RESUMO
Masses of ^{52g,52m}Co were measured for the first time with an accuracy of â¼10 keV, an unprecedented precision reached for short-lived nuclei in the isochronous mass spectrometry. Combining our results with the previous ß-γ measurements of ^{52}Ni, the T=2, J^{π}=0^{+} isobaric analog state (IAS) in ^{52}Co was newly assigned, questioning the conventional identification of IASs from the ß-delayed proton emissions. Using our energy of the IAS in ^{52}Co, the masses of the T=2 multiplet fit well into the isobaric multiplet mass equation. We find that the IAS in ^{52}Co decays predominantly via γ transitions while the proton emission is negligibly small. According to our large-scale shell model calculations, this phenomenon has been interpreted to be due to very low isospin mixing in the IAS.
RESUMO
Isochronous mass spectrometry has been applied to neutron-deficient 58Ni projectile fragments at the HIRFL-CSR facility in Lanzhou, China. Masses of a series of short-lived T(z)=-3/2 nuclides including 41Ti, 45Cr, 49Fe, and 53Ni have been measured with a precision of 20-40 keV. The new data enable us to test for the first time the isobaric multiplet mass equation (IMME) in fp-shell nuclei. We observe that the IMME is inconsistent with the generally accepted quadratic form for the A=53, T=3/2 quartet. We perform full space shell model calculations and compare them with the new experimental results.
RESUMO
UNLABELLED: BACKGROUND; Heavy ions represent the best tool for external radiotherapy (RT) of inoperable tumours. Heavy ion RT has been used in the treatment of various tumours, especially for radioresistant tumours mediated by hypoxia, localized near organs at risk. Most of these treatments are concentrated in deep-seated tumours such as those of the brain, head, lung, liver, rectum and urogenital organs, and treatment of skin carcinomas is limited. OBJECTIVES: To evaluate the outcome and toxicity after carbon ion RT for skin carcinomas at the Heavy Ion Research Facility in Lanzhou, China. METHODS: Between November 2006 and March 2009, 45 patients with skin carcinoma [squamous cell carcinoma (SCC) (n = 16), basal cell carcinoma (BCC) (n = 12), malignant melanoma (MM) (n = 7), Bowen disease (n = 8) and Paget disease (n = 2)] were treated with carbon ion RT within a clinical Phase I trial. Patients received total doses of 60-70 GyE for SCC and BCC, 61-75 GyE for MM, 60 GyE for Bowen disease and 42·5 GyE for Paget disease, administered in 6-11 fractions over 6-11 days, with a fraction dose of 7-10 GyE. RESULTS: The mean follow-up was 24 months, range 12-36 months. The actuarial local control rates at 1 and 3 years were 90·9% and 65·5% for SCC, 91·7% and 80·2% for BCC, 85·7% and 42·9% for MM, 90% and 90% for Bowen and Paget diseases, respectively. The actuarial 1- and 3-year overall survival rates for 45 patients were 88·9% and 86%, respectively. No severe side-effects greater than Common Toxicity Criteria grade 3 have been observed. CONCLUSIONS: The results demonstrated that heavy ion RT offers high local tumour control and progression-free survival rates without significant radiation-induced toxicity for patients with skin carcinomas.
Assuntos
Carbono/uso terapêutico , Radioterapia com Íons Pesados , Neoplasias Cutâneas/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Radioterapia/efeitos adversos , Resultado do TratamentoRESUMO
Mass excesses of short-lived A=2Z-1 nuclei (63)Ge, (65)As, (67)Se, and (71)Kr have been directly measured to be -46,921(37), -46,937(85), -46,580(67), and -46,320(141) keV, respectively. The deduced proton separation energy of -90(85) keV for (65)As shows that this nucleus is only slightly proton unbound. X-ray burst model calculations with the new mass excess of (65)As suggest that the majority of the reaction flow passes through (64)Ge via proton capture, indicating that (64)Ge is not a significant rp-process waiting point.