Search

Singly charged cluster-ion yield ϕ 1 of MeV/atom carbon cluster ions, generated using He and Ne gases as a charge-changing gas in tandem accelerator, is analytically formulated by six cross sections on the basis of the rate equation. These cross sections for electron-loss process from a cluster were estimated with use of the time-dependent quantum theory, assuming binary collision treatment and independent electron model. The cross sections in ϕ 1 estimated for MeV/atom Cn (n = 2–4) clusters were found to show the sub-linear dependence on the atom number n . The gas-pressure dependences of the ϕ 1 values calculated for the 2.5 MeV C 2 + and C 4 + ions using Ne gas are in good agreement with the experimental data obtained at TIARA.

Imaging mass spectrometry (IMS), based on linking mass-analysis data for ions and their original positions in a sample, allows the visualization of the spatial distribution of atomic and/or molecular species in the sample, and is therefore an essential analytical method for the characterization of chemical and biological materials. For sensitive elemental and chemical imaging using IMS, a sufficient amount of ions to be analyzed should be supplied from the analyzing area on the sample surface. Secondary ion mass spectrometry (SIMS) using energetic cluster ions (ECIs) with energies of sub-MeV and above as primary ions (ECI-SIMS) can provide the secondary ions necessary for the characterization of organic materials with high emission yields. Hence, ECI-SIMS is a good method for highly sensitive IMS. We report recent progress in ECI beam manipulation techniques for applications of ECI-SIMS to highly sensitive IMS together with the characteristics of ECI impacts on organic materials.

Modification of the gap at the Dirac point (DP) in axion antiferromagnetic topological insulator $${\hbox {MnBi}}_2 {\hbox {Te}}_4$$ MnBi 2 Te 4 and its electronic and spin structure have been studied by angle- and spin-resolved photoemission spectroscopy (ARPES) under laser excitation at various temperatures (9–35 K), light polarizations and photon energies. We have distinguished both large (60–70 meV) and reduced ( $$

Beard samples were collected every day from a single person (55 [at start] to 66- [at end] years old) over a 12-year period. Beard hair samples were analyzed by particle induced X-ray emission (PIXE) to determine variations in concentrations of aluminum, chromium, arsenic, mercury and lead over the sampling period. Only mercury showed a gentle upward trend with age, and a significant increase of 20–30% was observed. This fact was consistent with the results of our previous studies on more than 1250 hairs collected from healthy people. It was also found that concentrations of many toxic elements tended to be higher in summer than in winter, except for chromium. In particular, arsenic and mercury concentrations significantly increased in summer. Their concentrations in the winter dropped to less than 50% and 86% of those in the summer, respectively. These seasonal changes can be attributed to changes in the ingestion of season-specific foods, such as marine products. These findings indicate that beard analyses are a powerful tool for evaluating the exposure to toxic-element.

Mechanism of the ion track formation in crystalline silicon (c-Si) is discussed, particularly under 1–9 MeV C60 ion irradiation. In this energy region, the track formation was not expected because the energy E was much lower than the threshold of E th = 17 MeV determined by extrapolation from higher energy data in the past literature. The track formation is different between irradiations of C60 ions and of monoatomic ions: The tracks were observed under 3 MeV C60 ion irradiation but not under 200 MeV Xe ions, while both the irradiations have the same electronic stopping (S e) of 14 keV nm−1 but much higher nuclear stopping (S n) for the former ions. The involvement of S n is suggested for the C60 ions. While the inelastic thermal spike (i-TS) calculations predict that the high energy monoatomic ion irradiation forms the tracks, the tracks have never been experimentally detected, suggesting quick annihilation of the tracks by highly enhanced recrystallization in c-Si. Exceptions are C60 ions of 1–9 MeV, where the track radii are well reproduced by the i-TS theory with assuming the melting transition. Collisional damage induced by the high S n from C60 ions obstructs the recrystallization in c-Si. Then the tracks formed by the melting transition survive against the recrystallization. This is a new type of the synergy effect between S e and S n, different from the already-known mechanisms, i.e., the pre-damage effect and the unified thermal spike. While c-Si was believed as a radiation-hard material in the S e regime with high S e threshold, this study suggests that c-Si has a low S e threshold but with efficient recrystallization.

Amorphous silicon dioxide (hereafter SiO2) samples were implanted with 380 keV Fe ions at room temperature. After the implantation, some samples were irradiated with 16 MeV Au ions. The magnetic property was investigated by using a SQUID magnetometer, and the morphology of Fe-implanted SiO2 samples was examined by using a transmission electron microscope and x-ray absorption spectroscopy (extended x-ray absorption fine structure and x-ray absorption near edge structure). The size of Fe nanoparticles increases with an increase in the amount of Fe implantation. A part of Fe nanoparticles consists of Fe oxides, and with an increase in the amount of Fe implantation, the valence state of Fe atoms and the structure of Fe nanoparticles gets close to those of metallic α-Fe. The room temperature magnetism was observed in Fe-implanted SiO2 samples. The magnetization–magnetic field curves for samples implanted with a small amount of Fe are reproduced by the Langevin equation, implying that Fe nanoparticles present the superparamagnetic behavior. For a large amount of Fe implantation, the magnetization–magnetic field curve shows the ferromagnetic state. Such a result of magnetic property is consistent with the results of the x-ray absorption. By the subsequent 16 MeV Au irradiation, the Fe nanoparticles were fragmentated, resulting in the decrease in magnetization. The optical absorption property of the SiO2 samples is briefly discussed.

More than 4000 beard samples were collected from a single person every morning over a 12-year period and analyzed using a standard-free method. We detected significant annual variations in the concentrations of magnesium and calcium in the study period, although significant monthly and seasonal variations were not noted. Calcium tends not to be obtained from season-specific foods or drinks, so its variations may be affected by changes in the metabolism of the body. In contrast, however, potassium showed marked long-term variations with significant seasonal differences. As our previous studies confirmed that green vegetables contain large quantities of potassium and that their supply and consumption increase from May to July, the seasonal variations in potassium concentration were attributed to the ingestion of green vegetables. Although magnesium is also contained in green vegetables in large quantities, its principle supply sources are diverse and its concentration did not show any clear seasonal changes.

A total of 4269 beard samples were collected from the same person every day over a 12-year period and analyzed by PIXE using a standard-free method. It was found that the concentrations of copper and zinc showed certain short-term changes but did not show a noticeable long-term trend over the study period, with only iron showing a slightly decreasing tendency with age. All of these elements showed clear yearly variations with a cycle of a few years possibly due to periodic metabolic changes in the subject’s body or long-term changes in eating habits. In contrast, however, selenium showed clear seasonal variations. Its concentration significantly increased in the summer and decreased in the winter, just as was observed with arsenic and mercury. This suggests that most of the subject’s selenium intake was from marine products, whose supply and consumption were increased in the summer. These findings confirmed that beard analyses are useful not only for evaluating essential-element intake but also for estimating the relationship between the body-element concentrations and ingestion of certain foods.

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We report the elongation of embedded Au nanoparticles (NPs) in three different matrices, i.e. amorphous carbon (a-C), crystalline indium tin oxide (In

We investigated the relationships between the element concentrations in blood and hair to clarify the sex-specific differences in elemental movement from blood to hair, as we confirmed the presence of large sex-specific differences in the concentrations of certain elements in hair in our previous study. First, we compared the elemental concentrations in serum/plasma taken from healthy people ([Formula: see text] females, 142 males) and found that there were significant differences (up to 20%) between females and males in levels of phosphorus, sulfur, calcium, bromine, and lead. We then examined the sex-specific differences in the elemental transfer factors from blood to hair by analyzing plasma and hair samples that had been simultaneously collected from the same people (20 females, 21 males). Calcium and selenium showed significant differences in transfer factors from plasma to hair. Particularly, large sex-specific differences in the calcium concentration were explained by the difference in the transfer factors from blood to hair. We also examined the sex-specific differences among teenaged subjects alone ([Formula: see text] females, 9 males; average age was approximately 17 years old) and noted no significant difference in the transfer factors between sexes. Taken together, these findings indicate that the transfer factors themselves are influenced by the excretion of sex hormones.

We developed V-groove trench gate SiC MOSFETs with grounded buried p+ regions. An effective reduction can be seen in the feedback capacitance (Crss) of static characteristics, and a fast switching performance was achieved. The grounded buried p+ regions were found to be an effective structure for reducing a switching loss.

In recent years, the contamination of marine products with heavy toxic elements has become a problem in Japan, as the Japanese coastal sea water is confirmed to be highly contaminated with heavy elements. In this study, parts of scallops and ascidians, which are the main foods of the people living in the Sanriku District, including hijiki and the fatty meal of whale, were analyzed. We also analyzed some parts that are not commonly eaten in general but are often consumed by some local populations, such as the mantle, mid-gut gland, ovary and spermary of scallops, and the internal organs and pharyngeal basket of ascidians. Dangerous quantities were detected for mercury in fatty meal of whale and for arsenic in hijiki, the mid-gut gland and mantle of scallops and the internal organs and pharyngeal basket of ascidians. In addition, concentrations of cadmium in the mid-gut gland and mantle of scallops as well as in the internal organs and pharyngeal basket of ascidians also showed high values. These results suggested that, even in the daily diet, it is possible to consume arsenic and cadmium in greater-than-tolerable quantities.

At Nishina Memorial Cyclotron Center (NMCC), a large number of studies in various research fields have been pursued under nation-wide common usage since 1993. One of the features of NMCC’s PIXE is the performance of many problem-based studies in order to determine effective measures against a range of issues. Various samples must be quantitatively analyzed quickly and accurately to cope with environmental issues. We have developed several original methods for analyzing a variety of samples with good sensitivity. Specially designed absorbers were developed for sensitive analyses of samples composed of heavy elements. In addition, a powdered-internal-standard method was established for the accurate quantitative analyses of powdered samples whose matrixes are heavy elements. The standard-free method for bio-samples allowed us to quantitatively analyze untreated samples, micro samples of nearly 1 [Formula: see text]g, and live bio-samples. We have been tackling a number of environmental problems in many countries in Southeast and East Asia using these original methods. We also wrestled with environmental problems caused by the massive tsunami that struck the Sanriku district of Japan in March 2011.

This paper reports developments of indirectly cooled radiation-resistant magnet coils, which can be loaded with 2000-A dc. This current capacity is required for the most upstream magnets of a new high-momentum beam line to be constructed in the future extension of the J-PARC hadron experimental facility. Indirectly cooled coils using solid-conductor-type mineral insulation cables (MICs) and stainless-steel water pipes were adopted to achieve high radiation hardness. MICs were sandwiched by independent cooling water pipes and stacked in a casing, and the entire coil assembly was filled with solder. However, the maximum load applied to the indirectly cooled MIC coils was limited to 1000-A dc, mainly owing to a heat problem at the end parts of the coils. In pursuit of the required current capability, we have carried out load tests using a test sample of the end parts, which consists of MIC current leads and a copper bus bar connecting the MIC conductors, instead of a whole MIC coil. By improving the structure of the end parts, we have succeeded to operate the test piece stably with 2000-A dc in a vacuum.

In the present study, we used a silicon drift detector (SDD) for the quantitative analysis of in-air PIXE. First, we examined the basic performances of the detector. We found that the shift of the peak position was less than 0.45 eV, and the energy resolution was 130–136 eV at 5.98 keV. We then used the SDD for a quantitative analysis. Physical parameters, such as the X-ray production cross-sections, values of the transmission of X-rays through absorbers and the detection efficiencies, which are required for quantification, were obtained theoretically and experimentally. We confirmed that many elements, from magnesium to barium, were able to be detected without using any special device. The results of the quantitative analyses of a few standard materials showed good agreement with the certified values. This method was also used to analyze practical samples, including bio-medical samples, and the results were in good agreement with the results obtained with in-vacuum PIXE.

A standard-free method for untreated hairs has been applied to quantitative analysis of the hairs taken from 1256 healthy people living in the Iwate prefecture, Japan. It was found that there are clear sex-specific differences in the concentration of some elements. Concentrations of many essential elements, such as calcium, magnesium, iron, copper, zinc and bromine, are clearly higher for female. In particular, calcium concentration is 2.6 times higher for female in comparison with that for male. Contrarily, concentrations of some toxic elements such as chromium, arsenic and mercury are higher for male. On the other hand, concentrations of many elements vary with age. Those of calcium, magnesium and zinc start to increase in the middle of teens and reach maximum in the middle of twenties for female. Mercury concentration increases as the ages advance, while those of chromium, arsenic and lead show no clear changes with age.

We developed a standard-free method for untreated hairs and the method has been applied to quantitative analysis of more than 30,000 hairs taken from the people concerned in order to evaluate exposure to some toxic elements and intakes of essential elements. Besides these analyses, we have measured nearly 2000 hairs collected from healthy people in Japan over the past 20 years. It was found that concentrations of some elements, such as vanadium, chromium, manganese, copper and mercury, keep increasing up to the present. Such tendencies were particularly notable for female, while not clearly observed for male. Concentrations of some essential elements, such as calcium, magnesium and zinc, show no obvious long-term variations. On the other hand, iron and selenium show slightly decreasing tendencies. With regard to toxic elements, it was found that arsenic, chromium and mercury are tending to increase year by year.

In this paper, methods of quantitative elemental analysis of very small quantity of cultured cells were developed. First of all, an internal-standard method for the solution containing cells whose density is more than 1 × 106 cells/mL was established and then a standard-free method for cultured cells was developed. It was confirmed that the method allows us to quantitatively analyze more than 25 elements in the samples containing only 20,000 cells. Also, the methods for removing cultured cells from a flask were examined in order to improve accuracy and sensitivity of analysis since the use of trypsin and PBS sometimes brings a large amount of sodium, phosphorus and potassium, which have direct effect upon accuracy of analysis based on the standard-free method. It was found that the method of removing cells with a scraper without using trypsin and PBS is the best manner. Also, the effects of using thinner backing materials were examined in order to improve sensitivity of analyses. It is expected that accurate analysis of samples containing nearly two thousand cells is possible on the basis of the standard-free method when using a thinner backing material.

The 2011 tsunami not only caused significant damage, but also drew a large amount of sludge from the bottom of the sea. This may have exerted negative effects on human health. In order to evaluate changes in elemental concentrations in the body before and after the tsunami, we collected long hairs from victims of the disaster. Furthermore, sludge and plant samples were collected from three prefectures. The sludge samples on land were found to be still contaminated with heavy elements. The concentrations of heavy elements in the soils and plants gathered from the same tidelands decreased after one year. In hair analyses, no clear changes have been observed in heavy element concentrations measured before and after the tsunami. However, the concentration of some essential elements, such as Cu, Ca and Mg, showed a decreasing tendency after the tsunami.

Since the Great East Japan Earthquake on 11 March 2011, we have seen a rapid increase of requests for soil analysis by PIXE. In the Nishina Memorial Cyclotron Center (NMCC), a powdered internal standard method with palladium on carbon powder has been adopted for soil sample preparation. However, the method can be heavily laborious when many samples need to be handled in a limited time. Here, we report an alternative to the method which takes a standard in the liquid form with a few drops of acetone to be homogenized with soil sample in an agate mortar. The applicability of the moist method was examined using some standard reference materials by comparing the analyzed results with those from the conventional method and with the certified values. The results were generally satisfactory, although further examination is needed to improve the accuracy and reliability of the new method.

We developed and reported standard-free methods for various bio-samples in both invacuum and in-air PIXE and they have been applied to quantitative analyses of traces of bio-samples whose weights are less than 0.1 mg. In this study, we established a method of quantitative analysis for bio-samples of nearly [Formula: see text] in in-vacuum PIXE. In order to improve sensitivity and accuracy of analysis for smaller samples on the basis of the standard-free method, which makes use of continuous X-rays emitted from the sample, it is essential to design appropriate backing materials for supporting the sample. In the present study, we have examined various backing materials such as thinner and threadlike backings. As a result, it was found that a thread-like backing made of extended adhesive, which contains almost no impurity, is the most suitable for bio-samples of extremely small quantities, since it produces no large amount of continuous X-rays. The method has been applied to quantitative analyses of small insects and plants. Moreover, the method was applied to analyses of small marine organisms such as opossum shrimps and squilla shrimps which play important roles in a food chain in marine ecosystem. The results gave us valuable information about regeneration of marine ecosystem in the Sanriku district attacked by the huge tsunami that occurred on 11 March 2011.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief of British Journal of Anaesthesia. The study is retracted for the following reasons: Statistical analysis suggests that the data may be fabricated. Y Saitoh provided a statement in a personal communication to a member of the editorial board of British Journal of Anaesthesia that the study was not approved by the Institutional Review Board and that no evidence exists to support the study findings.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief of British Journal of Anaesthesia. The study is retracted for the following reasons: Y Saitoh provided a statement in a personal communication to a member of the editorial board of British Journal of Anaesthesia that the study was not approved by the Institutional Review Board and that no evidence exists to support the study findings.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief of British Journal of Anaesthesia. The study is retracted for the following reasons: Y Saitoh provided a statement in a personal communication to a member of the editorial board of British Journal of Anaesthesia that the study was not approved by the Institutional Review Board and that no evidence exists to support the study findings.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief of British Journal of Anaesthesia. The study is retracted for the following reasons: Y Saitoh provided a statement in a personal communication to a member of the editorial board of British Journal of Anaesthesia that the study was not approved by the Institutional Review Board and that no evidence exists to support the study findings.

A method of quantitative elemental analysis of mosquitoes which convey serious infectious diseases, such as Japanese encephalitis and Dengue fever, has been developed in order to clarify their mode of life and sphere of action. The method was developed on the basis of a standard-free method for biological samples. The method enables us to perform quantitative analysis of untreated mosquito. Moreover, the method was successfully applied to quantitative analysis of each part of mosquito's body such as head and chest, abdomen, leg and wing. It was found that there are clear differences among parts in the body of mosquito, and also among different species such as Culex tritaeniorhynchus and Aedes albopictus. The method was successfully applied to quantitative analysis of small fly belonging to Sciaridae (Bradysia.praecox) whose size is smaller than that of mosquito. It was also confirmed that the method is applicable to other kind of bio-samples of small quantities such as a grain of egg of Alaska pollock whose dry weight is less than 100 μg.

In this paper, a two-detector measuring system in in-air PIXE system composed of two Si(Li) detectors has been developed for simultaneous measurement of low- and high-Z elements. In order to improve detection sensitivity of the detector for low energy region, a new device which is attached at the tip of the detector has been designed. It is made of acryl and has a thin end on which a 1.5 μm-thick Mylar film is stuck. As a result, it exhibited a miraculous effect in improving detection sensitivity at low energies and it became possible to detect K X-rays of aluminium. In order to perform quantitative analysis in in-air system, we have measured detection efficiencies for the two Si(Li) detectors including the effect of X-ray absorption in air on the basis of the method that we developed. Concerning the beam energy at the target and corresponding X-ray production cross-sections, the same values as were reported in the previous paper were applicable since conditions of irradiating system were unchanged. It was confirmed that the new method allows us to quantitatively analyze all the elements heavier than aluminum and to obtain mostly the same results as those by in-vacuum PIXE for various kinds of samples. Accuracy of analysis was also confirmed by using a standard material.

The two methods, which enable us to observe changes in concentration of heavy elements in living plants and to perform quantitative analysis of all elements heavier than aluminum in in-air PIXE with two detectors, simultaneously, were successfully applied to studies on movement of light elements in plants. It was found that light elements including silicone, phosphorus and sulfur in leaves of living plants can be quantitatively analyzed. Accuracy of the method for light elements could be confirmed by comparing the results with those obtained by an internal-standard method. It was also confirmed that changes in elemental concentration with elapsed time after starting irradiation could be observed for silicone, phosphorus, sulfur and chlorine together with heavier elements at the same time. Interesting changes in elemental concentration with elapsed time were observed for phosphorus and sulfur together with heavier elements such as potassium, calcium and manganese. Moreover, quite interesting changes of concentration of some light elements were clearly observed after supplying water-soluble manure containing phosphorus acid and potassium to the plant.

We report probability distributions of the number of secondary ions (SIs) emitted by sub-MeV C

Nitric oxide (NO) gas concentrations are higher in expired air in asthmatics. NO is synthesized by three isoforms of NO synthase (NOS) encoded by three distinct genes, NOS1, NOS2, and NOS3. Genome-wide searches have identified linkages to asthma on chromosomes 7, 12, and 17 where these three genes are localized. No association study, however, has been reported to date. To test whether variants of NOS1, NOS2, and NOS3 relate to asthma, a genetic association study was conducted in a British population (n = 300). Intragenic microsatellite variants of NOS1 were significantly associated with asthma [odds ratio (OR) = 2.08, 95% CI: 1.20–3.57 (95% CI), P = 0.008 (Pc = 0.048)], but not with IgE levels. Neither NOS2 nor NOS3 variants showed any association with asthma nor IgE levels. These findings suggest that NOS1 variants may be a significant contributor to asthma in a British population.

The method, which was developed by our group, enables us to perform quantitative analysis of living plants. It has been applied to investigate the transport of heavy elements such as germanium, gallium, bromine and arsenic in plants. These heavy elements are transported to the leaf through vascular vessel, and changes of their concentration with elapsed time after absorption could be clearly observed. It was confirmed that the movement depends on elements, on the manner of absorption and on the states of plant growth. In addition to the movement of supplied elements, some elements in the plant show interesting changes in response to proton irradiation. It was found that the method is quite effective for examining elemental movement in living plants.

The tidelands (tidal flats) of the seaside district of Tohoku, Japan, which play an important role in maintaining the diversity of the marine ecosystem, were almost completely destroyed by the massive tsunami that occurred on March 11, 2011. The tsunami also brought large quantities of contaminated sludge from the bottom of the sea to the coastal lands including the tidelands. In this study, we collected sludge samples from three tidelands: the Tsugaruishi estuary tideland (Iwate pref.), the Orikasa estuary tideland (Iwate pref.), and the Gamou tideland (Miyagi pref.). We then analyzed the samples using PIXE in accordance with a powdered-internal-standard method that we developed. In order to investigate the effects of the contaminated sludge on the ecosystem, we gathered and analyzed various kinds of wild plants and seaweed. We found that the tidelands are contaminated with heavy elements, such as arsenic, lead, zirconium, and barium, although the contamination is less serious in the vicinity of the beach.

As a part of research project for food risk assesment in Asian countries, we have collected a variety of samples including dairy products from Mongolia for PIXE analysis. However, some kinds of milk products or fats such as butter, margarine, mayonnaise and cream are often hard to be homogenized with internal standards because of their viscosity and oiliness, which makes their sample preparation a tiresome work. We have tried to develop efficient preparation and measurement methods for in-air PIXE analysis of those samples. For butter and margarine, liquid internal standard method was taken after melting them with water bath. Pasty samples like mayonnaise and cream were mixed with liquid standard in agate mortar. The applicability of these methods was examined by checking homogeneity of so prepared samples on the basis of Ca concentration. Along with the internal standard methods, a standard-free method has also been worked out for those fatty samples. The obtained results have been fairly satisfactory and we have applied the methods to the Mongolian dairy samples.

A gigantic tsunami following Tohoku-Earthquake Disaster brought a large amount of sludge, which originated from the sediments pilling upon the bottom of the sea to the residential areas. As it is anticipated that the sludge contains a large amount of heavy toxic elements, its influence on the health of the suffered people will become a problem. In the present study, 72 sludge samples were taken from the stricken areas by the tsunami over the wide area; (Aomori, Iwate and Miyagi prefectures). These samples were treated on the basis of a powdered-internal-standard method and analyzed by means of PIXE with a specially-designed absorber. It was found that the sludge contains much amount of heavy elements such as arsenic, lead, zirconium, barium etc. in comparison with those in soils collected in the inland district of Iwate prefecture. Furthermore, 16 plant samples were gathered in the estuary area, on which the sludge deposited, and analyzed in order to evaluate the effect of the sludge on the ecosystem. These results were compared with those for 45 plant samples collected in the inland district of Iwate, Miyagi and Fukushima prefectures. It was found that these plants contain lager amount of heavy elements in comparison with those in the inland plants.

A standard-free method for living plants in in-air PIXE has been developed in order to clarify the mechanism of elemental transportation and movement in farm products. The components of the continuous X-rays originated from air and a backing film can be exactly subtracted using a blank spectrum after normalization by the yields of Ar K α X-rays. It is found by observing the yield of continuous X-rays with passage of time that water content is continuously decreasing during irradiation with a proton beam in a case of pinched leaves. In contrary, it is kept almost constant during irradiation for the living plants to which water is continuously provided through the roots. Stability of the yield of continuous X-rays is a required condition for a standard-free method, which makes use of the yield of continuous X-rays mainly emitted from water content. It is confirmed that potassium concentration shows no large position dependence on a leaf, and it keeps almost constant during irradiation, which also indicates that regular metabolism is going on. As potassium is always contained in all kinds of plants in large amount, it is designated as an index element. As a result, it is found that the potassium concentration obtained by the present standard-free method shows quite consistent values with those obtained by the internal-standard method. The present method is confirmed to be quite useful for investigating movement of not only toxic elements but also essential elements reflecting metabolism in plants.

Egg production capacity in Fasciola gigantica (Japanese strain) was estimated from egg count data obtained by the experimental infection of two goats. The goats were inoculated with a single dose of 50 metacercariae. The first goat was necropsied 132 days after infection (DAI) and the second goat 732 DAI. After patency, daily faecal production was collected and weighed and number of eggs per gram was counted. At necropsy, 23 flukes were recovered from the liver of the first goat, and five from the second goat. The mean number of eggs produced per day per worm (± 95 % confidence limits) was 9 477.9 (± 764.92) for the first goat at 106 to 132 DAI, and 8,064.1 (± 416.49) at 195 to 561 DAI for the second goat. The number of eggs produced per day per worm in F. gigantica (Japanese strain) has thus reached values ranged from approximately 8 000 to 10 000 eggs.

The target station in the hadron experimental facility at J-PARC consists of a production target and a huge vacuum chamber in which several secondary-beam-line magnets can work. This vacuum chamber system aims to remove the vacuum beam pipe from the magnet gap, because the cooling of the beam pipe is the most serious problem in the high intensity beam facility. We have developed indirectly cooled radiation-resistant magnets for the hadron target station. Their coils are made of solid-conductor type mineral-insulation cables and stainless-steel water pipes. They have the great advantages that electric circuits can be completely independent of water pass. The mechanical strength and the insulation performance of the coil are significantly improved also because the insulation water pipes can be avoided from the water pass. A C-type sector dipole and a figure-8-type quadrupole magnet have been fabricated by using indirectly cooled radiation-resistant magnet technology, and installed in the vacuum chamber. We have succeeded to operate them in vacuum stably with the current of DC 1000 A by improving the end structure of the MIC coils and increasing their emissivity. These magnets have been used for the real beam operation without any serious problems.

More than 50 radiation-resistant electromagnets were constructed for the primary proton and the secondary particle beam lines of the Hadron Experimental Hall of Japan Proton Accelerator Research Complex (J-PARC). The main radiation-resistant technologies we employed were the Polyimide-resin Insulation conductor for magnets at the relatively low radiation exposure and the Mineral Insulation Cable for magnets at the seriously high radiation environment. The remote handling and maintenance scheme of radiation-resistant magnets for seriously high radiation environment was developed also based on the Chimney magnet technology and applied to magnets near the production target in the Hadron Hall. On January 27th 2009, the first proton beam was successfully introduced to the Hadron Hall from the main accelerator of J-PARC, i.e. 50 GeV Proton Synchrotron. On February 10th, the secondary particles were extracted to the experimental area of the Hadron Hall through the secondary particle beam line. No serious problem happened on magnets of both primary proton and the secondary particle beam lines until the end of the beam operation scheduled on February 26th .

Arsenic concentration in 13 well waters, 9 pond waters, 10 agricultural waters and a coconut juice taken in Comilla district, Bangladesh, where the problem of arsenic pollution is the most severe, was investigated. High-level arsenic is detected even in the well water which has been kept drinking by the people. Relatively high arsenic concentration was detected for some pond and farm waters even though the sampling was performed just after the rainy season and the waters were expected to be highly diluted. Clear relationship was observed in elemental compositions between the pond water and the coconut juice collected at the edge of the water. These results are expected to become the basic information for evaluating the risk of individual food such as cultured fishes, shrimps and farm products, and for controlling total intakes of arsenic. In order to solve the problem of transportation of water samples internationally, a simple method of target preparation performed at the sampling cite was established and its validity was confirmed. All targets were prepared at the sampling cites in this study on the basis of this method.