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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
Advances in the Electrophoretic Deposition (EPD) Technology for Coatings and Self-Standing Structures Based on Biopolymers and Bioactive Glasses for Biomedical Applications
Full text linkTo tackle the drawbacks of metallic implants, such as infections caused by the implant or inadequate interaction with the biological environment, novel composite coating materials that are compatible with living tissues and possess antibacterial properties are being developed. The natural polymer chitosan (CS) is often used to achieve anti-infective devices due to its appealing intrinsic physical and biological characteristics. One key feature of CS is its ability to form complexes with a wide range of metal ions. In this context, the chelation of CS with therapeutic metal ions, which interact with a number of biological structures and metabolic systems, is a promising platform for biomedical applications.
In the first part of this work, functional coatings based on copper(II)-chitosan complexes were developed and used to coat metallic substrates by electrophoretic deposition (EPD). First, EPD parameters were optimized for the deposition of CS coatings by the Taguchi design of experiment (DoE) approach with a mixed-level design. Coatings were produced by using optimal EPD conditions. For this purpose, the previously fabricated copper(II)-chitosan complexes were dissolved and deposited on the cathode during EPD in the form of ionic complexes. After that, these complexes were deposited together with strontium-doped bioactive glasses. Different physicochemical and biological evaluations were performed on these coatings. On the whole, the application of copper(II)-chitosan complexed with strontium-doped bioactive glasses coating exhibited high promise in enhancing the biological efficacy of the implants.
After that, CS complexes were fabricated using another promising metal (gallium) with different concentrations of gallium ions. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the complexation between gallium and CS for all investigated concentrations, while Energy-Dispersive X-ray Spectroscopy (EDX) validated the homogenous distribution of the metal ions within the polymer matrix. The outcomes from the physicochemical characterization of the produced complexes, as well as the versatility of the production method encouraged further investigation of this material as coatings of medical devices. For that purpose, EPD was performed utilizing previously optimized parameters. The method of covalently attaching a biologically relevant metal ion to the polymer ligand effectively gave the required antibacterial capabilities to the CS-based coatings.
Recently, there has been increasing interest in using plant-derived medicines (phytotherapeutic drugs). For that reason, ferulic acid, which is usually derived from seeds, leaves, and plant cell walls was incorporated in the EPD coating. The DoE approach was used to obtain optimized ferulic acid loaded CS and CS complexed – bioactive glasses composite coatings. The produced coatings showed hydroxyapatite formation in simulated body fluid (SBF). The ferulic acid release profile showed a gradual release due to the incorporation of mesoporous bioactive glass (MBGNs). The release tended to reach a plateau after approximately 42 days. Furthermore, the synergistic effect of metal ions and a phytotherapeutic drug (FA) was observed during biological characterization. All coatings significantly enhanced MG-63 and MC3T3-E1 cell proliferation. The produced coatings represented effective antibacterial effects against S. aureus and E. coli bacteria after 1 day of incubation.
EPD is widely used in coating technology. However, in this thesis, EPD is proposed to fabricate self- and free-standing three-dimensional shapes for applications in tissue engineering. The aim is to successfully produce a novel asymmetric bilayer membrane for guided bone regeneration (GBR) applications, using the EPD process. Membranes were composed of two layers, namely a thin dense layer and a thick porous layer. The dense layer consists of CS and embedded MBGNs, whereas the porous layer consists of CS/gelatin/MBGNs and Cu(II)-CS/gelatin/MBGNs. The dense layer was further functionalized with a phytotherapeutic drug known as naringin (Nar). The produced bilayer membranes were extensively characterized using different physicochemical and biological characterization techniques. The produced bilayer films were stable enough for handling and tissue engineering applications. Highly distributed and embedded MBGNs were observed in both layers. SBF studies confirmed hydroxyapatite formation in the porous structure of the samples after 7 days. Enzymatic degradation showed continuous degradation behavior of the produced films. The release of Nar showed an initial burst release followed by continuous sustained release. The antibacterial effect of Cu(II) and Nar on gram-positive and gram-negative bacteria was observed. Finally, cell studies confirmed the cytocompatibility of the produced films. Overall, the results presented in this thesis affirm EPD as a powerful and versatile technique for multifunctional coatings as well as for free-standing three-dimensional film fabrication. The current research opens up several new research avenues for the use of EPD in the framework of tissue repair and regeneration applications.Um die Nachteile metallischer Implantate, wie beispielsweise durch das Implantat verursachte Infektionen oder unzureichende Wechselwirkungen mit der biologischen Umgebung, zu vermeiden, werden neuartige Verbundbeschichtungsmaterialien entwickelt, die mit lebendem Gewebe kompatibel sind und antibakterielle Eigenschaften besitzen. Das natürliche Polymer Chitosan (CS) wird aufgrund seiner attraktiven physikalischen und biologischen Eigenschaften häufig zur Herstellung antiinfektiöser Geräte verwendet. Ein wesentliches Merkmal von CS ist seine Fähigkeit, mit einer Vielzahl von Metallionen Komplexe zu bilden. In diesem Zusammenhang ist die Chelatisierung von CS mit therapeutischen Metallionen, die mit einer Reihe biologischer Strukturen und Stoffwechselsysteme interagieren, eine vielversprechende Plattform für biomedizinische Anwendungen.
Im ersten Teil dieser Arbeit wurden funktionelle Beschichtungen auf Basis von Kupfer(II)-Chitosan-Komplexen entwickelt und zur Beschichtung metallischer Substrate durch elektrophoretische Abscheidung (EPD) eingesetzt. Zunächst wurden die EPD-Parameter für die Abscheidung von CS-Beschichtungen durch den Taguchi-Design-of-Experiment-Ansatz (DoE) mit einem Mixed-Level-Design optimiert. Die Beschichtungen wurden unter den optimalen EPD-Bedingungen hergestellt. Zu diesem Zweck wurden die zuvor hergestellten Kupfer(II)-Chitosan-Komplexe gelöst und während der EPD in Form ionischer Komplexe auf der Kathode abgeschieden. Anschließend wurden diese Komplexe zusammen mit Strontium-dotierten bioaktiven Gläsern abgeschieden. An diesen Beschichtungen wurden verschiedene physikalisch-chemische und biologische Untersuchungen durchgeführt. Insgesamt erwies sich die Anwendung von Kupfer(II)-Chitosan, komplexiert mit einer Strontium-dotierten bioaktiven Glasbeschichtung, als vielversprechend für die Verbesserung der biologischen Wirksamkeit der Implantate.
Anschließend wurden CS-Komplexe unter Verwendung eines anderen vielversprechenden Metalls (Gallium) mit unterschiedlichen Konzentrationen an Galliumionen hergestellt. Die Fourier-Transformations-Infrarotspektroskopie (FTIR) bestätigte die Komplexierung zwischen Gallium und CS für alle untersuchten Konzentrationen, während die energiedispersive Röntgenspektroskopie (EDX) die homogene Verteilung der Metallionen innerhalb der Polymermatrix bestätigte. Die Ergebnisse der physikalisch-chemischen Charakterisierung der hergestellten Komplexe sowie die Vielseitigkeit der Produktionsmethode regten zu weiteren Untersuchungen dieses Materials als Beschichtungen für medizinische Geräte an. Zu diesem Zweck wurde die EPD unter Verwendung zuvor optimierter Parameter durchgeführt. Die Methode der kovalenten Bindung eines biologisch relevanten Metallions an den Polymerliganden verlieh den CS-basierten Beschichtungen effektiv die erforderlichen antibakteriellen Eigenschaften.
In letzter Zeit besteht ein zunehmendes Interesse an der Verwendung pflanzlicher Arzneimittel (Phytotherapeutika). Aus diesem Grund wurde Ferulasäure, die üblicherweise aus Samen, Blättern und pflanzlichen Zellwänden gewonnen wird, in die EPD-Beschichtung eingearbeitet. Der DoE-Ansatz wurde verwendet, um optimierte mit Ferulasäure beladene CS- und CS-komplexierte – bioaktive Glasverbundbeschichtungen zu erhalten. Die hergestellten Beschichtungen zeigten eine Hydroxylapatitbildung in simulierter Körperflüssigkeit (SBF). Das Ferulasäure-Freisetzungsprofil zeigte eine allmähliche Freisetzung aufgrund des Einbaus von mesoporösem bioaktivem Glas (MBGNs). Die Freisetzung erreichte tendenziell nach etwa 42 Tagen ein Plateau. Darüber hinaus wurde bei der biologischen Charakterisierung der synergistische Effekt von Metallionen und einem Phytotherapeutikum (FA) beobachtet. Alle Beschichtungen steigerten die Zellproliferation von MG-63 und MC3T3-E1 deutlich. Die hergestellten Beschichtungen zeigten nach einem Tag Inkubation eine wirksame antibakterielle Wirkung gegen S. aureus- und E. coli-Bakterien.
EPD wird häufig in der Beschichtungstechnik eingesetzt. In dieser Arbeit wird jedoch EPD zur Herstellung selbständiger und freistehender dreidimensionaler Formen für Anwendungen im Tissue Engineering vorgeschlagen. Ziel ist die erfolgreiche Herstellung einer neuartigen asymmetrischen Doppelschichtmembran für Anwendungen zur gesteuerten Knochenregeneration (GBR) mithilfe des EPD-Verfahrens. Membranen bestanden aus zwei Schichten, nämlich einer dünnen, dichten Schicht und einer dicken, porösen Schicht. Die dichte Schicht besteht aus CS und eingebetteten MBGNs, während die poröse Schicht aus CS/Gelatine/MBGNs und Cu(II)-CS/Gelatine/MBGNs besteht. Die dichte Schicht wurde mit dem Phytotherapeutikum Naringin (Nar) weiter funktionalisiert. Die hergestellten Doppelschichtmembranen wurden mithilfe verschiedener physikalisch-chemischer und biologischer Charakterisierungstechniken umfassend charakterisiert. Die hergestellten Doppelschichtfilme waren stabil genug für die Handhabung und Anwendungen im Tissue Engineering. In beiden Schichten wurden stark verteilte und eingebettete MBGNs beobachtet. SBF-Studien bestätigten die Bildung von Hydroxylapatit in der porösen Struktur der Proben nach 7 Tagen. Der enzymatische Abbau zeigte ein kontinuierliches Abbauverhalten der hergestellten Filme. Die Freisetzung von Nar zeigte eine anfängliche stoßweise Freisetzung, gefolgt von einer kontinuierlichen anhaltenden Freisetzung. Es wurde die antibakterielle Wirkung von Cu(II) und Nar auf grampositive und gramnegative Bakterien beobachtet. Schließlich bestätigten Zellstudien die Zytokompatibilität der hergestellten Filme. Insgesamt bestätigen die in dieser Arbeit präsentierten Ergebnisse, dass EPD eine leistungsstarke und vielseitige Technik für multifunktionale Beschichtungen sowie für die freistehende dreidimensionale Filmherstellung ist. Die aktuelle Forschung eröffnet mehrere neue Forschungswege für den Einsatz von EPD im Rahmen der Anwendung zur Gewebereparatur und -regeneration
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn 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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