1,721,021 research outputs found
Curcumin derivatives: Aβ-ligands as potential diagnostic and therapeutic tools for alzheimer's disease
No full textOne of the characteristic features of Alzheimer's disease (AD) is represented by the overexpression of amyloid-beta (Aβ) peptides, which play a central role in the onset and in the development of the pathology. The targeting of these peptides and aggregates is considered a possible strategy for the development of diagnostic and therapeutic tools for AD. The ability of curcumin to target Aβ plaques and to interfere with Aβ peptides interaction processes, along with other activities also correlated to AD, has already been shown. This review focuses on the synthesis of chemically stable and/or radiolabelled curcumin derivatives and their characterization as active compounds for the treatment/diagnosis of AD. Moreover, their use as potential diagnostic and therapeutic tools, alone or inserted in opportunely functionalized nanoparticles with ability to bind amyloid deposit, stain plaques and pass the blood brain barrier (BBB), is described
2D materials for hybrid laser wavelength tuning
No full textThis research project focuses on the improvement of Photo-Thermal Spectroscopy and Quartz
Enhanced Photo-Acoustic Spectroscopy systems that require precise control over the
operating wavelength of the optical source while maintaining constant output power. To
achieve this, a new approach using two-dimensional materials such as graphene is proposed,
which offers low driving voltage and power, tunability, and reconfigurability for advanced
sensing technology.
The main objective of this research is to design, fabricate, and characterize tunable devices
based on silicon-nitride resonant cavities operating at 1.55 microns, integrated with
monolayer or bilayer graphene sheets. By tuning a graphene capacitor integrated within an
optical device, it becomes possible to manipulate the wavelength and phase characteristics
of the resonance or the wavelength generated.
The ability to vary the graphene Fermi level will enable efficient control and engineering of
the complex refractive index of the resonant mode across a broad range of operating
conditions, leading to reconfigurable graphene-based devices that surpass current state-ofthe-
art technologies.
The fabrication of the device was carried out at the Tyndall National Institute and using
graphene deposition and its transfer - at the Apulian Graphene Lab. Characterization of the
fabricated prototypes was carried out at both Polytechnic University of Bari and Munster
Technological University
Nano-liquid chromatography for enantiomers separation of baclofen by using vancomycin silica stationary phase.
No full textThe chiral separation of baclofen (Bac) was obtained by nano-liquid chromatography tandem mass spectrometry (nano-LC-MS/MS) using a 100 μm I.D. fused silica capillary column packed with silica particles chemically modified with vancomycin. Various experimental parameters, such as composition (buffer concentration, water content, organic modifier) and pH of the mobile phase and sample solvent were investigated for method optimization. In order to increase the sensitivity an on-column focusing procedure was applied. Acceptable separation of Bac enantiomers was obtained in less than 11 min eluting in isocratic mode, with 90:10 MeOH/water (v/v) containing 10 mM ammonium acetate at pH 4.5. These optimized experimental conditions were applied to the analysis of human plasma samples spiked with racemic mixture of Bac. The use of a Buckypaper disc as sorbent membrane allows one to recover both enantiomers with yields ≥ 65%. The method was fully validated, following the identification criteria of the European Commission Decision 2002/657/EC
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
CFD simulation of gas-liquid stirred vessels
No full textComputational Fluid Dynamics is an increasingly important tool for carrying out realistic simulations of process apparatuses. As a difference from single phase systems, for multipliase systcms the
development of CFD models is still at its early stages. In the present work CFD simulations of gasliquid stirred tanks are reported. All bubbles are assumed to share the same size, and a simplified
approach is adopted for the description of momentum exchanges between tile two phases. In particular ir is shown that the only parameter needed for modeling drag forces is bubble terminal velocity.
Results show that in a quite wide range encompassing most practical applications, bubble size has a limited effect on flow fields as well as on total gas hold-up and ia distribution in the vessel space.
This result implies that coalescencelbreakage dynamics computations may be conveniently carried out off-line after having assessed the vessel flow field, with large savings of co~nputational demand
Enantioseparation of tryptophan and its unnatural derivatives by nano-LC on CSP-teicoplanin silica based
No full textThis work deals with the potentiality of nano liquid chromatography (Nano-LC) for the chiral separation of racemic mixture of tryptophan and some selected derivatives by using 100 μm i.d. fused silica capillary packed with teicoplanin bonded to 5 μm diol silica stationary phase. The experiments were carried out by using a cheap and laboratory-assembled nano-LC–UV system. Elution was done in an isocratic mode using a polar organic mobile phase. In order to find the optimum chiral separation of the studied enantiomers, some chromatographic experimental parameters were systematically studied and optimized. Among them, mobile phase composition, namely organic modifier type and concentration, buffer type and pH and aqueous content and sample solvent dilution on retention time, retention factor and enantioresolution factor were studied. Baseline enantioresolution and good peak shape was achieved utilizing the mobile phase containing 40 mM ammonium formate at pH pH 2.5 in ACN/water/acetone (60:30:10, v/v/v) at 520 nL/min in less than 8 min analysis time
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