1,720,972 research outputs found
Bereitstellung einer soliden Grundlage für microRNA Engineering in CHO Zellen
No full textChinesische Hamster Ovarien (CHO) Zellen sind die Zellfabrik der Wahl für die Produktion von komplexen, menschenähnlichen therapeutischen Proteinen. Viel Aufwand wurde aufgebracht, um diese Zellen zu optimieren, insbesondere durch gentechnische Veränderungen. Eine neue Methode ist die Verwendung von microRNAs (miRNAs), um Zellen in Richtung gewünschter Phänotypen zu lenken. Seitdem die erste genomische Sequenz von CHO Zellen im Jahr 2011 veröffentlicht wurde, wurden Bemühungen unternommen, um miRNAs im CHO-Genom zu identifizieren und zu annotieren. Wie es bei anderen Spezies gezeigt worden ist, sind miRNAs oft in chromosomaler Nähe zueinander (miRNA Cluster) angeordnet, und werden gemeinsam transkribiert und reguliert. Der Schwerpunkt dieser Arbeit war es, die neu gewonnenen Sequenzinformationen zu verwenden, um endogene miRNA Cluster zu vervielfältigen und zu überexprimieren, und ihre Wirksamkeit zu chimären zu vergleichen, welche in CHO-Zellen in der prä-genomischen Sequenz Ära Stand der Technik waren. Außerdem, um miRNAs, welche mit dem Zellwachstum verbunden sind, zu identifizieren, wurden die miRNA Expressionsprofile von mehreren CHO-Zelllinien in verschiedenen Kultiviergefäßen und Wachstumsphasen analysiert und es zeigte sich, dass mehrere miRNAs eine konstante Korrelation zur Wachstumsrate aufweisen.Chinese Hamster Ovary (CHO) cells are the cell factory of choice when producing complex human-like therapeutic proteins. Lots of effort has been taken to optimize these cells, especially by using genetic engineering. A novel method is the use of microRNAs (miRNAs) to drive cells towards desired phenotypes. When the first genomic sequence of CHO cells became publicly available in 2011, effort has been taken to identify and annotate miRNAs in the CHO genome. As it has been shown in other species, miRNAs are often located in close chromosomal proximity to each other (miRNA cluster), and are transcribed and regulated jointly. The focus of this thesis was to use the newly gained sequence information to amplify and overexpress endogenous miRNA cluster, and compare their effectivity to chimeric ones, which were state-of the art in CHO cells in the pre-genomic sequence era. In addition, to identify miRNAs connected to cell growth, miRNA expression profiles of several CHO cell lines in different cultivation vessels and growth phases were analyzed and indicated several miRNAs constantly correlating to the growth rate.eingereicht von: Dipl.-Ing. Gerald KlanertZusammenfassung in deutscher SpracheAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersDissertation Universität für Bodenkultur Wien 201
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
Enhancing Chinese Hamster Ovary cell phenotype : opportunities of microRNA engineering and cell sorting
No full textSeitdem Chinese Hamster Ovary Zellen im großen Umfang für die Herstellung von therapeutischen Proteinen verwendet werden, ist es wichtig, die Leistung der Produktionszellinien zu verbessern. Wir haben versucht, die Effizienz der Zellen durch microRNA Engineering und durch eine Kombination von Sortierung und Farbstoffverdünnung (engl.: Dye dilution) zu verbessern. Ein artifizieller und ein endogener miR221-222-Cluster wurden transfiziert, um die Auswirkungen auf den Zell-Phänotyp zu untersuchen. Die Ergebnisse zeigten, dass kein verbesserter Zell-Phänotyp entstanden ist, jedoch war die Anzahl der reifen MicroRNAs im artifiziellen Cluster sehr viel niedriger als im endogenen, vermutlich aufgrund unterschiedlicher Reifung. Die Überexpression des endogenen miR23b~24-2~27b Cluster führen zu einer erhöhten Produktivität und der spezifische Knockdown von miR21 führte zu einer besseren Leistung der Zelle unter suboptimalen Bedingungen. Zur Verbesserung der zellulären Wachstumsraten wurde eine neue Methode zur Farbstoffverdünnung für heterogen gefärbten Zellpopulationen entwickelt. Das Einfügen einer anfänglichen Sortierung führte zu einer homogen gefärbten Zellpopulation aus der es möglich war, die Zellteilung über einen begrenzten Zeitraum (48 – 72 Stunden) zu beobachten. Obwohl die Isolation von Zellen mit der höchsten Teilungsrate keine verbesserte Wachstumsrate hervorbrachte, kann diese Prozedur für viele andere Untersuchungen, welche von heterogen gefärbten Zellen ausgehen, angewendet werden.Since Chinese Hamster Ovary cells are extensively used for the production of therapeutic proteins, it is important to improve the performance of the producer cell lines. We tried to enhance the efficiency of the cells by microRNA engineering and by a combination of sorting and dye dilution. An artificial and an endogenous miR221-222 cluster were transfected to examine the impact on the cell phenotype. The results showed that no enhanced cell phenotype was obtained, but the mature MicroRNA levels were much lower in the artificial cluster than in the endogenous one, presumably due to different processing. The overexpression of the endogenous miR23b~24-2~27b cluster lead to an increased specific productivity and the knockdown of miR21 induced better cell performance under suboptimal conditions. To increase cellular growth rates a new method for dye dilution was implemented for heterogeneously stained cells populations. The addition of an initial sorting step led to a homogeneously dyed cell population from which it was possible to monitor cell division over a limited period of time (48 – 72 hours). Although sorting for cells with the highest division numbers did not improve the growth rate, this procedure can be applied to many other investigations that start out with heterogeneously stained cells.submitted by Gerald KlanertWien, Univ. für Bodenkultur, Masterarb., 2012Zsfassung in dt. Sprach
Bereitstellung einer soliden Grundlage für microRNA Engineering in CHO Zellen
No full textChinesische Hamster Ovarien (CHO) Zellen sind die Zellfabrik der Wahl für die Produktion von komplexen, menschenähnlichen therapeutischen Proteinen. Viel Aufwand wurde aufgebracht, um diese Zellen zu optimieren, insbesondere durch gentechnische Veränderungen. Eine neue Methode ist die Verwendung von microRNAs (miRNAs), um Zellen in Richtung gewünschter Phänotypen zu lenken. Seitdem die erste genomische Sequenz von CHO Zellen im Jahr 2011 veröffentlicht wurde, wurden Bemühungen unternommen, um miRNAs im CHO-Genom zu identifizieren und zu annotieren. Wie es bei anderen Spezies gezeigt worden ist, sind miRNAs oft in chromosomaler Nähe zueinander (miRNA Cluster) angeordnet, und werden gemeinsam transkribiert und reguliert. Der Schwerpunkt dieser Arbeit war es, die neu gewonnenen Sequenzinformationen zu verwenden, um endogene miRNA Cluster zu vervielfältigen und zu überexprimieren, und ihre Wirksamkeit zu chimären zu vergleichen, welche in CHO-Zellen in der prä-genomischen Sequenz Ära Stand der Technik waren. Außerdem, um miRNAs, welche mit dem Zellwachstum verbunden sind, zu identifizieren, wurden die miRNA Expressionsprofile von mehreren CHO-Zelllinien in verschiedenen Kultiviergefäßen und Wachstumsphasen analysiert und es zeigte sich, dass mehrere miRNAs eine konstante Korrelation zur Wachstumsrate aufweisen.Chinese Hamster Ovary (CHO) cells are the cell factory of choice when producing complex human-like therapeutic proteins. Lots of effort has been taken to optimize these cells, especially by using genetic engineering. A novel method is the use of microRNAs (miRNAs) to drive cells towards desired phenotypes. When the first genomic sequence of CHO cells became publicly available in 2011, effort has been taken to identify and annotate miRNAs in the CHO genome. As it has been shown in other species, miRNAs are often located in close chromosomal proximity to each other (miRNA cluster), and are transcribed and regulated jointly. The focus of this thesis was to use the newly gained sequence information to amplify and overexpress endogenous miRNA cluster, and compare their effectivity to chimeric ones, which were state-of the art in CHO cells in the pre-genomic sequence era. In addition, to identify miRNAs connected to cell growth, miRNA expression profiles of several CHO cell lines in different cultivation vessels and growth phases were analyzed and indicated several miRNAs constantly correlating to the growth rate.eingereicht von: Dipl.-Ing. Gerald KlanertZusammenfassung in deutscher SpracheAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersDissertation Universität für Bodenkultur Wien 201
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
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