1,721,151 research outputs found
Cheng Zhe Jin
No full text학위논문(박사)----아주대학교 일반대학원 :의학과,2007. 8In recent years, cartilage tissue engineering for reconstruction or repair of a cartilage injury has been emerged as alterative solutions based on the application of selected chondrocytes and scaffold. The purpose of present study is to evaluate the feasibility of novel cell-derived extracellular matrix (ECM) scaffold on cartilage tissue engineering in vitro and in vivo as nude mouse and rabbit model.
Chapter I: A porous cell-derived ECM scaffold was prepared with a freeze-drying protocol using porcine chondrocytes. The ECM scaffold had highly uniform porous microstructure by scanning electron microscope (SEM). It showed an average pore diameter of 504±108um, a porosity of 90±10.4%, a surface area of 905±204 m2/g and a tensile strength of 0.34±0.09 MPa, respectively. In vitro study, Then, rabbit chondrocytes were seeded dynamically on the ECM scaffold and cultured for 2 days, 1, 2 and 4 weeks in vitro for analysis. The neocartilage-like tissue was observed after 1 week of culture, and the volume and compressive strength were significantly increased with culture time. The DNA, glycosaminoglycan (GAG) and collagen contents also increased gradually with time. Histological staining for GAG (Safranin O staining) and type II collagen (immunohistochemistry) showed sustained accumulation of the ECM molecules along with time, which gradually and uniformly filled the porous space in the ECM scaffold.
Chapter II: In vivo study as nude mouse, cell-seeded ECM scaffold was cultured for 2 days in vitro, and then implanted into the nude mouse subcutaneously. They were retrieved at 1, 2, and 3 weeks post-implantation. Under macroscopic analysis, the cartilage-like tissue formation matured by time and developed a smooth, white surface. And, the size of the neocartilage tissue increased slightly by the 3rd week and remained more stable. Total GAG content and the GAG/DNA ratio increased significantly by time in the chemical analysis. The histology exhibited a sustained accumulation of newly synthesized sulfated proteoglycans. Immunohistochemistry, Western blot, and RT-PCR clearly identified type II collagen at all time points. Compressive strength of in vivo neocartilage increased from 0.45±0.06MPa at 1 week to 1.18±0.17MPa at 3 weeks.
Chapter III: In vivo study as rabbit model, the knee defects were implanted with in vitro cultured tissue engineering cartilage using ECM scaffold and allogenic rabbit chondrocytes as 2days, 2, and 4 weeks (experimental group 2, 3, and 4), respectively. The left knee defects were not implanted as control (group 1). The maturity of cultured implants was evaluated by histological, chemical and mechanical assay in chapter I. The repair examination was evaluated with macroscope and histological assay at 1 and 3 months post-surgery. After 1 month, fibro/hyalinecartilge was found on histological examination in the group 1, 2 and hyalinecartilage was found in group 3, 4. However, a mature matrix and a columnar organization of chondrocytes can be observed with Saflanin-O staining in group 4 at 3 months. Moreover, the subchondral bone was well remodeled and the more type II collagen was expressed at that time in the group 4. Thus ICRS histological score were significantly increased in the group 4 at that time.
In conclusion, this study demonstrated that the novel cell-derived ECM scaffold could provide a promising environment for generating a high quality cartilage in vitro and in vivo as nude mouse. Moreover, the engineered cartilage using the cell-derived ECM scaffold and allogenic chondrocytes could regenerate the cartilage defects particularly when cultured mature cartilage provided better results.ABSTRACT i
TABLE OF CONTENTS iv
LIST OF FIGURES vi
LIST OF TABLES viii
I.INTRODUCTION 1
II.MATERIALS AND METHODS 10
III.RESULTS 21
IV.DISCUSSION 42
V.CONCLUSION 54
REFERENCES 55
국문요약 67Maste
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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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