1,721,147 research outputs found
Special Issue in Honor of Shlomo Magdassi—Bringing Basic Colloid Science into Industrial Products
No full textThe majority of basic research that is conducted by Prof. Shlomo Magdassi in materials science [...] </disp-formula
Drug-loaded nanoparticles and supramolecular nanotubes formed from a volatile microemulsion with bile salt derivatives
No full textThe main objective of this study was to form nanoparticles of a model hydrophobic drug, celecoxib, from a volatile microemulsion stabilized by a bile salt derivative. Nanoparticles were obtained by conversion of the microemulsion nanodroplets with the dissolved drug into solid nanometric particles. The use of bile salt derivatives as the surfactants for the formation of a microemulsion enabled significantly higher loading of the drug in both the microemulsion and nanoparticles, compared with the native bile salt. In addition, superior stability of the particles was achieved with the bile salt derivatives, and drug crystallization was inhibited. Interestingly, differences in particle stability and crystallization inhibition were observed between two bile salt derivatives differing only by one hydroxyl group on the bile salt backbone, indicating the delicate balance of interactions in the system. For one of the derivatives, upon dispersion of the nanoparticles in water, they spontaneously arranged into well-defined elongated nanometric tubules as detected and attested by cryo-TEM. It was found that the drug present in nanoparticles induces formation of the nanotubes. This journal is © the Owner Societies.The main objective of this study was to form nanoparticles of a model hydrophobic drug, celecoxib, from a volatile microemulsion stabilized by a bile salt derivative. Nanoparticles were obtained by conversion of the microemulsion nanodroplets with the dissolved drug into solid nanometric particles. The use of bile salt derivatives as the surfactants for the formation of a microemulsion enabled significantly higher loading of the drug in both the microemulsion and nanoparticles, compared with the native bile salt. In addition, superior stability of the particles was achieved with the bile salt derivatives, and drug crystallization was inhibited. Interestingly, differences in particle stability and crystallization inhibition were observed between two bile salt derivatives differing only by one hydroxyl group on the bile salt backbone, indicating the delicate balance of interactions in the system. For one of the derivatives, upon dispersion of the nanoparticles in water, they spontaneous
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Formation of near-infrared fluorescent nanoparticles for medical imaging
No full text Aims: Indocyanine green (ICG) is a US FDA-approved near-infrared fluorescent, water-soluble dye used for diagnostics in vitro and in vivo. The aim of this study was to develop insoluble nanoparticles based on a cationic polymer, ICG and a targeting molecule. The particles are intended for oral administration in the colon, having fluorescence in near-infrared, thus enabling remote detection. Materials & methods: An aqueous dispersion of particles formed from Eudragit-RS by simple precipitation method possessing a mean size of approximately 100 nm and zeta potential of +16 mV was produced. Results: These particles are capable of binding both ICG and fluorescein isothiocyanate–IgG via noncovalent interactions. These composite particles retain the emission characteristics of the fluorescent precursors and also exhibit potential specific recognition ability. The particles were stable in intestinal fluid and are composed only of materials that are FDA approved. Conclusion: The nanoparticles may be suitable for in vivo imaging and therapy by oral delivery systems. </jats:p
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