Study of the biological activity of novel synthetic compounds with antiviral properties against human rhinoviruses

Picornaviridae represent a very large family of small RNA viruses, some of which are the cause of important human and animal diseases. Since no specific therapy against any of these viruses currently exists, palliative symptomatic treatments are employed. The early steps of the picornavirus replicative cycle seem to be privileged targets for some antiviral compounds like disoxaril and pirodavir. Pirodavir's main weakness is its cytotoxicity on cell cultures at relatively low doses. In this work some original synthetic compounds were tested, in order to find less toxic compounds with an improved protection index (PI) on infected cells. Using an amino group to substitute the oxygen atom in the central chain, such as that in the control molecule pirodavir, resulted in decreased activity against Rhinoviruses and Polioviruses. The presence of an -ethoxy-propoxy- group in the central chain (as in compound I-6602) resulted in decreased cell toxicity and in improved anti-Rhinovirus activity. This compound actually showed a PI >700 on HRV14, while pirodavir had a PI of 250. These results demonstrate that modification of pirodavir's central hydrocarbon chain can lead to the production of novel derivatives with low cytotoxicity and improved PI against some strains of Rhinoviruses.     

Isoperimetric inequalities for an ergodic stochastic control problem

In this paper we deal with blow-up solutions to an elliptic equation with a nonlinear gradient term. The problem under consideration can be seen as the ergodic limit of a stochastic control problem with state constraints. It is well known that it has a solution only when a parameter which appears in the equation assumes a particular value known as ergodic constant. For such a constant many properties similar to those of an eigenvalue hold true. We show that a Faber–Krahn inequality can be stated for the ergodic constant and that for the corresponding solution a comparison result in terms of the solution to a symmetrized problem can be proved.     

Functional Nickel Oxide Nanostructures for Ethanol Oxidation in Alkaline Media

Nickel oxide (NiO) nanostructures are employed in the basic medium for the oxidation of ethanol. A variety of NiO nanostructures are synthesized by wet chemical growth method, using different hydroxide (OH^?) ion sources, particularly from ammonia, hexamethylenetetramine, urea and sodium hydroxide. The use of urea as (OH^?) ion source results in flower‐like NiO structures composed by extremely thin nanowalls (thickness lower than 10 nm,), which demonstrated to be the most active for ethanol oxidation. All the samples exhibit NiO cubic phase, and no other impurity was detected. The cyclic voltammetry (CV) curves of NiO nanostructures were found linear over the concentration range 0.1–3.5 mM (R²=0.99) of ethanol, with the limit of detection estimated to be 0.013 mM for ethanol. The NiO nanostructures exhibit a selective signal towards ethanol oxidation in the presence of different members of alcohol family. The proposed NiO nanostructures showed a significant practicality for the reproducible and sensitive determination of ethanol from brandy, whisky, mixture of brandy and rum, and vodka samples. The nanomaterial was used as a surface modifying agent for the glassy carbon electrode and it showed a stable electro‐oxidation activity for the ethanol for 16 days. These findings indicate that the presented NiO nanomaterial can be applied in place of noble metals for ethanol sensing and other environmental applications (like fuel cells).     

Generalized discrepancies on the sphere

Generalized discrepancies are a class of discrepancies introduced in the seminal paper [1] to measure uniformity of points over the unit sphere in ℝ³. However, convergence to 0 of this quantity has been shown only in the case of spherical t –designs. In the following, we completely characterize sequences for which convergence to 0 of D (𝒫_N ; A ) holds. The interest of this result is that, when evaluating uniformity on the sphere, generalized discrepancies are much simpler to compute than the well-known spherical cap discrepancy. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

A generalized shortest path tour problem with time windows

Computational Optimization and Applications - This paper studies a generalization of the shortest path tour problem with time windows (GSPTPTW). The aim is to find a single-origin...     

Scenario Approximation of Robust and Chance-Constrained Programs

We consider scenario approximation of problems given by the optimization of a function over a constraint that is too difficult to be handled but can be efficiently approximated by a finite collection of constraints corresponding to alternative scenarios. The covered programs include min-max games, and semi-infinite, robust and chance-constrained programming problems. We prove convergence of the solutions of the approximated programs to the given ones, using mainly epigraphical convergence, a kind of variational convergence that has demonstrated to be a valuable tool in optimization problems.