1,721,016 research outputs found
Wild aromatic plants bioactivity: a function of their (poly)phenol seasonality? A case study from Mediterranean area
No full textWild medicinal and aromatic plants are in the market as herbal raw or processed and packaged materials, playing, even today, a strategic role in the production of plant-based products. Indeed, their content in active ingredients, mainly specialized secondary metabolites, is not constant; it undergoes significant seasonal variations, as abiotic stress heavily affects secondary metabolism network. The present review deals with the seasonality influence on the polyphenolic composition on antioxidant and anti-inflammatory properties of medicinal and aromatic plants. To this aim, firstly the factors influencing the content of active ingredients in a plant drug will be discussed, and, in particular, the increased occurrence of phenols as a response to abiotic stress. In the last part of the review a brief reference will be made to four meaningful case studies, which involve wild medicinal aromatic herbs, native to the Mediterranean area: Calamintha nepeta L. Savi, Foeniculum vulgare Mill., Ruta graveolens L. and Thymus longicaulis C. Presl. These species, grown in the same geographical area and collected at the same harvesting time, showed a great variability in phenol constituents throughout the year. The comparison among data acquired clearly evidences that the seasonal variation in polyphenols’ occurrence and amount leads to a more/less pronounced antioxidant and anti-inflammatory activity of the hydroalcoholic extract therefrom. It is worth of note that the presence of the same metabolite, but in different phytochemical complexes, could result in different biological activities
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
Chlorogenic acid/PEG-based organic-inorganic hybrids: A versatile sol-gel synthesis route for new bioactive materials
No full textNew organic-inorganic hybrid materials were synthesized by an acid catalysed sol-gel approach, using silicon alkoxide and low molecular weight polyethylene glycol (PEG400) as inorganic and organic precursor, respectively. Chlorogenic acid (CGA), an antioxidant natural phenol compound, enriched further the organic component. Hybrids synthesized, all identical in terms of their starting materials, but differing in terms of their relative proportions, were characterized by means of Fourier Transform InfraRed (FTIR) measurements, UV–Vis spectroscopy, and UHPLC-HRMS analysis. The preservation of the intrinsic chlorogenic acid ability to scavenge, in a dose-dependent manner, radical species was investigated by directly exposing the hybrids to DPPH radical and ABTS radical cation. The relative ratio of both the natural compound and PEG heavily affected the antiradical response, suggesting that chemical interactions in the established network were able, based on components’ ratio, to differently mask and/or display the CGA moieties, commonly deemed relevant for antioxidant power exerting. Cell culture MTT assay was used to assess the biocompatibility of hybrid materials towards fibroblast NIH-3 T3 cells and neuroblastoma SH-SY5Y cells. Cells tested appeared differently responsive. In particular, a marked cell viability increase was observed when hybrids with low PEG amount (6%) and high CGA (15%) were directly exposed to fibroblast cells, whose mitochondrial redox activity was negatively affected by hybrid synthesized using the highest organic component rate (both PEG and CGA). Cell viability and morphology of human neuroblastoma SH-SY5Y cells were broadly compromised regardless of organic/inorganic starting materials ratio, suggesting the ability of hybrids to exert pro-oxidant effect towards tumour cells and to selectively interfere with their growth. The hybrids, able to elicit cleverly anti- or proliferative effects, were also shown to be bioactive. In fact, a biologically active hydroxyapatite layer was observed to be formed on the surface of the smart synthesized materials. This feature, which makes them a valuable bonding interface with tissues, opens new scenario aiming at further investigating the employment of natural phenol compounds in versatile sol–gel synthesis routes
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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