Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Dokl Biol Sci ; 480(1): 85-89, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-30009346

RESUMO

It has been demonstrated that deuterium oxide enhances the SOS response of Escherichia coli cells induced by chemical genotoxicants and mutagens. This demonstrates that the heavy nonradioactive hydrogen isotope deuterium can be considered to be a comutagen.


Assuntos
Dano ao DNA , Óxido de Deutério/farmacologia , Escherichia coli K12/metabolismo , Mutagênicos/farmacologia , Resposta SOS em Genética/efeitos dos fármacos , Escherichia coli K12/genética
2.
Bioresour Technol ; 250: 538-547, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29197777

RESUMO

New strains of green microalgae were isolated and screened for growth and the production of lipids from municipal wastewater. It was shown that the strain Micractinium sp. IC-76 has a biomass productivity of 37.18 ±â€¯4.12 mg L-1 d-1 and a lipid content of 36.29 ±â€¯0.11%, with a total content of saturated and monounsaturated fatty acids of 71.9%. The efficiency of nitrogen (N-NH4) and phosphorus (P-PO4) removal was 96.4 ±â€¯0.7 and 77.8 ±â€¯5.6%, respectively. The metabolic differences at the exponential and stationary phases of growth between the closely related strains with different patterns of lipid accumulation were revealed via gas chromatography mass spectrometry metabolic profiling. The strain Micractinium sp. IC-76 in the stationary phase of growth shows a significant difference in carbohydrate metabolism, especially sucrose concentration. High lipid induction during cultivation in wastewater was also driven by changes in the biosynthesis of amino acids, fatty acids and the tricarboxylic acid cycle.


Assuntos
Microalgas , Águas Residuárias , Biocombustíveis , Biomassa , Ácidos Graxos , Lipídeos , Nitrogênio , Fósforo
3.
Magn Reson Imaging ; 19(3-4): 531-4, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11445349

RESUMO

NMR imaging is employed to study the preparation of supported catalysts and a number of mass transport processes in porous catalysts and sorbents. It is shown that, similar to Pt, adsorbed Pd leads to the increase of the relaxation times of liquids permeating porous alumina supports. A faster penetration of adsorbed water into the sorbent is observed when water vapor sorption by selective water sorbents is carried out under vacuum as compared to the sorption from moist air. An interruption of the capillary flow of water within the monolithic catalyst is shown to lead to a non-uniform drying along the monolith channels. Flow imaging of water inflowing into the monolith has revealed a complicated flow pattern characterized by the existence of counterflows in the entrance region.


Assuntos
Imageamento por Ressonância Magnética/métodos , Acetileno/química , Óxido de Alumínio/química , Butanos/química , Cloreto de Cálcio/química , Catálise , Porosidade , Propano/química , Sílica Gel , Dióxido de Silício/química
4.
Magn Reson Imaging ; 21(3-4): 337-43, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12850729

RESUMO

PFG NMR is employed to perform a comparative study of the filtration of water and propane through model porous media. It is shown that the dispersion coefficients for water are dominated by the holdup effects even in a bed of nonporous glass beads. It is demonstrated that correlation experiments such as VEXSY are applicable to gas flow despite the large diffusivity values of gases. The PFG NMR technique is applied to study the gravity driven flow of liquid-containing fine solid particles through a porous bed. The NMR imaging technique is employed to visualize the propagation of autocatalytic waves for the Belousov-Zhabotinsky reaction which is carried out in a model porous medium. It is demonstrated that the wave propagation velocity decreases as the wave crosses the boundary between the bulk liquid and the flooded bead pack. The images detected during the catalytic hydrogenation of alpha-methylstyrene on a single catalyst pellet at elevated temperatures have revealed that the reaction and the accompanying phase transition alter the distribution of the liquid phase within the pellet.


Assuntos
Espectroscopia de Ressonância Magnética/métodos , Estirenos/química , Vidro , Porosidade , Propano , Temperatura , Água
5.
J Hazard Mater ; 173(1-3): 40-6, 2010 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-19765900

RESUMO

A method for fast air purification using high concentration aerosol of TiO(2) nanoparticles is evaluated in a model chemical catastrophe involving toxic vapors of diisopropyl fluorophosphate (DFP). Mice are used as human model in a closed 100 dm(3) chamber. Exposure of mice to 37 ppm of DFP vapor for 15 min resulted in acute poisoning. Spraying TiO(2) aerosol in 2 min after the start of exposure to DFP vapors resulted in quick removal of DFP vapors from the chamber's air. Animals did not show signs of poisoning after the decontamination experiment and exposure to TiO(2) aerosol alone. Reactive oxygen species (ROS) and antioxidant activity (AOA) of mice blood plasma were measured for animals exposed to sound of aerosol generator, DFP vapors, TiO(2) aerosol and DFP vapors+TiO(2) aerosol. Reduced ROS and increased AOA were found for mice exposure to sound, DFP and TiO(2) aerosol. Exposure to DFP and decontamination with TiO(2) nanoparticles resulted in decreased AOA in 48 h following the exposure. The results suggest that application of TiO(2) aerosol is a powerful method of air purification from toxic hydrolysable compounds with moderate health aftermaths and requires further study and optimization.


Assuntos
Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Ar/análise , Titânio/química , Aerossóis , Animais , Antioxidantes/metabolismo , Câmaras de Exposição Atmosférica , Inibidores da Colinesterase/química , Inibidores da Colinesterase/toxicidade , Desastres , Radicais Livres/análise , Radicais Livres/metabolismo , Peróxido de Hidrogênio/química , Isoflurofato/química , Isoflurofato/toxicidade , Cinética , Luminescência , Camundongos , Nanopartículas , Oxidantes/química , Tamanho da Partícula , Som , Espectrofotometria Infravermelho
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa