1,721,036 research outputs found
Anticoagulant management for transition from failed thrombolysis to extra-corporeal membrane oxygenation in patients with high-risk pulmonary embolism: A thoughtful approach
No full textAcute venous thromboembolism represents a spectrum of clinical syndromes of which high-risk pulmonary embolism (PE) with consecutive right ventricular failure and cardiogenic shock (CS) is the most severe presentation. First-line treatment options are surgical pulmonary embolectomy, systemic thrombolysis or catheter-based therapies. The role of mechanical circulatory support with veno-arterial extracorporeal membrane oxygenation (V-A-ECMO) is multifarious in this setting and can be considered as either a bridge to pulmonary artery reperfusion by any of the aforementioned options or as salvage bridge intervention for patients in refractory CS after failure of another treatment. In the subpopulation of patients that are placed on V-A-ECMO after failed thrombolysis, the mortality rates are among the highest, partially due to the high rates of bleeding events. The challenges in the interpretation of anticoagulant monitoring and, consequently, the titration of anticoagulation at least contribute to this high mortality. Here, we discuss the strengths and limitations of different anticoagulant parameters in this setting and propose an approach based on monitoring of Heparin anti-factor Xa (anti-Xa) assay and activated partial thromboplastin time (APTT) in parallel to drive unfractionated heparin (UFH) titration in patients with high-risk PE after fibrinolysis during the first 24 h on V-A-ECMO.status: Publishe
How to unload the left ventricle during veno-arterial extracorporeal membrane oxygenation
No full textMechanical circulatory support in ventricular arrhythmias
No full textIn atrial and ventricular tachyarrhythmias, reduced time for ventricular filling and loss of atrial contribution lead to a significant reduction in cardiac output, resulting in cardiogenic shock. This may also occur during catheter ablation in 11% of overall procedures and is associated with increased mortality. Managing cardiogenic shock and (supra) ventricular arrhythmias is particularly challenging. Inotropic support may exacerbate tachyarrhythmias or accelerate heart rate; antiarrhythmic drugs often come with negative inotropic effects, and electrical reconversions may risk worsening circulatory failure or even cardiac arrest. The drop in native cardiac output during an arrhythmic storm can be partly covered by the insertion of percutaneous mechanical circulatory support (MCS) devices guaranteeing end-organ perfusion. This provides physicians a time window of stability to investigate the underlying cause of arrhythmia and allow proper therapeutic interventions (e.g., percutaneous coronary intervention and catheter ablation). Temporary MCS can be used in the case of overt hemodynamic decompensation or as a "preemptive strategy" to avoid circulatory instability during interventional cardiology procedures in high-risk patients. Despite the increasing use of MCS in cardiogenic shock and during catheter ablation procedures, the recommendation level is still low, considering the lack of large observational studies and randomized clinical trials. Therefore, the evidence on the timing and the kinds of MCS devices has also scarcely been investigated. In the current review, we discuss the available evidence in the literature and gaps in knowledge on the use of MCS devices in the setting of ventricular arrhythmias and arrhythmic storms, including a specific focus on pathophysiology and related therapies.sponsorship: Funding This manuscript adheres to the Ricerca Corrente Fondazione Policlinico San Matteo IRCCS (RCR-2021-23671212), from which the publication fees have been provided. (Ricerca Corrente Fondazione Policlinico San Matteo IRCCS, RCR-2021-23671212)status: Publishe
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
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