes, P; Ruiz, D


    Introduccion. El ictus es una causa principal de mortalidad y discapacidad. El policosanol ha sido eficaz en modelos de isquemia cerebral. Este estudio investiga si el tratamiento a largo plazo con policosanol, añadido a la terapia con acido acetilsalicilico (AAS), dentro de los 30 dias posteriores a un ictus, es mejor que el placebo + AAS en la recuperacion de los pacientes. Pacientes y metodos. Estudio aleatorizado, doble ciego, controlado con placebo. Se incluyeron 80 pacientes (edad media: 69 años) que sufrieron un ictus en los 30 dias previos y con una puntuacion de 2-4 en la escala de Rankin modificada (mRS). Se distribuyeron aleatoriamente en dos grupos y recibieron policosanol + AAS o placebo + AAS durante 12 meses. Resultados. El tratamiento con policosanol + AAS disminuyo significativamente la puntuacion en la mRS desde el primer control intermedio (1,5 meses). El efecto del tratamiento incluso mejoro con la terapia a largo plazo. El numero de pacientes que alcanzaron valores de mRS menores o iguales a 1 fue superior en el grupo de policosanol + AAS (87,5%) que en el de placebo + AAS (0%). El tratamiento con policosanol + AAS aumento significativamente el indice de Barthel, disminuyo el colesterol LDL y aumento el colesterol HDL frente a placebo + AAS. Conclusiones. El tratamiento a largo plazo (12 meses) con policosanol + AAS fue mas efectivo que el tratamiento con placebo + AAS en la recuperacion funcional de los pacientes despues de sufrir un ictus isquemico no cardioembolico de moderada gravedad.

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

    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


    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.

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

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


    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.

  5. 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

    Matías García


    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.

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

    Janaina Moreira de Souza


    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.

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

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


    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.

  8. Actividad antioxidante de compuestos naturales nitrogenados

    Maestro-Durán, R.


    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.
    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.
    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.

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

    El-Sayed, R.


    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.

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

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


    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.

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

    Alvis Rafael


    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.

  12. 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

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


    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

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

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


    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

  14. 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

    M. Valeria Bahamondes


    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

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

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


    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

  16. Diagnosis and treatment of polonium poisoning.

    Jefferson, Robert D; Goans, Ronald E; Blain, Peter G; Thomas, Simon H L


    of reduction in lymphocyte counts. Chromosome analysis, especially the dicentric count, may establish radiation effects and provides an estimation of dose. The diagnosis of (210)Po poisoning is established by the presence of (210)Po in urine and faeces and the exclusion of other possible causes. In the absence of a history of exposure, diagnosis is very difficult as clinical features are similar to those of much more common conditions, such as GI infections and bone marrow failure caused, for example, by drugs, other toxins, or infections. Good supportive care is essential and should be directed at controlling symptoms, preventing infections but treating those that do arise, and transfusion of blood and platelets as appropriate. Gastric aspiration or lavage may be useful if performed soon after ingestion. Chelation therapy is also likely to be beneficial, with research in animals suggesting reduced retention in the body and improvements in survival, although increased activity in some radiosensitive organs has also been reported with some chelating agents. Dimercaprol (British Anti-Lewisite) (with penicillamine as an alternative) is currently recommended for (210)Po poisoning, but animal models also indicate efficacy for 2,3,-dimercapto-1-propanesulfonic acid, meso-dimercaptosuccinic acid, or N,N -dihydroxyethylethelene-diamine-N,N -bis-dithiocarbamate. Internal contamination with (210)Po can cause ARS, which should be considered in patients presenting initially with unexplained emesis, followed later by bone marrow failure and hair loss.

  17. Electrochemical and Computational Studies on the Electrocatalytic Effect of Conducting Polymers toward the Redox Reactions of Thiadiazole-Based Thiolate Compounds

    Rodríguez-Calero, Gabriel G.


    We have studied the electrocatalytic effects of polythiophene-based conducting polymers toward the redox reactions of the dilithium salt of the thiadiazole-based dithiol compound 2,5-dimercapto-1,3,4-thiodiazole (DMcT-2Li) via cyclic voltammetry (CV), rotating-disk electrode voltammetry, and electrochemical impedance spectroscopy (EIS). We have found that the electrocatalytic activity of the conducting polymers is strongly influenced by the potential range over which the polymers are electrically conductive (i.e., window of conductivity), which was tuned by employing different electron-donating groups at the 3- or 3,4-positions of polythiophene (PTh). Both poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,4-propylenedioxythiophene) (PProDOT), whose windows of conductivity exhibited a good overlap with the formal potential for the dimerization process of DMcT-2Li; E0′ d (?0.54 V versus Ag/Ag+) exhibited electrocatalytic activity toward both the oxidation and reduction processes of DMcT-2Li. On the other hand, PTh, poly(3-methylthiophene) (PMTh), and poly(3,4- dimethoxythiophene) (PDMTh), whose windows of conductivity did not overlap with E0′d, did not exhibit electrocatalytic activity. The standard charge transfer rate constants for the dimerization process of DMcT-2Li at PEDOT, PProDOT, and PDMTh film-modified glassy carbon electrodes (GCEs) were estimated to be 7.4 - 10?4, 3.2 - 10?4, and 6.9 - 10?5 cm/s while the rate constant was 6.3 - 10?5 cm/s at an unmodified GCE. Moreover, EIS studies for PEDOT, PProDOT, and PDMTh film-modified GCEs indicated the smallest charge transfer resistance for a PEDOT film and highest for a PDMTh film at E0′d, indicating that the higher the electrical conductivity of a film at E 0′d the higher the electrocatalytic activity toward the redox reactions of DMcT-2Li. These results clearly indicate that in order to accelerate the redox reactions of DMcT-2Li (and likely of other organosulfur compounds) the window of conductivity

  18. Comparison on Antidotal Effects of Chelating Agents on Lung and Testicular Toxicity in Mice Induced by Acute Exposure to Manganese%几种螯合剂对锰致小鼠肺脏和睾丸毒性的解毒作用比较

    荆俊杰; 谢吉民; 陈敏; 陆晓菁; 吴云龙


    [Objective] To develop new antidotes of manganese (Mn). [ Methods ] Mice were injected intraperitoneally with MnCl2(100mg MnCl2/kg) 24 h before they were injected intraperitoneally with chelating agents, including L-Histidine (L-His), ethylene diaminetetraacetic acid(EDTA), Diethyldithiocarbamate (DDTC), meso-2, 3-dimercapto succinc acid (DMSA) and N-acetylcysteine (NAC). The effects of those chelating agents on lipid peroxidation (LPO) and concentrations of Mn, Ca, Zn in lung were observed. [ Results] The Mn injection significantly increased the LPO levels (2.42 ± 0.29) and (2.74 ± 0.33)μmol/(g.prot) respectively as well as the concentrations of Mn (2.60 ± 0.33) and (2.41 ± 0.68)μg/g wet tissue respectively in lung and testes of mice (P<0.05) in 2 days. L-His effectively prevented the increases of above indices. [ Conclusion ] L-His is more effective than the other chelating agents in preventing changes caused by acute exposure to Mn. L-His is a promising antidote to Mn.%[目的]寻找理想的锰中毒解毒剂.[方法]小鼠一次性腹腔注射MnCl2(100 mg MnCl2/kg)24h后分别给予L-组氨酸(L-His)、乙二胺四乙酸(EDTA)、二乙基二硫代氨基甲酸钠(DDTC)、meso-2,3-二巯基丁二酸(DMSA)及N-乙酸-L-半胱氨酸(NAC)等五种螯合剂(2 mmol/kg,腹腔注射),观察小鼠肺脏、睾丸脂质过氧化物值(LPO)和组织中锰、钙、锌浓度的变化.[结果]小鼠一次性腹腔注射 MnCl2(100 mg MnCl2/kg)2d后,小鼠肺脏和睾丸中LPO值分别为(2.42±0.29)和(2.74±0.33)μmol/g.prot,锰浓度分别为(2.60±0.33)和(2.41±0.68)μg/g,均明显高于对照组,差异有统计学意义(P<0.05).分别染锰24h后腹腔注射各螯合剂,治疗24h后L-His对锰引起的肺脏、睾丸LPO值和锰浓度的升高有显著的抑制作用.[结论]L-His对锰致小鼠肺脏和睾丸毒性有较好的解毒作用,且自身毒性小,有望成为理想的锰解毒剂.

  19. 不同螯合剂对锰致小鼠肝脏毒性解毒效果评价%Effects of chelating agents on liver toxicity induced by acute manganese exposure in mice

    荆俊杰; 谢吉民; 陈敏; 陆晓菁; 吴云龙


    目的 研发高效的锰中毒解毒剂.方法 小鼠一次性腹腔注射MnCl2( 100 mg/kg),24h后分别给予L-组氨酸(L-His)、乙二胺四乙酸(EDTA)、二乙基二硫代氨基甲酸钠(DDTC)、meso-2,3-二巯基丁二酸(DMSA)及N-乙酰-L-半胱氨酸(NAC)等五种螯合剂(2 mmoVkg,腹腔注射),观察小鼠血清天冬氨酸转氨酶(AST)、丙氨酸转氨酶(ALT)和乳酸脱氢酶(LDH)活性、肝脏脂质过氧化物值(LPO)和肝脏组织中锰、钙、锌浓度变化.结果 染锰2d后小鼠血清AST、ALT和LDH活性分别达(251.00±74.28)、(141.00±21.04)、(1393.51±202.01)U/L,肝脏中LPO值为(2.88±0.29) μmol/g prot,锰浓度(18.34±4.74) μg/g,明显高于对照组,差异有统计学意义(P<0.05),L-His和NAC对染锰引起的血清LDH、AST、ALT活性及肝LPO和锰含量升高有明显抑制作用.结论 L-His和NAC对锰致小鼠肝脏毒性有较好解毒作用,有望成为理想的锰解毒剂.%Objective To develop a new antidotes for manganese(Mn). Methods Mice were injected intraperitoneally with MnCl100mg MnCl2/kg). Twenty-four hours after the MnCl2 treatment, the mice were injected intraperitoneally with one of the five chelating agents (2 mmol/kg for each), such as L-histidine ( L-His), ethylene diaminetetraacetic acid (EDTA) , diethyldithiocarbamate (DDTC), meso-2,3-dimercapto succinc acid (DMSA), and N-acetylcysteine (NAC), respectively. The effects of the chelating agents on activities of lacatate dehydrogenase (LDH), aspartate transcarbamoylase (AST) and alanine aminotranferase( ALT) in serum,lipid peroxidation(LPO) ,and concentrations of Mn,Ca,Zn in liver of the mice induced by the acute manganese exposure were studied. Results Mn injection significantly increased the activities of AST(251.OO ±74.28), ALT (141.00 ±21.04), and LDH (1393.51 ±202.01IU/L) in serum, and LPO level (2. 88 ±0.29 n,mol/g prot) ,as well as the concentrations of Mn( 18.34 ±4.74 g/g wet tissue) in the liver of the mice (P <0.05) two days after

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

    Karen Belloso


    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.