二烯丙基二硫对12C6+离子束辐照损伤小鼠的保护作用研究

研究大蒜素重要活性成分二烯丙基二硫( Diallyl disulfide, 简称DADS) 对12C6+离子束辐照损伤小鼠的保护作用。利用4 Gy 剂量12C6+离子束对不同浓度DADS 预处理的雄性昆明小鼠进行单次全身照射。随后检测骨髓细胞微核率和肝组织中丙二醛(MDA) 含量、蛋白质总羰基含量、总抗氧化能力( TAOC)及谷丙转氨酶(ALT ) 活性。结果显示,与单纯照射组相比,低浓度DADS 预处理组骨髓细胞微核率和肝组织ALT 活性均显著降低(p<0.001),而肝组织T-AOC明显增强( p < 0.05 );中浓度DADS 预处理组肝组织中MDA 含量和蛋白质总羰基含量均显著减少( p < 0.05 )。结果提示,DADS通过抑制氧化应激,有效地保护了脂质、蛋白质和遗传物质免受12C6+离子束辐照引起的损伤。The radioprotective effect of Diallyl disulfide (DADS) on 12C6+ ion irradiation was studied. Pretreated with DADS of different concentration, male Kung-Ming mice were exposed to whole body irradiation with dosage of 4 Gy 12C6+ ion. The animals were sacrificed after irradiation. Then the bone marrow cells micronucleus rate, malondialdehyde (MDA) levels, content of protein carbonylation, total antioxidant capacity ( T-AOC) and alanine aminotransferase ( ALT ) activity were measured. As compared with those in irradiated group, the ratio of micronucleus cells in marrow and the hepatic ALT activity in the pretreatment group with low dose DADS decreased significantly ( p < 0.001 ). Similarly,the content of protein carbonylation and the levels of MDA droped dramatically in the group with middle dose DADS treatment ( p < 0.05 ). On the contrary, the hepatic T-AOC increased markedly in the group of pretreatment with low dose DADS ( p < 0.05 ). The results showed that DADS protect lipoid, protein and genetic material from 12C6+ ion irradiation by right of resisting oxidative stress.     

12C6+离子束辐照番茄种子当代效应

利用辐射能量为80 MeV/u 的12C6+重离子束辐照番茄种子, 辐照剂量分别为30, 60, 90, 120和160 Gy研究其对番茄M1代的生物学效应。结果表明, 随着辐照剂量的增大, 番茄的发芽率和成苗率降低, 且成苗率明显低于发芽率, 发现辐照损伤主要抑制了根的生长; MDA和脯氨酸含量变化的总体趋势为随着辐照剂量的增大先升后降再升高, 说明高剂量C离子辐照对生物膜造成更严重的损伤; APX活性随着辐照剂量的增大呈先升后降再升高的趋势, 表明APX在清除活性氧中起主要作用; POD和SOD活性的总体趋势是随着辐照剂量的增大而降低, 且明显低于对照组。综合分析表明, 12C6+重离子束辐照番茄种子, 对M1代具有明显的损伤效应, 高剂量辐照对番茄种子造成的损伤更大, 使酶的活性降低, 抑制植株生长。 To investigate the M1 biological effects of heavy ions irradiation on Lycopersicon esculentum Mill., its seeds were irradiated by 12C6+heavy ions (80 MeV/u) with the dosages of 30, 60, 90, 120 and 160 Gy respectively . The results showed that with doses increased gradually, germination rate and seedling rate of Lycopersicon esculentum Mill. were decreased, and the latter was lower than the former, mainly due to the inhibition of root growth. The irradiation increased the content of MDA and proline evidently, showing irradiation could damage biomembrane, and also decreased the activities of POD and SOD with distinct inhibition pattern. However, the low dose and high dose irradiation promoted APX activity, illustrating APX was induced to protect irradiation injury. In brief, exposure to 12C6+ heavy ions had obvious injury effects on the seeds of Lycopersicon esculentum Mill.. Heavy ions irradiation damaged biomembrane, inhibited activities of enzymes, and finally inhibited the growth of the first generation of these seeds.     

低剂量连续辐射引起的小鼠免疫系统的变化

为了评估低剂量X射线连续辐射对BALB/c小鼠健康机体免疫系统的影响, 实验采用X射线全身连续照射BALB/c小鼠, 照射第一天剂量为0.07 Gy, 剂量率0.2 Gy/min, 之后每天照射0.08 Gy, 共照射12 d, 累积剂量1.03 Gy, 照射后24和48 h取血、胸腺和脾脏。 流式细胞仪检测免疫细胞周期和凋亡的变化, 胸腺和脾脏指数用重量法获取。 实验结果表明, 小鼠胸腺细胞的周期在照射后24 h被阻滞在G2/M期; 外周血淋巴和胸腺细胞周期48 h被阻滞在 G0/G1期, 细胞凋亡比例在照射后两个时间点都显著增加; 脾脏淋巴细胞周期24 h被阻滞在 G0/G1期, 48 h被阻滞在 S期, 细胞凋亡比例在24和48 h显著减少; 脾脏指数在照射后48 h显著减少。 故低剂量X射线连续全身照射BALB/c小鼠可激活免疫细胞不同的周期监测点, 引起免疫细胞凋亡比例发生变化, 造成一定的辐射损伤, 且这种影响随着免疫器官的不同而不同。 For estimating the effect of low doses X ray continual irradiation to immunity system of mouse, BALB/c mice were continually irradiated to 1.03 Gy by X rays at a dose rate of 0.2 Gy/min in 13 d. At 24 or 48 h after irradiation, the immunocyte cycle and apoptosis were determined by flow cytometry, and the thymus and spleen weights were measured too. The results showed that the cycle of thymocyte were arrested in G2/M at 24 h, the number of peripheral blood lymphocytes and thymocytes in G0/G1 phase at 48 h was up and the percentage of apoptosis had a significance increase in both of time points; the cycle of spleen lymphocytes was delayed in G0/G1 at 24 h, in S phase at 48 h, the apoptosis had a significance decrase at 24 and 48 h; spleen index declined significantly at 48 h. The results suggested that low doses continual X ray whole body irradiation could activate different cell cycle checkpoints, and result in some changes of apoptosis and some damages to immunocytes. The continual X ray irradiation affects the organs differently, it might provide experiment basis for radioprotection.     

12C6+离子束辐照菘蓝干种子当代效应

利用兰州重离子研究装置(HIRFL) 提供的12C6+ 离子束辐照菘蓝干种子(辐照剂量为10,35,60,90 和140 Gy,剂量率20 Gy/min),探讨了重离子束辐照对菘蓝M1代的生物学效应。研究发现,不同剂量的12C6+ 离子束辐照后,菘蓝种子的发芽率、成苗率、株高、根长和根冠比等生物学性状以及对菘蓝中靛玉红和4(3H) 喹唑酮含量均发生了变化,其中株高和根长随辐照剂量的增加而降低;菘蓝叶和根中的4(3H) 喹唑酮和靛玉红的含量随辐照剂量增加呈马鞍形增加关系。这表明:12C6+ 重离子束辐照菘蓝种子具有明显的当代损伤效应, 并可显著提高菘蓝中靛玉红和4(3H) 喹唑酮的含量,其辐照适宜诱变剂量为35 Gy。To investigate the M1 biological effects of heavy ions on Isatis indigotica Fort, its dry seeds were irradiated by 12C6+ beam with the dose of 0, 10, 35, 60, 90 and 140 Gy respectively,at the rate of 20 Gy/min delivered by the Heavy Ion Research Facility in Lanzhou (HIRFL). The results showed that biological characters such as germinating rate, germinating potential, survival rate, plant height, root height and root-shoot ratio were changed after irradiation. Moreover, the plant height and root height decreased in a dos dependent manner. The indirubin and 4(3H) quinazolinone content of Isatis indigotica Fort was improved and exhibited obviously “saddle” trends with irradiation dose increasing.Data suggest that exposure with low-dose 12C6+ to seeds of Isatis indigotica Fort has obvious injury effects at the first generation, and the active ingredient content of Isatis indigotica Fort may be improved by carbon ion beamirradiation. It is concluded that the suitable irradiation dose of mutation breeding is 35 Gy for the seeds of Isatis indigotica Fort.     

GANRA类药物的抗辐射效应研究

以昆明小鼠为实验模型, 连续进行GANRA类药物灌胃3 d后, 使用8 Gy 100 kVp的X射线进行辐照处理, 然后对血象、 脏器指数、 小鼠存活率、 肝脏中丙二醛(MDA)含量以及超氧化物歧化酶(SOD)活性等参数进行了统计分析。 结果表明: (1) 药物灌胃对小鼠存活率没有影响。 辐照后, 小鼠存活率显著下降, 存活率下降至50%所需时间分别为: 照射对照组20 d、 DMSO组9 d、 1#药物组29 d、 5#药物组24 d; (2) 药物灌胃对小鼠脏器指数没有明显影响, 辐照后的对照组和DMSO组小鼠的肝脏指数、 脾脏指数升高, 药物组的脏器指数低于照射对照组和DMSO组; (3) 辐照导致各实验组的MDA水平升高、 SOD活性下降, 但是5#药物的SOD活性高于DMSO组、 MDA水平低于DMSO组; (4) 药物灌胃对小鼠血象没有产生明显毒性效应;辐照后各实验组小鼠的白细胞等都显著下降。 从上述实验结果可以看出, GANRA类1#和5#药物具有抗辐射作用, 其机制可能与GANRA类药物的自由基清除能力有关。 After three days of medicine administrated, Kunming mice were exposured to 8 Gy of 100 kVp X rays. Hemogram, viscere, survival, MDA yields and SOD activity were examined. Results showes that, (1) Survival of medicine administrated mice were similar to the control group. After irradiation, survival dropped significantly. It took 20 days for the control group to reach to 50% survival, while 9 days for DMSO group 29 days for 1# drug group, and 24 days for 5# drug group. (2) The medicine per se had no obvious impacts on visceral indexes. Liver index and spleen index of the control group and DMSO group were elevated after irradiated, while those of medicine administrated group did not change much. (3) The groups treated by DMSO and 1# drug had high yield of MDA, but low activity of SOD. Compared with DMSO group, 5# drug had high SOD activity while low MDA level. Irradiation increased MDA level but decreased SOD activity of every group, However, 5# drug still showed higher SOD activity and lower MDA level than DMSO group. (4) The medicine did not show distinctive contributions to variation of hemogram. In summary, our results demonstrated that GANRA like 1# and 5# medicine had radioprotective effects and their mechanisms might be related to the scavenging ability of free radicals.     

12C6+ 离子束辐照对大鼠离体主动脉环内皮依赖性舒张功能的影响

利用兰州重离子研究装置(HIRFL) 提供的高能12C6+离子束(能量为300 MeV/u,剂量率为0.5 Gy/min) 辐照大鼠离体胸主动脉环,考察了12C6+离子束辐照对主动脉环内皮依赖性舒张功能的影响,并采用NBT 还原法测定血管环生成超氧阴离子(O2􀀀) 水平,加入外源性超氧化物歧化酶(SOD) 干预探讨了O2􀀀在内皮功能损伤中的作用。研究结果表明,2.0,4.0 和6.0 Gy 的12C6+离子束辐照大鼠胸主动脉环后,可致血管内皮依赖性舒张功能的剂量依赖性明显受损(P <0.01 vs control group),并可致血管环NBT 还原能力剂量依赖性增加(4.0 Gy 时,P <0.05;6.0 Gy 时,P <0.01 vs control group)。辐照前加入外源性SOD 对6.0 Gy 12C6+离子束辐照所致血管环NBT 还原能力升高有明显抑制作用(P <0.01),对血管环内皮依赖性舒张功能也有明显的保护作用(P<0.01),但辐照后10 min 加入外源性SOD,其保护作用明显不及前者。结论显示,12C6+ 离子束辐照大鼠胸主动脉环可致血管内皮功能受损,O2 清除剂SOD 对内皮功能受损有保护作用,说明O2􀀀介导了辐照所致内皮功能损伤。Heavy ion beam has many characteristics,and it is expected to be the most suitable radiation therapy technique for malignant tumor. It is lack of depth-understanding on the potential adverse reactions caused by using this technique, because heavy ion radiotherapy is applied to clinical for a short time. Studies have shown that the vascular injury plays a pivotal role in normal tissue damage induced in the conventional radiation therapy, but there was no research report on heavy ion beam irradiation-induced vascular injury. In the present study, the isolated aortic rings of rats were irradiated by 12C6+ ion beam (300 MeV/u, 0.5 Gy/min) delivered by HIRFL(Heavy Ion Research Facility in Lanzhou), the effects of 12C6+ ion beam irradiation on aortic rings with endothelium dependent diastolic function have been investigated.NBT reduction method was used for assaying the vascular ring formation of superoxide anion (O2􀀀) level, and the involvement of superoxide anion in endothelial function injury in rats was investigated through the intervention test of exogenous superoxide dismutase (SOD) on O2. The results showed that, the vascular endothelial dependent vasodilation was impaired significantly (P < 0:01 vs control group) by irradiation with 2.0, 4.0 and 6.0 Gy 12C6+ ion beam in a dosedependent manner, and the NBT reduction of vascular rings increased dose-dependently (P <0.05 at 4.0 Gy, P <0.01 at 6.0 Gy vs control group). Adding exogenous SOD before irradiation could significantly inhibit the increasing of NBT reduction (P<0.01), and also had protective effect on vascular endothelium dependent diastolic function (P<0.01), but 10 min after irradiation with exogenous SOD, its protective function was significantly less than before. Conclusion indicated that 12C6+ ion beam irradiation could cause endothelial function impaired, O2􀀀 scavenger SOD has a protective effect on endothelial dysfunction, suggesting that O2􀀀 mediates endothelial injury induced by heavy ion irradiation.     

12C6+束辐照引起的实验猪皮肤急性损伤反应的研究

探讨了正常皮肤对重离子辐照急性损伤反应的耐受性, 为重离子治癌临床应用提供安全性检测的实验依据。实验前10 min, 实验猪肌肉注射复方氯胺酮1.2 mg/kg进行麻醉, 然后在兰州重离子研究装置（HIRFL）辐照终端利用12C6+束照射, 辐照剂量分别为0, 12, 21和27 Gy, 辐照分3次完成, 剂量率约为1.2 Gy/min, Bragg峰区照射, 辐照后每隔7 d对照射野拍照并活检取样, 做HE组织病理学观察。不同剂量12C6+离子束辐照实验猪皮肤后, 皮肤外观反应随辐照剂量增大而加快, 表现为肿胀和色素沉积等; 皮肤组织结构的变化明显, 上皮细胞排列紊乱、 萎缩、 空泡变性; 基本恢复正常所需时间也越长, 且都存在明显的剂量效应关系。结果表明, 辐照剂量范围为0—27 Gy时, 重离子对正常皮肤的辐照是安全的。The tolerance of the normal skin to the acute radiation injury reaction induced by heavy ion beams has been studied experimentally. The experimental pigs were injected with 1.2 mg/kg ketamine in 10 min before irradiation and were irradiated with 0, 12 , 21 and 27 Gy 12C6+ ion at a dose rate of 1.2 Gy/min at the Heavy Ion Research Facility in Lanzhou（HIRFL）. The total radiation dose was finished by 3 times at Bragg Peak Region of Heavy Ion Beams.The radiation fields of skin were taken photo and performed biopsy. The contaneous tissues of radiation fields were stained by HE and examined histopatholo gical changes every seven days after irradiation. The results indicated that the cutaneous appearance reaction became more faster with radiation dosage rising and presented with swollen, melanin forming and so on after irradiated by the carbon ions at different dosage. The Pathological examination showed noticeable changes in histological and structural of experimental pigs skin, such as atrophy, vacuolation, denaturation and arranged irregularly in epithelial cells. Furthermore, the time for return to normality became longer with the increasing of radiation dosage. All indexes demonstrated correlation between the does and effects. It is concluded that the irradiation of heavy ion beams to normal skin is security when the radiation dose range is about 0—27 Gy.     

低能N+ 离子预处理对水稻UV-B辐射的当代损伤效应的影响

采用3种不同注量的N离子对供试材料进行了离子注入预处理, 再用10.08 kJ/(m2d1)增强UV-B辐射对其幼苗进行辐照试验, 测定了过氧化物酶（POD）活性、 过氧化物歧化酶（SOD）活性、 过氧化氢酶（CAT）活性、 丙二醛（MDA）含量、 还原型谷胱甘肽（GSH）含量和可溶性糖含量的变化。 研究结果表明: 经N离子注入预处理的水稻材料受到UV-B辐射时其POD和SOD活性明显升高, 并在注量为2.0×1017 ions/cm2时活性达到最强; CAT活性和MDA含量明显降低, GSH含量显著增加, 而可溶性糖的含量则变化程度很小。 从这些研究结果可以看出, 经过一定注量离子注入预处理的水稻材料当受到UV B辐射时能产生较强的抗氧化能力和防御能力,而且抗氧化系统优于碳水化合物系统而先于表达。 由此可见, 离子注入预处理对水稻UV-B辐射的生物学效应的影响相当明显。 The seedlings of rice (xindao18) were exposed to UV B (10.08 kJ/(m2d1 )) irradiation follo wing the pretreatment with three different implantation dosages of low energy N+ ions. Changes in the levels of the superoxide (POD),superoxide dismutase (SOD),catalase (CAT), malondialdehyde (MDA),glutathione (GSH) and soluble sugar were measured. The result showed that the UV-B irradiation on the seedlings of rice pretreated with low energy ions implantation could lead to increase activities in POD and SOD,and the maximum appeared on the dose of 2.0×1017 ions/cm2. Meanwhile,it made the content of GSH increased, and caused the activity of CAT and the content of MDA to be decreased. But there was no obvious change in soluble sugar. It was suggested that the rice pretreated by low energy ion implantation could enhance the antioxidation capacity and defensive ability when irradiated by UV-B, and the antioxidation system could be induced earlier than carbohydrate system. Therefore, the biological effects of UV-B irradiation on rice pretreated by low energy ion implantation were quite obvious.     

辐照诱变对小麦生理学效应的影响

以小麦品种小偃81为材料, 利用低能N+离子, 60Co-γ射线以及紫外线UV-C等为诱变源, 对种子胚部进行辐照处理。 研究其对小麦发芽势、 发芽率、 根长及苗高等生理指标的影响。 以辐照后的幼苗为材料研究了低能N+注入对过氧化氢酶（CAT）、 过氧化物酶（POD）、 超氧化物歧化酶（SOD）活性及还原型谷胱甘肽（GSH）含量的影响。 研究结果表明: N+注入后种子活力先升高后降低, 苗高在5×1017 N+/cm2时显著低于对照; 60Co和紫外线辐照对种子活力有较显著的影响, 辐照后的根长和苗高均显著低于对照; N+束辐照后的幼苗CAT酶活随剂量的变化规律性不明显, POD和SOD酶活总体趋势随剂量的增加先升高后降低, GSH含量随剂量的增大先降低后升高。 由此可知, 辐照诱变可以诱导小麦一系列的生理变化。60Co-γ射线和紫外线UV C对小麦胚根的伤害较大, 导致幼苗在后期大量死亡。N+注入对小麦的损伤效应较60Co和紫外线γ射线和紫外线UV-C小, 一定注量的N+注入处理可促进小麦生长。 In this paper, the biological effects,such as germination percentage, germination index and the length of seedlings and roots were investigated by using low energy N+, 60Co- γ rays and ultraviolet UV C to irradiate the embryos of wheat seeds （Xiaoyan81）. The anti oxidative enzyme system (CAT,POD, SOD) and GSH content were studied as well. The results show that the vitality of seed increased and then reduced with increasing the dosage of N+ ion implantation. The length of roots and seedlings were significantly higher than control. The seed vigor was significant effected after irradiated by 60Co-γ rays and ultraviolet UV-C, but the length of roots and seedlings were significantly lower than control. After N+ implantation, the changing pattern of CAT was not obviously. The enzymatic activity of POD and SOD were increased at low dosage and reduced at high dosage. The content of GSH was reduced and then raised. The results proved that the damage induced by γ ray and UV C to the radicle of wheat was severe that result in a large number of seedling died. However the damage induced by N+ implantation was lower than that by rays and UV C irradiation. Certain dosage of ion implantation can promote the growth of wheat.     

Effects of Pre-exposure of Mouse Pituitary with Low-dose ^60Co γ-ray on Male Reproductive Endocrine Capacity Induced by Subsequent High-dose Irradiation

To investigate the effects of pre-exposure of mouse pituitary with low-dose ^60Co γ-ray on male reproductive endocrine capacity induced by subsequent high-dose irradiation, the pituitary of the B6C3F1 hybrid strain male mice were irradiated with 0.05 Gy of ^60Co γ-ray as the pre-exposure dose (D1), and were then irradiated with 2 Gy of ^60Co γ-ray as challenging irradiation dose (D2) at 4 h after per-exposure. Pituitary gonadotroping hormones --follicle-stimulating hormone (FSH) and luterinzing hormone (LH), serum testosterone, testis weight and sperm count were measured at 35th day after irradiation.     

12C6+离子辐照小鼠Lewis肿瘤的研究

研究了HIRFL提供的12C6+离子辐照C57BL/6J小鼠右后腿移植的Lewis肿瘤的生长延迟和碳离子辐照对Lewis肿瘤小鼠寿命的延长.结果表明,碳离子照射的小鼠肿瘤生长体积明显地小于对照的体积.在剂量相同、分次数辐照越多时,肿瘤生长就越缓慢,肿瘤抑制就越高.在辐照分次数相同时,不同剂量对受照肿瘤生长体积未产生差异.在4Gy×3,8Gy×3和12Gy×2组3种辐照剂量下,小鼠寿命的P值小于0.05;可知小鼠的寿命延长具有统计学意义. Growth delay of the transplantable Lewis tumors growing in right hind legs of C(57) BL/6J mice and life prolongation of the mice with Lewis tumors were investigated after()~(12)C~(6+) ion radiation at HIRFL. The results show that growth volumes of the mouse tumors following carbon radiation are distinctly less than control during 21 days; the more fractions of radiation with same doses, the slower growth of tumors and the higher inhibition of tumors; different doses with the same fractions of radiation ...     

微束技术在放射生物学中的应用

微束装置可以为生命科学研究提供微米定位、剂量特定的电离辐射,在生物体内的电离辐射靶物质及其敏感度、靶物质的损伤及修复机制研究中具有独特的作用。概述了生物微束装置和实验技术的发展及其在低剂量辐射效应、旁观者效应、信号传导研究中的主要应用;介绍了中国科学院近代物理研究所（IMP）重离子微束装置,该装置可以提供能量7~ 80 MeV/u、传能线密度为30~ 3000 keV/μm的重离子微束,实现了活细胞辐照和在线观察、小鼠定位辐照的实验技术;利用IMP微束装置在重离子诱导旁效应实验、小鼠下丘脑重离子辐照效应和DNA损伤快速修复动态等方面取得了一些实验成果。The microbeam facility can provide micrometer scale localized and predefined ionizing radiation in the life science study, and the microbeam techniques play a unique role in determining the target substances of ionizing radiation, as well as in the study of radiation sensitivity, mechanisms of radiation damage response and repair. This paper summarizes the technical developments of biological microbeam facilities and their applications in the studies of low-dose radiation effect, bystander effect and cellular signaling. This paper also introduces the recent developments at the heavy-ion microbeam facility in the Institute of Modern Physics (IMP), which can provide heavy ion microbeam irradiation with energy of 7~80 MeV/u and LET of 30~3000 keV/μm. The facility can perform radiobiological irradiation and online investigation in living cells and mice, including bystander effect study, sleeping system influence after irradiation to mice hypothalamus and the recruitment dynamics of XRCC1 protein.     

钨辐射损伤随辐照剂量变化的重离子辐照模拟研究

采用重离子辐照模拟方法和正电子湮没寿命测量技术研究了钨辐射损伤随辐照剂量的变化。20,60和90dpa（每个原子的位移次数）辐照损伤水平的实验结果表明,辐照在钨中产生单空位、双空位、位错和空位团等缺陷;随辐照剂量的增大,单空位、双空位和位错浓度增加,空位团的尺度和浓度都随之增大。Radiation damage in W has been studied as a function of irradiation dose by heavy ion simulation and positron annihilation lifetime measurement. The experimental results of 20, 60 and 90 dpa irradiations illustrate that the mono-and di-vacancies, dislocations and vacancy clusters are produced by the irradiation. The concentrations of the mono-and di-vacancies and dislocations and both the concentration and size of the vacancy clusters or voids all increase with the increasing of the irradiation dose.     

12C6+离子辐照对4种农作物种子出苗率

以能量为80 MeV/u的12C6+离子为诱变源辐照油菜、 胡麻、 大葱和兵豆的干种子后, 研究了不同剂量处理对4种农作物M1和M2代种子出苗率及幼苗生长的影响。 实验结果表明: 重离子所导致的M1代生物学效应因不同的物种而表现出一定的差异, 适当剂量C离子辐照促进了油菜和胡麻M1代出苗率和幼苗的生长; 而不同剂量的C离子辐照抑制了大葱的出苗率和幼苗的生长; 兵豆3个剂量下的出苗率和对照相差很小, 但90 Gy辐照有利于其生长。 到了M2代, 4种作物辐照组的发芽率都低于各自的对照组; 30 Gy剂量下的油菜、 胡麻和兵豆长势最好; 大葱依然是对照的长势最好。 Crops of Brassica napus L., Linum usitatissmum L., Allium fistulosum L. and Lens culinaris Medic. were irradiated by 80 MeV/u 12C6+ ion beams with doses of 30, 90 and 180 Gy. The germination rates and heights of seedlings of M1 and M2 generation of these four plants were studied. The results indicated that germination rates and average heights of the B. napus and L. usitatissmum were improved by appropriate dose treatment, while great suppression was found in the irradiated groups of the A. fistulosum. As far as the L. Culinaris was concerned, little differences was observed on M1 germination rate, but the 90 Gy irradiation was favorable to growth of plant. The treatments with 30, 90 and 180 Gy were inferior to contrast one on M2 germination rate of the four species. Seedlings of M2 generation of the B. napus, L. sitatissmum and L. culinaris under 30 Gy grew better than the other groups, while the best performance of the A. fistulosum was shown by the control group.     

快重离子辐照金红石型TiO2的肿胀效应及化学蚀刻行为研究

二氧化钛（Titatium Dioxide,简称TiO₂）晶体在中能重离子辐照时表面会出现肿胀效应, 肿胀高度与入射离子的电子能损和辐照注量有关。 辐照后的TiO₂在一定条件下能够被氢氟酸溶液化学蚀刻,化学蚀刻的电子能损阈值为8.2keV/nm,未辐照TiO₂呈现几乎零蚀刻率。要达到饱和蚀刻深度,辐照离子的注量必须大于或等于1×1013ions/cm2。采用离子辐照的潜径迹理论分析研究了辐照损伤及对化学蚀刻的影响, 快重离子辐照结合化学蚀刻是制备TiO₂微结构的有效方法。 There appears volume swelling on the surface of the irradiated rutile TiO₂ crystal and the volume swelling is affected by the ion fluence and the electronic stopping power. To induce adequate irradiation damage for the chemical etching, the irradiation parameters must fulfill some requirement. There is minimum electronic stopping power for the chemical etching of the irradiated region in TiO₂ crystal, which is about 8. 2 keV/nm. If the ion fluence is below 1×1013ions/cm2, the saturated etching depth of the irradiated region in TiO₂crystal cannot be reached. The irradiation damage based on latent track formation frame and the theoretical linkage to the etching technique is investigated. It is hopeful to fabricate micro and nano scale structurce in rutile TiO₂ crystal by using the ion irradiation and chemical etching technique.      

模拟微重力条件下C离子辐射对小鼠生殖器官的影响

探究模拟微重力条件下不同剂量C离子辐射对雄性动物生殖器官的急性影响, 以期了解空间环境辐射所致机体生殖系统的损伤。采用小鼠尾部悬吊模型地面模拟微重力状态1周后, 利用重离子加速器提供的C离子辐照处理, 检测了生殖器官脏器系数及精子密度、组织形态变化、DNA损伤以及细胞凋亡各项指标。结果表明, 微重力和C离子辐射均能引起睾丸损伤, 且1 Gy单纯辐照组中损伤最为严重。此外发现, 模拟微重力能够在一定程度上降低辐射诱导的损伤, 其内在机制有待于进一步的研究。In this paper it was investigated that the effect of modeled microgravity on the acute injury induced by low doses of carbon ions in the male reproductive organs of mice, assessing the risk associated with the space environments. In our study, outbred Kunming mice were stimulated in microgravity by tail suspension, and then were irradiated with the low doses of carbon ions diliuered by HIRFL, and measured the testis and epididymis coefficient, sperm number of epididymis, histological alterations, DNA strand breaks and cell apoptosis. The results demonstrated that carbon ions and stimulated microgravity could induce the damage in the present study. Moreover, most serious injury all occurred in the irradiation group. In addition, it was also found that the damage of the carbon ion irradiation combined microgravity group were lower than those of the irradiation group, while the related mechanism needs the further investigation.     

荷能离子在C60薄膜中引起的辐照效应

用 Raman散射和 XPS技术分析了能量为几百 ke V到几百 Me V的多种离子在 C60 薄膜中引起的辐照效应.分析结果表明 ,在低能重离子辐照的 C60 薄膜中 ,其晶态向非晶态的转变过程是由核碰撞主导的.在快离子 (1 2 0 ke V的 H离子和171.2 Me V的 S离子 )辐照的情况下,电子能损起主导作用.发现在H离子辐照过程中,电子能损有明显的退火效应 ,致使 C60 由晶态向非晶态转变的过程中,经历了一个石墨化的中间过程;而在 S离子辐照的情况下 ,电子能损的破坏作用超过了退火效应 ,因此 ,在C₆₀ 由晶态向非晶态转变的过程中,无石墨化的中间过程.Irradiation effecs (mainly including transformation from crystalline into amorphous state) of C 60 films induced by 120 keV H, He, N, Ar, Fe and Mo ions, 240 keV and 360 keV Ar ions, and 171.2 MeV, 125.3 MeV and 75.8 MeV S ions were analysed by means of Raman scattering and XPS technique. The analysis results indicate that amorphization process in the cases of N, Ar, Fe and Mo ions irradiation is dominated by nuclear collision, but in the case of H ion irradiation, the process is...     

羧甲基-β-1,3-葡聚糖对人肝癌HepG2细胞的放射增敏作用

本研究旨在探讨羧甲基-β-1,3葡聚糖（CMG）对人肝癌HepG2细胞X射线或12C6+离子束辐射敏感性的影响。首先用CCK-8法检测CMG对HepG2细胞的生长抑制情况,得到半数抑制浓度（IC50）为120.6μg/mL。用浓度为0.1×IC50的CMG预处理HepG2细胞24 h,再给予2 Gy X射线或12C6+离子束辐照（CMG+辐照组）;CMG未处理组直接接受2 Gy X射线或12C6+离子束辐照（辐照组）。对比分析辐照组和CMG+辐照组细胞的克隆存活、DNA损伤、凋亡与周期分布、细胞内活性氧（ROS）水平。发现:与X射线辐照组相比,相同剂量的12C6+离子辐照组克隆存活率更小,DNA损伤和周期阻滞更加严重,细胞凋亡率和细胞内ROS水平也更高。与单独X射线或12C6+离子束辐照组相比,CMG+辐照组克隆存活率明显降低,细胞凋亡率随辐照后CMG作用时间的延长而明显增加,CMG使辐照后细胞内ROS维持在一个较高的水平,同时CMG明显加重了单独辐照诱导的DNA损伤和周期阻滞。结果表明,与X射线相比,HepG2细胞对相同剂量的12C6+离子辐射更敏感;CMG可增加HepG2细胞对X射线或12C6+离子辐射的敏感性;CMG可能通过增加受照HepG2细胞内的ROS水平,加剧辐照诱导的DNA损伤,促进辐射诱导细胞凋亡而起到辐射增敏作用。This study aims to investigate the effect of carboxymethy-β-1, 3-glucan (CMG) on the sensitivity of human hepatoma HepG2 cells to X-rays or 12C6+ ions irradiation. First, the inhibitory effect of CMG on the growth of HepG2 cells was detected by CCK-8 assay, and the half maximal inhibitory concentration (IC50) was 120.6 μg/mL. HepG2 cells were pretreated with CMG at a concentration of 0.1×IC50 for 24 h and then irradiated with 2 Gy X-ray or 12C6+ ion beams (CMG + irradiation group). CMG untreated group was directly irradiated by 2 Gy X-rays or 12C6+ ions beam (irradiation group). The clone survival, DNA damage, cell apoptosis, cell cycle distribution, and intracellular reactive oxygen species (ROS) levels in irradiation group and CMG + irradiation group were comparatively analyzed. The results showed that the clone survival rate was lower, DNA damage and cycle arrest were more serious, and the rate of apoptosis and intracellular ROS levels were higher in 12C6+ ions irradiation group than those in the same dose of X-rays irradiation group. Compared with X-rays or 12C6+ ions irradiation group, the clone survival rate of CMG + irradiation group was significantly decreased, and the apoptosis rate significantly increased with the prolongation of CMG treatment post-irradiation; CMG maintained intracellular ROS at a higher level after irradiation, CMG also significantly aggravated radiation-induced DNA damage and cycle arrest. These results indicated that HepG2 cells were more sensitive to 12C6+ ions radiation than those at the same dose of X-rays. CMG increased the sensitivity of HepG2 cells to X-rays or 12C6+ ions irradiation by increasing intracellular ROS level, exacerbating radiation-induced DNA damage and promoting radiation-induced apoptosis in irradiated HepG2 cells.     

Neutron irradiation effects on A1GaN//GaN high electron mobility transistors

AlGaN/GaN high electron mobility transistors(HEMTs) were exposed to 1 MeV neutron irradiation at a neutron fluence of 1 × 10 15 cm 2.The dc characteristics of the devices,such as the drain saturation current and the maximum transconductance,decreased after neutron irradiation.The gate leakage currents increased obviously after neutron irradiation.However,the rf characteristics,such as the cut-off frequency and the maximum frequency,were hardly affected by neutron irradiation.The AlGaN/GaN heterojunctions have been employed for the better understanding of the degradation mechanism.It is shown in the Hall measurements and capacitance-voltage tests that the mobility and concentration of two-dimensional electron gas(2DEG) decreased after neutron irradiation.There was no evidence of the full-width at half-maximum of X-ray diffraction(XRD) rocking curve changing after irradiation,so the dislocation was not influenced by neutron irradiation.It is concluded that the point defects induced in AlGaN and GaN by neutron irradiation are the dominant mechanisms responsible for performance degradations of AlGaN/GaN HEMT devices.     

TILLING技术的最新进展及其在辐射诱变育种中的应用前景

定向诱导基因组局部突变技术(Targeting Induced Local Lesions IN Genomes, 简称TILLINC)是一种全新的、高通量和低成本反向遗传学研究方法。近年来, 随着突变筛选技术的革新, TILLING技术平台日趋多元化, 使得TILLING技术的操作更为简单﹑快速, 并广泛应用于作物育种研究领域。简要介绍了TILLING技术平台的最新发展动态, 并初步探讨了将辐射诱变处理与TILLING高通量筛选相结合在诱变育种中的应用前景。To investigate the M1 biological effects of heavy ions irradiation on Lycopersicon esculentum Mill., its seeds were irradiated by 12C6+heavy ions (80 MeV/u) with the dosages of 30, 60, 90, 120 and 160 Gy respectively . The results showed that with doses increased gradually, germination rate and seedling rate of Lycopersicon esculentum Mill. were decreased, and the latter was lower than the former, mainly due to the inhibition of root growth. The irradiation increased the content of MDA and proline evidently, showing irradiation could damage biomembrane, and also decreased the activities of POD and SOD with distinct inhibition pattern. However, the low dose and high dose irradiation promoted APX activity, illustrating APX was induced to protect irradiation injury. In brief, exposure to 12C6+ heavy ions had obvious injury effects on the seeds of Lycopersicon esculentum Mill.. Heavy ions irradiation damaged biomembrane, inhibited activities of enzymes, and finally inhibited the growth of the first generation of these seeds.