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가교가능한 재조합 효소의 조직 재생적 적용
Get PDF학위논문(석사) -- 서울대학교대학원 : 공과대학 화학생물공학부(에너지환경 화학융합기술전공), 2024. 2. 황석연.Application of recombinant crosslinkable enzymes in tissue regeneration Ye Sol Kim School of Chemical and Biological Engineering The Graduate School of Engineering Seoul National University In tissue regeneration applications, adhesiveness is an essential function of the hydrogel for stable contact with the tissue. Here, hydrogel cross-linked by recombinant tyrosinase demonstrated potential for application as an adhesive hydrogel. Among four types of recombinant tyrosinase, Sa-Ty (Streptomyces avermitilis derived tyrosinase) was selected as a suitable enzyme for hydrogel formation in terms of biocompatibility and enzymatic activity at neutral pH with macromolecules. The properties of Sa-Ty hydrogel were compared with HRP (horseradish peroxidase) hydrogel, another enzyme commonly used in hydrogel formation. The different mechanisms for crosslinking in each enzyme resulted in different chemical bonds and functional groups that caused a notable difference in the adhesiveness of the hydrogel. The variance in adhesion properties was investigated through a lap-shear test in vitro, an incisional wound model, and a liver resection model in vivo. For further application of the Sa-Ty crosslinked adhesive hydrogel, the conductive polymer, poly(3,4-ethylenedioxythiophene): poly(styrene sulphonate), was mixed to form conductive hydrogel. The hydrogel not only showed conductivity but also exhibited injectability. In addition, piezoelectric fibers were prepared by electrospinning for electrical stimulation that facilitated cell migration. Here in, the integration of conductive hydrogel and a piezoelectric fiber exhibited the potential to accelerate skin tissue regeneration.조직 재생 응용 분야에서 접착력은 조직과의 안정적인 접촉을 위한 하이드로겔의 중요한 기능입니다. 여기서 재조합 티로시나아제에 의해 가교된 하이드로겔은 접착성 하이드로겔로 응용될 수 있는 가능성을 보여주었습니다. 4가지 종류의 재조합 티로시나아제 중 생체 적합성 및 고분자와의 중성 pH에서의 효소 활성 측면에서 하이드로겔 형성에 적합한 효소로 Sa-Ty (스트렙토마이세스 아베르미틸리스 유래티로시나아제)를 선택했습니다. Sa-Ty 하이드로겔의 특성을 하이드로겔 형성에 일반적으로 사용되는 또 다른 효소인 HRP(고추냉이 과산화효소) 하이드로겔과 비교했습니다. 각 효소의 가교 메커니즘이 다르기 때문에 화학 결합과 작용기가 달라 하이드로겔의 접착력에 현저한 차이가 발생했습니다. 또한 생체 내 절개 상처 모델과 간 절제 모델을 사용하여 접착 특성의 차이를 확인하였습니다. 또한, Sa-Ty를 이용한 접착성 하이드로겔의 추가적 적용을 위해 전도성 고분자 폴리(3,4-에틸렌 디옥시 티오펜) : 폴리(스티렌 설포네이트)를 혼합하여 전도성 하이드로겔을 형성했습니다. 이 하이드로젤은 전도성뿐만 아니라 주입성도 나타냈습니다. 또한 전기 자극을 통해 압전 섬유를 전기방사하여 세포 이동을 용이하게 하는 전기자극을 내는 압전 섬유를 제조했습니다. 전도성 하이드로겔과 압전 섬유를 사용하는 시스템은
상처 재생 과정을 촉진하기 위해 사용될 수 있습니다.Abstract i
Table of Contents . iii
Chapter 1. Appropriate recombinant tyrosinase for enhancing
tissue adhesiveness of hydrogel 1
1. Introduction 1
1.1. Functional hydrogel 1
1.2. Recombinant tyrosinase . 3
1.3. Purpose of research . 4
2. Materials and Methods 5
2.1. Synthesis and purification of recombinant tyrosinases . 5
2.2. In vitro biocompatibility of crosslinkable enzymes 6
2.3. Measurement of enzymatic activity of tyrosinases 7
2.4. Synthesis of hyaluronic acid-tyramine (HA-T) conjugate 8
2.5. In vitro biocompatibility of enzyme-crosslinked hydrogel . 9
2.6. Formation and characterization of HA-T hydrogels 10
2.7. Measurement of tissue adhesiveness . 11
2.8. In vivo incisional wound model 11
2.9. Histological analysis of accelerated wound closure 12
2.10. Measurement of Hemostasis . 13
3. Results and Discussion . 14
3.1. Recombinant tyrosinase for hydrogel crosslinking 14
3.2. Synthesis of HA-T conjugate . 19
3.3. Biocompatibility of enzymes and enzyme-crosslinked hydrogels
21
3.4. Rheological and mechanical analysis of enzyme-crosslinked
hydrogel 25
3.5. Adhesive properties of enzyme-crosslinked hydrogel 28
3.6. In vivo incisional wound healing . 30
3.7. In vivo hemostatic performance . 32
iv
4. Conclusion . 34
Chapter 2. Injectable and conductive hydrogel with piezoelectric
fiber for wound healing . 36
1. Introduction . 36
1.1. Conductive hydrogel 36
1.2. Electrical stimulation using piezoelectricity 37
1.3. Purpose of research 38
2. Materials and Methods 39
2.1. Preparation of hydrogels . 39
2.2. Rheological properties of the hydrogel . 39
2.3. Electrical conductivity of the hydrogel 40
2.4. Biocompatibility of conductive hydrogel 41
2.5. Fabrication of piezoelectric fiber 42
2.6. Cell scratch assay 43
3. Results and Discussion . 44
3.1. Preparation and characterization of hydrogel 44
3.2. Biocompatibility of hydrogel . 47
3.3. Preparation and characterization of piezoelectric fiber 49
3.4. In vitro wound healing ability of piezoelectric fiber 51
4. Conclusion . 53
References 54
Abstract in Korean . 57석
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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