马铃薯重离子辐射育种研究

在2000—2005年将杂交技术和重离子辐射相结合, 采用55 MeV／u的 40Ar17+离子对马铃薯杂交种子和微型薯进行了不同剂量的贯穿辐射或离子注入处理。 结果表明, 对马铃薯微型薯进行重离子辐射能显著提高块茎的产量。 而杂交技术和重离子辐射相结合是一种更高效的育种方式, 不仅能提高块茎的增产幅度, 还能改善其加工品质。 微型薯重离子辐射的最佳剂量为60 Gy, 杂交种子辐射的适宜剂量范围在60—120 Gy之间。 通过对辐射后代的多年选育, 获得了几个产量显著高于对照、 品质优良的马铃薯新品系。 The effect of 55 MeV／u 40Ar17+ irradiation with different doses on hybrid seeds and micro tubers of potatoes were studied from year 2000 to 2005. The results showed that the yields of potatoes irradiated by heavy ions grew significantly. This new mutation method combining cross breeding technique with heavy ion irradiation is more effective, which could not only increase the yield of potatoes, but also improve their quality. The optimal mutagenic dose was 60 Gy to micro tubers of potatoes, 60—120 Gy to hybrid seeds, respectively. Finally, several new lines which have higher yield and better qualities were obtained through multi generation screening from the offspring of irradiated potatoes.     

重离子加速器的次级辐射和天空反照

综合了近年来发表的重离子加速器次级辐射的估算方法和测量结果，给出了重离子加速器天空反照剂量分布的估算方法。     

基于细胞红外光谱预测乙酰化细胞的辐射敏感性

组蛋白乙酰化是表观遗传修饰的一种重要方式。肿瘤细胞的组蛋白大部分呈现低乙酰化状态,而组蛋白去乙酰化酶抑制剂（histone deacetylase inhibitor,HDACi）可以增加肿瘤细胞的乙酰化水平,诱导细胞周期阻滞及凋亡。曲古菌素A （trichostatin A,TSA）是组蛋白去乙酰化酶抑制剂的代表药物之一,能够提高肿瘤细胞组蛋白和非组蛋白的乙酰化水平。傅里叶变换红外（Fourier Transform Infrared,FTIR）光谱可以对无染色、无标记的生物样品进行无损检测,具有特征性明显、快速、分辨率高、重复性好等优点,已被广泛用于细胞的微观生物过程的研究。本文利用红外光谱技术结合免疫荧光技术的手段,研究TSA处理细胞后的乙酰化作用效果,发现红外光谱中甲基与亚甲基的伸缩振动强度之比能够表征细胞内的乙酰化水平变化,然后基于红外光谱的分析结果预测了乙酰化状态不同的细胞辐射敏感性的变化。结果表明,乙酰化细胞的辐射损伤效应可以通过甲基与亚甲基的伸缩振动强度之比进行评价,且该比值与细胞的辐射敏感性呈正相关,表明红外光谱技术可以辅助预测细胞的辐射敏感性,并进行细胞表观遗传学特征与辐射效应关系的研究。Histone acetylation is one of important epigenetic modifications, and histone in most of tumor cells shows low acetylation state. However, histone deacetylase inhibitor (HDACi) can correct abnormal acetylation status, induce cell cycle arrest and apoptosis. Trichostatin A (TSA) is one of the representatives of histone deacetylase inhibitors, which can inhibit histone deacetylase, increase the acetylation level of histone and nonhistone in cell. Fourier transform infrared (FTIR) spectroscopy is a powerful analytical tool which can detect nondestructively, quatitatively and quantitatively biological samples without bio-tagging and bio-labeling. FTIR spectroscopy technology has multiple advantages, including finger-print characteristics, rapid analysis, high resolution and good repeatability. Therefore, it has been widely used in the research of biological processes. This work applied FTIR spectroscopy to study the changes in cells treated with TSA, compared the acetylation level according to FTIR intensity ratio of methyl to methylene stretching vibration, and based on the FTIR analysis predicted the radiosensitivity of the cells with different acetylation levels. As a result, we have verified that the damage caused by radiation in acetylated cells can be evaluated by the ratio of methyl and methylene intensity which is positively correlated with cellular radiosensitivity. Therefore, this work demonstrates that FTIR spectroscopy can be useful for the prediction of radiosensitivity and may also open a door for the study of relationship between epigenetics and radiation bio-effects.     

重离子辐射权重因数与辐射损伤模型研究进展

以第五届国际重离子在生物医学中应用会议和第十届国际辐射研究大会为背景,讨论了重离子生物学效应因数、辐射损伤生物物理模型和物理参数的表征等问题． Based on the fifth workshop on heavy charged particles in biology and medicine and the 10 th international congress of radiation research,the biological effects of heavy ions and biophysical models of heavy ions are discussed.     

人肝癌SMMC-7721细胞对低剂量γ射线辐射超敏感性的研究

研究了人肝癌细胞SMMC-7721在低剂量γ射线照射下超敏感性和增强的辐射抗性响应。选用对数生长期细胞接受0—6 Gy不同剂量的^60Coγ射线的照射。利用流式细胞仪对细胞进行分选计数,并用克隆形成法检测细胞存活率。发现SMMC-7721细胞存在低剂量辐射超敏感性和增强的辐射抗性响应,即在0—0．3Gy之间细胞表现出单位剂量杀伤增强现象,在0．3—1Gy细胞表现一定的辐射抗性,在1Gy以上,细胞的存活符合线性平方模型。     

黑体辐射的温度敏感性

导出理想黑体辐射强度的相对变化与温度的相对变化之比的一般形式,并给出一般的计算方法和结果。由此讨论理想黑体光谱和带辐射强度的温度敏感特性及其对温度遥感等的意义。     

肿瘤细胞辐射敏感性相关蛋白研究进展

重点综述了Siah, HIF, NF-κB和DNA-PK蛋白与肿瘤细胞辐射敏感性关系的最新研究进展。 总结了中国科学院重离子束辐射生物医学重点实验室近几年来在BRCA1等肿瘤细胞辐射敏感性相关蛋白方面的研究工作。 简介了HLET C离子束治疗肿瘤的优点。 展望了此实验室借助兰州重离子研究装置(HIRFL)提供的C离子束研究肿瘤细胞辐射敏感性相关蛋白的目标和方向。 The research progress of tumor cells radiosensitivity associated protein Siah, HIF,NF-κB and DNA-PK are summarized and reviewed. The recent works of our laboratory on tumor cells radiosensitivity associated proteins such as BRCA1 are demonstrated. In the present review, we focused on discussions about the advantages of heavy ion therapy and its possible application in the research of radiosensitivity associated proteins. At the end of this review, we highlighted the future trend and potential targets in the study of tumor cells radiosensitivity associated proteins.     

低剂量辐射超敏感性研究进展

细胞低剂量辐射反应是目前国际上研究的热点。 介绍了哺乳动物细胞的低剂量反应——辐射超敏感性(HRS)和增强的辐射抗性(IRR), 即细胞在大约0.1 Gy时会出现单位剂量细胞杀伤增强现象, 随着剂量的升高, 细胞的IRR增强, 到1 Gy以上细胞存活符合线性平方模型。 评述了近年来国际上低剂量HRS领域的研究进展, 着重讨论了HRS/IRR可能的分子机理及辐射传能线密度与HRS/IRR的关系, 并对HRS/IRR在肿瘤临床放射治疗中的应用做了初步的探讨, 最后提出了该领域进一步研究的一些问题。At present, cell response to low dose radiation is attracting growing interests all over the world. Hyper radiosensitivity (HRS) and increased radioresistance (IRR) were introduced in this paper. This phenomenon means that an excess cell killing per unit dose appears at about 0.1 Gy (HRS) and then the cell radiation sensitivity increases with increasing dose (IRR). When the dose outstrips 1 Gy, the cell surviving fraction coincides with the value predicted by the commonly accepted linear quadratic (LQ) model. We further reviewed the progress to date in the study of low dose HRS, especially the possible molecular mechanisms underlying HRS/IRR and the relationship between HRS/IRR and linear energy transfer (LET). An initial insight into the clinical application of HRS/IRR in tumor radiotherapy was presented as well.Moreover, several topics concerning the HRS/IRR investigation, which deserved to be reinforced, were put forward.     

呼吸缺陷型酵母菌株的离子束辐射敏感性研究

选取一株由离子束辐照诱变获得的呼吸缺陷型酵母菌株，研究其在不同离子辐照剂量范围的辐射敏感性。结果发现，呼吸缺陷型酵母菌株因其线粒体及线粒体DNA发生突变，在离子束辐照时，在低剂量区域表现出较高辐射敏感性，在高剂量区则表现出对于辐射的抗性。     

重离子束注入与生物体的相互作用及遗传诱变的分子机制

低能重离子与生物体系相互作用及其生物诱变效应的应用研究在我国率先兴起， 并在应用中取得了很大的成就。 介绍了重离子注入与生物有机体的相互作用及其主要的生物学效应， 包括细胞染色体水平、 生理生化效应， 以及对DNA损伤修复、 基因表达、 甲基化修饰的影响。 总结了离子注入诱变的分子遗传学机理的相关研究。 同时分析、 比较讨论了高能与低能离子、 离子束与射线的生物学效应的异同。 提出了离子注入今后的研究方向， 特别指出了离子注入对生物基因表达影响研究的重要性。 As a new mutagenesis technique, low energy heavy ion implantation started in China for the study of interaction effect between incident ions and organism, and great achievements have been obtained in crop breeding. The article reviewed the main biological effects induced by heavy ion implantation, including physiology, biochemistry and genetics effects, on levels of cell and chromosome, gene expression, DNA methylation, DNA damage and reparation etc. It compared the differences in mutagenesis for organism by high energy and low energy ion implantation, as well as γ ray radiaiton. Future investigation topics were proposed, the emphasis of researches in future was pointed out, i.e., the molecular mechanism and effects of gene differential expression of organism treated by ion implantation.     

核碎裂在离子与生物分子相互作用中的效应

讨论了重离子辐照生物中核碎裂效应,给出与此相关的核碎裂研究现状和进展。The effect of nuclear fragmentation discussed. The status and perspectives of this data. in the topic interactions of heavy ions with biological are presented based On calculations and molecules is experimental.     

质子与重离子肿瘤治疗的进展

简要介绍了质子与重离子肿瘤治疗的历史和现状.现在,全世界有质子治疗中心23家,治疗肿瘤患者总数为39 612人;重离子治疗设备有3台,治疗肿瘤患者4 511人（包括He离子治疗2 054例病人）.     

离子与生物分子相互作用的微观动力学理论

对X射线、γ射线、电子、中子、质子和重离子等对生物体系的辐照研究现状进行了评论。重离子辐照中特有的倒转深度剂量分布,即Bragg峰,成为放射治疗的理想工具。通过对重离子辐照生物组织物理过程的分析,提出了重离子与生物分子相互作用的三步物理过程,即核相互作用导致的核碎裂、库仑相互作用的电子激发和生物分子在周围环境相互作用下的弛豫,最终导致生物分子新结构的形成。由于物理过程是后期辐照化学过程、生物过程的基础,因此建立描述离子与生物分子相互作用物理过程的微观动力学理论是十分迫切的。The status of studying biology system therapy with X-rays, γ-rays, neutron, proton, and heavy ions is reviewed. The depth dose profile, called Bragg profile, makes heavy ion an ideal tool for radiotherapy. The physical process of therapy with heavy ions is analyzed and a 3-step interaction processes of heavy ions with biomolecules is proposed, that is, nuclear fragmentation in nuclear interaction, electron excitation in Coulomb interaction, and the biomolecules relaxation in surroundings, finally leads to a new structure of biomolecule. Since this physical process is the base of the following chemical process and biological process, a dynamical microscopic approach is strongly demanded to be built.     

用CR-39对空间重离子的鉴别模型

根据重离子在CR39中能量损失率公式,建立了一个鉴别空间重离子的数学模型LET=cZdRb.通过传能线密度与剩余射程之间的关系曲线,获得了该模型的系数.在实验中发现的CR39蚀刻率与离子有限传能线密度的关系VT=A·(REL)BE<350,被用来与该数学模型相关联,并得到一等式R=A0.0455Z3.18V–1T.最终,借助于标定实验得到了离子鉴别公式Z3.18=64541.08+2.53(dR/dV–1T).     

共振相干激发的最新实验研究(英文)

在满足沟道效应条件下 ,高能离子在穿过晶体时 ,离子穿过的是周期性的原子序列或者有序平面阵列 .在入射离子的坐标系中 ,离子感受到一种振动场的作用 .如果与此振动频率相关的能量与离子的电子态跃迁能量相匹配 ,则离子有可能被激发 ,这种现象就称为共振相干激发 (RCE) .1998年 ,成功地观测到了类氢Ar17+ 离子以相对论速度穿过Si晶体时 ,其 1s电子到n =2态的共振激发 .此后 ,有关出射离子电荷态分布以及退激X射线谱的实验研究取得了很大进展 ,近期的实验研究还观测到了类氢离子的 1s电子到更高电子态 (n =3,4 ,5 )的RCE和更重离子的RCE ,以及类氦离子的RCE .这些实验结果有助于详细研究这种共振现象 .实验结果表明 ,RCE也能够作为研究高精度原子谱学的一种潜在的工具 . When energetic ions penetrate into a crystal in a channeling condition, they travel across a periodic array of the atomic strings or ordered planes. These ions feel an oscillating field in the projectile frame. If the energy corresponding to this frequency matches with the transition energy of the electronic states of the ions, the ions have a chance to be excited. It is called Resonant Coherent Excitation (RCE). We have succeeded in observing resonant excitation of 1s electron to the n=2 states in H-like...     

高压条件下高能重离子辐照材料研究进展

高能重离子辐照处于高压条件下材料的研究,是随着高能重离子加速器技术的快速发展而出现的一个新的研究领域, 研究结果涉及材料学、 地质学、地质年代学、核废料处理学等学科。简要介绍最近几年国内外在高能重离子辐照高压条件下材料研究领域的研究现状及已取得的结果,并对未来在兰州重离子加速器冷却储存环（HIRFL CSR）上开展相关研究工作的前景作了展望。With development of high energy heavy ion accelerator, it is possible to perform heavy ion irradiation experiments of pressurized materials in diamond anvil cells(DACs). It is a new research field. The results expected from irradiation experiments under high pressure will have impacts on several scientific fields such as materials science,geo science,geochronology,and nuclear waste storage. In this paper, some of recent works in this field are presented and reviewed. Furthermore,the research plan of materials under high pressure based on HIRFL-CSR is introduced.     

快重离子在固体材料中的强电子激发效应

简要介绍了快重离子在固体材料中强电子激发效应的基本特点、研究现状和在HIRFL上获得的部分实验结果,并对今后的研究工作进行了展望。In this paper the outline of intense electronic excitation effects in solid materials induced by swift heavy ions and international research status were briefly reviewed. Few examples of experimental results obtained on HIRFL were presented. And also the developing tendency in the field was looked into the future.     

基于HIRFL-CSR测量丰中子重核质量的建议

丰中子重核区有大量原子核质量未知,迫切需要实验测量。我们建议,利用兰州重离子加速器研究装置HIRFL-CSR上的等时性质谱术,高精度测量204Pt等丰中子重核的质量。CSR质量测量实验中,在目标核产额尽可能高的前提下,需要每次注入都有多个离子同时储存到实验环CSRe中,才能针对逐次注入修正磁场晃动的影响,得到高精度测量结果。但在丰中子核区,当目标核产生截面非常低时,每次注入能储存到环中的离子数目太少。为了解决这个问题,我们提出了一种"混合厚度靶"的方法,在不明显改变目标核产额的情况下,显著增加同时储存在CSRe中的离子数,满足实验要求。模拟计算表明,在CSRe测量丰中子重核质量是可行的,并推荐了实验的设置。     

利用HIRFL高能重离子束的核能材料辐照损伤研究

载能重离子与高能中子在材料中能够产生相似的级联碰撞损伤,加之重离子具有大的离位损伤截面和在材料样品中低的感生放射性,载能重离子束成为模拟先进核能装置内部结构材料辐照损伤的重要手段。HIRFL能区的重离子在结构材料中的射程一般远大于晶粒尺寸,因此能够产生材料体损伤,借助小样品技术可以获得材料力学性能变化（尤其辐照脆化）的有用信息,为探讨材料辐照损伤微结构和宏观力学性能变化的关联提供了重要条件。本文简要介绍了近年来我们基于HIRFL高能离子束开展的聚变堆候选材料辐照损伤的研究,包括低活化钢的辐照脆化行为、氧化物弥散强化（ODS）铁素体钢的结构优化对于抗辐照性能的影响、不同载能粒子辐照条件下铁素体/马氏体钢的辐照肿胀数据的关联,以及高能重离子辐照的钨材料中氢同位素的滞留行为。研究表明,结合特殊的测试技术及数据分析方法,高能重离子可作为核能结构材料辐照损伤研究及评估的有效手段。Because of the similarity in cascade damage structure in materials produced by energetic heavy ions and by fast neutrons, and the high displacement rate and low induced radioactivity of samples by heavy ions, heavy ion beam becomes an important tool to simulate radiation damage by energetic neutrons in materials in advanced nuclear energy systems. The ranges of heavy ions provided by HIRFL (Heavy Ion Research Facility in Lanzhou) are generally much larger than the mean dimensions of grains in alloys candidate to advanced nuclear reactors, and is capable of producing radiation damage in bulk scale. It therefore makes possible the evaluation of change of mechanical properties including the radiation induced embrittlement from the irradiated specimens by using miniaturized specimen techniques. In the present paper, we provide an introduction of our recent studies of radiation damage of materials candidate to future fusion reactors by utilizing heavy ion beams in HIRFL.The studies include issues as follows:ductility loss of RAFM steels causes by high-energy Ne ions, impact of oxide dispersoids on the radiation resistance of ODS ferritic steels, correlation of void swelling of ferritic/martensitic steels under different particle irradiation, and behavior of deuterium retention in tungsten under irradiation with high-energy heavy ions. The results show that high-energy heavy ions can be used as a tool to efficiently investigate or evaluate radiation damage in structure materials if combined with some special test techniques and data analysis.