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Isolamento caratterizzazione chimica e biologica di estratti ottenuti da specie vegetali della famiglia delle Rosaceae
Get PDFThe spread of the antibiotic resistance of pathogenic microorganisms is increasingly evident and dramatic. Therefore, the aim of my PhD project was to identify extracts obtained from spp. of plants belonging to the Rosaceae family with antimicrobial properties. This study could contribute to the identification of compounds or class of bioactive compounds of plant origin, useful for the formulation of antimicrobial preparations. The extracts were obtained with the use of a technique that makes use of CO2 in the supercritical phase and other traditional methods. The chemical characterization was carried out with different chromatographic techniques, Nuclear Magnetic Resonance Spectrometry, NMR, spectrophotometry and low and high resolution mass spectrometry. The multidisciplinarity of my project allowed me to study biological activity: antimicrobial activity, using the antibiogram method, antioxidant activity, from spectrophotometric assays, and the enzymatic activity of inhibiting xanthine oxidase. In particular, the study focused on the Rubus ulmifolius and Rosa canina species. Among the main results, it should be noted that an extract obtained from the seeds of R. canina, with high antimicrobial activity, made it possible to propose an invention for which, on 22 December 2020, Alessandra Piras, Antonella Ibba, Germano Orrù and Silvia Porcedda filed international patent application, pending concession, transferring the title to UniCa. The supercritical extracts obtained at 300 bar and 40 C, SFE [300: 40], from the pulp of the rose hips of R. canina and from the fruits of R. ulmifolius have revealed important nutritional properties - due to their high content of essential fatty acids. The different extracts, obtained from the leaves of R. ulmifolius, have shown an important antimicrobial activity - including the ability to reduce the biofilm - against two main pathogens of the oral cavity
Diagnosi di Laboratorio per Infezione nel Distretto Parodontale, dalla PCR al “Molecular Beacon Array”
No full textI dati forniti dall’ Organizzazione Mondiale della Sanità (OMS) riportano che a fronte del 30% della popolazione italiana che presenta salute parodontale, il restante 70 % è affetta da una forma di patologia che può essere lieve (80%) e grave (5-20%). Si tratta dunque di una patologia che ha un forte impatto sociale, e quindi una notevole incidenza nei costi della spesa sanitaria. Si impone pertanto un corretto approccio in termini di: prevenzione della diagnosi clinica e di laboratorio, delle strategie terapeutiche. L ‘eziologia della malattia parodontale e di tipo infettivo ma rispetto ad altre patologie causate da microorganismi la parodontite presenta notevoli peculiarità, peculiarità che vanno ricercate nelle caratteristiche dei patogeni parodontali, in particolare : (a) sono descritte almeno 300 specie differenti ( la maggior parte non ancora identificate), (b) La maggior parte sono anaerobi, (c) difficoltà nella coltura, (d) crescita molto lenta ( anche 2 settimane), (e) presentano un' organizzazione a ” biofim complesso”. Attualmente, un aiuto importante alla diagnostica di laboratorio in parodontologia, viene dalla biologia molecolare. Le tecniche più efficaci e moderne attualmente in uso sono la Polymerase Chain Reaction (PCR), e la sua versione quantitativa : la PCR real-Time. Queste metodiche hanno come principio lo specifico riconoscimento di una sequenza di DNA/RNA appartenente al microorganismo patogeno. I vantaggi principali vengono rilevati nella sensibilita’ ( un incremento di 10-100 volte) e nel tempo del risultato (1- 6 ore ). Nonostante questi vantaggi notevoli , i metodi citati possono presentare una bassa specificità , dovuta a sequenze di DNA molto simili appartenenti a specie microbiche affini.
2 Recentemente un ulteriore passo nella diagnostica microbiologica molecolare e’ stato raggiunto con i “Molecular Beacon”MB, (Tyagi et al., 1996). I MB, ,rappresentano sonde fluorescenti a DNA con struttura circolare (Fig.1). La sonda presenta una sequenza nucleotidica che si apre (ed emette fluorescenza),solo se trova una regione complementare perfettamente identica nel DNA bersaglio del patogeno parodontale, questo determina il massimo grado di specificità possibile nella diagnostica molecolare, di conseguenza vengono ridotti i possibili falsi positivi della PCR tradizionale. L’utilizzo dei MB in un pannello analitico contenente tutte le specie rappresentative della malattia parodontale “molecular beacon array”, dispone per il clinico elementi più oggettivi e, soprattutto scientificamente/tecnologicamente più significativi, su cui basare la diagnosi di infezione per malattia parodontale
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
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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