1,720,953 research outputs found
Targeting the endoplasmic reticulum stress response in cancers with novel organometallic complexes
Get PDFThesis (MSc)--Stellenbosch University, 2024.ENGLISH ABSTRACT: Cancer continues to be a burden across the world, with breast cancer being the dominant cancer in women. Statistics released from the World Health Organisation each year reveal that, of the 10 million overall cancer deaths reported in 2020, 6.8% was due to breast cancer specifically. The well-known platinum-based drug, cisplatin, opened research into metallo-drug development specifically using ruthenium, rhodium and iridium. Inorganic drug discovery has, in recent years, shifted to using organometallic drug hybrids with known pharmacophores. Hybrids of breast cancer drugs, tamoxifen, 5-fluorouracil and paclitaxel linked to ferrocene and ruthenocene show good inhibitory effects against several cancer cell lines. Another pharmacophore studied is the antiplasmodial agent artesunate. Artesunate's mode of action is through the generation of reactive oxygen species, leading to endoplasmic reticulum stress and cell death. Dipyridyl ligands have shown good inhibitory activity against cancers linked to metal fragments. This project involves the synthesis and characterisation of novel organometallic complexes, containing dipyridyl-artesunate hybrids. The complexes were all obtained in moderate to good yields, with high purity. Characterisation done on these complexes include 1H and 13C NMR spectroscopy, FT-IR spectroscopy and electrospray ionisation mass spectrometry. The stability and solubility of these complexes were studied under physiological conditions to investigate how they could react once placed in an aqueous environment. The complexes were evaluated against two breast cancer cell lines, hormonal MCF-7 and onhormonal MDA-MB-231 and were found to have moderate to low activity against both cell lines. Complexes containing the artesunate moiety, TC1-TC3, showed higher activity compared to those without artesunate, LC1-LC3. LC1-LC3 showed low activity against the parasite Toxoplasma gondii and showed high cell viability. All complexes were relatively non-toxic against the normal breast cell line, MCF-12A and were selective for cancerous cells over normal cells.AFRIKAANSE OPSOMMING: Kanker bly 'n las regoor die wêreld, met borskanker wat die dominante kanker by vroue is. Statistieke, wat elke jaar van die Wêreldgesondheidsorganisasie vrygestel word, toon dat van die 10 miljoen algehele kankersterftes wat in 2020 aangemeld is, 6.8% spesifiek aan borskanker te wyte was. Die bekende platinum-gebaseerde middel, cisplatin, het navorsing geopen oor die ontwikkeling van metallo-geneesmiddels wat spesifiek rutenium, rodium en iridium gebruik. Die ontdekking van anorganiese geneesmiddels het in onlangse jare verskuif na die gebruik van organometaal-geneesmiddelsbasters met bekende farmakofore. Basters van borskankermiddels, tamoxifen, 5-fluorouracil en paclitaxel gekoppel aan ferroseen en rutenoseen toon goeie inhiberende effekte teen verskeie kankersellyne. Nog 'n farmakofoor wat bestudeer is, is die antiplasmodiale middel artesunaat. Artesunaat se werkingswyse is deur die generering van reaktiewe suurstofspesies, wat lei tot endoplasmiese retikulumstres en seldood. Dipiridielligande het goeie inhiberende aktiwiteit getoon teen kankers gekoppel aan metaalfragmente. Hierdie projek behels die sintese en karakterisering van nuwe organometaalkomplekse wat dipiridiel-artesunaatbasters bevat. Die komplekse is almal verkry in matige tot goeie opbrengste, met hoë suiwerheid. Karakterisering wat op hierdie komplekse gedoen word, sluit 1H en 13C KMRspektroskopie, FT-IR-spektroskopie en elektrosproei-ionisasie-massaspektrometrie in. Die stabiliteit en oplosbaarheid van hierdie komplekse is onder fisiologiese toestande bestudeer om te ondersoek hoe hulle kan reageer as dit in 'n waterige omgewing geplaas is. Die komplekse is geëvalueer teen twee borskankersellyne, hormonale MCF-7 en nie-hormonale MDA-MB-231 en daar is gevind dat dit matige tot lae aktiwiteit teen beide sellyne het. Komplekse wat die artesunaat-deel, TC1-TC3, bevat, het hoër aktiwiteit getoon in vergelyking met dié sonder artesunaat, LC1-LC3. LC1-LC3 het lae aktiwiteit teen die parasiet Toxoplasma gondii getoon en het hoë sellewensvatbaarheid getoon. Alle komplekse was relatief nie-giftig teen die normale borssellyn, MCF-12A en was selektief vir kankerselle bo normale selle.Master
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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