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Now showing items 31-40 of 173
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. ...
Synthesis and Crystal Structure of a Copper(II) Benzoate Complex Bearing a Bis-2,2′-Tetrahydrofuryl Peroxide Moiety
(2018-12)
Complex [Cu2(ben)4·2THF−(η1–O2)]∞ (2) (ben=C6H5CO2− benzoate; THF=tetrahydrofuran) was isolated when a solution of Cu2(ben)4·2THF (1) in THF upon natural sunlight irradiation yields crystals suitable for single-crystal ...
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 ...
Grids III: Hydrogen Bridges in Introductory Chemistry
Cuadrículas III: Puentes de Hidrógeno en Química General
(2021)
Based on IUPAC recommendations for the
definition of the hydrogen bond, a series of
grids is presented to provide instructors of
introductory chemistry courses with visual
examples of H-bridged systems. The grids ...
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 ...
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 ...
Effect on cell growth, viability and migration of geraniol and geraniol-containing essential oil from Lippia alba (Verbenaceae) on gastric carcinoma cells
(2021)
Natural products used to treat cancer, or as leads for the development of preventive and co-adjuvant treatment strategies, are still a current approach. We studied the effect of essential oils
from the medicinal plant ...
General Chemistry Without Orbitals
(2020)
We illustrate the solutions of Schroedinger's equation for the hydrogen atom in coordinates of all four systems, and differentiate the applicability of orbitals in these four systems. We present reasons that future textbooks ...
A Chronoamperometric Screen Printed Carbon Biosensor Based on Alkaline Phosphatase Inhibition for W(VI) Determination in Water, Using 2-Phospho-l-Ascorbic Acid Trisodium Salt as a Substrate
(2015)
This paper presents a chronoamperometric method to determine tungsten in water using screen-printed carbon electrodes modified with gold nanoparticles and cross linked alkaline phosphatase immobilized in the working ...
Estudio quimico de las hojas de tabernaemontana arborea rose
(1986)
From the leaves of Tabernaemontana arborea Rose (Apocynaceae) the triterpenoid lupeyl acetate and the indole alkaloids voacangine, 19 epivoacristine, vobasine and 19R-hydroxiconopharingine have been isolated and identified ...