1,720,995 research outputs found
Four selected commercial seaweeds: biologically active compounds, antioxidant and cytotoxic properties
Full text linkThe aim of this research work was to study the chemical characterisation, antioxidant and cytotoxic activity of ethanolic extracts of four commercial algae species Arame, Kombu, Hijiki and Wakame. The highest scavenging activity has been observed in Arame extract. Antioxidant potential of all extracts was in correlation with total phenol content (Arame extract: 319.15 + - 0,56 mg GAE/g. d.w) and it was not in correlation with total carotenoids content (Wakame: 75.15 + - 0.20 mg/g). Polyphenols were quantified using LC-MS/MS technique. Baicalein and amentoflavone were identified in higher amount in relation to other phenols. Intracellular antioxidant activity and cytotoxicity of algae extracts were evaluated on the human prostate cancer cell line PC3. Although presented biomolecules in the extracts have demonstrated in vitro antioxidant activity, they did not show a significant effect on PC3 cells. However, this study opens up a broad perspective for the further comprehensive investigaton of these, commercial, sea weed's biopotential
Expression pattern of the specific nuclear phospholipid hydroperoxide glutathione peroxidase during male germ cell differentiation in the rat
No full textBioavailability of flavonoids: The role of cell membrane transporters
No full textDietary flavonoids play an important role in the prevention of diseases related to oxidative stress in living systems. Although much attention has been focused on studying the protective functions of flavonoids, so far only limited biochemical research was done to tackle the fundamental issue of how flavonoids enter cells. Flavonoids have limited bioavailability, and consequently low plasma concentrations. Thus, in order to enter the intracellular compartment of cells in target tissues, flavonoids must exploit specific cell membrane transporter systems. This interaction between flavonoids and the proteins that mediate their transmembrane transport is of critical importance since it affects both the pharmacokinetic and pharmacodynamic properties of the flavonoids. Extensive knowledge of cell membrane transporters is therefore essential to fully understand the mechanisms of flavonoid-mediated protective activity in the cardiovascular, renal, hepatic, and central nervous systems, and also to elucidate flavonoid-drug interactions
Polymer Conjugates of Antimicrobial Peptides (AMPs) with D-Amino Acids (D-aa): State of the Art and Future Opportunities
Full text linkIn recent years, antimicrobial peptides (AMPs) have enjoyed a renaissance, as the world is currently facing an emergency in terms of severe infections that evade antibiotics’ treatment. This is due to the increasing emergence and spread of resistance mechanisms. Covalent conjugation with polymers is an interesting strategy to modulate the pharmacokinetic profile of AMPs and enhance their biocompatibility profile. It can also be an effective approach to develop active coatings for medical implants and devices, and to avoid biofilm formation on their surface. In this concise review, we focus on the last 5 years’ progress in this area, pertaining in particular to AMPs that contain D-amino acids, as well as their role, and the advantages that may arise from their introduction into AMPs
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
Exceptionally fast uptake and metabolism of cyanidin 3-glucoside by rat kidneys and liver
No full textTo asses the hypothesis that anthocyanins are
rapidly taken up from the blood into tissues, where they accumulate up to their bioactivity threshold, an intravenous
dose of cyanidin 3-glucoside (1) was administered to anaesthetized rats. Cyanidin 3-glucoside (1) and its metabolites were
analyzed in the plasma, kidneys, liver, urine, and bile, using lastgeneration
mass spectrometry. Compound 1 was found to
rapidly disappear from plasma (t/2 = 0.36 min). As soon as 15 s after its administration, both 1 and its methylation product, peonidin 3-glucoside (2), were detected in the plasma, kidneys, and liver. At 1 min, both 1 and 2 had almost disappeared from the plasma, but attained their peak concentrations in the kidneys and in the liver. Compound 2 was rapidly excreted both in the bile and in the urine. Three additional methylated metabolites were detected in traces, namely, delphinidin 3-glucoside (3), petunidin 3-glucoside (4), and malvidin 3-glucoside (5).
These data contribute to solving the paradox of the high bioactivity of anthocyanins in spite of their apparent low bioavailability
Target versus non-target analytical approach for describing the metabolism of anthocyanins in rat
No full textVariations 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
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