1,720,967 research outputs found

    AFM and FTIR Spectroscopy Investigation of the Inverted Hexagonal Phase of Cardiolipin

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    Atomic force microscopy (AFM) and FTIR spectroscopy techniques have been exploited to investigate the inverted hexagonal phase (HII) of cardiolipin obtained by dehydration of a phospholipid water dispersion on a solid support. The characteristic cylinders of the HII phase have been imaged by AFM and the effects of different preparation conditions (temperature and the presence of chemicals) on the structural parameters and on the presence of local nanoscale defects have been studied. It has been found that the measured repeat spacing of the HII cylinders decreases upon increase of temperature and addition of pentachlorophenol (PCP), a chemical which is known to affect the structure and function of lipid bilayers. It has been shown that AFM can help in revealing some features of the mechanism of the inverted hexagonal phase formation, corroborating the results of a recent molecular dynamics study on the HII phase formation from multilamellar phospholipid structures

    The diagnostic reliability of urinary cytology: A retrospective study.

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    The aim of this study was twofold. The first aim was to estimate the diagnostic reliability of urinary cytology for detection and management of urothelial neoplasms by using a specific preserving fluid for sample collection, and the liquid-based thin layer method for specimen preparation, the estimate was based on the correlation between the cytological findings of 10,000 non-hospitalized patients, and their histological diagnoses. A second aim was to compare the reliability of two instruments for thin-layer preparation, i.e., TP2000, TP3000, capable of processing the specimens at very different rates. The preservation of cell structure is ameliorated by the procedure of sample collection and treatment here described. This allows a more accurate reading of LBC slides as shown by: (a) the significant concordance between cytological and histological diagnosis (92%); (b) the significant number of low-grade urothelial carcinomas (20.5%) revealed by urinary cytology and validated by histologic diagnosis; (c) the low rate (8%) of misjudgement of cytological diagnosis reached in this study. The quality of performances of the two instruments tested for thin-layer preparation, i.e., TP2000 and TP3000, is statistically comparable. We recommend the procedure that makes use of preserving fluid for sample collection (cytolytTM) and treatment (preservcyt TM) as here described. We also recommend the use of thin-layer method for specimen preparation since it allows a more uniform distribution of the cells on the support with reduction of overlapping phenomena. Finally, economic considerations suggest the preferential use of Thin Prep 3000. Diagn. Cytopathol. 2011;. © 2011 Wiley-Liss, Inc

    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

    The rat liver during carbontetrachloride and 1,2-dibromoethane intoxication: a study on biochemical injury and energy state alteration

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    The rat liver during carbontetrachloride and 1,2-dibromoethane intoxication: a study on biochemical injury and energy state alteratio

    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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