| Project/Area Number |
16300143
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biomedical engineering/Biological material science
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
TADANO Shigeru Hokkaido University, Graduate School of Engineering, Professor, 大学院工学研究科, 教授 (50175444)
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| Co-Investigator(Kenkyū-buntansha) |
SASAKI Naoki Hokkaido University, Faculty of Science, Professor, 大学院工学研究科, 教授 (40142202)
SHIRATO Hiroki Hokkaido University, Graduate School of Medicine, Professor, 大学院工学研究科, 教授 (20187537)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥14,700,000 (Direct Cost: ¥14,700,000)
Fiscal Year 2006: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 2005: ¥4,100,000 (Direct Cost: ¥4,100,000)
Fiscal Year 2004: ¥8,200,000 (Direct Cost: ¥8,200,000)
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| Keywords | Biomechanics / Bone Structure / X-ray Diffraction / Stress Measurements / Imaging Plate / Residual Stress / HAp Crystal Strain / Bone Stress / バイオメカニズム / 解析X線 / 解析波形形態法 |
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| Research Abstract |
Cortical Bone is a composite material composed of hydroxyapatite (HAp) and collagen. As HAp is a crystalline structure, an X-ray diffraction method is available to measure the strain of HAp crystals. However, HAp crystals in bone tissue have been known to have the low degree of crystallization. X-ray diffraction method was proposed to measure the lattice strain of HAp crystals from the diffusive intensity profile due to low crystallinity. Also, in order to estimate the bone tissue strain with measurements of the strain of HAp crystals, this work investigates the relationship between bone tissue strain on a macroscopic scale and the lattice strain of HAp crystals on a microscopic scale. The X-ray diffraction experiments were performed under tensile loading. Strip bone specimens of 40x6x0.8 mm in size were cut from the cortical region of a shaft of bovine femur. By detecting the diffracted X-ray beam transmitted through the specimen, the lattice strain was directly measured in the loadin
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g direction. Three lattice strains at each lattice planes (002), (211) and (213) in the HAp crystals were measured by the X-ray diffraction system. The strain was calculated from the X-ray diffraction profiles at the non-strained and the strained state. All lattice strain increased linearly with the bone tissue strain and was everywhere lower than the bone tissue strain. The values of mean lattice strain increase linearly with the bone tissue strain. The mean strain ratio (mean lattice strain/ tissue strain) was higher for bone axial specimen. This tendency agreed with the differences in the elastic modulus of specimens. The lattice strain of HAp crystals aligned with a loading direction was obtained directly from diffracted and transmitted X-ray beams measured after penetration of cortical bone specimens under tensile loading. The lattice strain was lower than the macroscopic bone tissue strain in all specimens and higher for specimens with higher elastic modulus under similar macroscopic strains. The bone tissue strain could be estimated from the lattice strain calculated for the whole profile and the elastic modulus of the bone tissue. Less
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