1,721,121 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Langmuir-Schaefer films of Nafion with incorporated TiO2 nanoparticles

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    An easy method of incorporating TiO2 nanoparticles into Nafion perfluorinated ionomer is proposed. Ultrathin films of Nafion were prepared by employing the Langmuir-Schaefer (LS) technique. The pressure-area isotherm study of a Langmuir monolayer of Nafion at the air-water interface on different concentrations of NaCl as the subphase allowed us to find the best experimental conditions for the deposition of stable Langmuir-Schaefer films. Incorporation of TiO2 nanoparticles was performed by dipping Nafion LS films in a solution of TiO2 nanoparticles. The uniformity of the TiO2 incorporation was detected by UV-visible spectroscopy. The morphology of the Nafion, Nafion/TiO2 nanoparticles thin films, and the changes due to the annealing procedure were investigated by atomic force microscopy. Interestingly, the AFM investigation showed that Nafion and Nafion/TiO2 LS films have thermal stability up to 600°

    From Nanobiotechnology to Organic and Biological Monitoring of Health and Environment for Biosafety

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    This overview describes the optimal implementation and utilization of different, newly conceived nanosensors for human biosafety purposes, exploiting a variety of methods (amperometric, conductometric, spectrometric and nanogravimetric), and a wide range of nanocomposites, genes and recombinant enzymes. Namely, while biological nanosensors were designed based on Nucleic Acid Programmable Protein Arrays (NAPPA), with or without SNAPtag, and on Langmuir-Blodgett (LB) thin films of recombinant laccase (Rigidoporus lignosus, formerly known as Rigidoporus microporus), organic nanosensors were based on matrices of calcium oxide (CaO) and on carbon nanotubes-either multi-walled (MWNTs) or single-walled (SWNTs)- embedded in poly(o-methylaniline) (POTO). Special attention was paid both to detecting useful and relevant substances (such as carbon dioxide, phenols and phenolic derivatives and compounds) and designing devices and molecules for human biosafety like vaccines and others, by means of amperometry, conductimetry, mass spectrometry (MS) and other label-free technologies, such as quartz crystal microbalance with dissipation monitoring (QCM_D)

    Fratelli perduti

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    Si tratta della difficile elaborazione del lutto per la perdita di un fratello prendendo spunto da un caso narrato nel romanzo di Paul Auster 'Invisibile

    Nanoproteomics Enabling Personalized Nanomedicine

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    Nucleic Acid Programmable Protein Arrays utilize a complex mammalian cell free expression system to produce proteins in situ. In alternative to fluorescent-labeled approaches a new label free method, emerging from the combined utilization of three independent and complementary nanotechnological approaches, appears capable to analyze protein function and protein–protein interaction in studies promising for personalized medicine. Quartz Micro Circuit nanogravimetry, based on frequency and dissipation factor, mass spectrometry and anodic porous alumina overcomes indeed the limits of correlated fluorescence detection plagued by the background still present after extensive washes. This could be further optimized by a homogeneous and well defined bacterial cell free expression system capable to realize the ambitious objective to quantify the regulatory protein networks in humans. Implications for personalized medicine of the above label free protein array using different test genes proteins are reporte

    SpADS and SNAP-NAPPA Microarrays towards Biomarkers Identification in Humans: Background Subtraction in Mass Spectrometry with E.coli Cell Free Expression System

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    We present a useful approach towards for biomarkers identification in an innovative self-assembling protein microarray based on “Nucleic Acid Programmable Protein Array” (NAPPA) and SNAP tag coupled to E.coli cell free expression system. This approach prove capable to resolve the “background” problem associated to the above label free detection system for the identification of proteins and of protein-protein interaction in humans that could become used in clinical practice
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