Characteristics of the Oxygen Function in High Tc Copper Oxide Superconductors

Comments on the studies of the oxygen functions in high Tc copper oxide superconductors and the effects of isotope were made. And the characteristics of the oxygen functions in high Tc copper oxide superconductors were discussed on the basis of the dual-body structure model of superconductors. It is pointed out that the characteristics of the oxygen functions in high Tc copper oxide superconductors are that they influence the crystal structure and the carriers density and participate in the electron phonons coupling.     

^(99)Tc和^(90)Sr放化传感器研究进展北大核心CSCD

^(99)Tc和^(90)Sr是环境放射化学重点关注的两种β放射性核素,放化传感器可以实现水溶液中这两种核素的现场直接测量,有望用于核电站、后处理厂、放射性废物处理处置设施、医用同位素生产设施等核设施周边环境水和液态流出物中^(99)Tc和^(90)Sr的实时监测。本文系统介绍了^(99)Tc和^(90)Sr放化传感器的基本原理、双功能树脂类型、微型柱结构、研究及应用现状等,指出了制约放化传感器发展技术方面的主要因素,并对我国发展β核素放化传感器技术提出了建议。     

In Vitro and in Vivo Evaluation of Lactoferrin-Conjugated Liposomes as a Novel Carrier to Improve the Brain Delivery

In this study, lactoferrin-conjugated PEGylated liposomes (PL), a potential drug carrier for brain delivery, was loaded with radioisotope complex, ^99mTc labeled N,N-bis(2-mercaptoethyl)-N′,N′-diethylethylenediamine (^99mTc-BMEDA) for in vitro and in vivo evaluations. The hydrophilicity of liposomes was enhanced by PEGylation which was not an ideal brain delivery system for crossing the blood brain barrier (BBB). With the modification of a brain-targeting ligand, lactoferrin (Lf), the PEGylated liposome (PL) might become a potential brain delivery vehicle. In order to test the hypothesis in vitro and in vivo, ^99mTc-BMEDA was loaded into the liposomes as a reporter with or without Lf-conjugation. The mouse brain endothelia cell line, bEnd.3 cells, was cultured to investigate the potential uptake of liposomes in vitro. The in vivo uptake by the mouse brain of the liposomes was detected by tissue biodistribution study. The results indicated that Lf-conjugated PEGylated liposome showed more than three times better uptake efficiency in vitro and two-fold higher of brain uptake in vivo than PEGlyated liposome. With the success of loading the potential Single Photon Emission Tomography (SPECT) imaging probe, ^99mTc-BMEDA, Lf-PL might serve as a promising brain delivery system for loading diagnostics or therapeutics of various brain disorders.     

Magnetothermal transition in YBCO melt textured materials

Conductors cut from large YBCO single domains textured by a combination of Melt Texturing Growth and Top Seeding techniques were studied for Fault Current Limiter applications. In self field, homogeneous transport critical current densities as large as 4 10⁴ and 9 10⁴ A/cm² were measured in shaped YBCO single domains up to 5 cm in length. Above J_c, experiments focused on magnetothermal transitions showed that the silver coating should have an adequate thickness so as to prevent the conductors from burning. Capability of textured materials to support high instantaneous power (40 GW/m³) and energy dissipation (190 MJ/m³) during the transition was demonstrated in a 4 T magnetic field.     

萃取液闪法测定生产堆高放废液及其处理工艺中的^99Tc

本文在ＨＮＯ３和Ｈ２ＳＯ２混合介质中，用环己酮从高放废液及其处理 样品中定量萃取＾９９Ｔｃ，分别以Ｋ２ＣＯ３－Ｈ２Ｏ２及ＮａＣＯ２洗涤有机相去除钌，铑，碘等核素。有机相与溶水性的闪烁液混匀，液闪法测量＾９９Ｔｃ的活度。     

γ-硫脲基丙基锗倍半硫化物的合成,99Tcm 标记及生物分布研究

合成了γ 硫脲基丙基锗倍半硫化物 ,进行了99Tcm的标记 ,在配体量为 0 5mg,SnCl2 量为 0 .1mg ,pH =8.0 ,反应温度为 2 0℃ ,反应时间为 2 0min时 ,标记率可达 84 2 %。配合物在小鼠体内的生物分布实验结果表明 ,配合物主要浓集在肺中 ,其次是肝脏。在标记物质量浓度为 5 0 μg/mL时 ,测得它对KB(人鼻咽癌 ) ,HCT(人结肠癌 )和Bel(人肝癌 )细胞的抑制率分别为 69 0 % ,76 9% ,4 4 7%。     

自动绝对测量^9^9Tc活度

由配备通用自动计数与数据处理装置的液体闪烁计数器，采用４πβ（Ｌ．Ｓ）－γ符合效率示踪两种方法绝对测量了＾９＾９Ｔｃ标准溶液的活度。用ＨＰＧｅγ谱仪分析测定了放射性纯度。结果纯度大于９９．９％，活度的总不确定度（３δ）小于３％。     

99Tc在模拟地质条件下的迁移行为研究概况

介绍了99Tc在模拟地质条件下迁移行为研究概况,主要阐明了99Tc在模拟地质条件下迁移行为的研究意义、99Tc的水溶液化学性质、影响99Tc在地质介质中迁移的因素及99Tc在近场和远场的释放和迁移,并就国内外的研究概况进行了概要评述.