1,061 research outputs found

    Oxymoron, a Non-Distance Knowledge Sharing Tool for Social Science Students and Researchers

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    Oxymoron is a World Wide Web based knowledge capitalization and sharing tool that was conceived and developed by a multidisciplinary team, comprised of adult education and distributed systems professionals from France and Switzerland. Oxymorons aim is to support and facilitate the work of students and researchers in social science by providing them with a system where they can contribute and obtain knowledge about the relevant readings in their fields of interest

    Squaramide-catalyzed asymmetric Mannich reaction between 1,3-dicarbonyl compounds and pyrazolinone ketimines: A pathway to enantioenriched 4-pyrazolyl- and 4-isoxazolyl-4-aminopyrazolone derivatives

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    Producción CientíficaA series of N-Boc ketimines derived from pyrazolin-5-ones have been used as electrophiles in enantioselective Mannich reactions with different 1,3-dicarbonyl compounds. This method provides a direct pathway to access the 4-amino-5-pyrazolone derivatives bearing a quaternary substituted stereocenter and containing two privileged structure motifs, the β-diketone and pyrazolinone substructures. The adducts were obtained in excellent yields (up to 90%) and enantioselectivities (up to 94:6 er) by employing a very low loading of 2 mol% of a quinine-derived bifunctional squaramide as an organocatalyst for a wide range of substrates. In addition, the utility of the obtained products was demonstrated through one step transformations to enantioenriched diheterocyclic systems (4-pyrazolyl-pyrazolone and 4-isoxazolyl-pyrazolone), potentially promising candidates for drug discovery

    Lipidomic approach in young adult triathletes: effect of supplementation with a polyphenols-rich juice on neuroprostane and F2-dihomo-isoprostane markers

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    The aim of the this study was to determine the effect of a polyphenols-rich juice (aronia-citrus juice, ACJ) on F4-neuroprostanes and F2-dihomo-isoprostanes—markers of oxidative stress associated with the central nervous system (CNS)—in 16 elite triathletes under a controlled diet for triathlon training (145 days). In the triathletes, a decrease of the lipid peroxidation markers after ACJ intake, associated with neuronal membrane degradation (10-epi-10-F4t-neuroprostane and 10-F4t-neuroprostane), was observed when compared with placebo stage values. Regarding the F2-dihomo-isoprostanes, a significant decrease of the neuromotor system damage biomarkers (17-F2t-dihomo-isoprostane) with an increase of training load during the study was observed, although the decrease of the load training at the last stage showed a significant increase of the values of ent-7-(RS)-7-F2t-dihomo-IsoP, suggesting a possible role in adaptation post-training. On the other hand, the changes in the excretion of 17-epi-17-F2t-dihomo-IsoP provided a positive connection between physical exercise and ACJ intake. Thus, the results showed in this clinical study in young triathletes will help to elucidate novel interactions and mechanisms between the excretion of lipid peroxidation metabolites from CNS, supplementation of polyphenols-rich juice in the diet and physical exercise during a training season.This study was supported by the project AGL2011-23690 (CICYT) (Spanish Ministry of Economy and Competitiveness). This work has been partially funded by the “Fundación Séneca de la Región de Murcia” Grupo de Excelencia 19900/GERM/15. LAGF was granted a pre-doctoral FPI fellowship (BES2012-060185) by the Spanish government

    Assessment oxidative stress biomarkers –neuroprostanes and dihomo-isoprostanes- in elite triathletes urine after two weeks of moderate altitude training

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    This randomized and controlled trial investigated whether the increase in elite training at different altitudes altered the oxidative stress biomarkers of the nervous system. This is the first study to investigate four F4-neuroprostanes and four F2-dihomo-isoprostanes quantified in 24-hour urine. The quantification was carried out by Ultra High Pressure Liquid Chromatography-triple Quadrupole-Tandem Mass Spectrometry (UHPLC-QqQ-MS/MS). Sixteen elite triathletes agreed to participate in the project. They were randomized in two groups, a group submitted to Altitude Training (n=8) and a group submitted to Sea Level Training (n=8), with a Control group of non-athletes (n=8). After experimental period, the Altitude Training group triathletes gave significant data: 17-epi-17-F2t-dihomo-IsoP (from 5.2 ± 1.4 µg/mL 24 h-1 to 6.6 ± 0.6 µg/mL 24 h-1), ent-7(RS)-7-F2t-dihomo-IsoP (from 6.6 ± 1.7 µg/mL 24 h-1 to 8.6 ± 0.9 µg /mL 24 h-1), and ent-7-epi-7-F2t-dihomo-IsoP (from 8.4 ± 2.2 µg/mL 24 h-1 to 11.3 ± 1.8 µg/mL 24 h-1) increased, while, of the neuronal degeneration-related compounds, only 10-epi-10-F4t-NeuroP (8.4 ± 1.7 µg/mL 24 h-1) and 10-F4t-NeuroP (5.2 ± 2.9 µg/mL 24 h-1) were detected in this group. For the control group and sea level training groups, no significant changes had occurred at the end of the 2-weeks experimental period. Therefore, and as the main conclusion, the training at moderate altitude increased the F4-NeuroPs- and F2-dihomo-isoPs-related oxidative damage of the central nervous system (CNS) compared to similar training at sea level.This study was supported by the project AGL2011-23690 (CICYT) (Spanish Ministry of Economy and Competitiveness). LAGF was granted with a pre-doctoral FPI fellowship BES2012-060185 by the Spanish government. The authors are also grateful to the University of Alicante for its collaboration. Sonia Medina was appointed under a research contract from the project AGL2011-23690 (CICYT)

    Dietary antioxidant intake is inversely associated with 2,3-dinor oxylipin metabolites, the major excreted oxylipins in overweight and obese subjects

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    Cardiometabolic disease risk factors, including obesity, insulin resistance, high blood pressure, and dyslipidemia, are associated with elevated oxidative stress biomarkers like oxylipins. Increased adiposity by itself induces various isomers of this oxidized lipid family, while dietary polyphenols show benefits in its regulation. Previously, we showed that specific co-abundant microorganisms characterized the gut microbiota of Colombians and associated differentially with diet, lifestyle, obesity, and cardiometabolic health status, which led us to hypothesize that urinary oxylipins would reflect the intensity of oxidative metabolism linked to gut microbiota dysbiosis. Thus, we selected a convenience sample of 105 participants (age: 40.2 ± 11.9 years, 47.6% women), grouped according to microbiota, cardiometabolic health status, and body mass index (BMI); and evaluated 33 urinary oxylipins by HPLC-QqQ-MS/MS (e.g., isoprostanes, prostaglandins, and metabolites), paired with anthropometry and blood chemistry information and dietary antioxidants estimated from a 24-h food recall. In general, oxylipins did not show differences among individuals who differed in gut microbiota. While the unmetabolized oxylipin levels were not associated with BMI, the total content of oxylipin metabolites was highest in obese and cardiometabolically abnormal subjects (e.g., insulin resistant), mainly by prostaglandin-D (2,3-dinor-11β-PGF) and 15-F-IsoPs (2,3-dinor-15-F-IsoP and 2,3-dinor-15-epi-15-F-IsoP) metabolites. The total polyphenol intake in this cohort was 1070 ± 627 mg/day. After adjusting for body weight, the polyphenol intake was significantly higher in lean than overweight and showed an inverse association with dinor-oxylipin levels in principal component analysis. These results suggest that the 2,3-dinor-oxylipins could be more specific biomarkers associated with BMI than their parent oxylipins and that are sensitive to be regulated by dietary antioxidants.The authors thank the volunteers who agreed to participate in this study, the Colombian Ministry of science, technology, and innovation (Minciencias; grant number 832-2018), and Grupo Empresarial Nutresa. They also thank the Ibero-American Programme for Science, Technology and Development (CYTED) – Action 112RT0460 CORNUCOPIA networ

    Effect of Coffee and Cocoa-Based Confectionery Containing Coffee on Markers of DNA Damage and Lipid Peroxidation Products: Results from a Human Intervention Study

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    The effect of coffee and cocoa on oxidative damage to macromolecules has been investigated in several studies, often with controversial results. This study aimed to investigate the effect of one-month consumption of different doses of coffee or cocoa-based products containing coffee on markers of DNA damage and lipid peroxidation in young healthy volunteers. Twenty-one volunteers were randomly assigned into a three-arm, crossover, randomized trial. Subjects were assigned to consume one of the three following treatments: one cup of espresso coffee/day (1C), three cups of espresso coffee/day (3C), and one cup of espresso coffee plus two cocoa-based products containing coffee (PC) twice per day for 1 month. At the end of each treatment, blood samples were collected for the analysis of endogenous and H(2)O(2)-induced DNA damage and DNA oxidation catabolites, while urines were used for the analysis of oxylipins. On the whole, four DNA catabolites (cyclic guanosine monophosphate (cGMP), 8-OH-2′-deoxy-guanosine, 8-OH-guanine, and 8-NO2-cGMP) were detected in plasma samples following the one-month intervention. No significant modulation of DNA and lipid damage markers was documented among groups, apart from an effect of time for DNA strand breaks and some markers of lipid peroxidation. In conclusion, the consumption of coffee and cocoa-based confectionery containing coffee was apparently not able to affect oxidative stress markers. More studies are encouraged to better explain the findings obtained and to understand the impact of different dosages of these products on specific target groups

    Effect of Coffee and Cocoa-Based Confectionery Containing Coffee on Markers of DNA Damage and Lipid Peroxidation Products: Results from a Human Intervention Study

    Get PDF
    The effect of coffee and cocoa on oxidative damage to macromolecules has been investigated in several studies, often with controversial results. This study aimed to investigate the effect of one-month consumption of different doses of coffee or cocoa-based products containing coffee on markers of DNA damage and lipid peroxidation in young healthy volunteers. Twenty-one volunteers were randomly assigned into a three-arm, crossover, randomized trial. Subjects were assigned to consume one of the three following treatments: one cup of espresso coffee/day (1C), three cups of espresso coffee/day (3C), and one cup of espresso coffee plus two cocoa-based products containing coffee (PC) twice per day for 1 month. At the end of each treatment, blood samples were collected for the analysis of endogenous and H2O2-induced DNA damage and DNA oxidation catabolites, while urines were used for the analysis of oxylipins. On the whole, four DNA catabolites (cyclic guanosine monophosphate (cGMP), 8-OH-2′-deoxy-guanosine, 8-OH-guanine, and 8-NO2-cGMP) were detected in plasma samples following the one-month intervention. No significant modulation of DNA and lipid damage markers was documented among groups, apart from an effect of time for DNA strand breaks and some markers of lipid peroxidation. In conclusion, the consumption of coffee and cocoa-based confectionery containing coffee was apparently not able to affect oxidative stress markers. More studies are encouraged to better explain the findings obtained and to understand the impact of different dosages of these products on specific target groups
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