45 research outputs found

    Recent developments of the Hierarchical Reference Theory of Fluids and its relation to the Renormalization Group

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    The Hierarchical Reference Theory (HRT) of fluids is a general framework for the description of phase transitions in microscopic models of classical and quantum statistical physics. The foundations of HRT are briefly reviewed in a self-consistent formulation which includes both the original sharp cut-off procedure and the smooth cut-off implementation, which has been recently investigated. The critical properties of HRT are summarized, together with the behavior of the theory at first order phase transitions. However, the emphasis of this presentation is on the close relationship between HRT and non perturbative renormalization group methods, as well as on recent generalizations of HRT to microscopic models of interest in soft matter and quantum many body physics.Comment: 17 pages, 5 figures. Review paper to appear in Molecular Physic

    A Neural Network for Stance Phase detection in smart cane users

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    Slides from conferencePersons with disabilities often rely on assistive devices to carry on their Activities of Daily Living. Deploying sensors on these devices may provide continuous valuable knowledge on their state and condition. Canes are among the most frequently used assistive devices, regularly employed for ambulation by persons with pain on lower limbs and also for balance. Load on canes is reportedly a meaningful condition indicator. Ideally, it corresponds to the time cane users support weight on their lower limb (stance phase). However, in reality, this relationship is not straightforward. We present a Multilayer Perceptron to reliably predict the Stance Phase in cane users using a simple support detection module on commercial canes. The system has been successfully tested on five cane users in care facilities in Spain. It has been optimized to run on a low cost microcontroller.This work has been supported by: Proyectos Puente and programa operativo de empleo juvenil (UMAJI58) and Plan Propio de Investigación at University of Malaga and the Swedish Knowledge Foundation (KKS) through the research profile Embedded Sensor Systems for Health (ESS−H) at Malardalen University, Sweden. Authors would like to ac- knowledge PONIENTE and LOS NARANJOS senior centers for their support during the tests. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    Hierarchical reference theory study of the lattice restricted primitive model

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    A three dimensional model of point charges, named lattice restricted primitive model (LRPM), is investigated by using the hierachical reference theory of fluids. This approach, which generalizes the momentum renormalization group technique, is shown to capture the physics of the model and provides a quantitative description of the phase diagram. The comparison with recent numerical simulations and with other theoretical approaches is discussed both for the LRPM and for the Blume-Capel model, which can be seen as a screened version of LRPM. The nonuniversal crossover region close to the tricritical point is also discussed

    Construction of an effective Hamiltonian for a three-dimensional Ising universality class

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    The asymptotic and preasymptotic critical behavior in fluids, mixtures, and uniaxial magnets is believed to be described by an effective phi (4) scalar field theory with suitable, nonuniversal, coupling constants. The critical parameters as well as the extent of crossovers. and corrections to the leading critical behavior in physical systems, crucially depends on the choice of these couplings. Here we propose a new method for deriving the effective scalar field theory appropriate to a microscopic model in this universality class. Use is made of the hierarchical reference theory which implements the basic ideas of Wilson momentum space renormalization group to microscopic Hamiltonians. The effective low-energy field theory is then analyzed by the minimal subtraction scheme of Schloms and Dohm. We discuss the application of this method to the three-dimensional Ising model and to the liquid-vapor phase transition. We make comparison with high-temperature expansion results and with experimental data for rare gas

    Targeting pre-miRNA by Peptide Nucleic Acids: A new strategy to interfere in the miRNA maturation

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    PNA conjugated to carrier peptides have been employed for the targeting of miRNA precursor, with the aim to develop molecules able to interfere in the pre-miRNA processing. The capability of the molecules to bind pre-miRNA has been tested in vitro by fluorescence assayes on Thiazole Orange labeled molecules and in vivo, in K562 cells, evaluating the amount of miRNA produced after treatment of cells with two amounts of PNAs

    Design and Rapid Manufacturing of a customized foot orthosis: a first methodological study

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    A feasibility study was performed in order to demonstrate the benefits of designing and manufacturing a customized foot orthosis by means of digital technologies, such as Reverse Engineering (RE), Generative Design (GD) and Additive Manufacturing (AM). The aim of this work was to define the complete design-manufacturing process, starting from the 3D scanning of the human foot anatomy to the direct fabricating of the customized foot orthosis. Moreover, this first methodological study tries to combine a user-friendly semi-automatic modelling approach with the use of low-cost devices for the 3D laser scanning and the 3D printing processes. Finally, the result of this approach, based on digital technologies, was also compared with that achieved by means of conventional manual technique

    Mitochondrial DNA D-loop as a new target of Saporin 6 nuclease activity

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    The single-chain ribosome-inactivating proteins (RIPs) from plant origin, including Saporin 6 from the seeds of Saponaria officinalis, are ribotoxins known to act as N-glycosidases which depurinate the conserved alpha sarcin loop of large rRNAs. As a consequence, the eukaryotic ribosomes become inactivated, thereby arresting the protein synthesis at the elongation step. RIPs are currently under study as antiviral and antiproliferative agents. Additional in vitro activities of RIPs against either RNA or DNA have been recently described. A specific nuclease activity on plasmidic DNA was demonstrated by either purified or bacterial-recombinant molecules. We report here that human mitochondrial DNA (mtDNA) is a new specific target of Saporin 6 nuclease activity. A unique site of cleavage has been identified and mapped within the most variable part of the D-loop region of the covalently closed circular mtDNA molecule

    Light management in TiO2 thin films integrated with Au plasmonic nanoparticles

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    The light-harvesting properties of metal oxide thin films can be remarkably increased by the introduction of èplasmonic nanostructures, leading to higher efficiencies in photovoltaic or photoelectrochemical devices. In the prototypical material combination, Au-TiO2, nano- and mesoscale porosity of TiO2 is desirable to improve not only the light-harvesting, but also the available surface area for chemical reactions. Moreover, great attention has been given to the control of size and shape of Au nanoparticles (NPs) to increase the overall optical properties of the film. In this work, we investigate the optical properties of the composite Au-TiO2 films exhibiting remarkable light scattering properties. TiO2 is characterized by a tree-like hierarchical morphology produced by pulsed laser deposition, and two different configurations for Au integration, namely Au on top and at the bottom of TiO2 are explored by varying the size of Au NPs. The hierarchical oxide morphology allow to achieve superior scattering properties after the combination with Au NPs with respect to films obtained from a commercial paste deposition. Both the Au-top and Au-bottom configurations enable to tune the plasmonic properties of Au NPs. Specifically, outstanding scattering properties are exhibited by the composite TiO2 film grown on top of large (~100 nm) Au NPs. These results show the potential interest of employing such integrated films as photoanodes in dye-sensitized or perovskite-based solar cells, or in photoelectrochemical cells for water splitting. An analogous approach can be employed for alternative materials, both considering the plasmonic structures as well as the semiconductor layer

    Preparation of anti-miR PNAs for drug development and nanomedicine

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    Peptide Nucleic Acids (PNAs) are oligonucleotide mimics that can be used to block the biological action of microRNA, thus affecting gene expression post-transcriptionally. PNAs are obtained with solid-phase peptide synthesis, and can be easily conjugated to other peptides. Conjugation with R8-Peptide or modification of the PNA backbone (at C5 or C2 carbon) with arginine side chains allows efficient cellular uptake. The present protocol describes the synthesis of cationic PNAs that can be used alone as drugs or for efficient co-delivery in suitable inorganic nanocarriers
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