中子活化法研究硒在人体组织中的亚细胞分布

用细胞器的差速离心分离技术和中子活化分析法研究了微量元素硒在人体重要组织中的亚细胞分布 ,并用国际标准参考物质小牛肝 (NIST 15 77a)、马肾 (IAEA H8)等检验分析结果的准确性。结果表明 :不同个体的硒水平差异较大 ;在所研究的组织中 ,肾脏中硒含量最高。不同组织中硒的亚细胞分布模式明显不同 ,硒的浓度从高到低依次为 :肝脏 ,线粒体 >细胞核 >胞液 >溶酶体、微粒体 ;肾脏 ,细胞核 >线粒体 >胞液 >溶酶体、微粒体 ;心脏 ,细胞核、线粒体 >胞液、溶酶体、微粒体     

人体肝脏微量元素的亚细胞分布

将超离心分离技术与中子活化分析法相结合,分析测定了正常人肝亚细胞组分中的微量元素。介绍了样品的采集制备、微量元素的实验测定,使用标准参考物质NBS-1577a,IAEA-H8校对了方法的可靠性。报道了人肝5种亚细胞组分(核、线粒体、溶酶体、微粒体、胞液)中8种微量元素的含量,并对其分布进行了初步研究。     

人肝癌细胞内多种元素分布特征的分子活化研究

为探讨微量元素在原发性肝癌亚细胞组分中的分布及在肝癌发生发展中的变化,采用分子活化分析方法测定了肝癌和正常肝脏细胞亚细胞组分中的17种不同宏量和微量元素的分布,t检验比较两者之间的元素含量的差别。结果发现Br、Ca、Cd和Cs在肝癌各亚细胞组分中的含量明显高于正常人,大部分具有统计学显著性差异。肝癌微粒体Fe明显低于正常人肝,为正常人的一半(P<0.05),而其它亚细胞组分均高于正常人肝。La和Ce的分布与Fe类似。Sb和Zn在肝癌细胞核中的含量则明显低于正常人肝(P<0.05、P<0.05)。K、Na在肝癌胞浆的含量明显高于正常人(P<0.05)。Ba和Rb在肝癌和正常肝脏的分布没有显著性差异。本文还探讨了Fe、Cd和K等元素含量的变化与肝癌发生的关系。肝癌与正常肝脏的亚细胞组分之间,多数微量元素的空间分布有着显著不同,提示微量元素在肝癌发生发展中起着重要作用。     

应用PIXE分析胎儿肝、脑、肾、肺组织及其亚细胞组分中的元素分布

质子激发X射线荧光(PIXE)分析了上海市6例自然流产胎儿(5—6个月)的肝、脑、肾、肺的组织匀浆及其线粒体、溶酶体和微粒体中K、Ca、Mn、Fe、Cu、Zn、Pb、Rb、Sr的含量。结果显示了元素在不同脏器的分布以及同一脏器的亚细胞水平的分布,并且通过与成年人肝的数据比较,得出胎儿中必需微量元素Zn、Cu、Fe等含量显著高,并且有的亚细胞分布模式也不同,这一结果提示了必需微量元素的亚细胞分布与细胞发育有密切关系。     

电镜放射自显影研究浓缩铀UO_2F_2在体内亚细胞水平的沉积

运用电镜放射自显影术探讨了可溶性浓缩铀UO_2F_2在机体内亚细胞水平的蓄积动态。发现浓缩铀UO_2F_2在内污染危害早期集中于主要沉积器官肾脏,尤其呈选择性沉积于近曲细管上皮细胞核中和胞质的线粒体内,以及曲细尿管基底膜处,从而可导致近曲细管上皮细胞的变性、坏死和脱落。对肝组织细胞的电镜放射自显影观察表明,浓缩铀UO_2F_2开始主要沉积到肝细胞核中以及胞浆中可溶性蛋白质部位,随着观察时间的延长,浓缩铀UO_2F_2主要定位于肝细胞的线粒体上,其次是溶酶体中。浓缩铀UO_2F_2在骨组织细胞中的沉积是持续增升的,主要沉积在松质骨部位的骨细胞核和破骨细胞核中,而在胞质中,尤其是线粒体中,也有浓集的放射自显影径迹颗粒呈现,且其滞留期长,很难排除。     

电镜放射自显影研究浓缩铀UO_2F_2在体内亚细胞水平的沉积(英文)

运用电镜放射自显影术探讨了可溶性浓缩铀UO_2F_2在机体内亚细胞水平的蓄积动态。发现浓缩铀UO_2F_2在内污染危害早期集中于主要沉积器官肾脏,尤其呈选择性沉积于近曲细管上皮细胞核中和胞质的线粒体内,以及曲细尿管基底膜处,从而可导致近曲细管上皮细胞的变性、坏死和脱落。对肝组织细胞的电镜放射自显影观察表明,浓缩铀UO_2F_2开始主要沉积到肝细胞核中以及胞浆中可溶性蛋白质部位,随着观察时间的延长,浓缩铀UO_2F_2主要定位于肝细胞的线粒体上,其次是溶酶体中。浓缩铀UO_2F_2在骨组织细胞中的沉积是持续增升的,主要沉积在松质骨部位的骨细胞核和破骨细胞核中,而在胞质中,尤其是线粒体中,也有浓集的放射自显影径迹颗粒呈现,且其滞留期长,很难排除。     

WR-2721对辐射所致脂类过氧化的影响Ⅱ——照射小鼠肝与脑亚细胞各部分脂类过氧化值

小鼠经850rad照射后第1、3、5、7和10天,肝与脑的亚细胞各部分脂类过氧化率均有不同程度的增高,如微粒体>线粒体>胞核。其峰值出现于照射后第3天或第5天。腹腔注射WR-2721可使照射后亚细胞各部分的脂类过氧化程度显著减轻。     

核素^147Pm在细胞内滞留的电镜放射自显影研究

木文用电镜放射自显影术研究了重核裂片~(147)Pm在体内亚细胞水平滞留动态。发现~(147)Pm的内污染沉积早期在血细胞和血管内皮细胞中,尤以在红细胞的沉积为多。~(147)Pm呈选择性滞留于肝细胞亚微结构中,可较多的掺入枯否细胞、肝细胞核和核仁内,在胞质中的糙面内质网、线粒体、微体和糖元中亦有滞留,且主要沉积于糙面内质网和线粒体,在高尔基复合体与糙面内质网所芽生的转移小泡融合处,亦有~(147)Pm滞留的放射自显影象。而在肾小体足细胞的线粒体和溶酶体中,有浓集的放射自显影径迹呈现。在肾近端小管曲部上皮细胞核中和胞质的线粒体和微体中,亦有较多的~(147)Pm滞留。 随着观察时间的延续,~(147)Pm在骨有机质亚微结构中呈现选择性、持续性的沉积增多。可浓集于破骨细胞和成骨细胞核中。此外在骨组织细胞间质中的胶原纤维部位,亦有较多的~(147)Pm沉积,难以排除。     

γ射线合并丝裂霉素C对大鼠肝脏微粒体CYP2B1、CYP2E1活性影响的体外研究

研究不同剂量γ射线照射及γ射线和丝裂霉素C（Mitomycin C,MMC）联合用药对雄性SD（Sprague-Dawley）大鼠肝脏微粒体中CYP2B1、CYP2E1的影响。从空白组（未经苯巴比妥诱导）和经苯巴比妥（PB）诱导组大鼠的肝脏中提出微粒体,分别进行2Gy、8Gy和16Gy γ射线单纯照射;50μmol／LMMC单纯处理;γ射线照射后加MMC联合作用,不作任何处理的作为正常对照组,然后测定CYP2B1、CYP2E1活性。实验结果显示,无论是空白组,还是PB诱导组的微粒体,在各剂量γ射线照射后,CYP2B1、CYP2E1活性变化都没有统计学差异（P〉0．05）;50μmol／LMMC作用后,CYP281活性没有明显变化（P〉0．05）,但使CYP2E1活性下降明显（P〈0．01）。两因素析因分析发现对于微粒体中CYP2B1、CYP2E1活性,γ射线照射和MMC作用之间没有交互作用。说明在体外试验中,γ照射对大鼠肝脏微粒体CYP2B1、CYP2E1活性没有影响,50 μmol／LMMC的作用对CYP2B1活性也没有影响,但可以抑制CYP2E1活性。     

电镜放射自显影术研究裂片~(147)Pm在体内亚细胞水平的滞留

用电镜放射自显影术研究了重核裂片~(147)Pm在体内亚细胞水平滞留动态。发现~(147)Pm的内污染沉积危害早期是在血细胞和血管内皮细胞中,尤以在红细胞中的沉积为多。~(147)Pm呈选择性滞留于肝细胞亚微结构中。至于在肾小体的足细胞的细胞器中,尤以在线粒体和溶酶体中,有浓集的~(147)Pm放射自显影径迹呈现。在肾近端小管曲部上皮细胞核中,以及胞质中的线粒体和微体中亦有较多的~(147)Pm滞留。随着观察时间的延长,~(147)Pm在骨有机质亚微结构中呈现选择性的、持续性的沉积增生。该放射性核素可浓集于破骨细胞和成骨细胞核中,至于在细胞器中测主要沉积于糙面内质网和线粒体,尤其观察到在高尔基复合体与糙面内质网所芽生的转移小泡融合处,有~(147)Pm滞留的放射自显影象。     

DETERMINATION OF TRACE ELEMENTS IN SUBCELLULAR FRACTION OF HUMAN LIVER BY INAA

The concentrations of 18 elements in subcellular fractions of human liver were determined by combining differential centrifugation and INAA. Samples of human liver were homogenized in a buffer. The homogenate was separated into nuclei, mitochondrial, lysosomal, microsomal and cytosol fractions by successive differential centrifugation. Biological standard reference materials were used to evaluate the accuracy of the INAA method, and the results agree with the certified values. Element levels in subcellular fractions of human liver were discussed.     

Benchmark Critical Experiments of a Heterogeneous System of Uranium Fuel Rods and Uranium Solution Poisoned with Gadolinium,and Application of Their Results to JACS Validation

A series of critical experiments were performed using heterogeneous cores at the Static Experiment Critical Facility (STACY) of the Japan Atomic Energy Agency (JAEA) in order to obtain systematic benchmark criticality data concerning the dissolving process in reprocessing plants. Focusing on the use of gadolinium as a soluble poison, critical mass was measured for a combination of uranium dioxide fuel rods (5 wt% ²³⁵U) and uranyl nitrate solution (6 wt% ²³⁵U) poisoned with gadolinium (Gd). Fuel rods were arrayed with a 1.5 cm lattice interval in the poisoned fuel solution in a 60-cm-diameter cylindrical tank. The uranium concentration of the solution was roughly kept at about 330 gU/L, and the Gd concentrations were varied up to 0.1 gGd/L. The other series of experiments were also conducted, as reference cases, varying uranium concentration in the fuel solution without Gd. The results provided benchmark criticality data for validation of neutron multiplication factor calculation on heterogeneous systems such as a dissolver. Validation calculation of JACS based on the newly obtained benchmarks supports the justification of its utilization for the criticality safety analysis.     

铅对大鼠体内锌、铜、铁和锰含量的影响

雄性SD大鼠腹腔注射乙酸铅水溶液染毒25d后,通过饮水服用二巯基丁二酸(DMSA)10d。用X射线荧光法分析大脑、小脑、海马以及肝、肾和血中铅、锌、铜、铁和锰含量。结果表明,大脑中铅的质量分数高于小脑和海马;摄入铅后的海马中铜、铁和锰的质量分数升高,小脑中锰的质量分数明显上升(p<0.05);肾脏中的铜、铁、锌均显著降低,血液中锌和铜下降(p<0.05);DMSA能有效清除动物体内的铅,部分缓解铅造成的微量元素失衡。     

解毒健脾中药选择性驱铅的实验研究

用醋酸铅建立铅中毒动物模型,以EDTA为对照,观察解毒健脾中药驱铅疗效及机理,结果表明:与正常组比较,EDTA组除血铅趋正常外,其余指标虽有明显改变但未恢复至正常(p<0.05),且驱铅同时尿中排出多种必需微量元素(p<0.05);中药组各项指标均恢复正常(p>0.05),尿中必需微量元素无改变(p>0.05)。对中药疗效优于EDTA的可能机理进行了讨论,认为中药可加速粪铅排出,降低肝铅积累;可使FEP恢复正常,显示驱铅的相对完全,中药驱铅而不干扰微量元素的体内平衡。     

应用中子活化分析技术测定人脑肿瘤亚细胞组分中的微量元素

采用密度梯度离心分离技术结合仪器中子活化分析技术,分析测定了人脑(正常和肿瘤)亚细胞组分中11种微量元素的浓度,并对其分布进行了讨论。     

Phosphorous content and distribution in the NPP Kozloduy RPV Unit 1 Weld 4 metal

Phosphorous content and in depth distribution in the NPP Kozloduy Unit 1 Weld 4 metal were investigated. Wet chemical analysis was carried out on chips cut layer by layer at five levels reaching 7.1 mm distance from the inner RPV wall. The measured average concentration of P was 0.046% which is considerably lower than expected. No typical intercrystal fracture was found in 1 mm² specimen impact broken at −120°C under vacuum. Auger electron spectroscopy was applied in order to investigate the distribution of phosphorous on grain boundaries in the weld metal. Single regions of increased P content were found mainly on the periphery of secondary cracks or in zones of small size facets. In depth distribution of P in these regions was obtained by argon sputtering. The character of the in depth profile was more typical for the case of P-containing precipitations than of P segregation. The measured low P concentration and the character of P distribution could be regarded as less harmful to the mechanical properties, especially for the toughness of the weld metal, compared to the case of grain boundary segregation.     

毛发中铀的二次离子质谱分析研究

毛发对人体微量元素有一定的蓄积效应,且作为一种无创生物检材,在核取证、环境监测、职业暴露检测、医学等领域逐渐受到重视。目前,大多采用整体分析技术测量毛发中元素的平均含量,毛发微区分析相关研究较少。为拓展毛发分析方法应用,本研究通过喂养大鼠硝酸铀酰溶液的方式获得含铀量较高的鼠毛样品,对毛发样品预处理方法、毛发中铀的二次离子质谱（SIMS）测量方法开展研究。结果表明,使用SIMS测量毛发时,样品靶表面刻槽能有效提升信号强度稳定性;样品表面镀铜能有效降低表面电荷积累并减少多原子离子对铀离子信号干扰。使用多接收电感耦合等离子体质谱仪（MC-ICP-MS）和SIMS对鼠毛中铀分布、平均铀含量及同位素比进行测量。结果表明,该方法能有效判断大鼠是否摄铀,分辨大鼠摄铀类型。本研究可为毛发样品溯源分析提供技术支持,对毛发中微量元素的分析研究具有重要意义。     

Evaluation of specimen preparation techniques for micro-PIXE localisation of elements in hyperaccumulating plants

Hybanthus floribundus subsp. floribundus, a rare Australian Ni-hyperaccumulating shrub and Pityrogramma calomelanos var. austroamericana, an Australian naturalized As-hyperaccumulating fern are promising species for use in phytoremediation of contaminated sites. Micro-proton-induced X-ray emission (μ-PIXE) spectroscopy was used to map the elemental distribution of the accumulated metal(loid)s, Ca and K in leaf or pinnule tissues of the two plant species. Samples were prepared by two contrasting specimen preparation techniques: freeze-substitution in tetrahydrofuran (THF) and freeze-drying. The specimens were analysed to compare the suitability of each technique in preserving (i) the spatial elemental distribution and (ii) the tissue structure of the specimens. Further, the μ-PIXE results were compared with concentration of elements in the bulk tissue obtained by ICP-AES analysis.In H. floribundus subsp. floribundus, μ-PIXE analysis revealed Ni, Ca and K concentrations in freeze-dried leaf tissues were at par with bulk tissue concentrations. Elemental distribution maps illustrated that Ni was preferentially localised in the adaxial epidermal tissues (1% DW) and least concentration was found in spongy mesophyll tissues (0.53% DW). Conversely, elemental distribution maps of THF freeze-substituted tissues indicated significantly lower Ni, Ca and K concentrations than freeze-dried specimens and bulk tissue concentrations. Moreover, Ni concentrations were uniform across the whole specimen and no localisation was observed.In P. calomelanos var. austroamericana freeze-dried pinnule tissues, μ-PIXE revealed statistically similar As, Ca and K concentrations as compared to bulk tissue concentrations. Elemental distribution maps showed that As localisation was relatively uniform across the whole specimen. Once again, THF freeze-substituted tissues revealed a significant loss of As compared to freeze-dried specimens and the concentrations obtained by bulk tissue analysis.The results demonstrate that freeze-drying is a suitable sample preparation technique to study elemental distribution of ions in H. floribundus and P. calomelanos plant tissues using μ-PIXE spectroscopy. Furthermore, cellular structure was preserved in samples prepared using this technique.