503 resultados para Volatilização de NH3
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Despite the resistance developed by the Mycobacterium tuberculosis (MTb) strains, isoniazid (INK) has been recognized as one of the best drug for treatment of Tuberculosis (Tb). The coordination of INH to ruthenium metal centers was investigated as a strategy to enhance the activity of this drug against the sensitive and resistant strains of MTb. The complexes trans-[Ru(NH3)(4)(L)(INH)](2+) (L = SO2 or NH3) were isolated and their chemical and antituberculosis properties studied. The minimal inhibitory concentration (MIC) data show that [Ru(NH3)(5)(INH)](2+) was active in both resistant and sensitive strains, whereas free INK (non-coordinated) showed to be active only against the sensitive strain. The coordination of INH to the metal center in both [Ru(NH3)(5)(INH)](2+) and trans-[Ru(NH3)(4)(SO2)(INH)](2+) complexes led to a shift in the INH oxidation potential to less positive values compared to free INH. Despite, the ease of oxidation of INH did not lead to an increase in the in vitro INH activity against MTb, it might have provided sensitivity toward resistant strains. Furthermore, ruthenium complexes with chemical structures analogous to those described above were synthesized using the oxidation products of INK as ligands (namely, isonicotinic acid and isonicotinamide). These last compounds were not active against any strains of MTb. Moreover, according to DFT calculations the formation of the acyl radical, a proposed intermediate in the INH oxidation, is favored in the [Ru(NH3)(5)(INH)](2+) complex by 50.7 kcal mol(-1) with respect to the free INH. This result suggests that the stabilization of the acyl radical promoted by the metal center would be a more important feature than the oxidation potential of the INH for the antituberculosis activity against resistant strains. (C) 2015 Elsevier B.V. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Este trabalho foi conduzido para avaliar o valor nutritivo de silagens de capim-elefante (Pennisetum purpureum, Schum.) com 0, 4, 8, 12 e 16% de pedúnculo de caju (Anacardium occidentale L.) desidratado, com base na matéria natural. Utilizou-se o delineamento inteiramente casualizado com quatro repetições. Como silos experimentais, foram utilizados tambores plásticos de 210 L. Determinaram-se a composição nutricional, os valores de pH e os teores de nitrogênio amoniacal, ácido lático, acético, propiônico e butírico. A inclusão de pedúnculo de caju desidratado na ensilagem de capim-elefante promoveu aumento das concentrações de matéria seca (MS), proteína bruta (PB), extrato etéreo (EE), carboidratos não-fibrosos (CNF), nitrogênio insolúvel em detergente neutro (NIDN, % do N total), nitrogênio insolúvel em detergente ácido (NIDA, % do N total), pH e ácidos lático e propiônico. Por outro lado, os teores de FDN, FDA, hemicelulose, N-NH3 (% do N total) e ácido butírico diminuíram de forma linear conforme aumentaram os níveis do subproduto na ensilagem. O pedúnculo de caju desidratado não influenciou os teores de carboidratos totais e ácido acético das silagens. Esse subproduto pode ser ensilado com o capim-elefante até o nível de 16%, uma vez que aumenta os teores de PB e CNF e reduz os teores de FDN e FDA, melhorando o padrão de fermentação das silagens.
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Spills can ocurr during oil productive chain and contaminate various environments due to the toxicity of monoaromatics hidrocarbons. Toluene stands out for being agressive to the nervous sistem and teratogenic, with high mobility and solubility in water, which facilitates environmental impact. Studies show that fungi are potential aromatic compounds assimilators, encouraging new researches about its use on the recovery of contaminated sites. This study aimed to select and characterize fungus with potential for biorremediation of toluene. 50 fungi were selected of the Collection of Microorganisms of Interest for Oil Gas and Biofuels, of UNESP Rio Claro, all of which were isolated from sites contaminated with monoaromatic hydrocarbons. Two trials were realized to select the microorganism with greater potential. The first test evaluated fungal growth under toluene saturated atmosphere. 24 fungi were chosen because its greater biomass production to participate in the next trial, the degradation in plates test, where the blue redox agente, DCPIP, indicates the degradation reaction, turning colorless. From this teste was possible to select one isolate which showed higher growth and stronger medium discoloration as the microorganism with the greatest potential to assimilate toluene. The Trichoderma cf. koningii had its potential evaluated through gas cromatography. The experiment proved the efficiency of the methodology, with positives results from the method validation and the effectiveness demonstrated of the LA-PHA-PACK bottles to prevent the volatilization of toluene during the 21 days of experiment. Being reliable its use for monitoring toluene decay associating it with degradation. This results are important because there aren't many methodologies and vials efficient to the purpose of this work. In the present study the degradation rates demonstrated no significant decay of the concentration of hydrocarbon. That may be related to the...
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Pós-graduação em Zootecnia - FCAV
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The photopolimerization it is be widely used nowadays in different fields as materials, medicine and dentistry. To occur that synthesis is utilized dimethacrylates monomers and photoinitiators, the photoinitiator system more usual is camphorquinone/tertiary amine (ethyl-p-dimethylamino benzoate). However is knowledge that tertiary amines are toxics, so the aim of this work is replace toxic amine compounds to non-toxic compounds as glycerol and inositol. Therefore was used the FTIR technic to calculate the monomers conversion degree as well as Thermogravimetric Analysis-simultaneous differential thermal analysis (TG-DTA) and Differential Scanning Calorimetry (DSC) to evaluate thermal stability, combustion rate, degradation steps, oxidation and volatilization of all samples. The study shown no significant difference about thermal behavior of all polymers, the initiators system for efficient and more fastness was camphorquinone /tertiary amine system followed by ca mph o r quinone/glycerol system
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Two experiments in vitro were conducted to evaluate four Egyptian forage legume browses, i.e., leaves of prosopis (Prosopis juliflora), acacia (Acacia saligna), atriplex (A triplex halimus), and leucaena (Leucaena leucocephala), in comparison with Tifton (Cynodon sp.) grass hay for their gas production, methanogenic potential, and ruminal fermentation using a semi-automatic system for gas production (first experiment) and for ruminal and post ruminal protein degradability (second experiment). Acacia and leucaena showed pronounced methane inhibition compared with Tifton, while prosopis and leucaena decreased the acetate:propionate ratio (P<0.01). Acacia and leucaena presented a lower (P<0.01) ruminal NH3-N concentration associated with the decreasing (P<0.01) ruminal protein degradability. Leucaena, however, showed higher (P<0.01) intestinal protein digestibility than acacia. This study suggests that the potential methanogenic properties of leguminous browses may be related not only to tannin content, but also to other factors.
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The quantification of ammonia (NH3) losses from sugarcane straw fertilized with urea can be performed with collectors that recover the NH3 in acid-treated absorbers. Thus, the use of an open NH3 collector with a polytetrafluoroethylene (PTFE)-wrapped absorber is an interesting option since its cost is low, handling easy and microclimatic conditions irrelevant. The aim of this study was to evaluate the efficiency of an open collector for quantifying NH3-N volatilized from urea applied over the sugarcane straw. The experiment was carried out in a sugarcane field located near Piracicaba, Sao Paulo, Brazil. The NH3-N losses were estimated using a semi-open static collector calibrated with N-15 (reference method) and an open collector with an absorber wrapped in PTFE film. Urea was applied to the soil surface in treatments corresponding to rates of 50, 100, 150 and 200 kg ha(-1) N. Applying urea-N fertilizer on sugarcane straw resulted in losses NH3-N up to 24 % of the applied rate. The amount of volatile NH3-N measured in the open and the semi-open static collector did not differ. The effectiveness of the collection system varied non-linearly, with an average value of 58.4 % for the range of 100 to 200 kg ha(-1) of urea-N. The open collector showed significant potential for use; however, further research is needed to verify the suitability of the proposed method.
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Some atomic multipoles (charges, dipoles and quadrupoles) from the Quantum Theory of Atoms in Molecules (QTAIM) and CHELPG charges are used to investigate interactions between a proton and a molecule (F2, Cl2, BF, AlF, BeO, MgO, LiH, H2CO, NH3, PH3, BF3, and CO2). Calculations were done at the B3LYP/6-311G(3d,3p) level. The main aspect of this work is the investigation of polarization effects over electrostatic potentials and atomic multipoles along a medium to long range of interaction distances. Large electronic charge fluxes and polarization changes are induced by a proton mainly when this positive particle approaches the least electronegative atom of diatomic heteronuclear molecules. The search for simple equations to describe polarization on electrostatic potentials from QTAIM quantities resulted in linear relations with r-4 (r is the interaction distance) for many cases. Moreover, the contribution from atomic dipoles to these potentials is usually the most affected contribution by polarization what reinforces the need for these dipoles to a minimal description of purely electrostatic interactions. Finally, CHELPG charges provide a description of polarization effects on electrostatic potentials that is in disagreement with physical arguments for certain of these molecules. (c) 2012 Wiley Periodicals, Inc.
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Corrole and four of its isomers with subtle structural changes promoted by exchange of nitrogen and carbon atoms in the corrole ring have been studied by traveling wave ion mobility mass spectrometry and collision induced dissociation experiments. Significant differences in shapes and charge distributions for their protonated molecules were found to lead to contrasting gas phase mobilities, most particularly for corrorin, the most "confused" isomer. Accordingly, corrorin was predicted by B3LYP/6-31g(d,p) and collisional cross section calculations to display the most compact tri-dimensional structure, whereas NCC4 and corrole were found to be the most planar isomers. Better resolution between the corrole isomers was achieved using the more polarizable and massive CO2 as the drift gas. Sequential losses of HF molecules were found to dominate the dissociation chemistry of the protonated molecules of these corrole isomers, but their unique structures caused contrasting labilities towards CID, whereas NCC4 showed a peculiar and structurally diagnostic loss of NH3, allowing its prompt differentiation from the other isomers.