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Auto transplantation is a fast and economical option when a suitable donor tooth is available for replacement of a tooth considered impossible to treat. The purpose of this case report is to describe methods used for autotransplantation and its advantages for cases with a missing bilateral mandibular firstmolar, as compared with a dental implant, removable partial denture, and other methods of prosthesis. In the present patient who underwent auto transplantation, clinical and radiographic outcomes were considered satisfactory at one and two years postoperatively. Bone healing was observed around the roots of transplanted teeth, which showed good function. In autotransplantation cases, even when the donor tooth has complete root formation, a high success rate can be achieved when the patient is properly selected and treated. Although the chance of root resorption remains because of necrotic pulp and periodontal irritation during manipulation, auto transplantation should be considered as a good treatment modality in feasible cases. Based on the present findings, even though autotransplantation is not common in general dental practice, we consider that it offers a clinically and economically viable alternative as compared to other more complicated prosthetic and dental implant treatments. The purpose of this report is to show that auto transplantation is a superior treatment method for single molar defects as compared to other prosthetic methods, as the periodontal ligament of the patient can be used and cutting adjacent teeth is avoided. In addition, it is a treatment method that can effectively utilize a wisdom tooth.

Forecasting the long-term fate of plutonium (Pu) is becoming increasingly important as more worldwide military and nuclear-power waste is being generated. Nagasaki sediments containing bomb-derived Pu that was deposited in 1945 provided a unique opportunity to explore the long-term geochemical behavior of Pu. Through a combination of selective extractions and molecular characterization via electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry (ESI-FTICRMS), we determined that 55 ± 3% of the bomb-derived 239,240Pu was preferentially associated with more persistent organic matter compounds in Nagasaki sediments, particularly those natural organic matter (NOM) stabilized by Fe oxides (NOMFe-oxide). Other organic matter compounds served as a secondary sink of these bomb-derived 239,240Pu (31 ± 2% on average), and

In this study, hetero-interface-structured Bi2Te3-nanoplate/Bi2Se3-electrodeposited films were prepared using all solution processes. Single-crystalline Bi2Te3 nanoplates were synthesized using a solvothermal method, and Bi2Te3 nanoplate films were prepared by drop-casting followed by thermal annealing. The electrodeposition time of the Bi2Se3 layer was tuned to obtain hetero-interface-structured films, wherein the gap between the Bi2Te3 nanoplates was filled. Cross-sectional scanning electron microscopy showed that the heterointerface structured films had a boundary between the composite layer and the Bi2Te3-nanoplate film. The X-ray diffraction patterns of the hetero-interface-structured films without thermal annealing exhibited peaks arising from Bi2Te3, as well as Bi2Se3 with and without antisite defects (SeBi), while those of the annealed film exhibited peaks from Bi2Te3, Bi2Se3, and the ternary alloys due to mutual diffusion. The annealed hetero-interface-structured film with an electrodeposition time of 40 min exhibited the highest power factor of 1.70 μW/(cm∙K2), which is 12-fold and 30% higher than that of the Bi2Te3-nanoplate and homo-interface-structured films (Bi2Te3-nanoplate/Bi2Te3-electrodeposited film), respectively. This enhancement was observed due to (a) increased electrical conductivity arising from the improved crystallinity of the Bi2Se3 electrodeposited layer and (b) increased Seebeck coefficient, resulting presumably from the combined effect of the heterostructured interface, decrease in the number of antisite defects, and formation of ternary alloys. Our findings provide a route for fabricating high-performance thermoelectric materials with low manufacturing costs.

This chapter shows the results of a 5-year monitoring survey of radioactive contamination of fishes and shellfishes in lightly radioactively contaminated aquatic ecosystems. One of these ecosystems is Tokyo Bay and the Edogawa water system in the Tokyo metropolitan area, and the other is a small closed pond called Kejonuma in Miyagi Prefecture, approximately 150 km north of the FDNPP. In these water systems, water-soluble radioactive cesium deposited in the hydrosphere immediately after the accident was taken into the hydrosphere and is still recycled in the aquatic ecosystem. In general, radioactive cesium fixed to clay minerals plays an essential role in the transport process of radioactive cesium on the ground surface. However, radioactive cesium adsorbed to clay is thought to be excreted almost undigested even if organisms ingest it. When radioactive cesium in the ionized state enters the hydrosphere, it may continue to recycle in the aquatic ecosystem through the food chain. This recycling suggests that there is a high risk of long-term radiation contamination in aquatic ecosystems. The other form of cesium is ultrafine particles emitted from the reactor as a cesium solid-solution. However, little is known about the behavior of these microparticles in the hydrosphere. In this chapter, the effective half-life, biological half-life, and concentration factor were evaluated from the temporal changes of radioactive cesium contamination of seafood inhabiting the Tokyo Bay water system and Kejonuma pond. These ecological parameters seem to be strongly influenced by fish species and age.

The Tokyo metropolitan area is located in the Kanto Plain, which is found in roughly the center of Japan. The area of high-concentration pollution surrounding Tokyo are the catchments of rivers flowing into Tokyo Bay. Radioactive nuclides deposited there are carried by rainfall and river water and finally flow into Tokyo Bay. That is, Tokyo Bay serves as a reservoir for radioactive nuclides deposited in the Tokyo metropolitan area. Tokyo Bay functions in two ways as a reservoir for radionuclides. One function is to deposit radioactive material that has flowed into Tokyo Bay within sediments and to act as a natural storage facility. The other function is to work as a storage facility for decontaminated radioactive material, which is artificially collected from the land in the metropolitan area. The radioactive materials collected at wastewater treatment facilities in Tokyo are buried as sludge incineration ash at the Central Breakwater under construction in the northwestern part of Tokyo Bay. By the end of 2016, approximately 0.68 TBq of radioactive cesium had been buried in this landfill. In any case, clarifying the behavior of radioactive nuclides in Tokyo Bay is crucial. Therefore, to elucidate the dynamics of radioactive nuclides in the Tokyo metropolitan area, it is necessary to analyze the migration process of radionuclides in these watersheds and their accumulation mechanism in Tokyo Bay. Because the Tokyo metropolitan area has mountains, forests, rural areas, and urban areas, it is difficult to evaluate the routes by which radioactive nuclides deposited on the ground surface flow into Tokyo Bay. However, elucidating the influx processes of radioactive nuclides into Tokyo Bay and the advection, diffusion, and deposition processes into the sediment helps in understanding the role of Tokyo Bay as a reservoir for radioactive nuclides. The revelation of these dynamics is essential information to estimate the future fate of radioactive nuclides deposited in the Tokyo metropolitan area.

In the first stage after the FDNPP accident, radioactive contamination on the ground surface in the Tokyo metropolitan area was controlled by weather conditions such as wind direction and rainfall. Many radionuclides in the radioactive plume released from the FDNPP reactors were advected in the atmosphere without falling to the surface. However, some of them precipitated to the ground surface, causing environmental radiation contamination in Tokyo. These radionuclides diffused, which is believed to have caused temporary but significant external and internal exposure to the Japanese people. However, given the destruction of infrastructure due to the massive earthquake, there are almost no measurement data regarding environmental radioactive contamination immediately after the FDNPP nuclear accident. The collapse of infrastructure occurred not only in Fukushima Prefecture where the FDNPP operated but also in the capital Tokyo more than 200 km from the FDNPP. However, the status of environmental radioactive contamination immediately after the accident can be estimated by measuring the contamination by radioactive material recorded in the geosphere or hydrosphere. In this chapter, the geographic distribution of radioactive contamination of soil in the Tokyo metropolitan area during the initial phase of the FDNPP accident is discussed. The results of field sample measurements show that severe environmental radioactive contamination continued for approximately 5 years after the accident. However, after more than 9 years had passed, the radioactive contamination seemed to have changed as radionuclides migrated and were redistributed from the initial contamination situation.

The national and local governments measured the temporal changes in 131I in the atmosphere after the FDNPP accident. These results indicated that the radioactive plume released from the FDNPP spread from Fukushima to the Tokyo metropolitan area and Tokyo itself. The Tokyo metropolitan area was exposed in highly contaminated plumes on March 15–16 and 20–22 immediately after the accident. In central Tokyo, there was a single day with 0.0 mm of light rain on March 16 and a reasonably heavy rainfall of 33.5 mm on March 21–22. Coincidentally, on these rainy days, highly contaminated radioactive plumes had reached central Tokyo, causing radionuclides in the plumes to be washed out and precipitated and leading to radioactive contamination of the ground surface. The radioactive plume spread over in the Tokyo metropolitan area due to the FDNPP accident, significant heterogeneity in radioactive iodine and radioactive cesium was observed on the ground surface in a narrow area. Such non uniformity of the radioactive nuclides precipitated at the surface indicates that the plume, including radionuclides, was advancing with this uneven distribution. In this chapter, the characteristics of radioactive plumes that were transported into the Tokyo metropolitan area are evaluated from the geographic distribution of 131I and radioactive cesium.

A characteristic of the natural environment in the Tokyo metropolitan area is that forests and mountainous areas are close to urban areas. Such a geographic environment is an essential factor in analyzing the dynamics of radioactive contamination in the capital Tokyo. After the Fukushima disaster, the hinterland was exposed to high levels of radioactive contamination. Radioactive nuclides released from the FDNPP were transported to the forested areas through the air as radioactive plumes and deposited there. In such forest areas, the radionuclides deposited from radioactive plumes are strongly adsorbed not only onto the soil but also onto trees, deciduous leaves, humus, etc., causing environmental radioactive contamination. According to the MEXT airborne monitoring, radioactive cesium deposition may have reached 600 kBq/m2 or more in some places. These radioactivity levels are approximately the same as those in the contaminated area of Fukushima Prefecture, where the FDNPP is located. Since the decontamination of radioactively contaminated areas destroys the forest ecosystem, the SCJ (Science Council of Japan) has noted problems regarding the effects of radioactive contamination in forest areas on forestry and agriculture. Radioactive nuclides that are strongly adsorbed onto trees and litter are very likely to migrate from forest to downstream city as water-soluble humic acid and fulvic acid complexes along with the decomposition of litter. The decomposition and solubilization of these substances have progressed for more than 9 years after the accident, so it is necessary to discuss the redistribution of radionuclides in the environment. The analysis of radioactive contamination in forests cannot be avoided in resolving the radioactive contamination of the Tokyo metropolitan area.

The risk of radioactive contamination of densely populated urban areas is not due only to the leakage of radioactive materials from nuclear power plants and nuclear fuel reprocessing plants. Nuclear batteries and depleted uranium loaded on satellites and aircraft can be sources of radioactive contamination in urban areas. The risk of terrorism using nuclear materials cannot be ignored. Furthermore, radioactive materials used in medicine are also released daily into the environment along with patient excrement. Thus, not only the Tokyo metropolitan area but also many large cities around the world are exposed to these risks of radioactive contamination. Tokyo is likely the first metropolis in the world to be highly contaminated by radioactive materials. Radioactive nuclides deposited on the ground surface are known to be adsorbed and retained by clay minerals in the soil, but the behaviors of radioactive nuclides deposited on concrete and asphalt in urban areas are often unknown. The Tokyo special ward, which has a sewage treatment system that mixes domestic wastewater and rainwater for each region, is the best place to analyze the dynamics of radioactive materials in urban areas. In this chapter, the temporal changes in the radioactive cesium concentration in the sludge incineration ash of each sewage treatment plant, which were released on the Tokyo homepage after the Fukushima nuclear disaster, were analyzed. As a result, the spatiotemporal dynamics of radioactive cesium deposited in urbanized areas became apparent. The behavior of radioactive cesium deposited in the Tokyo special ward is strongly influenced by weather conditions such as rainfall.

Various studies have focused on the routes of advection and diffusion of radioactive materials released in the FDNPP accident via the atmosphere. Many of them have solved a three-dimensional advection-diffusion equation that combines a weather forecasting model and a mass transport model. The materials are usually assumed to be particles or puffs, but it is also possible to simulate the movement of the materials by mixing them and tracking them in a Lagrangian manner. Of course, it is indispensable to verify the results of the simulation by comparing them with the actual values measured in the field. This chapter suggested that the advection and diffusion through the atmosphere of radioactive materials released from the accident site had significant influences on environmental radioactive contamination and contamination processes by radioactive nuclides in the Tokyo metropolitan area at the beginning of the FDNPP accident. Additionally, the actual situation of environmental radioactive contamination in the Tokyo metropolitan area at the beginning of the accident is shown. Furthermore, the actual state of the radioactive plume diffusing over the land of Japan was verified by comparing the results of the simulation using the advection-diffusion model with the measurement results for radioactive nuclide concentrations in the atmospheric dust. In the process of measuring atmospheric dust radioactivity, high boiling-point fission nuclides were detected at an observation point more than 500 km from the FDNPP. This fact provided valuable information about the process of reactor collapse and the transport of radionuclides by plumes.

To accurately assess the current status of environmental radioactive contamination in FDNPP accident, it is necessary to understand the dynamics of radionuclides in the environment in the initial phase immediately after the Fukushima nuclear accident. Because the topography and weather in Japan are involved, it is difficult to accurately reproduce the behavior of radionuclides released from the FDNPP reactors. Furthermore, power lines were cut off in many areas of East Japan, including Tokyo, because of the effects of the Great East Japan Earthquake disaster. Therefore, many radiation monitoring systems failed immediately after the earthquake. As a result, available radiation monitoring data in East Japan are very limited. In this chapter, the situation in the early stage of the FDNPP accident is reviewed, and the behavior and amount of radioactive materials released from the broken reactor to the environment are considered. The author was unable to directly measure the status of radioactive contamination and changes in radiation dose on the FDNPP premises during this period. The data used for the discussions are based on those published by TEPCO.

Environmental contextPolycyclic aromatic hydrocarbons are carcinogenic environmental contaminants that tend to migrate into the sediments in oceans and seas. Their vertical distribution in sediments from the Seto Inland Sea matched their emission over time, which in turn reflected changes in energy sources and industrial activities in Japan. This study shows that human activities on land directly and significantly influence the concentration of polycyclic aromatic hydrocarbons in sediments. AbstractSeventeen polycyclic aromatic hydrocarbons (PAHs) were identified in sediment cores collected at several locations in the Seto Inland Sea in 2015 and 2016 to understand their spatial distribution and potential emission sources. PAHs were analysed using gas chromatography–mass spectrometry. The age of the sediment cores was analysed using radioisotopic dating techniques to reconstruct historical PAH emissions. The total concentrations of 17 PAHs in the sediment cores of Osaka Bay in 2015 were in the range of 108–2810ng g−1 dry weight (dw) with a mean concentration of 1050ng g−1 dw. The total concentrations of 17 PAHs in sediment cores from the Seto Inland Sea in 2016 were in the range of 52.6–941ng g−1 dw with a mean concentration of 313ng g−1 dw. The spatial distribution of PAHs showed the highest concentration in Osaka Bay and the lowest in Kii Channel in 2016. The horizontal PAH distribution showed a decreasing trend in concentrations from the estuary offshore to Osaka Bay and Aki-Nada. The vertical PAH distribution revealed that levels were higher before the 1980s–1990s, when oil consumption and industrial activities in the Osaka region reached a maximum in the 20th century. The diagnostic ratios of PAHs and a principal component analysis revealed three main emission sources of PAHs, industry, biomass burning and traffic activities.

This study developed the 2-step extraction method which eluted the Pb adsorbing on the surface of sediments in the first solution by aqua regia and extracted the Pb absorbed inside particles into the second solution by mixed acid of nitric acid, hydrofluoric acid and hydrogen peroxide solution. We applied the method to sediments in the enclosed water area and found out that the isotope ratios of Pb in the second solution represented those of natural origin. This advantage of the method makes it possible to distinguish the Pb between natural origin and anthropogenic source on the basis of the isotope ratios. The results showed that the method was useful to discuss the Pb sources and that anthropogenic Pb in the sediment samples analysed was mainly derived from China because of transboundary air pollution.

A monitoring survey was conducted from August 2011 to July 2016 of the spatiotemporal distribution in the 400 km2 area of the northern part of Tokyo Bay and in rivers flowing into it of radiocesium released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. The average inventory in the river mouth (10 km2) was 131 kBq⋅m-2 and 0.73 kBq⋅m-2 in the central bay (330 km2) as the decay corrected value on March 16, 2011. Most of the radiocesium that flowed into Tokyo Bay originated in the northeastern section of the Tokyo metropolitan area, where the highest precipitation zone of 137Cs in soil was almost the same level as that in Fukushima City, then flowed into and was deposited in the Old-Edogawa River estuary, deep in Tokyo Bay. The highest precipitation of radiocesium measured in the high contaminated zone was 460 kBq⋅m-2. The inventory in sediment off the estuary of Old-Edogawa was 20.1 kBq⋅m-2 in August 2011 immediately after the accident, but it increased to 104 kBq⋅m-2 in July 2016. However, the radiocesium diffused minimally in sediments in the central area of Tokyo Bay in the five years following the FDNPP accident. The flux of radiocesium off the estuary decreased slightly immediately after the accident and conformed almost exactly to the values predicted based on its radioactive decay. Contrarily, the inventory of radiocesium in the sediment has increased. It was estimated that of the 8.33 TBq precipitated from the atmosphere in the catchment regions of the rivers Edogawa and Old-Edogawa, 1.31 TBq migrated through rivers and was deposited in the sediments of the Old-Edogawa estuary by July 2016. Currently, 0.25 TBq⋅yr-1 of radiocesium continues to flow into the deep parts of Tokyo Bay.

Purpose: Chronic diseases have become a global epidemic among many developed countries. Japan has some chronic diseases as serious causes of death. They are called life-style related diseases and will be also risk factors of broken health. Furthermore, they have been steadily increasing. The purpose of the present study was to examine the semihealth condition which evaluated a level of dynamic state in a susceptibility phase based on the natural history of disease, and to reveal a distribution of them among the community-dwelling elderly in Japan. The authors have reported on findings about the semihealth index elsewhere. In this study, we discussed on a multidimensional structure of the semihealth condition and its distribution among them.

Accumulation of Ot alternative antifoulants in sediment is the focus of this research. Much research had been done on surface sediment, but in this report, the accumulation in the sediment core was studied. The Ot alternative antifoulants, Diuron, Sea-Nine211, and Irgarol 1051, and the latter's degradation product, M1, were investigated in five samples from the northern part of Hiroshima Bay. Ot compounds (tributyltin (TBT) and triphenyltin (TPT)) were also investigated for comparison. In addition, metal (Pb, Cu, Zn, Fe and Mn) levels and chronology were measured to better understand what happens after accumulation on the sea floor. It was discovered that Ot alternative antifoulant accumulation characteristics in sediment were like Ot compounds, with the concentration in the sediment core being much higher than surface sediment. The concentration in sediment seems to have been affected by the regulation of Ot compounds in 1990, due to the concentration of Ot alternative antifoulants and Ot compounds at the survey point in front of the dock, showing an increase from almost the same layer after the regulation.

Sediment core samples were obtained from Nishiyama Reservoir, 3 km east of the hypocenter of the Nagasaki atomic bomb, to evaluate both sources and inventories of lead delivery to the sediments. Using microwave digestions and ICP-MS analytical techniques, elevated concentrations of isotopically unique lead were identified in the 1945 sediment horizon. These results illustrate that the Nagasaki bomb attack can be linked with unique lead loading to the sediments in the region of the hypocenter. There is a possibility that the roll-up of in-situ lead accounted for a majority of the increase in lead flux delivered to reservoir sediments during the atomic bomb attack.

Spheroidal carbonaceous particles (SCPs) are produced by the high-temperature combustion of fossil fuels and emitted in to the atmosphere. The distribution and concentration of SCPs in sediments have been used as a proxy for the distribution of pollutants emitted to the atmosphere. However, the effect on the distribution of SCPs due to industrial activity at nearby industrial cities is yet to be quantified. To clarify the origin of SCPs of ~20 μm in size that are preserved in sediments, we evaluated the abundance, surface morphology, and chemical composition of SCPs in sediment core samples recovered from industrial cities in Japan (Tokyo, Osaka, and Nagasaki) and China (Beijing), with the cities being located at least ~500 km away from each other. Vertical profiles of SCP concentration in sediment cores from the Japanese cities and Beijing are different, reflecting the contrasting industrial histories of the two countries. The SCPs from different cities show contrasting morphological and chemical characteristics, suggesting that ~20 μm SCPs in sediments from the industrial cities could represent the local combustion history in detail, as the influx of local SCPs is dominant at such sites.

Background: The use of high-density barium sulfate was recommended by the Japan Society of Gastroenterological Cancer Screening (JSGCS) in 2004. We evaluated the diagnostic validity of gastric cancer screening that used high-density barium sulfate.Methods: The study subjects were 171 833 residents of Osaka, Japan who underwent gastric cancer screening tests at the Osaka Cancer Prevention and Detection Center during the period from 1 January 2000 through 31 December 2001. Screening was conducted using either high-density barium sulfate (n = 48 336) or moderate-density barium sulfate (n = 123 497). The subjects were followed up and their medical records were linked to those of the Osaka Cancer Registry through 31 December 2002. The results of follow-up during 1 year were defined as the gold standard, and test performance values were calculated.Results: The sensitivity and specificity of the screening test using moderate-density barium sulfate were 92.3% and 91.0%, respectively, while the sensitivity and specificity of the high-density barium test were 91.8% and 91.4%, respectively. The results of area under receiver-operating-characteristic (ROC) curve analysis revealed no significant difference between the 2 screening tests.Conclusions: Screening tests using high- and moderate-density barium sulfate had similar validity, as determined by sensitivity, specificity, and ROC curve analysis.

The aim of this study was to evaluate the film-reading ability of radiographers in detecting gastric cancer during screening X-ray examinations.A test set of 100 patients (50 negative and 50 positive; mean age 62 years, range 33-78 years) given a stomach X-ray examination were selected from those who underwent gastric cancer screening in Osaka, Japan, between 2000 and 2003. Eleven radiographers and four radiologists scored the test set on a five-point scale. A receiver operating characteristic (ROC) analysis was performed, and the area under the ROC curve (AUC) was defined as a measure of film-reading ability to detect cancer.No significant difference (two-tailed P = 0.962, Welch's t-test) was observed between averaged AUC values from radiographers (0.76, range 0.85-0.62) and radiologists (0.75, range 0.86-0.62).Film-reading ability of radiographers in detecting gastric cancer during screening X-ray examinations was not significantly different from that of radiologists. Our results suggest that radiographers can assist radiologists to detect gastric cancer during screening.

Thimerosal, an ethyl mercury compound, is used worldwide as a vaccine preservative. We previously observed that the mercury concentration in mouse brains did not increase with the clinical dose of thimerosal injection, but the concentration increased in the brain after the injection of thimerosal with lipopolysaccharide, even if a low dose of thimerosal was administered. Thimerosal may penetrate the brain, but is undetectable when a clinical dose of thimerosal is injected; therefore, the induction of metallothionein (MT) messenger RNA (mRNA) and protein was observed in the cerebellum and cerebrum of mice after thimerosal injection, as MT is an inducible protein. MT-1 mRNA was expressed at 6 and 9 h in both the cerebrum and cerebellum, but MT-1 mRNA expression in the cerebellum was three times higher than that in the cerebrum after the injection of 12 microg/kg thimerosal. MT-2 mRNA was not expressed until 24 h in both organs. MT-3 mRNA was expressed in the cerebellum from 6 to 15 h after the injection, but not in the cerebrum until 24 h. MT-1 and MT-3 mRNAs were expressed in the cerebellum in a dose-dependent manner. Furthermore, MT-1 protein was detected from 6 to 72 h in the cerebellum after 12 microg/kg of thimerosal was injected and peaked at 10 h. MT-2 was detected in the cerebellum only at 10 h. In the cerebrum, little MT-1 protein was detected at 10 and 24 h, and there were no peaks of MT-2 protein in the cerebrum. In conclusion, MT-1 and MT-3 mRNAs but not MT-2 mRNA are easily expressed in the cerebellum rather than in the cerebrum by the injection of low-dose thimerosal. It is thought that the cerebellum is a sensitive organ against thimerosal. As a result of the present findings, in combination with the brain pathology observed in patients diagnosed with autism, the present study helps to support the possible biological plausibility for how low-dose exposure to mercury from thimerosal-containing vaccines may be associated with autism.

Metal concentrations in a sediment core from a moat outside Osaka Castle in Japan were measured by ICP-MS following a microwave extraction method. Concentrations of metals in the sediment core samples peaked around 1945 when the World War II ended. This is in part due to great air raids on Osaka. In cluster analysis using metal concentrations, the fractions of sediment core samples were classified into two groups, representing natural sources (1795–1915) and anthropogenic sources (1922–1976), respectively. Results of lead isotope ratios also showed the anthropogenic influences from 1915 by changing the ratio values compared to those of natural sources. In addition, several components contributing to metal concentrations were identified by principal component analysis. The main component was controlled by natural sources and a decrease of the component score corresponded to an increased influence from anthropogenic sources. The largest impact of anthropogenic sources was shown around 1945.

This cross-sectional study examined the benefits of social dancing on postural stability and physical performance in dancers aged 50 years or more. Walking speed, lower limb reaction time and low back flexibility were measured in 202 social dancers and 202 community-dwelling comparison subjects aged 50-87 years. The results showed that dancers who were older than 60 years had better postural stability and faster leg reaction times, whilst dancers aged 50-59 showed only better flexibility, when compared with the controls. Male dancers had greater low back flexibility and leg reaction time compared to controls. In contrast, female dancers had superior performance only for leg reaction time when compared with controls. The results indicate that social dancing is associated with enhanced postural stability and physical performance in older adults.

Background: Gastric cancer is the leading cause of death from cancer in Japan. In 2004, there were 50 562 deaths from gastric cancer; they accounted for 15.8% of the total number of cancer deaths. Since 1983, under the Health Service Law for the Aged, gastric cancer screening has been conducted nationwide for all residents aged 40 years and over. Methods: On the basis of the standardized method developed for the Japanese Guidelines for Cancer Screening, the efficacies of various methods for gastric cancer screening were evaluated and the guideline was developed. Results: Four methods for gastric cancer screening were evaluated: photofluorography, endoscopy, serum pepsinogen testing and Helicobacter pylori antibody testing. On the basis of the analytic framework involving key questions, 1715 articles, published from January 1985 to February 2005, were selected using MEDLINE, the Japanese Medical Research Database and other methods. After the systematic literature review, 10 articles were identified as direct evidence and 49 articles as indirect evidence. The studies that evaluated mortality reduction from gastric cancer included five case‐control and two cohort studies for radiographic screening. On the basis of the balance of benefits and harms, the recommendations for population-based and opportunistic screening were formulated. Gastric cancer screening using photofluorography was recommended for both screening programs. The other methods were not recommended for population-based screening due to insufficient evidence. Conclusions: The guideline for gastric cancer screening guideline was developed based on the previously established method. Gastric cancer screening using photofluorography is recommended for population-based and opportunistic screening in Japan.

大阪湾において採取された柱状堆積物の珪藻分析を行い，過去約120年間の珪藻遺骸群集組成変化を明らかにし，環境の人為改変・汚染が群集に及ぼした影響を検討した．珪藻群集組成は，1900年頃，1960年頃および1980年頃に顕著な変化を示した．これらの変化は，それぞれ明治時代の干潟の干拓，戦後の高度経済成長期の沿岸域埋め立てと栄養塩の流入負荷の増大，および近年の沖出し埋め立てによる人為負荷物質輸送システムの変化など，人為改変・汚染に応答したものであると考えられる．また，1960年以降のChaetoceros属の休眠胞子の増加は，大阪湾における環境の人為改変・汚染の指標となることが示唆された．

In a sediment core of Nishiyama reservoir at Nagasaki city, depth profiles of (240)Pu/(239)Pu isotopic ratio, (239+240)Pu and (137)Cs activities were determined. Sediments containing plutonium and (137)Cs, which were deposited immediately after a detonation of Nagasaki atomic bomb, were identified in the core. Observed below the sediments were macroscopic charcoals, providing evidence for initial deposit of the fallout of the Nagasaki atomic bomb. This is the first entire depositional records of plutonium and (137)Cs released from the Nagasaki atomic bomb together with those from atmospheric nuclear tests.

大阪湾の現生底生有孔虫の分布を，TOC・TN・TS濃度などの底質項目と比較検討し，富栄養・貧酸素環境の指標（Ab-Espp index）を抽出した．大阪湾の柱状堆積物中に認められる底生有孔虫化石群集のAb-Espp indexを調べ，大阪湾における過去150年間の底生有孔虫・貝形虫化石記録との比較を行い，過去150年間の富栄養化過程を解明した．20世紀初頭以降の都市化に伴う富栄養化の進行は，大阪湾の柱状堆積物中に認められる底生有孔虫・貝形虫に克明に記録されている．20世紀初頭以降の富栄養化に伴って，Ab-Espp indexは急激に増加し，底層水の貧酸素が頻繁に発生した1970年代にピークを迎え，栄養塩類の排出規制が進んだ1980年以降は減少傾向を示した．一方，貝形虫の個体数は20世紀初頭以降急激に減少している．このような記録は，環境変遷と人間活動との関係を長期的かつ連続的に解読するために重要である．

Thimerosal is one of the best-known preservative agents for vaccines in the world but a relationship between its use and autism has long been suspected so that its effects on the brain need more detailed research. We here examined the influence of lipopolysaccharide injury to the blood-brain barrier on the penetration of mercury from thimerosal into mouse cerebrums, as well as the effect of chelator of heavy metals on cerebrum mercury content. Mercury can be expected to be detected in the cerebrum of normal mice, because the metal is present in standard mouse chow. When 60μg/kg of thimerosal was subcutaneously injected into the mouse, the mercury content in the cerebrum was significantly higher 48h after the thimerosal injection with a maximum peak after 72h. In addition, mercury content in the cerebrum was still higher on day 7 than in the control group. When lipopolysaccharide was pre-injected into mice to induce damage on blood-brain barrier, the mercury content in the cerebrum was significantly higher at 24 and 72h after the injection of 12μg/kg of thimerosal compared to the control group, this dose alone does not cause any increase. The mercury content in the cerebrums of mice was decreased to the control group level on day 7 when a chelator, dimercaprol, was administered once a day from days 3 to 6 after a 60μg/kg, s.c. injection. In addition, d-penicillamine as a chelator decreased the mercury contents in the cerebrum after the high dose administration. In conclusion, a physiological dose of thimerosal did not increase the content of mercury in the cerebrum, but levels were increased when damage to the blood-brain barrier occurred in mice injected with thimerosal. In addition, a chelator of heavy metals may be useful to remove mercury from the cerebrum.

In order to know the distribution of plutonium derived from the Nagasaki atomic bomb, soil samples were measured to determine the 240Pu/239Pu isotope ratio of and concentrations of 239+240Pu and 137Cs. The 239+240Pu concentrations in soils, except for Nishiyama area, were close to the average concentration of soil collected in Japan. In soils collected at the Nishiyama area and at the eastern area of Nagasaki Prefecture and at part of northern area in Kumamoto Prefecture, the 240Pu/239Pu ratios were lower than the global fallout values. This suggests that plutonium from the atomic bomb was deposited in the eastern area from the hypocenter reaching up to 100 km eastwards.

Concentrations of polycyclic aromatic hydrocarbons (PAHs) were measured in a dated sediment core from a reservoir at Osaka City, Southwest Japan. The sediment core consisted of deposits collected over a period of almost 70 years whose PAH content would serve as a historical record of atmospheric environment at Osaka City. Total PAH concentrations varied from 4.2 to 26 mg kg−1 dry wt, and peaked in the 1940s, reflecting the occurrence of a large fire due to air attacks during World War II. The results indicated that warfare had the largest impact on atmospheric environment in Osaka City. Total PAH concentrations decreased in the post-war period except for a small peak. In the 1950s, there was a downward trend from the 1970s to the present. These trends can be ascribed to the growth of industrial activities and the regulation of atmospheric pollutant emissions, respectively.

High-resolution foraminiferal analysis was conducted on a short sediment core from the inner part of Osaka Bay, Japan. Changes in foraminiferal assemblages were associated with eutrophication, bottom water hypoxia, and changes in red tide-causing algae. Before the 1920s, the calcareous species Ammonia beccarii , and the agglutinated species Eggerella advena and Trochammina hadai were rare, but calcareous foraminifers in general were abundant. Between the 1920s and 1940s, calcareous foraminifers decreased abruptly in abundance, while A . beccarii , E . advena and T . hadai increased in abundance. This faunal change corresponded in time to an increase in nutrients flowing in through the Yodo River, and bottom water hypoxia related to eutrophication. In the 1960s and 1970s, A. beccarii , E . advena and T . hadai further increased in abundance to become dominant, and many calcareous foraminifers nearly disappeared, corresponding to increasing bottom water hypoxia related to the rapid increase in discharged nutrients during the high economic growth period from 1953 to 1971. After the 1990s, A. beccarii decreased rapidly in abundance and E . advena and Uvigerinella glabra increased in abundance. The main components of red tide-causing algae changed from dinoflagellates to diatoms in the 1980s through 1990s, thus there was a change in the food supply to the benthos, which may have caused the increase in abundance of E. advena and U. glabra .

Heavy metal concentrations of the acid-soluble fraction in sediment core samples from Nagaike, a reservoir in Osaka City, Japan, were measured by ICP-MS following the microwave extraction method. Spiked peaks for several metals in the sediment core samples were observed around 1960. The results of correlation coefficient study and cluster analysis of heavy metal concentrations in the sediment core samples showed that some metals, such as Cr, Cd, Ni and Cu, in the period of the spiked peak were derived from the different emission sources from other periods. These metals are often used for metal plating, and it was concluded that the spiked peaks were caused by illegal effluent from the metal plating industry. The load amounts of heavy metals by illegal dumping were calculated and the magnitude of the pollution was estimated.

We examined the intra-individual variation in resting frequency of the constant-frequency component of the second harmonic of the pulse (F rest) over 4 years in a laboratory colony of the Taiwanese leaf-nosed bat (Hipposideros terasensis). Patterns of change in F rest were observed when individuals were added to or removed from the colony so that we investigated whether F rest was affected by neighboring colony members. F rest of each bat continually showed a long-term gradual change throughout the year, and all bats in the colony increased or decreased their F rest in the same direction as a group non-seasonally. The greatest short-term changes were observed when new bats with a relatively low F rest joined the colony and F rest of new bats converged with those of the original colony members around 8 –16 days after their introduction. Conversely, a single individual showed sudden short-term decrease in F rest after its isolation from other colony members. These findings strongly indicate that F rest is flexible according to the presence of neighboring conspecific bats. We suggest that the audio-vocal feedback for conspecific pulses appears to be involved in the short- or long-term intra-individual variation in F rest other than factors previously thought such as age or season.

The aim of this report is to investigate the effects of 8 weeks of intensive Tai Chi Chuan (TCC) training on physiological function and fear of falling (FOF) in the less-robust elderly. Forty-nine community-dwelling elderly, aged 60 or older, were classified randomly into a TCC training or control group. Physical performance measures (including one-leg stance, trunk flexion, and walking speed) and interviews were conducted before and after the intervention. The TCC group showed significant improvements in balance and flexibility, and a reduced FOF, when compared with the control group after the intervention. However, walking speed did not change significantly. The results suggest that a high-frequency, short-term TCC training program can improve balance, flexibility, and increase the confidence of less-robust elderly. These suggest the effectiveness of TCC for intervention as a means to prevent falling among high-risk elderly populations.