Anthropogenic Pu distribution in Tropical East Pacific

金沢大学理工研究域物質化学系The geographical distribution of the anthropogenic radionuclides 238Pu and 239+240Pu in the Tropical East Pacific in 2003 was studied from the viewpoint of material migration. We measured the contents of Pu isotopes in seawater and in sediment from the sea bottom. The distributions of Pu isotopes, together with those of coexisting nitrate and phosphate species and dissolved oxygen, are discussed in relation to the potential temperature and potential density (sigma-θ). The Pu contents in sediment samples were compared with those in the seawater. Horizontal migration across the Equator from north to south was investigated at depths down to ~800m in the eastern Pacific. The Pu distribution at 0-400m correlated well with the distribution of potential temperature. Maximum Pu levels were observed in the subsurface layer at 600-800m, corresponding to the depth where sigma-θ≈27.0. It is suggested that the Pu distribution depends on the structure of the water mass and the particular temperature and salinity. The water column/sediment column inventory ratio and the vertical distribution of Pu may reflect the efficiency of scavenging in the relevant water areas. © 2011 Elsevier B.V

Incorporation rate measurements of 10Be, 230Th, 231Pa, and 239,240Pu radionuclides in manganese crust in the Pacific Ocean: A search for extraterrestrial material

高エネルギー加速器研究機構　共通基盤研究施設・放射線科学センター金沢大学大学院自然科学研究科物質情報解析金沢大学理学部In order to estimate the deposition rate of extraterrestrial material onto a manganese crust in a search for supernova debris, we analyzed the contents of 10Be, 230Th, 231Pa, and 239,240Pu in a sample of manganese crust collected from the North Pacific Ocean. On the basis of the depth profile of 10Be, the growth rate of the manganese crust was determined to be 2.3 mm Myr-1. The uptake rates of 10Be, 230Th, and 231Pa onto the manganese crust were estimated to be 0.22-0.44%, 0.11-0.73%, and 1.4-4.5%, respectively, as compared to the deposition rates onto the deep-sea sediments near the sampling station, while that for 239,240Pu was 0.14% as compared to the total inventory of seawater and sediment column. Assuming that sinking particles represent 0.11-4.5% of the uptake rates, the deposition rate of extraterrestrial material onto the manganese crust was estimated to be 2-800 μ g cm-2Myr-1 according to the uptake of 10Be onto the manganese crust. Further, our estimate is similar to the value of 9-90 μ g cm-2Myr-1 obtained using the integrated global production rate of 10Be and the deposition rate of 10Be onto the manganese crust. © The Oceanographic Society of Japan/TERRAPUB/Springer 2007

Preoperative simulation with a 3-dimensional printed solid model for one-step reconstruction of multiple hepatic veins during living donor liver transplantation

Meticulous preoperative volumetry of the partial liver graft is essential for both assessing the postoperative graft function and to ensure the donor safety in the field of living donor liver transplantation (LDLT).We herein report the case of a 53-year-old patient who underwent LDLT for hepatitis C virusinfected liver cirrhosis complicated with hepatocellular carcinoma. Preoperative 3D images were obtained using a 3D image analysis system to evaluate the graft volume and possible congested volume after implantation in LDLT, which revealed that a large middle hepatic vein drained a vast area in the right lobe. The extended left graft was considered to be small for size of the recipient, with an estimated congested area of 407 ml, which was equivalent to 39% of the donor’s liver volume in the remnant right lobe.We decided to use a right lobe graft with the middle hepatic vein, because the volume was considered to be sufficient. A preoperative contrast-enhanced CT scan revealed a distance of 2 cm between the donor’s right hepatic vein and middle hepatic vein at the estimated Cantlie line. Because of the location, we planned to use autologous portal vein Y-graft interposition for the hepatic venous anastomosis. Three-dimensional printed solid models of the donor’s right lobe graft and the Y-graft from the recipient’s portal vein were also made for preoperative simulation using the Vincent program.Based on the estimation, we were able to evaluate whether to reconstruct the middle hepatic vein tributaries or anomalous hepatic veins in LDLT. The 3D solid model was effective for preoperative simulation and planning, which made it easy to imagine the reconstructed shape of the anastomosis with appropriate spatial perception

Standardized less invasive living donor hemihepatectomy by the hybrid method through short upper midline incision

Recently, applications of less invasive liver surgery in living donor hepatectomy (LDH) have been reported. The objective of this study was to evaluate the safety and efficacy of a hybrid method with a midline incision for LDH

Peritoneal Recurrence of Initially Controlled Hepatocellular Carcinoma after Living Donor Liver Transplantation

It is well known that the presence of end-stage liver disease increases the risk of developing hepatocellular carcinoma (HCC). Liver transplantation (LT) for patients within the Milan criteria has become a standard treatment for HCC in most developed centers worldwide. However, a major cause of death in cirrhotic patients with HCC after transplantation is tumor recurrence, including peritoneal recurrences, which develops rarely but presents a significant problem with regard to their management. Our experience includes two cases with HCC within the Milan criteria of peritoneal recurrences after living donor LT. Both patients had interventions for HCC in their medical history before LT, and we propose that these might have been a possible cause of the HCC peritoneal recurrence

Idobata-Nagaya: a community housing solution for socially isolated older adults following the great East Japan earthquake

IntroductionFollowing the Great East Japan Earthquake, the living environment of socially isolated older adults has become a pressing concern. In response, Nagaya, a collective housing program, was established in Soma City, Fukushima, Japan to address social isolation among older adults and support their long-term health. This study aimed to identify characteristics of individuals in Nagaya and examine the sustainability of this initiative.MethodsWe conducted a retrospective analysis of residents who were relocated to Nagaya, emphasizing their characteristics, the continuity of their stay in Nagaya, and their care certification levels, using data up to December 31, 2022. We employed Kaplan–Meier curves to analyze the duration for which residents continued to reside in Nagaya and the time leading up to the requiring care-level certification.ResultsOf 65 people who moved to Nagaya after the disaster, 30 people (46.2%) continued to live there, 21 (32.3%) died during their stay, and 14 (21.5%) moved out. The overall duration of occupancy averaged 6.39 years (SD 3.83 years). The proportion of requiring care-level certification occurrences per person-year was 0.0577 for those without care certification and 0.3358 for those with requiring support level at the time of moving in.ConclusionIn summary, Nagaya-style communal housing may offer suitable living environments for older adults with diverse needs during disasters and serve as a valuable tool for developing public policies in aging societies

Observation of α-decay of ^<229m>Th produced from ^<229>Ac(II. Radiochemistry)

We produced ^Th in the nuclear reaction ^Th(γ, p2n)^ Ac, followed by disintegration to ^Th. The α-decay signals from ^Th were searched for and the alpha-particle events of the energy region between 4.93MeV and 5.05MeV were observed in the separated thorium fraction from an actinium source highly purified from the ^Th+γ reaction products. The energy values of the α-particles coincide with those expected for ^Th