1,720,982 research outputs found
Mechanische Kreislaufunterstützung bei Patienten im akuten kardiogenen Shock
Full text linkObjectives
Cardiogenic shock (CS) as the final stage of Heart failure (HF) is present in approximately 25% of cases and is associated with high mortality. Temporary mechanical circulatory support (MCS) is widely used for CS therapy. In our research, we investigated and compared different temporary MCS concepts based on microaxial intraaortic impeller pumps.
Methods
The data of all patients who received MCS with a temporary microaxial left ventricular impeller pump in the German Heart Center Berlin (DHZB) since 01/2016 were collected retrospectively and used for a database establishment. The obtained data were analyzed in regard to different clinical aspects and published.
This dissertation summarizes and describes the results of three major publications.
Results
The results of the pilot study demonstrated a 43% survival in 28 patients on isolated impeller pump support, as well as 44% in 9 CS patients on combination of v a ECLS and Impella. Preoperative cardiopulmonary resuscitation (CPR) and an arterial pH 7.45 were associated with poor outcomes.
In the second study, 70 patients were supported with Impella 5.0/5.5®. The overall 30 day survival was 51%. An increase in arterial lactate (OR 1.217 per 1 mmol/L; p=0.015) and CPR before implantation (OR 16.74; p=0.009) were identified as predictors of 30 day mortality on Impella support. A cut-off of 8 mmol/L for preoperative lactate showed a specificity of 0.944 and a sensitivity of 0.294 (OR 7.083, CI 1.422 35.28; p=0.017) for 30 day mortality. Based on these data, an algorithm for optimal short-term MCS therapy was developed and thereafter applied as a standardized operational procedure at the DHZB.
In my third analysis we compared the percutaneously implanted Impella CP® and larger surgical Impella 5.0/5.5®. In unadjusted cohorts the 30 day survival was significantly higher in the Impella 5.0/5.5® group (58% vs. 36%, p=0.021). After propensity score adjustment for relevant preoperative demographic and hemodynamic parameters, the 30 day survival was similar between the groups (OR 1.23, 95% CI [0.34-4.18], p=0.744).
Preoperative lactate levels above 8 mmol/L and CPR before implantation were associated with poor outcomes in both cohorts (OR 10.7, 95% CI [3.45-47.34], p<0.001; OR 13.2, 95% CI [4.28-57.89], p<0.001). Based on these results the selection algorithm from the second study was amended to include the use of percutaneous impeller pumps.
Conclusions
A total of 203 patients treated with different MCS devices were analyzed. Our studies demonstrated that temporary MCS with microaxial impeller pumps is a feasible treatment in CS patients.
In cases with preoperative CPR or lactate levels ≥ 8 mmol/L an advanced treatment concept with a combination of Impella and v a ECLS should be pursued. An algorithm based on these parameters may prove useful for optimal patient selection and to identify optimal temporary MCS in CS patients.Ziele
Kardiogener Schock (KS) als Endstadium der Herzinsuffizienz (HI) tritt in ungefähr 25% der Fälle auf und ist mit einer hohen Sterblichkeit assoziiert. Temporäre mechanische Kreislaufunterstützung (MKU) wird in der Therapie des KS eigesetzt. In unseren Studien wurden verschiedene Konzepte für temporäre MKU auf der Basis der mikroaxialen int-raaortalen Impellerpumpe untersucht und verglichen.
Methoden
Die Daten von allen im Deutschen Herzzentrum Berlin (DHZB) seit 01/2016 zur mecha-nischen Kreislaufunterstützung mit einem temporären linksventrikulären mikroaxialen Impellersystem versorgten Patienten*innen wurden retrospektiv in einer Datenbank ge-sammelt, analysiert und publiziert.
Diese Dissertation ist eine Zusammenfassung der Ergebnisse der drei wichtigsten Pub-likationen.
Ergebnisse
Die Ergebnisse der Pilotstudie zeigten ein Überleben von 43% bei 28 Patienten*innen unter isolierter mikroaxialer Impellerpumpentherapie, sowie 44% bei 9 Patienten*innen mit Kombination von v-a ECLS und Impella. Präoperative kardiopulmonale Reanimati-on (KPR) sowie ein arterieller pH 7,45 waren mit einem schlechteren Überleben assoziiert.
In der zweiten Studie wurden 70 Patienten*innen isoliert mit Impella 5.0/5.5® behandelt. Das 30-Tage-Überleben betrug 51%. Ein präoperativer Anstieg des arteriellen Laktatwertes (OR 1.217 pro 1 mmol/l; p=0.015) sowie KPR (OR 16.74; p=0.009) wurden als Prädiktoren für die 30-Tage-Mortalität identifiziert. Ein arterielles Laktat von 8 mmol/l wies hierbei eine Spezifität von 0.944 und eine Sensitivität von 0.294 (OR 7.083, CI 1.422–35.28; p=0.017). Auf der Basis dieser Daten wurde ein Algorithmus für die Behandlung des KS mittels temporärer MKU entwickelt und folglich im DHZB im Rahmen einer SOP festgelegt.
In meiner dritten Analyse haben wir die perkutan implantierbaren Impella CP und die größeren chirurgischen Impella 5.0/5.5® Systeme verglichen. Das nicht adjustierte 30-Tage-Überleben war signifikant höher in der Impella 5.0/5.5® Kohorte (58% vs. 36%, p=0.021). Nach der Propensity-Score-Adjustierung waren die Kohorten ähnlich (OR 1.23, 95% CI [0.34-4.18], p=0.744). Ein präoperativer Laktatwert über 8 mmol/L sowie präoperative KPR gingen mit einer erhöhten Mortalität einher (OR 10.7, 95% CI [3.45-47.34], p<0.001; OR 13.2, 95% CI [4.28-57.89], p<0.001). Der Algorithmus aus der zweiten Studie wurde auf der Basis neuer Ergebnisse um die Anwendung der perkutan implantierbaren Impellerpumpen erweitert.
Schlussfolgerung
Insgesamt wurden von mir 203 Patienten*innen mit verschiedenen MKU-Systemen ana-lysiert. Unsere Studien haben gezeigt, dass mikroaxiale Impellerpumpen eine effektive Therapie im KS darstellen.
Präoperative KPR sowie Laktatwerte ≥ 8 mmol/L sollten eine erweiterte Therapie bestehend aus einer Kombination von einer Impellerpumpe und v-a ECLS nach sich ziehen. Ein Algorithmus basierend auf diesen Erkenntnissen kann helfen eine optimale temporäre MKU-Therapie auszuwählen
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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