ABSTRACT
The fission gaseous (138)Xe products play an important role in the research of nuclear-reaction products and radioisotope applications. Therefore, precise data for emission probabilities of gamma-ray from decay of (138)Xe are highly desired. However, a high precision is not achievable with a sufficient accuracy due to the limitations of the usual experimental techniques. In this paper, after the homogeneous sources of (138)Xe-(138)Cs were prepared, the activity of (138)Xe was obtained by the decay relationship between (138)Xe and (138)Cs using a HPGe detector. The full-energy peak efficiencies of gamma-ray for (138)Xe and (138)Cs were accurately calibrated using many activity standard sources and self-absorption was corrected. As a result, the absolute emission probabilities of the 258.4, 434.6 and 1768.3 keV gamma-ray from decay of (138)Xe were determined to be 34.9(10)%, 22.2(6)% and 18.8(5)%, respectively.
ABSTRACT
The half-lives of (88)Kr and (138)Xe have been determined with two high purity germanium (HPGe) detectors by the position relay method. Data have been recorded at regular time intervals during measurements covering more than nine times the respective half-lives. This article describes in detail the principle and process of the position relay method with two HPGe detectors. The determined half-lives of (88)Kr and (138)Xe are 2.804±0.015 h and 14.18±0.10 min, respectively.
Subject(s)
Krypton Radioisotopes/analysis , Krypton Radioisotopes/chemistry , Radiometry/instrumentation , Radiometry/standards , Xenon Radioisotopes/analysis , Xenon Radioisotopes/chemistry , China , Half-Life , Internationality , Radiation Dosage , Reference Standards , Reference ValuesABSTRACT
OBJECTIVE: To study the impact on pregnant outcome of reducing the number of embryos transferred from three to two in women at age less than 35 who received frozen-thawed embryo transfer (FET). METHODS: The analysis was performed on 90 FET cycles (77 infertile couples, less than 35 years old) with slow-freezing/rapid-thawing method, including 48 cycles with two embryos transferred and 42 cycles with three embryos transferred. The embryo survival rate, high quality embryo rate, clinical pregnancy rate, implantation rate and multiple pregnancies rate were analyzed. RESULTS: No significant differences in embryo survival rate (88.9% versus 88.1%), high quality embryo rate (89.6% versus 81.0%), clinical pregnancy rate (37.5% versus 42.9%), implantation rate (26.0% versus 18.3%) and multiple pregnancy rate (38.9% versus 16.7%) were observed between two and three embryos transferred group (all P > 0.05). However, there were 2 triple pregnancies in three embryos transferred group while none in two embryos transferred group. CONCLUSION: Reducing the number of high quality embryos transferred from three to two in women at age of less than 35 years old who received FET, could decrease the incidence of triple pregnancy and keep the similar clinical pregnancy rate.
