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Valutazione non invasiva mediante TC multislice delle sindromi coronariche acute senza sopraslivellamento del tratto ST
No full textScopo: Il quadro clinico dei pazienti con sindrome coronaria acuta (SCA) può essere atipico, con enzimi miocardiospecifici normali ed elettrocardiogrammi non diagnostici. Una percentuale dei pazienti (2-8%) con SCA giunti in pronto soccorso, viene erroneamente dimessa. Spesso i pazienti con angina instabile (UA) o infarto miocardico senza sopraslivellamento del tratto ST (NSTEMI) possono presentare malattia coronarica multivasale o lesioni critiche dei rami principali prossimali; è importante quindi una stratificazione del rischio per la scelta del timing terapeutico ottimale. Scopo del nostro studio è stato quello di valutare il ruolo della TCMS nella stratificazione del rischio di questi pazienti, confrontando tale tecnica con un’analisi clinica, biochimica e di funzionalità miocardica.
Materiali e Metodi: Sono stati arruolati nello studio 47 pazienti consecutivi (34 maschi, 13 femmine; età media 63.3 ± 11,6 anni) con NSTEMI (94%) o UA (6%). E’ stata effettuata una valutazione clinico-anamnestica, biochimica, elettrocardiografica ed ecocardiografica. Entro 12 ore dall’ingresso tutti i pazienti sono stati sottoposti ad esame TCMS 64-strati e suddivisi in monovasali, bivasali, trivasali, con patologia e del tronco comune e con stenosi < 50%. Successivamente tutti i pazienti sono stati sottoposti ad esame coronarografico.
Risultati: La TCMS ha mostrato una sensibilità nell’identificare malattia coronarica del 97%, una specificità dell’83%, un valore predittivo negativo dell’83%, un valore predittivo positivo del 97% ed un’accuratezza diagnostica del 95%. Un solo paziente con malattia coronarica, con un’importante componente vasospastica, non è stato identificato alla TCMS. La concordanza della TCMS con l’esame coronarografico nell’identificazione di pazienti monovasali, bivasali, trivasali, con malattia del tronco comune e con stenosi < 50% è stata rispettivamente dell’83%, 81%, 82%, 78%, 80%. Nessuno dei parametri clinici, biochimici, elettrocardiografici ed ecocardiografici ha invece mostrato una correlazione con l’estensione della malattia coronarica. Il 58% delle lesioni culprit aveva una componente lipidica, l’11% calcifica, il 30% mista. La TCMS ha identificato la lesione culprit della SCA nell’86% dei casi (densità media della placca: 76 ± 41 HU, densità minima: 50,9 ± 29 HU) e il vaso responsabile nel 92%.
Conclusioni: La TCMS è risultata affidabile nella stratificazione del rischio di pazienti con NSTEMI e UA, avendo correlato con l’estensione della malattia, avendo identificato i pazienti con malattia coronarica nel 97% dei casi e avendo identificato e caratterizzato la lesione responsabile. I dati clinici, elettrocardiografici, enzimatici ed ecocardiografici invece non si sono dimostrati utili strumenti nella stratificazione del rischio in tale gruppo di pazienti.Rationale and Objectives: Clinical presentations in acute coronary syndrome (ACS) are sometimes atypical consisting in normal initial cardiac enzymes and nondiagnostic electrocardiogram. Previous studies have found that between 2% and 8% of patients with ACS who present to the emergency department are inappropriately discharged home. Unstable angina and non-ST elevation myocardial infarction (NSTEMI) patients have usually multivessel disease or proximal coronary vessel disease and a non invasive coronary evaluation could be useful for risk stratification and for an optimal therapeutic strategy timing. The aim of our study was to evaluate multislice computed tomography (MSCT) role in risk stratification of ACS without ST elevation, comparing this technique with a clinical, biochemical and echocardiographic analysis.
Materials and Methods: Forty-seven consecutive patients (34 male, 13 female; mean age: 63.3 ± 11,6 years) admitted because of ACS [NSTEMI (94%), UA (6%)] were enrolled. All patients underwent a clinical, biochemical, electrocardiographic, echocardiographic evaluation. Sixty-four MSCT coronary angiography was performed in all patients within 12 hours of acute event. In a patient-based analysis all subjects were divided in 5 groups: 1-vessel, 2-vessels, 3-vessels, left main and non significant disease. Selective coronary angiography was performed within 12 hours after MSCT.
Results: Sensitivity, specificity, negative predictive value, positive predictive value and accuracy of MSCT for detecting coronary artery disease (CAD) were 97%, 83%, 83%, 97% and 95%, respectively. Only one patient with CAD and a vasospastic component was non identified by MSCT. MSCT correlation with coronary angiography in the identification of 1-vessel, 2-vessels, 3-vessels, left main and non significant disease patients was respectively 83%, 81%, 82%, 78%, 80%. Clinical, biochemical, electrocardiographic, echocardiographic parameters were not able to correlate with CAD severity and extension. Culprit lesion composition was lipidic in 58% of cases, calcified in 11%, mixed in 30%. MSCT identified ACS culprit lesion in 86% of patients (mean plaque density 76 ± 41 HU, minimum plaque density 50,9 ± 29 HU) and culprit vessel in 92% of cases.
Conclusions: In the majority of cases, MSCT definitively and non invasively establishes or excludes CAD as the cause of chest pain. Our results show that 64-slice CT is an accurate non invasive technique to detect CAD in NSTEMI/UA patients, useful for risk stratification, assessing CAD extension and culprit lesion composition. Clinical, biochemical, electrocardiographic, echocardiographic parameters resulted not useful in risk stratification in this group of patients
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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