1,720,967 research outputs found
Limbal and Conjunctival Epithelium After Corneal Cross-linking Using Riboflavin and UVA.
No full textPURPOSE:: To assess possible cellular damage in the corneal and conjunctival epithelium after corneal cross-linking treatment. METHODS:: Riboflavin-dextran solution was applied every 5 minutes to the right eyes of 3 rabbits 10 minutes before and 30 minutes during the irradiation with UVA light of 370 nm and an irradiance of 3 mW/cm at the 8- to 10-oclock position, including conjunctival, limbal, and central corneal epithelium. In addition, 3 rabbits were treated with UVA light only. The rabbits were killed 24 hours later. The treated eyes were examined histologically using hematoxylin-eosin and periodic acid-Schiff staining, immunohistochemistry, and a terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate-biotin nick-end labeling (TUNEL) apoptosis assay and compared with the left fellow eyes, which served as controls. RESULTS:: There was no epithelial defect on fluorescein staining. No apoptosis was found in the corneal limbal epithelium, keratocytes, or endothelial cells in the irradiated area. In the adjacent conjunctival epithelium, rare superficial conjunctival epithelial cells were positive in TUNEL staining in all animals. Anti-multicytokeratin-positive staining was demonstrated in both the limbal corneal and the conjunctival epithelium. The proliferation marker Ki-67 was identified in the basal cell layer of the limbal epithelium. The frequency and distribution pattern of goblet cells, multicytokeratin, and the proliferation marker Ki-67 were the same in all eyes compared with the untreated fellow control eyes. CONCLUSIONS:: Standard corneal cross-linking does not induce significant cellular epithelial damage as assessed by histological methods. Further studies on possible genotoxic and long-term changes would be helpful to complete the risk assessment. Copyright © 2011 by Lippincott Williams & Wilkins
Interlamellar cohesion after corneal crosslinking using riboflavin and ultraviolet A light.
No full textAims: Collagen crosslinking treatment of progressive keratoconus using the photosensitiser riboflavin and ultraviolet A light of 370 nm wavelength has been shown to increase significantly the tensile strength of corneal collagen by about 300%. In keratoconus, interlamellar and interfibrillar slippage have been proposed as pathogenetic mechanisms. Therefore, the aim of this study was to assess the impact of collagen crosslinking on the interlamellar cohesive force. Methods: 72 post mortem porcine eyes were divided into six different treatment groups: the untreated control group, the standard crosslinking group, the hypo-osmolar crosslinking group, the stromal swelling group, the formaldehyde group and the α-amylase group. An anterior 9X4 mm strip of 400 μm thickness was prepared using a lamellar rotating microkeratome. For interlamellar cohesive force measurements a splitting plane was created at 50% depth. Force-distance profiles were recorded using a microcomputer-controlled biomaterial testing machine. Results: The mean interlamellar cohesive force was 0.24 N/mm in the untreated control group, 0.26 N/mm in the standard crosslinking group, 0.25 N/mm in the hypoosmolar crosslinking group, 0.23 N/mm in hydrated corneas, 0.27 N/mm in the formaldehyde group without statistically significant difference. Only the values of the α-amylase group were statistically significantly lowered by 31.5% to 0.16 N/mm. Conclusions: Surprisingly, corneal crosslinking does not increase the interlamellar cohesive force. In the α-amylase group the cohesive force was mainly decreased because of the digestion of proteoglycans. Crosslinking seems to stabilise only inter- and intrafibrillar, but not interlamellar cohesion
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
Pseudotrisomy 13: Clinical findings and genetic implications
No full textThe combination of holoprosencephaly, postaxial polydactyly, and normal karyotype has been termed pseudotrisomy 13 syndrome. Here, we report the prenatal diagnosis of pseudotrisomy 13 in three siblings suggesting autosomal recessive inheritance of this syndrome. Clinical overlap with hydrolethalus syndrome, Smith-Lemli-Opitz syndrome, Meckel syndrome, and Pallister-Hall syndrome is discussed. Copyright (c) 2005 S. Karger AG, Basel
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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