40 research outputs found
Molecular Modelling and Simulations of Light-Harvesting Decanuclear Ru-Based Dendrimers for Artificial Photosynthesis
No full textThe structure of a decanuclear photo- and redox-active dendrimer based on Ru(II) polypyridine subunits, suitable as a light-harvesting multicomponent species for artificial photosynthesis, has been investigated by means of computer modelling. The compound has the general formula [Ru{(μ-dpp)Ru[(μ-dpp)Ru(bpy)2]2}3](PF6)20 (Ru10; bpy=2,2′-bipyridine; dpp=2,3-bis(2′-pyridyl)pyrazine). The stability of possible isomers of each monomer was investigated by performing classical molecular dynamics (MD) and quantum mechanics (QM) simulations on each monomer and comparing the results. The number of stable isomers is reduced to 36 with a prevalence of MER isomerism in the central core, as previously observed by NMR experiments. The simulations on decanuclear dendrimers suggest that the stability of the dendrimer is not linked to the stability of the individual monomers composing the dendrimer but rather governed by the steric constrains originated by the multimetallic assembly. Finally, the self-aggregation of Ru10 and the distribution of the counterions around the complexes is investigated using Molecular Dynamics both in implicit and explicit acetonitrile solution. In representative examples, with nine and four dendrimers, the calculated pair distribution function for the ruthenium centers suggests a self-aggregation mechanism in which the dendrimers are approaching in small blocks and then aggregate all together. Scanning transmission electron microscopy complements the investigation, supporting the formation of different aggregates at various concentrations
Lussazione anteriore recidivante di spalla: 25 anni di esperienza con l'intervento di Putti-Platt.
No full text
Identification of a Strigoterpenoid with Dual Nrf2 and Nf-κB Modulatory Activity
No full textThe
sesquiterpene–coumarin ether samarcandone provided a
suitable framework to replace the apocarotenoid A–C ring system
of strigol (1), replicating, after linking to a butenolide
moiety, the activity of the natural phytohormone on Nrf2 and also
showing potent NF-kB inhibitory activity, overall modulating two critical
pathways of inflammation and cancer
El programa de ocultaciones lunares de La Plata
No full textEI programa tradicional de ocultaciones comprende la observación por el método de vista y oido de: a) todas las ocultaciones programadas en Herstmonceux, y b) una serie especial de estrellas tomadas del Catálogo de Estrellas Zodiacales de Robertson y de los catálogos de Yale para los cuales se calculan los instantes de ocultación en el Departamento de Astrometría Extrameridiana. En conjunto se observan unos 300 ó 400 fenómenos. De un análisis comparativo de los fenómenos, presentado por Sadler en la reunión de la Unión Astronómica Internacional, de Dublin, resulta que la precisión de una ocultación es del orden de 0''30, aplicadas las correcciones de borde.Asociación Argentina de Astronomí
Epidemiology and Risk Factors Associated with Mortality in Consecutive Patients with Bacterial Bloodstream Infection: Impact of MDR and XDR Bacteria
No full textBackground. Mortality related to bloodstream infections (BSIs) is high. The epidemiology of BSIs is changing due to the increase in multidrug resistance, and it is unclear whether the presence of multidrug-resistant (MDR) organisms, per se, is an independent risk factor for mortality. Our objectives were, first, to describe the epidemiology and outcome of BSIs and, second, to determine the risk factors associated with mortality among patients with BSI. Methods. This research used a single-center retrospective observational study design. Patients were identified through microbiological reports. Data on medical history, clinical condition, bacteria, antimicrobial therapy, and mortality were collected. The primary outcome was crude mortality at 30 days. The relationships between mortality and demographic, clinical, and microbiological variables were analyzed by multivariate analysis. Results. A total of 1049 inpatients were included. MDR bacteria were isolated in 27.83% of patients, where 2.14% corresponded to an extremely drug-resistant (XDR) isolate. The crude mortality rates at days 7, 30, and 90 were 12.11%, 25.17%, and 36.13%, respectively. Pitt score >2, lung and abdomen as site of infection, and XDR Pseudomonas aeruginosa were independent risk factors for 7-, 30-, and 90-day mortality. Charlson score >4, carbapenem-resistant Klebsiella pneumoniae, and XDR Acinetobacter baumannii were independent risk factors for 30- and 90-day mortality. Infection by XDR gram-negative bacteria, Charlson score >4, and immunosuppression were independent risk factors for mortality in patients who were stable at the time of BSI. Conclusions. BSI is an event with an extreme impact on mortality. Patients with severe clinical condition are at higher risk of death. The presence of XDR gram-negative bacteria in blood is strongly and independently associated with patient death
A Classic Photochemical Approach Inducing an Unexpected Rearrangement: Exploring the Photoreactivity of Pentacyclic Triterpenic Acids
No full textThe discovery of new bioactivities is closely related to the generation of novel scaffolds, and in the past few years different strategies have been proposed to obtain unknown architectures from the manipulation of known compounds. In the present study, we exploited a vintage photochemical approach for the discovery of an unexpected pathway of reactivity related to Delta 1-3-oxo-pentacyclic triterpenic acids gaining access to a new class of natural-unnatural 5(10 -> 1)abeo-pentacyclic triterpenic acids
El programa de ocultaciones lunares de La Plata
No full textSI programa tradicional de ocultaciones comprende la observación por el método de vista y oido de: a) todas las ocultaciones programadas en Herstmon ceux, y b) una serie especial de estrellas tomadas del Catálogo de Estrellas Zodiacales de Robertson y de los catálogos de Yale para los cuales se calculan los instantes de ocultación en el Departamento de Astroraetria Extrameridiana. En conjunto se observan unos 300 ó 400 fenómenos. De un análisis comparativo de los fenómenos, presentado por Sadler en la reunión de la Unión Astronómica Internacional, de Dublin, resulta que la precisión de una oculta^ ción es del orden de 0''30, aplicadas las correcciones de borde.Asociación Argentina de Astronomí
