Decay spectroscopy of two-quasiparticle K isomers in Cm 246,248 via inelastic and transfer reactions

The decay of K isomers in Cm (Z = 96) isotopes has been studied using inelastic and transfer reactions. The half-life of a previously identified 2-quasiparticle (qp) Kπ=8- isomer in Cm246 has been measured. A new 2-qp isomer is observed in Cm248, its half-life measured and its decay scheme established. The reduced K hindrances extracted for the decay transitions from the isomers in Cm246,248 indicate K to be a robust quantum number and validate axial symmetry in these nuclei. The excitation energies of the 2-qp isomers in Cm246 (N = 150) and Cm248 (N = 152) support the persistence of a deformed subshell gap at N = 152 in the Z≈100 region down to Z = 96 nuclei

Band crossings in Ta166

High-spin states in the odd-odd nucleus Ta166 are investigated through the 5n channel of the V51+Sn120 reaction. Four new bands are observed and linked into the previous level scheme. Configurations for the bands are proposed, based on measured alignments and B(M1)/B(E2) transition strength ratios

Rotational structures and the wobbling mode in Ta167

Excited states in the neutron-deficient nucleus Ta167 were studied through the Sn120(V51,4n) reaction. Twelve rotational bands have been observed and the relative excitation energy of each sequence is now known owing to the multiple interband connections. Several quasineutron alignments were observed that aided in the quasiparticle assignments of these bands. The resulting interpretation is in line with observations in neighboring nuclei. Trends in the wobbling phonon energy seen in Lu161,163,165,167 and Ta167 are also discussed and particle-rotor model calculations (assuming constant moments of inertia) are found to be inconsistent with the experimental data

Population and decay of a Kπ=8- two-quasineutron isomer in Pu 244

The decay of a Kπ=8- isomer in Pu244 and the collective band structures populating the isomer were studied using deep inelastic excitations with Ti47 and Pb208 beams, respectively. Precise measurements of M1/E2 branching ratios in the band confirm a 9/2-[734]ν - 7/2+[624]ν configuration assignment for the isomer, validating the systematics of Kπ=8-, two-quasineutron isomers observed in even-Z, N=150 isotones. These isomers around the deformed shell gap at N=152 provide critical benchmarks for theoretical predictions of single-particle energies in this gateway region to superheavy nuclei

Search for a 2-quasiparticle high-K isomer in Rf256

The energies of 2-quasiparticle (2-qp) states in heavy shell-stabilized nuclei provide information on the single-particle states that are responsible for the stability of superheavy nuclei. We have calculated the energies of 2-qp states in Rf256, which suggest that a long-lived, low-energy 8- isomer should exist. A search was conducted for this isomer through a calorimetric conversion electron signal, sandwiched in time between implantation of a Rf256 nucleus and its fission decay, all within the same pixel of a double-sided Si strip detector. A 17(5)-μs isomer was identified. However, its low population, ~5(2)% that of the ground state instead of the expected ~30%, suggests that it is more likely a 4-qp isomer. Possible reasons for the absence of an electromagnetic signature of a 2-qp isomer decay are discussed. These include the favored possibility that the isomer decays by fission, with a half-life indistinguishably close to that of the ground state. Another possibility, that there is no 2-qp isomer at all, would imply an abrupt termination of axially symmetric deformed shapes at Z=104, which describes nuclei with Z=92-103 very well

N=151Pu, Cm and Cf nuclei under rotational stress: Role of higher-order deformations

Fast-rotating N=151 isotones 245Pu, 247Cm and 249Cf have been studied through inelastic excitation and transfer reactions with radioactive targets. While all have a ground-state band built on a νj15/2[734]9/2- Nilsson configuration, new excited bands have also been observed in each isotone. These odd-N excited bands allow a comparison of the alignment behavior for two different configurations, where the νj15/2 alignment is either blocked or allowed. The effect of higher order deformations is explored through cranking calculations, which help clarify the elusive nature of νj15/2 alignments

Evaluation of the door-to-needle time for fibrinolytic administration for acute myocardial infarction

Background: Fibrinolytic therapy has reduced mortality following acute myocardial infarction (AMI) with the major effect coming from early achievement of infarct-related artery patency. Aim: To evaluate the door-to-needle time for fibrinolytic administration for AMI and to identify factors associated with a prolonged door-to-needle time. Materials and Methods: Our study was a prospective audit of patients who were thrombolyzed for AMI at our hospital from July 1, 2004 to March 15, 2005. All patients admitted with AMI, who were candidates for fibrinolysis, were included. We recorded the door-to-needle time. Whenever possible, we tried to find out the reason for prolonged door-to-needle time. Results: A door-to-needle time of < 30 min could be achieved in 19 of our 35 patients (54.28%). Mean door-to-needle time was 45.25 min. Discussion: Although most guidelines recommend a door-to-needle time of less than 30 min, most hospitals fail to achieve this in most patients. A study conducted by Zed et al. at the Vancouver General Hospital showed that a door-to-needle time of less than 30 min was achieved in only 24.3%. The door-to-needle time achieved at our center was shorter. In most of our patients who were thrombolyzed late, a delay in taking or interpreting an electrocardiogram was responsible. Transfer to the intensive care unit for thrombolysis also resulted in considerable delay. Conclusions: A door-to-needle time of less than 30 mins could be achieved in 19 of our 35 patients (54.28%). A significant number of AMI patients thrombolyzed did not meet the guideline for door-to-needle time of less than 30 min

N=151Pu,Cm and Cf nuclei under rotational stress: Role of higher-order deformations

Fast-rotating N=151 isotones 245Pu, 247Cm and 249Cf have been studied through inelastic excitation and transfer reactions with radioactive targets. While all have a ground-state band built on a νj15/2[734]9/2− Nilsson configuration, new excited bands have also been observed in each isotone. These odd-N excited bands allow a comparison of the alignment behavior for two different configurations, where the νj15/2 alignment is either blocked or allowed. The effect of higher order deformations is explored through cranking calculations, which help clarify the elusive nature of νj15/2 alignments. Keywords: Superheavy, Neutron-rich, Inelastic and transfer reactions, Rotational alignments, Higher-order deformation