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Biomedical subjects

Y Murakami

Publications and source records attributed to Y Murakami.

At least 1,045 records · Page 58Linked to original sources
PubMed1977

[Production of 123I by alpha and 3He irradiation of natural tellurium].

In order to determine the optimum irradiation condition to produce 123I for nuclear medical use, excitation curves and thick-target yield curves were measured by means of stacked foil technique for alpha and 3He reactions producing 123Xe, 123I, 125Xe and 130I, both from natural tellurium. The 123Xe yields from natural tellurium are too low for routine production. However, by bombarding 76.5% isotopically enriched 123Te target with 30MeV 3He particles, 724 micronCi/micronAh of 123I would be obtained, whereas the level of 125I contaminat would be about 0.14%. 130Te contaminant in enriched 123Te target produces 130I alpha and 3He bombardment, although it has not been reported in the past. The 130I contaminant can be easily eliminated.

Alpha Particles↗
PubMed1977

[Radiochemical purity of 123I for medical use (author's transl)].

123I for use in clinical diagnostic procedures has been produced by bombarding antimony with 40 MeV 3He particles. The purity of 123I was measured with a Ge(Li)spectrometer and a low energy Ge(Li) detector. The 123I-product was followed for 1.5 months with a well-type NaI scintillation counter to establish the half-life and confirm the identity of the nuclides. In order to minimize the yield of 121I the optimum cooling time and chemical procedures are presented. After 20 h cooling, the 121I, 124I and 125I contaminants were about 1.8, 4.3 and 0.04% respectively. These values were in agreement with those calculated from the thick-target yield curves. The calculated absorbed dose to the thyroid by the 123I and by-product nuclides were only 4.3 and 7.3% of 131I. 123I could be measured at the window of 99mTc of a NaI scintillation camera and a curie-meter with an error of 10%.

Half-Life↗
PubMed1977

Mechanical behavior of tooth, periodontal membrane, and mandibular bone by the finite element method.

Simulation of the human tooth, periodontal membrane, and mandibular bone was attempted basing on the anatomical form and dimension, and the experimental data of each component were examined by the two-dimensional finite element method. Following problems were investigated: (1) Which of two factors, elastic modulus or Poisson's rate, in periodontal membrane played an important role for supporting the tooth, and (2) Characteristics of tooth and alveolar bone displacement, and stress distribution in periodontal membrane and mandibular bone were investigated under a definite condition. It is clarified that Poisson's ratio plays a much important role than the elastic modulus and this method is more suitable for simulating the model equivalent to human body and for examining the internal stress and it's displacement than the strain gauge and photoelastic method.

Dental Stress Analysis↗