نوع مقاله : مقاله پژوهشی

نویسندگان

1 گروه فیزیک، دانشکده علوم پایه، دانشگاه بوعلی سینا، کدپستی: 3697-19395، همدان- ایران

2 گروه فیزیک، دانشگاه پیام نور، صندوق پستی: 4697-19395، تهران-ایران

3 مرکز تحقیقات بیوشیمی و بیوفیزیک، دانشگاه تهران، صندوق پستی: 1384-13145،تهران – ایران

4 پژوهشکده کاربرد پرتوها، پژوهشگاه علوم و فنون هسته‌ای، صندوق پستی: 3486-11365، تهران-ایران

چکیده

مطالعه‌ی حاضر به بررسی اثرات مستقیم پرتوهای نوترون سریع در محدوده‌ی انرژی 2 تا MeV 14 و محاسبه‌ی شکست‌های تک­رشته‌ای و دو رشته‌ای ساختار اتمی DNA به روش مونت­کارلو می‌پردازد. بدین­منظور از ابزار Geant4 و بسته‌ی انرژی‌های پایین Geant4-DNA استفاده شد. ساختار اتمی DNA استخراج شده از بانک داده پروتیین و ماده‌ی آب به عنوان محیط زیستی انتخاب شدند. در فیزیک لیست مرتبط به انرژی‌های پایین، طول گام در مرتبه نانومتر و کم­تر است و از سوی دیگر مسیر آزاد متوسط نوترون‎‌ها در محدوده‌ی مورد بحث در مرتبه‌ی سانتی­متر به دست آمد. با این شرایط اجرای برنامه با استفاده از رایانه محاسباتی نیز طولانی خواهد بود. در نتیجه طیف ذرات ثانویه‌ی ناشی از برهم­کنش نوترون با اتم‌های مولکول‌های آب به هدف تابیده شد. طیف ذرات ثانویه با کمک کتابخانه ENDF و محاسبات نظری استخراج شد. با این روش مدت زمان اجرای برنامه به بیش از تقریباً یک دهم کاهش یافت. سپس اثر بخشی بیولوژیکی نسبی، RBE، نوترون‌ها با انتخاب پرتوهای گامای کبالت 60، به عنوان تابش مرجع محاسبه شد. نتایج، رفتار تقریباً ثابتی را برای RBE برحسب تابعی از انرژی پیش‌بینی می‌کند که هم­خوانی بسیار خوبی نیز با پژوهش‌های دیگر دارد.

کلیدواژه‌ها

عنوان مقاله [English]

Study of Biological Effects of Fast Neutrons (2-14 MeV) Using Monte Carlo Method on DNA Atomic Model

نویسندگان [English]

  • A. Zabihi 1
  • Gh. Forozani 2
  • F. Semsarha 3
  • A. Moslehi 4
  • P. Rezaeian 4

1 Physics Department, University of Bu-Ali Sina, Postalcode: 19395-3697, Hamedan- Iran

2 Physics Department, Payame Noor University, P.O. Box: 19395-3697, Tehran- Iran

3 Institute of Biochemistry and Biophysics (IBB), University of Tehran, P.O. Box: 13145-1384, Tehran- Iran

4 Radiation Applications Research School, Nuclear Science and Technology Research Institute, P.O. Box: 11365-3486, Tehran- Iran

چکیده [English]

This study investigates the direct effect of fast neutrons with the energy ranging from 2MeV to 14MeV, and calculates the single-strand break and double-strand break on the Deoxyribon Nucleic Acid (DNA) atomic structure, using Monte Carlo method. To this end, Geant4 toolkit and its low energy extension, known as Geant4-DNA, were used. The DNA atomic structure extracted from the Protein data bank and water was selected as a substance for the biological matter. The step length in low energy extension works is in the range of nanometer and less. On the other hand, the average free paths of neutrons in the energy rang from 2MeV to 14MeV was obtained in the unit of centimeters. Under these circumstances, running the program using a computing system will also be lengthy. As a result, the spectrum of secondary particles from neutron interactions with the atoms of water molecules was targeted. The Evaluated Nuclear Data File (ENDF) and the theoretical calculation were used to extract secondary particle spectra. This method reduces the execution time to more than about one-tenth. Then, the relative biological effectiveness (RBE) of the neutrons were also simulatedusing 60Co γ-rays as the reference quality. The model succeeded in reproducing the general behavior of RBE as a function of neutron energy, which agrees well with the data reported in the literature.

کلیدواژه‌ها [English]

  • Fast neutron
  • Single strand break
  • Double strand break
  • DNA
  • RBE
1.             J.H. Lawrence, E.O. Lawrence, The biological action of neutron rays, P Natl Acad Sci USA, 22(2), 124 (1936).
 
2.             R.E. Zirkle, P.C. Aebersold, E.R. Dempster, The relative biological effectiveness of fast neutrons and X-rays upon different organisms, Am. J. Cancer Res, 29(3), 556 (1937).
 
3.             I. Lampe, Ph.D thesis, University of Pennsylvania, (1938).
 
4.             R.S. Stone, Neutron therapy and specific ionization, Ajr 59, 771 (1948).
 
5.             L.H. Gray et al. The concentration of oxygen dissolved in tissues at the time of irradiation as a factor in radiotherapy, Bjr, 26(312), 638 (1953).
 
6.             A.D. Conger et al. Quantitative relation of RBE in Tradescantia and average LET of gamma-rays, X-rays, and 1.3-, 2.5-, and 14.1-Mev fast neutrons, Radiation Research, 9(5), 525 (1958).
 
7.             J. Fowler et al. Experiments with Fractionated X-irradiation of the Skin of Pigs II.–Fractionation up to Five Days, Bjr, 38(448), 278 (1965).
 
8.             J. Fowler et al. Experiments with fractionated X-ray treatment of the skin of pigs. I—Fractionation up to 28 days, Bjr, 36(423), 188 (1963).
 
9.             M. Catterall, M.S.c thesis, SAGE Publications, Sage Publications, (1972).
 
10.          R.L. Morgan, AIP Conference Proceedings, (American Institute of Physics, New York, 1972), 562-577 (1972).
 
11.          D. Bewley, A comparison of the response of mammalian cells to fast neutrons and charged particle beams, Radiat Res, 34(2), 446 (1968).
 
12.          W. Duncan, Exploitation of the oxygen enhancement ratio in clinical practice, Br. Med, 29(1), 33 (1973).
 
13.          F. Wagner, B. Loeper-Kabasakal, H. Breitkreutz, Neutron medical treatment of tumours—a survey of facilities, J Instrum, 7(03) C03041 (2012).
 
14.          O. Kozak et al. The role of heavy ions in fast neutron therapy, Rost, 1(2). 10 (2018).
 
15.          S.K. Schaub et al. Does Neutron Radiation Therapy Potentiate an Immune Response to Merkel Cell Carcinoma?, Ijpt, 5(1), 183 (2018).
 
16.          R.R. Wilson, Nuclear radiation at Hiroshima and Nagasaki, Radiat Res 4(5), 349 (1956).
 
17.          J. Malik, Yields of the Hiroshima and Nagasaki nuclear explosions, (Los Alamos National Lab.(LANL), United States, 1985).
 
18.          W.J. Schull, Late radiation responses in man: current evaluation from results from Hiroshima and Nagasaki, Adv Space Res, 3(8), 231 (1983).
 
19.          W. Rühm, L. Walsh, M. Chomentowski, Choice of model and uncertainties of the gamma-ray and neutron dosimetry in relation to the chromosome aberrations data in Hiroshima and Nagasaki, Radiat. Environ. Biophys, 42(2) 119 (2003).
 
20.          R. Sakata et al. Long-term effects of the rain exposure shortly after the atomic bombings in Hiroshima and Nagasaki, Radiat Res, 182(6), 599 (2014).
 
21.          A.S. Wilson, M.J. Ward, C.A. Haniff, High-resolution emission-line imaging of Seyfert galaxies. II. Evidence for anisotropic ionizing radiation, Apj, 334, 121 (1988).
 
22.          A. Edwards, RBE of radiations in space and the implications for space travel, Aifb, 17, 147 (2001).
 
23.          S. Kodaira et al. Verification of shielding effect by the water-filled materials for space radiation in the International Space Station using passive dosimeters, Adv Space Res, 53(1), 1 (2014).
 
24.          S.J. Mortazavi, J. Cameron, A. Niroomand-Rad, Adaptive response studies may help choose astronauts for long-term space travel, Adv Space Res, 31(6), 1543 (2003).
 
25.          U. Schneider, L. Walsh, Cancer risk above 1 Gy and the impact for space radiation protection, Adv Space Res, 44(2) 202 (2009).
 
26.          G. Baiocco et al. The origin of neutron biological effectiveness as a function of energy, Sci. Rep, 6, 4033 (2016).
 
27.          A. Ottolenghi et al. The ANDANTE project: a multidisciplinary approach to neutron RBE, Radiat Prot Dosim, 166(1-4), (2015).
 
28.          R.D. Stewart et al. Rapid MCNP simulation of DNA double strand break (DSB) relative biological effectiveness (RBE) for photons, neutrons, and light ions, Phys Med Biol 60(21), 8249. (2015).
 
29.          Seth et al. Neutron exposures in human cells: bystander effect and relative biological effectiveness, Plos One, 9(6), e98947 (2014).
 
30.          N. Gajendiran, K. Tanaka, N. Kamada, Comet assay to assess the non-target effect of neutron-radiation in human peripheral blood, Radiat Res, 42(2), 157 (2001).
 
31.          M. Mokari et al. Track structure simulation of low energy electron damage to DNA using Geant4-DNA, Biomed Phys Eng Express, 4, 6 (2018).
 
32.          F. Semsarha et al. Microdosimetry of DNA conformations: relation between direct effect of 60Co gamma rays and topology of DNA geometrical models in the calculation of A-, B-and Z-DNA radiation-induced damage yields, Radiat. Environ. Biophys, 55(2) 243 (2016).
 
33.          M. Bernal et al. The influence of DNA configuration on the direct strand break yield, Comput Math Method M, 2015.
 
34.          D. Charlton, H. Nikjoo, J. Humm, Calculation of initial yields of single-and double-strand breaks in cell nuclei from electrons, protons and alpha particles, Int J Radiat Oncol Biol Phys, 56(1), 1 (1989).
 
35.          W. Friedland et al. Track structures, DNA targets and radiation effects in the biophysical Monte Carlo simulation code PARTRAC, Utat Res-Fund Mol M, 711(1) 28 (2011).
 
36.          H. Nikjoo et al. Modelling of DNA damage induced by energetic electrons (100 eV to 100 keV), Radiat Prot Dosim, 99(1-4) 77 (2002).
 
37.          H.M. Berman et al. The protein data bank, Nucleic Acids Res, 28(1) 235 (2000).
 
38.          H.M. Berman, The protein data bank: a historical perspective, Acta Cryst, 64(1), 88 (2008).
 
39.          F. Semsarha et al. An investigation on the radiation sensitivity of DNA conformations to 60 Co gamma rays by using Geant4 toolkit, Nimb, 323, 75 (2014).
 
40.          S. Incerti. Comparison of GEANT4 very low energy cross section models with experimental data in water, Medical physics, 37(9), 4692 (2010).
 
41.          S. Incerti et al. Geant4-DNA example applications for track structure simulations in liquid water: A report from the Geant4-DNA Project, Med Phys, 45(8), 722 (2018).
 
42.          M. Chadwick et al. ENDF/B-VII. 1 nuclear data for science and technology: cross sections, covariances, fission product yields and decay data, Nucl. Data Sheets, 112(12), 2887 (2011).
 
43.          Y. Hsiao, R. Stewart, Monte Carlo simulation of DNA damage induction by x-rays and selected radioisotopes, Phys. Med, 53(1), 233 (2007).
 
44.          J.B. Marion, F.C. Young, Nuclear reaction analysis: graphs and tables, North-Holland (1968).
 
45.          A. Ribon et al. Status of Geant4 hadronic physics for the simulation of LHC experiments at the start of LHC physics program, Cern-Lcgapp-2010-02, 2010.
 
46.          M. Bernal, J. Liendo, An investigation on the capabilities of the PENELOPE MC code in nanodosimetry, Med Phys, 36(2), 62 (2009).
 
47.          E. Schmid et al. RBE of nearly monoenergetic neutrons at energies of 36 keV–14.6 MeV for induction of dicentrics in human lymphocytes, Radiat. Environ. Biophys, 42(2), 87 (2003).