1,720,977 research outputs found
Dynamic modulation of coronary arterio-venous communications
No full textA 62 year-old man with multiple coronary risk factors – including uncontrolled hypertension, smoking habit, abdominal obesity and family history of ischemic heart disease – was admitted to our Emergency Department for a prolonged episode of chest pain occurring at rest. He had no relevant past medical history except recently diagnosed chronic obstructive pulmonary disease; however, in the last year he suffered from sporadic episodes of effort angina (Canadian Class II–III) with spontaneous regression after few minutes of rest. During the last week he experienced worsening angina, with daily episodes of chest pain, mainly occurring during mild exertion but with some episodes occurring even at rest in the last two days. On admission the patient was symptomatic for angina. Physical examination was unremarkable, except for rhonchi and wheezing sounds in the chest, the blood pressure was 200/95 mmHg and the ECG revealed sinus tachycardia with ST segment elevation and QS waves in V1–V4 leads. Pharmacological treatment was immediately started with loading doses of Aspirin and Clopidogrel, iv. morphine, i.v. nitroglycerin and i.v. beta-blockers, with partial pain resolution. Cath lab team was promptly alerted for urgent coronary angiography. In the meantime, a trans-thoracic echocardiogram was performed, showing a hypertrophic and mildly dilated left ventricle with regional wall motion abnormalities in the left anterior descending (LAD) coronary artery territory: apical and mid septal akinesia, anterior wall hypokinesia. The estimated left ventricular ejection fraction was 35–40%. No other relevant findings. Fifteen minutes after the admission the patient was still mildly symptomatic for angina and ST segment elevation was still present on the ECG, although reduced, thus the patient was transferred directly to the cath lab to undergo coronary angiography. The selective right coronary angiography revealed significant stenosis of the posterolateral branch of the right coronary artery (RCA) and, more importantly, the presence of collaterals to the LAD and three artero-venous fistulae, which allowed the RCA to communicate with the pulmonary artery, the coronary sinus and a posterolateral branch of the cardiac venous system (Fig. 1A ). Prior to the selective angiography of the left coronary artery, the patient's chest pain resolved together with the concomitant resolution of the ST segment elevation. The left coronary angiography (Fig. 2C ) was performed and showed the presence of significant proximal LAD stenosis, likely representing the culprit lesion, which appeared spontaneously reperfused. Angiography also revealed sub-occlusion of the first diagonal and significant stenosis of the first obtuse marginal (OM) branch. Due to these findings, a new right coronary angiography was performed, which documented the disappearance of both arterial and venous communications (Fig. 1 B). Because of the spontaneous reperfusion of the culprit lesion, together with the total regression of symptoms and ST segment elevation, urgent revascularization was not deemed necessary. Furthermore, considering the presence of multivessel disease, a joint clinical case meeting with cardiac surgeons and invasive cardiologists was arranged and a staged PCI was felt to be the best treatment option and thus was scheduled the following day. A successful revascularization procedure was performed with the implantation of two everolimus eluting stents (EES), 2.75×23 mm on LAD and 2.75×32 mm on OM, and a POBA of the first diagonal branch with a 2.5×25 mm balloon. The patient was discharged with the indication to complete the percutaneous revascularization later. The pre-discharge echocardiogram confirmed global left ventricular dysfunction (LVEF 35–40%) with the above described regional wall motion abnormalities. One month later the revascularization was completed with an elective PCI of the posterolateral branch of the RCA with the implantation of another EES 2.75×16 mm and the angiography confirmed the complete disappearance of collateral circulation and arterio-venous fistulae (Fig. 2 D,E)
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
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