1,720,954 research outputs found
Evaluation of the use of two distinct techniques to close the transatrial access to the pericardial space in swine during a week: negative pressure and occlusion device
No full textIntrodução: O Acesso epicárdico transatrial pode ser uma alternativa ao acesso subxifoide para mapeamento e ablação de arritmias que envolvem fibras subepicárdicas. Estudos anteriores não avaliaram a segurança dessa estratégia após a fase aguda. Objetivos: Avaliar no período de uma semana a segurança do acesso pericárdico através de punção do apêndice atrial direito em suínos, usando duas diferentes técnicas para evitar sangramento pericárdico ao término do procedimento: manutenção de pressão negativa no espaço pericárdico por aspiração da bainha ou liberação de um dispositivo para oclusão do orifício de acesso ao pericárdio. Métodos: Foi realizada punção transatrial em 20 animais, seguida de mapeamento e ablação da superfície epicárdica por pelo menos 30 minutos com os animais heparinizados que foram divididos em dois grupos ao termino do procedimento: grupo A - composto por 10 animais, nos quais foi realizada aspiração da bainha com manutenção de pressão negativa do espaço pericárdico por 30 minutos, após a reitrada do cateter de ablação; e grupo B - composto também por 10 animais, nos quais um dispositivo de para ocluir o orifício atrial na retirada da bainha do espaço pericárdico. Após uma semana de observação, os animais foram sacrificados para verificação da presença de hemopericárdio e avaliação anatômica e histológica do coração. Resultados: No grupo A, foi possível atingir a superfície epicárdica em 9/10 animais após a punção transatrial. Um dos animais apresentou hemopericárdio com rápida deterioração da condição hemodinâmica, seguida de parada cardíaca. A análise post-mortem revelou laceração do AAD como causa do óbito. Excluindo esse animal, o volume médio de sangue aspirado durante os procedimentos sem acidentes foi de 7,0 ml ± 5,0 ml após a retirada da bainha e de 60,0 ml ± 28,0 ml ao seu término. Após um período de observação de 7 dias, pericardite fibrino-hemorrágica foi identificada em 3 animais, e em 6 deles o pericárdio tinha o aspecto usual. No grupo B foi possível atingir a superfície epicárdica em todos 10 animais. Após a punção transatrial, o volume médio de líquido aspirado no espaço pericárdico foi 4,5 ml ± 1,6 ml e de 5,5 ml ± 2,0 ml ao término da sessão. O posicionamento adequado da prótese oclusora (Konar-MF VSD) ao final do procedimento foi obtido em 90% (9/10) dos animais. Houve deslocamento da prótese para o espaço pericárdico em um dos animais. Ocorreu um óbito no pós-operatório imediato secundário a pneumotórax maciço (motivo). Após o período de observação de sete dias a análise post-mortem demonstrou, pericárdio de aspecto habitual, ausência de sangue ou aderências no espaço pericárdico, com a prótese adequadamente posicionada no apêndice atrial direito em 8 animais. No animal em que ocorreu embolização da prótese houve intensa reação inflamatória, com formação de pericardite fibrino-\\hemorrágica. Conclusão: O acesso transatrial por punção direta do apêndice atrial direito, na vigência de heparinização, permite o mapeamento e ablação da superfície epicárdica com segurança. A retirada da bainha após a manutenção da pressão negativa adiciona segurança com baixo sangramento no espaço pericárdico, mas não impede sua ocorrência. O uso do dispositivo de oclusão previne o sangramento após a retirada da bainha do espaço pericárdico desde que adequadamente posicionado e evitou a ocorrência da pericardite hemorrágica após uma semana de observaçãoIntroduction: Transatrial epicardial access may be an alternative to subxiphoid access in mapping and ablating arrhythmias involving subepicardial fibers. Previous studies have evaluated the safety of this strategy only acutely. Objectives: to assess the safety of pericardial access through the right atrial appendix in pigs during a period of one week evaluation, using two distinct techniques to close the access hole: negative pressure or release of the occlusion device at the end of the procedure. Methods: Transatrial puncture was performed in 20 animals, followed by mapping and epicardial surface ablation in heparinized animals. They were divided into the A (10 animals, whose pericardial space sheath was removed, maintaining a negative pressure for 30 min) and B (10 animals, placing the occlusion device in the hole through which the sheath passes through the appendix) groups. After a one-week observation, the animals were sacrificed to assess both the presence of hemopericardium and the anatomy and histology of the heart. Results: In Group A (10 animals), reaching the epicardial surface was possible in 9 animals. After transatrial puncture, the mean volume of blood aspirated during the procedure was 7.0 ml ± 5.0 ml (excluding the animal that died); after sheath removal at the end, the mean volume was 60.0 ml ± 28.0 ml. After transatrial puncture, one animal evolved with a rapid deterioration of its hemodynamic condition followed by cardiac arrest. Post-mortem analysis revealed DAA laceration as the cause of death. After the observation period, fibrino hemorrhagic pericarditis was identified in three animals, and the pericardium had the usual appearance in six of them. In Group B (10 animals), reaching the epicardial surface was possible in all animals. After transatrial puncture, the mean volume of fluid aspirated into the pericardial space was 4.5 ml ± 1.6 ml. At the end of the mapping, the mean volume of blood aspirated was 5.5 ml ± 2.0 ml. Proper positioning of the occluding prosthesis (Konar-MF VSD) at the end of the procedure was achieved in nine (90%) of the animals (in one animal, embolization to the epicardium occurred). One death occurred in the immediate postoperative period, secondary to massive pneumothorax. After the observation period, post-mortem analysis showed pericardium with the usual appearance, absence of blood or adhesion in the pericardial space, and the prosthesis properly positioned in the right atrial appendix in eight animals. In the animal in which prosthesis embolization occurred, an intense inflammatory reaction was identified with the formation of fibrino hemorrhagic pericarditis. Conclusion: In swine, the transatrial access for mapping and ablation of the epicardial surface is possible by direct puncture of the right atrial appendix in the presence of heparinization with the survival of the animals within a one-week observation. Negative pressure adds security to the control of bleeding after the sheath has been removed from the pericardial space but it does not prevent bleeding to occur. The use of the occlusion device prevents bleeding after the sheath is removed from the pericardial space provided that it is properly positioned, thus preventing hemorrhagic pericarditis occurs within a one-week observatio
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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