1,720,970 research outputs found
Obstructive neonatal atrial myxoma
No full textIntroduction Cardiac myxoma is a benign neoplasm representing the most common primary cardiac tumor in adults, however it is unusual in neonates. It is represented by an endocardial mass that occupies the cardiac chamber. Although the majority of myxomas are attached to the fossa ovalis of the interatrial septum, they also attach to the walls of the cardiac chambers and to valve leaflets surfaces. Approximately 75% of myxomas are found in the left atrium, 20% are located in the right atrium, and rarely in the ventricles. Presentation of case We describe a rare case of neonatal cardiac myxoma arising from interatrial septum, causing significant mechanical obstruction to blood flow through tricuspid valve, in an otherwise normal newborn. The patient underwent successful excision of the myxoma with an uneventful recovery [1]. Discussion Cardiac tumors are rare in children, thus an understanding of the common types of benign and malignant paediatric cardiac tumors and their imaging features, is important because the epidemiology and tumor types differ from those encountered in adults. Conclusion Large neonatal myxoma is exceptionally rare and even more infrequent is the surgical excision in the first day of life
Evolution of a rare ECG pattern in an aggressive case of neonatal tuberous sclerosis complex
No full textIntroduction: Rhabdomyomas are the most frequent cardiac tumors in children. Furthermore, they are often associated to tuberous sclerosis complex, an autosomal dominant neurocutaneous disorder characterized by tumor-like malformations that involve many organ systems. Presentation of the case: We describe a rare ECG pattern in a severe case of neonatal tuberous sclerosis complex. Discussion: In the presence of significant rhabdomyomatosis related to tuberous sclerosis, multiple clusters of rhabdomyoma-like cells can infiltrate the myocardium, with increased fibrosis areas. Conclusion: Considering the fact that rhabdomyomas often show spontaneous regression, close follow-up is sufficient in hemodynamically stable cases. Destruction of the conduction system, with arrhythmias as consequence, can be the presenting feature of diffuse rhabdomyomatosis
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
Efficacy of two mouthwashes on 3-day supragingival plaque regrowth: a randomized crossover clinical trial
No full textBackground: The aim of this study was to evaluate the antiplaque effects of an alcohol-free essential oil (alcohol-free EO) mouthwash and an amine fluoride/stannous fluoride with zinc lactate (SnFl-Zn) mouthwash compared to a positive control of chlorhexidine (CHX) mouthwash, using an in vivo plaque regrowth model of 3 days. Materials and methods: The study was designed as a double-masked, randomized, crossover clinical trial, involving 20 volunteers to compare two different mouthwashes, using a 3-day plaque accumulation model. After receiving thorough professional prophylaxis at baseline, over the next 3 days, each volunteer refrained from all oral hygiene measures and performed two daily rinses with 20 ml of the test mouthwashes. A 0.20% CHX rinse served as a positive control. At the end of each experimental period, plaque was assessed, and the panellists completed a questionnaire. Each subject underwent a 14-day washout period, and then, there was another allocation. Results: The SnFl-Zn mouthwash has shown a better inhibitory activity on plaque regrowth compared to the alcohol-free EO mouthwash in the whole mouth (plaque index = 1.93 against 2.45, respectively), but there was less of an effect compared to the CHX group, with an overall plaque index of 1.41. The differences of 0.52 between alcohol-free EO and SnFl-Zn and between SnFl-Zn and CHX and of 0.96 between alcohol-free EO and CHX were all statistically significant (P < 0.001). Conclusion: The alcohol-free EO mouthwash seemed to have less of an inhibiting effect on plaque regrowth than the amine fluoride/SnFl-Zn mouthwash and the CHX control. © 2015 John Wiley & Sons A/S.Background: The aim of this study was to evaluate the antiplaque effects of an alcohol-free essential oil (alcohol-free EO) mouthwash and an amine fluoride/stannous fluoride with zinc lactate (SnFl-Zn) mouthwash compared to a positive control of chlorhexidine (CHX) mouthwash, using an in vivo plaque regrowth model of 3 days. Materials and methods: The study was designed as a double-masked, randomized, crossover clinical trial, involving 20 volunteers to compare two different mouthwashes, using a 3-day plaque accumulation model. After receiving thorough professional prophylaxis at baseline, over the next 3 days, each volunteer refrained from all oral hygiene measures and performed two daily rinses with 20 ml of the test mouthwashes. A 0.20% CHX rinse served as a positive control. At the end of each experimental period, plaque was assessed, and the panellists completed a questionnaire. Each subject underwent a 14-day washout period, and then, there was another allocation. Results: The SnFl-Zn mouthwash has shown a better inhibitory activity on plaque regrowth compared to the alcohol-free EO mouthwash in the whole mouth (plaque index = 1.93 against 2.45, respectively), but there was less of an effect compared to the CHX group, with an overall plaque index of 1.41. The differences of 0.52 between alcohol-free EO and SnFl-Zn and between SnFl-Zn and CHX and of 0.96 between alcohol-free EO and CHX were all statistically significant (P < 0.001). Conclusion: The alcohol-free EO mouthwash seemed to have less of an inhibiting effect on plaque regrowth than the amine fluoride/SnFl-Zn mouthwash and the CHX control
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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