微波诱发工作人员外周血淋巴细胞亚群变化情况调查

对某研究所微波接触人员（接触组）和非微波作业人员（对照组）进行调查,调查指标为外周血白细胞数和淋巴细胞百分率,以及T淋巴细胞亚群CD3＋、CD4＋、CD8＋比例和CD4＋／CD8＋比值,探索长期低剂量高功率微波辐射对工作人员免疫功能的影响。结果表明：与对照组相比,接触组白细胞数和淋巴细胞百分比均降低,但差异不显著;接触组CD3＋、CD4＋、CD8＋比例均升高,CD4＋／CD8＋比值降低,差异显著;接触组≤10a组的T细胞亚群的变化差异不显著,接触组〉10a组CD3＋、CD4＋、CD8＋比例及CD4＋／CD8＋比值均升高,且CD3＋比例升高差异显著;接触组和对照组组内工龄≤10a和）10a间T淋巴细胞亚群的差异不显著。结果提示,低剂量高功率微波辐射能明显导致人体免疫功能紊乱,但未表现出累积效应。客观有效的职业防护应当引起关注。     

X射线低剂量多次辐射对小鼠外周血淋巴细胞的影响

为了评估低剂量多次辐射对健康机体产生的生物学风险,检测了X射线多次照射对BALB/c小鼠免疫系统的影响.采用X射线全身多次照射,第1天照射0.07 Gy,之后每天照射0.08 Gy共12 d,剂量率0.2 Gy/min,累积剂量为0、0.07、0.23、0.39、0.55、0.71、0.87和1.03 Gy时取样.照射24 h后取血,用流式细胞仪检测外周血中免疫细胞周期和死亡的变化.结果表明,外周血淋巴细胞的周期在0.39和1.03 Gy时,被阻滞在G2/M期,在0.07、0.23、0.71和0.87Gy时,被阻滞在G0/G1期;细胞的死亡随着累积剂量的增加而增加,在0.71Gy时达到峰值.经过X射线多次全身照射小鼠后,可引起外周血淋巴细胞周期和死亡比例发生变化,符合线性平方模型,造成其免疫系统一定的损伤.     

榄香烯对受照人淋巴细胞亚群及其调节的影响

应用同位素掺入法，观察榄香烯要巴细胞亚群，以及亚群间调节的影响。结果表明：榄香烯提高了外周血全淋巴细胞和各亚群的辐射抗性，加强ＣＤ４细胞对Ｂ细胞的辅助调节作用，减轻了膜受体的辐射损伤。     

低剂量X射线照射对小鼠脾淋巴细胞丝裂原反应的影响

本实验观察了低剂量 X 射线整体和离体照射后对小鼠脾淋巴细胞丝裂原反应的影响。结果表明,X 射线全身照射后小鼠脾脏 T、B 淋巴细胞对刀豆蛋白-A(Con A)和细菌脂多糖(LPS)的反应较对照组增强,尤以75 mGy 组最为明显。在离体照射后,脾淋巴细胞对 Con A 的反应未见明显改变,而对 LPS 反应则低于对照组。提示低剂量 X 射线照射可刺激 T 细胞反应增强。     

小剂量照射的淋巴细胞外液诱导其亚群细胞DNA合成…

预先给予４．０ｃＧｙγ射线照射的人外周血淋巴细胞，经ＰＨＡ刺激２４ｈ后提取细胞外液，观察其对大剂量照射后受损伤的亚群细胞的影响。结果表明，ＣＤ＾＋８，ＣＤ＾＋４细胞损伤明显减轻，且损伤剂量分别为１．５，３．０Ｇｙ时，适应性反应最强。结果还显示，ＣＤ＾＋８细胞较ＣＤ＾＋４细胞对辐射更敏感，     

碳离子束辐照对甜高粱主要性状的影响

利用兰州重离子加速器国家实验室(HIANLL)提供的100 MeV/u碳离子束对甜高粱品种BJ0601和BJ0602进行了不同剂量的辐照处理,并用SPSS13.0软件分析了碳离子束辐照剂量和甜高粱主要性状节间数、株高、茎粗、含糖量及单秆重的相关性,试验结果表明:不同的辐照剂量对甜高粱节间数、株高、茎粗、含糖量及单秆重产生了明显的影响,表现出不同程度的相关性.另外,早熟突变株BJ0601-1 M2代各节的平均含糖量高于BJ0601,说明碳离子束辐照可能引起甜高梁含糖量的提高.     

碳离子束辐照对甜高粱节间参数的影响

研究了碳离子束辐照剂量对甜高粱节间数的影响及辐照后不同节间长度、节间重量及糖锤度的变化规律.结果表明:(1)不同的辐照剂量对节间数影响差异不显著(p>0.05);(2)和对照BJ0601相比,碳离子束辐照后,KFJT-1的节间长度、节间重量及节间糖锤度的平均值均有所增加,增加量的平均值分别为0.6cm,18.9g,0.79%.     

用于模拟X射线热-力学效应的高功率脉冲离子束研究进展

计算了与黑体谱1keV X射线在材料中产生的应力波和冲量相当的质子束参数；给出了箍缩型二极管产生离子束的实验结果，以及在“闪光二号”加速器上已经获得的流强约50kA的脉冲质子束。     

Changes in percentage of lymphocyte subsets after ^131I treatment in patients with differentiated thyroid cancer

To monitor the extent and the duration of lymphocyte subset changes in patients with thyroid carcinoma undergoing therapeutic ^131I administration, the percentage of lymphocyte subsets were serially analyzed before and after ^131I treatment. In patients who received 1850 MBq of ^131I for ablation of thyroid remnants, only tor NK cells and B cells showed a significant reduction. In patients received 3700 MBq of ^131I for treatment of local lymph node metastases, NK cells, B cells and CD4＋ were found decreased. In patients received 7400 MBq of ^131I for treatment of distant metastases, NK cells, B cells and CD4＋ and CD8＋ were all affected. However, there is no significant reduction compared to the baseline in the percentage of all lymphocyte subsets three months after ^131I treatment. The results show that the sensitivity of lymphocytes to ^131I internal radiation depends upon lymphocyte phenotype and ^131I activity. The immunosuppression effects are temporary and reversible.     

碳离子辐照诱导的甜高梁花粉生活力及花粉母细胞减数分裂的研究

为研究重离子辐照突变株的细胞遗传学变化,以碳离子辐照选育出的甜高粱早熟突变株KFJT-1及其对照品种KFJT-CK为材料,比较研究了两者之间花粉生活力大小以及花粉母细胞减数分裂的差异。结果发现：KFJT-1的花粉生活力以及花粉总数大于KFJT-CK;KFJT-1花粉母细胞减数分裂大多进入第二次减数分裂时,KFJT-CK花粉母细胞集中在第一次减数分裂;在KFJT-1减数分裂末期II,出现了两组分裂时期不一致、3分体以及不均等分裂畸变状况,畸变率仅为4．5％,说明KFJT-1在生长繁殖过程中修复了大部分由于物理诱变造成的染色体畸变,且能稳定遗传。这些结果从生殖细胞水平进一步说明碳离子辐照早熟突变株KFJT-1较未突变株KFJT-CK成熟期早,且各项指标均优于KFJT-CK。     

Gate/Geant4-based Monte Carlo simulation for calculation of dose distribution of 400 MeV/u carbon ion beam and fragments in water

The applications of carbon ion beam in tumor therapy have attracted more attention in recent years.Monte Carlo simulation is an important approach to obtain accurate radiotherapy parameters. In this work, a400 Me V/u carbon ion beam incident on water phantom was simulated with Gate/Geant4 tools. In methods, the authors set up a carbon ion beam source according to the experiment parameters of Haettner, defined the geometries and materials, set up the physics processes, and designed the means of information collection. In results,the authors obtained the longitudinal dose distribution, the lateral dose distribution, and the relative uncertainty of dose. The dose contributions of all kinds of fragments were calculated detailedly and compared with the Francis results. This work is helpful for people's understanding of the dose distributions produced by carbon ion beam and fragments in water. The simulation method is also significative for radiotherapy treatment planning of carbon ion beam, and it is easy to extend. For obtaining a special result, we may change the particle energy, particle type,target material, target geometry, physics process, detector,etc.     

重离子束治癌装置及技术发展

首先简要回顾了重离子束治癌在我国的兴起与发展的情况.随后着重介绍了重离子束治癌装置及部分关键技术:总体布局方案、束流引出模式、束流配送系统、束流旋转机架、辐照门控系统、PET成像等.     

Lateral straggling and its influence on lateral diffusion in implantation with a focused ion beam

Parallel stripes of nanostructures on an n-type Si substrate have been fabricated by implanting 30 keV Ga⁺ ions from a focused ion beam (FIB) source at three different fluences: 1 × 10¹⁵, 2 × 10¹⁵ and 5 × 10¹⁵ ions/cm². Two sets of implantation were carried out. In one case, during implantation the substrate was held at room temperature and in the other case at 400 °C. Photoemission electron microscopy (PEEM) measurements were carried out on these samples. The implanted parallel stripes, each with a nominal dimension of 4000 × 100 nm², appear as bright regions in the PEEM image. Line scans of the intensities from PEEM images were recorded along and across these stripes. Intensity profile at the edges of a line scan is broader for the implantation carried out at 400 °C compared to room temperature. From the analysis of this intensity profile lateral diffusion coefficient of Ga in silicon was estimated assuming that the PEEM intensity is proportional to Ga concentration. The diffusion coefficient at 400 °C has been estimated to be ∼10⁻¹⁵ m²/s. No significant dependence of diffusion coefficient on ion fluence was observed in the fluence range investigated here. Radiation enhanced diffusion has been discussed in the light of the associated defect distribution due to lateral straggling of the implanted ions.     

极低频磁场联合或不联合X射线对CHO细胞动粒阳性和阴性微核生成的影响

Extremely low frequency magnetic field (ELFMF) produced by power lines and household electric appliances has been associated with increased incidence of cancers, as was suggested by several epidemiological studies. To test the genotoxic effects of ELFMF, the induction of micronuclei by exposure to ELFMF and/or X-rays was investigated by cytokinesis-block method in cultured Chinese Hamster Ovary (CHO) cells.