Publications

2018

• Analyse d’une carte du monde du VIIIe siècle : la Mappa mundi d’Albi
  
  • Robinet Laurianne
  • Deschaux Jocelyne
  • Tournié Aurélie
  • Stéphane Vaidelich
  • Latour Gael
  • Michelin Anne
  • Thao Sylvie
  • Andraud Christine
  • Schanne-Klein Marie-Claire
  • Lavédrine Bertrand
  Support Tracé, Association pour la Recherche Scientifique sur les Arts Graphiques (ARSAG), 2018, 17, pp.5-13.
• Cartographier l’altération des parchemins : l’émergence d’une nouvelle technique de microscopie
  
  • Robinet Laurianne
  • Latour Gaël
  , 2018, pp.119-136.
• Multiscale conformational dynamics probed by time-resolved circular dichroism.
  
  • Schmid Marco
  • Changenet Pascale
  • Hache François
  Proceedings of SPIE, the International Society for Optical Engineering, SPIE, The International Society for Optical Engineering, 2018.
• Dual-color deep-tissue three-photon microscopy with a multiband infrared laser
  
  • Guesmi Khmaies
  • Abdeladim Lamiae
  • Tozer Samuel
  • Mahou Pierre
  • Kumamoto Takuma
  • Jurkus Karolis
  • Rigaud Philippe
  • Loulier Karine
  • Dray Nicolas
  • Georges Patrick
  • Hanna Marc
  • Livet Jean
  • Supatto Willy
  • Beaurepaire Emmanuel
  • Druon Frédéric
  Light: Science and Applications, Nature Publishing Group, 2018, 7 (1), pp.12. Multiphoton microscopy combined with genetically encoded fluorescent indicators is a central tool in biology. Three-photon (3P) microscopy with excitation in the short-wavelength infrared (SWIR) water transparency bands at 1.3 and 1.7 µm opens up new opportunities for deep-tissue imaging. However, novel strategies are needed to enable in-depth multicolor fluorescence imaging and fully develop such an imaging approach. Here, we report on a novel multiband SWIR source that simultaneously emits ultrashort pulses at 1.3 and 1.7 µm that has characteristics optimized for 3P microscopy: sub-70 fs duration, 1.25 MHz repetition rate, and µJ-range pulse energy. In turn, we achieve simultaneous 3P excitation of green fluorescent protein (GFP) and red fluorescent proteins (mRFP, mCherry, tdTomato) along with third-harmonic generation. We demonstrate in-depth dual-color 3P imaging in a fixed mouse brain, chick embryo spinal cord, and live adult zebrafish brain, with an improved signal-to-background ratio compared to multicolor two-photon imaging. This development opens the way towards multiparametric imaging deep within scattering tissues. (10.1038/s41377-018-0012-2)
  DOI : 10.1038/s41377-018-0012-2
• A mechanism for CO regulation of ion channels
  
  • Kapetanaki Sofia M.
  • Burton Mark J.
  • Basran Jaswir
  • Uragami Chiasa
  • Moody Peter C. E.
  • Mitcheson John S.
  • Schmid Ralf
  • Davies Noel W.
  • Dorlet Pierre
  • Vos Marten H.
  • Storey Nina M.
  • Raven Emma
  Nature Communications, Nature Publishing Group, 2018, 9, pp.907. Despite being highly toxic, carbon monoxide (CO) is also an essential intracellular signalling molecule. The mechanisms of CO-dependent cell signalling are poorly defined, but are likely to involve interactions with heme proteins. One such role for CO is in ion channel regulation. Here, we examine the interaction of CO with K$_{ATP}$ channels. We find that CO activates K$_{ATP}$ channels and that heme binding to a CXXHX$_{16}$H motif on the SUR2A receptor is required for the CO-dependent increase in channel activity. Spectroscopic and kinetic data were used to quantify the interaction of CO with the ferrous heme-SUR2A complex. The results are significant because they directly connect CO-dependent regulation to a heme-binding event on the channel. We use this information to present molecular-level insight into the dynamic processes that control the interactions of CO with a heme-regulated channel protein, and we present a structural framework for understanding the complex interplay between heme and CO in ion channel regulation. (10.1038/s41467-018-03291-z)
  DOI : 10.1038/s41467-018-03291-z
• Generalization of the optical theorem: experimental proof for radially polarized beams
  
  • Krasavin Alexey V
  • Segovia Paulina
  • Dubrovka Rostyslav
  • Olivier Nicolas
  • Wurtz Gregory A
  • Ginzburg Pavel
  • Zayats Anatoly V
  Light: Science and Applications, Nature Publishing Group, 2018, 7 (1), pp.36. The optical theorem, which is a consequence of the energy conservation in scattering processes, directly relates the forward scattering amplitude to the extinction cross-section of the object. Originally derived for planar scalar waves, it neglects the complex structure of the focused beams and the vectorial nature of the electromagnetic field. On the other hand, radially or azimuthally polarized fields and various vortex beams, essential in modern photonic technologies, possess a prominent vectorial field structure. Here, we experimentally demonstrate a complete violation of the commonly used form of the optical theorem for radially polarized beams at both visible and microwave frequencies. We show that a plasmonic particle illuminated by such a beam exhibits strong extinction, while the scattering in the forward direction is zero. The generalized formulation of the optical theorem provides agreement with the observed results. The reported effect is vital for the understanding and design of the interaction of complex vector beams carrying longitudinal field components with subwavelength objects important in imaging, communications, nanoparticle manipulation, and detection, as well as metrology. (10.1038/s41377-018-0025-x)
  DOI : 10.1038/s41377-018-0025-x