碘-125标记甘胆酸

甘胆酸(CG)是主要胆汁酸之一。甘胆酸的基本结构是一个巢体核结构,不适宜直接碘化 标记,需在甘胆酸分子上接上组氨基团,进行标记。 一、前体合成:甘胆酸和盐酸组氨,在作为连接剂的碳化二亚胺作用下,反应生成甘胆酸组胺混合物,以正丁醇革取,获甘胆酸组胺。     

超氧物歧化酶的放射性碘标记

超氧物歧化酶(Superoxide dismutase简称SOD)是从红细胞、肝和其它哺乳动物组织分离而得的金属蛋白酶,主要存在于需氧环境的每一个器官中,分子量32000,含有两个相同的亚单位,每一亚单位含铜和锌原子各一个。 McCord提出此酶的功能是使氧代谢免受毒性效应。超氧物自由基是人体内的有毒物     

氯胺-T型氧化树脂的合成

将氧化剂氯胺-T的功能基团引入高分子载体上,合成了氯胺-T型氧化树脂并测定了它的氧化-还原特性。用这种氧化树脂进行碘标记人血清白蛋白,标记率大于90%,免疫反应活性为89%。建立了一种快速、简便的放射性碘标记化合物的制备方法。     

新型碘标记试剂的制备及其在放射性药物合成中的应用

本文合成了1,3,4,6-四氯-3α,6α-二苯甘脲。进行了元素分析、熔点、紫外谱、红外谱、~1H-NMR和质谱等测定,以及性能、储存条件研究。所合成的制品进行了放射性碘标记人纤维蛋白原的合成方法与条件研究,并与氯胺T方法进行了比较,表明1,3,4,6-四氯-3α,6α-二苯甘脲作为固体碘标记试剂反应温和、高效、没有严格的条件限制,操作简便,特别能很好地保留标记物的生物活性,而且重现性好。     

肿瘤坏死因子突变体的碘标记及其质量的检测

用Ｉｏｄｏｇｅｎ法对肿瘤坏死因子突变体进行磺标记用放射纸层析法及自身取代分析法对产物的放化纯度及比放射性活度进行了计算。结果表明，碘的利用率为７２．７５，纯化后标记物的游离碘为２．１２％，放化纯度为９３．１４％，比放射性活度为１．２ＴＢｑ／ｇ。标记后的肿瘤坏死因子突变体的细胞毒效应只下降４．３８％，提示Ｉｏｄｏｇｅｎ法标记肿瘤坏死因子突变体可获良好效果。     

用于放射性砹(碘)标记蛋白质的偶联剂SPC的合成及表征

以5-溴烟酸为起始物，通过3步主要反应合成了一种适用于蛋白质放射性砹(碘)标记的偶联剂——5-(三正丁基锡)-3-吡啶甲酸N-琥珀酰亚胺酯(SPC)，并用核磁共振(NMR)、质谱(MS)、高效液相色谱(HPLC)等进行了表征。以该试剂为双功能偶联剂，实现了IgG的^125I标记，标记率达30％以上。标记产物在体外具有较高的稳定性。     

蛋白质和多肽放射性碘标记方法比对

对氨胺Ｔ（Ｃｈ－Ｔ）法、氯甘脲（Ｉｏｄｏｇｅｎ）法和乳过氧化物酶法进行了比较研究。结果表明：ＬＰＯ具有碘化反应温和、放射性碘利用率高、反应完全、可控性强、标记产品纯度高等优点；特别是能最大限度的保持被标记物固有的生物活性和免疫活性。     

超氧化物歧化酶与阿米福汀对小鼠急性放射损伤预防作用的比较

本研究建立了小鼠全身放疗的损伤模型,以比较预给药超氧化物歧化酶(SOD)和阿米福汀对小鼠放射治疗损伤的防护效果。C57BL/6小鼠用6 Gy X射线进行全身一次性照射,在放射后24 h处死,测定小鼠外周血红、白细胞数量,胸腺指数和脾脏指数,以及肝脏抗氧化活力。结果表明:与放疗对照组相比,放疗前给药SOD组对放疗鼠的外周血白细胞数量和胸腺指数有显著的保护作用,使之分别增加66.7%和19.1%。测得放疗前给药阿米福汀对放射鼠的外周血白细胞数量和脾脏指数有显著的保护作用,使之分别增加106.9%和22.6%。此外,与放疗对照组相比,放疗前给药SOD对放疗鼠的肝脏抗氧化能力也有显著提高,可使肝脏的MDA水平下降12.7%,SOD活力增加10.8%,T-AOC活力增加45.0%,放疗前给药阿米福汀可使放疗鼠肝脏的MDA水平下降22.3%。     

邻菲罗啉的99mTc和188Re标记化学的研究

以ＳｎＣｌ２作还原剂,酒石酸钠钾作中间络合剂,以纸层析法通过三种展开体系,研究了邻菲罗啉（Ｐｈｅｎ）的＾９９ｍＴｃ、１８８Ｒｅ和稳定铼标记化学,并用离子交换法对＾９９ｍＴｃ－Ｐｈｅｎ的表观电荷进行了测定。结果显示,＾９９ｍＴｃ－Ｐｈｅｎ标记率可达９５％以上;在ｐＨ１．０、沸水浴标记条件下,＾９９ｍＴｃ－Ｐｈｅｎ为两种或两种以上不同结构标记物的混合物;在ｐＨ５．０、室温标记条件下,＾９９ｍＴｃ－Ｐｈ     

人血清IgG的188Re标记条件初探

以含葡萄糖酸钠配体的SnCl2为还原液,还原Na188ReO4后,标记人血清IgG,在pH=3的条件下,1g/L的蛋白质用高于5000倍摩尔过量的抗坏血酸(AA)还原2h后, 与2.6×10-28.0×10-2mol/L的SnCl2-葡萄糖酸钠溶液及188ReO4-反应3h,可以得到90%的标记率,在该标记条件下,对影响标记率的因素作了初步的研究和探讨。     

SOD对肿瘤细胞凋亡影响和抗氧化损伤的研究:Ⅰ.SOD与DDP、ADM、VP16合用对肿瘤细胞凋亡的影响

将顺铂(DDP)、阿霉素(ADM)和足叶乙甙(VP16)以不同时间作用于实验小鼠宫颈癌Hela细胞,测定细胞内活性氧(ROS)水平和细胞凋亡率,研究抗肿瘤药物诱导Hela细胞凋亡与细胞内ROS水平的关系。研究表明,在抗肿瘤药物作用前加入超氧化物歧化酶(SOD),会减少Hela细胞的凋亡,在抗肿瘤药物作用24h后加入SOD,对Hela细胞的凋亡无影响,而且对Hela细胞p53、c?fos基因产物表达也无影响。荷瘤小鼠机体整体水平研究表明,在给予化疗药物4h后连续5d注入SOD,与单纯化疗药物组相比,可显著减少荷瘤小鼠骨髓细胞,肝脏和脾脏组织匀浆中ROS水平。表明后注入SOD可直接清除重要脏器细胞内因化疗药物产生的过量ROS,还可提高其它抗氧化酶活性而协同清除化疗药物产生的过量ROS,从而避免正常器官的氧化性损伤。本研究结果为肿瘤化疗中适时施用SOD,减少化疗的毒副作用具有一定指导意义。     

A comparative study of ZPR-6/7 with MCNP/5 and MC-2/REBUS

This work models the INL ZPR-6/7 assembly employing two different approaches: a probabilistic approach using MCNP/5 and a deterministic one using MC²-2/REBUS. With MCNP/5, each drawer of the assembly is modeled in detail with regard to geometry and fuel loading. In the deterministic approach, the MC²-2 collapses cross-sections in energy and space into a 15 few group structure homogenized spatially over each drawer for the REBUS 3D model. Various reactivity coefficients and reaction rates at different locations inside the core were evaluated and compared for both approaches and contrasted to published experimental data and were found to be in good agreement.     

3D neutron diffusion computational code based on GFEM with unstructured tetrahedron elements: A comparative study for linear and quadratic approximations

In the present study, the comparison between the results obtained from the linear and quadratic approximations of the Galerkin Finite Element Method (GFEM) for neutronic reactor core calculation was reported. The sensitivity analysis of the calculated neutron multiplication factor, neutron flux and power distributions in the reactor core vs. the number of the unstructured tetrahedron elements and order of the considered shape function was performed. The cost of the performed calculation using linear and quadratic approximation was compared through the calculation of the FOM. The neutronic core calculation was performed for both rectangular and hexagonal geometries. Both the criticality and fixed source calculations were done using the developed GFEM-3D computational code. An acceptable accuracy with low computational cost is the main advantage of applying the unstructured tetrahedron elements. The generated unstructured tetrahedron elements with Gambit software were used in the GFEM-3D computational code via a developed interface. The criticality calculation was benchmarked against the valid data for IAEA-3D and VVER-1000 benchmark problems. Also, the neutron fixed source calculation was validated through the comparison with the similar computational code. The results show that the accuracy of the calculation for the both linear and quadratic approximations improves vs. the number of elements. Quadratic approximation gives acceptable results for almost all considered number of the elements, while the results obtained from the linear approximation have good accuracy for only high number of the elements.     

A comparative study of engineering options for the disposal of high-level radioactive waste with regard to thermal effects and chemical degradation

The disposal of high-level radioactive waste in deep geological repositories requires stable and foreseeable physical conditions over very long time scales. During this period, the chemical stability of both the natural and the engineered barriers is governed by thermally activated processes. These in turn are driven by the heat pulse generated by the nuclear decay of waste products. The technical concept to cap the temperature peak in the repository is thus an important aspect for the proof of safety of disposal facilities. It is shown that densely stocked repositories, as currently foreseen in several countries, do not necessarily represent the optimal choice with regard to temperature effects, long-term reaction kinetics and chemical degradation of components. It is suggested that the optimization of the temperature peak rather than the fulfillment of cut-off conditions for peak temperature should be a cardinal issue in engineering concepts.