1,720,966 research outputs found
Natural History, Diagnosis, and Management of Type II Endoleaks after Endovascular Aortic Repair: Review and Update
No full textEndoleaks (ELs), defined as continued perfusion of the aneurysm sac despite stent-graft deployment, are the most common adverse event after endovascular aortic repair (EVAR) and account for most of the reinterventions. Type 2 EL (T2EL), caused by backflow of collateral arteries into the aneurysm sac, are the most frequently encountered and may account for the need for secondary interventions after EVAR in up to 40% of the cases. Contrast-enhanced ultrasound and magnetic resonance imaging may be better able to quantify and characterize low-flow T2EL as compared with computed tomography angiography. Support for conservative management of T2EL derives from the relatively high percentage of T2EL that will resolve spontaneously over a variable period (more than 30%) and the estimated low risk of post-EVAR rupture secondary to isolated T2EL (less than 1%). Current guidelines are that a conservative approach is appropriate for isolated T2EL without sac expansion while intervention is recommended when sac enlargement of ≥10 mm as compared with pre-EVAR is detected. Although generally safe, secondary interventions for T2EL are often unsatisfactory since persistence and recurrence are commonly encountered problems and long-term follow-up is mandatory. Further investigation is required to determine the factors associated with abdominal aortic aneurysm progression in the presence of isolated T2EL and the most cost-effective technique to manage this complication
Coverage of visible intercostal and lumbar segmental arteries can predict the volume of cerebrospinal fluid drainage in elective endovascular repair of descending thoracic and thoracoabdominal aortic disease: A pilot study
No full textOBJECTIVES Our goal was to identify anatomical and physiological factors that could predict the amount of cerebrospinal fluid (CSF) drainage in patients undergoing elective endovascular repair of descending thoracic and thoracoabdominal aortic disease. METHODS All consecutive elective endovascular procedures performed for descending thoracic or thoracoabdominal aortic disease between January 2015 and December 2017 were included in the study. Routine use of CSF drainage was established in all patients. The goal of drainage was to reach a spinal fluid pressure of 10-12 mmHg by draining in 5-15-ml aliquots. The number of visible intercostal and lumbar segmental arteries (SAs) was evaluated before and after endovascular repair. The covering ratio of SAs was calculated as covered preoperative SAs/total preoperative SAs. RESULTS Twenty-four consecutive patients were included in the final analysis. The indication for the intervention was a descending thoracic aneurysm in 13 cases, a thoracoabdominal aneurysm in 4 cases and a chronic type B dissection in 7 cases. The procedure performed was thoracic endovascular aortic repair in 20 cases and fenestrated endovascular aneurysm repair in 4 cases. None of the patients developed spinal cord ischaemia. The mean volume of CSF drained was 46 ml. The mean length of aortic coverage was 231 mm. The mean number of total preoperative SAs and of covered preoperative SAs was, respectively, 22 and 9. The volume of CSF drained was significantly correlated with all these variables (length of aortic coverage, total visible SAs and covered SAs), but the most powerful correlation was individuated with the covering ratio of SAs. CONCLUSIONS Our findings suggest that the percentage of intercostal and lumbar SAs covered by placement of a stent graft can predict the volume of CSF drained in patients undergoing elective endovascular repair of descending thoracic and thoracoabdominal aortic disease
INTRAOPERATIVE ILIAC ANGIOPLASTY AND DISTAL REVASCULARIZATION: IS IT AN EFFICACIOUS METHOD IN THE HIGH-RISK PATIENT?
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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
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