1,720,976 research outputs found
Extraction and purification from Ceratonia siliqua of compounds acting on central andperipheral benzodiazepine receptors
No full textThe presence of molecules with high affinity for central and peripheral benzodiazepine receptors was determined in the pod and leaves of Ceratonia siliqua carob. The amount of the substances able to selectively bind the central benzodiazepine receptor recovered fromcarob pods and leaves was respectively 12.17 and 18.7 ng diazepam equivalentg. The amount of compounds active on peripheral benzodiazepine receptor in both pods and leaves was higher in comparison with the central one, being 49.83 and 40.00 PK 11195 equivalentg, respectively. In particular the compounds acting on peripheral benzodiazepine receptors were found to be extremely concentrated in the young leaves Ž2572.57 ng PK 11195equivalentg. The presence of substances with central benzodiazepine activity in carob extracts seems of great importance in view of the possibility to use carob extract as potential natural products with anxiolytic-sedative effects. Moreover, the prevalence in leaves ofsubstances acting on peripheral benzodiazepine receptor suggests the possible utilisation of leave extracts as chemopreventive agents
Caratterizzazione dell'attività farmacologica dell'iperforina in confronto all'estratto di Hypericum perforatum
No full textAllo scopo di chiarire il meccanismo con cui l'iperforina svolge la sua azione ansiolitica, sono stati eseguiti studi preliminari con antagonisti famcaologici che hanno suggerito un possibile coinvolgimento del sistema serotoninergico e una scarsa implicazione del sistema recettoriale benzodiazepinico
Characterisation of pharmacoligical activity of hyperforin in comparison with Hypericum extract
No full textIn our experiments we studied the influence of hyperforin on locomotor behavior of rats and evaluated its effect in two experimental models of anxiety in comparison with the administration of hypericum extract
Definizione delle attività farmacologiche dell'iperforina e relativi meccanismi d'azione
No full textnel nostro studio abbiamo preso in considerazione l'effetto dell'iperforina sul comportamento motorio del ratto e la sua influenza in modelli sperimentali di ansia. In tali esprimenti abbiamo messo a confronto l'attività dell'iperforina acetato con quella di un estratto totale di iperico ottenuto con la tecnica della CO2 supercritica
Prresenza di sostanze attive sia sul recettore centrale che periferico delle benzodiazepine in estratti di farina e foglie di carruba (Certonia siliqua)
No full textNell'ambito di numerose indagini dedicat alla determinazione di composti benzodiazepino-simili in diversi prodotti alimentari, parte delle ricerche hanno riguardato la presenza di tali composti nel bacello e nelle foglie di carruba (Ceratonia siliqua), pianta sempreverde ampiamentediffusa in tutta l'area mediterranea. Se i semi trovano una grande utilizzazione nell'indusria alimentare per l'alta concentrazione di gomme, l'utilizzo dell'intero bacello ha invece delle strette limitazioni per il prevalente carattere astringente dovuto alla presenza dei tannini
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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