1,720,959 research outputs found
Processing efficacy in relation to microbial contamination of skin allografts from 723 donors
No full textThe Siena Skin Bank, established in 2000, processes skin from more than 130 cadaveric donors per year (about 400,000 cm2) and distributes it for transplants to treat burns and other types of skin loss. More than 1,500,000 cm2 of homologous skin has been transplanted to date. At the Siena Skin Bank we conducted a retrospective study of our data to assess microbial contamination of skin specimens from 723 donors banked in the period 2000-2007. Our aim was to determine factors deleterious for skin quality, to optimize skin banking procedures and to reduce corrective actions. The factors analyzed were: type of donor (multi-organ, multi-tissue, live or cadaver), cause of death, time elapsing between death and procurement, different procurement centres and operator experience. Of the 723 donors considered, 26.55% (192/723) were positive for microbes, 22.68% (164) for bacteria and 5.39% (39) for mycetes. Of these 192 positives, 82 (42.70%) required corrective actions. The data obtained showed that the only variables significantly affecting microbial contamination of tissue were type of donor (live or cadaver) and type of processing (cryo- or glycerol preservation). © 2009 Elsevier Ltd and ISBI
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
Human de-epidermized dermis as a stem cell carrier
No full textRecently several types of skin equivalents have been developed, consisting of differentiated keratinocytes cultured on various dermal substitutes. Different models of reconstructed human skin have been proposed, such as human and animal de-epidermized dermis, inert filters, collagen matrices, lyophilized collagen membranes populated with fibroblasts, and other models populated with melanocytes and/or Langerhans cells. These skin equivalents mimic native skin in vivo. They have provided information about dermal-epidermal interactions, cell-cell, and cell-matrix interactions; responses of dermal and epithelial cells to biological signals and pharmacological agents; as well as effects of drugs and growth factors on wound healing. Human allodermis from tissue banks has been used for clinical purposes, namely, as support for autologous keratinocyte cultures and as a potentially ideal scaffold for dermal replacement. This bioproduct is considered to be the most suitable clinical carrier for autologous fibroblasts and keratinocytes, as well as an useful experimental model to study angiogenesis and to stimulate vascularization in reconstructed human skin. Because it is human-derived, it is in our opinion the safest of all available types of skin equivalent. Having epidermal and dermal structures, it can be used in one-stage grafting procedures for wound closure. © 2010 Elsevier Inc
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