1,720,954 research outputs found
Mechanistic Investigations on Transition Metal-Catalyzed Asymmetric Allylic and Propargylic Substitution Reactions
Full text linkForjar estereocentres altament congestionats de manera asimètrica és de gran interès per a la indústria química fina i
farmacèutica, ja que aquests motius estressats estèricament (normalment són estereocentres terciaris o quaternaris)
es troben dins de les estructures de moltes molècules bioactives i fàrmacs sintètics. En les últimes dues dècades,
s'han desenvolupat noves estratègies convergents utilitzant mètodes catalítics basats en metalls de transició (TM) que
ofereixen una manera convenient de formar compostos amb centres estereogènics tan atractius. Si bé les
transformacions que condueixen a aquests objectius han estat dominades durant molt de temps per l'ús de metalls de
transició de la segona fila, com ara Pd i Ir, treballs recents ha descobert el potencial important dels metalls de transició
de primera fila com el Cu, Ni i Co, que representen més sostenibles. i alternatives menys costoses.
El nostre grup ha desenvolupat diversos processos de substitució al·lílica asimètrica mediats per TM durant els darrers
8 anys, que abasten l'ús de metalls de 2a i 3a fila a 3d (de transició). Per tal de dissenyar més i noves metodologies
sostenibles per a la síntesi de bastides amb centres de carboni estereogènics terciaris/quaternaris, es planteja una
anàlisi acurada dels paràmetres de selectivitat i activitat que controlen aquestes transformacions.
Aquesta tesi presenta tres casos pràctics diferents que es centren en un racional mecanístic complet de les reaccions
de substitució al·líliques i propàrgíliques desenvolupades al nostre grup al llarg d'aquests últims anys.Forjar estereocentros altamente congestionados de manera asimétrica es de gran interés para la industria química
fina y farmacéutica, ya que estos motivos estéricamente estresados (por lo general, estereocentros terciarios o
cuaternarios) se encuentran dentro de las estructuras de muchas moléculas bioactivas y drogas sintéticas. En las
últimas dos décadas, se han desarrollado nuevas estrategias convergentes utilizando métodos catalíticos basados en
metales de transición (TM) que brindan una forma conveniente de formar compuestos que presentan centros
estereogénicos atractivos. Si bien las transformaciones que conducen a estos objetivos han estado dominadas
durante mucho tiempo por el uso de metales de transición de la segunda a la tercera fila, como Pd e Ir, un trabajo
reciente ha descubierto el potencial significativo de los metales de transición de la primera fila, como Cu, Ni y Co, que
representan más sostenible. y alternativas menos costosas.
Nuestro grupo ha desarrollado varios procesos de sustitución alílica asimétrica mediados por TM durante los últimos 8
años, que abarcan desde el uso de metales de segunda y tercera fila hasta metales de transición (transición). Con el
fin de diseñar más metodologías sostenibles y novedosas para la síntesis de andamios que presenten centros de
carbono terciario/cuaternario estereogénico, se plantea un análisis preciso de los parámetros de selectividad y
actividad que controlan estas transformaciones.Forging highly congested stereocenters in an asymmetric manner is of high interest to the fine chemical and
pharmaceutical industry as these sterically stressed motifs (typically being tertiary or quaternary stereocenters) are
found within the structures of many bio-active molecules and synthetic drugs. In the last couple of decades, new
converging strategies have been developed using transition metal (TM) based catalytic methods providing a
convenient way to form compounds featuring such appealing stereogenic centers. While transformations leading to
these targets have long been dominated by the use of 2nd 3rd row transition metals such as Pd and Ir, recent work
has uncovered the significant potential of first-row transition metals such as Cu, Ni and Co, which represent more
sustainable and less expensive alternatives.
Our group has developed various asymmetric allylic substitution processes mediated by TMs during the last 8 years,
spanning the use of 2nd and 3rd row to 3d (transition) metals. In order to design more and novel sustainable
methodologies for the synthesis of scaffolds that feature stereogenic tertiary/quaternary carbon centers, an accurate
analysis of the selectivity and activity parameters controlling these transformations is desired.
This thesis presents three different case studies that focus on a comprehensive mechanistic rational of allylic and
propargylic substitution reactions developed in our group over the year
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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