Ursula Keller wins “Swiss Nobel” Marcel Benoist Prize
Farewell: the NCCR MUST ended 
MUST2022 Conference
New scientific highlights
FELs of Europe prize for Jeremy Rouxel
Ruth Signorell wins Doron prize
New FAST-Fellow Uwe Thumm at ETH
International Day of Women and Girls in Science
New scientific highlight
EU XFEL Young Scientist Award for Camila Bacellar,
Prizes for Giulia Mancini and Rebeca Gomez Castillo
Nobel Prize in Chemistry awarded to RESOLV Member Benjamin List
Hans Jakob Wörner invited to give the „New Horizons Solvay Lectures” 
Unusual keynote talk at an international scientific conference
NCCR MUST at Scientifica 2021Ultrafast tryptophan-to-tryptophan energy transfer and superradiance in tubulin polymers
| Date | Do, 05.07.2018 | |
| Time | 16:00 | |
| Speaker | Dr. Philip Kurian, Howard University, Washington DC, USA | |
| Location | EPFL CH G1 495 | |
| Program | Abstract : Oxidative stress from aerobic processes is a pathological hallmark of degenerative disorders such as Alzheimer’s disease and cancer. The precise role of reactive oxygen species (ROS) in the disease process, however, is poorly understood. It is known that the production of ROS by mitochondria can result in ultraweak photon emission (UPE) within cells, and UPEs in the UV and visible ranges have been observed with modern equipment during different stages of the mitotic cycle [1]. Surrounding biomolecules can absorb these photons via aromatic amino acids (e.g., tryptophan and tyrosine), nucleobases (e.g., adenine, cytosine, guanine, thymine), and other chromophoric constituents, forming excited singlet or triplet transition states. One likely absorber is the microtubule cytoskeleton, as it forms a vast network spanning neurons, is highly co-localized with mitochondria, and shows a high density of aromatics, but DNA and the photoactive receptors in the mitochondrial membrane are also potential candidates. These networks may traffic ROS-generated endogenous photon energy for cellular signaling, or they may serve as dissipaters of such energy to protect the cell from potentially harmful effects. Recent modelling efforts based on ambient temperature experiment are presented [2], showing that such biopolymers can feasibly absorb and channel these photoexcitations via resonance energy transfer, on mesoscopic length scales of physiological significance. Additional simulations using a non-Hermitian Mukamel Hamiltonian [3] demonstrate the possible existence of superradiant states in microtubules corresponding to similar observed phenomena in cylindrical chlorophyll complexes. References: [1] R. N. Tilbury and T. I. Quickenden, Luminescence from the Yeast Candida utilis and Comparisons across Three Genera, Journal of Bioluminescence and Chemiluminescence 7, 245-253 (1992). [2] P. Kurian, T. O. Obisesan, and T. J. A. Craddock, Oxidative species-induced excitonic transport in tubulin aromatic networks: Potential implications for neurodegenerative disease, Journal of Photochemistry and Photobiology B: Biology 175, 109-124 (2017). [3] G. L. Celardo, G. G. Giusteri, and F. Borgonovi, Cooperative robustness to static disorder: Superradiance and localization in a nanoscale ring to model light-harvesting systems found in nature, Physical Review B 90, 075113 (2014). |
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