1,720,965 research outputs found
Aortic dissection and wall weakness : from clinical observation to preclinical model, new therapeutic approaches
No full textLa physiopathologie de la dissection aortique (DA) est complexe et les phénomènes qui aboutissent à la création d'une déchirure intimale sont pour l'instant incertains. La dissection implique une atteinte de la matrice extracellulaire (MEC) ainsi qu'un dysfonctionnement de la mécanotransduction de la cellule musculaire lisse (CML). Plusieurs pathologies génétiques humaines sont caractérisées par une atteinte d'un de ces deux mécanismes. Peu de modèles expérimentaux ont été mis au point pour explorer la conjonction de ces deux phénomènes afin d'essayer de reproduire au plus près la pathologie humaine. Dans une première partie, nous détaillerons l'atteinte pariétale dans un modèle humain de fragilité pariétale et de dissection : le syndrome de Marfan. Dans une seconde partie, nous décrirons un nouveau modèle expérimental murin de DA. Dans une troisième partie nous explorerons de nouvelles thérapeutiques précliniques et cliniques basées sur la diminution de la fibrinolyse pariétale. La description de la fragilité pariétale dans le syndrome de Marfan a permis de mettre en évidence une sous population de patients au phénotype cardiovasculaire sévère présentant notamment des anévrismes périphériques et un risque élevé de DA. Sensibilisés à la sévérité de l'atteinte pariétales dans cette maladie, nous avons proposé de nouvelles modalités techniques de réalisation du traitement endovasculaire des DA chez les patients atteint du syndrome de Marfan. Notre nouveau modèle expérimental basée sur une atteinte chimique de la MEC associée à une décompaction pariétale a permis d'induire une majoration de la dilatation aortique, une aggravation de la présentation clinique, et de reproduire de façon fidèle les caractéristiques histologiques des DA humaines. Enfin, l'inhibition de la fibrinolyse intrapariétale semble être une voie potentiellement intéressante pour freiner l'évolution de la dilatation sur ce modèle, étayant ainsi l'efficacité des techniques endovasculaire d'exclusion du faux chenal des DA humaines. Les connaissances sur l'atteinte pariétale artérielle dans le syndrome de Marfan ne cessent d'évoluer et permettent d'orienter les thérapeutiques endovasculaires. L'utilisation du nouveau modèle expérimental de DA par altération de la MEC et de la mécanotransduction pourra permettre de tester de nouvelles voies thérapeutiques.The physiopathology of aortic dissection (AD) is complex and the phenomena that result in the creation of an intimal tear remains unclear. The dissection involves extracellular matrix (ECM) damages as well as dysfunction of smooth muscle cell (SMC) mechanotransduction. Several human genetic pathologies are characterized by impairment of one of these two mechanisms. Experimental models have been developed to explore these phenomena and try to reproduce human pathology as closely as possible. In the first part, we will detail the arterial wall damage in a human model of parietal fragility and dissection, the Marfan syndrome and how aortic endovascular repair has been changed consequently. In a second part, we will describe a new experimental murine model of DA based on mechanotransduction disturbance. In a third part we will explore new preclinical and clinical therapies based on the reduction of parietal fibrinolysis. The description of arterial wall fragility in Marfan syndrome allowed us to highlight a subpopulation of patients with a severe cardiovascular phenotype presenting in particular peripheral aneurysms and a high risk of AD. Aware of the severity of the arterial damage in this disease, we proposed a modified technical protocol for endovascular repair of AD in patients with Marfan syndrome. Our new experimental model based on chemical impairment of ECM associated with aortic wall decompaction increased aortic dilation, worsened aortic clinical presentation and reproduced histological features of human AD. Finally, the inhibition of intraparietal fibrinolysis appears to be a potentially interesting pathway to slow the progression of aortic dilation, this being supported by endovascular false-lumen exclusion techniques of human AD. Knowledge on arterial wall involvement in Marfan syndrome continues to evolve and guides endovascular therapies. The use of the new experimental model of AD by alteration of ECM and mechanotransduction could allow new therapeutic approaches testing
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
Multicentre experience of antegrade thoracic endovascular aortic repair for the treatment of thoracic aortic diseases
No full textObjectives: The goal of this multicentre retrospective cohort study was to evaluate technical success and early and late outcomes of thoracic endovascular repair (TEVAR) with grafts deployed upside down through antegrade access, to treat thoracic aortic diseases. Methods: Antegrade TEVAR operations performed between January 2010 and December 2021 were collected and analysed. Both elective and urgent procedures were included. Exclusion criteria were endografts deployed in previous or concomitant surgical or endovascular repairs. Results: Fourteen patients were enrolled; 13 were males (94%) with a mean age of 71 years (interquartile range 62; 78). Five patients underwent urgent procedures (2 ruptured aortas and 3 symptomatic patients). Indications for treatment were 8 (57%) aneurysms/pseudoaneurysms, 3 (21%) dissections and 3 (21%) penetrating aortic ulcers. Technical success was achieved in all procedures. Early mortality occurred in 4 (28%) cases, all urgent procedures. Median follow-up was 13 months (interquartile range 1; 44). Late deaths occurred in 2 (20%) patients, both operated on in elective settings. The first died at 19 months of aortic-related reintervention; the second died at 34 months of a non-aortic-related cause. Two patients (14%) underwent aortic-related reinterventions for late type I endoleak. The survival rate of those having the elective procedures was 100%, 84% and 67% at 12, 24 and 36 months, respectively. Freedom from reintervention was 92%, 56% and 56% at 12, 24 and 36 months, respectively. Conclusions: Antegrade TEVAR can seldom be considered an alternative when traditional retrograde approach is not feasible. Despite good technical success and few access-site complications, this study demonstrates high rates of late type I endoleak and aortic-related reinterventions
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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