1,721,012 research outputs found

    Cryptogenic hepatitis masking the diagnosis of ornithine transcarbamylase deficiency

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    We describe three children with transaminase elevations and hepatic insufficiency who were given the diagnosis of cryptogenic hepatitis after the more common viral and metabolic diseases of the liver had been excluded. However, further laboratory investigations showed hyperammonemia, low blood urea levels, elevated plasma glutamine levels, and low citrulline levels. Urinary excretion of orotic acid was higher than normal, with absent urinary homocitrulline and normal fractional tubular reabsorption of lysine, ornithine, and arginine. These findings suggest the diagnosis of ornithine transcarbamylase deficiency. We emphasize the importance of investigating possible urea cycle disorders by determining ammonia plasma levels, both at baseline and after a protein load; urinary and plasma amino acids; and urinary orotic acid in all patients with liver disease of indeterminate etiology

    Biochemical evaluation of a patient with a familial form of leucine- sensitive hypoglycemia and concomitant hyperammonemia

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    A case of a child with recurrent episodes of severe hypoglycemia since the age of 6 months is reported. Biochemical evaluation extended to the first-degree relatives is consistent with a familial form of hypoglycemia due to a leucine-sensitive hyperinsulinism. In addition, this patient has a persistent elevation of serum ammonia levels of uncertain etiology that is more pronounced after meals. Urea cycle defects, organic acidurias, and β- oxidation defects have been ruled out, as well as a possible excessive deamination of glucogenetic amino acids. This unexpected hyperammonemia, which was also detected in the mother, might be related to leucine hypersensitivity

    Redox status in the diagnosis of mitochondrial diseases

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    The results of the study of «redox potential states» (Redox Status) in patients suffering from mitochondrial diseases are reported; this study is performed through fasting and postprandial measurements of plasmatic lactate, pyruvate, acetoacetate and β-hydroxybutyrate and it allows to obtain precious informations about metabolic status. This study, not too heavy or complex, allows a «redox metabolic screening», useful for indication more accurate for further examinations (biopsy, enzymatic assay, molecolar studies)

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

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    We 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

    Author Index

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