A5102909154- Laser-Plasma Interactions and Diagnostics
- Laser-Matter Interactions and Applications
- Laser-induced spectroscopy and plasma
- Genomics and Chromatin Dynamics
- Laser Design and Applications
- Chromosomal and Genetic Variations
- RNA Research and Splicing
- Atomic and Molecular Physics
- High-pressure geophysics and materials
- Advanced Fiber Laser Technologies
- RNA and protein synthesis mechanisms
- Ionosphere and magnetosphere dynamics
- Dust and Plasma Wave Phenomena
- CRISPR and Genetic Engineering
- Solar and Space Plasma Dynamics
- T-cell and B-cell Immunology
- RNA Interference and Gene Delivery
- Geomagnetism and Paleomagnetism Studies
- Advanced X-ray Imaging Techniques
- Earthquake Detection and Analysis
- Genetic Mapping and Diversity in Plants and Animals
- RNA modifications and cancer
- Photosynthetic Processes and Mechanisms
- Immune Cell Function and Interaction
- Microtubule and mitosis dynamics
University of Massachusetts Chan Medical School
2010-2019
Howard Hughes Medical Institute
2019
École Polytechnique
2007-2014
Centre National de la Recherche Scientifique
2007-2014
Russian Academy of Sciences
1996-2012
Laboratoire d'Optique Appliquée
2006-2011
École Nationale Supérieure de Techniques Avancées
2007-2011
University of Michigan
2003-2009
Laboratoire pour l'utilisation des lasers intenses
2009
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2009
Mitotic chromosomes are among the most recognizable structures in cell, yet for over a century their internal organization remains largely unsolved. We applied chromosome conformation capture methods, 5C and Hi-C, across cell cycle revealed two distinct three-dimensional folding states of human genome. show that highly compartmentalized type-specific described previously nonsynchronous cells is restricted to interphase. In metaphase, we identified homogenous state locus-independent, common...
Tracking mitotic chromosome formation How cells pack DNA into fully compact, rod-shaped chromosomes during mitosis has fascinated cell biologists for more than a century. Gibcus et al. delineated the conformational transition trajectory from interphase chromatin to minute by cycle. The is organized in spiral staircase architecture which loops emanate radially centrally located helical scaffold. molecular machines condensin I and II play distinct roles these processes: Condensin essential...
Recently achieved high intensities of short laser pulses open new prospects in their application to hole boring inhomogeneous overdense plasmas and for ignition precompressed DT fusion targets. A simple analytical model numerical simulations demonstrate that with exceeding ${10}^{22}\text{ }\text{ }\mathrm{W}/{\mathrm{cm}}^{2}$ may penetrate deeply into the plasma as a result efficient ponderomotive acceleration ions forward direction. The penetration depth big hundreds microns depends on...
Lasers that provide an energy encompassed in a focal volume of few cubic wavelengths (lambda(3)) can create relativistic intensity with maximal gradients, using minimal energy. With particle-in-cell simulations we found, single 200 attosecond pulses could be produced efficiently lambda(3) laser pulse reflection, via deflection and compression from the plasma mirror created by itself. An analytical model coherent radiation charged layer confirms is good agreement simulations. The novel...
Laser ponderomotive force at superhigh intensities provides an efficient ion acceleration in bulk dense targets and evacuates a channel enabling further laser beam propagation. The developed quasistationary model of piston—a double layer structure supported by the radiation pressure—predicts general parameters process homogeneous inhomogeneous overdense plasmas. Particle-in-cell simulations confirm estimated characteristics wide range densities show advantages circularly polarized pulses....
QED effects are known to occur in a strong laser pulse interaction with counterpropagating electron beam, among these being electron-positron pair creation. We discuss the range of intensities J≥5×10(22) W/cm2 combined beam energies tens GeV. In this regime multiple pairs may be generated from single electron, some newborn particles capable further production. Radiation backreaction prevents avalanche development and limits The system integro-differential kinetic equations for electrons,...
Electron bunches of attosecond duration may coherently interact with laser beams. We show how p-polarized ultraintense pulses interacting sharp boundaries overdense plasmas can produce such bunches. Particle-in-cell simulations demonstrate bunch generation during pulse propagation through a thin channel or in the course grazing incidence on plasma layer. In plasma, due to self-intersection electron trajectories, concentration is abruptly peaked. A group counterstream electrons pushed away...
The emission from an electron in the field of a relativistically strong laser pulse is analyzed. At intensities J>or=2x10(22) W/cm(2) counterpropagating electrons modified by effects quantum electrodynamics (QED), as long energy sufficiently high: E>or=1 GeV . radiation force experienced for first time derived QED principles and its applicability range extended toward QED-strong fields.
A new derivation of the motion a radiating electron is given, leading to formulation that differs from Lorentz–Abraham–Dirac equation and its published modifications. It satisfies proper conservation laws. Particularly, it conserves generalized momentum, eliminating symmetry-breaking runaway solution. The allows consistent calculation current, radiation effect on itself, for single or plasma electrons in strong electromagnetic fields. then applied simulation laser pulse interaction with...
We investigate the production of electron beams from interaction relativistically-intense laser pulses with a solid-density ${\mathrm{SiO}}_{2}$ target in regime where pulse energy is $\ensuremath{\sim}\mathrm{mJ}$ and repetition rate $\ensuremath{\sim}\mathrm{kHz}$. The beam spatial distribution spectrum were investigated as function plasma scale length, which was varied by deliberately introducing moderate-intensity prepulse. At optimum length $\ensuremath{\lambda}/2$, electrons are...
Ultra-strong laser pulses can be so intense that an electron in the focused beam loses significant energy due to γ-photon emission while its motion deviates via radiation back-reaction. Numerical methods and tools designed simulate radiation-dominated quantum-electrodynamically strong laser-plasma interactions are summarized here.
Genomes exist in vivo as complex physical structures, and their functional output (i.e. the gene expression profile of a cell) is related to spatial organization inside nucleus well local chromatin status. Chromatin modifications chromosome conformation are distinct different tissues cell types, which corresponds closely with diversity gene-expression patterns found body. The biological processes mechanisms driving these general correlations currently topic intense study. An emerging theme...
A study, with particle-in-cell simulations, of relativistic nonlinear optics in the regime tight focus and ultrashort pulse duration (the λ3 regime) reveals that synchronized attosecond electromagnetic pulses [N. M. Naumova, J. A. Nees, I. V. Sokolov, B. Hou, G. Mourou, Phys. Rev. Lett. 92, 063902 (2004)] electron bunches Maksimchuk, Yanovsky, 93, 195003 emerge efficiently from laser interaction overdense plasmas. The concept enables a more basic understanding practical implementation these...
Protein ADP ribosylation catalyzed by cellular poly(ADP-ribose) polymerases (PARPs) and tankyrases modulates chromatin structure, telomere elongation, DNA repair, the transcription of genes involved in stress resistance, hormone responses, immunity. Using Drosophila genetic tools, we characterize expression function glycohydrolase (PARG), primary enzyme responsible for degrading protein-bound ADP-ribose moieties. Strongly increasing or decreasing PARG levels mimics effects Parp mutation,...
The field of laser–matter interaction has branched out in two main directions. first, motivated by laser inertial confinement fusion, warm-dense-matter, fast ignition and astrophysics laboratory, the second driven ultra-high intensity, exotic physics, high-energy particle, photon beam generation time-resolved attosecond (zeptosecond) science. degree maturity from both experimental theoretical stand-points is such that a large European infrastructure for each branch contemplated as part...