1,720,962 research outputs found
Endovascular Management Of Acute Carotid-Artery Dissection With Waxing and Waning Neurological Deficit: A Case Report.
No full textPURPOSE: To evaluate the feasibility and efficacy of emergent carotid stenting for an acute internal carotid artery (ICA) dissection.
CASE REPORT: A 51-year-old man was admitted to our emergency department's stroke unit 1 hour after the onset of left hemiparesis. Computed tomographic and transcranial Doppler scans showed no pathological findings, but the color Doppler study detected a double lumen in the right carotid bifurcation extending to the proximal ICA. Within the first 2 hours after admission, the patient's neurological status began to fluctuate; the NIH Stroke Scale (NIHSS) and Rankin scores evaluated each hour after admission ranged from 0 to 12 and from 0 to 3, respectively. Emergency carotid angiography confirmed the dissection of the bulb and proximal right ICA, which prompted implantation of 2 Wallstents from the internal to common carotid artery. Forty-eight hours later, the patient was almost totally asymptomatic with an NIHSS score of 1 and a Rankin score of 0; he was discharged on postoperative day 3. At 3 months, the patient was free of neurological symptoms and the stented carotid artery was patent.
CONCLUSIONS: In patients with fluctuating neurological signs and symptoms consistent with carotid artery dissection that are refractory to medical therapy, a stent can be placed to prevent permanent neurological deficits provided that the anatomical conditions are suitabl
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
Use of stress test in noninvasive hemodynamic evaluation of chronic peripheral arteheriopaties
No full text
Somatosensory evoked potentials versus locoregional anesthesia in the monitoring of cerebral function during carotid artery surgery: preliminary results of a prospective study.
No full textOBJECTIVE: to relate changes in somatosensory-evoked potentials (SEPs) with onset of neurological deficits in patients having carotid endarterectomy (CEA) under locoregional anaesthesia.
METHODS: a prospective study of 50 consecutive patients.
RESULTS: SEPs yielded an accuracy of 98%, specificity 100%, and sensitivity 89%. In all concordant cases the onset of a neurological deficit in awake patients corresponded to a 30--40% reduction in amplitude of N20-P25 waveforms. After shunting, the N20-P25 took 2--3 min to return to normal.
CONCLUSIONS: SEPs are associated with a 2% false negative rate. Their threshold for detecting cerebral ischaemia is lower than the currently reported value for patients under general anaesthesia. The time needed for evoked potentials (2--3 min) to return to normal after shunting limits their usefulness in verifying effective shunting
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