重离子束~(12)C~(6+)照射人离体血建立淋巴细胞微核的剂量-效应曲线

目的　研究建立重离子束1 2 C6 + 照射人离体血诱发淋巴细胞微核的剂量 效应曲线。方法　用地面加速器产生的重离子1 2 C6 + (平均LET为 36 70keV μm) ,不同吸收剂量、不同吸收剂量率照射离体人血 ,用CB微核法观察双核淋巴细胞中的微核。结果　在 0～ 6Gy吸收剂量范围内 ,淋巴细胞微核率随吸收剂量的增加而增加 ,拟合的最佳方程为Y =6 6 5 0 9×D0 .85。结论　1 2 C6 + 照射人离体血诱发淋巴细胞微核在 0～ 6Gy吸收剂量范围内呈幂函数关系。

荷能~(12)C离子对抗癌药物VP_(16)的效应

本文采用 5 5MeV u1 2 C6+离子注入鬼臼衍生物之一———鬼臼乙叉甙 (VP1 6) ,针对它在临床上的缺点 ,试图利用重离子的能量转移和质量沉积对其分子组成与结构进行改造 ,以增加它的水溶性 ,提高疗效 ,减小毒性。实验样品在离子注入后 ,先后进行了紫外 (UV)、高效液相 (HPLC)和液质联用 (HPLC -MS)分析 ,并对癌细胞K5 6 2和HL- 6 0分别进行了药理活性测定 ,取得了初步结果和进行了简短讨论。

DNA���细胞对重离子辐照诱导DNA���链断裂的敏感性比较

用倒转脉冲场凝胶电泳 (PIGE)比较研究了 50 Me V/u1 2 C6 +辐照小鼠 B1 6黑色素瘤细胞及其脱蛋白 DNA���子 ,从而诱导 DNA���链断裂 (DSB)的辐射敏感性。结果表明 ,不论辐照脱蛋白 DNA���是辐照完整细胞 ,诱导的 DNA���段释放百分比 (PR)都随着剂量的增加而增加 ,在超过 4 0 Gy后 ,PR趋向一个近似相同的准阈值～ 81 %。辐照脱蛋白 DNA���导的 DSB产额为 0 .4 0 DSBs/1 0 0 Mbp/Gy,辐照完整细胞诱导的 DSB产额约为 0 .1 9DSBs/1 0 0 Mbp/Gy。说明脱蛋白 DNA���子比完整细胞对重离子辐照要敏感

重离子辐照乙酰甲喹对生物活性的影响

本文研究了重离子12 C6+、16O8+对乙酰甲喹 (MAQO)的作用。结果表明 :重离子16O8+可使其结构改变 1 4%以上。 3 82nm、2 62nm、2 40nm特征峰随其含量的下降而变低平 ,并生成多种辐射产物 ,辐照后其抗菌作用明显增强 ,而毒性基本未发生变化

重离子辐照苯并呋咱N-氧化物对其抗菌作用的影响

用重离子 12 C6+ ,16O8+辐照苯并呋咱 N-氧化物 ,结果表明 ,重离子 16C8+可使其结构改变10 %以上 ,382 nm、2 6 2 nm、2 4 0 nm特征峰随其含量的下降而变低平 ,并生成多种辐射产物 ,辐射后抗菌作用明显增强

An outlook of heavy ion driven plasma research at IMP-Lanzhou

Since the successful completion of the cooling storage ring (CSR) project in China at the end of 2007, high qualitative heavy ion beams with energy ranging from keV to GeV/u have been available at the Heavy Ion Research Facility at Lanzhou (HIRFL). More than 10(9) 1 GeVlu C6+ particles or 10(8) 235 MeV/u Xe particles can be stored in the CSR main-ring and extracted within hundred nano-seconds during the test running, the beam parameters will be improved in the coming years so that high energy density (HED) conditions could be achieved and investigated there. Recent scientific results from the experiments relevant to plasma research on HIRFL are summarized. Dense plasma research with intense heavy ion beams of CSR is proposed here.

Injection system design for a hadron therapy synchrotron

A synchrotron is designed for tumour therapy with C6+ ions or proton. Its injector is a cyclotron, which delivers C5+ or H-2(+) ions to the synchrotron. After comparing the methods of the single-turn injection, the multi-turn injection and the stripping injection, this paper chooses the stripping injection method. In addition, the concept design of the injection system is presented, in which the synchrotron lattice is optimized.

Slow isocharged sequence ions with helium collisions: Projectile core dependence

The collisions of the isocharged sequence ions of q=6 (C6+, N6+, O6+, F6+, Ne6+, Ar6+, and Ca6+), q=7 (F7+, Ne7+, S7+, Ar7+, and Ca7+), q=8 (F8+, Ne8+, Ar8+, and Ca8+), q=9 (F9+, Ne9+, Si9+, S9+, Ar9+, and Ca9+) and q=11 (Si11+, Ar11+, and Ca11+) with helium at the same velocities were investigated. The cross-section ratios of the double-electron transfer (DET) to the single-electron capture (SEC) sigma(DET)/sigma(SEC) and the true double-electron capture (TDC) to the double-electron transfer sigma(TDC)/sigma(DET) were measured. It shows that for different ions in an isocharged sequence, the experimental cross-section ratio sigma(DET)/sigma(SEC) varies by a factor of 3. The results confirm that the projectile core is another dominant factor besides the charge state and the collision velocity in slow (0.35-0.49v(0); v(0) denotes the Bohr velocity) highly charged ions (HCIs) with helium collisions. The experimental cross-section ratio sigma(DET)/sigma(SEC) is compared with the extended classical over-barrier model (ECBM) [A. Barany , Nucl. Instrum. Methods Phys. Res. B 9, 397 (1985)], the molecular Coulombic barrier model (MCBM) [A. Niehaus, J. Phys. B 19, 2925 (1986)], and the semiempirical scaling laws (SSL) [N. Selberg , Phys. Rev. A 54, 4127 (1996)]. It also shows that the projectile core properties affect the initial capture probabilities as well as the subsequent relaxation of the projectiles. The experimental cross-section ratio sigma(TDC)/sigma(DET) for those lower isocharged sequences is dramatically affected by the projectile core structure, while for those sufficiently highly isocharged sequences, the autoionization always dominates, hence the cross-section ratio sigma(TDC)/sigma(DET) is always small.

Two Electron Transfer and Stabilization in Slow O6+ and Rare-Gas Collisions

The stabilization ratios.. for double-electron transfer, i.e., the cross section ratios of true double capture to total double-electron transfer, are measured in O6++ He, Ne and Ar collisions at 6 keV/u. A high.. value about 68% is obtained for the He target, while for the Ar target, the.. value is only 8%. The high R value for the He target is due to the significant direct population of the (2l, nl') configurations with high n For the Ar target, the (quasi) symmetric configurations (3l, nl') lead to the much lower.. value. Neglecting the core effects, the O6+ ion can be taken as a bare ion C6+ except the occupied 1s shell, and then the measured R values are compared with previous experimental results of C6+ projectile ions at similar impact velocity. It yields good agreement with the Ne and Ar target, while the occupied 1s shell for the O6++ He system results in a higher R value than that in C6++He collisions.

Drift distance survey in direct plasma injection scheme for high current beam production

In a laser ion source, plasma drift distance is one of the most important design parameters. Ion current density and beam pulse width are defined by plasma drift distance between a laser target and beam extraction position. In direct plasma injection scheme, which uses a laser ion source and a radio frequency quadrupole linac, we can apply relatively higher electric field at beam extraction due to the unique shape of a positively biased electrode. However, when we aim at very high current acceleration such as several tens of milliamperes, we observed mismatched beam extraction conditions. We tested three different ion current at ion extraction region by changing plasma drift distance to study better extraction condition. In this experiment, C6+ beam was accelerated. We confirmed that matching condition can be improved by controlling plasma drift distance.

TIME-DEPENDENT DENSITY FUNCTIONAL STUDY OF MULTIELECTRON TRANSFER IN Cq+-Na-4 COLLISIONS

The process of multielectron transfer from a Na-4 cluster induced by highly charged C6+, C4+, C2+ and C+ ions is studied using the method of time-dependent density functional theory within the local density approximation combined with the use of pseudopotential. The evolution of dipole moment changes and emitted electrons in Na-4 isobtained and the time-dependent probabilities with various charges are deduced. It is shown that the Na-4 cluster is strongly ionized by C6+ and that the number of emitted electrons per atom of Na-4 is larger than that of Na-2 under the same condition. One can find that the detailed information of the emitted electrons from Na-4 is different from the same from Na-2, which is possibly related to the difference in structure between the two clusters.

基于ECRIS的等电荷态序列离子与氦、氖、氩碰撞反应中的多电子过程研究

本工作设计并建立了一个离子-原子碰撞实验终端。该终端具有一定的通用性，可用于我所EcRIS、ECRIS一300kV高压平台和兰州大学Zxl．7MV串列加速器。终端的设计特别考虑了气体靶实验中系统的动态真空和对高品质弱束流流强的控制。2004年7月-10月，利用我所ECRIS提供的束流，在该终端上进行了首轮实验。本工作指出，除了入射离子的电荷态和速度外，其空能级结构是碰撞反应的另一个主导因素，并在此基础上提出了等电荷态序列离子的概念。为了确定离子空能级结构对碰撞反应的影响，本工作系统研究了等速度的q＝6序列离子（C6＋、N6＋、。6＋、F6＋、Ne6＋、Ar6＋、co6＋）、q＝7序列离子（07＋、F7＋、Ne7＋、57＋、Ar7＋）、q＝8序列离子（FS＋、Nes＋、Ars＋、cos＋）、q：9序列离子（Fg＋、Neg＋、519＋、59＋、Arg＋、cag＋）和叮：11序列离子（Si1、Aill＋、Call＋）与氦、氖、氢的碰撞反应。实验证实，对于等速度、等电荷态序列离子，碰撞反应与离子种类强烈相关。利用同位素纯的13coZ作为EcRIs的工作气体，获得了纯净的全裸离子13C6＋束流，研究了13C6＋离子与氦、氖、氢碰撞反应与碰撞速度的关系。实验发现，在C6十一He的碰撞反应中，纯双电子俘获（DC）与双电子转移（DE）截面比JDcDIZ随碰撞速度的增加而明显下降，这暗示准分子俄歇机制在本能区C6＋一He碰撞反应中的贡献不可忽略。用MCBM描述离子-原子相互作用阶段，用电子蒸发模型统一处理碰撞后多电了激发态散射离子和反冲离子的衰变，作者编写了计算程序COBEEM。经典过垒模型（如ECBM和MCBM）仅用电荷态q一个参数描述入射离子，本工作实验证实了这种描述是不完备的。COBEEM程序对此问题进行了初步修正。该程序还包含了ECBM和Selberg等人提出了经验公式的计算。

高电荷态离子引起的富勒烯离子的碎裂研究

在里昂第一大学原子物理平台上，采用静电离子阱技术，我们在三个激发能区内研究了高电荷态离子与富勒烯作用后C603”离子的稳定性及其碎裂方式。在56 kev的Ars＋离子与富勒烯碰撞中，当碰撞参数很大时，稳定的C研离子被一个静电离子阱俘获，储存一段时间后存活的离子被探测器测量，实验结果显示C_16oll（l．＝2-5）离子的损失主要是由于与剩余气体发生电荷交换，其相对于碎裂衰变过程的寿命大于400毫秒。在‘擦边碰撞，过程条件下，研究了处于低激发态的C60r+离子在20微秒内蒸发CZ分子的过程。基于考虑了热辐射的统计模型，给出了碰撞产生的C60r+离子的激发能的分布。随着碰撞参数的减小，当入射离子穿过C6。分子时，由于电子阻止使C6厂离子处于高激发态。通过测量发射电子数目，实验上确定了C60r＋离子的初始电荷态，本工作分析了高激发态的C60r＋离子碎裂前的电荷态与入射离子速度之间的关系，发现C60r”离子的碎裂方式只与它的初始电荷态有关，而与入射离子速度无关；同时，发射电子的个数可以用来表征C60什离子的激发能的大小

抗HER2-hTNF-α新型免疫毒素的制备及功能研究

HER2/neu基因在肿瘤中的过度表达使其成为许多肿瘤的标志分子.为了增加过度表达HER2/neu的肿瘤细胞对肿瘤坏死因子(TNF)的敏感性和提高HER2/neu抗体的肿瘤杀伤效应,将抗HER2/neu单链抗体C6.5与人肿瘤坏死因子hTNF-α融合,构建了scFvC6.5-hTNF-α融合蛋白,完成了重组蛋白在大肠杆菌中的表达,产率为400μg/L菌液.经过亲和层析和柱复性,融合蛋白的纯度达95%以上.ELISA���验表明,scFvC6.5-hTNF-α能够特异结合HER2/neu阳性卵巢癌细胞SKOV-3和乳腺癌细胞MCF-7,而不结合HER2/neu阴性的黑色素瘤细胞A375.MTT试验表明,scFvC6.5-hTNF-α能够选择性地杀伤SKOV-3和MCF-7细胞,而不影响A375细胞的生长.这种肿瘤细胞特异性杀伤作用提示该免疫毒素具有肿瘤靶向治疗的潜在应用价值.

大鼠脑胶质瘤干细胞分离及作为树突状细胞治疗抗原来源的研究

脑胶质瘤是原发性恶性脑肿瘤中最常见的一类肿瘤，其具有较差的预后性和高致死率。尽管包括手术、化疗及放疗在内的综合治疗水平在不断提高，但由于胶质瘤细胞的高度侵袭性导致治疗结果仍未得到明显改善，病人常常在治疗后很短时间内发生复发。近年来在肿瘤发生的领域提出了一个新的理论，即肿瘤干细胞理论。这个理论认为，肿瘤干细胞是肿瘤中具有自我更新、无限增殖及分化潜能的细胞，这部分细胞虽然只占少部分，但却是肿瘤发生、发展的关键。本研究主要探讨了利用化疗药物秋水仙素分离大鼠胶质瘤细胞中的干细胞样肿瘤细胞（Stem-like Cancer Cell, SLCC）的可行性，负载胶质瘤SLCC的树突状细胞疫苗在体外对肿瘤细胞的杀伤能力，以及对秋水仙素处理胶质瘤细胞的基因组不稳定性的初步探索。 C6大鼠胶质瘤细胞经不同剂量水平（0、0.5、1.0、2.0μg/ml）的秋水仙素处理后，大部分细胞发生凋亡，剩下存活的细胞经过免疫荧光染色发现其表达干细胞标志分子Nestin，提示可能是SLCC。流式和RT-PCR实验表明，经过秋水仙素处理后的存活的C6细胞表达干细胞标志分子nestin，sox2和bmi1，并且其数量随着秋水仙素浓度的增加而增加。 树突状疫苗是一种脑肿瘤的生物治疗方法。本实验通过分离大鼠的树突状细胞和淋巴细胞，体外培养并用经不同剂量组处理分离的SLCC全蛋白刺激一周后，使用MTT法检测激活的细胞毒T淋巴细胞（cytotoxic T lymphocyte，CTL）体外对肿瘤细胞的杀伤效果。结果表明，经药物分离的SLCC组诱导的CTL效果明显大于对照组，提示脑胶质瘤SLCC可以作为树突状疫苗免疫治疗的新靶点。 此外RT-PCR证明经秋水仙素处理后的胶质瘤细胞中mad2水平明显升高，表明化疗药物可能增加了肿瘤细胞中基因组不稳定性，从而导致SLCC的聚集。 综上，本实验证明了利用化疗药物秋水仙素可以分离大鼠胶质瘤细胞C6中的SLCC细胞，且该分离可能与肿瘤细胞基因组不稳定性提高有关。同时，利用负载SLCC全蛋白的树突状细胞激活的T淋巴细胞在体外具备比对照组更强的细胞杀伤能力。这些结果为以脑胶质瘤SLCC最为靶点的免疫治疗方法开发提供了基础依据。