1,720,957 research outputs found
L'edema corneale, eziopatogenesi e trattamento
No full textThe corneal edema is not a rare condition secondary to the alteration of endothelial function, epithelial damage, ocular hypertension. This article gives an overview of pathophysiological causes of corneal edema, morphological slit lamp and confocal microscopy features, and histological changes in loading of endothelial cells. As the pathophysiological mechanism is well known this can allow an effìcient and rational therapeutic approach. Also in this study is reported the surgical treatment of this disease
IOL blu selettive: prevenzione per la maculopatia legata all’età
No full textNel lavoro vengono confrontate lenti intraoculari con filtro per la luce blu con lenti intraoculari tradizionali esaminando le funzioni visive così come rilevate da lavori della letteratura internazionale.
I risultati ottenuti hanno evidenziato un’equivalenza tra IOL tradizionali e blu selettive in merito alle funzioni visive ma con il vantaggio, quest’ultime, di proteggere dal danno fotochimica l’epitelio pigmentato retinico. Ciò sarebbe alla base della salvaguardia dei fotorecettori maculari e quindi una prevenzione per la degenerazione maculare legata all’età
Prevenzione della cataratta da stress ossidativo
No full textIl presente studio ha avuto lo scopo di rilevare e sintetizzare il ruolo dello stress ossidativo nella catarattogenesi e l’importanza delle sostanze antiossidanti enzimatiche e non nel prevenire la genesi e la progressione di questo evento.
Gli Autori, nel presente lavoro riportano gli studi su alcune di queste sostanze antiossidanti quali L-carnitina, acetil-L-carnitina, tiroxina e quercetina. Inoltre, il presente studio riporta anche il ruolo ossidante della radiazione UV ed il potenziale ruolo della proteina p53 e di sostanze come la tioredoxin-binding-protein-2 (TBP-2) che regola l’attività della tioredoxina, altra sostanza antiossidante. Il legame della kinurenina, naturale filtro UV, alle proteine della lente (cristalline) ed il potenziale protettivo del glutatione viene discusso
Il ruolo dell’acetil-L-Carnitina nella prevenzione della cataratta indotta da una sostanza ossidante
No full textCome già noto, lo stress ossdidativo è uno dei principali fattori nella genesi della cataratta. Nel cristallino umano sono presenti una serie di enzimi e sostanze antiossidanti che prevengono questo avvenimento. Gli Autori nel presente lavoro riportano gli studi più sull’acetil-L-carnitina, sostanza endogena con proprietà antiossidanti, e sulla sua azione nella prevenzione della cataratta indotta in acuto da una sostanza antiossidante quale la selenite su modelli sperimentali in vitro e in vivo
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
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