High Level Parallelization of a 3D Electromagnetic Simulation Code With Irregular Communication Patterns

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Complexation of Th(IV) and U(VI) with a new tetrahydroxamic acid by affinity capillary electrophoresis

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Complexation of Th(IV) and U(VI) with a new tetrahydroxamic acid by affinity capillary electrophoresis

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Parallelization of a Fortran 90 Program for Electromagnetic Problems

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Two distinct pathways account for EDHF-dependent dilatation in the gracilis artery of dyslipidaemic hApoB(+/+) mice

1. A universal endothelium-derived hyperpolarising factor (EDHF – non-NO/non-PGI(2)) has not been identified. EDHF, however, is essential for the physiological control of resistance artery tone. The impact of dyslipidaemia (DL), a risk factor for cardiovascular diseases, on the nature and the efficacy of EDHF has not been evaluated yet. 2. Pressurised (80 mmHg) gracilis arterial segments isolated from mice expressing the human apoB-100 and C57Bl/6 wild-type (WT) mice were used. EDHF-dependent dilatations to acetylcholine (ACh) were measured in the presence of L-NNA (100 μM, NOS inhibitor) and indomethacin (10 μM, COX inhibitor). 3. Maximal EDHF-induced dilatations were increased in DL when compared to WT (95±2 versus 86±4% in WT; P<0.05). Combination of apamin and charybdotoxin strongly reduced (P<0.05) ACh-induced dilatation in WT (22±4%) and DL (25±5%). 4. Combined addition of barium (Ba(2+)) and ouabain abolished EDHF-induced dilatations in WT arteries (13±3%; P<0.05). In vessels isolated from DL mice, however, only the addition of 14,15-EEZE (a 14,15-EET antagonist) to Ba(2+) and ouabain prevented EDHF-induced dilatations (5±3% compared to 54±11% in the presence of combined Ba(2+) and ouabain; P<0.05). 5. Our data suggest that EDHF-mediated dilatation depends on the opening of endothelial SK(Ca) and IK(Ca) channels. This is associated with the opening of K(ir) channels and activation of the Na(+)/K(+)-ATPase pump on smooth muscle cells leading to dilatation. In arteries from DL mice, a cytochrome P450 metabolite likely to be 14,15-EET equally contributes to the dilatory action of ACh. The early increased efficacy of EDHF in arteries isolated from DL mice may originate from the duplication of the EDHF pathways

Improving the performances of Diffusive Gradient in Thin-films (DGT) technique to measure the labile uranyl concentration in environmental waters by employing the chelating properties of siderochelates

International audienceUranium (U) presents a unique challenge for ecological risk assessments around installations related to the nuclear fuel cycle because of both chemical and radiological toxicity. Their relative importance depends on the chemical speciation and isotopic composition of the radionuclide, the latter being strongly correlated to its natural or anthropogenic origin (enriched or depleted U) [1]. In this framework, the Diffusive Gradient in Thin-films (DGT) technique is an appealing tool for monitoring the water quality around uranium processing plants, nuclear facilities or mining areas. Indeed, the DGT sampling allows to preconcentrate in situ the labile U(VI) species, allowing to simultaneously characterize the labile UO22+ fraction in aqueous phase (i.e., this provides qualitative information on the "available stock of UO22+ for the aquatic organisms") and the isotopic composition at trace levels [2]. Among the eleven DGT methods developed for UO22+ [3], the ones containing Chelex-100® (an ion-exchange resin with iminodiacetic acid functional groups) or Metsorb® (a TiO2-based adsorbent) are the most employed due to their commercial availability. Nevertheless, their performances can be significantly degraded by high concentration levels of competing ions like Ca2+ in the deployment solution, which results in the underestimation of the overall concentration of labile U(VI) species in environmental waters [3, 4]. To improve the reliability of measurements, further analytical developments are therefore required. One important research direction includes the design of more selective UO22+ sorbent materials.In this study, we propose new DGT samplers for labile UO22+ species that incorporate novel complexing materials obtained by the covalent grafting of siderophore-like chelators on a hydrophilic organic resin. Siderophores are well-known to exhibit a high affinity for strong Lewis acids, such as iron(III) and actinide cations [5-7]. Rigorous laboratory validation of the new DGT devices was conducted, confirming the suitability of the samplers to quantitatively measure all UO22+ species in simple matrices in which UO22+-CO32– complexes dominate the speciation of U. In addition, cross-tests were performed with commercial Chelex-100® and Metsorb® based-DGT devices on several types of moderately basic waters (pH ≈ 8), either in the laboratory (i.e., soft and hard mineral waters and seawater) or during field tests. DGT probes were deployed in the alkaline surface water of the Œuf River, a tributary to the Seine River (France), in which Ca2+-UO22+-CO32– complexes are the dominant U species according to speciation modelling calculations. These experiments highlighted the superiority of the new DGT devices over those incorporating either Chelex-100® or Metsorb® sorbents. Finally, thermodynamic speciation calculations were performed as a first approach to better understand the functioning and potential limitations of our new and Chelex-100®-based DGT samplers in different deployment conditions.Acknowledgements:This work has been supported by IRSN, CNRS, and the French grant agency Agence Nationale de la Recherche (project PLUTON, grant n° ANR-17-CE08-0053). Osian FONQUERNIE and Tony FERNANDES are grateful to the Conseil Régional de Bourgogne Franche-Comté and the European Regional Development Fund (FEDER) for granting them a PhD fellowship. The authors thank Graver Technologies (www.gravertech.com) for the provision of the Metsorb® HMRP 50 products used in this study. All DGT experiments were performed at LUTECE (the SEDRE's experimental platform), and isotopic measurements at PATERSON (the IRSN's mass spectrometry platform). This work benefited from the knowledge acquired on the spatial and temporal distribution of U concentration in the Œuf-Essonne River through the research project UTOPIA conducted by Dr Mathilde ZEBRACKI (IRSN) and funded by the French program NEEDS.References:[1]T. Mathews, K. Beaugelin-Seiller, J. Garnier-Laplace, R. Gilbin, C. Adam, C. Della-Vedova, Environ. Sci. Technol. 2009, 43, 6684-6690[2]G. S. C. Turner, G. A. Mills, M. J. Bowes, J. L. Burnett, S. Amos, G. R. Fones, Environ. Sci.: Processes Impacts 2014, 16, 393-403.[3]V. Smolíková, P. Pelcová, A. Ridošková, M. Leermakers, Talanta 2022, 240, 123168.[4]G. S. C. Turner, G. A. Mills, P. R. Teasdale, J. L. Burnett, S. Amos, G. R. Fones, Anal. Chim. Acta 2012, 739, 37-46.[5]M. P. Neu, J. H. Matonic, C. E. Ruggiero, B. L. Scott, Angew. Chem. Int. Ed. 2000, 39, 1442-1444.[6]H. Boukhalfa, G. A. Icopini, S. D. Reilly, M. P. Neu, Appl. Environ. Microbiol. 2007, 73, 5897-5903.[7]L. Février, F. Coppin, S. Pierrisnard, M. Bourdillon, L. V. Nguyen, N. Zaiter, S. Brandès, V. Sladkov, J.-C. Chambron, M. Meyer, J. Environ. Radioact. 2021, 235-236, 106645

Improving the performances of Diffusive Gradient in Thin-films (DGT) technique to measure the labile uranyl concentration in environmental waters by employing the chelating properties of siderochelates

International audienceUranium (U) presents a unique challenge for ecological risk assessments around installations related to the nuclear fuel cycle because of both chemical and radiological toxicity. Their relative importance depends on the chemical speciation and isotopic composition of the radionuclide, the latter being strongly correlated to its natural or anthropogenic origin (enriched or depleted U) [1]. In this framework, the Diffusive Gradient in Thin-films (DGT) technique is an appealing tool for monitoring the water quality around uranium processing plants, nuclear facilities or mining areas. Indeed, the DGT sampling allows to preconcentrate in situ the labile U(VI) species, allowing to simultaneously characterize the labile UO22+ fraction in aqueous phase (i.e., this provides qualitative information on the "available stock of UO22+ for the aquatic organisms") and the isotopic composition at trace levels [2]. Among the eleven DGT methods developed for UO22+ [3], the ones containing Chelex-100® (an ion-exchange resin with iminodiacetic acid functional groups) or Metsorb® (a TiO2-based adsorbent) are the most employed due to their commercial availability. Nevertheless, their performances can be significantly degraded by high concentration levels of competing ions like Ca2+ in the deployment solution, which results in the underestimation of the overall concentration of labile U(VI) species in environmental waters [3, 4]. To improve the reliability of measurements, further analytical developments are therefore required. One important research direction includes the design of more selective UO22+ sorbent materials.In this study, we propose new DGT samplers for labile UO22+ species that incorporate novel complexing materials obtained by the covalent grafting of siderophore-like chelators on a hydrophilic organic resin. Siderophores are well-known to exhibit a high affinity for strong Lewis acids, such as iron(III) and actinide cations [5-7]. Rigorous laboratory validation of the new DGT devices was conducted, confirming the suitability of the samplers to quantitatively measure all UO22+ species in simple matrices in which UO22+-CO32– complexes dominate the speciation of U. In addition, cross-tests were performed with commercial Chelex-100® and Metsorb® based-DGT devices on several types of moderately basic waters (pH ≈ 8), either in the laboratory (i.e., soft and hard mineral waters and seawater) or during field tests. DGT probes were deployed in the alkaline surface water of the Œuf River, a tributary to the Seine River (France), in which Ca2+-UO22+-CO32– complexes are the dominant U species according to speciation modelling calculations. These experiments highlighted the superiority of the new DGT devices over those incorporating either Chelex-100® or Metsorb® sorbents. Finally, thermodynamic speciation calculations were performed as a first approach to better understand the functioning and potential limitations of our new and Chelex-100®-based DGT samplers in different deployment conditions.Acknowledgements:This work has been supported by IRSN, CNRS, and the French grant agency Agence Nationale de la Recherche (project PLUTON, grant n° ANR-17-CE08-0053). Osian FONQUERNIE and Tony FERNANDES are grateful to the Conseil Régional de Bourgogne Franche-Comté and the European Regional Development Fund (FEDER) for granting them a PhD fellowship. The authors thank Graver Technologies (www.gravertech.com) for the provision of the Metsorb® HMRP 50 products used in this study. All DGT experiments were performed at LUTECE (the SEDRE's experimental platform), and isotopic measurements at PATERSON (the IRSN's mass spectrometry platform). This work benefited from the knowledge acquired on the spatial and temporal distribution of U concentration in the Œuf-Essonne River through the research project UTOPIA conducted by Dr Mathilde ZEBRACKI (IRSN) and funded by the French program NEEDS.References:[1]T. Mathews, K. Beaugelin-Seiller, J. Garnier-Laplace, R. Gilbin, C. Adam, C. Della-Vedova, Environ. Sci. Technol. 2009, 43, 6684-6690[2]G. S. C. Turner, G. A. Mills, M. J. Bowes, J. L. Burnett, S. Amos, G. R. Fones, Environ. Sci.: Processes Impacts 2014, 16, 393-403.[3]V. Smolíková, P. Pelcová, A. Ridošková, M. Leermakers, Talanta 2022, 240, 123168.[4]G. S. C. Turner, G. A. Mills, P. R. Teasdale, J. L. Burnett, S. Amos, G. R. Fones, Anal. Chim. Acta 2012, 739, 37-46.[5]M. P. Neu, J. H. Matonic, C. E. Ruggiero, B. L. Scott, Angew. Chem. Int. Ed. 2000, 39, 1442-1444.[6]H. Boukhalfa, G. A. Icopini, S. D. Reilly, M. P. Neu, Appl. Environ. Microbiol. 2007, 73, 5897-5903.[7]L. Février, F. Coppin, S. Pierrisnard, M. Bourdillon, L. V. Nguyen, N. Zaiter, S. Brandès, V. Sladkov, J.-C. Chambron, M. Meyer, J. Environ. Radioact. 2021, 235-236, 106645

Improving the performances of Diffusive Gradient in Thin-films (DGT) technique to measure the labile uranyl concentration in environmental waters by employing the chelating properties of siderochelates

International audienceUranium (U) presents a unique challenge for ecological risk assessments around installations related to the nuclear fuel cycle because of both chemical and radiological toxicity. Their relative importance depends on the chemical speciation and isotopic composition of the radionuclide, the latter being strongly correlated to its natural or anthropogenic origin (enriched or depleted U) [1]. In this framework, the Diffusive Gradient in Thin-films (DGT) technique is an appealing tool for monitoring the water quality around uranium processing plants, nuclear facilities or mining areas. Indeed, the DGT sampling allows to preconcentrate in situ the labile U(VI) species, allowing to simultaneously characterize the labile UO22+ fraction in aqueous phase (i.e., this provides qualitative information on the "available stock of UO22+ for the aquatic organisms") and the isotopic composition at trace levels [2]. Among the eleven DGT methods developed for UO22+ [3], the ones containing Chelex-100® (an ion-exchange resin with iminodiacetic acid functional groups) or Metsorb® (a TiO2-based adsorbent) are the most employed due to their commercial availability. Nevertheless, their performances can be significantly degraded by high concentration levels of competing ions like Ca2+ in the deployment solution, which results in the underestimation of the overall concentration of labile U(VI) species in environmental waters [3, 4]. To improve the reliability of measurements, further analytical developments are therefore required. One important research direction includes the design of more selective UO22+ sorbent materials.In this study, we propose new DGT samplers for labile UO22+ species that incorporate novel complexing materials obtained by the covalent grafting of siderophore-like chelators on a hydrophilic organic resin. Siderophores are well-known to exhibit a high affinity for strong Lewis acids, such as iron(III) and actinide cations [5-7]. Rigorous laboratory validation of the new DGT devices was conducted, confirming the suitability of the samplers to quantitatively measure all UO22+ species in simple matrices in which UO22+-CO32– complexes dominate the speciation of U. In addition, cross-tests were performed with commercial Chelex-100® and Metsorb® based-DGT devices on several types of moderately basic waters (pH ≈ 8), either in the laboratory (i.e., soft and hard mineral waters and seawater) or during field tests. DGT probes were deployed in the alkaline surface water of the Œuf River, a tributary to the Seine River (France), in which Ca2+-UO22+-CO32– complexes are the dominant U species according to speciation modelling calculations. These experiments highlighted the superiority of the new DGT devices over those incorporating either Chelex-100® or Metsorb® sorbents. Finally, thermodynamic speciation calculations were performed as a first approach to better understand the functioning and potential limitations of our new and Chelex-100®-based DGT samplers in different deployment conditions.Acknowledgements:This work has been supported by IRSN, CNRS, and the French grant agency Agence Nationale de la Recherche (project PLUTON, grant n° ANR-17-CE08-0053). Osian FONQUERNIE and Tony FERNANDES are grateful to the Conseil Régional de Bourgogne Franche-Comté and the European Regional Development Fund (FEDER) for granting them a PhD fellowship. The authors thank Graver Technologies (www.gravertech.com) for the provision of the Metsorb® HMRP 50 products used in this study. All DGT experiments were performed at LUTECE (the SEDRE's experimental platform), and isotopic measurements at PATERSON (the IRSN's mass spectrometry platform). This work benefited from the knowledge acquired on the spatial and temporal distribution of U concentration in the Œuf-Essonne River through the research project UTOPIA conducted by Dr Mathilde ZEBRACKI (IRSN) and funded by the French program NEEDS.References:[1]T. Mathews, K. Beaugelin-Seiller, J. Garnier-Laplace, R. Gilbin, C. Adam, C. Della-Vedova, Environ. Sci. Technol. 2009, 43, 6684-6690[2]G. S. C. Turner, G. A. Mills, M. J. Bowes, J. L. Burnett, S. Amos, G. R. Fones, Environ. Sci.: Processes Impacts 2014, 16, 393-403.[3]V. Smolíková, P. Pelcová, A. Ridošková, M. Leermakers, Talanta 2022, 240, 123168.[4]G. S. C. Turner, G. A. Mills, P. R. Teasdale, J. L. Burnett, S. Amos, G. R. Fones, Anal. Chim. Acta 2012, 739, 37-46.[5]M. P. Neu, J. H. Matonic, C. E. Ruggiero, B. L. Scott, Angew. Chem. Int. Ed. 2000, 39, 1442-1444.[6]H. Boukhalfa, G. A. Icopini, S. D. Reilly, M. P. Neu, Appl. Environ. Microbiol. 2007, 73, 5897-5903.[7]L. Février, F. Coppin, S. Pierrisnard, M. Bourdillon, L. V. Nguyen, N. Zaiter, S. Brandès, V. Sladkov, J.-C. Chambron, M. Meyer, J. Environ. Radioact. 2021, 235-236, 106645

Cobalt Corroles with Bis‐Ammonia or Mono‐DMSO Axial Ligands. Electrochemical, Spectroscopic Characterizations and Ligand Binding Properties

International audienceFour bis-ammonia ligated cobalt corroles and four mono-DMSO ligated cobalt corroles with different mesoaryl substituents on the macrocycle (A 2 Band A 3-corroles) were synthesized and investigated as to their electrochemical and spec-troscopic properties under different solution conditions. The complexation energies of the investigated cobalt corroles were theoretically calculated to illustrate the propensity of the cobalt center for pentacoordination or hexa-coordination with various axial ligands (DMSO, CO, py and NH 3). The structure of one hexacoordinate bis-NH 3 cobalt corrole complex was also determined by X-ray diffraction