~(125)I聚氨酯覆膜食道支架制备方法研究

以多异氰酸酯作为交联剂,采用放射性核素~(125)Ⅰ,制备出了表面覆有聚氨酯薄膜的放射性支架。对聚氨酯覆膜方法进行了研究,考察了影响膜厚度的因素,制得的支架膜厚度为7.9μm。考察了交联剂的浓度、交联方法、固化温度等影响因素,确定最佳的交联条件和方法。生理盐水浸泡30 d后,交联后的聚氨酯薄膜比未交联的聚氨酯薄膜放射性释放率显著降低,30 d放射性核素释放率为2.13%。考察了放射性膜与支架的结合力,实验中带薄膜的支架经过伸缩3次后,表面无裂纹产生,表明薄膜具有良好的结合力,放射性核素在支架表面均匀分布,已经初步达到支架的使用要求。     

^125I巩膜敷贴器的剂量学特性的研究

用经验公式按合适的几何模型作剂量学计算,可以得到对应于不同的几何形状和不同放射源活度的等剂量曲线。用LiF热释光片在水-有机玻璃体模及空气中,分别作     

钙调神经磷酸酶B亚基的125I标记及其血脑屏障的通透性

钙调神经磷酸酶与老年性痴呆密切相关,为了解其B亚基的血脑屏障的通透性,采用Iodogen法对钙调神经磷酸酶B亚基(CNB)进行125I标记,标记率高达85%,产物125I-CNB比活度为740GBq·     

N—琥珀酰亚胺3—[^125I]碘苯甲酸酯（S^125IB）的放射化学合成

利用Iodogen法成功地对N-琥珀酰亚胺3-（三正丁基锡）苯甲酸酯（ATE）进行了放射性碘-125标记，利用Sep-Pak硅胶柱实现了干扰蛋白标记的ATE及Iodogen与S^125IB的分离，得到了放射性碘间标蛋白质有用的中间体S^125IB，标记率93％以上。并研究了影响标记的因素，得出较佳标记条件为：ATE与Na^125I摩尔比6：1、氧化剂Iodogen用量7μg、室温反应5min。     

制备125I的堆照循环回路模拟系统调试

利用中国先进研究堆（CARR）辐照制备¹²⁵I的循环回路为全封闭的不锈钢细长管路系统。在入堆安装使用前,需对系统进行严格的调试实验,并测试系统的密封性,使其满足设计要求。本研究根据CARR的场所条件要求,设计¹²⁵I制备循环回路模拟系统并进行调试,包括真空调试和氙气充气收气实验。采用长管路分段调试验证系统真空度并测定真空泄漏率;系统安装调试合格后,充入不同压力的天然氙气进行循环回收模拟实验。结果表明,设计的¹²⁵I循环回路系统为细长多弯曲管路,系统密封性好,经氦质谱检漏测定值小于10^-6 Pa•m³/s;天然氙气在系统中的导气实验结果表明,回收时间约为120 s,符合堆照生产¹²⁵I的要求。实验结果证实了系统入堆安装调试的可行性,可为建立反应堆辐照制备¹²⁵I回路系统提供参考。     

6711型125I种子源剂量参数的蒙特卡罗研究

使用蒙特卡罗方法计算6711型125I种子源参数,采用新的种子源几何模型和新的光子截面数据(mcplib04),根据AAPM TG-43U1推荐的剂量参数计算公式,可以获得6711型125I种子源各参数。与AAPMTG-43U1推荐值比较,剂量常数相差0.62%,径向剂量函数值最大相差5.12%,最小相差0.15%。     

125I在压实北山花岗岩粉中毛细管内扩散

为了解¹²⁹I在我国深地质处置库重点研究区围岩中的迁移行为,为选址预评价提供基础数据,利用批式吸附实验法和改进的毛细管内扩散法研究了碘离子在北山花岗岩粉中的吸附和扩散行为,分析了不同控制条件对碘离子的表观扩散系数(D_a)的影响。结果表明：在固液比为20 g/L,碘离子在北山花岗岩粉上的吸附几乎可以忽略;扩散实验中¹²⁵I^-的D_a值为8.2×10^-11~1.4×10^-9 m²/s,表明碘离子在压实北山花岗岩岩粉中的扩散速率很快;¹²⁵I^-的D_a值随扩散温度的升高而变大,随扩散源液离子强度的增加而变大,随同位素载体浓度的升高而变大,¹²⁵I^-的扩散速率随溶液pH值的上升整体有减小的趋势。     

Monte Carlo Simulation of Dose Calculation Parameter of Radioactive 125I Brachytherapy Source

The end of silver rod of the domestic ¹²⁵I brachytherapy source is right angle type, which is slightly different from the typical model of 6711 ¹²⁵I brachytherapy source. And it can have influence on the dose calculation parameters. Based on the structure of domestic ¹²⁵I brachytherapy source, dose calculation parameters which are recommended by AAPM TG43-U1 were calculated by Monte Carlo method. The influence of the end of silver rod on the dose calculation parameters was studied. The simulation result of dose rate constant is 0.955 cGy·h-1·U-1 when the air kerma strength was calculated by the point detector, and the difference with the result of the TG43-U1 is within 1.03%. The radial dose function g(r) in the range of 0.05-10 cm at the transverse axis was calculated precisely. Then empiric equation was acquired by curve fitting. 2D anisotropy function F(r,θ) was calculated in 0°-90° and 0.25-7 cm. The source of the right angle structure of the end of the silver rod would cause a hump area of 2D anisotropy function when r equals 0.25 cm.     

New Structures in Odd-Odd 120I

The excited states of the doubly-odd 120 I have been investigated via the 110Pd(14N,4n) and the 114Cd(10B,4n) reactions at beam energies of 64 MeV and 48 MeV, re-spectively. The previously known bands are extended, and a new band structure is established. The yrast band is assigned to the πh11/2νh11/2 configuration instead of the previously as-signed πg7/2νh11/2 configuration. Possible configurations of the other observed bands are also discussed.     

甲状腺癌病人^131I治疗对唾液腺功能的影响

甲状腺癌病人在接受碘－131治疗时,唾液腺也会浓聚^131I而受到损伤。为了解大剂量^131I治疗后,唾液腺损务的程度以及与治疗剂量等方面的关系,用核素动态显像,定量计算唾液腺腺体的摄取率和排泄率。实验结果表明,全体病人组与正常人组相比较,摄取率没有显著性的差异（P＞0．05）,而排泄率两组均存在显著性的差异（P＜0．05）。随着治疗剂量的增加,摄取率和排泄率也渐次降低,37GBq以上组别的结果与正常人相比,摄取率和排泄率均存在显著性的差异（P＜0．05）,37GBq以下各组仅排泄率上存在显著性差异（P＜0．05）。颌下腺与腮腺相比较,颌下腺的受损程度较小。核素显像定量计算唾液腺摄取率和排泄率能反映腺体的功能及其受损程度,为临床诊疗提供一定的依据,接受^131I剂量的大小与腮腺功能的影响程度呈正相关。     

Yrast Band in 122I and Band Termination

High spin states of the odd-odd nucleus 122 I have been investigated via the fusion-evaporation reaction 116 Cd(11B, 5n) at a beam energy of 68 MeV. The yrast band is extended up to Iπ=(29+). The band termination at Iπ=(22+) reported in previous studies is confirmed and interpreted as arising from a shape change from collective prolate to noncollective oblate according to Total-Routhian-Surface (TRS) calculations. In addition, the Iπ=(29+) state is assigned to the [πh11/2(πg7/2)2]23/2-[(νh11/2)3(νd5/2)2]35/2-configuration corresponding to the full alignment of all valance nucleons outside the semi-closed shell.     

海水中~(131)I的快速检测技术

日本福岛核事故发生以后,对海洋环境中关键放射性核素的快速检测技术提出了更高的要求。人工放射性核素~(131)I在核反应裂变产物中活度相对较高且半衰期短,是用来快速评价核污染的关键性核素之一。本工作从亚铁氰化钾、硝酸铜及硝酸银为原料出发,制备出亚铁氰化铜和亚铁氰化银混合(CuFC/AgFC)吸附材料并分散于聚丙烯纤维富集柱上,来实现水环境中~(131)I现场快速富集。通过室内模拟实验发现:在流速为6.25L/min,~(131)I在海水中I~-初始浓度为24μmol/L时,单次吸附效率即可达到50%以上;而当海水中I~-初始浓度为4μmol/L时,一定体积的海水在连续循环8次后(CuFC/AgFC)聚丙烯纤维富集柱吸附效率达到100%。本方法制源时间约40min,测样时间约12~24h,故最快可在30h内完成海水中~(131)I的分析。本方法的检测限与分析周期均低于目前GB/T 13272-1991水中~(131)I的分析标准,极大地提高了~(131)I的分析时间。除此之外,该法可以同时分析海水中的~(137) Cs(~(134) Cs),有望作为淡水和近岸环境中常规监测和应急时对关键核素~(131)I和~(137) Cs(~(134) Cs)进行快速测定的备选方法之一。     

压水堆中嬗变99Tc和129I的计算研究

选取大亚湾压水堆作为嬗变参考堆,研究在压水堆中嬗变长寿命裂变产物⁹⁹Tc和¹²⁹I的可行性。计算结果表明：在1个换料周期（18个月）内,⁹⁹Tc的最大嬗变率为15.69%,¹²⁹I的最大嬗变率为9.18%。通过对不同堆芯方案进行安全性分析发现：添加⁹⁹Tc和¹²⁹I后,堆芯有效增殖因数k_eff降低且随燃耗变化的幅度变小;堆芯径向中子通量密度分布无明显变化但径向功率峰因子降低;考虑燃料温度系数、慢化剂温度系数、硼微分价值以及控制棒价值等,得出在反应性温度系数及反应性控制方面不会导致安全问题,相反有优化作用。因此,从安全角度分析,在压水堆中嬗变⁹⁹Tc和¹²⁹I是可行的。     

北京地区大气中7Be、137Cs和131I活度浓度分布规律初步研究

介绍了全面禁止核试验条约（CTBT）国际监测系统（IMS）北京核素台站和北京放射性核素实验室的大气气溶胶取样和测量过程;对核素台站和放射性核素实验室的大气气溶胶的长期监测数据进行了统计分析,得到了⁷Be、¹³⁷Cs和¹³¹I活度浓度的分布特点和规律,为深入研究大气中相关放射性核素浓度分布规律奠定了基础。     

Synthesis and Evaluation of 125I Labeled Chalcone Derivatives Containing Bithiophene Moiety as Potential Aβ Probes

In continuation of the investigation on the bithiophene structure as potential Aβ probes, two halogenated chalcone derivatives containing bithiophene moiety were designed and evaluated as imaging probes for Aβ plaques. In vitro fluorescence staining indicated that they could stain Aβ plaques in the brain sections of AD model mice specifically, in vitro binding assay further confirmed that they displayed high binding affinities to Aβ aggregates (K_i=2.33 nM and 0.88 nM). One radio-iodinated probe, ¹²⁵I labeleled chalcone derivatives was obtained via iododestannylation reaction with high radiochemical yield and purity (>99%). Moreover, the¹²⁵I-labeling compound displayed specific labeling of Aβ plaques in the brain sections of AD model mice with low background, and the specific labeling could be confirmed by thioflavin-S staining. In vivo biodistribution in normal mice indicated that the¹²⁵I labeling compound exhibited low initial brain uptake (1.19%ID/g at 2 min) and rapid clearance. These preliminary results suggest that¹²⁵I labeling compound may serve as novel Aβ imaging probe, although further modifications are needed to improve initial brain uptake.     

^125I—UdR的小鼠体内分布

本工作研究了^125I-UdR（脱氧尿啶核酸）在正常与荷瘤裸鼠动物模型（LOVO型结肠癌、小细胞肺癌和宫颈癌）中的生物分布。实验结果表明：在几种荷瘤裸鼠动物模型中的生物分布表现不同,有待进一步研究。     

便携式γ谱仪对137Cs、131I液样探测效率的刻度

便携式γ谱仪主要用于主冷却剂水样中典型核素的现场辅助识别及其活度浓度的测量分析。为确定典型核素特征峰净面积和水样中该核素活度浓度的关系,必须进行源峰效率刻度。本文通过测量¹³³Ba、¹³⁷Cs、⁶⁰Co 3种核素的混合溶液得到效率刻度曲线,然后对不同活度浓度的¹³⁷Cs标准溶液、¹³¹I标准模拟溶液进行测量。结果表明,谱仪均能正确识别¹³⁷Cs、¹³¹I核素,活度浓度测量的相对误差均<10%,初步满足元件破损监测精度和灵敏度的需求。     

Preclinical pharmacological study on 125I-IPPA

Myocardial uptake of ¹²⁵I-IPPAin rats showed a peak of 4.4% of injected dose per gram.The half elimination time ofmyocardium was 3.8min and the maximaluptake of thyroid is only 0.005%ID/organ at 120min.The initial halftime of 2.7min in rabbits was obtained from the elimination curveofradioactivity in blood. In vitro binding test for ¹²⁵I-IPPA to HSAshowedrather constant level of activation during two hours.The second peak of extraction wasobserved in major organs ofrats, in rabbits' elimination of radioactivity and inbindingtest for ¹²⁵I-IPPA to albumin in vivo. Toxicity trial was up tostandard.The tolerance of a mouse to IPPA was 560 times as highas that of a person to IPPA. Itdemonstrated that ¹²⁵I-IPPA couldbe quickly extracted by myocardium, and itscatabolites were excretedin the urine with almost no iodine loss. All the results werefound toagree with the expectations based on the principal metabolic path ofphenyl fattyacid.