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2.
R Soc Open Sci ; 6(3): 181738, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31032030

RESUMO

The design and synthesis of a series of theophylline derivatives containing 1,2,3-triazole moieties are presented. The corrosion inhibition activities of these new triazole-theophylline compounds were evaluated by studying the corrosion of API 5 L X52 steel in 1 M HCl medium. The results showed that an increase in the concentration of the theophylline-triazole derivatives also increases the charge transference resistance (R ct) value, enhancing inhibition efficiency and decreasing the corrosion process. The electrochemical impedance spectroscopy under static conditions studies revealed that the best inhibition efficiencies (approx. 90%) at 50 ppm are presented by the all-substituted compounds. According to the Langmuir isotherm, the compounds 4 and 5 analysed exhibit physisorption-chemisorption process, with exception of the hydrogen 3, bromo 6 and iodo 7 substituted compounds, which exhibit chemisorption process. The corrosion when submerging a steel bar in 1 M HCl was studied using SEM-EDS. This experiment showed that the corrosion process decreases considerably in the presence of 50 ppm of the organic inhibitors. Finally, the theoretical study showed a correlation between EHOMO, hardness (η), electrophilicity (W), atomic charge and the inhibition efficiency in which the iodo 7 substituted compound presents the best inhibitor behaviour.

3.
Appl Microbiol Biotechnol ; 97(22): 9847-58, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23354446

RESUMO

Secondary treatment of municipal wastewater affects the mechanical stability of polymer Ca-alginate beads containing the microalgae Chlorella vulgaris that are jointly immobilized with Azospirillum brasilense as treating agents whose presence do not affect bead stability. Nine strains of potential alginate-degrading bacteria were isolated from wastewater and identified, based on their nearly complete 16S rDNA sequence. Still, their population was relatively low. Attempts to enhance the strength of the beads, using different concentrations of alginate and CaCl2 or addition of either of three polymers (polyvinylpyrrolidone, polyvinyl alcohol, carboxymethylcellulose), CaCO3, or SrCl2, failed. Beads lost their mechanical strength after 24 h of incubation but not the integrity of their shape for at least 96 h, a fact that sustained successful tertiary wastewater treatment for 48 h. In small bioreactors, removal of phosphorus was low under sterile conditions but high in unsterile wastewater. Alginate beads did not absorb PO4 (-3) in sterile wastewater, but in natural wastewater, they contained PO4 (-3). Consequently, PO4 (-3) content declined in the wastewater. A supplement of 10 % beads (w/v) was significantly more efficient in removing nutrients than 4 %, especially in a jointly immobilized treatment where >90 % of PO4 (-3) and >50 % ammonium were removed. Tertiary wastewater treatment in 25-L triangular, airlift, autotrophic bioreactors showed, as in small bioreactors, very similar nutrient removal patterns, decline in bead strength phenomena, and increase in total bacteria during the wastewater treatment only in the presence of the immobilized treatment agents. This study demonstrates that partial biological degradation of alginate beads occurred during tertiary wastewater treatment, but the beads survive long enough to permit efficient nutrient removal.


Assuntos
Alginatos/metabolismo , Azospirillum brasilense/metabolismo , Bactérias/metabolismo , Células Imobilizadas/metabolismo , Chlorella vulgaris/metabolismo , Microesferas , Águas Residuárias/química , Bactérias/classificação , Bactérias/isolamento & purificação , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácido Glucurônico/metabolismo , Ácidos Hexurônicos/metabolismo , Dados de Sequência Molecular , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Purificação da Água/métodos
6.
Vet. Méx ; 25(3): 211-4, jul.-sept. 1994. tab, ilus
Artigo em Espanhol | LILACS | ID: lil-187971

RESUMO

El objetivo de este trabajo fue establecer si la furazolidona utiliza el sistema detoxificante de glutatión en el organismo, mediante la determinación de la cantidad (µmol/ml de sangre) de glutatión total (GT), glutatión oxidado (GSSG), y glutatión reducido (GSH) durante las 5 semanas de vida del pollo de engorda que no consumió aditivos (testigo), comparado con los niveles de GT, GSSG y GSH sanguíneo de las aves que consumieron furazolidona durante las 5 primeras semanas de vida. Hubo diferencia significativa entre el GT (µmol/ml de sangre) y el peso corporal de pollos del grupo testigo y el que consumió furazolidona (55 ppm en el alimento) (R²= -0.709; P< 0.05, y = 2.15 - 0.607x y R²=-0.820 P< 0.05, y = 2.17 -0.61x respectivamente) hubo diferencia significativa (P< 0.05) entre el peso de los pollos del grupo testigo y el de los que consumieron furazolidona (751.3 vs 884.35 g respectivamente)


Assuntos
Embrião de Galinha , Aves Domésticas/fisiologia , Aves Domésticas/metabolismo , Cruzamento , Cruzamento/normas , Furazolidona/administração & dosagem , Furazolidona/metabolismo , Furazolidona/farmacocinética , Glutationa/biossíntese , Glutationa/farmacocinética , Glutationa/metabolismo
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