Listar Química por título
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Aggregation Pheromones and Host Kairomones of West Indian Sugarcane Weevil, Metamasius hemipterus sericeus
(1997)Coupled gas chromatographic–electroantennographic detection (GC-EAD) analyses and coupled GC-mass spectrometry (MS) of volatiles produced by male and female West Indian sugarcane weevils (WISW), Metamasius hemipterus ... -
Alkaloid contents in members of Lycopodiales
(2001)The composition of alkaloids in fifteen species that belong to the Lycopodiales, which grow wild in Costa Rica were analysed by gas chromatography coupled with mass spectrometry. Several alkaloids were identified, ... -
Alternative approaches to determine the efficiency of biomixtures used for pesticide degradation in biopurification systems
(2018)Biopurification systems were developed for the biological treatment of pesticide-containing wastewaters originated from agricultural production. They are aimed at reducing point-source contamination related to the ... -
An improved stereospecific synthesis of (Z,E)-9, 11, 13-Tetradecatrienal. Sex pheromone component of Stenoma cecropia
(2000)(Z,E)-9,11,13-tetradecatrienal, a pheromone component of Stenoma cecropia, was prepared in 61% overall yield from 1-nonyne. The synthesis involved two palladium-catalyzed cros-couplings to afford a 1,3-dien5-yne, which was ... -
An Improved stereospecific synthesis of (Z,E)-tetradecadienal. Sex pheromone component of Stenoma cecropia
(1998)(Z,E)-9, 11-Tetradecadienal, a sex pheromone component of Stenoma cecropia, has been synthesized in 7 steps and 61% overall yield. The synthesis utilized a palladium catalyzed coupling between 9-decynyl tert-butyldinethylsilyl ... -
Analysis of glyphosate and aminomethylphosphonic acid in leaves from Coffea arabica using high performance liquid chromatography with quadrupole mass spectrometry detection
(2016-01-01)Glyphosate is a commonly applied herbicide in coffee plantations. Because of its non-selective mode of action it can damage the crop exposed through spray drift. Therefore, it is of interest to study glyphosate fate in ... -
Análisis de Plaguicidas Organoclorados en Grasa Humana en Población Costarricense sin Riesgo Ocupacional
(2005-06-09)Se estudió el contenido de residuos de plaguicidas organoclorados y otros hidrocarburos clorados en tejido adiposo de costarricenses de ambos sexos (25 hombres y 26 mujeres). Las muestras fueron tomadas durante intervenciones ... -
Análisis de residuos de plomo en repollo de Costa Rica
(1984)Lead residues analysis in cabbage. Cabbage and soil samples from the main cabbage growing areas of Costa Rica were analyzed for lead residues. Lead residues result from the use of lead arseniate as an insecticide and ... -
Análisis fisicoquímico no invasivo de colgantes hachoides de piedras verdes de las colecciones arqueológicas del Museo Nacional de Costa Rica y del Museo del Jade y de la Cultura Precolombina
(2021-05)Las sociedades precolombinas de la actual Costa Rica formaron uno de los principales centros de producción de artefactos de jade y piedras verdes de Mesoamérica, los colgantes hachoides fabricados en el actual territorio ... -
Anti-platelet activity and chemical characterization by UPLC-DAD-ESI-QTOF-MS of the main polyphenols in extracts from Psidium leaves and fruits
(2021)In Costa Rica, two species of Psidium fruits, P. guajava and P. friedrichsthalianum, are widely consumed as food and used in folk medicine. Although studies have revealed the health effects of these fruits, there has been ... -
Antimicrobial activity of different sodium and potassium salts of carboxylic acid against some common foodborne pathogens and spoilage-associated bacteria
(2018)Cleaning and disinfection represent the most important activities associated with the elimination of dirt and microorganisms at food processing plants. Improper procedures may lead to cross contamination of food leading ... -
Antimicrobial activity of sodium carboxylates against arcobacter sp. y campylobacter Sp.
(2019)Arcobacter and Campylobacter genres are pathogenic microorganisms associated with gastrointestinal diseases and their main transmission route is through food and water. Both genres have been strongly associated to poultry, ... -
Aprovechamiento de los desechos de la industria del anodizado de aluminio en la síntesis de zeotipos tipo AlPO4-X y aplicación de estos en la captura de amoniaco
(2020)La finalidad de este trabajo fue llevar a cabo la síntesis de zeotipos tipo AlPO4-X utilizando desechos provenientes de la industria de anodizado de aluminio (DAAl-1) en sustitución de la fuente de aluminio, estos desechos ... -
ArsH protects Pseudomonas putida from oxidative damage caused by exposure to arsenic
(2020-03-23)The two As resistance arsRBC operons of Pseudomonas putida KT2440 are followed by a downstream gene called arsH that encodes an NADPH‐dependent flavin mononucleotide reductase. In this work, we show that the arsH1 and (to ... -
Aspectos prácticos de la validación e incertidumbre en mediciones químicas
(Buenos Aires, Argentina, 2009)En este libro se abordan dos temas relacionados con uno de los más importantes aspectos en lo relativo a la calidad de la información generada por un laboratorio de análisis químico: la validación de los métodos utilizados, ... -
Assessing the reactive surface area of soils and the association of soil organic carbon with natural oxide nanoparticles using ferrihydrite as proxy
(2020-09-09)Assessment of the surface reactivity of natural metal-(hydr)oxide nanoparticles is necessary for predicting ion adsorption phenomena in soils using surface complexation modeling. Here, we describe how the equilibrium ... -
Baulamycins A and B, Broad-Spectrum Antibiotics Identified as Inhibitors of Siderophore Biosynthesis in Staphylococcus aureus and Bacillus anthracis
(2014)Siderophores are high-affinity iron chelators produced by microorganisms and frequently contribute to the virulence of human pathogens. Targeted inhibition of the biosynthesis of siderophores staphyloferrin B of Staphylococcus ... -
Bile salts and derivatives: Rigid unconventional amphiphiles as dispersants, carriers and superstructure building blocks
(2015)Steroidal surfactants like bile salts have a rigid amphiphilic structure significantly different from the typical head–tail one. As a result, these molecules show peculiar features in their self-assembly behavior and ... -
Bioactivity of prenylated hydroxybenzoic acids from Piper garagaranum C. DC
(2022)A bio-assay guided fractionation of Piper garagaranum C. DC. led to the isolation of two prenylated hydroxybenzoic acids (1-2) with anti-inflammatory and cytotoxic activities. The anti-inflammatory action was determined in ...