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Propolis: innovation and new applications based on its fine structural composition
No full textPropolis: innovation and new applications based on its fine structural compositio
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
Selective treatment to reduce contamination of propolis by polycyclic aromatic hydrocarbons (PAHs) still preserving its active polyphenol component and antioxidant activity
No full textThe adverse effects on health and environment caused by polycyclic aromatic hydrocarbons (PAHs) are critical problems. EFSA has defined 16 priority PAHs that are both genotoxic and carcinogenic, and identified eight (PAH8) priority PAHs as good indicators of the toxicity and occurrence in food. Food supplements containing propolis were also found to contain relatively high quantities of PAHs. We report about an extractive procedure which is able to purify propolis from a high content of PAHs using a balanced mixture of ethanol and water solvents. Extracts were characterised for total content of polyphenols, for in vitro antioxidant activity, and single classes of polyphenols evaluated by HPLC-ESI-MS. Obtained propolis extracts were found to have PAH8 and specific benzo[a]pyrene content below limits recommended by EFSA. The reported extractive procedure is easily applicable for possible industrial productions and may also be adopted to the purification of polyphenols from other plant extracts and natural sources
High quality Green (Brazilian) propolis extracts characterized for active biomolecules exert epigenetic effects able to have a positive influence on cell oxidative stress
No full textHigh quality Green (Brazilian) propolis extracts characterized for active biomolecules exert epigenetic effects able to have a positive influence on cell oxidative stress
1Daglia Maria, 1Valeria Curti, 1,2Vincenzo Zaccaria, 3Fabio Galeotti, 2Laura Crimaldi, 3Francesca Maccari, 2Alfredo Fachini, 3Nicola Volpi
1Department of Drug Sciences. University of Pavia, Via Taramelli 12. Pavia, Italy.
2B Natural R&D Unit, Via Gran Sasso 33. Corbetta (Milano), Italy
3Department of Life Sciences. University of Modena and Reggio Emilia, Via Campi 213/D, Modena, Italy.
Study Objective(s). Recently, EFSA (European Food Safety Authority) provided negative responses on the substantiation of health claims related to propolis based on two main points: I) propolis is very heterogeneous and its main active components (bio)flavonoids are not well characterized and II) due to the absence of structural characterization of propolis and related products, no structure/composition and effect/activity relationship may be established. Thus, the aim of this study is to show that a high quality Green Brazilian propolis extract GreenArt® (prepared according to proprietress and patented technology) exerts epigenetic effects, being able to modulate the expression levels of miRNAs connected with oxidative stress.
Method. High quality propolis extracts prepared from green propolis were manufactured by B Natural according to patented technology. Total polyphenols, phenolic acids and bioflavonoids, were characterized and quantified by HPLC-UV-ESI-MS (and tandem mass). The epigenetic effect of green propolis preparations was studied by evaluating the levels of two miRNA, miR-27a-3p able to modulate the expression of genes involved in oxidative stress responses. Moreover, its validated target, mRNA coding for nuclear factor (erythroid-derived 2)-like 2 (NFE2L2, involved in oxidative stress) was studied.
Results. The high quality Green Brazilian propolis extracts GreenArt® have been characterized for the presence and amount of phenolic acids (artepillin C, caffeic acid and derivatives, dicaffeic, ferulic, cinnamic and coumaric acids), bioflavonoids (quercetin and derivatives, kaempferol, apigenin, pinobanksin, isorhamnetin) and glycosylated forms. As regards miRNA expression levels, miR-27a-3p expression levels increased in cells treated with growing concentrations of green propolis preparation tested at sub-toxic concentrations in comparison with untreated cell cultures. The study of the validated mRNA target expression levels revealed that mRNA coding for NFE2L2 decreased in agreement with the increase of the corresponding miR-27a-3p.
Conclusions. The high quality Green Brazilian propolis extract GreenArt® with a well specific and characterized profile of active biomolecules is able to exert epigenetic effects at low concentrations, and to have a positive influence on the expression levels of mRNA coding for NFE2L2, a transcription factor marker of absence of cell oxidative stress. In conclusion, with this investigation, we showed that it is possible to characterize green propolis and its main active components, to have a specific fingerprint related to the products of different origin and preparations, using HPLC-UV-ESI-MS analytical technique. Furthermore, GreenArt® resulted to be able to reduce oxidative stress through epigenetic mechanism of action.
Funding. Structural characterization of green propolis extracts was funded by B Natural. Studies of miRNA expressions were financed within the project “Studio della composizione delle proprietà nutraceutiche dei prodotti dell’alveare” approved by Regione Lombardia - Direzione Generale Istruzione, Formazione e Lavoro (DD.n. 9089, published on 03/Oct/2014)
PURIFICATION OF PROPOLIS FROM POLYCYCLIC AROMATIC HYDROCARBONS AND PRESERVATION OF ACTIVE POLYPHENOL COMPONENT.
Get PDFOrganic pollutants have become an increasing concern due to their potential of mutagenicity, carcinogenicity, teratogenicity and high bioaccumulation. The adverse effects on health and environment caused by specific organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) have been considered as critical problems. The European Food Safety Authority (EFSA) has defined 16 priority PAH that are both genotoxic and carcinogenic and identified eight (PAH8) or four (PAH4) priority PAH as good indicators of the toxicity and occurrence of PAH in food. Several available techniques (photocatalytic degradation, combined photo-fenton and ultrasound, advanced oxidation, aerobic degradation, filtration, ozonation, coagulation, flocculation, distillation, extraction, precipitation, and adsorption, etc.) have been developed for PAH removal.
Food supplements containing propolis were also found to show relatively high PAHs. As a consequence, a main goal is to adopt purification procedures to remove PAH from propolis and preserve its polyphenol components before its use in finished products. Here we report an extractive procedure (M.E.D., Multi Dynamic Extraction) able to purify propolis from a great content of PAH by using a balanced mixture of organic and water solvents. Obtained propolis extracts are still rich in polyphenols and glycosylated derivatives showing PAH8 and specific benzo[a]pyrene content below limits recommended by EFSA
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