1,720,986 research outputs found
Biopolymeric Carriers for Nanomedical Applications
No full textNanomedicine offers the opportunity to develop novel nano and microcarriers for targeted drug therapy, reducing the undesirable side effects. This communication will discuss about multifunctional, highly biodegradable and biocompatible, (natural) biopolymeric drug carriers, having the following functionalities: 1) protection of drugs from chemical and biological degradation; 2) control of in vivo and in vitro distribution; 3) specific cell targeting. Several type of carriers will be examined. The first type is composed of biodegradable polyelectrolyte pairs (e.g. polysaccharides) with opposite charges, subsequently dissolved to obtain hollow capsules ready to encapsulate drugs [1, 2]. Selected fluorophores and magnetic nanoparticles have been included in the coating to allow in vitro and in vivo monitoring of microcapsule fate. In order to obtain cellular targeting, specific ligands can also be conjugated to the coating layers. The second type of carriers is represented by novel monodisperse micro and nanogels [3]. These are challenging drug delivery systems for the release of bioactive molecules, able to undergo reversible volume transition, when triggered by environmental factors such as temperature, ionic strength, or pH [4]. Nanogels, internalised inside cells through phagocytic pathways, release natural or synthetic drugs inside endosomes by pH-induced polymer removal. Biomolecules and biopolymers are therefore protected and released in a controlled manner. The third category of carriers discussed is the naturally “green” and cytocompatible halloysite nanotubes [5], used as novel hydrophobic drug carriers for targeted delivery into neoplastic cells. The internalisation and cytotoxicity of drug-loaded carriers has been evaluated in vitro on different cell lines.
Acknowledgments: “Con il contributo del Ministero degli Affari Esteri, Direzione Generale per la promozione e la Cooperazione Sociale ” (Large Scale ITA –USA Bilateral Project “Nano-trasportatori per la terapia del cancro”). G.L. thanks Regione Puglia for "Ritorno al Futuro" Fellowship INCANTO.
References
[1] V. Vergaro, F. Scarlino, C. Bellomo, R. Rinaldi, D. Vergara, M. Maffia, F. Baldassarre, G. Giannelli, X. Zhang, Y. M. Lvov and S. Leporatti Advanced Drug Delivery Review (2011), 63, 847-864.
[2] I.E Palamà, S. Leporatti, E. de Luca, N. Di Renzo, M. Maffia, C. Gambacorti-Passerini, R.Rinaldi, G. Gigli, R. Cingolani, A.ML Coluccia Nanomedicine Future Medicine Lt (2010) 5(3), 419-431.
[3] S. Argentiere, L. Blasi, G. Ciccarella, G. Barbarella, A. Cazzato, R. Cingolani, G. Gigli Small (2009) 4101-4103.
[4] S. Argentiere, L. Blasi, G. Ciccarella, G.Barbarella, R.Cingolani, G. Gigli Journal of Applied Polymer Science (2010), 116(5), 2808-2815.
[5] V.Vergaro, E.Abdullayev, Y.M. Lvov, A.Zeitoun, R. Cingolani, R. Rinaldi and S. Leporatti Biomacromolecules (2010) 11, 820–826
Biomechanical and proteomic analysis of INF- beta-treated astrocytes
No full textAstrocytes have a key role in the pathogenesis of several diseases including multiple sclerosis and were proposed as the designed target for immunotherapy. In this study we used atomic force microscopy (AFM) and proteomics methods to analyse and correlate the modifications induced in the viscoleastic properties of astrocytes to the changes induced in protein expression after interferon-β (IFN-β) treatment. Our results indicated that IFN-β treatment resulted in a significant decrease in the Young’s modulus, a measure of cell elasticity, in comparison with control cells. The molecular mechanisms that trigger these changes were investigated by 2DE (two-dimensional electrophoresis) and confocal analyses and confirmed by western blotting. Altered proteins were found to be involved in cytoskeleton organization and other important physiological processes
Measurements of Surface-roughness - Use of A Ccd Camera To Correlate Doubly Scattered Speckle Patterns
No full textWe describe an instrument, built around a commercial CCD camera and some fast image-processing boards, that evaluates roughness height by measuring the average size of doubly scattered speckle patterns. The device is a variant of a recent proposal that was based on the use of a spatial modulator to perform the Fourier transform of a speckle image. In the present setup, the Fourier transform is replaced by the direct evaluation of a second-order correlation function. Strictly speaking, the device proposed in this paper is not a real-time device but its response time (approximately 10 s) is sufficiently short to be of practical value for many applications. Updated CCD cameras that will significantly improve the performance of our prototype are already on the market
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
