1,720,969 research outputs found
Lenti a contatto terapeutiche
No full textL’idea di utilizzare le lenti a contatto a scopo terapeutico, al fine di migliorare la sintomatologia oculare ed il decorso di alcune malattie oculari, risale al 1859. Da allora notevoli progressi sono stati eseguiti ed abbiamo oggi a disposizione lenti idrogel, rigide gas-permeabili ed al collagene, per impieghi terapeutici a breve e lungo termine. Gli Autori descrivono per le varie lenti i criteri di applicazione (raggio di curvatura, spessore, grado di idrofilia, diametro, potere), le indicazioni (ruolo di riserva di farmaci e di enzimi, di cicatrizzazione, antalgico, di protezione e nelle tesaurismosi) e le loro complicazioni indotte
L’impiego di C.R.T. display per una guida sicura
No full textNumerosi studi recenti hanno sottolineato come molti test per la visione dei colori comunemente impiegati nella pratica clinica possano risultare non sufficientemente discriminanti per una serie di svariati fattori. Oltre a tali inconvenienti, la necessità sempre più avvertita di poter sottoporre ad elaborazione i dati ottenuti dai test, unita alla possibilità di introdurre nuovi parametri d’indagine in condizioni costanti e ripetibili, sembra rendere l’uso del CRT (Chatode Ray Tube) Display, con annesso elaboratore, particolarmente indicato nell’indagine e nella individuazione delle anomalie del senso cromatico
Il microsistema epitelio corneale- lenti a contatto
No full textGli AA riportano le manifestazioni sub-cliniche e cliniche indotte dalle lenti a contatto (lac) sull’epitelio corneale. Le manifestazioni sub-cliniche riconoscono cause meccaniche, metaboliche (termiche ed ipossiche), lacrimali ed iatrogene. Le manifestazioni cliniche daranno peraltro luogo ad i seguenti eventi: ipoestesia corneale, edema corneale, deficit lacrimale localizzato, fragilità epiteliale, complicanze propriamente dette (sindrome del rifiuto corneale, neovascolarizzazione, cheratiti infettive) e complicanze meccaniche (in rapporto alle lenti ed al materiale confinato sotto le lac).
Gli AA concludono osservando come l’applicazione di una lac perturbi un microsistema locale quale quello inter-oculo-palpebrale per cui l’applicazione deve essere sempre effettuata con scienza e controllata nel tempo
Microperimetry vs preferential hyperacuity perimetry in patients with intermediate age-related macular degeneration
No full text
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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