1,720,954 research outputs found
Valutazione comparativa dell’attivita’ antifungina di oli essenziali ottenuti da 4 cultivars di lavandino
No full textL'attività antimicrobica è una fra le caratteristiche più interessanti degli oli essenziali (o.e.) per le varie applicazioni in campo umano, animale e vegetale. Un grande interesse viene rivolto agli o.e. al fine di individuare nuove molecole in grado di contrastare ceppi microbici resistenti o multiresistenti agli antibiotici. Il lavandino è un ibrido ottenuto dall’incrocio di Lavandula angustifolia e L. latifolia che cresce con uno sviluppo maggiore sia in altezza che in diametro rispetto alla lavanda (Lavandula sp.) e da cui è possibile ottenere rese elevate di o.e. (fino all’1.4%). La coltivazione di lavandino, a parità di proprietà, potrebbe quindi risultare preferibile a quella della lavanda.
Lo scopo del presente lavoro è stato lo studio dell’attività antifungina degli oli di lavandino di diverse cultivars (cvs) (“Abrialis”, “Alba”, “Rinaldi Ceroni” e "Sumiens”) coltivate presso il Giardino delle Erbe di Casola Valsenio (Ravenna) verso diverse specie di Candida (C. albicans, C. tropicalis, C. utilis, C. stellata, C. pseudointermedia). I valori di MIC ottenuti sono stati confrontati con quelli di tea tree oil (TTO) commerciale con composizione prevista dalla norma ISO 4730. L’attività antifungina è stata valutata seguendo il metodo CLSI (CSLI, 2008).
Gli oli di lavandino saggiati mostrano un attività antimicrobica medio alta verso i ceppi di Candida saggiati. La Minimal Inhibitory Concentration (MIC) del TTO verso le candide saggiate è 0.5%. Considerando questa concentrazione di olio come valore di elevata attività antimicrobica, anche gli o.e. di lavandino saggiati mostrano elevata attività antimicrobica anche se con differenze fra le varie cvs di lavandino. “Sumiens” ha mostrato la maggiore attività con MIC comprese fra 0.125 e 0.5% verso tutte le candide saggiate. “Abrialis”, “Rinaldi Ceroni” e “Alba” hanno mostrato MIC di 0.25-0.5% verso C. albicans, C. tropicalis e C. utilis mentre MIC di 2-4% verso C. pseudointermedia e C. stellata. Le specie di Candida esaminate quindi hanno mostrato una diversa sensibilità agli o.e. di lavandino saggiati. L’impiego di tali o.e. come antimicrobici dovrebbe quindi essere valutato attentamente tenendo in considerazione anche la specie di Candida “bersaglio”. In conclusione, i risultati ottenuti mostrano che gli oli di lavandino sono prodotti naturali promettenti come antifungini in quanto attivi a basse concentrazioni. Al fine di indagare la loro potenziale applicazione in campo medico dovranno essere condotti studi clinici in vivo a supporto dei dati ottenuti in vitro
Effects of neurosteroids on a model membrane including cholesterol: A micropipette aspiration study
No full textAmphiphilic molecules supposed to affect membrane protein activity could strongly interact also with the lipid component of the membrane itself. Neurosteroids are amphiphilic molecules that bind to plasma membrane receptors of cells in the central nervous system but their effect on membrane is still under debate. For this reason it is interesting to investigate their effects on pure lipid bilayers as model systems. Using the micropipette aspiration technique (MAT), here we studied the effects of a neurosteroid, allopregnanolone (3α,5α-tetrahydroprogesterone or Allo) and of one of its isoforms, isoallopregnanolone (3β,5α-tetrahydroprogesterone or isoAllo), on the physical properties of pure lipid bilayers composed by DOPC/bSM/chol. Allo is a well-known positive allosteric modulator of GABAA receptor activity while isoAllo acts as a non-competitive functional antagonist of Allo modulation. We found that Allo, when applied at nanomolar concentrations (50-200 nM) to a lipid bilayer model system including cholesterol, induces an increase of the lipid bilayer area and a decrease of the mechanical parameters. Conversely, isoAllo, decreases the lipid bilayer area and, when applied, at the same nanomolar concentrations, it does not affect significantly its mechanical parameters. We characterized the kinetics of Allo uptake by the lipid bilayer and we also discussed its aspects in relation to the slow kinetics of Allo gating effects on GABAA receptors. The overall results presented here show that a correlation exists between the modulation of Allo and isoAllo of GABAA receptor activity and their effects on a lipid bilayer model system containing cholesterol
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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