1,720,956 research outputs found
Tissue transglutaminase in gastric biopsies: A marker of gastritis associated to Helicobacter pylori infection?
No full textMedicazioni intermedie in endodonzia: valutazione quantitativa in vitro di due derivati fenolici
No full textE' stata condotta un'indagine in vitro al fine di verificare la persistenza di 2 medicamenti endodontici nel lume canalare.
Per lo studio sono stati utilizzati 32 elementi dentari, in cui, a distanza di 3 e 7 giorni dal posizionamento nella camera endodontica, è stata eseguita la determinazione spettrofotometrica dei residui di concentrazioni standardizzate di p-clorofenolo e di eugenolo.
I risultati indicano che, dopo 3 e 7 giorni dal posizionamente nel lume canalare, il clorofenolo è presente nel pellet di cotone rispettivamente con concentrazione pari ad 1/4 ed ad 1/5 di quella iniziale. L'eugenolo, presente nel pellet dopo 3 giorni dalla medicazione è invece uguale ad 1/3 della concentrazione iniziale e dopo 7 giorni appare ridotto ad 1/6 rispetto ai valori iniziali della sperimentazione
POLYAMINE LEVELS DURING THE ONSET OF CAM IN OPUNTIA-F-INDICA (MILLER)
No full textPolyamines have been related to the ''Crassulacean Acid Metabolism'' (CAM) in higher plants. Such relationship was however observed in plants where CAM activity is inducible by external factors. Results presented here indicate that, in Opuntia F. indica, cladodes where onset of CAM is dependent on internal conditions, i.e. leaf age, the concentration of putrescine increases in parallel to the acidity of the cytoplasm. The parallel increase of putrescine concentration and acidity (malic acid concentration) can be best evaluated during the onset of CAM (young cladodes), while such correlation is not observed in mature cladodes where CAM is already in it's full function. Spermidine and spermine show no correlation with CAM activity neither during the onset of CAM nor during it's full function. However, spermidine levels correlate negatively to CAM activity when cladodes attain > 30 days of age. The results suggest that putrescine in free form could possibly counteract the increase of cellular acidity during onset of CAM in Opuntia F. indica; the possible roles of spermidine are discussed
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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