Relationships between Kováts Retention Indices and Molecular Descriptors of 1-(2-Hydroxy)-3-Arylpropane-1,3-Diones

Experimental and theoretical results for retention index of a set of 20 beta-diketones are given. The quantitative structure-chromatographic retention relationships (QSRR) theory is employed and six molecular descriptors are chosen to compute the fitting polynomials. Multiple regression analysis yields satisfactory results when one resorts to several variables equations, instead of computing just one-variable formulae. Average absolute deviations from experimental results are rather low, which seems to point out the suitability of the present approach

Potenciales plaguicidas amigables: sintesis de bajo impacto ambiental de heterociclos con subestructura de cromona

El uso de plaguicidas sintéticos ha generado una serie de efectos adversos tanto sobre el ambiente como la salud humana. Por ello resulta necesario considerar diferentes tácticas de control de plagas, incluyendo el uso de compuestos selectivos y compatibles con el ambiente. En dicho ámbito, los plaguicidas de origen vegetal adquieren importancia ya que serepresentan como una alternativa sustentable. Nuestro grupo de investigación ha encontrado que compuestos heterocíclicos naturales correspondientes a las familias de flavonas (esqueleto de cromona como subestructura), presentan baja toxicidad y buena capacidad para actuar como insecticidas.En el presente trabajo hemos desarrollado un procedimiento de síntesis de bajo impacto ambiental de derivados de 1,4-dihidropiridinas y 3,4-dihidropirimidinonas, empleando reacciones multicomponentes tipo Biginelli y Hanzsch. Particularmente se utilizó como uno de los sustratos de partida aldehídos con subestructura de cromona.Fil: Bernio, Flavia. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Exactas. Catedra de Quimica Organica; ArgentinaFil: Ruiz, Diego Manuel. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Exactas. Catedra de Quimica Organica; ArgentinaFil: Pasquale, Gustavo A.. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Exactas. Catedra de Quimica Organica; ArgentinaFil: Sanchez, Laura Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigación y Desarrollo En Ciencias Aplicadas; ArgentinaFil: Sathicq, Angel Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigación y Desarrollo En Ciencias Aplicadas; ArgentinaFil: Autino, Juan Carlos. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Exactas. Catedra de Quimica Organica; ArgentinaFil: Romanelli, Gustavo Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Centro de Investigación y Desarrollo En Ciencias Aplicadas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Exactas. Catedra de Quimica Organica; Argentin

Relationships between Kováts retention indices and molecular descriptors of 1-(2-hydroxy)-3-arylpropane-1,3-diones

Experimental and theoretical results for retention index of a set of 20 beta-diketones are given. The quantitative structure-chromatographic retention relationships (QSRR) theory is employed and six molecular descriptors are chosen to compute the fitting polynomials. Multiple regression analysis yields satisfactory results when one resorts to several variables equations, instead of computing just one-variable formulae. Average absolute deviations from experimental results are rather low, which seems to point out the suitability of the present approach.Facultad de Ciencias Exacta

Epidemiology of malaria in endemic areas

Malaria infection is still to be considered a major public health problem in those 106 countries where the risk of contracting the infection with one or more of the Plasmodium species exists. According to estimates from the World Health Organization, over 200 million cases and about 655.000 deaths have occurred in 2010. Estimating the real health and social burden of the disease is a difficult task, because many of the malaria endemic countries have limited diagnostic resources, especially in rural settings where conditions with similar clinical picture may coexist in the same geographical areas. Moreover, asymptomatic parasitaemia may occur in high transmission areas after childhood, when anti-malaria semi-immunity occurs. Malaria endemicity and control activities are very complex issues, that are influenced by factors related to the host, to the parasite, to the vector, to the environment and to the health system capacity to fully implement available anti-malaria weapons such as rapid diagnostic tests, artemisinin-based combination treatment, impregnated bed-nets and insecticide residual spraying while waiting for an effective vaccine to be made availabl

Understanding Total Monte Carlo uncertainty propagation in burn up calculations with Generalized Perturbation Theory

International audienceThe last few years has seen Total Monte Carlo becoming the most used method for uncertainty propagation in burn up calculations.This straightfoward approach allows for the direct observation of output uncertainties (keff, isotopic concentrations etc…)of the coupled Bateman equation (fuel depletion) and Boltzmann equation (neutron transport). The application of GPT in thiscoupled case implies not only the calculation of nuclide adjoint functions but also the calculation of a number of importancefunctions. The coupling is thus almost never done.In this paper, we compare the propagation of Pu239 fission, capture and (n,2n) cross sections’ uncertainties with both TMC andGPT methods in a simple Na-cooled fast reactor assembly. In such a case, the change of spectrum due to the change in in onenuclide’s cross sections is expected to be smaller than in a thermal spectrum where the importance of individual resonances ishigh. We will see that it can’t be negligeted. Thanks to the combined use of TMC and GPT we can separate the effects of uncertaintieson a selection of other heavy nuclide densitities.The power normalisation gives minor, but important contributions. The sensitivities to depletion terms are the dominant termsfor Pu239 and its direct daughters’ evolution. The minor actinide density uncertainties are dominated by the impact of Pu239on neutron spectrum and then on minor actinides’ average cross sections. The results of uncertainty analyses could thereforebe very different if basic uncertainties with complete energy and cross nuclide correlations were available