A Metabolomic Approach to the Study of Wine Micro-Oxygenation

Wine micro-oxygenation is a globally used treatment and its effects were studied here by analysing by untargeted LC-MS the wine metabolomic fingerprint. Eight different procedural variations, marked by the addition of oxygen (four levels) and iron (two levels) were applied to Sangiovese wine, before and after malolactic fermentation

Metabolic constituents of grapevine and grape-derived products

The numerous uses of the grapevine fruit, especially for wine and beverages, have made it one of the most important plants worldwide. The phytochemistry of grapevine is rich in a wide range of compounds. Many of them are renowned for their numerous medicinal uses. The production of grapevine metabolites is highly conditioned by many factors like environment or pathogen attack. Some grapevine phytoalexins have gained a great deal of attention due to their antimicrobial activities, being also involved in the induction of resistance in grapevine against those pathogens. Meanwhile grapevine biotechnology is still evolving, thanks to the technological advance of modern science, and biotechnologists are making huge efforts to produce grapevine cultivars of desired characteristics. In this paper, important metabolites from grapevine and grape derived products like wine will be reviewed with their health promoting effects and their role against certain stress factors in grapevine physiology

A Hybrid Electrochemical Energy Storage Device Using Sustainable Electrode Materials

2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim A new electrochemical energy storage device, comprising a faradaic rechargeable pseudo-capacitor type electrode with a non-faradaic rechargeable capacitor electrode, is successfully developed for potential applications in smart electric grids. Mapping new electrodes possessing both high energy and power densities as well as long cycle life is vital for the sustainable energy management. In this work, we present a new approach to design electrodes, fabricated from sustainable resources by hybridizing calcined eggshell capacitor anode with a mixed binary metal oxide pseudo-capacitor cathode. Calcium carbonate (calcite), obtained from the biowaste-derived eggshell, is an effective electrode material and operates via accumulation of ions on the electrode surface, providing a high discharge capacitance of 100 F/g through a non-faradaic process. The calcite present in eggshells is found to be a valuable renewable resource which can be utilized for energy storage through suitable process design. Otherwise, such potentially useful materials (eggshells) are generally discarded as landfill. The mixed binary metallic oxide (NiO/Co3O4) showed a typical pseudocapacitive behaviour associated with both charge transfer reactions and electrostatic means provided a high discharge capacitance of 225 F/g. The fabricated prototype hybrid device provides an energy density 35 Wh/Kg at a power density 420 W/Kg. The charge storage characteristics of the hybrid device depend heavily on the current rate employed. The design and fabrication of new sustainable electrode materials provides an understanding of materials and their electrochemical performance in the high-voltage window

Nanochannel arrays etched into hexagonal boron nitride meso-membranes by a focused ion beam

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An experimental set up to study the micro-mechanisms of stress corrosion cracking

International audienceAn experimental setup is presented. It aims at studying stress corrosion cracking in a U-notch aluminum alloy sample at a small scale, intermediate between the polycrystal (1mm) and the micro beam (10µm). Digital Image Correlation (DIC) is used to determine the amount of plasticity introduced before crack initiation from the notch tip. The elastic displacement field is also measured by DIC, and numerically calculated, in order to obtain the Stress Intensity Factor (SIF) during crack propagation. The plasticity introduced, at the load level necessary for obtaining initiation, is negligible. It is less than 0.5% at the tip of the notch and less than 0.2% for the rest of the sample. First stress corrosion cracking results show that the SIF values during crack propagation are in between 4 and 6 MPa √ m, being consistent with a SCC intergranular brittle fracture according to the literature. The intergranular nature of the crack is confirmed by a SEM observation of the final fracture surface.Un montage expérimental est présenté. Il est conçu pour l'étude de la fissuration par corrosion sous contrainte, à petite échelle, à partir de micro entailles. Les échantillons ont une taille intermédiaire entre les éprouvettes polycristallines classiques (quelques mm) et les micro-poutres (10 µm). La technique de "corrélation d'images numériques" (CIN) est utilisée pour quantifier la déformation plastique induite par le chargement mécanique nécessaire à l'amorçage de la fissuration depuis le fond d'entaille. Les champs de déplacement élastiques sont aussi mesurés et calculés par "éléments finis" pour obtenir le facteur d'intensité des contraintes (K). La plasticité introduite par le chargement mécanique initial est faible: moins de 0.5% à la pointe de l'entaille, et moins de 0.2% dans le reste de l'échantillon. Les premiers essais de fissuration donnent des valeurs de K entre 4 et 6 MPa √ m, en accord avec la littéra-ture. La nature intergranulaire de la fissuration est confirmée par des observations en microscopie à balayage de faciès de rupture.

Localization of plasmon modes in a 2D photonic nanostructure with a controlled disorder

International audienceIn this paper, we focus on the optical properties of disordered hole arrays etched in a gold thin film. The disorder is induced and controlled using hole displacements following a Gaussian distribution and starting from a periodic array. The nanostructures present a transition from ordered arrays to short-range ordered arrays and random arrays by increasing the disorder amount. The associated optical properties are characterized in far and near fields by complementary approaches (absorption spectroscopy, classical scanning near field optical microscopy (SNOM) and Finite Difference Time Domain (FDTD) simulations). By increasing the disorder, a broadened absorption up to 30% in the far-field is achieved. Experiments in agreement with FDTD simulations point out the energy localization induced by the disorder and the dependence on the amount of disorder and on the excitation wavelength. By using a controlled disorder, we also show that the effect of these two parameters is also closely linked

Assessment of the molecular weight distribution of tannin fractions through MALDI-TOF MS analysis of protein-tannin complexes

An innovative mass spectrometry method was developed for determining mass distributions of tannin fractions that cannot be approached through direct MALDI-TOF analysis. It was applied to three procyanidin fractions with average degrees of polymerizations = 3, 9, and 28, respectively, and one gallotannin fraction (Tara tannin). The proposed approach consists of MALDI-TOF analysis of the soluble complexes formed between these tannin fractions and bovine serum albumin (BSA). Complexes were detected as an unresolved "hump" following the BSA signal, and spectra were mathematically processed to determine the parameters relative to the protein-tannin complexes, which are the number-average molecular weight (Mn), the weight-average molecular weight (Mw), and the polydispersity index (PI) for each tannin fraction. Regarding condensed tannins, results are consistent with those of the standard method (thiolysis followed by HPLC separation) for all tested fractions. The method was successfully applied to a hydrolyzable tannin fraction but no standard method is available for comparison.Comite Interprofessionnel des Vins de Champagne (CIVC) and Moet & Chandon Compan

Detection of enzyme activity at trace levels: A new perspective for the direct screening of active catalytic antibodies

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