267 research outputs found
Use of Measurable Residual Disease to Evolve Transplant Policy in Acute Myeloid Leukemia: A 20-Year Monocentric Observation
Measurable residual disease (MRD) is increasingly employed as a biomarker of quality of
complete remission (CR) in intensively treated acute myeloid leukemia (AML) patients. We evaluated
if a MRD-driven transplant policy improved outcome as compared to a policy solely relying on a
familiar donor availability. High-risk patients (adverse karyotype, FLT3-ITD) received allogeneic
hematopoietic cell transplant (alloHCT) whereas for intermediate and low risk ones (CBF-AML and
NPM1-mutated), alloHCT or autologous SCT was delivered depending on the post-consolidation
measurable residual disease (MRD) status, as assessed by flow cytometry. For comparison, we
analyzed a matched historical cohort of patients in whom alloHCT was delivered based on the sole
availability of a matched sibling donor. Ten-years overall and disease-free survival were longer
in the MRD-driven cohort as compared to the historical cohort (47.7% vs. 28.7%, p = 0.012 and
42.0% vs. 19.5%, p = 0.0003). The favorable impact of this MRD-driven strategy was evident for
the intermediate-risk category, particularly for MRD positive patients. In the low-risk category, the
significantly lower CIR of the MRD-driven cohort did not translate into a survival advantage. In
conclusion, a MRD-driven transplant allocation may play a better role than the one based on the
simple donor availability. This approach determines a superior outcome of intermediate-risk patients
whereat in low-risk ones a careful evaluation is needed for transplant allocation
Proton inelastic scattering on Ni
The proton inelastic scattering on Ni isotopes was measured at the NSCL at MSU, employing the S800 spectrometer coupled to the GRETINA γ-ray array. The aim of the experiment was to determine the degree of collectivity in these neutron-rich Z = 28 isotopes. The use of a hadronic probe allows to complement previous Coulomb excitation measurements of the reduced transition probability B(E2; 0 → 2) and deduce the neutron-to-proton transition matrix elements ratio. The high resolution in γ-ray energy achievable with GRETINA gives large control on feeding transitions, thus reducing possible systematics errors in the determination of transition strengths
Probing core polarization around 78Ni: intermediate energy Coulomb excitation of 74Ni
The study of the evolution of nuclear shells far from stability provides fundamental information about the shape and symmetry of the nuclear mean field. Nuclei with large neutron/proton ratio allow to probe the density dependence of the effective interaction. Indeed, it was recently shown that tensor and three-body forces play an important role in breaking and creating magic numbers. Of particular interest is the region of 78Ni where the large neutron excess coincides with a double shell closure. We have recently measured the B(E2; 0+ → 2+) of the 74Ni nucleus in an intermediate-energy Coulomb excitation experiment performed at the National Superconducting Cyclotron Laboratory of the Michigan State University. The 74Ni secondary beam has been produced by fragmentation of 86Kr at 140 AMeV on a thick Be target. Selected radioactive fragments impinged on a secondary 197Au target where the measurement of the emitted γ-rays allows to extract the Coulomb excitation cross section and related structure information. Preliminary B(E2) values do not point towards an enhancement of the transition matrix element and the comparison to what was already measured by Aoi and co-workers in [1] opens new scenarios in the interpretation of the shell evolution of the Z=28 isotopes
Single-neutron orbits near Ni-78: Spectroscopy of the N=49 isotope Zn-79
5 pags., 6 figs.Single-neutron states in the , isotope 79Zn have been populated using the 78Zn(d, p)79Zn transfer reaction at REX-ISOLDE, CERN. The experimental setup allowed the combined detection of protons ejected in the reaction, and of γ rays emitted by 79Zn. The analysis reveals that the lowest excited states populated in the reaction lie at approximately 1 MeV of excitation, and involve neutron orbits above the shell gap. From the analysis of γ-ray data and of proton angular distributions, characteristic of the amount of angular momentum transferred, a configuration was assigned to a state at 983 keV. Comparison with large-scale-shell-model calculations supports a robust neutron shell-closure for 78Ni. These data constitute an important step towards the understanding of the magicity of 78Ni and of the structure of nuclei in the region.This work was supported by the European Commission through the Marie Curie Actions Contracts Nos. PIEFGA-2011-30096 (R.O.) and PIEFGA-2008-219175 (J.P.), by the Spanish Ministerio de Ciencia e Innovación under contracts FPA2009-13377-C02 and FPA2011-29854-C04, by the Spanish MEC Consolider – Ingenio 2010, Project No. CDS2007-00042 (CPAN), by FWO-Vlaanderen (Belgium), by GOA/2010/010 (BOF KU Leuven), by the Interuniversity Attraction Poles Programme initiated by the Belgian Science Policy Office (BriX network P7/12), by the European Union Seventh Framework Programme through ENSAR, contract no. RII3-CT-2010-262010, and by the German BMBF under contracts 05P09PKCI5, 05P12PKFNE, 05P12RDCIA and 06DA9036I. R.O., R.C., J.F.W.L., V.L. and J.F.S. also acknowledge support from STFC, Grant Nos. PP/F000944/1, ST/F007590/1, and ST/J000183/2
Spectroscopy of odd-mass cobalt isotopes toward the N=40 subshell closure and shell-model description of spherical and deformed states
The neutron-rich cobalt isotopes up to A = 67 have been studied through multinucleon transfer reactions by bombarding a 238U target with a 460-MeV 70Zn beam. Unambiguous identification of prompt γ rays belonging to each nucleus has been achieved using coincidence relationships with the ions detected in a high-acceptance magnetic spectrometer. The new data are discussed in terms of the systematics of the cobalt isotopes and interpreted with large-scale shell-model calculations in the fpgd model space. In particular, very different shapes can be described in 67Co, at the edge of the island of inversion at N = 40, where a low-lying highly deformed band coexists with a spherical structureThis work was partially supported by the European Community FP6, Structuring the ERA Integrated Infrastructure Initiative Contract No. EURONS RII3-CT-2004-506065, by MICINN, Spain (Contract No. FPA2011-29854), by IN2P3, France (Contract No. AIC-D-2011-648), by Comunidad de Madrid, Spain (Contract No. HEPHACOS S2009-ESP-1473), and by Generalitat Valenciana, Spain (Contract No. PROMETEO/ 2010/101). A. Gadea and E. Farnea acknowledge the support of MICINN, Spain, and INFN, Italy, through the AIC-D-2011-0746 bilateral actio
Identification of high-spin proton configurations in Ba 136 and Ba 137
19 pags., 11 figs., 3 tabs.The high-spin structures of Ba136 and Ba137 are investigated after multinucleon-transfer (MNT) and fusion-evaporation reactions. Ba136 is populated in a Xe136+U238 MNT reaction employing the high-resolution Advanced GAmma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA at the Laboratori Nazionali di Legnaro, Italy, and in two Be9+Te130 fusion-evaporation reactions using the High-efficiency Observatory for γ-Ray Unique Spectroscopy (HORUS) at the FN tandem accelerator of the University of Cologne, Germany. Furthermore, both isotopes are populated in an elusive reaction channel in the B11+Te130 fusion-evaporation reaction utilizing the HORUS γ-ray array. The level scheme above the Jπ=10+ isomer in Ba136 is revised and extended up to an excitation energy of approximately 5.5 MeV. From the results of angular-correlation measurements, the Ex=3707- and Ex=4920-keV states are identified as the bandheads of positive- and negative-parity cascades. While the high-spin regimes of both Te132 and Xe134 are characterized by high-energy 12+→10+ transitions, the Ba136E2 ground-state band is interrupted by negative-parity states only a few hundred keV above the Jπ=10+ isomer. Furthermore, spins are established for several hitherto unassigned high-spin states in Ba137. The new results close a gap along the high-spin structure of N<82 Ba isotopes. Experimental results are compared to large-scale shell-model calculations employing the GCN50:82, Realistic SM, PQM130, and SN100PN interactions. The calculations suggest that the bandheads of the positive-parity bands in both isotopes are predominantly of proton character.Furthermore, we express our
thanks to Dr. E. Teruya and Dr. N. Yoshinaga from Saitama
University, Japan, for providing the results of their shellmodel calculation with the PQM130 interaction. The research
leading to these results has received funding from the German BMBF under Contracts No. 05P15PKFN9 TP1 and
No. 05P18PKFN9 TP1, from the European Union Seventh
Framework Programme FP7/2007-2013 under Grant Agreement No. 262010 - ENSAR, from the Spanish Ministerio de
Ciencia e Innovación under Contract No. FPA2011-29854-
C04, from the Spanish Ministerio de Economía y Competitividad under Contract No. FPA2014-57196-C5, and from
the UK Science and Technology Facilities Council (STFC).
L.K. and A.V. thank the Bonn-Cologne Graduate School of
Physics and Astronomy (BCGS) for financial support. One of
the authors (A. Gadea) has been supported by the Generalitat
Valenciana, Spain, under Grant No. PROMETEOII/2014/019,
and EU under the FEDER program
Study of the γ decay of high-lying states in 208Pb via inelastic scattering of 17O ions
High-lying states in 208Pb nucleus were populated via inelastic scattering of a 17O beam at bombarding energy of 20 MeV/u. Their subsequent gamma decay was measured with the detector system AGATA Demonstrator based on HPGe detectors, coupled to an array of large volume LaBr3:Ce scintillators. Preliminary results in comparison with (γ,γ′) data, for states in the 5–8 MeV energy interval, seem to indicate that in that region the states belong to two different groups one with a isoscalar character and the other with a isovector nature. This is similar to what was observed in other stable nuclei with (α,α′γ) experiments. The multipolarity of the observed gamma transitions is determined with remarkable sensitivity thanks to angular distribution measurements. Data aiming at studying the neutron decay of the Giant Quadrupole Resonance in the 208Pb by the high resolution measurement of the following gamma decay are also presented in their preliminary form
Lifetime measurements of excited states in neutron-rich nuclei around 48 Ca
The lifetimes of the first excited states of the N = 30 isotones 50Ca and 51Sc and the Z = 18 isotopes 44−46Ar isotopes have been determined using a novel technique that combines the Recoil Distance Doppler Shift method with the CLARA-PRISMA spectrometers in multinucleon transfer reactions. The results allow determinination of the effective charges above 48Ca and test the strength of the N = 28 magic number when moving away from the stability line.Gadea Raga, Andrés, [email protected] ; Algora, Alejandro, [email protected] ; Rubio Barroso, Berta, [email protected]
- …