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Isao UCHIDA, Yasuhiko YAMADA, Shigeyasu OKIGAKI, Hiyoshimaru OYAMADA, ...
1995 Volume 44 Issue 10 Pages
687-692
Published: October 15, 1995
Released on J-STAGE: September 07, 2010
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In radiotherapy with radiopharmaceuticals, more accurate estimates of the three-dimensional (3-D) distribution of absorbed dose is important in specifying the activity to be administered to patients to deliver a prescribed absorbed dose to target volumes without exceeding the toxicity limit of normal tissues in the body. A calculation algorithm for the purpose has already been developed by the authors. An accurate 3-D distribution of absorbed dose based on the algorithm is given by convolution of the 3-D dose matrix for a unit cubic voxel containing unit cumulated activity, which is obtained by transforming a dose point kernel into a 3-D cubic dose matrix, with the 3-D cumulated activity distribution given by the same voxel size. However, beta-dose point kernels affecting accurate estimates of the 3-D absorbed dose distribution have been different among the investigators. The purpose of this study is to elucidate how different beta-dose point kernels in water influence on the estimates of the absorbed dose distribution due to the dose point kernel convolution method by the authors.
Computer simulations were performed using the MIRD thyroid and lung phantoms under assumption of uniform activity distribution of 32P. Using beta-dose point kernels derived from Monte Carlo simulations (EGS-4 or ACCEPT computer code), the differences among their point kernels gave little differences for the mean and maximum absorbed dose estimates for the MIRD phantoms used.
In the estimates of mean and maximum absorbed doses calculated using different cubic voxel sizes (4×4×4mm and 8×8×8mm) for the MIRD thyroid phantom, the maximum absorbed doses for the 4×4×4mm-voxel were estimated approximately 7% greater than the cases of the 8×8×8mm-voxel. They were found in every beta-dose point kernel used in this study. On the other hand, the percentage difference of the mean absorbed doses in the both voxel sizes for each beta-dose point kernel was less than approximately 0.6%.
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Tsuyoshi GOROMARU, Shoji SERA, Harumi IKEDA
1995 Volume 44 Issue 10 Pages
693-700
Published: October 15, 1995
Released on J-STAGE: September 07, 2010
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Isotopic fractionation of benzoic acid (BA) and hippuric acid (HA) from their deuterated analogues (BA-d5 and HA-d5) were examined by high performance liquid chromatography (HPLC) . Reversed-phase HPLC was used with C18column and McOH-phosphoric acid solution mixture as mobile phase. The resolution coefficients between protio-and deutero forms were 1.22 for BA and 1.05 for HA respectively
The present isotopic fractionation procedure was applied to the isotopic dilution analysis of BA and HA. Measurement of the samples contained known amount of protio-and deutero-forms allowed observation of linear relationship between peak area ratio and added amount ratio in the case of both compounds. The correlation coefficients obtained by regression analysis were 0.9995 for BA and 0.9999 for HA, respectively. The present method was applied to determine the urinary excretion of HA-d5in man after oral administration of BA-d5. Two methods were examined for determination of HA-d5. One was the measurement of BA-d5after hydrolysis of HA-d5, and another was direct measurement of HA-d5. Former method is superior to latter method in the separation of protio-and deutero-forms, while, requires the complex procedures, conversion, extraction and evaporation. These isotopic fractionation of BA from BA-d5and HA from HA-d5by HPLC are simple and specific methods for determination of exogenous HA without the interference of endogenous HA.
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Taeko DOI, Jun SATO
1995 Volume 44 Issue 10 Pages
701-709
Published: October 15, 1995
Released on J-STAGE: September 07, 2010
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Atmospheric concentrations of 210Pb
and their variations over Urumqi, Lanzhou and Baotou, cities located in inland area of Chinese continent, were observed for a period of 1 year in 1992. The monthly average concentrations ranged from 0.27 to 4.57 mBq/m3. The concentrations over these cities in winter were several times higher than that observed at Tsukuba Science City, Japan, and the range of variation was also larger. The variations in concentration over the 3 localities were similar to each other, showing the same seasonal variation pattern: low concentration appeared in summer and high in winter. This variation pattern was different from that observed at Tsukuba Science City. The variations in concentration over Chinese continent, where precipitation is much lower than that in Japan, correlated quite well with the variation in precipitation.
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Takatoshi HATTORI, Takeshi ICHIJI, Kenji ISHIDA
1995 Volume 44 Issue 10 Pages
710-714
Published: October 15, 1995
Released on J-STAGE: September 07, 2010
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In a suburb of Tokyo, the concentrations of 222Rn,
its progeny and aerosol particles in outdoor air were measured simultaneously from December 1993 to April 1995. Values of 0.69 and 0.024 were obtained for annual mean values of equilibrium factor, F, and unattached fraction of potential alpha energy, fp, respectively.The concentrations of 222Rn
were found to be high in winter and low in summer and to be high from night to morning and low during daytime. On the other hand, no clear seasonal and diurnal variations were observed in F and fp. The variations of fp and unattached fraction of 218Po,
fA, strongly depended on aerosol concentration. In cases where the aerosol concentrations were lower than 10000 cm-3,
it was found that values of F were relatively low and values of fp and fA were fairly high. However, such cases were only about 3% of all data observed in 1994. From the relation between fA and aerosol concentration, the representative value of aerosol particle diameter was estimated to be 0.1-0.15 μm.
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Takami KOMAE
1995 Volume 44 Issue 10 Pages
715-724
Published: October 15, 1995
Released on J-STAGE: July 21, 2010
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III. Gamma Counter
Toru AOKI
1995 Volume 44 Issue 10 Pages
725-731
Published: October 15, 1995
Released on J-STAGE: July 21, 2010
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Takeru MINAMISAWA
1995 Volume 44 Issue 10 Pages
732-743
Published: October 15, 1995
Released on J-STAGE: July 21, 2010
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3.5 Production of Porous membranes
Hideki OMICHI
1995 Volume 44 Issue 10 Pages
744-748
Published: October 15, 1995
Released on J-STAGE: July 21, 2010
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Takashi MURAKAMI
1995 Volume 44 Issue 10 Pages
749-753
Published: October 15, 1995
Released on J-STAGE: July 21, 2010
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Masago YAMAMOTO, Ken-ichi YAMADA
1995 Volume 44 Issue 10 Pages
754-758
Published: October 15, 1995
Released on J-STAGE: July 21, 2010
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[in Japanese]
1995 Volume 44 Issue 10 Pages
759-760
Published: October 15, 1995
Released on J-STAGE: July 21, 2010
JOURNAL
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[in Japanese]
1995 Volume 44 Issue 10 Pages
761-762
Published: October 15, 1995
Released on J-STAGE: July 21, 2010
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[in Japanese]
1995 Volume 44 Issue 10 Pages
763-764
Published: October 15, 1995
Released on J-STAGE: July 21, 2010
JOURNAL
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[in Japanese]
1995 Volume 44 Issue 10 Pages
765-766
Published: October 15, 1995
Released on J-STAGE: July 21, 2010
JOURNAL
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[in Japanese]
1995 Volume 44 Issue 10 Pages
767-768
Published: October 15, 1995
Released on J-STAGE: July 21, 2010
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[in Japanese]
1995 Volume 44 Issue 10 Pages
769-770
Published: October 15, 1995
Released on J-STAGE: July 21, 2010
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—Immunoassay on Immune Diseases and Chemiluminescence Immunoassay—
Immunoassay Research Society of Japan
1995 Volume 44 Issue 10 Pages
i-xiv
Published: October 15, 1995
Released on J-STAGE: July 21, 2010
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