In the rare-earth region of the nuclear table around the quasi-doubly magic nucleus Gd-146 is one of the very few places in which the Gamow-Teller (GT) resonance can be populated in beta decay. The ...appropriate technique to study such a phenomenon is the total absorption spectroscopy, thanks to which one can measure the B(GT) distribution in beta-decay experiments even when it is very fragmented and lies at high excitation energy in the daughter nucleus. These results on the GT resonance measured in the beta decay of the odd-Z, N = 83 nuclei Tb-148, Ho-150, and Tm-152 are presented in this work and compared with shell-model calculations. The tail of the resonance is clearly observed up to the limit imposed by the Q value. Our observation is important in the context of the understanding of the "quenching" of the GT strength.
Within the RISING (Rare ISotope INvestigations @ GSI) Collaboration at GSI, g factor measurements have been performed on isomeric states in neutron-rich isotopes approaching Sn-132 and in the neutron ...deficient Pb-region (the g-RISING campaign). We present the experimental technique and some typical aspects related to such studies on relativistic beams selected with the FRS fragment separator. First results are presented for the (19/2(+)) 4.5 mu s isomeric state in Sn-127, which has been produced by means of fission of a relativistic U-238 beam on the one hand, and by the fragmentation of a relativistic Xe-136 beam on the other hand. Spin-alignment has been observed in both reactions. It was the first time that spin-alignment has been established in a relativistic fission reaction.
The heaviest N=Z doubly-magic nucleus, \(^{100}\)Sn, and the neighboring nuclei offer unique opportunities to investigate the properties of nuclear interaction in extreme conditions. In particular, ...the Cd isotopes are expected to present features similar to those found in the Sn isotopic chain, since they have only two proton holes in the Z=50 shell. In this manuscript, the lifetime measurements of low-lying states in the even-mass \(^{102-108}\)Cd is presented. Thanks to the powerful detection capabilities of AGATA array and VAMOS++ spectrometer, the unusual employment of multi-nucleon transfer reactions permitted to investigate the first 2\(^+\) and 4\(^+\) states in all these nuclei, together with various deformed bands in \(^{106}\)Cd. The results were interpreted in the context of new state-of-the-art beyond-mean-field calculations, using the symmetry-conserving configuration-mixing approach. Despite the similarities in the electromagnetic properties of the low-lying states, there is a fundamental structural difference between the ground-state bands in the Z=48 and Z=50 isotopes. The comparison between experimental and theoretical results revealed a rotational character of the Cd nuclei, which have prolate-deformed ground states with \(\beta_2 \approx 0.2\). At this deformation Z=48 becomes a closed-shell configuration, which is favored with respect to the spherical one.
Classical novae are thermonuclear explosions in stellar binary systems, and important sources of Al-26 and Na-22. While ? rays from the decay of the former radioisotope have been observed throughout ...the Galaxy, Na-22 remains untraceable. Its half-life (2.6 yr) would allow the observation of its 1.275 MeV ?-ray line from a cosmic source. However, the prediction of such an observation requires good knowledge of its nucleosynthesis. The Na-22(p, ?)Mg-23 reaction remains the only source of large uncertainty about the amount of Na-22 ejected. Its rate is dominated by a single resonance on the short-lived state at 7785.0(7) keV in Mg-23. Here, we propose a combined analysis of particle-particle correlations and velocity-difference profiles to measure femtosecond nuclear lifetimes. The application of this method to the study of the Mg-23 states, places strong limits on the amount of Na-22 produced in novae and constrains its detectability with future space-borne observatories. The authors report a particle-particle correlation and velocity-difference profile method to measure nuclear lifetime. The results obtained for excited states of 23Mg are used to constrain the production of 22Na in the astrophysical novae explosions.
OBJECTIVE:To evaluate clinical, immunologic, and virologic performance of patients with nadir CD4 counts of >350cells/μL upon treatment interruption.
DESIGN:Randomized, open-label clinical trial of ...48 weeks' duration.
METHODS:Patients on effective highly active antiretroviral therapy, with nadir CD4 counts of >350 cells/μL and peak viral loads of <50,000 copies/mL were randomized to continue therapy or to interrupt antiretroviral medication. End points for patients with treatment interruption were CD4 counts of <350 cells/μL, viral loads of >1 log above the pretherapy values, or clinical symptoms attributable to HIV, at which point treatment was restarted. In the continuation group, the end points were virologic failure, opportunistic infections, and treatment discontinuation due to toxicities.
RESULTS:Twenty patients were randomized to stop therapy and 16 patients to continue. Median CD4 counts at baseline were 643 cells/μL for the interruption group and 633 cells/μL for the continuation group. No end points were reached in the interruption group. By week 8, viral load returned to values comparable to those of pretherapy in all patients in the interruption group and remained stable until week 48. CD4 counts dropped in the interruption group (median loss of 156 cells/μL) at week 48. Significant decreases in venous lactate were observed in the interruption group.
CONCLUSIONS:Treatment interruptions in patients with nadir CD4 counts of >350 cells/μL seem safe for at least 48 weeks. Pretherapy viral load appears as a valuable tool to predict its level at week 48.
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Background: CTLA-4 is a costimulatory molecule expressed on activated T cells that delivers an inhibitory signal to these T cells. CTLA4 blockade with antibody treatment has been ...shown to augment T cell responses and anti-tumor immunity in animal models. Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a bone marrow growth factor for antigen presenting cells, which has also been shown to enhance anti-tumor immune responses. Methods: A phase I trial in patients with metastatic, hormone refractory prostate cancer (HRPC) was undertaken to combine these immunotherapies. Sequential cohorts of 3–6 patients were treated with escalating doses (0.5, 1.5 or 3 mg/kg) of ipilimumab, a fully human anti-CTLA-4 antibody, given IV on day 1 of each 28-day cycle × 4 cycles. Patients also received GM-CSF 250 mg/m
2
/d SC on days 1–14 of the 28-day cycles. Patients were monitored for toxicity as well as for T cell activation. PSA and radiographic tests were performed at baseline and through therapy to evaluate for clinical response. Results: 24 patients have been treated. Of 6 patients treated on the highest dose level (3 mg/kg ×4), 3 (50%) had confirmed PSA declines of >50%, and one of these patients had a partial response in hepatic metastases. Immune-related adverse events associated with ipilimumab treatment consisted of a grade 3 rash in 1 patient at 1.5 mg/kg, a grade 3 rash and panhypopituitarism in 1 patient at 3.0 mg/kg, and a grade 3 colitis in one patient at 3.0 mg/kg. All events were successfully managed. A dose-response relationship was seen between ipilimumab dose and effector T cell activation. Expansion of circulating CD4+ FoxP3+ regulatory T cells was also seen with treatment. Conclusions: CTLA-4 blockade combined with GM-CSF treatment induces clinical responses in HRPC. Treatment induces both the expansion of activated effector and regulatory T cells in vivo in cancer patients. Finally, CD4 and CD8 T cell activation, adverse events, and clinical responses appear to be dose-dependant. Supported by NIH SPORE P50 CA89520.
No significant financial relationships to disclose.
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