Laser ablation inductively coupled plasma mass spectrometry （LA-ICP-MS） has been widely adopted for the direct multi-elemental analysis with high sensitivity. Especially analysis of fine ceramics by LA-ICP-MS withou...Laser ablation inductively coupled plasma mass spectrometry （LA-ICP-MS） has been widely adopted for the direct multi-elemental analysis with high sensitivity. Especially analysis of fine ceramics by LA-ICP-MS without time-consuming sample decomposition process has been one of the most expecting application field. Small additive elements in MgO powders were analyzed by LA-ICP-MS. For precise and accurate analysis influence of carrier gas （Ar or He） was presented by the signal intensities of ICP-MS, relative standard deviation of signal intensities and ablated particle size distribution. Ablated particles were collected and analyzed by scanning electron microscopy （SEM） to investigate the particle size distribution, and the ablated sample surface was examined by camscope. In He gas atmosphere, the signal was more stable than in Ar gas atmosphere. The signal intensity was higher in Ar than in He. Examination of ablated particles and sample surface reveals that more particles were generated in Ar atmosphere and the distribution of particle size was larger.展开更多
Accidentally or occupationally exposures to ionizing radiation generally involving the partial-body exposures and this may pose significant health hazards that are indicated by chromosome aberration （CA） induction. ...Accidentally or occupationally exposures to ionizing radiation generally involving the partial-body exposures and this may pose significant health hazards that are indicated by chromosome aberration （CA） induction. In this experiment, the quantification of the frequencies of CA was carried out based on cytogenetic analyses of peripheral blood samples obtained from 4 healthy volunteers as a result of simulation of partial-body exposures. The percentages of mixtures of blood samples irradiated in vitro with 2 Gy of gamma rays were 10, 25, 50, 75 and 100.0%. Lymphocytes were cultured and first-division metaphase cells were collected after culture times of 48 h and then harvested with standard procedures. The results showed that frequencies of unstable CA were depended on the percentage/portion of irradiated blood. All frequencies of observed CA was lower than that of calculated from 100% exposed blood, except in one case, indicating a phenomena of＂dilution＂ of unirradiated into irradiated lymphocytes though there could be a bystander effects taken place. The increasing in frequency for 25-100% portions was also comparable with other similar experiments. The quantification of CAs in lymphocytes is an important methodology of dose assessment for partial-body exposure to ionizing radiation, however, the scenario of exposure should be determined.展开更多
基金supported by grants-in-aid for the National Research Laboratory Program from MOST/KOSEF (No. R0A-2003-000-10320)partially supported by grants-in-aid for the National Core Research Center Program from MOST/KOSEF (No. R15-2006-022-01001-0)
文摘Laser ablation inductively coupled plasma mass spectrometry （LA-ICP-MS） has been widely adopted for the direct multi-elemental analysis with high sensitivity. Especially analysis of fine ceramics by LA-ICP-MS without time-consuming sample decomposition process has been one of the most expecting application field. Small additive elements in MgO powders were analyzed by LA-ICP-MS. For precise and accurate analysis influence of carrier gas （Ar or He） was presented by the signal intensities of ICP-MS, relative standard deviation of signal intensities and ablated particle size distribution. Ablated particles were collected and analyzed by scanning electron microscopy （SEM） to investigate the particle size distribution, and the ablated sample surface was examined by camscope. In He gas atmosphere, the signal was more stable than in Ar gas atmosphere. The signal intensity was higher in Ar than in He. Examination of ablated particles and sample surface reveals that more particles were generated in Ar atmosphere and the distribution of particle size was larger.
文摘Accidentally or occupationally exposures to ionizing radiation generally involving the partial-body exposures and this may pose significant health hazards that are indicated by chromosome aberration （CA） induction. In this experiment, the quantification of the frequencies of CA was carried out based on cytogenetic analyses of peripheral blood samples obtained from 4 healthy volunteers as a result of simulation of partial-body exposures. The percentages of mixtures of blood samples irradiated in vitro with 2 Gy of gamma rays were 10, 25, 50, 75 and 100.0%. Lymphocytes were cultured and first-division metaphase cells were collected after culture times of 48 h and then harvested with standard procedures. The results showed that frequencies of unstable CA were depended on the percentage/portion of irradiated blood. All frequencies of observed CA was lower than that of calculated from 100% exposed blood, except in one case, indicating a phenomena of＂dilution＂ of unirradiated into irradiated lymphocytes though there could be a bystander effects taken place. The increasing in frequency for 25-100% portions was also comparable with other similar experiments. The quantification of CAs in lymphocytes is an important methodology of dose assessment for partial-body exposure to ionizing radiation, however, the scenario of exposure should be determined.
