1,720,965 research outputs found
Functional MRI (fMRI) evaluation of hyperbaric oxygen therapy (HBOT) efficacy in chronic cerebral stroke: A small retrospective consecutive case series
No full textTopics: Functional Magnetic Resonance Imaging (fMRI) evaluation of HyberBaric Oxygen Therapy (HBOT) effects on chronic cerebral stroke Patients (Pts). Introduction: Our aim was to evaluate with fMRI, in a 3 Tesla system, the functional effects of HBOT on the Central Nervous System (CNS) in four Pts with established ischaemic and haemorrhagic cerebral strokes (2 Pts each). To our knowledge, no author used this Magnetic Resonance (MR) technique for this purpose, till now. Methods: All four Pts underwent a fMRI study before and after 40 HBOT sessions, with a time window of a few days. They carried out two language (text listening, silent word-verb generation) and two motor (hand and foot movements) tasks (30 s On-Off block paradigms). Results: After HBOT, all Pts reported a clinical improvement, mostly concerning language fluency and motor paresis. fMRI analysis demonstrated an increase in both the extent and the statistical significance of most of the examined eloquent areas. Conclusions: These changes were consistent with the clinical improvement in all Pts, suggesting a possible role of fMRI in revealing neuronal functional correlates of neuronal plasticity and HBOT-related neoangiogenesis. Although only four Pts were examined, fMRI proved to be a sensitive, non-invasive and reliable modality for monitoring neuronal functional changes before and after HBOT
A new approach for catheter ablation of atrial tachycardia following atrial fibrillation ablation.
No full textObjective The origin and mechanisms of focal and macro-re-entrant atrial tachycardia occurring after ablation of paroxysmal or persistent atrial fibrillation are difficult to determine and are often the cause of distress for both patients and electrophysiologists. The purpose of this study was to describe a novel practical approach which would be helpful in planning the treatment of atrial tachycardia in patients who had received prior atrial fibrillation ablation. We used an algorithm which aims to facilitate mapping and ablation strategies, using both conventional electrophysiological tools and a three-dimensional electroanatomic approach.
Methods We investigated a series of 40 patients with atrial tachycardia who had undergone a prior ablation procedure for paroxysmal or persistent atrial fibrillation with a step-wise approach. This approach consisted of four steps: the use of a decapolar catheter to assess the coronary sinus and an entrainment map to evaluate the cavotricuspid isthmus (CTI). If the CTI was not involved, we used a 20-pole dual-loop circular mapping catheter, AFocusII DL, to map the left atrium chamber rapidly during the rhythm of interest. We identified the target entrainment at the putative channels and performed catheter ablation at the critical isthmus of these macrocircuits until the restoration of sinus rhythm.
Results Seventy-five atrial tachycardias were identified in 40 consecutive patients (1.9 +/- 1.6 per patient). In 48, the mechanism was macro-re-entry, and the remaining 27 were focal. During 18 months of follow-up, the treated arrhythmia recurred in only three patients, whereas in another four patients, a different atrial tachycardia was observed. The remaining 33 patients maintained sinus rhythm.
Conclusion The increased acquisition speed by AFocusII DL facilitated the reconstruction of the geometric chamber, and the generation of an isochronal activation map reduced processing time and fluoroscopy time per patient, together with the radiation exposure and patient radiation dose. A novel algorithm combining both conventional electrophysiology and a three-dimensional electroanatomic approach for rapid diagnosis, accurate mapping and ablation of iatrogenic atrial tachycardias showed high reproducibility and a satisfactory overall success rate
UNFRACTIONED HEPARIN/CLOPIDOGREL INTERACTION IN PATIENTS WITH STEMI NOT UNDERGOING REPERFUSION
No full textBackground: A substantial proportion of patients with ST-segment elevation myocardial infarction (STEMI) do not receive reperfusion therapy.The aim of our study was to investigate the relative benefits of enoxaparine compared to unfractioned heparin (UFH) in association with clopidogrel in
STEMI patients not undergoing reperfusion therapy.
Methods: We enrolled 1440 consecutive patients with STEMI from 2007 to 2011. A total of 584 patients (40.6 %) did not receive reperfusion therapy. At admission, 223 were treated with enoxaparine and 292 patients with UFH. All patients received aspirin and/or clopidogrel. No significant differences were found in the concomitant medications between the group treated with enoxaparine compared to UFH treated patients.
Results: We found a significant interaction (p<0.001) between UFH and clopidogrel, consequently, we performed separate analysis for clopidogrel users and non users. After adjustment for cardiovascular risk factors, clinical history, time to hospitalization and in-hospital treatment with
clopidogrel and/or aspirin. UFH was associated (p=o.oo2) with a lower risk of in-hospital death in clopidogrel users (adjusted OR 0.38; 95%CI 0.30- 0.70). The rate of mortality in the association of enoxaparine and clopidogrel or enoxaparine and UFH alone, was not statistically significant (Figure).
Conclusions: We found evidence of UFH - clopidogrel interaction. The effect of UFH was favorable only in concomitant treatment with clopidogrel
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
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