1,720,962 research outputs found

    Polymeric microporous nanofilms as smart platforms for in vitro assessment of nanoparticle translocation and caco-2 cell culture

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    The study of nanomaterial translocation across epithelial barriers is often hindered by the low permeability of transwell membranes to nanoparticles. To address this issue ultra-thin poly(L-lactic acid) nanofilms with zero tortuosity micropores were developed for use in nanoparticle passage tests. In this study we demonstrate that microporous polymeric nanofilms allow a significantly higher passage of silver nanoparticles in comparison with commercial membranes normally used in transwell inserts. A reliable procedure for collecting free-standing nanofilms which enables their manipulation and use in lab-on-chip systems is described. We also demonstrate the cytocompatibility of porous nanofilms and their ability to sustain the adhesion and proliferation of Caco-2 cells. Ultra-thin microporous membranes show promise as low-cost nanomaterial screening tools and may be used as matrices for the development of bioengineered systems for mimicking the intestinal epithelium

    MULTI-WELL PLATE FOR CELL CULTURES

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    A multi-well plate (1) is provided for cell cultures comprising a plurality of wells (10) ordered in rows; each well (10) defines a chamber 10b) for cell cultures and an introduction section (10c) of the cell cultures in the chamber (10b); the multi-well plate (1) comprises culture modules (1a) suitable to be constrained to each other forming the multi-well plate (1); each culture module (1a) comprises a lower body (2) comprising bottom portions (2c) each of which comprising a chamber (10a) of said wells (10) arranged in a row; an upper body (3) comprising apex portions (3a) complementary to the bottom portions (c) and comprising the introduction sections (10c) of the wells (10) arranged in rows, suitable to rest on the lower body (2) and to be detachably constrained to an adjacent culture module (1a); and at least one cover (4) designed to fit through an introduction section (10c), in a well (10b) detachably engaging to the bottom portion (2c) and constraining the upper body (3) to the lower body (2)

    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

    Variations on the Author

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    “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

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    We 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

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    We 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

    Author Index

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