1,720,973 research outputs found
Mangan og hjertet: Intracellulær MR relaksasjon og vannutveksling over cellemembranen i hjertet
No full textNy kunnskap om billeddannelse av hjertet ved magnetisk resonans (MR) fremkommer i sivilingeniør Wibeke Nordhøys doktoravhandling ved Norges teknisk-naturvitenskapelige universitet (NTNU). Denne kunnskapen vil ha stor betydning for hvordan man kan finne fram til noninvasive undersøkelser, dvs. uten fysiske inngrep, av hjertemuskelens levedyktighet hos pasienter med tilstopninger i kransarterier (iskemisk hjertesykdom).
Mangan som kontrastmiddel og markør for levedyktighet (viabilitet)
Arbeidet har gitt ny kunnskap om mangan som intracellulær kontrastgiver og om vannutveksling i hjertemuskelen. Manganforbindelser har et stort potensial som kontrastmidler for MR av hjertet.
I dyreforsøk har Nordhøy vist hvordan det magnetiske sporstoffet mangan tas opp i hjerteceller via fysiologiske ionekanaler, og hvordan det øker kontrasten i MR-bilder ved å «lyse opp hjertecellene innenfra». Hun har også gitt viktige bidrag til forståelsen av hvordan man med MR kan skille mellom vann inne i og utenfor hjertecellene. I sum betyr dette at man har kommet et skritt videre mot at MR av hjertet vil gi gradert informasjon om nettopp hjertecellenes tilstand. Avhandlingen representerer derfor et viktig norsk bidrag til den internasjonale forskning innen molekylær billeddannelse.
Avhandlingen
Avhandlingen har tittelen «Manganese and the heart: Intracellular MR relaxation and water exchange across the cardiac cell membrane / Mangan og hjertet: Intracellulær MR relaksasjon og vannutveksling over cellemembranen i hjertet.» Avhandlingen er blitt til innenfor et tverrfaglig samarbeid mellom biofysiker, fysiologer og kjemikere med professor Per Jynge, Institutt for sirkulasjon og bildediagnostikk, NTNU, som hovedveileder og professor Jostein Krane, Kjemisk institutt, NTNU, som medveileder. Arbeidet har vært initiert via Norges forskningsråds strategiske universitetsprogram for medisinsk teknologi (SUP-I) i Trondheim. Det er finansiert av Norges forskningsråd, Det medisinske fakultet (NTNU) og Amersham Health.PhD i medisinsk teknologiPhD in Medical Technolog
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
Fundamentals of the Past : Cardioplegia: The First Period Revisited
No full textAlthough cardiac surgery has made an enormous progress during the last decades, the discipline has to cope with essential changes: Patients are increasingly cared for by cardiologists and therefore referred to the surgeon in a later stage of disease. Consequently, they are more often in an increasingly serious state or in advanced age with significant comorbidities. In order to meet the requirements of these different patient groups, cardiosurgical treatments require special protectional strategies for the heart in order to perform the planned operations safely. This book presents the latest knowledge of modern techniques of myocardial protection taking into consideration the different patient groups and current scientific strategies. Furthermore, it discusses present and future scientific approaches in myocardial protection and preservation.</p
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