小剂量辐射抑制肿瘤细胞播散的机理研究

观察了静脉注入肿瘤细胞前２４ｈ，７５ｍＧｙＸ射线全身照射对小鼠免疫功能的影响。结果表明照射组小鼠胸腺Ｓ期细胞百分数于照射后４ｄ，胸腺ＣＤ＾３＋细胞百分数于照射后２、８ｄ，脾细胞ＩＬ－２和γＩＦＮ分泌于照射后４ｄ，脾脏ＮＫ细胞活性于照射后２、４、６和８ｄ均较假照射组明显增高。     

大鼠卵巢局部照射对骨代谢与淋巴细胞免疫功能的影响

雌激素维护骨代谢，并抑制淋巴细胞免疫功能，以５０ＧｙＸ射线局部照射大鼠卵巢，造成卵泡闭锁，雌二醇低五，并致尿，ＨＯＰ／ｃｒ和血ＡＬＰ升高，骨小梁数和面积减小，淋巴细胞增殖和分泌ＩＬ－２的活性增加。淋巴细胞分泌ＩＬ－２的活性与血Ｅ２水平呈显著负相关，２４ｈ尿Ｃａ量与淋巴细胞分泌ＩＬ－２的活性呈显著正相关。     

EXTRACTION OF AMERICIUM AND LIGHT RARE EARTHS BY 2－ETHYL HEXYL PHOSPHONIC ACID 2－ETHYL HEXYL ESTER

ＥＸＴＲＡＣＴＩＯＮ　ＯＦ　ＡＭＥＲＩＣＩＵＭ　ＡＮＤ　ＬＩＧＨＴ　ＲＡＲＥ　ＥＡＲＴＨＳ　ＢＹ　２－ＥＴＨＹＬ　ＨＥＸＹＬ　ＰＨＯＳＰＨＯＮＩＣ　ＡＣＩＤ　２－ＥＴＨＹＬ　ＨＥＸＹＬ　ＥＳＴＥＲＺｈｕＹｏｎｇｊｕｎ（朱永）ａｎｄＪｉａｏＲｏｎｇｚｈ...     

X射线辐射对小麦幼苗生长及一些抗氧化酶活性的影响

萌发４８ｈ的小麦幼苗用Ｘ射线处理，高剂量Ｘ射线（８Ｇｙ、１４Ｇｙ）可导致小麦幼苗生长受抑制，鲜重降低，在Ｘ射线照射后第２ｄ和第４ｄ测定幼苗内蛋白质含量、抗坏血酸过氧化物酶（ＡＳＡ－ＰＯＤ）、谷胱甘肽过氧化酶（ＧＳＨ－Ｐｘ）及谷胱甘肽巯基转移酶（ＧＳＨ－Ｔｓ）活性的变化。结果可知：Ｘ射线可引起小麦幼苗内蛋白质含量的下降，１４ＧｙＸ射线照射的样品低于８Ｇｙ照射的，照射后第４ｄ的蛋白质含量高于照射后第２ｄ的，说明Ｘ射线引起的损伤可随照射后的培养而有所恢复；高剂量Ｘ射线可引起小麦幼苗内一些抗氧化酶活性的升高，且随照射剂量的增加酶活性的升高也越明显，在照射后第４ｄ幼苗的ＡＳＡ－ＰＯＤ和ＧＳＨ－Ｐｘ活性高于照射后第２ｄ的值，ＧＳＨ－Ｔｓ活性略有下降。而低剂量（２Ｇｙ）照射与对照相比，上述指标变化不大，说明Ｘ射线处理后可通过诱导这些抗氧化酶活性的升高起到减轻伤害的作用。     

小剂量单次全射照射诱导小鼠免疫适应性反应的剂量与…

采用Ｘ射线单次全射照射，观察诱导小鼠免疫适应性反应的预照射剂量（Ｄ１剂量）范围，损伤性剂量（Ｄ２剂量）范围，及Ｄ１与Ｄ２最佳间隔时间。实验证实，当Ｄ２为１．５Ｇｙ时，０．０２５－０．１Ｇｙ（剂量率０．０９１２５Ｇｙ／ｍｉｎ）可诱导胸腺细胞自发增殖及脾细胞对ＬＰＳ的适应性反应。当Ｄ１为０．０７５Ｇｙ时，Ｄ２在１．０－１．５Ｇｙ（剂量率０．３３Ｇｙ／ｍｉｎ）范围内，胸腺细胞自发增殖及脾细胞对ＣｏｎＡ、     

ASDEX装置及其运行经历

我们正在建造的ＨＬ－２Ａ主机是恢复原ＡＳＤＥＸ装置主机。本文介绍ＡＳＤＥＸ托卡马克的概况,以及装置的运行和停机情况,对其运行中发生的一些问题和改进作一概述,希望工程人员对原ＡＳＤＥＸ能有一定了解,以期对我们ＨＬ－２Ａ主机的恢复工作提供一定的帮助。     

小鼠受X射线全身照射后腹腔巨噬细胞TNFα和IL—1β转录水平的变化

应用原位杂交法观察了小鼠全身Ｘ射线照射后，腹腔巨噬细胞ＴＮＦα和ＩＬ－１β基因ｍＲＮＡ转录水平的变化，在照射后２ｈ的剂量效应研究中观察到，ＴＮＦα转录水平２．０Ｇｙ组达峰值，ＩＬ－１β转录水平于１．０Ｇｙ组达峰值，在不同剂量照射后的时程变化研究中发现７５ｍＧｙ照射后，ＴＮＦαｍＲＮＡ由照射后１５ｍｉｎ到１６ｈ均有表达，ＩＬ－１βｍＲＮＡ在０Ｇｙ组即在表达，１～２４ｈ有不同程度的表达上调，２．０Ｇｙ     

双嘧达莫和腺苷-磷酸对照射小鼠免疫功能的影响

研究了预先给予双嘧达莫（ＤＰ）和腺苷－磷酸（ＡＭＰ）对不同剂量Ｘ射线照射小鼠免疫功能的影响。采用ＢＡＬＢ／Ｃ纯系小鼠给予一次性不同剂量（０、１、２、４Ｇｙ）Ｘ射线照射。照射前给予ＤＰ２ｍｇ和ＡＭＰ５ｍｇ,检测胸腺细胞自发增殖反应能力和脾细胞对ＣｏｎＡ的增殖反应能力的变化。结果表明：单纯给予ＤＰ＋ＡＭＰ组胸腺自发增殖反应能力和脾细胞对ＣｏｎＡ的增殖反应能力较对照组明显下降,但１Ｇｙ和２ＧｙＸ射线照射前预先给予ＤＰ和ＡＭＰ能显著增强小鼠胸腺自发增殖反应能力和脾淋巴细胞对ＣｏｎＡ诱导的增殖反应能力。     

黄蘑多糖对受X射线照射小鼠的防护作用

本文观察了预防给予黄蘑多糖对受Ｘ射线照射小鼠的保护作用及其对免疫功能的影响。结果表明，黄蘑多糖可明显提高受８．０ＧｙＸ线照射小鼠３０日存活率，保护指数可达１．７２，防护效果与人参多糖相近。另外，黄蘑多糖可显著增强受２．０Ｇｙ照射小鼠脾脏淋巴细胞产生ＩＬ－２和γＩＦＮ的能力，激活脾脏ＮＫ细胞，加速胸腺细胞周期进程。说明黄蘑多糖对受Ｘ线照射小鼠有一定的防护作用，可明显增强其免疫功能。     

黄蘑多糖对受X射线照射大鼠的防护作用

本文观察了预防给予黄蘑多糖对受Ｘ射线照射小鼠的保护作用及其免疫功能的影响，结果表明，黄蘑多糖可明显提高受８．０ＧｙＸ线照射小鼠３０日存活率，保护指数可达１．７２，防护效果与人参多糖相近，另外，黄蘑多糖可显著增强受２．０Ｇｙ照射小鼠脾脏淋巴细胞产生ＩＬ－２和γＩＦＮ的能力，激活脾脏ＮＫ细胞，加速胸腺细胞周期里程，说明黄蘑多糖对受Ｘ线照射小鼠有一定的防护作用，可明显增强其免疫功能。     

细胞样品的高分辨率软X射线接触显微术图像的研究

在建立适于软Ｘ射线接触显微术（ＳＸＣＭ）观察细胞样品制备方法的基础上，以培养的肿瘤细胞为生物样品，应用细聚焦软Ｘ射线光源进行ＳＸＣＭ研究，获得了分辨率优于２８ｎｍ的高质量肿瘤细胞ＳＸＣＭ图像。     

SOFT X-RAY IMAGES OF CHROMOSOMES WITHIN INTACT TUMOR CELLS TREATED WITH COLCHICINE

In order to avoid any possible effect of separating procedures from intact cell on morphologic structure of the chromosomes, cultivated Hep-2 tumor cells were treated with colchicine and observed by soft X-ray contact microscopy for the first time. The fine structures of chromosomes are more clear with stereo features. The thread-like and coarse granular structures twine and tangle up together within chromosome masses which can not easily be revealed in Wright's stained sample by light microscope or osmium stained sample by transmission electron microscope     

Tumor targeting of 125I-labeled anti-EGFR monoclonal antibody LA22 in HT-29 human colon cancer

Epidermal growth factor receptor (EGFR) plays a critical role in proliferation, apoptosis, angiogenesis, invasiveness and distant metastasis of tumors. In this study, the tumor targeting properties of anti-EGFR monoclonal antibody (mAb) LA22 in a colon cancer mouse model are evaluated. The results from flow cytometry assay and immunofluorescent staining clearly showed that HT-29 human colon cancer cells were EGFR positive, and the binding of mAb LA22 to the HT-29 cell surface was specific. The saturation binding experiment of 125I-LA22 to HT-29 cells revealed that LA22 possessed moderate affinity to EGFR with the Kd value calculated to be 3.28±0.76 nM. The in vivo γ imaging demonstrated the specific accumulation of 125I-LA22 in HT-29 tumor xenografts. The specific tumor targeting properties of mAb LA22 make it a good candidate for tumor targeted radioimmunotherapy of EGFR-positive tumors when it is labeled with therapeutic nuclides, such as 131I, 177Lu, or 90Y.     

Development of a silver ion source using nanosecond pulses of a Nd:YAG laser at different wavelengths

A silver ion source was designed by focusing the fundamental and harmonics of Q-switched Nd:YAG laser pulses onto a silver target and simultaneously applying an electric potential in an argon environment. The silver ions were detected at a distance of 2 cm from the target surface using a Faraday cup ion probe after letting them pass through a retarding mesh grid (copper electrode). We aim to produce and characterize the silver ions generated by the laser radiation of different wavelengths and pulse energy, ambient gas pressure and the electrode spacing under applied electric field. In addition to this, the effect of laser radiation on plasma under vacuum and at different argon gas pressures was investigated. The velocity distribution function of the plasma emitted from the silver target was investigated under argon discharge. These measurements demonstrated clearly that the velocity distribution function and current signals depend on laser power, laser wavelength and argon pressure. We observed a ten fold increase in the plume current with increase in the applied voltage and ion velocity in the presence of a laser field. The surface morphology of the laser irradiated samples was investigated using reflection optical microscopy.     

In-situ reduction of silver by surface DBD plasma: a novel method for preparing highly effective electromagnetic interference shielding Ag/PET

Electromagnetic interference(EMI) shielding composites with good flexibility and weatherability properties have attracted increased attention. In this study, we combined the surface modification method of sub-atmospheric pressure glow discharge plasma with in situ atmospheric pressure surface dielectric barrier discharge plasma(APSDBD) reduction to prepare polyethylene terephthalate supported silver(Ag/PET). Due to the prominent surface modification of PET film, mild plasma reduction, and effective control of the silver morphology by polyvinylpyrrolidone(PVP), a 3.32 μm thick silver film with ultralow sliver loading(0.022 wt%) exhibited an EMI shielding efficiency(SE) of 39.45 d B at 0.01 GHz and 31.56 d B at 1.0 GHz(30 d B in the range of 0.01–1.0 GHz). The SEM results and EMI shielding analysis indicated that the high performance originated from the synergistic effect of the formation of silver nanoparticles(Ag NPs) with preferentially oriented cell-like surface morphologies and layer-by-layer-like superimposed microstructures inside, which demonstrated strong microwave reflection properties. Fourier transform infrared spectrometer and x-ray diffractometer showed that the surface structures of the heat-sensitive substrate materials were not destroyed by plasma.Additionally, APSDBD technology for preparing Ag/PET had no special requirements on the thickness, dielectric constant, and conductivity of the substrate, which provides an effective strategy for manufacturing metal or alloy films on surfaces of heat-sensitive materials at a relatively low cost.     

Radiochemical synthesis of silver nanoparticles onto textile fabrics and their antibacterial activity

This paper presents a new technique for synthesizing silver nanoparticles immobilized on textile fabrics using a radiochemical process. In this process, the irradiation of a high-energy electron beam on an aqueous solution containing silver ions induces a reducing reaction that forms metallic silver nanoparticles. Small Ag particles of about 2–4 nm were observed together with relatively large particles of more than 10 nm. These nanoparticles are firmly immobilized on the surface of a support textile fabric without the need for any binder or surfactant. The amount of silver nanoparticles immobilized was found to depend on the water content of the support textile fabric, suggesting that the silver ions are reduced not only by radiochemical species generated by the radiolysis of water, but also by radiochemical species generated in the irradiated support fabric itself. The silver nanoparticles that were immobilized on the support textile fabric exhibited an excellent antibacterial activity across a wide antibacterial spectrum, even after a durability test involving washing the fabric 100 times.     

Removal of radioactive methyl iodide by silver impregnated alumina and zeolite

The removal efficiency of methyl iodide for silver impregnated alumina and zeolite has been experimentally evaluated as functions of the relative humidity in the atmosphere and the amount of impregnated silver. At high relative humidities silver alumina performs with a larger removal efficiency using a smaller amount of impregnated silver than does silver zeolite. This difference is explained by effective reacting surface. The pore size dependency is correlated with the pore diffusion rate as the determining adsorption mechanism.     

Silver surface enrichment controlled by simultaneous RBS for reliable PIXE analysis of ancient coins

Evidence of silver surface enrichment of ancient silver-copper coins has been pointed out in the past years. Surface enrichment can be fortuitous or intentional. In this paper, we have investigated the cleaning procedures usually performed after excavation or in museums. We have shown that chemicals or commercial products routinely used dissolve preferentially the copper phase and consequently contribute to the silver surface enrichment. As a result, surface analyses such as PIXE or XRF can be strongly affected by this effect. By using simultaneously RBS and PIXE, it is possible to check through the silver surface enrichment and then select the reliable measurements, characteristic of the bulk composition. Results on coins recently discovered and mechanically or chemically cleaned are presented.     

辐射诱导分子lnc-RI稳定敲低细胞系建立及其功能

制备lnc-RI干涉表达的慢病毒颗粒,建立lnc-RI稳定下调的He La细胞系,探索lnc-RI对细胞辐射敏感性的作用。首先将lnc-RI特异性干涉序列插入干涉表达载体p GLV2中,并制备慢病毒颗粒;然后,将慢病毒颗粒感染He La细胞,建立lnc-RI稳定下调的细胞系,并通过RT-PCR检测不同干涉序列对lnc-RI表达的干涉效果;最后,通过平板克隆形成实验分析lnc-RI表达下调对He La细胞放射敏感性的影响。结果显示,成功制备了携带lnc-RI干涉序列的慢病毒颗粒,并成功感染He La细胞,通过RT-PCR实验鉴定获得两株lnc-RI稳定敲低细胞系。克隆形成实验发现,与对照相比,lnc-RI敲低的He La细胞系的放射敏感性增加。因此,初步证实lnc-RI表达下调增加He La细胞放射敏感性。     

Silver surface enrichment of silver–copper alloys: a limitation for the analysis of ancient silver coins by surface techniques

The surface enrichment of archaeological silver–copper alloys has been recognized for many years. However, the origin of this enrichment is not well defined and many hypotheses have been put forward to account for this behaviour: segregation of the components during casting, deliberate thermal and/or chemical post-treatment, abrasion or corrosion. Among the hypotheses mentioned above, we have focused our study on the first step of coin manufacturing. Replications of silver–copper standards of various compositions ranging from 30% to 80% Ag, reflecting the composition of silver blanks, have been produced. Metallographic examination, PIXE and SEM–EDS have been used for the characterization of each sample. A model of the direct enrichment has been established. This model allows us to propose a relationship between the surface composition and the silver content of the core. Comparison with data of Roman coins from the Roman site of Châteaubleau (France) and from the literature and consequences for the analyses of ancient coins by surface methods are presented.