1,720,954 research outputs found
Lin-28B expression promotes transformation and invasion in human hepatocellular carcinoma
No full text許多microRNA (miRNA) 於人類癌症中常受抑制，如let-7 miRNA 家族。let-7 miRNA 家族除了調節癌細胞的自體更新(self-renewal)及腫瘤形成能力(tumorigenecity)外，於胚胎發育中也扮演重要角色。最近研究發現RNA結合蛋白(RNA-binding protein) Lin-28及Lin-28B會透過let-7的前趨物(precursor)於末端之尿嘧啶化(uridylation)並使之分解，以致let-7生合成減少。在肝癌細胞中，我們發現只有Lin-28B會高度表現，而Lin-28並沒有此現象。此外，Lin-28B較常表現於高度表現α胎兒蛋白並且分級(grade)較高的肝癌。於肝癌細胞株中，Hep3B及HCC36所表現的Lin-28B量最多，因此我們選擇這兩株細胞株為研究之用。我們利用RNA干擾的方式將其Lin-28B 敲減(knockdown)。利用轉殖Lin-28B載體，使Lin-28B過度表現於HA22T。Lin-28B被knockdown的細胞株Hep3B及HCC36在體外增生的速度降低。Lin-28B敲減的Hep3B細胞株在免疫不全小鼠(NOD/SCID mice)生成腫瘤的速率也下降。相反地，Lin-28B過度表現的HA22T細胞生長速度較快，且生成腫瘤的能力也較高。我們也發現過度表現Lin-28B的HA22T會引起上皮-間質轉化(Epithelial-mesenchymal transition)，而使其侵犯(invasion)及移動(migration)能力皆提高。由於Lin-28B與let-7 miRNA的密切關係，我們以大規模即時PCR陣列(Large-scale real-time PCR array)進一步研究，分析顯示Lin-28B所調節最主要的miRNA是let-7/mir-98家族。Lin-28B過度表現會使let-7所抑制的基因c-myc及HMGA2表現量增加； Lin-28B過度表現也會使受let-7控制的第一型類胰島素成長因子受體(IGF1R)表現量上升。我們的研究結果顯示，透過共同抑制let-7/mir-98家族及許多致癌基因途徑，Lin-28B於肝癌腫瘤形成及轉移扮演著重要的角色。In human cancers, multiple members of microRNAs (miRNA) are often repressed, such as the let-7 family miRNA. The let-7 family regulates self-renewal and tumorigenicity of cancer cells, and plays critical roles in embryonic development. The RNA binding proteins Lin-28 and Lin-28B are recently demonstrated to negatively regulate let-7 biogenesis by inducing terminal uridylation and degradation of the let-7 precursors. In this study, we showed that in hepatocellular carcinoma (HCC), only Lin-28B but not Lin-28 was highly expressed. Lin-28B expression in HCC was more frequently found in high grade tumors with high α-fetoprotein levels. Among the HCC cell lines, Hep3B and HCC36 expressed higher levels of Lin-28B than the other cell lines, and were chosen for gene knockdown of Lin-28B. HA22T cell line which had very low level or undetectable Lin-28B, was chosen for ectopic expression of Lin-28B. Knockdown of Lin-28B by RNA interference in the Hep3B and HCC36 led to suppressed proliferation in vitro and reduced in vivo tumor growth in NOD/SCID mice. In contrast, overexpression of Lin-28B in HA22T enhanced proliferation and tumorigenecity. Moreover, overexpression of Lin-28B induced epithelial-mesenchymal transition in HA22T cells, accompanied by increased invasion and migration capacity. To further delineate the role of Lin-28B in the expression of miRNA family, we did a large-scale real-time PCR array analysis. The results revealed that only let-7/mir-98 family members were regulated by Lin-28B. Lin-28B overexpression enhanced the expression of the known let-7 targets c-myc and HMGA2. In this study, we also found that Lin-28B enhanced the expression of type 1 insulin-like growth factor receptor (IGF1R) in a let-7-dependent manner. These findings highlight the important role for Lin-28B in tumor formation and invasion in HCC, through coordinated repression of the let-7/mir-98 family and induction of multiple oncogenic pathways
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
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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