Elastic Time Reversal Mirror Experiment in a Mesoscopic Natural Medium at the Low Noise Underground Laboratory of Rustrel, France

A seismic time reversal experiment based on Time Reversal Mirror (TRM) technique was conducted in the mesoscopically scaled medium at the LSBB Laboratory, France. Two sets of 50 Hz geophones were distributed at one meter intervals in two horizontal and parallel galleries 100 m apart, buried 250 m below the surface. The shot source used was a 4 kg sledgehammer. Analysis shows that elastic seismic energy is refocused in space and time to the shot locations with good accuracy. The refocusing ability of seismic energy to the shot locations is roughly achieved for the direct field, and with excellent quality, for the early and later coda. Hyper-focussing is achieved at the shot points as a consequence of the fine scale randomly heterogeneous medium between the galleries. TRM experiment is sensitive to the roughness of the mirror used. Roughness induces a slight experimental discrepancy between recording and re-emitting directions degrading the quality of the reversal process.Comment: 7 pages, 7 figures - This paper aimed at describing time reversal mirror method applied at mesoscopic scale to a natural medium in the frame of an active seismic experiment. The results confirm the hyper-focusing process in an anelastic medium and the efficiency of scattered waves within the coda to refocus at the source using the time reversal mirro

Mutational analysis of the RB1 gene in Moroccan patients with retinoblastoma

PURPOSE: Retinoblastoma (RB), the most common intraocular tumor occurring in infancy and early childhood, is most often related to mutations in the RB1 gene. In this study, we screened the RB1 germline mutations in 41 unrelated Moroccan patients with retinoblastoma, 25 heritable cases, and 16 sporadic unilateral cases. METHODS: After complete ophthalmic examinations were performed and consent obtained, DNA was extracted from peripheral blood, and screening of RB1 mutations was performed with PCR direct sequencing of the promoter and the 27 coding exons of the RB1 gene. RESULTS: We identified ten germline mutations in 10/41 (24.39%) unrelated patients, among which three had not been previously reported. The mutation detection rate was 40% (10/25) in the heritable cases and 0% (0/16) in the sporadic unilateral cases. Of these mutations, six were nonsense, and three were frameshifts, all associated with severe phenotypes resulting in bilateral and multifocal tumors. One splice site mutation was found in a familial case associated with a low expressivity phenotype resulting in unilateral and unifocal tumors. Moreover, eight intronic variants were identified, three of which were novel. CONCLUSIONS: This first report of RB1 gene screening in Moroccan patients with retinoblastoma shows a comparable mutational spectrum to those reported previously, which has evident importance for managing patients with retinoblastoma and their families

Elaboration d'un projet d'éducation thérapeutique pour les patients à haut risque cardiovasculaire en prévention secondaire après un évènement coronarien aigu

DIJON-BU Médecine Pharmacie (212312103) / SudocSudocFranceF

Efficient Dibenzo[ c ]acridine Helicene-like Synthesis and Resolution: Scaleup, Structural Control, and High Chiroptical Properties

International audienc

Photophysical and Magnetic Properties in Complexes Containing 3d/4f Elements and Chiral Phenanthroline-Based Helicate-Like Ligands

International audienceThe reactions between the chiral helicene-like ligand (L) and either Ln(hfac)(3)2H(2)O (hfac(-) = 1,1,1,5,5,5-hexafluoroacetylacetonate), Ln(tta)(3)2H(2)O (tta(-) = 2-tenoyltrifluoroacetonate), iron(II) sulfate or chloride, or a combination of them led to the formation of five chiral 4f compounds of formula [HL][Ln(hfac)(4)]nCH(2)Cl(2) [Ln = Dy, n = 0.5 (1) and Ln = Yb, n = 1 (2)], [HL][Ln(tta)(4)]nC(6)H(14) [Ln = Dy, n = 0 (3) and Ln = Yb, n = 2.5 (4)], and [HL](2)[Yb-8(hfac)(12)(OH)(12)(O)]0.5C(6)H(14)H(2)O (5), a chiral 3d complex of formula [Fe(NCS)(2)(L)]CH3NO2 (6), and a chiral 3d/4f heterodimetallic compound of formula [Fe(tta)(L)][Dy(tta)(4)]2.5CH(2)Cl(2) (7). The influence of the nature of the ancillary ligand and the presence or absence of base during the synthesis on the homochiral or heterochiral arrangement of the ligands as well as the dimensionality and nuclearity of the complexes were studied. Ytterbium-based compounds 2, 4, and 5 display near-infrared (NIR) luminescence under irradiation at = 350 nm owing to the F-2(5/2) F-2(7/2) Yb-III transition (centered at = 1000 nm). Complex 2 displays a second NIR emission at = 1278 nm, which is attributed to singlet-oxygen phosphorescence (a(g)(1) X-3 sigma(-)(g)) at both room temperature and 77 K. Dynamic magnetic measurements show an out-of-phase signal for the magnetic susceptibility of 7, which can be depicted as a 3d/4f chiral heterodimetallic single-molecule magnet