1,720,989 research outputs found
Mechanical Circulatory Support and Stem Cell-Based Heart Treatment in Europe—2018 Clinical Update
No full textRobotic implant to apply tissue traction forces in the treatment of esophageal atresia2014 IEEE International Conference on Robotics and Automation (ICRA)
No full textEFFECTS OF INSIDE-OUT SUBMITOCHONDRIAL PARTICLES (IO-SMPS) ON MITOCHONDRIA ISOLATED FROM A PORCINE EX VIVO MODEL OF DONATION AFTER CARDIOCIRCULATORY DEATH (DCD) HEART
No full textWhen it comes to heart transplantation, donation after brain death (DBD) has become the standard of
care as this method is supported by many advantages, mainly due to the possibility to easily assess
donor heart function before retrieval and sensibly shorten the detrimental period of warm ischemia.
Lately, however, the ever-increasing number of patients in waitlist for heart transplantation has
pushed the interest of researchers to find new methods to increase the donor pool [1], including heart
donation after cardiocirculatory death (DCD). The latter, nonetheless, shows several disadvantages
including a longer period of warm ischemia, long-term outcomes uncertainty, and lack of
standardized reliable biomarkers and physiological parameters predictive of function and
transplantability of DCD hearts [2]. One of the earliest cardiomyocytes degenerations starting after
cardiac death is borne by mitochondria that are involved in some distinct types of cell death.
Therefore, studying such events may help better understanding the physiological processes
underlying DCD heart transplantability, eventually leading to definition of useful biomarkers. To
achieve this, the focus of this work was the F1Fo-ATPase complex, considered as the leading candidate
responsible for the opening of a channel though the inner membrane called mitochondrial
permeability transition pore (mPTP) when the natural cofactor (Mg2+) is replaced with the physio-
pathological cofactor (Ca2+) [3]. Specifically, trying to preserve mitochondrial bioener getics and
integrity, we assessed the efficacy of IO-SMPs (inside-out submitochondrial particles) obtained by
swine hearts isolated by stepwise centrifugation from mitochondria [4], on an ex-vivo porcine model
of DCD heart (20 min of no touch after cardiac arrest followed by 2h of warm ischemia). We
evaluated the effect of IO-SMPs on Oxidative Phosphorylation and their influence on mitochondria
calcium retention capacity (CRC), an indirect index of mPTP opening, as already highlighted in other
studies. Studies are currently ongoing, but the preliminary results show that IO-SMPs are capable of
delaying the mPTP opening when swine heart mitochondria are exposed to Ca2+. Overall, this study
represents a first step towards an in-depth characterization of the physiological process activated by
a prolonged warm ischemia within mitochondria, and investigates the potential beneficial effects of
IO-SMPs, that may be applicable to all DCD solid organ
Fast Simulation of Mitral Annuloplasty for Surgical PlanningFunctional Imaging and Modeling of the Heart
No full textMitral valve repair is a complex procedure that requires the ability to predict closed valve shape through the examination of an unpressurized, flaccid valve. These procedures typically include the remodeling of the mitral annulus through the insertion of an annuloplasty ring. While simulations could facilitate the planning of the procedure, traditional finite-element models of mitral annuloplasty are too slow to be clinically feasible and have never been validated in tissue. This work presents a fast method for simulating valve closure post-annuloplasty using a mass-spring tissue model and subject-specific valve geometry. Closed valve shape is predicted in less than one second. The results are validated by implanting an annuloplasty ring in an excised porcine heart and comparing simulated to imaged results. Results indicate that not only can mitral annuloplasty be simulated quickly, but also with sub-millimeter accuracy
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
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