The relative biological effectiveness （RBE） of carbon ions with linear energy transfer （LET） of 172 keV/μm and 13.7 keV/μm were determined in this study. The clonogenic survival and premature terminal differenti...The relative biological effectiveness （RBE） of carbon ions with linear energy transfer （LET） of 172 keV/μm and 13.7 keV/μm were determined in this study. The clonogenic survival and premature terminal differentiation were measured on normal human fibroblasts AG01522C and NHDF after exposure of the cells to 250 kV X-rays and carbon ions with different qualities. RBE was determined for these two biological end points. The results showed that the measured RBE10 with a survival fraction of 10% was 3.2 for LET 172 keV/μm, and 1.33 for LET 13.7 keV/μm carbon ions. RBE for a doubling of post-mitotic fibroblasts （PMF） in the population was 2.8 for LET 172 keV/μm, and 1 for LET 13.7 keV/μm carbon ions. For the carbon ion therapy, a high RBE value on the Bragg peak results in a high biological dose on the tumour. The tumour cells can be killed effectively. At the same time, the dose on healthy tissue would be reduced accordingly. This will lighten the late effect such as fibrosis on normal tissue.展开更多
Field cultivation experiments on white sesame(Sesamum indicum L.)seeds implanted with low-energy C ion showed that different dosages of C ion implantation pro-duce different biological effects.Sesame plants in 6 diffe...Field cultivation experiments on white sesame(Sesamum indicum L.)seeds implanted with low-energy C ion showed that different dosages of C ion implantation pro-duce different biological effects.Sesame plants in 6 different dosage groups with C ion density respectively at 1×10^(11),1×10^(12),1×10^(15),5×10^(15),1×10^(16),5×10^(16)ion/cm2 were superior to the control group in plant height,leaf number,stalk diameter and leaf size.Further,sesame plants in these groups flower and seed earlier than those in the control group,and single plant yield also increased.Of all the groups,the 5×10^(15)ion/cm2 dosage group yielded the best effect,whereas the 1×10^(17)/cm^(2)dosage group showed an evident inhibitory effect of ion implantation on the germination and growth of the sesame seeds.展开更多
[ Objective ] This study aimed to investigate the effects of carbon ion implantation and implantation times on growth and genetic variation of sunflowers. [ Method] Carbon ions were implanted into Bakui 138, Bakui i36...[ Objective ] This study aimed to investigate the effects of carbon ion implantation and implantation times on growth and genetic variation of sunflowers. [ Method] Carbon ions were implanted into Bakui 138, Bakui i36 and Bakui 118 seeds at dose of 5 - 10is C/cm2, before they were planted. Their Fl-generation seeds were irradiated again. Seeds of the both generations were planted and the growth d the seedlings was observed in field tests. Finally, their genetic variation was analyzed through RAPD. [ Result] The germination rate and several agronomic traits like plant height, stem diameter, leaf number and yields of Bakui 138 of once-irradiated group were significantly improved, while that of twice-irradiated group showed opposite trend. The variation of Bakui 136 and Bakui 118 was insig- nificant. At the molecular level, the genetic distance with the control group of once and twice-irradiated groups was 0. 111 1, 0. 108 7 in Bakui 138; 0. 068 O, O. 030 3 in Bakui 136 and 0.062 5,0.043 5 in Bakui 118. [Conclusion] Carbon ion implantation had a significant effect on the growth and development of Bakui 138, and the effect varied with irradiation times. Moreover, it caused genomic variation in the three sunflower cuhivars.展开更多
F2+ beam with 3 MeV is used to irradiate thin biological samples (onion innersurface membrane and kidney beau coat) in the transmission measurement, its current densityis 400-800 nA/cm2. Results show that the onion sa...F2+ beam with 3 MeV is used to irradiate thin biological samples (onion innersurface membrane and kidney beau coat) in the transmission measurement, its current densityis 400-800 nA/cm2. Results show that the onion samples can be broken up quickly under ionirradiating; as to kidney beau samples, about 60% of tile implanted ions penetrate the samples,most of them lose part of their energy, fewer ions are found to be able to transmit throughthe sample without energy loss. SEM experiments are carried out to study sample’s damageinduced by tile ions irradiation.展开更多
基金the"Xi Bu Zhi Guang"Project of Chinese Academy of Sciences(No.O606180XBO)
文摘The relative biological effectiveness （RBE） of carbon ions with linear energy transfer （LET） of 172 keV/μm and 13.7 keV/μm were determined in this study. The clonogenic survival and premature terminal differentiation were measured on normal human fibroblasts AG01522C and NHDF after exposure of the cells to 250 kV X-rays and carbon ions with different qualities. RBE was determined for these two biological end points. The results showed that the measured RBE10 with a survival fraction of 10% was 3.2 for LET 172 keV/μm, and 1.33 for LET 13.7 keV/μm carbon ions. RBE for a doubling of post-mitotic fibroblasts （PMF） in the population was 2.8 for LET 172 keV/μm, and 1 for LET 13.7 keV/μm carbon ions. For the carbon ion therapy, a high RBE value on the Bragg peak results in a high biological dose on the tumour. The tumour cells can be killed effectively. At the same time, the dose on healthy tissue would be reduced accordingly. This will lighten the late effect such as fibrosis on normal tissue.
基金This work was supported by the Country Natural Sciences Fund Subsidizes Project(No.10435020)was the project of the Undergraduate Student Scientific Research Foundation Funds in Beijing Normal University.
文摘Field cultivation experiments on white sesame(Sesamum indicum L.)seeds implanted with low-energy C ion showed that different dosages of C ion implantation pro-duce different biological effects.Sesame plants in 6 different dosage groups with C ion density respectively at 1×10^(11),1×10^(12),1×10^(15),5×10^(15),1×10^(16),5×10^(16)ion/cm2 were superior to the control group in plant height,leaf number,stalk diameter and leaf size.Further,sesame plants in these groups flower and seed earlier than those in the control group,and single plant yield also increased.Of all the groups,the 5×10^(15)ion/cm2 dosage group yielded the best effect,whereas the 1×10^(17)/cm^(2)dosage group showed an evident inhibitory effect of ion implantation on the germination and growth of the sesame seeds.
基金Supported by the Fund from Key Laboratory of Beam Technology and Material Modification of Ministry of Education(201123)
文摘[ Objective ] This study aimed to investigate the effects of carbon ion implantation and implantation times on growth and genetic variation of sunflowers. [ Method] Carbon ions were implanted into Bakui 138, Bakui i36 and Bakui 118 seeds at dose of 5 - 10is C/cm2, before they were planted. Their Fl-generation seeds were irradiated again. Seeds of the both generations were planted and the growth d the seedlings was observed in field tests. Finally, their genetic variation was analyzed through RAPD. [ Result] The germination rate and several agronomic traits like plant height, stem diameter, leaf number and yields of Bakui 138 of once-irradiated group were significantly improved, while that of twice-irradiated group showed opposite trend. The variation of Bakui 136 and Bakui 118 was insig- nificant. At the molecular level, the genetic distance with the control group of once and twice-irradiated groups was 0. 111 1, 0. 108 7 in Bakui 138; 0. 068 O, O. 030 3 in Bakui 136 and 0.062 5,0.043 5 in Bakui 118. [Conclusion] Carbon ion implantation had a significant effect on the growth and development of Bakui 138, and the effect varied with irradiation times. Moreover, it caused genomic variation in the three sunflower cuhivars.
文摘F2+ beam with 3 MeV is used to irradiate thin biological samples (onion innersurface membrane and kidney beau coat) in the transmission measurement, its current densityis 400-800 nA/cm2. Results show that the onion samples can be broken up quickly under ionirradiating; as to kidney beau samples, about 60% of tile implanted ions penetrate the samples,most of them lose part of their energy, fewer ions are found to be able to transmit throughthe sample without energy loss. SEM experiments are carried out to study sample’s damageinduced by tile ions irradiation.
