1,720,979 research outputs found
Penetration of gold nanoparticles through the skin
No full textThe assessment of nanoparticle penetration through skin is of increasing importance not only to evaluate the toxicity associated with occupational or environmental exposure to nanoparticles, but also to design rules for the fabrication of new types of transdermal drug delivery or diagnostics approaches. While these have been the subject of much research, the lack of a systematic approach in the penetration experiments has created controversial results regarding whether nanoparticles do or not penetrate the skin.The aim of the research presented in the thesis is to investigate the penetration of gold nanoparticles through human and mouse skin, focusing on the effect of surface charge, morphology and specific functionalisation. To study this, a penetration protocol using organ culture was designed and tested to assure the maintenance of the skin integrity in the course of our experiments. Skin samples incubated with gold nanoparticles were characterized for penetration by NPs using inductively coupled plasma atomic emission spectroscopy, transmission electron microscopy, energy-dispersive Xray spectroscopy and photoluminescence microscopy. Furthermore, epithelial cell monolayers were exposed to the gold nanoparticles to evaluate the transport through the cellular barrier. Transmission electron microscopy, light microscopy and trans epithelial electric resistance were used to characterise the cell monolayers exposed to gold nanoparticles.Results obtained are important to enhance our understanding of the interaction of gold nanoparticles with skin, providing valuable information for the design of new nanoparticle-based transdermal delivery systems
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
Interactions of gold nanoparticles with biological structures
No full textIn this paper we present our recent studies on understanding how gold nanoparticles with defined characteristics in terms of size, shape, charge and function a) influence the formation of tight junctions between MDCK-II cells and b) interact with the cellular barrier of MDCK-II cells. We focused our work to seven types of gold nanoparticles, which are promising for biological applications or often employed as reference particles in biological experiment
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
Formation and plasmonic response of self-assembled layers of colloidal gold nanorods and branched gold nanoparticles
No full textThe plasmonic properties of self-assembled layers of rod- and branched-shaped gold nanoparticles were investigated using optical techniques. Nanoparticles were synthesized by a surfactant-guided, seed-mediated growth method. The layers were obtained by gradual assembly of nanoparticles at the interface between a polar and a nonpolar solvent and were transferred to a glass slide. Polarization and angle-dependent extinction measurements showed that the layers made of gold nanorods were governed by an effective medium response. The response of the layers made by branched gold particles was characterized by random light scattering. Microscopic mapping of the spatial mode structure demonstrates a uniform optical response of the nanoparticle layers down to a submicrometer length scale.<br/
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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