Validation of a Mass Spectrometry Method To Quantify Oak Ellagitannins in Wine Samples

[EN] Detection and individual quantification of oak wood ellagitannins in oak barrel aged red wine samples are difficult mainly due to their low levels and the similarity between their structures. In this work, a quantification method using mass spectrometry has been developed and validated to quantify wine ellagitannins after sample fractionation with a previously reported method. The use of an internal standard is a requirement to correct mass signal variability. (−)-Gallocatechin, among the different tested compounds, was the only one that proved to be a suitable internal standard making possible the accurate and individual quantification of the main oak wood ellagitannins. The developed methodology has been used to detect and quantify these ellagitannins in different Spanish commercial wines, proving its usefulness

Altimetry for the future: Building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the ‘‘Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

Altimetry for the future: building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the “Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

Theoretical investigation of the ultrafast dissociation of core-ionized water and uracil molecules immersed in liquid water

International audienceWe present a series of ab initio density functional based calculations of the fragmentation dynamics of core-ionized biomolecules. The computations are performed for pure liquid water, aqueous and isolated Uracil. Core ionization is described by replacing the 1s2 pseudopotential of one atom of the target molecule (C, N or O) with a pseudopotential for a 1s1 core-hole state. Our results predict that the dissociation of core-ionized water molecules may be reached during the lifetime of inner-shell vacancy (less than 10 fs), leading to OH bond breakage as a primary outcome. We also observe a second fragmentation channel in which total Coulomb explosion of the ionized water molecule occurs. Fragmentation pathways are found similar for pure water or when the water molecule is in the primary hydration shell of the uracil molecule. In the latter case, the proton may be transferred towards the uracil oxygen atoms. When the core hole is located on the uracil molecule, ultrafast dissociation is only observed in the aqueous environment and for nitrogen-K vacancies, resulting in proton transfers towards the hydrogen-bonded water molecul

Polyphenols isolated from the bark of Castanea Sativa. Mill. Chemical structures and auto-association

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Theoretical investigation of the ultrafast dissociation of ionised biomolecules immersed in water: Direct and indirect effects

Theoretical simulations are particularly well suited to investigate, at a molecular level, direct and indirect effects of ionising radiations in DNA, as in the particular case of irradiation by swift heavy ions such as those used in hadron therapy. In the past recent years, we have developed the modeling at the microscopic level of the early stages of the Coulomb explosion of DNA molecules immersed in liquid water that follows the irradiation by swift heavy ions. To that end, Time-Dependent Density Functional Theory molecular dynamics simulations (TD-DFT MD) have been developed where localised Wannier orbitals are propagated. This latter enables to separate molecular orbitals of each water molecule from the molecular orbitals of the biomolecule

Theoretical investigation of the ultrafast dissociation of ionised biomolecules immersed in water: Direct and indirect effects

International audienceTheoretical simulations are particularly well suited to investigate, at a molecular level, direct and indirect effects of ionising radiations in DNA, as in the particular case of irradiation by swift heavy ions such as those used in hadron therapy. In the past recent years, we have developed the modeling at the microscopic level of the early stages of the Coulomb explosion of DNA molecules immersed in liquid water that follows the irradiation by swift heavy ions. To that end, Time-Dependent Density Functional Theory molecular dynamics simulations (TD-DFT MD) have been developed where localised Wannier orbitals are propagated. This latter enables to separate molecular orbitals of each water molecule from the molecular orbitals of the biomolecule.Our main objective is to demonstrate that the double ionisation of one molecule of the liquid sample, either one water molecule from the solvent or the biomolecule, may be in some cases responsible for the formation of an atomic oxygen as a direct consequence of the molecule Coulomb explosion. Our hypothesis is that the molecular double ionisation arising from irradiation by swift heavy ions (about 10% of ionisation events by ions whose velocity is about the third of speed of light), as a primary event, though maybe less probable than other events resulting from the electronic cascading (for instance, electronic excitations, electron attachments), may be systematically more damageable (and more lethal), as supported by experiments that have been carried out in our group in the 1990s (in studies of damages created by K holes in DNA). The chemical reactivity of the produced atomic oxygen with other radicals present in the medium will ultimately lead to chemical products that are harmful to DNA.In the present paper, we review our theoretical methodology in an attempt that the community be familiar with our new approach. Results on the production of atomic oxygen as a result of the double ionisation of water or as a result of the double ionisation of the Uracil RNA base will be presented

Coupling an Electron Time-of-flight Spectrometer and an under Vacuum Liquid Jet for Coincidence Measurements on Solvated Biomolecules

International audienceRadiation damage of biological systems is a complex multi-scale problem, not only in the spatial domain but also in the temporal domain. While interactions start at the atomic level (from atto-to femto-second), they can impact the molecular level (femto-to pico-second) and ultimately affect a cell's behavior over hours or days, culminating, in the worst case, in a full breakdown of a living organism over months to years. Photoelectron spectroscopy constitutes one of the basic experimental methods to study processes initiated by interaction of light with matter. It is widely applied in experiments or photoionization of gaseous, solid, and more recently, in liquid media. The Magnetic Bottle Time-Of-Flight (MB-TOF) is specially designed to study multi-electron processes. Indeed, due to its almost 4$\pi$ electron collection efficiency, it is well suited to studying the early stages of an inner-shell photoionization, via coincidence techniques between the photoelectron and the resulting Auger electrons. Thus, coupled with an under vacuum liquid jet, it allows to investigate the different relaxation pathways of biomolecules in an aqueous media, after being irradiated by soft X-ray radiation. We will present the first results obtained on different solutes and highlight how it is possible to clearly disentangle the liquid phase signal from the signal arising from the surrounding gas phase water. Particular attention will be drawn to non-local energy transfers (between the solute and water molecules) such as interatomic coulombic decay or electron transfer mediated decay

Sea surface temperature patterns in the Tropical Atlantic: Principal component analysis and nonlinear principal component analysis

The tropical Atlantic Ocean exhibits several modes of interannual variability such as the equatorial (or Atlantic Niño) mode, and meridional (or Atlantic dipole) mode. Nonlinear principal component analysis (NLPCA) is applied on detrended monthly Sea Surface Temperature Anomaly (SSTA) data from the tropical Atlantic Ocean (30°W - 20°E, 26°S - 22°N) for the period 1950 to 2005. The objective is to compare the modes extracted through this statistical analysis to those previously extracted through simpler principal component analysis (PCA). It is shown that the first NLPCA mode explains 38% of the total SST variance compared to 36% by the first PCA while the second NLPCA mode explains 22% of the total SST variance compared to 16% by the second PCA. The first two NLPCA modes marginally explain more of the total data variance than the first two PCA modes. Our analysis confirms results from previous studies and, in addition, shows that the Atlantic El Niño structure is spatially more stable than the Atlantic dipole structure

Modeling proton-induced damage on 2-deoxy-D-ribose. Conformational analysis

International audienceModeling proton-induced damage in biological systems, in particular in DNA building blocks, is of major concern in studies on cancer proton therapy. This is indeed an extremely complex process and analysis of the mechanism at the molecular level is of crucial interest. Such collision reactions of protons on biological targets induce different reactions: excitation and ionization of the biomolecule, fragmentation of the ionized species, and charge transfer from the projectile ion toward the biomolecular target. In order to have an insight into such mechanisms, we have performed a theoretical approach of two of the most important steps, the fragmentation and the charge transfer processes. For that purpose, we have considered collision of protons with isolated 2-deoxy-D-ribose by means of ab-initio molecular dynamics and quantum chemistry molecular methods. The conformation of the sugar moiety has been analyzed and appears to induce important effects, in particular different fragmentation patterns have been pointed out with regard to the conformation, and significant variations of the charge transfer cross sections have been exhibited