辐射免疫学研究进展

近年来辐射免疫学作为一门新兴学科进展迅速，特别是在低剂量辐射兴奋效应研究方面有较大发展，同时重离子辐射生物效应的研究在治疗肿瘤方面也有了明显进步。综述了国内、外辐射免疫学的现况，其目的是寻找出一种综合疗法，从而达到既可以较好的治疗肿瘤，又对病人损伤较小的目的。Radiation immunology as a new subject has made a great progress in recent years, especially in the radiation hormesis. At the same time, the research of radiobiological effect on heavy ions has played an important role in the cancer therapy, especially on the radiation immunology of heavy ions in the outer space. In this review, we summaried the status and development of radiation-immunology, and try to find out some better ways which can increase efficient killing on tumours, but reduce the damages on normal tissues.     

Irradiation effects of graphene and thin layer graphite induced by swift heavy ions

Graphene and thin graphite films deposited on SiO2/Si are irradiated by swift heavy ions(209Bi, 9.5 Me V/u) with the fluences in a range of 1011ions/cm2–1012ions/cm2 at room temperature. Both pristine and irradiated samples are investigated by Raman spectroscopy. For pristine graphite films, the "blue shift" of 2D bond and the "red shift" of G bond with the decrease of thickness are found in the Raman spectra. For both irradiated graphene and thin graphite films, the disorder-induced D peak and D' peak are detected at the fluence above a threshold Φth. The thinner the film, the lower the Φthis. In this work, the graphite films thicker than 60 nm reveal defect free via the absence of a D bond signal under the swift heavy ion irradiation till the fluence of 2.6 × 1012ions/cm2. For graphite films thinner than 6 nm, the area ratios between D peak and G peak increase sharply with reducing film thickness. It concludes that it is much easier to induce defects in thinner films than in thicker ones by swift heavy ions. The intensities of the D peak and D' peak increase with increasing ion fluence, which predicts the continuous impacting of swift heavy ions can lead to the increasing of defects in samples. Different defect types are detected in graphite films of different thickness values. The main defect types are discussed via the various intensity ratios between the D peak and D' peak(HD/HD).     

Pro duction of Exotic Nuclei in Low-Energy Multi-Nucleon Transfer Reactions

Multinucleon transfer processes in low-energy heavy ion collisions open a new field of research in nuclear physics, namely, production and studying properties of heavy neutron rich nuclei. This not-yet-explored area of the nuclear map is extremely important for understanding the astrophysical nucleosynthesis and the origin of heavy elements. Beams of very heavy U-like ions are needed to produce new long-living isotopes of transfermium and superheavy elements located very close to the island of stability.The calculated cross sections are high enough to perform the experiments at available accelerators.Beams of medium-mass ions (such as 136Xe, 192Os, 198Pt) can be used for the production of neutron rich nuclei located along the neutron closed shell N = 126 (the last waiting point) having the largest impact on the astrophysical r-process. The Low-energy multinucleon transfer reactions is a very efficient tool also for the production and spectroscopic study of light exotic nuclei. The corresponding cross sections are 2 or 3 orders of magnitude larger as compared with high energy fragmentation reactions.     

Conditions for the Observation of Two Ion-Acoustic Waves via Thomson Scattering

Observationof two ion-acoustic waves via Thomson scattering can provide precise measurements of plasma parameters. The conditions for the observation of two ion-acoustic modes in a two-ion plasma are discussed.The ratio of electron temperature Te to ion temperature Ti is the critical parameter for the presence of two ion-acoustic modes, which should be in the range of 4/ZL ≤ Te/Ti ≤ 2AH/ZHAL, where ZL,H are the charge states of light and heavy ions, and AL,H are the atomic numbers of light and heavy ions, respectively. As the temperature ratio varies in this range, the concentration of heavy ions must increase with the ratio Te/Ti so that the two ion-acoustic modes can have the same fluctuation levels.     

Effects of Charge in Heavy Ions on Solitary Kinetic Alfvén Waves in Double-Ion Plasmas

After the charge of heavy ions is considered, a Sagdeev equation is obtained for the solitary kinetic lfvén waves (SKAWs) in a low-β (m_e/m_p « β « or m_p/m_e » α » 1), three-component (electrons, protons, and highly charged heavy ions) plasma. Numerical results show that the charge number q of heavy ions can cause the width of the solitary structure to decrease, but increase for the maximum of electron density n_em≤ 1.2 and the initial abundance of heavy ions C_b0 ≤ 0.1. The parallel phase speed of the waves increases with larger q.     

Comparison study of the charge density distribution induced by heavy ions and pulsed lasers in silicon

Heavy ions and pulsed lasers are important means to simulate the ionization damage effects on semiconductor materials. The analytic solution of high-energy heavy ion energy loss in silicon has been obtained using the Bethe-Bloch formula and the Kobetich-Katz theory, and some ionization damage parameters of Fe ions in silicon, such as the track structure and ionized charge density distribution, have been calculated and analyzed according to the theoretical calculation results. Using the Gaussian function and Beer＇s law, the parameters of the track structure and charge density distribution induced by a pulsed laser in silicon have also been calculated and compared with those of Fe ions in silicon, which provides a theoretical basis for ionization damage effect modeling.     

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.     

The atomic structure and the properties of ununbium (<Emphasis Type="Italic">Z</Emphasis> = 112) and Mercury (<Emphasis Type="Italic">Z</Emphasis> = 80)

A super heavy element Uub (Z = 112) has been studied theoretically in conjunction with rela-tivistic effects and the effects of electron correlations. The atomic structure and the oscillator strengths of low-lying levels have been calculated, and the ground states have also been determined for the singly and doubly charged ions. The influence of relativity and correlation effects to the atomic properties of such a super heavy element has been investigated in detail. The results have been compared with the properties of an element Hg. Two energy levels at wave numbers 64470 and 94392 are suggested to be of good candidates for experimental observations.     

Atomic Force Microscopy Measurement of DNA Fragment Induced by Heavy Ions

Choosing ^7 Li and ^12C heavy ions respectively with different linear energy transfer (LET) values, purified plasmid DNA samples in aqueous solution are irradiated with various doses. The atomic force microscopy (AFM) is used for analysis of DNA fragments induced by both the kinds of heavy ions. There is a change of three forms of DNA, i.e. supercoiled, open circular and linear form, as the dose is observed. The distribution function of DNA fragment length is obtained for the first time and fitted with the Tsallis entropy statistical theory. The result indicates that AFM is a useful tool for analysis of the short fragment of DNA, high-LET heavy ion radiation induces DNA double strand breaks (DSBs) more effectively, and the distributions of the DSBs are more local and dense in comparison with low-LET radiation.     

Associated Production of a Photon with Dark Matter Pair at the ILC within the Littlest Higgs Model with T-parity

Within the context of the Littlest Higgs model with T -parity, the heavy photon (AH) is supposed to be an ideal dark matter (DM) candidate. One direct proof of validity of the model is to produce the heavy photon at collider. In this paper, we investigate the associated production of a photon with heavy photon pair at the planned international e+e- linear collider (ILC),i.e., e+e-→ AHAHγ and show the distributions of the transverse momenta of the photon. The numerical results indicate that the heavy photon production rate could reach several fb at the low mass parameter space and the characteristic signal is a single high energetic photon and missing energy, carried by the heavy photons. All in all, it can be a good chance to observe the heavy photon via this process with the high yearly luminosity of the ILC.     

p73变异体研究现状及其在肿瘤放疗中的应用前景

p73基因是p53抑癌基因家族的新成员。 p73有两组蛋白异构体: TAp73和DNp73。 TAp73具有诱导细胞周期停滞和细胞凋亡的能力, 而DNp73却有与之相反的能力, 具有肿瘤促进作用。 对p73基因两面性的特点及研究进展作一综述。 最后结合重离子治疗肿瘤, 探讨了p73联合重离子治疗的新思路。 p73 was the first identified homologue of the tumor suppressor gene, p53. p73 has two groups of protein isoforms: TAp73 and DNp73. TAp73 can induce cell cycle arrest, resulting in the ability of apoptosis, however DNp73 has antagonistic property of a tumor promoting effect. In this paper, the dual roles of p73 gene and its research progress was reviewed. Finally, combined with heavy ion treatment of tumor, we explored some new ideas of p73 heavy ion joint therapy.     

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）.     

HIRFL的辐照治癌终端

为了进行重离子束流的肿瘤治疗和生物效应的研究,HIRFL正在建造一个辐照治癌终端.主要介绍了该终端的束流制备方法和束流线的布局、性能参数和束流光学设计计算结果. A new experimental terminal is being constructed at HIRFL for research program of proton and heavy ion therapies and irradiation effects of living things . The beam preparation method and the layout, performance and beam optics calculation of the beam line are presented.     

Radiobiological response of human hepatoma and normal liver cells exposed to carbon ions generated by Heavy Ion Research Facility in Lanzhou

Human hepatoma and normal liver cells were irradiated with ¹²C⁶⁺ ion beams (LET = 96.05 keV/μm) and γ-rays at Heavy Ion Research Facility in Lanzhou (HIRFL). The chromatid breaks and break types were detected using the premature chromosome condensation technique. Our experimental results showed that chromatid breaks seem to have a good relation with ¹²C⁶⁺ absorbed dose and ¹²C⁶⁺ are more effective to induce chromatid breaks as compared to the γ-rays. For ¹²C⁶⁺ ion irradiation the major break was isochromatid break, while chromatid breaks were dominant for γ-ray irradiation. We also observed that the Relative Biology Effectiveness (RBE) of ¹²C⁶⁺ ion is about 2.5 times higher than that of γ-rays.     

重离子束治癌中深度剂量分布优化

针对兰州重离子研究装置所加速的120MeV/u ¹²C离子束,利用模拟退火优化算法进行了Bragg峰展宽的剂量优化.取相同的展宽区域(30mm),4种不同的步长(2,1,0.5,0.25mm)进行Bragg峰展宽模拟.对所得到的剂量平均值,均方差,入射口剂量,峰坪比等优化结果的参数做了比较.讨论了重离子束治癌临床上最优的Bragg峰展宽模型的选取.     

中能重离子剂量深度曲线计算

重离子束应用在治疗肿瘤上具有优越的深度剂量分布特点.发展精确计算剂量的物理模型理论成为其应用的关键,为此,首先从生物细胞的化学组成成分、放射生物学的特点和物理剂量计算的要求对理论计算的介质进行了选择.利用现有计算核反应部分截面和修正的总截面经验公式,同时考虑了不同影响理论计算的因素,提出了中能重离子理论计算深度剂量分布的方法,其计算结果与实验数据符合很好,可应用在重离子治癌和生物学效应研究中.     

Penning阱中离子谱的优化

根据Penning阱存储离子的探测原理,系统分析了阱内离子信号及信号本身的噪声、实验仪器及探测电路的噪声干扰,采用适当的品质因数和电子束流,得到较高信噪比和分辨率的离子谱。为深入开展Hn^＋（n≥3）对离子的形成机制、离子与中性气体原子或分子碰撞过程等问题的研究创造了更好的条件。     

Paul阱中离子运动及稳定性分析

Paul离子阱由于没有外加磁场所引起的塞曼效应的影响,已成为离子存储及研究离子的重要装置.根据在实验中所采用的Paul离子阱结构及电场分布特点,列出阱内离子运动方程并进行求解,对其中各种运动进行分析,同时还分析了离子存储稳定性.最后对所作的研究进行总结,得到如下结论:阱中离子的运动为谐振运动、基频微运动和高阶微振动.     

苦荞茶对水溶液中铅、铜、镉、锌、铬离子吸附作用的研究

生物吸附法以其材料易得、吸附效果好、易解析、环境友好等优点而被广泛的应用于水溶液中低浓度重金属离子的吸附去除。光谱学显示苦荞茶含有多种基团且表面结构疏松，对水溶液中金属离子具有一定吸附潜力。探讨苦荞茶对水溶液中铅、铜、镉、锌、铬离子吸附作用光谱分析。采用扫描电镜(SEM)、能谱分析(EDS)、傅里叶红外光谱(FTIR)对苦荞茶吸附铅、铜、镉、锌、铬前后进行表征，初步解析苦荞茶对水溶液中铅、铜、镉、锌、铬离子吸附作用。使用等温吸附方程(Langmuir，Freundlich，Temkin和Dubinin-Radushkevich) 与动力学方程(准一级、准二级和颗粒内扩散)来评价苦荞茶对水溶液中铅、铜、镉、锌、铬离子吸附方式及行为。响应面法是一种数学建模的优化方法，能回归拟合各因素与实验结果之间的函数关系，从而确定实验因素及其交互作用对目标值的影响程度。采用响应面法考察目标离子初始浓度(A)、吸附剂颗粒大小(B)、吸附剂投加量(C)和吸附时间(D)四个因素对苦荞茶吸附水溶液中铅、铜、镉、锌、铬离子能力的影响作用及程度。等温吸附方程显示，苦荞茶对水溶液中铅、铜、镉、锌、铬离子吸附方式以多层吸附方式为主，伴有其他吸附类型，苦荞茶对目标重金属吸附量排序为：铅＞镉＞铜＞锌＞铬，即为：30.67＞16.18＞13.85＞10.81＞8.43 mg·g-1。动力学方程与苦荞茶扫描电镜(SEM)提示，苦荞茶对水溶液中铅、铜、镉、锌、铬离子吸附过程符合准二级动力学，其吸附速率由液膜扩散和颗粒内扩散作用共同控制，而且苦荞茶表面疏松的结构出现表面趋于平滑，孔洞出现融合的现象。能谱分析(EDS)与傅里叶红外光谱(FTIR)证实了水溶液中铅、铜、镉、锌、铬离子被苦荞茶所吸附，苦荞茶中-OH，-CH₂，-CH₃，CO， -NH，-C-O，CH基团参与水溶液中铅、铜、镉、锌、镉离子结合吸附作用并存在同一类型的基团吸附结合不同目标离子的现象。响应面法构建考察因素影响苦荞茶对水溶液中铅、铜、镉、锌、铬离子去除能力模型，其调整回归决定系数分别为Adj R2_Pb=97.10，Adj R2_Cu=98.44，Adj R2_Cd=94.55，Adj R2_Zn=92.71，Adj R2_Cr=97.02，说明非线性模型可用来评价考察因素对苦荞茶吸附水溶液中铅、铜、镉、锌、铬离子影响作用。响应面法分析表明，考察因素[离子初始浓度(A)、吸附剂颗粒大小(B)、吸附剂投加量(C)和吸附时间(D)]对铅、铜、镉、锌、铬离子去除率影响作用大小排序为：铅离子(A＞D＞B＞C)、铜离子(A＞C＞D＞B)、镉离子(A＞B＞C＞D)、锌离子(B＞C＞A＞D)、铬离子(C＞B＞D＞A)。研究结果说明，苦荞茶对水溶液中铅、铜、镉、锌、铬离子具有良好的吸附作用，为苦荞茶拓展新的应用途径提供了参考依据。     

非对称离子门控制方法和对离子迁移谱分辨率的改善

为了改进离子门的驱动方式,简化离子门驱动电源设计和提高离子迁移谱分辨率,通过增加一组电阻实现离子门两端的不对称供电,再对低电压端的电压进行控制实现离子门功能。分析了该方式下的两种情况对迁移管内的电场、离子迁移谱的分辨率和信噪比的影响。借助SIMION7.0对离子门两边的电场分布进行了模拟和比较,并应用数值化拉普拉斯方程的方法计算了迁移管轴线的电场数据。实验证明：相比常规迁移谱的离子门浮地驱动电源,这种驱动方法成本低,离子门电源的设计简单,能够明显提高离子迁移谱的分辨率。该方法能够应用于离子迁移谱的测量仪器或实验设备。