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Full text linkBuffalo milk contributes to 13% of the world milk production and is abundantly produced in Southern Italy regions. Buffalo milk is appreciated for its nutritive properties and is highly suitable for the manufacturing of wide range of dairy products. Several studies showed many bioactive peptides in different dairy species such as bovine, ovine and caprine milk, but few studies have been conducted on the buffalo dairy products (1). The present work is focused on the identification of bioactive peptides released after in vitro simulated gastrointestinal digestion of protein fraction isolated from buffalo-milk dairy products by ultra- and nanofiltration pilot plant.
The gastrointestinal digests of protein fractions were monitored by RP-UHPLC-DAD, while, the peptide identification was carried out by UHPLC-Orbitrap-based tandem mass spectrometry. 165 peptides were identified in Yoghurt, 152 in Scamorza, 146 in Mozzarella, 136 in Grana and Ricotta and 120 in Ice Cream samples (1). The peptides belong to both buffalo caseins (αs1-, β-, k-CN) and whey proteins (α-LA, β-LG).
Six G.I. digests of dairy products were tested in a model of oxidative stress using IEC-6 cells. Among them, buffalo ricotta cheese was the most active. UHPLC-PDA-MS/MS analysis revealed the presence of two abundant β-lactoglobulin peptides (BRP: YVEELKPTPEGDL, f:60-72 and BRP2: SFNPTQL, f:168-174). To confirm the hypothesized chemical structures and study their specific biological activity, the peptides were synthesized by conventional solid-phase peptide synthesis methods. The antioxidant potential of the identified peptides was then evaluated in a model of hydrogen peroxide induced oxidative stress in IEC-6 cell line. The peptides reduce ROS release and increase nuclear factor (erythroid-derived 2)-like 2 activation and the expression of antioxidant cytoprotective factors such as heme oxygenase 1, NAD(P)H: quinone oxidoreductase 1 and superoxide dismutase (2). The bioavailability of β-lactoglobulin peptides was evaluated in intestinal transport studies through Caco-2 cell monolayer. Only BRP2 showed equal bi-directional transport and linear permeability, suggesting that it was mainly absorbed through passive diffusion. In addition to its local effects, administration of BPR2 on mice mesenteric arteries counteracts the Angiotensin II-induced vasoconstriction by Nrf2 nuclear translocation, reduction of active form of Ras-related C3 botulinum toxin substrate 1 (Rac1) and NADPH oxidase activity. The analysis at molecular level of treated vessels showed an induction of Nrf2 translocation to nucleus associated with increased expression of MnSOD and Rac1 deactivation.
The data indicate how protein fraction of buffalo ricotta cheese could be an important source of antioxidant compounds, as well as YVEELKPTPEGDL and SFNPTQL peptides could be considered as an “ingredient” for nutraceuticals formulations and functional and personalized foods, in order to prevent the onset of some gastrointestinal pathologies and cardiovascular diseases
XXVI National Meeting in Medicinal Chemistry
No full textBuffalo dairy products are an important source of bioactive peptides. These are inactive, since encrypted in
their parent sequences, but turn active when released by fermentation or ripening during food processing,
or by digestive enzymes during gastrointestinal transit.1 Once released, the bioactive peptides are able to
exert either local or systemic pharmacological effects, involving specific biochemical pathways and leading
to the identification of undisclosed drug-target interactions. This is why food-derived bioactive peptides,
particularly from dairy products, are attractive tools for drug discovery campaigns.2
In the present study, to evaluate the biological activities of encrypted peptide sequences from buffalo ricotta
cheese, a simulated gastrointestinal (GI) digestion of the raw material was performed.3 Chemical and
pharmacological characterization of the digest leads to the identification of a novel peptide endowed with
antioxidant and anti-hypertensive action. The GI digest was fractionated by Semiprep-HPLC and fractions
were tested against reactive oxygen species (ROS) release in H2O2-treated intestinal epithelial cell line.
UHPLC-PDA-MS/MS a -lactoglobulin peptide (SFNPTQL, BPR2)
in the most active fraction. The peptide was synthesized via Fmoc chemistry solid phase peptide synthesis
and pharmacologically characterized. Pharmacological assays revealed the antioxidant activity of BPR2,
involving ROS reduction, Nuclear factor erythroid 2-related factor 2 (Nrf2) activation and cytoprotective
enzymes expression. Bioavailability studies through Caco-2 cell monolayer3 revealed equal bi-directional
transport and linear permeability of BPR2, consistent with a passive diffusion mechanism. In addition to its
local effects, administration of BPR2 on mice mesenteric arteries counteracts the Angiotensin II-induced
vasoconstriction by Nrf2 nuclear translocation, reduction of active form of Ras-related C3 botulinum toxin
substrate 1 (Rac1) and NADPH oxidase activity. These data suggest a specific further highlight the role of
buffalo ricotta cheese-derived peptides against oxidative stress related diseases and suggest their health
promoting potential. Further studies are ongoing to identify the specific BPR2 structure-activity relationship
and to identify its biological targets
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
Leveraging the potential of 1.0-mm i.d. columns in UHPLC-HRMS-based untargeted metabolomics
No full textUntargeted metabolomics UHPLC-HRMS workflows typically employ narrowbore 2.1-mm inner diameter (i.d.) columns. However, the wide concentration range of the metabolome and the need to often analyze small sample amounts poses challenges to these approaches. Reducing the column diameter could be a potential solution. Herein, we evaluated the performance of a microbore 1.0-mm i.d. setup compared to the 2.1-mm i.d. benchmark for untargeted metabolomics. The 1.0-mm i.d. setup was implemented on a micro-UHPLC system, while the 2.1-mm i.d. on a standard UHPLC, both coupled to quadrupole-orbitrap HRMS. On polar standard metabolites, a sensitivity gain with an average 3.8-fold increase over the 2.1-mm i.d., along with lower LOD (LODavg 1.48 ng/mL vs. 6.18 ng/mL) and LOQ (LOQavg 4.94 ng/mL vs. 20.60 ng/mL), was observed. The microbore method detected and quantified all metabolites at LLOQ with respect to 2.1, also demonstrating good repeatability with lower CV% for retention times (0.29% vs. 0.63%) and peak areas (4.65% vs. 7.27%). The analysis of various samples, in both RP and HILIC modes, including different plasma volumes, dried blood spots (DBS), and colorectal cancer (CRC) patient-derived organoids (PDOs), in full scan-data dependent mode (FS-DDA) reported a significant increase in MS1 and MS2 features, as well as MS/MS spectral matches by 38.95%, 39.26%, and 18.23%, respectively. These findings demonstrate that 1.0-mm i.d. columns in UHPLC-HRMS could be a potential strategy to enhance coverage for low-amount samples while maintaining the same analytical throughput and robustness of 2.1-mm i.d. formats, with reduced solvent consumption
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