~(143)Dy和~(141)Dy的β缓发质子衰变与自旋指认

分析了143Dy和141Dy的β缓发质子衰变的数据,对比计算了这两种核的核位能面。从中看到了143Dy的衰变包括有1/2+基态和11/2-同核异能态的两种衰变成分,并且确定了它们的半衰期分别为(6.0±1.5)s和(3.0±0.5)s。同时也测定了141Dy的半衰期为(0.9±0.2)s,并指认了它的自旋宇称为9/2-。

~(140)Tb和~(141)Dy的β缓发质子衰变以及~(143)Dy的自旋宇称

利用40Ca+106Cd融合蒸发反应产生了近质子滴线核140Tb和141Dy,配合氦喷嘴带传输系统采用“质子-γ”符合方法观测了它们的β缓发质子衰变,其中包括半衰期、质子能谱和衰变到第二代子核不同低位态的分支比．通过统计理论拟合提取了140Tb和141Dy的基态自旋宇称分别为7±和9／2±．另一方面,用Woods-Saxon Strutinsky方法计算了这两种核限制组态的势能面,由此得到140Tb和141Dy的基态自旋宇称分别为7+和9／2-．此外用同一方法还计算了143Dy的核势能面,从中看出143Dy存在有自旋宇称为1／2+的基态和一个激发能为198keV的11／2-的同质异能态．该结果与2003年Eur．Phys．J． A16:347-351中的143Dy衰变实验数据相符．

~(143)Pm高自旋态研究

通过熔合蒸发反应12 8Te( 19F ,4nγ)布居了143Pm的高自旋态 ,利用在束γ谱学方法 ,对143Pm的高自旋态核结构进行了研究 .测量了γ射线单谱和γ -γ符合谱 ,并进行了γ射线各向异性以及DCO比率分析 ,建立了激发能高达1 0 53 5 4keV的能级纲图 ,其中包括新发现的 3 2条γ射线和 1 7个新能级 .用弱耦合模型对143Pm的晕态能级结构进行了解释

~(143)Nd中高自旋同质异能态的识别与研究

利用能量为 80MeV的18O束流 ,通过130 Te( 18O ,5n)反应研究了143Nd的高自旋态能级结构 .基于γ γ延迟符合、γ射线的角分布及线性极化测量 ,首次发现了143Nd的一个半寿命为 ( 35± 8)ns,自旋和宇称为 4 9/ 2 + 的同质异能态 .用形变独立粒子模型探讨了此同质异能态的形成机制

beta-delayed proton decays of Tb-140 and Dy-140 as well as the spin and parity of Dy-143

Tb-140 and Dy-141 were produced via fusion evaporation in the reaction Ca-40+Cd-106. Their beta-delayed proton decays were studied by means of "p-gamma" coincidence in combination with a He-jet tape transport system, including half-lives, proton energy spectra, gamma-transitions following the proton emissions, and the branching ratios to the low-lying states in the grand-daughter nuclei. The ground-state spins and parities of Tb-140 and Dy-141 were extracted as 7(+/-) and 9/2(+/-), respectively, by fitting the experimental data with a statistical model calculation. The configuration-constrained nuclear potential energy surfaces (NPES) of Tb-140 and Dy-141 were calculated by using the Woods-Saxon Strutinsky method, which indicate the ground-state spins and parities of Tb-140 and Dy-147 to be 7(+) and 9/2(-), respectively. In addition, the configuration-constrained NPES of Dy-143 was also calculated by using the same method. From the NPES a 1/2(+) ground state and a 11/2(-) isomer with the excitation energy of 198keV were found. The calculated results are consistent with our experimental data on the decay of Dy-143 reported in Eur. Phys. J., 2003, A16: 347-351.

beta-delayed proton decays and spin assignments for Tb-140, Dy-141 and Dy-143

The proton-rich isotopes Tb-140 and Dy-141 were produced via the fusion evaporation reaction Ca-40+ Cd-106. Their beta-delayed proton decays were studied by p-gamma coincidence in combination with a He-jet tape transport system, and half-lives, proton energy spectra, gamma-transitions following the proton emission, as well as beta-delayed proton branching ratios to the low-lying states in the grand-daughter nuclei were determined. Comparing the experimental data with statistical model calculations, the ground-state spins of Tb-140 and Dy-141 were found to be consistent with 7 and 9/2, respectively. The configuration-constrained nuclear potential energy surfaces (NPES) of Tb-140 and Dy-141 were calculated using the Woods-Saxon-Strutinsky method, which suggest the ground-state spins and parities of Tb-140 and Dy-141 to be 7(+) and 9/2(-), respectively. In addition, the configuration-constrained NPES of Dy-143 were calculated, which predict a 1/2(+) ground state and a 11/2(-) isomer with excitation energy of 198 keV. These findings are consistent with our previous experimental data on Dy-143 reported in Eur. Phys. J. A 16, 347 (2003).

Prévalence de la dénutrition chez 143 adultes en bilan prétransplantation hépatique. Experience lausannoise de 1997 a 2005 [Prevalence of undernutrition in 143 patients before liver transplantation. The Lausanne experience between 1997 and 2005]

The prevalence of undernutrition was prospectively studied in 143 patients before liver transplantation between 1997 and 2005. Nutritional assessment is a particularly tricky problem in cirrhosis and mid-arm muscle circumference is considered as the best reliable anthropometric tool. In this prospective study, prevalence rate is very high (61%) and undernutrition is more frequent in alcoholic cirrhotic patients. In conclusion, these patients should benefit from an early dietician intervention before liver transplantation.

Mortality among 24,865 workers exposed to polychlorinated biphenyls (PCBs) in three electrical capacitor manufacturing plants: a ten-year update.

The objective of this analysis was to evaluate mortality among a cohort of 24,865 capacitor-manufacturing workers exposed to polychlorinated biphenyls (PCBs) at plants in Indiana, Massachusetts, and New York and followed for mortality through 2008. Cumulative PCB exposure was estimated using plant-specific job-exposure matrices. External comparisons to US and state-specific populations used standardized mortality ratios, adjusted for gender, race, age and calendar year. Among long-term workers employed 3 months or longer, within-cohort comparisons used standardized rate ratios and multivariable Poisson regression modeling. Through 2008, more than one million person-years at risk and 8749 deaths were accrued. Among long-term employees, all-cause and all-cancer mortality were not elevated; of the a priori outcomes assessed only melanoma mortality was elevated. Mortality was elevated for some outcomes of a priori interest among subgroups of long-term workers: all cancer, intestinal cancer and amyotrophic lateral sclerosis (women); melanoma (men); melanoma and brain and nervous system cancer (Indiana plant); and melanoma and multiple myeloma (New York plant). Standardized rates of stomach and uterine cancer and multiple myeloma mortality increased with estimated cumulative PCB exposure. Poisson regression modeling showed significant associations with estimated cumulative PCB exposure for prostate and stomach cancer mortality. For other outcomes of a priori interest--rectal, liver, ovarian, breast, and thyroid cancer, non-Hodgkin lymphoma, Alzheimer disease, and Parkinson disease--neither elevated mortality nor positive associations with PCB exposure were observed. Associations between estimated cumulative PCB exposure and stomach, uterine, and prostate cancer and myeloma mortality confirmed our previous positive findings.