1,720,985 research outputs found
Investigating the Clinical and Imaging Factors Associated with Outcome and Treatment Response to Acute Stroke Therapies
No full text© 2024 Vignan YogendrakumarPatients having an acute ischemic stroke are routinely offered treatment in the hope of rapidly restoring blood flow and, in the process, limiting damage to the brain. Thrombolytic medications, such as alteplase, are a mainstay of acute treatment and function by enhancing the activation of plasmin, the major enzyme involved in the breakdown of fbrin within a clot. However, the effectiveness of alteplase is limited in patients with severe strokes due to large clot burden (referred to as a large vessel occlusion). As a result, patients with a large vessel occlusion routinely require endovascular therapy, a procedure to mechanically remove the clot. A novel treatment, tenecteplase, shows promise as a potential replacement to conventional treatments. Using data from randomized controlled trials and a large multicenter prospective observational registry, this thesis examines tenecteplase in further detail - evaluating its effectiveness in relation to time, highlighting its relative strengths and weaknesses, and assessing its safety and efficacy in historically under-studied patient subgroups
Improving our Ability to Define and Predict Hematoma Expansion in Intracerebral Hemorrhage: A Detailed Analysis of Prospective Intracerebral Hemorrhage Cohorts
No full textSpontaneous intracerebral hemorrhage, the non-traumatic rupture of cerebral blood vessels, is the most devastating form of stroke. The disease is dynamic, unpredictable, and patients can worsen acutely within the first 24 hours secondary to hematoma expansion: re-bleeding of a baseline hemorrhage. Hematoma expansion is a major predictor of mortality and poor long-term outcome. This secondary analysis thesis proposes to advance the current understanding of this phenomenon through three separate research endeavors: 1) a scoping review of hematoma expansion prediction scores, 2) an independent validation of a non-contrast prediction score, and 3) an assessment and revision of the dichotomous definition of hematoma expansion used in clinical trials. These three projects will offer different contributions that will advance the science of intracerebral hemorrhage, a field where treatment options, outcome measures, and basic definitions, are all under active debate
Emerg Infect Dis
Full text linkEvidence of spinal cord involvement in Powassan virus infection is largely limited to mouse models. We report a case of a polio-like illness caused by Powassan virus infection in a 62-year-old man in Canada. Magnetic resonance imaging showed T2 hyperintensities in the anterior horns of the cervical spinal cord
Adaptive Trials in Stroke
No full textInclusion of adaptive design features in a clinical trial provides preplanned flexibility to dynamically modify a trial during its conduct while preserving validity and integrity. Adaptive trials are needed to accelerate the conduct of more efficient, informative, and ethical clinical research in the field of neurology. Stroke is a natural candidate for adoption of these innovative approaches to trial design. This Research Methods in Neurology article is informed by a scoping review that identified 45 completed or ongoing adaptive clinical trials in stroke that were appraised: 15 trials had published results with or without a published protocol and 30 ongoing trials (14 trials had a published protocol, and 16 trials were registered only). Interventions spanned acute (n = 28), rehabilitation (n = 8), prevention (n = 8), and rehabilitation and prevention (n = 1). A subsample of these trials was selected to illustrate the utility of adaptive design features and discuss why each adaptive feature was incorporated in the design to best achieve the aim; whether each individual feature was used and whether it resulted in expected efficiencies; and any learnings during preparation, conduct, or reporting. We then discuss the operational, ethical, and regulatory considerations that warrant careful consideration during adaptive trial planning and reflect on the workforce readiness to deliver adaptive trials in practice. We conclude that adaptive trials can be designed, funded, conducted, and published for a wide range of research questions and offer future directions to support adoption of adaptive trial designs in stroke and neurologic research more broadly
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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