1,720,962 research outputs found
La capsula del cristallino e la prevenzione della cataratta secondaria
No full textSono state studiate le modificazioni della proliferazione e della sopravvivenza di cellule in coltura, al fine di individuare gli eventuali effetti tossici di due farmaci per anestesia locale, normalmente utilizzati negli interventi chirurgici oculari. I risultati ottenuti hanno dimostrato che la lidocaina possiede un’elevata azione citotossica e citostatica a concentrazioni dell’ordinedi 10mM, concentrazioni paragonabili a quelle normalmente utilizzate in sala operatoria per uso anestetico. Viceversa, la ropivacaina presenta una tossicità nettamente inferiore e sostanzialmente trascurabile alle concentrazioni da noi saggiate e paragonabili a quelle utilizzate in anestesia. E’ lecito ipotizzare che l’azione citotossica e citostatica della lidocaina può essere impiegata nella prevenzione della opacizzazione della capsula del cristallino (cataratta secondaria)
L’apoptosi delle cellule del cristallino umano in coltura
No full textIn questo studio si è utilizzato una coltura di cellule del cristallino umano prelevate dopo facoemulsione, per studiare le eventuali modificazioni della proliferazione e della sopravvivenza cellulare e per individuare effetti collaterali e secondari di sostanze normalmente utilizzate negli interventi chirurgici oculari. Sono stati esaminati due anestetici locali (la lidocaina e la ropivacaina) e l’eparina, di norma usata come anti-trombotico. I nostri risultati evidenziano che la lidocaina possiede un’elevata azione citotossica e citostatica, viceversa la ropivacaina presenta una tossicità nettamente inferiore. Inoltre dopo trattamento con diverse concentrazioni di eparina, sia UFH che LMWH, non si è riscontrato alcun effetto tossico e si è verificato che, a tempi brevi, l’eparina non sembra determinare inibizione della proliferazione cellulare, mentre sembra indurre la formazione di aggregati cellulari (sincizi), probabilmente modificando l’adesione cellulare con conseguenze non note. Quanto esposto porta a concludere che la lidocaina possa essere utilizzata per la prevenzione della cataratta secondari
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
Effect of basic fibroblast growth factor and cytochrome c peroxidase combination in transgenic mice corneal epithelial healing process after excimer laser photoablation
No full textPurpose: To evaluate the role of prepared basic fibroblast growth factor (bFGF) and cytochrome c peroxidase (CCP) combination eyedrops in corneal epithelial healing of transgenic mice (B6(A)-Rperd12/J ) after excimer laser photoablation.
Materials and methods: In this prospective study, 216 eyes of 108 mice underwent bilateral photorefractive keratectomy. We considered 4 groups: A, B, C, and D. Group A received standard topical postoperative therapy with tobramycin, diclofenac, and dexamethasone eyedrops plus CCP at 3 drops per day for a week or until corneal re-epithelialization was achieved. Group B received standard topical postoperative therapy plus bFGF eyedrops and phosphate-buffered saline (PBS) 3 drops per day for a week or until corneal re-epithelialization was complete. In group C, 1 eye received standard topical postoperative therapy plus CCP eyedrops, bFGF eyedrops, and PBS 3 drops per day for a week or until corneal re-epithelialization was complete. Control eyes (group D) received a standard topical postoperative therapy plus placebo eyedrops. Mice were followed-up for a week from the day after the surgery to evaluate the rate of corneal re-epithelialization.
Results: Data were analyzed by ANOVA using the XLSTAT 2010 software. Eyes in group A, B, and C healed completely before the fifth postoperative day, achieving, respectively, a re-epithelialization time of 92 hours ± 10 SD, 90 hours ± 12 SD, and 86 hours ± 12 SD. Group D had a re-epithelialization time of 121 hours ± 8 SD (P < 0.05). No side effects or toxic effects were documented
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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