121,899 research outputs found
Pushing the Limits proximally 1: Endovascular treatment of aortic arch disease with branch custom-made device
No full textN
Endovascular Management of Aortic Arch Disease
No full textEndovascular treatment of the aortic arch is an important challenge in the field of vascular surgery. Currently, open surgical repair of the aortic arch is still the gold standard in patients who are suitable for open surgery. The advantages of endovascular repair with mini-invasive approach are gaining interest in reducing rates of serious adverse events and expanding the indication to high-risk surgical patients. Different endovascular approaches are nowadays suitable to manage aortic arch diseases, and the type of repair depends on the clinical presentation, the lesion localization, the expertise of the surgical team, and the availability of endovascular devices. Elective and recommended options are fenestrated and branched custom-made endografts that are reaching high levels of results and experience in the main aortic centers. Parallel graft and in-situ/physician-modified options are instead considered as bail-out or urgent techniques. This chapter gives an overview on the indications, techniques, and results of the endovascular option for aortic arch diseases and some perspectives for future development in this intriguing and steeply rising field of vascular surgery
Short- and midterm outcomes of open repair and fenestrated endografting of pararenal aortic aneurysms in a concurrent propensity-adjusted comparison
No full textPurpose: To compare outcomes of patients treated for pararenal aortic aneurysms using fenestrated endovascular aneurysm repair (fEVAR) vs open surgical repair (OSR) in 3 high-volume centers.
MATERIALS AND METHODS:
A multicenter retrospective analysis was conducted of 200 pararenal abdominal aortic aneurysm patients electively treated with OSR (n=108) or fEVAR (n=92) from 1998 to 2015 at 3 tertiary institutions. Endpoints were 30-day morbidity and mortality, late reinterventions, visceral artery occlusion, and mortality. Analysis was conducted on the entire population and on a propensity score-matched population constructed on age, gender, coronary artery disease (CAD), and chronic renal failure.
RESULTS:
In the total cohort, fEVAR patients were significantly (p<0.001) older and had higher frequencies of CAD (p<0.001) and previous stroke (p=0.003). OSR patients had higher risk of perioperative morbidity (OR 2.5, 95% CI 1.09 to 5.71, p=0.033), specifically respiratory failure (OR 4.06, 95% CI 1.12 to 4.72, p=0.034). These findings were confirmed in the propensity-adjusted analysis, where cardiac complications were also higher after OSR (OR 12.8, 95% CI 0.07 to 0.21, p=0.02). No difference in perioperative mortality (2.2% in fEVAR vs 1.9% in OSR) was identified. Mean follow-up was 50 months (range 0-119). Four-year results showed higher survival (91.2% vs 69.3%, p=0.02) and freedom from reintervention (95.6% vs 77.8%, p=0.01) after OSR in the unmatched population, with a small but significant (p=0.021) difference in the risk of late visceral artery occlusion/stenosis after fEVAR. On propensity analysis, no differences in late survival were found between groups.
CONCLUSION:
fEVAR and OSR may afford similar early and midterm survival rates. Higher risks of perioperative systemic complications after OSR are counterbalanced by higher risks of late visceral vessel patency issues and need for reintervention after fEVAR. Both procedures are safe and effective in the long term in experienced centers, where patient evaluation should drive the treatment strategy
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
No full textAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
Additional Aortic Coverage With an Off The Shelf, Multibranched Endograft Compared With Custom Made Devices For Endovascular Repair of Pararenal Abdominal Aortic Aneurysms
No full textObjective: Pararenal abdominal aortic aneurysms (p-AAA) require complex endovascular aortic repair or open surgical repair with suprarenal clamping. Custom made devices (CMD), including fenestrated and branched endovascular aortic repair (F/B-EVAR) or off the shelf (OTS) multibranched devices, are available treatment options. The aim of this study was to determine the additional healthy aortic coverage using an OTS multibranched endograft vs. a CMD for the treatment of p-AAAs.
Methods: This was a retrospective single centre analysis of prospectively collected data. Consecutive patients with p-AAAs requiring a proximal landing zone above the coeliac artery (CA), planned and treated with CMDs (Zenith Fenestrated) between January 2017 and December 2021 were included in this study. Treatment with supracoeliac coverage using available OTS multibranched devices was simulated using available pre-operative images: T-Branch; E-nside; and TAMBE. Study endpoints included the need for additional proximal aortic coverage, and the number of the segmental arteries additionally covered proximally from the CA for OTS devices compared with CMDs.
Results: Eighty three patients with p-AAAs were treated with CMDs (all FEVAR), including juxtarenal AAAs (n = 46; 56%), suprarenal AAAs (n = 20; 24%), and short neck AAAs (n = 17; 20%). In this study, treatment with 249 (3 × 83) OTS endografts was simulated. When compared with CMDs, OTS devices required a mean of 74 ± 19 mm of additional proximal healthy aortic coverage from the CA (CMD: 33 ± 19 mm vs. OTS: 108 ± 6 mm; p ≤ .001), as well as an average sacrifice of 2.5 additional segmental arteries (CMD: 1.3 ± 0.8 vs. OTS: 3.8 ± 0.9; p ≤ .001). In 94% of patients, at least one of the available multibranched endografts could have been implanted in accordance with instructions for use.
Conclusion: Despite not requiring customisation time, OTS endografts for the treatment of p-AAA lead to more extensive healthy aortic coverage, as well as an average sacrifice of 2.5 additional segmental arteries, compared with CMDs. When compared with OTS devices, CMDs appear to limit the extent of unnecessary aortic coverage and the theoretical subsequent risk of spinal cord ischaemia
Dissipative Range Scaling of Higher Order Structure Functions for Velocity and Passive Scalars
No full textDifferently to Kolmogorov's second similarity hypothesis, we find that the 2n-th order velocity and scalar structure functions scale with n-th order moment of the energy dissipation and the scalar dissipation, respectively. The origins of this scaling are analyzed by the transport equations of the fourth order velocity and scalar increment moments and by direct numerical simulations
Fast implementation of iterative adaptive approach for wideband unambiguous radar detection
No full textAccepted author manuscriptMicrowave Sensing, Signals & System
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