표제지
초록
국문 초록
목차
약어 목록 17
1. 연구배경 21
1.1. 전리방사선과 생물학적 시스템의 상호작용 21
1.2. DNA 분자 및 주된 효과 설명 26
1.3. GEANT4 몬테카를로 시뮬레이션 툴킷 31
1.4. 물리화학적, 화학적, 생화학적, 생물학적 단계에서 GEANT4-DNA 시뮬레이션의 현재 상황 32
2. Geant4-DNA를 사용한 저에너지 전자의 직접, 간접적 영향 평가 42
2.1. 연구의 목적 42
2.2. 재료 및 방법 46
2.2.1. Geant4-DNA를 이용한 시뮬레이션 46
2.2.2. 화학적 결과물인 라디컬의 계산 47
2.2.3. DNA 원자 모델 제작 49
2.2.4. DNA 가닥 절단의 분류 50
2.3. 연구결과 51
2.3.1. 간접 영향의 계산 51
2.3.2. DNA strand break 발생량의 계산 56
2.4. 고찰 67
3. LET 함수에 따른 염기의 추가 손상에 대한 몬테카를로 시뮬레이션 68
3.1. 연구목적 68
3.2. 재료 및 방법 70
3.2.1. 시뮬레이션을 위한 Physics list 70
3.2.2. Particle LET 계산 71
3.2.3. 염기 손상의 계산 73
3.3. 연구결과 76
3.3.1. LET 계산 결과 76
3.3.2. LET 변화량에 따른 염기 손상 발생 80
3.4. 고찰 89
4. RBE 계산을 위한 0.1MeV 중성자 조사 시 3D 다세포 모델에서 선량 계산 90
4.1. 연구의 목적 90
4.2. 재료 및 방법 93
4.2.1. 단세포의 geometry 93
4.2.2. 3D 다세포 모델 셋업 97
4.2.3. Physics models 98
4.2.4. 흡수 선량의 계산 100
4.3. 연구결과 101
4.3.1. 3D 다세포 모델을 이용한 마이크로 수준의 선량 계산 101
4.3.2. 핵을 포함한 세포소기관의 흡수된 선량 비교 104
4.4. 고찰 109
5. 결론 및 향후 계획 110
References 113
Table 1. Corresponding Electron interactions model classes. 35
Table 2. Corresponding Proton interactions model classes. 37
Table 3. Corresponding Hydrogen interactions model classes. 38
Table 4. Corresponding Neutral Helium ionised twice (alpha) interactions model classes. 39
Table 5. Corresponding Neutral Helium ionised once (alpha+) interactions model classes. 40
Table 6. Corresponding Neutral Helium (helium) interactions model classes. 41
Table 7. Corresponding Li (3,7), Be (4,9), B (5,11), C (6,12), N (7,14), O (8,16), Si (14,28), Fe (26,56) interactions model classes. 41
Table 8. Comparison of Geant4-DNA Physics constructor. 47
Table 9. Ratios of ET=19, BP=10 in G4EmDNAPhysics_option8 / G4EmDNAPhysics_option2. 56
Table 10. Yield of strand breaks with various ETs for direct damage. 64
Table 11. Chemical composition of cellular materials by percentage mass fraction. 95
Table 12. Characteristics of the cell region geometries. 95
Table 13. Physics lists concerning low energy neutron interaction in GEANT4. 100
Figure 1. Representation of direct action pathways. 21
Figure 2. Representation of indirect action pathways. 24
Figure 3. Time-scale of the effects of radiation exposure on biological systems. 26
Figure 4. (a) The structure inside single cell. (b) The structure of a single strand of DNA. 28
Figure 5. Representation of single-and double strand DNA breaks induced by ionizing radiation. 30
Figure 6. B-DNA volume model. 43
Figure 7. The various types of DNA damage in 1ZBB PDB file. "Black circle" represents sugar-phosphates, "Gray circle" represents bases, and "White circle"... 51
Figure 8. G values of DNA damage due to OH over time and at different levels of electron energy. 52
Figure 9. G values of DNA damage due to e-aq over time and at different levels of electron energy.[이미지참조] 53
Figure 10. G values of DNA damage due to H3O+ over time and at different levels of electron energy.[이미지참조] 53
Figure 11. Total number of major species during 1 ps–106 ps in different electron energy.[이미지참조] 55
Figure 12. Total number of minor species during 1 ps–106 ps in different electron energy.[이미지참조] 55
Figure 13. DNA SSB classified by complexity with ETs and fixed 10 bp-irradiated monoenergetic electrons in G4EmDNAPhysics_option8. 58
Figure 14. DNA SSB+ classified by complexity with ETs and fixed 10 bp-irradiated monoenergetic electrons in G4EmDNAPhysics_option8. 59
Figure 15. DNA 2SSB classified by complexity with ETs and fixed 10 bp-irradiated monoenergetic electrons in G4EmDNAPhysics_option8. 59
Figure 16. DNA DSB classified by complexity with ETs and fixed 10 bp-irradiated monoenergetic electrons in G4EmDNAPhysics_option8. 60
Figure 17. DNA DSB+ classified by complexity with ETs and fixed 10 bp-irradiated monoenergetic electrons in G4EmDNAPhysics_option8. 60
Figure 18. DNA DSB++ classified by complexity with ETs and fixed 10 bp-irradiated monoenergetic electrons in G4EmDNAPhysics_option8. 61
Figure 19. Comparison of the DNA damage with this work using Geant4-DNA. 62
Figure 20. (a) Simulation results for irradiated tetranucleosome, a short complex of four nucleosomes. (b) Magnified view of the chemical elements expressed with... 74
Figure 21. Counting of the number of base- damages locations in each strand breaks by complexity. 76
Figure 22. Calculated LET for (a) electrons, (b) protons and (c) alpha particles in liquid water as a value of incident energy. 79
Figure 23. Frequency of base damage for electrons as a function of LET. Data are presented according to the number of locations of base damage (BD) within... 81
Figure 24. Frequency of base damage for protons as a function of LET. Data are presented according to the number of locations of base damage within 10 bp of... 83
Figure 25. Frequency of base damage for alpha particles as a function of LET. Data are presented according to the number of location of base... 86
Figure 26. (a) Seeded single cell in Geant4 (b) 3D multicellular model used in this simulation. 94
Figure 27. Illustration of various particles paths near the nucleus. The star marks show the position of the deposited energy. 97
Figure 28. Microdosimetry of neutron depending on volume size using 3D multicellular model. Dose of organelles filling chemical compositions with physics list assumed 1 103
Figure 29. Comparison of simulated nucleus and nucleolus dose depending on gap size with 21x21x21 cells. 105
Figure 30. The energy deposition frequency detected in the cytoplasm affected by scattering from the nucleus confirms as the existence of beam distribution. The... 106