Analysis of longitudinal bunching inan FEL driven two-beam accelerator

Recent experiments [1] have explored the use of a free-electron laser (FEL) as a buncher for a microwave two-beam accelerator, and the subsequent driving of a standing-wave rf output cavity. Here we present a deeper analysis of the longitudinal dynamics of the electron bunches as they are transported from the end of the FEL and through the output cavity. In particular, we examine the effect of the transport region and cavity aperture to filter the bunched portion of the beam. [1] T. Lefevre, et. al., Phys. Rev. Lett. 84 (2000), 1188.Comment: 3 pages, 8 figures. Submitted to XX Int'l LINAC Conferenc

Analysis of longitudinal bunching in an FEL driven two-beam accelerator

Recent experiments have explored the use of a free-electron laser (FEL) as a buncher for a microwave two-beam accelerator, and the subsequent driving of a standing-wave rf output cavity. Here we present a deeper analysis of the longitudinal dynamics of the electron bunches as they are transported from the end of the FEL and through the output cavity. In particular, we examine the effect of the transport region and cavity aperture to filter the bunched portion of the beam

Proton beam - target interactions at low and high power densities

SIGLEAvailable from CEN Saclay, Service de Documentation, 91191 Gif-sur-Yvette Cedex (France) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

RF9, a potent and selective neuropeptide FF receptor antagonist, prevents opioid-induced tolerance associated with hyperalgesia

Neuropeptide FF (NPFF) has been proposed to play a role in pain modulation, opioid tolerance, and several other physiological processes. However, pharmacological agents that would help define physiological roles for this peptide are still missing. Here we report the discovery of a potent and selective NPFF receptor antagonist, RF9, that can be administered systemically. This compound does not show any effects by itself but can block efficiently the increase in blood pressure and heart rate evoked by NPFF. When chronically coinjected with heroin, RF9 completely blocks the delayed and long-lasting paradoxical opioid-induced hyperalgesia and prevents the development of associated tolerance. Our data indicate that NPFF receptors are part of a bona fide antiopioid system and that selective antagonists of these receptors could represent useful therapeutic agents for improving the efficacy of opioids in chronic pain treatment

213Bi Radioimmunotherapy with an Anti-mCD138 Monoclonal Antibody in a Murine Model of Multiple Myeloma

Radioimmunotherapy (RIT) with beta-emetting emitting radionuclides is a promising treatment in lymphoma. Though However, the efficiency of beta-emitting radionuclides to kill isolated tumor cells is limited by the relatively long range of beta radiation in human tissue, resulting in deposition of most of the beta particle energy far from the targeted cell. For disease such as leukemia and for residual disease, the use of alpha emitters which deliver large amounts of energy (several MeV) in an area of less than 100 µm has been developed. Alpha emitting radionuclides such as 213Bi or 211At have short half-lives and therefore require a rapid targeting of the tumor. In this context, alpha RIT appears as a particularly attractive therapy in multiple myeloma (MM). Indeed, in MM since the marrow shows diffuse or focal radiosensitive plasma cells involvement, the use of a specific vector coupled with high energy particles such as alpha shall enable localized destruction of myeloma cells with limited damages to surrounding healthy tissues. Syndecan-1 (CD138), a heparan sulfate proteoglycan, is constantly expressed on tumor cells in MM. Therefore this surface antigen is an attractive candidate for targeted therapy. The aim of the study was to assess toxicity and efficacy of RIT using 213Bi-anti-mCD138 in a murine MM model. The model was obtained using the 5T33 line that spontaneously occurred in C57BL/KaLwRij mice and has been propagated in vivo by intravenous transfer into young syngeneic recipients. Mice were treated using 213Bi-anti-mCD138 at 4 injected activities (1.85, 3.7, 7.4 and 11.1 MBq). Groups treated with 3.7 and 7.4 MBq exhibited a median survival above 300 days and 227 days respectively compared to 45.5 days in control group. The highest activity (11.1 MBq) was rapidly toxic while the lowest activity (1.85 MBq) gave results similar to the control. With activities of 3.7 and 7.4 MBq, surviving mice exhibit a transient hematological toxicity and we observed at 7.4 MBq only, a temporary sign of low myelotoxicity. This study demonstrated excellent therapeutic efficacy of 213Bi-anti-mCD138 RIT in MM.JRC.E.5-Nuclear chemistr

Theoretical and experimental studies of electron deposition in thin targets

SIGLEAvailable from CEN Saclay, Service de Documentation, 91191 - Gif-surYvette Cedex (France) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc