Oxygen Sensors
Mostrando 13-24 de 34 artigos, teses e dissertações.
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13. Polimerização por plasma de éter e ésteres orgânicos: caracterização e possíveis usos em microeletrônica. / Plasma polymerization of ethyl ether and ethyl or methyl acetate: film caracterization and microeletronic uses.
The aim of this work is to characterize thin films obtained by plasma polymerization of ethyl ether, ethyl or methyl acetate. The films were tested for adsorption of polar organic compounds in order to evaluate their use for sensors or preconcentrators manufacturing. It was tried plasma polymerization of pure reactants and mixtures of ethyl ether with oxygen
Publicado em: 2004
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14. "Eletrólitos sólidos cerâmicos à base de óxido de zircônio para a detecção de oxigênio" / "Zirconium oxide based ceramic solid electrolytes for oxygen detection"
Taking advantage of the high thermal shock resistance of zirconia-magnesia ceramics and the high oxide ion conductivity of zirconia-yttria ceramics, composites of these ceramics were prepared by mixing, pressing and sintering different relative concentrations of ZrO2: 8.6 mol% MgO and ZrO2: 3mol% Y2O3 solid electrolytes. Microstructural analysis of the compo
Publicado em: 2003
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15. Ultrafast ligand rebinding in the heme domain of the oxygen sensors FixL and Dos: General regulatory implications for heme-based sensors
Heme-based oxygen sensors are part of ligand-specific two-component regulatory systems, which have both a relatively low oxygen affinity and a low oxygen-binding rate. To get insight into the dynamical aspects underlying these features and the ligand specificity of the signal transduction from the heme sensor domain, we used femtosecond spectroscopy to study
The National Academy of Sciences.
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16. Do cytochromes function as oxygen sensors in the regulation of nitrate reductase biosynthesis?
The observation that oxygen represses nitrate reductase biosynthesis in a hemA mutant grown aerobically with or without delta-aminolevulinic acid indicates that cytochromes are not responsible for nitrate reductase repression in aerobically grown cells.
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17. Globin-coupled sensors: A class of heme-containing sensors in Archaea and Bacteria
The recently discovered prokaryotic signal transducer HemAT, which has been described in both Archaea and Bacteria, mediates aerotactic responses. The N-terminal regions of HemAT from the archaeon Halobacterium salinarum (HemAT-Hs) and from the Gram-positive bacterium Bacillus subtilis (HemAT-Bs) contain a myoglobin-like motif, display characteristic heme–
The National Academy of Sciences.
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18. Use of an Oxygen-Insensitive Microscale Biosensor for Methane To Measure Methane Concentration Profiles in a Rice Paddy
An oxygen-insensitive microscale biosensor for methane was constructed by furnishing a previously described biosensor with an oxygen guard. The guard consisted of a glass capillary containing heterotrophic bacteria, which consumed oxygen diffusing through the tip membrane, thus preventing it from diffusing into the methane-sensing unit. Oxygen microprofiles
American Society for Microbiology.
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19. Ancestral hemoglobins in Archaea
Hemoglobins are ubiquitous in Eukarya and Bacteria but, until now, have not been found in Archaea. A phylogenetic analysis of the recently revealed microbial family of globin-coupled heme-based sensors suggests that these sensors descended from an ancient globin-only progenitor, or a protoglobin (Pgb). Here, we report the discovery and characterization of tw
National Academy of Sciences.
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20. Structure of a biological oxygen sensor: A new mechanism for heme-driven signal transduction
The FixL proteins are biological oxygen sensors that restrict the expression of specific genes to hypoxic conditions. FixL’s oxygen-detecting domain is a heme binding region that controls the activity of an attached histidine kinase. The FixL switch is regulated by binding of oxygen and other strong-field ligands. In the absence of bound ligand, the heme d
The National Academy of Sciences.
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21. ADP reduces the oxygen-binding affinity of a sensory histidine kinase, FixL: The possibility of an enhanced reciprocating kinase reaction
The rhizobial FixL/FixJ system, a paradigm of heme-based oxygen sensors, belongs to the ubiquitous two-component signal transduction system. Oxygen-free (deoxy) FixL is autophosphorylated at an invariant histidine residue by using ATP and catalyzes the concomitant phosphoryl transfer to FixJ, but oxygen binding to the FixL heme moiety inactivates the kinase
National Academy of Sciences.
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22. Three globin lineages belonging to two structural classes in genomes from the three kingdoms of life
Although most globins, including the N-terminal domains within chimeric proteins such as flavohemoglobins and globin-coupled sensors, exhibit a 3/3 helical sandwich structure, many bacterial, plant, and ciliate globins have a 2/2 helical sandwich structure. We carried out a comprehensive survey of globins in the genomes from the three kingdoms of life. Bayes
National Academy of Sciences.
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23. Structure of factor-inhibiting hypoxia-inducible factor 1: An asparaginyl hydroxylase involved in the hypoxic response pathway
Precise regulation of the evolutionarily conserved hypoxia-inducible transcription factor (HIF) ensures proper adaptation to variations in oxygen availability throughout development and into adulthood. Oxygen-dependent regulation of HIF stability and activity are mediated by hydroxylation of conserved proline and asparagine residues, respectively. Because th
National Academy of Sciences.
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24. PAS Domains: Internal Sensors of Oxygen, Redox Potential, and Light
PAS domains are newly recognized signaling domains that are widely distributed in proteins from members of the Archaea and Bacteria and from fungi, plants, insects, and vertebrates. They function as input modules in proteins that sense oxygen, redox potential, light, and some other stimuli. Specificity in sensing arises, in part, from different cofactors tha
American Society for Microbiology.