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Mostrando ítems 61-70 de 266
Phytochemical study of endemic Costa Rican Annonaceae species Annona pittieri and Cymbopetalum costaricense
(2021)
Phytochemical profile of the Central American rainforest endemic Annonaceae species, Annona pittieri and Cymbonopetallum costaricense, were studied in search
of novel bioactive compounds. The acetogenin squamocin (1) ...
Paraquat Behavior in Costa Rican Soils and Residues in Coffee
(1990)
The paraquat deactivation capacities of soils, from 20 coffee plantations, generally ranged from 100 to 500 mg of paraquat/kg of soil. Even when paraquat had been applied up to twice per year (1.2 kg ha-1 year) for 20 ...
Manganese and cobalt redox cycling in laterites; Biogeochemical and bioprocessing implications
(2020)
Cobalt is essential for the modern technology that underpins the decarbonisation of our economies, but its supply is limited leading to its designation as a critical metal. Cobalt biogeochemistry is poorly understood, yet ...
Reacciones del 2,2´-Tio-benzimidazol con Sulfato de Dimetilo
(1979)
Se efectuó la reacción del 2,2´-tiobis-benzimidazol con el sulfato de dimetilo por pasos. Se comprobó la formación de: 1,1´-dimetil-2,2´-tiobis-benzimidazol (2) y del diperclorato del 1,1´,3,3´-tetrametil-2,2´-tiobisbenz ...
Ent-clerodane derivatives and other constituents from representatives of the subgenus ageratina
(1989)
Ageratina ixiocladon afforded several p-hydroxyacetophenone derivatives and diterpenes including six new ent-clerodanes. Two further species, which are also placed in the subgenus Ageratina, gave p-hydroxyacetophenone ...
Empleo de técnicas y materiales biológicos en la búsqueda de productos activos contra la malaria
(2001)
Se describen los métodos empleados en el estudio del efecto de extractos de insectos preparados en el Instituto Nacional de Biodiversidad de Costa Rica, sobre un tipo de malaria murina producida por el Plasmodium bergheim. ...
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 ...
Bioavailability of Xenobiotics in the Soil Environment
(2010)
When synthetic, xenobiotic compounds such as agrochemicals and industrial chemicals are utilized, they eventually reach the soil environment where they are subject to degradation, leaching, volatilization, sorption, and ...
Crecimiento de estructuras de carbono mediante deposición química en fase de vapor a baja presión
Growth of carbon structures through low-pressure chemical vapor deposition
(2022)
Los alótropos de carbono han ganado interés en las últimas décadas debido a sus propiedades
y a la gran variedad de posibles aplicaciones tecnológicas que han demostrado. Por dichas
razones, la obtención de estos alótropos ...
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 ...