1,720,979 research outputs found
Sheath-Anchoring for Rail Guidewire Technique to Advance and Deploy Thoracic Endograft in Hostile Anatomy
No full textBackground: To describe a bailout technique to advance and precisely deploy thoracic endograft in the ascending aorta in case of difficulty crossing the aortic arch.Case Reports: A 73-year-old man presented with a large ruptured aneurysms in the descending aorta. During the TEVAR, stent-graft passage through the aortic arch was impossible due to the severe tor tuosity of the aor ta. The problem has been resolved using the sheath-anchoring rail guidewire (SARG) technique.Results: Through an axillary access, a snare was used to capture the stiff wire from the femoral access. A sheath was advanced over the stiff wire to the ascending aorta and placed there. By exploiting the grip of the sheath on the stiff in the ascending aorta, it was possible to handle the tension, move the delivery system through the arch and carefully deploy the graft.Conclusion: The SARG is a simple and quick learning technique which can be useful for Physicians dealing with complex aortic arch anatomy
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
Intraoperative Transit-Time Flow as a Predictor of Failure after Infrainguinal Revascularization with Heparin-Bonded Expanded Polytetrafluoroethylene Graft
No full textBackground: The heparin -bonded expanded polytetrafluoroethylene (He-ePTFE) conduit is an option for patients requiring infrainguinal revascularization (iIR), but the risk of failure may be unpredictable, especially in cases with poor run-off. Intraoperative transit -time flow (TTF) provides an automated and quantitative analysis of flow and may serve as an adjunct evaluation during surgical revascularization. The aim of this study was to assess TTF in patients undergoing iIR with He-PTFE at 3 referral hospitals and to establish a predictive flow threshold for graft occlusion. Methods: A prospective registry initiated in 2020 enrolled patients undergoing iIR using HePTFE for critical limb ischemia or severe claudication, and TTF measurement was analyzed. Preoperative assessments of anatomical and clinical characteristics were available for all patients. The HT353 Optima Meter (Transonic Systems Inc., Ithaca, NY, USA) was used in all procedures according to a standardized protocol. The institutional ethics committee approved the study. A predictive model using receiver operating characteristic curve analysis was utilized to establish the threshold of flow, and variables were compared. Anatomical and clinical evaluation were reported according to Rutherford grade, Global Limb Anatomic System and Wound, Ischemia, and foot Infection classification. The main outcome considered was the correlation between TTF and graft occlusion. Secondary outcomes included survival, other predictors of graft occlusion, freedom from major adverse cardiovascular events, and freedom from major amputation. Results: Among 68 patients, 55.8% had Rutherford 5-6, 45.6% had Global Limb Anatomic System 3 and 73.5% had Wound, Ischemia, and foot Infection 3-4. Distal anastomosis was at tibial level in 23.5% and mean diameter of conduit was 6.4 mm. Basal and postoperative TTF were 27.8 +/- 15.6 ml/min and 109.0 +/- 53.0 ml/min, respectively. After a mean follow-up of 18 +/- 13 months, 7 (10.9%) patients presented graft occlusion and 5 (7.8%) required major amputation. TTF threshold = 80 ml/min revealed a sensitivity and specificity of 81.8% (95% confidence interval 48.2-97.7) and 80.7% (95% confidence interval 68.1-90.0) respectively, and it was selected as cut-off for graft occlusion. Freedom from graft occlusion in patients with TTF >80 ml/min vs. TTF <= 80 ml/min at 6, 12, and 24 months was 95.7% (standard error (SE) = 0.030) vs. 65.5% (SE = 0.115), 95.7% (SE = 0.030) vs. 58.9% (SE = 0.120) and 90.9% (SE = 0.054) vs. 51.6% (SE = 0.126), P = 0.0003. No statistical difference in primary patency, secondary patency and limb salvage was observed. At multivariate analysis, distal anastomosis at tibial vessel (odds ratio 8.50) and TTF <= 80 ml/min (odds ratio 9.39) were independent predictors of graft occlusion. Conclusions: These results suggest that TTF may serve as a valuable tool in the management of iIR. A TTF measurement of <= 80 ml/min should be regarded as a predictor of graft occlusion, prompting consideration of additional intraoperative maneuvers to enhance arterial flow. Caution should be exercised in patients requiring direct tibial artery revascularization, as it represents a predictor of failure independent of TTF levels. Larger cohorts of patients and longer follow-up periods are necessary to confirm these findings
Novel application of custom-made stent-grafts with inner branches for secondary treatment after stent-graft migration of previous infrarenal endovascular aortic repair
No full textPurpose: We present a novel application of custom-made stent grafts (CMSGs) with inner branches to incorporate target vessels (TVs) as an alternative to fenestrations or directional branches for secondary treatment after stent graft migration of previous infrarenal endovascular aortic repair (EVAR).
Case report: Two consecutive patients with stent graft migration of previous EVAR were electively treated at our institution from January 1, 2018 through December 31, 2018. Stent graft migration was defined as radiologic evidence of stent graft displacement >10 mm. In both cases, a proximal type I endoleak was noted, and the residual infrarenal aorta above the previous endograft was unsuitable as the proximal landing zone for a nonfenestrated cuff. Repair was planned by means of a CMSG with 4 inner branches. The procedures were conducted in two-stage fashion to minimize the risk of spinal cord ischemia. The procedures were technically successful with a total of 8 TVs stented. Both patients did not suffer from any early (i.e., up to 30 days) major adverse events, and no access-site complications were noted. At one-year follow-up, computed tomography angiography showed regular placement of the CMSGs, widely patent TVs, absence of any type I or III endoleak, and stable sac size. No late reinterventions were recorded.
Conclusions: Secondary treatment of stent graft migration after previous EVAR is safe and feasible using CSMGs with 4 inner branches. This technique is effective as showed by stable sac size and 100% freedom from TVI at mid-term imaging follow-up. Larger cohorts and longer follow-up are needed to confirm the preliminary results
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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