1,720,968 research outputs found

    Chitosan-based Composite for Wound Healing & Biomedical Applications

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    Polymer composites have witnessed increased research interest in the last decades, and the applications of these materials include drug delivery, tissue engineering, and wound bandages and dressings. Numerous polymers have been studied to fabricate the ideal wound dressing. Making these polymer composites biocompatible, porous, and bioactive with high absorption capabilities is critical to guide cell growth and differentiation and limit their detrimental effects on incorporated therapeutic molecules. This research work aims to address shortcomings of available wound dressings by fabricating a biocompatible, porous, bioactive, and antimicrobial dressing using chitosan (CTS) and carboxymethyl cellulose (CMC) polymers incorporated with zinc-doped halloysites (ZnHNT). In line with the points mentioned earlier, three distinct objectives are proposed in this research that involve using natural biopolymers and nanomaterials. The first objective involves the fabrication and characterization of chitosan/carboxymethylcellulose composite incorporated with zinc-coated halloysites (HNTs) via the solution-gel method, without the use of chemical crosslinkers. Here, the individual biomaterial components used in this research were tested for their inherent antibacterial properties while determining the minimum inhibitory concentration of each constituent biomaterial. A modified physical crosslinking method was used to fabricate a hydrogel biocomposite comprising CTS, CMC, and zinc-coated HNT. The physical characteristics of the hydrogel were assessed via rheological studies. SEM and digital microscopy were used to observe zinc-coated halloysites and the character of the hydrogel produced. Additional characterization tests carried out in this study include Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis, x-ray fluorescence, and x-ray diffraction (XRD). The results showed that zinc doped HNTs, when loaded with a low dose of gentamicin sulfate, stagnated the growth of gram-positive and gram-negative bacteria for extended hours, suggesting the possibility of less dependence on the use of antibiotics. The results also demonstrate the feasibility of fabricating a CTS/CMC polymer conjugate via a simple physical crosslinking method devoid of harsh crosslinking chemical agents. The second project involved in vitro assessment of the effect of the fabricated chitosan-based composite on wound closure and cell migration. These properties were evaluated via in vitro assays, including proliferation and live/dead assays for cytotoxicity assessment, antimicrobial tests, alizarin red staining and scratch assay. The results suggested that the chitosan polymer conjugate had improved functionalities of biocompatibility, non-toxicity, and antimicrobial properties against gram-positive and gram-negative bacteria. In addition, the fabricated chitosan/CMC composite also showed an improved cell migration effect on human skin dermal fibroblast. This result suggests that the chitosan-based fabricated conjugate could serve as a new promising candidate for wound healing applications. In a closely related third study, the use of solvent casting method to fabricate CTS/CMC film membranes bearing added functionality for biomedical applications is reported. Material characterization tests were carried out to confirm the presence of the constituted biomaterials. The tests include microscopy imaging and SEM analysis to determine the physical and surface topography of the fabricated biomaterial. Additional tests carried out include, thermogravimetric analysis (TGA), tensile strength, cell proliferation, cytotoxicity (live/dead), and antibacterial studies. The results of this project showed that the prepared biomaterial was relatively hydrophobic and non-toxic with improved thermal stability. Additional tests will be performed in future studies to obtain the ideal film membrane

    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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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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

    Author Under Sail The Imagination of Jack London, 1893-1902

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    In Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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