1,720,953 research outputs found
PRE-PROCEDURAL ROLE OF COMPUTED TOMOGRAPHY IN TRANSVENOUS LEAD EXTRACTION
No full textopenIntroduzione: L’estrazione transvenosa di elettrocateteri (TLE) mediante sheath meccaniche rotazionali bidirezionali è una procedura consolidata. Sebbene sia stata perfezionata, è ancora una procedura complessa ed esposta a potenziali complicanze anche maggiori, tra cui la lacerazione della vena cava superiore. Si dedica crescente attenzione alla capacità di identificare fattori di rischio preoperatori al fine di predire la complessità della procedura, tuttavia i dati sono scarsi. La tomografia computerizzata (TC) si sta rivelando in grado di definire i rapporti tra elettrocateteri e strutture venose. Scopi dello studio: Lo studio si prefigge di valutare se la TC pre-procedurale possa identificare caratteristiche ad alto rischio che siano in grado di predire la complessità della procedura di estrazione transvenosa di elettrocateteri. Materiali e metodi: Sono stati arruolati 93 pazienti consecutivi secondo protocolli di TLE e TC standardizzati. L’endpoint combinato definisce la complessità della procedura ed include la necessità di impiego di multipli sistemi, tra cui sheath di calibro maggiore e sistemi di recupero per via femorale. Risultati: Da Settembre 2018 a Maggio 2024, 93 pazienti sono stati sottoposti a TLE e TC. L’età mediana della popolazione era di 63 anni (IQR: 55-75). Il tempo di impianto mediano degli elettrocateteri era di 86 mesi (IQR: 42-151). LA TC ha rilevato occlusioni venose (n=11), stenosi venose (n=4), assenza di aderenze (n=40), aderenze <1 cm (n=4), aderenze ≥1 cm (n=33), decorso intramurale (n=16), decorso intraosseo (n=7), versamento pericardico (n=8), trombosi a ridosso dell’elettrocatetere (n=4) e discontinuità dell’elettrocatetere (n=1). La procedura è risultata complessa in 64 casi (68.8%). I pazienti con decorso intramurale alla TC avevano più frequentemente elettrocateteri da defibrillazione (n=11 vs n=13 e n=11; p=0.011). I pazienti con aderenze ≥1 cm associate o meno a decorso intramurale avevano elettrocateteri defibrillatori dual coil con maggiore frequenza (n=12 e n=3 vs n=6; p=0.028), un tempo di impianto maggiore (147 mesi [IQR 84-171] e 76.5 mesi [IQR 46.3-137.5] vs 55 mesi [IQR 23-121.5]; p=0.001) e la procedura di estrazione richiedeva più spesso l’uso di tool multipli (n=31 e n=14 vs n=32; p=0.047). I pazienti con aderenze moderate-severe hanno avuto procedure più complesse rispetto ai pazienti che non le avevano (n=39 vs n=10; p=0.019), necessitavano più frequentemente sheath potenziate (n=45 vs n=34; p=0.050) e tool multipli per l’estrazione (n=45 vs n=33; p=0.028). I pazienti che raggiungevano l’endpoint combinato avevano un tempo di impianto maggiore (125 mesi [IQR 76-162] vs 36 mesi [IQR 8-54]; p=0.001), più frequentemente elettrocateteri a fissaggio passivo (n=48 vs n=11; p<0.001) ed una maggiore durata della procedura (120 minuti [IQR 85-170] vs 90 minuti [IQR 70-130]; p=0.023). La presenza di decorso intraosseo è significativamente associata all’uso di snare (OR: 20.750; 95% IC: 3.138-137.189) e al rischio di failure procedurale (OR: 11.067; 95% IC: 1.492-82.095). La TC ha rilevato reperti non correlati agli elettrocateteri in 57 pazienti. Conclusioni: La tomografia computerizzata è in grado di predire la necessità di impiego di multipli tool durante la procedura di estrazione e fornisce informazioni circa il rapporto tra elettrocatetere e sistema vascolare. Tuttavia, non è in grado di predire la complessità intraprocedurale in quanto la severità e l’estensione delle aderenze rappresentano un surrogato del tempo di impianto degli elettrocateteri. Il riscontro di reperti accidentali è utile per approfondire il quadro del paziente.Introduction: Transvenous lead extraction (TLE) using bidirectional rotational mechanical sheaths is a well-established interventional procedure used mainly for pocket infections, endocarditis or lead malfunction. Although it has been perfected, it is still to be considered a complex procedure and exposed to potential even major complications, including laceration of the superior vena cava. Increasing attention is being paid to the ability to identify preoperative risk factors in order to predict the complexity of the procedure; however, data are scarce. Computed tomography is proving capable of defining the relationships between leads and venous structures.
Study Aims: The purpose of the study is to evaluate whether pre-procedural computed tomography (CT) can identify high-risk features that are able to predict the complexity of the transvenous lead extraction procedure.
Materials and methods: Ninety-three consecutive patients were enrolled according to standardized TLE and computed tomography protocols. The combined endpoint defined the complexity of the procedure and included the need for the use of multiple systems, including larger gauge sheaths and femoral retrieval systems (snare).
Results: From September 2018 to May 2024, 93 patients underwent TLE and CT. The median age of the population was 63 years (IQR: 55-75) and 75.3% were male. The median lead dwelling-time was 86 months (IQR: 42-151). CT detected vein occlusions (n=11), vein stenosis (n=4), absence of adhesions (n=40), adhesions <1 cm (n=4), adhesions ≥1 cm (n=33), lead embedded (n=16), intraosseous course (n=7), pericardial effusion (n=8), lead thrombus (n=4), and lead fracture (n=1). The procedure was defined as complex in 64 cases (68.8%). Patients with intramural course at CT had defibrillation leads more frequently (n=11 vs n=13 and n=11; p=0.011). Patients with adhesions ≥1 cm associated or not with intramural course had dual coil defibrillator leads more frequently (n=12 and n=3 vs n=6; p=0. 028), longer dwelling-time (147 months [IQR 84-171] and 76.5 months [IQR 46.3-137.5] vs 55 months [IQR 23-121.5]; p=0.001), and the extraction procedure required multiple tools more often (n=31 and n=14 vs n=32; p=0.047). Patients with moderate-severe adhesions had more complex procedures than patients without them (n=39 vs n=10; p=0.019), needed more frequently at least one enhanced sheath (n=45 vs n=34; p=0.050) and multiple tools for extraction (n=45 vs n=33; p=0.028). Patients who reached the combined endpoint had a longer implantation time (125 months [IQR 76-162] vs 36 months [IQR 8-54]; p=0.001), more frequently passive fixation leads (n=48 vs n=11; p<0.001) and longer procedure duration (120 minutes [IQR 85-170] vs 90 minutes [IQR 70-130]; p=0.023). The presence of intraosseous course was significantly associated with the use of snare (OR: 20.750; 95% CI: 3.138-137.189) and the risk of procedural failure (OR: 11.067; 95% CI: 1.492-82.095). CT scans also revealed findings unrelated to leads in 57 patients (61.3%).
Conclusions: Computed tomography can predict the need for multiple tool use during the extraction procedure and provides information about the relationship between the lead and vascular system. However, it cannot predict intraprocedural complexity because the severity and extent of adhesions are a surrogate for lead implantation time. The finding of incidental findings is useful to further investigate the patient's situation
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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