1,720,956 research outputs found
Superficial vein thrombosis: differential diagnosis of circumscribed skin discolorations at autopsy
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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
Suctioning through a Double Lumen Endotracheal Tube helps to prevent alveolar collapse and to preserve ventilation
No full textEndotracheale Absaugung durch konventionelle einlumige Endotrachealtuben (SL-ETT) provoziert sowohl bei Durchführung im offenen wie auch im geschlossenen System alveoläre Kollapszustände, da mit subatmosphärischem Druck abgesaugt werden muß, der den Trachealdruck Ptr vermindert. Während endotrachealer Absaugung im offenen System fällt durch Diskonnektion von Patient und Beatmungsgerät der Trachealdruck Ptr auf Atmosphären-Niveau ab. Bei endotrachealer Absaugung im geschlossenen System resultiert durch den Druckabfall Delta P entlang des SL-ETT ebenfalls eine Verminderung von Ptr. Zudem kann es – bedingt durch den räumlichen Abstand vom Messort des Ptr und tatsächlichem Ptr – zu Verfälschungen des durch das Beatmungsgerät erhobenen Druckes kommen, so dass während endotrachealer Absaugung ein nicht der Realität entsprechender Beatmungsdruck vom Beatmungsgerät nachgeregelt wird. Bei Beatmung über einen doppellumigen Endotrachealtubus (DL-ETT) kann Ptr auch während endotrachealer Absaugmanöver auf eingestelltem Niveau gehalten werden, wenn dessen Inspirations- bzw. Exspirationslumina unabhängig voneinander an den Inspirations- bzw. Exspirationsschenkel des Beatmungsgerätes angeschlossen sind und das Beatmungsgerät während der Gaslieferung in Richtung Patient – also auch während endotrachealer Absaugung – den im Exspirationsschenkel gemessenen Druck der Regelung zugrundelegt.
Mit der vorgelegten Studie sollte überprüft werden, ob während endotrachealer Absaugmanöver durch einen DL-ETT alveoläre Kollapszustände vermieden werden können. Hierzu wurde an Schweinen mittels Lungenlavage ein Acute Respiratory Distress Syndrome (ARDS) mit erhöhter Kollapsneigung des Lungengewebes simuliert. Das Absaugen mit der neuen DL-ETT-Technik wurde bei jedem Tier mit konventionellem Absaugen im geschlossenen und im offenen System verglichen, die Daten wurden randomisiert.
Atemmechanik, Hämodynamik und Blutgase wurden sowohl während Absaugung als auch während Beatmung (vor / nach Absaugung) verfolgt; von einigen Tieren wurden Spiral-CT-Aufnahmen der Lunge angefertigt.
Es hat sich gezeigt, dass alveoläre Kollapszustände während endotrachealer Absaugmanöver im geschlossenen System durch die Verwendung eines DL-ETT vermieden werden können. Weiterhin ergaben sich folgende Vorteile:
· Verminderung des Totraumes;
· Verminderung des geräte-bedingten Widerstandes;
· Möglichkeit zur Anwendung einer Lungen-protektiven Beatmungsstrategie.INTRODUCTION
Tracheal suctioning through a single lumen endotracheal tube (SL-ETT) leads to a decrease in Ptr, loss of lung volume, and hypoxia. Extending the two limbs of ventilator tubing into the trachea via a double lumen ETT (DL-ETT) allows maintaining the set pressure in the trachea during suctioning. How beneficial is this for lungs prone to alveolar collapse?
METHODS
Seven anaesthetised pigs were subjected to lung lavage (PaO2/FiO2 < 100 mmHg at PEEP 5 mbar) and 3 runs (random) of ventilation and suction: 1 and 2 via SLETT (8 mm I.D.), 3 via DL-ETT (Mallinckrodt Bronchocath 41Fr O.D., lumina cut to equal length and connected separately to the limbs of the tubing). For suctioning (16 Fr catheter), in 1 the SL-ETT was disconnected, in 2 and 3 the systems stayed closed (CPAP mode). The ventilator (Siemens Servo 300) was modified to regulate pressure at Y-piece (SL-ETT) or trachea (DL-ETT) during CPAP. Sequence per run: 2 min PC ventilation (RR 15 / min, PEEP 30 mbar, Pinsp 60 mbar) for alveolar recruitment / 5 min of baseline ventilation (VC mode, RR 30/min, Vt 10-12 ml/kg, PEEP 16 mbar) / suction (20 s) / 5 min of baseline ventilation.
RESULTS
After recruitment, gas in lungs (CT, n=4) amounted to 1462 (1356/1558) ml and PaO2 to 532 (290/628) mmHg [mean(min/max)]. The suction flow of 20 l/min effected a dP along the SL-ETT of 8.0 (7.5 / 8.5) mbar and a relevant reduction of PaO2 and lung volume not seen with DL-ETT.
CONCLUSION
The DL-ETT technique is promising for ventilating patients with acutely injured lungs: Reduction of lung volume (= alveolar collapse) and subsequent re-recruitment, potentially damaging to lung tissue, can be reliably avoided even during suctioning
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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