7 research outputs found
Laser based synchrotron radiation
Beams of x rays in the kiloelectronvolt energy range have been produced from laser-matter interaction. Here, energetic electrons are accelerated by a laser wakefield, and experience betatron oscillations in an ion channel formed in the wake of the intense femtosecond laser pulse. Experiments using a 50 TW laser (30 fs duration) are described, as well as comparisons with numerical simulations. These results pave the way of a new generation of radiation in the x-ray spectral range, with a high collimation and an ultrafast pulse duration, produced by the use of compact laser system.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87767/2/023101_1.pd
Production of a keV X-Ray Beam from Synchrotron Radiation in Relativistic Laser-Plasma Interaction
Theater of the Object : Reconstructions, Re-Creations, Reconsiderations, 1958-1972
Frank addresses the concerns of multimedia experimental works produced in the 1960s by ten American artists. Texts by some of the artists. Biographical notes. 3 bibl. ref
Production of a keV X-Ray Beam from Synchrotron Radiation in Relativistic Laser-Plasma Interaction
International audienceWe demonstrate that a beam of x-ray radiation can be generated by simply focusing a single high-intensity laser pulse into a gas jet. A millimeter-scale laser-produced plasma creates, accelerates, and wiggles an ultrashort and relativistic electron bunch. As they propagate in the ion channel produced in the wake of the laser pulse, the accelerated electrons undergo betatron oscillations, generating a femtosecond pulse of synchrotron radiation, which has keV energy and lies within a narrow (50 mrad) cone angle
Selectivity, Cocrystal Structures, and Neuroprotective Properties of Leucettines, a Family of Protein Kinase Inhibitors Derived from the Marine Sponge Alkaloid Leucettamine B
DYRKs (dual specificity, tyrosine phosphorylation regulated
kinases)
and CLKs (cdc2-like kinases) are implicated in the onset and development
of Alzheimer’s disease and Down syndrome. The marine sponge
alkaloid leucettamine B was recently identified as an inhibitor of
DYRKs/CLKs. Synthesis of analogues (leucettines) led to an optimized
product, leucettine L41. Leucettines were cocrystallized with DYRK1A,
DYRK2, CLK3, PIM1, and GSK-3β. The selectivity of L41 was studied
by activity and interaction assays of recombinant kinases and affinity
chromatography and competition affinity assays. These approaches revealed
unexpected potential secondary targets such as CK2, SLK, and the lipid
kinase PIKfyve/Vac14/Fig4. L41 displayed neuroprotective effects on
glutamate-induced HT22 cell death. L41 also reduced amyloid precursor
protein-induced cell death in cultured rat brain slices. The unusual
multitarget selectivity of leucettines may account for their neuroprotective
effects. This family of kinase inhibitors deserves further optimization
as potential therapeutics against neurodegenerative diseases such
as Alzheimer’s disease