Uranium (238U and 234U) and Thorium (232Th and 230Th) Records in the Bottom

金沢大学自然計測応用研究センタ

Geochemical studies on environmental dynamics in lake system through naturally occurring radionuclides

取得学位：博士(理学)，学位授与番号：博甲第877号，学位授与年月日：平成19年3月22

Uranium in acidic mine drainage at the former Ogoya Mine in Ishikawa Prefecture of Japan

[研究報告

Uranium and Thorium Isotopes Distribution in a Bottom Sediment Core from the Academician Ridge, Lake Baical, Siberia

金沢大学環日本海域環境研究センター地球環境計測研究部門Promoting Environmental Pesearch in Pan-Japan Sea Area : Young Researchers\u27 Network, Schedule: March 8-10,2006,Kanazawa Excel Hotel Tokyu, Japan, Organized by: Kanazawa University 21st-Century COE Program, Environmental Monitoring and Prediction of Long- & Short- Term Dynamics of Pan-Japan Sea Area ; IICRC(Ishikawa International Cooperation Research Centre), Sponsors : Japan Sea Research ; UNU-IAS(United Nations University Institute of Advanced Studies)+Ishikawa Prefecture Government ; City of Kanazaw

Long-term prognostic value of cardiac autonomic nervous activity in postoperative patients with congenital heart disease

Background: Abnormal cardiac autonomic nervous activity (CANA) is not uncommon in postoperative patients with congenital heart disease (CHD). Methods and results: We attempted to clarify the prognostic value of the CANA variables in postoperative CHD patients and prospectively evaluated the CANA variables in 292 consecutive biventricular and 91 Fontan repair patients. The CANA variables included the heart rate variability, arterial baroreflex sensitivity (BRS), washout ratio of the myocardial metaiodobenzylguanidine scintigraphy, and plasma norepinephrine level. With a follow-up of 10 ± 2 years, 98 total events that required hospitalization, including 13 deaths and 48 unscheduled cardiac events (UCEs), occurred. In all the CHD patients, all the CANA indices predicted the total events and UCEs. Of those, the NE level (p = 0.0004) and BRS (p = 0.0373) predicted the mortality. In a multivariate analysis, the BRS was an independent CANA-predictor for the total events (p = 0.007). In the biventricular patients, the plasma NE level, heart rate variability, and BRS predicted the total events and UCEs and the BRS was the only independent CANA-predictor for the total events (p = 0.0329). In the Fontan patients, the plasma NE level was the only predictor for the UCEs (p = 0.0242) and no other CANA variables were independent predictors of the total events or UCEs. Conclusions: All CANA variables, especially the BRS, were useful predictors for future clinical events in biventricular CHD patients, whereas no CANA variables, except for the plasma NE level, predicted future clinical events in the Fontan patients

Uranium and thorium records in the Holocene high-resolution sediments from Borsog Bay in Lake Hovsgol, Mongolia

[研究報告

Atomic Bomb Fallout and “Black rain” at Manose District (Hirama-cho) Located Northeast of Nagasaki City

Plutonium atomic bomb (A-bomb) was exploded at 503 meters height above Nagasaki City on August 9, 1945. Many studies on radioactive contamination, radiation dose, effect to people and so on have been conducted until now. Local fallout from the A-bomb mainly spread a lot in the east direction centering on Nishiyama area located about 4 km east of the hypocenter. Like the Hiroshima A-bomb, black rain accompanied by radioactive materials fell shortly after the explosion, but relationship between local fallout fall zone and black rain fall area has not been sufficiently elucidated, which has enhanced the concerns on radiation exposure to the A-bomb survivor. Concerning the black rain due to the Nagasaki A-bomb, it has been said that black rain did not fall across a wide area in a comprehensive way, except for the heavily contaminated Nishiyama area, but fell at various areas with conditions of light rain and/or soaking after the explosion. Among many villages or towns, especially in the Manose District where is a small intermountain village about 7.5 km northeast of the hypocenter, it had always been heard and known that the residents living there encountered black rain and experienced hair loss. In this district, the hair loss of inhabitants occurred actually with high probability, but its reason has not been elucidated well. Therefore, in order to reevaluate the local fallout level in the Manose District by the A-bomb, residual long-lived radionuclides 137Cs and Pu isotopes were measured for soil samples collected at the Manose District including the surrounding areas in July, 2011. As a result, accumulated levels of 137Cs and 239,240Pu in the Manose District were not so high, each being nearly background (BG) level. The dispersion of local fallout Pu from the A-bomb was reconfirmed by 240Pu/239Pu atomic ratios measured in soil samples at the same time, and was found to be primarily limited in the east direction, especially around the Nishiyama area. Those results were consistent with results obtained so far. Further researches are needed for understanding scientifically the cause of the high incidence rate of hair loss in this district.This research was supported by JSPS KAKENHI Grants Numbers 23406002 (April 2011-March 2014) and 26257501 (April 2014-March 2018)

膵癌術後予防肝動注におけるリザーバー留置術の検討 : 従来法とcoaxialシステムの比較

PURPOSE: Previous reports have shown the effectiveness of adjuvant hepatic arterial infusion chemotherapy (HAIC) in pancreatic cancer. However, percutaneous catheter placement is technically difficult after pancreatic surgery. The purpose of this study was to evaluate the feasibility and outcome of HAIC using a coaxial technique compared with conventional technique for postoperative pancreatic cancer. MATERIALS AND METHODS: 93 consecutive patients who received percutaneous catheter-port system placement after pancreatectomy were enrolled. In 58 patients from March 2006 to August 2010 (Group A), a conventional technique with a 5-Fr indwelling catheter was used and in 35 patients from September 2010 to September 2012 (Group B), a coaxial technique with a 2.7-Fr coaxial catheter was used. RESULTS: The overall technical success rates were 97.1 % in Group B and 86.2 % in Group A. In cases with arterial tortuousness and stenosis, the success rate was significantly higher in Group B (91.7 vs. 53.8 %; P = 0.046). Fluoroscopic and total procedure times were significantly shorter in Group B: 14.7 versus 26.7 min (P = 0.001) and 64.8 versus 80.7 min (P = 0.0051), respectively. No differences were seen in the complication rate. The 1 year liver metastasis rates were 9.9 % using the conventional system and 9.1 % using the coaxial system (P = 0.678). The overall median survival time was 44 months. There was no difference in the survival period between two systems (P = 0.312). CONCLUSIONS: The coaxial technique is useful for catheter placement after pancreatectomy, achieving a high success rate and reducing fluoroscopic and procedure times, while maintaining the safety and efficacy for adjuvant HAIC in pancreatic cancer.博士（医学）・乙第1380号・平成28年7月8日© Springer Science+Business Media New York and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) 2016The final publication is available at Springer via http://dx.doi.org/10.1007/s00270-016-1292-

Developing Accelerator Mass Spectrometry Capabilities for Anthropogenic Radionuclide Analysis to Extend the Set of Oceanographic Tracers

Recent major advances in Accelerator Mass Spectrometry (AMS) at the Vienna Environmental Research Accelerator (VERA) regarding detection efficiency and isobar suppression have opened possibilities for the analysis of additional long-lived radionuclides at ultra-low environmental concentrations. These radionuclides, including $^{233}$U, $^{135}$Cs, $^{99}$Tc, and $^{90}$Sr, will become important for oceanographic tracer application due to their generally conservative behavior in ocean water. In particular, the isotope ratios $^{233}$U/$^{236}$U and $^{137}$Cs/$^{135}$Cs have proven to be powerful fingerprints for emission source identification as they are not affected by elemental fractionation. Improved detection efficiencies allowed us to analyze all major long-lived actinides, i.e., $^{236}$U, $^{237}$Np, $^{239,240}$Pu, $^{241}$Am as well as the very rare $^{233}$U, in the same 10 L water samples of a depth profile from the northwest Pacific Ocean. For this purpose, a simplified and very flexible chemical purification procedure based on extraction chromatography (a single UTEVA® column) was implemented which can be extended by a DGA® column for Am purification. The procedure was validated with the reference materials IAEA-381/385. With the additional increase in ionization efficiency expected for the extraction of actinides as fluoride molecules from the AMS ion source, a further reduction of chemical processing may become possible. This method was successfully applied to an exemplary set of air filter samples. In order to determine the quantitative $^{237}$Np concentration reliably, a $^{236}$Np spike material is being developed in collaboration with the University of Tsukuba, Japan. Ion-Laser Interaction Mass Spectrometry (ILIAMS), a novel technique for the efficient suppression of stable isobaric background, has been developed at VERA and provides unprecedented detection sensitivity for the fission fragments $^{135}$Cs, $^{99}$Tc, and $^{90}$Sr. The corresponding setup is fully operational now and the isobar suppression factors of >10$^{5}$ achieved, in principle, allow for the detection of the mentioned radionuclides in the environment. Especially for $^{90}$Sr analysis, this new approach has already been validated for selected reference materials (e.g., IAEA-A-12) and is ready for application in oceanographic studies. We estimate that a sample volume of only (1-3) L ocean water is sufficient for $^{90}$Sr as well as for $^{135}$Cs analysis, respectively