X射线辐照引起的线粒体D310片段突变的快速检测

采用4 Gy X射线辐照人乳腺癌细胞MCF 7, 分别在照射后0, 2, 4, 8, 16, 24, 48, 72和144 h时间点收集细胞, 提取DNA并以聚合酶链式反应进行扩增, 再以BsaXI限制性内切酶对扩增产物进行消化, 消化产物以琼脂糖凝胶电泳进行分离。 结果表明, 4 Gy X射线辐照可引起D310片段突变, 且该突变在经辐照之后144 h检测水平明显超过野生型。 Human breast cancer cell line MCF 7 was irradiated with 4 Gy X ray, collected at 0, 2, 4, 8, 16, 24, 48, 72, 144 h after irradiation, respectively. Whole genome DNA including mtDNA were extracted at each time point, and amplified by polymerase chain reaction(PCR). Then the PCR product was subjected to BSAXI digestion, all of digestion product then underwent a brief electrophoresis. Results showed D310 mutation can be induced by 4 Gy X ray irradiation and D310 mutation can overwhelm the normal phenotype 144 h after irradiation.     

电离辐射质粒pUC18 DNA结构变化的傅里叶变换拉曼光谱分析

采用傅里叶变换拉曼光谱研究了质粒pUC18DNA经过γ射线电离辐射以后结构的变化。其脱氧核糖－磷酸主链中各振动模式产生的谱带强度有所增加，包括884cm^-1处的脱氧核糖－磷酸主链振动谱带、1460cm^-1处的－CH2弯曲振动谱带和2939cm^-1处的C－H伸缩振动普带。碱基杂环弯曲振动谱带187cm^-1位移到208cm^-1处，强度明显减弱。在3298cm^-1处出现了一个源于N－H伸缩振动的新谱带。此结果表明碱基受损，主链断裂，超螺旋旋结构部分解旋。     

电离辐射在半导体器件中引起的光电流的数值模拟

电离辐射在半导体中引起光电流问题是半导体器件辐照效应研究中的一个带普遍性的课题，首先建立描述半导体中光电流过程的普遍性的物理模型，而后模拟一个实际ｐｎ结器件的光电流响应，给出模拟结果。     

低剂量电离辐射预处理对不同肿瘤细胞周期的影响

实验研究了低剂量γ射线预照射对人肝癌细胞系hepG2和人宫颈癌细胞系HeLa的细胞周期进程的影响.结果显示(1)低剂量(5cGy)辐射后,两种细胞的G2/M期细胞短暂累积;(2)低剂量辐射促进肿瘤细胞的生长;(3)高剂量(3Gy)辐射后,hepG2细胞发生G2期阻滞,HeLa细胞发生S期和G2期阻滞;(4)与单纯高剂量照射相比,低剂量辐射预处理后4h,再给予高剂量辐射,可进一步促进hepG2细胞在G2/M期累积,但是预照射对HeLa细胞的周期进程没有明显影响.因此,低剂量辐射预处理对高剂量诱导的细胞周期阻滞的影响依赖于肿瘤细胞的类型.     

电离辐射诱导组蛋白乙酰化引起的染色质结构解聚研究

真核生物的DNA分子经高度压缩以染色质形式存在于细胞核中,染色质动态结构在DNA复制、基因转录和DNA修复等过程中起着重要的调控作用。核内染色质结构的原位高分辨解析和其结构变化定量表征一直受困于显微成像观测分辨率的限制。通过点击化学荧光标记EdU和STORM单分子定位显微成像,实验得到了细胞核内超分辨率染色质结构图像。基于提出的单分子团簇分析和最近邻距离算法分析发现,X射线辐照和TSA处理后的细胞核内核小体团簇数量显著增多,核小体团簇所占细胞核内的面积比相对于对照组增加,且团簇内平均EdU分子数降低。同时,重离子辐照活细胞在线成像实验获得的XRCC1招募动力学速率常数表明乙酰化处理使得DNA损伤密度降低。这些结果表明电离辐射和乙酰化处理均导致了染色质结构的松散化。STORM超分辨成像方法和分析算法及其获得的核小体团簇分布规律为染色质结构的松散提供了直接的定量表征数据支持。     

电离辐射致植物诱变效应的损伤-修复模型

在电离辐射速率理论的基础上, 结合电离辐射诱导植物的微观与宏观生物效应, 建立了电离辐射致植物诱变效应的损伤-修复模型. 通过对理论模型平衡态的数值求解, 研究了辐照植物各状态相对浓度随电离辐射剂量的变化. 研究表明当考虑植物的修复作用时, 理论模型能够给出“马鞍型”的植物存活率-剂量关系. 为进一步验证模型, 对重离子⁷Li辐射玉米自交系的实验数据进行理论模型拟合, 确定重离子辐射玉米的诱变效应参数, 理论计算的结果与实验数据符合较好. 电离辐射诱导植物的损伤-修复模型的建立为电离辐射诱导植物生物效应的机理研究和辐射诱变植物育种提供了理论依据和参考.     

斑马鱼胚胎在电离辐射生物学研究中的应用

斑马鱼胚胎最初为研究发育生物学与分子遗传学的重要模式动物,20 世纪90 年代关于斑马鱼胚胎研究的文章每年不足100 篇,到本世纪初期已上升到每年1 000 余篇,目前这个数字正呈指数增长,斑马鱼胚胎的研究范围与应用价值正也随之逐步提升。该文综述了斑马鱼胚胎在电离辐射研究领域中的应用,包括电离辐射诱导斑马鱼的毒性作用、电离辐射引起的DNA损伤及其信号转导机制,以及利用斑马鱼对辐射防护剂与增敏剂进行评价。在此基础上还特别介绍了中国科学院近代物理研究所利用斑马鱼胚胎在放射生物学研究上取得的进展,其中包括一种具有物理激发、化学刺激作用的线粒体内活性氧(ROS) 诱导剂,在非条件刺激下利用斑马鱼检测该物质的毒性,发现6 10 μL/mL 的该物质无胚胎发育毒性,然而,在一定波长的光刺激下可造成DNA双链断裂,在理论上是一种潜在的辐射增敏剂。Zebrafish embryo is a classic animal model to study developmental and molecular biology. The relatedworks using zebrafish embryo arise from less than 100 papers per year in 90 s to more than 1 000 papers per year at the beginning of 21st century. The research scope and application value of zebrafish embryo in biology studies are gradually extending, along with the exponential increase of related papers. Here, the applications of zebrafish embryo in the field of radiation biology are reviewed, including radiation-induced toxicity, signal transduction in response to radiation-induced DNA damage, and the assessment of radio-protection and radiosensitizers, respectively. The progress in radiation biology employing zebrafish embryo in Institute of Modern Physics has also been reported, includinga novel mitochondrial reactive oxygen species inducer, which can be triggered by exogenous physical signal and exert chemical stimulation. This inducer shows no obvious embryo toxicity to zebrafish under 10 μL/mL. It can induce DNA double strand breaks if activated by certain wavelength of lights. Itisa potential radiosensitizerin theory.     

走近电离辐射

 提起辐射,人们很自然地联想到手机、电脑的电磁辐射,对电离辐射则比较陌生。其实,这种电磁辐射就是电离辐射的一种。电离辐射还包括电子、质子、中子及较重粒子的粒子源,微波辐射,光辐射,同步辐射等。我们的生活环境中存在着天然电离辐射和人工电离辐射,可以说,电离辐射就在我们身边。电离辐射可以造福于人类,它在工业、医学、农业上有着广泛的应用;电离辐射也可以给人类带来巨大的灾难,特别是核武器和辐射事故的发生。因此,我们对待电离辐射这把双刃剑时,既要充分利用它来造福人类,又要严防它的危害。     

不同LET辐射致DNA集簇性损伤的研究

利用辐照质粒DNA构象变化的分子模型,以DNA糖苷酶Fpg和AP核酸内切酶EndoIII识别并切割辐射所致DNA碱基损伤,将其转换为DNA断裂损伤,通过电泳分析DNA分子构象变化,研究比较γ射线、质子和7Li离子诱发DNA集簇性损伤。50Gy以上高剂量γ辐射对质粒DNA的损伤主要表现为单链断裂(SSB)和很少比例的双链断裂(DSB),并能产生一定水平的集簇性损伤。相比之下,高能质子束和高LET的7Li离子直接所致DNA的断裂损伤以及所产生的集簇性碱基损伤比γ射线的要严重,质子10Gy照射就可诱发明显的集簇损伤。     

Damage Mechanism Analysis and Protection Method of Ionizing Radiation Based on Electromagnetic Radiation Characteristics

Russian Physics Journal - This paper studies the damage mechanism and protection method of ionizing radiation damage based on electromagnetic radiation characteristics. In this paper, the...     

电离辐射诱导的旁观者效应研究

列举了一些具有代表性的研究结果， 概括介绍了一些产生旁观者效应的可能机制以及辐照引起的活性氧基团或分子、 细胞通讯和细胞因子在旁观者效应中的重要作用. 此外， 还讨论了旁观者效应的表达程度与辐照剂量和射线品质的关系. 旁观者效应的研究结果表明: 辐射产生的潜在危害可能要比以前估计的大， 这给如何评估辐射对人类造成的危害带来了新的冲击. Recent studies have indicated that biological effects, such as chromosomal aberration, gene mutation and cell death and so on, can be induced in cells that are not traversed by radiation directly. This phenomenon has been termed as bystander effects. In this paper, a few representative studies were reported and the possible mechanisms underlying the bystander effects were summarized. The reactive oxygen species (ROS) induced by ionizing radiation, cellular communication and some factors play important roles. Besides, the expression extent of bystander effects depended on radiation dose and quality were discussed. Bystander effects suggest that potential health risks associated with radiation exposure may be greater than those of original thought and this makes ultimate impact on human radiation risk assessment.     

集簇性DNA损伤在辐射研究中的进展

高LET重离子引起的集簇性DNA损伤会造成细胞突变、 癌变和凋亡。 促进肿瘤细胞凋亡一直是治愈肿瘤的出发点, 所以集簇性DNA损伤已经成为放射生物学领域研究的热点问题。 由于其提取和检测方法多样, 但并没有一个详细和完整的方案对集簇性DNA损伤进行透彻分析。 综述了集簇性DNA损伤的特点和详细讨论了集簇性DNA损伤最新研究进展, 简介了集簇性DNA损伤的研究方法, 以期为集簇性DNA损伤在放疗中的研究提供一些参考。 Clustered DNA damage which caused by high LET heavy ion radiation can lead to mutation, tumorigenesis and apoptosis. Promoting apoptosis of cancer cells is always the basis of cancer treatment. Clustered DNA damage has been the hot topic in radiobiology. The detect method is diversity, but there is not a detail and complete protocol to analyze clustered DNA damage. In order to provide reference for clustered DNA damage in the radiotherapy study, the clustered DNA damage characteristics, the latest progresses on clustered DNA damage and the detecting methods are reviewed and discussed in deteil in this paper.     

辐射致DNA损伤及相关生物-化学-物理问题(英文)

介绍了在DNA辐射损伤以及相关生物、物理、化学问题的一些研究工作。重点是径迹结构、DNA双链断裂和细胞学终点的关系。P53-Mdm2负反馈回路在DNA损伤的细胞响应方面起重要作用,用一个简单的模型研究了P53-Mdm2负反馈回路相互作用的动力学行为。Some of recent works are presented on radiation induced DNA damage being carried out at China Institute of Atomic Energy （CIAE） and related bio-chemi-physical problems. Emphasis is placed on track structure and its relation to the cell end-point, and a simple model proposed to study the dynamical behavior of P53-Mdm2 interaction which plays pivotal role in cellular response to DNA damage.     

钨酸铅晶体的辐照损伤研究

报道对钨酸铅晶体作低剂量辐照损伤研究的实验装置、方法、和结果.利用北京计量科学研究院的小型⁶⁰Co放射源对4块钨酸铅晶体作了辐照损伤的实验,发现光产额随辐照剂量的增加呈现指数衰减,最后趋于饱和.     

电离辐射对小鼠肾脏影响的代谢组学研究

电离辐射对生物体影响是目前生物医学领域研究的热点之一.本文利用基于核磁共振氢谱（¹H NMR）的代谢组学技术研究来自暴露于不同的电离辐射的C57BL/6J小鼠的肾脏的水溶性萃取物,并试图寻找电离辐射对小鼠肾脏影响的特异性生物标志物.分析结果表明,辐射组可与相应的对照组明显区分.在所发现的75个代谢物中,有6种代谢物的浓度发生显著性变化,分别为2-氨基丁酸、3-羟基丁酸、高丝氨酸、1,3-丙二胺、β-丙氨酸和抗坏血酸.这些代谢物可能成为高剂量电离辐射对生物体肾脏代谢影响的标志物.     

Fluorescent Study of Human Blood Plasma Albumin Alterations Induced by Ionizing Radiation

The use of hydrophobic fluorescent probe ABM (benzanthrone derivative) and albumin autofluorescence allowed show conformational alterations in Chernobyl clean-up workers blood plasma. Results obtained in 1996–1997 suggest that acidic expansion of plasma albumin takes place. Latest data (2006–2008) result in splitting of albumin alterations onto two stages - acidic expansion and N-F transition. The N-F transition is accompanied by the blue shift of fluorescence spectra and dehydration of tryptophanyl region of albumin molecule. In 2007 obtained.patterns of ABM spectra had never been previously seen in examined healthy individuals or patients with tuberculosis, multiple sclerosis, rheumatoid arthritis, etc. Patterns of ABM fluorescence spectra are associated with conformational changes of blood plasma albumin. The use of probe ABM and albumin auto-fluorescence allowed show conformational alterations in albumin of Chernobyl clean-up workers blood plasma. It is necessary to note that all investigated parameters significantly differ in observed groups of patients. These findings reinforce our understanding that the blood plasma albumin is a significant biological target of radiation. It may be concluded that fluorescence characteristics are representative of radiation induced albumin alterations and its carrier function.     

Effect of Radio-Frequency and Ionizing Radiation on the ATmega8515 Microcontroller

Technical Physics - Effect of ultrabroadband radiation and bremsstrahlung on a complicated device (ATmega8515) placed in a radio-transparent housing is studied. Similar results are obtained in the...