1,721,118 research outputs found
Valorização de Subprodutos de Maçã: Da Caracterização Nutricional e Bioativa ao Desenvolvimento de um Produto de Panificação Enriquecido
No full textEste trabalho foi financiado pelo programa Interreg VA Espanha-Portugal (POCTEP) através do projeto 0112_TRANSCOLAB_PLUS_2_
Bioactive and chemical characterization of medicinal plants
No full textMestrado de dupla diplomação com a UTFPR, Universidade Tecnológica Federal do ParanáMedicinal plants are used worldwide for the treatment of various diseases, and there is increasing interest in studying their bioactive properties and chemical composition. A deeper understanding of these properties could drive significant advancements in multiple industrial sectors. In this study, we investigated three medicinal plants traditionally used in Brazil and Portugal: Plantago major L., Bidens pilosa L., and Pistacia lentiscus L. The primary objective was to expand scientific knowledge of these species by characterizing their chemical composition and diverse bioactive properties.
The plants were characterized regarding their individual profiles in fatty acids, tocopherols, free sugars, and organic acids through adequate chromatographic methodologies. The hydroethanolic extracts were characterized in terms of phenolic composition and antioxidant and antimicrobial activities. The polyphenolic profile was
analyzed by HPLC-DAD-ESI/MS. The antioxidant activity was assessed through the thiobarbituric acid reactive substances (TBARS) formation inhibition. Finally, the antimicrobial activity was assessed by the microdilution method against bacteria and fungi.
P. major exhibited the highest lipid content (1.7 g/100 g dw), followed by P. lentiscus and B. pilosa (1.2 and 0.6 g/100 g dw, respectively). In all species, palmitic acid (C16:0) was the fatty acid detected in higher relative abundance (between 37.8% and 44.1%). The major tocopherol in P. major and P. lentiscus was alpha-tocopherol (35.5 and 1.7 mg/100 g, respectively), and gamma-tocopherol in B. pilosa (0.09 mg/100 g). B. pilosa contained the highest concentration of free sugars (4.5 g/100 g), followed by P. lentiscus and P. major (3.3 and 0.8 g/100 g, respectively). The most abundant organic acid in B. pilosa and P. lentiscus was quinic acid (0.76 and 0.46 g per 100 g, respectively).
In turn, succinic acid was the most abundant in P. major (1.62 g per 100 g), which was also the plant with higher total organic acids. A wide variety of phenolic compounds was identified in all the studied plants. The major phenolic compounds in P. major, B. pilosa,
and P. lentiscus were verbascoside, quercetin-dimethyl ether rutinoside, and galloylquinic acid, respectively. Regarding antioxidant activity, the hydroethanolic extract of P. lentiscus demonstrated the highest activity, followed by B. pilosa and P. major. For the antibacterial activity, P. major extract exhibited activity against all
bacterial strains tested. P. lentiscus was effective against Salmonella enterica, Yersinia enterocolitica, Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus, while B. pilosa was only effective against Escherichia coli and S. enterica. However, none of the plants showed significant antifungal activity against Aspergillus braziliensis and Aspergillus fumigatus.
In conclusion, the chemical composition, antioxidant, and antimicrobial activities of P. major, B. pilosa, and P. lentiscus were studied, which contributes to the scientific understanding of their potential. The results obtained in this study enable further investigation into their extracts and the validation of their traditional uses.As plantas medicinais são amplamente utilizadas em todo o mundo para o tratamento de diversas doenças. Por isso, há um interesse crescente no estudo propriedades bioativas e composição química dessas plantas, uma vez que este conhecimento pode impulsionar avanços significativos em vários setores industriais.
Neste estudo foram estudadas três plantas medicinais tradicionalmente usadas no Brasil e em Portugal: Plantago major L., Bidens pilosa L. e Pistacia lentiscus L. O objetivo principal foi expandir o conhecimento científico sobre essas espécies, através da
caracterização química e avaliação das propriedades bioativas.
As plantas foram caracterizadas quanto aos perfis individuais de ácidos gordos, tocoferóis, açúcares livres e ácidos orgânicos, através das metodologias cromatográficas adequadas. Por sua vez, os extratos hidroetanólicos foram caracterizados em termos de
composição fenólica e atividades antioxidante e antimicrobiana. A composição fenólica foi analisada por HPLC-DAD-ESI/MS. A atividade antioxidante foi avaliada através do ensaio de inibição da formação de substâncias reativas ao ácido tiobarbitúrico (TBARS).
Por fim, a atividade antimicrobiana foi avaliada pelo método de microdiluições sucessivas em bactérias e fungos.
Quanto ao teor lipídico a P. major apresentou o maior teor (1,7 g/100 g extrato), seguido da P. lentiscus e da B. pilosa (1,2 e 0,6 g/100 g extrato, respectivamente). Em todas as espécies estudadas, o ácido palmítico (C16:0) foi o ácido gordo detetado em maior abundância relativa (entre 37,8% e 44,1%). O alfa-tocoferol foi o tocoferol detetado em maior concentração na P. major e na P. lentiscus (35,5 e 1,7 mg/100 g,
respectivamente), enquanto o gama-tocoferol foi a isoforma que exibiu uma maior concentração na B. pilosa (0,09 mg/100 g). A B. pilosa exibiu ainda a maior concentração de açúcares livres (4,5 g/100 g), seguida da P. lentiscus e da P. major (3,3 e 0,8 g/100 g,
respectivamente). O ácido orgânico mais abundante na B. pilosa e P. lentiscus foi o ácido quínico (0,76 e 0,46 g por 100 g, respectivamente). Por outro lado, o mais abundante em P. major foi o ácido succínico (1,62 g por 100 g).
Uma ampla variedade de compostos fenólicos foi identificada em todas as plantas estudadas. Os compostos fenólicos detetados em maior concentração no extrato hidroetanolico da P. major, B. pilosa e P. lentiscus foram verbascosídeo, quercetina-dimetil éter rutinosídeo e ácido galoilquínico, respectivamente. Em relação à atividade
antioxidante, o extrato hidroetanólico da P. lentiscus demonstrou a maior atividade, seguido da B. pilosa e da P. major. Quanto à atividade antibacteriana, o extrato de P. major exibiu atividade contra todas as cepas bacterianas testadas. A P. lentiscus demonstrou atividade contra a Salmonella enterica, Yersinia enterocolitica, Bacillus
cereus, Listeria monocytogenes e Staphylococcus aureus, enquanto a B. pilosa foi eficaz apenas contra a Escherichia coli e a S. enterica. No entanto, nenhuma das plantas mostrou atividade antifúngica significativa contra a Aspergillus braziliensis e a Aspergillus fumigatus.
Em conclusão, foram estudadas a composição química, as atividades antioxidante e antimicrobiana de P. major, B. pilosa e P. lentiscus, o que contribui para o entendimento científico de seu potencial. Os resultados obtidos neste estudo permitem novas investigações sobre seus extratos e a validação de seus usos tradicionais
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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