1,720,991 research outputs found
The Carbon Dioxide Flushing Technique: A Novel Approach Using Oxygen Measurements to Evaluate the Elimination of Room Air from Thoracic Stent-Grafts
No full textSchlaganfälle und stille Hirninfarkte (SHI) gehören nach wie vor zu den schwerwiegendsten Komplikationen von TEVAR-Prozeduren. Eine potentielle Ursache für zerebrale Embolien ist die möglicherweise freigesetzte Luft aus den Stentgrafts. In vorherigen Arbeiten konnte eine deutliche Verringerung der freigesetzten Gasmenge durch die Zugabe von CO2 zur Standardspülung der Stentgrafts erreicht werden. Dabei ist der genaue Mechanismus nicht sicher nachvollzogen. In dieser Studie soll durch direkte Sauerstoffmessungen das Verhalten von CO2 im Gasgemisch, welches aus den Stentgrafts freigesetzt wird, indirekt bewertet und nachvollzogen werden.
Zehn Zenith TX2 ProForm Stentgrafts (ZDEG-PT-34-199-PF, Cook Medical, Bjæver-skov, Dänemark) wurden gleichmäßig in 2 Gruppen aufgeteilt. Eine Gruppe wurde mit 60 ml 0,9%iger Kochsalzlösung gespült. Die andere Gruppe wurde mit 100 % Kohlendioxidgas und anschließend mit 60 ml 0,9 %-iger Kochsalzlösung gespült. Die Stentgrafts wurden in einem gebogenen Kunststoffrohr freigesetzt, der auf dem Boden eines mit Wasser gefüllten und durchsichtigen Gefäßes befestigt war, um die von den Stentgrafts freigesetzte Luft aufzufangen. Anschließend wurde die Sauerstoffkonzentration (O2) und das Gasvolumen in dem freigesetzten Gas bestimmt.
Die Sauerstoffkonzentration war nach zusätzlicher Kohlendioxidspülung signifikant (p<0,001) niedriger als nach Standardspülung (18,5 % gegenüber 19,6 %).
Weiterhin war das Sauerstoffvolumen nach zusätzlicher Kohlendioxidspülung signifikant niedriger als ohne (0,18 ml vs. 0,32 ml, p=0,041). Die Gesamtmenge des freigesetzten Gases erschien mit der zusätzlichen Kohlendioxidspülung geringer aus als ohne (0,98 ml vs. 1,65 ml, p=0,058).
Wir gehen davon aus, dass CO2 einen Teil der Raumluft in den zusammengefalteten Stentgrafts ersetzt. Während der Spülung mit Kochsalzlösung und der anschließenden Ruhezeit wird CO2 absorbiert. Die geringere Menge an freigesetztem Gas und die niedrigere Sauerstoffkonzentration in der Gruppe mit zusätzlicher CO2-Spülung bestätigen unsere Annahme. Die Ergebnisse unterstützen die Hypothese, dass die Verwendung von CO2-Spülung dazu beitragen kann, bei der TEVAR-Prozedur Raumluft in den Stentgrafts durch ein weniger schädliches Gas zu ersetzen
Influence of music on cortical pain processing
No full textDas Experiment untersucht, welchen Einfluss Musik auf die Schmerzwahrnehmung hat und zeigt, welche neuronalen Mechanismen und Musikcharakteristika bei der kortikalen Schmerzmodulation durch Musik eine Rolle spielen.
Als Messmethode mit hoher zeitlicher und räumlicher Auflösung wurde die Magnetenzephalographie gewählt.This experiment investigates the influence of music on pain perception and shows, which neuronal mechanisms and characteristics of music play an important role in cortical pain processing during listening to music. Enabling high temporal and spatial resoution, 275-channel MEG was used for data aquisition
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
Design, evolution, and experience with the candy plug device for endovascular false lumen occlusion of chronic aortic dissections
No full textIntroduction: The management of the false lumen (FL) when dealing with aortic dissection is a crucial aspect since inducing its thrombosis is necessary in order to achieve aortic remodeling. One of the pitfalls of endovascular treatment of aortic dissection (AD) is retrograde distal FL perfusion and pressurization, which prevents FL thrombosis and thus aortic remodeling, while being associated with aneurysmal degeneration of the FL and poor long-term outcomes. Areas covered: Currently, there is no CE/FDA approved device for FL closure, however different techniques and devices have been proposed to overcome this challenge, the most known of which is the Candy Plug (CP). This review aims to describe the CP device, its implantation technique, and the available data in the literature (PubMed, Cochrane, and EMBASE databases; last queried, December 31, 2023). Expert opinions: While the treatment of AD remains technically challenging, the use of the CP technique to close any distal FL reperfusion proved to be feasible and safe with excellent rates of both technical and clinical success. Furthermore, recent studies have shown a quick learning curve with this technique
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
Combined Ascending Aortic Stent-Graft and Inner Branched Arch Device for Type A Aortic Dissection.
No full textPURPOSE
To report the use of the Zenith Ascend stent-graft in conjunction with the Zenith inner branched arch device to treat type A aortic dissection.
CASE REPORT
Five patients (mean age 66 years, range 52-78; 4 men) with type A aortic dissection (2 acute) and insufficient distal landing zones were treated with the Zenith Ascend stent-graft and inner branched arch devices to extend the distal landing zone. Left carotid-subclavian bypass was performed in a staged or simultaneous setting depending on the urgency of the condition. Technical success (no type I or III endoleak and successful revascularization of all supra-aortic vessels) was achieved in all patients. Median intensive care unit stay was 5 days (range 4-23) and the median hospital stay was 16 days (range 8-25). The 2 patients with acute dissection died in hospital and at 5 months, respectively. The 3 elective patients were followed for 7, 13, and 19 months, respectively. All had false lumen thrombosis with either a reduced or stable aneurysm diameter.
CONCLUSION
This limited experience demonstrated the feasibility and safety of the combined use of the Ascend stent-graft and inner branched arch devices. This strategy may sometimes be more beneficial than either stent-graft used alone
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