Search results for "cuba"
showing 10 items of 340 documents
Laundry detergent compatibility of the alkaline protease from Bacillus cereus.
2004
The endogenous protease activity in various commercially available laundry detergents of international companies was studied. The maximum protease activity was found at 50 degrees C in pH range 10.5-11.0 in all the tested laundry detergents. The endogenous protease activity in the tested detergents retained up to 70% on incubation at 40 degrees C for 1 h, whereas less than 30% activity was only found on incubation at 50 degrees C for 1 h. The alkaline protease from an alkalophilic strain of Bacillus cereus was studied for its compatibility in commercial detergents. The cell free fermented broth from shake flask culture of the organism showed maximum activity at pH 10.5 and 50 degrees C. The…
Intercultural integration in the university context of Cuba: psychosocial intervention program for its promotion
2022
La subjetividad es un factor mediador de la producción y reproducción de la contradicción integración - exclusión en el contacto intercultural. El presente estudio tuvo como objetivo proponer un programa de intervención psicosocial, para la promoción de la integración intercultural en la Universidad Central "Marta Abreu" de Las Villas, desde un enfoque histórico-cultural de las mediaciones por la subjetividad. La investigación se adscribió al modelo de investigación interventiva y a un enfoque cualitativo constructivo interpretativo. En este marco, se realizó una sistematización de experiencias y se propuso un programa de intervención psicosocial. El programa para la promoción de la integra…
Unraveling the kinetics and molecular mechanism of gas phase pyrolysis of cubane to [8]annulene
2020
The kinetic and electron density flows are studied theoretically for the gas phase pyrolysis of cubane via its cage opening to reach bicyclooctatriene and then thermal rearrangement of bicyclooctatriene to produce [8]annulene which is the experimentally observed major product. The observed kinetic data at the MN15-L/maug-cc-pVTZ level of theory were in good agreement with the experimental results as compared to the CBS-QB3 method. The cage opening and the thermal rearrangement steps at the experimentally employed temperature of 520 K were exergonic and exothermic. The atmospheric rate constants calculated by means of the RRKM theory show that the cage opening is the rate-determining step. T…
A new polyphosphate calcium material with morphogenetic activity
2015
Abstract Polyphosphate [polyP] has been proven to elicit morphogenetic activity on bone cells. By applying mild reaction conditions, a Ca-polyP material that displays a hardness of ≈1.3 GPa has been fabricated. The Ca-polyP granules are prone to hydrolytic degradation during in vitro incubation of the cells, suggesting that this property is associated with the observed bioactivity.
Remineralization ability of two hydraulic calcium-silicate based dental pulp capping materials: Cell-independent model
2019
Background This study aimed to evaluate remineralizing ability of two hydraulic calcium-silicate cements (Biodentine and TheraCal LC). Material and Methods Artificial carious lesions were introduced into the pulpal floors (1-1.5 mm) and axial walls of occlusal prepared cavity halves through pH cycling. Cycling was made through demineralizing solution (pH 3), for 8 hours and remineralizing solution (pH 7) for 16 hours. The total period of pH cycling was 14 days. Prepared cavities with the tested materials seated directly on the pulpal floor and in contact with the axial walls were stored in phosphate buffer solutions (PBS) (pH 7.2–7.4). The changes in the weight percentages (wt%) of calcium …
Imágenes de la liberación entre Rayuela y “Reunión” De la bohemia cultural a la guerrilla armada
2017
El artículo analiza las muy diferentes imágenes de la liberación que Cortázar muestra en Rayuela y “Reunión”. Ello da cuenta del año 1963 como un tiempo de conflicto y negociación, en el interior de la obra de Cortázar, entre diferentes visiones de los proyectos de emancipación Pero bajo esa divergencia de proyectos de liberación, ambos textos presentaban una similar concepción de la escritura. The article analyses the different images of liberation that Julio Cortázar displays in Hopscotch and “Meeting”. 1963 is a year of conflict and negotiation on Cortázar’s work, with differing views on emancipation projects. However, under this divergence of liberation projects, both texts present a si…
La revista Libre en la encrucijada: entre la autonomía estética y la revolución política.
2015
La breve existencia de la revista Libre coincidió con uno de los momentos de mayor tensión y conflicto vividos en el seno del campo cultural latinoamericano de la segunda mitad del siglo XX. La revista, publicada en Paris en los años 1971 y 1972, consi‐guió reunir a algunos de los escritores latinoamericanos de ma‐yor prestigio internacional (Mario Vargas Llosa, Julio Cortázar, Carlos Fuentes, Gabriel García Márquez) con miembros destaca‐dos del exilio español (Juan Goytisolo, Jorge Semprún) y colabo‐radores de talla europeos y norteamericanos (Jean Paul Sarte, Jean Genet, Susan Sontag).
Cuando digo futuro. Imaginario del desarrollo, cultura y anti-intelectualismo en Cuba
2012
A partir del análisis de canciones de Silvio Rodríguez y el Grupo de Experimentación, así como de otros textos culturales de los primeros años del periodo revolucionario en Cuba, se muestra cómo la articulación del imaginario del desarrollo en los discursos revolucionarios cubanos iría de la mano de una reformulación profunda del rol de la cultura en la sociedad revolucionaria y de una tematización crítica de la función de los intelectuales en ella. En ese sentido, y como se verá, la inclusión del léxico, la iconografía y buena parte de la sintaxis de los lenguajes del desarrollo en el pensamiento revolucionario cubano no estuvo desvinculada del crecimiento y la consolidación de lo que se h…
A microplate version of the SOS/umu-test for rapid detection of genotoxins and genotoxic potentials of environmental samples
1991
Abstract The umu-microtest is a miniaturized automated short-term test version proposed for screening of umuC-dependent mutagenic potentials of chemicals relevant to environmental pollution, river water and industrial waste water. The test is based on the SOS/umu-test and has been modified in order to allow extensive testing of environmental samples. Genetically engineered Salmonella typhimurium (TA1535/pSK1002) are incubated on a microplate rotor in a sloping position for 2 h with the test samples, followed by addition of fresh culture medium to reach a 10-fold dilution of the incubation medium. 2 h later, the activity of the β-galactosidase, which reflects umuC induction, is determined co…
Evaluation of the SOS/umu-test post-treatment assay for the detection of genotoxic activities of pure compounds and complex environmental mixtures.
2000
This study presents an evaluation of the SOS/umu-test after introducing an additional dilution and incubation in the post-treatment assay. This treatment reduces the influence of coloured test compounds that otherwise affect the colorimetric determination of the beta-galactosidase activity and the bacterial growth measurement during the testing of complex environmental samples. The post-treatment assay significantly increased the beta-galactosidase activity and consequently the enzyme induction ratios at higher doses of model genotoxins 4-nitroquinoline-N-oxide, N-methyl-N'-nitro-N-nitrosoguanidine, 2-aminoanthracene, benzo(a)pyrene with low or no effect on the sensitivity of the test itsel…