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1. Resolving the mass transfer in the symbiotic recurrent nova T Coronae Borealis

Author

Planquart, L., Jorissen, A., and Van Winckel, H.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

T Coronae Borealis (T CrB) is a symbiotic recurrent nova with an 80-year recurrence interval whose next eruption is imminent. We aim to resolve the accretion mechanism of the binary system governing the mass transfer during its super-active phase. Using phase-resolved high-resolution spectroscopy, we analyze the zoo of spectral-line profiles arising from the symbiotic activity. We perform Doppler tomography of selected emission lines to resolve the system's gaseous components and their different velocity regimes. We find evidence of enhanced accretion through Roche lobe overflow during the super-active phase, as traced by the oxygen, helium, and hydrogen lines. The accretion disc is found to be fully viscously evolved and extends up to its maximal radius. By mapping the kinematics of lines probing different excitation energies, we can identify distinct interaction sites. These include the bright spot at the stream impact on the accretion disc outer radius, the irradiation at the red-giant facing side, the stream-disc overflow, the accretion disk wind, and an expanding bipolar nebula. The bipolar jet emerged at the rise of the super-active phase and underwent an acceleration phase of about five years. The temporal evolution of the lines supports the scenario where the departure from quiescence started in the disc, likely triggered by a disc instability similar to what occurs in dwarf novae outburst, leading to an increased mass accretion and causing important irradiation of the giant that has further enhanced the mass-transfer rate during the super-active phase. Conclusions. Symbiotic recurrent novae, such as T CrB, are governed by similar mass-transfer mechanisms as found in cataclysmic variables despite their different orbital properties (longer orbital periods imposing larger accretion discs) and evolutionary pathways., Comment: Accepted for publication in Astronomy and Astrophysics

Published
2025

2. An impressionist view of V Hydrae. When MATISSE paints Asymmetric Giant Blobs

Author

Planquart, L., Paladini, C., Jorissen, A., Escorza, A., Pantin, E., Drevon, J., Aringer, B., Baron, F., Chiavassa, A., Cruzalèbes, P., Danchi, W., De Beck, E., Groenewegen, M. A. T., Höfner, S., Hron, J., Khouri, T., Lopez, B., Lykou, F., Montarges, M., Nardetto, N., Ohnaka, K., Olofsson, H., Rau, G., Rosales-Guzmán, A., Sanchez-Bermudez, J., Scicluna, P., Siess, L., Thévenin, F., Van Eck, S., Vlemmings, W. H. T., Weigelt, G., and Wittkowski, M.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

Our purpose is to study the effect of binary companions located within the first 10 stellar radii from the primary AGB star. In this work, we target the mass-losing carbon star V Hydrae (V Hya), looking for signatures of its companion in the dust forming region of the atmosphere. The star was observed in the L- and N-bands with the VLTI/MATISSE instrument at low spectral resolution. We reconstructed images of V Hya's photosphere and surroundings using the two bands and compared our interferometric observables with VLTI/MIDI and VISIR archival data. To constrain the dust properties, we used DUSTY to model the spectral energy distribution. The star is dominated by dust emission in the L- and N- bands. The VISIR image confirms the presence of a large-scale dusty circumstellar envelope surrounding V Hya. The MATISSE reconstructed images show asymmetric and elongated structures in both infrared bands. In the L-band, we detected an elongated shape of approximately 15 mas, likely to be of photospheric origin. In the N-band, we found a 20 mas extension North-East from the star, and perpendicular to the L-band elongated axis. The position angle and the size of the N-band extension match the prediction of the companion position at MATISSE epoch. By comparing MATISSE N-band with MIDI data, we deduce that the elongation axis in the N-band has rotated since the previous interferometric measurements 13 years ago, supporting the idea that the particle enhancement is related to the dusty clump moving along with the companion. The MATISSE images unveil the presence of a dust enhancement at the companion position, opening new doors for further analysis on the binary interaction with an AGB component., Comment: Accepted for publication in Astronomy & Astrophysics

Published
2024
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3. A dynamic view of V Hydrae. Monitoring of a spectroscopic-binary AGB star with an alkaline jet

Author

Planquart, L., Jorissen, A., Escorza, A., Verhamme, O., and Van Winckel, H.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

The well studied carbon star V Hydrae is known to exhibit a complex asymmetric environment made of a dense equatorial wind and high-velocity outflows, hinting at its transition from the AGB phase to the asymmetric planetary nebula phase. In addition, V Hydrae also exhibits a long secondary period of 17 years in its light curve, suggesting the presence of a binary companion that could shape the circumstellar environment. In this paper, we aim to confirm the binary nature of V Hydrae by deriving its orbital parameters and investigating the effect of the orbital motion on the circumbinary environment. In a first step, we used a radial-velocity monitoring performed with the HERMES spectrograph to disentangle the pulsation signal of the AGB from its orbital motion and to obtain the spectroscopic orbit. We combined the spectroscopic results with astrometric information to get the complete set of orbital parameters, including the system inclination. Next, we reported the time variations of the sodium and potassium resonance doublets. Finally, following the methods used for post-AGB stars, we carried out spatio-kinematic modelling of a conical jet to reproduce the observed spectral-line modulation. We found the orbital solution of V Hydrae for a period of 17 years. We correlated the companion passage across the line of sight with the obscuration event and the blue-shifted absorption of alkaline resonant lines. Those variations were modelled by a conical jet emitted from the companion, whose opening angle is wide and whose sky-projected orientation is found to be consistent with the axis of the large-scale bipolar outflow previously detected in the radio-emission lines of CO. We show that the periodic variation seen for V Hydrae is likely to be due to orbital motion. The presence of a conical jet offers a coherent model to explain the various features of V Hydrae environment.

Published
2024
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4. Discovery of a dormant 33 solar-mass black hole in pre-release Gaia astrometry

Author

Gaia Collaboration, Panuzzo, P., Mazeh, T., Arenou, F., Holl, B., Caffau, E., Jorissen, A., Babusiaux, C., Gavras, P., Sahlmann, J., Bastian, U., Wyrzykowski, Ł., Eyer, L., Leclerc, N., Bauchet, N., Bombrun, A., Mowlavi, N., Seabroke, G. M., Teyssier, D., Balbinot, E., Helmi, A., Brown, A. G. A., Vallenari, A., Prusti, T., de Bruijne, J. H. J., Barbier, A., Biermann, M., Creevey, O. L., Ducourant, C., Evans, D. W., Guerra, R., Hutton, A., Jordi, C., Klioner, S. A., Lammers, U., Lindegren, L., Luri, X., Mignard, F., Nicolas, C., Randich, S., Sartoretti, P., Smiljanic, R., Tanga, P., Walton, N. A., Aerts, C., Bailer-Jones, C. A. L., Cropper, M., Drimmel, R., Jansen, F., Katz, D., Lattanzi, M. G., Soubiran, C., Thévenin, F., van Leeuwen, F., Andrae, R., Audard, M., Bakker, J., Blomme, R., Castañeda, J., De Angeli, F., Fabricius, C., Fouesneau, M., Frémat, Y., Galluccio, L., Guerrier, A., Heiter, U., Masana, E., Messineo, R., Nienartowicz, K., Pailler, F., Riclet, F., Roux, W., Sordo, R., Gracia-Abril, G., Portell, J., Altmann, M., Benson, K., Berthier, J., Burgess, P. W., Busonero, D., Busso, G., Cacciari, C., Cánovas, H., Carrasco, J. M., Carry, B., Cellino, A., Cheek, N., Clementini, G., Damerdji, Y., Davidson, M., de Teodoro, P., Delchambre, L., Dell'Oro, A., Garcia, E. Fraile, Garabato, D., García-Lario, P., Haigron, R., Hambly, N. C., Harrison, D. L., Hatzidimitriou, D., Hernández, J., Hestroffer, D., Hodgkin, S. T., Jamal, S., de Fombelle, G. Jevardat, Jordan, S., Krone-Martins, A., Lanzafame, A. C., Löffler, W., Lorca, A., Marchal, O., Marrese, P. M., Moitinho, A., Muinonen, K., Campos, M. Nuñez, Oreshina-Slezak, I., Osborne, P., Pancino, E., Pauwels, T., Recio-Blanco, A., Riello, M., Rimoldini, L., Robin, A. C., Roegiers, T., Sarro, L. M., Schultheis, M., Smith, M., Sozzetti, A., Utrilla, E., van Leeuwen, M., Weingrill, K., Abbas, U., Ábrahám, P., Aramburu, A. Abreu, Ahmed, S., Altavilla, G., Álvarez, M. A., Anders, F., Anderson, R. I., Varela, E. Anglada, Antoja, T., Baig, S., Baines, D., Baker, S. G., Balaguer-Núñez, L., Balog, Z., Barache, C., Barros, M., Barstow, M. A., Bartolomé, S., Bashi, D., Bassilana, J. -L., Baudeau, N., Becciani, U., Bedin, L. R., Bellas-Velidis, I., Bellazzini, M., Beordo, W., Bernet, M., Bertolotto, C., Bertone, S., Bianchi, L., Binnenfeld, A., Blanco-Cuaresma, S., Bland-Hawthorn, J., Blazere, A., Boch, T., Bossini, D., Bouquillon, S., Bragaglia, A., Braine, J., Bratsolis, E., Breedt, E., Bressan, A., Brouillet, N., Brugaletta, E., Bucciarelli, B., Butkevich, A. G., Buzzi, R., Camut, A., Cancelliere, R., Cantat-Gaudin, T., Guilarte, D. Capilla, Carballo, R., Carlucci, T., Carnerero, M. I., Carretero, J., Carton, S., Casamiquela, L., Casey, A., Castellani, M., Castro-Ginard, A., Ceraj, L., Cesare, V., Charlot, P., Chaudet, C., Chemin, L., Chiavassa, A., Chornay, N., Chosson, D., Cooper, W. J., Cornez, T., Cowell, S., Crosta, M., Crowley, C., Reyes, M. Cruz, Dafonte, C., Ponte, M. Dal, David, M., de Laverny, P., De Luise, F., De March, R., De Ridder, J., de Torres, A., del Peloso, E. F., Delbo, M., Delgado, A., Delisle, J. -B., Demouchy, C., Denis, E., Dharmawardena, T. E., Di Giacomo, F., Diener, C., Distefano, E., Dolding, C., Dsilva, K., Enke, H., Fabre, C., Fabrizio, M., Faigler, S., Fatović, M., Fedorets, G., Fernández-Hernández, J., Fernique, P., Figueras, F., Fouron, C., Fragkoudi, F., Gai, M., Galinier, M., Garcia-Serrano, A., García-Torres, M., Garofalo, A., Gerlach, E., Geyer, R., Giacobbe, P., Gilmore, G., Girona, S., Giuffrida, G., Gomboc, A., Gomez, A., González-Santamaría, I., Gosset, E., Granvik, M., Barrera, V. Gregori, Gutiérrez-Sánchez, R., Haywood, M., Helmer, A., Hidalgo, S. L., Hilger, T., Hobbs, D., Hottier, C., Huckle, H. E., Jiménez-Arranz, Ó., Campillo, J. Juaristi, Kaczmarek, Z., Kervella, P., Khanna, S., Kontizas, M., Kordopatis, G., Korn, A. J., Kóspál, Á, Kostrzewa-Rutkowska, Z., Kruszyńska, K., Kun, M., Lambert, S., Lanza, A. F., Lebreton, Y., Lebzelter, T., Leccia, S., Lecoutre, G., Liao, S., Liberato, L., Licata, E., Livanou, E., Lobel, A., López-Miralles, J., Loup, C., Madarász, M., Mahy, L., Mann, R. G., Manteiga, M., Marinoni, S., Marcellino, C. P., Marshall, D. J., Mascarenhas, D., Marchant, J. M., Lozano, J. Martín, Masip, A., Marconi, M., Pina, D. Marín, Polo, L. Martin, Martín-Fleitas, J. M., Mastrobuono-Battisti, A., McMillan, P. J., Meichsner, J. G. Marton, Merc, J., Messina, S., Millar, N. R., Mints, A., Mohamed, D., Molina, D., Molinaro, R., Monguió, M., Montegriffo, P., Monti, L., Mora, A., Morbidelli, R., Morris, D., Mudimadugula, R., Muraveva, T., Musella, I., Nagy, Z., Nardetto, N., Navarrete, C., Oh, S., Ordenovic, C., Orenstein, O., Pagani, C., Pagano, I., Palaversa, L., Palicio, P. A., Pallas-Quintela, L., Pawlak, M., Penttilä, A., Pesciullesi, P., Pinamonti, M., Plachy, E., Planquart, L., Plum, G., Poggio, E., Pourbaix, D., Price-Whelan, A. M., Pulone, L., Rabin, V., Rainer, M., Raiteri, C. M., Ramos, P., Ramos-Lerate, M., Ratajczak, M., Fiorentin, P. Re, Regibo, S., Reylé, C., Ripepi, V., Riva, A., Rix, H. -W., Rixon, G., Robert, G., Robichon, N., Robin, C., Romero-Gómez, M., Rowell, N., Mieres, D. Ruz, Rybicki, K. A., Sadowski, G., Sellés, A. Sagristà, Sanna, N., Santoveña, R., Sarasso, M., Sarmiento, M. H., Riera, C. Sarrate, Sciacca, E., Ségransan, D., Semczuk, M., Shahaf, S., Siebert, A., Slezak18, E., Smart, R. L., Snaith, O. N., Solano, E., Solitro, F., Souami, D., Souchay, J., Spitoni, E., Spoto, F., Squillante, L. A., Steele, I. A., Steidelmüller, H., Surdej, J., Szabados, L., Taris, F., Taylor, M. B., Teixeira, R., Tepper-Garcia, T., Thuillot, W., Tolomei, L., Tonello, N., Torra, F., Elipe, G. Torralba, Trabucchi, M., Trentin, E., Tsantaki, M., Turon, C., Ulla, A., Unger, N., Valtchanov, I., Vanel, O., Vecchiato, A., Vicente, D., Villar, E., Weiler, M., Zhao, H., Zorec, J., Zucker, S., Župić, A., and Zwitter, T.

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics
Abstract

Gravitational waves from black-hole merging events have revealed a population of extra-galactic BHs residing in short-period binaries with masses that are higher than expected based on most stellar evolution models - and also higher than known stellar-origin black holes in our Galaxy. It has been proposed that those high-mass BHs are the remnants of massive metal-poor stars. Gaia astrometry is expected to uncover many Galactic wide-binary systems containing dormant BHs, which may not have been detected before. The study of this population will provide new information on the BH-mass distribution in binaries and shed light on their formation mechanisms and progenitors. As part of the validation efforts in preparation for the fourth Gaia data release (DR4), we analysed the preliminary astrometric binary solutions, obtained by the Gaia Non-Single Star pipeline, to verify their significance and to minimise false-detection rates in high-mass-function orbital solutions. The astrometric binary solution of one source, Gaia BH3, implies the presence of a 32.70 \pm 0.82 M\odot BH in a binary system with a period of 11.6 yr. Gaia radial velocities independently validate the astrometric orbit. Broad-band photometric and spectroscopic data show that the visible component is an old, very metal-poor giant of the Galactic halo, at a distance of 590 pc. The BH in the Gaia BH3 system is more massive than any other Galactic stellar-origin BH known thus far. The low metallicity of the star companion supports the scenario that metal-poor massive stars are progenitors of the high-mass BHs detected by gravitational-wave telescopes. The Galactic orbit of the system and its metallicity indicate that it might belong to the Sequoia halo substructure. Alternatively, and more plausibly, it could belong to the ED-2 stream, which likely originated from a globular cluster that had been disrupted by the Milky Way., Comment: 23 pages, accepted fro publication in A&A Letters. New version with small fixes

Published
2024
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5. Titans metal-poor reference stars II. Red giants and CEMP stars

Author

Giribaldi, Riano E., Van Eck, Sophie, Merle, Thibault, Jorissen, Alain, Krynski, Pawel, Planquart, Lea, Valentini, Marica, Chiappini, Cristina, and Van Winckel, Hans

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

Representative samples of F-, G-, K-type stars located out of the Solar Neighbourhood has started to be available in spectroscopic surveys. The fraction of metal-poor ([Fe/H]~$\lesssim -0.8$~dex) giants becomes increasingly relevant to far distances. In metal-poor stars, effective temperatures ($T_{\mathrm{eff}}$) based on LTE spectroscopy and on former colour-$T_{\mathrm{eff}}$ relations of still wide use have been reported to be inaccurate. It is necessary to re-calibrate chemical abundances based on these $T_{\mathrm{eff}}$ scales in the multiple available surveys to bring them to the same standard scale for their simultaneous use. For that, a complete sample of standards is required, which so far, is restricted to a few stars with quasi-direct $T_{\mathrm{eff}}$ measurements. We aim at providing a legacy sample of metal-poor standards with proven accurate atmospheric parameters. We add 47 giants to the sample of metal-poor dwarfs of Giribaldi et al. 2021, thereby constituting the Titans metal-poor reference stars. $T_{\mathrm{eff}}$ was derived by 3D non-LTE H$\alpha$ modelling, whose accuracy was tested against interferometry and InfraRed Flux Method (IRFM). Surface gravity (log $g$) was derived by fitting Mg~I~b triplet lines, whose accuracy was tested against asteroseismology. Metallicity was derived using Fe II lines, which was verified to be identical to the [Fe/H] derived from non-LTE spectral synthesis. $T_{\mathrm{eff}}$ from 3D non-LTE H$\alpha$ is equivalent to interferometric and IRFM temperatures within a $\pm$46~K uncertainty. We achieved precision of $\sim$50~K for 34 stars with spectra with the highest S/N. For log $g$, we achieved a total uncertainty of $\pm$0.15~dex. For [Fe/H], we obtained a total uncertainty of $\pm$0.09~dex. We find that the ionization equilibrium of Fe lines under LTE is not valid in metal-poor giants., Comment: Accepted in A&A

Published
2023

6. Gaia Data Release 3: Stellar multiplicity, a teaser for the hidden treasure

Author

Gaia Collaboration, Arenou, F., Babusiaux, C., Barstow, M. A., Faigler, S., Jorissen, A., Kervella, P., Mazeh, T., Mowlavi, N., Panuzzo, P., Sahlmann, J., Shahaf, S., Sozzetti, A., Bauchet, N., Damerdji, Y., Gavras, P., Giacobbe, P., Gosset, E., Halbwachs, J. -L., Holl, B., Lattanzi, M. G., Leclerc, N., Morel, T., Pourbaix, D., Fiorentin, P. Re, Sadowski, G., Ségransan, D., Siopis, C., Teyssier, D., Zwitter, T., Planquart, L., Brown, A. G. A., Vallenari, A., Prusti, T., de Bruijne, J. H. J., Biermann, M., Creevey, O. L., Ducourant, C., Evans, D. W., Eyer, L., Guerra, R., Hutton, A., Jordi, C., Klioner, S. A., Lammers, U. L., Lindegren, L., Luri, X., Mignard, F., Panem, C., Randich, S., Sartoretti, P., Soubiran, C., Tanga, P., Walton, N. A., Bailer-Jones, C. A. L., Bastian, U., Drimmel, R., Jansen, F., Katz, D., van Leeuwen, F., Bakker, J., Cacciari, C., Castañeda, J., De Angeli, F., Fabricius, C., Fouesneau, M., Frémat, Y., Galluccio, L., Guerrier, A., Heiter, U., Masana, E., Messineo, R., Nicolas, C., Nienartowicz, K., Pailler, F., Riclet, F., Roux, W., Seabroke, G. M., Sordo, R., Thévenin, F., Gracia-Abril, G., Portell, J., Altmann, M., Andrae, R., Audard, M., Bellas-Velidis, I., Benson, K., Berthier, J., Blomme, R., Burgess, P. W., Busonero, D., Busso, G., Cánovas, H., Carry, B., Cellino, A., Cheek, N., Clementini, G., Davidson, M., de Teodoro, P., Campos, M. Nuñez, Delchambre, L., Dell'Oro, A., Esquej, P., Fernández-Hernández, J., Fraile, E., Garabato, D., García-Lario, P., Haigron, R., Hambly, N. C., Harrison, D. L., Hernández, J., Hestroffer, D., Hodgkin, S. T., Janßen, K., de Fombelle, G. Jevardat, Jordan, S., Krone-Martins, A., Lanzafame, A. C., Löffler, W., Marchal, O., Marrese, P. M., Moitinho, A., Muinonen, K., Osborne, P., Pancino, E., Pauwels, T., Recio-Blanco, A., Reylé, C., Riello, M., Rimoldini, L., Roegiers, T., Rybizki, J., Sarro, L. M., Smith, M., Utrilla, E., van Leeuwen, M., Abbas, U., Ábrahám, P., Aramburu, A. Abreu, Aerts, C., Aguado, J. J., Ajaj, M., Aldea-Montero, F., Altavilla, G., Álvarez, M. A., Alves, J., Anders, F., Anderson, R. I., Varela, E. Anglada, Antoja, T., Baines, D., Baker, S. G., Balaguer-Núñez, L., Balbinot, E., Balog, Z., Barache, C., Barbato, D., Barros, M., Bartolomé, S., Bassilana, J. -L., Becciani, U., Bellazzini, M., Berihuete, A., Bernet, M., Bertone, S., Bianchi, L., Binnenfeld, A., Blanco-Cuaresma, S., Blazere, A., Boch, T., Bombrun, A., Bossini, D., Bouquillon, S., Bragaglia, A., Bramante, L., Breedt, E., Bressan, A., Brouillet, N., Brugaletta, E., Bucciarelli, B., Burlacu, A., Butkevich, A. G., Buzzi, R., Caffau, E., Cancelliere, R., Cantat-Gaudin, T., Carballo, R., Carlucci, T., Carnerero, M. I., Carrasco, J. M., Casamiquela, L., Castellani, M., Castro-Ginard, A., Chaoul, L., Charlot, P., Chemin, L., Chiaramida, V., Chiavassa, A., Chornay, N., Comoretto, G., Contursi, G., Cooper, W. J., Cornez, T., Cowell, S., Crifo, F., Cropper, M., Crosta, M., Crowley, C., Dafonte, C., Dapergolas, A., David, P., de Laverny, P., De Luise, F., De March, R., De Ridder, J., de Souza, R., de Torres, A., del Peloso, E. F., del Pozo, E., Delbo, M., Delgado, A., Delisle, J. -B., Demouchy, C., Dharmawardena, T. E., Diakite, S., Diener, C., Distefano, E., Dolding, C., Enke, H., Fabre, C., Fabrizio, M., Fedorets, G., Fernique, P., Figueras, F., Fournier, Y., Fouron, C., Fragkoudi, F., Gai, M., Garcia-Gutierrez, A., Garcia-Reinaldos, M., García-Torres, M., Garofalo, A., Gavel, A., Gerlach, E., Geyer, R., Gilmore, G., Girona, S., Giuffrida, G., Gomel, R., Gomez, A., González-Núñez, J., González-Santamaría, I., González-Vidal, J. J., Granvik, M., Guillout, P., Guiraud, J., Gutiérrez-Sánchez, R., Guy, L. P., Hatzidimitriou, D., Hauser, M., Haywood, M., Helmer, A., Helmi, A., Sarmiento, M. H., Hidalgo, S. L., Hładczuk, N., Hobbs, D., Holland, G., Huckle, H. E., Jardine, K., Jasniewicz, G., Piccolo, A. Jean-Antoine, Jiménez-Arranz, Ó., Campillo, J. Juaristi, Julbe, F., Karbevska, L., Khanna, S., Kordopatis, G., Korn, A. J., Kóspál, Á, Kostrzewa-Rutkowska, Z., Kruszyńska, K., Kun, M., Laizeau, P., Lambert, S., Lanza, A. F., Lasne, Y., Campion, J. -F. Le, Lebreton, Y., Lebzelter, T., Leccia, S., Lecoeur-Taibi, I., Liao, S., Licata, E. L., Lindstrøm, H. E. P., Lister, T. A., Livanou, E., Lobel, A., Lorca, A., Loup, C., Pardo, P. Madrero, Romeo, A. Magdaleno, Managau, S., Mann, R. G., Manteiga, M., Marchant, J. M., Marconi, M., Marcos, J., Santos, M. M. S. Marcos, Pina, D. Marín, Marinoni, S., Marocco, F., Marshall, D. J., Polo, L. Martin, Martín-Fleitas, J. M., Marton, G., Mary, N., Masip, A., Massari, D., Mastrobuono-Battisti, A., McMillan, P. J., Messina, S., Michalik, D., Millar, N. R., Mints, A., Molina, D., Molinaro, R., Molnár, L., Monari, G., Monguió, M., Montegriffo, P., Montero, A., Mor, R., Mora, A., Morbidelli, R., Morris, D., Muraveva, T., Murphy, C. P., Musella, I., Nagy, Z., Noval, L., Ocaña, F., Ogden, A., Ordenovic, C., Osinde, J. O., Pagani, C., Pagano, I., Palaversa, L., Palicio, P. A., Pallas-Quintela, L., Panahi, A., Payne-Wardenaar, S., Esteller, X. Peñalosa, Penttilä, A., Pichon, B., Piersimoni, A. M., Pineau, F. -X., Plachy, E., Plum, G., Poggio, E., Prša, A., Pulone, L., Racero, E., Ragaini, S., Rainer, M., Raiteri, C. M., Ramos, P., Ramos-Lerate, M., Regibo, S., Richards, P. J., Diaz, C. Rios, Ripepi, V., Riva, A., Rix, H. -W., Rixon, G., Robichon, N., Robin, A. C., Robin, C., Roelens, M., Rogues, H. R. O., Rohrbasser, L., Romero-Gómez, M., Rowell, N., Royer, F., Mieres, D. Ruz, Rybicki, K. A., Núñez, A. Sáez, Sellés, A. Sagristà, Salguero, E., Samaras, N., Gimenez, V. Sanchez, Sanna, N., Santoveña, R., Sarasso, M., Schultheis, M. S., Sciacca, E., Segol, M., Segovia, J. C., Semeux, D., Siddiqui, H. I., Siebert, A., Siltala, L., Silvelo, A., Slezak, E., Slezak, I., Smart, R. L., Snaith, O. N., Solano, E., Solitro, F., Souami, D., Souchay, J., Spagna, A., Spina, L., Spoto, F., Steele, I. A., Steidelmüller, H., Stephenson, C. A., Süveges, M., Surdej, J., Szabados, L., Szegedi-Elek, E., Taris, F., Taylor, M. B., Teixeira, R., Tolomei, L., Tonello, N., Torra, F., Torra, J., Elipe, G. Torralba, Trabucchi, M., Tsounis, A. T., Turon, C., Ulla, A., Unger, N., Vaillant, M. V., van Dillen, E., van Reeven, W., Vanel, O., Vecchiato, A., Viala, Y., Vicente, D., Voutsinas, S., Weiler, M., Wevers, T., Wyrzykowski, Ł., Yoldas, A., Yvard, P., Zhao, H., Zorec, J., and Zucker, S.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The Gaia DR3 Catalogue contains for the first time about eight hundred thousand solutions with either orbital elements or trend parameters for astrometric, spectroscopic and eclipsing binaries, and combinations of them. This paper aims to illustrate the huge potential of this large non-single star catalogue. Using the orbital solutions together with models of the binaries, a catalogue of tens of thousands of stellar masses, or lower limits, partly together with consistent flux ratios, has been built. Properties concerning the completeness of the binary catalogues are discussed, statistical features of the orbital elements are explained and a comparison with other catalogues is performed. Illustrative applications are proposed for binaries across the H-R diagram. The binarity is studied in the RGB/AGB and a search for genuine SB1 among long-period variables is performed. The discovery of new EL CVn systems illustrates the potential of combining variability and binarity catalogues. Potential compact object companions are presented, mainly white dwarf companions or double degenerates, but one candidate neutron star is also presented. Towards the bottom of the main sequence, the orbits of previously-suspected binary ultracool dwarfs are determined and new candidate binaries are discovered. The long awaited contribution of Gaia to the analysis of the substellar regime shows the brown dwarf desert around solar-type stars using true, rather than minimum, masses, and provides new important constraints on the occurrence rates of substellar companions to M dwarfs. Several dozen new exoplanets are proposed, including two with validated orbital solutions and one super-Jupiter orbiting a white dwarf, all being candidates requiring confirmation. Beside binarity, higher order multiple systems are also found., Comment: 60 pages, 60 figures. Accepted for publication in Astronomy & Astrophysics (2022-06-09). The catalogue of binary masses is available for download from the ESA Gaia DR3 Archive and will be available from the CDS/VizieR service

Published
2022
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8. The European GO-VIKING project on flow-induced vibrations: overview and current status

Author

Papukchiev, Angel, Zwijsen, Kevin, Vivaldi, Daniele, Hadžić, Hidajet, Benhamadouche, Sofiane, Benguigui, William, and Planquart, Philippe

Abstract

The interaction between cooling fluid and solid structures (rods, tubes) in nuclear power plants may lead to flow-induced vibrations (FIV), causing material fatigue, fretting wear, and eventually loss of component integrity. This can cause further safety issues as well as substantial standstill costs due to longer or unplanned outages. With the growing computational power, the application of modern 3D numerical simulation tools for the accurate prediction of FIV phenomena is rapidly increasing. In 2022, the GO-VIKING (Gathering expertise On Vibration ImpaKt In Nuclear power Generation) project received a grant within the Horizon Europe research and innovation funding program. Sixteen European and two US partners started their collaboration in the field of FIV experiments and analysis. Over four years, the GO-VIKING project investigates FIV phenomena occurring in nuclear reactor cores and steam generators under single- and two-phase flow conditions. The project’s main objectives are to expand the expertise in the field of FIV through generation of new experimental and high-resolution numerical data; development, improvement, and validation of fluid-structure interaction (FSI) methods for FIV evaluation; training stakeholders in the application of these methods; and synthesizing guidelines for the prediction and assessment of FIV phenomena in nuclear reactors. This paper provides an overview of the GO-VIKING objectives, scientific program, as well as of the main scientific achievements in the first project year.

Published
2024
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9. AERODYNAMIC CHARACTERIZATION OF IN-AIR CAPTURING VEHICLES USING CFD SIMULATIONS

Author

Y.C. KUCUKOSMAN, S. LOPES, S. BUCKINGHAM, P. PLANQUART, S. SINGH, L. BUSSLER, S. STAPPERT, and M. SIPPEL

Subjects
SPACE ACCESS, FALCON, REUSABLE SYSTEMS
Abstract

The sustainability of the complex, high performance, high-cost rocket stages and engines has drawn attention to the innovative return modes with the aim of bringing them back to their launch site. One of the return modes, in-air capturing (IAC), where a reusable launcher vehicle (RLV) is towed back by an aircraft with the assistance of an aerodynamically controlled capturing device (ACCD) which helps to connect the two vehicles. This return mode is found to be more promising as it eliminates the additional propulsion system during the descent which reduces the mass and the cost of the system. The first and integral step of IAC requires the two vehicles to be in a parallel formation for at least 60s to enable the ACCD released from the aircraft to reach the RLV. This would require both vehicles to maintain similar aerodynamic performance to achieve comparable velocities and altitude. Typical long-range commercial aircrafts have a lift to drag ratio between 17 to 19. However, during IAC, this ratio must be brought down to a value of around 6 for the vehicles to remain within the capture envelope. Empirical methods are typically used to determine the optimum capturing aircraft configurations by combining the drag generated by the various components [1]. However, the drag components create additional turbulence structures that the empirical methods are unable to estimate. Therefore, it is important to critically analyse the formation flight configurations using high-fidelity CFD simulations, while taking into consideration the atmospheric perturbations. In this paper, the methodology for the high-fidelity simulations is presented. A sensitivity study is performed on the type of boundary conditions, the choice of the solver, the domain size and turbulence model, by referring to experimental results obtained on a NACA 0012 airfoil. Best practice guidelines are then applied to all three vehicles: the towing aircraft, the ACCD and the RLV alone, with the aim of providing high-fidelity aerodynamic data for different angle of attacks. This paper is a part of H2020 FALCon project and continuation of the work by Singh, S. et al. (2021). [1] Singh, S.; Stappert, S.; Bussler, L.; Sippel, M.; Buckingham, S.; Kucukosman, C.: A Full-Scale Simulation and Analysis of Formation Flight during In-Air-Capturing, IAC-21-D2.5.2, 72nd International Astronautical Congress (IAC) Dubai, October 2021)

Published
2022
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10. Air ejector analysis in normal and abnormal modes, oriented to control purposes in aircraft systems

Author

C. OLIET, J. VEMULA, E. SCHILLACI, M. DUPONCHEEL, Y. BARTOSIEWICZ, P. PLANQUART, Universitat Politècnica de Catalunya. Departament de Màquines i Motors Tèrmics, and Universitat Politècnica de Catalunya. CTTC - Centre Tecnològic de Transferència de Calor

Subjects
Aeronàutica i espai::Sistemes CNS/ATM (Communication, Navigation, Surveillance/Air Traffic Management) [Àrees temàtiques de la UPC], Enginyeria mecànica [Àrees temàtiques de la UPC], Avions -- Motors, Airplanes - Motors, Pumping machinery, SYSTEM INTEGRATION, Maquinària de bombament, Dinàmica de fluids computacional, Computational fluid dynamics, AERONAUTICS
Abstract

The implementation of ejectors is getting an increasing interest in many sectors, in order to improve the efficiency and reliability of several systems. The aircraft sector is also integrating ejectors for bleed air management, recirculation or ram-air ventilation. Understanding the physics and the modelling of ejectors in normal mode (on and off design, that is, the generation of the usual characteristic curves) is in a mature development, including several simplified models [1][2] available. They have demonstrated a good accuracy under low computational times, thus being useful for control purposes. However, to achieve a robust and general system level modelling, there is the need for 0D/1D models suitable to tackle abnormal functioning modes (including reverse flow occurrence at any inlet/outlet port of the ejector), and transient operation during transition between different modes of operation. In this sense, the current research done by the authors is focusing on the understanding of the air ejectors under a broader operation perimeter than what can be found in the usual literature, through an operating map covering all modes of interest for aircraft systems. Computational Fluid Dynamics (CFD) simulations and experiments are being collected, to confirm the expected behavior under normal operation, and to extend the knowledge to abnormal operation. All this understanding will be synthetized in new simplified models, that will be implemented in a Modelica ejector object, for its integration in the whole system simulations. The final objective will be to use the tool for design and control purposes at the system level. This paper presents the current status of simulations, experiments and Modelica model developments concerning the ejector working in different steady modes (normal and abnormal).

Published
2022

14. Insights into the ligand binding specificity of SREC‐II (scavenger receptor expressed by endothelial cells).

Author

Wicker‐Planquart, Catherine, Tacnet‐Delorme, Pascale, Preisser, Laurence, Dufour, Samy, Delneste, Yves, Housset, Dominique, Frachet, Philippe, Thielens, Nicole M, and Kobarg, Jörg

Subjects
LIGAND binding (Biochemistry), ENDOTHELIAL cells, COMPLEMENT (Immunology), CHO cell, MEMBRANE proteins
Abstract

SREC‐II (scavenger receptor expressed by endothelial cells II) is a membrane protein encoded by the SCARF2 gene, with high homology to class F scavenger receptor SR‐F1, but no known scavenging function. We produced the extracellular domain of SREC‐II in a recombinant form and investigated its capacity to interact with common scavenger receptor ligands, including acetylated low‐density lipoprotein (AcLDL) and maleylated or acetylated BSA (MalBSA or AcBSA). Whereas no binding was observed for AcLDL, SREC‐II ectodomain interacted strongly with MalBSA and bound with high affinity to AcBSA, a property shared with the SR‐F1 ectodomain. SREC‐II ectodomain also interacted with two SR‐F1‐specific ligands, complement C1q and calreticulin, with affinities in the 100 nm range. We proceeded to generate a stable CHO cell line overexpressing full‐length SREC‐II; binding of MalBSA to these cells was significantly increased compared with nontransfected CHO cells. In contrast, no increase in binding could be detected for C1q and calreticulin. We show for the first time that SREC‐II has the capacity to interact with the common scavenger receptor ligand MalBSA. In addition, our data highlight similarities and differences in the ligand binding properties of SREC‐II in soluble form and at the cell surface, and show that endogenous protein ligands of the ectodomain of SREC‐II, such as C1q and calreticulin, are shared with the corresponding domain of SR‐F1. [ABSTRACT FROM AUTHOR]

Published
2021
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15. Contributors

Author

D. Angeli, Y. Bartosiewicz, S. Bassini, F. Bertocchi, D. Castelliti, X. Cheng, M. Daubner, L. De Moerloose, J. De Ridder, J. Degroote, A. Del Nevo, I. Di Piazza, M. Duponcheel, S. Eckert, F. Fellmoser, N. Forgione, S. Franke, C. Geffray, A. Gerschenfeld, D. Grishchenko, W. Hering, R. Hu, W. Jäger, M. Jeltsov, G. Kennedy, L. Koloszar, K. Kööp, N. Krauter, P. Kudinov, P. Lorusso, R. Marinari, D. Martelli, E. Merzari, I. Mickus, V. Moreau, J. Oder, J. Pacio, A. Pesetti, P. Planquart, W.D. Pointer, M. Polidori, F. Roelofs, M. Rohde, D. Rozzia, A. Shams, C. Spaccapaniccia, E. Stalio, R. Stieglitz, M. Tarantino, J. Thomas, I. Tiselj, K. Van Tichelen, J. Vierendeels, T. Wetzel, and T. Wondrak

Published
2019
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17. Experimental and Numerical Characterization of the Flow Field at the Core Entrance of a Water Model of a Heavy Liquid Metal–Cooled Reactor.

Author

Planquart, Philippe, Spaccapaniccia, Chiara, Alessi, Giacomo, Buckingham, Sophia, and Van Tichelen, Katrien

Abstract

The thermal-hydraulic challenges of a nuclear reactor are numerous and mastering them is crucial for the design and safety of new reactors. Numerical simulation through computational fluid dynamics (CFD) codes or system thermal-hydraulic codes can address a lot of the different questions, nevertheless the use of water modeling for the study of the thermal-hydraulic behavior of a new primary system and the validation of codes remains an extremely valuable tool. A water model of the pool-type PbBi-cooled MYRRHA reactor has been developed at the von Karman Institute in collaboration with SCK•CEN. It is a full plexiglass model at a geometrical scale 1/5 of MYRRHA. This transparent water model allows the application of optical measurement techniques like particle image velocimetry (PIV) for flow characterization. Local results of PIV measurements performed in the lower plenum at the entrance of the core are presented and compared with CFD results for nominal operating condition and a natural convection case simulating decay heat removal. Very good agreement has been found in the velocity field. The results also show the importance of the radial flow entering the core of the water model in natural convection. [ABSTRACT FROM AUTHOR]

Published
2020
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18. Advanced Liquid-Metal Thermal-Hydraulic Research for MYRRHA.

Author

Van Tichelen, Katrien, Kennedy, Graham, Mirelli, Fabio, Marino, Alessandro, Toti, Antonio, Rozzia, Davide, Cascioli, Edoardo, Keijers, Steven, and Planquart, Philippe

Abstract

The Belgian Nuclear Research Centre (SCK•CEN) is at the forefront of heavy liquid-metal (HLM) nuclear technology worldwide with the development of the Multi-purpose hYbrid Research Reactor for High-tech Applications (MYRRHA) accelerator-driven system. MYRRHA is a flexible fast-spectrum pool-type research reactor cooled by lead bismuth eutectic (LBE) and has been identified as the European Technology Pilot Plant for the lead-cooled fast reactor. Given the innovative nature of MYRRHA, the project is currently going through a prelicensing phase. The MYRRHA research and development (R&D) program is driven by this prelicensing process and aims to fill the existing gaps in knowledge with respect to LBE chemistry, material behavior, fuel behavior, instrumentation, and HLM thermal hydraulics. In this critical review we present selected topics from the R&D program on HLM thermal hydraulics that are essential for the design, engineering, and safety analysis of MYRRHA and other HLM-cooled reactors. The topics addressed include turbulent heat transfer in HLM, fuel assembly thermal hydraulics and flow-induced vibrations, control rod hydrodynamics, primary heat exchanger pool and integral system thermal hydraulics, sloshing, and multiphysics modeling. [ABSTRACT FROM AUTHOR]

Published
2020
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19. Distribution, movement and plant availability of trace metals in soils amended with sewage sludge composts: application to low metal loadings

Author

G. Bonin, Catherine Massiani, A. Prone, and P. Planquart

Subjects
Environmental Engineering, Compost, Chemistry, engineering.material, Pollution, Soil contamination, Nutrient, Agronomy, Soil pH, Soil water, engineering, Environmental Chemistry, Trace metal, Leachate, Waste Management and Disposal, Calcareous
Abstract

Three soils, representative of various physico–chemical properties, an acid soil from a granitic arena with a sandy texture, a calcareous soil with a sandy silty texture and a clayey and silty one, were used in a lysimetric experiment to evaluate the ecotoxicological risks associated with the disposal of sewage sludge composts (SSC) containing trace metal contents below the recommended limit values established by the French legislation. A crop of colza (Brassica napus) was grown on the amended soils. Based on the results from this experiment, SSC application enhanced the nutritional levels of the soils and stimulated the growth of plants. Chemical fractionation of composts and amended soils was performed using a sequential extraction technique. The pattern of metal distribution in the five fractions gave a good prediction of the trace metal behaviour in soils. Among the metals studied, Zn was the one that moved most readily in the soils (except in the calcareous soil) since compost application increased the proportion of the most labile forms of Zn and especially its pH 4.7 acid-soluble forms in the amended soils. The migration of Cu and Pb within the profiles of amended soils was significantly influenced by the release of soluble organics from the amended layers during the sludge–soil equilibration period. However, leachates were very little affected by SSC application as metal redistribution took place in deep layers of these amended soils. The movement of Pb within the profiles of the amended soils was not pH dependent whereas the mobility and plant availability of Cu and Zn increased as soil pH decreased. The sequence of trace metal concentrations in all plant parts was: Zn⪢Cu>Pb. Colza leaves were the organs of accumulation of trace metals and nutrients (except Na). Zn contents in leaves were governed by SSC loading rates. Principal component analysis performed on the ‘total’ metal and nutrient concentrations in plants showed on the one hand that no deficiency in nutrients caused by interactions with trace metals arose in the plant organs and on the other hand that the nutrient and trace metal contents in plants were more influenced by soil nature than compost application.

Published
1999
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20. Study of Thermal Conductance in a Strip-Roll System

Author

Jean-Marie Buchlin, M. DelsipГ©e, P. Planquart, and M. Renard

Subjects
Engineering, business.industry, Annealing (metallurgy), Continuous annealing, Mechanical engineering, STRIPS, law.invention, Thermal conductivity, law, Thermocouple, Thermal, Heat transfer, Ultimate tensile strength, business
Abstract

The paper describes an experimental investigation carried out on a semi-industrial prototype of regenerative roll quench unit to determine the contact thermal conductance ( CTC ) between a roll and a moving strip. The quantitative infrared thermograpy allows the temperature mapping of the strip while the angular evolution of the roll temperature is obtained by mean of thermocouples connected to a telemetry acquisition system. A thermal model allows the determination of the CTC . Typical results emphasize the effect of some parameters such as the velocity, the temperature and the tensile strength of the strip. KEY WORDS: Measurement and instrumentation – contact thermal conductance 1. INTRODUCTION The knowledge of heat transfer between two solids is often required when designing thermal systems. A typical example is the continuous annealing of moving strip based on the roll quench process [1-2]. The von Karman Institute has undertaken in close collaboration with DREVER International S.A, a research programme aiming to develop a new concept of annealing furnace for the treatment of steel strips. Called the roll regenerative furnace (RRF), this innovative technique, few energy intensive, consists of benefiting from the thermal potential provided by the hot strip leaving the furnace to preheat the cold strip entering the furnace by means of a set of rolls as illustrated in Fig. 1 [patent No WO 2009/007362 by DREVER International].

Published
2014
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22. Experimental characterization of bubbling in submerged lance injection

Author

A. Gosset, P. Rambaud, P. Planquart, J.-M. Buchlin, E. Robert, Liejin Guo, D. D. Joseph, Y. Matsumoto, Y. Sommerfeld, and Yueshe Wang

Subjects
Physics::Fluid Dynamics, Flow visualization, Hydrology, Materials science, Bubble, Nozzle, Water model, Mechanics, Control parameters, Flow measurement, Volumetric flow rate, Dimensionless quantity
Abstract

The bubbling phenomena from a downward facing nozzle immersed in a liquid bath are studied experimentally on a water model facility. The pressure fluctuations in the injection lance are correlated to the bubble growth and detachment thanks to simultaneous visualizations and digital processing of the resulting images. The main control parameters for the bubbling frequency are identified within an important experimental database for submerged injection. The effect of the gas volumetric flow rate, the lance submergence depth in the bath, the tip diameter and the gas properties are characterized in particular. An empirical dimensionless correlation is proposed for the frequency prediction.

Published
2010
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24. Modulation of the Expression Level of Human Acidic Lipases by Various Signal Peptides.

Author

Walker, John M., Doolittle, Mark, Reue, Karen, Canaan, Stéphane, Dupuis, Liliane, Rivière, Mireille, Verger, Robert, and Wicker-Planquart, Catherine

Abstract

Mammalian acidic lipases belong to a family of lipases that share the ability to maintain activity under acidic conditions. This family includes pre-duodenal lipases and lysosomal lipase and shows no sequence homology with other known lipase families (1,2). Human gastric lipase (glycerol ester hydrolase, EC 3.1.1.3, HGL) is secreted by chief cells of the fundic part of the stomach (3) where it initiates the digestion of triacylglycerols (4). Human lysosomal acid lipase (HLAL , EC 3.1.1.13) hydrolyzes cholesteryl esters and triglycerides that are delivered to the lysosomes by low density lipoprotein receptor-mediated endocytosis (5). [ABSTRACT FROM AUTHOR]

Published
1999
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25. Fibrosarcoma of the nasal cavity: A case report.

Author

Maliki, Omar, Aleksandrov, Oleksandr, Carles, Phillipes, Planquart, Xavier, Vaz, Emmanuelle, Bertrand, Catherine, and Rosikon, Andrzej

Abstract

Nasal fibrosarcoma is an infrequent malignant neoplasm. It usually presents as other sarcomas in this region, with nasal obstruction and epistaxis. The final diagnosis is based on the histopathology and immunohistochemistry. We report the case of a 37-year-old man with a 3-month history of recurrent epistaxis and nasal obstruction. Nasal endoscopy confirmed a right nasal neoplasia. Computed tomography and magnetic resonance image showed the tumor. TEP scan showed no metastasis. Complete removal was achieved through a combined surgery, by endoscopic endonasal approach and by incision in the right upper oral vestibule. Fibrosarcoma was found on histopathologic and immunohistochemistric examinations. After 12 months, the postoperative course was uneventful and follow-up information showed no recurrence of metastasis. However, in the 13th month, the patient suddenly died at home. Autopsy found no obvious cause for his death. To the best of our knowledge, no case of a fibrosarcoma of the nasal cavity with sudden death has been previously reported in the English-language. [ABSTRACT FROM AUTHOR]

Published
2014
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26. Rapid cooling in continuous annealing and galvanizing lines

Author

Renard, M., Gouriet, J.-B., Planquart, Ph., Van Beek, J., and Buchlin, J.-M.

Abstract

The production of new steel grades - such as dual phase and TRIP steels - requires improvements to both process and equipment of continuous galvanizing lines. In particular, progress has to be obtained in cooling technology in order to get the desired mechanical properties. This paper presents a study of design parameters allowing the optimization of fast gas multi-jet cooling systems. The thermal study involves the application of infrared thermography and three-dimensional numerical simulations. Furthermore, a dynamic study is performed in order to reduce steel strip vibration.

Published
2003
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28. CFD Wind Tunnel Assessment on the case study of the MOTHIF Blown Flap

Author

D’Alesio, Paolo, Travostino, Giorgio, Planquart, Philippe, and Glabeke, Gertjan

Abstract

The increasing interest in Small Air Transportation (SAT), to enhance global connectivity, is highlighting the need for reducing take-off distance: lift coefficient has to be increased without penalizing the configuration drag, weight and complexity.

Published
2022
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29. Bovine Pancreatic Preproelastases I and II: Comparison of Nucleotide and Amino Acid Sequences and Tissue Specific Expression

Author

Gestin, Martine, Le Huërou-Luron, Isabelle, Wicker-Planquart, Catherine, Le Dréan, Gwenola, Chaix, Jean-Claude, Puigserver, Antoine, and Guilloteau, Paul

Abstract

Clones encoding bovine preproelastases I and II were isolated from a pancreatic cDNA library and were sequenced in order to define the structural characteristics of these enzymes. The bovine 947- and 884- nucleotide preproelastase I and II cDNAs encode proteins containing a signal peptide of the same length (16 amino acids), but with a slightly different number of amino acids for the activation peptide (10 and 12, respectively) and the mature enzyme (240 and 241, respectively). Considering amino acid sequences, each enzyme shares a high degree of identity (76–86%) within species. In contrast, only 55.3% identity is found between bovine elastases I and II. This difference could explain partly their own specificity. Analysis of the expression of the elastases in various bovine tissues demonstrated that they are specifically expressed in high levels in the pancreatic gland. These two approaches (structure and expression) allowed us to characterize the bovine pancreatic elastases I and II.

Published
1997
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30. Purification and Interfacial Behavior of Recombinant Human Gastric Lipase Produced from Insect Cells in a Bioreactor

Author

Canaan, Stéphane, Dupuis, Liliane, Rivière, Mireille, Faessel, Karine, Romette, Jean-Louis, Verger, Robert, and Wicker-Planquart, Catherine

Abstract

Recombinant human gastric lipase (rHGL) (EC 3.1.1.3) was produced on a large scale (5–13 mg/liter) from recombinant baculovirus-infected insect cells using a bioreactor apparatus. Here an improved procedure is described for purifying rHGL involving the use of cation exchange chromatography followed by immunoaffinity column methods, which gives a total yield of 62% and a purification factor of 464, using 10% isopropanol in all the purification buffers. The presence of isopropanol was necessary to preserve the stability of the enzyme during the chromatographic separation steps. The specific activity of rHGL on tributyroylglycerol (700 U/mg) was lower than that of native HGL (nHGL) (1080 U/mg). The rHGL interfacial adsorption kinetics were studied by recording the changes in the surface pressure with time in the presence or absence of an egg phosphatidycholine monomolecular film spread at the air/water interface at various initial surface pressures. The surface behavior of rHGL was similar to that of nHGL. It can be concluded that the lipid binding affinity of rHGL is identical to that of the native lipase and, consequently, that the presence of detergents and lipids in the insect cell culture media did not affect the interfacial behavior of the purified rHGL. It will be therefore possible to specifically study the binding step of HGL mutants to a lipid monolayer.

Published
1998
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31. Primary structure of rat pancreatic lipase mRNA

Author

Wicker-Planquart, Catherine and Puigserver, Antoine

Abstract

The sequence of a rat pancreatic lipase mRNA was determined. The data have been assigned the following accession number, X61925, in the EMBL data library. The total length of the messenger is 1531 nucleotides, plus a poly(A) stretch of about 60 nucleotides. A 72-nucleotides 5′-noncoding region is followed by a 1419-nucleotides open reading frame which encodes a protein of 473 amino acids, including the 17 amino acid signal peptide. The mature enzyme (456 residues) has 6 additional C-terminal amino acids, as compared with the amino acid sequence of pig (direct amino acid sequence), dog, man and rat isoenzyme from Genbank, M58369 (all deduced from the nucleotide sequence). A higher degree of homology exists between the amino acid sequence of rat mature enzyme with those of dog (88%), pig (75%) and man (75%) than with that of rat isolipase (74%).

Published
1992
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32. Caerulein and gastrin(2–17 ds) regulate differently synthesis of secretory enzymes, mRNA levels and cell proliferation in pancreatic acinar cells (AR4-2J)

Author

Pradel, P, Estival, A, Seva, C, Wicker-Planquart, C, Puigserver, A, Vaysse, N, and Clemente, F

Abstract

In order to characterize the biological functions coupled to cholecystokinin (CCK) A and B receptors, the effects of gastrin(2-17 ds) and caerulein were compared. An isolated cell model, the pancreatic acinar cell line AR4-2J, was used and the experiments were carried out in serum-free media. Caerulein was found to evoke no mitogenic effects either alone or in the presence of the CCK antagonists L364,718 and CR1409. Gastrin(2-17 ds) increased cell proliferation by 2-fold with an IC50 of 150 pM, corresponding to the occupancy of the CCK B receptors. CR1409, at concentrations that fully occupied CCK B receptors, inhibited the gastrin(2-17 ds) effects. Caerulein enhanced chymotrypsinogen biosynthesis by 100% and the corresponding mRNA level by 75%; amylase biosynthesis and mRNA level were enhanced by 40% only. Half-maximal increases in chymotrypsin activity and mRNA level were recorded in response to caerulein at concentrations of 100 pM and 50 pM respectively. Gastrin(2-17 ds) at 100 nM enhanced chymotrypsinogen biosynthesis by 26% and its mRNA level by 35%; these responses were lower than those evoked by 0.1 nM caerulein. Furthermore, CR1409 completely inhibited caerulein- and gastrin(2-17 ds)-stimulated chymotrypsinogen synthesis, with similar IC50 (4 microM). These results suggest that both peptides induced the synthesis of the secretory enzyme after occupancy of CCK A receptors.

Published
1993
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33. Regulation of amylase and chymotrypsinogen expression by dexamethasone and caerulein in serum-free-cultured pancreatic acinar AR4-2J cells. Influence of glucose

Author

Estival, A, Pradel, P, Wicker-Planquart, C, Vaysse, N, Puigserver, A, and Clemente, F

Abstract

The direct effects of dexamethasone and caerulein on two pancreatic enzymes, amylase and chymotrypsin, were determined in AR4-2J cells cultured under serum-free conditions at two glucose concentrations (1.0 and 4.5 g/l). In the absence of any hormone, the higher glucose concentration resulted in a 1.6-1.8-fold increase in the basal levels of amylase and chymotrypsinogen. Dexamethasone (50 nM) increased the biosynthesis and mRNA levels of both enzymes at both glucose concentrations. However, dexamethasone had a more pronounced effect on amylase biosynthesis (5-fold induction) than on chymotrypsinogen biosynthesis (1.8-fold induction). The parallel increases in mRNA and protein indicated the existence of pre-translational regulation. This is in contrast with what was observed in serum-containing media, where a translational regulation of amylase biosynthesis took place, probably under the control of both glucose and some serum factors. By contrast, caerulein (10 nM) exerted a more specific action on chymotrypsinogen. The increases in chymotrypsinogen mRNA were 2.2- and 2.1-fold, and increases in chymotrypsin activity were 1.6- and 2.9-fold at 1.0 and 4.5 g of glucose/litre respectively. Thus the regulation by caerulein occurred mainly through the enhancement of chymotrypsinogen transcription and/or mRNA stabilization.

Published
1991
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34. cDNA cloning and sequence analysis of human pancreatic procarboxypeptidase A1

Author

Catasús, L, Villegas, V, Pascual, R, Avilés, F X, Wicker-Planquart, C, and Puigserver, A

Abstract

Using polyclonal antibodies raised against human pancreatic procarboxypeptidases, a full-length cDNA coding for an A-type proenzyme was isolated from a lambda gt11 human pancreatic library. This cDNA contains standard 3′ and 5′ flanking regions, a poly(A)+ tail and a central region of 1260 nucleotides coding for a protein of 419 amino acids. On the basis of sequence comparisons, the human protein was classified as a procarboxypeptidase A1 which is very similar to the previously described A1 forms from rat and bovine pancreatic glands. The presence of the amino acid sequences assumed to be of importance for the zymogen inhibition by its activation segment, primarily on the basis of the recently reported crystal structure of the B form, further supports the proposed classification.

Published
1992
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35. Gastric and Pancreatic Enzyme Activities and their Relationship with Some Gut Regulatory Peptides during Postnatal Development and Weaning in Calves1

Author

Le Huerou-Luron, Isabelle, Guilloteau, Paul, Wicker-Planquart, Catherine, Chayvialle, Jean-Alain, Burton, John, Mouats, Aziz, Toullec, Rene, and Puigserver, Antoine

Abstract

Changes in the activities of three gastric and nine pancreatic enzymes plus colipase were determined during postnatal development and weaning in calves. In calves exclusively milk-fed for 2, 7, 28, 56, 70 and 119 d, the enzyme activities per kilogram of empty live weight increased with age for chymotrypsin, elastase, carboxypeptidases A and B, ribonuclease and α-amylase, decreased for chymosin, lysozyme and colipase but showed no change in the case of pepsin, trypsin, lipase and phospholipase A2 compared with animals at birth. The greatest increase was that in α-amylase activity (about 50-fold between d 2 and 119). In calves weaned between d 28 and 56, all the activities were higher than in milk-fed animals, except that of chymosin (which was slightly lower) and that of colipase (which did not change). At 119 d of age, chymotrypsin, carboxypeptidase A, α-amylase and lipase were 1.6- to fourfold higher in ruminants than in preruminants. Thus, most enzyme activities were modified first by colostrum and milk intake, and again upon weaning by development of the forestomachs and ingestion of solid food. These ontogenic patterns might be under the control of many gut regulatory peptides, the plasma concentrations of which changed simultaneously. Some gastric and pancreatic enzymes were correlated to plasma concentrations of these gut regulatory peptides.

Published
1992
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