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Mostrando ítems 214-233 de 360
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Microbial Community Structure Alogn a Horizontal Oxygen Gradient in a Costa Rican Volcanic Influeced Acid Rock Drainage System
(2020-06-22)We describe the geochemistry and microbial diversity of a pristine environment that resembles an acid rock drainage (ARD) but it is actually the result of hydrothermal and volcanic influences. We designate this environment, ... -
Microorganismos electroactivos en el agua residual de beneficiado de café (procesos redox de hierro)
(2024)Introduction: Wastewater is often a good source for electrogenic bacteria, which are essential for Microbial Fuel Cells (MFCs). The electrons they release while metabolizing organic matter is evidence of their electrogenic ... -
Microwave assisted synthesis: A Mn/Ni reaction system affording Mn5Ni4, Mn2Ni2 and Mn7 complexes
(2013-11)Following our interest in microwave assisted synthesis in coordination chemistry; we report here the results of the study of a mixed metal Mn/Ni system under common bench-top conditions and using the microwave reactor. ... -
Microwave-Assisted Extraction of Chloride Followed by Ion Chromatography as an Alternative to the ASTM D6470 Method for the Determination of Crude Oil Salinity
(2020)The presence of chloride in crude oil can result in a number of drawbacks, with technical and economic impacts on the production of petroleum derivatives. For this reason, it must be carefully monitored in this kind of ... -
Modified Laccase-Gold Nanoparticles-Tetrathiafulvalene-SPCEs Based Biosensor to Determine W(VI) in Water
(2017)It was developed an amperometric biosensor to determine tungsten in water, based on the inhibition of laccase enzyme, by tungsten ions using pyrocathecol as a substrate. The enzyme was immobilized with a proper mixture ... -
Monomeric Germanium(II) Amides Bearing β-Diketiminato Ligands: Synthesis, Structural Characterization, and Thermal Properties
(2014-09)Germanium(II) compounds featuring β-diketiminate-type ligands are attractive for applications as nanoparticle precursors, imaging agents, and components of electronic devices. In this work, we report the synthesis of ... -
N-[3-(Prop-1-yn-1-yl)phenyl]benzenesulfonamide
(2019)In the title sulfanilamide derivative, C15H13NO2S, which shows significant activity against Staphylococcus aureus and Escherichia coli, the dihedral angle between the planes of the aromatic rings is 62.15 (19)° and the ... -
Naphthalenones and Isocoumarins from a Costa Rican Fungus Xylariaceae sp. CR1546C
(2014)A new naphthalenone, (R)-4,6,8-trihydroxy-3,4-dihydro-1(2H)-naphthalenone and a new isocoumarin, 6,8-dihydroxy-(3R)-(2-oxopropyl)-3,4-dihydroisocoumarin, together with eight related known compounds were isolated from the ... -
Naproxen degradation test to monitor Trametes versicolor activity in solid-state bioremediation processes
(2010-07-15)The white-rot fungus Trametes versicolor has been studied as a potential agent for the removal of envi ronmental pollutants. For long-time solid-phase bioremediation systems a test is required to monitor the metabolic ... -
Natural product based inhibitors of the thioredoxin-thioredoxin reductase system
(2004)Spiroketal naphthodecalins are readily assembled by Barton's base mediated Ullmann binaphthyl ether coupling, Dakin reactions and hypervalent iodine spirocyclization. The core structures can be further diversified by enone ... -
Neutral organic redox pairs based on sterically hindered hydroquinone/benzoquinone derivatives for dye-sensitized solar cells
(2018-06)Substituted derivatives of hydroquinone/benzoquinone were studied as organic redox mediators in the electrolyte for dye-sensitized solar cells (DSSCs). Thus, di-tert-butylhydroquinone (DTHQ), thymohydroquinone (ThymHQ) and ... -
Nickel-iron catalysts for electrochemical water oxidation – redox synergism investigated by in situ X-ray spectroscopy with millisecond time resolution
(2018)In future technological systems for chemical storage of renewable energy and production of non-fossil fuels, NiFe oxyhydroxides are prime candidates for efficient alkaline water oxidation (oxygen evolution reaction, OER). ... -
Norstictic Acid Is a Selective Allosteric Transcriptional Regulator
(2021-06-17)Inhibitors of transcriptional protein–protein interactions (PPIs) have high value both as tools and for therapeutic applications. The PPI network mediated by the transcriptional coactivator Med25, for example, regulates ... -
Nota sobre la Preparación de un Dicatión Cuaternario de Azufre Divalente
(1979)A synthesis has been developed for the previously unreported salts of S,S-di-(1-methylbenzimidazol-2-yl)-S,S-dimethylsulfonium dication [3] derived from the sulfide [2] and dimethyl-sulfate. -
Una nueva ruta para la sintesis de la feromona sexual de la polilla de la papa, Scrobipalpopsis solanivora
(1996)Acetato de (E)-3-dodecenilo, principal componente de feromona de Scrobipal-popsis solanivora, se preparó con un rendimiento total del 61 %. El precursor, 3-dodecin-1-ol, se preparó en el paso de un recipiente mediante la ... -
Nueva síntesis de la feromona sexual de la polilla del repollo Plutella Xylostella
(2007)El compuesto (Z)-11-hexadecenal, feromona sexual de la polilla Plutella xylostella, fue preparado mediante tres secuencias sintéticas. La primer secuencia consistió de siete pasos y un rendimiento total de 47%. En las otras ... -
Nuevos métodos de preparación del 1,3-Dilitiopropino y sus aplicaciones en la síntesis de compuestos bioactivos
(2006)Se desarrolló un método para la preparación del 1,3-dilitiopropino, a partir de bromuro de propargilo. Este procedimiento ha sido usado para desarrollar nuevos métodos de síntesis de alcoholes homopropargílicos, 1,5-diinos, ... -
One-Pot Conversion of Aldehydes and Ketones into 1-Substituted and 1,4-Disubstituted 1,3-Enynes
(2018)Sequential treatment of 2,3-dichloropropene with magnesium and n-BuLi generates the operational equivalent of 1,3-dilithiopropyne, which upon treatment with aldehydes or ketones, produces the corresponding alkoxy lithium ...